bcachefs: Add new helper to retrieve bch_member from sb

Prep work for introducing bch_sb_field_members_v2 - introduce new
helpers that will check for members_v2 if it exists, otherwise using v1

Signed-off-by: Hunter Shaffer <huntershaffer182456@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

8 files changed, 62 insertions, 65 deletions

diff --git a/fs/bcachefs/disk_groups.c b/fs/bcachefs/disk_groups.c
index b292dbef7992..1bf47a6209dd 100644
--- a/fs/bcachefs/disk_groups.c
+++ b/fs/bcachefs/disk_groups.c
@@ -25,19 +25,18 @@ static int bch2_sb_disk_groups_validate(struct bch_sb *sb,
 	struct bch_sb_field_disk_groups *groups =
 		field_to_type(f, disk_groups);
 	struct bch_disk_group *g, *sorted = NULL;
-	struct bch_sb_field_members *mi = bch2_sb_get_members(sb);
 	unsigned nr_groups = disk_groups_nr(groups);
 	unsigned i, len;
 	int ret = 0;
 
 	for (i = 0; i < sb->nr_devices; i++) {
-		struct bch_member *m = mi->members + i;
+		struct bch_member m = bch2_sb_member_get(sb, i);
 		unsigned group_id;
 
-		if (!BCH_MEMBER_GROUP(m))
+		if (!BCH_MEMBER_GROUP(&m))
 			continue;
 
-		group_id = BCH_MEMBER_GROUP(m) - 1;
+		group_id = BCH_MEMBER_GROUP(&m) - 1;
 
 		if (group_id >= nr_groups) {
 			prt_printf(err, "disk %u has invalid label %u (have %u)",
@@ -152,14 +151,12 @@ const struct bch_sb_field_ops bch_sb_field_ops_disk_groups = {
 
 int bch2_sb_disk_groups_to_cpu(struct bch_fs *c)
 {
-	struct bch_sb_field_members *mi;
 	struct bch_sb_field_disk_groups *groups;
 	struct bch_disk_groups_cpu *cpu_g, *old_g;
 	unsigned i, g, nr_groups;
 
 	lockdep_assert_held(&c->sb_lock);
 
-	mi		= bch2_sb_get_members(c->disk_sb.sb);
 	groups		= bch2_sb_get_disk_groups(c->disk_sb.sb);
 	nr_groups	= disk_groups_nr(groups);
 
@@ -182,13 +179,13 @@ int bch2_sb_disk_groups_to_cpu(struct bch_fs *c)
 	}
 
 	for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
-		struct bch_member *m = mi->members + i;
+		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_exists(&m))
 			continue;
 
-		g = BCH_MEMBER_GROUP(m);
+		g = BCH_MEMBER_GROUP(&m);
 		while (g) {
 			dst = &cpu_g->entries[g - 1];
 			__set_bit(i, dst->devs.d);
@@ -528,12 +525,11 @@ void bch2_opt_target_to_text(struct printbuf *out,
 
 			rcu_read_unlock();
 		} else {
-			struct bch_sb_field_members *mi = bch2_sb_get_members(sb);
-			struct bch_member *m = mi->members + t.dev;
+			struct bch_member m = bch2_sb_member_get(sb, t.dev);
 
-			if (bch2_dev_exists(sb, mi, t.dev)) {
+			if (bch2_dev_exists(sb, t.dev)) {
 				prt_printf(out, "Device ");
-				pr_uuid(out, m->uuid.b);
+				pr_uuid(out, m.uuid.b);
 				prt_printf(out, " (%u)", t.dev);
 			} else {
 				prt_printf(out, "Bad device %u", t.dev);
diff --git a/fs/bcachefs/journal_sb.c b/fs/bcachefs/journal_sb.c
index cc41bff86d6b..3c5a95e29463 100644
--- a/fs/bcachefs/journal_sb.c
+++ b/fs/bcachefs/journal_sb.c
@@ -21,7 +21,7 @@ static int bch2_sb_journal_validate(struct bch_sb *sb,
 				    struct printbuf *err)
 {
 	struct bch_sb_field_journal *journal = field_to_type(f, journal);
-	struct bch_member *m = bch2_sb_get_members(sb)->members + sb->dev_idx;
+	struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
 	int ret = -BCH_ERR_invalid_sb_journal;
 	unsigned nr;
 	unsigned i;
@@ -45,15 +45,15 @@ static int bch2_sb_journal_validate(struct bch_sb *sb,
 		goto err;
 	}
 
