bcachefs: Pull out data_update.c

This is the start of reorganizing the data IO paths. The plan is to also
break apart io.c into data_read.c and data_write.c, and migrate_write
will be renamed to the data_update path.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

7 files changed, 452 insertions, 428 deletions

diff --git a/fs/bcachefs/Makefile b/fs/bcachefs/Makefile
index fada601c10db..95b990ad0196 100644
--- a/fs/bcachefs/Makefile
+++ b/fs/bcachefs/Makefile
@@ -25,6 +25,7 @@ bcachefs-y		:=	\
 	debug.o			\
 	dirent.o		\
 	disk_groups.o		\
+	data_update.o		\
 	ec.o			\
 	error.o			\
 	extents.o		\
diff --git a/fs/bcachefs/data_update.c b/fs/bcachefs/data_update.c
new file mode 100644
index 000000000000..0161b0a9f36e
--- /dev/null
+++ b/fs/bcachefs/data_update.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "bcachefs.h"
+#include "alloc_foreground.h"
+#include "bkey_buf.h"
+#include "btree_update.h"
+#include "buckets.h"
+#include "data_update.h"
+#include "ec.h"
+#include "extents.h"
+#include "io.h"
+#include "keylist.h"
+#include "move.h"
+#include "subvolume.h"
+#include "trace.h"
+
+static int insert_snapshot_whiteouts(struct btree_trans *trans,
+				     enum btree_id id,
+				     struct bpos old_pos,
+				     struct bpos new_pos)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter iter, update_iter;
+	struct bkey_s_c k;
+	struct snapshots_seen s;
+	int ret;
+
+	if (!btree_type_has_snapshots(id))
+		return 0;
+
+	snapshots_seen_init(&s);
+
+	if (!bkey_cmp(old_pos, new_pos))
+		return 0;
+
+	if (!snapshot_t(c, old_pos.snapshot)->children[0])
+		return 0;
+
+	bch2_trans_iter_init(trans, &iter, id, old_pos,
+			     BTREE_ITER_NOT_EXTENTS|
+			     BTREE_ITER_ALL_SNAPSHOTS);
+	while (1) {
+next:
+		k = bch2_btree_iter_prev(&iter);
+		ret = bkey_err(k);
+		if (ret)
+			break;
+
+		if (bkey_cmp(old_pos, k.k->p))
+			break;
+
+		if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, old_pos.snapshot)) {
+			struct bkey_i *update;
+			u32 *i;
+
+			darray_for_each(s.ids, i)
+				if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, *i))
+					goto next;
+
+			update = bch2_trans_kmalloc(trans, sizeof(struct bkey_i));
+
+			ret = PTR_ERR_OR_ZERO(update);
+			if (ret)
+				break;
+
+			bkey_init(&update->k);
+			update->k.p = new_pos;
+			update->k.p.snapshot = k.k->p.snapshot;
+
+			bch2_trans_iter_init(trans, &update_iter, id, update->k.p,
+					     BTREE_ITER_NOT_EXTENTS|
+					     BTREE_ITER_ALL_SNAPSHOTS|
+					     BTREE_ITER_INTENT);
+			ret   = bch2_btree_iter_traverse(&update_iter) ?:
+				bch2_trans_update(trans, &update_iter, update,
+					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
+			bch2_trans_iter_exit(trans, &update_iter);
+			if (ret)
+				break;
+
+			ret = snapshots_seen_add(c, &s, k.k->p.snapshot);
+			if (ret)
+				break;
+		}
+	}
+	bch2_trans_iter_exit(trans, &iter);
+	darray_exit(&s.ids);
+
+	return ret;
+}
+
+int bch2_data_update_index_update(struct bch_write_op *op)
+{
+	struct bch_fs *c = op->c;
+	struct btree_trans trans;
+	struct btree_iter iter;
+	struct data_update *m =
+		container_of(op, struct data_update, op);
+	struct open_bucket *ec_ob = ec_open_bucket(c, &op->open_buckets);
+	struct keylist *keys = &op->insert_keys;
+	struct bkey_buf _new, _insert;
+	int ret = 0;
+
+	bch2_bkey_buf_init(&_new);
+	bch2_bkey_buf_init(&_insert);
+	bch2_bkey_buf_realloc(&_insert, c, U8_MAX);
+
+	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 1024);
+
+	bch2_trans_iter_init(&trans, &iter, m->btree_id,
+			     bkey_start_pos(&bch2_keylist_front(keys)->k),
+			     BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+
+	while (1) {
+		struct bkey_s_c k;
+		struct bkey_i *insert;
+		struct bkey_i_extent *new;
+		const union bch_extent_entry *entry;
+		struct extent_ptr_decoded p;
+		struct bpos next_pos;
+		bool did_work = false;
+		bool extending = false, should_check_enospc;
+		s64 i_sectors_delta = 0, disk_sectors_delta = 0;
+
+		bch2_trans_begin(&trans);
+
+		k = bch2_btree_iter_peek_slot(&iter);
+		ret = bkey_err(k);
+		if (ret)
+			goto err;
+
