Update bcachefs sources to a180af9dd349 bcachefs: Refactor memcpy into direct assignment

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

30 files changed, 156 insertions, 126 deletions

diff --git a/.bcachefs_revision b/.bcachefs_revision
index 48318a75..6f98bb84 100644
--- a/.bcachefs_revision
+++ b/.bcachefs_revision
@@ -1 +1 @@
-7bf1ac0d46ebede68561e0476f7af9c07ac21de8
+a180af9dd349d9819b13af43f877bea4f94c1c79
diff --git a/cmd_format.c b/cmd_format.c
index 42f3fc6c..954d40fe 100644
--- a/cmd_format.c
+++ b/cmd_format.c
@@ -348,7 +348,7 @@ int cmd_show_super(int argc, char *argv[])
 		die("Error opening %s: %s", dev, bch2_err_str(ret));
 
 	if (print_default_fields)
-		fields = bch2_sb_get_members_v2(sb.sb)
+		fields = bch2_sb_field_get(sb.sb, members_v2)
 			? 1 << BCH_SB_FIELD_members_v2
 			: 1 << BCH_SB_FIELD_members_v1;
 
diff --git a/cmd_key.c b/cmd_key.c
index d3e5d7bd..96206c4c 100644
--- a/cmd_key.c
+++ b/cmd_key.c
@@ -92,7 +92,7 @@ int cmd_set_passphrase(int argc, char *argv[])
 	if (IS_ERR(c))
 		die("Error opening %s: %s", argv[1], bch2_err_str(PTR_ERR(c)));
 
-	struct bch_sb_field_crypt *crypt = bch2_sb_get_crypt(c->disk_sb.sb);
+	struct bch_sb_field_crypt *crypt = bch2_sb_field_get(c->disk_sb.sb, crypt);
 	if (!crypt)
 		die("Filesystem does not have encryption enabled");
 
@@ -130,7 +130,7 @@ int cmd_remove_passphrase(int argc, char *argv[])
 	if (IS_ERR(c))
 		die("Error opening %s: %s", argv[1], bch2_err_str(PTR_ERR(c)));
 
-	struct bch_sb_field_crypt *crypt = bch2_sb_get_crypt(c->disk_sb.sb);
+	struct bch_sb_field_crypt *crypt = bch2_sb_field_get(c->disk_sb.sb, crypt);
 	if (!crypt)
 		die("Filesystem does not have encryption enabled");
 
diff --git a/crypto.c b/crypto.c
index 4e4d15a9..32671bd8 100644
--- a/crypto.c
+++ b/crypto.c
@@ -105,7 +105,7 @@ bool bch2_sb_is_encrypted(struct bch_sb *sb)
 {
 	struct bch_sb_field_crypt *crypt;
 
-	return (crypt = bch2_sb_get_crypt(sb)) &&
+	return (crypt = bch2_sb_field_get(sb, crypt)) &&
 		bch2_key_is_encrypted(&crypt->key);
 }
 
@@ -113,7 +113,7 @@ void bch2_passphrase_check(struct bch_sb *sb, const char *passphrase,
 			   struct bch_key *passphrase_key,
 			   struct bch_encrypted_key *sb_key)
 {
-	struct bch_sb_field_crypt *crypt = bch2_sb_get_crypt(sb);
+	struct bch_sb_field_crypt *crypt = bch2_sb_field_get(sb, crypt);
 	if (!crypt)
 		die("filesystem is not encrypted");
 
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index b9486dbe..61beee94 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -66,6 +66,7 @@
 #define __same_type(a, b)	__builtin_types_compatible_p(typeof(a), typeof(b))
 #define fallthrough		__attribute__((__fallthrough__))
 #define __noreturn		__attribute__((__noreturn__))
+#define __counted_by(nr)
 
 #define ___PASTE(a,b) a##b
 #define __PASTE(a,b) ___PASTE(a,b)
diff --git a/libbcachefs.c b/libbcachefs.c
index 499badb1..577ccac1 100644
--- a/libbcachefs.c
+++ b/libbcachefs.c
@@ -221,7 +221,7 @@ struct bch_sb *bch2_format(struct bch_opt_strs	fs_opt_strs,
 
