Merge tag 'bcachefs-2024-05-19' of https://evilpiepirate.org/git/bcachefs

Pull bcachefs updates from Kent Overstreet:

 - More safety fixes, primarily found by syzbot

 - Run the upgrade/downgrade paths in nochnages mode. Nochanges mode is
   primarily for testing fsck/recovery in dry run mode, so it shouldn't
   change anything besides disabling writes and holding dirty metadata
   in memory.

   The idea here was to reduce the amount of activity if we can't write
   anything out, so that bringing up a filesystem in "super ro" mode
   would be more lilkely to work for data recovery - but norecovery is
   the correct option for this.

 - btree_trans->locked; we now track whether a btree_trans has any btree
   nodes locked, and this is used for improved assertions related to
   trans_unlock() and trans_relock(). We'll also be using it for
   improving how we work with lockdep in the future: we don't want
   lockdep to be tracking individual btree node locks because we take
   too many for lockdep to track, and it's not necessary since we have a
   cycle detector.

 - Trigger improvements that are prep work for online fsck

 - BTREE_TRIGGER_check_repair; this regularizes how we do some repair
   work for extents that goes with running triggers in fsck, and fixes
   some subtle issues with transaction restarts there.

 - bch2_snapshot_equiv() has now been ripped out of fsck.c; snapshot
   equivalence classes are for when snapshot deletion leaves behind
   redundant snapshot nodes, but snapshot deletion now cleans this up
   right away, so the abstraction doesn't need to leak.

 - Improvements to how we resume writing to the journal in recovery. The
   code for picking the new place to write when reading the journal is
   greatly simplified and we also store the position in the superblock
   for when we don't read the journal; this means that we preserve more
   of the journal for list_journal debugging.

 - Improvements to sysfs btree_cache and btree_node_cache, for debugging
   memory reclaim.

 - We now detect when we've blocked for 10 seconds on the allocator in
   the write path and dump some useful info.

 - Safety fixes for devices references: this is a big series that
   changes almost all device lookups to properly check if the device
   exists and take a reference to it.

   Previously we assumed that if a bkey exists that references a device
   then the device must exist, and this was enforced in .invalid
   methods, but this was incorrect because it meant device removal
   relied on accounting being correct to not leave keys pointing to
   invalid devices, and that's not something we can assume.

   Getting the "pointer to invalid device" checks out of our .invalid()
   methods fixes some long standing device removal bugs; the only
   outstanding bug with device removal now is a race between the discard
   path and deleting alloc info, which should be easily fixed.

 - The allocator now prefers not to expand the new
   member_info.btree_allocated bitmap, meaning if repair ever requires
   scanning for btree nodes (because of a corrupt interior nodes) we
   won't have to scan the whole device(s).

 - New coding style document, which among other things talks about the
   correct usage of assertions

* tag 'bcachefs-2024-05-19' of https://evilpiepirate.org/git/bcachefs: (155 commits)
  bcachefs: add no_invalid_checks flag
  bcachefs: add counters for failed shrinker reclaim
  bcachefs: Fix sb_field_downgrade validation
  bcachefs: Plumb bch_validate_flags to sb_field_ops.validate()
  bcachefs: s/bkey_invalid_flags/bch_validate_flags
  bcachefs: fsync() should not return -EROFS
  bcachefs: Invalid devices are now checked for by fsck, not .invalid methods
  bcachefs: kill bch2_dev_bkey_exists() in bch2_check_fix_ptrs()
  bcachefs: kill bch2_dev_bkey_exists() in bch2_read_endio()
  bcachefs: bch2_dev_get_ioref() checks for device not present
  bcachefs: bch2_dev_get_ioref2(); io_read.c
  bcachefs: bch2_dev_get_ioref2(); debug.c
  bcachefs: bch2_dev_get_ioref2(); journal_io.c
  bcachefs: bch2_dev_get_ioref2(); io_write.c
  bcachefs: bch2_dev_get_ioref2(); btree_io.c
  bcachefs: bch2_dev_get_ioref2(); backpointers.c
  bcachefs: bch2_dev_get_ioref2(); alloc_background.c
  bcachefs: for_each_bset() declares loop iter
  bcachefs: Move BCACHEFS_STATFS_MAGIC value to UAPI magic.h
  bcachefs: Improve sysfs internal/btree_cache
  ...

123 files changed, 4632 insertions, 4324 deletions

diff --git a/Documentation/filesystems/bcachefs/CodingStyle.rst b/Documentation/filesystems/bcachefs/CodingStyle.rst
new file mode 100644
index 000000000000..0c45829a4899
--- /dev/null
+++ b/Documentation/filesystems/bcachefs/CodingStyle.rst
@@ -0,0 +1,186 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+bcachefs coding style
+=====================
+
+Good development is like gardening, and codebases are our gardens. Tend to them
+every day; look for little things that are out of place or in need of tidying.
+A little weeding here and there goes a long way; don't wait until things have
+spiraled out of control.
+
+Things don't always have to be perfect - nitpicking often does more harm than
+good. But appreciate beauty when you see it - and let people know.
+
+The code that you are afraid to touch is the code most in need of refactoring.
+
+A little organizing here and there goes a long way.
+
+Put real thought into how you organize things.
+
+Good code is readable code, where the structure is simple and leaves nowhere
+for bugs to hide.
+
+Assertions are one of our most important tools for writing reliable code. If in
+the course of writing a patchset you encounter a condition that shouldn't
+happen (and will have unpredictable or undefined behaviour if it does), or
+you're not sure if it can happen and not sure how to handle it yet - make it a
+BUG_ON(). Don't leave undefined or unspecified behavior lurking in the codebase.
+
+By the time you finish the patchset, you should understand better which
+assertions need to be handled and turned into checks with error paths, and
+which should be logically impossible. Leave the BUG_ON()s in for the ones which
+are logically impossible. (Or, make them debug mode assertions if they're
+expensive - but don't turn everything into a debug mode assertion, so that
+we're not stuck debugging undefined behaviour should it turn out that you were
+wrong).
+
+Assertions are documentation that can't go out of date. Good assertions are
+wonderful.
+
+Good assertions drastically and dramatically reduce the amount of testing
+required to shake out bugs.
+
+Good assertions are based on state, not logic. To write good assertions, you
+have to think about what the invariants on your state are.
+
+Good invariants and assertions will hold everywhere in your codebase. This
+means that you can run them in only a few places in the checked in version, but
+should you need to debug something that caused the assertion to fail, you can
+quickly shotgun them everywhere to find the codepath that broke the invariant.
+
+A good assertion checks something that the compiler could check for us, and
+elide - if we were working in a language with embedded correctness proofs that
+the compiler could check. This is something that exists today, but it'll likely
+still be a few decades before it comes to systems programming languages. But we
+can still incorporate that kind of thinking into our code and document the
+invariants with runtime checks - much like the way people working in
+dynamically typed languages may add type annotations, gradually making their
+code statically typed.
+
+Looking for ways to make your assertions simpler - and higher level - will
+often nudge you towards making the entire system simpler and more robust.
+
+Good code is code where you can poke around and see what it's doing -
+introspection. We can't debug anything if we can't see what's going on.
+
+Whenever we're debugging, and the solution isn't immediately obvious, if the
+issue is that we don't know where the issue is because we can't see what's
+going on - fix that first.
+
+We have the tools to make anything visible at runtime, efficiently - RCU and
+percpu data structures among them. Don't let things stay hidden.
+
+The most important tool for introspection is the humble pretty printer - in
+bcachefs, this means `*_to_text()` functions, which output to printbufs.
+
+Pretty printers are wonderful, because they compose and you can use them
+everywhere. Having functions to print whatever object you're working with will
+make your error messages much easier to write (therefore they will actually
+exist) and much more informative. And they can be used from sysfs/debugfs, as
+well as tracepoints.
+
+Runtime info and debugging tools should come with clear descriptions and
+labels, and good structure - we don't want files with a list of bare integers,
+like in procfs. Part of the job of the debugging tools is to educate users and
+new developers as to how the system works.
+
+Error messages should, whenever possible, tell you everything you need to debug
+the issue. It's worth putting effort into them.
+
+Tracepoints shouldn't be the first thing you reach for. They're an important
+tool, but always look for more immediate ways to make things visible. When we
+have to rely on tracing, we have to know which tracepoints we're looking for,
+and then we have to run the troublesome workload, and then we have to sift
+through logs. This is a lot of steps to go through when a user is hitting
+something, and if it's intermittent it may not even be possible.
+
+The humble counter is an incredibly useful tool. They're cheap and simple to
+use, and many complicated internal operations with lots of things that can
+behave weirdly (anything involving memory reclaim, for example) become
+shockingly easy to debug once you have counters on every distinct codepath.
+
+Persistent counters are even better.
+
+When debugging, try to get the most out of every bug you come across; don't
+rush to fix the initial issue. Look for things that will make related bugs
+easier the next time around - introspection, new assertions, better error
+messages, new debug tools, and do those first. Look for ways to make the system
+better behaved; often one bug will uncover several other bugs through
+downstream effects.
+
+Fix all that first, and then the original bug last - even if that means keeping
+a user waiting. They'll thank you in the long run, and when they understand
+what you're doing you'll be amazed at how patient they're happy to be. Users
+like to help - otherwise they wouldn't be reporting the bug in the first place.
+
+Talk to your users. Don't isolate yourself.
+
+Users notice all sorts of interesting things, and by just talking to them and
+interacting with them you can benefit from their experience.
+
+Spend time doing support and helpdesk stuff. Don't just write code - code isn't
+finished until it's being used trouble free.
+
+This will also motivate you to make your debugging tools as good as possible,
+and perhaps even your documentation, too. Like anything else in life, the more
+time you spend at it the better you'll get, and you the developer are the
+person most able to improve the tools to make debugging quick and easy.
+
+Be wary of how you take on and commit to big projects. Don't let development
+become product-manager focused. Often time an idea is a good one but needs to
+wait for its proper time - but you won't know if it's the proper time for an
+idea until you start writing code.
+
+Expect to throw a lot of things away, or leave them half finished for later.
+Nobody writes all perfect code that all gets shipped, and you'll be much more
+productive in the long run if you notice this early and shift to something
+else. The experience gained and lessons learned will be valuable for all the
+other work you do.
+
+But don't be afraid to tackle projects that require significant rework of
+existing code. Sometimes these can be the best projects, because they can lead
+us to make existing code more general, more flexible, more multipurpose and
+perhaps more robust. Just don't hesitate to abandon the idea if it looks like
+it's going to make a mess of things.
+
+Complicated features can often be done as a series of refactorings, with the
+final change that actually implements the feature as a quite small patch at the
+end. It's wonderful when this happens, especially when those refactorings are
+things that improve the codebase in their own right. When that happens there's
+much less risk of wasted effort if the feature you were going for doesn't work
+out.
+
+Always strive to work incrementally. Always strive to turn the big projects
+into little bite sized projects that can prove their own merits.
+
+Instead of always tackling those big projects, look for little things that
+will be useful, and make the big projects easier.
+
+The question of what's likely to be useful is where junior developers most
+often go astray - doing something because it seems like it'll be useful often
+leads to overengineering. Knowing what's useful comes from many years of
+experience, or talking with people who have that experience - or from simply
+reading lots of code and looking for common patterns and issues. Don't be
+afraid to throw things away and do something simpler.
+
+Talk about your ideas with your fellow developers; often times the best things
+come from relaxed conversations where people aren't afraid to say "what if?".
+
+Don't neglect your tools.
+
+The most important tools (besides the compiler and our text editor) are the
+tools we use for testing. The shortest possible edit/test/debug cycle is
+essential for working productively. We learn, gain experience, and discover the
+errors in our thinking by running our code and seeing what happens. If your
+time is being wasted because your tools are bad or too slow - don't accept it,
+fix it.
+
+Put effort into your documentation, commmit messages, and code comments - but
+don't go overboard. A good commit message is wonderful - but if the information
+was important enough to go in a commit message, ask yourself if it would be
+even better as a code comment.
+
+A good code comment is wonderful, but even better is the comment that didn't
+need to exist because the code was so straightforward as to be obvious;
+organized into small clean and tidy modules, with clear and descriptive names
+for functions and variable, where every line of code has a clear purpose.
diff --git a/Documentation/filesystems/bcachefs/index.rst b/Documentation/filesystems/bcachefs/index.rst
index e2bd61ccd96f..95fc4b90739e 100644
--- a/Documentation/filesystems/bcachefs/index.rst
+++ b/Documentation/filesystems/bcachefs/index.rst
@@ -8,4 +8,5 @@ bcachefs Documentation
    :maxdepth: 2
    :numbered:
 
+   CodingStyle
    errorcodes
diff --git a/fs/bcachefs/acl.c b/fs/bcachefs/acl.c
index 5c180fdc3efb..250d6c6d3a3a 100644
--- a/fs/bcachefs/acl.c
+++ b/fs/bcachefs/acl.c
@@ -282,18 +282,12 @@ struct posix_acl *bch2_get_acl(struct mnt_idmap *idmap,
 	struct btree_trans *trans = bch2_trans_get(c);
 	struct btree_iter iter = { NULL };
 	struct posix_acl *acl = NULL;
-	struct bkey_s_c k;
-	int ret;
 retry:
 	bch2_trans_begin(trans);
 
-	ret = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
-			&hash, inode_inum(inode), &search, 0);
-	if (ret)
-		goto err;
-
-	k = bch2_btree_iter_peek_slot(&iter);
-	ret = bkey_err(k);
+	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
+					     &hash, inode_inum(inode), &search, 0);
+	int ret = bkey_err(k);
 	if (ret)
 		goto err;
 
@@ -366,7 +360,7 @@ retry:
 
 	ret   = bch2_subvol_is_ro_trans(trans, inode->ei_subvol) ?:
 		bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
-			      BTREE_ITER_INTENT);
+			      BTREE_ITER_intent);
 	if (ret)
 		goto btree_err;
 
@@ -414,39 +408,30 @@ int bch2_acl_chmod(struct btree_trans *trans, subvol_inum inum,
 	struct bch_hash_info hash_info = bch2_hash_info_init(trans->c, inode);
 	struct xattr_search_key search = X_SEARCH(KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS, "", 0);
 	struct btree_iter iter;
-	struct bkey_s_c_xattr xattr;
-	struct bkey_i_xattr *new;
 	struct posix_acl *acl = NULL;
-	struct bkey_s_c k;
-	int ret;
 
-	ret = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
-			       &hash_info, inum, &search, BTREE_ITER_INTENT);
+	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc,
+			       &hash_info, inum, &search, BTREE_ITER_intent);
+	int ret = bkey_err(k);
 	if (ret)
 		return bch2_err_matches(ret, ENOENT) ? 0 : ret;
 
-	k = bch2_btree_iter_peek_slot(&iter);
-	ret = bkey_err(k);
-	if (ret)
-		goto err;
-	xattr = bkey_s_c_to_xattr(k);
+	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
 
 	acl = bch2_acl_from_disk(trans, xattr_val(xattr.v),
 			le16_to_cpu(xattr.v->x_val_len));
 	ret = PTR_ERR_OR_ZERO(acl);
-	if (IS_ERR_OR_NULL(acl))
+	if (ret)
 		goto err;
 
-	ret = allocate_dropping_locks_errcode(trans,
-				__posix_acl_chmod(&acl, _gfp, mode));
+	ret = allocate_dropping_locks_errcode(trans, __posix_acl_chmod(&acl, _gfp, mode));
 	if (ret)
 		goto err;
 
-	new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);
-	if (IS_ERR(new)) {
-		ret = PTR_ERR(new);
+	struct bkey_i_xattr *new = bch2_acl_to_xattr(trans, acl, ACL_TYPE_ACCESS);
+	ret = PTR_ERR_OR_ZERO(new);
+	if (ret)
 		goto err;
-	}
 
 	new->k.p = iter.pos;
 	ret = bch2_trans_update(trans, &iter, &new->k_i, 0);
diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 534ba2b02bd6..346cd91f91f9 100644
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -195,7 +195,7 @@ static unsigned bch_alloc_v1_val_u64s(const struct bch_alloc *a)
 }
 
 int bch2_alloc_v1_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
 	struct bkey_s_c_alloc a = bkey_s_c_to_alloc(k);
@@ -211,7 +211,7 @@ fsck_err:
 }
 
 int bch2_alloc_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
 	struct bkey_alloc_unpacked u;
@@ -225,7 +225,7 @@ fsck_err:
 }
 
 int bch2_alloc_v3_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
 	struct bkey_alloc_unpacked u;
@@ -239,7 +239,7 @@ fsck_err:
 }
 
 int bch2_alloc_v4_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags, struct printbuf *err)
+			  enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bkey_s_c_alloc_v4 a = bkey_s_c_to_alloc_v4(k);
 	int ret = 0;
@@ -263,7 +263,7 @@ int bch2_alloc_v4_invalid(struct bch_fs *c, struct bkey_s_c k,
 	case BCH_DATA_free:
 	case BCH_DATA_need_gc_gens:
 	case BCH_DATA_need_discard:
-		bkey_fsck_err_on(bch2_bucket_sectors(*a.v) || a.v->stripe,
+		bkey_fsck_err_on(bch2_bucket_sectors_total(*a.v) || a.v->stripe,
 				 c, err, alloc_key_empty_but_have_data,
 				 "empty data type free but have data");
 		break;
@@ -330,27 +330,17 @@ void bch2_alloc_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c
 	prt_printf(out, "gen %u oldest_gen %u data_type ", a->gen, a->oldest_gen);
 	bch2_prt_data_type(out, a->data_type);
 	prt_newline(out);
-	prt_printf(out, "journal_seq       %llu",	a->journal_seq);
-	prt_newline(out);
-	prt_printf(out, "need_discard      %llu",	BCH_ALLOC_V4_NEED_DISCARD(a));
-	prt_newline(out);
-	prt_printf(out, "need_inc_gen      %llu",	BCH_ALLOC_V4_NEED_INC_GEN(a));
-	prt_newline(out);
-	prt_printf(out, "dirty_sectors     %u",	a->dirty_sectors);
-	prt_newline(out);
-	prt_printf(out, "cached_sectors    %u",	a->cached_sectors);
-	prt_newline(out);
-	prt_printf(out, "stripe            %u",	a->stripe);
-	prt_newline(out);
-	prt_printf(out, "stripe_redundancy %u",	a->stripe_redundancy);
-	prt_newline(out);
-	prt_printf(out, "io_time[READ]     %llu",	a->io_time[READ]);
-	prt_newline(out);
-	prt_printf(out, "io_time[WRITE]    %llu",	a->io_time[WRITE]);
-	prt_newline(out);
-	prt_printf(out, "fragmentation     %llu",	a->fragmentation_lru);
-	prt_newline(out);
-	prt_printf(out, "bp_start          %llu", BCH_ALLOC_V4_BACKPOINTERS_START(a));
+	prt_printf(out, "journal_seq       %llu\n",	a->journal_seq);
+	prt_printf(out, "need_discard      %llu\n",	BCH_ALLOC_V4_NEED_DISCARD(a));
+	prt_printf(out, "need_inc_gen      %llu\n",	BCH_ALLOC_V4_NEED_INC_GEN(a));
+	prt_printf(out, "dirty_sectors     %u\n",	a->dirty_sectors);
+	prt_printf(out, "cached_sectors    %u\n",	a->cached_sectors);
+	prt_printf(out, "stripe            %u\n",	a->stripe);
+	prt_printf(out, "stripe_redundancy %u\n",	a->stripe_redundancy);
+	prt_printf(out, "io_time[READ]     %llu\n",	a->io_time[READ]);
+	prt_printf(out, "io_time[WRITE]    %llu\n",	a->io_time[WRITE]);
+	prt_printf(out, "fragmentation     %llu\n",	a->fragmentation_lru);
+	prt_printf(out, "bp_start          %llu\n", BCH_ALLOC_V4_BACKPOINTERS_START(a));
 	printbuf_indent_sub(out, 2);
 }
 
@@ -439,22 +429,18 @@ struct bkey_i_alloc_v4 *bch2_alloc_to_v4_mut(struct btree_trans *trans, struct b
 }
 
 struct bkey_i_alloc_v4 *
-bch2_trans_start_alloc_update(struct btree_trans *trans, struct btree_iter *iter,
-			      struct bpos pos)
+bch2_trans_start_alloc_update_noupdate(struct btree_trans *trans, struct btree_iter *iter,
+				       struct bpos pos)
 {
-	struct bkey_s_c k;
-	struct bkey_i_alloc_v4 *a;
-	int ret;
-
-	k = bch2_bkey_get_iter(trans, iter, BTREE_ID_alloc, pos,
-			     BTREE_ITER_WITH_UPDATES|
-			     BTREE_ITER_CACHED|
-			     BTREE_ITER_INTENT);
-	ret = bkey_err(k);
+	struct bkey_s_c k = bch2_bkey_get_iter(trans, iter, BTREE_ID_alloc, pos,
+					       BTREE_ITER_with_updates|
+					       BTREE_ITER_cached|
+					       BTREE_ITER_intent);
+	int ret = bkey_err(k);
 	if (unlikely(ret))
 		return ERR_PTR(ret);
 
-	a = bch2_alloc_to_v4_mut_inlined(trans, k);
+	struct bkey_i_alloc_v4 *a = bch2_alloc_to_v4_mut_inlined(trans, k);
 	ret = PTR_ERR_OR_ZERO(a);
 	if (unlikely(ret))
 		goto err;
@@ -464,6 +450,20 @@ err:
 	return ERR_PTR(ret);
 }
 
+__flatten
+struct bkey_i_alloc_v4 *bch2_trans_start_alloc_update(struct btree_trans *trans, struct bpos pos)
+{
+	struct btree_iter iter;
+	struct bkey_i_alloc_v4 *a = bch2_trans_start_alloc_update_noupdate(trans, &iter, pos);
+	int ret = PTR_ERR_OR_ZERO(a);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = bch2_trans_update(trans, &iter, &a->k_i, 0);
+	bch2_trans_iter_exit(trans, &iter);
+	return unlikely(ret) ? ERR_PTR(ret) : a;
+}
+
 static struct bpos alloc_gens_pos(struct bpos pos, unsigned *offset)
 {
 	*offset = pos.offset & KEY_TYPE_BUCKET_GENS_MASK;
@@ -487,7 +487,7 @@ static unsigned alloc_gen(struct bkey_s_c k, unsigned offset)
 }
 
 int bch2_bucket_gens_invalid(struct bch_fs *c, struct bkey_s_c k,
-			     enum bkey_invalid_flags flags,
+			     enum bch_validate_flags flags,
 			     struct printbuf *err)
 {
 	int ret = 0;
@@ -520,7 +520,7 @@ int bch2_bucket_gens_init(struct bch_fs *c)
 	int ret;
 
 	ret = for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
-				 BTREE_ITER_PREFETCH, k, ({
+				 BTREE_ITER_prefetch, k, ({
 		/*
 		 * Not a fsck error because this is checked/repaired by
 		 * bch2_check_alloc_key() which runs later:
@@ -567,29 +567,31 @@ iter_err:
 int bch2_alloc_read(struct bch_fs *c)
 {
 	struct btree_trans *trans = bch2_trans_get(c);
+	struct bch_dev *ca = NULL;
 	int ret;
 
 	down_read(&c->gc_lock);
 
 	if (c->sb.version_upgrade_complete >= bcachefs_metadata_version_bucket_gens) {
 		ret = for_each_btree_key(trans, iter, BTREE_ID_bucket_gens, POS_MIN,
-					 BTREE_ITER_PREFETCH, k, ({
+					 BTREE_ITER_prefetch, k, ({
 			u64 start = bucket_gens_pos_to_alloc(k.k->p, 0).offset;
 			u64 end = bucket_gens_pos_to_alloc(bpos_nosnap_successor(k.k->p), 0).offset;
 
 			if (k.k->type != KEY_TYPE_bucket_gens)
 				continue;
 
-			const struct bch_bucket_gens *g = bkey_s_c_to_bucket_gens(k).v;
-
+			ca = bch2_dev_iterate(c, ca, k.k->p.inode);
 			/*
 			 * Not a fsck error because this is checked/repaired by
 			 * bch2_check_alloc_key() which runs later:
 			 */
-			if (!bch2_dev_exists2(c, k.k->p.inode))
+			if (!ca) {
+				bch2_btree_iter_set_pos(&iter, POS(k.k->p.inode + 1, 0));
 				continue;
+			}
 
-			struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
+			const struct bch_bucket_gens *g = bkey_s_c_to_bucket_gens(k).v;
 
 			for (u64 b = max_t(u64, ca->mi.first_bucket, start);
 			     b < min_t(u64, ca->mi.nbuckets, end);
@@ -599,15 +601,16 @@ int bch2_alloc_read(struct bch_fs *c)
 		}));
 	} else {
 		ret = for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
-					 BTREE_ITER_PREFETCH, k, ({
+					 BTREE_ITER_prefetch, k, ({
+			ca = bch2_dev_iterate(c, ca, k.k->p.inode);
 			/*
 			 * Not a fsck error because this is checked/repaired by
 			 * bch2_check_alloc_key() which runs later:
 			 */
-			if (!bch2_dev_bucket_exists(c, k.k->p))
+			if (!ca) {
+				bch2_btree_iter_set_pos(&iter, POS(k.k->p.inode + 1, 0));
 				continue;
-
-			struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
+			}
 
 			struct bch_alloc_v4 a;
 			*bucket_gen(ca, k.k->p.offset) = bch2_alloc_to_v4(k, &a)->gen;
@@ -615,6 +618,7 @@ int bch2_alloc_read(struct bch_fs *c)
 		}));
 	}
 
+	bch2_dev_put(ca);
 	bch2_trans_put(trans);
 	up_read(&c->gc_lock);
 
@@ -625,12 +629,12 @@ int bch2_alloc_read(struct bch_fs *c)
 /* Free space/discard btree: */
 
 static int bch2_bucket_do_index(struct btree_trans *trans,
+				struct bch_dev *ca,
 				struct bkey_s_c alloc_k,
 				const struct bch_alloc_v4 *a,
 				bool set)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, alloc_k.k->p.inode);
 	struct btree_iter iter;
 	struct bkey_s_c old;
 	struct bkey_i *k;
@@ -667,7 +671,7 @@ static int bch2_bucket_do_index(struct btree_trans *trans,
 
 	old = bch2_bkey_get_iter(trans, &iter, btree,
 			     bkey_start_pos(&k->k),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	ret = bkey_err(old);
 	if (ret)
 		return ret;
@@ -711,8 +715,8 @@ static noinline int bch2_bucket_gen_update(struct btree_trans *trans,
 		return ret;
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_bucket_gens, pos,
-			       BTREE_ITER_INTENT|
-			       BTREE_ITER_WITH_UPDATES);
+			       BTREE_ITER_intent|
+			       BTREE_ITER_with_updates);
 	ret = bkey_err(k);
 	if (ret)
 		return ret;
@@ -734,26 +738,24 @@ static noinline int bch2_bucket_gen_update(struct btree_trans *trans,
 int bch2_trigger_alloc(struct btree_trans *trans,
 		       enum btree_id btree, unsigned level,
 		       struct bkey_s_c old, struct bkey_s new,
-		       unsigned flags)
+		       enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
 	int ret = 0;
 
-	if (bch2_trans_inconsistent_on(!bch2_dev_bucket_exists(c, new.k->p), trans,
-				       "alloc key for invalid device or bucket"))
+	struct bch_dev *ca = bch2_dev_bucket_tryget(c, new.k->p);
+	if (!ca)
 		return -EIO;
 
-	struct bch_dev *ca = bch_dev_bkey_exists(c, new.k->p.inode);
-
 	struct bch_alloc_v4 old_a_convert;
 	const struct bch_alloc_v4 *old_a = bch2_alloc_to_v4(old, &old_a_convert);
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
 
-		new_a->data_type = alloc_data_type(*new_a, new_a->data_type);
+		alloc_data_type_set(new_a, new_a->data_type);
 
-		if (bch2_bucket_sectors(*new_a) > bch2_bucket_sectors(*old_a)) {
+		if (bch2_bucket_sectors_total(*new_a) > bch2_bucket_sectors_total(*old_a)) {
 			new_a->io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
 			new_a->io_time[WRITE]= max_t(u64, 1, atomic64_read(&c->io_clock[WRITE].now));
 			SET_BCH_ALLOC_V4_NEED_INC_GEN(new_a, true);
@@ -770,10 +772,10 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 		if (old_a->data_type != new_a->data_type ||
 		    (new_a->data_type == BCH_DATA_free &&
 		     alloc_freespace_genbits(*old_a) != alloc_freespace_genbits(*new_a))) {
-			ret =   bch2_bucket_do_index(trans, old, old_a, false) ?:
-				bch2_bucket_do_index(trans, new.s_c, new_a, true);
+			ret =   bch2_bucket_do_index(trans, ca, old, old_a, false) ?:
+				bch2_bucket_do_index(trans, ca, new.s_c, new_a, true);
 			if (ret)
-				return ret;
+				goto err;
 		}
 
 		if (new_a->data_type == BCH_DATA_cached &&
@@ -787,24 +789,23 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 					      bucket_to_u64(new.k->p),
 					      old_lru, new_lru);
 			if (ret)
-				return ret;
+				goto err;
 		}
 
-		new_a->fragmentation_lru = alloc_lru_idx_fragmentation(*new_a,
-						bch_dev_bkey_exists(c, new.k->p.inode));
+		new_a->fragmentation_lru = alloc_lru_idx_fragmentation(*new_a, ca);
 		if (old_a->fragmentation_lru != new_a->fragmentation_lru) {
 			ret = bch2_lru_change(trans,
 					BCH_LRU_FRAGMENTATION_START,
 					bucket_to_u64(new.k->p),
 					old_a->fragmentation_lru, new_a->fragmentation_lru);
 			if (ret)
-				return ret;
+				goto err;
 		}
 
 		if (old_a->gen != new_a->gen) {
 			ret = bch2_bucket_gen_update(trans, new.k->p, new_a->gen);
 			if (ret)
-				return ret;
+				goto err;
 		}
 
 		/*
@@ -812,21 +813,21 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 		 * not:
 		 */
 
-		if ((flags & BTREE_TRIGGER_BUCKET_INVALIDATE) &&
+		if ((flags & BTREE_TRIGGER_bucket_invalidate) &&
 		    old_a->cached_sectors) {
 			ret = bch2_update_cached_sectors_list(trans, new.k->p.inode,
 							      -((s64) old_a->cached_sectors));
 			if (ret)
-				return ret;
+				goto err;
 		}
 	}
 
-	if ((flags & BTREE_TRIGGER_ATOMIC) && (flags & BTREE_TRIGGER_INSERT)) {
+	if ((flags & BTREE_TRIGGER_atomic) && (flags & BTREE_TRIGGER_insert)) {
 		struct bch_alloc_v4 *new_a = bkey_s_to_alloc_v4(new).v;
 		u64 journal_seq = trans->journal_res.seq;
 		u64 bucket_journal_seq = new_a->journal_seq;
 
-		if ((flags & BTREE_TRIGGER_INSERT) &&
+		if ((flags & BTREE_TRIGGER_insert) &&
 		    data_type_is_empty(old_a->data_type) !=
 		    data_type_is_empty(new_a->data_type) &&
 		    new.k->type == KEY_TYPE_alloc_v4) {
@@ -854,7 +855,7 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 			if (ret) {
 				bch2_fs_fatal_error(c,
 					"setting bucket_needs_journal_commit: %s", bch2_err_str(ret));
-				return ret;
+				goto err;
 			}
 		}
 
@@ -884,11 +885,11 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 			bch2_do_invalidates(c);
 
 		if (statechange(a->data_type == BCH_DATA_need_gc_gens))
-			bch2_do_gc_gens(c);
+			bch2_gc_gens_async(c);
 	}
 
-	if ((flags & BTREE_TRIGGER_GC) &&
-	    (flags & BTREE_TRIGGER_BUCKET_INVALIDATE)) {
+	if ((flags & BTREE_TRIGGER_gc) &&
+	    (flags & BTREE_TRIGGER_bucket_invalidate)) {
 		struct bch_alloc_v4 new_a_convert;
 		const struct bch_alloc_v4 *new_a = bch2_alloc_to_v4(new.s_c, &new_a_convert);
 
@@ -908,12 +909,13 @@ int bch2_trigger_alloc(struct btree_trans *trans,
 		bucket_unlock(g);
 		percpu_up_read(&c->mark_lock);
 	}
-
-	return 0;
+err:
+	bch2_dev_put(ca);
+	return ret;
 }
 
 /*
- * This synthesizes deleted extents for holes, similar to BTREE_ITER_SLOTS for
+ * This synthesizes deleted extents for holes, similar to BTREE_ITER_slots for
  * extents style btrees, but works on non-extents btrees:
  */
 static struct bkey_s_c bch2_get_key_or_hole(struct btree_iter *iter, struct bpos end, struct bkey *hole)
@@ -958,35 +960,34 @@ static struct bkey_s_c bch2_get_key_or_hole(struct btree_iter *iter, struct bpos
 	}
 }
 
-static bool next_bucket(struct bch_fs *c, struct bpos *bucket)
+static bool next_bucket(struct bch_fs *c, struct bch_dev **ca, struct bpos *bucket)
 {
-	struct bch_dev *ca;
+	if (*ca) {
+		if (bucket->offset < (*ca)->mi.first_bucket)
+			bucket->offset = (*ca)->mi.first_bucket;
 
-	if (bch2_dev_bucket_exists(c, *bucket))
-		return true;
-
-	if (bch2_dev_exists2(c, bucket->inode)) {
-		ca = bch_dev_bkey_exists(c, bucket->inode);
-
-		if (bucket->offset < ca->mi.first_bucket) {
-			bucket->offset = ca->mi.first_bucket;
+		if (bucket->offset < (*ca)->mi.nbuckets)
 			return true;
-		}
 
+		bch2_dev_put(*ca);
+		*ca = NULL;
 		bucket->inode++;
 		bucket->offset = 0;
 	}
 
 	rcu_read_lock();
-	ca = __bch2_next_dev_idx(c, bucket->inode, NULL);
-	if (ca)
-		*bucket = POS(ca->dev_idx, ca->mi.first_bucket);
+	*ca = __bch2_next_dev_idx(c, bucket->inode, NULL);
+	if (*ca) {
+		*bucket = POS((*ca)->dev_idx, (*ca)->mi.first_bucket);
+		bch2_dev_get(*ca);
+	}
 	rcu_read_unlock();
 
-	return ca != NULL;
+	return *ca != NULL;
 }
 
-static struct bkey_s_c bch2_get_key_or_real_bucket_hole(struct btree_iter *iter, struct bkey *hole)
+static struct bkey_s_c bch2_get_key_or_real_bucket_hole(struct btree_iter *iter,
+					struct bch_dev **ca, struct bkey *hole)
 {
 	struct bch_fs *c = iter->trans->c;
 	struct bkey_s_c k;
@@ -995,22 +996,21 @@ again:
 	if (bkey_err(k))
 		return k;
 
+	*ca = bch2_dev_iterate_noerror(c, *ca, k.k->p.inode);
+
 	if (!k.k->type) {
-		struct bpos bucket = bkey_start_pos(k.k);
+		struct bpos hole_start = bkey_start_pos(k.k);
 
-		if (!bch2_dev_bucket_exists(c, bucket)) {
-			if (!next_bucket(c, &bucket))
+		if (!*ca || !bucket_valid(*ca, hole_start.offset)) {
+			if (!next_bucket(c, ca, &hole_start))
 				return bkey_s_c_null;
 
-			bch2_btree_iter_set_pos(iter, bucket);
+			bch2_btree_iter_set_pos(iter, hole_start);
 			goto again;
 		}
 
-		if (!bch2_dev_bucket_exists(c, k.k->p)) {
-			struct bch_dev *ca = bch_dev_bkey_exists(c, bucket.inode);
-
-			bch2_key_resize(hole, ca->mi.nbuckets - bucket.offset);
-		}
+		if (k.k->p.offset > (*ca)->mi.nbuckets)
+			bch2_key_resize(hole, (*ca)->mi.nbuckets - hole_start.offset);
 	}
 
 	return k;
@@ -1025,24 +1025,25 @@ int bch2_check_alloc_key(struct btree_trans *trans,
 			 struct btree_iter *bucket_gens_iter)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca;
 	struct bch_alloc_v4 a_convert;
 	const struct bch_alloc_v4 *a;
 	unsigned discard_key_type, freespace_key_type;
 	unsigned gens_offset;
 	struct bkey_s_c k;
 	struct printbuf buf = PRINTBUF;
-	int ret;
+	int ret = 0;
 
-	if (fsck_err_on(!bch2_dev_bucket_exists(c, alloc_k.k->p), c,
-			alloc_key_to_missing_dev_bucket,
+	struct bch_dev *ca = bch2_dev_bucket_tryget_noerror(c, alloc_k.k->p);
+	if (fsck_err_on(!ca,
+			c, alloc_key_to_missing_dev_bucket,
 			"alloc key for invalid device:bucket %llu:%llu",
 			alloc_k.k->p.inode, alloc_k.k->p.offset))
-		return bch2_btree_delete_at(trans, alloc_iter, 0);
+		ret = bch2_btree_delete_at(trans, alloc_iter, 0);
+	if (!ca)
+		return ret;
 
-	ca = bch_dev_bkey_exists(c, alloc_k.k->p.inode);
 	if (!ca->mi.freespace_initialized)
-		return 0;
+		goto out;
 
 	a = bch2_alloc_to_v4(alloc_k, &a_convert);
 
@@ -1141,25 +1142,26 @@ int bch2_check_alloc_key(struct btree_trans *trans,
 		if (ret)
 			goto err;
 	}
+out:
 err:
 fsck_err:
+	bch2_dev_put(ca);
 	printbuf_exit(&buf);
 	return ret;
 }
 
 static noinline_for_stack
 int bch2_check_alloc_hole_freespace(struct btree_trans *trans,
+				    struct bch_dev *ca,
 				    struct bpos start,
 				    struct bpos *end,
 				    struct btree_iter *freespace_iter)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca;
 	struct bkey_s_c k;
 	struct printbuf buf = PRINTBUF;
 	int ret;
 
-	ca = bch_dev_bkey_exists(c, start.inode);
 	if (!ca->mi.freespace_initialized)
 		return 0;
 
@@ -1313,7 +1315,7 @@ static noinline_for_stack int bch2_check_discard_freespace_key(struct btree_tran
 		goto delete;
 out:
 fsck_err:
-	set_btree_iter_dontneed(&alloc_iter);
+	bch2_set_btree_iter_dontneed(&alloc_iter);
 	bch2_trans_iter_exit(trans, &alloc_iter);
 	printbuf_exit(&buf);
 	return ret;
@@ -1337,30 +1339,25 @@ int bch2_check_bucket_gens_key(struct btree_trans *trans,
 {
 	struct bch_fs *c = trans->c;
 	struct bkey_i_bucket_gens g;
-	struct bch_dev *ca;
 	u64 start = bucket_gens_pos_to_alloc(k.k->p, 0).offset;
 	u64 end = bucket_gens_pos_to_alloc(bpos_nosnap_successor(k.k->p), 0).offset;
 	u64 b;
-	bool need_update = false, dev_exists;
+	bool need_update = false;
 	struct printbuf buf = PRINTBUF;
 	int ret = 0;
 
 	BUG_ON(k.k->type != KEY_TYPE_bucket_gens);
 	bkey_reassemble(&g.k_i, k);
 
-	/* if no bch_dev, skip out whether we repair or not */
-	dev_exists = bch2_dev_exists2(c, k.k->p.inode);
-	if (!dev_exists) {
-		if (fsck_err_on(!dev_exists, c,
-				bucket_gens_to_invalid_dev,
-				"bucket_gens key for invalid device:\n  %s",
-				(bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+	struct bch_dev *ca = bch2_dev_tryget_noerror(c, k.k->p.inode);
+	if (!ca) {
+		if (fsck_err(c, bucket_gens_to_invalid_dev,
+			     "bucket_gens key for invalid device:\n  %s",
+			     (bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
 			ret = bch2_btree_delete_at(trans, iter, 0);
-		}
 		goto out;
 	}
 
-	ca = bch_dev_bkey_exists(c, k.k->p.inode);
 	if (fsck_err_on(end <= ca->mi.first_bucket ||
 			start >= ca->mi.nbuckets, c,
 			bucket_gens_to_invalid_buckets,
@@ -1398,6 +1395,7 @@ int bch2_check_bucket_gens_key(struct btree_trans *trans,
 	}
 out:
 fsck_err:
+	bch2_dev_put(ca);
 	printbuf_exit(&buf);
 	return ret;
 }
@@ -1406,25 +1404,26 @@ int bch2_check_alloc_info(struct bch_fs *c)
 {
 	struct btree_trans *trans = bch2_trans_get(c);
 	struct btree_iter iter, discard_iter, freespace_iter, bucket_gens_iter;
+	struct bch_dev *ca = NULL;
 	struct bkey hole;
 	struct bkey_s_c k;
 	int ret = 0;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, POS_MIN,
-			     BTREE_ITER_PREFETCH);
+			     BTREE_ITER_prefetch);
 	bch2_trans_iter_init(trans, &discard_iter, BTREE_ID_need_discard, POS_MIN,
-			     BTREE_ITER_PREFETCH);
+			     BTREE_ITER_prefetch);
 	bch2_trans_iter_init(trans, &freespace_iter, BTREE_ID_freespace, POS_MIN,
-			     BTREE_ITER_PREFETCH);
+			     BTREE_ITER_prefetch);
 	bch2_trans_iter_init(trans, &bucket_gens_iter, BTREE_ID_bucket_gens, POS_MIN,
-			     BTREE_ITER_PREFETCH);
+			     BTREE_ITER_prefetch);
 
 	while (1) {
 		struct bpos next;
 
 		bch2_trans_begin(trans);
 
-		k = bch2_get_key_or_real_bucket_hole(&iter, &hole);
+		k = bch2_get_key_or_real_bucket_hole(&iter, &ca, &hole);
 		ret = bkey_err(k);
 		if (ret)
 			goto bkey_err;
@@ -1445,7 +1444,7 @@ int bch2_check_alloc_info(struct bch_fs *c)
 		} else {
 			next = k.k->p;
 
-			ret = bch2_check_alloc_hole_freespace(trans,
+			ret = bch2_check_alloc_hole_freespace(trans, ca,
 						    bkey_start_pos(k.k),
 						    &next,
 						    &freespace_iter) ?:
@@ -1473,19 +1472,21 @@ bkey_err:
 	bch2_trans_iter_exit(trans, &freespace_iter);
 	bch2_trans_iter_exit(trans, &discard_iter);
 	bch2_trans_iter_exit(trans, &iter);
+	bch2_dev_put(ca);
+	ca = NULL;
 
 	if (ret < 0)
 		goto err;
 
 	ret = for_each_btree_key(trans, iter,
 			BTREE_ID_need_discard, POS_MIN,
-			BTREE_ITER_PREFETCH, k,
+			BTREE_ITER_prefetch, k,
 		bch2_check_discard_freespace_key(trans, &iter));
 	if (ret)
 		goto err;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_freespace, POS_MIN,
-			     BTREE_ITER_PREFETCH);
+			     BTREE_ITER_prefetch);
 	while (1) {
 		bch2_trans_begin(trans);
 		k = bch2_btree_iter_peek(&iter);
@@ -1515,7 +1516,7 @@ bkey_err:
 
 	ret = for_each_btree_key_commit(trans, iter,
 			BTREE_ID_bucket_gens, POS_MIN,
-			BTREE_ITER_PREFETCH, k,
+			BTREE_ITER_prefetch, k,
 			NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 		bch2_check_bucket_gens_key(trans, &iter, k));
 err:
@@ -1562,7 +1563,7 @@ static int bch2_check_alloc_to_lru_ref(struct btree_trans *trans,
 
 		a_mut->v.io_time[READ] = atomic64_read(&c->io_clock[READ].now);
 		ret = bch2_trans_update(trans, alloc_iter,
-					&a_mut->k_i, BTREE_TRIGGER_NORUN);
+					&a_mut->k_i, BTREE_TRIGGER_norun);
 		if (ret)
 			goto err;
 
@@ -1601,7 +1602,7 @@ int bch2_check_alloc_to_lru_refs(struct bch_fs *c)
 {
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_alloc,
-				POS_MIN, BTREE_ITER_PREFETCH, k,
+				POS_MIN, BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			bch2_check_alloc_to_lru_ref(trans, &iter)));
 	bch_err_fn(c, ret);
@@ -1657,9 +1658,7 @@ static void discard_buckets_next_dev(struct bch_fs *c, struct discard_buckets_st
 		bch2_journal_flush_async(&c->journal, NULL);
 
 	if (s->ca)
-		percpu_ref_put(&s->ca->ref);
-	if (ca)
-		percpu_ref_get(&ca->ref);
+		percpu_ref_put(&s->ca->io_ref);
 	s->ca = ca;
 	s->need_journal_commit_this_dev = 0;
 }
@@ -1673,15 +1672,15 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
 	struct bpos pos = need_discard_iter->pos;
 	struct btree_iter iter = { NULL };
 	struct bkey_s_c k;
-	struct bch_dev *ca;
 	struct bkey_i_alloc_v4 *a;
 	struct printbuf buf = PRINTBUF;
 	bool discard_locked = false;
 	int ret = 0;
 
-	ca = bch_dev_bkey_exists(c, pos.inode);
-
-	if (!percpu_ref_tryget(&ca->io_ref)) {
+	struct bch_dev *ca = s->ca && s->ca->dev_idx == pos.inode
+		? s->ca
+		: bch2_dev_get_ioref(c, pos.inode, WRITE);
+	if (!ca) {
 		bch2_btree_iter_set_pos(need_discard_iter, POS(pos.inode + 1, 0));
 		return 0;
 	}
@@ -1703,7 +1702,7 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_alloc,
 			       need_discard_iter->pos,
-			       BTREE_ITER_CACHED);
+			       BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (ret)
 		goto out;
@@ -1713,7 +1712,7 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
 	if (ret)
 		goto out;
 
-	if (a->v.dirty_sectors) {
+	if (bch2_bucket_sectors_total(a->v)) {
 		if (bch2_trans_inconsistent_on(c->curr_recovery_pass > BCH_RECOVERY_PASS_check_alloc_info,
 					       trans, "attempting to discard bucket with dirty data\n%s",
 					       (bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
@@ -1771,7 +1770,7 @@ static int bch2_discard_one_bucket(struct btree_trans *trans,
 	}
 
 	SET_BCH_ALLOC_V4_NEED_DISCARD(&a->v, false);
-	a->v.data_type = alloc_data_type(a->v, a->v.data_type);
+	alloc_data_type_set(&a->v, a->v.data_type);
 write:
 	ret =   bch2_trans_update(trans, &iter, &a->k_i, 0) ?:
 		bch2_trans_commit(trans, NULL, NULL,
@@ -1787,7 +1786,6 @@ out:
 		discard_in_flight_remove(c, iter.pos);
 	s->seen++;
 	bch2_trans_iter_exit(trans, &iter);
-	percpu_ref_put(&ca->io_ref);
 	printbuf_exit(&buf);
 	return ret;
 }
@@ -1827,7 +1825,7 @@ void bch2_do_discards(struct bch_fs *c)
 static int bch2_clear_bucket_needs_discard(struct btree_trans *trans, struct bpos bucket)
 {
 	struct btree_iter iter;
-	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, bucket, BTREE_ITER_INTENT);
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, bucket, BTREE_ITER_intent);
 	struct bkey_s_c k = bch2_btree_iter_peek_slot(&iter);
 	int ret = bkey_err(k);
 	if (ret)
@@ -1840,7 +1838,7 @@ static int bch2_clear_bucket_needs_discard(struct btree_trans *trans, struct bpo
 
 	BUG_ON(a->v.dirty_sectors);
 	SET_BCH_ALLOC_V4_NEED_DISCARD(&a->v, false);
-	a->v.data_type = alloc_data_type(a->v, a->v.data_type);
+	alloc_data_type_set(&a->v, a->v.data_type);
 
 	ret = bch2_trans_update(trans, &iter, &a->k_i, 0);
 err:
@@ -1862,9 +1860,8 @@ static void bch2_do_discards_fast_work(struct work_struct *work)
 			if (i->snapshot)
 				continue;
 
-			ca = bch_dev_bkey_exists(c, i->inode);
-
-			if (!percpu_ref_tryget(&ca->io_ref)) {
+			ca = bch2_dev_get_ioref(c, i->inode, WRITE);
+			if (!ca) {
 				darray_remove_item(&c->discard_buckets_in_flight, i);
 				continue;
 			}
@@ -1903,9 +1900,12 @@ static void bch2_do_discards_fast_work(struct work_struct *work)
 
 static void bch2_discard_one_bucket_fast(struct bch_fs *c, struct bpos bucket)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, bucket.inode);
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, bucket.inode);
+	bool dead = !ca || percpu_ref_is_dying(&ca->io_ref);
+	rcu_read_unlock();
 
-	if (!percpu_ref_is_dying(&ca->io_ref) &&
+	if (!dead &&
 	    !discard_in_flight_add(c, bucket) &&
 	    bch2_write_ref_tryget(c, BCH_WRITE_REF_discard_fast) &&
 	    !queue_work(c->write_ref_wq, &c->discard_fast_work))
@@ -1918,7 +1918,6 @@ static int invalidate_one_bucket(struct btree_trans *trans,
 				 s64 *nr_to_invalidate)
 {
 	struct bch_fs *c = trans->c;
-	struct btree_iter alloc_iter = { NULL };
 	struct bkey_i_alloc_v4 *a = NULL;
 	struct printbuf buf = PRINTBUF;
 	struct bpos bucket = u64_to_bucket(lru_k.k->p.offset);
@@ -1936,7 +1935,7 @@ static int invalidate_one_bucket(struct btree_trans *trans,
 	if (bch2_bucket_is_open_safe(c, bucket.inode, bucket.offset))
 		return 0;
 
-	a = bch2_trans_start_alloc_update(trans, &alloc_iter, bucket);
+	a = bch2_trans_start_alloc_update(trans, bucket);
 	ret = PTR_ERR_OR_ZERO(a);
 	if (ret)
 		goto out;
@@ -1961,18 +1960,15 @@ static int invalidate_one_bucket(struct btree_trans *trans,
 	a->v.io_time[READ]	= atomic64_read(&c->io_clock[READ].now);
 	a->v.io_time[WRITE]	= atomic64_read(&c->io_clock[WRITE].now);
 
-	ret =   bch2_trans_update(trans, &alloc_iter, &a->k_i,
-				BTREE_TRIGGER_BUCKET_INVALIDATE) ?:
-		bch2_trans_commit(trans, NULL, NULL,
-				  BCH_WATERMARK_btree|
-				  BCH_TRANS_COMMIT_no_enospc);
+	ret = bch2_trans_commit(trans, NULL, NULL,
+				BCH_WATERMARK_btree|
+				BCH_TRANS_COMMIT_no_enospc);
 	if (ret)
 		goto out;
 
 	trace_and_count(c, bucket_invalidate, c, bucket.inode, bucket.offset, cached_sectors);
 	--*nr_to_invalidate;
 out:
-	bch2_trans_iter_exit(trans, &alloc_iter);
 	printbuf_exit(&buf);
 	return ret;
 err:
@@ -2014,11 +2010,11 @@ static void bch2_do_invalidates_work(struct work_struct *work)
 		ret = for_each_btree_key_upto(trans, iter, BTREE_ID_lru,
 				lru_pos(ca->dev_idx, 0, 0),
 				lru_pos(ca->dev_idx, U64_MAX, LRU_TIME_MAX),
-				BTREE_ITER_INTENT, k,
+				BTREE_ITER_intent, k,
 			invalidate_one_bucket(trans, &iter, k, &nr_to_invalidate));
 
 		if (ret < 0) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			break;
 		}
 	}
@@ -2051,7 +2047,7 @@ int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
 		POS(ca->dev_idx, max_t(u64, ca->mi.first_bucket, bucket_start)),
-		BTREE_ITER_PREFETCH);
+		BTREE_ITER_prefetch);
 	/*
 	 * Scan the alloc btree for every bucket on @ca, and add buckets to the
 	 * freespace/need_discard/need_gc_gens btrees as needed:
@@ -2083,7 +2079,7 @@ int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
 			struct bch_alloc_v4 a_convert;
 			const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
 
-			ret =   bch2_bucket_do_index(trans, k, a, true) ?:
+			ret =   bch2_bucket_do_index(trans, ca, k, a, true) ?:
 				bch2_trans_commit(trans, NULL, NULL,
 						  BCH_TRANS_COMMIT_no_enospc);
 			if (ret)
@@ -2155,7 +2151,7 @@ int bch2_fs_freespace_init(struct bch_fs *c)
 
 		ret = bch2_dev_freespace_init(c, ca, 0, ca->mi.nbuckets);
 		if (ret) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			bch_err_fn(c, ret);
 			return ret;
 		}
@@ -2182,7 +2178,10 @@ int bch2_bucket_io_time_reset(struct btree_trans *trans, unsigned dev,
 	u64 now;
 	int ret = 0;
 
-	a = bch2_trans_start_alloc_update(trans, &iter,  POS(dev, bucket_nr));
+	if (bch2_trans_relock(trans))
+		bch2_trans_begin(trans);
+
+	a = bch2_trans_start_alloc_update_noupdate(trans, &iter, POS(dev, bucket_nr));
 	ret = PTR_ERR_OR_ZERO(a);
 	if (ret)
 		return ret;
diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h
index 2790e516383d..ae31a94be6f9 100644
--- a/fs/bcachefs/alloc_background.h
+++ b/fs/bcachefs/alloc_background.h
@@ -8,21 +8,18 @@
 #include "debug.h"
 #include "super.h"
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 
 /* How out of date a pointer gen is allowed to be: */
 #define BUCKET_GC_GEN_MAX	96U
 
 static inline bool bch2_dev_bucket_exists(struct bch_fs *c, struct bpos pos)
 {
-	struct bch_dev *ca;
-
-	if (!bch2_dev_exists2(c, pos.inode))
-		return false;
-
-	ca = bch_dev_bkey_exists(c, pos.inode);
-	return pos.offset >= ca->mi.first_bucket &&
-		pos.offset < ca->mi.nbuckets;
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, pos.inode);
+	bool ret = ca && bucket_valid(ca, pos.offset);
+	rcu_read_unlock();
+	return ret;
 }
 
 static inline u64 bucket_to_u64(struct bpos bucket)
@@ -40,38 +37,50 @@ static inline u8 alloc_gc_gen(struct bch_alloc_v4 a)
 	return a.gen - a.oldest_gen;
 }
 
-static inline enum bch_data_type __alloc_data_type(u32 dirty_sectors,
-						   u32 cached_sectors,
-						   u32 stripe,
-						   struct bch_alloc_v4 a,
-						   enum bch_data_type data_type)
+static inline void alloc_to_bucket(struct bucket *dst, struct bch_alloc_v4 src)
 {
-	if (stripe)
-		return data_type == BCH_DATA_parity ? data_type : BCH_DATA_stripe;
-	if (dirty_sectors)
-		return data_type;
-	if (cached_sectors)
-		return BCH_DATA_cached;
-	if (BCH_ALLOC_V4_NEED_DISCARD(&a))
-		return BCH_DATA_need_discard;
-	if (alloc_gc_gen(a) >= BUCKET_GC_GEN_MAX)
-		return BCH_DATA_need_gc_gens;
-	return BCH_DATA_free;
+	dst->gen		= src.gen;
+	dst->data_type		= src.data_type;
+	dst->dirty_sectors	= src.dirty_sectors;
+	dst->cached_sectors	= src.cached_sectors;
+	dst->stripe		= src.stripe;
 }
 
-static inline enum bch_data_type alloc_data_type(struct bch_alloc_v4 a,
-						 enum bch_data_type data_type)
+static inline void __bucket_m_to_alloc(struct bch_alloc_v4 *dst, struct bucket src)
 {
-	return __alloc_data_type(a.dirty_sectors, a.cached_sectors,
-				 a.stripe, a, data_type);
+	dst->gen		= src.gen;
+	dst->data_type		= src.data_type;
+	dst->dirty_sectors	= src.dirty_sectors;
+	dst->cached_sectors	= src.cached_sectors;
+	dst->stripe		= src.stripe;
+}
+
+static inline struct bch_alloc_v4 bucket_m_to_alloc(struct bucket b)
+{
+	struct bch_alloc_v4 ret = {};
+	__bucket_m_to_alloc(&ret, b);
+	return ret;
 }
 
 static inline enum bch_data_type bucket_data_type(enum bch_data_type data_type)
 {
-	return data_type == BCH_DATA_stripe ? BCH_DATA_user : data_type;
+	switch (data_type) {
+	case BCH_DATA_cached:
+	case BCH_DATA_stripe:
+		return BCH_DATA_user;
+	default:
+		return data_type;
+	}
+}
+
+static inline bool bucket_data_type_mismatch(enum bch_data_type bucket,
+					     enum bch_data_type ptr)
+{
+	return !data_type_is_empty(bucket) &&
+		bucket_data_type(bucket) != bucket_data_type(ptr);
 }
 
-static inline unsigned bch2_bucket_sectors(struct bch_alloc_v4 a)
+static inline unsigned bch2_bucket_sectors_total(struct bch_alloc_v4 a)
 {
 	return a.dirty_sectors + a.cached_sectors;
 }
@@ -89,6 +98,27 @@ static inline unsigned bch2_bucket_sectors_fragmented(struct bch_dev *ca,
 	return d ? max(0, ca->mi.bucket_size - d) : 0;
 }
 
+static inline enum bch_data_type alloc_data_type(struct bch_alloc_v4 a,
+						 enum bch_data_type data_type)
+{
+	if (a.stripe)
+		return data_type == BCH_DATA_parity ? data_type : BCH_DATA_stripe;
+	if (a.dirty_sectors)
+		return data_type;
+	if (a.cached_sectors)
+		return BCH_DATA_cached;
+	if (BCH_ALLOC_V4_NEED_DISCARD(&a))
+		return BCH_DATA_need_discard;
+	if (alloc_gc_gen(a) >= BUCKET_GC_GEN_MAX)
+		return BCH_DATA_need_gc_gens;
+	return BCH_DATA_free;
+}
+
+static inline void alloc_data_type_set(struct bch_alloc_v4 *a, enum bch_data_type data_type)
+{
+	a->data_type = alloc_data_type(*a, data_type);
+}
+
 static inline u64 alloc_lru_idx_read(struct bch_alloc_v4 a)
 {
 	return a.data_type == BCH_DATA_cached ? a.io_time[READ] : 0;
@@ -147,7 +177,9 @@ static inline void set_alloc_v4_u64s(struct bkey_i_alloc_v4 *a)
 }
 
 struct bkey_i_alloc_v4 *
-bch2_trans_start_alloc_update(struct btree_trans *, struct btree_iter *, struct bpos);
+bch2_trans_start_alloc_update_noupdate(struct btree_trans *, struct btree_iter *, struct bpos);
+struct bkey_i_alloc_v4 *
+bch2_trans_start_alloc_update(struct btree_trans *, struct bpos);
 
 void __bch2_alloc_to_v4(struct bkey_s_c, struct bch_alloc_v4 *);
 
@@ -173,13 +205,13 @@ struct bkey_i_alloc_v4 *bch2_alloc_to_v4_mut(struct btree_trans *, struct bkey_s
 int bch2_bucket_io_time_reset(struct btree_trans *, unsigned, size_t, int);
 
 int bch2_alloc_v1_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 int bch2_alloc_v2_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 int bch2_alloc_v3_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 int bch2_alloc_v4_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 void bch2_alloc_v4_swab(struct bkey_s);
 void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
@@ -213,7 +245,7 @@ void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 })
 
 int bch2_bucket_gens_invalid(struct bch_fs *, struct bkey_s_c,
-			     enum bkey_invalid_flags, struct printbuf *);
+			     enum bch_validate_flags, struct printbuf *);
 void bch2_bucket_gens_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 #define bch2_bkey_ops_bucket_gens ((struct bkey_ops) {	\
@@ -233,7 +265,8 @@ static inline bool bkey_is_alloc(const struct bkey *k)
 int bch2_alloc_read(struct bch_fs *);
 
 int bch2_trigger_alloc(struct btree_trans *, enum btree_id, unsigned,
-		       struct bkey_s_c, struct bkey_s, unsigned);
+		       struct bkey_s_c, struct bkey_s,
+		       enum btree_iter_update_trigger_flags);
 int bch2_check_alloc_info(struct bch_fs *);
 int bch2_check_alloc_to_lru_refs(struct bch_fs *);
 void bch2_do_discards(struct bch_fs *);
diff --git a/fs/bcachefs/alloc_foreground.c b/fs/bcachefs/alloc_foreground.c
index a1fc30adf912..927a5f300b30 100644
--- a/fs/bcachefs/alloc_foreground.c
+++ b/fs/bcachefs/alloc_foreground.c
@@ -71,7 +71,7 @@ void bch2_reset_alloc_cursors(struct bch_fs *c)
 {
 	rcu_read_lock();
 	for_each_member_device_rcu(c, ca, NULL)
-		ca->alloc_cursor = 0;
+		memset(ca->alloc_cursor, 0, sizeof(ca->alloc_cursor));
 	rcu_read_unlock();
 }
 
@@ -100,7 +100,7 @@ static void bch2_open_bucket_hash_remove(struct bch_fs *c, struct open_bucket *o
 
 void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
+	struct bch_dev *ca = ob_dev(c, ob);
 
 	if (ob->ec) {
 		ec_stripe_new_put(c, ob->ec, STRIPE_REF_io);
@@ -300,7 +300,7 @@ static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bc
 
 	k = bch2_bkey_get_iter(trans, &iter,
 			       BTREE_ID_alloc, POS(ca->dev_idx, b),
-			       BTREE_ITER_CACHED);
+			       BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (ret) {
 		ob = ERR_PTR(ret);
@@ -342,9 +342,9 @@ static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bc
 		struct bch_backpointer bp;
 		struct bpos bp_pos = POS_MIN;
 
-		ret = bch2_get_next_backpointer(trans, POS(ca->dev_idx, b), -1,
+		ret = bch2_get_next_backpointer(trans, ca, POS(ca->dev_idx, b), -1,
 						&bp_pos, &bp,
-						BTREE_ITER_NOPRESERVE);
+						BTREE_ITER_nopreserve);
 		if (ret) {
 			ob = ERR_PTR(ret);
 			goto err;
@@ -363,10 +363,10 @@ static struct open_bucket *try_alloc_bucket(struct btree_trans *trans, struct bc
 
 	ob = __try_alloc_bucket(c, ca, b, watermark, a, s, cl);
 	if (!ob)
-		set_btree_iter_dontneed(&iter);
+		bch2_set_btree_iter_dontneed(&iter);
 err:
 	if (iter.path)
-		set_btree_iter_dontneed(&iter);
+		bch2_set_btree_iter_dontneed(&iter);
 	bch2_trans_iter_exit(trans, &iter);
 	printbuf_exit(&buf);
 	return ob;
@@ -389,7 +389,8 @@ bch2_bucket_alloc_early(struct btree_trans *trans,
 	struct bkey_s_c k, ck;
 	struct open_bucket *ob = NULL;
 	u64 first_bucket = max_t(u64, ca->mi.first_bucket, ca->new_fs_bucket_idx);
-	u64 alloc_start = max(first_bucket, READ_ONCE(ca->alloc_cursor));
+	u64 *dev_alloc_cursor = &ca->alloc_cursor[s->btree_bitmap];
+	u64 alloc_start = max(first_bucket, *dev_alloc_cursor);
 	u64 alloc_cursor = alloc_start;
 	int ret;
 
@@ -404,9 +405,8 @@ bch2_bucket_alloc_early(struct btree_trans *trans,
 	 */
 again:
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_alloc, POS(ca->dev_idx, alloc_cursor),
-			   BTREE_ITER_SLOTS, k, ret) {
-		struct bch_alloc_v4 a_convert;
-		const struct bch_alloc_v4 *a;
+			   BTREE_ITER_slots, k, ret) {
+		u64 bucket = k.k->p.offset;
 
 		if (bkey_ge(k.k->p, POS(ca->dev_idx, ca->mi.nbuckets)))
 			break;
@@ -415,12 +415,29 @@ again:
 		    is_superblock_bucket(ca, k.k->p.offset))
 			continue;
 
-		a = bch2_alloc_to_v4(k, &a_convert);
+		if (s->btree_bitmap != BTREE_BITMAP_ANY &&
+		    s->btree_bitmap != bch2_dev_btree_bitmap_marked_sectors(ca,
+				bucket_to_sector(ca, bucket), ca->mi.bucket_size)) {
+			if (s->btree_bitmap == BTREE_BITMAP_YES &&
+			    bucket_to_sector(ca, bucket) > 64ULL << ca->mi.btree_bitmap_shift)
+				break;
+
+			bucket = sector_to_bucket(ca,
+					round_up(bucket_to_sector(ca, bucket) + 1,
+						 1ULL << ca->mi.btree_bitmap_shift));
+			bch2_btree_iter_set_pos(&iter, POS(ca->dev_idx, bucket));
+			s->buckets_seen++;
+			s->skipped_mi_btree_bitmap++;
+			continue;
+		}
+
+		struct bch_alloc_v4 a_convert;
+		const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
 		if (a->data_type != BCH_DATA_free)
 			continue;
 
 		/* now check the cached key to serialize concurrent allocs of the bucket */
-		ck = bch2_bkey_get_iter(trans, &citer, BTREE_ID_alloc, k.k->p, BTREE_ITER_CACHED);
+		ck = bch2_bkey_get_iter(trans, &citer, BTREE_ID_alloc, k.k->p, BTREE_ITER_cached);
 		ret = bkey_err(ck);
 		if (ret)
 			break;
@@ -433,7 +450,7 @@ again:
 
 		ob = __try_alloc_bucket(trans->c, ca, k.k->p.offset, watermark, a, s, cl);
 next:
-		set_btree_iter_dontneed(&citer);
+		bch2_set_btree_iter_dontneed(&citer);
 		bch2_trans_iter_exit(trans, &citer);
 		if (ob)
 			break;
@@ -441,7 +458,6 @@ next:
 	bch2_trans_iter_exit(trans, &iter);
 
 	alloc_cursor = iter.pos.offset;
-	ca->alloc_cursor = alloc_cursor;
 
 	if (!ob && ret)
 		ob = ERR_PTR(ret);
@@ -451,6 +467,8 @@ next:
 		goto again;
 	}
 
+	*dev_alloc_cursor = alloc_cursor;
+
 	return ob;
 }
 
@@ -463,7 +481,8 @@ static struct open_bucket *bch2_bucket_alloc_freelist(struct btree_trans *trans,
 	struct btree_iter iter;
 	struct bkey_s_c k;
 	struct open_bucket *ob = NULL;
-	u64 alloc_start = max_t(u64, ca->mi.first_bucket, READ_ONCE(ca->alloc_cursor));
+	u64 *dev_alloc_cursor = &ca->alloc_cursor[s->btree_bitmap];
+	u64 alloc_start = max_t(u64, ca->mi.first_bucket, READ_ONCE(*dev_alloc_cursor));
 	u64 alloc_cursor = alloc_start;
 	int ret;
 
@@ -485,10 +504,30 @@ again:
 
 			s->buckets_seen++;
 
+			u64 bucket = alloc_cursor & ~(~0ULL << 56);
+			if (s->btree_bitmap != BTREE_BITMAP_ANY &&
+			    s->btree_bitmap != bch2_dev_btree_bitmap_marked_sectors(ca,
+					bucket_to_sector(ca, bucket), ca->mi.bucket_size)) {
+				if (s->btree_bitmap == BTREE_BITMAP_YES &&
+				    bucket_to_sector(ca, bucket) > 64ULL << ca->mi.btree_bitmap_shift)
+					goto fail;
+
+				bucket = sector_to_bucket(ca,
+						round_up(bucket_to_sector(ca, bucket) + 1,
+							 1ULL << ca->mi.btree_bitmap_shift));
+				u64 genbits = alloc_cursor >> 56;
+				alloc_cursor = bucket | (genbits << 56);
+
+				if (alloc_cursor > k.k->p.offset)
+					bch2_btree_iter_set_pos(&iter, POS(ca->dev_idx, alloc_cursor));
+				s->skipped_mi_btree_bitmap++;
+				continue;
+			}
+
 			ob = try_alloc_bucket(trans, ca, watermark,
 					      alloc_cursor, s, k, cl);
 			if (ob) {
-				set_btree_iter_dontneed(&iter);
+				bch2_set_btree_iter_dontneed(&iter);
 				break;
 			}
 		}
@@ -496,10 +535,9 @@ again:
 		if (ob || ret)
 			break;
 	}
+fail:
 	bch2_trans_iter_exit(trans, &iter);
 
-	ca->alloc_cursor = alloc_cursor;
-
 	if (!ob && ret)
 		ob = ERR_PTR(ret);
 
@@ -508,14 +546,56 @@ again:
 		goto again;
 	}
 
+	*dev_alloc_cursor = alloc_cursor;
+
 	return ob;
 }
 
+static noinline void trace_bucket_alloc2(struct bch_fs *c, struct bch_dev *ca,
+					 enum bch_watermark watermark,
+					 enum bch_data_type data_type,
+					 struct closure *cl,
+					 struct bch_dev_usage *usage,
+					 struct bucket_alloc_state *s,
+					 struct open_bucket *ob)
+{
+	struct printbuf buf = PRINTBUF;
+
+	printbuf_tabstop_push(&buf, 24);
+
+	prt_printf(&buf, "dev\t%s (%u)\n",	ca->name, ca->dev_idx);
+	prt_printf(&buf, "watermark\t%s\n",	bch2_watermarks[watermark]);
+	prt_printf(&buf, "data type\t%s\n",	__bch2_data_types[data_type]);
+	prt_printf(&buf, "blocking\t%u\n",	cl != NULL);
+	prt_printf(&buf, "free\t%llu\n",	usage->d[BCH_DATA_free].buckets);
+	prt_printf(&buf, "avail\t%llu\n",	dev_buckets_free(ca, *usage, watermark));
+	prt_printf(&buf, "copygc_wait\t%lu/%lli\n",
+		   bch2_copygc_wait_amount(c),
+		   c->copygc_wait - atomic64_read(&c->io_clock[WRITE].now));
+	prt_printf(&buf, "seen\t%llu\n",	s->buckets_seen);
+	prt_printf(&buf, "open\t%llu\n",	s->skipped_open);
+	prt_printf(&buf, "need journal commit\t%llu\n", s->skipped_need_journal_commit);
+	prt_printf(&buf, "nocow\t%llu\n",	s->skipped_nocow);
+	prt_printf(&buf, "nouse\t%llu\n",	s->skipped_nouse);
+	prt_printf(&buf, "mi_btree_bitmap\t%llu\n", s->skipped_mi_btree_bitmap);
+
+	if (!IS_ERR(ob)) {
+		prt_printf(&buf, "allocated\t%llu\n", ob->bucket);
+		trace_bucket_alloc(c, buf.buf);
+	} else {
+		prt_printf(&buf, "err\t%s\n", bch2_err_str(PTR_ERR(ob)));
+		trace_bucket_alloc_fail(c, buf.buf);
+	}
+
+	printbuf_exit(&buf);
+}
+
 /**
  * bch2_bucket_alloc_trans - allocate a single bucket from a specific device
  * @trans:	transaction object
  * @ca:		device to allocate from
  * @watermark:	how important is this allocation?
+ * @data_type:	BCH_DATA_journal, btree, user...
  * @cl:		if not NULL, closure to be used to wait if buckets not available
  * @usage:	for secondarily also returning the current device usage
  *
@@ -524,6 +604,7 @@ again:
 static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans,
 				      struct bch_dev *ca,
 				      enum bch_watermark watermark,
+				      enum bch_data_type data_type,
 				      struct closure *cl,
 				      struct bch_dev_usage *usage)
 {
@@ -531,7 +612,9 @@ static struct open_bucket *bch2_bucket_alloc_trans(struct btree_trans *trans,
 	struct open_bucket *ob = NULL;
 	bool freespace = READ_ONCE(ca->mi.freespace_initialized);
 	u64 avail;
-	struct bucket_alloc_state s = { 0 };
+	struct bucket_alloc_state s = {
+		.btree_bitmap = data_type == BCH_DATA_btree,
+	};
 	bool waiting = false;
 again:
 	bch2_dev_usage_read_fast(ca, usage);
@@ -541,7 +624,7 @@ again:
 		bch2_do_discards(c);
 
 	if (usage->d[BCH_DATA_need_gc_gens].buckets > avail)
-		bch2_do_gc_gens(c);
+		bch2_gc_gens_async(c);
 
 	if (should_invalidate_buckets(ca, *usage))
 		bch2_do_invalidates(c);
@@ -569,6 +652,11 @@ alloc:
 	if (s.skipped_need_journal_commit * 2 > avail)
 		bch2_journal_flush_async(&c->journal, NULL);
 
+	if (!ob && s.btree_bitmap != BTREE_BITMAP_ANY) {
+		s.btree_bitmap = BTREE_BITMAP_ANY;
+		goto alloc;
+	}
+
 	if (!ob && freespace && c->curr_recovery_pass <= BCH_RECOVERY_PASS_check_alloc_info) {
 		freespace = false;
 		goto alloc;
@@ -578,33 +666,24 @@ err:
 		ob = ERR_PTR(-BCH_ERR_no_buckets_found);
 
 	if (!IS_ERR(ob))
-		trace_and_count(c, bucket_alloc, ca,
-				bch2_watermarks[watermark],
-				ob->bucket,
-				usage->d[BCH_DATA_free].buckets,
-				avail,
-				bch2_copygc_wait_amount(c),
-				c->copygc_wait - atomic64_read(&c->io_clock[WRITE].now),
-				&s,
-				cl == NULL,
-				"");
+		ob->data_type = data_type;
+
+	if (!IS_ERR(ob))
+		count_event(c, bucket_alloc);
 	else if (!bch2_err_matches(PTR_ERR(ob), BCH_ERR_transaction_restart))
-		trace_and_count(c, bucket_alloc_fail, ca,
-				bch2_watermarks[watermark],
-				0,
-				usage->d[BCH_DATA_free].buckets,
-				avail,
-				bch2_copygc_wait_amount(c),
-				c->copygc_wait - atomic64_read(&c->io_clock[WRITE].now),
-				&s,
-				cl == NULL,
-				bch2_err_str(PTR_ERR(ob)));
+		count_event(c, bucket_alloc_fail);
+
+	if (!IS_ERR(ob)
+	    ? trace_bucket_alloc_enabled()
+	    : trace_bucket_alloc_fail_enabled())
+		trace_bucket_alloc2(c, ca, watermark, data_type, cl, usage, &s, ob);
 
 	return ob;
 }
 
 struct open_bucket *bch2_bucket_alloc(struct bch_fs *c, struct bch_dev *ca,
 				      enum bch_watermark watermark,
+				      enum bch_data_type data_type,
 				      struct closure *cl)
 {
 	struct bch_dev_usage usage;
@@ -612,7 +691,7 @@ struct open_bucket *bch2_bucket_alloc(struct bch_fs *c, struct bch_dev *ca,
 
 	bch2_trans_do(c, NULL, NULL, 0,
 		      PTR_ERR_OR_ZERO(ob = bch2_bucket_alloc_trans(trans, ca, watermark,
-							cl, &usage)));
+							data_type, cl, &usage)));
 	return ob;
 }
 
@@ -678,8 +757,7 @@ static int add_new_bucket(struct bch_fs *c,
 			   unsigned flags,
 			   struct open_bucket *ob)
 {
-	unsigned durability =
-		bch_dev_bkey_exists(c, ob->dev)->mi.durability;
+	unsigned durability = ob_dev(c, ob)->mi.durability;
 
 	BUG_ON(*nr_effective >= nr_replicas);
 
@@ -711,37 +789,28 @@ int bch2_bucket_alloc_set_trans(struct btree_trans *trans,
 	struct bch_fs *c = trans->c;
 	struct dev_alloc_list devs_sorted =
 		bch2_dev_alloc_list(c, stripe, devs_may_alloc);
-	unsigned dev;
-	struct bch_dev *ca;
 	int ret = -BCH_ERR_insufficient_devices;
-	unsigned i;
 
 	BUG_ON(*nr_effective >= nr_replicas);
 
-	for (i = 0; i < devs_sorted.nr; i++) {
+	for (unsigned i = 0; i < devs_sorted.nr; i++) {
 		struct bch_dev_usage usage;
 		struct open_bucket *ob;
 
-		dev = devs_sorted.devs[i];
-
-		rcu_read_lock();
-		ca = rcu_dereference(c->devs[dev]);
-		if (ca)
-			percpu_ref_get(&ca->ref);
-		rcu_read_unlock();
-
+		unsigned dev = devs_sorted.devs[i];
+		struct bch_dev *ca = bch2_dev_tryget_noerror(c, dev);
 		if (!ca)
 			continue;
 
 		if (!ca->mi.durability && *have_cache) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			continue;
 		}
 
-		ob = bch2_bucket_alloc_trans(trans, ca, watermark, cl, &usage);
+		ob = bch2_bucket_alloc_trans(trans, ca, watermark, data_type, cl, &usage);
 		if (!IS_ERR(ob))
 			bch2_dev_stripe_increment_inlined(ca, stripe, &usage);
-		percpu_ref_put(&ca->ref);
+		bch2_dev_put(ca);
 
 		if (IS_ERR(ob)) {
 			ret = PTR_ERR(ob);
@@ -750,8 +819,6 @@ int bch2_bucket_alloc_set_trans(struct btree_trans *trans,
 			continue;
 		}
 
-		ob->data_type = data_type;
-
 		if (add_new_bucket(c, ptrs, devs_may_alloc,
 				   nr_replicas, nr_effective,
 				   have_cache, flags, ob)) {
@@ -836,7 +903,7 @@ static bool want_bucket(struct bch_fs *c,
 			bool *have_cache, bool ec,
 			struct open_bucket *ob)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
+	struct bch_dev *ca = ob_dev(c, ob);
 
 	if (!test_bit(ob->dev, devs_may_alloc->d))
 		return false;
@@ -906,7 +973,7 @@ static int bucket_alloc_set_partial(struct bch_fs *c,
 		struct open_bucket *ob = c->open_buckets + c->open_buckets_partial[i];
 
 		if (want_bucket(c, wp, devs_may_alloc, have_cache, ec, ob)) {
-			struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
+			struct bch_dev *ca = ob_dev(c, ob);
 			struct bch_dev_usage usage;
 			u64 avail;
 
@@ -1291,7 +1358,7 @@ deallocate_extra_replicas(struct bch_fs *c,
 	unsigned i;
 
 	open_bucket_for_each(c, ptrs, ob, i) {
-		unsigned d = bch_dev_bkey_exists(c, ob->dev)->mi.durability;
+		unsigned d = ob_dev(c, ob)->mi.durability;
 
 		if (d && d <= extra_replicas) {
 			extra_replicas -= d;
@@ -1342,6 +1409,10 @@ retry:
 
 	*wp_ret = wp = writepoint_find(trans, write_point.v);
 
+	ret = bch2_trans_relock(trans);
+	if (ret)
+		goto err;
+
 	/* metadata may not allocate on cache devices: */
 	if (wp->data_type != BCH_DATA_user)
 		have_cache = true;
@@ -1444,7 +1515,7 @@ err:
 
 struct bch_extent_ptr bch2_ob_ptr(struct bch_fs *c, struct open_bucket *ob)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
+	struct bch_dev *ca = ob_dev(c, ob);
 
 	return (struct bch_extent_ptr) {
 		.type	= 1 << BCH_EXTENT_ENTRY_ptr,
@@ -1520,7 +1591,7 @@ void bch2_fs_allocator_foreground_init(struct bch_fs *c)
 
 static void bch2_open_bucket_to_text(struct printbuf *out, struct bch_fs *c, struct open_bucket *ob)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
+	struct bch_dev *ca = ob_dev(c, ob);
 	unsigned data_type = ob->data_type;
 	barrier(); /* READ_ONCE() doesn't work on bitfields */
 
@@ -1622,3 +1693,104 @@ void bch2_write_points_to_text(struct printbuf *out, struct bch_fs *c)
 	prt_str(out, "Btree write point\n");
 	bch2_write_point_to_text(out, c, &c->btree_write_point);
 }
+
+void bch2_fs_alloc_debug_to_text(struct printbuf *out, struct bch_fs *c)
+{
+	unsigned nr[BCH_DATA_NR];
+
+	memset(nr, 0, sizeof(nr));
+
+	for (unsigned i = 0; i < ARRAY_SIZE(c->open_buckets); i++)
+		nr[c->open_buckets[i].data_type]++;
+
+	printbuf_tabstop_push(out, 24);
+
+	percpu_down_read(&c->mark_lock);
+	prt_printf(out, "hidden\t%llu\n",			bch2_fs_usage_read_one(c, &c->usage_base->b.hidden));
+	prt_printf(out, "btree\t%llu\n",			bch2_fs_usage_read_one(c, &c->usage_base->b.btree));
+	prt_printf(out, "data\t%llu\n",				bch2_fs_usage_read_one(c, &c->usage_base->b.data));
+	prt_printf(out, "cached\t%llu\n",			bch2_fs_usage_read_one(c, &c->usage_base->b.cached));
+	prt_printf(out, "reserved\t%llu\n",			bch2_fs_usage_read_one(c, &c->usage_base->b.reserved));
+	prt_printf(out, "online_reserved\t%llu\n",		percpu_u64_get(c->online_reserved));
+	prt_printf(out, "nr_inodes\t%llu\n",			bch2_fs_usage_read_one(c, &c->usage_base->b.nr_inodes));
+	percpu_up_read(&c->mark_lock);
+
+	prt_newline(out);
+	prt_printf(out, "freelist_wait\t%s\n",			c->freelist_wait.list.first ? "waiting" : "empty");
+	prt_printf(out, "open buckets allocated\t%i\n",		OPEN_BUCKETS_COUNT - c->open_buckets_nr_free);
+	prt_printf(out, "open buckets total\t%u\n",		OPEN_BUCKETS_COUNT);
+	prt_printf(out, "open_buckets_wait\t%s\n",		c->open_buckets_wait.list.first ? "waiting" : "empty");
+	prt_printf(out, "open_buckets_btree\t%u\n",		nr[BCH_DATA_btree]);
+	prt_printf(out, "open_buckets_user\t%u\n",		nr[BCH_DATA_user]);
+	prt_printf(out, "btree reserve cache\t%u\n",		c->btree_reserve_cache_nr);
+}
+
+void bch2_dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
+{
+	struct bch_fs *c = ca->fs;
+	struct bch_dev_usage stats = bch2_dev_usage_read(ca);
+	unsigned nr[BCH_DATA_NR];
+
+	memset(nr, 0, sizeof(nr));
+
+	for (unsigned i = 0; i < ARRAY_SIZE(c->open_buckets); i++)
+		nr[c->open_buckets[i].data_type]++;
+
+	printbuf_tabstop_push(out, 12);
+	printbuf_tabstop_push(out, 16);
+	printbuf_tabstop_push(out, 16);
+	printbuf_tabstop_push(out, 16);
+	printbuf_tabstop_push(out, 16);
+
+	bch2_dev_usage_to_text(out, &stats);
+
+	prt_newline(out);
+
+	prt_printf(out, "reserves:\n");
+	for (unsigned i = 0; i < BCH_WATERMARK_NR; i++)
+		prt_printf(out, "%s\t%llu\r\n", bch2_watermarks[i], bch2_dev_buckets_reserved(ca, i));
+
+	prt_newline(out);
+
+	printbuf_tabstops_reset(out);
+	printbuf_tabstop_push(out, 12);
+	printbuf_tabstop_push(out, 16);
+
+	prt_printf(out, "open buckets\t%i\r\n",	ca->nr_open_buckets);
+	prt_printf(out, "buckets to invalidate\t%llu\r\n",	should_invalidate_buckets(ca, stats));
+}
+
+void bch2_print_allocator_stuck(struct bch_fs *c)
+{
+	struct printbuf buf = PRINTBUF;
+
+	prt_printf(&buf, "Allocator stuck? Waited for 10 seconds\n");
+
+	prt_printf(&buf, "Allocator debug:\n");
+	printbuf_indent_add(&buf, 2);
+	bch2_fs_alloc_debug_to_text(&buf, c);
+	printbuf_indent_sub(&buf, 2);
+	prt_newline(&buf);
+
+	for_each_online_member(c, ca) {
+		prt_printf(&buf, "Dev %u:\n", ca->dev_idx);
+		printbuf_indent_add(&buf, 2);
+		bch2_dev_alloc_debug_to_text(&buf, ca);
+		printbuf_indent_sub(&buf, 2);
+		prt_newline(&buf);
+	}
+
+	prt_printf(&buf, "Copygc debug:\n");
+	printbuf_indent_add(&buf, 2);
+	bch2_copygc_wait_to_text(&buf, c);
+	printbuf_indent_sub(&buf, 2);
+	prt_newline(&buf);
+
+	prt_printf(&buf, "Journal debug:\n");
+	printbuf_indent_add(&buf, 2);
+	bch2_journal_debug_to_text(&buf, &c->journal);
+	printbuf_indent_sub(&buf, 2);
+
+	bch2_print_string_as_lines(KERN_ERR, buf.buf);
+	printbuf_exit(&buf);
+}
diff --git a/fs/bcachefs/alloc_foreground.h b/fs/bcachefs/alloc_foreground.h
index 7aaeec44c746..a42c9730d32a 100644
--- a/fs/bcachefs/alloc_foreground.h
+++ b/fs/bcachefs/alloc_foreground.h
@@ -30,8 +30,14 @@ void bch2_dev_stripe_increment(struct bch_dev *, struct dev_stripe_state *);
 
 long bch2_bucket_alloc_new_fs(struct bch_dev *);
 
+static inline struct bch_dev *ob_dev(struct bch_fs *c, struct open_bucket *ob)
+{
+	return bch2_dev_have_ref(c, ob->dev);
+}
+
 struct open_bucket *bch2_bucket_alloc(struct bch_fs *, struct bch_dev *,
-				      enum bch_watermark, struct closure *);
+				      enum bch_watermark, enum bch_data_type,
+				      struct closure *);
 
 static inline void ob_push(struct bch_fs *c, struct open_buckets *obs,
 			   struct open_bucket *ob)
@@ -184,7 +190,7 @@ bch2_alloc_sectors_append_ptrs_inlined(struct bch_fs *c, struct write_point *wp,
 	wp->sectors_allocated	+= sectors;
 
 	open_bucket_for_each(c, &wp->ptrs, ob, i) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
+		struct bch_dev *ca = ob_dev(c, ob);
 		struct bch_extent_ptr ptr = bch2_ob_ptr(c, ob);
 
 		ptr.cached = cached ||
@@ -221,4 +227,9 @@ void bch2_open_buckets_partial_to_text(struct printbuf *, struct bch_fs *);
 
 void bch2_write_points_to_text(struct printbuf *, struct bch_fs *);
 
+void bch2_fs_alloc_debug_to_text(struct printbuf *, struct bch_fs *);
+void bch2_dev_alloc_debug_to_text(struct printbuf *, struct bch_dev *);
+
+void bch2_print_allocator_stuck(struct bch_fs *);
+
 #endif /* _BCACHEFS_ALLOC_FOREGROUND_H */
diff --git a/fs/bcachefs/alloc_types.h b/fs/bcachefs/alloc_types.h
index c2226e947c41..9bbb28e90b93 100644
--- a/fs/bcachefs/alloc_types.h
+++ b/fs/bcachefs/alloc_types.h
@@ -9,11 +9,18 @@
 #include "fifo.h"
 
 struct bucket_alloc_state {
+	enum {
+		BTREE_BITMAP_NO,
+		BTREE_BITMAP_YES,
+		BTREE_BITMAP_ANY,
+	}	btree_bitmap;
+
 	u64	buckets_seen;
 	u64	skipped_open;
 	u64	skipped_need_journal_commit;
 	u64	skipped_nocow;
 	u64	skipped_nouse;
+	u64	skipped_mi_btree_bitmap;
 };
 
 #define BCH_WATERMARKS()		\
diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c
index af7a71de1bdf..692b1c7d5018 100644
--- a/fs/bcachefs/backpointers.c
+++ b/fs/bcachefs/backpointers.c
@@ -23,6 +23,7 @@ static bool extent_matches_bp(struct bch_fs *c,
 	const union bch_extent_entry *entry;
 	struct extent_ptr_decoded p;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
 		struct bpos bucket2;
 		struct bch_backpointer bp2;
@@ -30,31 +31,43 @@ static bool extent_matches_bp(struct bch_fs *c,
 		if (p.ptr.cached)
 			continue;
 
-		bch2_extent_ptr_to_bp(c, btree_id, level, k, p, entry, &bucket2, &bp2);
+		struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
+		if (!ca)
+			continue;
+
+		bch2_extent_ptr_to_bp(c, ca, btree_id, level, k, p, entry, &bucket2, &bp2);
 		if (bpos_eq(bucket, bucket2) &&
-		    !memcmp(&bp, &bp2, sizeof(bp)))
+		    !memcmp(&bp, &bp2, sizeof(bp))) {
+			rcu_read_unlock();
 			return true;
+		}
 	}
+	rcu_read_unlock();
 
 	return false;
 }
 
 int bch2_backpointer_invalid(struct bch_fs *c, struct bkey_s_c k,
-			     enum bkey_invalid_flags flags,
+			     enum bch_validate_flags flags,
 			     struct printbuf *err)
 {
 	struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(k);
 
-	/* these will be caught by fsck */
-	if (!bch2_dev_exists2(c, bp.k->p.inode))
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, bp.k->p.inode);
+	if (!ca) {
+		/* these will be caught by fsck */
+		rcu_read_unlock();
 		return 0;
+	}
 
-	struct bch_dev *ca = bch_dev_bkey_exists(c, bp.k->p.inode);
-	struct bpos bucket = bp_pos_to_bucket(c, bp.k->p);
+	struct bpos bucket = bp_pos_to_bucket(ca, bp.k->p);
+	struct bpos bp_pos = bucket_pos_to_bp_noerror(ca, bucket, bp.v->bucket_offset);
+	rcu_read_unlock();
 	int ret = 0;
 
 	bkey_fsck_err_on((bp.v->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT) >= ca->mi.bucket_size ||
-			 !bpos_eq(bp.k->p, bucket_pos_to_bp_noerror(ca, bucket, bp.v->bucket_offset)),
+			 !bpos_eq(bp.k->p, bp_pos),
 			 c, err,
 			 backpointer_bucket_offset_wrong,
 			 "backpointer bucket_offset wrong");
@@ -75,10 +88,16 @@ void bch2_backpointer_to_text(struct printbuf *out, const struct bch_backpointer
 
 void bch2_backpointer_k_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
 {
-	if (bch2_dev_exists2(c, k.k->p.inode)) {
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, k.k->p.inode);
+	if (ca) {
+		struct bpos bucket = bp_pos_to_bucket(ca, k.k->p);
+		rcu_read_unlock();
 		prt_str(out, "bucket=");
-		bch2_bpos_to_text(out, bp_pos_to_bucket(c, k.k->p));
+		bch2_bpos_to_text(out, bucket);
 		prt_str(out, " ");
+	} else {
+		rcu_read_unlock();
 	}
 
 	bch2_backpointer_to_text(out, bkey_s_c_to_backpointer(k).v);
@@ -117,8 +136,7 @@ static noinline int backpointer_mod_err(struct btree_trans *trans,
 
 		bch_err(c, "%s", buf.buf);
 	} else if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
-		prt_printf(&buf, "backpointer not found when deleting");
-		prt_newline(&buf);
+		prt_printf(&buf, "backpointer not found when deleting\n");
 		printbuf_indent_add(&buf, 2);
 
 		prt_printf(&buf, "searching for ");
@@ -145,6 +163,7 @@ static noinline int backpointer_mod_err(struct btree_trans *trans,
 }
 
 int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans,
+				struct bch_dev *ca,
 				struct bpos bucket,
 				struct bch_backpointer bp,
 				struct bkey_s_c orig_k,
@@ -161,7 +180,7 @@ int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans,
 		return ret;
 
 	bkey_backpointer_init(&bp_k->k_i);
-	bp_k->k.p = bucket_pos_to_bp(trans->c, bucket, bp.bucket_offset);
+	bp_k->k.p = bucket_pos_to_bp(ca, bucket, bp.bucket_offset);
 	bp_k->v = bp;
 
 	if (!insert) {
@@ -171,9 +190,9 @@ int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans,
 
 	k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
 			       bp_k->k.p,
-			       BTREE_ITER_INTENT|
-			       BTREE_ITER_SLOTS|
-			       BTREE_ITER_WITH_UPDATES);
+			       BTREE_ITER_intent|
+			       BTREE_ITER_slots|
+			       BTREE_ITER_with_updates);
 	ret = bkey_err(k);
 	if (ret)
 		goto err;
@@ -197,13 +216,13 @@ err:
  * Find the next backpointer >= *bp_offset:
  */
 int bch2_get_next_backpointer(struct btree_trans *trans,
+			      struct bch_dev *ca,
 			      struct bpos bucket, int gen,
 			      struct bpos *bp_pos,
 			      struct bch_backpointer *bp,
 			      unsigned iter_flags)
 {
-	struct bch_fs *c = trans->c;
-	struct bpos bp_end_pos = bucket_pos_to_bp(c, bpos_nosnap_successor(bucket), 0);
+	struct bpos bp_end_pos = bucket_pos_to_bp(ca, bpos_nosnap_successor(bucket), 0);
 	struct btree_iter alloc_iter = { NULL }, bp_iter = { NULL };
 	struct bkey_s_c k;
 	int ret = 0;
@@ -213,7 +232,7 @@ int bch2_get_next_backpointer(struct btree_trans *trans,
 
 	if (gen >= 0) {
 		k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
-				       bucket, BTREE_ITER_CACHED|iter_flags);
+				       bucket, BTREE_ITER_cached|iter_flags);
 		ret = bkey_err(k);
 		if (ret)
 			goto out;
@@ -223,7 +242,7 @@ int bch2_get_next_backpointer(struct btree_trans *trans,
 			goto done;
 	}
 
-	*bp_pos = bpos_max(*bp_pos, bucket_pos_to_bp(c, bucket, 0));
+	*bp_pos = bpos_max(*bp_pos, bucket_pos_to_bp(ca, bucket, 0));
 
 	for_each_btree_key_norestart(trans, bp_iter, BTREE_ID_backpointers,
 				     *bp_pos, iter_flags, k, ret) {
@@ -249,7 +268,6 @@ static void backpointer_not_found(struct btree_trans *trans,
 {
 	struct bch_fs *c = trans->c;
 	struct printbuf buf = PRINTBUF;
-	struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
 
 	/*
 	 * If we're using the btree write buffer, the backpointer we were
@@ -259,6 +277,10 @@ static void backpointer_not_found(struct btree_trans *trans,
 	if (likely(!bch2_backpointers_no_use_write_buffer))
 		return;
 
+	struct bpos bucket;
+	if (!bp_pos_to_bucket_nodev(c, bp_pos, &bucket))
+		return;
+
 	prt_printf(&buf, "backpointer doesn't match %s it points to:\n  ",
 		   bp.level ? "btree node" : "extent");
 	prt_printf(&buf, "bucket: ");
@@ -288,15 +310,17 @@ struct bkey_s_c bch2_backpointer_get_key(struct btree_trans *trans,
 {
 	if (likely(!bp.level)) {
 		struct bch_fs *c = trans->c;
-		struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
-		struct bkey_s_c k;
+
+		struct bpos bucket;
+		if (!bp_pos_to_bucket_nodev(c, bp_pos, &bucket))
+			return bkey_s_c_err(-EIO);
 
 		bch2_trans_node_iter_init(trans, iter,
 					  bp.btree_id,
 					  bp.pos,
 					  0, 0,
 					  iter_flags);
-		k = bch2_btree_iter_peek_slot(iter);
+		struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
 		if (bkey_err(k)) {
 			bch2_trans_iter_exit(trans, iter);
 			return k;
@@ -325,18 +349,20 @@ struct btree *bch2_backpointer_get_node(struct btree_trans *trans,
 					struct bch_backpointer bp)
 {
 	struct bch_fs *c = trans->c;
-	struct bpos bucket = bp_pos_to_bucket(c, bp_pos);
-	struct btree *b;
 
 	BUG_ON(!bp.level);
 
+	struct bpos bucket;
+	if (!bp_pos_to_bucket_nodev(c, bp_pos, &bucket))
+		return ERR_PTR(-EIO);
+
 	bch2_trans_node_iter_init(trans, iter,
 				  bp.btree_id,
 				  bp.pos,
 				  0,
 				  bp.level - 1,
 				  0);
-	b = bch2_btree_iter_peek_node(iter);
+	struct btree *b = bch2_btree_iter_peek_node(iter);
 	if (IS_ERR_OR_NULL(b))
 		goto err;
 
@@ -367,16 +393,16 @@ static int bch2_check_btree_backpointer(struct btree_trans *trans, struct btree_
 	struct printbuf buf = PRINTBUF;
 	int ret = 0;
 
-	if (fsck_err_on(!bch2_dev_exists2(c, k.k->p.inode), c,
-			backpointer_to_missing_device,
-			"backpointer for missing device:\n%s",
-			(bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
-		ret = bch2_btree_delete_at(trans, bp_iter, 0);
+	struct bpos bucket;
+	if (!bp_pos_to_bucket_nodev_noerror(c, k.k->p, &bucket)) {
+		if (fsck_err(c, backpointer_to_missing_device,
+			     "backpointer for missing device:\n%s",
+			     (bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+			ret = bch2_btree_delete_at(trans, bp_iter, 0);
 		goto out;
 	}
 
-	alloc_k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
-				     bp_pos_to_bucket(c, k.k->p), 0);
+	alloc_k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc, bucket, 0);
 	ret = bkey_err(alloc_k);
 	if (ret)
 		goto out;
@@ -460,8 +486,8 @@ found:
 
 	bytes = p.crc.compressed_size << 9;
 
-	struct bch_dev *ca = bch_dev_bkey_exists(c, dev);
-	if (!bch2_dev_get_ioref(ca, READ))
+	struct bch_dev *ca = bch2_dev_get_ioref(c, dev, READ);
+	if (!ca)
 		return false;
 
 	data_buf = kvmalloc(bytes, GFP_KERNEL);
@@ -511,25 +537,27 @@ static int check_bp_exists(struct btree_trans *trans,
 	struct printbuf buf = PRINTBUF;
 	struct bkey_s_c bp_k;
 	struct bkey_buf tmp;
-	int ret;
+	int ret = 0;
 
 	bch2_bkey_buf_init(&tmp);
 
-	if (!bch2_dev_bucket_exists(c, bucket)) {
+	struct bch_dev *ca = bch2_dev_bucket_tryget(c, bucket);
+	if (!ca) {
 		prt_str(&buf, "extent for nonexistent device:bucket ");
 		bch2_bpos_to_text(&buf, bucket);
 		prt_str(&buf, "\n  ");
 		bch2_bkey_val_to_text(&buf, c, orig_k);
 		bch_err(c, "%s", buf.buf);
-		return -BCH_ERR_fsck_repair_unimplemented;
+		ret = -BCH_ERR_fsck_repair_unimplemented;
+		goto err;
 	}
 
 	if (bpos_lt(bucket, s->bucket_start) ||
 	    bpos_gt(bucket, s->bucket_end))
-		return 0;
+		goto out;
 
 	bp_k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
-				  bucket_pos_to_bp(c, bucket, bp.bucket_offset),
+				  bucket_pos_to_bp(ca, bucket, bp.bucket_offset),
 				  0);
 	ret = bkey_err(bp_k);
 	if (ret)
@@ -562,6 +590,7 @@ fsck_err:
 	bch2_trans_iter_exit(trans, &other_extent_iter);
 	bch2_trans_iter_exit(trans, &bp_iter);
 	bch2_bkey_buf_exit(&tmp, c);
+	bch2_dev_put(ca);
 	printbuf_exit(&buf);
 	return ret;
 check_existing_bp:
@@ -637,13 +666,13 @@ missing:
 
 	struct bkey_i_backpointer n_bp_k;
 	bkey_backpointer_init(&n_bp_k.k_i);
-	n_bp_k.k.p = bucket_pos_to_bp(trans->c, bucket, bp.bucket_offset);
+	n_bp_k.k.p = bucket_pos_to_bp(ca, bucket, bp.bucket_offset);
 	n_bp_k.v = bp;
 	prt_printf(&buf, "\n  want:  ");
 	bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&n_bp_k.k_i));
 
 	if (fsck_err(c, ptr_to_missing_backpointer, "%s", buf.buf))
-		ret = bch2_bucket_backpointer_mod(trans, bucket, bp, orig_k, true);
+		ret = bch2_bucket_backpointer_mod(trans, ca, bucket, bp, orig_k, true);
 
 	goto out;
 }
@@ -667,7 +696,14 @@ static int check_extent_to_backpointers(struct btree_trans *trans,
 		if (p.ptr.cached)
 			continue;
 