+		new = bkey_i_to_extent(bch2_keylist_front(keys));
+
+		if (bversion_cmp(k.k->version, new->k.version) ||
+		    !bch2_bkey_matches_ptr(c, k, m->ptr, m->offset))
+			goto nomatch;
+
+		bkey_reassemble(_insert.k, k);
+		insert = _insert.k;
+
+		bch2_bkey_buf_copy(&_new, c, bch2_keylist_front(keys));
+		new = bkey_i_to_extent(_new.k);
+		bch2_cut_front(iter.pos, &new->k_i);
+
+		bch2_cut_front(iter.pos,	insert);
+		bch2_cut_back(new->k.p,		insert);
+		bch2_cut_back(insert->k.p,	&new->k_i);
+
+		if (m->data_cmd == DATA_REWRITE) {
+			struct bch_extent_ptr *new_ptr, *old_ptr = (void *)
+				bch2_bkey_has_device(bkey_i_to_s_c(insert),
+						     m->data_opts.rewrite_dev);
+			if (!old_ptr)
+				goto nomatch;
+
+			if (old_ptr->cached)
+				extent_for_each_ptr(extent_i_to_s(new), new_ptr)
+					new_ptr->cached = true;
+
+			__bch2_bkey_drop_ptr(bkey_i_to_s(insert), old_ptr);
+		}
+
+		extent_for_each_ptr_decode(extent_i_to_s(new), p, entry) {
+			if (bch2_bkey_has_device(bkey_i_to_s_c(insert), p.ptr.dev)) {
+				/*
+				 * raced with another move op? extent already
+				 * has a pointer to the device we just wrote
+				 * data to
+				 */
+				continue;
+			}
+
+			bch2_extent_ptr_decoded_append(insert, &p);
+			did_work = true;
+		}
+
+		if (!did_work)
+			goto nomatch;
+
+		bch2_bkey_narrow_crcs(insert,
+				(struct bch_extent_crc_unpacked) { 0 });
+		bch2_extent_normalize(c, bkey_i_to_s(insert));
+		bch2_bkey_mark_replicas_cached(c, bkey_i_to_s(insert),
+					       op->opts.background_target,
+					       op->opts.data_replicas);
+
+		ret = bch2_sum_sector_overwrites(&trans, &iter, insert,
+						 &extending,
+						 &should_check_enospc,
+						 &i_sectors_delta,
+						 &disk_sectors_delta);
+		if (ret)
+			goto err;
+
+		if (disk_sectors_delta > (s64) op->res.sectors) {
+			ret = bch2_disk_reservation_add(c, &op->res,
+						disk_sectors_delta - op->res.sectors,
+						!should_check_enospc
+						? BCH_DISK_RESERVATION_NOFAIL : 0);
+			if (ret)
+				goto out;
+		}
+
+		next_pos = insert->k.p;
+
+		ret   = insert_snapshot_whiteouts(&trans, m->btree_id,
+						  k.k->p, insert->k.p) ?:
+			bch2_trans_update(&trans, &iter, insert,
+				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
+			bch2_trans_commit(&trans, &op->res,
+				op_journal_seq(op),
+				BTREE_INSERT_NOFAIL|
+				m->data_opts.btree_insert_flags);
+		if (!ret) {
+			bch2_btree_iter_set_pos(&iter, next_pos);
+			atomic_long_inc(&c->extent_migrate_done);
+			if (ec_ob)
+				bch2_ob_add_backpointer(c, ec_ob, &insert->k);
+		}
+err:
+		if (ret == -EINTR)
+			ret = 0;
+		if (ret)
+			break;
+next:
+		while (bkey_cmp(iter.pos, bch2_keylist_front(keys)->k.p) >= 0) {
+			bch2_keylist_pop_front(keys);
+			if (bch2_keylist_empty(keys))
+				goto out;
+		}
+		continue;
+nomatch:
+		if (m->ctxt) {
+			BUG_ON(k.k->p.offset <= iter.pos.offset);
+			atomic64_inc(&m->ctxt->stats->keys_raced);
+			atomic64_add(k.k->p.offset - iter.pos.offset,
+				     &m->ctxt->stats->sectors_raced);
+		}
+		atomic_long_inc(&c->extent_migrate_raced);
+		trace_move_race(&new->k);
+		bch2_btree_iter_advance(&iter);
+		goto next;
+	}
+out:
+	bch2_trans_iter_exit(&trans, &iter);
+	bch2_trans_exit(&trans);
+	bch2_bkey_buf_exit(&_insert, c);
+	bch2_bkey_buf_exit(&_new, c);
+	BUG_ON(ret == -EINTR);
+	return ret;
+}
+
+void bch2_data_update_read_done(struct data_update *m, struct bch_read_bio *rbio)
+{
+	/* write bio must own pages: */
+	BUG_ON(!m->op.wbio.bio.bi_vcnt);
+
+	m->ptr		= rbio->pick.ptr;
+	m->offset	= rbio->data_pos.offset - rbio->pick.crc.offset;
+	m->op.devs_have	= rbio->devs_have;
+	m->op.pos	= rbio->data_pos;
+	m->op.version	= rbio->version;
+	m->op.crc	= rbio->pick.crc;
+	m->op.wbio.bio.bi_iter.bi_size = m->op.crc.compressed_size << 9;
+
+	if (m->data_cmd == DATA_REWRITE)
+		bch2_dev_list_drop_dev(&m->op.devs_have, m->data_opts.rewrite_dev);
+}
+
+int bch2_data_update_init(struct bch_fs *c, struct data_update *m,
+			  struct write_point_specifier wp,
+			  struct bch_io_opts io_opts,
+			  enum data_cmd data_cmd,
+			  struct data_opts data_opts,
+			  enum btree_id btree_id,