-	if (b[0] < le16_to_cpu(m->first_bucket)) {
+	if (b[0] < le16_to_cpu(m.first_bucket)) {
 		prt_printf(err, "journal bucket %llu before first bucket %u",
-		       b[0], le16_to_cpu(m->first_bucket));
+		       b[0], le16_to_cpu(m.first_bucket));
 		goto err;
 	}
 
-	if (b[nr - 1] >= le64_to_cpu(m->nbuckets)) {
+	if (b[nr - 1] >= le64_to_cpu(m.nbuckets)) {
 		prt_printf(err, "journal bucket %llu past end of device (nbuckets %llu)",
-		       b[nr - 1], le64_to_cpu(m->nbuckets));
+		       b[nr - 1], le64_to_cpu(m.nbuckets));
 		goto err;
 	}
 
@@ -104,7 +104,7 @@ static int bch2_sb_journal_v2_validate(struct bch_sb *sb,
 				    struct printbuf *err)
 {
 	struct bch_sb_field_journal_v2 *journal = field_to_type(f, journal_v2);
-	struct bch_member *m = bch2_sb_get_members(sb)->members + sb->dev_idx;
+	struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
 	int ret = -BCH_ERR_invalid_sb_journal;
 	unsigned nr;
 	unsigned i;
@@ -130,15 +130,15 @@ static int bch2_sb_journal_v2_validate(struct bch_sb *sb,
 		goto err;
 	}
 
-	if (b[0].start < le16_to_cpu(m->first_bucket)) {
+	if (b[0].start < le16_to_cpu(m.first_bucket)) {
 		prt_printf(err, "journal bucket %llu before first bucket %u",
-		       b[0].start, le16_to_cpu(m->first_bucket));
+		       b[0].start, le16_to_cpu(m.first_bucket));
 		goto err;
 	}
 
-	if (b[nr - 1].end > le64_to_cpu(m->nbuckets)) {
+	if (b[nr - 1].end > le64_to_cpu(m.nbuckets)) {
 		prt_printf(err, "journal bucket %llu past end of device (nbuckets %llu)",
-		       b[nr - 1].end - 1, le64_to_cpu(m->nbuckets));
+		       b[nr - 1].end - 1, le64_to_cpu(m.nbuckets));
 		goto err;
 	}
 
diff --git a/fs/bcachefs/replicas.c b/fs/bcachefs/replicas.c
index dbef41cd8593..a9a694fb0b18 100644
--- a/fs/bcachefs/replicas.c
+++ b/fs/bcachefs/replicas.c
@@ -805,7 +805,6 @@ static int bch2_cpu_replicas_validate(struct bch_replicas_cpu *cpu_r,
 				      struct bch_sb *sb,
 				      struct printbuf *err)
 {
-	struct bch_sb_field_members *mi = bch2_sb_get_members(sb);
 	unsigned i, j;
 
 	sort_cmp_size(cpu_r->entries,
@@ -837,7 +836,7 @@ static int bch2_cpu_replicas_validate(struct bch_replicas_cpu *cpu_r,
 		}
 
 		for (j = 0; j < e->nr_devs; j++)
-			if (!bch2_dev_exists(sb, mi, e->devs[j])) {
+			if (!bch2_dev_exists(sb, e->devs[j])) {
 				prt_printf(err, "invalid device %u in entry ", e->devs[j]);
 				bch2_replicas_entry_to_text(err, e);
 				return -BCH_ERR_invalid_sb_replicas;
diff --git a/fs/bcachefs/sb-members.c b/fs/bcachefs/sb-members.c
index 16a2b3389525..0be51d082043 100644
--- a/fs/bcachefs/sb-members.c
+++ b/fs/bcachefs/sb-members.c
@@ -7,6 +7,23 @@
 #include "super-io.h"
 