-		bch2_extent_ptr_to_bp(c, btree, level, k, p, entry, &bucket_pos, &bp);
+		rcu_read_lock();
+		struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
+		if (ca)
+			bch2_extent_ptr_to_bp(c, ca, btree, level, k, p, entry, &bucket_pos, &bp);
+		rcu_read_unlock();
+
+		if (!ca)
+			continue;
 
 		ret = check_bp_exists(trans, s, bucket_pos, bp, k);
 		if (ret)
@@ -760,7 +796,7 @@ static int bch2_get_btree_in_memory_pos(struct btree_trans *trans,
 
 		__for_each_btree_node(trans, iter, btree,
 				      btree == start.btree ? start.pos : POS_MIN,
-				      0, depth, BTREE_ITER_PREFETCH, b, ret) {
+				      0, depth, BTREE_ITER_prefetch, b, ret) {
 			mem_may_pin -= btree_buf_bytes(b);
 			if (mem_may_pin <= 0) {
 				c->btree_cache.pinned_nodes_end = *end =
@@ -794,31 +830,13 @@ static int bch2_check_extents_to_backpointers_pass(struct btree_trans *trans,
 
 		while (level >= depth) {
 			struct btree_iter iter;
-			bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0,
-						  level,
-						  BTREE_ITER_PREFETCH);
-			while (1) {
-				bch2_trans_begin(trans);
-
-				struct bkey_s_c k = bch2_btree_iter_peek(&iter);
-				if (!k.k)
-					break;
-				ret = bkey_err(k) ?:
-					check_extent_to_backpointers(trans, s, btree_id, level, k) ?:
-					bch2_trans_commit(trans, NULL, NULL,
-							  BCH_TRANS_COMMIT_no_enospc);
-				if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) {
-					ret = 0;
-					continue;
-				}
-				if (ret)
-					break;
-				if (bpos_eq(iter.pos, SPOS_MAX))
-					break;
-				bch2_btree_iter_advance(&iter);
-			}
-			bch2_trans_iter_exit(trans, &iter);
+			bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, level,
+						  BTREE_ITER_prefetch);
 
+			ret = for_each_btree_key_continue(trans, iter, 0, k, ({
+				check_extent_to_backpointers(trans, s, btree_id, level, k) ?:
+				bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
+			}));
 			if (ret)
 				return ret;
 
@@ -936,7 +954,7 @@ static int bch2_check_backpointers_to_extents_pass(struct btree_trans *trans,
 	struct bpos last_flushed_pos = SPOS_MAX;
 
 	return for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,
-				  POS_MIN, BTREE_ITER_PREFETCH, k,
+				  POS_MIN, BTREE_ITER_prefetch, k,
 				  NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 		check_one_backpointer(trans, start, end,
 				      bkey_s_c_to_backpointer(k),
diff --git a/fs/bcachefs/backpointers.h b/fs/bcachefs/backpointers.h
index c1b274eadda1..6021de1c5e98 100644
--- a/fs/bcachefs/backpointers.h
+++ b/fs/bcachefs/backpointers.h
@@ -6,6 +6,7 @@
 #include "btree_iter.h"
 #include "btree_update.h"
 #include "buckets.h"
+#include "error.h"
 #include "super.h"
 
 static inline u64 swab40(u64 x)
@@ -18,7 +19,7 @@ static inline u64 swab40(u64 x)
 }
 
 int bch2_backpointer_invalid(struct bch_fs *, struct bkey_s_c k,
-			     enum bkey_invalid_flags, struct printbuf *);
+			     enum bch_validate_flags, struct printbuf *);
 void bch2_backpointer_to_text(struct printbuf *, const struct bch_backpointer *);
 void bch2_backpointer_k_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 void bch2_backpointer_swab(struct bkey_s);
@@ -36,15 +37,29 @@ void bch2_backpointer_swab(struct bkey_s);
  * Convert from pos in backpointer btree to pos of corresponding bucket in alloc
  * btree:
  */
-static inline struct bpos bp_pos_to_bucket(const struct bch_fs *c,
-					   struct bpos bp_pos)
+static inline struct bpos bp_pos_to_bucket(const struct bch_dev *ca, struct bpos bp_pos)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, bp_pos.inode);
 	u64 bucket_sector = bp_pos.offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT;
 
 	return POS(bp_pos.inode, sector_to_bucket(ca, bucket_sector));
 }
 
+static inline bool bp_pos_to_bucket_nodev_noerror(struct bch_fs *c, struct bpos bp_pos, struct bpos *bucket)
+{
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, bp_pos.inode);
+	if (ca)
+		*bucket = bp_pos_to_bucket(ca, bp_pos);
+	rcu_read_unlock();
+	return ca != NULL;
+}
+
+static inline bool bp_pos_to_bucket_nodev(struct bch_fs *c, struct bpos bp_pos, struct bpos *bucket)
+{
+	return !bch2_fs_inconsistent_on(!bp_pos_to_bucket_nodev_noerror(c, bp_pos, bucket),
+					c, "backpointer for missing device %llu", bp_pos.inode);
+}
+
 static inline struct bpos bucket_pos_to_bp_noerror(const struct bch_dev *ca,
 						   struct bpos bucket,
 						   u64 bucket_offset)
@@ -57,32 +72,32 @@ static inline struct bpos bucket_pos_to_bp_noerror(const struct bch_dev *ca,
 /*
  * Convert from pos in alloc btree + bucket offset to pos in backpointer btree:
  */
-static inline struct bpos bucket_pos_to_bp(const struct bch_fs *c,
+static inline struct bpos bucket_pos_to_bp(const struct bch_dev *ca,
 					   struct bpos bucket,
 					   u64 bucket_offset)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, bucket.inode);
 	struct bpos ret = bucket_pos_to_bp_noerror(ca, bucket, bucket_offset);
-	EBUG_ON(!bkey_eq(bucket, bp_pos_to_bucket(c, ret)));
+	EBUG_ON(!bkey_eq(bucket, bp_pos_to_bucket(ca, ret)));
 	return ret;
 }
 
-int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *, struct bpos bucket,
-				struct bch_backpointer, struct bkey_s_c, bool);
+int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *, struct bch_dev *,
+				struct bpos bucket, struct bch_backpointer, struct bkey_s_c, bool);
 
 static inline int bch2_bucket_backpointer_mod(struct btree_trans *trans,
+				struct bch_dev *ca,
 				struct bpos bucket,
 				struct bch_backpointer bp,
 				struct bkey_s_c orig_k,
 				bool insert)
 {
 	if (unlikely(bch2_backpointers_no_use_write_buffer))
-		return bch2_bucket_backpointer_mod_nowritebuffer(trans, bucket, bp, orig_k, insert);
+		return bch2_bucket_backpointer_mod_nowritebuffer(trans, ca, bucket, bp, orig_k, insert);
 
 	struct bkey_i_backpointer bp_k;
 
 	bkey_backpointer_init(&bp_k.k_i);
-	bp_k.k.p = bucket_pos_to_bp(trans->c, bucket, bp.bucket_offset);
+	bp_k.k.p = bucket_pos_to_bp(ca, bucket, bp.bucket_offset);
 	bp_k.v = bp;
 
 	if (!insert) {
@@ -120,7 +135,7 @@ static inline enum bch_data_type bch2_bkey_ptr_data_type(struct bkey_s_c k,
 	}
 }
 
-static inline void bch2_extent_ptr_to_bp(struct bch_fs *c,
+static inline void bch2_extent_ptr_to_bp(struct bch_fs *c, struct bch_dev *ca,
 			   enum btree_id btree_id, unsigned level,
 			   struct bkey_s_c k, struct extent_ptr_decoded p,
 			   const union bch_extent_entry *entry,
@@ -130,7 +145,7 @@ static inline void bch2_extent_ptr_to_bp(struct bch_fs *c,
 	s64 sectors = level ? btree_sectors(c) : k.k->size;
 	u32 bucket_offset;
 
-	*bucket_pos = PTR_BUCKET_POS_OFFSET(c, &p.ptr, &bucket_offset);
+	*bucket_pos = PTR_BUCKET_POS_OFFSET(ca, &p.ptr, &bucket_offset);
 	*bp = (struct bch_backpointer) {
 		.btree_id	= btree_id,
 		.level		= level,
@@ -142,7 +157,7 @@ static inline void bch2_extent_ptr_to_bp(struct bch_fs *c,
 	};
 }
 
-int bch2_get_next_backpointer(struct btree_trans *, struct bpos, int,
+int bch2_get_next_backpointer(struct btree_trans *, struct bch_dev *ca, struct bpos, int,
 			      struct bpos *, struct bch_backpointer *, unsigned);
 struct bkey_s_c bch2_backpointer_get_key(struct btree_trans *, struct btree_iter *,
 					 struct bpos, struct bch_backpointer,
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 91c3c1fef233..bc0ea2c4efef 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -359,6 +359,8 @@ do {									\
 #define BCH_DEBUG_PARAMS_ALWAYS()					\
 	BCH_DEBUG_PARAM(key_merging_disabled,				\
 		"Disables merging of extents")				\
+	BCH_DEBUG_PARAM(btree_node_merging_disabled,			\
+		"Disables merging of btree nodes")			\
 	BCH_DEBUG_PARAM(btree_gc_always_rewrite,			\
 		"Causes mark and sweep to compact and rewrite every "	\
 		"btree node it traverses")				\
@@ -468,6 +470,7 @@ enum bch_time_stats {
 #include "quota_types.h"
 #include "rebalance_types.h"
 #include "replicas_types.h"
+#include "sb-members_types.h"
 #include "subvolume_types.h"
 #include "super_types.h"
 #include "thread_with_file_types.h"
@@ -516,8 +519,8 @@ enum gc_phase {
 
 struct gc_pos {
 	enum gc_phase		phase;
+	u16			level;
 	struct bpos		pos;
-	unsigned		level;
 };
 
 struct reflink_gc {
@@ -534,7 +537,13 @@ struct io_count {
 
 struct bch_dev {
 	struct kobject		kobj;
+#ifdef CONFIG_BCACHEFS_DEBUG
+	atomic_long_t		ref;
+	bool			dying;
+	unsigned long		last_put;
+#else
 	struct percpu_ref	ref;
+#endif
 	struct completion	ref_completion;
 	struct percpu_ref	io_ref;
 	struct completion	io_ref_completion;
@@ -560,14 +569,11 @@ struct bch_dev {
 
 	struct bch_devs_mask	self;
 
-	/* biosets used in cloned bios for writing multiple replicas */
-	struct bio_set		replica_set;
-
 	/*
 	 * Buckets:
 	 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and
 	 * gc_lock, for device resize - holding any is sufficient for access:
-	 * Or rcu_read_lock(), but only for ptr_stale():
+	 * Or rcu_read_lock(), but only for dev_ptr_stale():
 	 */
 	struct bucket_array __rcu *buckets_gc;
 	struct bucket_gens __rcu *bucket_gens;
@@ -581,7 +587,7 @@ struct bch_dev {
 
 	/* Allocator: */
 	u64			new_fs_bucket_idx;
-	u64			alloc_cursor;
+	u64			alloc_cursor[3];
 
 	unsigned		nr_open_buckets;
 	unsigned		nr_btree_reserve;
@@ -627,12 +633,12 @@ struct bch_dev {
 	x(clean_shutdown)		\
 	x(fsck_running)			\
 	x(initial_gc_unfixed)		\
-	x(need_another_gc)		\
 	x(need_delete_dead_snapshots)	\
 	x(error)			\
 	x(topology_error)		\
 	x(errors_fixed)			\
-	x(errors_not_fixed)
+	x(errors_not_fixed)		\
+	x(no_invalid_checks)
 
 enum bch_fs_flags {
 #define x(n)		BCH_FS_##n,
@@ -715,6 +721,7 @@ struct btree_trans_buf {
 	x(discard_fast)							\
 	x(invalidate)							\
 	x(delete_dead_snapshots)					\
+	x(gc_gens)							\
 	x(snapshot_delete_pagecache)					\
 	x(sysfs)							\
 	x(btree_write_buffer)
@@ -926,7 +933,6 @@ struct bch_fs {
 	/* JOURNAL SEQ BLACKLIST */
 	struct journal_seq_blacklist_table *
 				journal_seq_blacklist_table;
-	struct work_struct	journal_seq_blacklist_gc_work;
 
 	/* ALLOCATOR */
 	spinlock_t		freelist_lock;
@@ -957,8 +963,7 @@ struct bch_fs {
 	struct work_struct	discard_fast_work;
 
 	/* GARBAGE COLLECTION */
-	struct task_struct	*gc_thread;
-	atomic_t		kick_gc;
+	struct work_struct	gc_gens_work;
 	unsigned long		gc_count;
 
 	enum btree_id		gc_gens_btree;
@@ -988,6 +993,7 @@ struct bch_fs {
 	struct bio_set		bio_read;
 	struct bio_set		bio_read_split;
 	struct bio_set		bio_write;
+	struct bio_set		replica_set;
 	struct mutex		bio_bounce_pages_lock;
 	mempool_t		bio_bounce_pages;
 	struct bucket_nocow_lock_table
@@ -1115,7 +1121,6 @@ struct bch_fs {
 	u64			counters_on_mount[BCH_COUNTER_NR];
 	u64 __percpu		*counters;
 
-	unsigned		btree_gc_periodic:1;
 	unsigned		copy_gc_enabled:1;
 	bool			promote_whole_extents;
 
@@ -1250,11 +1255,6 @@ static inline s64 bch2_current_time(const struct bch_fs *c)
 	return timespec_to_bch2_time(c, now);
 }
 
-static inline bool bch2_dev_exists2(const struct bch_fs *c, unsigned dev)
-{
-	return dev < c->sb.nr_devices && c->devs[dev];
-}
-
 static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c)
 {
 	struct stdio_redirect *stdio = c->stdio;
diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 2e8b1a489c20..1bebba881d89 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -76,6 +76,7 @@
 #include <asm/byteorder.h>
 #include <linux/kernel.h>
 #include <linux/uuid.h>
+#include <uapi/linux/magic.h>
 #include "vstructs.h"
 
 #ifdef __KERNEL__
@@ -589,6 +590,13 @@ struct bch_member {
 	__le64			errors_reset_time;
 	__le64			seq;
 	__le64			btree_allocated_bitmap;
+	/*
+	 * On recovery from a clean shutdown we don't normally read the journal,
+	 * but we still want to resume writing from where we left off so we
+	 * don't overwrite more than is necessary, for list journal debugging:
+	 */
+	__le32			last_journal_bucket;
+	__le32			last_journal_bucket_offset;
 };
 
 /*
@@ -1283,7 +1291,7 @@ enum bch_compression_opts {
 	UUID_INIT(0xc68573f6, 0x66ce, 0x90a9,				\
 		  0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
 
-#define BCACHEFS_STATFS_MAGIC		0xca451a4e
+#define BCACHEFS_STATFS_MAGIC		BCACHEFS_SUPER_MAGIC
 
 #define JSET_MAGIC		__cpu_to_le64(0x245235c1a3625032ULL)
 #define BSET_MAGIC		__cpu_to_le64(0x90135c78b99e07f5ULL)
diff --git a/fs/bcachefs/bkey.c b/fs/bcachefs/bkey.c
index 76e79a15ba08..f46978e5cb7c 100644
--- a/fs/bcachefs/bkey.c
+++ b/fs/bcachefs/bkey.c
@@ -640,7 +640,7 @@ struct bkey_format bch2_bkey_format_done(struct bkey_format_state *s)
 
 int bch2_bkey_format_invalid(struct bch_fs *c,
 			     struct bkey_format *f,
-			     enum bkey_invalid_flags flags,
+			     enum bch_validate_flags flags,
 			     struct printbuf *err)
 {
 	unsigned i, bits = KEY_PACKED_BITS_START;
@@ -656,20 +656,17 @@ int bch2_bkey_format_invalid(struct bch_fs *c,
 	 * unpacked format:
 	 */
 	for (i = 0; i < f->nr_fields; i++) {
-		if (!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) {
+		if ((!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) &&
+		    bch2_bkey_format_field_overflows(f, i)) {
 			unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
 			u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
 			u64 packed_max = f->bits_per_field[i]
 				? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
 				: 0;
-			u64 field_offset = le64_to_cpu(f->field_offset[i]);
 
-			if (packed_max + field_offset < packed_max ||
-			    packed_max + field_offset > unpacked_max) {
-				prt_printf(err, "field %u too large: %llu + %llu > %llu",
-					   i, packed_max, field_offset, unpacked_max);
-				return -BCH_ERR_invalid;
-			}
+			prt_printf(err, "field %u too large: %llu + %llu > %llu",
+				   i, packed_max, le64_to_cpu(f->field_offset[i]), unpacked_max);
+			return -BCH_ERR_invalid;
 		}
 
 		bits += f->bits_per_field[i];
diff --git a/fs/bcachefs/bkey.h b/fs/bcachefs/bkey.h
index 3a45d128f608..fcd43915df07 100644
--- a/fs/bcachefs/bkey.h
+++ b/fs/bcachefs/bkey.h
@@ -9,10 +9,10 @@
 #include "util.h"
 #include "vstructs.h"
 
-enum bkey_invalid_flags {
-	BKEY_INVALID_WRITE		= (1U << 0),
-	BKEY_INVALID_COMMIT		= (1U << 1),
-	BKEY_INVALID_JOURNAL		= (1U << 2),
+enum bch_validate_flags {
+	BCH_VALIDATE_write		= (1U << 0),
+	BCH_VALIDATE_commit		= (1U << 1),
+	BCH_VALIDATE_journal		= (1U << 2),
 };
 
 #if 0
@@ -574,8 +574,31 @@ static inline void bch2_bkey_format_add_key(struct bkey_format_state *s, const s
 
 void bch2_bkey_format_add_pos(struct bkey_format_state *, struct bpos);
 struct bkey_format bch2_bkey_format_done(struct bkey_format_state *);
+
+static inline bool bch2_bkey_format_field_overflows(struct bkey_format *f, unsigned i)
+{
+	unsigned f_bits = f->bits_per_field[i];
+	unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
+	u64 unpacked_mask = ~((~0ULL << 1) << (unpacked_bits - 1));
+	u64 field_offset = le64_to_cpu(f->field_offset[i]);
+
+	if (f_bits > unpacked_bits)
+		return true;
+
+	if ((f_bits == unpacked_bits) && field_offset)
+		return true;
+
+	u64 f_mask = f_bits
+		? ~((~0ULL << (f_bits - 1)) << 1)
+		: 0;
+
+	if (((field_offset + f_mask) & unpacked_mask) < field_offset)
+		return true;
+	return false;
+}
+
 int bch2_bkey_format_invalid(struct bch_fs *, struct bkey_format *,
-			     enum bkey_invalid_flags, struct printbuf *);
+			     enum bch_validate_flags, struct printbuf *);
 void bch2_bkey_format_to_text(struct printbuf *, const struct bkey_format *);
 
 #endif /* _BCACHEFS_BKEY_H */
diff --git a/fs/bcachefs/bkey_methods.c b/fs/bcachefs/bkey_methods.c
index a275a9e8e341..c2c3dae52186 100644
--- a/fs/bcachefs/bkey_methods.c
+++ b/fs/bcachefs/bkey_methods.c
@@ -27,7 +27,7 @@ const char * const bch2_bkey_types[] = {
 };
 
 static int deleted_key_invalid(struct bch_fs *c, struct bkey_s_c k,
-			       enum bkey_invalid_flags flags, struct printbuf *err)
+			       enum bch_validate_flags flags, struct printbuf *err)
 {
 	return 0;
 }
@@ -41,7 +41,7 @@ static int deleted_key_invalid(struct bch_fs *c, struct bkey_s_c k,
 })
 
 static int empty_val_key_invalid(struct bch_fs *c, struct bkey_s_c k,
-				 enum bkey_invalid_flags flags, struct printbuf *err)
+				 enum bch_validate_flags flags, struct printbuf *err)
 {
 	int ret = 0;
 
@@ -58,7 +58,7 @@ fsck_err:
 })
 
 static int key_type_cookie_invalid(struct bch_fs *c, struct bkey_s_c k,
-				   enum bkey_invalid_flags flags, struct printbuf *err)
+				   enum bch_validate_flags flags, struct printbuf *err)
 {
 	return 0;
 }
@@ -82,7 +82,7 @@ static void key_type_cookie_to_text(struct printbuf *out, struct bch_fs *c,
 })
 
 static int key_type_inline_data_invalid(struct bch_fs *c, struct bkey_s_c k,
-					enum bkey_invalid_flags flags, struct printbuf *err)
+					enum bch_validate_flags flags, struct printbuf *err)
 {
 	return 0;
 }
@@ -123,9 +123,12 @@ const struct bkey_ops bch2_bkey_null_ops = {
 };
 
 int bch2_bkey_val_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
+	if (test_bit(BCH_FS_no_invalid_checks, &c->flags))
+		return 0;
+
 	const struct bkey_ops *ops = bch2_bkey_type_ops(k.k->type);
 	int ret = 0;
 
@@ -159,9 +162,12 @@ const char *bch2_btree_node_type_str(enum btree_node_type type)
 
 int __bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
 			enum btree_node_type type,
-			enum bkey_invalid_flags flags,
+			enum bch_validate_flags flags,
 			struct printbuf *err)
 {
+	if (test_bit(BCH_FS_no_invalid_checks, &c->flags))
+		return 0;
+
 	int ret = 0;
 
 	bkey_fsck_err_on(k.k->u64s < BKEY_U64s, c, err,
@@ -172,7 +178,7 @@ int __bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
 		return 0;
 
 	bkey_fsck_err_on(k.k->type < KEY_TYPE_MAX &&
-			 (type == BKEY_TYPE_btree || (flags & BKEY_INVALID_COMMIT)) &&
+			 (type == BKEY_TYPE_btree || (flags & BCH_VALIDATE_commit)) &&
 			 !(bch2_key_types_allowed[type] & BIT_ULL(k.k->type)), c, err,
 			 bkey_invalid_type_for_btree,
 			 "invalid key type for btree %s (%s)",
@@ -224,7 +230,7 @@ fsck_err:
 
 int bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
 		      enum btree_node_type type,
-		      enum bkey_invalid_flags flags,
+		      enum bch_validate_flags flags,
 		      struct printbuf *err)
 {
 	return __bch2_bkey_invalid(c, k, type, flags, err) ?:
diff --git a/fs/bcachefs/bkey_methods.h b/fs/bcachefs/bkey_methods.h
index 03efe8ee565a..726ef7483763 100644
--- a/fs/bcachefs/bkey_methods.h
+++ b/fs/bcachefs/bkey_methods.h
@@ -22,14 +22,15 @@ extern const struct bkey_ops bch2_bkey_null_ops;
  */
 struct bkey_ops {
 	int		(*key_invalid)(struct bch_fs *c, struct bkey_s_c k,
-				       enum bkey_invalid_flags flags, struct printbuf *err);
+				       enum bch_validate_flags flags, struct printbuf *err);
 	void		(*val_to_text)(struct printbuf *, struct bch_fs *,
 				       struct bkey_s_c);
 	void		(*swab)(struct bkey_s);
 	bool		(*key_normalize)(struct bch_fs *, struct bkey_s);
 	bool		(*key_merge)(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 	int		(*trigger)(struct btree_trans *, enum btree_id, unsigned,
-				   struct bkey_s_c, struct bkey_s, unsigned);
+				   struct bkey_s_c, struct bkey_s,
+				   enum btree_iter_update_trigger_flags);
 	void		(*compat)(enum btree_id id, unsigned version,
 				  unsigned big_endian, int write,
 				  struct bkey_s);
@@ -48,11 +49,11 @@ static inline const struct bkey_ops *bch2_bkey_type_ops(enum bch_bkey_type type)
 }
 
 int bch2_bkey_val_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 int __bch2_bkey_invalid(struct bch_fs *, struct bkey_s_c, enum btree_node_type,
-			enum bkey_invalid_flags, struct printbuf *);
+			enum bch_validate_flags, struct printbuf *);
 int bch2_bkey_invalid(struct bch_fs *, struct bkey_s_c, enum btree_node_type,
-		      enum bkey_invalid_flags, struct printbuf *);
+		      enum bch_validate_flags, struct printbuf *);
 int bch2_bkey_in_btree_node(struct bch_fs *, struct btree *,
 			    struct bkey_s_c, struct printbuf *);
 
@@ -76,56 +77,10 @@ static inline bool bch2_bkey_maybe_mergable(const struct bkey *l, const struct b
 
 bool bch2_bkey_merge(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 
-enum btree_update_flags {
-	__BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE = __BTREE_ITER_FLAGS_END,
-	__BTREE_UPDATE_NOJOURNAL,
-	__BTREE_UPDATE_KEY_CACHE_RECLAIM,
-
-	__BTREE_TRIGGER_NORUN,
-	__BTREE_TRIGGER_TRANSACTIONAL,
-	__BTREE_TRIGGER_ATOMIC,
-	__BTREE_TRIGGER_GC,
-	__BTREE_TRIGGER_INSERT,
-	__BTREE_TRIGGER_OVERWRITE,
-	__BTREE_TRIGGER_BUCKET_INVALIDATE,
-};
-
-#define BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE (1U << __BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE)
-#define BTREE_UPDATE_NOJOURNAL		(1U << __BTREE_UPDATE_NOJOURNAL)
-#define BTREE_UPDATE_KEY_CACHE_RECLAIM	(1U << __BTREE_UPDATE_KEY_CACHE_RECLAIM)
-
-/* Don't run triggers at all */
-#define BTREE_TRIGGER_NORUN		(1U << __BTREE_TRIGGER_NORUN)
-
-/*
- * If set, we're running transactional triggers as part of a transaction commit:
- * triggers may generate new updates
- *
- * If cleared, and either BTREE_TRIGGER_INSERT|BTREE_TRIGGER_OVERWRITE are set,
- * we're running atomic triggers during a transaction commit: we have our
- * journal reservation, we're holding btree node write locks, and we know the
- * transaction is going to commit (returning an error here is a fatal error,
- * causing us to go emergency read-only)
- */
-#define BTREE_TRIGGER_TRANSACTIONAL	(1U << __BTREE_TRIGGER_TRANSACTIONAL)
-#define BTREE_TRIGGER_ATOMIC		(1U << __BTREE_TRIGGER_ATOMIC)
-
-/* We're in gc/fsck: running triggers to recalculate e.g. disk usage */
-#define BTREE_TRIGGER_GC		(1U << __BTREE_TRIGGER_GC)
-
-/* @new is entering the btree */
-#define BTREE_TRIGGER_INSERT		(1U << __BTREE_TRIGGER_INSERT)
-
-/* @old is leaving the btree */
-#define BTREE_TRIGGER_OVERWRITE		(1U << __BTREE_TRIGGER_OVERWRITE)
-
-/* signal from bucket invalidate path to alloc trigger */
-#define BTREE_TRIGGER_BUCKET_INVALIDATE	(1U << __BTREE_TRIGGER_BUCKET_INVALIDATE)
-
 static inline int bch2_key_trigger(struct btree_trans *trans,
 		enum btree_id btree, unsigned level,
 		struct bkey_s_c old, struct bkey_s new,
-		unsigned flags)
+		enum btree_iter_update_trigger_flags flags)
 {
 	const struct bkey_ops *ops = bch2_bkey_type_ops(old.k->type ?: new.k->type);
 
@@ -135,8 +90,9 @@ static inline int bch2_key_trigger(struct btree_trans *trans,
 }
 
 static inline int bch2_key_trigger_old(struct btree_trans *trans,
-				       enum btree_id btree_id, unsigned level,
-				       struct bkey_s_c old, unsigned flags)
+			enum btree_id btree_id, unsigned level,
+			struct bkey_s_c old,
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_i deleted;
 
@@ -144,12 +100,13 @@ static inline int bch2_key_trigger_old(struct btree_trans *trans,
 	deleted.k.p = old.k->p;
 
 	return bch2_key_trigger(trans, btree_id, level, old, bkey_i_to_s(&deleted),
-				BTREE_TRIGGER_OVERWRITE|flags);
+				BTREE_TRIGGER_overwrite|flags);
 }
 
 static inline int bch2_key_trigger_new(struct btree_trans *trans,
-				       enum btree_id btree_id, unsigned level,
-				       struct bkey_s new, unsigned flags)
+			enum btree_id btree_id, unsigned level,
+			struct bkey_s new,
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_i deleted;
 
@@ -157,7 +114,7 @@ static inline int bch2_key_trigger_new(struct btree_trans *trans,
 	deleted.k.p = new.k->p;
 
 	return bch2_key_trigger(trans, btree_id, level, bkey_i_to_s_c(&deleted), new,
-				BTREE_TRIGGER_INSERT|flags);
+				BTREE_TRIGGER_insert|flags);
 }
 
 void bch2_bkey_renumber(enum btree_node_type, struct bkey_packed *, int);
diff --git a/fs/bcachefs/bkey_sort.c b/fs/bcachefs/bkey_sort.c
index bcca9e76a0b4..4536eb50fc40 100644
--- a/fs/bcachefs/bkey_sort.c
+++ b/fs/bcachefs/bkey_sort.c
@@ -6,9 +6,9 @@
 #include "bset.h"
 #include "extents.h"
 
-typedef int (*sort_cmp_fn)(struct btree *,
-			   struct bkey_packed *,
-			   struct bkey_packed *);
+typedef int (*sort_cmp_fn)(const struct btree *,
+			   const struct bkey_packed *,
+			   const struct bkey_packed *);
 
 static inline bool sort_iter_end(struct sort_iter *iter)
 {
@@ -70,9 +70,9 @@ static inline struct bkey_packed *sort_iter_next(struct sort_iter *iter,
 /*
  * If keys compare equal, compare by pointer order:
  */
-static inline int key_sort_fix_overlapping_cmp(struct btree *b,
-					       struct bkey_packed *l,
-					       struct bkey_packed *r)
+static inline int key_sort_fix_overlapping_cmp(const struct btree *b,
+					       const struct bkey_packed *l,
+					       const struct bkey_packed *r)
 {
 	return bch2_bkey_cmp_packed(b, l, r) ?:
 		cmp_int((unsigned long) l, (unsigned long) r);
@@ -154,46 +154,59 @@ bch2_sort_repack(struct bset *dst, struct btree *src,
 	return nr;
 }
 
-static inline int sort_keys_cmp(struct btree *b,
-				struct bkey_packed *l,
-				struct bkey_packed *r)
+static inline int keep_unwritten_whiteouts_cmp(const struct btree *b,
+				const struct bkey_packed *l,
+				const struct bkey_packed *r)
 {
 	return bch2_bkey_cmp_packed_inlined(b, l, r) ?:
 		(int) bkey_deleted(r) - (int) bkey_deleted(l) ?:
-		(int) l->needs_whiteout - (int) r->needs_whiteout;
+		(long) l - (long) r;
 }
 
-unsigned bch2_sort_keys(struct bkey_packed *dst,
-			struct sort_iter *iter,
-			bool filter_whiteouts)
+#include "btree_update_interior.h"
+
+/*
+ * For sorting in the btree node write path: whiteouts not in the unwritten
+ * whiteouts area are dropped, whiteouts in the unwritten whiteouts area are
+ * dropped if overwritten by real keys:
+ */
+unsigned bch2_sort_keys_keep_unwritten_whiteouts(struct bkey_packed *dst, struct sort_iter *iter)
 {
-	const struct bkey_format *f = &iter->b->format;
 	struct bkey_packed *in, *next, *out = dst;
 
-	sort_iter_sort(iter, sort_keys_cmp);
+	sort_iter_sort(iter, keep_unwritten_whiteouts_cmp);
 
-	while ((in = sort_iter_next(iter, sort_keys_cmp))) {
-		bool needs_whiteout = false;
+	while ((in = sort_iter_next(iter, keep_unwritten_whiteouts_cmp))) {
+		if (bkey_deleted(in) && in < unwritten_whiteouts_start(iter->b))
+			continue;
 
-		if (bkey_deleted(in) &&
-		    (filter_whiteouts || !in->needs_whiteout))
+		if ((next = sort_iter_peek(iter)) &&
+		    !bch2_bkey_cmp_packed_inlined(iter->b, in, next))
 			continue;
 
-		while ((next = sort_iter_peek(iter)) &&
-		       !bch2_bkey_cmp_packed_inlined(iter->b, in, next)) {
-			BUG_ON(in->needs_whiteout &&
-			       next->needs_whiteout);
-			needs_whiteout |= in->needs_whiteout;
-			in = sort_iter_next(iter, sort_keys_cmp);
-		}
+		bkey_p_copy(out, in);
+		out = bkey_p_next(out);
+	}
 
-		if (bkey_deleted(in)) {
-			memcpy_u64s_small(out, in, bkeyp_key_u64s(f, in));
-			set_bkeyp_val_u64s(f, out, 0);
-		} else {
-			bkey_p_copy(out, in);
-		}
-		out->needs_whiteout |= needs_whiteout;
+	return (u64 *) out - (u64 *) dst;
+}
+
+/*
+ * Main sort routine for compacting a btree node in memory: we always drop
+ * whiteouts because any whiteouts that need to be written are in the unwritten
+ * whiteouts area:
+ */
+unsigned bch2_sort_keys(struct bkey_packed *dst, struct sort_iter *iter)
+{
+	struct bkey_packed *in, *out = dst;
+
+	sort_iter_sort(iter, bch2_bkey_cmp_packed_inlined);
+
+	while ((in = sort_iter_next(iter, bch2_bkey_cmp_packed_inlined))) {
+		if (bkey_deleted(in))
+			continue;
+
+		bkey_p_copy(out, in);
 		out = bkey_p_next(out);
 	}
 
diff --git a/fs/bcachefs/bkey_sort.h b/fs/bcachefs/bkey_sort.h
index 7c0f0b160f18..9be969d46890 100644
--- a/fs/bcachefs/bkey_sort.h
+++ b/fs/bcachefs/bkey_sort.h
@@ -48,7 +48,7 @@ bch2_sort_repack(struct bset *, struct btree *,
 		 struct btree_node_iter *,
 		 struct bkey_format *, bool);
 
-unsigned bch2_sort_keys(struct bkey_packed *,
-			struct sort_iter *, bool);
+unsigned bch2_sort_keys_keep_unwritten_whiteouts(struct bkey_packed *, struct sort_iter *);
+unsigned bch2_sort_keys(struct bkey_packed *, struct sort_iter *);
 
 #endif /* _BCACHEFS_BKEY_SORT_H */
diff --git a/fs/bcachefs/bset.c b/fs/bcachefs/bset.c
index 3bb477840eab..575e1d0b6eeb 100644
--- a/fs/bcachefs/bset.c
+++ b/fs/bcachefs/bset.c
@@ -103,8 +103,6 @@ void bch2_dump_bset(struct bch_fs *c, struct btree *b,
 
 void bch2_dump_btree_node(struct bch_fs *c, struct btree *b)
 {
-	struct bset_tree *t;
-
 	console_lock();
 	for_each_bset(b, t)
 		bch2_dump_bset(c, b, bset(b, t), t - b->set);
@@ -136,7 +134,6 @@ void bch2_dump_btree_node_iter(struct btree *b,
 
 struct btree_nr_keys bch2_btree_node_count_keys(struct btree *b)
 {
-	struct bset_tree *t;
 	struct bkey_packed *k;
 	struct btree_nr_keys nr = {};
 
@@ -198,7 +195,6 @@ void bch2_btree_node_iter_verify(struct btree_node_iter *iter,
 {
 	struct btree_node_iter_set *set, *s2;
 	struct bkey_packed *k, *p;
-	struct bset_tree *t;
 
 	if (bch2_btree_node_iter_end(iter))
 		return;
@@ -213,12 +209,14 @@ void bch2_btree_node_iter_verify(struct btree_node_iter *iter,
 	/* Verify that set->end is correct: */
 	btree_node_iter_for_each(iter, set) {
 		for_each_bset(b, t)
-			if (set->end == t->end_offset)
+			if (set->end == t->end_offset) {
+				BUG_ON(set->k < btree_bkey_first_offset(t) ||
+				       set->k >= t->end_offset);
 				goto found;
+			}
 		BUG();
 found:
-		BUG_ON(set->k < btree_bkey_first_offset(t) ||
-		       set->k >= t->end_offset);
+		do {} while (0);
 	}
 
 	/* Verify iterator is sorted: */
@@ -377,11 +375,9 @@ static struct bkey_float *bkey_float(const struct btree *b,
 	return ro_aux_tree_base(b, t)->f + idx;
 }
 
-static void bset_aux_tree_verify(const struct btree *b)
+static void bset_aux_tree_verify(struct btree *b)
 {
 #ifdef CONFIG_BCACHEFS_DEBUG
-	const struct bset_tree *t;
-
 	for_each_bset(b, t) {
 		if (t->aux_data_offset == U16_MAX)
 			continue;
@@ -685,20 +681,20 @@ static __always_inline void make_bfloat(struct btree *b, struct bset_tree *t,
 }
 
 /* bytes remaining - only valid for last bset: */
-static unsigned __bset_tree_capacity(const struct btree *b, const struct bset_tree *t)
+static unsigned __bset_tree_capacity(struct btree *b, const struct bset_tree *t)
 {
 	bset_aux_tree_verify(b);
 
 	return btree_aux_data_bytes(b) - t->aux_data_offset * sizeof(u64);
 }
 
-static unsigned bset_ro_tree_capacity(const struct btree *b, const struct bset_tree *t)
+static unsigned bset_ro_tree_capacity(struct btree *b, const struct bset_tree *t)
 {
 	return __bset_tree_capacity(b, t) /
 		(sizeof(struct bkey_float) + sizeof(u8));
 }
 
-static unsigned bset_rw_tree_capacity(const struct btree *b, const struct bset_tree *t)
+static unsigned bset_rw_tree_capacity(struct btree *b, const struct bset_tree *t)
 {
 	return __bset_tree_capacity(b, t) / sizeof(struct rw_aux_tree);
 }
@@ -1374,8 +1370,6 @@ void bch2_btree_node_iter_init(struct btree_node_iter *iter,
 void bch2_btree_node_iter_init_from_start(struct btree_node_iter *iter,
 					  struct btree *b)
 {
-	struct bset_tree *t;
-
 	memset(iter, 0, sizeof(*iter));
 
 	for_each_bset(b, t)
@@ -1481,7 +1475,6 @@ struct bkey_packed *bch2_btree_node_iter_prev_all(struct btree_node_iter *iter,
 {
 	struct bkey_packed *k, *prev = NULL;
 	struct btree_node_iter_set *set;
-	struct bset_tree *t;
 	unsigned end = 0;
 
 	if (bch2_expensive_debug_checks)
@@ -1550,9 +1543,7 @@ struct bkey_s_c bch2_btree_node_iter_peek_unpack(struct btree_node_iter *iter,
 
 void bch2_btree_keys_stats(const struct btree *b, struct bset_stats *stats)
 {
-	const struct bset_tree *t;
-
-	for_each_bset(b, t) {
+	for_each_bset_c(b, t) {
 		enum bset_aux_tree_type type = bset_aux_tree_type(t);
 		size_t j;
 
diff --git a/fs/bcachefs/bset.h b/fs/bcachefs/bset.h
index 120a79fd456b..5c6c7a14fa0f 100644
--- a/fs/bcachefs/bset.h
+++ b/fs/bcachefs/bset.h
@@ -206,7 +206,10 @@ static inline size_t btree_aux_data_u64s(const struct btree *b)
 }
 
 #define for_each_bset(_b, _t)						\
-	for (_t = (_b)->set; _t < (_b)->set + (_b)->nsets; _t++)
+	for (struct bset_tree *_t = (_b)->set; _t < (_b)->set + (_b)->nsets; _t++)
+
+#define for_each_bset_c(_b, _t)						\
+	for (const struct bset_tree *_t = (_b)->set; _t < (_b)->set + (_b)->nsets; _t++)
 
 #define bset_tree_for_each_key(_b, _t, _k)				\
 	for (_k = btree_bkey_first(_b, _t);				\
@@ -294,7 +297,6 @@ static inline struct bset_tree *
 bch2_bkey_to_bset_inlined(struct btree *b, struct bkey_packed *k)
 {
 	unsigned offset = __btree_node_key_to_offset(b, k);
-	struct bset_tree *t;
 
 	for_each_bset(b, t)
 		if (offset <= t->end_offset) {
diff --git a/fs/bcachefs/btree_cache.c b/fs/bcachefs/btree_cache.c
index 02c70e813fac..9e4ed75d3675 100644
--- a/fs/bcachefs/btree_cache.c
+++ b/fs/bcachefs/btree_cache.c
@@ -16,6 +16,12 @@
 #include <linux/prefetch.h>
 #include <linux/sched/mm.h>
 
+#define BTREE_CACHE_NOT_FREED_INCREMENT(counter) \
+do {						 \
+	if (shrinker_counter)			 \
+		bc->not_freed_##counter++;	 \
+} while (0)
+
 const char * const bch2_btree_node_flags[] = {
 #define x(f)	#f,
 	BTREE_FLAGS()
@@ -162,6 +168,9 @@ void bch2_btree_node_hash_remove(struct btree_cache *bc, struct btree *b)
 
 	/* Cause future lookups for this node to fail: */
 	b->hash_val = 0;
+
+	if (b->c.btree_id < BTREE_ID_NR)
+		--bc->used_by_btree[b->c.btree_id];
 }
 
 int __bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b)
@@ -169,8 +178,11 @@ int __bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b)
 	BUG_ON(b->hash_val);
 	b->hash_val = btree_ptr_hash_val(&b->key);
 
-	return rhashtable_lookup_insert_fast(&bc->table, &b->hash,
-					     bch_btree_cache_params);
+	int ret = rhashtable_lookup_insert_fast(&bc->table, &b->hash,
+						bch_btree_cache_params);
+	if (!ret && b->c.btree_id < BTREE_ID_NR)
+		bc->used_by_btree[b->c.btree_id]++;
+	return ret;
 }
 
 int bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b,
@@ -190,6 +202,35 @@ int bch2_btree_node_hash_insert(struct btree_cache *bc, struct btree *b,
 	return ret;
 }
 
+void bch2_btree_node_update_key_early(struct btree_trans *trans,
+				      enum btree_id btree, unsigned level,
+				      struct bkey_s_c old, struct bkey_i *new)
+{
+	struct bch_fs *c = trans->c;
+	struct btree *b;
+	struct bkey_buf tmp;
+	int ret;
+
+	bch2_bkey_buf_init(&tmp);
+	bch2_bkey_buf_reassemble(&tmp, c, old);
+
+	b = bch2_btree_node_get_noiter(trans, tmp.k, btree, level, true);
+	if (!IS_ERR_OR_NULL(b)) {
+		mutex_lock(&c->btree_cache.lock);
+
+		bch2_btree_node_hash_remove(&c->btree_cache, b);
+
+		bkey_copy(&b->key, new);
+		ret = __bch2_btree_node_hash_insert(&c->btree_cache, b);
+		BUG_ON(ret);
+
+		mutex_unlock(&c->btree_cache.lock);
+		six_unlock_read(&b->c.lock);
+	}
+
+	bch2_bkey_buf_exit(&tmp, c);
+}
+
 __flatten
 static inline struct btree *btree_cache_find(struct btree_cache *bc,
 				     const struct bkey_i *k)
@@ -203,7 +244,7 @@ static inline struct btree *btree_cache_find(struct btree_cache *bc,
  * this version is for btree nodes that have already been freed (we're not
  * reaping a real btree node)
  */
-static int __btree_node_reclaim(struct bch_fs *c, struct btree *b, bool flush)
+static int __btree_node_reclaim(struct bch_fs *c, struct btree *b, bool flush, bool shrinker_counter)
 {
 	struct btree_cache *bc = &c->btree_cache;
 	int ret = 0;
@@ -225,38 +266,64 @@ wait_on_io:
 	if (b->flags & ((1U << BTREE_NODE_dirty)|
 			(1U << BTREE_NODE_read_in_flight)|
 			(1U << BTREE_NODE_write_in_flight))) {
-		if (!flush)
+		if (!flush) {
+			if (btree_node_dirty(b))
+				BTREE_CACHE_NOT_FREED_INCREMENT(dirty);
+			else if (btree_node_read_in_flight(b))
+				BTREE_CACHE_NOT_FREED_INCREMENT(read_in_flight);
+			else if (btree_node_write_in_flight(b))
+				BTREE_CACHE_NOT_FREED_INCREMENT(write_in_flight);
 			return -BCH_ERR_ENOMEM_btree_node_reclaim;
+		}
 
 		/* XXX: waiting on IO with btree cache lock held */
 		bch2_btree_node_wait_on_read(b);
 		bch2_btree_node_wait_on_write(b);
 	}
 
-	if (!six_trylock_intent(&b->c.lock))
+	if (!six_trylock_intent(&b->c.lock)) {
+		BTREE_CACHE_NOT_FREED_INCREMENT(lock_intent);
 		return -BCH_ERR_ENOMEM_btree_node_reclaim;
+	}
 
-	if (!six_trylock_write(&b->c.lock))
+	if (!six_trylock_write(&b->c.lock)) {
+		BTREE_CACHE_NOT_FREED_INCREMENT(lock_write);
 		goto out_unlock_intent;
+	}
 
 	/* recheck under lock */
 	if (b->flags & ((1U << BTREE_NODE_read_in_flight)|
 			(1U << BTREE_NODE_write_in_flight))) {
-		if (!flush)
+		if (!flush) {
+			if (btree_node_read_in_flight(b))
+				BTREE_CACHE_NOT_FREED_INCREMENT(read_in_flight);
+			else if (btree_node_write_in_flight(b))
+				BTREE_CACHE_NOT_FREED_INCREMENT(write_in_flight);
 			goto out_unlock;
+		}
 		six_unlock_write(&b->c.lock);
 		six_unlock_intent(&b->c.lock);
 		goto wait_on_io;
 	}
 
-	if (btree_node_noevict(b) ||
-	    btree_node_write_blocked(b) ||
-	    btree_node_will_make_reachable(b))
+	if (btree_node_noevict(b)) {
+		BTREE_CACHE_NOT_FREED_INCREMENT(noevict);
+		goto out_unlock;
+	}
+	if (btree_node_write_blocked(b)) {
+		BTREE_CACHE_NOT_FREED_INCREMENT(write_blocked);
 		goto out_unlock;
+	}
+	if (btree_node_will_make_reachable(b)) {
+		BTREE_CACHE_NOT_FREED_INCREMENT(will_make_reachable);
+		goto out_unlock;
+	}
 
 	if (btree_node_dirty(b)) {
-		if (!flush)
+		if (!flush) {
+			BTREE_CACHE_NOT_FREED_INCREMENT(dirty);
 			goto out_unlock;
+		}
 		/*
 		 * Using the underscore version because we don't want to compact
 		 * bsets after the write, since this node is about to be evicted
@@ -286,14 +353,14 @@ out_unlock_intent:
 	goto out;
 }
 
-static int btree_node_reclaim(struct bch_fs *c, struct btree *b)
+static int btree_node_reclaim(struct bch_fs *c, struct btree *b, bool shrinker_counter)
 {
-	return __btree_node_reclaim(c, b, false);
+	return __btree_node_reclaim(c, b, false, shrinker_counter);
 }
 
 static int btree_node_write_and_reclaim(struct bch_fs *c, struct btree *b)
 {
-	return __btree_node_reclaim(c, b, true);
+	return __btree_node_reclaim(c, b, true, false);
 }
 
 static unsigned long bch2_btree_cache_scan(struct shrinker *shrink,
@@ -341,11 +408,12 @@ static unsigned long bch2_btree_cache_scan(struct shrinker *shrink,
 		if (touched >= nr)
 			goto out;
 
-		if (!btree_node_reclaim(c, b)) {
+		if (!btree_node_reclaim(c, b, true)) {
 			btree_node_data_free(c, b);
 			six_unlock_write(&b->c.lock);
 			six_unlock_intent(&b->c.lock);
 			freed++;
+			bc->freed++;
 		}
 	}
 restart:
@@ -354,9 +422,11 @@ restart:
 
 		if (btree_node_accessed(b)) {
 			clear_btree_node_accessed(b);
-		} else if (!btree_node_reclaim(c, b)) {
+			bc->not_freed_access_bit++;
+		} else if (!btree_node_reclaim(c, b, true)) {
 			freed++;
 			btree_node_data_free(c, b);
+			bc->freed++;
 
 			bch2_btree_node_hash_remove(bc, b);
 			six_unlock_write(&b->c.lock);
@@ -564,7 +634,7 @@ static struct btree *btree_node_cannibalize(struct bch_fs *c)
 	struct btree *b;
 
 	list_for_each_entry_reverse(b, &bc->live, list)
-		if (!btree_node_reclaim(c, b))
+		if (!btree_node_reclaim(c, b, false))
 			return b;
 
 	while (1) {
@@ -600,7 +670,7 @@ struct btree *bch2_btree_node_mem_alloc(struct btree_trans *trans, bool pcpu_rea
 	 * disk node. Check the freed list before allocating a new one:
 	 */
 	list_for_each_entry(b, freed, list)
-		if (!btree_node_reclaim(c, b)) {
+		if (!btree_node_reclaim(c, b, false)) {
 			list_del_init(&b->list);
 			goto got_node;
 		}
@@ -626,7 +696,7 @@ got_node:
 	 * the list. Check if there's any freed nodes there:
 	 */
 	list_for_each_entry(b2, &bc->freeable, list)
-		if (!btree_node_reclaim(c, b2)) {
+		if (!btree_node_reclaim(c, b2, false)) {
 			swap(b->data, b2->data);
 			swap(b->aux_data, b2->aux_data);
 			btree_node_to_freedlist(bc, b2);
@@ -846,7 +916,6 @@ static struct btree *__bch2_btree_node_get(struct btree_trans *trans, struct btr
 	struct bch_fs *c = trans->c;
 	struct btree_cache *bc = &c->btree_cache;
 	struct btree *b;
-	struct bset_tree *t;
 	bool need_relock = false;
 	int ret;
 
@@ -966,7 +1035,6 @@ struct btree *bch2_btree_node_get(struct btree_trans *trans, struct btree_path *
 {
 	struct bch_fs *c = trans->c;
 	struct btree *b;
-	struct bset_tree *t;
 	int ret;
 
 	EBUG_ON(level >= BTREE_MAX_DEPTH);
@@ -1043,7 +1111,6 @@ struct btree *bch2_btree_node_get_noiter(struct btree_trans *trans,
 	struct bch_fs *c = trans->c;
 	struct btree_cache *bc = &c->btree_cache;
 	struct btree *b;
-	struct bset_tree *t;
 	int ret;
 
 	EBUG_ON(level >= BTREE_MAX_DEPTH);
@@ -1240,9 +1307,39 @@ void bch2_btree_node_to_text(struct printbuf *out, struct bch_fs *c, const struc
 	       stats.failed);
 }
 
-void bch2_btree_cache_to_text(struct printbuf *out, const struct bch_fs *c)
+static void prt_btree_cache_line(struct printbuf *out, const struct bch_fs *c,
+				 const char *label, unsigned nr)
 {
-	prt_printf(out, "nr nodes:\t\t%u\n", c->btree_cache.used);
-	prt_printf(out, "nr dirty:\t\t%u\n", atomic_read(&c->btree_cache.dirty));
-	prt_printf(out, "cannibalize lock:\t%p\n", c->btree_cache.alloc_lock);
+	prt_printf(out, "%s\t", label);
+	prt_human_readable_u64(out, nr * c->opts.btree_node_size);
+	prt_printf(out, " (%u)\n", nr);
+}
+
+void bch2_btree_cache_to_text(struct printbuf *out, const struct btree_cache *bc)
+{
+	struct bch_fs *c = container_of(bc, struct bch_fs, btree_cache);
+
+	if (!out->nr_tabstops)
+		printbuf_tabstop_push(out, 32);
+
+	prt_btree_cache_line(out, c, "total:",		bc->used);
+	prt_btree_cache_line(out, c, "nr dirty:",	atomic_read(&bc->dirty));
+	prt_printf(out, "cannibalize lock:\t%p\n",	bc->alloc_lock);
+	prt_newline(out);
+
+	for (unsigned i = 0; i < ARRAY_SIZE(bc->used_by_btree); i++)
+		prt_btree_cache_line(out, c, bch2_btree_id_str(i), bc->used_by_btree[i]);
+
+	prt_newline(out);
+	prt_printf(out, "freed:\t%u\n", bc->freed);
+	prt_printf(out, "not freed:\n");
+	prt_printf(out, "  dirty\t%u\n", bc->not_freed_dirty);
+	prt_printf(out, "  write in flight\t%u\n", bc->not_freed_write_in_flight);
+	prt_printf(out, "  read in flight\t%u\n", bc->not_freed_read_in_flight);
+	prt_printf(out, "  lock intent failed\t%u\n", bc->not_freed_lock_intent);
+	prt_printf(out, "  lock write failed\t%u\n", bc->not_freed_lock_write);
+	prt_printf(out, "  access bit\t%u\n", bc->not_freed_access_bit);
+	prt_printf(out, "  no evict failed\t%u\n", bc->not_freed_noevict);
+	prt_printf(out, "  write blocked\t%u\n", bc->not_freed_write_blocked);
+	prt_printf(out, "  will make reachable\t%u\n", bc->not_freed_will_make_reachable);
 }
diff --git a/fs/bcachefs/btree_cache.h b/fs/bcachefs/btree_cache.h
index 6d33885fdbde..fed35de3e4de 100644
--- a/fs/bcachefs/btree_cache.h
+++ b/fs/bcachefs/btree_cache.h
@@ -17,6 +17,9 @@ int __bch2_btree_node_hash_insert(struct btree_cache *, struct btree *);
 int bch2_btree_node_hash_insert(struct btree_cache *, struct btree *,
 				unsigned, enum btree_id);
 
+void bch2_btree_node_update_key_early(struct btree_trans *, enum btree_id, unsigned,
+				      struct bkey_s_c, struct bkey_i *);
+
 void bch2_btree_cache_cannibalize_unlock(struct btree_trans *);
 int bch2_btree_cache_cannibalize_lock(struct btree_trans *, struct closure *);
 
@@ -131,6 +134,6 @@ static inline struct btree *btree_node_root(struct bch_fs *c, struct btree *b)
 const char *bch2_btree_id_str(enum btree_id);
 void bch2_btree_pos_to_text(struct printbuf *, struct bch_fs *, const struct btree *);
 void bch2_btree_node_to_text(struct printbuf *, struct bch_fs *, const struct btree *);
-void bch2_btree_cache_to_text(struct printbuf *, const struct bch_fs *);
+void bch2_btree_cache_to_text(struct printbuf *, const struct btree_cache *);
 
 #endif /* _BCACHEFS_BTREE_CACHE_H */
diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
index 791470b0c654..8035c8b797ab 100644
--- a/fs/bcachefs/btree_gc.c
+++ b/fs/bcachefs/btree_gc.c
@@ -52,12 +52,6 @@ static struct bkey_s unsafe_bkey_s_c_to_s(struct bkey_s_c k)
 	}}};
 }
 
-static bool should_restart_for_topology_repair(struct bch_fs *c)
-{
-	return c->opts.fix_errors != FSCK_FIX_no &&
-		!(c->recovery_passes_complete & BIT_ULL(BCH_RECOVERY_PASS_check_topology));
-}
-
 static inline void __gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
 {
 	preempt_disable();
@@ -69,7 +63,7 @@ static inline void __gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
 
 static inline void gc_pos_set(struct bch_fs *c, struct gc_pos new_pos)
 {
-	BUG_ON(gc_pos_cmp(new_pos, c->gc_pos) <= 0);
+	BUG_ON(gc_pos_cmp(new_pos, c->gc_pos) < 0);
 	__gc_pos_set(c, new_pos);
 }
 
@@ -97,35 +91,6 @@ static void btree_ptr_to_v2(struct btree *b, struct bkey_i_btree_ptr_v2 *dst)
 	}
 }
 
-static void bch2_btree_node_update_key_early(struct btree_trans *trans,
-					     enum btree_id btree, unsigned level,
-					     struct bkey_s_c old, struct bkey_i *new)
-{
-	struct bch_fs *c = trans->c;
-	struct btree *b;
-	struct bkey_buf tmp;
-	int ret;
-
-	bch2_bkey_buf_init(&tmp);
-	bch2_bkey_buf_reassemble(&tmp, c, old);
-
-	b = bch2_btree_node_get_noiter(trans, tmp.k, btree, level, true);
-	if (!IS_ERR_OR_NULL(b)) {
-		mutex_lock(&c->btree_cache.lock);
-
-		bch2_btree_node_hash_remove(&c->btree_cache, b);
-
-		bkey_copy(&b->key, new);
-		ret = __bch2_btree_node_hash_insert(&c->btree_cache, b);
-		BUG_ON(ret);
-
-		mutex_unlock(&c->btree_cache.lock);
-		six_unlock_read(&b->c.lock);
-	}
-
-	bch2_bkey_buf_exit(&tmp, c);
-}
-
 static int set_node_min(struct bch_fs *c, struct btree *b, struct bpos new_min)
 {
 	struct bkey_i_btree_ptr_v2 *new;
@@ -546,9 +511,9 @@ reconstruct_root:
 			if (!bch2_btree_has_scanned_nodes(c, i)) {
 				mustfix_fsck_err(c, btree_root_unreadable_and_scan_found_nothing,
 						 "no nodes found for btree %s, continue?", bch2_btree_id_str(i));
-				bch2_btree_root_alloc_fake(c, i, 0);
+				bch2_btree_root_alloc_fake_trans(trans, i, 0);
 			} else {
-				bch2_btree_root_alloc_fake(c, i, 1);
+				bch2_btree_root_alloc_fake_trans(trans, i, 1);
 				bch2_shoot_down_journal_keys(c, i, 1, BTREE_MAX_DEPTH, POS_MIN, SPOS_MAX);
 				ret = bch2_get_scanned_nodes(c, i, 0, POS_MIN, SPOS_MAX);
 				if (ret)
@@ -576,7 +541,7 @@ reconstruct_root:
 				goto reconstruct_root;
 
 			bch_err(c, "empty btree root %s", bch2_btree_id_str(i));
-			bch2_btree_root_alloc_fake(c, i, 0);
+			bch2_btree_root_alloc_fake_trans(trans, i, 0);
 			r->alive = false;
 			ret = 0;
 		}
@@ -586,495 +551,123 @@ fsck_err:
 	return ret;
 }
 
-static int bch2_check_fix_ptrs(struct btree_trans *trans, enum btree_id btree_id,
-			       unsigned level, bool is_root,
-			       struct bkey_s_c *k)
+/* marking of btree keys/nodes: */
+
+static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
+			    unsigned level, struct btree **prev,
+			    struct btree_iter *iter, struct bkey_s_c k,
+			    bool initial)
 {
 	struct bch_fs *c = trans->c;
-	struct bkey_ptrs_c ptrs_c = bch2_bkey_ptrs_c(*k);
-	const union bch_extent_entry *entry_c;
-	struct extent_ptr_decoded p = { 0 };
-	bool do_update = false;
-	struct printbuf buf = PRINTBUF;
-	int ret = 0;
-
-	/*
-	 * XXX
-	 * use check_bucket_ref here
-	 */
-	bkey_for_each_ptr_decode(k->k, ptrs_c, p, entry_c) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, p.ptr.dev);
-		struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);
-		enum bch_data_type data_type = bch2_bkey_ptr_data_type(*k, p, entry_c);
-
-		if (fsck_err_on(!g->gen_valid,
-				c, ptr_to_missing_alloc_key,
-				"bucket %u:%zu data type %s ptr gen %u missing in alloc btree\n"
-				"while marking %s",
-				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
-				bch2_data_type_str(ptr_data_type(k->k, &p.ptr)),
-				p.ptr.gen,
-				(printbuf_reset(&buf),
-				 bch2_bkey_val_to_text(&buf, c, *k), buf.buf))) {
-			if (!p.ptr.cached) {
-				g->gen_valid		= true;
-				g->gen			= p.ptr.gen;
-			} else {
-				do_update = true;
-			}
-		}
-
-		if (fsck_err_on(gen_cmp(p.ptr.gen, g->gen) > 0,
-				c, ptr_gen_newer_than_bucket_gen,
-				"bucket %u:%zu data type %s ptr gen in the future: %u > %u\n"
-				"while marking %s",
-				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
-				bch2_data_type_str(ptr_data_type(k->k, &p.ptr)),
-				p.ptr.gen, g->gen,
-				(printbuf_reset(&buf),
-				 bch2_bkey_val_to_text(&buf, c, *k), buf.buf))) {
-			if (!p.ptr.cached) {
-				g->gen_valid		= true;
-				g->gen			= p.ptr.gen;
-				g->data_type		= 0;
-				g->dirty_sectors	= 0;
-				g->cached_sectors	= 0;
-				set_bit(BCH_FS_need_another_gc, &c->flags);
-			} else {
-				do_update = true;
-			}
-		}
-
-		if (fsck_err_on(gen_cmp(g->gen, p.ptr.gen) > BUCKET_GC_GEN_MAX,
-				c, ptr_gen_newer_than_bucket_gen,
-				"bucket %u:%zu gen %u data type %s: ptr gen %u too stale\n"
-				"while marking %s",
-				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr), g->gen,
-				bch2_data_type_str(ptr_data_type(k->k, &p.ptr)),
-				p.ptr.gen,
-				(printbuf_reset(&buf),
-				 bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))
-			do_update = true;
-
-		if (fsck_err_on(!p.ptr.cached && gen_cmp(p.ptr.gen, g->gen) < 0,
-				c, stale_dirty_ptr,
-				"bucket %u:%zu data type %s stale dirty ptr: %u < %u\n"
-				"while marking %s",
-				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
-				bch2_data_type_str(ptr_data_type(k->k, &p.ptr)),
-				p.ptr.gen, g->gen,
-				(printbuf_reset(&buf),
-				 bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))
-			do_update = true;
-
-		if (data_type != BCH_DATA_btree && p.ptr.gen != g->gen)
-			continue;
-
-		if (fsck_err_on(bucket_data_type(g->data_type) &&
-				bucket_data_type(g->data_type) !=
-				bucket_data_type(data_type), c,
-				ptr_bucket_data_type_mismatch,
-				"bucket %u:%zu different types of data in same bucket: %s, %s\n"
-				"while marking %s",
-				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
-				bch2_data_type_str(g->data_type),
-				bch2_data_type_str(data_type),
-				(printbuf_reset(&buf),
-				 bch2_bkey_val_to_text(&buf, c, *k), buf.buf))) {
-			if (data_type == BCH_DATA_btree) {
-				g->data_type	= data_type;
-				set_bit(BCH_FS_need_another_gc, &c->flags);
-			} else {
-				do_update = true;
-			}
-		}
-
-		if (p.has_ec) {
-			struct gc_stripe *m = genradix_ptr(&c->gc_stripes, p.ec.idx);
-
-			if (fsck_err_on(!m || !m->alive, c,
-					ptr_to_missing_stripe,
-					"pointer to nonexistent stripe %llu\n"
-					"while marking %s",
-					(u64) p.ec.idx,
-					(printbuf_reset(&buf),
-					 bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))
-				do_update = true;
-
-			if (fsck_err_on(m && m->alive && !bch2_ptr_matches_stripe_m(m, p), c,
-					ptr_to_incorrect_stripe,
-					"pointer does not match stripe %llu\n"
-					"while marking %s",
-					(u64) p.ec.idx,
-					(printbuf_reset(&buf),
-					 bch2_bkey_val_to_text(&buf, c, *k), buf.buf)))
-				do_update = true;
-		}
-	}
-
-	if (do_update) {
-		if (is_root) {
-			bch_err(c, "cannot update btree roots yet");
-			ret = -EINVAL;
-			goto err;
-		}
-
-		struct bkey_i *new = kmalloc(bkey_bytes(k->k), GFP_KERNEL);
-		if (!new) {
-			ret = -BCH_ERR_ENOMEM_gc_repair_key;
-			bch_err_msg(c, ret, "allocating new key");
-			goto err;
-		}
-
-		bkey_reassemble(new, *k);
-
-		if (level) {
-			/*
-			 * We don't want to drop btree node pointers - if the
-			 * btree node isn't there anymore, the read path will
-			 * sort it out:
-			 */
-			struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
-			bkey_for_each_ptr(ptrs, ptr) {
-				struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-				struct bucket *g = PTR_GC_BUCKET(ca, ptr);
-
-				ptr->gen = g->gen;
-			}
-		} else {
-			struct bkey_ptrs ptrs;
-			union bch_extent_entry *entry;
-restart_drop_ptrs:
-			ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
-			bkey_for_each_ptr_decode(bkey_i_to_s(new).k, ptrs, p, entry) {
-				struct bch_dev *ca = bch_dev_bkey_exists(c, p.ptr.dev);
-				struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);
-				enum bch_data_type data_type = bch2_bkey_ptr_data_type(bkey_i_to_s_c(new), p, entry);
-
-				if ((p.ptr.cached &&
-				     (!g->gen_valid || gen_cmp(p.ptr.gen, g->gen) > 0)) ||
-				    (!p.ptr.cached &&
-				     gen_cmp(p.ptr.gen, g->gen) < 0) ||
-				    gen_cmp(g->gen, p.ptr.gen) > BUCKET_GC_GEN_MAX ||
-				    (g->data_type &&
-				     g->data_type != data_type)) {
-					bch2_bkey_drop_ptr(bkey_i_to_s(new), &entry->ptr);
-					goto restart_drop_ptrs;
-				}
-			}
-again:
-			ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
-			bkey_extent_entry_for_each(ptrs, entry) {
-				if (extent_entry_type(entry) == BCH_EXTENT_ENTRY_stripe_ptr) {
-					struct gc_stripe *m = genradix_ptr(&c->gc_stripes,
-									entry->stripe_ptr.idx);
-					union bch_extent_entry *next_ptr;
-
-					bkey_extent_entry_for_each_from(ptrs, next_ptr, entry)
-						if (extent_entry_type(next_ptr) == BCH_EXTENT_ENTRY_ptr)
-							goto found;
-					next_ptr = NULL;
-found:
-					if (!next_ptr) {
-						bch_err(c, "aieee, found stripe ptr with no data ptr");
-						continue;
-					}
-
-					if (!m || !m->alive ||
-					    !__bch2_ptr_matches_stripe(&m->ptrs[entry->stripe_ptr.block],
-								       &next_ptr->ptr,
-								       m->sectors)) {
-						bch2_bkey_extent_entry_drop(new, entry);
-						goto again;
-					}
-				}
-			}
-		}
 
-		if (level)
-			bch2_btree_node_update_key_early(trans, btree_id, level - 1, *k, new);
+	if (iter) {
+		struct btree_path *path = btree_iter_path(trans, iter);
+		struct btree *b = path_l(path)->b;
 
-		if (0) {
-			printbuf_reset(&buf);
-			bch2_bkey_val_to_text(&buf, c, *k);
-			bch_info(c, "updated %s", buf.buf);
-
-			printbuf_reset(&buf);
-			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(new));
-			bch_info(c, "new key %s", buf.buf);
-		}
-
-		ret = bch2_journal_key_insert_take(c, btree_id, level, new);
-		if (ret) {
-			kfree(new);
-			goto err;
+		if (*prev != b) {
+			int ret = bch2_btree_node_check_topology(trans, b);
+			if (ret)
+				return ret;
 		}
-
-		*k = bkey_i_to_s_c(new);
+		*prev = b;
 	}
-err:
-fsck_err:
-	printbuf_exit(&buf);
-	return ret;
-}
 
-/* marking of btree keys/nodes: */
-
-static int bch2_gc_mark_key(struct btree_trans *trans, enum btree_id btree_id,
-			    unsigned level, bool is_root,
-			    struct bkey_s_c *k,
-			    bool initial)
-{
-	struct bch_fs *c = trans->c;
 	struct bkey deleted = KEY(0, 0, 0);
 	struct bkey_s_c old = (struct bkey_s_c) { &deleted, NULL };
 	struct printbuf buf = PRINTBUF;
 	int ret = 0;
 
-	deleted.p = k->k->p;
+	deleted.p = k.k->p;
 
 	if (initial) {
 		BUG_ON(bch2_journal_seq_verify &&
-		       k->k->version.lo > atomic64_read(&c->journal.seq));
+		       k.k->version.lo > atomic64_read(&c->journal.seq));
 
-		if (fsck_err_on(k->k->version.lo > atomic64_read(&c->key_version), c,
+		if (fsck_err_on(k.k->version.lo > atomic64_read(&c->key_version), c,
 				bkey_version_in_future,
 				"key version number higher than recorded: %llu > %llu",
-				k->k->version.lo,
+				k.k->version.lo,
 				atomic64_read(&c->key_version)))
-			atomic64_set(&c->key_version, k->k->version.lo);
+			atomic64_set(&c->key_version, k.k->version.lo);
 	}
 
-	ret = bch2_check_fix_ptrs(trans, btree_id, level, is_root, k);
-	if (ret)
-		goto err;
-
-	if (mustfix_fsck_err_on(level && !bch2_dev_btree_bitmap_marked(c, *k),
+	if (mustfix_fsck_err_on(level && !bch2_dev_btree_bitmap_marked(c, k),
 				c, btree_bitmap_not_marked,
 				"btree ptr not marked in member info btree allocated bitmap\n  %s",
-				(bch2_bkey_val_to_text(&buf, c, *k),
+				(bch2_bkey_val_to_text(&buf, c, k),
 				 buf.buf))) {
 		mutex_lock(&c->sb_lock);
-		bch2_dev_btree_bitmap_mark(c, *k);
+		bch2_dev_btree_bitmap_mark(c, k);
 		bch2_write_super(c);
 		mutex_unlock(&c->sb_lock);
 	}
 
-	ret = commit_do(trans, NULL, NULL, 0,
-			bch2_key_trigger(trans, btree_id, level, old,
-					 unsafe_bkey_s_c_to_s(*k), BTREE_TRIGGER_GC));
-fsck_err:
-err:
-	printbuf_exit(&buf);
-	bch_err_fn(c, ret);
-	return ret;
-}
-
-static int btree_gc_mark_node(struct btree_trans *trans, struct btree *b, bool initial)
-{
-	struct btree_node_iter iter;
-	struct bkey unpacked;
-	struct bkey_s_c k;
-	int ret = 0;
+	/*
+	 * We require a commit before key_trigger() because
+	 * key_trigger(BTREE_TRIGGER_GC) is not idempotant; we'll calculate the
+	 * wrong result if we run it multiple times.
+	 */
+	unsigned flags = !iter ? BTREE_TRIGGER_is_root : 0;
 
-	ret = bch2_btree_node_check_topology(trans, b);
+	ret = bch2_key_trigger(trans, btree_id, level, old, unsafe_bkey_s_c_to_s(k),
+			       BTREE_TRIGGER_check_repair|flags);
 	if (ret)
-		return ret;
-
-	if (!btree_node_type_needs_gc(btree_node_type(b)))
-		return 0;
-
-	bch2_btree_node_iter_init_from_start(&iter, b);
-
-	while ((k = bch2_btree_node_iter_peek_unpack(&iter, b, &unpacked)).k) {
-		ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level, false,
-				       &k, initial);
-		if (ret)
-			return ret;
+		goto out;
 
-		bch2_btree_node_iter_advance(&iter, b);
+	if (trans->nr_updates) {
+		ret = bch2_trans_commit(trans, NULL, NULL, 0) ?:
+			-BCH_ERR_transaction_restart_nested;
+		goto out;
 	}
 
-	return 0;
+	ret = bch2_key_trigger(trans, btree_id, level, old, unsafe_bkey_s_c_to_s(k),
+			       BTREE_TRIGGER_gc|flags);
+out:
+fsck_err:
+	printbuf_exit(&buf);
+	bch_err_fn(c, ret);
+	return ret;
 }
 
-static int bch2_gc_btree(struct btree_trans *trans, enum btree_id btree_id,
-			 bool initial, bool metadata_only)
+static int bch2_gc_btree(struct btree_trans *trans, enum btree_id btree, bool initial)
 {
 	struct bch_fs *c = trans->c;
-	struct btree_iter iter;
-	struct btree *b;
-	unsigned depth = metadata_only ? 1 : 0;
+	int level = 0, target_depth = btree_node_type_needs_gc(__btree_node_type(0, btree)) ? 0 : 1;
 	int ret = 0;
 
-	gc_pos_set(c, gc_pos_btree(btree_id, POS_MIN, 0));
-
-	__for_each_btree_node(trans, iter, btree_id, POS_MIN,
-			      0, depth, BTREE_ITER_PREFETCH, b, ret) {
-		bch2_verify_btree_nr_keys(b);
-
-		gc_pos_set(c, gc_pos_btree_node(b));
-
-		ret = btree_gc_mark_node(trans, b, initial);
-		if (ret)
-			break;
-	}
-	bch2_trans_iter_exit(trans, &iter);
-
-	if (ret)
-		return ret;
+	/* We need to make sure every leaf node is readable before going RW */
+	if (initial)
+		target_depth = 0;
 
+	/* root */
 	mutex_lock(&c->btree_root_lock);
-	b = bch2_btree_id_root(c, btree_id)->b;
+	struct btree *b = bch2_btree_id_root(c, btree)->b;
 	if (!btree_node_fake(b)) {
-		struct bkey_s_c k = bkey_i_to_s_c(&b->key);
-
-		ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level + 1,
-				       true, &k, initial);
+		gc_pos_set(c, gc_pos_btree(btree, b->c.level + 1, SPOS_MAX));
+		ret = lockrestart_do(trans,
+			bch2_gc_mark_key(trans, b->c.btree_id, b->c.level + 1,
+					 NULL, NULL, bkey_i_to_s_c(&b->key), initial));
+		level = b->c.level;
 	}
-	gc_pos_set(c, gc_pos_btree_root(b->c.btree_id));
 	mutex_unlock(&c->btree_root_lock);
 
-	return ret;
-}
-
-static int bch2_gc_btree_init_recurse(struct btree_trans *trans, struct btree *b,
-				      unsigned target_depth)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_and_journal_iter iter;
-	struct bkey_s_c k;
-	struct bkey_buf cur;
-	struct printbuf buf = PRINTBUF;
-	int ret = 0;
-
-	ret = bch2_btree_node_check_topology(trans, b);
 	if (ret)
 		return ret;
 
-	bch2_btree_and_journal_iter_init_node_iter(trans, &iter, b);
-	bch2_bkey_buf_init(&cur);
-
-	while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
-		BUG_ON(bpos_lt(k.k->p, b->data->min_key));
-		BUG_ON(bpos_gt(k.k->p, b->data->max_key));
+	for (; level >= target_depth; --level) {
+		struct btree *prev = NULL;
+		struct btree_iter iter;
+		bch2_trans_node_iter_init(trans, &iter, btree, POS_MIN, 0, level,
+					  BTREE_ITER_prefetch);
 
-		ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level,
-				       false, &k, true);
+		ret = for_each_btree_key_continue(trans, iter, 0, k, ({
+			gc_pos_set(c, gc_pos_btree(btree, level, k.k->p));
+			bch2_gc_mark_key(trans, btree, level, &prev, &iter, k, initial);
+		}));
 		if (ret)
-			goto fsck_err;
-
-		bch2_btree_and_journal_iter_advance(&iter);
-	}
-
-	if (b->c.level > target_depth) {
-		bch2_btree_and_journal_iter_exit(&iter);
-		bch2_btree_and_journal_iter_init_node_iter(trans, &iter, b);
-		iter.prefetch = true;
-
-		while ((k = bch2_btree_and_journal_iter_peek(&iter)).k) {
-			struct btree *child;
-
-			bch2_bkey_buf_reassemble(&cur, c, k);
-			bch2_btree_and_journal_iter_advance(&iter);
-
-			child = bch2_btree_node_get_noiter(trans, cur.k,
-						b->c.btree_id, b->c.level - 1,
-						false);
-			ret = PTR_ERR_OR_ZERO(child);
-
-			if (bch2_err_matches(ret, EIO)) {
-				bch2_topology_error(c);
-
-				if (__fsck_err(c,
-					  FSCK_CAN_FIX|
-					  FSCK_CAN_IGNORE|
-					  FSCK_NO_RATELIMIT,
-					  btree_node_read_error,
-					  "Unreadable btree node at btree %s level %u:\n"
-					  "  %s",
-					  bch2_btree_id_str(b->c.btree_id),
-					  b->c.level - 1,
-					  (printbuf_reset(&buf),
-					   bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(cur.k)), buf.buf)) &&
-				    should_restart_for_topology_repair(c)) {
-					bch_info(c, "Halting mark and sweep to start topology repair pass");
-					ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology);
-					goto fsck_err;
-				} else {
-					/* Continue marking when opted to not
-					 * fix the error: */
-					ret = 0;
-					set_bit(BCH_FS_initial_gc_unfixed, &c->flags);
-					continue;
-				}
-			} else if (ret) {
-				bch_err_msg(c, ret, "getting btree node");
-				break;
-			}
-
-			ret = bch2_gc_btree_init_recurse(trans, child,
-							 target_depth);
-			six_unlock_read(&child->c.lock);
-
-			if (ret)
-				break;
-		}
-	}
-fsck_err:
-	bch2_bkey_buf_exit(&cur, c);
-	bch2_btree_and_journal_iter_exit(&iter);
-	printbuf_exit(&buf);
-	return ret;
-}
-
-static int bch2_gc_btree_init(struct btree_trans *trans,
-			      enum btree_id btree_id,
-			      bool metadata_only)
-{
-	struct bch_fs *c = trans->c;
-	struct btree *b;
-	unsigned target_depth = metadata_only ? 1 : 0;
-	struct printbuf buf = PRINTBUF;
-	int ret = 0;
-
-	b = bch2_btree_id_root(c, btree_id)->b;
-
-	six_lock_read(&b->c.lock, NULL, NULL);
-	printbuf_reset(&buf);
-	bch2_bpos_to_text(&buf, b->data->min_key);
-	if (mustfix_fsck_err_on(!bpos_eq(b->data->min_key, POS_MIN), c,
-				btree_root_bad_min_key,
-			"btree root with incorrect min_key: %s", buf.buf)) {
-		bch_err(c, "repair unimplemented");
-		ret = -BCH_ERR_fsck_repair_unimplemented;
-		goto fsck_err;
-	}
-
-	printbuf_reset(&buf);
-	bch2_bpos_to_text(&buf, b->data->max_key);
-	if (mustfix_fsck_err_on(!bpos_eq(b->data->max_key, SPOS_MAX), c,
-				btree_root_bad_max_key,
-			"btree root with incorrect max_key: %s", buf.buf)) {
-		bch_err(c, "repair unimplemented");
-		ret = -BCH_ERR_fsck_repair_unimplemented;
-		goto fsck_err;
-	}
-
-	if (b->c.level >= target_depth)
-		ret = bch2_gc_btree_init_recurse(trans, b, target_depth);
-
-	if (!ret) {
-		struct bkey_s_c k = bkey_i_to_s_c(&b->key);
-
-		ret = bch2_gc_mark_key(trans, b->c.btree_id, b->c.level + 1, true,
-				       &k, true);
+			break;
 	}
-fsck_err:
-	six_unlock_read(&b->c.lock);
 
-	bch_err_fn(c, ret);
-	printbuf_exit(&buf);
 	return ret;
 }
 
@@ -1084,7 +677,7 @@ static inline int btree_id_gc_phase_cmp(enum btree_id l, enum btree_id r)
 		(int) btree_id_to_gc_phase(r);
 }
 
-static int bch2_gc_btrees(struct bch_fs *c, bool initial, bool metadata_only)
+static int bch2_gc_btrees(struct bch_fs *c)
 {
 	struct btree_trans *trans = bch2_trans_get(c);
 	enum btree_id ids[BTREE_ID_NR];
@@ -1095,98 +688,36 @@ static int bch2_gc_btrees(struct bch_fs *c, bool initial, bool metadata_only)
 		ids[i] = i;
 	bubble_sort(ids, BTREE_ID_NR, btree_id_gc_phase_cmp);
 
-	for (i = 0; i < BTREE_ID_NR && !ret; i++)
-		ret = initial
-			? bch2_gc_btree_init(trans, ids[i], metadata_only)
-			: bch2_gc_btree(trans, ids[i], initial, metadata_only);
+	for (i = 0; i < btree_id_nr_alive(c) && !ret; i++) {
+		unsigned btree = i < BTREE_ID_NR ? ids[i] : i;
 
-	for (i = BTREE_ID_NR; i < btree_id_nr_alive(c) && !ret; i++) {
-		if (!bch2_btree_id_root(c, i)->alive)
+		if (IS_ERR_OR_NULL(bch2_btree_id_root(c, btree)->b))
 			continue;
 
-		ret = initial
-			? bch2_gc_btree_init(trans, i, metadata_only)
-			: bch2_gc_btree(trans, i, initial, metadata_only);
-	}
+		ret = bch2_gc_btree(trans, btree, true);
 
+		if (mustfix_fsck_err_on(bch2_err_matches(ret, EIO),
+					c, btree_node_read_error,
+			       "btree node read error for %s",
+			       bch2_btree_id_str(btree)))
+			ret = bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_check_topology);
+	}
+fsck_err:
 	bch2_trans_put(trans);
 	bch_err_fn(c, ret);
 	return ret;
 }
 
-static void mark_metadata_sectors(struct bch_fs *c, struct bch_dev *ca,
-				  u64 start, u64 end,
-				  enum bch_data_type type,
-				  unsigned flags)
-{
-	u64 b = sector_to_bucket(ca, start);
-
-	do {
-		unsigned sectors =
-			min_t(u64, bucket_to_sector(ca, b + 1), end) - start;
-
-		bch2_mark_metadata_bucket(c, ca, b, type, sectors,
-					  gc_phase(GC_PHASE_SB), flags);
-		b++;
-		start += sectors;
-	} while (start < end);
-}
-
-static void bch2_mark_dev_superblock(struct bch_fs *c, struct bch_dev *ca,
-				     unsigned flags)
-{
-	struct bch_sb_layout *layout = &ca->disk_sb.sb->layout;
-	unsigned i;
-	u64 b;
-
-	for (i = 0; i < layout->nr_superblocks; i++) {
-		u64 offset = le64_to_cpu(layout->sb_offset[i]);
-
-		if (offset == BCH_SB_SECTOR)
-			mark_metadata_sectors(c, ca, 0, BCH_SB_SECTOR,
-					      BCH_DATA_sb, flags);
-
-		mark_metadata_sectors(c, ca, offset,
-				      offset + (1 << layout->sb_max_size_bits),
-				      BCH_DATA_sb, flags);
-	}
-
-	for (i = 0; i < ca->journal.nr; i++) {
-		b = ca->journal.buckets[i];
-		bch2_mark_metadata_bucket(c, ca, b, BCH_DATA_journal,
-					  ca->mi.bucket_size,
-					  gc_phase(GC_PHASE_SB), flags);
-	}
-}
-
-static void bch2_mark_superblocks(struct bch_fs *c)
+static int bch2_mark_superblocks(struct bch_fs *c)
 {
 	mutex_lock(&c->sb_lock);
 	gc_pos_set(c, gc_phase(GC_PHASE_SB));
 
-	for_each_online_member(c, ca)
-		bch2_mark_dev_superblock(c, ca, BTREE_TRIGGER_GC);
+	int ret = bch2_trans_mark_dev_sbs_flags(c, BTREE_TRIGGER_gc);
 	mutex_unlock(&c->sb_lock);
+	return ret;
 }
 
-#if 0
-/* Also see bch2_pending_btree_node_free_insert_done() */
-static void bch2_mark_pending_btree_node_frees(struct bch_fs *c)
-{
-	struct btree_update *as;
-	struct pending_btree_node_free *d;
-
-	mutex_lock(&c->btree_interior_update_lock);
-	gc_pos_set(c, gc_phase(GC_PHASE_PENDING_DELETE));
-
-	for_each_pending_btree_node_free(c, as, d)
-		if (d->index_update_done)
-			bch2_mark_key(c, bkey_i_to_s_c(&d->key), BTREE_TRIGGER_GC);
-
-	mutex_unlock(&c->btree_interior_update_lock);
-}
-#endif
-
 static void bch2_gc_free(struct bch_fs *c)
 {
 	genradix_free(&c->reflink_gc_table);
@@ -1204,28 +735,23 @@ static void bch2_gc_free(struct bch_fs *c)
 	c->usage_gc = NULL;
 }
 
-static int bch2_gc_done(struct bch_fs *c,
-			bool initial, bool metadata_only)
+static int bch2_gc_done(struct bch_fs *c)
 {
 	struct bch_dev *ca = NULL;
 	struct printbuf buf = PRINTBUF;
-	bool verify = !metadata_only &&
-		!c->opts.reconstruct_alloc &&
-		(!initial || (c->sb.compat & (1ULL << BCH_COMPAT_alloc_info)));
 	unsigned i;
 	int ret = 0;
 
 	percpu_down_write(&c->mark_lock);
 
-#define copy_field(_err, _f, _msg, ...)					\
-	if (dst->_f != src->_f &&					\
-	    (!verify ||							\
-	     fsck_err(c, _err, _msg ": got %llu, should be %llu"	\
-		      , ##__VA_ARGS__, dst->_f, src->_f)))		\
+#define copy_field(_err, _f, _msg, ...)						\
+	if (fsck_err_on(dst->_f != src->_f, c, _err,				\
+			_msg ": got %llu, should be %llu" , ##__VA_ARGS__,	\
+			dst->_f, src->_f))					\
 		dst->_f = src->_f
-#define copy_dev_field(_err, _f, _msg, ...)				\
+#define copy_dev_field(_err, _f, _msg, ...)					\
 	copy_field(_err, _f, "dev %u has wrong " _msg, ca->dev_idx, ##__VA_ARGS__)
-#define copy_fs_field(_err, _f, _msg, ...)				\
+#define copy_fs_field(_err, _f, _msg, ...)					\
 	copy_field(_err, _f, "fs has wrong " _msg, ##__VA_ARGS__)
 
 	for (i = 0; i < ARRAY_SIZE(c->usage); i++)
@@ -1258,31 +784,24 @@ static int bch2_gc_done(struct bch_fs *c,
 		copy_fs_field(fs_usage_btree_wrong,
 			      b.btree,		"btree");
 
-		if (!metadata_only) {
-			copy_fs_field(fs_usage_data_wrong,
-				      b.data,	"data");
-			copy_fs_field(fs_usage_cached_wrong,
-				      b.cached,	"cached");
-			copy_fs_field(fs_usage_reserved_wrong,
-				      b.reserved,	"reserved");
-			copy_fs_field(fs_usage_nr_inodes_wrong,
-				      b.nr_inodes,"nr_inodes");
-
-			for (i = 0; i < BCH_REPLICAS_MAX; i++)
-				copy_fs_field(fs_usage_persistent_reserved_wrong,
-					      persistent_reserved[i],
-					      "persistent_reserved[%i]", i);
-		}
+		copy_fs_field(fs_usage_data_wrong,
+			      b.data,	"data");
+		copy_fs_field(fs_usage_cached_wrong,
+			      b.cached,	"cached");
+		copy_fs_field(fs_usage_reserved_wrong,
+			      b.reserved,	"reserved");
+		copy_fs_field(fs_usage_nr_inodes_wrong,
+			      b.nr_inodes,"nr_inodes");
+
+		for (i = 0; i < BCH_REPLICAS_MAX; i++)
+			copy_fs_field(fs_usage_persistent_reserved_wrong,
+				      persistent_reserved[i],
+				      "persistent_reserved[%i]", i);
 
 		for (i = 0; i < c->replicas.nr; i++) {
 			struct bch_replicas_entry_v1 *e =
 				cpu_replicas_entry(&c->replicas, i);
 
-			if (metadata_only &&
-			    (e->data_type == BCH_DATA_user ||
-			     e->data_type == BCH_DATA_cached))
-				continue;
-
 			printbuf_reset(&buf);
 			bch2_replicas_entry_to_text(&buf, e);
 
@@ -1296,10 +815,8 @@ static int bch2_gc_done(struct bch_fs *c,
 #undef copy_stripe_field
 #undef copy_field
 fsck_err:
-	if (ca)
-		percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 	bch_err_fn(c, ret);
-
 	percpu_up_write(&c->mark_lock);
 	printbuf_exit(&buf);
 	return ret;
@@ -1322,7 +839,7 @@ static int bch2_gc_start(struct bch_fs *c)
 		ca->usage_gc = alloc_percpu(struct bch_dev_usage);
 		if (!ca->usage_gc) {
 			bch_err(c, "error allocating ca->usage_gc");
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			return -BCH_ERR_ENOMEM_gc_start;
 		}
 
@@ -1333,19 +850,6 @@ static int bch2_gc_start(struct bch_fs *c)
 	return 0;
 }
 
-static int bch2_gc_reset(struct bch_fs *c)
-{
-	for_each_member_device(c, ca) {
-		free_percpu(ca->usage_gc);
-		ca->usage_gc = NULL;
-	}
-
-	free_percpu(c->usage_gc);
-	c->usage_gc = NULL;
-
-	return bch2_gc_start(c);
-}
-
 /* returns true if not equal */
 static inline bool bch2_alloc_v4_cmp(struct bch_alloc_v4 l,
 				     struct bch_alloc_v4 r)
@@ -1361,56 +865,41 @@ static inline bool bch2_alloc_v4_cmp(struct bch_alloc_v4 l,
 
 static int bch2_alloc_write_key(struct btree_trans *trans,
 				struct btree_iter *iter,
-				struct bkey_s_c k,
-				bool metadata_only)
+				struct bch_dev *ca,
+				struct bkey_s_c k)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, iter->pos.inode);
-	struct bucket old_gc, gc, *b;
 	struct bkey_i_alloc_v4 *a;
-	struct bch_alloc_v4 old_convert, new;
+	struct bch_alloc_v4 old_gc, gc, old_convert, new;
 	const struct bch_alloc_v4 *old;
 	int ret;
 
 	old = bch2_alloc_to_v4(k, &old_convert);
-	new = *old;
+	gc = new = *old;
 
 	percpu_down_read(&c->mark_lock);
-	b = gc_bucket(ca, iter->pos.offset);
-	old_gc = *b;
+	__bucket_m_to_alloc(&gc, *gc_bucket(ca, iter->pos.offset));
+
+	old_gc = gc;
 
 	if ((old->data_type == BCH_DATA_sb ||
 	     old->data_type == BCH_DATA_journal) &&
 	    !bch2_dev_is_online(ca)) {
-		b->data_type = old->data_type;
-		b->dirty_sectors = old->dirty_sectors;
+		gc.data_type = old->data_type;
+		gc.dirty_sectors = old->dirty_sectors;
 	}
 
 	/*
-	 * b->data_type doesn't yet include need_discard & need_gc_gen states -
+	 * gc.data_type doesn't yet include need_discard & need_gc_gen states -
 	 * fix that here:
 	 */
-	b->data_type = __alloc_data_type(b->dirty_sectors,
-					 b->cached_sectors,
-					 b->stripe,
-					 *old,
-					 b->data_type);
-	gc = *b;
+	alloc_data_type_set(&gc, gc.data_type);
 
 	if (gc.data_type != old_gc.data_type ||
 	    gc.dirty_sectors != old_gc.dirty_sectors)
-		bch2_dev_usage_update_m(c, ca, &old_gc, &gc);
+		bch2_dev_usage_update(c, ca, &old_gc, &gc, 0, true);
 	percpu_up_read(&c->mark_lock);
 
-	if (metadata_only &&
-	    gc.data_type != BCH_DATA_sb &&
-	    gc.data_type != BCH_DATA_journal &&
-	    gc.data_type != BCH_DATA_btree)
-		return 0;
-
-	if (gen_after(old->gen, gc.gen))
-		return 0;
-
 	if (fsck_err_on(new.data_type != gc.data_type, c,
 			alloc_key_data_type_wrong,
 			"bucket %llu:%llu gen %u has wrong data_type"
@@ -1460,12 +949,12 @@ static int bch2_alloc_write_key(struct btree_trans *trans,
 	if (a->v.data_type == BCH_DATA_cached && !a->v.io_time[READ])
 		a->v.io_time[READ] = max_t(u64, 1, atomic64_read(&c->io_clock[READ].now));
 
-	ret = bch2_trans_update(trans, iter, &a->k_i, BTREE_TRIGGER_NORUN);
+	ret = bch2_trans_update(trans, iter, &a->k_i, BTREE_TRIGGER_norun);
 fsck_err:
 	return ret;
 }
 
-static int bch2_gc_alloc_done(struct bch_fs *c, bool metadata_only)
+static int bch2_gc_alloc_done(struct bch_fs *c)
 {
 	int ret = 0;
 
@@ -1474,11 +963,11 @@ static int bch2_gc_alloc_done(struct bch_fs *c, bool metadata_only)
 			for_each_btree_key_upto_commit(trans, iter, BTREE_ID_alloc,
 					POS(ca->dev_idx, ca->mi.first_bucket),
 					POS(ca->dev_idx, ca->mi.nbuckets - 1),
-					BTREE_ITER_SLOTS|BTREE_ITER_PREFETCH, k,
+					BTREE_ITER_slots|BTREE_ITER_prefetch, k,
 					NULL, NULL, BCH_TRANS_COMMIT_lazy_rw,
-				bch2_alloc_write_key(trans, &iter, k, metadata_only)));
+				bch2_alloc_write_key(trans, &iter, ca, k)));
 		if (ret) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			break;
 		}
 	}
@@ -1487,14 +976,14 @@ static int bch2_gc_alloc_done(struct bch_fs *c, bool metadata_only)
 	return ret;
 }
 
-static int bch2_gc_alloc_start(struct bch_fs *c, bool metadata_only)
+static int bch2_gc_alloc_start(struct bch_fs *c)
 {
 	for_each_member_device(c, ca) {
 		struct bucket_array *buckets = kvmalloc(sizeof(struct bucket_array) +
 				ca->mi.nbuckets * sizeof(struct bucket),
 				GFP_KERNEL|__GFP_ZERO);
 		if (!buckets) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			bch_err(c, "error allocating ca->buckets[gc]");
 			return -BCH_ERR_ENOMEM_gc_alloc_start;
 		}
@@ -1504,54 +993,29 @@ static int bch2_gc_alloc_start(struct bch_fs *c, bool metadata_only)
 		rcu_assign_pointer(ca->buckets_gc, buckets);
 	}
 
+	struct bch_dev *ca = NULL;
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter, BTREE_ID_alloc, POS_MIN,
-					 BTREE_ITER_PREFETCH, k, ({
-			struct bch_dev *ca = bch_dev_bkey_exists(c, k.k->p.inode);
-			struct bucket *g = gc_bucket(ca, k.k->p.offset);
+					 BTREE_ITER_prefetch, k, ({
+			ca = bch2_dev_iterate(c, ca, k.k->p.inode);
+			if (!ca) {
+				bch2_btree_iter_set_pos(&iter, POS(k.k->p.inode + 1, 0));
+				continue;
+			}
 
 			struct bch_alloc_v4 a_convert;
 			const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
 
+			struct bucket *g = gc_bucket(ca, k.k->p.offset);
 			g->gen_valid	= 1;
 			g->gen		= a->gen;
-
-			if (metadata_only &&
-			    (a->data_type == BCH_DATA_user ||
-			     a->data_type == BCH_DATA_cached ||
-			     a->data_type == BCH_DATA_parity)) {
-				g->data_type		= a->data_type;
-				g->dirty_sectors	= a->dirty_sectors;
-				g->cached_sectors	= a->cached_sectors;
-				g->stripe		= a->stripe;
-				g->stripe_redundancy	= a->stripe_redundancy;
-			}
-
 			0;
 		})));
+	bch2_dev_put(ca);
 	bch_err_fn(c, ret);
 	return ret;
 }
 
-static void bch2_gc_alloc_reset(struct bch_fs *c, bool metadata_only)
-{
-	for_each_member_device(c, ca) {
-		struct bucket_array *buckets = gc_bucket_array(ca);
-		struct bucket *g;
-
-		for_each_bucket(g, buckets) {
-			if (metadata_only &&
-			    (g->data_type == BCH_DATA_user ||
-			     g->data_type == BCH_DATA_cached ||
-			     g->data_type == BCH_DATA_parity))
-				continue;
-			g->data_type = 0;
-			g->dirty_sectors = 0;
-			g->cached_sectors = 0;
-		}
-	}
-}
-
 static int bch2_gc_write_reflink_key(struct btree_trans *trans,
 				     struct btree_iter *iter,
 				     struct bkey_s_c k,
@@ -1601,35 +1065,27 @@ fsck_err:
 	return ret;
 }
 
-static int bch2_gc_reflink_done(struct bch_fs *c, bool metadata_only)
+static int bch2_gc_reflink_done(struct bch_fs *c)
 {
 	size_t idx = 0;
 
-	if (metadata_only)
-		return 0;
-
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
 				BTREE_ID_reflink, POS_MIN,
-				BTREE_ITER_PREFETCH, k,
+				BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			bch2_gc_write_reflink_key(trans, &iter, k, &idx)));
 	c->reflink_gc_nr = 0;
 	return ret;
 }
 
-static int bch2_gc_reflink_start(struct bch_fs *c,
-				 bool metadata_only)
+static int bch2_gc_reflink_start(struct bch_fs *c)
 {
-
-	if (metadata_only)
-		return 0;
-
 	c->reflink_gc_nr = 0;
 
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter, BTREE_ID_reflink, POS_MIN,
-				   BTREE_ITER_PREFETCH, k, ({
+				   BTREE_ITER_prefetch, k, ({
 			const __le64 *refcount = bkey_refcount_c(k);
 
 			if (!refcount)
@@ -1652,15 +1108,6 @@ static int bch2_gc_reflink_start(struct bch_fs *c,
 	return ret;
 }
 
-static void bch2_gc_reflink_reset(struct bch_fs *c, bool metadata_only)
-{
-	struct genradix_iter iter;
-	struct reflink_gc *r;
-
-	genradix_for_each(&c->reflink_gc_table, iter, r)
-		r->refcount = 0;
-}
-
 static int bch2_gc_write_stripes_key(struct btree_trans *trans,
 				     struct btree_iter *iter,
 				     struct bkey_s_c k)
@@ -1714,30 +1161,20 @@ fsck_err:
 	return ret;
 }
 
-static int bch2_gc_stripes_done(struct bch_fs *c, bool metadata_only)
+static int bch2_gc_stripes_done(struct bch_fs *c)
 {
-	if (metadata_only)
-		return 0;
-
 	return bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
 				BTREE_ID_stripes, POS_MIN,
-				BTREE_ITER_PREFETCH, k,
+				BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			bch2_gc_write_stripes_key(trans, &iter, k)));
 }
 
-static void bch2_gc_stripes_reset(struct bch_fs *c, bool metadata_only)
-{
-	genradix_free(&c->gc_stripes);
-}
-
 /**
- * bch2_gc - walk _all_ references to buckets, and recompute them:
+ * bch2_check_allocations - walk all references to buckets, and recompute them:
  *
  * @c:			filesystem object
- * @initial:		are we in recovery?
- * @metadata_only:	are we just checking metadata references, or everything?
  *
  * Returns: 0 on success, or standard errcode on failure
  *
@@ -1756,9 +1193,8 @@ static void bch2_gc_stripes_reset(struct bch_fs *c, bool metadata_only)
  *    move around - if references move backwards in the ordering GC
  *    uses, GC could skip past them
  */
-int bch2_gc(struct bch_fs *c, bool initial, bool metadata_only)
+int bch2_check_allocations(struct bch_fs *c)
 {
-	unsigned iter = 0;
 	int ret;
 
 	lockdep_assert_held(&c->state_lock);
@@ -1768,62 +1204,30 @@ int bch2_gc(struct bch_fs *c, bool initial, bool metadata_only)
 	bch2_btree_interior_updates_flush(c);
 
 	ret   = bch2_gc_start(c) ?:
-		bch2_gc_alloc_start(c, metadata_only) ?:
-		bch2_gc_reflink_start(c, metadata_only);
+		bch2_gc_alloc_start(c) ?:
+		bch2_gc_reflink_start(c);
 	if (ret)
 		goto out;
-again:
-	gc_pos_set(c, gc_phase(GC_PHASE_START));
 
-	bch2_mark_superblocks(c);
+	gc_pos_set(c, gc_phase(GC_PHASE_START));
 
-	ret = bch2_gc_btrees(c, initial, metadata_only);
+	ret = bch2_mark_superblocks(c);
+	BUG_ON(ret);
 
+	ret = bch2_gc_btrees(c);
 	if (ret)
 		goto out;
 
-#if 0
-	bch2_mark_pending_btree_node_frees(c);
-#endif
 	c->gc_count++;
 