+			  struct bkey_s_c k)
+{
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+	const union bch_extent_entry *entry;
+	struct bch_extent_crc_unpacked crc;
+	struct extent_ptr_decoded p;
+	int ret;
+
+	m->btree_id	= btree_id;
+	m->data_cmd	= data_cmd;
+	m->data_opts	= data_opts;
+	m->nr_ptrs_reserved = 0;
+
+	bch2_write_op_init(&m->op, c, io_opts);
+
+	if (!bch2_bkey_is_incompressible(k))
+		m->op.compression_type =
+			bch2_compression_opt_to_type[io_opts.background_compression ?:
+						     io_opts.compression];
+	else
+		m->op.incompressible = true;
+
+	m->op.target	= data_opts.target,
+	m->op.write_point = wp;
+
+	/*
+	 * op->csum_type is normally initialized from the fs/file's current
+	 * options - but if an extent is encrypted, we require that it stays
+	 * encrypted:
+	 */
+	bkey_for_each_crc(k.k, ptrs, crc, entry)
+		if (bch2_csum_type_is_encryption(crc.csum_type)) {
+			m->op.nonce	= crc.nonce + crc.offset;
+			m->op.csum_type = crc.csum_type;
+			break;
+		}
+
+	if (m->data_opts.btree_insert_flags & BTREE_INSERT_USE_RESERVE) {
+		m->op.alloc_reserve = RESERVE_movinggc;
+	} else {
+		/* XXX: this should probably be passed in */
+		m->op.flags |= BCH_WRITE_ONLY_SPECIFIED_DEVS;
+	}
+
+	m->op.flags |= BCH_WRITE_PAGES_STABLE|
+		BCH_WRITE_PAGES_OWNED|
+		BCH_WRITE_DATA_ENCODED|
+		BCH_WRITE_FROM_INTERNAL|
+		BCH_WRITE_MOVE;
+
+	m->op.nr_replicas	= data_opts.nr_replicas;
+	m->op.nr_replicas_required = data_opts.nr_replicas;
+
+	switch (data_cmd) {
+	case DATA_ADD_REPLICAS: {
+		/*
+		 * DATA_ADD_REPLICAS is used for moving data to a different
+		 * device in the background, and due to compression the new copy
+		 * might take up more space than the old copy:
+		 */
+#if 0
+		int nr = (int) io_opts.data_replicas -
+			bch2_bkey_nr_ptrs_allocated(k);
+#endif
+		int nr = (int) io_opts.data_replicas;
+
+		if (nr > 0) {
+			m->op.nr_replicas = m->nr_ptrs_reserved = nr;
+
+			ret = bch2_disk_reservation_get(c, &m->op.res,
+					k.k->size, m->op.nr_replicas, 0);
+			if (ret)
+				return ret;
+		}
+		break;
+	}
+	case DATA_REWRITE: {
+		unsigned compressed_sectors = 0;
+
+		bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
+			if (p.ptr.dev == data_opts.rewrite_dev) {
+				if (p.ptr.cached)
+					m->op.flags |= BCH_WRITE_CACHED;
+
+				if (!p.ptr.cached &&
+				    crc_is_compressed(p.crc))
+					compressed_sectors += p.crc.compressed_size;
+			}
+
+		if (compressed_sectors) {
+			ret = bch2_disk_reservation_add(c, &m->op.res,
+					k.k->size * m->op.nr_replicas,
+					BCH_DISK_RESERVATION_NOFAIL);
+			if (ret)
+				return ret;
+		}
+		break;
+	}
+	case DATA_PROMOTE:
+		m->op.flags	|= BCH_WRITE_ALLOC_NOWAIT;
+		m->op.flags	|= BCH_WRITE_CACHED;
+		break;
+	default:
+		BUG();
+	}
+
+	return 0;
+}
diff --git a/fs/bcachefs/data_update.h b/fs/bcachefs/data_update.h
new file mode 100644
index 000000000000..03b4ca5a4ee8
--- /dev/null
+++ b/fs/bcachefs/data_update.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _BCACHEFS_DATA_UPDATE_H
+#define _BCACHEFS_DATA_UPDATE_H
+
+#include "io_types.h"
+
+enum data_cmd {
+	DATA_SKIP,
+	DATA_SCRUB,
+	DATA_ADD_REPLICAS,
+	DATA_REWRITE,
+	DATA_PROMOTE,
+};
+
+struct data_opts {
+	u16		target;
+	u8		rewrite_dev;
+	u8		nr_replicas;
+	int		btree_insert_flags;
+};
+
+struct data_update {
+	enum btree_id		btree_id;
+	enum data_cmd		data_cmd;
+	struct data_opts	data_opts;
+
+	unsigned		nr_ptrs_reserved;
+
+	struct moving_context	*ctxt;
+
+	/* what we read: */
+	struct bch_extent_ptr	ptr;
+	u64			offset;
+
+	struct bch_write_op	op;
+};
+
+int bch2_data_update_index_update(struct bch_write_op *);
+
+void bch2_data_update_read_done(struct data_update *, struct bch_read_bio *);
+int bch2_data_update_init(struct bch_fs *, struct data_update *,
+			  struct write_point_specifier,
+			  struct bch_io_opts,
+			  enum data_cmd, struct data_opts,
+			  enum btree_id, struct bkey_s_c);
+
+#endif /* _BCACHEFS_DATA_UPDATE_H */
diff --git a/fs/bcachefs/ec.h b/fs/bcachefs/ec.h
index a4c13d61af10..c53187df4651 100644
--- a/fs/bcachefs/ec.h
+++ b/fs/bcachefs/ec.h
@@ -4,6 +4,7 @@
 