 /* Code for bch_sb_field_members: */
+static struct bch_member *members_v1_get_mut(struct bch_sb_field_members *mi, int i)
+{
+	return mi->members + i;
+}
+
+static struct bch_member members_v1_get(struct bch_sb_field_members *mi, int i)
+{
+	struct bch_member ret, *p = members_v1_get_mut(mi, i);
+	memset(&ret, 0, sizeof(ret));
+	memcpy(&ret, p, min_t(size_t, sizeof(struct bch_member), sizeof(ret))); return ret;
+}
+
+struct bch_member bch2_sb_member_get(struct bch_sb *sb, int i)
+{
+	struct bch_sb_field_members *mi1 = bch2_sb_get_members(sb);
+	return members_v1_get(mi1, i);
+}
 
 static int bch2_sb_members_validate(struct bch_sb *sb,
 				    struct bch_sb_field *f,
diff --git a/fs/bcachefs/sb-members.h b/fs/bcachefs/sb-members.h
index 34e1cf6046e3..85d1af6a990c 100644
--- a/fs/bcachefs/sb-members.h
+++ b/fs/bcachefs/sb-members.h
@@ -2,6 +2,8 @@
 #ifndef _BCACHEFS_SB_MEMBERS_H
 #define _BCACHEFS_SB_MEMBERS_H
 
+struct bch_member bch2_sb_member_get(struct bch_sb *sb, int i);
+
 static inline bool bch2_dev_is_online(struct bch_dev *ca)
 {
 	return !percpu_ref_is_zero(&ca->io_ref);
diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c
index c9bf342d14aa..16e3a8aa290d 100644
--- a/fs/bcachefs/super-io.c
+++ b/fs/bcachefs/super-io.c
@@ -485,7 +485,6 @@ static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
 static void bch2_sb_update(struct bch_fs *c)
 {
 	struct bch_sb *src = c->disk_sb.sb;
-	struct bch_sb_field_members *mi = bch2_sb_get_members(src);
 	struct bch_dev *ca;
 	unsigned i;
 
@@ -511,8 +510,10 @@ static void bch2_sb_update(struct bch_fs *c)
 	c->sb.features		= le64_to_cpu(src->features[0]);
 	c->sb.compat		= le64_to_cpu(src->compat[0]);
 
-	for_each_member_device(ca, c, i)
-		ca->mi = bch2_mi_to_cpu(mi->members + i);
+	for_each_member_device(ca, c, i) {
+		struct bch_member m = bch2_sb_member_get(src, i);
+		ca->mi = bch2_mi_to_cpu(&m);
+	}
 }
 
 static int __copy_super(struct bch_sb_handle *dst_handle, struct bch_sb *src)
@@ -1125,7 +1126,6 @@ void bch2_sb_layout_to_text(struct printbuf *out, struct bch_sb_layout *l)
 void bch2_sb_to_text(struct printbuf *out, struct bch_sb *sb,
 		     bool print_layout, unsigned fields)
 {
-	struct bch_sb_field_members *mi;
 	struct bch_sb_field *f;
 	u64 fields_have = 0;
 	unsigned nr_devices = 0;
@@ -1133,15 +1133,8 @@ void bch2_sb_to_text(struct printbuf *out, struct bch_sb *sb,
 	if (!out->nr_tabstops)
 		printbuf_tabstop_push(out, 44);
 