-	if (test_bit(BCH_FS_need_another_gc, &c->flags) ||
-	    (!iter && bch2_test_restart_gc)) {
-		if (iter++ > 2) {
-			bch_info(c, "Unable to fix bucket gens, looping");
-			ret = -EINVAL;
-			goto out;
-		}
-
-		/*
-		 * XXX: make sure gens we fixed got saved
-		 */
-		bch_info(c, "Second GC pass needed, restarting:");
-		clear_bit(BCH_FS_need_another_gc, &c->flags);
-		__gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
-
-		bch2_gc_stripes_reset(c, metadata_only);
-		bch2_gc_alloc_reset(c, metadata_only);
-		bch2_gc_reflink_reset(c, metadata_only);
-		ret = bch2_gc_reset(c);
-		if (ret)
-			goto out;
-
-		/* flush fsck errors, reset counters */
-		bch2_flush_fsck_errs(c);
-		goto again;
-	}
+	bch2_journal_block(&c->journal);
 out:
-	if (!ret) {
-		bch2_journal_block(&c->journal);
+	ret   = bch2_gc_alloc_done(c) ?:
+		bch2_gc_done(c) ?:
+		bch2_gc_stripes_done(c) ?:
+		bch2_gc_reflink_done(c);
 
-		ret   = bch2_gc_alloc_done(c, metadata_only) ?:
-			bch2_gc_done(c, initial, metadata_only) ?:
-			bch2_gc_stripes_done(c, metadata_only) ?:
-			bch2_gc_reflink_done(c, metadata_only);
-
-		bch2_journal_unblock(&c->journal);
-	}
+	bch2_journal_unblock(&c->journal);
 
 	percpu_down_write(&c->mark_lock);
 	/* Indicates that gc is no longer in progress: */
@@ -1852,23 +1256,33 @@ static int gc_btree_gens_key(struct btree_trans *trans,
 	struct bkey_i *u;
 	int ret;
 
+	if (unlikely(test_bit(BCH_FS_going_ro, &c->flags)))
+		return -EROFS;
+
 	percpu_down_read(&c->mark_lock);
+	rcu_read_lock();
 	bkey_for_each_ptr(ptrs, ptr) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+		struct bch_dev *ca = bch2_dev_rcu(c, ptr->dev);
+		if (!ca)
+			continue;
 
-		if (ptr_stale(ca, ptr) > 16) {
+		if (dev_ptr_stale(ca, ptr) > 16) {
+			rcu_read_unlock();
 			percpu_up_read(&c->mark_lock);
 			goto update;
 		}
 	}
 
 	bkey_for_each_ptr(ptrs, ptr) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-		u8 *gen = &ca->oldest_gen[PTR_BUCKET_NR(ca, ptr)];
+		struct bch_dev *ca = bch2_dev_rcu(c, ptr->dev);
+		if (!ca)
+			continue;
 
+		u8 *gen = &ca->oldest_gen[PTR_BUCKET_NR(ca, ptr)];
 		if (gen_after(*gen, ptr->gen))
 			*gen = ptr->gen;
 	}
+	rcu_read_unlock();
 	percpu_up_read(&c->mark_lock);
 	return 0;
 update:
@@ -1881,10 +1295,9 @@ update:
 	return 0;
 }
 
-static int bch2_alloc_write_oldest_gen(struct btree_trans *trans, struct btree_iter *iter,
-				       struct bkey_s_c k)
+static int bch2_alloc_write_oldest_gen(struct btree_trans *trans, struct bch_dev *ca,
+				       struct btree_iter *iter, struct bkey_s_c k)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(trans->c, iter->pos.inode);
 	struct bch_alloc_v4 a_convert;
 	const struct bch_alloc_v4 *a = bch2_alloc_to_v4(k, &a_convert);
 	struct bkey_i_alloc_v4 *a_mut;
@@ -1899,7 +1312,7 @@ static int bch2_alloc_write_oldest_gen(struct btree_trans *trans, struct btree_i
 		return ret;
 
 	a_mut->v.oldest_gen = ca->oldest_gen[iter->pos.offset];
-	a_mut->v.data_type = alloc_data_type(a_mut->v, a_mut->v.data_type);
+	alloc_data_type_set(&a_mut->v, a_mut->v.data_type);
 
 	return bch2_trans_update(trans, iter, &a_mut->k_i, 0);
 }
@@ -1927,7 +1340,7 @@ int bch2_gc_gens(struct bch_fs *c)
 
 		ca->oldest_gen = kvmalloc(gens->nbuckets, GFP_KERNEL);
 		if (!ca->oldest_gen) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			ret = -BCH_ERR_ENOMEM_gc_gens;
 			goto err;
 		}
@@ -1945,7 +1358,7 @@ int bch2_gc_gens(struct bch_fs *c)
 			ret = bch2_trans_run(c,
 				for_each_btree_key_commit(trans, iter, i,
 						POS_MIN,
-						BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS,
+						BTREE_ITER_prefetch|BTREE_ITER_all_snapshots,
 						k,
 						NULL, NULL,
 						BCH_TRANS_COMMIT_no_enospc,
@@ -1954,14 +1367,23 @@ int bch2_gc_gens(struct bch_fs *c)
 				goto err;
 		}
 
+	struct bch_dev *ca = NULL;
 	ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_alloc,
 				POS_MIN,
-				BTREE_ITER_PREFETCH,
+				BTREE_ITER_prefetch,
 				k,
 				NULL, NULL,
-				BCH_TRANS_COMMIT_no_enospc,
-			bch2_alloc_write_oldest_gen(trans, &iter, k)));
+				BCH_TRANS_COMMIT_no_enospc, ({
+			ca = bch2_dev_iterate(c, ca, k.k->p.inode);
+			if (!ca) {
+				bch2_btree_iter_set_pos(&iter, POS(k.k->p.inode + 1, 0));
+				continue;
+			}
+			bch2_alloc_write_oldest_gen(trans, ca, &iter, k);
+		})));
+	bch2_dev_put(ca);
+
 	if (ret)
 		goto err;
 
@@ -1985,87 +1407,23 @@ err:
 	return ret;
 }
 
-static int bch2_gc_thread(void *arg)
+static void bch2_gc_gens_work(struct work_struct *work)
 {
-	struct bch_fs *c = arg;
-	struct io_clock *clock = &c->io_clock[WRITE];
-	unsigned long last = atomic64_read(&clock->now);
-	unsigned last_kick = atomic_read(&c->kick_gc);
-
-	set_freezable();
-
-	while (1) {
-		while (1) {
-			set_current_state(TASK_INTERRUPTIBLE);
-
-			if (kthread_should_stop()) {
-				__set_current_state(TASK_RUNNING);
-				return 0;
-			}
-
-			if (atomic_read(&c->kick_gc) != last_kick)
-				break;
-
-			if (c->btree_gc_periodic) {
-				unsigned long next = last + c->capacity / 16;
-
-				if (atomic64_read(&clock->now) >= next)
-					break;
-
-				bch2_io_clock_schedule_timeout(clock, next);
-			} else {
-				schedule();
-			}
-
-			try_to_freeze();
-		}
-		__set_current_state(TASK_RUNNING);
-
-		last = atomic64_read(&clock->now);
-		last_kick = atomic_read(&c->kick_gc);
-
-		/*
-		 * Full gc is currently incompatible with btree key cache:
-		 */
-#if 0
-		ret = bch2_gc(c, false, false);
-#else
-		bch2_gc_gens(c);
-#endif
-		debug_check_no_locks_held();
-	}
-
-	return 0;
+	struct bch_fs *c = container_of(work, struct bch_fs, gc_gens_work);
+	bch2_gc_gens(c);
+	bch2_write_ref_put(c, BCH_WRITE_REF_gc_gens);
 }
 
-void bch2_gc_thread_stop(struct bch_fs *c)
+void bch2_gc_gens_async(struct bch_fs *c)
 {
-	struct task_struct *p;
-
-	p = c->gc_thread;
-	c->gc_thread = NULL;
-
-	if (p) {
-		kthread_stop(p);
-		put_task_struct(p);
-	}
+	if (bch2_write_ref_tryget(c, BCH_WRITE_REF_gc_gens) &&
+	    !queue_work(c->write_ref_wq, &c->gc_gens_work))
+		bch2_write_ref_put(c, BCH_WRITE_REF_gc_gens);
 }
 
-int bch2_gc_thread_start(struct bch_fs *c)
+void bch2_fs_gc_init(struct bch_fs *c)
 {
-	struct task_struct *p;
+	seqcount_init(&c->gc_pos_lock);
 
-	if (c->gc_thread)
-		return 0;
-
-	p = kthread_create(bch2_gc_thread, c, "bch-gc/%s", c->name);
-	if (IS_ERR(p)) {
-		bch_err_fn(c, PTR_ERR(p));
-		return PTR_ERR(p);
-	}
-
-	get_task_struct(p);
-	c->gc_thread = p;
-	wake_up_process(p);
-	return 0;
+	INIT_WORK(&c->gc_gens_work, bch2_gc_gens_work);
 }
diff --git a/fs/bcachefs/btree_gc.h b/fs/bcachefs/btree_gc.h
index 607575f83a00..1b6489d8e0f4 100644
--- a/fs/bcachefs/btree_gc.h
+++ b/fs/bcachefs/btree_gc.h
@@ -6,10 +6,7 @@
 #include "btree_types.h"
 
 int bch2_check_topology(struct bch_fs *);
-int bch2_gc(struct bch_fs *, bool, bool);
-int bch2_gc_gens(struct bch_fs *);
-void bch2_gc_thread_stop(struct bch_fs *);
-int bch2_gc_thread_start(struct bch_fs *);
+int bch2_check_allocations(struct bch_fs *);
 
 /*
  * For concurrent mark and sweep (with other index updates), we define a total
@@ -37,16 +34,16 @@ static inline struct gc_pos gc_phase(enum gc_phase phase)
 {
 	return (struct gc_pos) {
 		.phase	= phase,
-		.pos	= POS_MIN,
 		.level	= 0,
+		.pos	= POS_MIN,
 	};
 }
 
 static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r)
 {
-	return  cmp_int(l.phase, r.phase) ?:
-		bpos_cmp(l.pos, r.pos) ?:
-		cmp_int(l.level, r.level);
+	return   cmp_int(l.phase, r.phase) ?:
+		-cmp_int(l.level, r.level) ?:
+		 bpos_cmp(l.pos, r.pos);
 }
 
 static inline enum gc_phase btree_id_to_gc_phase(enum btree_id id)
@@ -60,13 +57,13 @@ static inline enum gc_phase btree_id_to_gc_phase(enum btree_id id)
 	}
 }
 
-static inline struct gc_pos gc_pos_btree(enum btree_id id,
-					 struct bpos pos, unsigned level)
+static inline struct gc_pos gc_pos_btree(enum btree_id btree, unsigned level,
+					 struct bpos pos)
 {
 	return (struct gc_pos) {
-		.phase	= btree_id_to_gc_phase(id),
-		.pos	= pos,
+		.phase	= btree_id_to_gc_phase(btree),
 		.level	= level,
+		.pos	= pos,
 	};
 }
 
@@ -76,19 +73,7 @@ static inline struct gc_pos gc_pos_btree(enum btree_id id,
  */
 static inline struct gc_pos gc_pos_btree_node(struct btree *b)
 {
-	return gc_pos_btree(b->c.btree_id, b->key.k.p, b->c.level);
-}
-
-/*
- * GC position of the pointer to a btree root: we don't use
- * gc_pos_pointer_to_btree_node() here to avoid a potential race with
- * btree_split() increasing the tree depth - the new root will have level > the
- * old root and thus have a greater gc position than the old root, but that
- * would be incorrect since once gc has marked the root it's not coming back.
- */
-static inline struct gc_pos gc_pos_btree_root(enum btree_id id)
-{
-	return gc_pos_btree(id, SPOS_MAX, BTREE_MAX_DEPTH);
+	return gc_pos_btree(b->c.btree_id, b->c.level, b->key.k.p);
 }
 
 static inline bool gc_visited(struct bch_fs *c, struct gc_pos pos)
@@ -104,11 +89,8 @@ static inline bool gc_visited(struct bch_fs *c, struct gc_pos pos)
 	return ret;
 }
 
-static inline void bch2_do_gc_gens(struct bch_fs *c)
-{
-	atomic_inc(&c->kick_gc);
-	if (c->gc_thread)
-		wake_up_process(c->gc_thread);
-}
+int bch2_gc_gens(struct bch_fs *);
+void bch2_gc_gens_async(struct bch_fs *);
+void bch2_fs_gc_init(struct bch_fs *);
 
 #endif /* _BCACHEFS_BTREE_GC_H */
diff --git a/fs/bcachefs/btree_io.c b/fs/bcachefs/btree_io.c
index debb0edc3455..cbf8f5d90602 100644
--- a/fs/bcachefs/btree_io.c
+++ b/fs/bcachefs/btree_io.c
@@ -23,6 +23,18 @@
 
 #include <linux/sched/mm.h>
 
+static void bch2_btree_node_header_to_text(struct printbuf *out, struct btree_node *bn)
+{
+	prt_printf(out, "btree=%s l=%u seq %llux\n",
+		   bch2_btree_id_str(BTREE_NODE_ID(bn)),
+		   (unsigned) BTREE_NODE_LEVEL(bn), bn->keys.seq);
+	prt_str(out, "min: ");
+	bch2_bpos_to_text(out, bn->min_key);
+	prt_newline(out);
+	prt_str(out, "max: ");
+	bch2_bpos_to_text(out, bn->max_key);
+}
+
 void bch2_btree_node_io_unlock(struct btree *b)
 {
 	EBUG_ON(!btree_node_write_in_flight(b));
@@ -217,7 +229,6 @@ static bool should_compact_bset(struct btree *b, struct bset_tree *t,
 
 static bool bch2_drop_whiteouts(struct btree *b, enum compact_mode mode)
 {
-	struct bset_tree *t;
 	bool ret = false;
 
 	for_each_bset(b, t) {
@@ -288,8 +299,7 @@ bool bch2_compact_whiteouts(struct bch_fs *c, struct btree *b,
 
 static void btree_node_sort(struct bch_fs *c, struct btree *b,
 			    unsigned start_idx,
-			    unsigned end_idx,
-			    bool filter_whiteouts)
+			    unsigned end_idx)
 {
 	struct btree_node *out;
 	struct sort_iter_stack sort_iter;
@@ -320,7 +330,7 @@ static void btree_node_sort(struct bch_fs *c, struct btree *b,
 
 	start_time = local_clock();
 
-	u64s = bch2_sort_keys(out->keys.start, &sort_iter.iter, filter_whiteouts);
+	u64s = bch2_sort_keys(out->keys.start, &sort_iter.iter);
 
 	out->keys.u64s = cpu_to_le16(u64s);
 
@@ -426,13 +436,12 @@ static bool btree_node_compact(struct bch_fs *c, struct btree *b)
 			break;
 
 	if (b->nsets - unwritten_idx > 1) {
-		btree_node_sort(c, b, unwritten_idx,
-				b->nsets, false);
+		btree_node_sort(c, b, unwritten_idx, b->nsets);
 		ret = true;
 	}
 
 	if (unwritten_idx > 1) {
-		btree_node_sort(c, b, 0, unwritten_idx, false);
+		btree_node_sort(c, b, 0, unwritten_idx);
 		ret = true;
 	}
 
@@ -441,8 +450,6 @@ static bool btree_node_compact(struct bch_fs *c, struct btree *b)
 
 void bch2_btree_build_aux_trees(struct btree *b)
 {
-	struct bset_tree *t;
-
 	for_each_bset(b, t)
 		bch2_bset_build_aux_tree(b, t,
 				!bset_written(b, bset(b, t)) &&
@@ -524,7 +531,9 @@ static void btree_err_msg(struct printbuf *out, struct bch_fs *c,
 	prt_printf(out, "at btree ");
 	bch2_btree_pos_to_text(out, c, b);
 
-	prt_printf(out, "\n  node offset %u/%u",
+	printbuf_indent_add(out, 2);
+
+	prt_printf(out, "\nnode offset %u/%u",
 		   b->written, btree_ptr_sectors_written(&b->key));
 	if (i)
 		prt_printf(out, " bset u64s %u", le16_to_cpu(i->u64s));
@@ -543,6 +552,7 @@ static int __btree_err(int ret,
 		       const char *fmt, ...)
 {
 	struct printbuf out = PRINTBUF;
+	bool silent = c->curr_recovery_pass == BCH_RECOVERY_PASS_scan_for_btree_nodes;
 	va_list args;
 
 	btree_err_msg(&out, c, ca, b, i, b->written, write);
@@ -564,12 +574,14 @@ static int __btree_err(int ret,
 	if (!have_retry && ret == -BCH_ERR_btree_node_read_err_must_retry)
 		ret = -BCH_ERR_btree_node_read_err_bad_node;
 
-	if (ret != -BCH_ERR_btree_node_read_err_fixable)
+	if (!silent && ret != -BCH_ERR_btree_node_read_err_fixable)
 		bch2_sb_error_count(c, err_type);
 
 	switch (ret) {
 	case -BCH_ERR_btree_node_read_err_fixable:
-		ret = bch2_fsck_err(c, FSCK_CAN_FIX, err_type, "%s", out.buf);
+		ret = !silent
+			? bch2_fsck_err(c, FSCK_CAN_FIX, err_type, "%s", out.buf)
+			: -BCH_ERR_fsck_fix;
 		if (ret != -BCH_ERR_fsck_fix &&
 		    ret != -BCH_ERR_fsck_ignore)
 			goto fsck_err;
@@ -577,14 +589,17 @@ static int __btree_err(int ret,
 		break;
 	case -BCH_ERR_btree_node_read_err_want_retry:
 	case -BCH_ERR_btree_node_read_err_must_retry:
-		bch2_print_string_as_lines(KERN_ERR, out.buf);
+		if (!silent)
+			bch2_print_string_as_lines(KERN_ERR, out.buf);
 		break;
 	case -BCH_ERR_btree_node_read_err_bad_node:
-		bch2_print_string_as_lines(KERN_ERR, out.buf);
+		if (!silent)
+			bch2_print_string_as_lines(KERN_ERR, out.buf);
 		ret = bch2_topology_error(c);
 		break;
 	case -BCH_ERR_btree_node_read_err_incompatible:
-		bch2_print_string_as_lines(KERN_ERR, out.buf);
+		if (!silent)
+			bch2_print_string_as_lines(KERN_ERR, out.buf);
 		ret = -BCH_ERR_fsck_errors_not_fixed;
 		break;
 	default:
@@ -619,8 +634,6 @@ fsck_err:
 __cold
 void bch2_btree_node_drop_keys_outside_node(struct btree *b)
 {
-	struct bset_tree *t;
-
 	for_each_bset(b, t) {
 		struct bset *i = bset(b, t);
 		struct bkey_packed *k;
@@ -1021,18 +1034,19 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 			     -BCH_ERR_btree_node_read_err_must_retry,
 			     c, ca, b, NULL,
 			     btree_node_bad_seq,
-			     "got wrong btree node (want %llx got %llx)\n"
-			     "got btree %s level %llu pos %s",
-			     bp->seq, b->data->keys.seq,
-			     bch2_btree_id_str(BTREE_NODE_ID(b->data)),
-			     BTREE_NODE_LEVEL(b->data),
-			     buf.buf);
+			     "got wrong btree node: got\n%s",
+			     (printbuf_reset(&buf),
+			      bch2_btree_node_header_to_text(&buf, b->data),
+			      buf.buf));
 	} else {
 		btree_err_on(!b->data->keys.seq,
 			     -BCH_ERR_btree_node_read_err_must_retry,
 			     c, ca, b, NULL,
 			     btree_node_bad_seq,
-			     "bad btree header: seq 0");
+			     "bad btree header: seq 0\n%s",
+			     (printbuf_reset(&buf),
+			      bch2_btree_node_header_to_text(&buf, b->data),
+			      buf.buf));
 	}
 
 	while (b->written < (ptr_written ?: btree_sectors(c))) {
@@ -1095,7 +1109,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 			nonce = btree_nonce(i, b->written << 9);
 			struct bch_csum csum = csum_vstruct(c, BSET_CSUM_TYPE(i), nonce, bne);
 			csum_bad = bch2_crc_cmp(bne->csum, csum);
-			if (csum_bad)
+			if (ca && csum_bad)
 				bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
 
 			btree_err_on(csum_bad,
@@ -1249,12 +1263,14 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 	btree_node_reset_sib_u64s(b);
 
+	rcu_read_lock();
 	bkey_for_each_ptr(bch2_bkey_ptrs(bkey_i_to_s(&b->key)), ptr) {
-		struct bch_dev *ca2 = bch_dev_bkey_exists(c, ptr->dev);
+		struct bch_dev *ca2 = bch2_dev_rcu(c, ptr->dev);
 
-		if (ca2->mi.state != BCH_MEMBER_STATE_rw)
+		if (!ca2 || ca2->mi.state != BCH_MEMBER_STATE_rw)
 			set_btree_node_need_rewrite(b);
 	}
+	rcu_read_unlock();
 
 	if (!ptr_written)
 		set_btree_node_need_rewrite(b);
@@ -1279,8 +1295,8 @@ static void btree_node_read_work(struct work_struct *work)
 	struct btree_read_bio *rb =
 		container_of(work, struct btree_read_bio, work);
 	struct bch_fs *c	= rb->c;
+	struct bch_dev *ca	= rb->have_ioref ? bch2_dev_have_ref(c, rb->pick.ptr.dev) : NULL;
 	struct btree *b		= rb->b;
-	struct bch_dev *ca	= bch_dev_bkey_exists(c, rb->pick.ptr.dev);
 	struct bio *bio		= &rb->bio;
 	struct bch_io_failures failed = { .nr = 0 };
 	struct printbuf buf = PRINTBUF;
@@ -1292,8 +1308,8 @@ static void btree_node_read_work(struct work_struct *work)
 	while (1) {
 		retry = true;
 		bch_info(c, "retrying read");
-		ca = bch_dev_bkey_exists(c, rb->pick.ptr.dev);
-		rb->have_ioref		= bch2_dev_get_ioref(ca, READ);
+		ca = bch2_dev_get_ioref(c, rb->pick.ptr.dev, READ);
+		rb->have_ioref		= ca != NULL;
 		bio_reset(bio, NULL, REQ_OP_READ|REQ_SYNC|REQ_META);
 		bio->bi_iter.bi_sector	= rb->pick.ptr.offset;
 		bio->bi_iter.bi_size	= btree_buf_bytes(b);
@@ -1307,7 +1323,7 @@ static void btree_node_read_work(struct work_struct *work)
 start:
 		printbuf_reset(&buf);
 		bch2_btree_pos_to_text(&buf, c, b);
-		bch2_dev_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read,
+		bch2_dev_io_err_on(ca && bio->bi_status, ca, BCH_MEMBER_ERROR_read,
 				   "btree read error %s for %s",
 				   bch2_blk_status_to_str(bio->bi_status), buf.buf);
 		if (rb->have_ioref)
@@ -1363,7 +1379,7 @@ static void btree_node_read_endio(struct bio *bio)
 	struct bch_fs *c	= rb->c;
 
 	if (rb->have_ioref) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, rb->pick.ptr.dev);
+		struct bch_dev *ca = bch2_dev_have_ref(c, rb->pick.ptr.dev);
 
 		bch2_latency_acct(ca, rb->start_time, READ);
 	}
@@ -1560,7 +1576,7 @@ static void btree_node_read_all_replicas_endio(struct bio *bio)
 	struct btree_node_read_all *ra = rb->ra;
 
 	if (rb->have_ioref) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, rb->pick.ptr.dev);
+		struct bch_dev *ca = bch2_dev_have_ref(c, rb->pick.ptr.dev);
 
 		bch2_latency_acct(ca, rb->start_time, READ);
 	}
@@ -1602,14 +1618,14 @@ static int btree_node_read_all_replicas(struct bch_fs *c, struct btree *b, bool
 
 	i = 0;
 	bkey_for_each_ptr_decode(k.k, ptrs, pick, entry) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, pick.ptr.dev);
+		struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
 		struct btree_read_bio *rb =
 			container_of(ra->bio[i], struct btree_read_bio, bio);
 		rb->c			= c;
 		rb->b			= b;
 		rb->ra			= ra;
 		rb->start_time		= local_clock();
-		rb->have_ioref		= bch2_dev_get_ioref(ca, READ);
+		rb->have_ioref		= ca != NULL;
 		rb->idx			= i;
 		rb->pick		= pick;
 		rb->bio.bi_iter.bi_sector = pick.ptr.offset;
@@ -1679,7 +1695,7 @@ void bch2_btree_node_read(struct btree_trans *trans, struct btree *b,
 		return;
 	}
 
-	ca = bch_dev_bkey_exists(c, pick.ptr.dev);
+	ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
 
 	bio = bio_alloc_bioset(NULL,
 			       buf_pages(b->data, btree_buf_bytes(b)),
@@ -1691,7 +1707,7 @@ void bch2_btree_node_read(struct btree_trans *trans, struct btree *b,
 	rb->b			= b;
 	rb->ra			= NULL;
 	rb->start_time		= local_clock();
-	rb->have_ioref		= bch2_dev_get_ioref(ca, READ);
+	rb->have_ioref		= ca != NULL;
 	rb->pick		= pick;
 	INIT_WORK(&rb->work, btree_node_read_work);
 	bio->bi_iter.bi_sector	= pick.ptr.offset;
@@ -1846,7 +1862,6 @@ static void btree_node_write_work(struct work_struct *work)
 		container_of(work, struct btree_write_bio, work);
 	struct bch_fs *c	= wbio->wbio.c;
 	struct btree *b		= wbio->wbio.bio.bi_private;
-	struct bch_extent_ptr *ptr;
 	int ret = 0;
 
 	btree_bounce_free(c,
@@ -1896,13 +1911,14 @@ static void btree_node_write_endio(struct bio *bio)
 	struct btree_write_bio *wb	= container_of(orig, struct btree_write_bio, wbio);
 	struct bch_fs *c		= wbio->c;
 	struct btree *b			= wbio->bio.bi_private;
-	struct bch_dev *ca		= bch_dev_bkey_exists(c, wbio->dev);
+	struct bch_dev *ca		= wbio->have_ioref ? bch2_dev_have_ref(c, wbio->dev) : NULL;
 	unsigned long flags;
 
 	if (wbio->have_ioref)
 		bch2_latency_acct(ca, wbio->submit_time, WRITE);
 
-	if (bch2_dev_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_write,
+	if (!ca ||
+	    bch2_dev_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_write,
 			       "btree write error: %s",
 			       bch2_blk_status_to_str(bio->bi_status)) ||
 	    bch2_meta_write_fault("btree")) {
@@ -1969,7 +1985,6 @@ static void btree_write_submit(struct work_struct *work)
 void __bch2_btree_node_write(struct bch_fs *c, struct btree *b, unsigned flags)
 {
 	struct btree_write_bio *wbio;
-	struct bset_tree *t;
 	struct bset *i;
 	struct btree_node *bn = NULL;
 	struct btree_node_entry *bne = NULL;
@@ -2095,11 +2110,11 @@ do_write:
 		      unwritten_whiteouts_end(b));
 	SET_BSET_SEPARATE_WHITEOUTS(i, false);
 
-	b->whiteout_u64s = 0;
-
-	u64s = bch2_sort_keys(i->start, &sort_iter.iter, false);
+	u64s = bch2_sort_keys_keep_unwritten_whiteouts(i->start, &sort_iter.iter);
 	le16_add_cpu(&i->u64s, u64s);
 
+	b->whiteout_u64s = 0;
+
 	BUG_ON(!b->written && i->u64s != b->data->keys.u64s);
 
 	set_needs_whiteout(i, false);
@@ -2226,7 +2241,6 @@ bool bch2_btree_post_write_cleanup(struct bch_fs *c, struct btree *b)
 {
 	bool invalidated_iter = false;
 	struct btree_node_entry *bne;
-	struct bset_tree *t;
 
 	if (!btree_node_just_written(b))
 		return false;
@@ -2249,7 +2263,7 @@ bool bch2_btree_post_write_cleanup(struct bch_fs *c, struct btree *b)
 	 * single bset:
 	 */
 	if (b->nsets > 1) {
-		btree_node_sort(c, b, 0, b->nsets, true);
+		btree_node_sort(c, b, 0, b->nsets);
 		invalidated_iter = true;
 	} else {
 		invalidated_iter = bch2_drop_whiteouts(b, COMPACT_ALL);
@@ -2346,20 +2360,13 @@ void bch2_btree_write_stats_to_text(struct printbuf *out, struct bch_fs *c)
 	printbuf_tabstop_push(out, 20);
 	printbuf_tabstop_push(out, 10);
 
-	prt_tab(out);
-	prt_str(out, "nr");
-	prt_tab(out);
-	prt_str(out, "size");
-	prt_newline(out);
+	prt_printf(out, "\tnr\tsize\n");
 
 	for (unsigned i = 0; i < BTREE_WRITE_TYPE_NR; i++) {
 		u64 nr		= atomic64_read(&c->btree_write_stats[i].nr);
 		u64 bytes	= atomic64_read(&c->btree_write_stats[i].bytes);
 
-		prt_printf(out, "%s:", bch2_btree_write_types[i]);
-		prt_tab(out);
-		prt_u64(out, nr);
-		prt_tab(out);
+		prt_printf(out, "%s:\t%llu\t", bch2_btree_write_types[i], nr);
 		prt_human_readable_u64(out, nr ? div64_u64(bytes, nr) : 0);
 		prt_newline(out);
 	}
diff --git a/fs/bcachefs/btree_io.h b/fs/bcachefs/btree_io.h
index e251cb6b965f..2b8b564fc560 100644
--- a/fs/bcachefs/btree_io.h
+++ b/fs/bcachefs/btree_io.h
@@ -81,8 +81,6 @@ static inline bool should_compact_bset_lazy(struct btree *b,
 
 static inline bool bch2_maybe_compact_whiteouts(struct bch_fs *c, struct btree *b)
 {
-	struct bset_tree *t;
-
 	for_each_bset(b, t)
 		if (should_compact_bset_lazy(b, t))
 			return bch2_compact_whiteouts(c, b, COMPACT_LAZY);
diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 2a211a4bebd1..5bf98cb8b15d 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -61,7 +61,7 @@ static inline int btree_path_cmp(const struct btree_path *l,
 static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p)
 {
 	/* Are we iterating over keys in all snapshots? */
-	if (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) {
+	if (iter->flags & BTREE_ITER_all_snapshots) {
 		p = bpos_successor(p);
 	} else {
 		p = bpos_nosnap_successor(p);
@@ -74,7 +74,7 @@ static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p)
 static inline struct bpos bkey_predecessor(struct btree_iter *iter, struct bpos p)
 {
 	/* Are we iterating over keys in all snapshots? */
-	if (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) {
+	if (iter->flags & BTREE_ITER_all_snapshots) {
 		p = bpos_predecessor(p);
 	} else {
 		p = bpos_nosnap_predecessor(p);
@@ -88,7 +88,7 @@ static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
 {
 	struct bpos pos = iter->pos;
 
-	if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+	if ((iter->flags & BTREE_ITER_is_extents) &&
 	    !bkey_eq(pos, POS_MAX))
 		pos = bkey_successor(iter, pos);
 	return pos;
@@ -253,13 +253,13 @@ static void bch2_btree_iter_verify(struct btree_iter *iter)
 
 	BUG_ON(iter->btree_id >= BTREE_ID_NR);
 
-	BUG_ON(!!(iter->flags & BTREE_ITER_CACHED) != btree_iter_path(trans, iter)->cached);
+	BUG_ON(!!(iter->flags & BTREE_ITER_cached) != btree_iter_path(trans, iter)->cached);
 
-	BUG_ON((iter->flags & BTREE_ITER_IS_EXTENTS) &&
-	       (iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
+	BUG_ON((iter->flags & BTREE_ITER_is_extents) &&
+	       (iter->flags & BTREE_ITER_all_snapshots));
 
-	BUG_ON(!(iter->flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
-	       (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+	BUG_ON(!(iter->flags & BTREE_ITER_snapshot_field) &&
+	       (iter->flags & BTREE_ITER_all_snapshots) &&
 	       !btree_type_has_snapshot_field(iter->btree_id));
 
 	if (iter->update_path)
@@ -269,10 +269,10 @@ static void bch2_btree_iter_verify(struct btree_iter *iter)
 
 static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter)
 {
-	BUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
+	BUG_ON((iter->flags & BTREE_ITER_filter_snapshots) &&
 	       !iter->pos.snapshot);
 
-	BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+	BUG_ON(!(iter->flags & BTREE_ITER_all_snapshots) &&
 	       iter->pos.snapshot != iter->snapshot);
 
 	BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) ||
@@ -289,7 +289,7 @@ static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k
 	if (!bch2_debug_check_iterators)
 		return 0;
 
-	if (!(iter->flags & BTREE_ITER_FILTER_SNAPSHOTS))
+	if (!(iter->flags & BTREE_ITER_filter_snapshots))
 		return 0;
 
 	if (bkey_err(k) || !k.k)
@@ -300,8 +300,8 @@ static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k
 					  k.k->p.snapshot));
 
 	bch2_trans_iter_init(trans, &copy, iter->btree_id, iter->pos,
-			     BTREE_ITER_NOPRESERVE|
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_nopreserve|
+			     BTREE_ITER_all_snapshots);
 	prev = bch2_btree_iter_prev(&copy);
 	if (!prev.k)
 		goto out;
@@ -897,7 +897,7 @@ static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans,
 
 	bch2_bkey_buf_reassemble(out, c, k);
 
-	if ((flags & BTREE_ITER_PREFETCH) &&
+	if ((flags & BTREE_ITER_prefetch) &&
 	    c->opts.btree_node_prefetch)
 		ret = btree_path_prefetch_j(trans, path, &jiter);
 
@@ -944,7 +944,7 @@ static __always_inline int btree_path_down(struct btree_trans *trans,
 
 		bch2_bkey_buf_unpack(&tmp, c, l->b, k);
 
-		if ((flags & BTREE_ITER_PREFETCH) &&
+		if ((flags & BTREE_ITER_prefetch) &&
 		    c->opts.btree_node_prefetch) {
 			ret = btree_path_prefetch(trans, path);
 			if (ret)
@@ -999,6 +999,7 @@ retry_all:
 
 	bch2_trans_unlock(trans);
 	cond_resched();
+	trans->locked = true;
 
 	if (unlikely(trans->memory_allocation_failure)) {
 		struct closure cl;
@@ -1162,6 +1163,7 @@ int bch2_btree_path_traverse_one(struct btree_trans *trans,
 		goto out_uptodate;
 
 	path->level = btree_path_up_until_good_node(trans, path, 0);
+	unsigned max_level = path->level;
 
 	EBUG_ON(btree_path_node(path, path->level) &&
 		!btree_node_locked(path, path->level));
@@ -1192,6 +1194,16 @@ int bch2_btree_path_traverse_one(struct btree_trans *trans,
 			goto out;
 		}
 	}
+
+	if (unlikely(max_level > path->level)) {
+		struct btree_path *linked;
+		unsigned iter;
+
+		trans_for_each_path_with_node(trans, path_l(path)->b, linked, iter)
+			for (unsigned j = path->level + 1; j < max_level; j++)
+				linked->l[j] = path->l[j];
+	}
+
 out_uptodate:
 	path->uptodate = BTREE_ITER_UPTODATE;
 out:
@@ -1221,11 +1233,14 @@ static inline void btree_path_copy(struct btree_trans *trans, struct btree_path
 }
 
 static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src,
-					 bool intent)
+					 bool intent, unsigned long ip)
 {
 	btree_path_idx_t new = btree_path_alloc(trans, src);
 	btree_path_copy(trans, trans->paths + new, trans->paths + src);
 	__btree_path_get(trans->paths + new, intent);
+#ifdef TRACK_PATH_ALLOCATED
+	trans->paths[new].ip_allocated = ip;
+#endif
 	return new;
 }
 
@@ -1234,7 +1249,7 @@ btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans,
 			btree_path_idx_t path, bool intent, unsigned long ip)
 {
 	__btree_path_put(trans->paths + path, intent);
-	path = btree_path_clone(trans, path, intent);
+	path = btree_path_clone(trans, path, intent, ip);
 	trans->paths[path].preserve = false;
 	return path;
 }
@@ -1334,6 +1349,26 @@ static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t
 	__clear_bit(path, trans->paths_allocated);
 }
 
+static bool bch2_btree_path_can_relock(struct btree_trans *trans, struct btree_path *path)
+{
+	unsigned l = path->level;
+
+	do {
+		if (!btree_path_node(path, l))
+			break;
+
+		if (!is_btree_node(path, l))
+			return false;
+
+		if (path->l[l].lock_seq != path->l[l].b->c.lock.seq)
+			return false;
+
+		l++;
+	} while (l < path->locks_want);
+
+	return true;
+}
+
 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent)
 {
 	struct btree_path *path = trans->paths + path_idx, *dup;
@@ -1348,10 +1383,15 @@ void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool in
 	if (!dup && !(!path->preserve && !is_btree_node(path, path->level)))
 		return;
 
-	if (path->should_be_locked &&
-	    !trans->restarted &&
-	    (!dup || !bch2_btree_path_relock_norestart(trans, dup)))
-		return;
+	if (path->should_be_locked && !trans->restarted) {
+		if (!dup)
+			return;
+
+		if (!(trans->locked
+		      ? bch2_btree_path_relock_norestart(trans, dup)
+		      : bch2_btree_path_can_relock(trans, dup)))
+			return;
+	}
 
 	if (dup) {
 		dup->preserve		|= path->preserve;
@@ -1384,22 +1424,26 @@ void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans)
 	      (void *) trans->last_restarted_ip);
 }
 
+void __noreturn bch2_trans_unlocked_error(struct btree_trans *trans)
+{
+	panic("trans should be locked, unlocked by %pS\n",
+	      (void *) trans->last_unlock_ip);
+}
+
 noinline __cold
 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans)
 {
-	prt_printf(buf, "transaction updates for %s journal seq %llu",
+	prt_printf(buf, "transaction updates for %s journal seq %llu\n",
 	       trans->fn, trans->journal_res.seq);
-	prt_newline(buf);
 	printbuf_indent_add(buf, 2);
 
 	trans_for_each_update(trans, i) {
 		struct bkey_s_c old = { &i->old_k, i->old_v };
 
-		prt_printf(buf, "update: btree=%s cached=%u %pS",
+		prt_printf(buf, "update: btree=%s cached=%u %pS\n",
 		       bch2_btree_id_str(i->btree_id),
 		       i->cached,
 		       (void *) i->ip_allocated);
-		prt_newline(buf);
 
 		prt_printf(buf, "  old ");
 		bch2_bkey_val_to_text(buf, trans->c, old);
@@ -1428,23 +1472,63 @@ void bch2_dump_trans_updates(struct btree_trans *trans)
 	printbuf_exit(&buf);
 }
 
-static void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
+static void bch2_btree_path_to_text_short(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
 {
 	struct btree_path *path = trans->paths + path_idx;
 
-	prt_printf(out, "path: idx %2u ref %u:%u %c %c btree=%s l=%u pos ",
+	prt_printf(out, "path: idx %2u ref %u:%u %c %c %c btree=%s l=%u pos ",
 		   path_idx, path->ref, path->intent_ref,
 		   path->preserve ? 'P' : ' ',
 		   path->should_be_locked ? 'S' : ' ',
+		   path->cached ? 'C' : 'B',
 		   bch2_btree_id_str(path->btree_id),
 		   path->level);
 	bch2_bpos_to_text(out, path->pos);
 
-	prt_printf(out, " locks %u", path->nodes_locked);
 #ifdef TRACK_PATH_ALLOCATED
 	prt_printf(out, " %pS", (void *) path->ip_allocated);
 #endif
+}
+
+static const char *btree_node_locked_str(enum btree_node_locked_type t)
+{
+	switch (t) {
+	case BTREE_NODE_UNLOCKED:
+		return "unlocked";
+	case BTREE_NODE_READ_LOCKED:
+		return "read";
+	case BTREE_NODE_INTENT_LOCKED:
+		return "intent";
+	case BTREE_NODE_WRITE_LOCKED:
+		return "write";
+	default:
+		return NULL;
+	}
+}
+
+void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
+{
+	bch2_btree_path_to_text_short(out, trans, path_idx);
+
+	struct btree_path *path = trans->paths + path_idx;
+
+	prt_printf(out, " uptodate %u locks_want %u", path->uptodate, path->locks_want);
 	prt_newline(out);
+
+	printbuf_indent_add(out, 2);
+	for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) {
+		prt_printf(out, "l=%u locks %s seq %u node ", l,
+			   btree_node_locked_str(btree_node_locked_type(path, l)),
+			   path->l[l].lock_seq);
+
+		int ret = PTR_ERR_OR_ZERO(path->l[l].b);
+		if (ret)
+			prt_str(out, bch2_err_str(ret));
+		else
+			prt_printf(out, "%px", path->l[l].b);
+		prt_newline(out);
+	}
+	printbuf_indent_sub(out, 2);
 }
 
 static noinline __cold
@@ -1456,8 +1540,10 @@ void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans,
 	if (!nosort)
 		btree_trans_sort_paths(trans);
 
-	trans_for_each_path_idx_inorder(trans, iter)
-		bch2_btree_path_to_text(out, trans, iter.path_idx);
+	trans_for_each_path_idx_inorder(trans, iter) {
+		bch2_btree_path_to_text_short(out, trans, iter.path_idx);
+		prt_newline(out);
+	}
 }
 
 noinline __cold
@@ -1608,11 +1694,12 @@ btree_path_idx_t bch2_path_get(struct btree_trans *trans,
 			     unsigned flags, unsigned long ip)
 {
 	struct btree_path *path;
-	bool cached = flags & BTREE_ITER_CACHED;
-	bool intent = flags & BTREE_ITER_INTENT;
+	bool cached = flags & BTREE_ITER_cached;
+	bool intent = flags & BTREE_ITER_intent;
 	struct trans_for_each_path_inorder_iter iter;
 	btree_path_idx_t path_pos = 0, path_idx;
 
+	bch2_trans_verify_not_unlocked(trans);
 	bch2_trans_verify_not_in_restart(trans);
 	bch2_trans_verify_locks(trans);
 
@@ -1657,7 +1744,7 @@ btree_path_idx_t bch2_path_get(struct btree_trans *trans,
 		trans->paths_sorted		= false;
 	}
 
-	if (!(flags & BTREE_ITER_NOPRESERVE))
+	if (!(flags & BTREE_ITER_nopreserve))
 		path->preserve = true;
 
 	if (path->intent_ref)
@@ -1678,6 +1765,22 @@ btree_path_idx_t bch2_path_get(struct btree_trans *trans,
 	return path_idx;
 }
 
+btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *trans,
+					    enum btree_id btree_id,
+					    unsigned level,
+					    struct bpos pos)
+{
+	btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level,
+			     BTREE_ITER_nopreserve|
+			     BTREE_ITER_intent, _RET_IP_);
+	path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_);
+
+	struct btree_path *path = trans->paths + path_idx;
+	bch2_btree_path_downgrade(trans, path);
+	__bch2_btree_path_unlock(trans, path);
+	return path_idx;
+}
+
 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
 {
 
@@ -1719,6 +1822,19 @@ hole:
 	return (struct bkey_s_c) { u, NULL };
 }
 
+
+void bch2_set_btree_iter_dontneed(struct btree_iter *iter)
+{
+	struct btree_trans *trans = iter->trans;
+
+	if (!iter->path || trans->restarted)
+		return;
+
+	struct btree_path *path = btree_iter_path(trans, iter);
+	path->preserve		= false;
+	if (path->ref == 1)
+		path->should_be_locked	= false;
+}
 /* Btree iterators: */
 
 int __must_check
@@ -1733,9 +1849,11 @@ bch2_btree_iter_traverse(struct btree_iter *iter)
 	struct btree_trans *trans = iter->trans;
 	int ret;
 
+	bch2_trans_verify_not_unlocked(trans);
+
 	iter->path = bch2_btree_path_set_pos(trans, iter->path,
 					btree_iter_search_key(iter),
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 
 	ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
@@ -1774,7 +1892,7 @@ struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
 	iter->k.p = iter->pos = b->key.k.p;
 
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 	btree_path_set_should_be_locked(btree_iter_path(trans, iter));
 out:
@@ -1835,13 +1953,16 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 	if (bpos_eq(iter->pos, b->key.k.p)) {
 		__btree_path_set_level_up(trans, path, path->level++);
 	} else {
+		if (btree_lock_want(path, path->level + 1) == BTREE_NODE_UNLOCKED)
+			btree_node_unlock(trans, path, path->level + 1);
+
 		/*
 		 * Haven't gotten to the end of the parent node: go back down to
 		 * the next child node
 		 */
 		iter->path = bch2_btree_path_set_pos(trans, iter->path,
 					bpos_successor(iter->pos),
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 
 		path = btree_iter_path(trans, iter);
@@ -1859,7 +1980,7 @@ struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
 	iter->k.p = iter->pos = b->key.k.p;
 
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 	btree_path_set_should_be_locked(btree_iter_path(trans, iter));
 	EBUG_ON(btree_iter_path(trans, iter)->uptodate);
@@ -1878,11 +1999,11 @@ err:
 inline bool bch2_btree_iter_advance(struct btree_iter *iter)
 {
 	struct bpos pos = iter->k.p;
-	bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
+	bool ret = !(iter->flags & BTREE_ITER_all_snapshots
 		     ? bpos_eq(pos, SPOS_MAX)
 		     : bkey_eq(pos, SPOS_MAX));
 
-	if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+	if (ret && !(iter->flags & BTREE_ITER_is_extents))
 		pos = bkey_successor(iter, pos);
 	bch2_btree_iter_set_pos(iter, pos);
 	return ret;
@@ -1891,11 +2012,11 @@ inline bool bch2_btree_iter_advance(struct btree_iter *iter)
 inline bool bch2_btree_iter_rewind(struct btree_iter *iter)
 {
 	struct bpos pos = bkey_start_pos(&iter->k);
-	bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
+	bool ret = !(iter->flags & BTREE_ITER_all_snapshots
 		     ? bpos_eq(pos, POS_MIN)
 		     : bkey_eq(pos, POS_MIN));
 
-	if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+	if (ret && !(iter->flags & BTREE_ITER_is_extents))
 		pos = bkey_predecessor(iter, pos);
 	bch2_btree_iter_set_pos(iter, pos);
 	return ret;
@@ -2006,7 +2127,10 @@ struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos
 	struct bkey_s_c k;
 	int ret;
 
-	if ((iter->flags & BTREE_ITER_KEY_CACHE_FILL) &&
+	bch2_trans_verify_not_in_restart(trans);
+	bch2_trans_verify_not_unlocked(trans);
+
+	if ((iter->flags & BTREE_ITER_key_cache_fill) &&
 	    bpos_eq(iter->pos, pos))
 		return bkey_s_c_null;
 
@@ -2015,17 +2139,17 @@ struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos
 
 	if (!iter->key_cache_path)
 		iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
-						     iter->flags & BTREE_ITER_INTENT, 0,
-						     iter->flags|BTREE_ITER_CACHED|
-						     BTREE_ITER_CACHED_NOFILL,
+						     iter->flags & BTREE_ITER_intent, 0,
+						     iter->flags|BTREE_ITER_cached|
+						     BTREE_ITER_cached_nofill,
 						     _THIS_IP_);
 
 	iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos,
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 
 	ret =   bch2_btree_path_traverse(trans, iter->key_cache_path,
-					 iter->flags|BTREE_ITER_CACHED) ?:
+					 iter->flags|BTREE_ITER_cached) ?:
 		bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_);
 	if (unlikely(ret))
 		return bkey_s_c_err(ret);
@@ -2053,7 +2177,7 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
 		struct btree_path_level *l;
 
 		iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 
 		ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
@@ -2078,7 +2202,7 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
 
 		k = btree_path_level_peek_all(trans->c, l, &iter->k);
 
-		if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
+		if (unlikely(iter->flags & BTREE_ITER_with_key_cache) &&
 		    k.k &&
 		    (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) {
 			k = k2;
@@ -2089,10 +2213,10 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
 			}
 		}
 
-		if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL))
+		if (unlikely(iter->flags & BTREE_ITER_with_journal))
 			k = btree_trans_peek_journal(trans, iter, k);
 
-		if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
+		if (unlikely((iter->flags & BTREE_ITER_with_updates) &&
 			     trans->nr_updates))
 			bch2_btree_trans_peek_updates(trans, iter, &k);
 
@@ -2144,11 +2268,12 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 	struct bpos iter_pos;
 	int ret;
 
-	EBUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) && bkey_eq(end, POS_MAX));
+	bch2_trans_verify_not_unlocked(trans);
+	EBUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && bkey_eq(end, POS_MAX));
 
 	if (iter->update_path) {
 		bch2_path_put_nokeep(trans, iter->update_path,
-				     iter->flags & BTREE_ITER_INTENT);
+				     iter->flags & BTREE_ITER_intent);
 		iter->update_path = 0;
 	}
 
@@ -2171,7 +2296,7 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 		 * isn't monotonically increasing before FILTER_SNAPSHOTS, and
 		 * that's what we check against in extents mode:
 		 */
-		if (unlikely(!(iter->flags & BTREE_ITER_IS_EXTENTS)
+		if (unlikely(!(iter->flags & BTREE_ITER_is_extents)
 			     ? bkey_gt(k.k->p, end)
 			     : k.k->p.inode > end.inode))
 			goto end;
@@ -2179,13 +2304,13 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 		if (iter->update_path &&
 		    !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) {
 			bch2_path_put_nokeep(trans, iter->update_path,
-					     iter->flags & BTREE_ITER_INTENT);
+					     iter->flags & BTREE_ITER_intent);
 			iter->update_path = 0;
 		}
 
-		if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
-		    (iter->flags & BTREE_ITER_INTENT) &&
-		    !(iter->flags & BTREE_ITER_IS_EXTENTS) &&
+		if ((iter->flags & BTREE_ITER_filter_snapshots) &&
+		    (iter->flags & BTREE_ITER_intent) &&
+		    !(iter->flags & BTREE_ITER_is_extents) &&
 		    !iter->update_path) {
 			struct bpos pos = k.k->p;
 
@@ -2200,12 +2325,12 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 			 * advance, same as on exit for iter->path, but only up
 			 * to snapshot
 			 */
-			__btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_INTENT);
+			__btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_intent);
 			iter->update_path = iter->path;
 
 			iter->update_path = bch2_btree_path_set_pos(trans,
 						iter->update_path, pos,
-						iter->flags & BTREE_ITER_INTENT,
+						iter->flags & BTREE_ITER_intent,
 						_THIS_IP_);
 			ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags);
 			if (unlikely(ret)) {
@@ -2218,7 +2343,7 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 		 * We can never have a key in a leaf node at POS_MAX, so
 		 * we don't have to check these successor() calls:
 		 */
-		if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
+		if ((iter->flags & BTREE_ITER_filter_snapshots) &&
 		    !bch2_snapshot_is_ancestor(trans->c,
 					       iter->snapshot,
 					       k.k->p.snapshot)) {
@@ -2227,7 +2352,7 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 		}
 
 		if (bkey_whiteout(k.k) &&
-		    !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
+		    !(iter->flags & BTREE_ITER_all_snapshots)) {
 			search_key = bkey_successor(iter, k.k->p);
 			continue;
 		}
@@ -2237,12 +2362,12 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 		 * equal to the key we just returned - except extents can
 		 * straddle iter->pos:
 		 */
-		if (!(iter->flags & BTREE_ITER_IS_EXTENTS))
+		if (!(iter->flags & BTREE_ITER_is_extents))
 			iter_pos = k.k->p;
 		else
 			iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k));
 
-		if (unlikely(!(iter->flags & BTREE_ITER_IS_EXTENTS)
+		if (unlikely(!(iter->flags & BTREE_ITER_is_extents)
 			     ? bkey_gt(iter_pos, end)
 			     : bkey_ge(iter_pos, end)))
 			goto end;
@@ -2253,7 +2378,7 @@ struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos e
 	iter->pos = iter_pos;
 
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p,
-				iter->flags & BTREE_ITER_INTENT,
+				iter->flags & BTREE_ITER_intent,
 				btree_iter_ip_allocated(iter));
 
 	btree_path_set_should_be_locked(btree_iter_path(trans, iter));
@@ -2266,7 +2391,7 @@ out_no_locked:
 			btree_path_set_should_be_locked(trans->paths + iter->update_path);
 	}
 
-	if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
+	if (!(iter->flags & BTREE_ITER_all_snapshots))
 		iter->pos.snapshot = iter->snapshot;
 
 	ret = bch2_btree_iter_verify_ret(iter, k);
@@ -2316,21 +2441,22 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 	btree_path_idx_t saved_path = 0;
 	int ret;
 
+	bch2_trans_verify_not_unlocked(trans);
 	EBUG_ON(btree_iter_path(trans, iter)->cached ||
 		btree_iter_path(trans, iter)->level);
 
-	if (iter->flags & BTREE_ITER_WITH_JOURNAL)
+	if (iter->flags & BTREE_ITER_with_journal)
 		return bkey_s_c_err(-BCH_ERR_btree_iter_with_journal_not_supported);
 
 	bch2_btree_iter_verify(iter);
 	bch2_btree_iter_verify_entry_exit(iter);
 
-	if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
+	if (iter->flags & BTREE_ITER_filter_snapshots)
 		search_key.snapshot = U32_MAX;
 
 	while (1) {
 		iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
-						iter->flags & BTREE_ITER_INTENT,
+						iter->flags & BTREE_ITER_intent,
 						btree_iter_ip_allocated(iter));
 
 		ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
@@ -2345,17 +2471,17 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 
 		k = btree_path_level_peek(trans, path, &path->l[0], &iter->k);
 		if (!k.k ||
-		    ((iter->flags & BTREE_ITER_IS_EXTENTS)
+		    ((iter->flags & BTREE_ITER_is_extents)
 		     ? bpos_ge(bkey_start_pos(k.k), search_key)
 		     : bpos_gt(k.k->p, search_key)))
 			k = btree_path_level_prev(trans, path, &path->l[0], &iter->k);
 
-		if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
+		if (unlikely((iter->flags & BTREE_ITER_with_updates) &&
 			     trans->nr_updates))
 			bch2_btree_trans_peek_prev_updates(trans, iter, &k);
 
 		if (likely(k.k)) {
-			if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) {
+			if (iter->flags & BTREE_ITER_filter_snapshots) {
 				if (k.k->p.snapshot == iter->snapshot)
 					goto got_key;
 
@@ -2366,7 +2492,7 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 				 */
 				if (saved_path && !bkey_eq(k.k->p, saved_k.p)) {
 					bch2_path_put_nokeep(trans, iter->path,
-						      iter->flags & BTREE_ITER_INTENT);
+						      iter->flags & BTREE_ITER_intent);
 					iter->path = saved_path;
 					saved_path = 0;
 					iter->k	= saved_k;
@@ -2379,9 +2505,10 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 							      k.k->p.snapshot)) {
 					if (saved_path)
 						bch2_path_put_nokeep(trans, saved_path,
-						      iter->flags & BTREE_ITER_INTENT);
+						      iter->flags & BTREE_ITER_intent);
 					saved_path = btree_path_clone(trans, iter->path,
-								iter->flags & BTREE_ITER_INTENT);
+								iter->flags & BTREE_ITER_intent,
+								_THIS_IP_);
 					path = btree_iter_path(trans, iter);
 					saved_k = *k.k;
 					saved_v = k.v;
@@ -2392,9 +2519,9 @@ struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
 			}
 got_key:
 			if (bkey_whiteout(k.k) &&
-			    !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
+			    !(iter->flags & BTREE_ITER_all_snapshots)) {
 				search_key = bkey_predecessor(iter, k.k->p);
-				if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
+				if (iter->flags & BTREE_ITER_filter_snapshots)
 					search_key.snapshot = U32_MAX;
 				continue;
 			}
@@ -2418,11 +2545,11 @@ got_key:
 	if (bkey_lt(k.k->p, iter->pos))
 		iter->pos = k.k->p;
 
-	if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
+	if (iter->flags & BTREE_ITER_filter_snapshots)
 		iter->pos.snapshot = iter->snapshot;
 out_no_locked:
 	if (saved_path)
-		bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_INTENT);
+		bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_intent);
 
 	bch2_btree_iter_verify_entry_exit(iter);
 	bch2_btree_iter_verify(iter);
@@ -2452,12 +2579,13 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 	struct bkey_s_c k;
 	int ret;
 
+	bch2_trans_verify_not_unlocked(trans);
 	bch2_btree_iter_verify(iter);
 	bch2_btree_iter_verify_entry_exit(iter);
-	EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_WITH_KEY_CACHE));
+	EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_with_key_cache));
 
 	/* extents can't span inode numbers: */
-	if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
+	if ((iter->flags & BTREE_ITER_is_extents) &&
 	    unlikely(iter->pos.offset == KEY_OFFSET_MAX)) {
 		if (iter->pos.inode == KEY_INODE_MAX)
 			return bkey_s_c_null;
@@ -2467,7 +2595,7 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 
 	search_key = btree_iter_search_key(iter);
 	iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
-					iter->flags & BTREE_ITER_INTENT,
+					iter->flags & BTREE_ITER_intent,
 					btree_iter_ip_allocated(iter));
 
 	ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
@@ -2476,22 +2604,22 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 		goto out_no_locked;
 	}
 
-	if ((iter->flags & BTREE_ITER_CACHED) ||
-	    !(iter->flags & (BTREE_ITER_IS_EXTENTS|BTREE_ITER_FILTER_SNAPSHOTS))) {
+	if ((iter->flags & BTREE_ITER_cached) ||
+	    !(iter->flags & (BTREE_ITER_is_extents|BTREE_ITER_filter_snapshots))) {
 		k = bkey_s_c_null;
 
-		if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
+		if (unlikely((iter->flags & BTREE_ITER_with_updates) &&
 			     trans->nr_updates)) {
 			bch2_btree_trans_peek_slot_updates(trans, iter, &k);
 			if (k.k)
 				goto out;
 		}
 
-		if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL) &&
+		if (unlikely(iter->flags & BTREE_ITER_with_journal) &&
 		    (k = btree_trans_peek_slot_journal(trans, iter)).k)
 			goto out;
 
-		if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
+		if (unlikely(iter->flags & BTREE_ITER_with_key_cache) &&
 		    (k = btree_trans_peek_key_cache(iter, iter->pos)).k) {
 			if (!bkey_err(k))
 				iter->k = *k.k;
@@ -2506,12 +2634,12 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 		struct bpos next;
 		struct bpos end = iter->pos;
 
-		if (iter->flags & BTREE_ITER_IS_EXTENTS)
+		if (iter->flags & BTREE_ITER_is_extents)
 			end.offset = U64_MAX;
 
 		EBUG_ON(btree_iter_path(trans, iter)->level);
 
-		if (iter->flags & BTREE_ITER_INTENT) {
+		if (iter->flags & BTREE_ITER_intent) {
 			struct btree_iter iter2;
 
 			bch2_trans_copy_iter(&iter2, iter);
@@ -2542,7 +2670,7 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
 			bkey_init(&iter->k);
 			iter->k.p = iter->pos;
 
-			if (iter->flags & BTREE_ITER_IS_EXTENTS) {
+			if (iter->flags & BTREE_ITER_is_extents) {
 				bch2_key_resize(&iter->k,
 						min_t(u64, KEY_SIZE_MAX,
 						      (next.inode == iter->pos.inode
@@ -2726,13 +2854,13 @@ void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter)
 {
 	if (iter->update_path)
 		bch2_path_put_nokeep(trans, iter->update_path,
-			      iter->flags & BTREE_ITER_INTENT);
+			      iter->flags & BTREE_ITER_intent);
 	if (iter->path)
 		bch2_path_put(trans, iter->path,
-			      iter->flags & BTREE_ITER_INTENT);
+			      iter->flags & BTREE_ITER_intent);
 	if (iter->key_cache_path)
 		bch2_path_put(trans, iter->key_cache_path,
-			      iter->flags & BTREE_ITER_INTENT);
+			      iter->flags & BTREE_ITER_intent);
 	iter->path		= 0;
 	iter->update_path	= 0;
 	iter->key_cache_path	= 0;
@@ -2757,9 +2885,9 @@ void bch2_trans_node_iter_init(struct btree_trans *trans,
 			       unsigned depth,
 			       unsigned flags)
 {
-	flags |= BTREE_ITER_NOT_EXTENTS;
-	flags |= __BTREE_ITER_ALL_SNAPSHOTS;
-	flags |= BTREE_ITER_ALL_SNAPSHOTS;
+	flags |= BTREE_ITER_not_extents;
+	flags |= BTREE_ITER_snapshot_field;
+	flags |= BTREE_ITER_all_snapshots;
 
 	bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth,
 			       __bch2_btree_iter_flags(trans, btree_id, flags),
@@ -2782,9 +2910,9 @@ void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src)
 	dst->ip_allocated = _RET_IP_;
 #endif
 	if (src->path)
-		__btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_INTENT);
+		__btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_intent);
 	if (src->update_path)
-		__btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_INTENT);
+		__btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_intent);
 	dst->key_cache_path = 0;
 }
 
@@ -2953,7 +3081,8 @@ u32 bch2_trans_begin(struct btree_trans *trans)
 	if (!trans->restarted &&
 	    (need_resched() ||
 	     time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) {
-		drop_locks_do(trans, (cond_resched(), 0));
+		bch2_trans_unlock(trans);
+		cond_resched();
 		now = local_clock();
 	}
 	trans->last_begin_time = now;
@@ -2963,11 +3092,14 @@ u32 bch2_trans_begin(struct btree_trans *trans)
 		bch2_trans_srcu_unlock(trans);
 
 	trans->last_begin_ip = _RET_IP_;
+	trans->locked  = true;
+
 	if (trans->restarted) {
 		bch2_btree_path_traverse_all(trans);
 		trans->notrace_relock_fail = false;
 	}
 
+	bch2_trans_verify_not_unlocked(trans);
 	return trans->restart_count;
 }
 
@@ -3020,7 +3152,7 @@ struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx)
 			 */
 			BUG_ON(pos_task &&
 			       pid == pos_task->pid &&
-			       bch2_trans_locked(pos));
+			       pos->locked);
 
 			if (pos_task && pid < pos_task->pid) {
 				list_add_tail(&trans->list, &pos->list);
@@ -3036,8 +3168,9 @@ got_trans:
 	trans->last_begin_time	= local_clock();
 	trans->fn_idx		= fn_idx;
 	trans->locking_wait.task = current;
+	trans->locked		= true;
 	trans->journal_replay_not_finished =
-		unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)) &&
+		unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)) &&
 		atomic_inc_not_zero(&c->journal_keys.ref);
 	trans->nr_paths		= ARRAY_SIZE(trans->_paths);
 	trans->paths_allocated	= trans->_paths_allocated;
@@ -3166,13 +3299,11 @@ bch2_btree_bkey_cached_common_to_text(struct printbuf *out,
 	pid = owner ? owner->pid : 0;
 	rcu_read_unlock();
 
-	prt_tab(out);
-	prt_printf(out, "%px %c l=%u %s:", b, b->cached ? 'c' : 'b',
+	prt_printf(out, "\t%px %c l=%u %s:", b, b->cached ? 'c' : 'b',
 		   b->level, bch2_btree_id_str(b->btree_id));
 	bch2_bpos_to_text(out, btree_node_pos(b));
 
-	prt_tab(out);
-	prt_printf(out, " locks %u:%u:%u held by pid %u",
+	prt_printf(out, "\t locks %u:%u:%u held by pid %u",
 		   c.n[0], c.n[1], c.n[2], pid);
 }
 
@@ -3229,10 +3360,8 @@ void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans)
 
 	b = READ_ONCE(trans->locking);
 	if (b) {
-		prt_printf(out, "  blocked for %lluus on",
-			   div_u64(local_clock() - trans->locking_wait.start_time,
-				   1000));
-		prt_newline(out);
+		prt_printf(out, "  blocked for %lluus on\n",
+			   div_u64(local_clock() - trans->locking_wait.start_time, 1000));
 		prt_printf(out, "    %c", lock_types[trans->locking_wait.lock_want]);
 		bch2_btree_bkey_cached_common_to_text(out, b);
 		prt_newline(out);
diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 1c70836dd7cc..eab2a25bdc7a 100644
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -216,9 +216,13 @@ int __must_check bch2_btree_path_traverse_one(struct btree_trans *,
 					      btree_path_idx_t,
 					      unsigned, unsigned long);
 
+static inline void bch2_trans_verify_not_unlocked(struct btree_trans *);
+
 static inline int __must_check bch2_btree_path_traverse(struct btree_trans *trans,
 					  btree_path_idx_t path, unsigned flags)
 {
+	bch2_trans_verify_not_unlocked(trans);
+
 	if (trans->paths[path].uptodate < BTREE_ITER_NEED_RELOCK)
 		return 0;
 
@@ -227,6 +231,9 @@ static inline int __must_check bch2_btree_path_traverse(struct btree_trans *tran
 
 btree_path_idx_t bch2_path_get(struct btree_trans *, enum btree_id, struct bpos,
 				 unsigned, unsigned, unsigned, unsigned long);
+btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *, enum btree_id,
+					    unsigned, struct bpos);
+
 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *, struct bkey *);
 
 /*
@@ -283,7 +290,6 @@ int bch2_trans_relock(struct btree_trans *);
 int bch2_trans_relock_notrace(struct btree_trans *);
 void bch2_trans_unlock(struct btree_trans *);
 void bch2_trans_unlock_long(struct btree_trans *);
-bool bch2_trans_locked(struct btree_trans *);
 
 static inline int trans_was_restarted(struct btree_trans *trans, u32 restart_count)
 {
@@ -309,6 +315,14 @@ static inline void bch2_trans_verify_not_in_restart(struct btree_trans *trans)
 		bch2_trans_in_restart_error(trans);
 }
 
+void __noreturn bch2_trans_unlocked_error(struct btree_trans *);
+
+static inline void bch2_trans_verify_not_unlocked(struct btree_trans *trans)
+{
+	if (!trans->locked)
+		bch2_trans_unlocked_error(trans);
+}
+
 __always_inline
 static int btree_trans_restart_nounlock(struct btree_trans *trans, int err)
 {
@@ -386,10 +400,10 @@ static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos
 
 	if (unlikely(iter->update_path))
 		bch2_path_put(trans, iter->update_path,
-			      iter->flags & BTREE_ITER_INTENT);
+			      iter->flags & BTREE_ITER_intent);
 	iter->update_path = 0;
 
-	if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
+	if (!(iter->flags & BTREE_ITER_all_snapshots))
 		new_pos.snapshot = iter->snapshot;
 
 	__bch2_btree_iter_set_pos(iter, new_pos);
@@ -397,7 +411,7 @@ static inline void bch2_btree_iter_set_pos(struct btree_iter *iter, struct bpos
 
 static inline void bch2_btree_iter_set_pos_to_extent_start(struct btree_iter *iter)
 {
-	BUG_ON(!(iter->flags & BTREE_ITER_IS_EXTENTS));
+	BUG_ON(!(iter->flags & BTREE_ITER_is_extents));
 	iter->pos = bkey_start_pos(&iter->k);
 }
 
@@ -416,20 +430,20 @@ static inline unsigned __bch2_btree_iter_flags(struct btree_trans *trans,
 					       unsigned btree_id,
 					       unsigned flags)
 {
-	if (!(flags & (BTREE_ITER_ALL_SNAPSHOTS|BTREE_ITER_NOT_EXTENTS)) &&
+	if (!(flags & (BTREE_ITER_all_snapshots|BTREE_ITER_not_extents)) &&
 	    btree_id_is_extents(btree_id))
-		flags |= BTREE_ITER_IS_EXTENTS;
+		flags |= BTREE_ITER_is_extents;
 
-	if (!(flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
+	if (!(flags & BTREE_ITER_snapshot_field) &&
 	    !btree_type_has_snapshot_field(btree_id))
-		flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
+		flags &= ~BTREE_ITER_all_snapshots;
 
-	if (!(flags & BTREE_ITER_ALL_SNAPSHOTS) &&
+	if (!(flags & BTREE_ITER_all_snapshots) &&
 	    btree_type_has_snapshots(btree_id))
-		flags |= BTREE_ITER_FILTER_SNAPSHOTS;
+		flags |= BTREE_ITER_filter_snapshots;
 
 	if (trans->journal_replay_not_finished)
-		flags |= BTREE_ITER_WITH_JOURNAL;
+		flags |= BTREE_ITER_with_journal;
 
 	return flags;
 }
@@ -439,10 +453,10 @@ static inline unsigned bch2_btree_iter_flags(struct btree_trans *trans,
 					     unsigned flags)
 {
 	if (!btree_id_cached(trans->c, btree_id)) {
-		flags &= ~BTREE_ITER_CACHED;
-		flags &= ~BTREE_ITER_WITH_KEY_CACHE;
-	} else if (!(flags & BTREE_ITER_CACHED))
-		flags |= BTREE_ITER_WITH_KEY_CACHE;
+		flags &= ~BTREE_ITER_cached;
+		flags &= ~BTREE_ITER_with_key_cache;
+	} else if (!(flags & BTREE_ITER_cached))
+		flags |= BTREE_ITER_with_key_cache;
 
 	return __bch2_btree_iter_flags(trans, btree_id, flags);
 }
@@ -494,18 +508,7 @@ void bch2_trans_node_iter_init(struct btree_trans *, struct btree_iter *,
 			       unsigned, unsigned, unsigned);
 void bch2_trans_copy_iter(struct btree_iter *, struct btree_iter *);
 
-static inline void set_btree_iter_dontneed(struct btree_iter *iter)
-{
-	struct btree_trans *trans = iter->trans;
-
-	if (!iter->path || trans->restarted)
-		return;
-
-	struct btree_path *path = btree_iter_path(trans, iter);
-	path->preserve		= false;
-	if (path->ref == 1)
-		path->should_be_locked	= false;
-}
+void bch2_set_btree_iter_dontneed(struct btree_iter *);
 
 void *__bch2_trans_kmalloc(struct btree_trans *, size_t);
 
@@ -619,14 +622,14 @@ u32 bch2_trans_begin(struct btree_trans *);
 static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,
 							     unsigned flags)
 {
-	return  flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
+	return  flags & BTREE_ITER_slots      ? bch2_btree_iter_peek_slot(iter) :
 						bch2_btree_iter_peek_prev(iter);
 }
 
 static inline struct bkey_s_c bch2_btree_iter_peek_type(struct btree_iter *iter,
 							unsigned flags)
 {
-	return  flags & BTREE_ITER_SLOTS      ? bch2_btree_iter_peek_slot(iter) :
+	return  flags & BTREE_ITER_slots      ? bch2_btree_iter_peek_slot(iter) :
 						bch2_btree_iter_peek(iter);
 }
 
@@ -634,7 +637,7 @@ static inline struct bkey_s_c bch2_btree_iter_peek_upto_type(struct btree_iter *
 							     struct bpos end,
 							     unsigned flags)
 {
-	if (!(flags & BTREE_ITER_SLOTS))
+	if (!(flags & BTREE_ITER_slots))
 		return bch2_btree_iter_peek_upto(iter, end);
 
 	if (bkey_gt(iter->pos, end))
@@ -699,16 +702,12 @@ transaction_restart:							\
 	_ret2 ?: trans_was_restarted(_trans, _restart_count);		\
 })
 
-#define for_each_btree_key_upto(_trans, _iter, _btree_id,		\
-				_start, _end, _flags, _k, _do)		\
+#define for_each_btree_key_upto_continue(_trans, _iter,			\
+					 _end, _flags, _k, _do)		\
 ({									\
-	struct btree_iter _iter;					\
 	struct bkey_s_c _k;						\
 	int _ret3 = 0;							\
 									\
-	bch2_trans_iter_init((_trans), &(_iter), (_btree_id),		\
-			     (_start), (_flags));			\
-									\
 	do {								\
 		_ret3 = lockrestart_do(_trans, ({			\
 			(_k) = bch2_btree_iter_peek_upto_type(&(_iter),	\
@@ -724,6 +723,21 @@ transaction_restart:							\
 	_ret3;								\
 })
 
+#define for_each_btree_key_continue(_trans, _iter, _flags, _k, _do)	\
+	for_each_btree_key_upto_continue(_trans, _iter, SPOS_MAX, _flags, _k, _do)
+
+#define for_each_btree_key_upto(_trans, _iter, _btree_id,		\
+				_start, _end, _flags, _k, _do)		\
+({									\
+	bch2_trans_begin(trans);					\
+									\
+	struct btree_iter _iter;					\
+	bch2_trans_iter_init((_trans), &(_iter), (_btree_id),		\
+			     (_start), (_flags));			\
+									\
+	for_each_btree_key_upto_continue(_trans, _iter, _end, _flags, _k, _do);\
+})
+
 #define for_each_btree_key(_trans, _iter, _btree_id,			\
 			   _start, _flags, _k, _do)			\
 	for_each_btree_key_upto(_trans, _iter, _btree_id, _start,	\
@@ -794,14 +808,6 @@ __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 	return k;
 }
 
-#define for_each_btree_key_old(_trans, _iter, _btree_id,		\
-			   _start, _flags, _k, _ret)			\
-	for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),	\
-				  (_start), (_flags));			\
-	     (_k) = __bch2_btree_iter_peek_and_restart((_trans), &(_iter), _flags),\
-	     !((_ret) = bkey_err(_k)) && (_k).k;			\
-	     bch2_btree_iter_advance(&(_iter)))
-
 #define for_each_btree_key_upto_norestart(_trans, _iter, _btree_id,	\
 			   _start, _end, _flags, _k, _ret)		\
 	for (bch2_trans_iter_init((_trans), &(_iter), (_btree_id),	\
@@ -861,6 +867,7 @@ __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 })
 
 void bch2_trans_updates_to_text(struct printbuf *, struct btree_trans *);
+void bch2_btree_path_to_text(struct printbuf *, struct btree_trans *, btree_path_idx_t);
 void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
 void bch2_dump_trans_updates(struct btree_trans *);
 void bch2_dump_trans_paths_updates(struct btree_trans *);
diff --git a/fs/bcachefs/btree_journal_iter.c b/fs/bcachefs/btree_journal_iter.c
index 1e8cf49a6935..332dbf164929 100644
--- a/fs/bcachefs/btree_journal_iter.c
+++ b/fs/bcachefs/btree_journal_iter.c
@@ -623,3 +623,20 @@ void bch2_shoot_down_journal_keys(struct bch_fs *c, enum btree_id btree,
 			keys->data[dst++] = *i;
 	keys->nr = keys->gap = dst;
 }
+
+void bch2_journal_keys_dump(struct bch_fs *c)
+{
+	struct journal_keys *keys = &c->journal_keys;
+	struct printbuf buf = PRINTBUF;
+
+	pr_info("%zu keys:", keys->nr);
+
+	move_gap(keys, keys->nr);
+
+	darray_for_each(*keys, i) {
+		printbuf_reset(&buf);
+		bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(i->k));
+		pr_err("%s l=%u %s", bch2_btree_id_str(i->btree_id), i->level, buf.buf);
+	}
+	printbuf_exit(&buf);
+}
diff --git a/fs/bcachefs/btree_journal_iter.h b/fs/bcachefs/btree_journal_iter.h
index af25046ebcaa..1ba4a79b0ef9 100644
--- a/fs/bcachefs/btree_journal_iter.h
+++ b/fs/bcachefs/btree_journal_iter.h
@@ -70,4 +70,6 @@ void bch2_shoot_down_journal_keys(struct bch_fs *, enum btree_id,
 				  unsigned, unsigned,
 				  struct bpos, struct bpos);
 
+void bch2_journal_keys_dump(struct bch_fs *);
+
 #endif /* _BCACHEFS_BTREE_JOURNAL_ITER_H */
diff --git a/fs/bcachefs/btree_key_cache.c b/fs/bcachefs/btree_key_cache.c
index 7dafa1accec2..75f5e6fe4634 100644
--- a/fs/bcachefs/btree_key_cache.c
+++ b/fs/bcachefs/btree_key_cache.c
@@ -383,9 +383,9 @@ static int btree_key_cache_fill(struct btree_trans *trans,
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, ck->key.btree_id, ck->key.pos,
-			     BTREE_ITER_KEY_CACHE_FILL|
-			     BTREE_ITER_CACHED_NOFILL);
-	iter.flags &= ~BTREE_ITER_WITH_JOURNAL;
+			     BTREE_ITER_key_cache_fill|
+			     BTREE_ITER_cached_nofill);
+	iter.flags &= ~BTREE_ITER_with_journal;
 	k = bch2_btree_iter_peek_slot(&iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -456,7 +456,7 @@ static int btree_key_cache_fill(struct btree_trans *trans,
 	bch2_btree_node_unlock_write(trans, ck_path, ck_path->l[0].b);
 
 	/* We're not likely to need this iterator again: */
-	set_btree_iter_dontneed(&iter);
+	bch2_set_btree_iter_dontneed(&iter);
 err:
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
@@ -515,23 +515,10 @@ retry:
 fill:
 	path->uptodate = BTREE_ITER_UPTODATE;
 
-	if (!ck->valid && !(flags & BTREE_ITER_CACHED_NOFILL)) {
-		/*
-		 * Using the underscore version because we haven't set
-		 * path->uptodate yet:
-		 */
-		if (!path->locks_want &&
-		    !__bch2_btree_path_upgrade(trans, path, 1, NULL)) {
-			trace_and_count(trans->c, trans_restart_key_cache_upgrade, trans, _THIS_IP_);
-			ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_key_cache_upgrade);
-			goto err;
-		}
-
-		ret = btree_key_cache_fill(trans, path, ck);
-		if (ret)
-			goto err;
-
-		ret = bch2_btree_path_relock(trans, path, _THIS_IP_);
+	if (!ck->valid && !(flags & BTREE_ITER_cached_nofill)) {
+		ret =   bch2_btree_path_upgrade(trans, path, 1) ?:
+			btree_key_cache_fill(trans, path, ck) ?:
+			bch2_btree_path_relock(trans, path, _THIS_IP_);
 		if (ret)
 			goto err;
 
@@ -622,13 +609,13 @@ static int btree_key_cache_flush_pos(struct btree_trans *trans,
 	int ret;
 
 	bch2_trans_iter_init(trans, &b_iter, key.btree_id, key.pos,
-			     BTREE_ITER_SLOTS|
-			     BTREE_ITER_INTENT|
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_slots|
+			     BTREE_ITER_intent|
+			     BTREE_ITER_all_snapshots);
 	bch2_trans_iter_init(trans, &c_iter, key.btree_id, key.pos,
-			     BTREE_ITER_CACHED|
-			     BTREE_ITER_INTENT);
-	b_iter.flags &= ~BTREE_ITER_WITH_KEY_CACHE;
+			     BTREE_ITER_cached|
+			     BTREE_ITER_intent);
+	b_iter.flags &= ~BTREE_ITER_with_key_cache;
 
 	ret = bch2_btree_iter_traverse(&c_iter);
 	if (ret)
@@ -661,14 +648,14 @@ static int btree_key_cache_flush_pos(struct btree_trans *trans,
 		commit_flags |= BCH_WATERMARK_reclaim;
 
 	if (ck->journal.seq != journal_last_seq(j) ||
-	    !test_bit(JOURNAL_SPACE_LOW, &c->journal.flags))
+	    !test_bit(JOURNAL_space_low, &c->journal.flags))
 		commit_flags |= BCH_TRANS_COMMIT_no_journal_res;
 
 	ret   = bch2_btree_iter_traverse(&b_iter) ?:
 		bch2_trans_update(trans, &b_iter, ck->k,
-				  BTREE_UPDATE_KEY_CACHE_RECLAIM|
-				  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
-				  BTREE_TRIGGER_NORUN) ?:
+				  BTREE_UPDATE_key_cache_reclaim|
+				  BTREE_UPDATE_internal_snapshot_node|
+				  BTREE_TRIGGER_norun) ?:
 		bch2_trans_commit(trans, NULL, NULL,
 				  BCH_TRANS_COMMIT_no_check_rw|
 				  BCH_TRANS_COMMIT_no_enospc|
@@ -790,7 +777,7 @@ bool bch2_btree_insert_key_cached(struct btree_trans *trans,
 	 * flushing. The flush callback will not proceed unless ->seq matches
 	 * the latest pin, so make sure it starts with a consistent value.
 	 */
-	if (!(insert_entry->flags & BTREE_UPDATE_NOJOURNAL) ||
+	if (!(insert_entry->flags & BTREE_UPDATE_nojournal) ||
 	    !journal_pin_active(&ck->journal)) {
 		ck->seq = trans->journal_res.seq;
 	}
@@ -835,6 +822,8 @@ static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
 	int srcu_idx;
 
 	mutex_lock(&bc->lock);
+	bc->requested_to_free += sc->nr_to_scan;
+
 	srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
 	flags = memalloc_nofs_save();
 
@@ -853,6 +842,7 @@ static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
 		atomic_long_dec(&bc->nr_freed);
 		freed++;
 		bc->nr_freed_nonpcpu--;
+		bc->freed++;
 	}
 
 	list_for_each_entry_safe(ck, t, &bc->freed_pcpu, list) {
@@ -866,6 +856,7 @@ static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
 		atomic_long_dec(&bc->nr_freed);
 		freed++;
 		bc->nr_freed_pcpu--;
+		bc->freed++;
 	}
 
 	rcu_read_lock();
@@ -884,13 +875,18 @@ static unsigned long bch2_btree_key_cache_scan(struct shrinker *shrink,
 			ck = container_of(pos, struct bkey_cached, hash);
 
 			if (test_bit(BKEY_CACHED_DIRTY, &ck->flags)) {
+				bc->skipped_dirty++;
 				goto next;
 			} else if (test_bit(BKEY_CACHED_ACCESSED, &ck->flags)) {
 				clear_bit(BKEY_CACHED_ACCESSED, &ck->flags);
+				bc->skipped_accessed++;
 				goto next;
 			} else if (bkey_cached_lock_for_evict(ck)) {
 				bkey_cached_evict(bc, ck);
 				bkey_cached_free(bc, ck);
+				bc->moved_to_freelist++;
+			} else {
+				bc->skipped_lock_fail++;
 			}
 
 			scanned++;
@@ -1037,14 +1033,47 @@ int bch2_fs_btree_key_cache_init(struct btree_key_cache *bc)
 	return 0;
 }
 
-void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *c)
+void bch2_btree_key_cache_to_text(struct printbuf *out, struct btree_key_cache *bc)
 {
-	prt_printf(out, "nr_freed:\t%lu",	atomic_long_read(&c->nr_freed));
-	prt_newline(out);
-	prt_printf(out, "nr_keys:\t%lu",	atomic_long_read(&c->nr_keys));
-	prt_newline(out);
-	prt_printf(out, "nr_dirty:\t%lu",	atomic_long_read(&c->nr_dirty));
-	prt_newline(out);
+	struct bch_fs *c = container_of(bc, struct bch_fs, btree_key_cache);
+
+	printbuf_tabstop_push(out, 24);
+	printbuf_tabstop_push(out, 12);
+
+	unsigned flags = memalloc_nofs_save();
+	mutex_lock(&bc->lock);
+	prt_printf(out, "keys:\t%lu\r\n",		atomic_long_read(&bc->nr_keys));
+	prt_printf(out, "dirty:\t%lu\r\n",		atomic_long_read(&bc->nr_dirty));
+	prt_printf(out, "freelist:\t%lu\r\n",		atomic_long_read(&bc->nr_freed));
+	prt_printf(out, "nonpcpu freelist:\t%zu\r\n",	bc->nr_freed_nonpcpu);
+	prt_printf(out, "pcpu freelist:\t%zu\r\n",	bc->nr_freed_pcpu);
+
+	prt_printf(out, "\nshrinker:\n");
+	prt_printf(out, "requested_to_free:\t%lu\r\n",	bc->requested_to_free);
+	prt_printf(out, "freed:\t%lu\r\n",		bc->freed);
+	prt_printf(out, "moved_to_freelist:\t%lu\r\n",	bc->moved_to_freelist);
+	prt_printf(out, "skipped_dirty:\t%lu\r\n",	bc->skipped_dirty);
+	prt_printf(out, "skipped_accessed:\t%lu\r\n",	bc->skipped_accessed);
+	prt_printf(out, "skipped_lock_fail:\t%lu\r\n",	bc->skipped_lock_fail);
+
+	prt_printf(out, "srcu seq:\t%lu\r\n",		get_state_synchronize_srcu(&c->btree_trans_barrier));
+
+	struct bkey_cached *ck;
+	unsigned iter = 0;
+	list_for_each_entry(ck, &bc->freed_nonpcpu, list) {
+		prt_printf(out, "freed_nonpcpu:\t%lu\r\n", ck->btree_trans_barrier_seq);
+		if (++iter > 10)
+			break;
+	}
+
+	iter = 0;
+	list_for_each_entry(ck, &bc->freed_pcpu, list) {
+		prt_printf(out, "freed_pcpu:\t%lu\r\n", ck->btree_trans_barrier_seq);
+		if (++iter > 10)
+			break;
+	}
+	mutex_unlock(&bc->lock);
+	memalloc_flags_restore(flags);
 }
 
 void bch2_btree_key_cache_exit(void)
diff --git a/fs/bcachefs/btree_key_cache_types.h b/fs/bcachefs/btree_key_cache_types.h
index 290e4e57df5b..237e8bb3ac40 100644
--- a/fs/bcachefs/btree_key_cache_types.h
+++ b/fs/bcachefs/btree_key_cache_types.h
@@ -24,6 +24,14 @@ struct btree_key_cache {
 	atomic_long_t		nr_freed;
 	atomic_long_t		nr_keys;
 	atomic_long_t		nr_dirty;
+
+	/* shrinker stats */
+	unsigned long		requested_to_free;
+	unsigned long		freed;
+	unsigned long		moved_to_freelist;
+	unsigned long		skipped_dirty;
+	unsigned long		skipped_accessed;
+	unsigned long		skipped_lock_fail;
 };
 
 struct bkey_cached_key {
diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c
index f2caf491957e..c3e9b0cc7bbd 100644
--- a/fs/bcachefs/btree_locking.c
+++ b/fs/bcachefs/btree_locking.c
@@ -83,8 +83,7 @@ static noinline void print_cycle(struct printbuf *out, struct lock_graph *g)
 {
 	struct trans_waiting_for_lock *i;
 
-	prt_printf(out, "Found lock cycle (%u entries):", g->nr);
-	prt_newline(out);
+	prt_printf(out, "Found lock cycle (%u entries):\n", g->nr);
 
 	for (i = g->g; i < g->g + g->nr; i++) {
 		struct task_struct *task = READ_ONCE(i->trans->locking_wait.task);
@@ -224,8 +223,7 @@ static noinline int break_cycle(struct lock_graph *g, struct printbuf *cycle)
 
 			bch2_btree_trans_to_text(&buf, trans);
 
-			prt_printf(&buf, "backtrace:");
-			prt_newline(&buf);
+			prt_printf(&buf, "backtrace:\n");
 			printbuf_indent_add(&buf, 2);
 			bch2_prt_task_backtrace(&buf, trans->locking_wait.task, 2, GFP_NOWAIT);
 			printbuf_indent_sub(&buf, 2);
@@ -492,8 +490,6 @@ static inline bool btree_path_get_locks(struct btree_trans *trans,
 	if (path->uptodate == BTREE_ITER_NEED_RELOCK)
 		path->uptodate = BTREE_ITER_UPTODATE;
 
-	bch2_trans_verify_locks(trans);
-
 	return path->uptodate < BTREE_ITER_NEED_RELOCK;
 }
 
@@ -609,7 +605,9 @@ bool bch2_btree_path_relock_norestart(struct btree_trans *trans, struct btree_pa
 {
 	struct get_locks_fail f;
 
-	return btree_path_get_locks(trans, path, false, &f);
+	bool ret = btree_path_get_locks(trans, path, false, &f);
+	bch2_trans_verify_locks(trans);
+	return ret;
 }
 
 int __bch2_btree_path_relock(struct btree_trans *trans,
@@ -632,7 +630,9 @@ bool bch2_btree_path_upgrade_noupgrade_sibs(struct btree_trans *trans,
 
 	path->locks_want = new_locks_want;
 
-	return btree_path_get_locks(trans, path, true, f);
+	bool ret = btree_path_get_locks(trans, path, true, f);
+	bch2_trans_verify_locks(trans);
+	return ret;
 }
 
 bool __bch2_btree_path_upgrade(struct btree_trans *trans,
@@ -640,8 +640,9 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
 			       unsigned new_locks_want,
 			       struct get_locks_fail *f)
 {
-	if (bch2_btree_path_upgrade_noupgrade_sibs(trans, path, new_locks_want, f))
-		return true;
+	bool ret = bch2_btree_path_upgrade_noupgrade_sibs(trans, path, new_locks_want, f);
+	if (ret)
+		goto out;
 
 	/*
 	 * XXX: this is ugly - we'd prefer to not be mucking with other
@@ -675,8 +676,9 @@ bool __bch2_btree_path_upgrade(struct btree_trans *trans,
 				btree_path_get_locks(trans, linked, true, NULL);
 			}
 	}
-
-	return false;
+out:
+	bch2_trans_verify_locks(trans);
+	return ret;
 }
 
 void __bch2_btree_path_downgrade(struct btree_trans *trans,
@@ -725,82 +727,100 @@ void bch2_trans_downgrade(struct btree_trans *trans)
 			bch2_btree_path_downgrade(trans, path);
 }
 
-int bch2_trans_relock(struct btree_trans *trans)
+static inline void __bch2_trans_unlock(struct btree_trans *trans)
 {
 	struct btree_path *path;
 	unsigned i;
 
-	if (unlikely(trans->restarted))
-		return -((int) trans->restarted);
+	trans_for_each_path(trans, path, i)
+		__bch2_btree_path_unlock(trans, path);
+}
 
-	trans_for_each_path(trans, path, i) {
-		struct get_locks_fail f;
+static noinline __cold int bch2_trans_relock_fail(struct btree_trans *trans, struct btree_path *path,
+						  struct get_locks_fail *f, bool trace)
+{
+	if (!trace)
+		goto out;
 
-		if (path->should_be_locked &&
-		    !btree_path_get_locks(trans, path, false, &f)) {
-			if (trace_trans_restart_relock_enabled()) {
-				struct printbuf buf = PRINTBUF;
-
-				bch2_bpos_to_text(&buf, path->pos);
-				prt_printf(&buf, " l=%u seq=%u node seq=",
-					   f.l, path->l[f.l].lock_seq);
-				if (IS_ERR_OR_NULL(f.b)) {
-					prt_str(&buf, bch2_err_str(PTR_ERR(f.b)));
-				} else {
-					prt_printf(&buf, "%u", f.b->c.lock.seq);
-
-					struct six_lock_count c =
-						bch2_btree_node_lock_counts(trans, NULL, &f.b->c, f.l);
-					prt_printf(&buf, " self locked %u.%u.%u", c.n[0], c.n[1], c.n[2]);
-
-					c = six_lock_counts(&f.b->c.lock);
-					prt_printf(&buf, " total locked %u.%u.%u", c.n[0], c.n[1], c.n[2]);
-				}
+	if (trace_trans_restart_relock_enabled()) {
+		struct printbuf buf = PRINTBUF;
 
-				trace_trans_restart_relock(trans, _RET_IP_, buf.buf);
-				printbuf_exit(&buf);
-			}
+		bch2_bpos_to_text(&buf, path->pos);
+		prt_printf(&buf, " l=%u seq=%u node seq=", f->l, path->l[f->l].lock_seq);
+		if (IS_ERR_OR_NULL(f->b)) {
+			prt_str(&buf, bch2_err_str(PTR_ERR(f->b)));
+		} else {
+			prt_printf(&buf, "%u", f->b->c.lock.seq);
 
-			count_event(trans->c, trans_restart_relock);
-			return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
+			struct six_lock_count c =
+				bch2_btree_node_lock_counts(trans, NULL, &f->b->c, f->l);
+			prt_printf(&buf, " self locked %u.%u.%u", c.n[0], c.n[1], c.n[2]);
+
+			c = six_lock_counts(&f->b->c.lock);
+			prt_printf(&buf, " total locked %u.%u.%u", c.n[0], c.n[1], c.n[2]);
 		}
+
+		trace_trans_restart_relock(trans, _RET_IP_, buf.buf);
+		printbuf_exit(&buf);
 	}
 
-	return 0;
+	count_event(trans->c, trans_restart_relock);
+out:
+	__bch2_trans_unlock(trans);
+	bch2_trans_verify_locks(trans);
+	return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
 }
 
-int bch2_trans_relock_notrace(struct btree_trans *trans)
+static inline int __bch2_trans_relock(struct btree_trans *trans, bool trace)
 {
-	struct btree_path *path;
-	unsigned i;
+	bch2_trans_verify_locks(trans);
 
 	if (unlikely(trans->restarted))
 		return -((int) trans->restarted);
+	if (unlikely(trans->locked))
+		goto out;
+
+	struct btree_path *path;
+	unsigned i;
+
+	trans_for_each_path(trans, path, i) {
+		struct get_locks_fail f;
 
-	trans_for_each_path(trans, path, i)
 		if (path->should_be_locked &&
-		    !bch2_btree_path_relock_norestart(trans, path)) {
-			return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
-		}
+		    !btree_path_get_locks(trans, path, false, &f))
+			return bch2_trans_relock_fail(trans, path, &f, trace);
+	}
+
+	trans->locked = true;
+out:
+	bch2_trans_verify_locks(trans);
 	return 0;
 }
 
+int bch2_trans_relock(struct btree_trans *trans)
+{
+	return __bch2_trans_relock(trans, true);
+}
+
+int bch2_trans_relock_notrace(struct btree_trans *trans)
+{
+	return __bch2_trans_relock(trans, false);
+}
+
 void bch2_trans_unlock_noassert(struct btree_trans *trans)
 {
-	struct btree_path *path;
-	unsigned i;
+	__bch2_trans_unlock(trans);
 
-	trans_for_each_path(trans, path, i)
-		__bch2_btree_path_unlock(trans, path);
+	trans->locked = false;
+	trans->last_unlock_ip = _RET_IP_;
 }
 
 void bch2_trans_unlock(struct btree_trans *trans)
 {
-	struct btree_path *path;
-	unsigned i;
+	__bch2_trans_unlock(trans);
 
-	trans_for_each_path(trans, path, i)
-		__bch2_btree_path_unlock(trans, path);
+	trans->locked = false;
+	trans->last_unlock_ip = _RET_IP_;
 }
 
 void bch2_trans_unlock_long(struct btree_trans *trans)
@@ -809,17 +829,6 @@ void bch2_trans_unlock_long(struct btree_trans *trans)
 	bch2_trans_srcu_unlock(trans);
 }
 
-bool bch2_trans_locked(struct btree_trans *trans)
-{
-	struct btree_path *path;
-	unsigned i;
-
-	trans_for_each_path(trans, path, i)
-		if (path->nodes_locked)
-			return true;
-	return false;
-}
-
 int __bch2_trans_mutex_lock(struct btree_trans *trans,
 			    struct mutex *lock)
 {
@@ -836,15 +845,19 @@ int __bch2_trans_mutex_lock(struct btree_trans *trans,
 
 void bch2_btree_path_verify_locks(struct btree_path *path)
 {
-	unsigned l;
+	/*
+	 * A path may be uptodate and yet have nothing locked if and only if
+	 * there is no node at path->level, which generally means we were
+	 * iterating over all nodes and got to the end of the btree
+	 */
+	BUG_ON(path->uptodate == BTREE_ITER_UPTODATE &&
+	       btree_path_node(path, path->level) &&
+	       !path->nodes_locked);
 
-	if (!path->nodes_locked) {
-		BUG_ON(path->uptodate == BTREE_ITER_UPTODATE &&
-		       btree_path_node(path, path->level));
+	if (!path->nodes_locked)
 		return;
-	}
 
-	for (l = 0; l < BTREE_MAX_DEPTH; l++) {
+	for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) {
 		int want = btree_lock_want(path, l);
 		int have = btree_node_locked_type(path, l);
 
@@ -857,8 +870,24 @@ void bch2_btree_path_verify_locks(struct btree_path *path)
 	}
 }
 
+static bool bch2_trans_locked(struct btree_trans *trans)
+{
+	struct btree_path *path;
+	unsigned i;
+
+	trans_for_each_path(trans, path, i)
+		if (path->nodes_locked)
+			return true;
+	return false;
+}
+
 void bch2_trans_verify_locks(struct btree_trans *trans)
 {
+	if (!trans->locked) {
+		BUG_ON(bch2_trans_locked(trans));
+		return;
+	}
+
 	struct btree_path *path;
 	unsigned i;
 
diff --git a/fs/bcachefs/btree_locking.h b/fs/bcachefs/btree_locking.h
index 4bd72c855da1..7f41545b9147 100644
--- a/fs/bcachefs/btree_locking.h
+++ b/fs/bcachefs/btree_locking.h
@@ -364,14 +364,14 @@ static inline int bch2_btree_path_upgrade(struct btree_trans *trans,
 					  struct btree_path *path,
 					  unsigned new_locks_want)
 {
-	struct get_locks_fail f;
+	struct get_locks_fail f = {};
 	unsigned old_locks_want = path->locks_want;
 
 	new_locks_want = min(new_locks_want, BTREE_MAX_DEPTH);
 
 	if (path->locks_want < new_locks_want
 	    ? __bch2_btree_path_upgrade(trans, path, new_locks_want, &f)
-	    : path->uptodate == BTREE_ITER_UPTODATE)
+	    : path->nodes_locked)
 		return 0;
 
 	trace_and_count(trans->c, trans_restart_upgrade, trans, _THIS_IP_, path,
diff --git a/fs/bcachefs/btree_trans_commit.c b/fs/bcachefs/btree_trans_commit.c
index bbec91e8e650..74e1ff225674 100644
--- a/fs/bcachefs/btree_trans_commit.c
+++ b/fs/bcachefs/btree_trans_commit.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include "bcachefs.h"
+#include "alloc_foreground.h"
 #include "btree_gc.h"
 #include "btree_io.h"
 #include "btree_iter.h"
@@ -19,6 +20,26 @@
 
 #include <linux/prefetch.h>
 
+static const char * const trans_commit_flags_strs[] = {
+#define x(n, ...) #n,
+	BCH_TRANS_COMMIT_FLAGS()
+#undef x
+	NULL
+};
+
+void bch2_trans_commit_flags_to_text(struct printbuf *out, enum bch_trans_commit_flags flags)
+{
+	enum bch_watermark watermark = flags & BCH_WATERMARK_MASK;
+
+	prt_printf(out, "watermark=%s", bch2_watermarks[watermark]);
+
+	flags >>= BCH_WATERMARK_BITS;
+	if (flags) {
+		prt_char(out, ' ');
+		bch2_prt_bitflags(out, trans_commit_flags_strs, flags);
+	}
+}
+
 static void verify_update_old_key(struct btree_trans *trans, struct btree_insert_entry *i)
 {
 #ifdef CONFIG_BCACHEFS_DEBUG
@@ -315,8 +336,8 @@ static inline void btree_insert_entry_checks(struct btree_trans *trans,
 	BUG_ON(i->btree_id	!= path->btree_id);
 	EBUG_ON(!i->level &&
 		btree_type_has_snapshots(i->btree_id) &&
-		!(i->flags & BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) &&
-		test_bit(JOURNAL_REPLAY_DONE, &trans->c->journal.flags) &&
+		!(i->flags & BTREE_UPDATE_internal_snapshot_node) &&
+		test_bit(JOURNAL_replay_done, &trans->c->journal.flags) &&
 		i->k->k.p.snapshot &&
 		bch2_snapshot_is_internal_node(trans->c, i->k->k.p.snapshot) > 0);
 }
@@ -443,13 +464,13 @@ static int run_one_mem_trigger(struct btree_trans *trans,
 
 	verify_update_old_key(trans, i);
 
-	if (unlikely(flags & BTREE_TRIGGER_NORUN))
+	if (unlikely(flags & BTREE_TRIGGER_norun))
 		return 0;
 
 	if (old_ops->trigger == new_ops->trigger) {
 		ret   = bch2_key_trigger(trans, i->btree_id, i->level,
 				old, bkey_i_to_s(new),
-				BTREE_TRIGGER_INSERT|BTREE_TRIGGER_OVERWRITE|flags);
+				BTREE_TRIGGER_insert|BTREE_TRIGGER_overwrite|flags);
 	} else {
 		ret   = bch2_key_trigger_new(trans, i->btree_id, i->level,
 				bkey_i_to_s(new), flags) ?:
@@ -472,11 +493,11 @@ static int run_one_trans_trigger(struct btree_trans *trans, struct btree_insert_
 	struct bkey_s_c old = { &old_k, i->old_v };
 	const struct bkey_ops *old_ops = bch2_bkey_type_ops(old.k->type);
 	const struct bkey_ops *new_ops = bch2_bkey_type_ops(i->k->k.type);
-	unsigned flags = i->flags|BTREE_TRIGGER_TRANSACTIONAL;
+	unsigned flags = i->flags|BTREE_TRIGGER_transactional;
 
 	verify_update_old_key(trans, i);
 