 #include "ec_types.h"
 #include "buckets_types.h"
+#include "extents_types.h"
 #include "keylist_types.h"
 
 int bch2_stripe_invalid(const struct bch_fs *, struct bkey_s_c,
diff --git a/fs/bcachefs/io.c b/fs/bcachefs/io.c
index ca72a31da502..743449ed7fae 100644
--- a/fs/bcachefs/io.c
+++ b/fs/bcachefs/io.c
@@ -16,6 +16,7 @@
 #include "checksum.h"
 #include "compress.h"
 #include "clock.h"
+#include "data_update.h"
 #include "debug.h"
 #include "disk_groups.h"
 #include "ec.h"
@@ -660,7 +661,7 @@ static void __bch2_write_index(struct bch_write_op *op)
 
 		ret = !(op->flags & BCH_WRITE_MOVE)
 			? bch2_write_index_default(op)
-			: bch2_migrate_index_update(op);
+			: bch2_data_update_index_update(op);
 
 		BUG_ON(ret == -EINTR);
 		BUG_ON(keylist_sectors(keys) && !ret);
@@ -1433,7 +1434,7 @@ struct promote_op {
 	struct rhash_head	hash;
 	struct bpos		pos;
 
-	struct migrate_write	write;
+	struct data_update	write;
 	struct bio_vec		bi_inline_vecs[0]; /* must be last */
 };
 
@@ -1508,7 +1509,7 @@ static void promote_start(struct promote_op *op, struct bch_read_bio *rbio)
 	       sizeof(struct bio_vec) * rbio->bio.bi_vcnt);
 	swap(bio->bi_vcnt, rbio->bio.bi_vcnt);
 
-	bch2_migrate_read_done(&op->write, rbio);
+	bch2_data_update_read_done(&op->write, rbio);
 
 	closure_call(&op->write.op.cl, bch2_write, c->btree_update_wq, NULL);
 }
@@ -1565,7 +1566,7 @@ static struct promote_op *__promote_alloc(struct bch_fs *c,
 	bio = &op->write.op.wbio.bio;
 	bio_init(bio, NULL, bio->bi_inline_vecs, pages, 0);
 