-	mi = bch2_sb_get_members(sb);
-	if (mi) {
-		struct bch_member *m;
-
-		for (m = mi->members;
-		     m < mi->members + sb->nr_devices;
-		     m++)
-			nr_devices += bch2_member_exists(m);
-	}
+	for (int i = 0; i < sb->nr_devices; i++)
+		nr_devices += bch2_dev_exists(sb, i);
 
 	prt_printf(out, "External UUID:");
 	prt_tab(out);
diff --git a/fs/bcachefs/super-io.h b/fs/bcachefs/super-io.h
index d51c0a19586f..817c3d790acd 100644
--- a/fs/bcachefs/super-io.h
+++ b/fs/bcachefs/super-io.h
@@ -6,6 +6,7 @@
 #include "eytzinger.h"
 #include "super_types.h"
 #include "super.h"
+#include "sb-members.h"
 
 #include <asm/byteorder.h>
 
@@ -97,11 +98,13 @@ static inline bool bch2_member_exists(struct bch_member *m)
 }
 
 static inline bool bch2_dev_exists(struct bch_sb *sb,
-				   struct bch_sb_field_members *mi,
 				   unsigned dev)
 {
-	return dev < sb->nr_devices &&
-		bch2_member_exists(&mi->members[dev]);
+	if (dev < sb->nr_devices) {
+	struct bch_member m = bch2_sb_member_get(sb, dev);
+		return bch2_member_exists(&m);
+	}
+	return false;
 }
 
 static inline struct bch_member_cpu bch2_mi_to_cpu(struct bch_member *mi)
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index 1347270e5045..7ba1ebabc176 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -49,6 +49,7 @@
 #include "recovery.h"
 #include "replicas.h"
 #include "sb-clean.h"
+#include "sb-members.h"
 #include "snapshot.h"
 #include "subvolume.h"
 #include "super.h"
@@ -662,7 +663,6 @@ err:
 
 static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 {
-	struct bch_sb_field_members *mi;
 	struct bch_fs *c;
 	struct printbuf name = PRINTBUF;
 	unsigned i, iter_size;
@@ -858,9 +858,8 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 	if (ret)
 		goto err;
 
-	mi = bch2_sb_get_members(c->disk_sb.sb);
 	for (i = 0; i < c->sb.nr_devices; i++)
-		if (bch2_dev_exists(c->disk_sb.sb, mi, i) &&
+		if (bch2_dev_exists(c->disk_sb.sb, i) &&
 		    bch2_dev_alloc(c, i)) {
 			ret = -EEXIST;
 			goto err;
@@ -997,16 +996,12 @@ err:
 
 static int bch2_dev_may_add(struct bch_sb *sb, struct bch_fs *c)
 {
-	struct bch_sb_field_members *sb_mi;
-
-	sb_mi = bch2_sb_get_members(sb);
-	if (!sb_mi)
-		return -BCH_ERR_member_info_missing;
+	struct bch_member m = bch2_sb_member_get(sb, sb->dev_idx);
 
 	if (le16_to_cpu(sb->block_size) != block_sectors(c))
 		return -BCH_ERR_mismatched_block_size;
 
-	if (le16_to_cpu(sb_mi->members[sb->dev_idx].bucket_size) <
+	if (le16_to_cpu(m.bucket_size) <
 	    BCH_SB_BTREE_NODE_SIZE(c->disk_sb.sb))
 		return -BCH_ERR_bucket_size_too_small;
 
@@ -1017,12 +1012,11 @@ static int bch2_dev_in_fs(struct bch_sb *fs, struct bch_sb *sb)
 {
 	struct bch_sb *newest =
 		le64_to_cpu(fs->seq) > le64_to_cpu(sb->seq) ? fs : sb;
-	struct bch_sb_field_members *mi = bch2_sb_get_members(newest);
 
 	if (!uuid_equal(&fs->uuid, &sb->uuid))
 		return -BCH_ERR_device_not_a_member_of_filesystem;
 