-	if ((i->flags & BTREE_TRIGGER_NORUN) ||
+	if ((i->flags & BTREE_TRIGGER_norun) ||
 	    !(BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS & (1U << i->bkey_type)))
 		return 0;
 
@@ -486,8 +507,8 @@ static int run_one_trans_trigger(struct btree_trans *trans, struct btree_insert_
 		i->overwrite_trigger_run = true;
 		i->insert_trigger_run = true;
 		return bch2_key_trigger(trans, i->btree_id, i->level, old, bkey_i_to_s(i->k),
-					BTREE_TRIGGER_INSERT|
-					BTREE_TRIGGER_OVERWRITE|flags) ?: 1;
+					BTREE_TRIGGER_insert|
+					BTREE_TRIGGER_overwrite|flags) ?: 1;
 	} else if (overwrite && !i->overwrite_trigger_run) {
 		i->overwrite_trigger_run = true;
 		return bch2_key_trigger_old(trans, i->btree_id, i->level, old, flags) ?: 1;
@@ -572,7 +593,7 @@ static int bch2_trans_commit_run_triggers(struct btree_trans *trans)
 
 #ifdef CONFIG_BCACHEFS_DEBUG
 	trans_for_each_update(trans, i)
-		BUG_ON(!(i->flags & BTREE_TRIGGER_NORUN) &&
+		BUG_ON(!(i->flags & BTREE_TRIGGER_norun) &&
 		       (BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS & (1U << i->bkey_type)) &&
 		       (!i->insert_trigger_run || !i->overwrite_trigger_run));
 #endif
@@ -590,7 +611,7 @@ static noinline int bch2_trans_commit_run_gc_triggers(struct btree_trans *trans)
 
 		if (btree_node_type_needs_gc(__btree_node_type(i->level, i->btree_id)) &&
 		    gc_visited(trans->c, gc_pos_btree_node(insert_l(trans, i)->b))) {
-			int ret = run_one_mem_trigger(trans, i, i->flags|BTREE_TRIGGER_GC);
+			int ret = run_one_mem_trigger(trans, i, i->flags|BTREE_TRIGGER_gc);
 			if (ret)
 				return ret;
 		}
@@ -609,6 +630,9 @@ bch2_trans_commit_write_locked(struct btree_trans *trans, unsigned flags,
 	unsigned u64s = 0;
 	int ret;
 
+	bch2_trans_verify_not_unlocked(trans);
+	bch2_trans_verify_not_in_restart(trans);
+
 	if (race_fault()) {
 		trace_and_count(c, trans_restart_fault_inject, trans, trace_ip);
 		return btree_trans_restart_nounlock(trans, BCH_ERR_transaction_restart_fault_inject);
@@ -686,7 +710,7 @@ bch2_trans_commit_write_locked(struct btree_trans *trans, unsigned flags,
 
 	trans_for_each_update(trans, i)
 		if (BTREE_NODE_TYPE_HAS_ATOMIC_TRIGGERS & (1U << i->bkey_type)) {
-			ret = run_one_mem_trigger(trans, i, BTREE_TRIGGER_ATOMIC|i->flags);
+			ret = run_one_mem_trigger(trans, i, BTREE_TRIGGER_atomic|i->flags);
 			if (ret)
 				goto fatal_err;
 		}
@@ -705,7 +729,7 @@ bch2_trans_commit_write_locked(struct btree_trans *trans, unsigned flags,
 			if (i->key_cache_already_flushed)
 				continue;
 
-			if (i->flags & BTREE_UPDATE_NOJOURNAL)
+			if (i->flags & BTREE_UPDATE_nojournal)
 				continue;
 
 			verify_update_old_key(trans, i);
@@ -766,16 +790,15 @@ static noinline void bch2_drop_overwrites_from_journal(struct btree_trans *trans
 }
 
 static noinline int bch2_trans_commit_bkey_invalid(struct btree_trans *trans,
-						   enum bkey_invalid_flags flags,
+						   enum bch_validate_flags flags,
 						   struct btree_insert_entry *i,
 						   struct printbuf *err)
 {
 	struct bch_fs *c = trans->c;
 
 	printbuf_reset(err);
-	prt_printf(err, "invalid bkey on insert from %s -> %ps",
+	prt_printf(err, "invalid bkey on insert from %s -> %ps\n",
 		   trans->fn, (void *) i->ip_allocated);
-	prt_newline(err);
 	printbuf_indent_add(err, 2);
 
 	bch2_bkey_val_to_text(err, c, bkey_i_to_s_c(i->k));
@@ -796,8 +819,7 @@ static noinline int bch2_trans_commit_journal_entry_invalid(struct btree_trans *
 	struct bch_fs *c = trans->c;
 	struct printbuf buf = PRINTBUF;
 
-	prt_printf(&buf, "invalid bkey on insert from %s", trans->fn);
-	prt_newline(&buf);
+	prt_printf(&buf, "invalid bkey on insert from %s\n", trans->fn);
 	printbuf_indent_add(&buf, 2);
 
 	bch2_journal_entry_to_text(&buf, c, i);
@@ -988,6 +1010,9 @@ int __bch2_trans_commit(struct btree_trans *trans, unsigned flags)
 	struct bch_fs *c = trans->c;
 	int ret = 0;
 
+	bch2_trans_verify_not_unlocked(trans);
+	bch2_trans_verify_not_in_restart(trans);
+
 	if (!trans->nr_updates &&
 	    !trans->journal_entries_u64s)
 		goto out_reset;
@@ -1000,10 +1025,10 @@ int __bch2_trans_commit(struct btree_trans *trans, unsigned flags)
 
 	trans_for_each_update(trans, i) {
 		struct printbuf buf = PRINTBUF;
-		enum bkey_invalid_flags invalid_flags = 0;
+		enum bch_validate_flags invalid_flags = 0;
 
 		if (!(flags & BCH_TRANS_COMMIT_no_journal_res))
-			invalid_flags |= BKEY_INVALID_WRITE|BKEY_INVALID_COMMIT;
+			invalid_flags |= BCH_VALIDATE_write|BCH_VALIDATE_commit;
 
 		if (unlikely(bch2_bkey_invalid(c, bkey_i_to_s_c(i->k),
 					       i->bkey_type, invalid_flags, &buf)))
@@ -1018,10 +1043,10 @@ int __bch2_trans_commit(struct btree_trans *trans, unsigned flags)
 	for (struct jset_entry *i = trans->journal_entries;
 	     i != (void *) ((u64 *) trans->journal_entries + trans->journal_entries_u64s);
 	     i = vstruct_next(i)) {
-		enum bkey_invalid_flags invalid_flags = 0;
+		enum bch_validate_flags invalid_flags = 0;
 
 		if (!(flags & BCH_TRANS_COMMIT_no_journal_res))
-			invalid_flags |= BKEY_INVALID_WRITE|BKEY_INVALID_COMMIT;
+			invalid_flags |= BCH_VALIDATE_write|BCH_VALIDATE_commit;
 
 		if (unlikely(bch2_journal_entry_validate(c, NULL, i,
 					bcachefs_metadata_version_current,
@@ -1065,7 +1090,7 @@ int __bch2_trans_commit(struct btree_trans *trans, unsigned flags)
 		if (i->key_cache_already_flushed)
 			continue;
 
-		if (i->flags & BTREE_UPDATE_NOJOURNAL)
+		if (i->flags & BTREE_UPDATE_nojournal)
 			continue;
 
 		/* we're going to journal the key being updated: */
@@ -1086,6 +1111,7 @@ int __bch2_trans_commit(struct btree_trans *trans, unsigned flags)
 	}
 retry:
 	errored_at = NULL;
+	bch2_trans_verify_not_unlocked(trans);
 	bch2_trans_verify_not_in_restart(trans);
 	if (likely(!(flags & BCH_TRANS_COMMIT_no_journal_res)))
 		memset(&trans->journal_res, 0, sizeof(trans->journal_res));
diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h
index c69b233c41bb..d63db4fefe73 100644
--- a/fs/bcachefs/btree_types.h
+++ b/fs/bcachefs/btree_types.h
@@ -163,9 +163,21 @@ struct btree_cache {
 	/* Number of elements in live + freeable lists */
 	unsigned		used;
 	unsigned		reserve;
+	unsigned		freed;
+	unsigned		not_freed_lock_intent;
+	unsigned		not_freed_lock_write;
+	unsigned		not_freed_dirty;
+	unsigned		not_freed_read_in_flight;
+	unsigned		not_freed_write_in_flight;
+	unsigned		not_freed_noevict;
+	unsigned		not_freed_write_blocked;
+	unsigned		not_freed_will_make_reachable;
+	unsigned		not_freed_access_bit;
 	atomic_t		dirty;
 	struct shrinker		*shrink;
 
+	unsigned		used_by_btree[BTREE_ID_NR];
+
 	/*
 	 * If we need to allocate memory for a new btree node and that
 	 * allocation fails, we can cannibalize another node in the btree cache
@@ -187,36 +199,89 @@ struct btree_node_iter {
 	} data[MAX_BSETS];
 };
 
+#define BTREE_ITER_FLAGS()			\
+	x(slots)				\
+	x(intent)				\
+	x(prefetch)				\
+	x(is_extents)				\
+	x(not_extents)				\
+	x(cached)				\
+	x(with_key_cache)			\
+	x(with_updates)				\
+	x(with_journal)				\
+	x(snapshot_field)			\
+	x(all_snapshots)			\
+	x(filter_snapshots)			\
+	x(nopreserve)				\
+	x(cached_nofill)			\
+	x(key_cache_fill)			\
+
+#define STR_HASH_FLAGS()			\
+	x(must_create)				\
+	x(must_replace)
+
+#define BTREE_UPDATE_FLAGS()			\
+	x(internal_snapshot_node)		\
+	x(nojournal)				\
+	x(key_cache_reclaim)
+
+
 /*
- * Iterate over all possible positions, synthesizing deleted keys for holes:
- */
-static const __maybe_unused u16 BTREE_ITER_SLOTS		= 1 << 0;
-/*
- * Indicates that intent locks should be taken on leaf nodes, because we expect
- * to be doing updates:
- */
-static const __maybe_unused u16 BTREE_ITER_INTENT		= 1 << 1;
-/*
- * Causes the btree iterator code to prefetch additional btree nodes from disk:
- */
-static const __maybe_unused u16 BTREE_ITER_PREFETCH		= 1 << 2;
-/*
- * Used in bch2_btree_iter_traverse(), to indicate whether we're searching for
- * @pos or the first key strictly greater than @pos
+ * BTREE_TRIGGER_norun - don't run triggers at all
+ *
+ * BTREE_TRIGGER_transactional - we're running transactional triggers as part of
+ * a transaction commit: triggers may generate new updates
+ *
+ * BTREE_TRIGGER_atomic - we're running atomic triggers during a transaction
+ * commit: we have our journal reservation, we're holding btree node write
+ * locks, and we know the transaction is going to commit (returning an error
+ * here is a fatal error, causing us to go emergency read-only)
+ *
+ * BTREE_TRIGGER_gc - we're in gc/fsck: running triggers to recalculate e.g. disk usage
+ *
+ * BTREE_TRIGGER_insert - @new is entering the btree
+ * BTREE_TRIGGER_overwrite - @old is leaving the btree
+ *
+ * BTREE_TRIGGER_bucket_invalidate - signal from bucket invalidate path to alloc
+ * trigger
  */
-static const __maybe_unused u16 BTREE_ITER_IS_EXTENTS		= 1 << 3;
-static const __maybe_unused u16 BTREE_ITER_NOT_EXTENTS		= 1 << 4;
-static const __maybe_unused u16 BTREE_ITER_CACHED		= 1 << 5;
-static const __maybe_unused u16 BTREE_ITER_WITH_KEY_CACHE	= 1 << 6;
-static const __maybe_unused u16 BTREE_ITER_WITH_UPDATES		= 1 << 7;
-static const __maybe_unused u16 BTREE_ITER_WITH_JOURNAL		= 1 << 8;
-static const __maybe_unused u16 __BTREE_ITER_ALL_SNAPSHOTS	= 1 << 9;
-static const __maybe_unused u16 BTREE_ITER_ALL_SNAPSHOTS	= 1 << 10;
-static const __maybe_unused u16 BTREE_ITER_FILTER_SNAPSHOTS	= 1 << 11;
-static const __maybe_unused u16 BTREE_ITER_NOPRESERVE		= 1 << 12;
-static const __maybe_unused u16 BTREE_ITER_CACHED_NOFILL	= 1 << 13;
-static const __maybe_unused u16 BTREE_ITER_KEY_CACHE_FILL	= 1 << 14;
-#define __BTREE_ITER_FLAGS_END					       15
+#define BTREE_TRIGGER_FLAGS()			\
+	x(norun)				\
+	x(transactional)			\
+	x(atomic)				\
+	x(check_repair)				\
+	x(gc)					\
+	x(insert)				\
+	x(overwrite)				\
+	x(is_root)				\
+	x(bucket_invalidate)
+
+enum {
+#define x(n) BTREE_ITER_FLAG_BIT_##n,
+	BTREE_ITER_FLAGS()
+	STR_HASH_FLAGS()
+	BTREE_UPDATE_FLAGS()
+	BTREE_TRIGGER_FLAGS()
+#undef x
+};
+
+/* iter flags must fit in a u16: */
+//BUILD_BUG_ON(BTREE_ITER_FLAG_BIT_key_cache_fill > 15);
+
+enum btree_iter_update_trigger_flags {
+#define x(n) BTREE_ITER_##n	= 1U << BTREE_ITER_FLAG_BIT_##n,
+	BTREE_ITER_FLAGS()
+#undef x
+#define x(n) STR_HASH_##n	= 1U << BTREE_ITER_FLAG_BIT_##n,
+	STR_HASH_FLAGS()
+#undef x
+#define x(n) BTREE_UPDATE_##n	= 1U << BTREE_ITER_FLAG_BIT_##n,
+	BTREE_UPDATE_FLAGS()
+#undef x
+#define x(n) BTREE_TRIGGER_##n	= 1U << BTREE_ITER_FLAG_BIT_##n,
+	BTREE_TRIGGER_FLAGS()
+#undef x
+};
 
 enum btree_path_uptodate {
 	BTREE_ITER_UPTODATE		= 0,
@@ -307,7 +372,7 @@ struct btree_iter {
 	 */
 	struct bkey		k;
 
-	/* BTREE_ITER_WITH_JOURNAL: */
+	/* BTREE_ITER_with_journal: */
 	size_t			journal_idx;
 #ifdef TRACK_PATH_ALLOCATED
 	unsigned long		ip_allocated;
@@ -418,6 +483,8 @@ struct btree_trans {
 	u8			lock_must_abort;
 	bool			lock_may_not_fail:1;
 	bool			srcu_held:1;
+	bool			locked:1;
+	bool			write_locked:1;
 	bool			used_mempool:1;
 	bool			in_traverse_all:1;
 	bool			paths_sorted:1;
@@ -425,13 +492,13 @@ struct btree_trans {
 	bool			journal_transaction_names:1;
 	bool			journal_replay_not_finished:1;
 	bool			notrace_relock_fail:1;
-	bool			write_locked:1;
 	enum bch_errcode	restarted:16;
 	u32			restart_count;
 
 	u64			last_begin_time;
 	unsigned long		last_begin_ip;
 	unsigned long		last_restarted_ip;
+	unsigned long		last_unlock_ip;
 	unsigned long		srcu_lock_time;
 
 	const char		*fn;
diff --git a/fs/bcachefs/btree_update.c b/fs/bcachefs/btree_update.c
index 8e47e260eba5..f3c645a43dcb 100644
--- a/fs/bcachefs/btree_update.c
+++ b/fs/bcachefs/btree_update.c
@@ -25,14 +25,14 @@ static inline int btree_insert_entry_cmp(const struct btree_insert_entry *l,
 
 static int __must_check
 bch2_trans_update_by_path(struct btree_trans *, btree_path_idx_t,
-			  struct bkey_i *, enum btree_update_flags,
+			  struct bkey_i *, enum btree_iter_update_trigger_flags,
 			  unsigned long ip);
 
 static noinline int extent_front_merge(struct btree_trans *trans,
 				       struct btree_iter *iter,
 				       struct bkey_s_c k,
 				       struct bkey_i **insert,
-				       enum btree_update_flags flags)
+				       enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
 	struct bkey_i *update;
@@ -104,8 +104,8 @@ static int need_whiteout_for_snapshot(struct btree_trans *trans,
 	pos.snapshot++;
 
 	for_each_btree_key_norestart(trans, iter, btree_id, pos,
-			   BTREE_ITER_ALL_SNAPSHOTS|
-			   BTREE_ITER_NOPRESERVE, k, ret) {
+			   BTREE_ITER_all_snapshots|
+			   BTREE_ITER_nopreserve, k, ret) {
 		if (!bkey_eq(k.k->p, pos))
 			break;
 
@@ -138,8 +138,8 @@ int __bch2_insert_snapshot_whiteouts(struct btree_trans *trans,
 	darray_init(&s);
 
 	bch2_trans_iter_init(trans, &old_iter, id, old_pos,
-			     BTREE_ITER_NOT_EXTENTS|
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_not_extents|
+			     BTREE_ITER_all_snapshots);
 	while ((old_k = bch2_btree_iter_prev(&old_iter)).k &&
 	       !(ret = bkey_err(old_k)) &&
 	       bkey_eq(old_pos, old_k.k->p)) {
@@ -151,8 +151,8 @@ int __bch2_insert_snapshot_whiteouts(struct btree_trans *trans,
 			continue;
 
 		new_k = bch2_bkey_get_iter(trans, &new_iter, id, whiteout_pos,
-					   BTREE_ITER_NOT_EXTENTS|
-					   BTREE_ITER_INTENT);
+					   BTREE_ITER_not_extents|
+					   BTREE_ITER_intent);
 		ret = bkey_err(new_k);
 		if (ret)
 			break;
@@ -168,7 +168,7 @@ int __bch2_insert_snapshot_whiteouts(struct btree_trans *trans,
 			update->k.type		= KEY_TYPE_whiteout;
 
 			ret = bch2_trans_update(trans, &new_iter, update,
-						BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+						BTREE_UPDATE_internal_snapshot_node);
 		}
 		bch2_trans_iter_exit(trans, &new_iter);
 
@@ -185,7 +185,7 @@ int __bch2_insert_snapshot_whiteouts(struct btree_trans *trans,
 
 int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
 				       struct btree_iter *iter,
-				       enum btree_update_flags flags,
+				       enum btree_iter_update_trigger_flags flags,
 				       struct bkey_s_c old,
 				       struct bkey_s_c new)
 {
@@ -218,7 +218,7 @@ int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
 		ret =   bch2_insert_snapshot_whiteouts(trans, btree_id,
 					old.k->p, update->k.p) ?:
 			bch2_btree_insert_nonextent(trans, btree_id, update,
-					BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|flags);
+					BTREE_UPDATE_internal_snapshot_node|flags);
 		if (ret)
 			return ret;
 	}
@@ -235,7 +235,7 @@ int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
 		ret =   bch2_insert_snapshot_whiteouts(trans, btree_id,
 					old.k->p, update->k.p) ?:
 			bch2_btree_insert_nonextent(trans, btree_id, update,
-					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|flags);
+					  BTREE_UPDATE_internal_snapshot_node|flags);
 		if (ret)
 			return ret;
 	}
@@ -260,7 +260,7 @@ int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
 		}
 
 		ret = bch2_btree_insert_nonextent(trans, btree_id, update,
-					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|flags);
+					  BTREE_UPDATE_internal_snapshot_node|flags);
 		if (ret)
 			return ret;
 	}
@@ -273,7 +273,7 @@ int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
 		bch2_cut_front(new.k->p, update);
 
 		ret = bch2_trans_update_by_path(trans, iter->path, update,
-					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
+					  BTREE_UPDATE_internal_snapshot_node|
 					  flags, _RET_IP_);
 		if (ret)
 			return ret;
@@ -285,7 +285,7 @@ int bch2_trans_update_extent_overwrite(struct btree_trans *trans,
 static int bch2_trans_update_extent(struct btree_trans *trans,
 				    struct btree_iter *orig_iter,
 				    struct bkey_i *insert,
-				    enum btree_update_flags flags)
+				    enum btree_iter_update_trigger_flags flags)
 {
 	struct btree_iter iter;
 	struct bkey_s_c k;
@@ -293,9 +293,9 @@ static int bch2_trans_update_extent(struct btree_trans *trans,
 	int ret = 0;
 
 	bch2_trans_iter_init(trans, &iter, btree_id, bkey_start_pos(&insert->k),
-			     BTREE_ITER_INTENT|
-			     BTREE_ITER_WITH_UPDATES|
-			     BTREE_ITER_NOT_EXTENTS);
+			     BTREE_ITER_intent|
+			     BTREE_ITER_with_updates|
+			     BTREE_ITER_not_extents);
 	k = bch2_btree_iter_peek_upto(&iter, POS(insert->k.p.inode, U64_MAX));
 	if ((ret = bkey_err(k)))
 		goto err;
@@ -346,7 +346,7 @@ err:
 
 static noinline int flush_new_cached_update(struct btree_trans *trans,
 					    struct btree_insert_entry *i,
-					    enum btree_update_flags flags,
+					    enum btree_iter_update_trigger_flags flags,
 					    unsigned long ip)
 {
 	struct bkey k;
@@ -354,7 +354,7 @@ static noinline int flush_new_cached_update(struct btree_trans *trans,
 
 	btree_path_idx_t path_idx =
 		bch2_path_get(trans, i->btree_id, i->old_k.p, 1, 0,
-			      BTREE_ITER_INTENT, _THIS_IP_);
+			      BTREE_ITER_intent, _THIS_IP_);
 	ret = bch2_btree_path_traverse(trans, path_idx, 0);
 	if (ret)
 		goto out;
@@ -372,7 +372,7 @@ static noinline int flush_new_cached_update(struct btree_trans *trans,
 		goto out;
 
 	i->key_cache_already_flushed = true;
-	i->flags |= BTREE_TRIGGER_NORUN;
+	i->flags |= BTREE_TRIGGER_norun;
 
 	btree_path_set_should_be_locked(btree_path);
 	ret = bch2_trans_update_by_path(trans, path_idx, i->k, flags, ip);
@@ -383,7 +383,7 @@ out:
 
 static int __must_check
 bch2_trans_update_by_path(struct btree_trans *trans, btree_path_idx_t path_idx,
-			  struct bkey_i *k, enum btree_update_flags flags,
+			  struct bkey_i *k, enum btree_iter_update_trigger_flags flags,
 			  unsigned long ip)
 {
 	struct bch_fs *c = trans->c;
@@ -479,15 +479,15 @@ static noinline int bch2_trans_update_get_key_cache(struct btree_trans *trans,
 		if (!iter->key_cache_path)
 			iter->key_cache_path =
 				bch2_path_get(trans, path->btree_id, path->pos, 1, 0,
-					      BTREE_ITER_INTENT|
-					      BTREE_ITER_CACHED, _THIS_IP_);
+					      BTREE_ITER_intent|
+					      BTREE_ITER_cached, _THIS_IP_);
 
 		iter->key_cache_path =
 			bch2_btree_path_set_pos(trans, iter->key_cache_path, path->pos,
-						iter->flags & BTREE_ITER_INTENT,
+						iter->flags & BTREE_ITER_intent,
 						_THIS_IP_);
 
-		ret = bch2_btree_path_traverse(trans, iter->key_cache_path, BTREE_ITER_CACHED);
+		ret = bch2_btree_path_traverse(trans, iter->key_cache_path, BTREE_ITER_cached);
 		if (unlikely(ret))
 			return ret;
 
@@ -505,17 +505,17 @@ static noinline int bch2_trans_update_get_key_cache(struct btree_trans *trans,
 }
 
 int __must_check bch2_trans_update(struct btree_trans *trans, struct btree_iter *iter,
-				   struct bkey_i *k, enum btree_update_flags flags)
+				   struct bkey_i *k, enum btree_iter_update_trigger_flags flags)
 {
 	btree_path_idx_t path_idx = iter->update_path ?: iter->path;
 	int ret;
 
-	if (iter->flags & BTREE_ITER_IS_EXTENTS)
+	if (iter->flags & BTREE_ITER_is_extents)
 		return bch2_trans_update_extent(trans, iter, k, flags);
 
 	if (bkey_deleted(&k->k) &&
-	    !(flags & BTREE_UPDATE_KEY_CACHE_RECLAIM) &&
-	    (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)) {
+	    !(flags & BTREE_UPDATE_key_cache_reclaim) &&
+	    (iter->flags & BTREE_ITER_filter_snapshots)) {
 		ret = need_whiteout_for_snapshot(trans, iter->btree_id, k->k.p);
 		if (unlikely(ret < 0))
 			return ret;
@@ -528,7 +528,7 @@ int __must_check bch2_trans_update(struct btree_trans *trans, struct btree_iter
 	 * Ensure that updates to cached btrees go to the key cache:
 	 */
 	struct btree_path *path = trans->paths + path_idx;
-	if (!(flags & BTREE_UPDATE_KEY_CACHE_RECLAIM) &&
+	if (!(flags & BTREE_UPDATE_key_cache_reclaim) &&
 	    !path->cached &&
 	    !path->level &&
 	    btree_id_cached(trans->c, path->btree_id)) {
@@ -587,7 +587,7 @@ int bch2_bkey_get_empty_slot(struct btree_trans *trans, struct btree_iter *iter,
 	struct bkey_s_c k;
 	int ret = 0;
 
-	bch2_trans_iter_init(trans, iter, btree, POS_MAX, BTREE_ITER_INTENT);
+	bch2_trans_iter_init(trans, iter, btree, POS_MAX, BTREE_ITER_intent);
 	k = bch2_btree_iter_prev(iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -621,15 +621,15 @@ void bch2_trans_commit_hook(struct btree_trans *trans,
 
 int bch2_btree_insert_nonextent(struct btree_trans *trans,
 				enum btree_id btree, struct bkey_i *k,
-				enum btree_update_flags flags)
+				enum btree_iter_update_trigger_flags flags)
 {
 	struct btree_iter iter;
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, btree, k->k.p,
-			     BTREE_ITER_CACHED|
-			     BTREE_ITER_NOT_EXTENTS|
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_cached|
+			     BTREE_ITER_not_extents|
+			     BTREE_ITER_intent);
 	ret   = bch2_btree_iter_traverse(&iter) ?:
 		bch2_trans_update(trans, &iter, k, flags);
 	bch2_trans_iter_exit(trans, &iter);
@@ -637,16 +637,13 @@ int bch2_btree_insert_nonextent(struct btree_trans *trans,
 }
 
 int bch2_btree_insert_trans(struct btree_trans *trans, enum btree_id id,
-			    struct bkey_i *k, enum btree_update_flags flags)
+			    struct bkey_i *k, enum btree_iter_update_trigger_flags flags)
 {
 	struct btree_iter iter;
-	int ret;
-
 	bch2_trans_iter_init(trans, &iter, id, bkey_start_pos(&k->k),
-			     BTREE_ITER_CACHED|
-			     BTREE_ITER_INTENT);
-	ret   = bch2_btree_iter_traverse(&iter) ?:
-		bch2_trans_update(trans, &iter, k, flags);
+			     BTREE_ITER_intent|flags);
+	int ret = bch2_btree_iter_traverse(&iter) ?:
+		  bch2_trans_update(trans, &iter, k, flags);
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }
@@ -698,8 +695,8 @@ int bch2_btree_delete(struct btree_trans *trans,
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, btree, pos,
-			     BTREE_ITER_CACHED|
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_cached|
+			     BTREE_ITER_intent);
 	ret   = bch2_btree_iter_traverse(&iter) ?:
 		bch2_btree_delete_at(trans, &iter, update_flags);
 	bch2_trans_iter_exit(trans, &iter);
@@ -717,7 +714,7 @@ int bch2_btree_delete_range_trans(struct btree_trans *trans, enum btree_id id,
 	struct bkey_s_c k;
 	int ret = 0;
 
-	bch2_trans_iter_init(trans, &iter, id, start, BTREE_ITER_INTENT);
+	bch2_trans_iter_init(trans, &iter, id, start, BTREE_ITER_intent);
 	while ((k = bch2_btree_iter_peek_upto(&iter, end)).k) {
 		struct disk_reservation disk_res =
 			bch2_disk_reservation_init(trans->c, 0);
@@ -745,7 +742,7 @@ int bch2_btree_delete_range_trans(struct btree_trans *trans, enum btree_id id,
 		 */
 		delete.k.p = iter.pos;
 
-		if (iter.flags & BTREE_ITER_IS_EXTENTS)
+		if (iter.flags & BTREE_ITER_is_extents)
 			bch2_key_resize(&delete.k,
 					bpos_min(end, k.k->p).offset -
 					iter.pos.offset);
@@ -804,7 +801,7 @@ int bch2_btree_bit_mod(struct btree_trans *trans, enum btree_id btree,
 	k->k.p = pos;
 
 	struct btree_iter iter;
-	bch2_trans_iter_init(trans, &iter, btree, pos, BTREE_ITER_INTENT);
+	bch2_trans_iter_init(trans, &iter, btree, pos, BTREE_ITER_intent);
 
 	ret   = bch2_btree_iter_traverse(&iter) ?:
 		bch2_trans_update(trans, &iter, k, 0);
@@ -852,7 +849,7 @@ __bch2_fs_log_msg(struct bch_fs *c, unsigned commit_flags, const char *fmt,
 	if (ret)
 		goto err;
 
-	if (!test_bit(JOURNAL_STARTED, &c->journal.flags)) {
+	if (!test_bit(JOURNAL_running, &c->journal.flags)) {
 		ret = darray_make_room(&c->journal.early_journal_entries, jset_u64s(u64s));
 		if (ret)
 			goto err;
diff --git a/fs/bcachefs/btree_update.h b/fs/bcachefs/btree_update.h
index cc7c53e83f89..b4894e4d5447 100644
--- a/fs/bcachefs/btree_update.h
+++ b/fs/bcachefs/btree_update.h
@@ -44,16 +44,18 @@ enum bch_trans_commit_flags {
 #undef x
 };
 
+void bch2_trans_commit_flags_to_text(struct printbuf *, enum bch_trans_commit_flags);
+
 int bch2_btree_delete_extent_at(struct btree_trans *, struct btree_iter *,
 				unsigned, unsigned);
 int bch2_btree_delete_at(struct btree_trans *, struct btree_iter *, unsigned);
 int bch2_btree_delete(struct btree_trans *, enum btree_id, struct bpos, unsigned);
 
 int bch2_btree_insert_nonextent(struct btree_trans *, enum btree_id,
-				struct bkey_i *, enum btree_update_flags);
+				struct bkey_i *, enum btree_iter_update_trigger_flags);
 
 int bch2_btree_insert_trans(struct btree_trans *, enum btree_id, struct bkey_i *,
-			enum btree_update_flags);
+			enum btree_iter_update_trigger_flags);
 int bch2_btree_insert(struct bch_fs *, enum btree_id, struct bkey_i *,
 		     struct disk_reservation *, int flags);
 
@@ -94,14 +96,14 @@ static inline int bch2_insert_snapshot_whiteouts(struct btree_trans *trans,
 }
 
 int bch2_trans_update_extent_overwrite(struct btree_trans *, struct btree_iter *,
-				       enum btree_update_flags,
+				       enum btree_iter_update_trigger_flags,
 				       struct bkey_s_c, struct bkey_s_c);
 
 int bch2_bkey_get_empty_slot(struct btree_trans *, struct btree_iter *,
 			     enum btree_id, struct bpos);
 
 int __must_check bch2_trans_update(struct btree_trans *, struct btree_iter *,
-				   struct bkey_i *, enum btree_update_flags);
+				   struct bkey_i *, enum btree_iter_update_trigger_flags);
 
 struct jset_entry *__bch2_trans_jset_entry_alloc(struct btree_trans *, unsigned);
 
@@ -276,7 +278,7 @@ static inline struct bkey_i *__bch2_bkey_get_mut_noupdate(struct btree_trans *tr
 					 unsigned flags, unsigned type, unsigned min_bytes)
 {
 	struct bkey_s_c k = __bch2_bkey_get_iter(trans, iter,
-				btree_id, pos, flags|BTREE_ITER_INTENT, type);
+				btree_id, pos, flags|BTREE_ITER_intent, type);
 	struct bkey_i *ret = IS_ERR(k.k)
 		? ERR_CAST(k.k)
 		: __bch2_bkey_make_mut_noupdate(trans, k, 0, min_bytes);
@@ -299,7 +301,7 @@ static inline struct bkey_i *__bch2_bkey_get_mut(struct btree_trans *trans,
 					 unsigned flags, unsigned type, unsigned min_bytes)
 {
 	struct bkey_i *mut = __bch2_bkey_get_mut_noupdate(trans, iter,
-				btree_id, pos, flags|BTREE_ITER_INTENT, type, min_bytes);
+				btree_id, pos, flags|BTREE_ITER_intent, type, min_bytes);
 	int ret;
 
 	if (IS_ERR(mut))
diff --git a/fs/bcachefs/btree_update_interior.c b/fs/bcachefs/btree_update_interior.c
index b4efd8cc4d1a..60b8544cea48 100644
--- a/fs/bcachefs/btree_update_interior.c
+++ b/fs/bcachefs/btree_update_interior.c
@@ -38,22 +38,6 @@ static int bch2_btree_insert_node(struct btree_update *, struct btree_trans *,
 				  btree_path_idx_t, struct btree *, struct keylist *);
 static void bch2_btree_update_add_new_node(struct btree_update *, struct btree *);
 
-static btree_path_idx_t get_unlocked_mut_path(struct btree_trans *trans,
-					      enum btree_id btree_id,
-					      unsigned level,
-					      struct bpos pos)
-{
-	btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level,
-			     BTREE_ITER_NOPRESERVE|
-			     BTREE_ITER_INTENT, _RET_IP_);
-	path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_);
-
-	struct btree_path *path = trans->paths + path_idx;
-	bch2_btree_path_downgrade(trans, path);
-	__bch2_btree_path_unlock(trans, path);
-	return path_idx;
-}
-
 /*
  * Verify that child nodes correctly span parent node's range:
  */
@@ -73,6 +57,24 @@ int bch2_btree_node_check_topology(struct btree_trans *trans, struct btree *b)
 	       !bpos_eq(bkey_i_to_btree_ptr_v2(&b->key)->v.min_key,
 			b->data->min_key));
 
+	if (b == btree_node_root(c, b)) {
+		if (!bpos_eq(b->data->min_key, POS_MIN)) {
+			printbuf_reset(&buf);
+			bch2_bpos_to_text(&buf, b->data->min_key);
+			need_fsck_err(c, btree_root_bad_min_key,
+				      "btree root with incorrect min_key: %s", buf.buf);
+			goto topology_repair;
+		}
+
+		if (!bpos_eq(b->data->max_key, SPOS_MAX)) {
+			printbuf_reset(&buf);
+			bch2_bpos_to_text(&buf, b->data->max_key);
+			need_fsck_err(c, btree_root_bad_max_key,
+				      "btree root with incorrect max_key: %s", buf.buf);
+			goto topology_repair;
+		}
+	}
+
 	if (!b->c.level)
 		return 0;
 
@@ -158,7 +160,6 @@ topology_repair:
 static void __bch2_btree_calc_format(struct bkey_format_state *s, struct btree *b)
 {
 	struct bkey_packed *k;
-	struct bset_tree *t;
 	struct bkey uk;
 
 	for_each_bset(b, t)
@@ -646,7 +647,7 @@ static int btree_update_nodes_written_trans(struct btree_trans *trans,
 		unsigned level = bkey_i_to_btree_ptr_v2(k)->v.mem_ptr;
 
 		ret = bch2_key_trigger_old(trans, as->btree_id, level, bkey_i_to_s_c(k),
-					   BTREE_TRIGGER_TRANSACTIONAL);
+					   BTREE_TRIGGER_transactional);
 		if (ret)
 			return ret;
 	}
@@ -655,7 +656,7 @@ static int btree_update_nodes_written_trans(struct btree_trans *trans,
 		unsigned level = bkey_i_to_btree_ptr_v2(k)->v.mem_ptr;
 
 		ret = bch2_key_trigger_new(trans, as->btree_id, level, bkey_i_to_s(k),
-					   BTREE_TRIGGER_TRANSACTIONAL);
+					   BTREE_TRIGGER_transactional);
 		if (ret)
 			return ret;
 	}
@@ -735,9 +736,6 @@ err:
 	 */
 	b = READ_ONCE(as->b);
 	if (b) {
-		btree_path_idx_t path_idx = get_unlocked_mut_path(trans,
-						as->btree_id, b->c.level, b->key.k.p);
-		struct btree_path *path = trans->paths + path_idx;
 		/*
 		 * @b is the node we did the final insert into:
 		 *
@@ -755,12 +753,16 @@ err:
 		 * btree_node_lock_nopath() (the use of which is always suspect,
 		 * we need to work on removing this in the future)
 		 *
-		 * It should be, but get_unlocked_mut_path() -> bch2_path_get()
+		 * It should be, but bch2_path_get_unlocked_mut() -> bch2_path_get()
 		 * calls bch2_path_upgrade(), before we call path_make_mut(), so
 		 * we may rarely end up with a locked path besides the one we
 		 * have here:
 		 */
 		bch2_trans_unlock(trans);
+		bch2_trans_begin(trans);
+		btree_path_idx_t path_idx = bch2_path_get_unlocked_mut(trans,
+						as->btree_id, b->c.level, b->key.k.p);
+		struct btree_path *path = trans->paths + path_idx;
 		btree_node_lock_nopath_nofail(trans, &b->c, SIX_LOCK_intent);
 		mark_btree_node_locked(trans, path, b->c.level, BTREE_NODE_INTENT_LOCKED);
 		path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock);
@@ -1154,13 +1156,12 @@ bch2_btree_update_start(struct btree_trans *trans, struct btree_path *path,
 	flags |= watermark;
 
 	if (watermark < BCH_WATERMARK_reclaim &&
-	    test_bit(JOURNAL_SPACE_LOW, &c->journal.flags)) {
+	    test_bit(JOURNAL_space_low, &c->journal.flags)) {
 		if (flags & BCH_TRANS_COMMIT_journal_reclaim)
 			return ERR_PTR(-BCH_ERR_journal_reclaim_would_deadlock);
 
-		bch2_trans_unlock(trans);
-		wait_event(c->journal.wait, !test_bit(JOURNAL_SPACE_LOW, &c->journal.flags));
-		ret = bch2_trans_relock(trans);
+		ret = drop_locks_do(trans,
+			({ wait_event(c->journal.wait, !test_bit(JOURNAL_space_low, &c->journal.flags)); 0; }));
 		if (ret)
 			return ERR_PTR(ret);
 	}
@@ -1206,7 +1207,7 @@ bch2_btree_update_start(struct btree_trans *trans, struct btree_path *path,
 	as->start_time		= start_time;
 	as->ip_started		= _RET_IP_;
 	as->mode		= BTREE_UPDATE_none;
-	as->watermark		= watermark;
+	as->flags		= flags;
 	as->took_gc_lock	= true;
 	as->btree_id		= path->btree_id;
 	as->update_level_start	= level_start;
@@ -1360,7 +1361,7 @@ static void bch2_insert_fixup_btree_ptr(struct btree_update *as,
 	BUG_ON(insert->k.type == KEY_TYPE_btree_ptr_v2 &&
 	       !btree_ptr_sectors_written(insert));
 
-	if (unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)))
+	if (unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)))
 		bch2_journal_key_overwritten(c, b->c.btree_id, b->c.level, insert->k.p);
 
 	if (bch2_bkey_invalid(c, bkey_i_to_s_c(insert),
@@ -1619,12 +1620,12 @@ static int btree_split(struct btree_update *as, struct btree_trans *trans,
 		six_unlock_write(&n2->c.lock);
 		six_unlock_write(&n1->c.lock);
 
-		path1 = get_unlocked_mut_path(trans, as->btree_id, n1->c.level, n1->key.k.p);
+		path1 = bch2_path_get_unlocked_mut(trans, as->btree_id, n1->c.level, n1->key.k.p);
 		six_lock_increment(&n1->c.lock, SIX_LOCK_intent);
 		mark_btree_node_locked(trans, trans->paths + path1, n1->c.level, BTREE_NODE_INTENT_LOCKED);
 		bch2_btree_path_level_init(trans, trans->paths + path1, n1);
 
-		path2 = get_unlocked_mut_path(trans, as->btree_id, n2->c.level, n2->key.k.p);
+		path2 = bch2_path_get_unlocked_mut(trans, as->btree_id, n2->c.level, n2->key.k.p);
 		six_lock_increment(&n2->c.lock, SIX_LOCK_intent);
 		mark_btree_node_locked(trans, trans->paths + path2, n2->c.level, BTREE_NODE_INTENT_LOCKED);
 		bch2_btree_path_level_init(trans, trans->paths + path2, n2);
@@ -1669,7 +1670,7 @@ static int btree_split(struct btree_update *as, struct btree_trans *trans,
 		bch2_btree_update_add_new_node(as, n1);
 		six_unlock_write(&n1->c.lock);
 
-		path1 = get_unlocked_mut_path(trans, as->btree_id, n1->c.level, n1->key.k.p);
+		path1 = bch2_path_get_unlocked_mut(trans, as->btree_id, n1->c.level, n1->key.k.p);
 		six_lock_increment(&n1->c.lock, SIX_LOCK_intent);
 		mark_btree_node_locked(trans, trans->paths + path1, n1->c.level, BTREE_NODE_INTENT_LOCKED);
 		bch2_btree_path_level_init(trans, trans->paths + path1, n1);
@@ -1947,6 +1948,8 @@ int __bch2_foreground_maybe_merge(struct btree_trans *trans,
 	u64 start_time = local_clock();
 	int ret = 0;
 
+	bch2_trans_verify_not_in_restart(trans);
+	bch2_trans_verify_not_unlocked(trans);
 	BUG_ON(!trans->paths[path].should_be_locked);
 	BUG_ON(!btree_node_locked(&trans->paths[path], level));
 
@@ -1979,7 +1982,7 @@ int __bch2_foreground_maybe_merge(struct btree_trans *trans,
 		: bpos_successor(b->data->max_key);
 
 	sib_path = bch2_path_get(trans, btree, sib_pos,
-				 U8_MAX, level, BTREE_ITER_INTENT, _THIS_IP_);
+				 U8_MAX, level, BTREE_ITER_intent, _THIS_IP_);
 	ret = bch2_btree_path_traverse(trans, sib_path, false);
 	if (ret)
 		goto err;
@@ -2072,7 +2075,7 @@ int __bch2_foreground_maybe_merge(struct btree_trans *trans,
 	bch2_btree_update_add_new_node(as, n);
 	six_unlock_write(&n->c.lock);
 
-	new_path = get_unlocked_mut_path(trans, btree, n->c.level, n->key.k.p);
+	new_path = bch2_path_get_unlocked_mut(trans, btree, n->c.level, n->key.k.p);
 	six_lock_increment(&n->c.lock, SIX_LOCK_intent);
 	mark_btree_node_locked(trans, trans->paths + new_path, n->c.level, BTREE_NODE_INTENT_LOCKED);
 	bch2_btree_path_level_init(trans, trans->paths + new_path, n);
@@ -2150,7 +2153,7 @@ int bch2_btree_node_rewrite(struct btree_trans *trans,
 	bch2_btree_update_add_new_node(as, n);
 	six_unlock_write(&n->c.lock);
 
-	new_path = get_unlocked_mut_path(trans, iter->btree_id, n->c.level, n->key.k.p);
+	new_path = bch2_path_get_unlocked_mut(trans, iter->btree_id, n->c.level, n->key.k.p);
 	six_lock_increment(&n->c.lock, SIX_LOCK_intent);
 	mark_btree_node_locked(trans, trans->paths + new_path, n->c.level, BTREE_NODE_INTENT_LOCKED);
 	bch2_btree_path_level_init(trans, trans->paths + new_path, n);
@@ -2333,10 +2336,10 @@ static int __bch2_btree_node_update_key(struct btree_trans *trans,
 	if (!skip_triggers) {
 		ret   = bch2_key_trigger_old(trans, b->c.btree_id, b->c.level + 1,
 					     bkey_i_to_s_c(&b->key),
-					     BTREE_TRIGGER_TRANSACTIONAL) ?:
+					     BTREE_TRIGGER_transactional) ?:
 			bch2_key_trigger_new(trans, b->c.btree_id, b->c.level + 1,
 					     bkey_i_to_s(new_key),
-					     BTREE_TRIGGER_TRANSACTIONAL);
+					     BTREE_TRIGGER_transactional);
 		if (ret)
 			return ret;
 	}
@@ -2353,7 +2356,7 @@ static int __bch2_btree_node_update_key(struct btree_trans *trans,
 		bch2_trans_copy_iter(&iter2, iter);
 
 		iter2.path = bch2_btree_path_make_mut(trans, iter2.path,
-				iter2.flags & BTREE_ITER_INTENT,
+				iter2.flags & BTREE_ITER_intent,
 				_THIS_IP_);
 
 		struct btree_path *path2 = btree_iter_path(trans, &iter2);
@@ -2365,7 +2368,7 @@ static int __bch2_btree_node_update_key(struct btree_trans *trans,
 		trans->paths_sorted = false;
 
 		ret   = bch2_btree_iter_traverse(&iter2) ?:
-			bch2_trans_update(trans, &iter2, new_key, BTREE_TRIGGER_NORUN);
+			bch2_trans_update(trans, &iter2, new_key, BTREE_TRIGGER_norun);
 		if (ret)
 			goto err;
 	} else {
@@ -2473,7 +2476,7 @@ int bch2_btree_node_update_key_get_iter(struct btree_trans *trans,
 
 	bch2_trans_node_iter_init(trans, &iter, b->c.btree_id, b->key.k.p,
 				  BTREE_MAX_DEPTH, b->c.level,
-				  BTREE_ITER_INTENT);
+				  BTREE_ITER_intent);
 	ret = bch2_btree_iter_traverse(&iter);
 	if (ret)
 		goto out;
@@ -2487,7 +2490,6 @@ int bch2_btree_node_update_key_get_iter(struct btree_trans *trans,
 
 	BUG_ON(!btree_node_hashed(b));
 
-	struct bch_extent_ptr *ptr;
 	bch2_bkey_drop_ptrs(bkey_i_to_s(new_key), ptr,
 			    !bch2_bkey_has_device(bkey_i_to_s(&b->key), ptr->dev));
 
@@ -2511,7 +2513,7 @@ void bch2_btree_set_root_for_read(struct bch_fs *c, struct btree *b)
 	bch2_btree_set_root_inmem(c, b);
 }
 
-static int __bch2_btree_root_alloc_fake(struct btree_trans *trans, enum btree_id id, unsigned level)
+int bch2_btree_root_alloc_fake_trans(struct btree_trans *trans, enum btree_id id, unsigned level)
 {
 	struct bch_fs *c = trans->c;
 	struct closure cl;
@@ -2559,17 +2561,18 @@ static int __bch2_btree_root_alloc_fake(struct btree_trans *trans, enum btree_id
 
 void bch2_btree_root_alloc_fake(struct bch_fs *c, enum btree_id id, unsigned level)
 {
-	bch2_trans_run(c, __bch2_btree_root_alloc_fake(trans, id, level));
+	bch2_trans_run(c, bch2_btree_root_alloc_fake_trans(trans, id, level));
 }
 
 static void bch2_btree_update_to_text(struct printbuf *out, struct btree_update *as)
 {
-	prt_printf(out, "%ps: btree=%s l=%u-%u watermark=%s mode=%s nodes_written=%u cl.remaining=%u journal_seq=%llu\n",
-		   (void *) as->ip_started,
+	prt_printf(out, "%ps: ", (void *) as->ip_started);
+	bch2_trans_commit_flags_to_text(out, as->flags);
+
+	prt_printf(out, " btree=%s l=%u-%u mode=%s nodes_written=%u cl.remaining=%u journal_seq=%llu\n",
 		   bch2_btree_id_str(as->btree_id),
 		   as->update_level_start,
 		   as->update_level_end,
-		   bch2_watermarks[as->watermark],
 		   bch2_btree_update_modes[as->mode],
 		   as->nodes_written,
 		   closure_nr_remaining(&as->cl),
diff --git a/fs/bcachefs/btree_update_interior.h b/fs/bcachefs/btree_update_interior.h
index c1a479ebaad1..b5b76ce01cfc 100644
--- a/fs/bcachefs/btree_update_interior.h
+++ b/fs/bcachefs/btree_update_interior.h
@@ -52,7 +52,7 @@ struct btree_update {
 	struct list_head		unwritten_list;
 
 	enum btree_update_mode		mode;
-	enum bch_watermark		watermark;
+	enum bch_trans_commit_flags	flags;
 	unsigned			nodes_written:1;
 	unsigned			took_gc_lock:1;
 
@@ -144,6 +144,9 @@ static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans,
 
 	EBUG_ON(!btree_node_locked(path, level));
 
+	if (bch2_btree_node_merging_disabled)
+		return 0;
+
 	b = path->l[level].b;
 	if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold)
 		return 0;
@@ -172,6 +175,8 @@ int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *,
 					struct bkey_i *, unsigned, bool);
 
 void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *);
+
+int bch2_btree_root_alloc_fake_trans(struct btree_trans *, enum btree_id, unsigned);
 void bch2_btree_root_alloc_fake(struct bch_fs *, enum btree_id, unsigned);
 
 static inline unsigned btree_update_reserve_required(struct bch_fs *c,
diff --git a/fs/bcachefs/btree_write_buffer.c b/fs/bcachefs/btree_write_buffer.c
index 36a6f42aba5e..75c8a196b3f6 100644
--- a/fs/bcachefs/btree_write_buffer.c
+++ b/fs/bcachefs/btree_write_buffer.c
@@ -122,7 +122,7 @@ static noinline int wb_flush_one_slowpath(struct btree_trans *trans,
 	trans->journal_res.seq = wb->journal_seq;
 
 	return bch2_trans_update(trans, iter, &wb->k,
-				 BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+				 BTREE_UPDATE_internal_snapshot_node) ?:
 		bch2_trans_commit(trans, NULL, NULL,
 				  BCH_TRANS_COMMIT_no_enospc|
 				  BCH_TRANS_COMMIT_no_check_rw|
@@ -191,13 +191,13 @@ btree_write_buffered_insert(struct btree_trans *trans,
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, wb->btree, bkey_start_pos(&wb->k.k),
-			     BTREE_ITER_CACHED|BTREE_ITER_INTENT);
+			     BTREE_ITER_cached|BTREE_ITER_intent);
 
 	trans->journal_res.seq = wb->journal_seq;
 
 	ret   = bch2_btree_iter_traverse(&iter) ?:
 		bch2_trans_update(trans, &iter, &wb->k,
-				  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				  BTREE_UPDATE_internal_snapshot_node);
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }
@@ -332,7 +332,7 @@ static int bch2_btree_write_buffer_flush_locked(struct btree_trans *trans)
 		if (!iter.path || iter.btree_id != k->btree) {
 			bch2_trans_iter_exit(trans, &iter);
 			bch2_trans_iter_init(trans, &iter, k->btree, k->k.k.p,
-					     BTREE_ITER_INTENT|BTREE_ITER_ALL_SNAPSHOTS);
+					     BTREE_ITER_intent|BTREE_ITER_all_snapshots);
 		}
 
 		bch2_btree_iter_set_pos(&iter, k->k.k.p);
diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index 82f179258867..e28d28ac2a13 100644
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -274,25 +274,14 @@ void bch2_dev_usage_init(struct bch_dev *ca)
 
 void bch2_dev_usage_to_text(struct printbuf *out, struct bch_dev_usage *usage)
 {
-	prt_tab(out);
-	prt_str(out, "buckets");
-	prt_tab_rjust(out);
-	prt_str(out, "sectors");
-	prt_tab_rjust(out);
-	prt_str(out, "fragmented");
-	prt_tab_rjust(out);
-	prt_newline(out);
+	prt_printf(out, "\tbuckets\rsectors\rfragmented\r\n");
 
 	for (unsigned i = 0; i < BCH_DATA_NR; i++) {
 		bch2_prt_data_type(out, i);
-		prt_tab(out);
-		prt_u64(out, usage->d[i].buckets);
-		prt_tab_rjust(out);
-		prt_u64(out, usage->d[i].sectors);
-		prt_tab_rjust(out);
-		prt_u64(out, usage->d[i].fragmented);
-		prt_tab_rjust(out);
-		prt_newline(out);
+		prt_printf(out, "\t%llu\r%llu\r%llu\r\n",
+			usage->d[i].buckets,
+			usage->d[i].sectors,
+			usage->d[i].fragmented);
 	}
 }
 
@@ -329,26 +318,6 @@ void bch2_dev_usage_update(struct bch_fs *c, struct bch_dev *ca,
 	preempt_enable();
 }
 
-static inline struct bch_alloc_v4 bucket_m_to_alloc(struct bucket b)
-{
-	return (struct bch_alloc_v4) {
-		.gen		= b.gen,
-		.data_type	= b.data_type,
-		.dirty_sectors	= b.dirty_sectors,
-		.cached_sectors	= b.cached_sectors,
-		.stripe		= b.stripe,
-	};
-}
-
-void bch2_dev_usage_update_m(struct bch_fs *c, struct bch_dev *ca,
-			     struct bucket *old, struct bucket *new)
-{
-	struct bch_alloc_v4 old_a = bucket_m_to_alloc(*old);
-	struct bch_alloc_v4 new_a = bucket_m_to_alloc(*new);
-
-	bch2_dev_usage_update(c, ca, &old_a, &new_a, 0, true);
-}
-
 static inline int __update_replicas(struct bch_fs *c,
 				    struct bch_fs_usage *fs_usage,
 				    struct bch_replicas_entry_v1 *r,
@@ -496,78 +465,276 @@ int bch2_update_cached_sectors_list(struct btree_trans *trans, unsigned dev, s64
 	return bch2_update_replicas_list(trans, &r.e, sectors);
 }
 
-int bch2_mark_metadata_bucket(struct bch_fs *c, struct bch_dev *ca,
-			      size_t b, enum bch_data_type data_type,
-			      unsigned sectors, struct gc_pos pos,
-			      unsigned flags)
+int bch2_check_fix_ptrs(struct btree_trans *trans,
+			enum btree_id btree, unsigned level, struct bkey_s_c k,
+			enum btree_iter_update_trigger_flags flags)
 {
-	struct bucket old, new, *g;
+	struct bch_fs *c = trans->c;
+	struct bkey_ptrs_c ptrs_c = bch2_bkey_ptrs_c(k);
+	const union bch_extent_entry *entry_c;
+	struct extent_ptr_decoded p = { 0 };
+	bool do_update = false;
+	struct printbuf buf = PRINTBUF;
 	int ret = 0;
 
-	BUG_ON(!(flags & BTREE_TRIGGER_GC));
-	BUG_ON(data_type != BCH_DATA_sb &&
-	       data_type != BCH_DATA_journal);
+	percpu_down_read(&c->mark_lock);
 
-	/*
-	 * Backup superblock might be past the end of our normal usable space:
-	 */
-	if (b >= ca->mi.nbuckets)
-		return 0;
+	rcu_read_lock();
+	bkey_for_each_ptr_decode(k.k, ptrs_c, p, entry_c) {
+		struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
+		if (!ca) {
+			if (fsck_err(c, ptr_to_invalid_device,
+				     "pointer to missing device %u\n"
+				     "while marking %s",
+				     p.ptr.dev,
+				     (printbuf_reset(&buf),
+				      bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+				do_update = true;
+			continue;
+		}
 
-	percpu_down_read(&c->mark_lock);
-	g = gc_bucket(ca, b);
+		struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);
+		enum bch_data_type data_type = bch2_bkey_ptr_data_type(k, p, entry_c);
+
+		if (fsck_err_on(!g->gen_valid,
+				c, ptr_to_missing_alloc_key,
+				"bucket %u:%zu data type %s ptr gen %u missing in alloc btree\n"
+				"while marking %s",
+				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+				bch2_data_type_str(ptr_data_type(k.k, &p.ptr)),
+				p.ptr.gen,
+				(printbuf_reset(&buf),
+				 bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+			if (!p.ptr.cached) {
+				g->gen_valid		= true;
+				g->gen			= p.ptr.gen;
+			} else {
+				do_update = true;
+			}
+		}
 
-	bucket_lock(g);
-	old = *g;
+		if (fsck_err_on(gen_cmp(p.ptr.gen, g->gen) > 0,
+				c, ptr_gen_newer_than_bucket_gen,
+				"bucket %u:%zu data type %s ptr gen in the future: %u > %u\n"
+				"while marking %s",
+				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+				bch2_data_type_str(ptr_data_type(k.k, &p.ptr)),
+				p.ptr.gen, g->gen,
+				(printbuf_reset(&buf),
+				 bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+			if (!p.ptr.cached &&
+			    (g->data_type != BCH_DATA_btree ||
+			     data_type == BCH_DATA_btree)) {
+				g->gen_valid		= true;
+				g->gen			= p.ptr.gen;
+				g->data_type		= 0;
+				g->dirty_sectors	= 0;
+				g->cached_sectors	= 0;
+			} else {
+				do_update = true;
+			}
+		}
 
-	if (bch2_fs_inconsistent_on(g->data_type &&
-			g->data_type != data_type, c,
-			"different types of data in same bucket: %s, %s",
-			bch2_data_type_str(g->data_type),
-			bch2_data_type_str(data_type))) {
-		ret = -EIO;
-		goto err;
-	}
+		if (fsck_err_on(gen_cmp(g->gen, p.ptr.gen) > BUCKET_GC_GEN_MAX,
+				c, ptr_gen_newer_than_bucket_gen,
+				"bucket %u:%zu gen %u data type %s: ptr gen %u too stale\n"
+				"while marking %s",
+				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr), g->gen,
+				bch2_data_type_str(ptr_data_type(k.k, &p.ptr)),
+				p.ptr.gen,
+				(printbuf_reset(&buf),
+				 bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+			do_update = true;
+
+		if (fsck_err_on(!p.ptr.cached && gen_cmp(p.ptr.gen, g->gen) < 0,
+				c, stale_dirty_ptr,
+				"bucket %u:%zu data type %s stale dirty ptr: %u < %u\n"
+				"while marking %s",
+				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr),
+				bch2_data_type_str(ptr_data_type(k.k, &p.ptr)),
+				p.ptr.gen, g->gen,
+				(printbuf_reset(&buf),
+				 bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+			do_update = true;
+
+		if (data_type != BCH_DATA_btree && p.ptr.gen != g->gen)
+			continue;
+
+		if (fsck_err_on(bucket_data_type_mismatch(g->data_type, data_type),
+				c, ptr_bucket_data_type_mismatch,
+				"bucket %u:%zu gen %u different types of data in same bucket: %s, %s\n"
+				"while marking %s",
+				p.ptr.dev, PTR_BUCKET_NR(ca, &p.ptr), g->gen,
+				bch2_data_type_str(g->data_type),
+				bch2_data_type_str(data_type),
+				(printbuf_reset(&buf),
+				 bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+			if (data_type == BCH_DATA_btree) {
+				g->gen_valid		= true;
+				g->gen			= p.ptr.gen;
+				g->data_type		= data_type;
+				g->dirty_sectors	= 0;
+				g->cached_sectors	= 0;
+			} else {
+				do_update = true;
+			}
+		}
 
-	if (bch2_fs_inconsistent_on((u64) g->dirty_sectors + sectors > ca->mi.bucket_size, c,
-			"bucket %u:%zu gen %u data type %s sector count overflow: %u + %u > bucket size",
-			ca->dev_idx, b, g->gen,
-			bch2_data_type_str(g->data_type ?: data_type),
-			g->dirty_sectors, sectors)) {
-		ret = -EIO;
-		goto err;
+		if (p.has_ec) {
+			struct gc_stripe *m = genradix_ptr(&c->gc_stripes, p.ec.idx);
+
+			if (fsck_err_on(!m || !m->alive, c,
+					ptr_to_missing_stripe,
+					"pointer to nonexistent stripe %llu\n"
+					"while marking %s",
+					(u64) p.ec.idx,
+					(printbuf_reset(&buf),
+					 bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+				do_update = true;
+
+			if (fsck_err_on(m && m->alive && !bch2_ptr_matches_stripe_m(m, p), c,
+					ptr_to_incorrect_stripe,
+					"pointer does not match stripe %llu\n"
+					"while marking %s",
+					(u64) p.ec.idx,
+					(printbuf_reset(&buf),
+					 bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
+				do_update = true;
+		}
 	}
+	rcu_read_unlock();
 
-	g->data_type = data_type;
-	g->dirty_sectors += sectors;
-	new = *g;
+	if (do_update) {
+		if (flags & BTREE_TRIGGER_is_root) {
+			bch_err(c, "cannot update btree roots yet");
+			ret = -EINVAL;
+			goto err;
+		}
+
+		struct bkey_i *new = bch2_bkey_make_mut_noupdate(trans, k);
+		ret = PTR_ERR_OR_ZERO(new);
+		if (ret)
+			goto err;
+
+		rcu_read_lock();
+		bch2_bkey_drop_ptrs(bkey_i_to_s(new), ptr, !bch2_dev_rcu(c, ptr->dev));
+		rcu_read_unlock();
+
+		if (level) {
+			/*
+			 * We don't want to drop btree node pointers - if the
+			 * btree node isn't there anymore, the read path will
+			 * sort it out:
+			 */
+			struct bkey_ptrs ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
+			rcu_read_lock();
+			bkey_for_each_ptr(ptrs, ptr) {
+				struct bch_dev *ca = bch2_dev_rcu(c, ptr->dev);
+				struct bucket *g = PTR_GC_BUCKET(ca, ptr);
+
+				ptr->gen = g->gen;
+			}
+			rcu_read_unlock();
+		} else {
+			struct bkey_ptrs ptrs;
+			union bch_extent_entry *entry;
+restart_drop_ptrs:
+			ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
+			rcu_read_lock();
+			bkey_for_each_ptr_decode(bkey_i_to_s(new).k, ptrs, p, entry) {
+				struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
+				struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);
+				enum bch_data_type data_type = bch2_bkey_ptr_data_type(bkey_i_to_s_c(new), p, entry);
+
+				if ((p.ptr.cached &&
+				     (!g->gen_valid || gen_cmp(p.ptr.gen, g->gen) > 0)) ||
+				    (!p.ptr.cached &&
+				     gen_cmp(p.ptr.gen, g->gen) < 0) ||
+				    gen_cmp(g->gen, p.ptr.gen) > BUCKET_GC_GEN_MAX ||
+				    (g->data_type &&
+				     g->data_type != data_type)) {
+					bch2_bkey_drop_ptr(bkey_i_to_s(new), &entry->ptr);
+					goto restart_drop_ptrs;
+				}
+			}
+			rcu_read_unlock();
+again:
+			ptrs = bch2_bkey_ptrs(bkey_i_to_s(new));
+			bkey_extent_entry_for_each(ptrs, entry) {
+				if (extent_entry_type(entry) == BCH_EXTENT_ENTRY_stripe_ptr) {
+					struct gc_stripe *m = genradix_ptr(&c->gc_stripes,
+									entry->stripe_ptr.idx);
+					union bch_extent_entry *next_ptr;
+
+					bkey_extent_entry_for_each_from(ptrs, next_ptr, entry)
+						if (extent_entry_type(next_ptr) == BCH_EXTENT_ENTRY_ptr)
+							goto found;
+					next_ptr = NULL;
+found:
+					if (!next_ptr) {
+						bch_err(c, "aieee, found stripe ptr with no data ptr");
+						continue;
+					}
+
+					if (!m || !m->alive ||
+					    !__bch2_ptr_matches_stripe(&m->ptrs[entry->stripe_ptr.block],
+								       &next_ptr->ptr,
+								       m->sectors)) {
+						bch2_bkey_extent_entry_drop(new, entry);
+						goto again;
+					}
+				}
+			}
+		}
+
+		if (0) {
+			printbuf_reset(&buf);
+			bch2_bkey_val_to_text(&buf, c, k);
+			bch_info(c, "updated %s", buf.buf);
+
+			printbuf_reset(&buf);
+			bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(new));
+			bch_info(c, "new key %s", buf.buf);
+		}
+
+		percpu_up_read(&c->mark_lock);
+		struct btree_iter iter;
+		bch2_trans_node_iter_init(trans, &iter, btree, new->k.p, 0, level,
+					  BTREE_ITER_intent|BTREE_ITER_all_snapshots);
+		ret =   bch2_btree_iter_traverse(&iter) ?:
+			bch2_trans_update(trans, &iter, new,
+					  BTREE_UPDATE_internal_snapshot_node|
+					  BTREE_TRIGGER_norun);
+		bch2_trans_iter_exit(trans, &iter);
+		percpu_down_read(&c->mark_lock);
+
+		if (ret)
+			goto err;
+
+		if (level)
+			bch2_btree_node_update_key_early(trans, btree, level - 1, k, new);
+	}
 err:
-	bucket_unlock(g);
-	if (!ret)
-		bch2_dev_usage_update_m(c, ca, &old, &new);
+fsck_err:
 	percpu_up_read(&c->mark_lock);
+	printbuf_exit(&buf);
 	return ret;
 }
 
-int bch2_check_bucket_ref(struct btree_trans *trans,
-			  struct bkey_s_c k,
-			  const struct bch_extent_ptr *ptr,
-			  s64 sectors, enum bch_data_type ptr_data_type,
-			  u8 b_gen, u8 bucket_data_type,
-			  u32 bucket_sectors)
+int bch2_bucket_ref_update(struct btree_trans *trans, struct bch_dev *ca,
+			   struct bkey_s_c k,
+			   const struct bch_extent_ptr *ptr,
+			   s64 sectors, enum bch_data_type ptr_data_type,
+			   u8 b_gen, u8 bucket_data_type,
+			   u32 *bucket_sectors)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 	size_t bucket_nr = PTR_BUCKET_NR(ca, ptr);
 	struct printbuf buf = PRINTBUF;
+	bool inserting = sectors > 0;
 	int ret = 0;
 
-	if (bucket_data_type == BCH_DATA_cached)
-		bucket_data_type = BCH_DATA_user;
-
-	if ((bucket_data_type == BCH_DATA_stripe && ptr_data_type == BCH_DATA_user) ||
-	    (bucket_data_type == BCH_DATA_user   && ptr_data_type == BCH_DATA_stripe))
-		bucket_data_type = ptr_data_type = BCH_DATA_stripe;
+	BUG_ON(!sectors);
 
 	if (gen_after(ptr->gen, b_gen)) {
 		bch2_fsck_err(c, FSCK_CAN_IGNORE|FSCK_NEED_FSCK,
@@ -578,8 +745,9 @@ int bch2_check_bucket_ref(struct btree_trans *trans,
 			bch2_data_type_str(bucket_data_type ?: ptr_data_type),
 			ptr->gen,
 			(bch2_bkey_val_to_text(&buf, c, k), buf.buf));
-		ret = -EIO;
-		goto err;
+		if (inserting)
+			goto err;
+		goto out;
 	}
 
 	if (gen_cmp(b_gen, ptr->gen) > BUCKET_GC_GEN_MAX) {
@@ -592,11 +760,17 @@ int bch2_check_bucket_ref(struct btree_trans *trans,
 			ptr->gen,
 			(printbuf_reset(&buf),
 			 bch2_bkey_val_to_text(&buf, c, k), buf.buf));
-		ret = -EIO;
-		goto err;
+		if (inserting)
+			goto err;
+		goto out;
+	}
+
+	if (b_gen != ptr->gen && ptr->cached) {
+		ret = 1;
+		goto out;
 	}
 
-	if (b_gen != ptr->gen && !ptr->cached) {
+	if (b_gen != ptr->gen) {
 		bch2_fsck_err(c, FSCK_CAN_IGNORE|FSCK_NEED_FSCK,
 			      BCH_FSCK_ERR_stale_dirty_ptr,
 			"bucket %u:%zu gen %u (mem gen %u) data type %s: stale dirty ptr (gen %u)\n"
@@ -607,18 +781,12 @@ int bch2_check_bucket_ref(struct btree_trans *trans,
 			ptr->gen,
 			(printbuf_reset(&buf),
 			 bch2_bkey_val_to_text(&buf, c, k), buf.buf));
-		ret = -EIO;
-		goto err;
-	}
-
-	if (b_gen != ptr->gen) {
-		ret = 1;
+		if (inserting)
+			goto err;
 		goto out;
 	}
 
-	if (!data_type_is_empty(bucket_data_type) &&
-	    ptr_data_type &&
-	    bucket_data_type != ptr_data_type) {
+	if (bucket_data_type_mismatch(bucket_data_type, ptr_data_type)) {
 		bch2_fsck_err(c, FSCK_CAN_IGNORE|FSCK_NEED_FSCK,
 			      BCH_FSCK_ERR_ptr_bucket_data_type_mismatch,
 			"bucket %u:%zu gen %u different types of data in same bucket: %s, %s\n"
@@ -628,28 +796,33 @@ int bch2_check_bucket_ref(struct btree_trans *trans,
 			bch2_data_type_str(ptr_data_type),
 			(printbuf_reset(&buf),
 			 bch2_bkey_val_to_text(&buf, c, k), buf.buf));
-		ret = -EIO;
-		goto err;
+		if (inserting)
+			goto err;
+		goto out;
 	}
 
-	if ((u64) bucket_sectors + sectors > U32_MAX) {
+	if ((u64) *bucket_sectors + sectors > U32_MAX) {
 		bch2_fsck_err(c, FSCK_CAN_IGNORE|FSCK_NEED_FSCK,
 			      BCH_FSCK_ERR_bucket_sector_count_overflow,
 			"bucket %u:%zu gen %u data type %s sector count overflow: %u + %lli > U32_MAX\n"
 			"while marking %s",
 			ptr->dev, bucket_nr, b_gen,
 			bch2_data_type_str(bucket_data_type ?: ptr_data_type),
-			bucket_sectors, sectors,
+			*bucket_sectors, sectors,
 			(printbuf_reset(&buf),
 			 bch2_bkey_val_to_text(&buf, c, k), buf.buf));
-		ret = -EIO;
-		goto err;
+		if (inserting)
+			goto err;
+		sectors = -*bucket_sectors;
 	}
+
+	*bucket_sectors += sectors;
 out:
 	printbuf_exit(&buf);
 	return ret;
 err:
 	bch2_dump_trans_updates(trans);
+	ret = -EIO;
 	goto out;
 }
 
@@ -786,29 +959,22 @@ need_mark:
 
 /* KEY_TYPE_extent: */
 
-static int __mark_pointer(struct btree_trans *trans,
+static int __mark_pointer(struct btree_trans *trans, struct bch_dev *ca,
 			  struct bkey_s_c k,
 			  const struct bch_extent_ptr *ptr,
 			  s64 sectors, enum bch_data_type ptr_data_type,
-			  u8 bucket_gen, u8 *bucket_data_type,
-			  u32 *dirty_sectors, u32 *cached_sectors)
+			  struct bch_alloc_v4 *a)
 {
 	u32 *dst_sectors = !ptr->cached
-		? dirty_sectors
-		: cached_sectors;
-	int ret = bch2_check_bucket_ref(trans, k, ptr, sectors, ptr_data_type,
-				   bucket_gen, *bucket_data_type, *dst_sectors);
+		? &a->dirty_sectors
+		: &a->cached_sectors;
+	int ret = bch2_bucket_ref_update(trans, ca, k, ptr, sectors, ptr_data_type,
+					 a->gen, a->data_type, dst_sectors);
 
 	if (ret)
 		return ret;
 
-	*dst_sectors += sectors;
-
-	if (!*dirty_sectors && !*cached_sectors)
-		*bucket_data_type = 0;
-	else if (*bucket_data_type != BCH_DATA_stripe)
-		*bucket_data_type = ptr_data_type;
-
+	alloc_data_type_set(a, ptr_data_type);
 	return 0;
 }
 
@@ -816,81 +982,69 @@ static int bch2_trigger_pointer(struct btree_trans *trans,
 			enum btree_id btree_id, unsigned level,
 			struct bkey_s_c k, struct extent_ptr_decoded p,
 			const union bch_extent_entry *entry,
-			s64 *sectors, unsigned flags)
+			s64 *sectors,
+			enum btree_iter_update_trigger_flags flags)
 {
-	bool insert = !(flags & BTREE_TRIGGER_OVERWRITE);
+	bool insert = !(flags & BTREE_TRIGGER_overwrite);
+	int ret = 0;
+
+	struct bch_fs *c = trans->c;
+	struct bch_dev *ca = bch2_dev_tryget(c, p.ptr.dev);
+	if (unlikely(!ca)) {
+		if (insert)
+			ret = -EIO;
+		goto err;
+	}
+
 	struct bpos bucket;
 	struct bch_backpointer bp;
-
-	bch2_extent_ptr_to_bp(trans->c, btree_id, level, k, p, entry, &bucket, &bp);
+	bch2_extent_ptr_to_bp(trans->c, ca, btree_id, level, k, p, entry, &bucket, &bp);
 	*sectors = insert ? bp.bucket_len : -((s64) bp.bucket_len);
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
-		struct btree_iter iter;
-		struct bkey_i_alloc_v4 *a = bch2_trans_start_alloc_update(trans, &iter, bucket);
-		int ret = PTR_ERR_OR_ZERO(a);
+	if (flags & BTREE_TRIGGER_transactional) {
+		struct bkey_i_alloc_v4 *a = bch2_trans_start_alloc_update(trans, bucket);
+		ret = PTR_ERR_OR_ZERO(a) ?:
+			__mark_pointer(trans, ca, k, &p.ptr, *sectors, bp.data_type, &a->v);
 		if (ret)
-			return ret;
-
-		ret = __mark_pointer(trans, k, &p.ptr, *sectors, bp.data_type,
-				     a->v.gen, &a->v.data_type,
-				     &a->v.dirty_sectors, &a->v.cached_sectors) ?:
-			bch2_trans_update(trans, &iter, &a->k_i, 0);
-		bch2_trans_iter_exit(trans, &iter);
-
-		if (ret)
-			return ret;
+			goto err;
 
 		if (!p.ptr.cached) {
-			ret = bch2_bucket_backpointer_mod(trans, bucket, bp, k, insert);
+			ret = bch2_bucket_backpointer_mod(trans, ca, bucket, bp, k, insert);
 			if (ret)
-				return ret;
+				goto err;
 		}
 	}
 
-	if (flags & BTREE_TRIGGER_GC) {
-		struct bch_fs *c = trans->c;
-		struct bch_dev *ca = bch_dev_bkey_exists(c, p.ptr.dev);
-		enum bch_data_type data_type = bch2_bkey_ptr_data_type(k, p, entry);
-
+	if (flags & BTREE_TRIGGER_gc) {
 		percpu_down_read(&c->mark_lock);
-		struct bucket *g = PTR_GC_BUCKET(ca, &p.ptr);
+		struct bucket *g = gc_bucket(ca, bucket.offset);
 		bucket_lock(g);
-		struct bucket old = *g;
-
-		u8 bucket_data_type = g->data_type;
-		int ret = __mark_pointer(trans, k, &p.ptr, *sectors,
-				     data_type, g->gen,
-				     &bucket_data_type,
-				     &g->dirty_sectors,
-				     &g->cached_sectors);
-		if (ret) {
-			bucket_unlock(g);
-			percpu_up_read(&c->mark_lock);
-			return ret;
+		struct bch_alloc_v4 old = bucket_m_to_alloc(*g), new = old;
+		ret = __mark_pointer(trans, ca, k, &p.ptr, *sectors, bp.data_type, &new);
+		if (!ret) {
+			alloc_to_bucket(g, new);
+			bch2_dev_usage_update(c, ca, &old, &new, 0, true);
 		}
-
-		g->data_type = bucket_data_type;
-		struct bucket new = *g;
 		bucket_unlock(g);
-		bch2_dev_usage_update_m(c, ca, &old, &new);
 		percpu_up_read(&c->mark_lock);
 	}
-
-	return 0;
+err:
+	bch2_dev_put(ca);
+	return ret;
 }
 
 static int bch2_trigger_stripe_ptr(struct btree_trans *trans,
 				struct bkey_s_c k,
 				struct extent_ptr_decoded p,
 				enum bch_data_type data_type,
-				s64 sectors, unsigned flags)
+				s64 sectors,
+				enum btree_iter_update_trigger_flags flags)
 {
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		struct btree_iter iter;
 		struct bkey_i_stripe *s = bch2_bkey_get_mut_typed(trans, &iter,
 				BTREE_ID_stripes, POS(0, p.ec.idx),
-				BTREE_ITER_WITH_UPDATES, stripe);
+				BTREE_ITER_with_updates, stripe);
 		int ret = PTR_ERR_OR_ZERO(s);
 		if (unlikely(ret)) {
 			bch2_trans_inconsistent_on(bch2_err_matches(ret, ENOENT), trans,
@@ -920,10 +1074,10 @@ err:
 		return ret;
 	}
 
-	if (flags & BTREE_TRIGGER_GC) {
+	if (flags & BTREE_TRIGGER_gc) {
 		struct bch_fs *c = trans->c;
 
-		BUG_ON(!(flags & BTREE_TRIGGER_GC));
+		BUG_ON(!(flags & BTREE_TRIGGER_gc));
 
 		struct gc_stripe *m = genradix_ptr_alloc(&c->gc_stripes, p.ec.idx, GFP_KERNEL);
 		if (!m) {
@@ -959,9 +1113,10 @@ err:
 
 static int __trigger_extent(struct btree_trans *trans,
 			    enum btree_id btree_id, unsigned level,
-			    struct bkey_s_c k, unsigned flags)
+			    struct bkey_s_c k,
+			    enum btree_iter_update_trigger_flags flags)
 {
-	bool gc = flags & BTREE_TRIGGER_GC;
+	bool gc = flags & BTREE_TRIGGER_gc;
 	struct bch_fs *c = trans->c;
 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 	const union bch_extent_entry *entry;
@@ -970,7 +1125,7 @@ static int __trigger_extent(struct btree_trans *trans,
 	enum bch_data_type data_type = bkey_is_btree_ptr(k.k)
 		? BCH_DATA_btree
 		: BCH_DATA_user;
-	s64 dirty_sectors = 0;
+	s64 replicas_sectors = 0;
 	int ret = 0;
 
 	r.e.data_type	= data_type;
@@ -996,7 +1151,7 @@ static int __trigger_extent(struct btree_trans *trans,
 					return ret;
 			}
 		} else if (!p.has_ec) {
-			dirty_sectors	       += disk_sectors;
+			replicas_sectors       += disk_sectors;
 			r.e.devs[r.e.nr_devs++]	= p.ptr.dev;
 		} else {
 			ret = bch2_trigger_stripe_ptr(trans, k, p, data_type, disk_sectors, flags);
@@ -1014,8 +1169,8 @@ static int __trigger_extent(struct btree_trans *trans,
 
 	if (r.e.nr_devs) {
 		ret = !gc
-			? bch2_update_replicas_list(trans, &r.e, dirty_sectors)
-			: bch2_update_replicas(c, k, &r.e, dirty_sectors, 0, true);
+			? bch2_update_replicas_list(trans, &r.e, replicas_sectors)
+			: bch2_update_replicas(c, k, &r.e, replicas_sectors, 0, true);
 		if (unlikely(ret && gc)) {
 			struct printbuf buf = PRINTBUF;
 
@@ -1031,15 +1186,18 @@ static int __trigger_extent(struct btree_trans *trans,
 }
 
 int bch2_trigger_extent(struct btree_trans *trans,
-			enum btree_id btree_id, unsigned level,
+			enum btree_id btree, unsigned level,
 			struct bkey_s_c old, struct bkey_s new,
-			unsigned flags)
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_ptrs_c new_ptrs = bch2_bkey_ptrs_c(new.s_c);
 	struct bkey_ptrs_c old_ptrs = bch2_bkey_ptrs_c(old);
 	unsigned new_ptrs_bytes = (void *) new_ptrs.end - (void *) new_ptrs.start;
 	unsigned old_ptrs_bytes = (void *) old_ptrs.end - (void *) old_ptrs.start;
 
+	if (unlikely(flags & BTREE_TRIGGER_check_repair))
+		return bch2_check_fix_ptrs(trans, btree, level, new.s_c, flags);
+
 	/* if pointers aren't changing - nothing to do: */
 	if (new_ptrs_bytes == old_ptrs_bytes &&
 	    !memcmp(new_ptrs.start,
@@ -1047,7 +1205,7 @@ int bch2_trigger_extent(struct btree_trans *trans,
 		    new_ptrs_bytes))
 		return 0;
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		struct bch_fs *c = trans->c;
 		int mod = (int) bch2_bkey_needs_rebalance(c, new.s_c) -
 			  (int) bch2_bkey_needs_rebalance(c, old);
@@ -1060,8 +1218,8 @@ int bch2_trigger_extent(struct btree_trans *trans,
 		}
 	}
 
-	if (flags & (BTREE_TRIGGER_TRANSACTIONAL|BTREE_TRIGGER_GC))
-		return trigger_run_overwrite_then_insert(__trigger_extent, trans, btree_id, level, old, new, flags);
+	if (flags & (BTREE_TRIGGER_transactional|BTREE_TRIGGER_gc))
+		return trigger_run_overwrite_then_insert(__trigger_extent, trans, btree, level, old, new, flags);
 
 	return 0;
 }
@@ -1069,17 +1227,17 @@ int bch2_trigger_extent(struct btree_trans *trans,
 /* KEY_TYPE_reservation */
 
 static int __trigger_reservation(struct btree_trans *trans,
-				 enum btree_id btree_id, unsigned level,
-				 struct bkey_s_c k, unsigned flags)
+			enum btree_id btree_id, unsigned level, struct bkey_s_c k,
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
 	unsigned replicas = bkey_s_c_to_reservation(k).v->nr_replicas;
 	s64 sectors = (s64) k.k->size * replicas;
 
-	if (flags & BTREE_TRIGGER_OVERWRITE)
+	if (flags & BTREE_TRIGGER_overwrite)
 		sectors = -sectors;
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		int ret = bch2_replicas_deltas_realloc(trans, 0);
 		if (ret)
 			return ret;
@@ -1090,7 +1248,7 @@ static int __trigger_reservation(struct btree_trans *trans,
 		d->persistent_reserved[replicas - 1] += sectors;
 	}
 
-	if (flags & BTREE_TRIGGER_GC) {
+	if (flags & BTREE_TRIGGER_gc) {
 		percpu_down_read(&c->mark_lock);
 		preempt_disable();
 
@@ -1110,7 +1268,7 @@ static int __trigger_reservation(struct btree_trans *trans,
 int bch2_trigger_reservation(struct btree_trans *trans,
 			  enum btree_id btree_id, unsigned level,
 			  struct bkey_s_c old, struct bkey_s new,
-			  unsigned flags)
+			  enum btree_iter_update_trigger_flags flags)
 {
 	return trigger_run_overwrite_then_insert(__trigger_reservation, trans, btree_id, level, old, new, flags);
 }
@@ -1118,22 +1276,16 @@ int bch2_trigger_reservation(struct btree_trans *trans,
 /* Mark superblocks: */
 
 static int __bch2_trans_mark_metadata_bucket(struct btree_trans *trans,
-				    struct bch_dev *ca, size_t b,
+				    struct bch_dev *ca, u64 b,
 				    enum bch_data_type type,
 				    unsigned sectors)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_iter iter;
-	struct bkey_i_alloc_v4 *a;
 	int ret = 0;
 
-	/*
-	 * Backup superblock might be past the end of our normal usable space:
-	 */
-	if (b >= ca->mi.nbuckets)
-		return 0;
-
-	a = bch2_trans_start_alloc_update(trans, &iter, POS(ca->dev_idx, b));
+	struct bkey_i_alloc_v4 *a =
+		bch2_trans_start_alloc_update_noupdate(trans, &iter, POS(ca->dev_idx, b));
 	if (IS_ERR(a))
 		return PTR_ERR(a);
 
@@ -1161,20 +1313,75 @@ err:
 	return ret;
 }
 
+static int bch2_mark_metadata_bucket(struct bch_fs *c, struct bch_dev *ca,
+			u64 b, enum bch_data_type data_type, unsigned sectors,
+			enum btree_iter_update_trigger_flags flags)
+{
+	int ret = 0;
+
+	percpu_down_read(&c->mark_lock);
+	struct bucket *g = gc_bucket(ca, b);
+
+	bucket_lock(g);
+	struct bch_alloc_v4 old = bucket_m_to_alloc(*g);
+
+	if (bch2_fs_inconsistent_on(g->data_type &&
+			g->data_type != data_type, c,
+			"different types of data in same bucket: %s, %s",
+			bch2_data_type_str(g->data_type),
+			bch2_data_type_str(data_type))) {
+		ret = -EIO;
+		goto err;
+	}
+
+	if (bch2_fs_inconsistent_on((u64) g->dirty_sectors + sectors > ca->mi.bucket_size, c,
+			"bucket %u:%llu gen %u data type %s sector count overflow: %u + %u > bucket size",
+			ca->dev_idx, b, g->gen,
+			bch2_data_type_str(g->data_type ?: data_type),
+			g->dirty_sectors, sectors)) {
+		ret = -EIO;
+		goto err;
+	}
+
+	g->data_type = data_type;
+	g->dirty_sectors += sectors;
+	struct bch_alloc_v4 new = bucket_m_to_alloc(*g);
+err:
+	bucket_unlock(g);
+	if (!ret)
+		bch2_dev_usage_update(c, ca, &old, &new, 0, true);
+	percpu_up_read(&c->mark_lock);
+	return ret;
+}
+
 int bch2_trans_mark_metadata_bucket(struct btree_trans *trans,
-				    struct bch_dev *ca, size_t b,
-				    enum bch_data_type type,
-				    unsigned sectors)
+			struct bch_dev *ca, u64 b,
+			enum bch_data_type type, unsigned sectors,
+			enum btree_iter_update_trigger_flags flags)
 {
-	return commit_do(trans, NULL, NULL, 0,
-			__bch2_trans_mark_metadata_bucket(trans, ca, b, type, sectors));
+	BUG_ON(type != BCH_DATA_free &&
+	       type != BCH_DATA_sb &&
+	       type != BCH_DATA_journal);
+
+	/*
+	 * Backup superblock might be past the end of our normal usable space:
+	 */
+	if (b >= ca->mi.nbuckets)
+		return 0;
+
+	if (flags & BTREE_TRIGGER_gc)
+		return bch2_mark_metadata_bucket(trans->c, ca, b, type, sectors, flags);
+	else if (flags & BTREE_TRIGGER_transactional)
+		return commit_do(trans, NULL, NULL, 0,
+				 __bch2_trans_mark_metadata_bucket(trans, ca, b, type, sectors));
+	else
+		BUG();
 }
 
 static int bch2_trans_mark_metadata_sectors(struct btree_trans *trans,
-					    struct bch_dev *ca,
-					    u64 start, u64 end,
-					    enum bch_data_type type,
-					    u64 *bucket, unsigned *bucket_sectors)
+			struct bch_dev *ca, u64 start, u64 end,
+			enum bch_data_type type, u64 *bucket, unsigned *bucket_sectors,
+			enum btree_iter_update_trigger_flags flags)
 {
 	do {
 		u64 b = sector_to_bucket(ca, start);
@@ -1183,7 +1390,7 @@ static int bch2_trans_mark_metadata_sectors(struct btree_trans *trans,
 
 		if (b != *bucket && *bucket_sectors) {
 			int ret = bch2_trans_mark_metadata_bucket(trans, ca, *bucket,
-								  type, *bucket_sectors);
+							type, *bucket_sectors, flags);
 			if (ret)
 				return ret;
 
@@ -1198,8 +1405,8 @@ static int bch2_trans_mark_metadata_sectors(struct btree_trans *trans,
 	return 0;
 }
 
-static int __bch2_trans_mark_dev_sb(struct btree_trans *trans,
-				    struct bch_dev *ca)
+static int __bch2_trans_mark_dev_sb(struct btree_trans *trans, struct bch_dev *ca,
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_sb_layout *layout = &ca->disk_sb.sb->layout;
 	u64 bucket = 0;
@@ -1212,21 +1419,21 @@ static int __bch2_trans_mark_dev_sb(struct btree_trans *trans,
 		if (offset == BCH_SB_SECTOR) {
 			ret = bch2_trans_mark_metadata_sectors(trans, ca,
 						0, BCH_SB_SECTOR,
-						BCH_DATA_sb, &bucket, &bucket_sectors);
+						BCH_DATA_sb, &bucket, &bucket_sectors, flags);
 			if (ret)
 				return ret;
 		}
 
 		ret = bch2_trans_mark_metadata_sectors(trans, ca, offset,
 				      offset + (1 << layout->sb_max_size_bits),
-				      BCH_DATA_sb, &bucket, &bucket_sectors);
+				      BCH_DATA_sb, &bucket, &bucket_sectors, flags);
 		if (ret)
 			return ret;
 	}
 
 	if (bucket_sectors) {
 		ret = bch2_trans_mark_metadata_bucket(trans, ca,
-				bucket, BCH_DATA_sb, bucket_sectors);
+				bucket, BCH_DATA_sb, bucket_sectors, flags);
 		if (ret)
 			return ret;
 	}
@@ -1234,7 +1441,7 @@ static int __bch2_trans_mark_dev_sb(struct btree_trans *trans,
 	for (i = 0; i < ca->journal.nr; i++) {
 		ret = bch2_trans_mark_metadata_bucket(trans, ca,
 				ca->journal.buckets[i],
-				BCH_DATA_journal, ca->mi.bucket_size);
+				BCH_DATA_journal, ca->mi.bucket_size, flags);
 		if (ret)
 			return ret;
 	}
@@ -1242,20 +1449,22 @@ static int __bch2_trans_mark_dev_sb(struct btree_trans *trans,
 	return 0;
 }
 
-int bch2_trans_mark_dev_sb(struct bch_fs *c, struct bch_dev *ca)
+int bch2_trans_mark_dev_sb(struct bch_fs *c, struct bch_dev *ca,
+			enum btree_iter_update_trigger_flags flags)
 {
-	int ret = bch2_trans_run(c, __bch2_trans_mark_dev_sb(trans, ca));
-
+	int ret = bch2_trans_run(c,
+		__bch2_trans_mark_dev_sb(trans, ca, flags));
 	bch_err_fn(c, ret);
 	return ret;
 }
 
-int bch2_trans_mark_dev_sbs(struct bch_fs *c)
+int bch2_trans_mark_dev_sbs_flags(struct bch_fs *c,
+			enum btree_iter_update_trigger_flags flags)
 {
 	for_each_online_member(c, ca) {
-		int ret = bch2_trans_mark_dev_sb(c, ca);
+		int ret = bch2_trans_mark_dev_sb(c, ca, flags);
 		if (ret) {
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			return ret;
 		}
 	}
@@ -1263,6 +1472,11 @@ int bch2_trans_mark_dev_sbs(struct bch_fs *c)
 	return 0;
 }
 
+int bch2_trans_mark_dev_sbs(struct bch_fs *c)
+{
+	return bch2_trans_mark_dev_sbs_flags(c, BTREE_TRIGGER_transactional);
+}
+
 /* Disk reservations: */
 
 #define SECTORS_CACHE	1024
@@ -1331,6 +1545,31 @@ recalculate:
 
 /* Startup/shutdown: */
 
+void bch2_buckets_nouse_free(struct bch_fs *c)
+{
+	for_each_member_device(c, ca) {
+		kvfree_rcu_mightsleep(ca->buckets_nouse);
+		ca->buckets_nouse = NULL;
+	}
+}
+
+int bch2_buckets_nouse_alloc(struct bch_fs *c)
+{
+	for_each_member_device(c, ca) {
+		BUG_ON(ca->buckets_nouse);
+
+		ca->buckets_nouse = kvmalloc(BITS_TO_LONGS(ca->mi.nbuckets) *
+					    sizeof(unsigned long),
+					    GFP_KERNEL|__GFP_ZERO);
+		if (!ca->buckets_nouse) {
+			bch2_dev_put(ca);
+			return -BCH_ERR_ENOMEM_buckets_nouse;
+		}
+	}
+
+	return 0;
+}
+
 static void bucket_gens_free_rcu(struct rcu_head *rcu)
 {
 	struct bucket_gens *buckets =
@@ -1342,24 +1581,17 @@ static void bucket_gens_free_rcu(struct rcu_head *rcu)
 int bch2_dev_buckets_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 {
 	struct bucket_gens *bucket_gens = NULL, *old_bucket_gens = NULL;
-	unsigned long *buckets_nouse = NULL;
 	bool resize = ca->bucket_gens != NULL;
 	int ret;
 
+	BUG_ON(resize && ca->buckets_nouse);
+
 	if (!(bucket_gens	= kvmalloc(sizeof(struct bucket_gens) + nbuckets,
 					   GFP_KERNEL|__GFP_ZERO))) {
 		ret = -BCH_ERR_ENOMEM_bucket_gens;
 		goto err;
 	}
 
-	if ((c->opts.buckets_nouse &&
-	     !(buckets_nouse	= kvmalloc(BITS_TO_LONGS(nbuckets) *
-					   sizeof(unsigned long),
-					   GFP_KERNEL|__GFP_ZERO)))) {
-		ret = -BCH_ERR_ENOMEM_buckets_nouse;
-		goto err;
-	}
-
 	bucket_gens->first_bucket = ca->mi.first_bucket;
 	bucket_gens->nbuckets	= nbuckets;
 
@@ -1377,17 +1609,11 @@ int bch2_dev_buckets_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 		memcpy(bucket_gens->b,
 		       old_bucket_gens->b,
 		       n);
-		if (buckets_nouse)
-			memcpy(buckets_nouse,
-			       ca->buckets_nouse,
-			       BITS_TO_LONGS(n) * sizeof(unsigned long));
 	}
 
 	rcu_assign_pointer(ca->bucket_gens, bucket_gens);
 	bucket_gens	= old_bucket_gens;
 
-	swap(ca->buckets_nouse, buckets_nouse);
-
 	nbuckets = ca->mi.nbuckets;
 
 	if (resize) {
@@ -1398,7 +1624,6 @@ int bch2_dev_buckets_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 
 	ret = 0;
 err:
-	kvfree(buckets_nouse);
 	if (bucket_gens)
 		call_rcu(&bucket_gens->rcu, bucket_gens_free_rcu);
 
diff --git a/fs/bcachefs/buckets.h b/fs/bcachefs/buckets.h
index f9af5adabe83..617ffde2fb7a 100644
--- a/fs/bcachefs/buckets.h
+++ b/fs/bcachefs/buckets.h
@@ -12,7 +12,7 @@
 #include "extents.h"
 #include "sb-members.h"
 
-static inline size_t sector_to_bucket(const struct bch_dev *ca, sector_t s)
+static inline u64 sector_to_bucket(const struct bch_dev *ca, sector_t s)
 {
 	return div_u64(s, ca->mi.bucket_size);
 }
@@ -30,8 +30,7 @@ static inline sector_t bucket_remainder(const struct bch_dev *ca, sector_t s)
 	return remainder;
 }
 
-static inline size_t sector_to_bucket_and_offset(const struct bch_dev *ca, sector_t s,
-						 u32 *offset)
+static inline u64 sector_to_bucket_and_offset(const struct bch_dev *ca, sector_t s, u32 *offset)
 {
 	return div_u64_rem(s, ca->mi.bucket_size, offset);
 }
@@ -94,7 +93,7 @@ static inline struct bucket *gc_bucket(struct bch_dev *ca, size_t b)
 {
 	struct bucket_array *buckets = gc_bucket_array(ca);
 
-	BUG_ON(b < buckets->first_bucket || b >= buckets->nbuckets);
+	BUG_ON(!bucket_valid(ca, b));
 	return buckets->b + b;
 }
 
@@ -111,7 +110,7 @@ static inline u8 *bucket_gen(struct bch_dev *ca, size_t b)
 {
 	struct bucket_gens *gens = bucket_gens(ca);
 
-	BUG_ON(b < gens->first_bucket || b >= gens->nbuckets);
+	BUG_ON(!bucket_valid(ca, b));
 	return gens->b + b;
 }
 
@@ -121,20 +120,16 @@ static inline size_t PTR_BUCKET_NR(const struct bch_dev *ca,
 	return sector_to_bucket(ca, ptr->offset);
 }
 
-static inline struct bpos PTR_BUCKET_POS(const struct bch_fs *c,
-				   const struct bch_extent_ptr *ptr)
+static inline struct bpos PTR_BUCKET_POS(const struct bch_dev *ca,
+					 const struct bch_extent_ptr *ptr)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-
 	return POS(ptr->dev, PTR_BUCKET_NR(ca, ptr));
 }
 
-static inline struct bpos PTR_BUCKET_POS_OFFSET(const struct bch_fs *c,
+static inline struct bpos PTR_BUCKET_POS_OFFSET(const struct bch_dev *ca,
 						const struct bch_extent_ptr *ptr,
 						u32 *bucket_offset)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-
 	return POS(ptr->dev, sector_to_bucket_and_offset(ca, ptr->offset, bucket_offset));
 }
 
@@ -175,17 +170,19 @@ static inline int gen_after(u8 a, u8 b)
 	return r > 0 ? r : 0;
 }
 
+static inline u8 dev_ptr_stale_rcu(struct bch_dev *ca, const struct bch_extent_ptr *ptr)
+{
+	return gen_after(*bucket_gen(ca, PTR_BUCKET_NR(ca, ptr)), ptr->gen);
+}
+
 /**
- * ptr_stale() - check if a pointer points into a bucket that has been
+ * dev_ptr_stale() - check if a pointer points into a bucket that has been
  * invalidated.
  */
-static inline u8 ptr_stale(struct bch_dev *ca,
-			   const struct bch_extent_ptr *ptr)
+static inline u8 dev_ptr_stale(struct bch_dev *ca, const struct bch_extent_ptr *ptr)
 {
-	u8 ret;
-
 	rcu_read_lock();
-	ret = gen_after(*bucket_gen(ca, PTR_BUCKET_NR(ca, ptr)), ptr->gen);
+	u8 ret = dev_ptr_stale_rcu(ca, ptr);
 	rcu_read_unlock();
 
 	return ret;
@@ -306,8 +303,6 @@ bch2_fs_usage_read_short(struct bch_fs *);
 void bch2_dev_usage_update(struct bch_fs *, struct bch_dev *,
 			   const struct bch_alloc_v4 *,
 			   const struct bch_alloc_v4 *, u64, bool);
-void bch2_dev_usage_update_m(struct bch_fs *, struct bch_dev *,
-			     struct bucket *, struct bucket *);
 
 /* key/bucket marking: */
 
@@ -333,27 +328,29 @@ int bch2_replicas_deltas_realloc(struct btree_trans *, unsigned);
 
 void bch2_fs_usage_initialize(struct bch_fs *);
 
-int bch2_check_bucket_ref(struct btree_trans *, struct bkey_s_c,
-			  const struct bch_extent_ptr *,
-			  s64, enum bch_data_type, u8, u8, u32);
+int bch2_bucket_ref_update(struct btree_trans *, struct bch_dev *,
+			   struct bkey_s_c, const struct bch_extent_ptr *,
+			   s64, enum bch_data_type, u8, u8, u32 *);
 
-int bch2_mark_metadata_bucket(struct bch_fs *, struct bch_dev *,
-			      size_t, enum bch_data_type, unsigned,
-			      struct gc_pos, unsigned);
+int bch2_check_fix_ptrs(struct btree_trans *,
+			enum btree_id, unsigned, struct bkey_s_c,
+			enum btree_iter_update_trigger_flags);
 
 int bch2_trigger_extent(struct btree_trans *, enum btree_id, unsigned,
-			struct bkey_s_c, struct bkey_s, unsigned);
+			struct bkey_s_c, struct bkey_s,
+			enum btree_iter_update_trigger_flags);
 int bch2_trigger_reservation(struct btree_trans *, enum btree_id, unsigned,
-			  struct bkey_s_c, struct bkey_s, unsigned);
+			  struct bkey_s_c, struct bkey_s,
+			  enum btree_iter_update_trigger_flags);
 
 #define trigger_run_overwrite_then_insert(_fn, _trans, _btree_id, _level, _old, _new, _flags)\
 ({												\
 	int ret = 0;										\
 												\
 	if (_old.k->type)									\
-		ret = _fn(_trans, _btree_id, _level, _old, _flags & ~BTREE_TRIGGER_INSERT);	\
+		ret = _fn(_trans, _btree_id, _level, _old, _flags & ~BTREE_TRIGGER_insert);	\
 	if (!ret && _new.k->type)								\
-		ret = _fn(_trans, _btree_id, _level, _new.s_c, _flags & ~BTREE_TRIGGER_OVERWRITE);\
+		ret = _fn(_trans, _btree_id, _level, _new.s_c, _flags & ~BTREE_TRIGGER_overwrite);\
 	ret;											\
 })
 