-	ret = bch2_migrate_write_init(c, &op->write,
+	ret = bch2_data_update_init(c, &op->write,
 			writepoint_hashed((unsigned long) current),
 			opts,
 			DATA_PROMOTE,
diff --git a/fs/bcachefs/move.c b/fs/bcachefs/move.c
index 08fb8c71893f..a3a486cff28e 100644
--- a/fs/bcachefs/move.c
+++ b/fs/bcachefs/move.c
@@ -6,7 +6,6 @@
 #include "btree_gc.h"
 #include "btree_update.h"
 #include "btree_update_interior.h"
-#include "buckets.h"
 #include "disk_groups.h"
 #include "ec.h"
 #include "inode.h"
@@ -15,7 +14,6 @@
 #include "keylist.h"
 #include "move.h"
 #include "replicas.h"
-#include "subvolume.h"
 #include "super-io.h"
 #include "trace.h"
 
@@ -32,394 +30,11 @@ struct moving_io {
 
 	struct bch_read_bio	rbio;
 
-	struct migrate_write	write;
+	struct data_update	write;
 	/* Must be last since it is variable size */
 	struct bio_vec		bi_inline_vecs[0];
 };
 
-struct moving_context {
-	/* Closure for waiting on all reads and writes to complete */
-	struct closure		cl;
-
-	struct bch_move_stats	*stats;
-
-	struct list_head	reads;
-
-	/* in flight sectors: */
-	atomic_t		read_sectors;
-	atomic_t		write_sectors;
-
-	wait_queue_head_t	wait;
-};
-
-static int insert_snapshot_whiteouts(struct btree_trans *trans,
-				     enum btree_id id,
-				     struct bpos old_pos,
-				     struct bpos new_pos)
-{
-	struct bch_fs *c = trans->c;
-	struct btree_iter iter, update_iter;
-	struct bkey_s_c k;
-	struct snapshots_seen s;
-	int ret;
-
-	if (!btree_type_has_snapshots(id))
-		return 0;
-
-	snapshots_seen_init(&s);
-
-	if (!bkey_cmp(old_pos, new_pos))
-		return 0;
-
-	if (!snapshot_t(c, old_pos.snapshot)->children[0])
-		return 0;
-
-	bch2_trans_iter_init(trans, &iter, id, old_pos,
-			     BTREE_ITER_NOT_EXTENTS|
-			     BTREE_ITER_ALL_SNAPSHOTS);
-	while (1) {
-next:
-		k = bch2_btree_iter_prev(&iter);
-		ret = bkey_err(k);
-		if (ret)
-			break;
-
-		if (bkey_cmp(old_pos, k.k->p))
-			break;
-
-		if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, old_pos.snapshot)) {
-			struct bkey_i *update;
-			u32 *i;
-
-			darray_for_each(s.ids, i)
-				if (bch2_snapshot_is_ancestor(c, k.k->p.snapshot, *i))
-					goto next;
-
-			update = bch2_trans_kmalloc(trans, sizeof(struct bkey_i));
-
-			ret = PTR_ERR_OR_ZERO(update);
-			if (ret)
-				break;
-
-			bkey_init(&update->k);
-			update->k.p = new_pos;
-			update->k.p.snapshot = k.k->p.snapshot;
-
-			bch2_trans_iter_init(trans, &update_iter, id, update->k.p,
-					     BTREE_ITER_NOT_EXTENTS|
-					     BTREE_ITER_ALL_SNAPSHOTS|
-					     BTREE_ITER_INTENT);
-			ret   = bch2_btree_iter_traverse(&update_iter) ?:
-				bch2_trans_update(trans, &update_iter, update,
-					  BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE);
-			bch2_trans_iter_exit(trans, &update_iter);
-			if (ret)
-				break;
-
-			ret = snapshots_seen_add(c, &s, k.k->p.snapshot);
-			if (ret)
-				break;
-		}
-	}
-	bch2_trans_iter_exit(trans, &iter);
-	darray_exit(&s.ids);
-
-	return ret;
-}
-
-int bch2_migrate_index_update(struct bch_write_op *op)
-{
-	struct bch_fs *c = op->c;
-	struct btree_trans trans;
-	struct btree_iter iter;
-	struct migrate_write *m =
-		container_of(op, struct migrate_write, op);
-	struct open_bucket *ec_ob = ec_open_bucket(c, &op->open_buckets);
-	struct keylist *keys = &op->insert_keys;
-	struct bkey_buf _new, _insert;
-	int ret = 0;
-
-	bch2_bkey_buf_init(&_new);
-	bch2_bkey_buf_init(&_insert);
-	bch2_bkey_buf_realloc(&_insert, c, U8_MAX);
-
-	bch2_trans_init(&trans, c, BTREE_ITER_MAX, 1024);
-
-	bch2_trans_iter_init(&trans, &iter, m->btree_id,
-			     bkey_start_pos(&bch2_keylist_front(keys)->k),
-			     BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
-
-	while (1) {
-		struct bkey_s_c k;
-		struct bkey_i *insert;