-	if (!bch2_dev_exists(newest, mi, sb->dev_idx))
+	if (!bch2_dev_exists(newest, sb->dev_idx))
 		return -BCH_ERR_device_has_been_removed;
 
 	if (fs->block_size != sb->block_size)
@@ -1192,15 +1186,14 @@ static void bch2_dev_attach(struct bch_fs *c, struct bch_dev *ca,
 
 static int bch2_dev_alloc(struct bch_fs *c, unsigned dev_idx)
 {
-	struct bch_member *member =
-		bch2_sb_get_members(c->disk_sb.sb)->members + dev_idx;
+	struct bch_member member = bch2_sb_member_get(c->disk_sb.sb, dev_idx);
 	struct bch_dev *ca = NULL;
 	int ret = 0;
 
 	if (bch2_fs_init_fault("dev_alloc"))
 		goto err;
 
-	ca = __bch2_dev_alloc(c, member);
+	ca = __bch2_dev_alloc(c, &member);
 	if (!ca)
 		goto err;
 
@@ -1335,7 +1328,6 @@ bool bch2_dev_state_allowed(struct bch_fs *c, struct bch_dev *ca,
 
 static bool bch2_fs_may_start(struct bch_fs *c)
 {
-	struct bch_sb_field_members *mi;
 	struct bch_dev *ca;
 	unsigned i, flags = 0;
 
@@ -1348,10 +1340,9 @@ static bool bch2_fs_may_start(struct bch_fs *c)
 	if (!c->opts.degraded &&
 	    !c->opts.very_degraded) {
 		mutex_lock(&c->sb_lock);
-		mi = bch2_sb_get_members(c->disk_sb.sb);
 
 		for (i = 0; i < c->disk_sb.sb->nr_devices; i++) {
-			if (!bch2_dev_exists(c->disk_sb.sb, mi, i))
+			if (!bch2_dev_exists(c->disk_sb.sb, i))
 				continue;
 
 			ca = bch_dev_locked(c, i);
@@ -1588,7 +1579,7 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
 		goto err;
 	}
 
-	dev_mi = bch2_sb_get_members(sb.sb)->members[sb.sb->dev_idx];
+	dev_mi = bch2_sb_member_get(sb.sb, sb.sb->dev_idx);
 
 	if (BCH_MEMBER_GROUP(&dev_mi)) {
 		bch2_disk_path_to_text(&label, sb.sb, BCH_MEMBER_GROUP(&dev_mi) - 1);
@@ -1644,9 +1635,8 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
 	if (dynamic_fault("bcachefs:add:no_slot"))
 		goto no_slot;
 
-	mi = bch2_sb_get_members(c->disk_sb.sb);
 	for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
-		if (!bch2_dev_exists(c->disk_sb.sb, mi, dev_idx))
+		if (!bch2_dev_exists(c->disk_sb.sb, dev_idx))
 			goto have_slot;
 no_slot:
 	ret = -BCH_ERR_ENOSPC_sb_members;
@@ -1875,7 +1865,6 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
 {
 	struct bch_sb_handle *sb = NULL;
 	struct bch_fs *c = NULL;
-	struct bch_sb_field_members *mi;
 	unsigned i, best_sb = 0;
 	struct printbuf errbuf = PRINTBUF;
 	int ret = 0;
@@ -1906,12 +1895,10 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices,
 		    le64_to_cpu(sb[best_sb].sb->seq))
 			best_sb = i;
 
-	mi = bch2_sb_get_members(sb[best_sb].sb);
-
 	i = 0;
 	while (i < nr_devices) {
 		if (i != best_sb &&
-		    !bch2_dev_exists(sb[best_sb].sb, mi, sb[i].sb->dev_idx)) {
+		    !bch2_dev_exists(sb[best_sb].sb, sb[i].sb->dev_idx)) {
 			pr_info("%pg has been removed, skipping", sb[i].bdev);
 			bch2_free_super(&sb[i]);
 			array_remove_item(sb, nr_devices, i);