@@ -362,9 +359,13 @@ void bch2_trans_account_disk_usage_change(struct btree_trans *);
 void bch2_trans_fs_usage_revert(struct btree_trans *, struct replicas_delta_list *);
 int bch2_trans_fs_usage_apply(struct btree_trans *, struct replicas_delta_list *);
 
-int bch2_trans_mark_metadata_bucket(struct btree_trans *, struct bch_dev *,
-				    size_t, enum bch_data_type, unsigned);
-int bch2_trans_mark_dev_sb(struct bch_fs *, struct bch_dev *);
+int bch2_trans_mark_metadata_bucket(struct btree_trans *, struct bch_dev *, u64,
+				    enum bch_data_type, unsigned,
+				    enum btree_iter_update_trigger_flags);
+int bch2_trans_mark_dev_sb(struct bch_fs *, struct bch_dev *,
+				    enum btree_iter_update_trigger_flags);
+int bch2_trans_mark_dev_sbs_flags(struct bch_fs *,
+				    enum btree_iter_update_trigger_flags);
 int bch2_trans_mark_dev_sbs(struct bch_fs *);
 
 static inline bool is_superblock_bucket(struct bch_dev *ca, u64 b)
@@ -464,6 +465,9 @@ static inline u64 avail_factor(u64 r)
 	return div_u64(r << RESERVE_FACTOR, (1 << RESERVE_FACTOR) + 1);
 }
 
+void bch2_buckets_nouse_free(struct bch_fs *);
+int bch2_buckets_nouse_alloc(struct bch_fs *);
+
 int bch2_dev_buckets_resize(struct bch_fs *, struct bch_dev *, u64);
 void bch2_dev_buckets_free(struct bch_dev *);
 int bch2_dev_buckets_alloc(struct bch_fs *, struct bch_dev *);
diff --git a/fs/bcachefs/chardev.c b/fs/bcachefs/chardev.c
index 4d14f19f5185..9e54323f0f5f 100644
--- a/fs/bcachefs/chardev.c
+++ b/fs/bcachefs/chardev.c
@@ -32,12 +32,7 @@ static struct bch_dev *bch2_device_lookup(struct bch_fs *c, u64 dev,
 		if (dev >= c->sb.nr_devices)
 			return ERR_PTR(-EINVAL);
 
-		rcu_read_lock();
-		ca = rcu_dereference(c->devs[dev]);
-		if (ca)
-			percpu_ref_get(&ca->ref);
-		rcu_read_unlock();
-
+		ca = bch2_dev_tryget_noerror(c, dev);
 		if (!ca)
 			return ERR_PTR(-EINVAL);
 	} else {
@@ -391,7 +386,7 @@ static long bch2_ioctl_disk_offline(struct bch_fs *c, struct bch_ioctl_disk arg)
 		return PTR_ERR(ca);
 
 	ret = bch2_dev_offline(c, ca, arg.flags);
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 	return ret;
 }
 
@@ -420,7 +415,7 @@ static long bch2_ioctl_disk_set_state(struct bch_fs *c,
 	if (ret)
 		bch_err(c, "Error setting device state: %s", bch2_err_str(ret));
 
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 	return ret;
 }
 
@@ -615,7 +610,7 @@ static long bch2_ioctl_dev_usage(struct bch_fs *c,
 		arg.d[i].fragmented	= src.d[i].fragmented;
 	}
 
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 
 	return copy_to_user_errcode(user_arg, &arg, sizeof(arg));
 }
@@ -667,7 +662,7 @@ static long bch2_ioctl_dev_usage_v2(struct bch_fs *c,
 			goto err;
 	}
 err:
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 	return ret;
 }
 
@@ -689,11 +684,9 @@ static long bch2_ioctl_read_super(struct bch_fs *c,
 
 	if (arg.flags & BCH_READ_DEV) {
 		ca = bch2_device_lookup(c, arg.dev, arg.flags);
-
-		if (IS_ERR(ca)) {
-			ret = PTR_ERR(ca);
-			goto err;
-		}
+		ret = PTR_ERR_OR_ZERO(ca);
+		if (ret)
+			goto err_unlock;
 
 		sb = ca->disk_sb.sb;
 	} else {
@@ -708,8 +701,8 @@ static long bch2_ioctl_read_super(struct bch_fs *c,
 	ret = copy_to_user_errcode((void __user *)(unsigned long)arg.sb, sb,
 				   vstruct_bytes(sb));
 err:
-	if (!IS_ERR_OR_NULL(ca))
-		percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
+err_unlock:
 	mutex_unlock(&c->sb_lock);
 	return ret;
 }
@@ -753,7 +746,7 @@ static long bch2_ioctl_disk_resize(struct bch_fs *c,
 
 	ret = bch2_dev_resize(c, ca, arg.nbuckets);
 
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 	return ret;
 }
 
@@ -779,7 +772,7 @@ static long bch2_ioctl_disk_resize_journal(struct bch_fs *c,
 
 	ret = bch2_set_nr_journal_buckets(c, ca, arg.nbuckets);
 
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 	return ret;
 }
 
@@ -961,7 +954,9 @@ static const struct file_operations bch_chardev_fops = {
 };
 
 static int bch_chardev_major;
-static struct class *bch_chardev_class;
+static const struct class bch_chardev_class = {
+	.name = "bcachefs",
+};
 static struct device *bch_chardev;
 
 void bch2_fs_chardev_exit(struct bch_fs *c)
@@ -978,7 +973,7 @@ int bch2_fs_chardev_init(struct bch_fs *c)
 	if (c->minor < 0)
 		return c->minor;
 
-	c->chardev = device_create(bch_chardev_class, NULL,
+	c->chardev = device_create(&bch_chardev_class, NULL,
 				   MKDEV(bch_chardev_major, c->minor), c,
 				   "bcachefs%u-ctl", c->minor);
 	if (IS_ERR(c->chardev))
@@ -989,32 +984,39 @@ int bch2_fs_chardev_init(struct bch_fs *c)
 
 void bch2_chardev_exit(void)
 {
-	if (!IS_ERR_OR_NULL(bch_chardev_class))
-		device_destroy(bch_chardev_class,
-			       MKDEV(bch_chardev_major, U8_MAX));
-	if (!IS_ERR_OR_NULL(bch_chardev_class))
-		class_destroy(bch_chardev_class);
+	device_destroy(&bch_chardev_class, MKDEV(bch_chardev_major, U8_MAX));
+	class_unregister(&bch_chardev_class);
 	if (bch_chardev_major > 0)
 		unregister_chrdev(bch_chardev_major, "bcachefs");
 }
 
 int __init bch2_chardev_init(void)
 {
+	int ret;
+
 	bch_chardev_major = register_chrdev(0, "bcachefs-ctl", &bch_chardev_fops);
 	if (bch_chardev_major < 0)
 		return bch_chardev_major;
 
-	bch_chardev_class = class_create("bcachefs");
-	if (IS_ERR(bch_chardev_class))
-		return PTR_ERR(bch_chardev_class);
+	ret = class_register(&bch_chardev_class);
+	if (ret)
+		goto major_out;
 
-	bch_chardev = device_create(bch_chardev_class, NULL,
+	bch_chardev = device_create(&bch_chardev_class, NULL,
 				    MKDEV(bch_chardev_major, U8_MAX),
 				    NULL, "bcachefs-ctl");
-	if (IS_ERR(bch_chardev))
-		return PTR_ERR(bch_chardev);
+	if (IS_ERR(bch_chardev)) {
+		ret = PTR_ERR(bch_chardev);
+		goto class_out;
+	}
 
 	return 0;
+
+class_out:
+	class_unregister(&bch_chardev_class);
+major_out:
+	unregister_chrdev(bch_chardev_major, "bcachefs-ctl");
+	return ret;
 }
 
 #endif /* NO_BCACHEFS_CHARDEV */
diff --git a/fs/bcachefs/checksum.c b/fs/bcachefs/checksum.c
index 088fd2e7bdf1..85198f391e9c 100644
--- a/fs/bcachefs/checksum.c
+++ b/fs/bcachefs/checksum.c
@@ -469,9 +469,8 @@ int bch2_rechecksum_bio(struct bch_fs *c, struct bio *bio,
 
 /* BCH_SB_FIELD_crypt: */
 
-static int bch2_sb_crypt_validate(struct bch_sb *sb,
-				  struct bch_sb_field *f,
-				  struct printbuf *err)
+static int bch2_sb_crypt_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				  enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_crypt *crypt = field_to_type(f, crypt);
 
@@ -494,14 +493,10 @@ static void bch2_sb_crypt_to_text(struct printbuf *out, struct bch_sb *sb,
 {
 	struct bch_sb_field_crypt *crypt = field_to_type(f, crypt);
 
-	prt_printf(out, "KFD:               %llu", BCH_CRYPT_KDF_TYPE(crypt));
-	prt_newline(out);
-	prt_printf(out, "scrypt n:          %llu", BCH_KDF_SCRYPT_N(crypt));
-	prt_newline(out);
-	prt_printf(out, "scrypt r:          %llu", BCH_KDF_SCRYPT_R(crypt));
-	prt_newline(out);
-	prt_printf(out, "scrypt p:          %llu", BCH_KDF_SCRYPT_P(crypt));
-	prt_newline(out);
+	prt_printf(out, "KFD:               %llu\n", BCH_CRYPT_KDF_TYPE(crypt));
+	prt_printf(out, "scrypt n:          %llu\n", BCH_KDF_SCRYPT_N(crypt));
+	prt_printf(out, "scrypt r:          %llu\n", BCH_KDF_SCRYPT_R(crypt));
+	prt_printf(out, "scrypt p:          %llu\n", BCH_KDF_SCRYPT_P(crypt));
 }
 
 const struct bch_sb_field_ops bch_sb_field_ops_crypt = {
diff --git a/fs/bcachefs/data_update.c b/fs/bcachefs/data_update.c
index 0022b51ce3c0..0d807c2ce9c6 100644
--- a/fs/bcachefs/data_update.c
+++ b/fs/bcachefs/data_update.c
@@ -106,7 +106,7 @@ static int __bch2_data_update_index_update(struct btree_trans *trans,
 
 	bch2_trans_iter_init(trans, &iter, m->btree_id,
 			     bkey_start_pos(&bch2_keylist_front(keys)->k),
-			     BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+			     BTREE_ITER_slots|BTREE_ITER_intent);
 
 	while (1) {
 		struct bkey_s_c k;
@@ -203,6 +203,8 @@ restart_drop_conflicting_replicas:
 
 		/* Now, drop excess replicas: */
 restart_drop_extra_replicas:
+
+		rcu_read_lock();
 		bkey_for_each_ptr_decode(old.k, bch2_bkey_ptrs(bkey_i_to_s(insert)), p, entry) {
 			unsigned ptr_durability = bch2_extent_ptr_durability(c, &p);
 
@@ -214,6 +216,7 @@ restart_drop_extra_replicas:
 				goto restart_drop_extra_replicas;
 			}
 		}
+		rcu_read_unlock();
 
 		/* Finally, add the pointers we just wrote: */
 		extent_for_each_ptr_decode(extent_i_to_s(new), p, entry)
@@ -288,7 +291,7 @@ restart_drop_extra_replicas:
 						k.k->p, insert->k.p) ?:
 			bch2_bkey_set_needs_rebalance(c, insert, &op->opts) ?:
 			bch2_trans_update(trans, &iter, insert,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+				BTREE_UPDATE_internal_snapshot_node) ?:
 			bch2_trans_commit(trans, &op->res,
 				NULL,
 				BCH_TRANS_COMMIT_no_check_rw|
@@ -357,10 +360,11 @@ void bch2_data_update_exit(struct data_update *update)
 		bch2_bkey_ptrs_c(bkey_i_to_s_c(update->k.k));
 
 	bkey_for_each_ptr(ptrs, ptr) {
+		struct bch_dev *ca = bch2_dev_have_ref(c, ptr->dev);
 		if (c->opts.nocow_enabled)
 			bch2_bucket_nocow_unlock(&c->nocow_locks,
-						 PTR_BUCKET_POS(c, ptr), 0);
-		percpu_ref_put(&bch_dev_bkey_exists(c, ptr->dev)->ref);
+						 PTR_BUCKET_POS(ca, ptr), 0);
+		bch2_dev_put(ca);
 	}
 
 	bch2_bkey_buf_exit(&update->k, c);
@@ -386,8 +390,10 @@ static void bch2_update_unwritten_extent(struct btree_trans *trans,
 	while (bio_sectors(bio)) {
 		unsigned sectors = bio_sectors(bio);
 
+		bch2_trans_begin(trans);
+
 		bch2_trans_iter_init(trans, &iter, update->btree_id, update->op.pos,
-				     BTREE_ITER_SLOTS);
+				     BTREE_ITER_slots);
 		ret = lockrestart_do(trans, ({
 			k = bch2_btree_iter_peek_slot(&iter);
 			bkey_err(k);
@@ -465,7 +471,6 @@ int bch2_extent_drop_ptrs(struct btree_trans *trans,
 
 	while (data_opts.kill_ptrs) {
 		unsigned i = 0, drop = __fls(data_opts.kill_ptrs);
-		struct bch_extent_ptr *ptr;
 
 		bch2_bkey_drop_ptrs(bkey_i_to_s(n), ptr, i++ == drop);
 		data_opts.kill_ptrs ^= 1U << drop;
@@ -480,15 +485,15 @@ int bch2_extent_drop_ptrs(struct btree_trans *trans,
 
 	/*
 	 * Since we're not inserting through an extent iterator
-	 * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
+	 * (BTREE_ITER_all_snapshots iterators aren't extent iterators),
 	 * we aren't using the extent overwrite path to delete, we're
 	 * just using the normal key deletion path:
 	 */
-	if (bkey_deleted(&n->k) && !(iter->flags & BTREE_ITER_IS_EXTENTS))
+	if (bkey_deleted(&n->k) && !(iter->flags & BTREE_ITER_is_extents))
 		n->k.size = 0;
 
 	return bch2_trans_relock(trans) ?:
-		bch2_trans_update(trans, iter, n, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+		bch2_trans_update(trans, iter, n, BTREE_UPDATE_internal_snapshot_node) ?:
 		bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
 }
 
@@ -539,15 +544,26 @@ int bch2_data_update_init(struct btree_trans *trans,
 	m->op.compression_opt	= background_compression(io_opts);
 	m->op.watermark		= m->data_opts.btree_insert_flags & BCH_WATERMARK_MASK;
 
-	bkey_for_each_ptr(ptrs, ptr)
-		percpu_ref_get(&bch_dev_bkey_exists(c, ptr->dev)->ref);
+	bkey_for_each_ptr(ptrs, ptr) {
+		if (!bch2_dev_tryget(c, ptr->dev)) {
+			bkey_for_each_ptr(ptrs, ptr2) {
+				if (ptr2 == ptr)
+					break;
+				bch2_dev_put(bch2_dev_have_ref(c, ptr2->dev));
+			}
+			return -BCH_ERR_data_update_done;
+		}
+	}
 
 	unsigned durability_have = 0, durability_removing = 0;
 
 	i = 0;
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
+		struct bch_dev *ca = bch2_dev_have_ref(c, p.ptr.dev);
+		struct bpos bucket = PTR_BUCKET_POS(ca, &p.ptr);
 		bool locked;
 
+		rcu_read_lock();
 		if (((1U << i) & m->data_opts.rewrite_ptrs)) {
 			BUG_ON(p.ptr.cached);
 
@@ -561,6 +577,7 @@ int bch2_data_update_init(struct btree_trans *trans,
 			bch2_dev_list_add_dev(&m->op.devs_have, p.ptr.dev);
 			durability_have += bch2_extent_ptr_durability(c, &p);
 		}
+		rcu_read_unlock();
 
 		/*
 		 * op->csum_type is normally initialized from the fs/file's
@@ -579,15 +596,13 @@ int bch2_data_update_init(struct btree_trans *trans,
 			if (ctxt) {
 				move_ctxt_wait_event(ctxt,
 						(locked = bch2_bucket_nocow_trylock(&c->nocow_locks,
-									  PTR_BUCKET_POS(c, &p.ptr), 0)) ||
+									  bucket, 0)) ||
 						list_empty(&ctxt->ios));
 
 				if (!locked)
-					bch2_bucket_nocow_lock(&c->nocow_locks,
-							       PTR_BUCKET_POS(c, &p.ptr), 0);
+					bch2_bucket_nocow_lock(&c->nocow_locks, bucket, 0);
 			} else {
-				if (!bch2_bucket_nocow_trylock(&c->nocow_locks,
-							       PTR_BUCKET_POS(c, &p.ptr), 0)) {
+				if (!bch2_bucket_nocow_trylock(&c->nocow_locks, bucket, 0)) {
 					ret = -BCH_ERR_nocow_lock_blocked;
 					goto err;
 				}
@@ -649,10 +664,11 @@ int bch2_data_update_init(struct btree_trans *trans,
 err:
 	i = 0;
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
+		struct bch_dev *ca = bch2_dev_have_ref(c, p.ptr.dev);
+		struct bpos bucket = PTR_BUCKET_POS(ca, &p.ptr);
 		if ((1U << i) & ptrs_locked)
-			bch2_bucket_nocow_unlock(&c->nocow_locks,
-						 PTR_BUCKET_POS(c, &p.ptr), 0);
-		percpu_ref_put(&bch_dev_bkey_exists(c, p.ptr.dev)->ref);
+			bch2_bucket_nocow_unlock(&c->nocow_locks, bucket, 0);
+		bch2_dev_put(ca);
 		i++;
 	}
 
diff --git a/fs/bcachefs/debug.c b/fs/bcachefs/debug.c
index cd99b7399414..51cbf3928361 100644
--- a/fs/bcachefs/debug.c
+++ b/fs/bcachefs/debug.c
@@ -37,11 +37,11 @@ static bool bch2_btree_verify_replica(struct bch_fs *c, struct btree *b,
 	struct btree_node *n_ondisk = c->verify_ondisk;
 	struct btree_node *n_sorted = c->verify_data->data;
 	struct bset *sorted, *inmemory = &b->data->keys;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, pick.ptr.dev);
 	struct bio *bio;
 	bool failed = false, saw_error = false;
 
-	if (!bch2_dev_get_ioref(ca, READ))
+	struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
+	if (!ca)
 		return false;
 
 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
@@ -194,8 +194,8 @@ void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
 		return;
 	}
 
-	ca = bch_dev_bkey_exists(c, pick.ptr.dev);
-	if (!bch2_dev_get_ioref(ca, READ)) {
+	ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
+	if (!ca) {
 		prt_printf(out, "error getting device to read from: not online\n");
 		return;
 	}
@@ -375,8 +375,8 @@ static ssize_t bch2_read_btree(struct file *file, char __user *buf,
 	return flush_buf(i) ?:
 		bch2_trans_run(i->c,
 			for_each_btree_key(trans, iter, i->id, i->from,
-					   BTREE_ITER_PREFETCH|
-					   BTREE_ITER_ALL_SNAPSHOTS, k, ({
+					   BTREE_ITER_prefetch|
+					   BTREE_ITER_all_snapshots, k, ({
 				bch2_bkey_val_to_text(&i->buf, i->c, k);
 				prt_newline(&i->buf);
 				bch2_trans_unlock(trans);
@@ -459,8 +459,8 @@ static ssize_t bch2_read_bfloat_failed(struct file *file, char __user *buf,
 	return flush_buf(i) ?:
 		bch2_trans_run(i->c,
 			for_each_btree_key(trans, iter, i->id, i->from,
-					   BTREE_ITER_PREFETCH|
-					   BTREE_ITER_ALL_SNAPSHOTS, k, ({
+					   BTREE_ITER_prefetch|
+					   BTREE_ITER_all_snapshots, k, ({
 				struct btree_path_level *l =
 					&btree_iter_path(trans, &iter)->l[0];
 				struct bkey_packed *_k =
@@ -492,51 +492,26 @@ static void bch2_cached_btree_node_to_text(struct printbuf *out, struct bch_fs *
 	if (!out->nr_tabstops)
 		printbuf_tabstop_push(out, 32);
 
-	prt_printf(out, "%px btree=%s l=%u ",
-	       b,
-	       bch2_btree_id_str(b->c.btree_id),
-	       b->c.level);
-	prt_newline(out);
+	prt_printf(out, "%px btree=%s l=%u\n", b, bch2_btree_id_str(b->c.btree_id), b->c.level);
 
 	printbuf_indent_add(out, 2);
 
 	bch2_bkey_val_to_text(out, c, bkey_i_to_s_c(&b->key));
 	prt_newline(out);
 
-	prt_printf(out, "flags: ");
-	prt_tab(out);
+	prt_printf(out, "flags:\t");
 	prt_bitflags(out, bch2_btree_node_flags, b->flags);
 	prt_newline(out);
 
-	prt_printf(out, "pcpu read locks: ");
-	prt_tab(out);
-	prt_printf(out, "%u", b->c.lock.readers != NULL);
-	prt_newline(out);
-
-	prt_printf(out, "written:");
-	prt_tab(out);
-	prt_printf(out, "%u", b->written);
-	prt_newline(out);
-
-	prt_printf(out, "writes blocked:");
-	prt_tab(out);
-	prt_printf(out, "%u", !list_empty_careful(&b->write_blocked));
-	prt_newline(out);
-
-	prt_printf(out, "will make reachable:");
-	prt_tab(out);
-	prt_printf(out, "%lx", b->will_make_reachable);
-	prt_newline(out);
-
-	prt_printf(out, "journal pin %px:", &b->writes[0].journal);
-	prt_tab(out);
-	prt_printf(out, "%llu", b->writes[0].journal.seq);
-	prt_newline(out);
+	prt_printf(out, "pcpu read locks:\t%u\n",	b->c.lock.readers != NULL);
+	prt_printf(out, "written:\t%u\n",		b->written);
+	prt_printf(out, "writes blocked:\t%u\n",	!list_empty_careful(&b->write_blocked));
+	prt_printf(out, "will make reachable:\t%lx\n",	b->will_make_reachable);
 
-	prt_printf(out, "journal pin %px:", &b->writes[1].journal);
-	prt_tab(out);
-	prt_printf(out, "%llu", b->writes[1].journal.seq);
-	prt_newline(out);
+	prt_printf(out, "journal pin %px:\t%llu\n",
+		   &b->writes[0].journal, b->writes[0].journal.seq);
+	prt_printf(out, "journal pin %px:\t%llu\n",
+		   &b->writes[1].journal, b->writes[1].journal.seq);
 
 	printbuf_indent_sub(out, 2);
 }
@@ -625,8 +600,7 @@ restart:
 
 		bch2_btree_trans_to_text(&i->buf, trans);
 
-		prt_printf(&i->buf, "backtrace:");
-		prt_newline(&i->buf);
+		prt_printf(&i->buf, "backtrace:\n");
 		printbuf_indent_add(&i->buf, 2);
 		bch2_prt_task_backtrace(&i->buf, task, 0, GFP_KERNEL);
 		printbuf_indent_sub(&i->buf, 2);
@@ -782,25 +756,20 @@ static ssize_t btree_transaction_stats_read(struct file *file, char __user *buf,
 		    !bch2_btree_transaction_fns[i->iter])
 			break;
 
-		prt_printf(&i->buf, "%s: ", bch2_btree_transaction_fns[i->iter]);
-		prt_newline(&i->buf);
+		prt_printf(&i->buf, "%s:\n", bch2_btree_transaction_fns[i->iter]);
 		printbuf_indent_add(&i->buf, 2);
 
 		mutex_lock(&s->lock);
 
-		prt_printf(&i->buf, "Max mem used: %u", s->max_mem);
-		prt_newline(&i->buf);
-
-		prt_printf(&i->buf, "Transaction duration:");
-		prt_newline(&i->buf);
+		prt_printf(&i->buf, "Max mem used: %u\n", s->max_mem);
+		prt_printf(&i->buf, "Transaction duration:\n");
 
 		printbuf_indent_add(&i->buf, 2);
 		bch2_time_stats_to_text(&i->buf, &s->duration);
 		printbuf_indent_sub(&i->buf, 2);
 
 		if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) {
-			prt_printf(&i->buf, "Lock hold times:");
-			prt_newline(&i->buf);
+			prt_printf(&i->buf, "Lock hold times:\n");
 
 			printbuf_indent_add(&i->buf, 2);
 			bch2_time_stats_to_text(&i->buf, &s->lock_hold_times);
@@ -808,8 +777,7 @@ static ssize_t btree_transaction_stats_read(struct file *file, char __user *buf,
 		}
 
 		if (s->max_paths_text) {
-			prt_printf(&i->buf, "Maximum allocated btree paths (%u):", s->nr_max_paths);
-			prt_newline(&i->buf);
+			prt_printf(&i->buf, "Maximum allocated btree paths (%u):\n", s->nr_max_paths);
 
 			printbuf_indent_add(&i->buf, 2);
 			prt_str_indented(&i->buf, s->max_paths_text);
diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
index d37bd07afbfe..6bbf9a7d9e4d 100644
--- a/fs/bcachefs/dirent.c
+++ b/fs/bcachefs/dirent.c
@@ -98,7 +98,7 @@ const struct bch_hash_desc bch2_dirent_hash_desc = {
 };
 
 int bch2_dirent_invalid(struct bch_fs *c, struct bkey_s_c k,
-			enum bkey_invalid_flags flags,
+			enum bch_validate_flags flags,
 			struct printbuf *err)
 {
 	struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
@@ -118,7 +118,7 @@ int bch2_dirent_invalid(struct bch_fs *c, struct bkey_s_c k,
 	 * Check new keys don't exceed the max length
 	 * (older keys may be larger.)
 	 */
-	bkey_fsck_err_on((flags & BKEY_INVALID_COMMIT) && d_name.len > BCH_NAME_MAX, c, err,
+	bkey_fsck_err_on((flags & BCH_VALIDATE_commit) && d_name.len > BCH_NAME_MAX, c, err,
 			 dirent_name_too_long,
 			 "dirent name too big (%u > %u)",
 			 d_name.len, BCH_NAME_MAX);
@@ -205,7 +205,7 @@ int bch2_dirent_create_snapshot(struct btree_trans *trans,
 			const struct bch_hash_info *hash_info,
 			u8 type, const struct qstr *name, u64 dst_inum,
 			u64 *dir_offset,
-			bch_str_hash_flags_t str_hash_flags)
+			enum btree_iter_update_trigger_flags flags)
 {
 	subvol_inum dir_inum = { .subvol = dir_subvol, .inum = dir };
 	struct bkey_i_dirent *dirent;
@@ -220,9 +220,8 @@ int bch2_dirent_create_snapshot(struct btree_trans *trans,
 	dirent->k.p.snapshot	= snapshot;
 
 	ret = bch2_hash_set_in_snapshot(trans, bch2_dirent_hash_desc, hash_info,
-					dir_inum, snapshot,
-					&dirent->k_i, str_hash_flags,
-					BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+					dir_inum, snapshot, &dirent->k_i,
+					flags|BTREE_UPDATE_internal_snapshot_node);
 	*dir_offset = dirent->k.p.offset;
 
 	return ret;
@@ -232,7 +231,7 @@ int bch2_dirent_create(struct btree_trans *trans, subvol_inum dir,
 		       const struct bch_hash_info *hash_info,
 		       u8 type, const struct qstr *name, u64 dst_inum,
 		       u64 *dir_offset,
-		       bch_str_hash_flags_t str_hash_flags)
+		       enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_i_dirent *dirent;
 	int ret;
@@ -243,7 +242,7 @@ int bch2_dirent_create(struct btree_trans *trans, subvol_inum dir,
 		return ret;
 
 	ret = bch2_hash_set(trans, bch2_dirent_hash_desc, hash_info,
-			    dir, &dirent->k_i, str_hash_flags);
+			    dir, &dirent->k_i, flags);
 	*dir_offset = dirent->k.p.offset;
 
 	return ret;
@@ -272,7 +271,7 @@ int bch2_dirent_read_target(struct btree_trans *trans, subvol_inum dir,
 	} else {
 		target->subvol	= le32_to_cpu(d.v->d_child_subvol);
 
-		ret = bch2_subvolume_get(trans, target->subvol, true, BTREE_ITER_CACHED, &s);
+		ret = bch2_subvolume_get(trans, target->subvol, true, BTREE_ITER_cached, &s);
 
 		target->inum	= le64_to_cpu(s.inode);
 	}
@@ -301,13 +300,9 @@ int bch2_dirent_rename(struct btree_trans *trans,
 	memset(dst_inum, 0, sizeof(*dst_inum));
 
 	/* Lookup src: */
-	ret = bch2_hash_lookup(trans, &src_iter, bch2_dirent_hash_desc,
-			       src_hash, src_dir, src_name,
-			       BTREE_ITER_INTENT);
-	if (ret)
-		goto out;
-
-	old_src = bch2_btree_iter_peek_slot(&src_iter);
+	old_src = bch2_hash_lookup(trans, &src_iter, bch2_dirent_hash_desc,
+				   src_hash, src_dir, src_name,
+				   BTREE_ITER_intent);
 	ret = bkey_err(old_src);
 	if (ret)
 		goto out;
@@ -329,13 +324,9 @@ int bch2_dirent_rename(struct btree_trans *trans,
 		if (ret)
 			goto out;
 	} else {
-		ret = bch2_hash_lookup(trans, &dst_iter, bch2_dirent_hash_desc,
-				       dst_hash, dst_dir, dst_name,
-				       BTREE_ITER_INTENT);
-		if (ret)
-			goto out;
-
-		old_dst = bch2_btree_iter_peek_slot(&dst_iter);
+		old_dst = bch2_hash_lookup(trans, &dst_iter, bch2_dirent_hash_desc,
+					    dst_hash, dst_dir, dst_name,
+					    BTREE_ITER_intent);
 		ret = bkey_err(old_dst);
 		if (ret)
 			goto out;
@@ -450,7 +441,7 @@ out_set_src:
 	if (delete_src) {
 		bch2_btree_iter_set_snapshot(&src_iter, old_src.k->p.snapshot);
 		ret =   bch2_btree_iter_traverse(&src_iter) ?:
-			bch2_btree_delete_at(trans, &src_iter, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+			bch2_btree_delete_at(trans, &src_iter, BTREE_UPDATE_internal_snapshot_node);
 		if (ret)
 			goto out;
 	}
@@ -458,7 +449,7 @@ out_set_src:
 	if (delete_dst) {
 		bch2_btree_iter_set_snapshot(&dst_iter, old_dst.k->p.snapshot);
 		ret =   bch2_btree_iter_traverse(&dst_iter) ?:
-			bch2_btree_delete_at(trans, &dst_iter, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+			bch2_btree_delete_at(trans, &dst_iter, BTREE_UPDATE_internal_snapshot_node);
 		if (ret)
 			goto out;
 	}
@@ -479,13 +470,9 @@ int bch2_dirent_lookup_trans(struct btree_trans *trans,
 			     const struct qstr *name, subvol_inum *inum,
 			     unsigned flags)
 {
-	int ret = bch2_hash_lookup(trans, iter, bch2_dirent_hash_desc,
-				   hash_info, dir, name, flags);
-	if (ret)
-		return ret;
-
-	struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
-	ret = bkey_err(k);
+	struct bkey_s_c k = bch2_hash_lookup(trans, iter, bch2_dirent_hash_desc,
+					     hash_info, dir, name, flags);
+	int ret = bkey_err(k);
 	if (ret)
 		goto err;
 
@@ -541,16 +528,26 @@ int bch2_empty_dir_trans(struct btree_trans *trans, subvol_inum dir)
 		bch2_empty_dir_snapshot(trans, dir.inum, dir.subvol, snapshot);
 }
 
+static int bch2_dir_emit(struct dir_context *ctx, struct bkey_s_c_dirent d, subvol_inum target)
+{
+	struct qstr name = bch2_dirent_get_name(d);
+	bool ret = dir_emit(ctx, name.name,
+		      name.len,
+		      target.inum,
+		      vfs_d_type(d.v->d_type));
+	if (ret)
+		ctx->pos = d.k->p.offset + 1;
+	return ret;
+}
+
 int bch2_readdir(struct bch_fs *c, subvol_inum inum, struct dir_context *ctx)
 {
 	struct btree_trans *trans = bch2_trans_get(c);
 	struct btree_iter iter;
 	struct bkey_s_c k;
-	struct bkey_s_c_dirent dirent;
 	subvol_inum target;
 	u32 snapshot;
 	struct bkey_buf sk;
-	struct qstr name;
 	int ret;
 
 	bch2_bkey_buf_init(&sk);
@@ -567,7 +564,9 @@ retry:
 		if (k.k->type != KEY_TYPE_dirent)
 			continue;
 
-		dirent = bkey_s_c_to_dirent(k);
+		/* dir_emit() can fault and block: */
+		bch2_bkey_buf_reassemble(&sk, c, k);
+		struct bkey_s_c_dirent dirent = bkey_i_to_s_c_dirent(sk.k);
 
 		ret = bch2_dirent_read_target(trans, inum, dirent, &target);
 		if (ret < 0)
@@ -575,28 +574,22 @@ retry:
 		if (ret)
 			continue;
 
-		/* dir_emit() can fault and block: */
-		bch2_bkey_buf_reassemble(&sk, c, k);
-		dirent = bkey_i_to_s_c_dirent(sk.k);
-		bch2_trans_unlock(trans);
-
-		name = bch2_dirent_get_name(dirent);
-
-		ctx->pos = dirent.k->p.offset;
-		if (!dir_emit(ctx, name.name,
-			      name.len,
-			      target.inum,
-			      vfs_d_type(dirent.v->d_type)))
-			break;
-		ctx->pos = dirent.k->p.offset + 1;
-
 		/*
 		 * read_target looks up subvolumes, we can overflow paths if the
 		 * directory has many subvolumes in it
+		 *
+		 * XXX: btree_trans_too_many_iters() is something we'd like to
+		 * get rid of, and there's no good reason to be using it here
+		 * except that we don't yet have a for_each_btree_key() helper
+		 * that does subvolume_get_snapshot().
 		 */
-		ret = btree_trans_too_many_iters(trans);
-		if (ret)
+		ret =   drop_locks_do(trans,
+				bch2_dir_emit(ctx, dirent, target)) ?:
+			btree_trans_too_many_iters(trans);
+		if (ret) {
+			ret = ret < 0 ? ret : 0;
 			break;
+		}
 	}
 	bch2_trans_iter_exit(trans, &iter);
 err:
diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
index bee55cca2aa0..24037e6e0a09 100644
--- a/fs/bcachefs/dirent.h
+++ b/fs/bcachefs/dirent.h
@@ -4,11 +4,11 @@
 
 #include "str_hash.h"
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 extern const struct bch_hash_desc bch2_dirent_hash_desc;
 
 int bch2_dirent_invalid(struct bch_fs *, struct bkey_s_c,
-			enum bkey_invalid_flags, struct printbuf *);
+			enum bch_validate_flags, struct printbuf *);
 void bch2_dirent_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 #define bch2_bkey_ops_dirent ((struct bkey_ops) {	\
@@ -38,11 +38,11 @@ int bch2_dirent_read_target(struct btree_trans *, subvol_inum,
 int bch2_dirent_create_snapshot(struct btree_trans *, u32, u64, u32,
 			const struct bch_hash_info *, u8,
 			const struct qstr *, u64, u64 *,
-			bch_str_hash_flags_t);
+			enum btree_iter_update_trigger_flags);
 int bch2_dirent_create(struct btree_trans *, subvol_inum,
 		       const struct bch_hash_info *, u8,
 		       const struct qstr *, u64, u64 *,
-		       bch_str_hash_flags_t);
+		       enum btree_iter_update_trigger_flags);
 
 static inline unsigned vfs_d_type(unsigned type)
 {
diff --git a/fs/bcachefs/disk_groups.c b/fs/bcachefs/disk_groups.c
index 06a7df529b40..521a86df5e52 100644
--- a/fs/bcachefs/disk_groups.c
+++ b/fs/bcachefs/disk_groups.c
@@ -18,9 +18,8 @@ static int group_cmp(const void *_l, const void *_r)
 		strncmp(l->label, r->label, sizeof(l->label));
 }
 
-static int bch2_sb_disk_groups_validate(struct bch_sb *sb,
-					struct bch_sb_field *f,
-					struct printbuf *err)
+static int bch2_sb_disk_groups_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_disk_groups *groups =
 		field_to_type(f, disk_groups);
@@ -177,7 +176,7 @@ int bch2_sb_disk_groups_to_cpu(struct bch_fs *c)
 		struct bch_member m = bch2_sb_member_get(c->disk_sb.sb, i);
 		struct bch_disk_group_cpu *dst;
 
-		if (!bch2_member_exists(&m))
+		if (!bch2_member_alive(&m))
 			continue;
 
 		g = BCH_MEMBER_GROUP(&m);
@@ -523,7 +522,7 @@ int bch2_opt_target_parse(struct bch_fs *c, const char *val, u64 *res,
 	ca = bch2_dev_lookup(c, val);
 	if (!IS_ERR(ca)) {
 		*res = dev_to_target(ca->dev_idx);
-		percpu_ref_put(&ca->ref);
+		bch2_dev_put(ca);
 		return 0;
 	}
 
@@ -588,7 +587,7 @@ static void bch2_target_to_text_sb(struct printbuf *out, struct bch_sb *sb, unsi
 	case TARGET_DEV: {
 		struct bch_member m = bch2_sb_member_get(sb, t.dev);
 
-		if (bch2_dev_exists(sb, t.dev)) {
+		if (bch2_member_exists(sb, t.dev)) {
 			prt_printf(out, "Device ");
 			pr_uuid(out, m.uuid.b);
 			prt_printf(out, " (%u)", t.dev);
diff --git a/fs/bcachefs/ec.c b/fs/bcachefs/ec.c
index 556a217108d3..b26dc7424662 100644
--- a/fs/bcachefs/ec.c
+++ b/fs/bcachefs/ec.c
@@ -107,7 +107,7 @@ struct ec_bio {
 /* Stripes btree keys: */
 
 int bch2_stripe_invalid(struct bch_fs *c, struct bkey_s_c k,
-			enum bkey_invalid_flags flags,
+			enum bch_validate_flags flags,
 			struct printbuf *err)
 {
 	const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
@@ -163,146 +163,189 @@ void bch2_stripe_to_text(struct printbuf *out, struct bch_fs *c,
 
 /* Triggers: */
 
-static int bch2_trans_mark_stripe_bucket(struct btree_trans *trans,
-					 struct bkey_s_c_stripe s,
-					 unsigned idx, bool deleting)
+static int __mark_stripe_bucket(struct btree_trans *trans,
+				struct bch_dev *ca,
+				struct bkey_s_c_stripe s,
+				unsigned ptr_idx, bool deleting,
+				struct bpos bucket,
+				struct bch_alloc_v4 *a,
+				enum btree_iter_update_trigger_flags flags)
 {
-	struct bch_fs *c = trans->c;
-	const struct bch_extent_ptr *ptr = &s.v->ptrs[idx];
-	struct btree_iter iter;
-	struct bkey_i_alloc_v4 *a;
-	enum bch_data_type data_type = idx >= s.v->nr_blocks - s.v->nr_redundant
-		? BCH_DATA_parity : 0;
-	s64 sectors = data_type ? le16_to_cpu(s.v->sectors) : 0;
+	const struct bch_extent_ptr *ptr = s.v->ptrs + ptr_idx;
+	unsigned nr_data = s.v->nr_blocks - s.v->nr_redundant;
+	bool parity = ptr_idx >= nr_data;
+	enum bch_data_type data_type = parity ? BCH_DATA_parity : BCH_DATA_stripe;
+	s64 sectors = parity ? le16_to_cpu(s.v->sectors) : 0;
+	struct printbuf buf = PRINTBUF;
 	int ret = 0;
 
+	struct bch_fs *c = trans->c;
 	if (deleting)
 		sectors = -sectors;
 
-	a = bch2_trans_start_alloc_update(trans, &iter, PTR_BUCKET_POS(c, ptr));
-	if (IS_ERR(a))
-		return PTR_ERR(a);
-
-	ret = bch2_check_bucket_ref(trans, s.s_c, ptr, sectors, data_type,
-				    a->v.gen, a->v.data_type,
-				    a->v.dirty_sectors);
-	if (ret)
-		goto err;
-
 	if (!deleting) {
-		if (bch2_trans_inconsistent_on(a->v.stripe ||
-					       a->v.stripe_redundancy, trans,
-				"bucket %llu:%llu gen %u data type %s dirty_sectors %u: multiple stripes using same bucket (%u, %llu)",
-				iter.pos.inode, iter.pos.offset, a->v.gen,
-				bch2_data_type_str(a->v.data_type),
-				a->v.dirty_sectors,
-				a->v.stripe, s.k->p.offset)) {
+		if (bch2_trans_inconsistent_on(a->stripe ||
+					       a->stripe_redundancy, trans,
+				"bucket %llu:%llu gen %u data type %s dirty_sectors %u: multiple stripes using same bucket (%u, %llu)\n%s",
+				bucket.inode, bucket.offset, a->gen,
+				bch2_data_type_str(a->data_type),
+				a->dirty_sectors,
+				a->stripe, s.k->p.offset,
+				(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 			ret = -EIO;
 			goto err;
 		}
 
-		if (bch2_trans_inconsistent_on(data_type && a->v.dirty_sectors, trans,
-				"bucket %llu:%llu gen %u data type %s dirty_sectors %u: data already in stripe bucket %llu",
-				iter.pos.inode, iter.pos.offset, a->v.gen,
-				bch2_data_type_str(a->v.data_type),
-				a->v.dirty_sectors,
-				s.k->p.offset)) {
+		if (bch2_trans_inconsistent_on(parity && bch2_bucket_sectors_total(*a), trans,
+				"bucket %llu:%llu gen %u data type %s dirty_sectors %u cached_sectors %u: data already in parity bucket\n%s",
+				bucket.inode, bucket.offset, a->gen,
+				bch2_data_type_str(a->data_type),
+				a->dirty_sectors,
+				a->cached_sectors,
+				(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 			ret = -EIO;
 			goto err;
 		}
-
-		a->v.stripe		= s.k->p.offset;
-		a->v.stripe_redundancy	= s.v->nr_redundant;
-		a->v.data_type		= BCH_DATA_stripe;
 	} else {
-		if (bch2_trans_inconsistent_on(a->v.stripe != s.k->p.offset ||
-					       a->v.stripe_redundancy != s.v->nr_redundant, trans,
-				"bucket %llu:%llu gen %u: not marked as stripe when deleting stripe %llu (got %u)",
-				iter.pos.inode, iter.pos.offset, a->v.gen,
-				s.k->p.offset, a->v.stripe)) {
+		if (bch2_trans_inconsistent_on(a->stripe != s.k->p.offset ||
+					       a->stripe_redundancy != s.v->nr_redundant, trans,
+				"bucket %llu:%llu gen %u: not marked as stripe when deleting stripe (got %u)\n%s",
+				bucket.inode, bucket.offset, a->gen,
+				a->stripe,
+				(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
 			ret = -EIO;
 			goto err;
 		}
 
-		a->v.stripe		= 0;
-		a->v.stripe_redundancy	= 0;
-		a->v.data_type		= alloc_data_type(a->v, BCH_DATA_user);
+		if (bch2_trans_inconsistent_on(a->data_type != data_type, trans,
+				"bucket %llu:%llu gen %u data type %s: wrong data type when stripe, should be %s\n%s",
+				bucket.inode, bucket.offset, a->gen,
+				bch2_data_type_str(a->data_type),
+				bch2_data_type_str(data_type),
+				(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
+			ret = -EIO;
+			goto err;
+		}
+
+		if (bch2_trans_inconsistent_on(parity &&
+					       (a->dirty_sectors != -sectors ||
+						a->cached_sectors), trans,
+				"bucket %llu:%llu gen %u dirty_sectors %u cached_sectors %u: wrong sectors when deleting parity block of stripe\n%s",
+				bucket.inode, bucket.offset, a->gen,
+				a->dirty_sectors,
+				a->cached_sectors,
+				(bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
+			ret = -EIO;
+			goto err;
+		}
 	}
 
-	a->v.dirty_sectors += sectors;
-	if (data_type)
-		a->v.data_type = !deleting ? data_type : 0;
+	if (sectors) {
+		ret = bch2_bucket_ref_update(trans, ca, s.s_c, ptr, sectors, data_type,
+					     a->gen, a->data_type, &a->dirty_sectors);
+		if (ret)
+			goto err;
+	}
 
-	ret = bch2_trans_update(trans, &iter, &a->k_i, 0);
-	if (ret)
-		goto err;
+	if (!deleting) {
+		a->stripe		= s.k->p.offset;
+		a->stripe_redundancy	= s.v->nr_redundant;
+	} else {
+		a->stripe		= 0;
+		a->stripe_redundancy	= 0;
+	}
+
+	alloc_data_type_set(a, data_type);
 err:
-	bch2_trans_iter_exit(trans, &iter);
+	printbuf_exit(&buf);
 	return ret;
 }
 
 static int mark_stripe_bucket(struct btree_trans *trans,
-			      struct bkey_s_c k,
-			      unsigned ptr_idx,
-			      unsigned flags)
+			      struct bkey_s_c_stripe s,
+			      unsigned ptr_idx, bool deleting,
+			      enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
-	const struct bch_stripe *s = bkey_s_c_to_stripe(k).v;
-	unsigned nr_data = s->nr_blocks - s->nr_redundant;
-	bool parity = ptr_idx >= nr_data;
-	enum bch_data_type data_type = parity ? BCH_DATA_parity : BCH_DATA_stripe;
-	s64 sectors = parity ? le16_to_cpu(s->sectors) : 0;
-	const struct bch_extent_ptr *ptr = s->ptrs + ptr_idx;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-	struct bucket old, new, *g;
-	struct printbuf buf = PRINTBUF;
+	const struct bch_extent_ptr *ptr = s.v->ptrs + ptr_idx;
 	int ret = 0;
 
-	BUG_ON(!(flags & BTREE_TRIGGER_GC));
+	struct bch_dev *ca = bch2_dev_tryget(c, ptr->dev);
+	if (unlikely(!ca)) {
+		if (!(flags & BTREE_TRIGGER_overwrite))
+			ret = -EIO;
+		goto err;
+	}
 
-	/* * XXX doesn't handle deletion */
+	struct bpos bucket = PTR_BUCKET_POS(ca, ptr);
 
-	percpu_down_read(&c->mark_lock);
-	g = PTR_GC_BUCKET(ca, ptr);
+	if (flags & BTREE_TRIGGER_transactional) {
+		struct bkey_i_alloc_v4 *a =
+			bch2_trans_start_alloc_update(trans, bucket);
+		ret = PTR_ERR_OR_ZERO(a) ?:
+			__mark_stripe_bucket(trans, ca, s, ptr_idx, deleting, bucket, &a->v, flags);
+	}
 
-	if (g->dirty_sectors ||
-	    (g->stripe && g->stripe != k.k->p.offset)) {
-		bch2_fs_inconsistent(c,
-			      "bucket %u:%zu gen %u: multiple stripes using same bucket\n%s",
-			      ptr->dev, PTR_BUCKET_NR(ca, ptr), g->gen,
-			      (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
-		ret = -EINVAL;
-		goto err;
+	if (flags & BTREE_TRIGGER_gc) {
+		percpu_down_read(&c->mark_lock);
+		struct bucket *g = gc_bucket(ca, bucket.offset);
+		bucket_lock(g);
+		struct bch_alloc_v4 old = bucket_m_to_alloc(*g), new = old;
+		ret = __mark_stripe_bucket(trans, ca, s, ptr_idx, deleting, bucket, &new, flags);
+		if (!ret) {
+			alloc_to_bucket(g, new);
+			bch2_dev_usage_update(c, ca, &old, &new, 0, true);
+		}
+		bucket_unlock(g);
+		percpu_up_read(&c->mark_lock);
 	}
+err:
+	bch2_dev_put(ca);
+	return ret;
+}
 
-	bucket_lock(g);
-	old = *g;
+static int mark_stripe_buckets(struct btree_trans *trans,
+			       struct bkey_s_c old, struct bkey_s_c new,
+			       enum btree_iter_update_trigger_flags flags)
+{
+	const struct bch_stripe *old_s = old.k->type == KEY_TYPE_stripe
+		? bkey_s_c_to_stripe(old).v : NULL;
+	const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
+		? bkey_s_c_to_stripe(new).v : NULL;
 
-	ret = bch2_check_bucket_ref(trans, k, ptr, sectors, data_type,
-				    g->gen, g->data_type,
-				    g->dirty_sectors);
-	if (ret)
-		goto err;
+	BUG_ON(old_s && new_s && old_s->nr_blocks != new_s->nr_blocks);
 
-	g->data_type = data_type;
-	g->dirty_sectors += sectors;
+	unsigned nr_blocks = new_s ? new_s->nr_blocks : old_s->nr_blocks;
 
-	g->stripe		= k.k->p.offset;
-	g->stripe_redundancy	= s->nr_redundant;
-	new = *g;
-err:
-	bucket_unlock(g);
-	if (!ret)
-		bch2_dev_usage_update_m(c, ca, &old, &new);
-	percpu_up_read(&c->mark_lock);
-	printbuf_exit(&buf);
-	return ret;
+	for (unsigned i = 0; i < nr_blocks; i++) {
+		if (new_s && old_s &&
+		    !memcmp(&new_s->ptrs[i],
+			    &old_s->ptrs[i],
+			    sizeof(new_s->ptrs[i])))
+			continue;
+
+		if (new_s) {
+			int ret = mark_stripe_bucket(trans,
+					bkey_s_c_to_stripe(new), i, false, flags);
+			if (ret)
+				return ret;
+		}
+
+		if (old_s) {
+			int ret = mark_stripe_bucket(trans,
+					bkey_s_c_to_stripe(old), i, true, flags);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
 }
 
 int bch2_trigger_stripe(struct btree_trans *trans,
-			enum btree_id btree_id, unsigned level,
+			enum btree_id btree, unsigned level,
 			struct bkey_s_c old, struct bkey_s _new,
-			unsigned flags)
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_s_c new = _new.s_c;
 	struct bch_fs *c = trans->c;
@@ -312,7 +355,10 @@ int bch2_trigger_stripe(struct btree_trans *trans,
 	const struct bch_stripe *new_s = new.k->type == KEY_TYPE_stripe
 		? bkey_s_c_to_stripe(new).v : NULL;
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (unlikely(flags & BTREE_TRIGGER_check_repair))
+		return bch2_check_fix_ptrs(trans, btree, level, _new.s_c, flags);
+
+	if (flags & BTREE_TRIGGER_transactional) {
 		/*
 		 * If the pointers aren't changing, we don't need to do anything:
 		 */
@@ -347,31 +393,12 @@ int bch2_trigger_stripe(struct btree_trans *trans,
 				return ret;
 		}
 
-		unsigned nr_blocks = new_s ? new_s->nr_blocks : old_s->nr_blocks;
-		for (unsigned i = 0; i < nr_blocks; i++) {
-			if (new_s && old_s &&
-			    !memcmp(&new_s->ptrs[i],
-				    &old_s->ptrs[i],
-				    sizeof(new_s->ptrs[i])))
-				continue;
-
-			if (new_s) {
-				int ret = bch2_trans_mark_stripe_bucket(trans,
-						bkey_s_c_to_stripe(new), i, false);
-				if (ret)
-					return ret;
-			}
-
-			if (old_s) {
-				int ret = bch2_trans_mark_stripe_bucket(trans,
-						bkey_s_c_to_stripe(old), i, true);
-				if (ret)
-					return ret;
-			}
-		}
+		int ret = mark_stripe_buckets(trans, old, new, flags);
+		if (ret)
+			return ret;
 	}
 
-	if (flags & BTREE_TRIGGER_ATOMIC) {
+	if (flags & BTREE_TRIGGER_atomic) {
 		struct stripe *m = genradix_ptr(&c->stripes, idx);
 
 		if (!m) {
@@ -410,7 +437,7 @@ int bch2_trigger_stripe(struct btree_trans *trans,
 		}
 	}
 
-	if (flags & BTREE_TRIGGER_GC) {
+	if (flags & BTREE_TRIGGER_gc) {
 		struct gc_stripe *m =
 			genradix_ptr_alloc(&c->gc_stripes, idx, GFP_KERNEL);
 
@@ -439,13 +466,11 @@ int bch2_trigger_stripe(struct btree_trans *trans,
 		 */
 		memset(m->block_sectors, 0, sizeof(m->block_sectors));
 
-		for (unsigned i = 0; i < new_s->nr_blocks; i++) {
-			int ret = mark_stripe_bucket(trans, new, i, flags);
-			if (ret)
-				return ret;
-		}
+		int ret = mark_stripe_buckets(trans, old, new, flags);
+		if (ret)
+			return ret;
 
-		int ret = bch2_update_replicas(c, new, &m->r.e,
+		ret = bch2_update_replicas(c, new, &m->r.e,
 				      ((s64) m->sectors * m->nr_redundant),
 				      0, true);
 		if (ret) {
@@ -608,19 +633,21 @@ static void ec_validate_checksums(struct bch_fs *c, struct ec_stripe_buf *buf)
 			struct bch_csum got = ec_block_checksum(buf, i, offset);
 
 			if (bch2_crc_cmp(want, got)) {
-				struct printbuf err = PRINTBUF;
-				struct bch_dev *ca = bch_dev_bkey_exists(c, v->ptrs[i].dev);
+				struct bch_dev *ca = bch2_dev_tryget(c, v->ptrs[i].dev);
+				if (ca) {
+					struct printbuf err = PRINTBUF;
 
-				prt_str(&err, "stripe ");
-				bch2_csum_err_msg(&err, v->csum_type, want, got);
-				prt_printf(&err, "  for %ps at %u of\n  ", (void *) _RET_IP_, i);
-				bch2_bkey_val_to_text(&err, c, bkey_i_to_s_c(&buf->key));
-				bch_err_ratelimited(ca, "%s", err.buf);
-				printbuf_exit(&err);
+					prt_str(&err, "stripe ");
+					bch2_csum_err_msg(&err, v->csum_type, want, got);
+					prt_printf(&err, "  for %ps at %u of\n  ", (void *) _RET_IP_, i);
+					bch2_bkey_val_to_text(&err, c, bkey_i_to_s_c(&buf->key));
+					bch_err_ratelimited(ca, "%s", err.buf);
+					printbuf_exit(&err);
 
-				clear_bit(i, buf->valid);
+					bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
+				}
 
-				bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
+				clear_bit(i, buf->valid);
 				break;
 			}
 
@@ -687,7 +714,7 @@ static void ec_block_endio(struct bio *bio)
 			       bch2_blk_status_to_str(bio->bi_status)))
 		clear_bit(ec_bio->idx, ec_bio->buf->valid);
 
-	if (ptr_stale(ca, ptr)) {
+	if (dev_ptr_stale(ca, ptr)) {
 		bch_err_ratelimited(ca->fs,
 				    "error %s stripe: stale pointer after io",
 				    bio_data_dir(bio) == READ ? "reading from" : "writing to");
@@ -705,25 +732,26 @@ static void ec_block_io(struct bch_fs *c, struct ec_stripe_buf *buf,
 	struct bch_stripe *v = &bkey_i_to_stripe(&buf->key)->v;
 	unsigned offset = 0, bytes = buf->size << 9;
 	struct bch_extent_ptr *ptr = &v->ptrs[idx];
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 	enum bch_data_type data_type = idx < v->nr_blocks - v->nr_redundant
 		? BCH_DATA_user
 		: BCH_DATA_parity;
 	int rw = op_is_write(opf);
 
-	if (ptr_stale(ca, ptr)) {
-		bch_err_ratelimited(c,
-				    "error %s stripe: stale pointer",
-				    rw == READ ? "reading from" : "writing to");
+	struct bch_dev *ca = bch2_dev_get_ioref(c, ptr->dev, rw);
+	if (!ca) {
 		clear_bit(idx, buf->valid);
 		return;
 	}
 
-	if (!bch2_dev_get_ioref(ca, rw)) {
+	if (dev_ptr_stale(ca, ptr)) {
+		bch_err_ratelimited(c,
+				    "error %s stripe: stale pointer",
+				    rw == READ ? "reading from" : "writing to");
 		clear_bit(idx, buf->valid);
 		return;
 	}
 
+
 	this_cpu_add(ca->io_done->sectors[rw][data_type], buf->size);
 
 	while (offset < bytes) {
@@ -769,7 +797,7 @@ static int get_stripe_key_trans(struct btree_trans *trans, u64 idx,
 	int ret;
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
-			       POS(0, idx), BTREE_ITER_SLOTS);
+			       POS(0, idx), BTREE_ITER_slots);
 	ret = bkey_err(k);
 	if (ret)
 		goto err;
@@ -1060,7 +1088,7 @@ static int ec_stripe_delete(struct btree_trans *trans, u64 idx)
 	int ret;
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes, POS(0, idx),
-			       BTREE_ITER_INTENT);
+			       BTREE_ITER_intent);
 	ret = bkey_err(k);
 	if (ret)
 		goto err;
@@ -1131,7 +1159,7 @@ static int ec_stripe_key_update(struct btree_trans *trans,
 	int ret;
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_stripes,
-			       new->k.p, BTREE_ITER_INTENT);
+			       new->k.p, BTREE_ITER_intent);
 	ret = bkey_err(k);
 	if (ret)
 		goto err;
@@ -1173,6 +1201,7 @@ err:
 }
 
 static int ec_stripe_update_extent(struct btree_trans *trans,
+				   struct bch_dev *ca,
 				   struct bpos bucket, u8 gen,
 				   struct ec_stripe_buf *s,
 				   struct bpos *bp_pos)
@@ -1183,13 +1212,13 @@ static int ec_stripe_update_extent(struct btree_trans *trans,
 	struct btree_iter iter;
 	struct bkey_s_c k;
 	const struct bch_extent_ptr *ptr_c;
-	struct bch_extent_ptr *ptr, *ec_ptr = NULL;
+	struct bch_extent_ptr *ec_ptr = NULL;
 	struct bch_extent_stripe_ptr stripe_ptr;
 	struct bkey_i *n;
 	int ret, dev, block;
 
-	ret = bch2_get_next_backpointer(trans, bucket, gen,
-				bp_pos, &bp, BTREE_ITER_CACHED);
+	ret = bch2_get_next_backpointer(trans, ca, bucket, gen,
+				bp_pos, &bp, BTREE_ITER_cached);
 	if (ret)
 		return ret;
 	if (bpos_eq(*bp_pos, SPOS_MAX))
@@ -1214,7 +1243,7 @@ static int ec_stripe_update_extent(struct btree_trans *trans,
 		return -EIO;
 	}
 
-	k = bch2_backpointer_get_key(trans, &iter, *bp_pos, bp, BTREE_ITER_INTENT);
+	k = bch2_backpointer_get_key(trans, &iter, *bp_pos, bp, BTREE_ITER_intent);
 	ret = bkey_err(k);
 	if (ret)
 		return ret;
@@ -1272,17 +1301,21 @@ static int ec_stripe_update_bucket(struct btree_trans *trans, struct ec_stripe_b
 {
 	struct bch_fs *c = trans->c;
 	struct bch_stripe *v = &bkey_i_to_stripe(&s->key)->v;
-	struct bch_extent_ptr bucket = v->ptrs[block];
-	struct bpos bucket_pos = PTR_BUCKET_POS(c, &bucket);
+	struct bch_extent_ptr ptr = v->ptrs[block];
 	struct bpos bp_pos = POS_MIN;
 	int ret = 0;
 
+	struct bch_dev *ca = bch2_dev_tryget(c, ptr.dev);
+	if (!ca)
+		return -EIO;
+
+	struct bpos bucket_pos = PTR_BUCKET_POS(ca, &ptr);
+
 	while (1) {
 		ret = commit_do(trans, NULL, NULL,
 				BCH_TRANS_COMMIT_no_check_rw|
 				BCH_TRANS_COMMIT_no_enospc,
-			ec_stripe_update_extent(trans, bucket_pos, bucket.gen,
-						s, &bp_pos));
+			ec_stripe_update_extent(trans, ca, bucket_pos, ptr.gen, s, &bp_pos));
 		if (ret)
 			break;
 		if (bkey_eq(bp_pos, POS_MAX))
@@ -1291,6 +1324,7 @@ static int ec_stripe_update_bucket(struct btree_trans *trans, struct ec_stripe_b
 		bp_pos = bpos_nosnap_successor(bp_pos);
 	}
 
+	bch2_dev_put(ca);
 	return ret;
 }
 
@@ -1321,20 +1355,18 @@ static void zero_out_rest_of_ec_bucket(struct bch_fs *c,
 				       unsigned block,
 				       struct open_bucket *ob)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ob->dev);
-	unsigned offset = ca->mi.bucket_size - ob->sectors_free;
-	int ret;
-
-	if (!bch2_dev_get_ioref(ca, WRITE)) {
+	struct bch_dev *ca = bch2_dev_get_ioref(c, ob->dev, WRITE);
+	if (!ca) {
 		s->err = -BCH_ERR_erofs_no_writes;
 		return;
 	}
 
+	unsigned offset = ca->mi.bucket_size - ob->sectors_free;
 	memset(s->new_stripe.data[block] + (offset << 9),
 	       0,
 	       ob->sectors_free << 9);
 
-	ret = blkdev_issue_zeroout(ca->disk_sb.bdev,
+	int ret = blkdev_issue_zeroout(ca->disk_sb.bdev,
 			ob->bucket * ca->mi.bucket_size + offset,
 			ob->sectors_free,
 			GFP_KERNEL, 0);
@@ -1519,16 +1551,13 @@ void bch2_ec_bucket_cancel(struct bch_fs *c, struct open_bucket *ob)
 void *bch2_writepoint_ec_buf(struct bch_fs *c, struct write_point *wp)
 {
 	struct open_bucket *ob = ec_open_bucket(c, &wp->ptrs);
-	struct bch_dev *ca;
-	unsigned offset;
-
 	if (!ob)
 		return NULL;
 
 	BUG_ON(!ob->ec->new_stripe.data[ob->ec_idx]);
 
-	ca	= bch_dev_bkey_exists(c, ob->dev);
-	offset	= ca->mi.bucket_size - ob->sectors_free;
+	struct bch_dev *ca	= ob_dev(c, ob);
+	unsigned offset		= ca->mi.bucket_size - ob->sectors_free;
 
 	return ob->ec->new_stripe.data[ob->ec_idx] + (offset << 9);
 }
@@ -1937,7 +1966,7 @@ static int __bch2_ec_stripe_head_reserve(struct btree_trans *trans, struct ec_st
 	}
 
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_stripes, start_pos,
-			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
+			   BTREE_ITER_slots|BTREE_ITER_intent, k, ret) {
 		if (bkey_gt(k.k->p, POS(0, U32_MAX))) {
 			if (start_pos.offset) {
 				start_pos = min_pos;
@@ -2127,7 +2156,7 @@ int bch2_stripes_read(struct bch_fs *c)
 {
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter, BTREE_ID_stripes, POS_MIN,
-				   BTREE_ITER_PREFETCH, k, ({
+				   BTREE_ITER_prefetch, k, ({
 			if (k.k->type != KEY_TYPE_stripe)
 				continue;
 
diff --git a/fs/bcachefs/ec.h b/fs/bcachefs/ec.h
index f042616888b0..84a23eeb6249 100644
--- a/fs/bcachefs/ec.h
+++ b/fs/bcachefs/ec.h
@@ -6,14 +6,15 @@
 #include "buckets_types.h"
 #include "extents_types.h"
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 
 int bch2_stripe_invalid(struct bch_fs *, struct bkey_s_c,
-			enum bkey_invalid_flags, struct printbuf *);
+			enum bch_validate_flags, struct printbuf *);
 void bch2_stripe_to_text(struct printbuf *, struct bch_fs *,
 			 struct bkey_s_c);
 int bch2_trigger_stripe(struct btree_trans *, enum btree_id, unsigned,
-			struct bkey_s_c, struct bkey_s, unsigned);
+			struct bkey_s_c, struct bkey_s,
+			enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_stripe ((struct bkey_ops) {	\
 	.key_invalid	= bch2_stripe_invalid,		\
diff --git a/fs/bcachefs/error.c b/fs/bcachefs/error.c
index 82a6656c941c..c66eeffcd7f2 100644
--- a/fs/bcachefs/error.c
+++ b/fs/bcachefs/error.c
@@ -176,6 +176,21 @@ static struct fsck_err_state *fsck_err_get(struct bch_fs *c, const char *fmt)
 	return s;
 }
 
+/* s/fix?/fixing/ s/recreate?/recreating/ */
+static void prt_actioning(struct printbuf *out, const char *action)
+{
+	unsigned len = strlen(action);
+
+	BUG_ON(action[len - 1] != '?');
+	--len;
+
+	if (action[len - 1] == 'e')
+		--len;
+
+	prt_bytes(out, action, len);
+	prt_str(out, "ing");
+}
+
 int bch2_fsck_err(struct bch_fs *c,
 		  enum bch_fsck_flags flags,
 		  enum bch_sb_error_id err,
@@ -186,6 +201,7 @@ int bch2_fsck_err(struct bch_fs *c,
 	bool print = true, suppressing = false, inconsistent = false;
 	struct printbuf buf = PRINTBUF, *out = &buf;
 	int ret = -BCH_ERR_fsck_ignore;
+	const char *action_orig = "fix?", *action = action_orig;
 
 	if ((flags & FSCK_CAN_FIX) &&
 	    test_bit(err, c->sb.errors_silent))
@@ -197,6 +213,19 @@ int bch2_fsck_err(struct bch_fs *c,
 	prt_vprintf(out, fmt, args);
 	va_end(args);
 
+	/* Custom fix/continue/recreate/etc.? */
+	if (out->buf[out->pos - 1] == '?') {
+		const char *p = strrchr(out->buf, ',');
+		if (p) {
+			out->pos = p - out->buf;
+			action = kstrdup(p + 2, GFP_KERNEL);
+			if (!action) {
+				ret = -ENOMEM;
+				goto err;
+			}
+		}
+	}
+
 	mutex_lock(&c->fsck_error_msgs_lock);
 	s = fsck_err_get(c, fmt);
 	if (s) {
@@ -208,12 +237,16 @@ int bch2_fsck_err(struct bch_fs *c,
 		if (s->last_msg && !strcmp(buf.buf, s->last_msg)) {
 			ret = s->ret;
 			mutex_unlock(&c->fsck_error_msgs_lock);
-			printbuf_exit(&buf);
-			return ret;
+			goto err;
 		}
 
 		kfree(s->last_msg);
 		s->last_msg = kstrdup(buf.buf, GFP_KERNEL);
+		if (!s->last_msg) {
+			mutex_unlock(&c->fsck_error_msgs_lock);
+			ret = -ENOMEM;
+			goto err;
+		}
 
 		if (c->opts.ratelimit_errors &&
 		    !(flags & FSCK_NO_RATELIMIT) &&
@@ -239,7 +272,8 @@ int bch2_fsck_err(struct bch_fs *c,
 			inconsistent = true;
 			ret = -BCH_ERR_fsck_errors_not_fixed;
 		} else if (flags & FSCK_CAN_FIX) {
-			prt_str(out, ", fixing");
+			prt_str(out, ", ");
+			prt_actioning(out, action);
 			ret = -BCH_ERR_fsck_fix;
 		} else {
 			prt_str(out, ", continuing");
@@ -254,16 +288,16 @@ int bch2_fsck_err(struct bch_fs *c,
 			: c->opts.fix_errors;
 
 		if (fix == FSCK_FIX_ask) {
-			int ask;
+			prt_str(out, ", ");
+			prt_str(out, action);
 
-			prt_str(out, ": fix?");
 			if (bch2_fs_stdio_redirect(c))
 				bch2_print(c, "%s", out->buf);
 			else
 				bch2_print_string_as_lines(KERN_ERR, out->buf);
 			print = false;
 
-			ask = bch2_fsck_ask_yn(c);
+			int ask = bch2_fsck_ask_yn(c);
 
 			if (ask >= YN_ALLNO && s)
 				s->fix = ask == YN_ALLNO
@@ -276,10 +310,12 @@ int bch2_fsck_err(struct bch_fs *c,
 		} else if (fix == FSCK_FIX_yes ||
 			   (c->opts.nochanges &&
 			    !(flags & FSCK_CAN_IGNORE))) {
-			prt_str(out, ", fixing");
+			prt_str(out, ", ");
+			prt_actioning(out, action);
 			ret = -BCH_ERR_fsck_fix;
 		} else {
-			prt_str(out, ", not fixing");
+			prt_str(out, ", not ");
+			prt_actioning(out, action);
 		}
 	} else if (flags & FSCK_NEED_FSCK) {
 		prt_str(out, " (run fsck to correct)");
@@ -311,8 +347,6 @@ int bch2_fsck_err(struct bch_fs *c,
 
 	mutex_unlock(&c->fsck_error_msgs_lock);
 
-	printbuf_exit(&buf);
-
 	if (inconsistent)
 		bch2_inconsistent_error(c);
 
@@ -322,7 +356,10 @@ int bch2_fsck_err(struct bch_fs *c,
 		set_bit(BCH_FS_errors_not_fixed, &c->flags);
 		set_bit(BCH_FS_error, &c->flags);
 	}
-
+err:
+	if (action != action_orig)
+		kfree(action);
+	printbuf_exit(&buf);
 	return ret;
 }
 
diff --git a/fs/bcachefs/extent_update.c b/fs/bcachefs/extent_update.c
index b9033bb4f11c..5f4fecb358da 100644
--- a/fs/bcachefs/extent_update.c
+++ b/fs/bcachefs/extent_update.c
@@ -72,7 +72,7 @@ static int count_iters_for_insert(struct btree_trans *trans,
 
 		for_each_btree_key_norestart(trans, iter,
 				   BTREE_ID_reflink, POS(0, idx + offset),
-				   BTREE_ITER_SLOTS, r_k, ret2) {
+				   BTREE_ITER_slots, r_k, ret2) {
 			if (bkey_ge(bkey_start_pos(r_k.k), POS(0, idx + sectors)))
 				break;
 
diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index 1a331e539204..469037929685 100644
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -71,6 +71,12 @@ void bch2_mark_io_failure(struct bch_io_failures *failed,
 	}
 }
 
+static inline u64 dev_latency(struct bch_fs *c, unsigned dev)
+{
+	struct bch_dev *ca = bch2_dev_rcu(c, dev);
+	return ca ? atomic64_read(&ca->cur_latency[READ]) : S64_MAX;
+}
+
 /*
  * returns true if p1 is better than p2:
  */
@@ -79,11 +85,8 @@ static inline bool ptr_better(struct bch_fs *c,
 			      const struct extent_ptr_decoded p2)
 {
 	if (likely(!p1.idx && !p2.idx)) {
-		struct bch_dev *dev1 = bch_dev_bkey_exists(c, p1.ptr.dev);
-		struct bch_dev *dev2 = bch_dev_bkey_exists(c, p2.ptr.dev);
-
-		u64 l1 = atomic64_read(&dev1->cur_latency[READ]);
-		u64 l2 = atomic64_read(&dev2->cur_latency[READ]);
+		u64 l1 = dev_latency(c, p1.ptr.dev);
+		u64 l2 = dev_latency(c, p2.ptr.dev);
 
 		/* Pick at random, biased in favor of the faster device: */
 
@@ -109,21 +112,21 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
 	const union bch_extent_entry *entry;
 	struct extent_ptr_decoded p;
 	struct bch_dev_io_failures *f;
-	struct bch_dev *ca;
 	int ret = 0;
 
 	if (k.k->type == KEY_TYPE_error)
 		return -EIO;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
 		/*
 		 * Unwritten extent: no need to actually read, treat it as a
 		 * hole and return 0s:
 		 */
-		if (p.ptr.unwritten)
-			return 0;
-
-		ca = bch_dev_bkey_exists(c, p.ptr.dev);
+		if (p.ptr.unwritten) {
+			ret = 0;
+			break;
+		}
 
 		/*
 		 * If there are any dirty pointers it's an error if we can't
@@ -132,7 +135,9 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
 		if (!ret && !p.ptr.cached)
 			ret = -EIO;
 
-		if (p.ptr.cached && ptr_stale(ca, &p.ptr))
+		struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
+
+		if (p.ptr.cached && (!ca || dev_ptr_stale(ca, &p.ptr)))
 			continue;
 
 		f = failed ? dev_io_failures(failed, p.ptr.dev) : NULL;
@@ -141,12 +146,13 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
 				? f->idx
 				: f->idx + 1;
 
-		if (!p.idx &&
-		    !bch2_dev_is_readable(ca))
+		if (!p.idx && !ca)
 			p.idx++;
 
-		if (bch2_force_reconstruct_read &&
-		    !p.idx && p.has_ec)
+		if (!p.idx && p.has_ec && bch2_force_reconstruct_read)
+			p.idx++;
+
+		if (!p.idx && !bch2_dev_is_readable(ca))
 			p.idx++;
 
 		if (p.idx >= (unsigned) p.has_ec + 1)
@@ -158,6 +164,7 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
 		*pick = p;
 		ret = 1;
 	}
+	rcu_read_unlock();
 
 	return ret;
 }
@@ -165,7 +172,7 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
 /* KEY_TYPE_btree_ptr: */
 
 int bch2_btree_ptr_invalid(struct bch_fs *c, struct bkey_s_c k,
-			   enum bkey_invalid_flags flags,
+			   enum bch_validate_flags flags,
 			   struct printbuf *err)
 {
 	int ret = 0;
@@ -186,7 +193,7 @@ void bch2_btree_ptr_to_text(struct printbuf *out, struct bch_fs *c,
 }
 
 int bch2_btree_ptr_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
-			      enum bkey_invalid_flags flags,
+			      enum bch_validate_flags flags,
 			      struct printbuf *err)
 {
 	struct bkey_s_c_btree_ptr_v2 bp = bkey_s_c_to_btree_ptr_v2(k);
@@ -201,6 +208,11 @@ int bch2_btree_ptr_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
 			 c, err, btree_ptr_v2_min_key_bad,
 			 "min_key > key");
 
+	if (flags & BCH_VALIDATE_write)
+		bkey_fsck_err_on(!bp.v->sectors_written,
+				 c, err, btree_ptr_v2_written_0,
+				 "sectors_written == 0");
+
 	ret = bch2_bkey_ptrs_invalid(c, k, flags, err);
 fsck_err:
 	return ret;
@@ -247,7 +259,6 @@ bool bch2_extent_merge(struct bch_fs *c, struct bkey_s l, struct bkey_s_c r)
 	const union bch_extent_entry *en_r;
 	struct extent_ptr_decoded lp, rp;
 	bool use_right_ptr;
-	struct bch_dev *ca;
 
 	en_l = l_ptrs.start;
 	en_r = r_ptrs.start;
@@ -278,8 +289,12 @@ bool bch2_extent_merge(struct bch_fs *c, struct bkey_s l, struct bkey_s_c r)
 			return false;
 
 		/* Extents may not straddle buckets: */
-		ca = bch_dev_bkey_exists(c, lp.ptr.dev);
-		if (PTR_BUCKET_NR(ca, &lp.ptr) != PTR_BUCKET_NR(ca, &rp.ptr))
+		rcu_read_lock();
+		struct bch_dev *ca = bch2_dev_rcu(c, lp.ptr.dev);
+		bool same_bucket = ca && PTR_BUCKET_NR(ca, &lp.ptr) == PTR_BUCKET_NR(ca, &rp.ptr);
+		rcu_read_unlock();
+
+		if (!same_bucket)
 			return false;
 
 		if (lp.has_ec			!= rp.has_ec ||
@@ -385,7 +400,7 @@ bool bch2_extent_merge(struct bch_fs *c, struct bkey_s l, struct bkey_s_c r)
 /* KEY_TYPE_reservation: */
 
 int bch2_reservation_invalid(struct bch_fs *c, struct bkey_s_c k,
-			     enum bkey_invalid_flags flags,
+			     enum bch_validate_flags flags,
 			     struct printbuf *err)
 {
 	struct bkey_s_c_reservation r = bkey_s_c_to_reservation(k);
@@ -667,16 +682,16 @@ static inline unsigned __extent_ptr_durability(struct bch_dev *ca, struct extent
 
 unsigned bch2_extent_ptr_desired_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, p->ptr.dev);
+	struct bch_dev *ca = bch2_dev_rcu(c, p->ptr.dev);
 
-	return __extent_ptr_durability(ca, p);
+	return ca ? __extent_ptr_durability(ca, p) : 0;
 }
 
 unsigned bch2_extent_ptr_durability(struct bch_fs *c, struct extent_ptr_decoded *p)
 {
-	struct bch_dev *ca = bch_dev_bkey_exists(c, p->ptr.dev);
+	struct bch_dev *ca = bch2_dev_rcu(c, p->ptr.dev);
 
-	if (ca->mi.state == BCH_MEMBER_STATE_failed)
+	if (!ca || ca->mi.state == BCH_MEMBER_STATE_failed)
 		return 0;
 
 	return __extent_ptr_durability(ca, p);
@@ -689,8 +704,10 @@ unsigned bch2_bkey_durability(struct bch_fs *c, struct bkey_s_c k)
 	struct extent_ptr_decoded p;
 	unsigned durability = 0;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
 		durability += bch2_extent_ptr_durability(c, &p);
+	rcu_read_unlock();
 
 	return durability;
 }
@@ -702,9 +719,11 @@ static unsigned bch2_bkey_durability_safe(struct bch_fs *c, struct bkey_s_c k)
 	struct extent_ptr_decoded p;
 	unsigned durability = 0;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
 		if (p.ptr.dev < c->sb.nr_devices && c->devs[p.ptr.dev])
 			durability += bch2_extent_ptr_durability(c, &p);
+	rcu_read_unlock();
 
 	return durability;
 }
@@ -833,8 +852,6 @@ union bch_extent_entry *bch2_bkey_drop_ptr(struct bkey_s k,
 
 void bch2_bkey_drop_device(struct bkey_s k, unsigned dev)
 {
-	struct bch_extent_ptr *ptr;
-
 	bch2_bkey_drop_ptrs(k, ptr, ptr->dev == dev);
 }
 
@@ -860,14 +877,21 @@ const struct bch_extent_ptr *bch2_bkey_has_device_c(struct bkey_s_c k, unsigned
 bool bch2_bkey_has_target(struct bch_fs *c, struct bkey_s_c k, unsigned target)
 {
 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+	struct bch_dev *ca;
+	bool ret = false;
 
+	rcu_read_lock();
 	bkey_for_each_ptr(ptrs, ptr)
 		if (bch2_dev_in_target(c, ptr->dev, target) &&
+		    (ca = bch2_dev_rcu(c, ptr->dev)) &&
 		    (!ptr->cached ||
-		     !ptr_stale(bch_dev_bkey_exists(c, ptr->dev), ptr)))
-			return true;
+		     !dev_ptr_stale_rcu(ca, ptr))) {
+			ret = true;
+			break;
+		}
+	rcu_read_unlock();
 
-	return false;
+	return ret;
 }
 
 bool bch2_bkey_matches_ptr(struct bch_fs *c, struct bkey_s_c k,
@@ -969,21 +993,23 @@ void bch2_extent_ptr_set_cached(struct bkey_s k, struct bch_extent_ptr *ptr)
  */
 bool bch2_extent_normalize(struct bch_fs *c, struct bkey_s k)
 {
-	struct bch_extent_ptr *ptr;
+	struct bch_dev *ca;
 
+	rcu_read_lock();
 	bch2_bkey_drop_ptrs(k, ptr,
 		ptr->cached &&
-		ptr_stale(bch_dev_bkey_exists(c, ptr->dev), ptr));
+		(ca = bch2_dev_rcu(c, ptr->dev)) &&
+		dev_ptr_stale_rcu(ca, ptr));
+	rcu_read_unlock();
 
 	return bkey_deleted(k.k);
 }
 
 void bch2_extent_ptr_to_text(struct printbuf *out, struct bch_fs *c, const struct bch_extent_ptr *ptr)
 {
-	struct bch_dev *ca = c && ptr->dev < c->sb.nr_devices && c->devs[ptr->dev]
-		? bch_dev_bkey_exists(c, ptr->dev)
-		: NULL;
-
+	out->atomic++;
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, ptr->dev);
 	if (!ca) {
 		prt_printf(out, "ptr: %u:%llu gen %u%s", ptr->dev,
 			   (u64) ptr->offset, ptr->gen,
@@ -998,11 +1024,11 @@ void bch2_extent_ptr_to_text(struct printbuf *out, struct bch_fs *c, const struc
 			prt_str(out, " cached");
 		if (ptr->unwritten)
 			prt_str(out, " unwritten");
-		if (b >= ca->mi.first_bucket &&
-		    b <  ca->mi.nbuckets &&
-		    ptr_stale(ca, ptr))
+		if (bucket_valid(ca, b) && dev_ptr_stale_rcu(ca, ptr))
 			prt_printf(out, " stale");
 	}
+	rcu_read_unlock();
+	--out->atomic;
 }
 
 void bch2_bkey_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
@@ -1069,55 +1095,50 @@ void bch2_bkey_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
 
 static int extent_ptr_invalid(struct bch_fs *c,
 			      struct bkey_s_c k,
-			      enum bkey_invalid_flags flags,
+			      enum bch_validate_flags flags,
 			      const struct bch_extent_ptr *ptr,
 			      unsigned size_ondisk,
 			      bool metadata,
 			      struct printbuf *err)
 {
-	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
-	u64 bucket;
-	u32 bucket_offset;
-	struct bch_dev *ca;
 	int ret = 0;
 
-	if (!bch2_dev_exists2(c, ptr->dev)) {
-		/*
-		 * If we're in the write path this key might have already been
-		 * overwritten, and we could be seeing a device that doesn't
-		 * exist anymore due to racing with device removal:
-		 */
-		if (flags & BKEY_INVALID_WRITE)
-			return 0;
-
-		bkey_fsck_err(c, err, ptr_to_invalid_device,
-			   "pointer to invalid device (%u)", ptr->dev);
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, ptr->dev);
+	if (!ca) {
+		rcu_read_unlock();
+		return 0;
 	}
+	u32 bucket_offset;
+	u64 bucket = sector_to_bucket_and_offset(ca, ptr->offset, &bucket_offset);
+	unsigned first_bucket	= ca->mi.first_bucket;
+	u64 nbuckets		= ca->mi.nbuckets;
+	unsigned bucket_size	= ca->mi.bucket_size;
+	rcu_read_unlock();
 
-	ca = bch_dev_bkey_exists(c, ptr->dev);
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 	bkey_for_each_ptr(ptrs, ptr2)
 		bkey_fsck_err_on(ptr != ptr2 && ptr->dev == ptr2->dev, c, err,
 				 ptr_to_duplicate_device,
 				 "multiple pointers to same device (%u)", ptr->dev);
 
-	bucket = sector_to_bucket_and_offset(ca, ptr->offset, &bucket_offset);
 
-	bkey_fsck_err_on(bucket >= ca->mi.nbuckets, c, err,
+	bkey_fsck_err_on(bucket >= nbuckets, c, err,
 			 ptr_after_last_bucket,
-			 "pointer past last bucket (%llu > %llu)", bucket, ca->mi.nbuckets);
-	bkey_fsck_err_on(ptr->offset < bucket_to_sector(ca, ca->mi.first_bucket), c, err,
+			 "pointer past last bucket (%llu > %llu)", bucket, nbuckets);
+	bkey_fsck_err_on(bucket < first_bucket, c, err,
 			 ptr_before_first_bucket,
-			 "pointer before first bucket (%llu < %u)", bucket, ca->mi.first_bucket);
-	bkey_fsck_err_on(bucket_offset + size_ondisk > ca->mi.bucket_size, c, err,
+			 "pointer before first bucket (%llu < %u)", bucket, first_bucket);
+	bkey_fsck_err_on(bucket_offset + size_ondisk > bucket_size, c, err,
 			 ptr_spans_multiple_buckets,
 			 "pointer spans multiple buckets (%u + %u > %u)",
-		       bucket_offset, size_ondisk, ca->mi.bucket_size);
+		       bucket_offset, size_ondisk, bucket_size);
 fsck_err:
 	return ret;
 }
 
 int bch2_bkey_ptrs_invalid(struct bch_fs *c, struct bkey_s_c k,
-			   enum bkey_invalid_flags flags,
+			   enum bch_validate_flags flags,
 			   struct printbuf *err)
 {
 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
@@ -1193,7 +1214,7 @@ int bch2_bkey_ptrs_invalid(struct bch_fs *c, struct bkey_s_c k,
 
 			bkey_fsck_err_on(crc_is_encoded(crc) &&
 					 (crc.uncompressed_size > c->opts.encoded_extent_max >> 9) &&
-					 (flags & (BKEY_INVALID_WRITE|BKEY_INVALID_COMMIT)), c, err,
+					 (flags & (BCH_VALIDATE_write|BCH_VALIDATE_commit)), c, err,
 					 ptr_crc_uncompressed_size_too_big,
 					 "too large encoded extent");
 
diff --git a/fs/bcachefs/extents.h b/fs/bcachefs/extents.h
index 528e817eacbd..1ade959652b2 100644
--- a/fs/bcachefs/extents.h
+++ b/fs/bcachefs/extents.h
@@ -8,7 +8,7 @@
 
 struct bch_fs;
 struct btree_trans;
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 
 /* extent entries: */
 
@@ -406,12 +406,12 @@ int bch2_bkey_pick_read_device(struct bch_fs *, struct bkey_s_c,
 /* KEY_TYPE_btree_ptr: */
 
 int bch2_btree_ptr_invalid(struct bch_fs *, struct bkey_s_c,
-			   enum bkey_invalid_flags, struct printbuf *);
+			   enum bch_validate_flags, struct printbuf *);
 void bch2_btree_ptr_to_text(struct printbuf *, struct bch_fs *,
 			    struct bkey_s_c);
 
 int bch2_btree_ptr_v2_invalid(struct bch_fs *, struct bkey_s_c,
-			      enum bkey_invalid_flags, struct printbuf *);
+			      enum bch_validate_flags, struct printbuf *);
 void bch2_btree_ptr_v2_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 void bch2_btree_ptr_v2_compat(enum btree_id, unsigned, unsigned,
 			      int, struct bkey_s);
@@ -448,7 +448,7 @@ bool bch2_extent_merge(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 /* KEY_TYPE_reservation: */
 
 int bch2_reservation_invalid(struct bch_fs *, struct bkey_s_c,
-			     enum bkey_invalid_flags, struct printbuf *);
+			     enum bch_validate_flags, struct printbuf *);
 void bch2_reservation_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 bool bch2_reservation_merge(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 
@@ -654,7 +654,7 @@ union bch_extent_entry *bch2_bkey_drop_ptr(struct bkey_s,
 do {									\
 	struct bkey_ptrs _ptrs = bch2_bkey_ptrs(_k);			\
 									\
-	_ptr = &_ptrs.start->ptr;					\
+	struct bch_extent_ptr *_ptr = &_ptrs.start->ptr;		\
 									\
 	while ((_ptr = bkey_ptr_next(_ptrs, _ptr))) {			\
 		if (_cond) {						\
@@ -680,7 +680,7 @@ void bch2_extent_ptr_to_text(struct printbuf *out, struct bch_fs *, const struct
 void bch2_bkey_ptrs_to_text(struct printbuf *, struct bch_fs *,
 			    struct bkey_s_c);
 int bch2_bkey_ptrs_invalid(struct bch_fs *, struct bkey_s_c,
-			   enum bkey_invalid_flags, struct printbuf *);
+			   enum bch_validate_flags, struct printbuf *);
 
 void bch2_ptr_swab(struct bkey_s);
 
diff --git a/fs/bcachefs/eytzinger.c b/fs/bcachefs/eytzinger.c
index 0f955c3c76a7..2eaffe37b5e7 100644
--- a/fs/bcachefs/eytzinger.c
+++ b/fs/bcachefs/eytzinger.c
@@ -171,7 +171,7 @@ void eytzinger0_sort_r(void *base, size_t n, size_t size,
 		       swap_r_func_t swap_func,
 		       const void *priv)
 {
-	int i, c, r;
+	int i, j, k;
 
 	/* called from 'sort' without swap function, let's pick the default */
 	if (swap_func == SWAP_WRAPPER && !((struct wrapper *)priv)->swap_func)
@@ -188,17 +188,22 @@ void eytzinger0_sort_r(void *base, size_t n, size_t size,
 
 	/* heapify */
 	for (i = n / 2 - 1; i >= 0; --i) {
-		for (r = i; r * 2 + 1 < n; r = c) {
-			c = r * 2 + 1;
+		/* Find the sift-down path all the way to the leaves. */
+		for (j = i; k = j * 2 + 1, k + 1 < n;)
+			j = eytzinger0_do_cmp(base, n, size, cmp_func, priv, k, k + 1) > 0 ? k : k + 1;
 
-			if (c + 1 < n &&
-			    eytzinger0_do_cmp(base, n, size, cmp_func, priv, c, c + 1) < 0)
-				c++;
+		/* Special case for the last leaf with no sibling. */
+		if (j * 2 + 2 == n)
+			j = j * 2 + 1;
 
-			if (eytzinger0_do_cmp(base, n, size, cmp_func, priv, r, c) >= 0)
-				break;
+		/* Backtrack to the correct location. */
+		while (j != i && eytzinger0_do_cmp(base, n, size, cmp_func, priv, i, j) >= 0)
+			j = (j - 1) / 2;
 
-			eytzinger0_do_swap(base, n, size, swap_func, priv, r, c);
+		/* Shift the element into its correct place. */
+		for (k = j; j != i;) {
+			j = (j - 1) / 2;
+			eytzinger0_do_swap(base, n, size, swap_func, priv, j, k);
 		}
 	}
 
@@ -206,17 +211,22 @@ void eytzinger0_sort_r(void *base, size_t n, size_t size,
 	for (i = n - 1; i > 0; --i) {
 		eytzinger0_do_swap(base, n, size, swap_func, priv, 0, i);
 
-		for (r = 0; r * 2 + 1 < i; r = c) {
-			c = r * 2 + 1;
+		/* Find the sift-down path all the way to the leaves. */
+		for (j = 0; k = j * 2 + 1, k + 1 < i;)
+			j = eytzinger0_do_cmp(base, n, size, cmp_func, priv, k, k + 1) > 0 ? k : k + 1;
 
-			if (c + 1 < i &&
-			    eytzinger0_do_cmp(base, n, size, cmp_func, priv, c, c + 1) < 0)
-				c++;
+		/* Special case for the last leaf with no sibling. */
+		if (j * 2 + 2 == i)
+			j = j * 2 + 1;
 
-			if (eytzinger0_do_cmp(base, n, size, cmp_func, priv, r, c) >= 0)
-				break;
+		/* Backtrack to the correct location. */
+		while (j && eytzinger0_do_cmp(base, n, size, cmp_func, priv, 0, j) >= 0)
+			j = (j - 1) / 2;
 
-			eytzinger0_do_swap(base, n, size, swap_func, priv, r, c);
+		/* Shift the element into its correct place. */
+		for (k = j; j;) {
+			j = (j - 1) / 2;
+			eytzinger0_do_swap(base, n, size, swap_func, priv, j, k);
 		}
 	}
 }
@@ -232,3 +242,64 @@ void eytzinger0_sort(void *base, size_t n, size_t size,
 
 	return eytzinger0_sort_r(base, n, size, _CMP_WRAPPER, SWAP_WRAPPER, &w);
 }
+
+#if 0
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/ktime.h>
+
+static u64 cmp_count;
+
+static int mycmp(const void *a, const void *b)
+{
+	u32 _a = *(u32 *)a;
+	u32 _b = *(u32 *)b;
+
+	cmp_count++;
+	if (_a < _b)
+		return -1;
+	else if (_a > _b)
+		return 1;
+	else
+		return 0;
+}
+
+static int test(void)
+{
+	size_t N, i;
+	ktime_t start, end;
+	s64 delta;
+	u32 *arr;
+
+	for (N = 10000; N <= 100000; N += 10000) {
+		arr = kmalloc_array(N, sizeof(u32), GFP_KERNEL);
+		cmp_count = 0;
+
+		for (i = 0; i < N; i++)
+			arr[i] = get_random_u32();
+
+		start = ktime_get();
+		eytzinger0_sort(arr, N, sizeof(u32), mycmp, NULL);
+		end = ktime_get();
+
+		delta = ktime_us_delta(end, start);
+		printk(KERN_INFO "time: %lld\n", delta);
+		printk(KERN_INFO "comparisons: %lld\n", cmp_count);
+
+		u32 prev = 0;
+
+		eytzinger0_for_each(i, N) {
+			if (prev > arr[i])
+				goto err;
+			prev = arr[i];
+		}
+
+		kfree(arr);
+	}
+	return 0;
+
+err:
+	kfree(arr);
+	return -1;
+}
+#endif
diff --git a/fs/bcachefs/fs-common.c b/fs/bcachefs/fs-common.c
index 624e6f963240..508d029ac53d 100644
--- a/fs/bcachefs/fs-common.c
+++ b/fs/bcachefs/fs-common.c
@@ -42,7 +42,7 @@ int bch2_create_trans(struct btree_trans *trans,
 	if (ret)
 		goto err;
 
-	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
+	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
@@ -70,7 +70,7 @@ int bch2_create_trans(struct btree_trans *trans,
 			struct bch_subvolume s;
 
 			ret = bch2_subvolume_get(trans, snapshot_src.subvol, true,
-						 BTREE_ITER_CACHED, &s);
+						 BTREE_ITER_cached, &s);
 			if (ret)
 				goto err;
 
@@ -78,7 +78,7 @@ int bch2_create_trans(struct btree_trans *trans,
 		}
 
 		ret = bch2_inode_peek(trans, &inode_iter, new_inode, snapshot_src,
-				      BTREE_ITER_INTENT);
+				      BTREE_ITER_intent);
 		if (ret)
 			goto err;
 
@@ -163,7 +163,7 @@ int bch2_create_trans(struct btree_trans *trans,
 					 name,
 					 dir_target,
 					 &dir_offset,
-					 BCH_HASH_SET_MUST_CREATE);
+					 STR_HASH_must_create);
 		if (ret)
 			goto err;
 
@@ -171,7 +171,7 @@ int bch2_create_trans(struct btree_trans *trans,
 		new_inode->bi_dir_offset	= dir_offset;
 	}
 
-	inode_iter.flags &= ~BTREE_ITER_ALL_SNAPSHOTS;
+	inode_iter.flags &= ~BTREE_ITER_all_snapshots;
 	bch2_btree_iter_set_snapshot(&inode_iter, snapshot);
 
 	ret   = bch2_btree_iter_traverse(&inode_iter) ?:
@@ -198,16 +198,16 @@ int bch2_link_trans(struct btree_trans *trans,
 	if (dir.subvol != inum.subvol)
 		return -EXDEV;
 
-	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_INTENT);
+	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_intent);
 	if (ret)
-		goto err;
+		return ret;
 
 	inode_u->bi_ctime = now;
 	ret = bch2_inode_nlink_inc(inode_u);
 	if (ret)
-		return ret;
+		goto err;
 
-	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
+	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
@@ -223,7 +223,7 @@ int bch2_link_trans(struct btree_trans *trans,
 	ret = bch2_dirent_create(trans, dir, &dir_hash,
 				 mode_to_type(inode_u->bi_mode),
 				 name, inum.inum, &dir_offset,
-				 BCH_HASH_SET_MUST_CREATE);
+				 STR_HASH_must_create);
 	if (ret)
 		goto err;
 
@@ -255,19 +255,19 @@ int bch2_unlink_trans(struct btree_trans *trans,
 	struct bkey_s_c k;
 	int ret;
 
-	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
+	ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
 	dir_hash = bch2_hash_info_init(c, dir_u);
 
 	ret = bch2_dirent_lookup_trans(trans, &dirent_iter, dir, &dir_hash,
-				       name, &inum, BTREE_ITER_INTENT);
+				       name, &inum, BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
 	ret = bch2_inode_peek(trans, &inode_iter, inode_u, inum,
-			      BTREE_ITER_INTENT);
+			      BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
@@ -322,7 +322,7 @@ int bch2_unlink_trans(struct btree_trans *trans,
 
 	ret =   bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
 				    &dir_hash, &dirent_iter,
-				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+				    BTREE_UPDATE_internal_snapshot_node) ?:
 		bch2_inode_write(trans, &dir_iter, dir_u) ?:
 		bch2_inode_write(trans, &inode_iter, inode_u);
 err:
@@ -363,7 +363,7 @@ static int subvol_update_parent(struct btree_trans *trans, u32 subvol, u32 new_p
 	struct bkey_i_subvolume *s =
 		bch2_bkey_get_mut_typed(trans, &iter,
 			BTREE_ID_subvolumes, POS(0, subvol),
-			BTREE_ITER_CACHED, subvolume);
+			BTREE_ITER_cached, subvolume);
 	int ret = PTR_ERR_OR_ZERO(s);
 	if (ret)
 		return ret;
@@ -394,7 +394,7 @@ int bch2_rename_trans(struct btree_trans *trans,
 	int ret;
 
 	ret = bch2_inode_peek(trans, &src_dir_iter, src_dir_u, src_dir,
-			      BTREE_ITER_INTENT);
+			      BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
@@ -403,7 +403,7 @@ int bch2_rename_trans(struct btree_trans *trans,
 	if (dst_dir.inum	!= src_dir.inum ||
 	    dst_dir.subvol	!= src_dir.subvol) {
 		ret = bch2_inode_peek(trans, &dst_dir_iter, dst_dir_u, dst_dir,
-				      BTREE_ITER_INTENT);
+				      BTREE_ITER_intent);
 		if (ret)
 			goto err;
 
@@ -423,13 +423,13 @@ int bch2_rename_trans(struct btree_trans *trans,
 		goto err;
 
 	ret = bch2_inode_peek(trans, &src_inode_iter, src_inode_u, src_inum,
-			      BTREE_ITER_INTENT);
+			      BTREE_ITER_intent);
 	if (ret)
 		goto err;
 
 	if (dst_inum.inum) {
 		ret = bch2_inode_peek(trans, &dst_inode_iter, dst_inode_u, dst_inum,
-				      BTREE_ITER_INTENT);
+				      BTREE_ITER_intent);
 		if (ret)
 			goto err;
 	}
diff --git a/fs/bcachefs/fs-io-buffered.c b/fs/bcachefs/fs-io-buffered.c
index 39292e7ef342..b0a33fabadf8 100644
--- a/fs/bcachefs/fs-io-buffered.c
+++ b/fs/bcachefs/fs-io-buffered.c
@@ -30,15 +30,8 @@ static void bch2_readpages_end_io(struct bio *bio)
 {
 	struct folio_iter fi;
 
-	bio_for_each_folio_all(fi, bio) {
-		if (!bio->bi_status) {
-			folio_mark_uptodate(fi.folio);
-		} else {
-			folio_clear_uptodate(fi.folio);
-			folio_set_error(fi.folio);
-		}
-		folio_unlock(fi.folio);
-	}
+	bio_for_each_folio_all(fi, bio)
+		folio_end_read(fi.folio, bio->bi_status == BLK_STS_OK);
 
 	bio_put(bio);
 }
@@ -176,7 +169,7 @@ retry:
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			     SPOS(inum.inum, rbio->bio.bi_iter.bi_sector, snapshot),
-			     BTREE_ITER_SLOTS);
+			     BTREE_ITER_slots);
 	while (1) {
 		struct bkey_s_c k;
 		unsigned bytes, sectors, offset_into_extent;
@@ -408,7 +401,6 @@ static void bch2_writepage_io_done(struct bch_write_op *op)
 		bio_for_each_folio_all(fi, bio) {
 			struct bch_folio *s;
 
-			folio_set_error(fi.folio);
 			mapping_set_error(fi.folio->mapping, -EIO);
 
 			s = __bch2_folio(fi.folio);
diff --git a/fs/bcachefs/fs-io-direct.c b/fs/bcachefs/fs-io-direct.c
index b889370a5088..09d21aef879a 100644
--- a/fs/bcachefs/fs-io-direct.c
+++ b/fs/bcachefs/fs-io-direct.c
@@ -254,7 +254,7 @@ retry:
 
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_extents,
 			   SPOS(inum.inum, offset, snapshot),
-			   BTREE_ITER_SLOTS, k, err) {
+			   BTREE_ITER_slots, k, err) {
 		if (bkey_ge(bkey_start_pos(k.k), POS(inum.inum, end)))
 			break;
 
diff --git a/fs/bcachefs/fs-io-pagecache.c b/fs/bcachefs/fs-io-pagecache.c
index d359aa9b33b8..872283e5bd1e 100644
--- a/fs/bcachefs/fs-io-pagecache.c
+++ b/fs/bcachefs/fs-io-pagecache.c
@@ -214,7 +214,7 @@ retry:
 