-		struct bkey_i_extent *new;
-		const union bch_extent_entry *entry;
-		struct extent_ptr_decoded p;
-		struct bpos next_pos;
-		bool did_work = false;
-		bool extending = false, should_check_enospc;
-		s64 i_sectors_delta = 0, disk_sectors_delta = 0;
-
-		bch2_trans_begin(&trans);
-
-		k = bch2_btree_iter_peek_slot(&iter);
-		ret = bkey_err(k);
-		if (ret)
-			goto err;
-
-		new = bkey_i_to_extent(bch2_keylist_front(keys));
-
-		if (bversion_cmp(k.k->version, new->k.version) ||
-		    !bch2_bkey_matches_ptr(c, k, m->ptr, m->offset))
-			goto nomatch;
-
-		bkey_reassemble(_insert.k, k);
-		insert = _insert.k;
-
-		bch2_bkey_buf_copy(&_new, c, bch2_keylist_front(keys));
-		new = bkey_i_to_extent(_new.k);
-		bch2_cut_front(iter.pos, &new->k_i);
-
-		bch2_cut_front(iter.pos,	insert);
-		bch2_cut_back(new->k.p,		insert);
-		bch2_cut_back(insert->k.p,	&new->k_i);
-
-		if (m->data_cmd == DATA_REWRITE) {
-			struct bch_extent_ptr *new_ptr, *old_ptr = (void *)
-				bch2_bkey_has_device(bkey_i_to_s_c(insert),
-						     m->data_opts.rewrite_dev);
-			if (!old_ptr)
-				goto nomatch;
-
-			if (old_ptr->cached)
-				extent_for_each_ptr(extent_i_to_s(new), new_ptr)
-					new_ptr->cached = true;
-
-			__bch2_bkey_drop_ptr(bkey_i_to_s(insert), old_ptr);
-		}
-
-		extent_for_each_ptr_decode(extent_i_to_s(new), p, entry) {
-			if (bch2_bkey_has_device(bkey_i_to_s_c(insert), p.ptr.dev)) {
-				/*
-				 * raced with another move op? extent already
-				 * has a pointer to the device we just wrote
-				 * data to
-				 */
-				continue;
-			}
-
-			bch2_extent_ptr_decoded_append(insert, &p);
-			did_work = true;
-		}
-
-		if (!did_work)
-			goto nomatch;
-
-		bch2_bkey_narrow_crcs(insert,
-				(struct bch_extent_crc_unpacked) { 0 });
-		bch2_extent_normalize(c, bkey_i_to_s(insert));
-		bch2_bkey_mark_replicas_cached(c, bkey_i_to_s(insert),
-					       op->opts.background_target,
-					       op->opts.data_replicas);
-
-		ret = bch2_sum_sector_overwrites(&trans, &iter, insert,
-						 &extending,
-						 &should_check_enospc,
-						 &i_sectors_delta,
-						 &disk_sectors_delta);
-		if (ret)
-			goto err;
-
-		if (disk_sectors_delta > (s64) op->res.sectors) {
-			ret = bch2_disk_reservation_add(c, &op->res,
-						disk_sectors_delta - op->res.sectors,
-						!should_check_enospc
-						? BCH_DISK_RESERVATION_NOFAIL : 0);
-			if (ret)
-				goto out;
-		}
-
-		next_pos = insert->k.p;
-
-		ret   = insert_snapshot_whiteouts(&trans, m->btree_id,
-						  k.k->p, insert->k.p) ?:
-			bch2_trans_update(&trans, &iter, insert,
-				BTREE_UPDATE_INTERNAL_SNAPSHOT_NODE) ?:
-			bch2_trans_commit(&trans, &op->res,
-				op_journal_seq(op),
-				BTREE_INSERT_NOFAIL|
-				m->data_opts.btree_insert_flags);
-		if (!ret) {
-			bch2_btree_iter_set_pos(&iter, next_pos);
-			atomic_long_inc(&c->extent_migrate_done);
-			if (ec_ob)
-				bch2_ob_add_backpointer(c, ec_ob, &insert->k);
-		}
-err:
-		if (ret == -EINTR)
-			ret = 0;
-		if (ret)
-			break;
-next:
-		while (bkey_cmp(iter.pos, bch2_keylist_front(keys)->k.p) >= 0) {
-			bch2_keylist_pop_front(keys);
-			if (bch2_keylist_empty(keys))
-				goto out;
-		}
-		continue;
-nomatch:
-		if (m->ctxt) {
-			BUG_ON(k.k->p.offset <= iter.pos.offset);
-			atomic64_inc(&m->ctxt->stats->keys_raced);
-			atomic64_add(k.k->p.offset - iter.pos.offset,
-				     &m->ctxt->stats->sectors_raced);
-		}
-		atomic_long_inc(&c->extent_migrate_raced);
-		trace_move_race(&new->k);
-		bch2_btree_iter_advance(&iter);
-		goto next;
-	}
-out:
-	bch2_trans_iter_exit(&trans, &iter);
-	bch2_trans_exit(&trans);
-	bch2_bkey_buf_exit(&_insert, c);
-	bch2_bkey_buf_exit(&_new, c);
-	BUG_ON(ret == -EINTR);
-	return ret;
-}
-
-void bch2_migrate_read_done(struct migrate_write *m, struct bch_read_bio *rbio)