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_extents,
 			   SPOS(inum.inum, offset, snapshot),
-			   BTREE_ITER_SLOTS, k, ret) {
+			   BTREE_ITER_slots, k, ret) {
 		unsigned nr_ptrs = bch2_bkey_nr_ptrs_fully_allocated(k);
 		unsigned state = bkey_to_sector_state(k);
 
diff --git a/fs/bcachefs/fs-io.c b/fs/bcachefs/fs-io.c
index 20b40477425f..ef20b64033e0 100644
--- a/fs/bcachefs/fs-io.c
+++ b/fs/bcachefs/fs-io.c
@@ -202,7 +202,10 @@ int bch2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 		goto out;
 	ret = bch2_flush_inode(c, inode);
 out:
-	return bch2_err_class(ret);
+	ret = bch2_err_class(ret);
+	if (ret == -EROFS)
+		ret = -EIO;
+	return ret;
 }
 
 /* truncate: */
@@ -594,7 +597,7 @@ static int __bchfs_fallocate(struct bch_inode_info *inode, int mode,
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			POS(inode->v.i_ino, start_sector),
-			BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+			BTREE_ITER_slots|BTREE_ITER_intent);
 
 	while (!ret && bkey_lt(iter.pos, end_pos)) {
 		s64 i_sectors_delta = 0;
@@ -1009,7 +1012,7 @@ retry:
 
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_extents,
 			   SPOS(inode->v.i_ino, offset >> 9, snapshot),
-			   BTREE_ITER_SLOTS, k, ret) {
+			   BTREE_ITER_slots, k, ret) {
 		if (k.k->p.inode != inode->v.i_ino) {
 			next_hole = bch2_seek_pagecache_hole(&inode->v,
 					offset, MAX_LFS_FILESIZE, 0, false);
diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c
index 3dc8630ff9fe..205a323ffc6d 100644
--- a/fs/bcachefs/fs-ioctl.c
+++ b/fs/bcachefs/fs-ioctl.c
@@ -548,7 +548,7 @@ long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 {
 	/* These are just misnamed, they actually get/put from/to user an int */
 	switch (cmd) {
-	case FS_IOC_GETFLAGS:
+	case FS_IOC32_GETFLAGS:
 		cmd = FS_IOC_GETFLAGS;
 		break;
 	case FS_IOC32_SETFLAGS:
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index 65b04b3c2679..fd851f10d11c 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -90,7 +90,7 @@ retry:
 	bch2_trans_begin(trans);
 
 	ret   = bch2_inode_peek(trans, &iter, &inode_u, inode_inum(inode),
-				BTREE_ITER_INTENT) ?:
+				BTREE_ITER_intent) ?:
 		(set ? set(trans, inode, &inode_u, p) : 0) ?:
 		bch2_inode_write(trans, &iter, &inode_u) ?:
 		bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
@@ -213,19 +213,43 @@ static struct bch_inode_info *bch2_inode_insert(struct bch_fs *c, struct bch_ino
 	_ret;									\
 })
 
+static struct inode *bch2_alloc_inode(struct super_block *sb)
+{
+	BUG();
+}
+
+static struct bch_inode_info *__bch2_new_inode(struct bch_fs *c)
+{
+	struct bch_inode_info *inode = kmem_cache_alloc(bch2_inode_cache, GFP_NOFS);
+	if (!inode)
+		return NULL;
+
+	inode_init_once(&inode->v);
+	mutex_init(&inode->ei_update_lock);
+	two_state_lock_init(&inode->ei_pagecache_lock);
+	INIT_LIST_HEAD(&inode->ei_vfs_inode_list);
+	mutex_init(&inode->ei_quota_lock);
+	inode->v.i_state = 0;
+
+	if (unlikely(inode_init_always(c->vfs_sb, &inode->v))) {
+		kmem_cache_free(bch2_inode_cache, inode);
+		return NULL;
+	}
+
+	return inode;
+}
+
 /*
  * Allocate a new inode, dropping/retaking btree locks if necessary:
  */
 static struct bch_inode_info *bch2_new_inode(struct btree_trans *trans)
 {
-	struct bch_fs *c = trans->c;
-
 	struct bch_inode_info *inode =
 		memalloc_flags_do(PF_MEMALLOC_NORECLAIM|PF_MEMALLOC_NOWARN,
-				  to_bch_ei(new_inode(c->vfs_sb)));
+				  __bch2_new_inode(trans->c));
 
 	if (unlikely(!inode)) {
-		int ret = drop_locks_do(trans, (inode = to_bch_ei(new_inode(c->vfs_sb))) ? 0 : -ENOMEM);
+		int ret = drop_locks_do(trans, (inode = __bch2_new_inode(trans->c)) ? 0 : -ENOMEM);
 		if (ret && inode) {
 			__destroy_inode(&inode->v);
 			kmem_cache_free(bch2_inode_cache, inode);
@@ -290,7 +314,7 @@ __bch2_create(struct mnt_idmap *idmap,
 	if (ret)
 		return ERR_PTR(ret);
 #endif
-	inode = to_bch_ei(new_inode(c->vfs_sb));
+	inode = __bch2_new_inode(c);
 	if (unlikely(!inode)) {
 		inode = ERR_PTR(-ENOMEM);
 		goto err;
@@ -323,7 +347,7 @@ retry:
 	inum.inum = inode_u.bi_inum;
 
 	ret   = bch2_subvolume_get(trans, inum.subvol, true,
-				   BTREE_ITER_WITH_UPDATES, &subvol) ?:
+				   BTREE_ITER_with_updates, &subvol) ?:
 		bch2_trans_commit(trans, NULL, &journal_seq, 0);
 	if (unlikely(ret)) {
 		bch2_quota_acct(c, bch_qid(&inode_u), Q_INO, -1,
@@ -376,17 +400,14 @@ static struct bch_inode_info *bch2_lookup_trans(struct btree_trans *trans,
 	struct bch_fs *c = trans->c;
 	struct btree_iter dirent_iter = {};
 	subvol_inum inum = {};
+	struct printbuf buf = PRINTBUF;
 
-	int ret = bch2_hash_lookup(trans, &dirent_iter, bch2_dirent_hash_desc,
-				   dir_hash_info, dir, name, 0);
+	struct bkey_s_c k = bch2_hash_lookup(trans, &dirent_iter, bch2_dirent_hash_desc,
+					     dir_hash_info, dir, name, 0);
+	int ret = bkey_err(k);
 	if (ret)
 		return ERR_PTR(ret);
 
-	struct bkey_s_c k = bch2_btree_iter_peek_slot(&dirent_iter);
-	ret = bkey_err(k);
-	if (ret)
-		goto err;
-
 	ret = bch2_dirent_read_target(trans, dir, bkey_s_c_to_dirent(k), &inum);
 	if (ret > 0)
 		ret = -ENOENT;
@@ -406,20 +427,31 @@ static struct bch_inode_info *bch2_lookup_trans(struct btree_trans *trans,
 	ret =   bch2_subvolume_get(trans, inum.subvol, true, 0, &subvol) ?:
 		bch2_inode_find_by_inum_nowarn_trans(trans, inum, &inode_u) ?:
 		PTR_ERR_OR_ZERO(inode = bch2_new_inode(trans));
-	if (bch2_err_matches(ret, ENOENT)) {
-		struct printbuf buf = PRINTBUF;
 
-		bch2_bkey_val_to_text(&buf, c, k);
-		bch_err(c, "%s points to missing inode", buf.buf);
-		printbuf_exit(&buf);
-	}
+	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT),
+				c, "dirent to missing inode:\n  %s",
+				(bch2_bkey_val_to_text(&buf, c, k), buf.buf));
 	if (ret)
 		goto err;
 
+	/* regular files may have hardlinks: */
+	if (bch2_fs_inconsistent_on(bch2_inode_should_have_bp(&inode_u) &&
+				    !bkey_eq(k.k->p, POS(inode_u.bi_dir, inode_u.bi_dir_offset)),
+				    c,
+				    "dirent points to inode that does not point back:\n  %s",
+				    (bch2_bkey_val_to_text(&buf, c, k),
+				     prt_printf(&buf, "\n  "),
+				     bch2_inode_unpacked_to_text(&buf, &inode_u),
+				     buf.buf))) {
+		ret = -ENOENT;
+		goto err;
+	}
+
 	bch2_vfs_inode_init(trans, inum, inode, &inode_u, &subvol);
 	inode = bch2_inode_insert(c, inode);
 out:
 	bch2_trans_iter_exit(trans, &dirent_iter);
+	printbuf_exit(&buf);
 	return inode;
 err:
 	inode = ERR_PTR(ret);
@@ -787,7 +819,7 @@ retry:
 	acl = NULL;
 
 	ret = bch2_inode_peek(trans, &inode_iter, &inode_u, inode_inum(inode),
-			      BTREE_ITER_INTENT);
+			      BTREE_ITER_intent);
 	if (ret)
 		goto btree_err;
 
@@ -1043,6 +1075,10 @@ retry:
 
 		bch2_btree_iter_set_pos(&iter,
 			POS(iter.pos.inode, iter.pos.offset + sectors));
+
+		ret = bch2_trans_relock(trans);
+		if (ret)
+			break;
 	}
 	start = iter.pos.offset;
 	bch2_trans_iter_exit(trans, &iter);
@@ -1490,34 +1526,9 @@ static void bch2_vfs_inode_init(struct btree_trans *trans, subvol_inum inum,
 	mapping_set_large_folios(inode->v.i_mapping);
 }
 
-static struct inode *bch2_alloc_inode(struct super_block *sb)
-{
-	struct bch_inode_info *inode;
-
-	inode = kmem_cache_alloc(bch2_inode_cache, GFP_NOFS);
-	if (!inode)
-		return NULL;
-
-	inode_init_once(&inode->v);
-	mutex_init(&inode->ei_update_lock);
-	two_state_lock_init(&inode->ei_pagecache_lock);
-	INIT_LIST_HEAD(&inode->ei_vfs_inode_list);
-	mutex_init(&inode->ei_quota_lock);
-
-	return &inode->v;
-}
-
-static void bch2_i_callback(struct rcu_head *head)
-{
-	struct inode *vinode = container_of(head, struct inode, i_rcu);
-	struct bch_inode_info *inode = to_bch_ei(vinode);
-
-	kmem_cache_free(bch2_inode_cache, inode);
-}
-
-static void bch2_destroy_inode(struct inode *vinode)
+static void bch2_free_inode(struct inode *vinode)
 {
-	call_rcu(&vinode->i_rcu, bch2_i_callback);
+	kmem_cache_free(bch2_inode_cache, to_bch_ei(vinode));
 }
 
 static int inode_update_times_fn(struct btree_trans *trans,
@@ -1825,7 +1836,7 @@ static int bch2_unfreeze(struct super_block *sb)
 
 static const struct super_operations bch_super_operations = {
 	.alloc_inode	= bch2_alloc_inode,
-	.destroy_inode	= bch2_destroy_inode,
+	.free_inode	= bch2_free_inode,
 	.write_inode	= bch2_vfs_write_inode,
 	.evict_inode	= bch2_evict_inode,
 	.sync_fs	= bch2_sync_fs,
diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index 8e2010212cc3..c8f57465131c 100644
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -79,7 +79,7 @@ static int lookup_first_inode(struct btree_trans *trans, u64 inode_nr,
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_inodes,
 			     POS(0, inode_nr),
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_all_snapshots);
 	k = bch2_btree_iter_peek(&iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -127,13 +127,13 @@ static int lookup_dirent_in_snapshot(struct btree_trans *trans,
 			   u64 *target, unsigned *type, u32 snapshot)
 {
 	struct btree_iter iter;
-	struct bkey_s_c_dirent d;
-	int ret = bch2_hash_lookup_in_snapshot(trans, &iter, bch2_dirent_hash_desc,
-			       &hash_info, dir, name, 0, snapshot);
+	struct bkey_s_c k = bch2_hash_lookup_in_snapshot(trans, &iter, bch2_dirent_hash_desc,
+							 &hash_info, dir, name, 0, snapshot);
+	int ret = bkey_err(k);
 	if (ret)
 		return ret;
 
-	d = bkey_s_c_to_dirent(bch2_btree_iter_peek_slot(&iter));
+	struct bkey_s_c_dirent d = bkey_s_c_to_dirent(bch2_btree_iter_peek_slot(&iter));
 	*target = le64_to_cpu(d.v->d_inum);
 	*type = d.v->d_type;
 	bch2_trans_iter_exit(trans, &iter);
@@ -154,12 +154,12 @@ static int __remove_dirent(struct btree_trans *trans, struct bpos pos)
 
 	dir_hash_info = bch2_hash_info_init(c, &dir_inode);
 
-	bch2_trans_iter_init(trans, &iter, BTREE_ID_dirents, pos, BTREE_ITER_INTENT);
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_dirents, pos, BTREE_ITER_intent);
 
 	ret =   bch2_btree_iter_traverse(&iter) ?:
 		bch2_hash_delete_at(trans, bch2_dirent_hash_desc,
 				    &dir_hash_info, &iter,
-				    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				    BTREE_UPDATE_internal_snapshot_node);
 	bch2_trans_iter_exit(trans, &iter);
 err:
 	bch_err_fn(c, ret);
@@ -274,9 +274,9 @@ create_lostfound:
 				&lostfound_str,
 				lostfound->bi_inum,
 				&lostfound->bi_dir_offset,
-				BCH_HASH_SET_MUST_CREATE) ?:
+				STR_HASH_must_create) ?:
 		bch2_inode_write_flags(trans, &lostfound_iter, lostfound,
-				       BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				       BTREE_UPDATE_internal_snapshot_node);
 err:
 	bch_err_msg(c, ret, "creating lost+found");
 	bch2_trans_iter_exit(trans, &lostfound_iter);
@@ -333,7 +333,7 @@ static int reattach_inode(struct btree_trans *trans,
 				&name,
 				inode->bi_subvol ?: inode->bi_inum,
 				&dir_offset,
-				BCH_HASH_SET_MUST_CREATE);
+				STR_HASH_must_create);
 	if (ret)
 		return ret;
 
@@ -486,14 +486,9 @@ static int reconstruct_reg_inode(struct btree_trans *trans, u32 snapshot, u64 in
 	return reconstruct_inode(trans, snapshot, inum, k.k->p.offset << 9, S_IFREG);
 }
 
-struct snapshots_seen_entry {
-	u32				id;
-	u32				equiv;
-};
-
 struct snapshots_seen {
 	struct bpos			pos;
-	DARRAY(struct snapshots_seen_entry) ids;
+	snapshot_id_list		ids;
 };
 
 static inline void snapshots_seen_exit(struct snapshots_seen *s)
@@ -508,20 +503,15 @@ static inline void snapshots_seen_init(struct snapshots_seen *s)
 
 static int snapshots_seen_add_inorder(struct bch_fs *c, struct snapshots_seen *s, u32 id)
 {
-	struct snapshots_seen_entry *i, n = {
-		.id	= id,
-		.equiv	= bch2_snapshot_equiv(c, id),
-	};
-	int ret = 0;
-
+	u32 *i;
 	__darray_for_each(s->ids, i) {
-		if (i->id == id)
+		if (*i == id)
 			return 0;
-		if (i->id > id)
+		if (*i > id)
 			break;
 	}
 
-	ret = darray_insert_item(&s->ids, i - s->ids.data, n);
+	int ret = darray_insert_item(&s->ids, i - s->ids.data, id);
 	if (ret)
 		bch_err(c, "error reallocating snapshots_seen table (size %zu)",
 			s->ids.size);
@@ -531,42 +521,11 @@ static int snapshots_seen_add_inorder(struct bch_fs *c, struct snapshots_seen *s
 static int snapshots_seen_update(struct bch_fs *c, struct snapshots_seen *s,
 				 enum btree_id btree_id, struct bpos pos)
 {
-	struct snapshots_seen_entry n = {
-		.id	= pos.snapshot,
-		.equiv	= bch2_snapshot_equiv(c, pos.snapshot),
-	};
-	int ret = 0;
-
 	if (!bkey_eq(s->pos, pos))
 		s->ids.nr = 0;
-
 	s->pos = pos;
-	s->pos.snapshot = n.equiv;
 
-	darray_for_each(s->ids, i) {
-		if (i->id == n.id)
-			return 0;
-
-		/*
-		 * We currently don't rigorously track for snapshot cleanup
-		 * needing to be run, so it shouldn't be a fsck error yet:
-		 */
-		if (i->equiv == n.equiv) {
-			bch_err(c, "snapshot deletion did not finish:\n"
-				"  duplicate keys in btree %s at %llu:%llu snapshots %u, %u (equiv %u)\n",
-				bch2_btree_id_str(btree_id),
-				pos.inode, pos.offset,
-				i->id, n.id, n.equiv);
-			set_bit(BCH_FS_need_delete_dead_snapshots, &c->flags);
-			return bch2_run_explicit_recovery_pass(c, BCH_RECOVERY_PASS_delete_dead_snapshots);
-		}
-	}
-
-	ret = darray_push(&s->ids, n);
-	if (ret)
-		bch_err(c, "error reallocating snapshots_seen table (size %zu)",
-			s->ids.size);
-	return ret;
+	return snapshot_list_add_nodup(c, &s->ids, pos.snapshot);
 }
 
 /**
@@ -586,12 +545,10 @@ static bool key_visible_in_snapshot(struct bch_fs *c, struct snapshots_seen *see
 	ssize_t i;
 
 	EBUG_ON(id > ancestor);
-	EBUG_ON(!bch2_snapshot_is_equiv(c, id));
-	EBUG_ON(!bch2_snapshot_is_equiv(c, ancestor));
 
 	/* @ancestor should be the snapshot most recently added to @seen */
 	EBUG_ON(ancestor != seen->pos.snapshot);
-	EBUG_ON(ancestor != seen->ids.data[seen->ids.nr - 1].equiv);
+	EBUG_ON(ancestor != darray_last(seen->ids));
 
 	if (id == ancestor)
 		return true;
@@ -610,9 +567,9 @@ static bool key_visible_in_snapshot(struct bch_fs *c, struct snapshots_seen *see
 	 */
 
 	for (i = seen->ids.nr - 2;
-	     i >= 0 && seen->ids.data[i].equiv >= id;
+	     i >= 0 && seen->ids.data[i] >= id;
 	     --i)
-		if (bch2_snapshot_is_ancestor(c, id, seen->ids.data[i].equiv))
+		if (bch2_snapshot_is_ancestor(c, id, seen->ids.data[i]))
 			return false;
 
 	return true;
@@ -643,9 +600,6 @@ static int ref_visible2(struct bch_fs *c,
 			u32 src, struct snapshots_seen *src_seen,
 			u32 dst, struct snapshots_seen *dst_seen)
 {
-	src = bch2_snapshot_equiv(c, src);
-	dst = bch2_snapshot_equiv(c, dst);
-
 	if (dst > src) {
 		swap(dst, src);
 		swap(dst_seen, src_seen);
@@ -692,7 +646,7 @@ static int add_inode(struct bch_fs *c, struct inode_walker *w,
 
 	return darray_push(&w->inodes, ((struct inode_walker_entry) {
 		.inode		= u,
-		.snapshot	= bch2_snapshot_equiv(c, inode.k->p.snapshot),
+		.snapshot	= inode.k->p.snapshot,
 	}));
 }
 
@@ -708,7 +662,7 @@ static int get_inodes_all_snapshots(struct btree_trans *trans,
 	w->inodes.nr = 0;
 
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_inodes, POS(0, inum),
-				     BTREE_ITER_ALL_SNAPSHOTS, k, ret) {
+				     BTREE_ITER_all_snapshots, k, ret) {
 		if (k.k->p.offset != inum)
 			break;
 
@@ -728,21 +682,20 @@ static struct inode_walker_entry *
 lookup_inode_for_snapshot(struct bch_fs *c, struct inode_walker *w, struct bkey_s_c k)
 {
 	bool is_whiteout = k.k->type == KEY_TYPE_whiteout;
-	u32 snapshot = bch2_snapshot_equiv(c, k.k->p.snapshot);
 
 	struct inode_walker_entry *i;
 	__darray_for_each(w->inodes, i)
-		if (bch2_snapshot_is_ancestor(c, snapshot, i->snapshot))
+		if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, i->snapshot))
 			goto found;
 
 	return NULL;
 found:
-	BUG_ON(snapshot > i->snapshot);
+	BUG_ON(k.k->p.snapshot > i->snapshot);
 
-	if (snapshot != i->snapshot && !is_whiteout) {
+	if (k.k->p.snapshot != i->snapshot && !is_whiteout) {
 		struct inode_walker_entry new = *i;
 
-		new.snapshot = snapshot;
+		new.snapshot = k.k->p.snapshot;
 		new.count = 0;
 
 		struct printbuf buf = PRINTBUF;
@@ -751,10 +704,10 @@ found:
 		bch_info(c, "have key for inode %llu:%u but have inode in ancestor snapshot %u\n"
 			 "unexpected because we should always update the inode when we update a key in that inode\n"
 			 "%s",
-			 w->last_pos.inode, snapshot, i->snapshot, buf.buf);
+			 w->last_pos.inode, k.k->p.snapshot, i->snapshot, buf.buf);
 		printbuf_exit(&buf);
 
-		while (i > w->inodes.data && i[-1].snapshot > snapshot)
+		while (i > w->inodes.data && i[-1].snapshot > k.k->p.snapshot)
 			--i;
 
 		size_t pos = i - w->inodes.data;
@@ -786,10 +739,10 @@ static struct inode_walker_entry *walk_inode(struct btree_trans *trans,
 	return lookup_inode_for_snapshot(trans->c, w, k);
 }
 
-static int __get_visible_inodes(struct btree_trans *trans,
-				struct inode_walker *w,
-				struct snapshots_seen *s,
-				u64 inum)
+static int get_visible_inodes(struct btree_trans *trans,
+			      struct inode_walker *w,
+			      struct snapshots_seen *s,
+			      u64 inum)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_iter iter;
@@ -799,19 +752,17 @@ static int __get_visible_inodes(struct btree_trans *trans,
 	w->inodes.nr = 0;
 
 	for_each_btree_key_norestart(trans, iter, BTREE_ID_inodes, POS(0, inum),
-			   BTREE_ITER_ALL_SNAPSHOTS, k, ret) {
-		u32 equiv = bch2_snapshot_equiv(c, k.k->p.snapshot);
-
+			   BTREE_ITER_all_snapshots, k, ret) {
 		if (k.k->p.offset != inum)
 			break;
 
-		if (!ref_visible(c, s, s->pos.snapshot, equiv))
+		if (!ref_visible(c, s, s->pos.snapshot, k.k->p.snapshot))
 			continue;
 
 		if (bkey_is_inode(k.k))
 			add_inode(c, w, k);
 
-		if (equiv >= s->pos.snapshot)
+		if (k.k->p.snapshot >= s->pos.snapshot)
 			break;
 	}
 	bch2_trans_iter_exit(trans, &iter);
@@ -832,7 +783,7 @@ static int check_key_has_snapshot(struct btree_trans *trans,
 				"key in missing snapshot: %s",
 				(bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
 		ret = bch2_btree_delete_at(trans, iter,
-					    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?: 1;
+					    BTREE_UPDATE_internal_snapshot_node) ?: 1;
 fsck_err:
 	printbuf_exit(&buf);
 	return ret;
@@ -861,8 +812,8 @@ static int hash_redo_key(struct btree_trans *trans,
 		bch2_hash_set_in_snapshot(trans, desc, hash_info,
 				       (subvol_inum) { 0, k.k->p.inode },
 				       k.k->p.snapshot, tmp,
-				       BCH_HASH_SET_MUST_CREATE,
-				       BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+				       STR_HASH_must_create|
+				       BTREE_UPDATE_internal_snapshot_node) ?:
 		bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
 }
 
@@ -891,7 +842,7 @@ static int hash_check_key(struct btree_trans *trans,
 
 	for_each_btree_key_norestart(trans, iter, desc.btree_id,
 				     SPOS(hash_k.k->p.inode, hash, hash_k.k->p.snapshot),
-				     BTREE_ITER_SLOTS, k, ret) {
+				     BTREE_ITER_slots, k, ret) {
 		if (bkey_eq(k.k->p, hash_k.k->p))
 			break;
 
@@ -1233,7 +1184,7 @@ int bch2_check_inodes(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_inodes,
 				POS_MIN,
-				BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			check_inode(trans, &iter, k, &prev, &s, full)));
 
@@ -1362,8 +1313,8 @@ static int overlapping_extents_found(struct btree_trans *trans,
 	BUG_ON(bkey_le(pos1, bkey_start_pos(&pos2)));
 
 	bch2_trans_iter_init(trans, &iter1, btree, pos1,
-			     BTREE_ITER_ALL_SNAPSHOTS|
-			     BTREE_ITER_NOT_EXTENTS);
+			     BTREE_ITER_all_snapshots|
+			     BTREE_ITER_not_extents);
 	k1 = bch2_btree_iter_peek_upto(&iter1, POS(pos1.inode, U64_MAX));
 	ret = bkey_err(k1);
 	if (ret)
@@ -1425,7 +1376,7 @@ static int overlapping_extents_found(struct btree_trans *trans,
 		trans->extra_disk_res += bch2_bkey_sectors_compressed(k2);
 
 		ret =   bch2_trans_update_extent_overwrite(trans, old_iter,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE,
+				BTREE_UPDATE_internal_snapshot_node,
 				k1, k2) ?:
 			bch2_trans_commit(trans, &res, NULL, BCH_TRANS_COMMIT_no_enospc);
 		bch2_disk_reservation_put(c, &res);
@@ -1466,7 +1417,6 @@ static int check_overlapping_extents(struct btree_trans *trans,
 			      struct snapshots_seen *seen,
 			      struct extent_ends *extent_ends,
 			      struct bkey_s_c k,
-			      u32 equiv,
 			      struct btree_iter *iter,
 			      bool *fixed)
 {
@@ -1535,11 +1485,8 @@ static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
 	struct bch_fs *c = trans->c;
 	struct inode_walker_entry *i;
 	struct printbuf buf = PRINTBUF;
-	struct bpos equiv = k.k->p;
 	int ret = 0;
 
-	equiv.snapshot = bch2_snapshot_equiv(c, k.k->p.snapshot);
-
 	ret = check_key_has_snapshot(trans, iter, k);
 	if (ret) {
 		ret = ret < 0 ? ret : 0;
@@ -1589,8 +1536,7 @@ static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
 				 bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
 			goto delete;
 
-		ret = check_overlapping_extents(trans, s, extent_ends, k,
-						equiv.snapshot, iter,
+		ret = check_overlapping_extents(trans, s, extent_ends, k, iter,
 						&inode->recalculate_sums);
 		if (ret)
 			goto err;
@@ -1607,8 +1553,8 @@ static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
 	for (;
 	     inode->inodes.data && i >= inode->inodes.data;
 	     --i) {
-		if (i->snapshot > equiv.snapshot ||
-		    !key_visible_in_snapshot(c, s, i->snapshot, equiv.snapshot))
+		if (i->snapshot > k.k->p.snapshot ||
+		    !key_visible_in_snapshot(c, s, i->snapshot, k.k->p.snapshot))
 			continue;
 
 		if (k.k->type != KEY_TYPE_whiteout) {
@@ -1625,7 +1571,7 @@ static int check_extent(struct btree_trans *trans, struct btree_iter *iter,
 				bch2_btree_iter_set_snapshot(&iter2, i->snapshot);
 				ret =   bch2_btree_iter_traverse(&iter2) ?:
 					bch2_btree_delete_at(trans, &iter2,
-						BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+						BTREE_UPDATE_internal_snapshot_node);
 				bch2_trans_iter_exit(trans, &iter2);
 				if (ret)
 					goto err;
@@ -1652,7 +1598,7 @@ fsck_err:
 	bch_err_fn(c, ret);
 	return ret;
 delete:
-	ret = bch2_btree_delete_at(trans, iter, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+	ret = bch2_btree_delete_at(trans, iter, BTREE_UPDATE_internal_snapshot_node);
 	goto out;
 }
 
@@ -1673,7 +1619,7 @@ int bch2_check_extents(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_extents,
 				POS(BCACHEFS_ROOT_INO, 0),
-				BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 				&res, NULL,
 				BCH_TRANS_COMMIT_no_enospc, ({
 			bch2_disk_reservation_put(c, &res);
@@ -1698,7 +1644,7 @@ int bch2_check_indirect_extents(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_reflink,
 				POS_MIN,
-				BTREE_ITER_PREFETCH, k,
+				BTREE_ITER_prefetch, k,
 				&res, NULL,
 				BCH_TRANS_COMMIT_no_enospc, ({
 			bch2_disk_reservation_put(c, &res);
@@ -1767,6 +1713,15 @@ static int check_dirent_inode_dirent(struct btree_trans *trans,
 	if (inode_points_to_dirent(target, d))
 		return 0;
 
+	if (bch2_inode_should_have_bp(target) &&
+	    !fsck_err(c, inode_wrong_backpointer,
+		      "dirent points to inode that does not point back:\n  %s",
+		      (bch2_bkey_val_to_text(&buf, c, d.s_c),
+		       prt_printf(&buf, "\n  "),
+		       bch2_inode_unpacked_to_text(&buf, target),
+		       buf.buf)))
+		goto out_noiter;
+
 	if (!target->bi_dir &&
 	    !target->bi_dir_offset) {
 		target->bi_dir		= d.k->p.inode;
@@ -1835,6 +1790,7 @@ out:
 err:
 fsck_err:
 	bch2_trans_iter_exit(trans, &bp_iter);
+out_noiter:
 	printbuf_exit(&buf);
 	bch_err_fn(c, ret);
 	return ret;
@@ -2052,7 +2008,6 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 	struct bch_fs *c = trans->c;
 	struct inode_walker_entry *i;
 	struct printbuf buf = PRINTBUF;
-	struct bpos equiv;
 	int ret = 0;
 
 	ret = check_key_has_snapshot(trans, iter, k);
@@ -2061,9 +2016,6 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 		goto out;
 	}
 
-	equiv = k.k->p;
-	equiv.snapshot = bch2_snapshot_equiv(c, k.k->p.snapshot);
-
 	ret = snapshots_seen_update(c, s, iter->btree_id, k.k->p);
 	if (ret)
 		goto err;
@@ -2104,7 +2056,7 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 			(printbuf_reset(&buf),
 			 bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
 		ret = bch2_btree_delete_at(trans, iter,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				BTREE_UPDATE_internal_snapshot_node);
 		goto out;
 	}
 
@@ -2140,14 +2092,13 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 		if (ret)
 			goto err;
 	} else {
-		ret = __get_visible_inodes(trans, target, s, le64_to_cpu(d.v->d_inum));
+		ret = get_visible_inodes(trans, target, s, le64_to_cpu(d.v->d_inum));
 		if (ret)
 			goto err;
 
 		if (fsck_err_on(!target->inodes.nr,
 				c, dirent_to_missing_inode,
-				"dirent points to missing inode: (equiv %u)\n%s",
-				equiv.snapshot,
+				"dirent points to missing inode:\n%s",
 				(printbuf_reset(&buf),
 				 bch2_bkey_val_to_text(&buf, c, k),
 				 buf.buf))) {
@@ -2164,7 +2115,7 @@ static int check_dirent(struct btree_trans *trans, struct btree_iter *iter,
 		}
 
 		if (d.v->d_type == DT_DIR)
-			for_each_visible_inode(c, s, dir, equiv.snapshot, i)
+			for_each_visible_inode(c, s, dir, d.k->p.snapshot, i)
 				i->count++;
 	}
 out:
@@ -2191,7 +2142,7 @@ int bch2_check_dirents(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_dirents,
 				POS(BCACHEFS_ROOT_INO, 0),
-				BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS,
+				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots,
 				k,
 				NULL, NULL,
 				BCH_TRANS_COMMIT_no_enospc,
@@ -2255,7 +2206,7 @@ int bch2_check_xattrs(struct bch_fs *c)
 	ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_xattrs,
 			POS(BCACHEFS_ROOT_INO, 0),
-			BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS,
+			BTREE_ITER_prefetch|BTREE_ITER_all_snapshots,
 			k,
 			NULL, NULL,
 			BCH_TRANS_COMMIT_no_enospc,
@@ -2422,7 +2373,7 @@ int bch2_check_subvolume_structure(struct bch_fs *c)
 {
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
-				BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k,
+				BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			check_subvol_path(trans, &iter, k)));
 	bch_err_fn(c, ret);
@@ -2457,7 +2408,7 @@ static int check_path(struct btree_trans *trans, pathbuf *p, struct bkey_s_c ino
 	struct btree_iter inode_iter = {};
 	struct bch_inode_unpacked inode;
 	struct printbuf buf = PRINTBUF;
-	u32 snapshot = bch2_snapshot_equiv(c, inode_k.k->p.snapshot);
+	u32 snapshot = inode_k.k->p.snapshot;
 	int ret = 0;
 
 	p->nr = 0;
@@ -2559,9 +2510,9 @@ int bch2_check_directory_structure(struct bch_fs *c)
 
 	ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_inodes, POS_MIN,
-					  BTREE_ITER_INTENT|
-					  BTREE_ITER_PREFETCH|
-					  BTREE_ITER_ALL_SNAPSHOTS, k,
+					  BTREE_ITER_intent|
+					  BTREE_ITER_prefetch|
+					  BTREE_ITER_all_snapshots, k,
 					  NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
 			if (!bkey_is_inode(k.k))
 				continue;
@@ -2661,9 +2612,9 @@ static int check_nlinks_find_hardlinks(struct bch_fs *c,
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter, BTREE_ID_inodes,
 				   POS(0, start),
-				   BTREE_ITER_INTENT|
-				   BTREE_ITER_PREFETCH|
-				   BTREE_ITER_ALL_SNAPSHOTS, k, ({
+				   BTREE_ITER_intent|
+				   BTREE_ITER_prefetch|
+				   BTREE_ITER_all_snapshots, k, ({
 			if (!bkey_is_inode(k.k))
 				continue;
 
@@ -2704,9 +2655,9 @@ static int check_nlinks_walk_dirents(struct bch_fs *c, struct nlink_table *links
 
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter, BTREE_ID_dirents, POS_MIN,
-				   BTREE_ITER_INTENT|
-				   BTREE_ITER_PREFETCH|
-				   BTREE_ITER_ALL_SNAPSHOTS, k, ({
+				   BTREE_ITER_intent|
+				   BTREE_ITER_prefetch|
+				   BTREE_ITER_all_snapshots, k, ({
 			ret = snapshots_seen_update(c, &s, iter.btree_id, k.k->p);
 			if (ret)
 				break;
@@ -2717,8 +2668,7 @@ static int check_nlinks_walk_dirents(struct bch_fs *c, struct nlink_table *links
 				if (d.v->d_type != DT_DIR &&
 				    d.v->d_type != DT_SUBVOL)
 					inc_link(c, &s, links, range_start, range_end,
-						 le64_to_cpu(d.v->d_inum),
-						 bch2_snapshot_equiv(c, d.k->p.snapshot));
+						 le64_to_cpu(d.v->d_inum), d.k->p.snapshot);
 			}
 			0;
 		})));
@@ -2781,7 +2731,7 @@ static int check_nlinks_update_hardlinks(struct bch_fs *c,
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_inodes,
 				POS(0, range_start),
-				BTREE_ITER_INTENT|BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_intent|BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			check_nlinks_update_inode(trans, &iter, k, links, &idx, range_end)));
 	if (ret < 0) {
@@ -2849,7 +2799,7 @@ static int fix_reflink_p_key(struct btree_trans *trans, struct btree_iter *iter,
 	u->v.front_pad	= 0;
 	u->v.back_pad	= 0;
 
-	return bch2_trans_update(trans, iter, &u->k_i, BTREE_TRIGGER_NORUN);
+	return bch2_trans_update(trans, iter, &u->k_i, BTREE_TRIGGER_norun);
 }
 
 int bch2_fix_reflink_p(struct bch_fs *c)
@@ -2860,8 +2810,8 @@ int bch2_fix_reflink_p(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
 				BTREE_ID_extents, POS_MIN,
-				BTREE_ITER_INTENT|BTREE_ITER_PREFETCH|
-				BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_intent|BTREE_ITER_prefetch|
+				BTREE_ITER_all_snapshots, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			fix_reflink_p_key(trans, &iter, k)));
 	bch_err_fn(c, ret);
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 0f95d7fb5ec0..aafa79fa6351 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -339,7 +339,7 @@ int bch2_inode_peek_nowarn(struct btree_trans *trans,
 
 	k = bch2_bkey_get_iter(trans, iter, BTREE_ID_inodes,
 			       SPOS(0, inum.inum, snapshot),
-			       flags|BTREE_ITER_CACHED);
+			       flags|BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (ret)
 		return ret;
@@ -371,7 +371,7 @@ int bch2_inode_peek(struct btree_trans *trans,
 int bch2_inode_write_flags(struct btree_trans *trans,
 		     struct btree_iter *iter,
 		     struct bch_inode_unpacked *inode,
-		     enum btree_update_flags flags)
+		     enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_inode_buf *inode_p;
 
@@ -399,7 +399,7 @@ int __bch2_fsck_write_inode(struct btree_trans *trans,
 
 	return bch2_btree_insert_nonextent(trans, BTREE_ID_inodes,
 				&inode_p->inode.k_i,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				BTREE_UPDATE_internal_snapshot_node);
 }
 
 int bch2_fsck_write_inode(struct btree_trans *trans,
@@ -473,7 +473,7 @@ fsck_err:
 }
 
 int bch2_inode_invalid(struct bch_fs *c, struct bkey_s_c k,
-		       enum bkey_invalid_flags flags,
+		       enum bch_validate_flags flags,
 		       struct printbuf *err)
 {
 	struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
@@ -490,7 +490,7 @@ fsck_err:
 }
 
 int bch2_inode_v2_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
 	struct bkey_s_c_inode_v2 inode = bkey_s_c_to_inode_v2(k);
@@ -507,7 +507,7 @@ fsck_err:
 }
 
 int bch2_inode_v3_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
 	struct bkey_s_c_inode_v3 inode = bkey_s_c_to_inode_v3(k);
@@ -535,29 +535,19 @@ static void __bch2_inode_unpacked_to_text(struct printbuf *out,
 					  struct bch_inode_unpacked *inode)
 {
 	printbuf_indent_add(out, 2);
-	prt_printf(out, "mode=%o", inode->bi_mode);
-	prt_newline(out);
+	prt_printf(out, "mode=%o\n", inode->bi_mode);
 
 	prt_str(out, "flags=");
 	prt_bitflags(out, bch2_inode_flag_strs, inode->bi_flags & ((1U << 20) - 1));
-	prt_printf(out, " (%x)", inode->bi_flags);
-	prt_newline(out);
+	prt_printf(out, " (%x)\n", inode->bi_flags);
 
-	prt_printf(out, "journal_seq=%llu", inode->bi_journal_seq);
-	prt_newline(out);
-
-	prt_printf(out, "bi_size=%llu", inode->bi_size);
-	prt_newline(out);
-
-	prt_printf(out, "bi_sectors=%llu", inode->bi_sectors);
-	prt_newline(out);
-
-	prt_printf(out, "bi_version=%llu", inode->bi_version);
-	prt_newline(out);
+	prt_printf(out, "journal_seq=%llu\n",	inode->bi_journal_seq);
+	prt_printf(out, "bi_size=%llu\n",	inode->bi_size);
+	prt_printf(out, "bi_sectors=%llu\n",	inode->bi_sectors);
+	prt_printf(out, "bi_version=%llu\n",	inode->bi_version);
 
 #define x(_name, _bits)						\
-	prt_printf(out, #_name "=%llu", (u64) inode->_name);	\
-	prt_newline(out);
+	prt_printf(out, #_name "=%llu\n", (u64) inode->_name);
 	BCH_INODE_FIELDS_v3()
 #undef  x
 	printbuf_indent_sub(out, 2);
@@ -604,11 +594,11 @@ int bch2_trigger_inode(struct btree_trans *trans,
 		       enum btree_id btree_id, unsigned level,
 		       struct bkey_s_c old,
 		       struct bkey_s new,
-		       unsigned flags)
+		       enum btree_iter_update_trigger_flags flags)
 {
 	s64 nr = (s64) bkey_is_inode(new.k) - (s64) bkey_is_inode(old.k);
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		if (nr) {
 			int ret = bch2_replicas_deltas_realloc(trans, 0);
 			if (ret)
@@ -627,13 +617,13 @@ int bch2_trigger_inode(struct btree_trans *trans,
 		}
 	}
 
-	if ((flags & BTREE_TRIGGER_ATOMIC) && (flags & BTREE_TRIGGER_INSERT)) {
+	if ((flags & BTREE_TRIGGER_atomic) && (flags & BTREE_TRIGGER_insert)) {
 		BUG_ON(!trans->journal_res.seq);
 
 		bkey_s_to_inode_v3(new).v->bi_journal_seq = cpu_to_le64(trans->journal_res.seq);
 	}
 
-	if (flags & BTREE_TRIGGER_GC) {
+	if (flags & BTREE_TRIGGER_gc) {
 		struct bch_fs *c = trans->c;
 
 		percpu_down_read(&c->mark_lock);
@@ -645,7 +635,7 @@ int bch2_trigger_inode(struct btree_trans *trans,
 }
 
 int bch2_inode_generation_invalid(struct bch_fs *c, struct bkey_s_c k,
-				  enum bkey_invalid_flags flags,
+				  enum bch_validate_flags flags,
 				  struct printbuf *err)
 {
 	int ret = 0;
@@ -762,8 +752,8 @@ int bch2_inode_create(struct btree_trans *trans,
 
 	pos = start;
 	bch2_trans_iter_init(trans, iter, BTREE_ID_inodes, POS(0, pos),
-			     BTREE_ITER_ALL_SNAPSHOTS|
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_all_snapshots|
+			     BTREE_ITER_intent);
 again:
 	while ((k = bch2_btree_iter_peek(iter)).k &&
 	       !(ret = bkey_err(k)) &&
@@ -824,7 +814,7 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
 	 * extent iterator:
 	 */
 	bch2_trans_iter_init(trans, &iter, id, POS(inum.inum, 0),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 
 	while (1) {
 		bch2_trans_begin(trans);
@@ -846,7 +836,7 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
 		bkey_init(&delete.k);
 		delete.k.p = iter.pos;
 
-		if (iter.flags & BTREE_ITER_IS_EXTENTS)
+		if (iter.flags & BTREE_ITER_is_extents)
 			bch2_key_resize(&delete.k,
 					bpos_min(end, k.k->p).offset -
 					iter.pos.offset);
@@ -895,7 +885,7 @@ retry:
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
 			       SPOS(0, inum.inum, snapshot),
-			       BTREE_ITER_INTENT|BTREE_ITER_CACHED);
+			       BTREE_ITER_intent|BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (ret)
 		goto err;
@@ -1055,7 +1045,7 @@ retry:
 	bch2_trans_begin(trans);
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
-			       SPOS(0, inum, snapshot), BTREE_ITER_INTENT);
+			       SPOS(0, inum, snapshot), BTREE_ITER_intent);
 	ret = bkey_err(k);
 	if (ret)
 		goto err;
@@ -1100,7 +1090,7 @@ static int may_delete_deleted_inode(struct btree_trans *trans,
 	struct bch_inode_unpacked inode;
 	int ret;
 
-	k = bch2_bkey_get_iter(trans, &inode_iter, BTREE_ID_inodes, pos, BTREE_ITER_CACHED);
+	k = bch2_bkey_get_iter(trans, &inode_iter, BTREE_ID_inodes, pos, BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (ret)
 		return ret;
@@ -1152,7 +1142,7 @@ static int may_delete_deleted_inode(struct btree_trans *trans,
 		inode.bi_flags &= ~BCH_INODE_unlinked;
 
 		ret = bch2_inode_write_flags(trans, &inode_iter, &inode,
-					     BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+					     BTREE_UPDATE_internal_snapshot_node);
 		bch_err_msg(c, ret, "clearing inode unlinked flag");
 		if (ret)
 			goto out;
@@ -1199,7 +1189,7 @@ again:
 	 * flushed and we'd spin:
 	 */
 	ret = for_each_btree_key_commit(trans, iter, BTREE_ID_deleted_inodes, POS_MIN,
-					BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+					BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 					NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
 		ret = may_delete_deleted_inode(trans, &iter, k.k->p, &need_another_pass);
 		if (ret > 0) {
diff --git a/fs/bcachefs/inode.h b/fs/bcachefs/inode.h
index 056298050550..679f5f5e5d15 100644
--- a/fs/bcachefs/inode.h
+++ b/fs/bcachefs/inode.h
@@ -6,19 +6,20 @@
 #include "bkey_methods.h"
 #include "opts.h"
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 extern const char * const bch2_inode_opts[];
 
 int bch2_inode_invalid(struct bch_fs *, struct bkey_s_c,
-		       enum bkey_invalid_flags, struct printbuf *);
+		       enum bch_validate_flags, struct printbuf *);
 int bch2_inode_v2_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 int bch2_inode_v3_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 void bch2_inode_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 int bch2_trigger_inode(struct btree_trans *, enum btree_id, unsigned,
-			  struct bkey_s_c, struct bkey_s, unsigned);
+		       struct bkey_s_c, struct bkey_s,
+		       enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_inode ((struct bkey_ops) {	\
 	.key_invalid	= bch2_inode_invalid,		\
@@ -49,7 +50,7 @@ static inline bool bkey_is_inode(const struct bkey *k)
 }
 
 int bch2_inode_generation_invalid(struct bch_fs *, struct bkey_s_c,
-				  enum bkey_invalid_flags, struct printbuf *);
+				  enum bch_validate_flags, struct printbuf *);
 void bch2_inode_generation_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 #define bch2_bkey_ops_inode_generation ((struct bkey_ops) {	\
@@ -101,7 +102,7 @@ int bch2_inode_peek(struct btree_trans *, struct btree_iter *,
 		    struct bch_inode_unpacked *, subvol_inum, unsigned);
 
 int bch2_inode_write_flags(struct btree_trans *, struct btree_iter *,
-		     struct bch_inode_unpacked *, enum btree_update_flags);
+		     struct bch_inode_unpacked *, enum btree_iter_update_trigger_flags);
 
 static inline int bch2_inode_write(struct btree_trans *trans,
 		     struct btree_iter *iter,
@@ -220,6 +221,14 @@ static inline void bch2_inode_nlink_set(struct bch_inode_unpacked *bi,
 int bch2_inode_nlink_inc(struct bch_inode_unpacked *);
 void bch2_inode_nlink_dec(struct btree_trans *, struct bch_inode_unpacked *);
 
+static inline bool bch2_inode_should_have_bp(struct bch_inode_unpacked *inode)
+{
+	bool inode_has_bp = inode->bi_dir || inode->bi_dir_offset;
+
+	return S_ISDIR(inode->bi_mode) ||
+		(!inode->bi_nlink && inode_has_bp);
+}
+
 struct bch_opts bch2_inode_opts_to_opts(struct bch_inode_unpacked *);
 void bch2_inode_opts_get(struct bch_io_opts *, struct bch_fs *,
 			 struct bch_inode_unpacked *);
diff --git a/fs/bcachefs/io_misc.c b/fs/bcachefs/io_misc.c
index 82f9170dab3f..4ec979b4b23e 100644
--- a/fs/bcachefs/io_misc.c
+++ b/fs/bcachefs/io_misc.c
@@ -198,7 +198,7 @@ int bch2_fpunch(struct bch_fs *c, subvol_inum inum, u64 start, u64 end,
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			     POS(inum.inum, start),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 
 	ret = bch2_fpunch_at(trans, &iter, inum, end, i_sectors_delta);
 
@@ -230,7 +230,7 @@ static int truncate_set_isize(struct btree_trans *trans,
 	struct bch_inode_unpacked inode_u;
 	int ret;
 
-	ret   = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_INTENT) ?:
+	ret   = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_intent) ?:
 		(inode_u.bi_size = new_i_size, 0) ?:
 		bch2_inode_write(trans, &iter, &inode_u);
 
@@ -256,7 +256,7 @@ static int __bch2_resume_logged_op_truncate(struct btree_trans *trans,
 
 	bch2_trans_iter_init(trans, &fpunch_iter, BTREE_ID_extents,
 			     POS(inum.inum, round_up(new_i_size, block_bytes(c)) >> 9),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	ret = bch2_fpunch_at(trans, &fpunch_iter, inum, U64_MAX, i_sectors_delta);
 	bch2_trans_iter_exit(trans, &fpunch_iter);
 
@@ -317,7 +317,7 @@ static int adjust_i_size(struct btree_trans *trans, subvol_inum inum, u64 offset
 	offset	<<= 9;
 	len	<<= 9;
 
-	ret = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_INTENT);
+	ret = bch2_inode_peek(trans, &iter, &inode_u, inum, BTREE_ITER_intent);
 	if (ret)
 		return ret;
 
@@ -365,7 +365,7 @@ static int __bch2_resume_logged_op_finsert(struct btree_trans *trans,
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			     POS(inum.inum, 0),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 
 	switch (op->v.state) {
 case LOGGED_OP_FINSERT_start:
diff --git a/fs/bcachefs/io_read.c b/fs/bcachefs/io_read.c
index 8a556e6d1ab6..f57486794484 100644
--- a/fs/bcachefs/io_read.c
+++ b/fs/bcachefs/io_read.c
@@ -378,7 +378,7 @@ static void bch2_read_retry_nodecode(struct bch_fs *c, struct bch_read_bio *rbio
 	bch2_bkey_buf_init(&sk);
 
 	bch2_trans_iter_init(trans, &iter, rbio->data_btree,
-			     rbio->read_pos, BTREE_ITER_SLOTS);
+			     rbio->read_pos, BTREE_ITER_slots);
 retry:
 	rbio->bio.bi_status = 0;
 
@@ -487,7 +487,7 @@ static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
 		return 0;
 
 	k = bch2_bkey_get_iter(trans, &iter, rbio->data_btree, rbio->data_pos,
-			       BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+			       BTREE_ITER_slots|BTREE_ITER_intent);
 	if ((ret = bkey_err(k)))
 		goto out;
 
@@ -523,7 +523,7 @@ static int __bch2_rbio_narrow_crcs(struct btree_trans *trans,
 		goto out;
 
 	ret = bch2_trans_update(trans, &iter, new,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				BTREE_UPDATE_internal_snapshot_node);
 out:
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
@@ -541,7 +541,6 @@ static void __bch2_read_endio(struct work_struct *work)
 	struct bch_read_bio *rbio =
 		container_of(work, struct bch_read_bio, work);
 	struct bch_fs *c	= rbio->c;
-	struct bch_dev *ca	= bch_dev_bkey_exists(c, rbio->pick.ptr.dev);
 	struct bio *src		= &rbio->bio;
 	struct bio *dst		= &bch2_rbio_parent(rbio)->bio;
 	struct bvec_iter dst_iter = rbio->bvec_iter;
@@ -647,13 +646,15 @@ csum_err:
 	prt_str(&buf, "data ");
 	bch2_csum_err_msg(&buf, crc.csum_type, rbio->pick.crc.csum, csum);
 
-	bch_err_inum_offset_ratelimited(ca,
-		rbio->read_pos.inode,
-		rbio->read_pos.offset << 9,
-		"data %s", buf.buf);
+	struct bch_dev *ca = rbio->have_ioref ? bch2_dev_have_ref(c, rbio->pick.ptr.dev) : NULL;
+	if (ca) {
+		bch_err_inum_offset_ratelimited(ca,
+			rbio->read_pos.inode,
+			rbio->read_pos.offset << 9,
+			"data %s", buf.buf);
+		bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
+	}
 	printbuf_exit(&buf);
-
-	bch2_io_error(ca, BCH_MEMBER_ERROR_checksum);
 	bch2_rbio_error(rbio, READ_RETRY_AVOID, BLK_STS_IOERR);
 	goto out;
 decompression_err:
@@ -675,7 +676,7 @@ static void bch2_read_endio(struct bio *bio)
 	struct bch_read_bio *rbio =
 		container_of(bio, struct bch_read_bio, bio);
 	struct bch_fs *c	= rbio->c;
-	struct bch_dev *ca	= bch_dev_bkey_exists(c, rbio->pick.ptr.dev);
+	struct bch_dev *ca = rbio->have_ioref ? bch2_dev_have_ref(c, rbio->pick.ptr.dev) : NULL;
 	struct workqueue_struct *wq = NULL;
 	enum rbio_context context = RBIO_CONTEXT_NULL;
 
@@ -687,17 +688,21 @@ static void bch2_read_endio(struct bio *bio)
 	if (!rbio->split)
 		rbio->bio.bi_end_io = rbio->end_io;
 
-	if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_read,
-				    rbio->read_pos.inode,
-				    rbio->read_pos.offset,
-				    "data read error: %s",
-			       bch2_blk_status_to_str(bio->bi_status))) {
+	if (bio->bi_status) {
+		if (ca) {
+			bch_err_inum_offset_ratelimited(ca,
+				rbio->read_pos.inode,
+				rbio->read_pos.offset,
+				"data read error: %s",
+				bch2_blk_status_to_str(bio->bi_status));
+			bch2_io_error(ca, BCH_MEMBER_ERROR_read);
+		}
 		bch2_rbio_error(rbio, READ_RETRY_AVOID, bio->bi_status);
 		return;
 	}
 
 	if (((rbio->flags & BCH_READ_RETRY_IF_STALE) && race_fault()) ||
-	    ptr_stale(ca, &rbio->pick.ptr)) {
+	    (ca && dev_ptr_stale(ca, &rbio->pick.ptr))) {
 		trace_and_count(c, read_reuse_race, &rbio->bio);
 
 		if (rbio->flags & BCH_READ_RETRY_IF_STALE)
@@ -758,22 +763,21 @@ err:
 }
 
 static noinline void read_from_stale_dirty_pointer(struct btree_trans *trans,
+						   struct bch_dev *ca,
 						   struct bkey_s_c k,
 						   struct bch_extent_ptr ptr)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr.dev);
 	struct btree_iter iter;
 	struct printbuf buf = PRINTBUF;
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
-			     PTR_BUCKET_POS(c, &ptr),
-			     BTREE_ITER_CACHED);
+			     PTR_BUCKET_POS(ca, &ptr),
+			     BTREE_ITER_cached);
 
-	prt_printf(&buf, "Attempting to read from stale dirty pointer:");
+	prt_printf(&buf, "Attempting to read from stale dirty pointer:\n");
 	printbuf_indent_add(&buf, 2);
-	prt_newline(&buf);
 
 	bch2_bkey_val_to_text(&buf, c, k);
 	prt_newline(&buf);
@@ -801,7 +805,6 @@ int __bch2_read_extent(struct btree_trans *trans, struct bch_read_bio *orig,
 	struct bch_fs *c = trans->c;
 	struct extent_ptr_decoded pick;
 	struct bch_read_bio *rbio = NULL;
-	struct bch_dev *ca = NULL;
 	struct promote_op *promote = NULL;
 	bool bounce = false, read_full = false, narrow_crcs = false;
 	struct bpos data_pos = bkey_start_pos(k.k);
@@ -832,7 +835,7 @@ retry_pick:
 		goto err;
 	}
 
-	ca = bch_dev_bkey_exists(c, pick.ptr.dev);
+	struct bch_dev *ca = bch2_dev_get_ioref(c, pick.ptr.dev, READ);
 
 	/*
 	 * Stale dirty pointers are treated as IO errors, but @failed isn't
@@ -842,9 +845,11 @@ retry_pick:
 	 */
 	if ((flags & BCH_READ_IN_RETRY) &&
 	    !pick.ptr.cached &&
-	    unlikely(ptr_stale(ca, &pick.ptr))) {
-		read_from_stale_dirty_pointer(trans, k, pick.ptr);
+	    ca &&
+	    unlikely(dev_ptr_stale(ca, &pick.ptr))) {
+		read_from_stale_dirty_pointer(trans, ca, k, pick.ptr);
 		bch2_mark_io_failure(failed, &pick);
+		percpu_ref_put(&ca->io_ref);
 		goto retry_pick;
 	}
 
@@ -859,8 +864,11 @@ retry_pick:
 		 * can happen if we retry, and the extent we were going to read
 		 * has been merged in the meantime:
 		 */
-		if (pick.crc.compressed_size > orig->bio.bi_vcnt * PAGE_SECTORS)
+		if (pick.crc.compressed_size > orig->bio.bi_vcnt * PAGE_SECTORS) {
+			if (ca)
+				percpu_ref_put(&ca->io_ref);
 			goto hole;
+		}
 
 		iter.bi_size	= pick.crc.compressed_size << 9;
 		goto get_bio;
@@ -965,7 +973,7 @@ get_bio:
 	rbio->bvec_iter		= iter;
 	rbio->offset_into_extent= offset_into_extent;
 	rbio->flags		= flags;
-	rbio->have_ioref	= pick_ret > 0 && bch2_dev_get_ioref(ca, READ);
+	rbio->have_ioref	= ca != NULL;
 	rbio->narrow_crcs	= narrow_crcs;
 	rbio->hole		= 0;
 	rbio->retry		= 0;
@@ -995,7 +1003,7 @@ get_bio:
 	 * If it's being moved internally, we don't want to flag it as a cache
 	 * hit:
 	 */
-	if (pick.ptr.cached && !(flags & BCH_READ_NODECODE))
+	if (ca && pick.ptr.cached && !(flags & BCH_READ_NODECODE))
 		bch2_bucket_io_time_reset(trans, pick.ptr.dev,
 			PTR_BUCKET_NR(ca, &pick.ptr), READ);
 
@@ -1113,7 +1121,7 @@ retry:
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			     SPOS(inum.inum, bvec_iter.bi_sector, snapshot),
-			     BTREE_ITER_SLOTS);
+			     BTREE_ITER_slots);
 	while (1) {
 		unsigned bytes, sectors, offset_into_extent;
 		enum btree_id data_btree = BTREE_ID_extents;
diff --git a/fs/bcachefs/io_write.c b/fs/bcachefs/io_write.c
index 40d7df7607df..9401d13e31bb 100644
--- a/fs/bcachefs/io_write.c
+++ b/fs/bcachefs/io_write.c
@@ -166,7 +166,7 @@ int bch2_sum_sector_overwrites(struct btree_trans *trans,
 	bch2_trans_copy_iter(&iter, extent_iter);
 
 	for_each_btree_key_upto_continue_norestart(iter,
-				new->k.p, BTREE_ITER_SLOTS, old, ret) {
+				new->k.p, BTREE_ITER_slots, old, ret) {
 		s64 sectors = min(new->k.p.offset, old.k->p.offset) -
 			max(bkey_start_offset(&new->k),
 			    bkey_start_offset(old.k));
@@ -210,14 +210,14 @@ static inline int bch2_extent_update_i_size_sectors(struct btree_trans *trans,
 	 * to be journalled - if we crash, the bi_journal_seq update will be
 	 * lost, but that's fine.
 	 */
-	unsigned inode_update_flags = BTREE_UPDATE_NOJOURNAL;
+	unsigned inode_update_flags = BTREE_UPDATE_nojournal;
 
 	struct btree_iter iter;
 	struct bkey_s_c k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
 			      SPOS(0,
 				   extent_iter->pos.inode,
 				   extent_iter->snapshot),
-			      BTREE_ITER_CACHED);
+			      BTREE_ITER_cached);
 	int ret = bkey_err(k);
 	if (unlikely(ret))
 		return ret;
@@ -259,7 +259,7 @@ static inline int bch2_extent_update_i_size_sectors(struct btree_trans *trans,
 	}
 
 	ret = bch2_trans_update(trans, &iter, &inode->k_i,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE|
+				BTREE_UPDATE_internal_snapshot_node|
 				inode_update_flags);
 err:
 	bch2_trans_iter_exit(trans, &iter);
@@ -368,7 +368,7 @@ static int bch2_write_index_default(struct bch_write_op *op)
 
 		bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 				     bkey_start_pos(&sk.k->k),
-				     BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+				     BTREE_ITER_slots|BTREE_ITER_intent);
 
 		ret =   bch2_bkey_set_needs_rebalance(c, sk.k, &op->opts) ?:
 			bch2_extent_update(trans, inum, &iter, sk.k,
@@ -407,13 +407,12 @@ void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
 	BUG_ON(c->opts.nochanges);
 
 	bkey_for_each_ptr(ptrs, ptr) {
-		BUG_ON(!bch2_dev_exists2(c, ptr->dev));
-
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+		struct bch_dev *ca = nocow
+			? bch2_dev_have_ref(c, ptr->dev)
+			: bch2_dev_get_ioref(c, ptr->dev, type == BCH_DATA_btree ? READ : WRITE);
 
 		if (to_entry(ptr + 1) < ptrs.end) {
-			n = to_wbio(bio_alloc_clone(NULL, &wbio->bio,
-						GFP_NOFS, &ca->replica_set));
+			n = to_wbio(bio_alloc_clone(NULL, &wbio->bio, GFP_NOFS, &c->replica_set));
 
 			n->bio.bi_end_io	= wbio->bio.bi_end_io;
 			n->bio.bi_private	= wbio->bio.bi_private;
@@ -430,11 +429,12 @@ void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
 
 		n->c			= c;
 		n->dev			= ptr->dev;
-		n->have_ioref		= nocow || bch2_dev_get_ioref(ca,
-					type == BCH_DATA_btree ? READ : WRITE);
+		n->have_ioref		= ca != NULL;
 		n->nocow		= nocow;
 		n->submit_time		= local_clock();
 		n->inode_offset		= bkey_start_offset(&k->k);
+		if (nocow)
+			n->nocow_bucket	= PTR_BUCKET_NR(ca, ptr);
 		n->bio.bi_iter.bi_sector = ptr->offset;
 
 		if (likely(n->have_ioref)) {
@@ -481,7 +481,6 @@ static void bch2_write_done(struct closure *cl)
 static noinline int bch2_write_drop_io_error_ptrs(struct bch_write_op *op)
 {
 	struct keylist *keys = &op->insert_keys;
-	struct bch_extent_ptr *ptr;
 	struct bkey_i *src, *dst = keys->keys, *n;
 
 	for (src = keys->keys; src != keys->top; src = n) {
@@ -650,7 +649,9 @@ static void bch2_write_endio(struct bio *bio)
 	struct bch_write_bio *wbio	= to_wbio(bio);
 	struct bch_write_bio *parent	= wbio->split ? wbio->parent : NULL;
 	struct bch_fs *c		= wbio->c;
-	struct bch_dev *ca		= bch_dev_bkey_exists(c, wbio->dev);
+	struct bch_dev *ca		= wbio->have_ioref
+		? bch2_dev_have_ref(c, wbio->dev)
+		: NULL;
 
 	if (bch2_dev_inum_io_err_on(bio->bi_status, ca, BCH_MEMBER_ERROR_write,
 				    op->pos.inode,
@@ -661,8 +662,12 @@ static void bch2_write_endio(struct bio *bio)
 		op->flags |= BCH_WRITE_IO_ERROR;
 	}
 
-	if (wbio->nocow)
+	if (wbio->nocow) {
+		bch2_bucket_nocow_unlock(&c->nocow_locks,
+					 POS(ca->dev_idx, wbio->nocow_bucket),
+					 BUCKET_NOCOW_LOCK_UPDATE);
 		set_bit(wbio->dev, op->devs_need_flush->d);
+	}
 
 	if (wbio->have_ioref) {
 		bch2_latency_acct(ca, wbio->submit_time, WRITE);
@@ -1101,30 +1106,21 @@ static bool bch2_extent_is_writeable(struct bch_write_op *op,
 		return false;
 
 	e = bkey_s_c_to_extent(k);
+
+	rcu_read_lock();
 	extent_for_each_ptr_decode(e, p, entry) {
-		if (crc_is_encoded(p.crc) || p.has_ec)
+		if (crc_is_encoded(p.crc) || p.has_ec) {
+			rcu_read_unlock();
 			return false;
+		}
 
 		replicas += bch2_extent_ptr_durability(c, &p);
 	}
+	rcu_read_unlock();
 
 	return replicas >= op->opts.data_replicas;
 }
 
-static inline void bch2_nocow_write_unlock(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-
-	for_each_keylist_key(&op->insert_keys, k) {
-		struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(bkey_i_to_s_c(k));
-
-		bkey_for_each_ptr(ptrs, ptr)
-			bch2_bucket_nocow_unlock(&c->nocow_locks,
-						 PTR_BUCKET_POS(c, ptr),
-						 BUCKET_NOCOW_LOCK_UPDATE);
-	}
-}
-
 static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
 						  struct btree_iter *iter,
 						  struct bkey_i *orig,
@@ -1158,7 +1154,7 @@ static int bch2_nocow_write_convert_one_unwritten(struct btree_trans *trans,
 	return  bch2_extent_update_i_size_sectors(trans, iter,
 					min(new->k.p.offset << 9, new_i_size), 0) ?:
 		bch2_trans_update(trans, iter, new,
-				  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				  BTREE_UPDATE_internal_snapshot_node);
 }
 
 static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
@@ -1169,7 +1165,7 @@ static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
 	for_each_keylist_key(&op->insert_keys, orig) {
 		int ret = for_each_btree_key_upto_commit(trans, iter, BTREE_ID_extents,
 				     bkey_start_pos(&orig->k), orig->k.p,
-				     BTREE_ITER_INTENT, k,
+				     BTREE_ITER_intent, k,
 				     NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
 			bch2_nocow_write_convert_one_unwritten(trans, &iter, orig, k, op->new_i_size);
 		}));
@@ -1195,8 +1191,6 @@ static void bch2_nocow_write_convert_unwritten(struct bch_write_op *op)
 
 static void __bch2_nocow_write_done(struct bch_write_op *op)
 {
-	bch2_nocow_write_unlock(op);
-
 	if (unlikely(op->flags & BCH_WRITE_IO_ERROR)) {
 		op->error = -EIO;
 	} else if (unlikely(op->flags & BCH_WRITE_CONVERT_UNWRITTEN))
@@ -1242,12 +1236,16 @@ retry:
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_extents,
 			     SPOS(op->pos.inode, op->pos.offset, snapshot),
-			     BTREE_ITER_SLOTS);
+			     BTREE_ITER_slots);
 	while (1) {
 		struct bio *bio = &op->wbio.bio;
 
 		buckets.nr = 0;
 
+		ret = bch2_trans_relock(trans);
+		if (ret)
+			break;
+
 		k = bch2_btree_iter_peek_slot(&iter);
 		ret = bkey_err(k);
 		if (ret)
@@ -1267,14 +1265,15 @@ retry:
 		/* Get iorefs before dropping btree locks: */
 		struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 		bkey_for_each_ptr(ptrs, ptr) {
-			struct bpos b = PTR_BUCKET_POS(c, ptr);
+			struct bch_dev *ca = bch2_dev_get_ioref(c, ptr->dev, WRITE);
+			if (unlikely(!ca))
+				goto err_get_ioref;
+
+			struct bpos b = PTR_BUCKET_POS(ca, ptr);
 			struct nocow_lock_bucket *l =
 				bucket_nocow_lock(&c->nocow_locks, bucket_to_u64(b));
 			prefetch(l);
 
-			if (unlikely(!bch2_dev_get_ioref(bch_dev_bkey_exists(c, ptr->dev), WRITE)))
-				goto err_get_ioref;
-
 			/* XXX allocating memory with btree locks held - rare */
 			darray_push_gfp(&buckets, ((struct bucket_to_lock) {
 						   .b = b, .gen = ptr->gen, .l = l,
@@ -1293,7 +1292,7 @@ retry:
 			bch2_cut_back(POS(op->pos.inode, op->pos.offset + bio_sectors(bio)), op->insert_keys.top);
 
 		darray_for_each(buckets, i) {
-			struct bch_dev *ca = bch_dev_bkey_exists(c, i->b.inode);
+			struct bch_dev *ca = bch2_dev_have_ref(c, i->b.inode);
 
 			__bch2_bucket_nocow_lock(&c->nocow_locks, i->l,
 						 bucket_to_u64(i->b),
@@ -1370,7 +1369,7 @@ err:
 	return;
 err_get_ioref:
 	darray_for_each(buckets, i)
-		percpu_ref_put(&bch_dev_bkey_exists(c, i->b.inode)->io_ref);
+		percpu_ref_put(&bch2_dev_have_ref(c, i->b.inode)->io_ref);
 
 	/* Fall back to COW path: */
 	goto out;
@@ -1491,7 +1490,11 @@ err:
 	if ((op->flags & BCH_WRITE_SYNC) ||
 	    (!(op->flags & BCH_WRITE_DONE) &&
 	     !(op->flags & BCH_WRITE_IN_WORKER))) {
-		closure_sync(&op->cl);
+		if (closure_sync_timeout(&op->cl, HZ * 10)) {
+			bch2_print_allocator_stuck(c);
+			closure_sync(&op->cl);
+		}
+
 		__bch2_write_index(op);
 
 		if (!(op->flags & BCH_WRITE_DONE))
@@ -1649,8 +1652,7 @@ void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
 	prt_bitflags(out, bch2_write_flags, op->flags);
 	prt_newline(out);
 
-	prt_printf(out, "ref: %u", closure_nr_remaining(&op->cl));
-	prt_newline(out);
+	prt_printf(out, "ref: %u\n", closure_nr_remaining(&op->cl));
 
 	printbuf_indent_sub(out, 2);
 }
@@ -1658,13 +1660,14 @@ void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
 void bch2_fs_io_write_exit(struct bch_fs *c)
 {
 	mempool_exit(&c->bio_bounce_pages);
+	bioset_exit(&c->replica_set);
 	bioset_exit(&c->bio_write);
 }
 
 int bch2_fs_io_write_init(struct bch_fs *c)
 {
-	if (bioset_init(&c->bio_write, 1, offsetof(struct bch_write_bio, bio),
-			BIOSET_NEED_BVECS))
+	if (bioset_init(&c->bio_write,   1, offsetof(struct bch_write_bio, bio), BIOSET_NEED_BVECS) ||
+	    bioset_init(&c->replica_set, 4, offsetof(struct bch_write_bio, bio), 0))
 		return -BCH_ERR_ENOMEM_bio_write_init;
 
 	if (mempool_init_page_pool(&c->bio_bounce_pages,
diff --git a/fs/bcachefs/io_write_types.h b/fs/bcachefs/io_write_types.h
index c7f97c2c4805..6e878a6f2f0b 100644
--- a/fs/bcachefs/io_write_types.h
+++ b/fs/bcachefs/io_write_types.h
@@ -20,6 +20,7 @@ struct bch_write_bio {
 
 	u64			submit_time;
 	u64			inode_offset;
+	u64			nocow_bucket;
 
 	struct bch_devs_list	failed;
 	u8			dev;
diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c
index a8b08e76d0d0..adec8e1ea73e 100644
--- a/fs/bcachefs/journal.c
+++ b/fs/bcachefs/journal.c
@@ -53,29 +53,19 @@ static void bch2_journal_buf_to_text(struct printbuf *out, struct journal *j, u6
 	unsigned i = seq & JOURNAL_BUF_MASK;
 	struct journal_buf *buf = j->buf + i;
 
-	prt_str(out, "seq:");
-	prt_tab(out);
-	prt_printf(out, "%llu", seq);
-	prt_newline(out);
+	prt_printf(out, "seq:\t%llu\n", seq);
 	printbuf_indent_add(out, 2);
 
-	prt_str(out, "refcount:");
-	prt_tab(out);
-	prt_printf(out, "%u", journal_state_count(s, i));
-	prt_newline(out);
+	prt_printf(out, "refcount:\t%u\n", journal_state_count(s, i));
 
-	prt_str(out, "size:");
-	prt_tab(out);
+	prt_printf(out, "size:\t");
 	prt_human_readable_u64(out, vstruct_bytes(buf->data));
 	prt_newline(out);
 
-	prt_str(out, "expires:");
-	prt_tab(out);
-	prt_printf(out, "%li jiffies", buf->expires - jiffies);
-	prt_newline(out);
+	prt_printf(out, "expires:\t");
+	prt_printf(out, "%li jiffies\n", buf->expires - jiffies);
 
-	prt_str(out, "flags:");
-	prt_tab(out);
+	prt_printf(out, "flags:\t");
 	if (buf->noflush)
 		prt_str(out, "noflush ");
 	if (buf->must_flush)
@@ -87,9 +77,9 @@ static void bch2_journal_buf_to_text(struct printbuf *out, struct journal *j, u6
 	if (buf->write_started)
 		prt_str(out, "write_started ");
 	if (buf->write_allocated)
-		prt_str(out, "write allocated ");
+		prt_str(out, "write_allocated ");
 	if (buf->write_done)
-		prt_str(out, "write done");
+		prt_str(out, "write_done");
 	prt_newline(out);
 
 	printbuf_indent_sub(out, 2);
@@ -948,7 +938,8 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
 				break;
 			}
 		} else {
-			ob[nr_got] = bch2_bucket_alloc(c, ca, BCH_WATERMARK_normal, cl);
+			ob[nr_got] = bch2_bucket_alloc(c, ca, BCH_WATERMARK_normal,
+						       BCH_DATA_journal, cl);
 			ret = PTR_ERR_OR_ZERO(ob[nr_got]);
 			if (ret)
 				break;
@@ -956,7 +947,7 @@ static int __bch2_set_nr_journal_buckets(struct bch_dev *ca, unsigned nr,
 			ret = bch2_trans_run(c,
 				bch2_trans_mark_metadata_bucket(trans, ca,
 						ob[nr_got]->bucket, BCH_DATA_journal,
-						ca->mi.bucket_size));
+						ca->mi.bucket_size, BTREE_TRIGGER_transactional));
 			if (ret) {
 				bch2_open_bucket_put(c, ob[nr_got]);
 				bch_err_msg(c, ret, "marking new journal buckets");
@@ -1036,7 +1027,8 @@ err_unblock:
 		for (i = 0; i < nr_got; i++)
 			bch2_trans_run(c,
 				bch2_trans_mark_metadata_bucket(trans, ca,
-						bu[i], BCH_DATA_free, 0));
+						bu[i], BCH_DATA_free, 0,
+						BTREE_TRIGGER_transactional));
 err_free:
 	if (!new_fs)
 		for (i = 0; i < nr_got; i++)
@@ -1187,12 +1179,14 @@ void bch2_fs_journal_stop(struct journal *j)
 	bch2_journal_meta(j);
 
 	journal_quiesce(j);
+	cancel_delayed_work_sync(&j->write_work);
 
 	BUG_ON(!bch2_journal_error(j) &&
-	       test_bit(JOURNAL_REPLAY_DONE, &j->flags) &&
+	       test_bit(JOURNAL_replay_done, &j->flags) &&
 	       j->last_empty_seq != journal_cur_seq(j));
 
-	cancel_delayed_work_sync(&j->write_work);
+	if (!bch2_journal_error(j))
+		clear_bit(JOURNAL_running, &j->flags);
 }
 
 int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
@@ -1266,7 +1260,7 @@ int bch2_fs_journal_start(struct journal *j, u64 cur_seq)
 
 	spin_lock(&j->lock);
 
-	set_bit(JOURNAL_STARTED, &j->flags);
+	set_bit(JOURNAL_running, &j->flags);
 	j->last_flush_write = jiffies;
 
 	j->reservations.idx = j->reservations.unwritten_idx = journal_cur_seq(j);
@@ -1407,6 +1401,13 @@ int bch2_fs_journal_init(struct journal *j)
 
 /* debug: */
 
+static const char * const bch2_journal_flags_strs[] = {
+#define x(n)	#n,
+	JOURNAL_FLAGS()
+#undef x
+	NULL
+};
+
 void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
 {
 	struct bch_fs *c = container_of(j, struct bch_fs, journal);
@@ -1415,19 +1416,22 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
 	u64 nr_writes = j->nr_flush_writes + j->nr_noflush_writes;
 
 	if (!out->nr_tabstops)
-		printbuf_tabstop_push(out, 24);
+		printbuf_tabstop_push(out, 28);
 	out->atomic++;
 
 	rcu_read_lock();
 	s = READ_ONCE(j->reservations);
 
+	prt_printf(out, "flags:\t");
+	prt_bitflags(out, bch2_journal_flags_strs, j->flags);
+	prt_newline(out);
 	prt_printf(out, "dirty journal entries:\t%llu/%llu\n",	fifo_used(&j->pin), j->pin.size);
-	prt_printf(out, "seq:\t\t\t%llu\n",			journal_cur_seq(j));
-	prt_printf(out, "seq_ondisk:\t\t%llu\n",		j->seq_ondisk);
-	prt_printf(out, "last_seq:\t\t%llu\n",			journal_last_seq(j));
+	prt_printf(out, "seq:\t%llu\n",				journal_cur_seq(j));
+	prt_printf(out, "seq_ondisk:\t%llu\n",			j->seq_ondisk);
+	prt_printf(out, "last_seq:\t%llu\n",			journal_last_seq(j));
 	prt_printf(out, "last_seq_ondisk:\t%llu\n",		j->last_seq_ondisk);
 	prt_printf(out, "flushed_seq_ondisk:\t%llu\n",		j->flushed_seq_ondisk);
-	prt_printf(out, "watermark:\t\t%s\n",			bch2_watermarks[j->watermark]);
+	prt_printf(out, "watermark:\t%s\n",			bch2_watermarks[j->watermark]);
 	prt_printf(out, "each entry reserved:\t%u\n",		j->entry_u64s_reserved);
 	prt_printf(out, "nr flush writes:\t%llu\n",		j->nr_flush_writes);
 	prt_printf(out, "nr noflush writes:\t%llu\n",		j->nr_noflush_writes);
@@ -1436,48 +1440,44 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
 	prt_newline(out);
 	prt_printf(out, "nr direct reclaim:\t%llu\n",		j->nr_direct_reclaim);
 	prt_printf(out, "nr background reclaim:\t%llu\n",	j->nr_background_reclaim);
-	prt_printf(out, "reclaim kicked:\t\t%u\n",		j->reclaim_kicked);
+	prt_printf(out, "reclaim kicked:\t%u\n",		j->reclaim_kicked);
 	prt_printf(out, "reclaim runs in:\t%u ms\n",		time_after(j->next_reclaim, now)
 	       ? jiffies_to_msecs(j->next_reclaim - jiffies) : 0);
-	prt_printf(out, "blocked:\t\t%u\n",			j->blocked);
+	prt_printf(out, "blocked:\t%u\n",			j->blocked);
 	prt_printf(out, "current entry sectors:\t%u\n",		j->cur_entry_sectors);
 	prt_printf(out, "current entry error:\t%s\n",		bch2_journal_errors[j->cur_entry_error]);
-	prt_printf(out, "current entry:\t\t");
+	prt_printf(out, "current entry:\t");
 
 	switch (s.cur_entry_offset) {
 	case JOURNAL_ENTRY_ERROR_VAL:
-		prt_printf(out, "error");
+		prt_printf(out, "error\n");
 		break;
 	case JOURNAL_ENTRY_CLOSED_VAL:
-		prt_printf(out, "closed");
+		prt_printf(out, "closed\n");
 		break;
 	default:
-		prt_printf(out, "%u/%u", s.cur_entry_offset, j->cur_entry_u64s);
+		prt_printf(out, "%u/%u\n", s.cur_entry_offset, j->cur_entry_u64s);
 		break;
 	}
 
-	prt_newline(out);
-	prt_printf(out, "unwritten entries:");
-	prt_newline(out);
+	prt_printf(out, "unwritten entries:\n");
 	bch2_journal_bufs_to_text(out, j);
 
-	prt_printf(out,
-	       "replay done:\t\t%i\n",
-	       test_bit(JOURNAL_REPLAY_DONE,	&j->flags));
-
 	prt_printf(out, "space:\n");
-	prt_printf(out, "\tdiscarded\t%u:%u\n",
+	printbuf_indent_add(out, 2);
+	prt_printf(out, "discarded\t%u:%u\n",
 	       j->space[journal_space_discarded].next_entry,
 	       j->space[journal_space_discarded].total);
-	prt_printf(out, "\tclean ondisk\t%u:%u\n",
+	prt_printf(out, "clean ondisk\t%u:%u\n",
 	       j->space[journal_space_clean_ondisk].next_entry,
 	       j->space[journal_space_clean_ondisk].total);
-	prt_printf(out, "\tclean\t\t%u:%u\n",
+	prt_printf(out, "clean\t%u:%u\n",
 	       j->space[journal_space_clean].next_entry,
 	       j->space[journal_space_clean].total);
-	prt_printf(out, "\ttotal\t\t%u:%u\n",
+	prt_printf(out, "total\t%u:%u\n",
 	       j->space[journal_space_total].next_entry,
 	       j->space[journal_space_total].total);
+	printbuf_indent_sub(out, 2);
 
 	for_each_member_device_rcu(c, ca, &c->rw_devs[BCH_DATA_journal]) {
 		struct journal_device *ja = &ca->journal;
@@ -1488,14 +1488,16 @@ void __bch2_journal_debug_to_text(struct printbuf *out, struct journal *j)
 		if (!ja->nr)
 			continue;
 
-		prt_printf(out, "dev %u:\n",		ca->dev_idx);
-		prt_printf(out, "\tnr\t\t%u\n",		ja->nr);
-		prt_printf(out, "\tbucket size\t%u\n",	ca->mi.bucket_size);
-		prt_printf(out, "\tavailable\t%u:%u\n",	bch2_journal_dev_buckets_available(j, ja, journal_space_discarded), ja->sectors_free);
-		prt_printf(out, "\tdiscard_idx\t%u\n",	ja->discard_idx);
-		prt_printf(out, "\tdirty_ondisk\t%u (seq %llu)\n", ja->dirty_idx_ondisk,	ja->bucket_seq[ja->dirty_idx_ondisk]);
-		prt_printf(out, "\tdirty_idx\t%u (seq %llu)\n", ja->dirty_idx,		ja->bucket_seq[ja->dirty_idx]);
-		prt_printf(out, "\tcur_idx\t\t%u (seq %llu)\n", ja->cur_idx,		ja->bucket_seq[ja->cur_idx]);
+		prt_printf(out, "dev %u:\n",			ca->dev_idx);
+		printbuf_indent_add(out, 2);
+		prt_printf(out, "nr\t%u\n",			ja->nr);
+		prt_printf(out, "bucket size\t%u\n",		ca->mi.bucket_size);
+		prt_printf(out, "available\t%u:%u\n",		bch2_journal_dev_buckets_available(j, ja, journal_space_discarded), ja->sectors_free);
+		prt_printf(out, "discard_idx\t%u\n",		ja->discard_idx);
+		prt_printf(out, "dirty_ondisk\t%u (seq %llu)\n",ja->dirty_idx_ondisk,	ja->bucket_seq[ja->dirty_idx_ondisk]);
+		prt_printf(out, "dirty_idx\t%u (seq %llu)\n",	ja->dirty_idx,		ja->bucket_seq[ja->dirty_idx]);
+		prt_printf(out, "cur_idx\t%u (seq %llu)\n",	ja->cur_idx,		ja->bucket_seq[ja->cur_idx]);
+		printbuf_indent_sub(out, 2);
 	}
 
 	rcu_read_unlock();
@@ -1527,25 +1529,18 @@ bool bch2_journal_seq_pins_to_text(struct printbuf *out, struct journal *j, u64
 
 	pin_list = journal_seq_pin(j, *seq);
 
-	prt_printf(out, "%llu: count %u", *seq, atomic_read(&pin_list->count));
-	prt_newline(out);
+	prt_printf(out, "%llu: count %u\n", *seq, atomic_read(&pin_list->count));
 	printbuf_indent_add(out, 2);
 
 	for (unsigned i = 0; i < ARRAY_SIZE(pin_list->list); i++)
-		list_for_each_entry(pin, &pin_list->list[i], list) {
-			prt_printf(out, "\t%px %ps", pin, pin->flush);
-			prt_newline(out);
-		}
+		list_for_each_entry(pin, &pin_list->list[i], list)
+			prt_printf(out, "\t%px %ps\n", pin, pin->flush);
 
-	if (!list_empty(&pin_list->flushed)) {
-		prt_printf(out, "flushed:");
-		prt_newline(out);
-	}
+	if (!list_empty(&pin_list->flushed))
+		prt_printf(out, "flushed:\n");
 
-	list_for_each_entry(pin, &pin_list->flushed, list) {
-		prt_printf(out, "\t%px %ps", pin, pin->flush);
-		prt_newline(out);
-	}
+	list_for_each_entry(pin, &pin_list->flushed, list)
+		prt_printf(out, "\t%px %ps\n", pin, pin->flush);
 
 	printbuf_indent_sub(out, 2);
 
diff --git a/fs/bcachefs/journal.h b/fs/bcachefs/journal.h
index 7c7528f839c5..fd1f7cdaa8bc 100644
--- a/fs/bcachefs/journal.h
+++ b/fs/bcachefs/journal.h
@@ -372,7 +372,7 @@ static inline int bch2_journal_res_get(struct journal *j, struct journal_res *re
 	int ret;
 
 	EBUG_ON(res->ref);
-	EBUG_ON(!test_bit(JOURNAL_STARTED, &j->flags));
+	EBUG_ON(!test_bit(JOURNAL_running, &j->flags));
 
 	res->u64s = u64s;
 
@@ -418,8 +418,8 @@ struct bch_dev;
 
 static inline void bch2_journal_set_replay_done(struct journal *j)
 {
-	BUG_ON(!test_bit(JOURNAL_STARTED, &j->flags));
-	set_bit(JOURNAL_REPLAY_DONE, &j->flags);
+	BUG_ON(!test_bit(JOURNAL_running, &j->flags));
+	set_bit(JOURNAL_replay_done, &j->flags);
 }
 
 void bch2_journal_unblock(struct journal *);
diff --git a/fs/bcachefs/journal_io.c b/fs/bcachefs/journal_io.c
index eb1f9d6f5a19..cdcb1ad49af4 100644
--- a/fs/bcachefs/journal_io.c
+++ b/fs/bcachefs/journal_io.c
@@ -17,15 +17,38 @@
 #include "sb-clean.h"
 #include "trace.h"
 
+void bch2_journal_pos_from_member_info_set(struct bch_fs *c)
+{
+	lockdep_assert_held(&c->sb_lock);
+
+	for_each_member_device(c, ca) {
+		struct bch_member *m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
+
+		m->last_journal_bucket = cpu_to_le32(ca->journal.cur_idx);
+		m->last_journal_bucket_offset = cpu_to_le32(ca->mi.bucket_size - ca->journal.sectors_free);
+	}
+}
+
+void bch2_journal_pos_from_member_info_resume(struct bch_fs *c)
+{
+	mutex_lock(&c->sb_lock);
+	for_each_member_device(c, ca) {
+		struct bch_member m = bch2_sb_member_get(c->disk_sb.sb, ca->dev_idx);
+
+		unsigned idx = le32_to_cpu(m.last_journal_bucket);
+		if (idx < ca->journal.nr)
+			ca->journal.cur_idx = idx;
+		unsigned offset = le32_to_cpu(m.last_journal_bucket_offset);
+		if (offset <= ca->mi.bucket_size)
+			ca->journal.sectors_free = ca->mi.bucket_size - offset;
+	}
+	mutex_unlock(&c->sb_lock);
+}
+
 void bch2_journal_ptrs_to_text(struct printbuf *out, struct bch_fs *c,
 			       struct journal_replay *j)
 {
 	darray_for_each(j->ptrs, i) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, i->dev);
-		u64 offset;
-
-		div64_u64_rem(i->sector, ca->mi.bucket_size, &offset);
-
 		if (i != j->ptrs.data)
 			prt_printf(out, " ");
 		prt_printf(out, "%u:%u:%u (sector %llu)",
@@ -122,6 +145,10 @@ static int journal_entry_add(struct bch_fs *c, struct bch_dev *ca,
 	struct printbuf buf = PRINTBUF;
 	int ret = JOURNAL_ENTRY_ADD_OK;
 
+	if (!c->journal.oldest_seq_found_ondisk ||
+	    le64_to_cpu(j->seq) < c->journal.oldest_seq_found_ondisk)
+		c->journal.oldest_seq_found_ondisk = le64_to_cpu(j->seq);
+
 	/* Is this entry older than the range we need? */
 	if (!c->opts.read_entire_journal &&
 	    le64_to_cpu(j->seq) < jlist->last_seq)
@@ -272,7 +299,7 @@ static void journal_entry_err_msg(struct printbuf *out,
 	journal_entry_err_msg(&_buf, version, jset, entry);		\
 	prt_printf(&_buf, msg, ##__VA_ARGS__);				\
 									\
-	switch (flags & BKEY_INVALID_WRITE) {				\
+	switch (flags & BCH_VALIDATE_write) {				\
 	case READ:							\
 		mustfix_fsck_err(c, _err, "%s", _buf.buf);		\
 		break;							\
@@ -301,9 +328,9 @@ static int journal_validate_key(struct bch_fs *c,
 				unsigned level, enum btree_id btree_id,
 				struct bkey_i *k,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
-	int write = flags & BKEY_INVALID_WRITE;
+	int write = flags & BCH_VALIDATE_write;
 	void *next = vstruct_next(entry);
 	struct printbuf buf = PRINTBUF;
 	int ret = 0;
@@ -376,7 +403,7 @@ static int journal_entry_btree_keys_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct bkey_i *k = entry->start;
 
@@ -385,7 +412,7 @@ static int journal_entry_btree_keys_validate(struct bch_fs *c,
 					       entry->level,
 					       entry->btree_id,
 					       k, version, big_endian,
-					       flags|BKEY_INVALID_JOURNAL);
+					       flags|BCH_VALIDATE_journal);
 		if (ret == FSCK_DELETED_KEY)
 			continue;
 
@@ -416,7 +443,7 @@ static int journal_entry_btree_root_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct bkey_i *k = entry->start;
 	int ret = 0;
@@ -455,7 +482,7 @@ static int journal_entry_prio_ptrs_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	/* obsolete, don't care: */
 	return 0;
@@ -470,7 +497,7 @@ static int journal_entry_blacklist_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	int ret = 0;
 
@@ -497,7 +524,7 @@ static int journal_entry_blacklist_v2_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct jset_entry_blacklist_v2 *bl_entry;
 	int ret = 0;
@@ -539,7 +566,7 @@ static int journal_entry_usage_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct jset_entry_usage *u =
 		container_of(entry, struct jset_entry_usage, entry);
@@ -573,7 +600,7 @@ static int journal_entry_data_usage_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct jset_entry_data_usage *u =
 		container_of(entry, struct jset_entry_data_usage, entry);
@@ -617,7 +644,7 @@ static int journal_entry_clock_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct jset_entry_clock *clock =
 		container_of(entry, struct jset_entry_clock, entry);
@@ -657,13 +684,12 @@ static int journal_entry_dev_usage_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	struct jset_entry_dev_usage *u =
 		container_of(entry, struct jset_entry_dev_usage, entry);
 	unsigned bytes = jset_u64s(le16_to_cpu(entry->u64s)) * sizeof(u64);
 	unsigned expected = sizeof(*u);
-	unsigned dev;
 	int ret = 0;
 
 	if (journal_entry_err_on(bytes < expected,
@@ -675,16 +701,6 @@ static int journal_entry_dev_usage_validate(struct bch_fs *c,
 		return ret;
 	}
 
-	dev = le32_to_cpu(u->dev);
-
-	if (journal_entry_err_on(!bch2_dev_exists2(c, dev),
-				 c, version, jset, entry,
-				 journal_entry_dev_usage_bad_dev,
-				 "bad dev")) {
-		journal_entry_null_range(entry, vstruct_next(entry));
-		return ret;
-	}
-
 	if (journal_entry_err_on(u->pad,
 				 c, version, jset, entry,
 				 journal_entry_dev_usage_bad_pad,
@@ -719,7 +735,7 @@ static int journal_entry_log_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	return 0;
 }
@@ -737,7 +753,7 @@ static int journal_entry_overwrite_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	return journal_entry_btree_keys_validate(c, jset, entry,
 				version, big_endian, READ);
@@ -753,7 +769,7 @@ static int journal_entry_write_buffer_keys_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	return journal_entry_btree_keys_validate(c, jset, entry,
 				version, big_endian, READ);
@@ -769,7 +785,7 @@ static int journal_entry_datetime_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	unsigned bytes = vstruct_bytes(entry);
 	unsigned expected = 16;
@@ -799,7 +815,7 @@ static void journal_entry_datetime_to_text(struct printbuf *out, struct bch_fs *
 struct jset_entry_ops {
 	int (*validate)(struct bch_fs *, struct jset *,
 			struct jset_entry *, unsigned, int,
-			enum bkey_invalid_flags);
+			enum bch_validate_flags);
 	void (*to_text)(struct printbuf *, struct bch_fs *, struct jset_entry *);
 };
 
@@ -817,7 +833,7 @@ int bch2_journal_entry_validate(struct bch_fs *c,
 				struct jset *jset,
 				struct jset_entry *entry,
 				unsigned version, int big_endian,
-				enum bkey_invalid_flags flags)
+				enum bch_validate_flags flags)
 {
 	return entry->type < BCH_JSET_ENTRY_NR
 		? bch2_jset_entry_ops[entry->type].validate(c, jset, entry,
@@ -837,7 +853,7 @@ void bch2_journal_entry_to_text(struct printbuf *out, struct bch_fs *c,
 }
 
 static int jset_validate_entries(struct bch_fs *c, struct jset *jset,
-				 enum bkey_invalid_flags flags)
+				 enum bch_validate_flags flags)
 {
 	unsigned version = le32_to_cpu(jset->version);
 	int ret = 0;
@@ -863,7 +879,7 @@ fsck_err:
 static int jset_validate(struct bch_fs *c,
 			 struct bch_dev *ca,
 			 struct jset *jset, u64 sector,
-			 enum bkey_invalid_flags flags)
+			 enum bch_validate_flags flags)
 {
 	unsigned version;
 	int ret = 0;
@@ -918,7 +934,7 @@ static int jset_validate_early(struct bch_fs *c,
 {
 	size_t bytes = vstruct_bytes(jset);
 	unsigned version;
-	enum bkey_invalid_flags flags = BKEY_INVALID_JOURNAL;
+	enum bch_validate_flags flags = BCH_VALIDATE_journal;
 	int ret = 0;
 
 	if (le64_to_cpu(jset->magic) != jset_magic(c))
@@ -1057,6 +1073,13 @@ reread:
 			goto err;
 		}
 
+		if (le64_to_cpu(j->seq) > ja->highest_seq_found) {
+			ja->highest_seq_found = le64_to_cpu(j->seq);
+			ja->cur_idx = bucket;
+			ja->sectors_free = ca->mi.bucket_size -
+				bucket_remainder(ca, offset) - sectors;
+		}
+
 		/*
 		 * This happens sometimes if we don't have discards on -
 		 * when we've partially overwritten a bucket with new
@@ -1125,8 +1148,6 @@ static CLOSURE_CALLBACK(bch2_journal_read_device)
 	struct bch_fs *c = ca->fs;
 	struct journal_list *jlist =
 		container_of(cl->parent, struct journal_list, cl);
-	struct journal_replay *r, **_r;
-	struct genradix_iter iter;
 	struct journal_read_buf buf = { NULL, 0 };
 	unsigned i;
 	int ret = 0;
@@ -1146,47 +1167,6 @@ static CLOSURE_CALLBACK(bch2_journal_read_device)
 			goto err;
 	}
 
-	ja->sectors_free = ca->mi.bucket_size;
-
-	mutex_lock(&jlist->lock);
-	genradix_for_each_reverse(&c->journal_entries, iter, _r) {
-		r = *_r;
-
-		if (!r)
-			continue;
-
-		darray_for_each(r->ptrs, i)
-			if (i->dev == ca->dev_idx) {
-				unsigned wrote = bucket_remainder(ca, i->sector) +
-					vstruct_sectors(&r->j, c->block_bits);
-
-				ja->cur_idx = i->bucket;
-				ja->sectors_free = ca->mi.bucket_size - wrote;
-				goto found;
-			}
-	}
-found:
-	mutex_unlock(&jlist->lock);
-
-	if (ja->bucket_seq[ja->cur_idx] &&
-	    ja->sectors_free == ca->mi.bucket_size) {
-#if 0
-		/*
-		 * Debug code for ZNS support, where we (probably) want to be
-		 * correlated where we stopped in the journal to the zone write
-		 * points:
-		 */
-		bch_err(c, "ja->sectors_free == ca->mi.bucket_size");
-		bch_err(c, "cur_idx %u/%u", ja->cur_idx, ja->nr);
-		for (i = 0; i < 3; i++) {
-			unsigned idx = (ja->cur_idx + ja->nr - 1 + i) % ja->nr;
-
-			bch_err(c, "bucket_seq[%u] = %llu", idx, ja->bucket_seq[idx]);
-		}
-#endif
-		ja->sectors_free = 0;
-	}
-
 	/*
 	 * Set dirty_idx to indicate the entire journal is full and needs to be
 	 * reclaimed - journal reclaim will immediately reclaim whatever isn't
@@ -1255,7 +1235,7 @@ int bch2_journal_read(struct bch_fs *c,
 	 * those entries will be blacklisted:
 	 */
 	genradix_for_each_reverse(&c->journal_entries, radix_iter, _i) {
-		enum bkey_invalid_flags flags = BKEY_INVALID_JOURNAL;
+		enum bch_validate_flags flags = BCH_VALIDATE_journal;
 
 		i = *_i;
 
@@ -1366,7 +1346,7 @@ int bch2_journal_read(struct bch_fs *c,
 			fsck_err(c, journal_entries_missing,
 				 "journal entries %llu-%llu missing! (replaying %llu-%llu)\n"
 				 "  prev at %s\n"
-				 "  next at %s",
+				 "  next at %s, continue?",
 				 missing_start, missing_end,
 				 *last_seq, *blacklist_seq - 1,
 				 buf1.buf, buf2.buf);
@@ -1390,7 +1370,7 @@ int bch2_journal_read(struct bch_fs *c,
 			continue;
 
 		darray_for_each(i->ptrs, ptr) {
-			struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+			struct bch_dev *ca = bch2_dev_have_ref(c, ptr->dev);
 
 			if (!ptr->csum_good)
 				bch_err_dev_offset(ca, ptr->sector,
@@ -1400,7 +1380,7 @@ int bch2_journal_read(struct bch_fs *c,
 		}
 
 		ret = jset_validate(c,
-				    bch_dev_bkey_exists(c, i->ptrs.data[0].dev),
+				    bch2_dev_have_ref(c, i->ptrs.data[0].dev),
 				    &i->j,
 				    i->ptrs.data[0].sector,
 				    READ);
@@ -1731,10 +1711,8 @@ static CLOSURE_CALLBACK(journal_write_submit)
 	unsigned sectors = vstruct_sectors(w->data, c->block_bits);
 
 	extent_for_each_ptr(bkey_i_to_s_extent(&w->key), ptr) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
-		struct journal_device *ja = &ca->journal;
-
-		if (!percpu_ref_tryget(&ca->io_ref)) {
+		struct bch_dev *ca = bch2_dev_get_ioref(c, ptr->dev, WRITE);
+		if (!ca) {
 			/* XXX: fix this */
 			bch_err(c, "missing device for journal write\n");
 			continue;
@@ -1743,6 +1721,7 @@ static CLOSURE_CALLBACK(journal_write_submit)
 		this_cpu_add(ca->io_done->sectors[WRITE][BCH_DATA_journal],
 			     sectors);
 
+		struct journal_device *ja = &ca->journal;
 		struct bio *bio = &ja->bio[w->idx]->bio;
 		bio_reset(bio, ca->disk_sb.bdev, REQ_OP_WRITE|REQ_SYNC|REQ_META);
 		bio->bi_iter.bi_sector	= ptr->offset;
@@ -1958,14 +1937,14 @@ static int bch2_journal_write_pick_flush(struct journal *j, struct journal_buf *
 	 * So if we're in an error state, and we're still starting up, we don't
 	 * write anything at all.
 	 */
-	if (error && test_bit(JOURNAL_NEED_FLUSH_WRITE, &j->flags))
+	if (error && test_bit(JOURNAL_need_flush_write, &j->flags))
 		return -EIO;
 
 	if (error ||
 	    w->noflush ||
 	    (!w->must_flush &&
 	     (jiffies - j->last_flush_write) < msecs_to_jiffies(c->opts.journal_flush_delay) &&
-	     test_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags))) {
+	     test_bit(JOURNAL_may_skip_flush, &j->flags))) {
 		w->noflush = true;
 		SET_JSET_NO_FLUSH(w->data, true);
 		w->data->last_seq	= 0;
@@ -1976,7 +1955,7 @@ static int bch2_journal_write_pick_flush(struct journal *j, struct journal_buf *
 		w->must_flush = true;
 		j->last_flush_write = jiffies;
 		j->nr_flush_writes++;
-		clear_bit(JOURNAL_NEED_FLUSH_WRITE, &j->flags);
+		clear_bit(JOURNAL_need_flush_write, &j->flags);
 	}
 
 	return 0;
diff --git a/fs/bcachefs/journal_io.h b/fs/bcachefs/journal_io.h
index 4f1e763ab506..2ca9cde30ea8 100644
--- a/fs/bcachefs/journal_io.h
+++ b/fs/bcachefs/journal_io.h
@@ -4,6 +4,9 @@
 
 #include "darray.h"
 
+void bch2_journal_pos_from_member_info_set(struct bch_fs *);
+void bch2_journal_pos_from_member_info_resume(struct bch_fs *);
+
 struct journal_ptr {
 	bool		csum_good;
 	u8		dev;
@@ -60,7 +63,7 @@ static inline struct jset_entry *__jset_entry_type_next(struct jset *jset,
 
 int bch2_journal_entry_validate(struct bch_fs *, struct jset *,
 				struct jset_entry *, unsigned, int,
-				enum bkey_invalid_flags);
+				enum bch_validate_flags);
 void bch2_journal_entry_to_text(struct printbuf *, struct bch_fs *,
 				struct jset_entry *);
 
diff --git a/fs/bcachefs/journal_reclaim.c b/fs/bcachefs/journal_reclaim.c
index 04a577848b01..79be0eaddfa0 100644
--- a/fs/bcachefs/journal_reclaim.c
+++ b/fs/bcachefs/journal_reclaim.c
@@ -67,7 +67,7 @@ void bch2_journal_set_watermark(struct journal *j)
 	    track_event_change(&c->times[BCH_TIME_blocked_write_buffer_full], low_on_wb))
 		trace_and_count(c, journal_full, c);
 
-	mod_bit(JOURNAL_SPACE_LOW, &j->flags, low_on_space || low_on_pin);
+	mod_bit(JOURNAL_space_low, &j->flags, low_on_space || low_on_pin);
 
 	swap(watermark, j->watermark);
 	if (watermark > j->watermark)
@@ -225,9 +225,9 @@ void bch2_journal_space_available(struct journal *j)
 	     j->space[journal_space_clean_ondisk].total) &&
 	    (clean - clean_ondisk <= total / 8) &&
 	    (clean_ondisk * 2 > clean))
-		set_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
+		set_bit(JOURNAL_may_skip_flush, &j->flags);
 	else
-		clear_bit(JOURNAL_MAY_SKIP_FLUSH, &j->flags);
+		clear_bit(JOURNAL_may_skip_flush, &j->flags);
 
 	bch2_journal_set_watermark(j);
 out:
@@ -818,7 +818,7 @@ static int journal_flush_done(struct journal *j, u64 seq_to_flush,
 	 * If journal replay hasn't completed, the unreplayed journal entries
 	 * hold refs on their corresponding sequence numbers
 	 */
-	ret = !test_bit(JOURNAL_REPLAY_DONE, &j->flags) ||
+	ret = !test_bit(JOURNAL_replay_done, &j->flags) ||
 		journal_last_seq(j) > seq_to_flush ||
 		!fifo_used(&j->pin);
 
@@ -833,7 +833,7 @@ bool bch2_journal_flush_pins(struct journal *j, u64 seq_to_flush)
 	/* time_stats this */
 	bool did_work = false;
 
-	if (!test_bit(JOURNAL_STARTED, &j->flags))
+	if (!test_bit(JOURNAL_running, &j->flags))
 		return false;
 
 	closure_wait_event(&j->async_wait,
diff --git a/fs/bcachefs/journal_sb.c b/fs/bcachefs/journal_sb.c
index ae4fb8c3a2bc..db80e506e3ab 100644
--- a/fs/bcachefs/journal_sb.c
+++ b/fs/bcachefs/journal_sb.c
@@ -16,9 +16,8 @@ static int u64_cmp(const void *_l, const void *_r)
 	return cmp_int(*l, *r);
 }
 
-static int bch2_sb_journal_validate(struct bch_sb *sb,
-				    struct bch_sb_field *f,
-				    struct printbuf *err)
+static int bch2_sb_journal_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_journal *journal = field_to_type(f, journal);
 	struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
@@ -99,9 +98,8 @@ static int u64_range_cmp(const void *_l, const void *_r)
 	return cmp_int(l->start, r->start);
 }
 
-static int bch2_sb_journal_v2_validate(struct bch_sb *sb,
-				    struct bch_sb_field *f,
-				    struct printbuf *err)
+static int bch2_sb_journal_v2_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_journal_v2 *journal = field_to_type(f, journal_v2);
 	struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
diff --git a/fs/bcachefs/journal_seq_blacklist.c b/fs/bcachefs/journal_seq_blacklist.c
index 37a024e034d4..ed4846709611 100644
--- a/fs/bcachefs/journal_seq_blacklist.c
+++ b/fs/bcachefs/journal_seq_blacklist.c
@@ -1,8 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include "bcachefs.h"
-#include "btree_iter.h"
 #include "eytzinger.h"
+#include "journal.h"
 #include "journal_seq_blacklist.h"
 #include "super-io.h"
 
@@ -162,9 +162,8 @@ int bch2_blacklist_table_initialize(struct bch_fs *c)
 	return 0;
 }
 
-static int bch2_sb_journal_seq_blacklist_validate(struct bch_sb *sb,
-						  struct bch_sb_field *f,
-						  struct printbuf *err)
+static int bch2_sb_journal_seq_blacklist_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_journal_seq_blacklist *bl =
 		field_to_type(f, journal_seq_blacklist);
@@ -217,78 +216,40 @@ const struct bch_sb_field_ops bch_sb_field_ops_journal_seq_blacklist = {
 	.to_text	= bch2_sb_journal_seq_blacklist_to_text
 };
 
-void bch2_blacklist_entries_gc(struct work_struct *work)
+bool bch2_blacklist_entries_gc(struct bch_fs *c)
 {
-	struct bch_fs *c = container_of(work, struct bch_fs,
-					journal_seq_blacklist_gc_work);
-	struct journal_seq_blacklist_table *t;
-	struct bch_sb_field_journal_seq_blacklist *bl;
 	struct journal_seq_blacklist_entry *src, *dst;
-	struct btree_trans *trans = bch2_trans_get(c);
-	unsigned i, nr, new_nr;
-	int ret;
-
-	for (i = 0; i < BTREE_ID_NR; i++) {
-		struct btree_iter iter;
-		struct btree *b;
-
-		bch2_trans_node_iter_init(trans, &iter, i, POS_MIN,
-					  0, 0, BTREE_ITER_PREFETCH);
-retry:
-		bch2_trans_begin(trans);
-
-		b = bch2_btree_iter_peek_node(&iter);
-
-		while (!(ret = PTR_ERR_OR_ZERO(b)) &&
-		       b &&
-		       !test_bit(BCH_FS_stopping, &c->flags))
-			b = bch2_btree_iter_next_node(&iter);
-
-		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
-			goto retry;
 
-		bch2_trans_iter_exit(trans, &iter);
-	}
-
-	bch2_trans_put(trans);
-	if (ret)
-		return;
-
-	mutex_lock(&c->sb_lock);
-	bl = bch2_sb_field_get(c->disk_sb.sb, journal_seq_blacklist);
+	struct bch_sb_field_journal_seq_blacklist *bl =
+		bch2_sb_field_get(c->disk_sb.sb, journal_seq_blacklist);
 	if (!bl)
-		goto out;
+		return false;
 
-	nr = blacklist_nr_entries(bl);
+	unsigned nr = blacklist_nr_entries(bl);
 	dst = bl->start;
 
-	t = c->journal_seq_blacklist_table;
+	struct journal_seq_blacklist_table *t = c->journal_seq_blacklist_table;
 	BUG_ON(nr != t->nr);
 
+	unsigned i;
 	for (src = bl->start, i = eytzinger0_first(t->nr);
 	     src < bl->start + nr;
 	     src++, i = eytzinger0_next(i, nr)) {
 		BUG_ON(t->entries[i].start	!= le64_to_cpu(src->start));
 		BUG_ON(t->entries[i].end	!= le64_to_cpu(src->end));
 
-		if (t->entries[i].dirty)
+		if (t->entries[i].dirty || t->entries[i].end >= c->journal.oldest_seq_found_ondisk)
 			*dst++ = *src;
 	}
 
-	new_nr = dst - bl->start;
-
-	bch_info(c, "nr blacklist entries was %u, now %u", nr, new_nr);
-
-	if (new_nr != nr) {
-		bl = bch2_sb_field_resize(&c->disk_sb, journal_seq_blacklist,
-				new_nr ? sb_blacklist_u64s(new_nr) : 0);
-		BUG_ON(new_nr && !bl);
+	unsigned new_nr = dst - bl->start;
+	if (new_nr == nr)
+		return false;
 
-		if (!new_nr)
-			c->disk_sb.sb->features[0] &= cpu_to_le64(~(1ULL << BCH_FEATURE_journal_seq_blacklist_v3));
+	bch_verbose(c, "nr blacklist entries was %u, now %u", nr, new_nr);
 
-		bch2_write_super(c);
-	}
-out:
-	mutex_unlock(&c->sb_lock);
+	bl = bch2_sb_field_resize(&c->disk_sb, journal_seq_blacklist,
+				  new_nr ? sb_blacklist_u64s(new_nr) : 0);
+	BUG_ON(new_nr && !bl);
+	return true;
 }
diff --git a/fs/bcachefs/journal_seq_blacklist.h b/fs/bcachefs/journal_seq_blacklist.h
index afb886ec8e25..d47636f96fdc 100644
--- a/fs/bcachefs/journal_seq_blacklist.h
+++ b/fs/bcachefs/journal_seq_blacklist.h
@@ -17,6 +17,6 @@ int bch2_blacklist_table_initialize(struct bch_fs *);
 
 extern const struct bch_sb_field_ops bch_sb_field_ops_journal_seq_blacklist;
 
-void bch2_blacklist_entries_gc(struct work_struct *);
+bool bch2_blacklist_entries_gc(struct bch_fs *);
 
 #endif /* _BCACHEFS_JOURNAL_SEQ_BLACKLIST_H */
diff --git a/fs/bcachefs/journal_types.h b/fs/bcachefs/journal_types.h
index b5161b5d76a0..19183fcf7ad7 100644
--- a/fs/bcachefs/journal_types.h
+++ b/fs/bcachefs/journal_types.h
@@ -129,12 +129,17 @@ enum journal_space_from {
 	journal_space_nr,
 };
 
+#define JOURNAL_FLAGS()			\
+	x(replay_done)			\
+	x(running)			\
+	x(may_skip_flush)		\
+	x(need_flush_write)		\
+	x(space_low)
+
 enum journal_flags {
-	JOURNAL_REPLAY_DONE,
-	JOURNAL_STARTED,
-	JOURNAL_MAY_SKIP_FLUSH,
-	JOURNAL_NEED_FLUSH_WRITE,
-	JOURNAL_SPACE_LOW,
+#define x(n)	JOURNAL_##n,
+	JOURNAL_FLAGS()
+#undef x
 };
 
 /* Reasons we may fail to get a journal reservation: */
@@ -229,6 +234,7 @@ struct journal {
 	u64			last_seq_ondisk;
 	u64			err_seq;
 	u64			last_empty_seq;
+	u64			oldest_seq_found_ondisk;
 
 	/*
 	 * FIFO of journal entries whose btree updates have not yet been
@@ -326,6 +332,7 @@ struct journal_device {
 
 	/* for bch_journal_read_device */
 	struct closure		read;
+	u64			highest_seq_found;
 };
 
 /*
diff --git a/fs/bcachefs/logged_ops.c b/fs/bcachefs/logged_ops.c
index b82f8209041f..f49fdca1d07d 100644
--- a/fs/bcachefs/logged_ops.c
+++ b/fs/bcachefs/logged_ops.c
@@ -56,7 +56,7 @@ int bch2_resume_logged_ops(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter,
 				   BTREE_ID_logged_ops, POS_MIN,
-				   BTREE_ITER_PREFETCH, k,
+				   BTREE_ITER_prefetch, k,
 			resume_logged_op(trans, &iter, k)));
 	bch_err_fn(c, ret);
 	return ret;
diff --git a/fs/bcachefs/lru.c b/fs/bcachefs/lru.c
index 26569043e368..a40d116224ed 100644
--- a/fs/bcachefs/lru.c
+++ b/fs/bcachefs/lru.c
@@ -11,7 +11,7 @@
 
 /* KEY_TYPE_lru is obsolete: */
 int bch2_lru_invalid(struct bch_fs *c, struct bkey_s_c k,
-		     enum bkey_invalid_flags flags,
+		     enum bch_validate_flags flags,
 		     struct printbuf *err)
 {
 	int ret = 0;
@@ -149,7 +149,7 @@ int bch2_check_lrus(struct bch_fs *c)
 	struct bpos last_flushed_pos = POS_MIN;
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
-				BTREE_ID_lru, POS_MIN, BTREE_ITER_PREFETCH, k,
+				BTREE_ID_lru, POS_MIN, BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc|BCH_TRANS_COMMIT_lazy_rw,
 			bch2_check_lru_key(trans, &iter, k, &last_flushed_pos)));
 	bch_err_fn(c, ret);
diff --git a/fs/bcachefs/lru.h b/fs/bcachefs/lru.h
index 429dca816df5..fb11ab0dd00e 100644
--- a/fs/bcachefs/lru.h
+++ b/fs/bcachefs/lru.h
@@ -49,7 +49,7 @@ static inline enum bch_lru_type lru_type(struct bkey_s_c l)
 }
 
 int bch2_lru_invalid(struct bch_fs *, struct bkey_s_c,
-		     enum bkey_invalid_flags, struct printbuf *);
+		     enum bch_validate_flags, struct printbuf *);
 void bch2_lru_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 void bch2_lru_pos_to_text(struct printbuf *, struct bpos);
diff --git a/fs/bcachefs/migrate.c b/fs/bcachefs/migrate.c
index 69098eeb5d48..ddc187fb693d 100644
--- a/fs/bcachefs/migrate.c
+++ b/fs/bcachefs/migrate.c
@@ -49,7 +49,7 @@ static int bch2_dev_usrdata_drop_key(struct btree_trans *trans,
 	if (!bch2_bkey_has_device_c(k, dev_idx))
 		return 0;
 
-	n = bch2_bkey_make_mut(trans, iter, &k, BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+	n = bch2_bkey_make_mut(trans, iter, &k, BTREE_UPDATE_internal_snapshot_node);
 	ret = PTR_ERR_OR_ZERO(n);
 	if (ret)
 		return ret;
@@ -67,7 +67,7 @@ static int bch2_dev_usrdata_drop_key(struct btree_trans *trans,
 
 	/*
 	 * Since we're not inserting through an extent iterator
-	 * (BTREE_ITER_ALL_SNAPSHOTS iterators aren't extent iterators),
+	 * (BTREE_ITER_all_snapshots iterators aren't extent iterators),
 	 * we aren't using the extent overwrite path to delete, we're
 	 * just using the normal key deletion path:
 	 */
@@ -87,7 +87,7 @@ static int bch2_dev_usrdata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 			continue;
 
 		ret = for_each_btree_key_commit(trans, iter, id, POS_MIN,
-				BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			bch2_dev_usrdata_drop_key(trans, &iter, k, dev_idx, flags));
 		if (ret)
@@ -119,7 +119,7 @@ static int bch2_dev_metadata_drop(struct bch_fs *c, unsigned dev_idx, int flags)
 
 	for (id = 0; id < BTREE_ID_NR; id++) {
 		bch2_trans_node_iter_init(trans, &iter, id, POS_MIN, 0, 0,
-					  BTREE_ITER_PREFETCH);
+					  BTREE_ITER_prefetch);
 retry:
 		ret = 0;
 		while (bch2_trans_begin(trans),
diff --git a/fs/bcachefs/move.c b/fs/bcachefs/move.c
index 4d94b7742dbb..8171f947fac8 100644
--- a/fs/bcachefs/move.c
+++ b/fs/bcachefs/move.c
@@ -41,28 +41,23 @@ static void bch2_data_update_opts_to_text(struct printbuf *out, struct bch_fs *c
 					  struct data_update_opts *data_opts)
 {
 	printbuf_tabstop_push(out, 20);
-	prt_str(out, "rewrite ptrs:");
-	prt_tab(out);
+	prt_str(out, "rewrite ptrs:\t");
 	bch2_prt_u64_base2(out, data_opts->rewrite_ptrs);
 	prt_newline(out);
 
-	prt_str(out, "kill ptrs: ");
-	prt_tab(out);
+	prt_str(out, "kill ptrs:\t");
 	bch2_prt_u64_base2(out, data_opts->kill_ptrs);
 	prt_newline(out);
 
-	prt_str(out, "target: ");
-	prt_tab(out);
+	prt_str(out, "target:\t");
 	bch2_target_to_text(out, c, data_opts->target);
 	prt_newline(out);
 
-	prt_str(out, "compression: ");
-	prt_tab(out);
+	prt_str(out, "compression:\t");
 	bch2_compression_opt_to_text(out, background_compression(*io_opts));
 	prt_newline(out);
 
-	prt_str(out, "extra replicas: ");
-	prt_tab(out);
+	prt_str(out, "extra replicas:\t");
 	prt_u64(out, data_opts->extra_replicas);
 }
 
@@ -421,7 +416,7 @@ struct bch_io_opts *bch2_move_get_io_opts(struct btree_trans *trans,
 		io_opts->d.nr = 0;
 
 		ret = for_each_btree_key(trans, iter, BTREE_ID_inodes, POS(0, extent_k.k->p.inode),
-					 BTREE_ITER_ALL_SNAPSHOTS, k, ({
+					 BTREE_ITER_all_snapshots, k, ({
 			if (k.k->p.offset != extent_k.k->p.inode)
 				break;
 
@@ -467,7 +462,7 @@ int bch2_move_get_io_opts_one(struct btree_trans *trans,
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
 			       SPOS(0, extent_k.k->p.inode, extent_k.k->p.snapshot),
-			       BTREE_ITER_CACHED);
+			       BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 		return ret;
@@ -553,8 +548,8 @@ static int bch2_move_data_btree(struct moving_context *ctxt,
 	}
 
 	bch2_trans_iter_init(trans, &iter, btree_id, start,
-			     BTREE_ITER_PREFETCH|
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_prefetch|
+			     BTREE_ITER_all_snapshots);
 
 	if (ctxt->rate)
 		bch2_ratelimit_reset(ctxt->rate);
@@ -695,6 +690,10 @@ int bch2_evacuate_bucket(struct moving_context *ctxt,
 	struct bpos bp_pos = POS_MIN;
 	int ret = 0;
 
+	struct bch_dev *ca = bch2_dev_tryget(c, bucket.inode);
+	if (!ca)
+		return 0;
+
 	trace_bucket_evacuate(c, &bucket);
 
 	bch2_bkey_buf_init(&sk);
@@ -705,7 +704,7 @@ int bch2_evacuate_bucket(struct moving_context *ctxt,
 	bch2_trans_begin(trans);
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc,
-			     bucket, BTREE_ITER_CACHED);
+			     bucket, BTREE_ITER_cached);
 	ret = lockrestart_do(trans,
 			bkey_err(k = bch2_btree_iter_peek_slot(&iter)));
 	bch2_trans_iter_exit(trans, &iter);
@@ -716,7 +715,7 @@ int bch2_evacuate_bucket(struct moving_context *ctxt,
 
 	a = bch2_alloc_to_v4(k, &a_convert);
 	dirty_sectors = bch2_bucket_sectors_dirty(*a);
-	bucket_size = bch_dev_bkey_exists(c, bucket.inode)->mi.bucket_size;
+	bucket_size = ca->mi.bucket_size;
 	fragmentation = a->fragmentation_lru;
 
 	ret = bch2_btree_write_buffer_tryflush(trans);
@@ -730,9 +729,9 @@ int bch2_evacuate_bucket(struct moving_context *ctxt,
 
 		bch2_trans_begin(trans);
 
-		ret = bch2_get_next_backpointer(trans, bucket, gen,
+		ret = bch2_get_next_backpointer(trans, ca, bucket, gen,
 						&bp_pos, &bp,
-						BTREE_ITER_CACHED);
+						BTREE_ITER_cached);
 		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
 			continue;
 		if (ret)
@@ -828,6 +827,7 @@ next:
 
 	trace_evacuate_bucket(c, &bucket, dirty_sectors, bucket_size, fragmentation, ret);
 err:
+	bch2_dev_put(ca);
 	bch2_bkey_buf_exit(&sk, c);
 	return ret;
 }
@@ -868,7 +868,7 @@ static int bch2_move_btree(struct bch_fs *c,
 			continue;
 
 		bch2_trans_node_iter_init(trans, &iter, btree, POS_MIN, 0, 0,
-					  BTREE_ITER_PREFETCH);
+					  BTREE_ITER_prefetch);
 retry:
 		ret = 0;
 		while (bch2_trans_begin(trans),
@@ -975,26 +975,10 @@ static bool migrate_btree_pred(struct bch_fs *c, void *arg,
  */
 static bool bformat_needs_redo(struct bkey_format *f)
 {
-	for (unsigned i = 0; i < f->nr_fields; i++) {
-		unsigned f_bits = f->bits_per_field[i];
-		unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
-		u64 unpacked_mask = ~((~0ULL << 1) << (unpacked_bits - 1));
-		u64 field_offset = le64_to_cpu(f->field_offset[i]);
-
-		if (f_bits > unpacked_bits)
-			return true;
-
-		if ((f_bits == unpacked_bits) && field_offset)
+	for (unsigned i = 0; i < f->nr_fields; i++)
+		if (bch2_bkey_format_field_overflows(f, i))
 			return true;
 
-		u64 f_mask = f_bits
-			? ~((~0ULL << (f_bits - 1)) << 1)
-			: 0;
-
-		if (((field_offset + f_mask) & unpacked_mask) < field_offset)
-			return true;
-	}
-
 	return false;
 }
 
@@ -1049,6 +1033,7 @@ static bool drop_extra_replicas_pred(struct bch_fs *c, void *arg,
 	struct extent_ptr_decoded p;
 	unsigned i = 0;
 
+	rcu_read_lock();
 	bkey_for_each_ptr_decode(k.k, bch2_bkey_ptrs_c(k), p, entry) {
 		unsigned d = bch2_extent_ptr_durability(c, &p);
 
@@ -1059,6 +1044,7 @@ static bool drop_extra_replicas_pred(struct bch_fs *c, void *arg,
 
 		i++;
 	}
+	rcu_read_unlock();
 
 	return data_opts->kill_ptrs != 0;
 }
@@ -1143,23 +1129,17 @@ void bch2_move_stats_to_text(struct printbuf *out, struct bch_move_stats *stats)
 	prt_newline(out);
 	printbuf_indent_add(out, 2);
 
-	prt_str(out, "keys moved:  ");
-	prt_u64(out, atomic64_read(&stats->keys_moved));
-	prt_newline(out);
-
-	prt_str(out, "keys raced:  ");
-	prt_u64(out, atomic64_read(&stats->keys_raced));
-	prt_newline(out);
-
-	prt_str(out, "bytes seen:  ");
+	prt_printf(out, "keys moved:  %llu\n",	atomic64_read(&stats->keys_moved));
+	prt_printf(out, "keys raced:  %llu\n",	atomic64_read(&stats->keys_raced));
+	prt_printf(out, "bytes seen:  ");
 	prt_human_readable_u64(out, atomic64_read(&stats->sectors_seen) << 9);
 	prt_newline(out);
 
-	prt_str(out, "bytes moved: ");
+	prt_printf(out, "bytes moved: ");
 	prt_human_readable_u64(out, atomic64_read(&stats->sectors_moved) << 9);
 	prt_newline(out);
 
-	prt_str(out, "bytes raced: ");
+	prt_printf(out, "bytes raced: ");
 	prt_human_readable_u64(out, atomic64_read(&stats->sectors_raced) << 9);
 	prt_newline(out);
 
@@ -1173,19 +1153,17 @@ static void bch2_moving_ctxt_to_text(struct printbuf *out, struct bch_fs *c, str
 	bch2_move_stats_to_text(out, ctxt->stats);
 	printbuf_indent_add(out, 2);
 
-	prt_printf(out, "reads: ios %u/%u sectors %u/%u",
+	prt_printf(out, "reads: ios %u/%u sectors %u/%u\n",
 		   atomic_read(&ctxt->read_ios),
 		   c->opts.move_ios_in_flight,
 		   atomic_read(&ctxt->read_sectors),
 		   c->opts.move_bytes_in_flight >> 9);
-	prt_newline(out);
 
-	prt_printf(out, "writes: ios %u/%u sectors %u/%u",
+	prt_printf(out, "writes: ios %u/%u sectors %u/%u\n",
 		   atomic_read(&ctxt->write_ios),
 		   c->opts.move_ios_in_flight,
 		   atomic_read(&ctxt->write_sectors),
 		   c->opts.move_bytes_in_flight >> 9);
-	prt_newline(out);
 
 	printbuf_indent_add(out, 2);
 
diff --git a/fs/bcachefs/movinggc.c b/fs/bcachefs/movinggc.c
index 0d2b82d8d11f..10bfb31c151b 100644
--- a/fs/bcachefs/movinggc.c
+++ b/fs/bcachefs/movinggc.c
@@ -84,7 +84,7 @@ static int bch2_bucket_is_movable(struct btree_trans *trans,
 		return 0;
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_alloc,
-			       b->k.bucket, BTREE_ITER_CACHED);
+			       b->k.bucket, BTREE_ITER_cached);
 	ret = bkey_err(k);
 	if (ret)
 		return ret;
@@ -158,6 +158,8 @@ static int bch2_copygc_get_buckets(struct moving_context *ctxt,
 	if (bch2_fs_fatal_err_on(ret, c, "%s: from bch2_btree_write_buffer_tryflush()", bch2_err_str(ret)))
 		return ret;
 
+	bch2_trans_begin(trans);
+
 	ret = for_each_btree_key_upto(trans, iter, BTREE_ID_lru,
 				  lru_pos(BCH_LRU_FRAGMENTATION_START, 0, 0),
 				  lru_pos(BCH_LRU_FRAGMENTATION_START, U64_MAX, LRU_TIME_MAX),
diff --git a/fs/bcachefs/opts.h b/fs/bcachefs/opts.h
index 84e452835a17..25530e0bb2f3 100644
--- a/fs/bcachefs/opts.h
+++ b/fs/bcachefs/opts.h
@@ -426,11 +426,6 @@ enum fsck_err_opts {
 	  BCH_SB_VERSION_UPGRADE,	BCH_VERSION_UPGRADE_compatible,	\
 	  NULL,		"Set superblock to latest version,\n"		\
 			"allowing any new features to be used")		\
-	x(buckets_nouse,		u8,				\
-	  0,								\
-	  OPT_BOOL(),							\
-	  BCH2_NO_SB_OPT,		false,				\
-	  NULL,		"Allocate the buckets_nouse bitmap")		\
 	x(stdio,			u64,				\
 	  0,								\
 	  OPT_UINT(0, S64_MAX),						\
@@ -480,7 +475,7 @@ enum fsck_err_opts {
 	  OPT_FS|OPT_MOUNT|OPT_RUNTIME,					\
 	  OPT_BOOL(),							\
 	  BCH2_NO_SB_OPT,		true,				\
-	  NULL,		"BTREE_ITER_PREFETCH casuse btree nodes to be\n"\
+	  NULL,		"BTREE_ITER_prefetch casuse btree nodes to be\n"\
 	  " prefetched sequentially")
 
 struct bch_opts {
diff --git a/fs/bcachefs/printbuf.c b/fs/bcachefs/printbuf.c
index b27d22925929..8b0369185f5c 100644
--- a/fs/bcachefs/printbuf.c
+++ b/fs/bcachefs/printbuf.c
@@ -10,35 +10,50 @@
 
 #include "printbuf.h"
 
-static inline unsigned printbuf_linelen(struct printbuf *buf)
+static inline unsigned __printbuf_linelen(struct printbuf *buf, unsigned pos)
 {
-	return buf->pos - buf->last_newline;
+	return pos - buf->last_newline;
 }
 
-int bch2_printbuf_make_room(struct printbuf *out, unsigned extra)
+static inline unsigned printbuf_linelen(struct printbuf *buf)
 {
-	unsigned new_size;
-	char *buf;
+	return __printbuf_linelen(buf, buf->pos);
+}
 
-	if (!out->heap_allocated)
-		return 0;
+/*
+ * Returns spaces from start of line, if set, or 0 if unset:
+ */
+static inline unsigned cur_tabstop(struct printbuf *buf)
+{
+	return buf->cur_tabstop < buf->nr_tabstops
+		? buf->_tabstops[buf->cur_tabstop]
+		: 0;
+}
 
+int bch2_printbuf_make_room(struct printbuf *out, unsigned extra)
+{
 	/* Reserved space for terminating nul: */
 	extra += 1;
 
-	if (out->pos + extra < out->size)
+	if (out->pos + extra <= out->size)
 		return 0;
 
-	new_size = roundup_pow_of_two(out->size + extra);
+	if (!out->heap_allocated) {
+		out->overflow = true;
+		return 0;
+	}
+
+	unsigned new_size = roundup_pow_of_two(out->size + extra);
 
 	/*
 	 * Note: output buffer must be freeable with kfree(), it's not required
 	 * that the user use printbuf_exit().
 	 */
-	buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT);
+	char *buf = krealloc(out->buf, new_size, !out->atomic ? GFP_KERNEL : GFP_NOWAIT);
 
 	if (!buf) {
 		out->allocation_failure = true;
+		out->overflow = true;
 		return -ENOMEM;
 	}
 
@@ -47,6 +62,92 @@ int bch2_printbuf_make_room(struct printbuf *out, unsigned extra)
 	return 0;
 }
 
+static void printbuf_advance_pos(struct printbuf *out, unsigned len)
+{
+	out->pos += min(len, printbuf_remaining(out));
+}
+
+static void printbuf_insert_spaces(struct printbuf *out, unsigned pos, unsigned nr)
+{
+	unsigned move = out->pos - pos;
+
+	bch2_printbuf_make_room(out, nr);
+
+	if (pos + nr < out->size)
+		memmove(out->buf + pos + nr,
+			out->buf + pos,
+			min(move, out->size - 1 - pos - nr));
+
+	if (pos < out->size)
+		memset(out->buf + pos, ' ', min(nr, out->size - pos));
+
+	printbuf_advance_pos(out, nr);
+	printbuf_nul_terminate_reserved(out);
+}
+
+static void __printbuf_do_indent(struct printbuf *out, unsigned pos)
+{
+	while (true) {
+		int pad;
+		unsigned len = out->pos - pos;
+		char *p = out->buf + pos;
+		char *n = memscan(p, '\n', len);
+		if (cur_tabstop(out)) {
+			n = min(n, (char *) memscan(p, '\r', len));
+			n = min(n, (char *) memscan(p, '\t', len));
+		}
+
+		pos = n - out->buf;
+		if (pos == out->pos)
+			break;
+
+		switch (*n) {
+		case '\n':
+			pos++;
+			out->last_newline = pos;
+
+			printbuf_insert_spaces(out, pos, out->indent);
+
+			pos = min(pos + out->indent, out->pos);
+			out->last_field = pos;
+			out->cur_tabstop = 0;
+			break;
+		case '\r':
+			memmove(n, n + 1, out->pos - pos);
+			--out->pos;
+			pad = (int) cur_tabstop(out) - (int) __printbuf_linelen(out, pos);
+			if (pad > 0) {
+				printbuf_insert_spaces(out, out->last_field, pad);
+				pos += pad;
+			}
+
+			out->last_field = pos;
+			out->cur_tabstop++;
+			break;
+		case '\t':
+			pad = (int) cur_tabstop(out) - (int) __printbuf_linelen(out, pos) - 1;
+			if (pad > 0) {
+				*n = ' ';
+				printbuf_insert_spaces(out, pos, pad - 1);
+				pos += pad;
+			} else {
+				memmove(n, n + 1, out->pos - pos);
+				--out->pos;
+			}
+
+			out->last_field = pos;
+			out->cur_tabstop++;
+			break;
+		}
+	}
+}
+
+static inline void printbuf_do_indent(struct printbuf *out, unsigned pos)
+{
+	if (out->has_indent_or_tabstops && !out->suppress_indent_tabstop_handling)
+		__printbuf_do_indent(out, pos);
+}
+
 void bch2_prt_vprintf(struct printbuf *out, const char *fmt, va_list args)
 {
 	int len;
@@ -55,14 +156,14 @@ void bch2_prt_vprintf(struct printbuf *out, const char *fmt, va_list args)
 		va_list args2;
 
 		va_copy(args2, args);
-		len = vsnprintf(out->buf + out->pos, printbuf_remaining(out), fmt, args2);
+		len = vsnprintf(out->buf + out->pos, printbuf_remaining_size(out), fmt, args2);
 		va_end(args2);
-	} while (len + 1 >= printbuf_remaining(out) &&
-		 !bch2_printbuf_make_room(out, len + 1));
+	} while (len > printbuf_remaining(out) &&
+		 !bch2_printbuf_make_room(out, len));
 
-	len = min_t(size_t, len,
-		  printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0);
-	out->pos += len;
+	unsigned indent_pos = out->pos;
+	printbuf_advance_pos(out, len);
+	printbuf_do_indent(out, indent_pos);
 }
 
 void bch2_prt_printf(struct printbuf *out, const char *fmt, ...)
@@ -72,14 +173,14 @@ void bch2_prt_printf(struct printbuf *out, const char *fmt, ...)
 
 	do {
 		va_start(args, fmt);
-		len = vsnprintf(out->buf + out->pos, printbuf_remaining(out), fmt, args);
+		len = vsnprintf(out->buf + out->pos, printbuf_remaining_size(out), fmt, args);
 		va_end(args);
-	} while (len + 1 >= printbuf_remaining(out) &&
-		 !bch2_printbuf_make_room(out, len + 1));
+	} while (len > printbuf_remaining(out) &&
+		 !bch2_printbuf_make_room(out, len));
 
-	len = min_t(size_t, len,
-		  printbuf_remaining(out) ? printbuf_remaining(out) - 1 : 0);
-	out->pos += len;
+	unsigned indent_pos = out->pos;
+	printbuf_advance_pos(out, len);
+	printbuf_do_indent(out, indent_pos);
 }
 
 /**
@@ -194,33 +295,20 @@ void bch2_printbuf_indent_sub(struct printbuf *buf, unsigned spaces)
 
 void bch2_prt_newline(struct printbuf *buf)
 {
-	unsigned i;
-
 	bch2_printbuf_make_room(buf, 1 + buf->indent);
 
-	__prt_char(buf, '\n');
+	__prt_char_reserved(buf, '\n');
 
 	buf->last_newline	= buf->pos;
 
-	for (i = 0; i < buf->indent; i++)
-		__prt_char(buf, ' ');
+	__prt_chars_reserved(buf, ' ', buf->indent);
 
-	printbuf_nul_terminate(buf);
+	printbuf_nul_terminate_reserved(buf);
 
 	buf->last_field		= buf->pos;
 	buf->cur_tabstop	= 0;
 }
 
-/*
- * Returns spaces from start of line, if set, or 0 if unset:
- */
-static inline unsigned cur_tabstop(struct printbuf *buf)
-{
-	return buf->cur_tabstop < buf->nr_tabstops
-		? buf->_tabstops[buf->cur_tabstop]
-		: 0;
-}
-
 static void __prt_tab(struct printbuf *out)
 {
 	int spaces = max_t(int, 0, cur_tabstop(out) - printbuf_linelen(out));
@@ -247,24 +335,9 @@ void bch2_prt_tab(struct printbuf *out)
 
 static void __prt_tab_rjust(struct printbuf *buf)
 {
-	unsigned move = buf->pos - buf->last_field;
 	int pad = (int) cur_tabstop(buf) - (int) printbuf_linelen(buf);
-
-	if (pad > 0) {
-		bch2_printbuf_make_room(buf, pad);
-
-		if (buf->last_field + pad < buf->size)
-			memmove(buf->buf + buf->last_field + pad,
-				buf->buf + buf->last_field,
-				min(move, buf->size - 1 - buf->last_field - pad));
-
-		if (buf->last_field < buf->size)
-			memset(buf->buf + buf->last_field, ' ',
-			       min((unsigned) pad, buf->size - buf->last_field));
-
-		buf->pos += pad;
-		printbuf_nul_terminate(buf);
-	}
+	if (pad > 0)
+		printbuf_insert_spaces(buf, buf->last_field, pad);
 
 	buf->last_field = buf->pos;
 	buf->cur_tabstop++;
@@ -301,41 +374,9 @@ void bch2_prt_tab_rjust(struct printbuf *buf)
  */
 void bch2_prt_bytes_indented(struct printbuf *out, const char *str, unsigned count)
 {
-	const char *unprinted_start = str;
-	const char *end = str + count;
-
-	if (!out->has_indent_or_tabstops || out->suppress_indent_tabstop_handling) {
-		prt_bytes(out, str, count);
-		return;
-	}
-
-	while (str != end) {
-		switch (*str) {
-		case '\n':
-			prt_bytes(out, unprinted_start, str - unprinted_start);
-			unprinted_start = str + 1;
-			bch2_prt_newline(out);
-			break;
-		case '\t':
-			if (likely(cur_tabstop(out))) {
-				prt_bytes(out, unprinted_start, str - unprinted_start);
-				unprinted_start = str + 1;
-				__prt_tab(out);
-			}
-			break;
-		case '\r':
-			if (likely(cur_tabstop(out))) {
-				prt_bytes(out, unprinted_start, str - unprinted_start);
-				unprinted_start = str + 1;
-				__prt_tab_rjust(out);
-			}
-			break;
-		}
-
-		str++;
-	}
-
-	prt_bytes(out, unprinted_start, str - unprinted_start);
+	unsigned indent_pos = out->pos;
+	prt_bytes(out, str, count);
+	printbuf_do_indent(out, indent_pos);
 }
 
 /**
@@ -348,9 +389,10 @@ void bch2_prt_bytes_indented(struct printbuf *out, const char *str, unsigned cou
 void bch2_prt_human_readable_u64(struct printbuf *out, u64 v)
 {
 	bch2_printbuf_make_room(out, 10);
-	out->pos += string_get_size(v, 1, !out->si_units,
-				    out->buf + out->pos,
-				    printbuf_remaining_size(out));
+	unsigned len = string_get_size(v, 1, !out->si_units,
+				       out->buf + out->pos,
+				       printbuf_remaining_size(out));
+	printbuf_advance_pos(out, len);
 }
 
 /**
@@ -402,9 +444,7 @@ void bch2_prt_string_option(struct printbuf *out,
 			    const char * const list[],
 			    size_t selected)
 {
-	size_t i;
-
-	for (i = 0; list[i]; i++)
+	for (size_t i = 0; list[i]; i++)
 		bch2_prt_printf(out, i == selected ? "[%s] " : "%s ", list[i]);
 }
 
diff --git a/fs/bcachefs/printbuf.h b/fs/bcachefs/printbuf.h
index 9a4a56c40937..9ecc56bc9635 100644
--- a/fs/bcachefs/printbuf.h
+++ b/fs/bcachefs/printbuf.h
@@ -86,6 +86,7 @@ struct printbuf {
 	u8			atomic;
 	bool			allocation_failure:1;
 	bool			heap_allocated:1;
+	bool			overflow:1;
 	enum printbuf_si	si_units:1;
 	bool			human_readable_units:1;
 	bool			has_indent_or_tabstops:1;
@@ -142,7 +143,9 @@ void bch2_prt_bitflags_vector(struct printbuf *, const char * const[],
  */
 static inline unsigned printbuf_remaining_size(struct printbuf *out)
 {
-	return out->pos < out->size ? out->size - out->pos : 0;
+	if (WARN_ON(out->size && out->pos >= out->size))
+		out->pos = out->size - 1;
+	return out->size - out->pos;
 }
 
 /*
@@ -151,7 +154,7 @@ static inline unsigned printbuf_remaining_size(struct printbuf *out)
  */
 static inline unsigned printbuf_remaining(struct printbuf *out)
 {
-	return out->pos < out->size ? out->size - out->pos - 1 : 0;
+	return out->size ? printbuf_remaining_size(out) - 1 : 0;
 }
 
 static inline unsigned printbuf_written(struct printbuf *out)
@@ -159,30 +162,25 @@ static inline unsigned printbuf_written(struct printbuf *out)
 	return out->size ? min(out->pos, out->size - 1) : 0;
 }
 
-/*
- * Returns true if output was truncated:
- */
-static inline bool printbuf_overflowed(struct printbuf *out)
+static inline void printbuf_nul_terminate_reserved(struct printbuf *out)
 {
-	return out->pos >= out->size;
+	if (WARN_ON(out->size && out->pos >= out->size))
+		out->pos = out->size - 1;
+	if (out->size)
+		out->buf[out->pos] = 0;
 }
 
 static inline void printbuf_nul_terminate(struct printbuf *out)
 {
 	bch2_printbuf_make_room(out, 1);
-
-	if (out->pos < out->size)
-		out->buf[out->pos] = 0;
-	else if (out->size)
-		out->buf[out->size - 1] = 0;
+	printbuf_nul_terminate_reserved(out);
 }
 
 /* Doesn't call bch2_printbuf_make_room(), doesn't nul terminate: */
 static inline void __prt_char_reserved(struct printbuf *out, char c)
 {
 	if (printbuf_remaining(out))
-		out->buf[out->pos] = c;
-	out->pos++;
+		out->buf[out->pos++] = c;
 }
 
 /* Doesn't nul terminate: */
@@ -194,37 +192,34 @@ static inline void __prt_char(struct printbuf *out, char c)
 
 static inline void prt_char(struct printbuf *out, char c)
 {
-	__prt_char(out, c);
-	printbuf_nul_terminate(out);
+	bch2_printbuf_make_room(out, 2);
+	__prt_char_reserved(out, c);
+	printbuf_nul_terminate_reserved(out);
 }
 
 static inline void __prt_chars_reserved(struct printbuf *out, char c, unsigned n)
 {
-	unsigned i, can_print = min(n, printbuf_remaining(out));
+	unsigned can_print = min(n, printbuf_remaining(out));
 
-	for (i = 0; i < can_print; i++)
+	for (unsigned i = 0; i < can_print; i++)
 		out->buf[out->pos++] = c;
-	out->pos += n - can_print;
 }
 
 static inline void prt_chars(struct printbuf *out, char c, unsigned n)
 {
 	bch2_printbuf_make_room(out, n);
 	__prt_chars_reserved(out, c, n);
-	printbuf_nul_terminate(out);
+	printbuf_nul_terminate_reserved(out);
 }
 
 static inline void prt_bytes(struct printbuf *out, const void *b, unsigned n)
 {
-	unsigned i, can_print;
-
 	bch2_printbuf_make_room(out, n);
 
-	can_print = min(n, printbuf_remaining(out));
+	unsigned can_print = min(n, printbuf_remaining(out));
 
-	for (i = 0; i < can_print; i++)
+	for (unsigned i = 0; i < can_print; i++)
 		out->buf[out->pos++] = ((char *) b)[i];
-	out->pos += n - can_print;
 
 	printbuf_nul_terminate(out);
 }
@@ -241,18 +236,18 @@ static inline void prt_str_indented(struct printbuf *out, const char *str)
 
 static inline void prt_hex_byte(struct printbuf *out, u8 byte)
 {
-	bch2_printbuf_make_room(out, 2);
+	bch2_printbuf_make_room(out, 3);
 	__prt_char_reserved(out, hex_asc_hi(byte));
 	__prt_char_reserved(out, hex_asc_lo(byte));
-	printbuf_nul_terminate(out);
+	printbuf_nul_terminate_reserved(out);
 }
 
 static inline void prt_hex_byte_upper(struct printbuf *out, u8 byte)
 {
-	bch2_printbuf_make_room(out, 2);
+	bch2_printbuf_make_room(out, 3);
 	__prt_char_reserved(out, hex_asc_upper_hi(byte));
 	__prt_char_reserved(out, hex_asc_upper_lo(byte));
-	printbuf_nul_terminate(out);
+	printbuf_nul_terminate_reserved(out);
 }
 
 /**
diff --git a/fs/bcachefs/quota.c b/fs/bcachefs/quota.c
index 556da0738106..a0cca8b70e0a 100644
--- a/fs/bcachefs/quota.c
+++ b/fs/bcachefs/quota.c
@@ -20,7 +20,7 @@ static const char * const bch2_quota_counters[] = {
 };
 
 static int bch2_sb_quota_validate(struct bch_sb *sb, struct bch_sb_field *f,
-				  struct printbuf *err)
+				  enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_quota *q = field_to_type(f, quota);
 
@@ -60,8 +60,7 @@ const struct bch_sb_field_ops bch_sb_field_ops_quota = {
 };
 
 int bch2_quota_invalid(struct bch_fs *c, struct bkey_s_c k,
-		       enum bkey_invalid_flags flags,
-		       struct printbuf *err)
+		       enum bch_validate_flags flags, struct printbuf *err)
 {
 	int ret = 0;
 
@@ -97,45 +96,14 @@ static void qc_info_to_text(struct printbuf *out, struct qc_info *i)
 	printbuf_tabstops_reset(out);
 	printbuf_tabstop_push(out, 20);
 
-	prt_str(out, "i_fieldmask");
-	prt_tab(out);
-	prt_printf(out, "%x", i->i_fieldmask);
-	prt_newline(out);
-
-	prt_str(out, "i_flags");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_flags);
-	prt_newline(out);
-
-	prt_str(out, "i_spc_timelimit");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_spc_timelimit);
-	prt_newline(out);
-
-	prt_str(out, "i_ino_timelimit");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_ino_timelimit);
-	prt_newline(out);
-
-	prt_str(out, "i_rt_spc_timelimit");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_rt_spc_timelimit);
-	prt_newline(out);
-
-	prt_str(out, "i_spc_warnlimit");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_spc_warnlimit);
-	prt_newline(out);
-
-	prt_str(out, "i_ino_warnlimit");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_ino_warnlimit);
-	prt_newline(out);
-
-	prt_str(out, "i_rt_spc_warnlimit");
-	prt_tab(out);
-	prt_printf(out, "%u", i->i_rt_spc_warnlimit);
-	prt_newline(out);
+	prt_printf(out, "i_fieldmask\t%x\n",		i->i_fieldmask);
+	prt_printf(out, "i_flags\t%u\n",		i->i_flags);
+	prt_printf(out, "i_spc_timelimit\t%u\n",	i->i_spc_timelimit);
+	prt_printf(out, "i_ino_timelimit\t%u\n",	i->i_ino_timelimit);
+	prt_printf(out, "i_rt_spc_timelimit\t%u\n",	i->i_rt_spc_timelimit);
+	prt_printf(out, "i_spc_warnlimit\t%u\n",	i->i_spc_warnlimit);
+	prt_printf(out, "i_ino_warnlimit\t%u\n",	i->i_ino_warnlimit);
+	prt_printf(out, "i_rt_spc_warnlimit\t%u\n",	i->i_rt_spc_warnlimit);
 }
 
 static void qc_dqblk_to_text(struct printbuf *out, struct qc_dqblk *q)
@@ -143,60 +111,17 @@ static void qc_dqblk_to_text(struct printbuf *out, struct qc_dqblk *q)
 	printbuf_tabstops_reset(out);
 	printbuf_tabstop_push(out, 20);
 
-	prt_str(out, "d_fieldmask");
-	prt_tab(out);
-	prt_printf(out, "%x", q->d_fieldmask);
-	prt_newline(out);
-
-	prt_str(out, "d_spc_hardlimit");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_spc_hardlimit);
-	prt_newline(out);
-
-	prt_str(out, "d_spc_softlimit");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_spc_softlimit);
-	prt_newline(out);
-
-	prt_str(out, "d_ino_hardlimit");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_ino_hardlimit);
-	prt_newline(out);
-
-	prt_str(out, "d_ino_softlimit");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_ino_softlimit);
-	prt_newline(out);
-
-	prt_str(out, "d_space");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_space);
-	prt_newline(out);
-
-	prt_str(out, "d_ino_count");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_ino_count);
-	prt_newline(out);
-
-	prt_str(out, "d_ino_timer");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_ino_timer);
-	prt_newline(out);
-
-	prt_str(out, "d_spc_timer");
-	prt_tab(out);
-	prt_printf(out, "%llu", q->d_spc_timer);
-	prt_newline(out);
-
-	prt_str(out, "d_ino_warns");
-	prt_tab(out);
-	prt_printf(out, "%i", q->d_ino_warns);
-	prt_newline(out);
-
-	prt_str(out, "d_spc_warns");
-	prt_tab(out);
-	prt_printf(out, "%i", q->d_spc_warns);
-	prt_newline(out);
+	prt_printf(out, "d_fieldmask\t%x\n",		q->d_fieldmask);
+	prt_printf(out, "d_spc_hardlimit\t%llu\n",	q->d_spc_hardlimit);
+	prt_printf(out, "d_spc_softlimit\t%llu\n",	q->d_spc_softlimit);
+	prt_printf(out, "d_ino_hardlimit\%llu\n",	q->d_ino_hardlimit);
+	prt_printf(out, "d_ino_softlimit\t%llu\n",	q->d_ino_softlimit);
+	prt_printf(out, "d_space\t%llu\n",		q->d_space);
+	prt_printf(out, "d_ino_count\t%llu\n",		q->d_ino_count);
+	prt_printf(out, "d_ino_timer\t%llu\n",		q->d_ino_timer);
+	prt_printf(out, "d_spc_timer\t%llu\n",		q->d_spc_timer);
+	prt_printf(out, "d_ino_warns\t%i\n",		q->d_ino_warns);
+	prt_printf(out, "d_spc_warns\t%i\n",		q->d_spc_warns);
 }
 
 static inline unsigned __next_qtype(unsigned i, unsigned qtypes)
@@ -610,10 +535,10 @@ int bch2_fs_quota_read(struct bch_fs *c)
 
 	int ret = bch2_trans_run(c,
 		for_each_btree_key(trans, iter, BTREE_ID_quotas, POS_MIN,
-				   BTREE_ITER_PREFETCH, k,
+				   BTREE_ITER_prefetch, k,
 			__bch2_quota_set(c, k, NULL)) ?:
 		for_each_btree_key(trans, iter, BTREE_ID_inodes, POS_MIN,
-				   BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				   BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 			bch2_fs_quota_read_inode(trans, &iter, k)));
 	bch_err_fn(c, ret);
 	return ret;
@@ -900,7 +825,7 @@ static int bch2_set_quota_trans(struct btree_trans *trans,
 	int ret;
 
 	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_quotas, new_quota->k.p,
-			       BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+			       BTREE_ITER_slots|BTREE_ITER_intent);
 	ret = bkey_err(k);
 	if (unlikely(ret))
 		return ret;
diff --git a/fs/bcachefs/quota.h b/fs/bcachefs/quota.h
index 884f601f41c4..02d37a332218 100644
--- a/fs/bcachefs/quota.h
+++ b/fs/bcachefs/quota.h
@@ -5,11 +5,11 @@
 #include "inode.h"
 #include "quota_types.h"
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 extern const struct bch_sb_field_ops bch_sb_field_ops_quota;
 
 int bch2_quota_invalid(struct bch_fs *, struct bkey_s_c,
-		       enum bkey_invalid_flags, struct printbuf *);
+		       enum bch_validate_flags, struct printbuf *);
 void bch2_quota_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 #define bch2_bkey_ops_quota ((struct bkey_ops) {	\
diff --git a/fs/bcachefs/rebalance.c b/fs/bcachefs/rebalance.c
index 56336f3dd1d0..cf81e5128c3a 100644
--- a/fs/bcachefs/rebalance.c
+++ b/fs/bcachefs/rebalance.c
@@ -42,7 +42,7 @@ static int __bch2_set_rebalance_needs_scan(struct btree_trans *trans, u64 inum)
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work,
 			     SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	k = bch2_btree_iter_peek_slot(&iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -89,7 +89,7 @@ static int bch2_clear_rebalance_needs_scan(struct btree_trans *trans, u64 inum,
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_rebalance_work,
 			     SPOS(inum, REBALANCE_WORK_SCAN_OFFSET, U32_MAX),
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	k = bch2_btree_iter_peek_slot(&iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -140,7 +140,7 @@ static struct bkey_s_c next_rebalance_extent(struct btree_trans *trans,
 	bch2_trans_iter_init(trans, extent_iter,
 			     work_pos.inode ? BTREE_ID_extents : BTREE_ID_reflink,
 			     work_pos,
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_all_snapshots);
 	k = bch2_btree_iter_peek_slot(extent_iter);
 	if (bkey_err(k))
 		return k;
@@ -323,12 +323,14 @@ static int do_rebalance(struct moving_context *ctxt)
 	struct bkey_s_c k;
 	int ret = 0;
 
+	bch2_trans_begin(trans);
+
 	bch2_move_stats_init(&r->work_stats, "rebalance_work");
 	bch2_move_stats_init(&r->scan_stats, "rebalance_scan");
 
 	bch2_trans_iter_init(trans, &rebalance_work_iter,
 			     BTREE_ID_rebalance_work, POS_MIN,
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_all_snapshots);
 
 	while (!bch2_move_ratelimit(ctxt)) {
 		if (!r->enabled) {
diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 8091d0686029..1266916ac03f 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -65,9 +65,20 @@ static void bch2_reconstruct_alloc(struct bch_fs *c)
 	__set_bit_le64(BCH_FSCK_ERR_ptr_to_missing_alloc_key, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_ptr_gen_newer_than_bucket_gen, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_stale_dirty_ptr, ext->errors_silent);
+
+	__set_bit_le64(BCH_FSCK_ERR_dev_usage_buckets_wrong, ext->errors_silent);
+	__set_bit_le64(BCH_FSCK_ERR_dev_usage_sectors_wrong, ext->errors_silent);
+	__set_bit_le64(BCH_FSCK_ERR_dev_usage_fragmented_wrong, ext->errors_silent);
+
+	__set_bit_le64(BCH_FSCK_ERR_fs_usage_btree_wrong, ext->errors_silent);
+	__set_bit_le64(BCH_FSCK_ERR_fs_usage_cached_wrong, ext->errors_silent);
+	__set_bit_le64(BCH_FSCK_ERR_fs_usage_persistent_reserved_wrong, ext->errors_silent);
+	__set_bit_le64(BCH_FSCK_ERR_fs_usage_replicas_wrong, ext->errors_silent);
+
 	__set_bit_le64(BCH_FSCK_ERR_alloc_key_data_type_wrong, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_alloc_key_gen_wrong, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_alloc_key_dirty_sectors_wrong, ext->errors_silent);
+	__set_bit_le64(BCH_FSCK_ERR_alloc_key_cached_sectors_wrong, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_alloc_key_stripe_wrong, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_alloc_key_stripe_redundancy_wrong, ext->errors_silent);
 	__set_bit_le64(BCH_FSCK_ERR_need_discard_key_wrong, ext->errors_silent);
@@ -125,9 +136,9 @@ static int bch2_journal_replay_key(struct btree_trans *trans,
 {
 	struct btree_iter iter;
 	unsigned iter_flags =
-		BTREE_ITER_INTENT|
-		BTREE_ITER_NOT_EXTENTS;
-	unsigned update_flags = BTREE_TRIGGER_NORUN;
+		BTREE_ITER_intent|
+		BTREE_ITER_not_extents;
+	unsigned update_flags = BTREE_TRIGGER_norun;
 	int ret;
 
 	if (k->overwritten)
@@ -136,17 +147,17 @@ static int bch2_journal_replay_key(struct btree_trans *trans,
 	trans->journal_res.seq = k->journal_seq;
 
 	/*
-	 * BTREE_UPDATE_KEY_CACHE_RECLAIM disables key cache lookup/update to
+	 * BTREE_UPDATE_key_cache_reclaim disables key cache lookup/update to
 	 * keep the key cache coherent with the underlying btree. Nothing
 	 * besides the allocator is doing updates yet so we don't need key cache
 	 * coherency for non-alloc btrees, and key cache fills for snapshots
-	 * btrees use BTREE_ITER_FILTER_SNAPSHOTS, which isn't available until
+	 * btrees use BTREE_ITER_filter_snapshots, which isn't available until
 	 * the snapshots recovery pass runs.
 	 */
 	if (!k->level && k->btree_id == BTREE_ID_alloc)
-		iter_flags |= BTREE_ITER_CACHED;
+		iter_flags |= BTREE_ITER_cached;
 	else
-		update_flags |= BTREE_UPDATE_KEY_CACHE_RECLAIM;
+		update_flags |= BTREE_UPDATE_key_cache_reclaim;
 
 	bch2_trans_node_iter_init(trans, &iter, k->btree_id, k->k->k.p,
 				  BTREE_MAX_DEPTH, k->level,
@@ -191,7 +202,7 @@ int bch2_journal_replay(struct bch_fs *c)
 	struct journal *j = &c->journal;
 	u64 start_seq	= c->journal_replay_seq_start;
 	u64 end_seq	= c->journal_replay_seq_start;
-	struct btree_trans *trans = bch2_trans_get(c);
+	struct btree_trans *trans = NULL;
 	bool immediate_flush = false;
 	int ret = 0;
 
@@ -205,6 +216,7 @@ int bch2_journal_replay(struct bch_fs *c)
 	BUG_ON(!atomic_read(&keys->ref));
 
 	move_gap(keys, keys->nr);
+	trans = bch2_trans_get(c);
 
 	/*
 	 * First, attempt to replay keys in sorted order. This is more
@@ -361,14 +373,17 @@ static int journal_replay_entry_early(struct bch_fs *c,
 	case BCH_JSET_ENTRY_dev_usage: {
 		struct jset_entry_dev_usage *u =
 			container_of(entry, struct jset_entry_dev_usage, entry);
-		struct bch_dev *ca = bch_dev_bkey_exists(c, le32_to_cpu(u->dev));
-		unsigned i, nr_types = jset_entry_dev_usage_nr_types(u);
-
-		for (i = 0; i < min_t(unsigned, nr_types, BCH_DATA_NR); i++) {
-			ca->usage_base->d[i].buckets	= le64_to_cpu(u->d[i].buckets);
-			ca->usage_base->d[i].sectors	= le64_to_cpu(u->d[i].sectors);
-			ca->usage_base->d[i].fragmented	= le64_to_cpu(u->d[i].fragmented);
-		}
+		unsigned nr_types = jset_entry_dev_usage_nr_types(u);
+
+		rcu_read_lock();
+		struct bch_dev *ca = bch2_dev_rcu(c, le32_to_cpu(u->dev));
+		if (ca)
+			for (unsigned i = 0; i < min_t(unsigned, nr_types, BCH_DATA_NR); i++) {
+				ca->usage_base->d[i].buckets	= le64_to_cpu(u->d[i].buckets);
+				ca->usage_base->d[i].sectors	= le64_to_cpu(u->d[i].sectors);
+				ca->usage_base->d[i].fragmented	= le64_to_cpu(u->d[i].fragmented);
+			}
+		rcu_read_unlock();
 
 		break;
 	}
@@ -597,56 +612,54 @@ int bch2_fs_recovery(struct bch_fs *c)
 	if (c->opts.norecovery)
 		c->opts.recovery_pass_last = BCH_RECOVERY_PASS_journal_replay - 1;
 
-	if (!c->opts.nochanges) {
-		mutex_lock(&c->sb_lock);
-		struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
-		bool write_sb = false;
-
-		if (BCH_SB_HAS_TOPOLOGY_ERRORS(c->disk_sb.sb)) {
-			ext->recovery_passes_required[0] |=
-				cpu_to_le64(bch2_recovery_passes_to_stable(BIT_ULL(BCH_RECOVERY_PASS_check_topology)));
-			write_sb = true;
-		}
+	mutex_lock(&c->sb_lock);
+	struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
+	bool write_sb = false;
 
-		u64 sb_passes = bch2_recovery_passes_from_stable(le64_to_cpu(ext->recovery_passes_required[0]));
-		if (sb_passes) {
-			struct printbuf buf = PRINTBUF;
-			prt_str(&buf, "superblock requires following recovery passes to be run:\n  ");
-			prt_bitflags(&buf, bch2_recovery_passes, sb_passes);
-			bch_info(c, "%s", buf.buf);
-			printbuf_exit(&buf);
-		}
+	if (BCH_SB_HAS_TOPOLOGY_ERRORS(c->disk_sb.sb)) {
+		ext->recovery_passes_required[0] |=
+			cpu_to_le64(bch2_recovery_passes_to_stable(BIT_ULL(BCH_RECOVERY_PASS_check_topology)));
+		write_sb = true;
+	}
 
-		if (bch2_check_version_downgrade(c)) {
-			struct printbuf buf = PRINTBUF;
+	u64 sb_passes = bch2_recovery_passes_from_stable(le64_to_cpu(ext->recovery_passes_required[0]));
+	if (sb_passes) {
+		struct printbuf buf = PRINTBUF;
+		prt_str(&buf, "superblock requires following recovery passes to be run:\n  ");
+		prt_bitflags(&buf, bch2_recovery_passes, sb_passes);
+		bch_info(c, "%s", buf.buf);
+		printbuf_exit(&buf);
+	}
 
-			prt_str(&buf, "Version downgrade required:");
+	if (bch2_check_version_downgrade(c)) {
+		struct printbuf buf = PRINTBUF;
 
-			__le64 passes = ext->recovery_passes_required[0];
-			bch2_sb_set_downgrade(c,
-					BCH_VERSION_MINOR(bcachefs_metadata_version_current),
-					BCH_VERSION_MINOR(c->sb.version));
-			passes = ext->recovery_passes_required[0] & ~passes;
-			if (passes) {
-				prt_str(&buf, "\n  running recovery passes: ");
-				prt_bitflags(&buf, bch2_recovery_passes,
-					     bch2_recovery_passes_from_stable(le64_to_cpu(passes)));
-			}
+		prt_str(&buf, "Version downgrade required:");
 
-			bch_info(c, "%s", buf.buf);
-			printbuf_exit(&buf);
-			write_sb = true;
+		__le64 passes = ext->recovery_passes_required[0];
+		bch2_sb_set_downgrade(c,
+				      BCH_VERSION_MINOR(bcachefs_metadata_version_current),
+				      BCH_VERSION_MINOR(c->sb.version));
+		passes = ext->recovery_passes_required[0] & ~passes;
+		if (passes) {
+			prt_str(&buf, "\n  running recovery passes: ");
+			prt_bitflags(&buf, bch2_recovery_passes,
+				     bch2_recovery_passes_from_stable(le64_to_cpu(passes)));
 		}
 
-		if (check_version_upgrade(c))
-			write_sb = true;
+		bch_info(c, "%s", buf.buf);
+		printbuf_exit(&buf);
+		write_sb = true;
+	}
 
-		if (write_sb)
-			bch2_write_super(c);
+	if (check_version_upgrade(c))
+		write_sb = true;
 
-		c->recovery_passes_explicit |= bch2_recovery_passes_from_stable(le64_to_cpu(ext->recovery_passes_required[0]));
-		mutex_unlock(&c->sb_lock);
-	}
+	if (write_sb)
+		bch2_write_super(c);
+
+	c->recovery_passes_explicit |= bch2_recovery_passes_from_stable(le64_to_cpu(ext->recovery_passes_required[0]));
+	mutex_unlock(&c->sb_lock);
 
 	if (c->opts.fsck && IS_ENABLED(CONFIG_BCACHEFS_DEBUG))
 		c->recovery_passes_explicit |= BIT_ULL(BCH_RECOVERY_PASS_check_topology);
@@ -660,7 +673,9 @@ int bch2_fs_recovery(struct bch_fs *c)
 		goto err;
 	}
 
-	if (!c->sb.clean || c->opts.fsck || c->opts.retain_recovery_info) {
+	bch2_journal_pos_from_member_info_resume(c);
+
+	if (!c->sb.clean || c->opts.retain_recovery_info) {
 		struct genradix_iter iter;
 		struct journal_replay **i;
 
@@ -832,8 +847,8 @@ use_clean:
 	}
 
 	mutex_lock(&c->sb_lock);
-	struct bch_sb_field_ext *ext = bch2_sb_field_get(c->disk_sb.sb, ext);
-	bool write_sb = false;
+	ext = bch2_sb_field_get(c->disk_sb.sb, ext);
+	write_sb = false;
 
 	if (BCH_SB_VERSION_UPGRADE_COMPLETE(c->disk_sb.sb) != le16_to_cpu(c->disk_sb.sb->version)) {
 		SET_BCH_SB_VERSION_UPGRADE_COMPLETE(c->disk_sb.sb, le16_to_cpu(c->disk_sb.sb->version));
@@ -868,6 +883,9 @@ use_clean:
 		write_sb = true;
 	}
 
+	if (bch2_blacklist_entries_gc(c))
+		write_sb = true;
+
 	if (write_sb)
 		bch2_write_super(c);
 	mutex_unlock(&c->sb_lock);
@@ -890,10 +908,6 @@ use_clean:
 		bch_info(c, "scanning for old btree nodes done");
 	}
 
-	if (c->journal_seq_blacklist_table &&
-	    c->journal_seq_blacklist_table->nr > 128)
-		queue_work(system_long_wq, &c->journal_seq_blacklist_gc_work);
-
 	ret = 0;
 out:
 	bch2_flush_fsck_errs(c);
diff --git a/fs/bcachefs/recovery_passes.c b/fs/bcachefs/recovery_passes.c
index 0cec0f7d9703..4a9eb9582b6e 100644
--- a/fs/bcachefs/recovery_passes.c
+++ b/fs/bcachefs/recovery_passes.c
@@ -26,11 +26,6 @@ const char * const bch2_recovery_passes[] = {
 	NULL
 };
 
-static int bch2_check_allocations(struct bch_fs *c)
-{
-	return bch2_gc(c, true, false);
-}
-
 static int bch2_set_may_go_rw(struct bch_fs *c)
 {
 	struct journal_keys *keys = &c->journal_keys;
@@ -227,7 +222,8 @@ int bch2_run_recovery_passes(struct bch_fs *c)
 		if (should_run_recovery_pass(c, c->curr_recovery_pass)) {
 			unsigned pass = c->curr_recovery_pass;
 
-			ret = bch2_run_recovery_pass(c, c->curr_recovery_pass);
+			ret =   bch2_run_recovery_pass(c, c->curr_recovery_pass) ?:
+				bch2_journal_flush(&c->journal);
 			if (bch2_err_matches(ret, BCH_ERR_restart_recovery) ||
 			    (ret && c->curr_recovery_pass < pass))
 				continue;
diff --git a/fs/bcachefs/reflink.c b/fs/bcachefs/reflink.c
index ff7864731a07..9ac6cf21cfbf 100644
--- a/fs/bcachefs/reflink.c
+++ b/fs/bcachefs/reflink.c
@@ -30,7 +30,7 @@ static inline unsigned bkey_type_to_indirect(const struct bkey *k)
 /* reflink pointers */
 
 int bch2_reflink_p_invalid(struct bch_fs *c, struct bkey_s_c k,
-			   enum bkey_invalid_flags flags,
+			   enum bch_validate_flags flags,
 			   struct printbuf *err)
 {
 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
@@ -74,20 +74,20 @@ bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r
 }
 
 static int trans_trigger_reflink_p_segment(struct btree_trans *trans,
-			struct bkey_s_c_reflink_p p,
-			u64 *idx, unsigned flags)
+			struct bkey_s_c_reflink_p p, u64 *idx,
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
 	struct btree_iter iter;
 	struct bkey_i *k;
 	__le64 *refcount;
-	int add = !(flags & BTREE_TRIGGER_OVERWRITE) ? 1 : -1;
+	int add = !(flags & BTREE_TRIGGER_overwrite) ? 1 : -1;
 	struct printbuf buf = PRINTBUF;
 	int ret;
 
 	k = bch2_bkey_get_mut_noupdate(trans, &iter,
 			BTREE_ID_reflink, POS(0, *idx),
-			BTREE_ITER_WITH_UPDATES);
+			BTREE_ITER_with_updates);
 	ret = PTR_ERR_OR_ZERO(k);
 	if (ret)
 		goto err;
@@ -102,7 +102,7 @@ static int trans_trigger_reflink_p_segment(struct btree_trans *trans,
 		goto err;
 	}
 
-	if (!*refcount && (flags & BTREE_TRIGGER_OVERWRITE)) {
+	if (!*refcount && (flags & BTREE_TRIGGER_overwrite)) {
 		bch2_bkey_val_to_text(&buf, c, p.s_c);
 		bch2_trans_inconsistent(trans,
 			"indirect extent refcount underflow at %llu while marking\n  %s",
@@ -111,7 +111,7 @@ static int trans_trigger_reflink_p_segment(struct btree_trans *trans,
 		goto err;
 	}
 
-	if (flags & BTREE_TRIGGER_INSERT) {
+	if (flags & BTREE_TRIGGER_insert) {
 		struct bch_reflink_p *v = (struct bch_reflink_p *) p.v;
 		u64 pad;
 
@@ -141,12 +141,13 @@ err:
 }
 
 static s64 gc_trigger_reflink_p_segment(struct btree_trans *trans,
-				struct bkey_s_c_reflink_p p,
-				u64 *idx, unsigned flags, size_t r_idx)
+				struct bkey_s_c_reflink_p p, u64 *idx,
+				enum btree_iter_update_trigger_flags flags,
+				size_t r_idx)
 {
 	struct bch_fs *c = trans->c;
 	struct reflink_gc *r;
-	int add = !(flags & BTREE_TRIGGER_OVERWRITE) ? 1 : -1;
+	int add = !(flags & BTREE_TRIGGER_overwrite) ? 1 : -1;
 	u64 start = le64_to_cpu(p.v->idx);
 	u64 end = le64_to_cpu(p.v->idx) + p.k->size;
 	u64 next_idx = end + le32_to_cpu(p.v->back_pad);
@@ -163,10 +164,13 @@ static s64 gc_trigger_reflink_p_segment(struct btree_trans *trans,
 
 	BUG_ON((s64) r->refcount + add < 0);
 
-	r->refcount += add;
+	if (flags & BTREE_TRIGGER_gc)
+		r->refcount += add;
 	*idx = r->offset;
 	return 0;
 not_found:
+	BUG_ON(!(flags & BTREE_TRIGGER_check_repair));
+
 	if (fsck_err(c, reflink_p_to_missing_reflink_v,
 		     "pointer to missing indirect extent\n"
 		     "  %s\n"
@@ -189,7 +193,7 @@ not_found:
 			set_bkey_val_u64s(&update->k, 0);
 		}
 
-		ret = bch2_btree_insert_trans(trans, BTREE_ID_extents, update, BTREE_TRIGGER_NORUN);
+		ret = bch2_btree_insert_trans(trans, BTREE_ID_extents, update, BTREE_TRIGGER_norun);
 	}
 
 	*idx = next_idx;
@@ -200,8 +204,8 @@ fsck_err:
 }
 
 static int __trigger_reflink_p(struct btree_trans *trans,
-			    enum btree_id btree_id, unsigned level,
-			    struct bkey_s_c k, unsigned flags)
+		enum btree_id btree_id, unsigned level, struct bkey_s_c k,
+		enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
@@ -210,12 +214,12 @@ static int __trigger_reflink_p(struct btree_trans *trans,
 	u64 idx = le64_to_cpu(p.v->idx) - le32_to_cpu(p.v->front_pad);
 	u64 end = le64_to_cpu(p.v->idx) + p.k->size + le32_to_cpu(p.v->back_pad);
 
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		while (idx < end && !ret)
 			ret = trans_trigger_reflink_p_segment(trans, p, &idx, flags);
 	}
 
-	if (flags & BTREE_TRIGGER_GC) {
+	if (flags & (BTREE_TRIGGER_check_repair|BTREE_TRIGGER_gc)) {
 		size_t l = 0, r = c->reflink_gc_nr;
 
 		while (l < r) {
@@ -238,10 +242,10 @@ int bch2_trigger_reflink_p(struct btree_trans *trans,
 			   enum btree_id btree_id, unsigned level,
 			   struct bkey_s_c old,
 			   struct bkey_s new,
-			   unsigned flags)
+			   enum btree_iter_update_trigger_flags flags)
 {
-	if ((flags & BTREE_TRIGGER_TRANSACTIONAL) &&
-	    (flags & BTREE_TRIGGER_INSERT)) {
+	if ((flags & BTREE_TRIGGER_transactional) &&
+	    (flags & BTREE_TRIGGER_insert)) {
 		struct bch_reflink_p *v = bkey_s_to_reflink_p(new).v;
 
 		v->front_pad = v->back_pad = 0;
@@ -253,7 +257,7 @@ int bch2_trigger_reflink_p(struct btree_trans *trans,
 /* indirect extents */
 
 int bch2_reflink_v_invalid(struct bch_fs *c, struct bkey_s_c k,
-			   enum bkey_invalid_flags flags,
+			   enum bch_validate_flags flags,
 			   struct printbuf *err)
 {
 	return bch2_bkey_ptrs_invalid(c, k, flags, err);
@@ -281,23 +285,25 @@ bool bch2_reflink_v_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r
 }
 #endif
 
-static inline void check_indirect_extent_deleting(struct bkey_s new, unsigned *flags)
+static inline void
+check_indirect_extent_deleting(struct bkey_s new,
+			       enum btree_iter_update_trigger_flags *flags)
 {
-	if ((*flags & BTREE_TRIGGER_INSERT) && !*bkey_refcount(new)) {
+	if ((*flags & BTREE_TRIGGER_insert) && !*bkey_refcount(new)) {
 		new.k->type = KEY_TYPE_deleted;
 		new.k->size = 0;
 		set_bkey_val_u64s(new.k, 0);
-		*flags &= ~BTREE_TRIGGER_INSERT;
+		*flags &= ~BTREE_TRIGGER_insert;
 	}
 }
 
 int bch2_trigger_reflink_v(struct btree_trans *trans,
 			   enum btree_id btree_id, unsigned level,
 			   struct bkey_s_c old, struct bkey_s new,
-			   unsigned flags)
+			   enum btree_iter_update_trigger_flags flags)
 {
-	if ((flags & BTREE_TRIGGER_TRANSACTIONAL) &&
-	    (flags & BTREE_TRIGGER_INSERT))
+	if ((flags & BTREE_TRIGGER_transactional) &&
+	    (flags & BTREE_TRIGGER_insert))
 		check_indirect_extent_deleting(new, &flags);
 
 	return bch2_trigger_extent(trans, btree_id, level, old, new, flags);
@@ -306,7 +312,7 @@ int bch2_trigger_reflink_v(struct btree_trans *trans,
 /* indirect inline data */
 
 int bch2_indirect_inline_data_invalid(struct bch_fs *c, struct bkey_s_c k,
-				      enum bkey_invalid_flags flags,
+				      enum bch_validate_flags flags,
 				      struct printbuf *err)
 {
 	return 0;
@@ -326,7 +332,7 @@ void bch2_indirect_inline_data_to_text(struct printbuf *out,
 int bch2_trigger_indirect_inline_data(struct btree_trans *trans,
 			      enum btree_id btree_id, unsigned level,
 			      struct bkey_s_c old, struct bkey_s new,
-			      unsigned flags)
+			      enum btree_iter_update_trigger_flags flags)
 {
 	check_indirect_extent_deleting(new, &flags);
 
@@ -349,7 +355,7 @@ static int bch2_make_extent_indirect(struct btree_trans *trans,
 		bch2_check_set_feature(c, BCH_FEATURE_reflink_inline_data);
 
 	bch2_trans_iter_init(trans, &reflink_iter, BTREE_ID_reflink, POS_MAX,
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	k = bch2_btree_iter_peek_prev(&reflink_iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -394,7 +400,7 @@ static int bch2_make_extent_indirect(struct btree_trans *trans,
 	r_p->v.idx = cpu_to_le64(bkey_start_offset(&r_v->k));
 
 	ret = bch2_trans_update(trans, extent_iter, &r_p->k_i,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+				BTREE_UPDATE_internal_snapshot_node);
 err:
 	bch2_trans_iter_exit(trans, &reflink_iter);
 
@@ -455,9 +461,9 @@ s64 bch2_remap_range(struct bch_fs *c,
 		goto err;
 
 	bch2_trans_iter_init(trans, &src_iter, BTREE_ID_extents, src_start,
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	bch2_trans_iter_init(trans, &dst_iter, BTREE_ID_extents, dst_start,
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 
 	while ((ret == 0 ||
 		bch2_err_matches(ret, BCH_ERR_transaction_restart)) &&
@@ -567,7 +573,7 @@ s64 bch2_remap_range(struct bch_fs *c,
 		bch2_trans_begin(trans);
 
 		ret2 = bch2_inode_peek(trans, &inode_iter, &inode_u,
-				       dst_inum, BTREE_ITER_INTENT);
+				       dst_inum, BTREE_ITER_intent);
 
 		if (!ret2 &&
 		    inode_u.bi_size < new_i_size) {
diff --git a/fs/bcachefs/reflink.h b/fs/bcachefs/reflink.h
index 4d8867289717..e894f3a2c67a 100644
--- a/fs/bcachefs/reflink.h
+++ b/fs/bcachefs/reflink.h
@@ -2,15 +2,16 @@
 #ifndef _BCACHEFS_REFLINK_H
 #define _BCACHEFS_REFLINK_H
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 
 int bch2_reflink_p_invalid(struct bch_fs *, struct bkey_s_c,
-			   enum bkey_invalid_flags, struct printbuf *);
+			   enum bch_validate_flags, struct printbuf *);
 void bch2_reflink_p_to_text(struct printbuf *, struct bch_fs *,
 			    struct bkey_s_c);
 bool bch2_reflink_p_merge(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 int bch2_trigger_reflink_p(struct btree_trans *, enum btree_id, unsigned,
-			   struct bkey_s_c, struct bkey_s, unsigned);
+			   struct bkey_s_c, struct bkey_s,
+			   enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_reflink_p ((struct bkey_ops) {		\
 	.key_invalid	= bch2_reflink_p_invalid,		\
@@ -21,11 +22,12 @@ int bch2_trigger_reflink_p(struct btree_trans *, enum btree_id, unsigned,
 })
 
 int bch2_reflink_v_invalid(struct bch_fs *, struct bkey_s_c,
-			   enum bkey_invalid_flags, struct printbuf *);
+			   enum bch_validate_flags, struct printbuf *);
 void bch2_reflink_v_to_text(struct printbuf *, struct bch_fs *,
 			    struct bkey_s_c);
 int bch2_trigger_reflink_v(struct btree_trans *, enum btree_id, unsigned,
-			      struct bkey_s_c, struct bkey_s, unsigned);
+			   struct bkey_s_c, struct bkey_s,
+			   enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_reflink_v ((struct bkey_ops) {		\
 	.key_invalid	= bch2_reflink_v_invalid,		\
@@ -36,13 +38,13 @@ int bch2_trigger_reflink_v(struct btree_trans *, enum btree_id, unsigned,
 })
 
 int bch2_indirect_inline_data_invalid(struct bch_fs *, struct bkey_s_c,
-				      enum bkey_invalid_flags, struct printbuf *);
+				      enum bch_validate_flags, struct printbuf *);
 void bch2_indirect_inline_data_to_text(struct printbuf *,
 				struct bch_fs *, struct bkey_s_c);
 int bch2_trigger_indirect_inline_data(struct btree_trans *,
 					 enum btree_id, unsigned,
 			      struct bkey_s_c, struct bkey_s,
-			      unsigned);
+			      enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_indirect_inline_data ((struct bkey_ops) {	\
 	.key_invalid	= bch2_indirect_inline_data_invalid,	\
diff --git a/fs/bcachefs/replicas.c b/fs/bcachefs/replicas.c
index 678b9c20e251..bd1d5d085e23 100644
--- a/fs/bcachefs/replicas.c
+++ b/fs/bcachefs/replicas.c
@@ -84,7 +84,7 @@ int bch2_replicas_entry_validate(struct bch_replicas_entry_v1 *r,
 	}
 
 	for (unsigned i = 0; i < r->nr_devs; i++)
-		if (!bch2_dev_exists(sb, r->devs[i])) {
+		if (!bch2_member_exists(sb, r->devs[i])) {
 			prt_printf(err, "invalid device %u in entry ", r->devs[i]);
 			goto bad;
 		}
@@ -200,7 +200,7 @@ cpu_replicas_add_entry(struct bch_fs *c,
 	};
 
 	for (i = 0; i < new_entry->nr_devs; i++)
-		BUG_ON(!bch2_dev_exists2(c, new_entry->devs[i]));
+		BUG_ON(!bch2_dev_exists(c, new_entry->devs[i]));
 
 	BUG_ON(!new_entry->data_type);
 	verify_replicas_entry(new_entry);
@@ -860,7 +860,7 @@ static int bch2_cpu_replicas_validate(struct bch_replicas_cpu *cpu_r,
 }
 
 static int bch2_sb_replicas_validate(struct bch_sb *sb, struct bch_sb_field *f,
-				     struct printbuf *err)
+				     enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_replicas *sb_r = field_to_type(f, replicas);
 	struct bch_replicas_cpu cpu_r;
@@ -899,7 +899,7 @@ const struct bch_sb_field_ops bch_sb_field_ops_replicas = {
 };
 
 static int bch2_sb_replicas_v0_validate(struct bch_sb *sb, struct bch_sb_field *f,
-					struct printbuf *err)
+					enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_replicas_v0 *sb_r = field_to_type(f, replicas_v0);
 	struct bch_replicas_cpu cpu_r;
@@ -947,18 +947,20 @@ bool bch2_have_enough_devs(struct bch_fs *c, struct bch_devs_mask devs,
 
 	percpu_down_read(&c->mark_lock);
 	for_each_cpu_replicas_entry(&c->replicas, e) {
-		unsigned i, nr_online = 0, nr_failed = 0, dflags = 0;
+		unsigned nr_online = 0, nr_failed = 0, dflags = 0;
 		bool metadata = e->data_type < BCH_DATA_user;
 
 		if (e->data_type == BCH_DATA_cached)
 			continue;
 
-		for (i = 0; i < e->nr_devs; i++) {
-			struct bch_dev *ca = bch_dev_bkey_exists(c, e->devs[i]);
-
+		rcu_read_lock();
+		for (unsigned i = 0; i < e->nr_devs; i++) {
 			nr_online += test_bit(e->devs[i], devs.d);
-			nr_failed += ca->mi.state == BCH_MEMBER_STATE_failed;
+
+			struct bch_dev *ca = bch2_dev_rcu(c, e->devs[i]);
+			nr_failed += ca && ca->mi.state == BCH_MEMBER_STATE_failed;
 		}
+		rcu_read_unlock();
 
 		if (nr_failed == e->nr_devs)
 			continue;
diff --git a/fs/bcachefs/sb-clean.c b/fs/bcachefs/sb-clean.c
index 194e55b11137..47f10ab57f40 100644
--- a/fs/bcachefs/sb-clean.c
+++ b/fs/bcachefs/sb-clean.c
@@ -266,9 +266,8 @@ void bch2_journal_super_entries_add_common(struct bch_fs *c,
 	}
 }
 
-static int bch2_sb_clean_validate(struct bch_sb *sb,
-				  struct bch_sb_field *f,
-				  struct printbuf *err)
+static int bch2_sb_clean_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				  enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_clean *clean = field_to_type(f, clean);
 
@@ -283,7 +282,7 @@ static int bch2_sb_clean_validate(struct bch_sb *sb,
 	     entry = vstruct_next(entry)) {
 		if ((void *) vstruct_next(entry) > vstruct_end(&clean->field)) {
 			prt_str(err, "entry type ");
-			bch2_prt_jset_entry_type(err, le16_to_cpu(entry->type));
+			bch2_prt_jset_entry_type(err, entry->type);
 			prt_str(err, " overruns end of section");
 			return -BCH_ERR_invalid_sb_clean;
 		}
@@ -298,10 +297,8 @@ static void bch2_sb_clean_to_text(struct printbuf *out, struct bch_sb *sb,
 	struct bch_sb_field_clean *clean = field_to_type(f, clean);
 	struct jset_entry *entry;
 
-	prt_printf(out, "flags:          %x",	le32_to_cpu(clean->flags));
-	prt_newline(out);
-	prt_printf(out, "journal_seq:    %llu",	le64_to_cpu(clean->journal_seq));
-	prt_newline(out);
+	prt_printf(out, "flags:          %x\n",		le32_to_cpu(clean->flags));
+	prt_printf(out, "journal_seq:    %llu\n",	le64_to_cpu(clean->journal_seq));
 
 	for (entry = clean->start;
 	     entry != vstruct_end(&clean->field);
@@ -392,6 +389,8 @@ void bch2_fs_mark_clean(struct bch_fs *c)
 		goto out;
 	}
 
+	bch2_journal_pos_from_member_info_set(c);
+
 	bch2_write_super(c);
 out:
 	mutex_unlock(&c->sb_lock);
diff --git a/fs/bcachefs/sb-counters.c b/fs/bcachefs/sb-counters.c
index 7dc898761bb3..6992e7469112 100644
--- a/fs/bcachefs/sb-counters.c
+++ b/fs/bcachefs/sb-counters.c
@@ -20,9 +20,8 @@ static size_t bch2_sb_counter_nr_entries(struct bch_sb_field_counters *ctrs)
 	return (__le64 *) vstruct_end(&ctrs->field) - &ctrs->d[0];
 };
 
-static int bch2_sb_counters_validate(struct bch_sb *sb,
-				     struct bch_sb_field *f,
-				     struct printbuf *err)
+static int bch2_sb_counters_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	return 0;
 };
@@ -31,19 +30,12 @@ static void bch2_sb_counters_to_text(struct printbuf *out, struct bch_sb *sb,
 			      struct bch_sb_field *f)
 {
 	struct bch_sb_field_counters *ctrs = field_to_type(f, counters);
-	unsigned int i;
 	unsigned int nr = bch2_sb_counter_nr_entries(ctrs);
 
-	for (i = 0; i < nr; i++) {
-		if (i < BCH_COUNTER_NR)
-			prt_printf(out, "%s ", bch2_counter_names[i]);
-		else
-			prt_printf(out, "(unknown)");
-
-		prt_tab(out);
-		prt_printf(out, "%llu", le64_to_cpu(ctrs->d[i]));
-		prt_newline(out);
-	}
+	for (unsigned i = 0; i < nr; i++)
+		prt_printf(out, "%s \t%llu\n",
+			   i < BCH_COUNTER_NR ? bch2_counter_names[i] : "(unknown)",
+			   le64_to_cpu(ctrs->d[i]));
 };
 
 int bch2_sb_counters_to_cpu(struct bch_fs *c)
diff --git a/fs/bcachefs/sb-downgrade.c b/fs/bcachefs/sb-downgrade.c
index a98ef940b7a3..390a1bbd2567 100644
--- a/fs/bcachefs/sb-downgrade.c
+++ b/fs/bcachefs/sb-downgrade.c
@@ -134,15 +134,25 @@ downgrade_entry_next_c(const struct bch_sb_field_downgrade_entry *e)
 #define for_each_downgrade_entry(_d, _i)						\
 	for (const struct bch_sb_field_downgrade_entry *_i = (_d)->entries;		\
 	     (void *) _i	< vstruct_end(&(_d)->field) &&				\
-	     (void *) &_i->errors[0] < vstruct_end(&(_d)->field);			\
+	     (void *) &_i->errors[0] <= vstruct_end(&(_d)->field) &&			\
+	     (void *) downgrade_entry_next_c(_i) <= vstruct_end(&(_d)->field);		\
 	     _i = downgrade_entry_next_c(_i))
 
 static int bch2_sb_downgrade_validate(struct bch_sb *sb, struct bch_sb_field *f,
-				      struct printbuf *err)
+				      enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_downgrade *e = field_to_type(f, downgrade);
 
-	for_each_downgrade_entry(e, i) {
+	for (const struct bch_sb_field_downgrade_entry *i = e->entries;
+	     (void *) i	< vstruct_end(&e->field);
+	     i = downgrade_entry_next_c(i)) {
+		if (flags & BCH_VALIDATE_write &&
+		    ((void *) &i->errors[0] > vstruct_end(&e->field) ||
+		     (void *) downgrade_entry_next_c(i) > vstruct_end(&e->field))) {
+			prt_printf(err, "downgrade entry overruns end of superblock section)");
+			return -BCH_ERR_invalid_sb_downgrade;
+		}
+
 		if (BCH_VERSION_MAJOR(le16_to_cpu(i->version)) !=
 		    BCH_VERSION_MAJOR(le16_to_cpu(sb->version))) {
 			prt_printf(err, "downgrade entry with mismatched major version (%u != %u)",
@@ -164,19 +174,16 @@ static void bch2_sb_downgrade_to_text(struct printbuf *out, struct bch_sb *sb,
 		printbuf_tabstop_push(out, 16);
 
 	for_each_downgrade_entry(e, i) {
-		prt_str(out, "version:");
-		prt_tab(out);
+		prt_str(out, "version:\t");
 		bch2_version_to_text(out, le16_to_cpu(i->version));
 		prt_newline(out);
 
-		prt_str(out, "recovery passes:");
-		prt_tab(out);
+		prt_str(out, "recovery passes:\t");
 		prt_bitflags(out, bch2_recovery_passes,
 			     bch2_recovery_passes_from_stable(le64_to_cpu(i->recovery_passes[0])));
 		prt_newline(out);
 
-		prt_str(out, "errors:");
-		prt_tab(out);
+		prt_str(out, "errors:\t");
 		bool first = true;
 		for (unsigned j = 0; j < le16_to_cpu(i->nr_errors); j++) {
 			if (!first)
diff --git a/fs/bcachefs/sb-errors.c b/fs/bcachefs/sb-errors.c
index 5f5bcae391fb..bda33e59e226 100644
--- a/fs/bcachefs/sb-errors.c
+++ b/fs/bcachefs/sb-errors.c
@@ -30,7 +30,7 @@ static inline unsigned bch2_sb_field_errors_u64s(unsigned nr)
 }
 
 static int bch2_sb_errors_validate(struct bch_sb *sb, struct bch_sb_field *f,
-				   struct printbuf *err)
+				   enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_errors *e = field_to_type(f, errors);
 	unsigned i, nr = bch2_sb_field_errors_nr_entries(e);
diff --git a/fs/bcachefs/sb-errors_types.h b/fs/bcachefs/sb-errors_types.h
index 06c7a644f4a4..87324747351a 100644
--- a/fs/bcachefs/sb-errors_types.h
+++ b/fs/bcachefs/sb-errors_types.h
@@ -272,7 +272,8 @@
 	x(snapshot_node_missing,				264)	\
 	x(dup_backpointer_to_bad_csum_extent,			265)	\
 	x(btree_bitmap_not_marked,				266)	\
-	x(sb_clean_entry_overrun,				267)
+	x(sb_clean_entry_overrun,				267)	\
+	x(btree_ptr_v2_written_0,				268)
 
 enum bch_sb_error_id {
 #define x(t, n) BCH_FSCK_ERR_##t = n,
diff --git a/fs/bcachefs/sb-members.c b/fs/bcachefs/sb-members.c
index 44b3f0cb7b49..39196f2a4197 100644
--- a/fs/bcachefs/sb-members.c
+++ b/fs/bcachefs/sb-members.c
@@ -3,11 +3,22 @@
 #include "bcachefs.h"
 #include "btree_cache.h"
 #include "disk_groups.h"
+#include "error.h"
 #include "opts.h"
 #include "replicas.h"
 #include "sb-members.h"
 #include "super-io.h"
 
+void bch2_dev_missing(struct bch_fs *c, unsigned dev)
+{
+	bch2_fs_inconsistent(c, "pointer to nonexistent device %u", dev);
+}
+
+void bch2_dev_bucket_missing(struct bch_fs *c, struct bpos bucket)
+{
+	bch2_fs_inconsistent(c, "pointer to nonexistent bucket %llu:%llu", bucket.inode, bucket.offset);
+}
+
 #define x(t, n, ...) [n] = #t,
 static const char * const bch2_iops_measurements[] = {
 	BCH_IOPS_MEASUREMENTS()
@@ -164,18 +175,14 @@ static void member_to_text(struct printbuf *out,
 	u64 bucket_size = le16_to_cpu(m.bucket_size);
 	u64 device_size = le64_to_cpu(m.nbuckets) * bucket_size;
 
-	if (!bch2_member_exists(&m))
+	if (!bch2_member_alive(&m))
 		return;
 
-	prt_printf(out, "Device:");
-	prt_tab(out);
-	prt_printf(out, "%u", i);
-	prt_newline(out);
+	prt_printf(out, "Device:\t%u\n", i);
 
 	printbuf_indent_add(out, 2);
 
-	prt_printf(out, "Label:");
-	prt_tab(out);
+	prt_printf(out, "Label:\t");
 	if (BCH_MEMBER_GROUP(&m)) {
 		unsigned idx = BCH_MEMBER_GROUP(&m) - 1;
 
@@ -189,103 +196,73 @@ static void member_to_text(struct printbuf *out,
 	}
 	prt_newline(out);
 
-	prt_printf(out, "UUID:");
-	prt_tab(out);
+	prt_printf(out, "UUID:\t");
 	pr_uuid(out, m.uuid.b);
 	prt_newline(out);
 
-	prt_printf(out, "Size:");
-	prt_tab(out);
+	prt_printf(out, "Size:\t");
 	prt_units_u64(out, device_size << 9);
 	prt_newline(out);
 
-	for (unsigned i = 0; i < BCH_MEMBER_ERROR_NR; i++) {
-		prt_printf(out, "%s errors:", bch2_member_error_strs[i]);
-		prt_tab(out);
-		prt_u64(out, le64_to_cpu(m.errors[i]));
-		prt_newline(out);
-	}
+	for (unsigned i = 0; i < BCH_MEMBER_ERROR_NR; i++)
+		prt_printf(out, "%s errors:\t%llu\n", bch2_member_error_strs[i], le64_to_cpu(m.errors[i]));
 
-	for (unsigned i = 0; i < BCH_IOPS_NR; i++) {
-		prt_printf(out, "%s iops:", bch2_iops_measurements[i]);
-		prt_tab(out);
-		prt_printf(out, "%u", le32_to_cpu(m.iops[i]));
-		prt_newline(out);
-	}
+	for (unsigned i = 0; i < BCH_IOPS_NR; i++)
+		prt_printf(out, "%s iops:\t%u\n", bch2_iops_measurements[i], le32_to_cpu(m.iops[i]));
 
-	prt_printf(out, "Bucket size:");
-	prt_tab(out);
+	prt_printf(out, "Bucket size:\t");
 	prt_units_u64(out, bucket_size << 9);
 	prt_newline(out);
 
-	prt_printf(out, "First bucket:");
-	prt_tab(out);
-	prt_printf(out, "%u", le16_to_cpu(m.first_bucket));
-	prt_newline(out);
-
-	prt_printf(out, "Buckets:");
-	prt_tab(out);
-	prt_printf(out, "%llu", le64_to_cpu(m.nbuckets));
-	prt_newline(out);
+	prt_printf(out, "First bucket:\t%u\n", le16_to_cpu(m.first_bucket));
+	prt_printf(out, "Buckets:\t%llu\n", le64_to_cpu(m.nbuckets));
 
-	prt_printf(out, "Last mount:");
-	prt_tab(out);
+	prt_printf(out, "Last mount:\t");
 	if (m.last_mount)
 		bch2_prt_datetime(out, le64_to_cpu(m.last_mount));
 	else
 		prt_printf(out, "(never)");
 	prt_newline(out);
 
-	prt_printf(out, "Last superblock write:");
-	prt_tab(out);
-	prt_u64(out, le64_to_cpu(m.seq));
-	prt_newline(out);
+	prt_printf(out, "Last superblock write:\t%llu\n", le64_to_cpu(m.seq));
 
-	prt_printf(out, "State:");
-	prt_tab(out);
-	prt_printf(out, "%s",
+	prt_printf(out, "State:\t%s\n",
 		   BCH_MEMBER_STATE(&m) < BCH_MEMBER_STATE_NR
 		   ? bch2_member_states[BCH_MEMBER_STATE(&m)]
 		   : "unknown");
-	prt_newline(out);
 
-	prt_printf(out, "Data allowed:");
-	prt_tab(out);
+	prt_printf(out, "Data allowed:\t");
 	if (BCH_MEMBER_DATA_ALLOWED(&m))
 		prt_bitflags(out, __bch2_data_types, BCH_MEMBER_DATA_ALLOWED(&m));
 	else
 		prt_printf(out, "(none)");
 	prt_newline(out);
 
-	prt_printf(out, "Has data:");
-	prt_tab(out);
+	prt_printf(out, "Has data:\t");
 	if (data_have)
 		prt_bitflags(out, __bch2_data_types, data_have);
 	else
 		prt_printf(out, "(none)");
 	prt_newline(out);
 
-	prt_str(out, "Durability:");
-	prt_tab(out);
-	prt_printf(out, "%llu", BCH_MEMBER_DURABILITY(&m) ? BCH_MEMBER_DURABILITY(&m) - 1 : 1);
+	prt_printf(out, "Btree allocated bitmap blocksize:\t");
+	prt_units_u64(out, 1ULL << m.btree_bitmap_shift);
 	prt_newline(out);
 
-	prt_printf(out, "Discard:");
-	prt_tab(out);
-	prt_printf(out, "%llu", BCH_MEMBER_DISCARD(&m));
+	prt_printf(out, "Btree allocated bitmap:\t");
+	bch2_prt_u64_base2_nbits(out, le64_to_cpu(m.btree_allocated_bitmap), 64);
 	prt_newline(out);
 
-	prt_printf(out, "Freespace initialized:");
-	prt_tab(out);
-	prt_printf(out, "%llu", BCH_MEMBER_FREESPACE_INITIALIZED(&m));
-	prt_newline(out);
+	prt_printf(out, "Durability:\t%llu\n", BCH_MEMBER_DURABILITY(&m) ? BCH_MEMBER_DURABILITY(&m) - 1 : 1);
+
+	prt_printf(out, "Discard:\t%llu\n", BCH_MEMBER_DISCARD(&m));
+	prt_printf(out, "Freespace initialized:\t%llu\n", BCH_MEMBER_FREESPACE_INITIALIZED(&m));
 
 	printbuf_indent_sub(out, 2);
 }
 
-static int bch2_sb_members_v1_validate(struct bch_sb *sb,
-				    struct bch_sb_field *f,
-				    struct printbuf *err)
+static int bch2_sb_members_v1_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_members_v1 *mi = field_to_type(f, members_v1);
 	unsigned i;
@@ -333,9 +310,8 @@ static void bch2_sb_members_v2_to_text(struct printbuf *out, struct bch_sb *sb,
 		member_to_text(out, members_v2_get(mi, i), gi, sb, i);
 }
 
-static int bch2_sb_members_v2_validate(struct bch_sb *sb,
-				       struct bch_sb_field *f,
-				       struct printbuf *err)
+static int bch2_sb_members_v2_validate(struct bch_sb *sb, struct bch_sb_field *f,
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	struct bch_sb_field_members_v2 *mi = field_to_type(f, members_v2);
 	size_t mi_bytes = (void *) __bch2_members_v2_get_mut(mi, sb->nr_devices) -
@@ -390,12 +366,8 @@ void bch2_dev_io_errors_to_text(struct printbuf *out, struct bch_dev *ca)
 	prt_newline(out);
 
 	printbuf_indent_add(out, 2);
-	for (unsigned i = 0; i < BCH_MEMBER_ERROR_NR; i++) {
-		prt_printf(out, "%s:", bch2_member_error_strs[i]);
-		prt_tab(out);
-		prt_u64(out, atomic64_read(&ca->errors[i]));
-		prt_newline(out);
-	}
+	for (unsigned i = 0; i < BCH_MEMBER_ERROR_NR; i++)
+		prt_printf(out, "%s:\t%llu\n", bch2_member_error_strs[i], atomic64_read(&ca->errors[i]));
 	printbuf_indent_sub(out, 2);
 
 	prt_str(out, "IO errors since ");
@@ -404,12 +376,9 @@ void bch2_dev_io_errors_to_text(struct printbuf *out, struct bch_dev *ca)
 	prt_newline(out);
 
 	printbuf_indent_add(out, 2);
-	for (unsigned i = 0; i < BCH_MEMBER_ERROR_NR; i++) {
-		prt_printf(out, "%s:", bch2_member_error_strs[i]);
-		prt_tab(out);
-		prt_u64(out, atomic64_read(&ca->errors[i]) - le64_to_cpu(m.errors_at_reset[i]));
-		prt_newline(out);
-	}
+	for (unsigned i = 0; i < BCH_MEMBER_ERROR_NR; i++)
+		prt_printf(out, "%s:\t%llu\n", bch2_member_error_strs[i],
+			   atomic64_read(&ca->errors[i]) - le64_to_cpu(m.errors_at_reset[i]));
 	printbuf_indent_sub(out, 2);
 }
 