-{
-	/* write bio must own pages: */
-	BUG_ON(!m->op.wbio.bio.bi_vcnt);
-
-	m->ptr		= rbio->pick.ptr;
-	m->offset	= rbio->data_pos.offset - rbio->pick.crc.offset;
-	m->op.devs_have	= rbio->devs_have;
-	m->op.pos	= rbio->data_pos;
-	m->op.version	= rbio->version;
-	m->op.crc	= rbio->pick.crc;
-	m->op.wbio.bio.bi_iter.bi_size = m->op.crc.compressed_size << 9;
-
-	if (m->data_cmd == DATA_REWRITE)
-		bch2_dev_list_drop_dev(&m->op.devs_have, m->data_opts.rewrite_dev);
-}
-
-int bch2_migrate_write_init(struct bch_fs *c, struct migrate_write *m,
-			    struct write_point_specifier wp,
-			    struct bch_io_opts io_opts,
-			    enum data_cmd data_cmd,
-			    struct data_opts data_opts,
-			    enum btree_id btree_id,
-			    struct bkey_s_c k)
-{
-	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
-	const union bch_extent_entry *entry;
-	struct bch_extent_crc_unpacked crc;
-	struct extent_ptr_decoded p;
-	int ret;
-
-	m->btree_id	= btree_id;
-	m->data_cmd	= data_cmd;
-	m->data_opts	= data_opts;
-	m->nr_ptrs_reserved = 0;
-
-	bch2_write_op_init(&m->op, c, io_opts);
-
-	if (!bch2_bkey_is_incompressible(k))
-		m->op.compression_type =
-			bch2_compression_opt_to_type[io_opts.background_compression ?:
-						     io_opts.compression];
-	else
-		m->op.incompressible = true;
-
-	m->op.target	= data_opts.target,
-	m->op.write_point = wp;
-
-	/*
-	 * op->csum_type is normally initialized from the fs/file's current
-	 * options - but if an extent is encrypted, we require that it stays
-	 * encrypted:
-	 */
-	bkey_for_each_crc(k.k, ptrs, crc, entry)
-		if (bch2_csum_type_is_encryption(crc.csum_type)) {
-			m->op.nonce	= crc.nonce + crc.offset;
-			m->op.csum_type = crc.csum_type;
-			break;
-		}
-
-	if (m->data_opts.btree_insert_flags & BTREE_INSERT_USE_RESERVE) {
-		m->op.alloc_reserve = RESERVE_movinggc;
-	} else {
-		/* XXX: this should probably be passed in */
-		m->op.flags |= BCH_WRITE_ONLY_SPECIFIED_DEVS;
-	}
-
-	m->op.flags |= BCH_WRITE_PAGES_STABLE|
-		BCH_WRITE_PAGES_OWNED|
-		BCH_WRITE_DATA_ENCODED|
-		BCH_WRITE_FROM_INTERNAL|
-		BCH_WRITE_MOVE;
-
-	m->op.nr_replicas	= data_opts.nr_replicas;
-	m->op.nr_replicas_required = data_opts.nr_replicas;
-
-	switch (data_cmd) {
-	case DATA_ADD_REPLICAS: {
-		/*
-		 * DATA_ADD_REPLICAS is used for moving data to a different
-		 * device in the background, and due to compression the new copy
-		 * might take up more space than the old copy:
-		 */
-#if 0
-		int nr = (int) io_opts.data_replicas -
-			bch2_bkey_nr_ptrs_allocated(k);
-#endif
-		int nr = (int) io_opts.data_replicas;
-
-		if (nr > 0) {
-			m->op.nr_replicas = m->nr_ptrs_reserved = nr;
-
-			ret = bch2_disk_reservation_get(c, &m->op.res,
-					k.k->size, m->op.nr_replicas, 0);
-			if (ret)
-				return ret;
-		}
-		break;
-	}
-	case DATA_REWRITE: {
-		unsigned compressed_sectors = 0;
-
-		bkey_for_each_ptr_decode(k.k, ptrs, p, entry)
-			if (p.ptr.dev == data_opts.rewrite_dev) {
-				if (p.ptr.cached)
-					m->op.flags |= BCH_WRITE_CACHED;
-
-				if (!p.ptr.cached &&
-				    crc_is_compressed(p.crc))
-					compressed_sectors += p.crc.compressed_size;
-			}
-
-		if (compressed_sectors) {
-			ret = bch2_disk_reservation_add(c, &m->op.res,
-					k.k->size * m->op.nr_replicas,
-					BCH_DISK_RESERVATION_NOFAIL);
-			if (ret)
-				return ret;
-		}
-		break;
-	}
-	case DATA_PROMOTE:
-		m->op.flags	|= BCH_WRITE_ALLOC_NOWAIT;
-		m->op.flags	|= BCH_WRITE_CACHED;
-		break;
-	default:
-		BUG();
-	}
-
-	return 0;
-}
-
 static void move_free(struct moving_io *io)
 {
 	struct moving_context *ctxt = io->write.ctxt;
@@ -457,7 +72,7 @@ static void move_write(struct moving_io *io)
 	closure_get(&io->write.ctxt->cl);
 	atomic_add(io->write_sectors, &io->write.ctxt->write_sectors);
 
-	bch2_migrate_read_done(&io->write, &io->rbio);
+	bch2_data_update_read_done(&io->write, &io->rbio);
 	closure_call(&io->write.op.cl, bch2_write, NULL, NULL);
 }
 
@@ -564,8 +179,8 @@ static int bch2_move_extent(struct btree_trans *trans,
 	io->rbio.bio.bi_iter.bi_sector	= bkey_start_offset(k.k);
 	io->rbio.bio.bi_end_io		= move_read_endio;
 
-	ret = bch2_migrate_write_init(c, &io->write, wp, io_opts,
-				      data_cmd, data_opts, btree_id, k);
+	ret = bch2_data_update_init(c, &io->write, wp, io_opts,
+				    data_cmd, data_opts, btree_id, k);
 	if (ret)
 		goto err_free_pages;
 
diff --git a/fs/bcachefs/move.h b/fs/bcachefs/move.h
index 901d8f875946..6d273f67a82c 100644
--- a/fs/bcachefs/move.h
+++ b/fs/bcachefs/move.h
@@ -4,51 +4,26 @@
 
 #include "btree_iter.h"
 #include "buckets.h"
-#include "io_types.h"
+#include "data_update.h"
 #include "move_types.h"
 
 struct bch_read_bio;
-struct moving_context;
 
-enum data_cmd {
-	DATA_SKIP,
-	DATA_SCRUB,
-	DATA_ADD_REPLICAS,
-	DATA_REWRITE,
-	DATA_PROMOTE,
-};
-
-struct data_opts {
-	u16		target;
-	u8		rewrite_dev;
-	u8		nr_replicas;
-	int		btree_insert_flags;
-};
+struct moving_context {
+	/* Closure for waiting on all reads and writes to complete */
+	struct closure		cl;
 
-struct migrate_write {
-	enum btree_id		btree_id;
-	enum data_cmd		data_cmd;
-	struct data_opts	data_opts;
+	struct bch_move_stats	*stats;
 
-	unsigned		nr_ptrs_reserved;
+	struct list_head	reads;
 
-	struct moving_context	*ctxt;
+	/* in flight sectors: */
+	atomic_t		read_sectors;
+	atomic_t		write_sectors;
 
-	/* what we read: */
-	struct bch_extent_ptr	ptr;
-	u64			offset;
-
-	struct bch_write_op	op;
+	wait_queue_head_t	wait;
 };
 
-int bch2_migrate_index_update(struct bch_write_op *);
-void bch2_migrate_read_done(struct migrate_write *, struct bch_read_bio *);
-int bch2_migrate_write_init(struct bch_fs *, struct migrate_write *,
-			    struct write_point_specifier,
-			    struct bch_io_opts,
-			    enum data_cmd, struct data_opts,
-			    enum btree_id, struct bkey_s_c);
-
 typedef enum data_cmd (*move_pred_fn)(struct bch_fs *, void *,
 				struct bkey_s_c,
 				struct bch_io_opts *, struct data_opts *);