@@ -437,11 +406,20 @@ void bch2_dev_errors_reset(struct bch_dev *ca)
 
 bool bch2_dev_btree_bitmap_marked(struct bch_fs *c, struct bkey_s_c k)
 {
-	bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr)
-		if (!bch2_dev_btree_bitmap_marked_sectors(bch_dev_bkey_exists(c, ptr->dev),
-							  ptr->offset, btree_sectors(c)))
-			return false;
-	return true;
+	bool ret = true;
+	rcu_read_lock();
+	bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr) {
+		struct bch_dev *ca = bch2_dev_rcu(c, ptr->dev);
+		if (!ca)
+			continue;
+
+		if (!bch2_dev_btree_bitmap_marked_sectors(ca, ptr->offset, btree_sectors(c))) {
+			ret = false;
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return ret;
 }
 
 static void __bch2_dev_btree_bitmap_mark(struct bch_sb_field_members_v2 *mi, unsigned dev,
@@ -463,6 +441,9 @@ static void __bch2_dev_btree_bitmap_mark(struct bch_sb_field_members_v2 *mi, uns
 		m->btree_bitmap_shift += resize;
 	}
 
+	BUG_ON(m->btree_bitmap_shift > 57);
+	BUG_ON(end > 64ULL << m->btree_bitmap_shift);
+
 	for (unsigned bit = start >> m->btree_bitmap_shift;
 	     (u64) bit << m->btree_bitmap_shift < end;
 	     bit++)
@@ -476,6 +457,10 @@ void bch2_dev_btree_bitmap_mark(struct bch_fs *c, struct bkey_s_c k)
 	lockdep_assert_held(&c->sb_lock);
 
 	struct bch_sb_field_members_v2 *mi = bch2_sb_field_get(c->disk_sb.sb, members_v2);
-	bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr)
+	bkey_for_each_ptr(bch2_bkey_ptrs_c(k), ptr) {
+		if (!bch2_member_exists(c->disk_sb.sb, ptr->dev))
+			continue;
+
 		__bch2_dev_btree_bitmap_mark(mi, ptr->dev, ptr->offset, btree_sectors(c));
+	}
 }
diff --git a/fs/bcachefs/sb-members.h b/fs/bcachefs/sb-members.h
index 5bf27d30ca29..dd93192ec065 100644
--- a/fs/bcachefs/sb-members.h
+++ b/fs/bcachefs/sb-members.h
@@ -29,19 +29,6 @@ static inline bool bch2_dev_is_readable(struct bch_dev *ca)
 		ca->mi.state != BCH_MEMBER_STATE_failed;
 }
 
-static inline bool bch2_dev_get_ioref(struct bch_dev *ca, int rw)
-{
-	if (!percpu_ref_tryget(&ca->io_ref))
-		return false;
-
-	if (ca->mi.state == BCH_MEMBER_STATE_rw ||
-	    (ca->mi.state == BCH_MEMBER_STATE_ro && rw == READ))
-		return true;
-
-	percpu_ref_put(&ca->io_ref);
-	return false;
-}
-
 static inline unsigned dev_mask_nr(const struct bch_devs_mask *devs)
 {
 	return bitmap_weight(devs->d, BCH_SB_MEMBERS_MAX);
@@ -105,14 +92,41 @@ static inline struct bch_dev *__bch2_next_dev(struct bch_fs *c, struct bch_dev *
 	for (struct bch_dev *_ca = NULL;				\
 	     (_ca = __bch2_next_dev((_c), _ca, (_mask)));)
 
-static inline struct bch_dev *bch2_get_next_dev(struct bch_fs *c, struct bch_dev *ca)
+static inline void bch2_dev_get(struct bch_dev *ca)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+	BUG_ON(atomic_long_inc_return(&ca->ref) <= 1L);
+#else
+	percpu_ref_get(&ca->ref);
+#endif
+}
+
+static inline void __bch2_dev_put(struct bch_dev *ca)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+	long r = atomic_long_dec_return(&ca->ref);
+	if (r < (long) !ca->dying)
+		panic("bch_dev->ref underflow, last put: %pS\n", (void *) ca->last_put);
+	ca->last_put = _THIS_IP_;
+	if (!r)
+		complete(&ca->ref_completion);
+#else
+	percpu_ref_put(&ca->ref);
+#endif
+}
+
+static inline void bch2_dev_put(struct bch_dev *ca)
 {
-	rcu_read_lock();
 	if (ca)
-		percpu_ref_put(&ca->ref);
+		__bch2_dev_put(ca);
+}
 
+static inline struct bch_dev *bch2_get_next_dev(struct bch_fs *c, struct bch_dev *ca)
+{
+	rcu_read_lock();
+	bch2_dev_put(ca);
 	if ((ca = __bch2_next_dev(c, ca, NULL)))
-		percpu_ref_get(&ca->ref);
+		bch2_dev_get(ca);
 	rcu_read_unlock();
 
 	return ca;
@@ -158,26 +172,113 @@ static inline struct bch_dev *bch2_get_next_online_dev(struct bch_fs *c,
 #define for_each_readable_member(c, ca)				\
 	__for_each_online_member(c, ca,	BIT( BCH_MEMBER_STATE_rw)|BIT(BCH_MEMBER_STATE_ro))
 
-/*
- * If a key exists that references a device, the device won't be going away and
- * we can omit rcu_read_lock():
- */
-static inline struct bch_dev *bch_dev_bkey_exists(const struct bch_fs *c, unsigned idx)
+static inline bool bch2_dev_exists(const struct bch_fs *c, unsigned dev)
 {
-	EBUG_ON(idx >= c->sb.nr_devices || !c->devs[idx]);
+	return dev < c->sb.nr_devices && c->devs[dev];
+}
 
-	return rcu_dereference_check(c->devs[idx], 1);
+static inline bool bucket_valid(const struct bch_dev *ca, u64 b)
+{
+	return b - ca->mi.first_bucket < ca->mi.nbuckets_minus_first;
 }
 
-static inline struct bch_dev *bch_dev_locked(struct bch_fs *c, unsigned idx)
+static inline struct bch_dev *bch2_dev_have_ref(const struct bch_fs *c, unsigned dev)
 {
-	EBUG_ON(idx >= c->sb.nr_devices || !c->devs[idx]);
+	EBUG_ON(!bch2_dev_exists(c, dev));
+
+	return rcu_dereference_check(c->devs[dev], 1);
+}
 
-	return rcu_dereference_protected(c->devs[idx],
+static inline struct bch_dev *bch2_dev_locked(struct bch_fs *c, unsigned dev)
+{
+	EBUG_ON(!bch2_dev_exists(c, dev));
+
+	return rcu_dereference_protected(c->devs[dev],
 					 lockdep_is_held(&c->sb_lock) ||
 					 lockdep_is_held(&c->state_lock));
 }
 
+static inline struct bch_dev *bch2_dev_rcu(struct bch_fs *c, unsigned dev)
+{
+	return c && dev < c->sb.nr_devices
+		? rcu_dereference(c->devs[dev])
+		: NULL;
+}
+
+static inline struct bch_dev *bch2_dev_tryget_noerror(struct bch_fs *c, unsigned dev)
+{
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, dev);
+	if (ca)
+		bch2_dev_get(ca);
+	rcu_read_unlock();
+	return ca;
+}
+
+void bch2_dev_missing(struct bch_fs *, unsigned);
+
+static inline struct bch_dev *bch2_dev_tryget(struct bch_fs *c, unsigned dev)
+{
+	struct bch_dev *ca = bch2_dev_tryget_noerror(c, dev);
+	if (!ca)
+		bch2_dev_missing(c, dev);
+	return ca;
+}
+
+static inline struct bch_dev *bch2_dev_bucket_tryget_noerror(struct bch_fs *c, struct bpos bucket)
+{
+	struct bch_dev *ca = bch2_dev_tryget_noerror(c, bucket.inode);
+	if (ca && !bucket_valid(ca, bucket.offset)) {
+		bch2_dev_put(ca);
+		ca = NULL;
+	}
+	return ca;
+}
+
+void bch2_dev_bucket_missing(struct bch_fs *, struct bpos);
+
+static inline struct bch_dev *bch2_dev_bucket_tryget(struct bch_fs *c, struct bpos bucket)
+{
+	struct bch_dev *ca = bch2_dev_bucket_tryget_noerror(c, bucket);
+	if (!ca)
+		bch2_dev_bucket_missing(c, bucket);
+	return ca;
+}
+
+static inline struct bch_dev *bch2_dev_iterate_noerror(struct bch_fs *c, struct bch_dev *ca, unsigned dev_idx)
+{
+	if (ca && ca->dev_idx == dev_idx)
+		return ca;
+	bch2_dev_put(ca);
+	return bch2_dev_tryget_noerror(c, dev_idx);
+}
+
+static inline struct bch_dev *bch2_dev_iterate(struct bch_fs *c, struct bch_dev *ca, unsigned dev_idx)
+{
+	if (ca && ca->dev_idx == dev_idx)
+		return ca;
+	bch2_dev_put(ca);
+	return bch2_dev_tryget(c, dev_idx);
+}
+
+static inline struct bch_dev *bch2_dev_get_ioref(struct bch_fs *c, unsigned dev, int rw)
+{
+	rcu_read_lock();
+	struct bch_dev *ca = bch2_dev_rcu(c, dev);
+	if (ca && !percpu_ref_tryget(&ca->io_ref))
+		ca = NULL;
+	rcu_read_unlock();
+
+	if (ca &&
+	    (ca->mi.state == BCH_MEMBER_STATE_rw ||
+	    (ca->mi.state == BCH_MEMBER_STATE_ro && rw == READ)))
+		return ca;
+
+	if (ca)
+		percpu_ref_put(&ca->io_ref);
+	return NULL;
+}
+
 /* XXX kill, move to struct bch_fs */
 static inline struct bch_devs_mask bch2_online_devs(struct bch_fs *c)
 {
@@ -192,16 +293,16 @@ static inline struct bch_devs_mask bch2_online_devs(struct bch_fs *c)
 extern const struct bch_sb_field_ops bch_sb_field_ops_members_v1;
 extern const struct bch_sb_field_ops bch_sb_field_ops_members_v2;
 
-static inline bool bch2_member_exists(struct bch_member *m)
+static inline bool bch2_member_alive(struct bch_member *m)
 {
 	return !bch2_is_zero(&m->uuid, sizeof(m->uuid));
 }
 
-static inline bool bch2_dev_exists(struct bch_sb *sb, unsigned dev)
+static inline bool bch2_member_exists(struct bch_sb *sb, unsigned dev)
 {
 	if (dev < sb->nr_devices) {
 		struct bch_member m = bch2_sb_member_get(sb, dev);
-		return bch2_member_exists(&m);
+		return bch2_member_alive(&m);
 	}
 	return false;
 }
@@ -210,6 +311,8 @@ static inline struct bch_member_cpu bch2_mi_to_cpu(struct bch_member *mi)
 {
 	return (struct bch_member_cpu) {
 		.nbuckets	= le64_to_cpu(mi->nbuckets),
+		.nbuckets_minus_first = le64_to_cpu(mi->nbuckets) -
+			le16_to_cpu(mi->first_bucket),
 		.first_bucket	= le16_to_cpu(mi->first_bucket),
 		.bucket_size	= le16_to_cpu(mi->bucket_size),
 		.group		= BCH_MEMBER_GROUP(mi),
@@ -220,7 +323,7 @@ static inline struct bch_member_cpu bch2_mi_to_cpu(struct bch_member *mi)
 			? BCH_MEMBER_DURABILITY(mi) - 1
 			: 1,
 		.freespace_initialized = BCH_MEMBER_FREESPACE_INITIALIZED(mi),
-		.valid		= bch2_member_exists(mi),
+		.valid		= bch2_member_alive(mi),
 		.btree_bitmap_shift	= mi->btree_bitmap_shift,
 		.btree_allocated_bitmap = le64_to_cpu(mi->btree_allocated_bitmap),
 	};
diff --git a/fs/bcachefs/sb-members_types.h b/fs/bcachefs/sb-members_types.h
new file mode 100644
index 000000000000..c0eda888fe39
--- /dev/null
+++ b/fs/bcachefs/sb-members_types.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_SB_MEMBERS_TYPES_H
+#define _BCACHEFS_SB_MEMBERS_TYPES_H
+
+struct bch_member_cpu {
+	u64			nbuckets;	/* device size */
+	u64			nbuckets_minus_first;
+	u16			first_bucket;   /* index of first bucket used */
+	u16			bucket_size;	/* sectors */
+	u16			group;
+	u8			state;
+	u8			discard;
+	u8			data_allowed;
+	u8			durability;
+	u8			freespace_initialized;
+	u8			valid;
+	u8			btree_bitmap_shift;
+	u64			btree_allocated_bitmap;
+};
+
+#endif /* _BCACHEFS_SB_MEMBERS_H */
diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c
index 544322d5c251..629900a5e641 100644
--- a/fs/bcachefs/snapshot.c
+++ b/fs/bcachefs/snapshot.c
@@ -32,7 +32,7 @@ void bch2_snapshot_tree_to_text(struct printbuf *out, struct bch_fs *c,
 }
 
 int bch2_snapshot_tree_invalid(struct bch_fs *c, struct bkey_s_c k,
-			       enum bkey_invalid_flags flags,
+			       enum bch_validate_flags flags,
 			       struct printbuf *err)
 {
 	int ret = 0;
@@ -49,7 +49,7 @@ int bch2_snapshot_tree_lookup(struct btree_trans *trans, u32 id,
 			      struct bch_snapshot_tree *s)
 {
 	int ret = bch2_bkey_get_val_typed(trans, BTREE_ID_snapshot_trees, POS(0, id),
-					  BTREE_ITER_WITH_UPDATES, snapshot_tree, s);
+					  BTREE_ITER_with_updates, snapshot_tree, s);
 
 	if (bch2_err_matches(ret, ENOENT))
 		ret = -BCH_ERR_ENOENT_snapshot_tree;
@@ -223,7 +223,7 @@ void bch2_snapshot_to_text(struct printbuf *out, struct bch_fs *c,
 }
 
 int bch2_snapshot_invalid(struct bch_fs *c, struct bkey_s_c k,
-			  enum bkey_invalid_flags flags,
+			  enum bch_validate_flags flags,
 			  struct printbuf *err)
 {
 	struct bkey_s_c_snapshot s;
@@ -298,7 +298,7 @@ static void set_is_ancestor_bitmap(struct bch_fs *c, u32 id)
 static int __bch2_mark_snapshot(struct btree_trans *trans,
 		       enum btree_id btree, unsigned level,
 		       struct bkey_s_c old, struct bkey_s_c new,
-		       unsigned flags)
+		       enum btree_iter_update_trigger_flags flags)
 {
 	struct bch_fs *c = trans->c;
 	struct snapshot_t *t;
@@ -352,7 +352,7 @@ err:
 int bch2_mark_snapshot(struct btree_trans *trans,
 		       enum btree_id btree, unsigned level,
 		       struct bkey_s_c old, struct bkey_s new,
-		       unsigned flags)
+		       enum btree_iter_update_trigger_flags flags)
 {
 	return __bch2_mark_snapshot(trans, btree, level, old, new.s_c, flags);
 }
@@ -361,7 +361,7 @@ int bch2_snapshot_lookup(struct btree_trans *trans, u32 id,
 			 struct bch_snapshot *s)
 {
 	return bch2_bkey_get_val_typed(trans, BTREE_ID_snapshots, POS(0, id),
-				       BTREE_ITER_WITH_UPDATES, snapshot, s);
+				       BTREE_ITER_with_updates, snapshot, s);
 }
 
 static int bch2_snapshot_live(struct btree_trans *trans, u32 id)
@@ -618,7 +618,7 @@ int bch2_check_snapshot_trees(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
 			BTREE_ID_snapshot_trees, POS_MIN,
-			BTREE_ITER_PREFETCH, k,
+			BTREE_ITER_prefetch, k,
 			NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 		check_snapshot_tree(trans, &iter, k)));
 	bch_err_fn(c, ret);
@@ -695,7 +695,7 @@ static int snapshot_tree_ptr_repair(struct btree_trans *trans,
 
 	root = bch2_bkey_get_iter_typed(trans, &root_iter,
 			       BTREE_ID_snapshots, POS(0, root_id),
-			       BTREE_ITER_WITH_UPDATES, snapshot);
+			       BTREE_ITER_with_updates, snapshot);
 	ret = bkey_err(root);
 	if (ret)
 		goto err;
@@ -886,7 +886,7 @@ int bch2_check_snapshots(struct bch_fs *c)
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_reverse_commit(trans, iter,
 				BTREE_ID_snapshots, POS_MAX,
-				BTREE_ITER_PREFETCH, k,
+				BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			check_snapshot(trans, &iter, k)));
 	bch_err_fn(c, ret);
@@ -900,7 +900,8 @@ static int check_snapshot_exists(struct btree_trans *trans, u32 id)
 	if (bch2_snapshot_equiv(c, id))
 		return 0;
 
-	u32 tree_id;
+	/* 0 is an invalid tree ID */
+	u32 tree_id = 0;
 	int ret = bch2_snapshot_tree_create(trans, id, 0, &tree_id);
 	if (ret)
 		return ret;
@@ -1001,7 +1002,7 @@ int bch2_reconstruct_snapshots(struct bch_fs *c)
 			r.btree = btree;
 
 			ret = for_each_btree_key(trans, iter, btree, POS_MIN,
-					BTREE_ITER_ALL_SNAPSHOTS|BTREE_ITER_PREFETCH, k, ({
+					BTREE_ITER_all_snapshots|BTREE_ITER_prefetch, k, ({
 				get_snapshot_trees(c, &r, k.k->p);
 			}));
 			if (ret)
@@ -1018,7 +1019,7 @@ int bch2_reconstruct_snapshots(struct bch_fs *c)
 		darray_for_each(*t, id) {
 			if (fsck_err_on(!bch2_snapshot_equiv(c, *id),
 					c, snapshot_node_missing,
-					"snapshot node %u from tree %s missing", *id, buf.buf)) {
+					"snapshot node %u from tree %s missing, recreate?", *id, buf.buf)) {
 				if (t->nr > 1) {
 					bch_err(c, "cannot reconstruct snapshot trees with multiple nodes");
 					ret = -BCH_ERR_fsck_repair_unimplemented;
@@ -1090,7 +1091,7 @@ static int bch2_snapshot_node_delete(struct btree_trans *trans, u32 id)
 	int ret = 0;
 
 	s = bch2_bkey_get_iter_typed(trans, &iter, BTREE_ID_snapshots, POS(0, id),
-				     BTREE_ITER_INTENT, snapshot);
+				     BTREE_ITER_intent, snapshot);
 	ret = bkey_err(s);
 	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
 				"missing snapshot %u", id);
@@ -1199,7 +1200,7 @@ static int create_snapids(struct btree_trans *trans, u32 parent, u32 tree,
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots,
-			     POS_MIN, BTREE_ITER_INTENT);
+			     POS_MIN, BTREE_ITER_intent);
 	k = bch2_btree_iter_peek(&iter);
 	ret = bkey_err(k);
 	if (ret)
@@ -1367,7 +1368,7 @@ static int snapshot_delete_key(struct btree_trans *trans,
 	if (snapshot_list_has_id(deleted, k.k->p.snapshot) ||
 	    snapshot_list_has_id(equiv_seen, equiv)) {
 		return bch2_btree_delete_at(trans, iter,
-					    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+					    BTREE_UPDATE_internal_snapshot_node);
 	} else {
 		return snapshot_list_add(c, equiv_seen, equiv);
 	}
@@ -1404,15 +1405,15 @@ static int move_key_to_correct_snapshot(struct btree_trans *trans,
 		new->k.p.snapshot = equiv;
 
 		bch2_trans_iter_init(trans, &new_iter, iter->btree_id, new->k.p,
-				     BTREE_ITER_ALL_SNAPSHOTS|
-				     BTREE_ITER_CACHED|
-				     BTREE_ITER_INTENT);
+				     BTREE_ITER_all_snapshots|
+				     BTREE_ITER_cached|
+				     BTREE_ITER_intent);
 
 		ret =   bch2_btree_iter_traverse(&new_iter) ?:
 			bch2_trans_update(trans, &new_iter, new,
-					BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+					BTREE_UPDATE_internal_snapshot_node) ?:
 			bch2_btree_delete_at(trans, iter,
-					BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+					BTREE_UPDATE_internal_snapshot_node);
 		bch2_trans_iter_exit(trans, &new_iter);
 		if (ret)
 			return ret;
@@ -1603,12 +1604,12 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 
 		ret = for_each_btree_key_commit(trans, iter,
 				id, POS_MIN,
-				BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 				&res, NULL, BCH_TRANS_COMMIT_no_enospc,
 			snapshot_delete_key(trans, &iter, k, &deleted, &equiv_seen, &last_pos)) ?:
 		      for_each_btree_key_commit(trans, iter,
 				id, POS_MIN,
-				BTREE_ITER_PREFETCH|BTREE_ITER_ALL_SNAPSHOTS, k,
+				BTREE_ITER_prefetch|BTREE_ITER_all_snapshots, k,
 				&res, NULL, BCH_TRANS_COMMIT_no_enospc,
 			move_key_to_correct_snapshot(trans, &iter, k));
 
@@ -1643,7 +1644,7 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 	 * nodes some depth fields will be off:
 	 */
 	ret = for_each_btree_key_commit(trans, iter, BTREE_ID_snapshots, POS_MIN,
-				  BTREE_ITER_INTENT, k,
+				  BTREE_ITER_intent, k,
 				  NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 		bch2_fix_child_of_deleted_snapshot(trans, &iter, k, &deleted_interior));
 	if (ret)
@@ -1699,8 +1700,8 @@ int __bch2_key_has_snapshot_overwrites(struct btree_trans *trans,
 	int ret;
 
 	bch2_trans_iter_init(trans, &iter, id, pos,
-			     BTREE_ITER_NOT_EXTENTS|
-			     BTREE_ITER_ALL_SNAPSHOTS);
+			     BTREE_ITER_not_extents|
+			     BTREE_ITER_all_snapshots);
 	while (1) {
 		k = bch2_btree_iter_prev(&iter);
 		ret = bkey_err(k);
@@ -1752,7 +1753,7 @@ static int bch2_propagate_key_to_snapshot_leaf(struct btree_trans *trans,
 
 	pos.snapshot = leaf_id;
 
-	bch2_trans_iter_init(trans, &iter, btree, pos, BTREE_ITER_INTENT);
+	bch2_trans_iter_init(trans, &iter, btree, pos, BTREE_ITER_intent);
 	k = bch2_btree_iter_peek_slot(&iter);
 	ret = bkey_err(k);
 	if (ret)
diff --git a/fs/bcachefs/snapshot.h b/fs/bcachefs/snapshot.h
index b7d2fed37c4f..bd5d74269d15 100644
--- a/fs/bcachefs/snapshot.h
+++ b/fs/bcachefs/snapshot.h
@@ -2,11 +2,11 @@
 #ifndef _BCACHEFS_SNAPSHOT_H
 #define _BCACHEFS_SNAPSHOT_H
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 
 void bch2_snapshot_tree_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 int bch2_snapshot_tree_invalid(struct bch_fs *, struct bkey_s_c,
-			       enum bkey_invalid_flags, struct printbuf *);
+			       enum bch_validate_flags, struct printbuf *);
 
 #define bch2_bkey_ops_snapshot_tree ((struct bkey_ops) {	\
 	.key_invalid	= bch2_snapshot_tree_invalid,		\
@@ -20,9 +20,10 @@ int bch2_snapshot_tree_lookup(struct btree_trans *, u32, struct bch_snapshot_tre
 
 void bch2_snapshot_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 int bch2_snapshot_invalid(struct bch_fs *, struct bkey_s_c,
-			  enum bkey_invalid_flags, struct printbuf *);
+			  enum bch_validate_flags, struct printbuf *);
 int bch2_mark_snapshot(struct btree_trans *, enum btree_id, unsigned,
-		       struct bkey_s_c, struct bkey_s, unsigned);
+		       struct bkey_s_c, struct bkey_s,
+		       enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_snapshot ((struct bkey_ops) {		\
 	.key_invalid	= bch2_snapshot_invalid,		\
@@ -77,7 +78,7 @@ static inline u32 __bch2_snapshot_parent(struct bch_fs *c, u32 id)
 		return 0;
 
 	u32 parent = s->parent;
-	if (IS_ENABLED(CONFIG_BCACHEFS_DEBU) &&
+	if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
 	    parent &&
 	    s->depth != snapshot_t(c, parent)->depth + 1)
 		panic("id %u depth=%u parent %u depth=%u\n",
@@ -135,11 +136,6 @@ static inline u32 bch2_snapshot_equiv(struct bch_fs *c, u32 id)
 	return id;
 }
 
-static inline bool bch2_snapshot_is_equiv(struct bch_fs *c, u32 id)
-{
-	return id == bch2_snapshot_equiv(c, id);
-}
-
 static inline int bch2_snapshot_is_internal_node(struct bch_fs *c, u32 id)
 {
 	rcu_read_lock();
diff --git a/fs/bcachefs/str_hash.h b/fs/bcachefs/str_hash.h
index 3976f80721bf..cbad9b27874f 100644
--- a/fs/bcachefs/str_hash.h
+++ b/fs/bcachefs/str_hash.h
@@ -15,16 +15,6 @@
 #include <crypto/hash.h>
 #include <crypto/sha2.h>
 
-typedef unsigned __bitwise bch_str_hash_flags_t;
-
-enum bch_str_hash_flags {
-	__BCH_HASH_SET_MUST_CREATE,
-	__BCH_HASH_SET_MUST_REPLACE,
-};
-
-#define BCH_HASH_SET_MUST_CREATE	(__force bch_str_hash_flags_t) BIT(__BCH_HASH_SET_MUST_CREATE)
-#define BCH_HASH_SET_MUST_REPLACE	(__force bch_str_hash_flags_t) BIT(__BCH_HASH_SET_MUST_REPLACE)
-
 static inline enum bch_str_hash_type
 bch2_str_hash_opt_to_type(struct bch_fs *c, enum bch_str_hash_opts opt)
 {
@@ -159,13 +149,14 @@ static inline bool is_visible_key(struct bch_hash_desc desc, subvol_inum inum, s
 		 desc.is_visible(inum, k));
 }
 
-static __always_inline int
+static __always_inline struct bkey_s_c
 bch2_hash_lookup_in_snapshot(struct btree_trans *trans,
 		 struct btree_iter *iter,
 		 const struct bch_hash_desc desc,
 		 const struct bch_hash_info *info,
 		 subvol_inum inum, const void *key,
-		 unsigned flags, u32 snapshot)
+		 enum btree_iter_update_trigger_flags flags,
+		 u32 snapshot)
 {
 	struct bkey_s_c k;
 	int ret;
@@ -173,10 +164,10 @@ bch2_hash_lookup_in_snapshot(struct btree_trans *trans,
 	for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,
 			   SPOS(inum.inum, desc.hash_key(info, key), snapshot),
 			   POS(inum.inum, U64_MAX),
-			   BTREE_ITER_SLOTS|flags, k, ret) {
+			   BTREE_ITER_slots|flags, k, ret) {
 		if (is_visible_key(desc, inum, k)) {
 			if (!desc.cmp_key(k, key))
-				return 0;
+				return k;
 		} else if (k.k->type == KEY_TYPE_hash_whiteout) {
 			;
 		} else {
@@ -186,20 +177,23 @@ bch2_hash_lookup_in_snapshot(struct btree_trans *trans,
 	}
 	bch2_trans_iter_exit(trans, iter);
 
-	return ret ?: -BCH_ERR_ENOENT_str_hash_lookup;
+	return bkey_s_c_err(ret ?: -BCH_ERR_ENOENT_str_hash_lookup);
 }
 
-static __always_inline int
+static __always_inline struct bkey_s_c
 bch2_hash_lookup(struct btree_trans *trans,
 		 struct btree_iter *iter,
 		 const struct bch_hash_desc desc,
 		 const struct bch_hash_info *info,
 		 subvol_inum inum, const void *key,
-		 unsigned flags)
+		 enum btree_iter_update_trigger_flags flags)
 {
 	u32 snapshot;
-	return  bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot) ?:
-		bch2_hash_lookup_in_snapshot(trans, iter, desc, info, inum, key, flags, snapshot);
+	int ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
+	if (ret)
+		return bkey_s_c_err(ret);
+
+	return bch2_hash_lookup_in_snapshot(trans, iter, desc, info, inum, key, flags, snapshot);
 }
 
 static __always_inline int
@@ -220,7 +214,7 @@ bch2_hash_hole(struct btree_trans *trans,
 	for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,
 			   SPOS(inum.inum, desc.hash_key(info, key), snapshot),
 			   POS(inum.inum, U64_MAX),
-			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret)
+			   BTREE_ITER_slots|BTREE_ITER_intent, k, ret)
 		if (!is_visible_key(desc, inum, k))
 			return 0;
 	bch2_trans_iter_exit(trans, iter);
@@ -242,7 +236,7 @@ int bch2_hash_needs_whiteout(struct btree_trans *trans,
 
 	bch2_btree_iter_advance(&iter);
 
-	for_each_btree_key_continue_norestart(iter, BTREE_ITER_SLOTS, k, ret) {
+	for_each_btree_key_continue_norestart(iter, BTREE_ITER_slots, k, ret) {
 		if (k.k->type != desc.key_type &&
 		    k.k->type != KEY_TYPE_hash_whiteout)
 			break;
@@ -264,8 +258,7 @@ int bch2_hash_set_in_snapshot(struct btree_trans *trans,
 			   const struct bch_hash_info *info,
 			   subvol_inum inum, u32 snapshot,
 			   struct bkey_i *insert,
-			   bch_str_hash_flags_t str_hash_flags,
-			   int update_flags)
+			   enum btree_iter_update_trigger_flags flags)
 {
 	struct btree_iter iter, slot = { NULL };
 	struct bkey_s_c k;
@@ -277,7 +270,7 @@ int bch2_hash_set_in_snapshot(struct btree_trans *trans,
 				desc.hash_bkey(info, bkey_i_to_s_c(insert)),
 				snapshot),
 			   POS(insert->k.p.inode, U64_MAX),
-			   BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
+			   BTREE_ITER_slots|BTREE_ITER_intent, k, ret) {
 		if (is_visible_key(desc, inum, k)) {
 			if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
 				goto found;
@@ -286,8 +279,7 @@ int bch2_hash_set_in_snapshot(struct btree_trans *trans,
 			continue;
 		}
 
-		if (!slot.path &&
-		    !(str_hash_flags & BCH_HASH_SET_MUST_REPLACE))
+		if (!slot.path && !(flags & STR_HASH_must_replace))
 			bch2_trans_copy_iter(&slot, &iter);
 
 		if (k.k->type != KEY_TYPE_hash_whiteout)
@@ -305,16 +297,16 @@ found:
 	found = true;
 not_found:
 
-	if (!found && (str_hash_flags & BCH_HASH_SET_MUST_REPLACE)) {
+	if (!found && (flags & STR_HASH_must_replace)) {
 		ret = -BCH_ERR_ENOENT_str_hash_set_must_replace;
-	} else if (found && (str_hash_flags & BCH_HASH_SET_MUST_CREATE)) {
+	} else if (found && (flags & STR_HASH_must_create)) {
 		ret = -EEXIST;
 	} else {
 		if (!found && slot.path)
 			swap(iter, slot);
 
 		insert->k.p = iter.pos;
-		ret = bch2_trans_update(trans, &iter, insert, update_flags);
+		ret = bch2_trans_update(trans, &iter, insert, flags);
 	}
 
 	goto out;
@@ -326,14 +318,14 @@ int bch2_hash_set(struct btree_trans *trans,
 		  const struct bch_hash_info *info,
 		  subvol_inum inum,
 		  struct bkey_i *insert,
-		  bch_str_hash_flags_t str_hash_flags)
+		  enum btree_iter_update_trigger_flags flags)
 {
 	insert->k.p.inode = inum.inum;
 
 	u32 snapshot;
 	return  bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot) ?:
 		bch2_hash_set_in_snapshot(trans, desc, info, inum,
-					  snapshot, insert, str_hash_flags, 0);
+					  snapshot, insert, flags);
 }
 
 static __always_inline
@@ -341,7 +333,7 @@ int bch2_hash_delete_at(struct btree_trans *trans,
 			const struct bch_hash_desc desc,
 			const struct bch_hash_info *info,
 			struct btree_iter *iter,
-			unsigned update_flags)
+			enum btree_iter_update_trigger_flags flags)
 {
 	struct bkey_i *delete;
 	int ret;
@@ -359,7 +351,7 @@ int bch2_hash_delete_at(struct btree_trans *trans,
 	delete->k.p = iter->pos;
 	delete->k.type = ret ? KEY_TYPE_hash_whiteout : KEY_TYPE_deleted;
 
-	return bch2_trans_update(trans, iter, delete, update_flags);
+	return bch2_trans_update(trans, iter, delete, flags);
 }
 
 static __always_inline
@@ -369,14 +361,10 @@ int bch2_hash_delete(struct btree_trans *trans,
 		     subvol_inum inum, const void *key)
 {
 	struct btree_iter iter;
-	int ret;
-
-	ret = bch2_hash_lookup(trans, &iter, desc, info, inum, key,
-				BTREE_ITER_INTENT);
-	if (ret)
-		return ret;
-
-	ret = bch2_hash_delete_at(trans, desc, info, &iter, 0);
+	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, desc, info, inum, key,
+					     BTREE_ITER_intent);
+	int ret = bkey_err(k) ?:
+		  bch2_hash_delete_at(trans, desc, info, &iter, 0);
 	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }
diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c
index 88a79c823276..132213761ef6 100644
--- a/fs/bcachefs/subvolume.c
+++ b/fs/bcachefs/subvolume.c
@@ -162,7 +162,7 @@ int bch2_check_subvols(struct bch_fs *c)
 {
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
-				BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k,
+				BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			check_subvol(trans, &iter, k)));
 	bch_err_fn(c, ret);
@@ -198,7 +198,7 @@ int bch2_check_subvol_children(struct bch_fs *c)
 {
 	int ret = bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter,
-				BTREE_ID_subvolume_children, POS_MIN, BTREE_ITER_PREFETCH, k,
+				BTREE_ID_subvolume_children, POS_MIN, BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			check_subvol_child(trans, &iter, k)));
 	bch_err_fn(c, ret);
@@ -208,7 +208,7 @@ int bch2_check_subvol_children(struct bch_fs *c)
 /* Subvolumes: */
 
 int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k,
-			   enum bkey_invalid_flags flags, struct printbuf *err)
+			   enum bch_validate_flags flags, struct printbuf *err)
 {
 	int ret = 0;
 
@@ -245,9 +245,9 @@ static int subvolume_children_mod(struct btree_trans *trans, struct bpos pos, bo
 int bch2_subvolume_trigger(struct btree_trans *trans,
 			   enum btree_id btree_id, unsigned level,
 			   struct bkey_s_c old, struct bkey_s new,
-			   unsigned flags)
+			   enum btree_iter_update_trigger_flags flags)
 {
-	if (flags & BTREE_TRIGGER_TRANSACTIONAL) {
+	if (flags & BTREE_TRIGGER_transactional) {
 		struct bpos children_pos_old = subvolume_children_pos(old);
 		struct bpos children_pos_new = subvolume_children_pos(new.s_c);
 
@@ -333,7 +333,7 @@ int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvolid,
 
 	subvol = bch2_bkey_get_iter_typed(trans, &iter,
 					  BTREE_ID_subvolumes, POS(0, subvolid),
-					  BTREE_ITER_CACHED|BTREE_ITER_WITH_UPDATES,
+					  BTREE_ITER_cached|BTREE_ITER_with_updates,
 					  subvolume);
 	ret = bkey_err(subvol);
 	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
@@ -383,9 +383,9 @@ static int bch2_subvolumes_reparent(struct btree_trans *trans, u32 subvolid_to_d
 
 	return lockrestart_do(trans,
 			bch2_subvolume_get(trans, subvolid_to_delete, true,
-				   BTREE_ITER_CACHED, &s)) ?:
+				   BTREE_ITER_cached, &s)) ?:
 		for_each_btree_key_commit(trans, iter,
-				BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_PREFETCH, k,
+				BTREE_ID_subvolumes, POS_MIN, BTREE_ITER_prefetch, k,
 				NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
 			bch2_subvolume_reparent(trans, &iter, k,
 					subvolid_to_delete, le32_to_cpu(s.creation_parent)));
@@ -404,7 +404,7 @@ static int __bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
 
 	subvol = bch2_bkey_get_iter_typed(trans, &iter,
 				BTREE_ID_subvolumes, POS(0, subvolid),
-				BTREE_ITER_CACHED|BTREE_ITER_INTENT,
+				BTREE_ITER_cached|BTREE_ITER_intent,
 				subvolume);
 	ret = bkey_err(subvol);
 	bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
@@ -505,7 +505,7 @@ int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
 
 	n = bch2_bkey_get_mut_typed(trans, &iter,
 			BTREE_ID_subvolumes, POS(0, subvolid),
-			BTREE_ITER_CACHED, subvolume);
+			BTREE_ITER_cached, subvolume);
 	ret = PTR_ERR_OR_ZERO(n);
 	if (unlikely(ret)) {
 		bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), trans->c,
@@ -547,7 +547,7 @@ int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
 
 		src_subvol = bch2_bkey_get_mut_typed(trans, &src_iter,
 				BTREE_ID_subvolumes, POS(0, src_subvolid),
-				BTREE_ITER_CACHED, subvolume);
+				BTREE_ITER_cached, subvolume);
 		ret = PTR_ERR_OR_ZERO(src_subvol);
 		if (unlikely(ret)) {
 			bch2_fs_inconsistent_on(bch2_err_matches(ret, ENOENT), c,
diff --git a/fs/bcachefs/subvolume.h b/fs/bcachefs/subvolume.h
index d2015d549bd2..afa5e871efb2 100644
--- a/fs/bcachefs/subvolume.h
+++ b/fs/bcachefs/subvolume.h
@@ -5,16 +5,17 @@
 #include "darray.h"
 #include "subvolume_types.h"
 
-enum bkey_invalid_flags;
+enum bch_validate_flags;
 
 int bch2_check_subvols(struct bch_fs *);
 int bch2_check_subvol_children(struct bch_fs *);
 
 int bch2_subvolume_invalid(struct bch_fs *, struct bkey_s_c,
-			   enum bkey_invalid_flags, struct printbuf *);
+			   enum bch_validate_flags, struct printbuf *);
 void bch2_subvolume_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 int bch2_subvolume_trigger(struct btree_trans *, enum btree_id, unsigned,
-			   struct bkey_s_c, struct bkey_s, unsigned);
+			   struct bkey_s_c, struct bkey_s,
+			   enum btree_iter_update_trigger_flags);
 
 #define bch2_bkey_ops_subvolume ((struct bkey_ops) {		\
 	.key_invalid	= bch2_subvolume_invalid,		\
diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c
index bfdb15e7d778..f1bee6c5222d 100644
--- a/fs/bcachefs/super-io.c
+++ b/fs/bcachefs/super-io.c
@@ -76,7 +76,7 @@ const char * const bch2_sb_fields[] = {
 };
 
 static int bch2_sb_field_validate(struct bch_sb *, struct bch_sb_field *,
-				  struct printbuf *);
+				  enum bch_validate_flags, struct printbuf *);
 
 struct bch_sb_field *bch2_sb_field_get_id(struct bch_sb *sb,
 				      enum bch_sb_field_type type)
@@ -344,8 +344,8 @@ static int bch2_sb_compatible(struct bch_sb *sb, struct printbuf *out)
 	return 0;
 }
 
-static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
-			    int rw)
+static int bch2_sb_validate(struct bch_sb_handle *disk_sb,
+			    enum bch_validate_flags flags, struct printbuf *out)
 {
 	struct bch_sb *sb = disk_sb->sb;
 	struct bch_sb_field_members_v1 *mi;
@@ -401,7 +401,7 @@ static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
 		return -BCH_ERR_invalid_sb_time_precision;
 	}
 
-	if (rw == READ) {
+	if (!flags) {
 		/*
 		 * Been seeing a bug where these are getting inexplicably
 		 * zeroed, so we're now validating them, but we have to be
@@ -457,7 +457,7 @@ static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
 		return -BCH_ERR_invalid_sb_members_missing;
 	}
 
-	ret = bch2_sb_field_validate(sb, &mi->field, out);
+	ret = bch2_sb_field_validate(sb, &mi->field, flags, out);
 	if (ret)
 		return ret;
 
@@ -465,12 +465,12 @@ static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
 		if (le32_to_cpu(f->type) == BCH_SB_FIELD_members_v1)
 			continue;
 
-		ret = bch2_sb_field_validate(sb, f, out);
+		ret = bch2_sb_field_validate(sb, f, flags, out);
 		if (ret)
 			return ret;
 	}
 
-	if (rw == WRITE &&
+	if ((flags & BCH_VALIDATE_write) &&
 	    bch2_sb_member_get(sb, sb->dev_idx).seq != sb->seq) {
 		prt_printf(out, "Invalid superblock: member seq %llu != sb seq %llu",
 			   le64_to_cpu(bch2_sb_member_get(sb, sb->dev_idx).seq),
@@ -819,7 +819,7 @@ got_super:
 
 	sb->have_layout = true;
 
-	ret = bch2_sb_validate(sb, &err, READ);
+	ret = bch2_sb_validate(sb, 0, &err);
 	if (ret) {
 		bch2_print_opts(opts, KERN_ERR "bcachefs (%s): error validating superblock: %s\n",
 				path, err.buf);
@@ -975,7 +975,7 @@ int bch2_write_super(struct bch_fs *c)
 	darray_for_each(online_devices, ca) {
 		printbuf_reset(&err);
 
-		ret = bch2_sb_validate(&(*ca)->disk_sb, &err, WRITE);
+		ret = bch2_sb_validate(&(*ca)->disk_sb, BCH_VALIDATE_write, &err);
 		if (ret) {
 			bch2_fs_inconsistent(c, "sb invalid before write: %s", err.buf);
 			goto out;
@@ -1020,26 +1020,35 @@ int bch2_write_super(struct bch_fs *c)
 			continue;
 
 		if (le64_to_cpu(ca->sb_read_scratch->seq) < ca->disk_sb.seq) {
-			bch2_fs_fatal_error(c,
+			struct printbuf buf = PRINTBUF;
+			prt_char(&buf, ' ');
+			prt_bdevname(&buf, ca->disk_sb.bdev);
+			prt_printf(&buf,
 				": Superblock write was silently dropped! (seq %llu expected %llu)",
 				le64_to_cpu(ca->sb_read_scratch->seq),
 				ca->disk_sb.seq);
-			percpu_ref_put(&ca->io_ref);
+			bch2_fs_fatal_error(c, "%s", buf.buf);
+			printbuf_exit(&buf);
 			ret = -BCH_ERR_erofs_sb_err;
-			goto out;
 		}
 
 		if (le64_to_cpu(ca->sb_read_scratch->seq) > ca->disk_sb.seq) {
-			bch2_fs_fatal_error(c,
+			struct printbuf buf = PRINTBUF;
+			prt_char(&buf, ' ');
+			prt_bdevname(&buf, ca->disk_sb.bdev);
+			prt_printf(&buf,
 				": Superblock modified by another process (seq %llu expected %llu)",
 				le64_to_cpu(ca->sb_read_scratch->seq),
 				ca->disk_sb.seq);
-			percpu_ref_put(&ca->io_ref);
+			bch2_fs_fatal_error(c, "%s", buf.buf);
+			printbuf_exit(&buf);
 			ret = -BCH_ERR_erofs_sb_err;
-			goto out;
 		}
 	}
 
+	if (ret)
+		goto out;
+
 	do {
 		wrote = false;
 		darray_for_each(online_devices, cap) {
@@ -1152,7 +1161,7 @@ void bch2_sb_upgrade(struct bch_fs *c, unsigned new_version)
 }
 
 static int bch2_sb_ext_validate(struct bch_sb *sb, struct bch_sb_field *f,
-				struct printbuf *err)
+				enum bch_validate_flags flags, struct printbuf *err)
 {
 	if (vstruct_bytes(f) < 88) {
 		prt_printf(err, "field too small (%zu < %u)", vstruct_bytes(f), 88);
@@ -1167,8 +1176,7 @@ static void bch2_sb_ext_to_text(struct printbuf *out, struct bch_sb *sb,
 {
 	struct bch_sb_field_ext *e = field_to_type(f, ext);
 
-	prt_printf(out, "Recovery passes required:");
-	prt_tab(out);
+	prt_printf(out, "Recovery passes required:\t");
 	prt_bitflags(out, bch2_recovery_passes,
 		     bch2_recovery_passes_from_stable(le64_to_cpu(e->recovery_passes_required[0])));
 	prt_newline(out);
@@ -1177,16 +1185,14 @@ static void bch2_sb_ext_to_text(struct printbuf *out, struct bch_sb *sb,
 	if (errors_silent) {
 		le_bitvector_to_cpu(errors_silent, (void *) e->errors_silent, sizeof(e->errors_silent) * 8);
 
-		prt_printf(out, "Errors to silently fix:");
-		prt_tab(out);
+		prt_printf(out, "Errors to silently fix:\t");
 		prt_bitflags_vector(out, bch2_sb_error_strs, errors_silent, sizeof(e->errors_silent) * 8);
 		prt_newline(out);
 
 		kfree(errors_silent);
 	}
 
-	prt_printf(out, "Btrees with missing data:");
-	prt_tab(out);
+	prt_printf(out, "Btrees with missing data:\t");
 	prt_bitflags(out, __bch2_btree_ids, le64_to_cpu(e->btrees_lost_data));
 	prt_newline(out);
 }
@@ -1213,14 +1219,14 @@ static const struct bch_sb_field_ops *bch2_sb_field_type_ops(unsigned type)
 }
 
 static int bch2_sb_field_validate(struct bch_sb *sb, struct bch_sb_field *f,
-				  struct printbuf *err)
+				  enum bch_validate_flags flags, struct printbuf *err)
 {
 	unsigned type = le32_to_cpu(f->type);
 	struct printbuf field_err = PRINTBUF;
 	const struct bch_sb_field_ops *ops = bch2_sb_field_type_ops(type);
 	int ret;
 
-	ret = ops->validate ? ops->validate(sb, f, &field_err) : 0;
+	ret = ops->validate ? ops->validate(sb, f, flags, &field_err) : 0;
 	if (ret) {
 		prt_printf(err, "Invalid superblock section %s: %s",
 			   bch2_sb_fields[type], field_err.buf);
@@ -1294,97 +1300,73 @@ void bch2_sb_to_text(struct printbuf *out, struct bch_sb *sb,
 		printbuf_tabstop_push(out, 44);
 
 	for (int i = 0; i < sb->nr_devices; i++)
-		nr_devices += bch2_dev_exists(sb, i);
+		nr_devices += bch2_member_exists(sb, i);
 
-	prt_printf(out, "External UUID:");
-	prt_tab(out);
+	prt_printf(out, "External UUID:\t");
 	pr_uuid(out, sb->user_uuid.b);
 	prt_newline(out);
 
-	prt_printf(out, "Internal UUID:");
-	prt_tab(out);
+	prt_printf(out, "Internal UUID:\t");
 	pr_uuid(out, sb->uuid.b);
 	prt_newline(out);
 
-	prt_printf(out, "Magic number:");
-	prt_tab(out);
+	prt_printf(out, "Magic number:\t");
 	pr_uuid(out, sb->magic.b);
 	prt_newline(out);
 
-	prt_str(out, "Device index:");
-	prt_tab(out);
-	prt_printf(out, "%u", sb->dev_idx);
-	prt_newline(out);
+	prt_printf(out, "Device index:\t%u\n", sb->dev_idx);
 
-	prt_str(out, "Label:");
-	prt_tab(out);
+	prt_str(out, "Label:\t");
 	prt_printf(out, "%.*s", (int) sizeof(sb->label), sb->label);
 	prt_newline(out);
 
-	prt_str(out, "Version:");
-	prt_tab(out);
+	prt_str(out, "Version:\t");
 	bch2_version_to_text(out, le16_to_cpu(sb->version));
 	prt_newline(out);
 
-	prt_str(out, "Version upgrade complete:");
-	prt_tab(out);
+	prt_str(out, "Version upgrade complete:\t");
 	bch2_version_to_text(out, BCH_SB_VERSION_UPGRADE_COMPLETE(sb));
 	prt_newline(out);
 
-	prt_printf(out, "Oldest version on disk:");
-	prt_tab(out);
+	prt_printf(out, "Oldest version on disk:\t");
 	bch2_version_to_text(out, le16_to_cpu(sb->version_min));
 	prt_newline(out);
 
-	prt_printf(out, "Created:");
-	prt_tab(out);
+	prt_printf(out, "Created:\t");
 	if (sb->time_base_lo)
 		bch2_prt_datetime(out, div_u64(le64_to_cpu(sb->time_base_lo), NSEC_PER_SEC));
 	else
 		prt_printf(out, "(not set)");
 	prt_newline(out);
 
-	prt_printf(out, "Sequence number:");
-	prt_tab(out);
+	prt_printf(out, "Sequence number:\t");
 	prt_printf(out, "%llu", le64_to_cpu(sb->seq));
 	prt_newline(out);
 
-	prt_printf(out, "Time of last write:");
-	prt_tab(out);
+	prt_printf(out, "Time of last write:\t");
 	bch2_prt_datetime(out, le64_to_cpu(sb->write_time));
 	prt_newline(out);
 
-	prt_printf(out, "Superblock size:");
-	prt_tab(out);
+	prt_printf(out, "Superblock size:\t");
 	prt_units_u64(out, vstruct_bytes(sb));
 	prt_str(out, "/");
 	prt_units_u64(out, 512ULL << sb->layout.sb_max_size_bits);
 	prt_newline(out);
 
-	prt_printf(out, "Clean:");
-	prt_tab(out);
-	prt_printf(out, "%llu", BCH_SB_CLEAN(sb));
-	prt_newline(out);
-
-	prt_printf(out, "Devices:");
-	prt_tab(out);
-	prt_printf(out, "%u", nr_devices);
-	prt_newline(out);
+	prt_printf(out, "Clean:\t%llu\n", BCH_SB_CLEAN(sb));
+	prt_printf(out, "Devices:\t%u\n", nr_devices);
 
-	prt_printf(out, "Sections:");
+	prt_printf(out, "Sections:\t");
 	vstruct_for_each(sb, f)
 		fields_have |= 1 << le32_to_cpu(f->type);
-	prt_tab(out);
 	prt_bitflags(out, bch2_sb_fields, fields_have);
 	prt_newline(out);
 
-	prt_printf(out, "Features:");
-	prt_tab(out);
+	prt_printf(out, "Features:\t");
 	prt_bitflags(out, bch2_sb_features, le64_to_cpu(sb->features[0]));
 	prt_newline(out);
 
-	prt_printf(out, "Compat features:");
-	prt_tab(out);
+	prt_printf(out, "Compat features:\t");
 	prt_bitflags(out, bch2_sb_compat, le64_to_cpu(sb->compat[0]));
 	prt_newline(out);
 
@@ -1401,8 +1383,7 @@ void bch2_sb_to_text(struct printbuf *out, struct bch_sb *sb,
 			if (opt->get_sb != BCH2_NO_SB_OPT) {
 				u64 v = bch2_opt_from_sb(sb, id);
 
-				prt_printf(out, "%s:", opt->attr.name);
-				prt_tab(out);
+				prt_printf(out, "%s:\t", opt->attr.name);
 				bch2_opt_to_text(out, NULL, sb, opt, v,
 						 OPT_HUMAN_READABLE|OPT_SHOW_FULL_LIST);
 				prt_newline(out);
diff --git a/fs/bcachefs/super-io.h b/fs/bcachefs/super-io.h
index 95e80e06316b..fadd364e2802 100644
--- a/fs/bcachefs/super-io.h
+++ b/fs/bcachefs/super-io.h
@@ -51,7 +51,8 @@ void bch2_sb_field_delete(struct bch_sb_handle *, enum bch_sb_field_type);
 extern const char * const bch2_sb_fields[];
 
 struct bch_sb_field_ops {
-	int	(*validate)(struct bch_sb *, struct bch_sb_field *, struct printbuf *);
+	int	(*validate)(struct bch_sb *, struct bch_sb_field *,
+			    enum bch_validate_flags, struct printbuf *);
 	void	(*to_text)(struct printbuf *, struct bch_sb *, struct bch_sb_field *);
 };
 
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index dddf57ec4511..294a9d35a9f2 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -264,7 +264,6 @@ static void __bch2_fs_read_only(struct bch_fs *c)
 	bch2_open_buckets_stop(c, NULL, true);
 	bch2_rebalance_stop(c);
 	bch2_copygc_stop(c);
-	bch2_gc_thread_stop(c);
 	bch2_fs_ec_flush(c);
 
 	bch_verbose(c, "flushing journal and stopping allocators, journal seq %llu",
@@ -285,7 +284,7 @@ static void __bch2_fs_read_only(struct bch_fs *c)
 	bch_verbose(c, "flushing journal and stopping allocators complete, journal seq %llu",
 		    journal_cur_seq(&c->journal));
 
-	if (test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags) &&
+	if (test_bit(JOURNAL_replay_done, &c->journal.flags) &&
 	    !test_bit(BCH_FS_emergency_ro, &c->flags))
 		set_bit(BCH_FS_clean_shutdown, &c->flags);
 
@@ -467,7 +466,8 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 	 * overwriting whatever was there previously, and there must always be
 	 * at least one non-flush write in the journal or recovery will fail:
 	 */
-	set_bit(JOURNAL_NEED_FLUSH_WRITE, &c->journal.flags);
+	set_bit(JOURNAL_need_flush_write, &c->journal.flags);
+	set_bit(JOURNAL_running, &c->journal.flags);
 
 	for_each_rw_member(c, ca)
 		bch2_dev_allocator_add(c, ca);
@@ -485,12 +485,6 @@ static int __bch2_fs_read_write(struct bch_fs *c, bool early)
 	}
 #endif
 
-	ret = bch2_gc_thread_start(c);
-	if (ret) {
-		bch_err(c, "error starting gc thread");
-		return ret;
-	}
-
 	ret = bch2_journal_reclaim_start(&c->journal);
 	if (ret)
 		goto err;
@@ -537,9 +531,7 @@ int bch2_fs_read_write_early(struct bch_fs *c)
 
 static void __bch2_fs_free(struct bch_fs *c)
 {
-	unsigned i;
-
-	for (i = 0; i < BCH_TIME_STAT_NR; i++)
+	for (unsigned i = 0; i < BCH_TIME_STAT_NR; i++)
 		bch2_time_stats_exit(&c->times[i]);
 
 	bch2_find_btree_nodes_exit(&c->found_btree_nodes);
@@ -572,6 +564,7 @@ static void __bch2_fs_free(struct bch_fs *c)
 	BUG_ON(atomic_read(&c->journal_keys.ref));
 	bch2_fs_btree_write_buffer_exit(c);
 	percpu_free_rwsem(&c->mark_lock);
+	EBUG_ON(percpu_u64_get(c->online_reserved));
 	free_percpu(c->online_reserved);
 
 	darray_exit(&c->btree_roots_extra);
@@ -616,8 +609,6 @@ void __bch2_fs_stop(struct bch_fs *c)
 
 	set_bit(BCH_FS_stopping, &c->flags);
 
-	cancel_work_sync(&c->journal_seq_blacklist_gc_work);
-
 	down_write(&c->state_lock);
 	bch2_fs_read_only(c);
 	up_write(&c->state_lock);
@@ -665,6 +656,7 @@ void bch2_fs_free(struct bch_fs *c)
 		struct bch_dev *ca = rcu_dereference_protected(c->devs[i], true);
 
 		if (ca) {
+			EBUG_ON(atomic_long_read(&ca->ref) != 1);
 			bch2_free_super(&ca->disk_sb);
 			bch2_dev_free(ca);
 		}
@@ -719,7 +711,7 @@ static int bch2_fs_online(struct bch_fs *c)
 		ret = bch2_dev_sysfs_online(c, ca);
 		if (ret) {
 			bch_err(c, "error creating sysfs objects");
-			percpu_ref_put(&ca->ref);
+			bch2_dev_put(ca);
 			goto err;
 		}
 	}
@@ -778,6 +770,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 	for (i = 0; i < BCH_TIME_STAT_NR; i++)
 		bch2_time_stats_init(&c->times[i]);
 
+	bch2_fs_gc_init(c);
 	bch2_fs_copygc_init(c);
 	bch2_fs_btree_key_cache_init_early(&c->btree_key_cache);
 	bch2_fs_btree_iter_init_early(c);
@@ -800,16 +793,11 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
 	spin_lock_init(&c->btree_write_error_lock);
 
-	INIT_WORK(&c->journal_seq_blacklist_gc_work,
-		  bch2_blacklist_entries_gc);
-
 	INIT_LIST_HEAD(&c->journal_iters);
 
 	INIT_LIST_HEAD(&c->fsck_error_msgs);
 	mutex_init(&c->fsck_error_msgs_lock);
 
-	seqcount_init(&c->gc_pos_lock);
-
 	seqcount_init(&c->usage_lock);
 
 	sema_init(&c->io_in_flight, 128);
@@ -940,7 +928,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 		goto err;
 
 	for (i = 0; i < c->sb.nr_devices; i++)
-		if (bch2_dev_exists(c->disk_sb.sb, i) &&
+		if (bch2_member_exists(c->disk_sb.sb, i) &&
 		    bch2_dev_alloc(c, i)) {
 			ret = -EEXIST;
 			goto err;
@@ -1101,7 +1089,7 @@ static int bch2_dev_in_fs(struct bch_sb_handle *fs,
 	if (!uuid_equal(&fs->sb->uuid, &sb->sb->uuid))
 		return -BCH_ERR_device_not_a_member_of_filesystem;
 
-	if (!bch2_dev_exists(fs->sb, sb->sb->dev_idx))
+	if (!bch2_member_exists(fs->sb, sb->sb->dev_idx))
 		return -BCH_ERR_device_has_been_removed;
 
 	if (fs->sb->block_size != sb->sb->block_size)
@@ -1200,11 +1188,11 @@ static void bch2_dev_free(struct bch_dev *ca)
 	if (ca->kobj.state_in_sysfs)
 		kobject_del(&ca->kobj);
 
+	kfree(ca->buckets_nouse);
 	bch2_free_super(&ca->disk_sb);
 	bch2_dev_journal_exit(ca);
 
 	free_percpu(ca->io_done);
-	bioset_exit(&ca->replica_set);
 	bch2_dev_buckets_free(ca);
 	free_page((unsigned long) ca->sb_read_scratch);
 
@@ -1212,7 +1200,9 @@ static void bch2_dev_free(struct bch_dev *ca)
 	bch2_time_stats_quantiles_exit(&ca->io_latency[READ]);
 
 	percpu_ref_exit(&ca->io_ref);
+#ifndef CONFIG_BCACHEFS_DEBUG
 	percpu_ref_exit(&ca->ref);
+#endif
 	kobject_put(&ca->kobj);
 }
 
@@ -1239,12 +1229,14 @@ static void __bch2_dev_offline(struct bch_fs *c, struct bch_dev *ca)
 	bch2_dev_journal_exit(ca);
 }
 
+#ifndef CONFIG_BCACHEFS_DEBUG
 static void bch2_dev_ref_complete(struct percpu_ref *ref)
 {
 	struct bch_dev *ca = container_of(ref, struct bch_dev, ref);
 
 	complete(&ca->ref_completion);
 }
+#endif
 
 static void bch2_dev_io_ref_complete(struct percpu_ref *ref)
 {
@@ -1313,14 +1305,17 @@ static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
 	ca->nr_btree_reserve = DIV_ROUND_UP(BTREE_NODE_RESERVE,
 			     ca->mi.bucket_size / btree_sectors(c));
 
-	if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete,
-			    0, GFP_KERNEL) ||
-	    percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
+#ifndef CONFIG_BCACHEFS_DEBUG
+	if (percpu_ref_init(&ca->ref, bch2_dev_ref_complete, 0, GFP_KERNEL))
+		goto err;
+#else
+	atomic_long_set(&ca->ref, 1);
+#endif
+
+	if (percpu_ref_init(&ca->io_ref, bch2_dev_io_ref_complete,
 			    PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 	    !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
 	    bch2_dev_buckets_alloc(c, ca) ||
-	    bioset_init(&ca->replica_set, 4,
-			offsetof(struct bch_write_bio, bio), 0) ||
 	    !(ca->io_done	= alloc_percpu(*ca->io_done)))
 		goto err;
 
@@ -1411,10 +1406,9 @@ static int bch2_dev_attach_bdev(struct bch_fs *c, struct bch_sb_handle *sb)
 	    le64_to_cpu(c->disk_sb.sb->seq))
 		bch2_sb_to_fs(c, sb->sb);
 
-	BUG_ON(sb->sb->dev_idx >= c->sb.nr_devices ||
-	       !c->devs[sb->sb->dev_idx]);
+	BUG_ON(!bch2_dev_exists(c, sb->sb->dev_idx));
 
-	ca = bch_dev_locked(c, sb->sb->dev_idx);
+	ca = bch2_dev_locked(c, sb->sb->dev_idx);
 
 	ret = __bch2_dev_attach_bdev(ca, sb);
 	if (ret)
@@ -1506,10 +1500,10 @@ static bool bch2_fs_may_start(struct bch_fs *c)
 		mutex_lock(&c->sb_lock);
 
 		for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
-			if (!bch2_dev_exists(c->disk_sb.sb, i))
+			if (!bch2_member_exists(c->disk_sb.sb, i))
 				continue;
 
-			ca = bch_dev_locked(c, i);
+			ca = bch2_dev_locked(c, i);
 
 			if (!bch2_dev_is_online(ca) &&
 			    (ca->mi.state == BCH_MEMBER_STATE_rw ||
@@ -1599,17 +1593,17 @@ static int bch2_dev_remove_alloc(struct bch_fs *c, struct bch_dev *ca)
 	 * with bch2_do_invalidates() and bch2_do_discards()
 	 */
 	ret =   bch2_btree_delete_range(c, BTREE_ID_lru, start, end,
-					BTREE_TRIGGER_NORUN, NULL) ?:
+					BTREE_TRIGGER_norun, NULL) ?:
 		bch2_btree_delete_range(c, BTREE_ID_need_discard, start, end,
-					BTREE_TRIGGER_NORUN, NULL) ?:
+					BTREE_TRIGGER_norun, NULL) ?:
 		bch2_btree_delete_range(c, BTREE_ID_freespace, start, end,
-					BTREE_TRIGGER_NORUN, NULL) ?:
+					BTREE_TRIGGER_norun, NULL) ?:
 		bch2_btree_delete_range(c, BTREE_ID_backpointers, start, end,
-					BTREE_TRIGGER_NORUN, NULL) ?:
+					BTREE_TRIGGER_norun, NULL) ?:
 		bch2_btree_delete_range(c, BTREE_ID_alloc, start, end,
-					BTREE_TRIGGER_NORUN, NULL) ?:
+					BTREE_TRIGGER_norun, NULL) ?:
 		bch2_btree_delete_range(c, BTREE_ID_bucket_gens, start, end,
-					BTREE_TRIGGER_NORUN, NULL);
+					BTREE_TRIGGER_norun, NULL);
 	bch_err_msg(c, ret, "removing dev alloc info");
 	return ret;
 }
@@ -1626,7 +1620,7 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 	 * We consume a reference to ca->ref, regardless of whether we succeed
 	 * or fail:
 	 */
-	percpu_ref_put(&ca->ref);
+	bch2_dev_put(ca);
 
 	if (!bch2_dev_state_allowed(c, ca, BCH_MEMBER_STATE_failed, flags)) {
 		bch_err(ca, "Cannot remove without losing data");
@@ -1678,7 +1672,12 @@ int bch2_dev_remove(struct bch_fs *c, struct bch_dev *ca, int flags)
 	rcu_assign_pointer(c->devs[ca->dev_idx], NULL);
 	mutex_unlock(&c->sb_lock);
 
+#ifndef CONFIG_BCACHEFS_DEBUG
 	percpu_ref_kill(&ca->ref);
+#else
+	ca->dying = true;
+	bch2_dev_put(ca);
+#endif
 	wait_for_completion(&ca->ref_completion);
 
 	bch2_dev_free(ca);
@@ -1777,9 +1776,28 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
 	if (dynamic_fault("bcachefs:add:no_slot"))
 		goto no_slot;
 
-	for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
-		if (!bch2_dev_exists(c->disk_sb.sb, dev_idx))
-			goto have_slot;
+	if (c->sb.nr_devices < BCH_SB_MEMBERS_MAX) {
+		dev_idx = c->sb.nr_devices;
+		goto have_slot;
+	}
+
+	int best = -1;
+	u64 best_last_mount = 0;
+	for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++) {
+		struct bch_member m = bch2_sb_member_get(c->disk_sb.sb, dev_idx);
+		if (bch2_member_alive(&m))
+			continue;
+
+		u64 last_mount = le64_to_cpu(m.last_mount);
+		if (best < 0 || last_mount < best_last_mount) {
+			best = dev_idx;
+			best_last_mount = last_mount;
+		}
+	}
+	if (best >= 0) {
+		dev_idx = best;
+		goto have_slot;
+	}
 no_slot:
 	ret = -BCH_ERR_ENOSPC_sb_members;
 	bch_err_msg(c, ret, "setting up new superblock");
@@ -1821,7 +1839,7 @@ have_slot:
 
 	bch2_dev_usage_journal_reserve(c);
 
-	ret = bch2_trans_mark_dev_sb(c, ca);
+	ret = bch2_trans_mark_dev_sb(c, ca, BTREE_TRIGGER_transactional);
 	bch_err_msg(ca, ret, "marking new superblock");
 	if (ret)
 		goto err_late;
@@ -1884,9 +1902,9 @@ int bch2_dev_online(struct bch_fs *c, const char *path)
 	if (ret)
 		goto err;
 
-	ca = bch_dev_locked(c, dev_idx);
+	ca = bch2_dev_locked(c, dev_idx);
 
-	ret = bch2_trans_mark_dev_sb(c, ca);
+	ret = bch2_trans_mark_dev_sb(c, ca, BTREE_TRIGGER_transactional);
 	bch_err_msg(c, ret, "bringing %s online: error from bch2_trans_mark_dev_sb", path);
 	if (ret)
 		goto err;
@@ -1979,7 +1997,7 @@ int bch2_dev_resize(struct bch_fs *c, struct bch_dev *ca, u64 nbuckets)
 	if (ret)
 		goto err;
 
-	ret = bch2_trans_mark_dev_sb(c, ca);
+	ret = bch2_trans_mark_dev_sb(c, ca, BTREE_TRIGGER_transactional);
 	if (ret)
 		goto err;
 
diff --git a/fs/bcachefs/super_types.h b/fs/bcachefs/super_types.h
index 11bcef170c2c..368a63d938cf 100644
--- a/fs/bcachefs/super_types.h
+++ b/fs/bcachefs/super_types.h
@@ -26,19 +26,4 @@ struct bch_devs_list {
 	u8			data[BCH_BKEY_PTRS_MAX];
 };
 
-struct bch_member_cpu {
-	u64			nbuckets;	/* device size */
-	u16			first_bucket;   /* index of first bucket used */
-	u16			bucket_size;	/* sectors */
-	u16			group;
-	u8			state;
-	u8			discard;
-	u8			data_allowed;
-	u8			durability;
-	u8			freespace_initialized;
-	u8			valid;
-	u8			btree_bitmap_shift;
-	u64			btree_allocated_bitmap;
-};
-
 #endif /* _BCACHEFS_SUPER_TYPES_H */
diff --git a/fs/bcachefs/sysfs.c b/fs/bcachefs/sysfs.c
index 5be92fe3f4ea..93ca74d108b1 100644
--- a/fs/bcachefs/sysfs.c
+++ b/fs/bcachefs/sysfs.c
@@ -140,9 +140,8 @@ write_attribute(trigger_gc);
 write_attribute(trigger_discards);
 write_attribute(trigger_invalidates);
 write_attribute(trigger_journal_flush);
-write_attribute(prune_cache);
-write_attribute(btree_wakeup);
-rw_attribute(btree_gc_periodic);
+write_attribute(trigger_btree_cache_shrink);
+write_attribute(trigger_btree_key_cache_shrink);
 rw_attribute(gc_gens_pos);
 
 read_attribute(uuid);
@@ -189,12 +188,8 @@ static void bch2_write_refs_to_text(struct printbuf *out, struct bch_fs *c)
 {
 	bch2_printbuf_tabstop_push(out, 24);
 
-	for (unsigned i = 0; i < ARRAY_SIZE(c->writes); i++) {
-		prt_str(out, bch2_write_refs[i]);
-		prt_tab(out);
-		prt_printf(out, "%li", atomic_long_read(&c->writes[i]));
-		prt_newline(out);
-	}
+	for (unsigned i = 0; i < ARRAY_SIZE(c->writes); i++)
+		prt_printf(out, "%s\t%li\n", bch2_write_refs[i], atomic_long_read(&c->writes[i]));
 }
 #endif
 
@@ -278,7 +273,7 @@ static int bch2_compression_stats_to_text(struct printbuf *out, struct bch_fs *c
 			continue;
 
 		ret = for_each_btree_key(trans, iter, id, POS_MIN,
-					 BTREE_ITER_ALL_SNAPSHOTS, k, ({
+					 BTREE_ITER_all_snapshots, k, ({
 			struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
 			struct bch_extent_crc_unpacked crc;
 			const union bch_extent_entry *entry;
@@ -313,22 +308,11 @@ static int bch2_compression_stats_to_text(struct printbuf *out, struct bch_fs *c
 	if (ret)
 		return ret;
 
-	prt_str(out, "type");
 	printbuf_tabstop_push(out, 12);
-	prt_tab(out);
-
-	prt_str(out, "compressed");
 	printbuf_tabstop_push(out, 16);
-	prt_tab_rjust(out);
-
-	prt_str(out, "uncompressed");
 	printbuf_tabstop_push(out, 16);
-	prt_tab_rjust(out);
-
-	prt_str(out, "average extent size");
 	printbuf_tabstop_push(out, 24);
-	prt_tab_rjust(out);
-	prt_newline(out);
+	prt_printf(out, "type\tcompressed\runcompressed\raverage extent size\r\n");
 
 	for (unsigned i = 0; i < ARRAY_SIZE(s); i++) {
 		bch2_prt_compression_type(out, i);
@@ -362,21 +346,6 @@ static void bch2_gc_gens_pos_to_text(struct printbuf *out, struct bch_fs *c)
 	prt_printf(out, "\n");
 }
 
-static void bch2_btree_wakeup_all(struct bch_fs *c)
-{
-	struct btree_trans *trans;
-
-	seqmutex_lock(&c->btree_trans_lock);
-	list_for_each_entry(trans, &c->btree_trans_list, list) {
-		struct btree_bkey_cached_common *b = READ_ONCE(trans->locking);
-
-		if (b)
-			six_lock_wakeup_all(&b->lock);
-
-	}
-	seqmutex_unlock(&c->btree_trans_lock);
-}
-
 SHOW(bch2_fs)
 {
 	struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
@@ -392,8 +361,6 @@ SHOW(bch2_fs)
 	if (attr == &sysfs_btree_write_stats)
 		bch2_btree_write_stats_to_text(out, c);
 
-	sysfs_printf(btree_gc_periodic, "%u",	(int) c->btree_gc_periodic);
-
 	if (attr == &sysfs_gc_gens_pos)
 		bch2_gc_gens_pos_to_text(out, c);
 
@@ -416,7 +383,7 @@ SHOW(bch2_fs)
 		bch2_journal_debug_to_text(out, &c->journal);
 
 	if (attr == &sysfs_btree_cache)
-		bch2_btree_cache_to_text(out, c);
+		bch2_btree_cache_to_text(out, &c->btree_cache);
 
 	if (attr == &sysfs_btree_key_cache)
 		bch2_btree_key_cache_to_text(out, &c->btree_key_cache);
@@ -459,6 +426,9 @@ SHOW(bch2_fs)
 	if (attr == &sysfs_disk_groups)
 		bch2_disk_groups_to_text(out, c);
 
+	if (attr == &sysfs_alloc_debug)
+		bch2_fs_alloc_debug_to_text(out, c);
+
 	return 0;
 }
 
@@ -466,14 +436,6 @@ STORE(bch2_fs)
 {
 	struct bch_fs *c = container_of(kobj, struct bch_fs, kobj);
 
-	if (attr == &sysfs_btree_gc_periodic) {
-		ssize_t ret = strtoul_safe(buf, c->btree_gc_periodic)
-			?: (ssize_t) size;
-
-		wake_up_process(c->gc_thread);
-		return ret;
-	}
-
 	if (attr == &sysfs_copy_gc_enabled) {
 		ssize_t ret = strtoul_safe(buf, c->copy_gc_enabled)
 			?: (ssize_t) size;
@@ -505,7 +467,7 @@ STORE(bch2_fs)
 	if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_sysfs))
 		return -EROFS;
 
-	if (attr == &sysfs_prune_cache) {
+	if (attr == &sysfs_trigger_btree_cache_shrink) {
 		struct shrink_control sc;
 
 		sc.gfp_mask = GFP_KERNEL;
@@ -513,22 +475,17 @@ STORE(bch2_fs)
 		c->btree_cache.shrink->scan_objects(c->btree_cache.shrink, &sc);
 	}
 
-	if (attr == &sysfs_btree_wakeup)
-		bch2_btree_wakeup_all(c);
-
-	if (attr == &sysfs_trigger_gc) {
-		/*
-		 * Full gc is currently incompatible with btree key cache:
-		 */
-#if 0
-		down_read(&c->state_lock);
-		bch2_gc(c, false, false);
-		up_read(&c->state_lock);
-#else
-		bch2_gc_gens(c);
-#endif
+	if (attr == &sysfs_trigger_btree_key_cache_shrink) {
+		struct shrink_control sc;
+
+		sc.gfp_mask = GFP_KERNEL;
+		sc.nr_to_scan = strtoul_or_return(buf);
+		c->btree_key_cache.shrink->scan_objects(c->btree_cache.shrink, &sc);
 	}
 
+	if (attr == &sysfs_trigger_gc)
+		bch2_gc_gens(c);
+
 	if (attr == &sysfs_trigger_discards)
 		bch2_do_discards(c);
 
@@ -594,13 +551,11 @@ SHOW(bch2_fs_counters)
 		if (attr == &sysfs_##t) {					\
 			counter             = percpu_u64_get(&c->counters[BCH_COUNTER_##t]);\
 			counter_since_mount = counter - c->counters_on_mount[BCH_COUNTER_##t];\
-			prt_printf(out, "since mount:");				\
-			prt_tab(out);						\
+			prt_printf(out, "since mount:\t");			\
 			prt_human_readable_u64(out, counter_since_mount);	\
 			prt_newline(out);					\
 										\
-			prt_printf(out, "since filesystem creation:");		\
-			prt_tab(out);						\
+			prt_printf(out, "since filesystem creation:\t");	\
 			prt_human_readable_u64(out, counter);			\
 			prt_newline(out);					\
 		}
@@ -660,8 +615,8 @@ struct attribute *bch2_fs_internal_files[] = {
 	&sysfs_trigger_discards,
 	&sysfs_trigger_invalidates,
 	&sysfs_trigger_journal_flush,
-	&sysfs_prune_cache,
-	&sysfs_btree_wakeup,
+	&sysfs_trigger_btree_cache_shrink,
+	&sysfs_trigger_btree_key_cache_shrink,
 
 	&sysfs_gc_gens_pos,
 
@@ -677,6 +632,7 @@ struct attribute *bch2_fs_internal_files[] = {
 	&sysfs_internal_uuid,
 
 	&sysfs_disk_groups,
+	&sysfs_alloc_debug,
 	NULL
 };
 
@@ -792,88 +748,6 @@ struct attribute *bch2_fs_time_stats_files[] = {
 	NULL
 };
 
-static void dev_alloc_debug_to_text(struct printbuf *out, struct bch_dev *ca)
-{
-	struct bch_fs *c = ca->fs;
-	struct bch_dev_usage stats = bch2_dev_usage_read(ca);
-	unsigned i, nr[BCH_DATA_NR];
-
-	memset(nr, 0, sizeof(nr));
-
-	for (i = 0; i < ARRAY_SIZE(c->open_buckets); i++)
-		nr[c->open_buckets[i].data_type]++;
-
-	printbuf_tabstop_push(out, 8);
-	printbuf_tabstop_push(out, 16);
-	printbuf_tabstop_push(out, 16);
-	printbuf_tabstop_push(out, 16);
-	printbuf_tabstop_push(out, 16);
-
-	bch2_dev_usage_to_text(out, &stats);
-
-	prt_newline(out);
-
-	prt_printf(out, "reserves:");
-	prt_newline(out);
-	for (i = 0; i < BCH_WATERMARK_NR; i++) {
-		prt_str(out, bch2_watermarks[i]);
-		prt_tab(out);
-		prt_u64(out, bch2_dev_buckets_reserved(ca, i));
-		prt_tab_rjust(out);
-		prt_newline(out);
-	}
-
-	prt_newline(out);
-
-	printbuf_tabstops_reset(out);
-	printbuf_tabstop_push(out, 24);
-
-	prt_str(out, "freelist_wait");
-	prt_tab(out);
-	prt_str(out, c->freelist_wait.list.first ? "waiting" : "empty");
-	prt_newline(out);
-
-	prt_str(out, "open buckets allocated");
-	prt_tab(out);
-	prt_u64(out, OPEN_BUCKETS_COUNT - c->open_buckets_nr_free);
-	prt_newline(out);
-
-	prt_str(out, "open buckets this dev");
-	prt_tab(out);
-	prt_u64(out, ca->nr_open_buckets);
-	prt_newline(out);
-
-	prt_str(out, "open buckets total");
-	prt_tab(out);
-	prt_u64(out, OPEN_BUCKETS_COUNT);
-	prt_newline(out);
-
-	prt_str(out, "open_buckets_wait");
-	prt_tab(out);
-	prt_str(out, c->open_buckets_wait.list.first ? "waiting" : "empty");
-	prt_newline(out);
-
-	prt_str(out, "open_buckets_btree");
-	prt_tab(out);
-	prt_u64(out, nr[BCH_DATA_btree]);
-	prt_newline(out);
-
-	prt_str(out, "open_buckets_user");
-	prt_tab(out);
-	prt_u64(out, nr[BCH_DATA_user]);
-	prt_newline(out);
-
-	prt_str(out, "buckets_to_invalidate");
-	prt_tab(out);
-	prt_u64(out, should_invalidate_buckets(ca, stats));
-	prt_newline(out);
-
-	prt_str(out, "btree reserve cache");
-	prt_tab(out);
-	prt_u64(out, c->btree_reserve_cache_nr);
-	prt_newline(out);
-}
-
 static const char * const bch2_rw[] = {
 	"read",
 	"write",
@@ -943,7 +817,7 @@ SHOW(bch2_dev)
 		     * 100 / CONGESTED_MAX);
 
 	if (attr == &sysfs_alloc_debug)
-		dev_alloc_debug_to_text(out, ca);
+		bch2_dev_alloc_debug_to_text(out, ca);
 
 	return 0;
 }
diff --git a/fs/bcachefs/tests.c b/fs/bcachefs/tests.c
index bfec656f94c0..68104b2056d9 100644
--- a/fs/bcachefs/tests.c
+++ b/fs/bcachefs/tests.c
@@ -40,7 +40,7 @@ static int test_delete(struct bch_fs *c, u64 nr)
 	k.k.p.snapshot = U32_MAX;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs, k.k.p,
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 
 	ret = commit_do(trans, NULL, NULL, 0,
 		bch2_btree_iter_traverse(&iter) ?:
@@ -81,7 +81,7 @@ static int test_delete_written(struct bch_fs *c, u64 nr)
 	k.k.p.snapshot = U32_MAX;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs, k.k.p,
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 
 	ret = commit_do(trans, NULL, NULL, 0,
 		bch2_btree_iter_traverse(&iter) ?:
@@ -261,7 +261,7 @@ static int test_iterate_slots(struct bch_fs *c, u64 nr)
 	ret = bch2_trans_run(c,
 		for_each_btree_key_upto(trans, iter, BTREE_ID_xattrs,
 					SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
-					BTREE_ITER_SLOTS, k, ({
+					BTREE_ITER_slots, k, ({
 			if (i >= nr * 2)
 				break;
 
@@ -322,7 +322,7 @@ static int test_iterate_slots_extents(struct bch_fs *c, u64 nr)
 	ret = bch2_trans_run(c,
 		for_each_btree_key_upto(trans, iter, BTREE_ID_extents,
 					SPOS(0, 0, U32_MAX), POS(0, U64_MAX),
-					BTREE_ITER_SLOTS, k, ({
+					BTREE_ITER_slots, k, ({
 			if (i == nr)
 				break;
 			BUG_ON(bkey_deleted(k.k) != !(i % 16));
@@ -452,7 +452,7 @@ static int insert_test_overlapping_extent(struct bch_fs *c, u64 inum, u64 start,
 
 	ret = bch2_trans_do(c, NULL, NULL, 0,
 		bch2_btree_insert_nonextent(trans, BTREE_ID_extents, &k.k_i,
-					    BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE));
+					    BTREE_UPDATE_internal_snapshot_node));
 	bch_err_fn(c, ret);
 	return ret;
 }
@@ -671,7 +671,7 @@ static int __do_delete(struct btree_trans *trans, struct bpos pos)
 	int ret = 0;
 
 	bch2_trans_iter_init(trans, &iter, BTREE_ID_xattrs, pos,
-			     BTREE_ITER_INTENT);
+			     BTREE_ITER_intent);
 	k = bch2_btree_iter_peek_upto(&iter, POS(0, U64_MAX));
 	ret = bkey_err(k);
 	if (ret)
@@ -714,7 +714,7 @@ static int seq_insert(struct bch_fs *c, u64 nr)
 	return bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_xattrs,
 					SPOS(0, 0, U32_MAX),
-					BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k,
+					BTREE_ITER_slots|BTREE_ITER_intent, k,
 					NULL, NULL, 0, ({
 			if (iter.pos.offset >= nr)
 				break;
@@ -737,7 +737,7 @@ static int seq_overwrite(struct bch_fs *c, u64 nr)
 	return bch2_trans_run(c,
 		for_each_btree_key_commit(trans, iter, BTREE_ID_xattrs,
 					SPOS(0, 0, U32_MAX),
-					BTREE_ITER_INTENT, k,
+					BTREE_ITER_intent, k,
 					NULL, NULL, 0, ({
 			struct bkey_i_cookie u;
 
diff --git a/fs/bcachefs/trace.h b/fs/bcachefs/trace.h
index 6aa81d1e6d36..362e1fc7ef6a 100644
--- a/fs/bcachefs/trace.h
+++ b/fs/bcachefs/trace.h
@@ -638,99 +638,14 @@ DEFINE_EVENT(bch_fs, gc_gens_end,
 
 /* Allocator */
 
-DECLARE_EVENT_CLASS(bucket_alloc,
-	TP_PROTO(struct bch_dev *ca, const char *alloc_reserve,
-		 u64 bucket,
-		 u64 free,
-		 u64 avail,
-		 u64 copygc_wait_amount,
-		 s64 copygc_waiting_for,
-		 struct bucket_alloc_state *s,
-		 bool nonblocking,
-		 const char *err),
-	TP_ARGS(ca, alloc_reserve, bucket, free, avail,
-		copygc_wait_amount, copygc_waiting_for,
-		s, nonblocking, err),
-
-	TP_STRUCT__entry(
-		__field(u8,			dev			)
-		__array(char,	reserve,	16			)
-		__field(u64,			bucket	)
-		__field(u64,			free			)
-		__field(u64,			avail			)
-		__field(u64,			copygc_wait_amount	)
-		__field(s64,			copygc_waiting_for	)
-		__field(u64,			seen			)
-		__field(u64,			open			)
-		__field(u64,			need_journal_commit	)
-		__field(u64,			nouse			)
-		__field(bool,			nonblocking		)
-		__field(u64,			nocow			)
-		__array(char,			err,	32		)
-	),
-
-	TP_fast_assign(
-		__entry->dev		= ca->dev_idx;
-		strscpy(__entry->reserve, alloc_reserve, sizeof(__entry->reserve));
-		__entry->bucket		= bucket;
-		__entry->free		= free;
-		__entry->avail		= avail;
-		__entry->copygc_wait_amount	= copygc_wait_amount;
-		__entry->copygc_waiting_for	= copygc_waiting_for;
-		__entry->seen		= s->buckets_seen;
-		__entry->open		= s->skipped_open;
-		__entry->need_journal_commit = s->skipped_need_journal_commit;
-		__entry->nouse		= s->skipped_nouse;
-		__entry->nonblocking	= nonblocking;
-		__entry->nocow		= s->skipped_nocow;
-		strscpy(__entry->err, err, sizeof(__entry->err));
-	),
-
-	TP_printk("reserve %s bucket %u:%llu free %llu avail %llu copygc_wait %llu/%lli seen %llu open %llu need_journal_commit %llu nouse %llu nocow %llu nonblocking %u err %s",
-		  __entry->reserve,
-		  __entry->dev,
-		  __entry->bucket,
-		  __entry->free,
-		  __entry->avail,
-		  __entry->copygc_wait_amount,
-		  __entry->copygc_waiting_for,
-		  __entry->seen,
-		  __entry->open,
-		  __entry->need_journal_commit,
-		  __entry->nouse,
-		  __entry->nocow,
-		  __entry->nonblocking,
-		  __entry->err)
+DEFINE_EVENT(fs_str, bucket_alloc,
+	TP_PROTO(struct bch_fs *c, const char *str),
+	TP_ARGS(c, str)
 );
 
-DEFINE_EVENT(bucket_alloc, bucket_alloc,
-	TP_PROTO(struct bch_dev *ca, const char *alloc_reserve,
-		 u64 bucket,
-		 u64 free,
-		 u64 avail,
-		 u64 copygc_wait_amount,
-		 s64 copygc_waiting_for,
-		 struct bucket_alloc_state *s,
-		 bool nonblocking,
-		 const char *err),
-	TP_ARGS(ca, alloc_reserve, bucket, free, avail,
-		copygc_wait_amount, copygc_waiting_for,
-		s, nonblocking, err)
-);
-
-DEFINE_EVENT(bucket_alloc, bucket_alloc_fail,
-	TP_PROTO(struct bch_dev *ca, const char *alloc_reserve,
-		 u64 bucket,
-		 u64 free,
-		 u64 avail,
-		 u64 copygc_wait_amount,
-		 s64 copygc_waiting_for,
-		 struct bucket_alloc_state *s,
-		 bool nonblocking,
-		 const char *err),
-	TP_ARGS(ca, alloc_reserve, bucket, free, avail,
-		copygc_wait_amount, copygc_waiting_for,
-		s, nonblocking, err)
+DEFINE_EVENT(fs_str, bucket_alloc_fail,
+	TP_PROTO(struct bch_fs *c, const char *str),
+	TP_ARGS(c, str)
 );
 
 TRACE_EVENT(discard_buckets,
diff --git a/fs/bcachefs/util.c b/fs/bcachefs/util.c
index 92c6ad75e702..de331dec2a99 100644
--- a/fs/bcachefs/util.c
+++ b/fs/bcachefs/util.c
@@ -348,15 +348,12 @@ static void bch2_pr_time_units_aligned(struct printbuf *out, u64 ns)
 {
 	const struct time_unit *u = bch2_pick_time_units(ns);
 
-	prt_printf(out, "%llu ", div64_u64(ns, u->nsecs));
-	prt_tab_rjust(out);
-	prt_printf(out, "%s", u->name);
+	prt_printf(out, "%llu \r%s", div64_u64(ns, u->nsecs), u->name);
 }
 
 static inline void pr_name_and_units(struct printbuf *out, const char *name, u64 ns)
 {
-	prt_str(out, name);
-	prt_tab(out);
+	prt_printf(out, "%s\t", name);
 	bch2_pr_time_units_aligned(out, ns);
 	prt_newline(out);
 }
@@ -389,12 +386,8 @@ void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats
 	}
 
 	printbuf_tabstop_push(out, out->indent + TABSTOP_SIZE);
-	prt_printf(out, "count:");
-	prt_tab(out);
-	prt_printf(out, "%llu ",
-			 stats->duration_stats.n);
+	prt_printf(out, "count:\t%llu\n", stats->duration_stats.n);
 	printbuf_tabstop_pop(out);
-	prt_newline(out);
 
 	printbuf_tabstops_reset(out);
 
@@ -403,13 +396,8 @@ void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats
 	printbuf_tabstop_push(out, 0);
 	printbuf_tabstop_push(out, TABSTOP_SIZE + 2);
 
-	prt_tab(out);
-	prt_printf(out, "since mount");
-	prt_tab_rjust(out);
-	prt_tab(out);
+	prt_printf(out, "\tsince mount\r\trecent\r\n");
 	prt_printf(out, "recent");
-	prt_tab_rjust(out);
-	prt_newline(out);
 
 	printbuf_tabstops_reset(out);
 	printbuf_tabstop_push(out, out->indent + 20);
@@ -417,23 +405,20 @@ void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats
 	printbuf_tabstop_push(out, 2);
 	printbuf_tabstop_push(out, TABSTOP_SIZE);
 
-	prt_printf(out, "duration of events");
-	prt_newline(out);
+	prt_printf(out, "duration of events\n");
 	printbuf_indent_add(out, 2);
 
 	pr_name_and_units(out, "min:", stats->min_duration);
 	pr_name_and_units(out, "max:", stats->max_duration);
 	pr_name_and_units(out, "total:", stats->total_duration);
 
-	prt_printf(out, "mean:");
-	prt_tab(out);
+	prt_printf(out, "mean:\t");
 	bch2_pr_time_units_aligned(out, d_mean);
 	prt_tab(out);
 	bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
 	prt_newline(out);
 
-	prt_printf(out, "stddev:");
-	prt_tab(out);
+	prt_printf(out, "stddev:\t");
 	bch2_pr_time_units_aligned(out, d_stddev);
 	prt_tab(out);
 	bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
@@ -441,22 +426,19 @@ void bch2_time_stats_to_text(struct printbuf *out, struct bch2_time_stats *stats
 	printbuf_indent_sub(out, 2);
 	prt_newline(out);
 
-	prt_printf(out, "time between events");
-	prt_newline(out);
+	prt_printf(out, "time between events\n");
 	printbuf_indent_add(out, 2);
 
 	pr_name_and_units(out, "min:", stats->min_freq);
 	pr_name_and_units(out, "max:", stats->max_freq);
 
-	prt_printf(out, "mean:");
-	prt_tab(out);
+	prt_printf(out, "mean:\t");
 	bch2_pr_time_units_aligned(out, f_mean);
 	prt_tab(out);
 	bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
 	prt_newline(out);
 
-	prt_printf(out, "stddev:");
-	prt_tab(out);
+	prt_printf(out, "stddev:\t");
 	bch2_pr_time_units_aligned(out, f_stddev);
 	prt_tab(out);
 	bch2_pr_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
@@ -589,40 +571,31 @@ void bch2_pd_controller_debug_to_text(struct printbuf *out, struct bch_pd_contro
 	if (!out->nr_tabstops)
 		printbuf_tabstop_push(out, 20);
 
-	prt_printf(out, "rate:");
-	prt_tab(out);
+	prt_printf(out, "rate:\t");
 	prt_human_readable_s64(out, pd->rate.rate);
 	prt_newline(out);
 
-	prt_printf(out, "target:");
-	prt_tab(out);
+	prt_printf(out, "target:\t");
 	prt_human_readable_u64(out, pd->last_target);
 	prt_newline(out);
 
-	prt_printf(out, "actual:");
-	prt_tab(out);
+	prt_printf(out, "actual:\t");
 	prt_human_readable_u64(out, pd->last_actual);
 	prt_newline(out);
 
-	prt_printf(out, "proportional:");
-	prt_tab(out);
+	prt_printf(out, "proportional:\t");
 	prt_human_readable_s64(out, pd->last_proportional);
 	prt_newline(out);
 
-	prt_printf(out, "derivative:");
-	prt_tab(out);
+	prt_printf(out, "derivative:\t");
 	prt_human_readable_s64(out, pd->last_derivative);
 	prt_newline(out);
 
-	prt_printf(out, "change:");
-	prt_tab(out);
+	prt_printf(out, "change:\t");
 	prt_human_readable_s64(out, pd->last_change);
 	prt_newline(out);
 
-	prt_printf(out, "next io:");
-	prt_tab(out);
-	prt_printf(out, "%llims", div64_s64(pd->rate.next - local_clock(), NSEC_PER_MSEC));
-	prt_newline(out);
+	prt_printf(out, "next io:\t%llims\n", div64_s64(pd->rate.next - local_clock(), NSEC_PER_MSEC));
 }
 
 /* misc: */
diff --git a/fs/bcachefs/xattr.c b/fs/bcachefs/xattr.c
index 754f17bba68e..c11bf6dacc2c 100644
--- a/fs/bcachefs/xattr.c
+++ b/fs/bcachefs/xattr.c
@@ -71,7 +71,7 @@ const struct bch_hash_desc bch2_xattr_hash_desc = {
 };
 
 int bch2_xattr_invalid(struct bch_fs *c, struct bkey_s_c k,
-		       enum bkey_invalid_flags flags,
+		       enum bch_validate_flags flags,
 		       struct printbuf *err)
 {
 	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
@@ -118,11 +118,17 @@ void bch2_xattr_to_text(struct printbuf *out, struct bch_fs *c,
 	else
 		prt_printf(out, "(unknown type %u)", xattr.v->x_type);
 
+	unsigned name_len = xattr.v->x_name_len;
+	unsigned val_len  = le16_to_cpu(xattr.v->x_val_len);
+	unsigned max_name_val_bytes = bkey_val_bytes(xattr.k) -
+		offsetof(struct bch_xattr, x_name);
+
+	val_len  = min_t(int, val_len, max_name_val_bytes - name_len);
+	name_len = min(name_len, max_name_val_bytes);
+
 	prt_printf(out, "%.*s:%.*s",
-	       xattr.v->x_name_len,
-	       xattr.v->x_name,
-	       le16_to_cpu(xattr.v->x_val_len),
-	       (char *) xattr_val(xattr.v));
+		   name_len, xattr.v->x_name,
+		   val_len,  (char *) xattr_val(xattr.v));
 
 	if (xattr.v->x_type == KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS ||
 	    xattr.v->x_type == KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT) {
@@ -138,21 +144,13 @@ static int bch2_xattr_get_trans(struct btree_trans *trans, struct bch_inode_info
 	struct bch_hash_info hash = bch2_hash_info_init(trans->c, &inode->ei_inode);
 	struct xattr_search_key search = X_SEARCH(type, name, strlen(name));
 	struct btree_iter iter;
-	struct bkey_s_c_xattr xattr;
-	struct bkey_s_c k;
-	int ret;
-
-	ret = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc, &hash,
-			       inode_inum(inode), &search, 0);
+	struct bkey_s_c k = bch2_hash_lookup(trans, &iter, bch2_xattr_hash_desc, &hash,
+					     inode_inum(inode), &search, 0);
+	int ret = bkey_err(k);
 	if (ret)
-		goto err1;
-
-	k = bch2_btree_iter_peek_slot(&iter);
-	ret = bkey_err(k);
-	if (ret)
-		goto err2;
+		return ret;
 
-	xattr = bkey_s_c_to_xattr(k);
+	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
 	ret = le16_to_cpu(xattr.v->x_val_len);
 	if (buffer) {
 		if (ret > size)
@@ -160,10 +158,8 @@ static int bch2_xattr_get_trans(struct btree_trans *trans, struct bch_inode_info
 		else
 			memcpy(buffer, xattr_val(xattr.v), ret);
 	}
-err2:
 	bch2_trans_iter_exit(trans, &iter);
-err1:
-	return ret < 0 && bch2_err_matches(ret, ENOENT) ? -ENODATA : ret;
+	return ret;
 }
 
 int bch2_xattr_set(struct btree_trans *trans, subvol_inum inum,
@@ -177,7 +173,7 @@ int bch2_xattr_set(struct btree_trans *trans, subvol_inum inum,
 	int ret;
 
 	ret   = bch2_subvol_is_ro_trans(trans, inum.subvol) ?:
-		bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_INTENT);
+		bch2_inode_peek(trans, &inode_iter, inode_u, inum, BTREE_ITER_intent);
 	if (ret)
 		return ret;
 
@@ -212,8 +208,8 @@ int bch2_xattr_set(struct btree_trans *trans, subvol_inum inum,
 
 		ret = bch2_hash_set(trans, bch2_xattr_hash_desc, hash_info,
 			      inum, &xattr->k_i,
-			      (flags & XATTR_CREATE ? BCH_HASH_SET_MUST_CREATE : 0)|
-			      (flags & XATTR_REPLACE ? BCH_HASH_SET_MUST_REPLACE : 0));
+			      (flags & XATTR_CREATE ? STR_HASH_must_create : 0)|
+			      (flags & XATTR_REPLACE ? STR_HASH_must_replace : 0));
 	} else {
 		struct xattr_search_key search =
 			X_SEARCH(type, name, strlen(name));
@@ -359,6 +355,9 @@ static int bch2_xattr_get_handler(const struct xattr_handler *handler,
 	int ret = bch2_trans_do(c, NULL, NULL, 0,
 		bch2_xattr_get_trans(trans, inode, name, buffer, size, handler->flags));
 
+	if (ret < 0 && bch2_err_matches(ret, ENOENT))
+		ret = -ENODATA;
+
 	return bch2_err_class(ret);
 }
 
diff --git a/fs/bcachefs/xattr.h b/fs/bcachefs/xattr.h
index 1337f31a5c49..1574b9eb4c85 100644
--- a/fs/bcachefs/xattr.h
+++ b/fs/bcachefs/xattr.h
@@ -7,7 +7,7 @@
 extern const struct bch_hash_desc bch2_xattr_hash_desc;
 
 int bch2_xattr_invalid(struct bch_fs *, struct bkey_s_c,
-		       enum bkey_invalid_flags, struct printbuf *);
+		       enum bch_validate_flags, struct printbuf *);
 void bch2_xattr_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 #define bch2_bkey_ops_xattr ((struct bkey_ops) {	\
diff --git a/include/linux/closure.h b/include/linux/closure.h
index c554c6a08768..99155df162d0 100644
--- a/include/linux/closure.h
+++ b/include/linux/closure.h
@@ -194,6 +194,18 @@ static inline void closure_sync(struct closure *cl)
 		__closure_sync(cl);
 }
 
+int __closure_sync_timeout(struct closure *cl, unsigned long timeout);
+
+static inline int closure_sync_timeout(struct closure *cl, unsigned long timeout)
+{
+#ifdef CONFIG_DEBUG_CLOSURES
+	BUG_ON(closure_nr_remaining(cl) != 1 && !cl->closure_get_happened);
+#endif
+	return cl->closure_get_happened
+		? __closure_sync_timeout(cl, timeout)
+		: 0;
+}
+
 #ifdef CONFIG_DEBUG_CLOSURES
 
 void closure_debug_create(struct closure *cl);
diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h
index 1b40a968ba91..bb575f3ab45e 100644
--- a/include/uapi/linux/magic.h
+++ b/include/uapi/linux/magic.h
@@ -37,6 +37,7 @@
 #define HOSTFS_SUPER_MAGIC	0x00c0ffee
 #define OVERLAYFS_SUPER_MAGIC	0x794c7630
 #define FUSE_SUPER_MAGIC	0x65735546
+#define BCACHEFS_SUPER_MAGIC	0xca451a4e
 
 #define MINIX_SUPER_MAGIC	0x137F		/* minix v1 fs, 14 char names */
 #define MINIX_SUPER_MAGIC2	0x138F		/* minix v1 fs, 30 char names */
diff --git a/lib/closure.c b/lib/closure.c
index c16540552d61..07409e9e35a5 100644
--- a/lib/closure.c
+++ b/lib/closure.c
@@ -139,6 +139,43 @@ void __sched __closure_sync(struct closure *cl)
 }
 EXPORT_SYMBOL(__closure_sync);
 
+int __sched __closure_sync_timeout(struct closure *cl, unsigned long timeout)
+{
+	struct closure_syncer s = { .task = current };
+	int ret = 0;
+
+	cl->s = &s;
+	continue_at(cl, closure_sync_fn, NULL);
+
+	while (1) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (s.done)
+			break;
+		if (!timeout) {
+			/*
+			 * Carefully undo the continue_at() - but only if it
+			 * hasn't completed, i.e. the final closure_put() hasn't
+			 * happened yet:
+			 */
+			unsigned old, new, v = atomic_read(&cl->remaining);
+			do {
+				old = v;
+				if (!old || (old & CLOSURE_RUNNING))
+					goto success;
+
+				new = old + CLOSURE_REMAINING_INITIALIZER;
+			} while ((v = atomic_cmpxchg(&cl->remaining, old, new)) != old);
+			ret = -ETIME;
+		}
+
+		timeout = schedule_timeout(timeout);
+	}
+success:
+	__set_current_state(TASK_RUNNING);
+	return ret;
+}
+EXPORT_SYMBOL(__closure_sync_timeout);
+
 #ifdef CONFIG_DEBUG_CLOSURES
 
 static LIST_HEAD(closure_list);