 	/* Member info: */
 	struct bch_sb_field_members_v2 *mi =
-		bch2_sb_resize_members_v2(&sb,
+		bch2_sb_field_resize(&sb, members_v2,
 			(sizeof(*mi) + sizeof(struct bch_member) *
 			nr_devs) / sizeof(u64));
 	mi->member_bytes = cpu_to_le16(sizeof(struct bch_member));
@@ -270,7 +270,7 @@ struct bch_sb *bch2_format(struct bch_opt_strs	fs_opt_strs,
 	/* Crypt: */
 	if (opts.encrypted) {
 		struct bch_sb_field_crypt *crypt =
-			bch2_sb_resize_crypt(&sb, sizeof(*crypt) / sizeof(u64));
+			bch2_sb_field_resize(&sb, crypt, sizeof(*crypt) / sizeof(u64));
 
 		bch_sb_crypt_init(sb.sb, crypt, opts.passphrase);
 		SET_BCH_SB_ENCRYPTION_TYPE(sb.sb, 1);
diff --git a/libbcachefs/alloc_background.c b/libbcachefs/alloc_background.c
index d1c323fd..2d516207 100644
--- a/libbcachefs/alloc_background.c
+++ b/libbcachefs/alloc_background.c
@@ -1839,7 +1839,7 @@ int bch2_dev_freespace_init(struct bch_fs *c, struct bch_dev *ca,
 	struct bkey_s_c k;
 	struct bkey hole;
 	struct bpos end = POS(ca->dev_idx, bucket_end);
-	struct bch_member m;
+	struct bch_member *m;
 	unsigned long last_updated = jiffies;
 	int ret;
 
@@ -1926,8 +1926,8 @@ bkey_err:
 	}
 
 	mutex_lock(&c->sb_lock);
-	m = bch2_sb_member_get(c->disk_sb.sb, ca->dev_idx);
-	SET_BCH_MEMBER_FREESPACE_INITIALIZED(&m, true);
+	m = bch2_members_v2_get_mut(c->disk_sb.sb, ca->dev_idx);
+	SET_BCH_MEMBER_FREESPACE_INITIALIZED(m, true);
 	mutex_unlock(&c->sb_lock);
 
 	return 0;
diff --git a/libbcachefs/bcachefs.h b/libbcachefs/bcachefs.h
index e9d07f9f..53ffa88c 100644
--- a/libbcachefs/bcachefs.h
+++ b/libbcachefs/bcachefs.h
@@ -746,6 +746,7 @@ struct bch_fs {
 	struct snapshot_table __rcu *snapshots;
 	size_t			snapshot_table_size;
 	struct mutex		snapshot_table_lock;
+	struct rw_semaphore	snapshot_create_lock;
 
 	struct work_struct	snapshot_delete_work;
 	struct work_struct	snapshot_wait_for_pagecache_and_delete_work;
diff --git a/libbcachefs/bkey_methods.c b/libbcachefs/bkey_methods.c
index be9f012f..d9fb1fc8 100644
--- a/libbcachefs/bkey_methods.c
+++ b/libbcachefs/bkey_methods.c
@@ -121,7 +121,6 @@ const struct bkey_ops bch2_bkey_ops[] = {
 };
 
 const struct bkey_ops bch2_bkey_null_ops = {
-	.min_val_size = U8_MAX,
 };
 
 int bch2_bkey_val_invalid(struct bch_fs *c, struct bkey_s_c k,
diff --git a/libbcachefs/buckets.c b/libbcachefs/buckets.c
index 46b6406d..a1a4b5fe 100644
--- a/libbcachefs/buckets.c
+++ b/libbcachefs/buckets.c
@@ -473,8 +473,9 @@ static inline int update_replicas_list(struct btree_trans *trans,
 	d = trans->fs_usage_deltas;
 	n = (void *) d->d + d->used;
 	n->delta = sectors;
-	memcpy((void *) n + offsetof(struct replicas_delta, r),
-	       r, replicas_entry_bytes(r));
+	unsafe_memcpy((void *) n + offsetof(struct replicas_delta, r),
+		      r, replicas_entry_bytes(r),
+		      "flexible array member embedded in strcuct with padding");
 	bch2_replicas_entry_sort(&n->r);
 	d->used += b;
 	return 0;
diff --git a/libbcachefs/checksum.c b/libbcachefs/checksum.c
index 839f00dc..3c761ad6 100644
--- a/libbcachefs/checksum.c
+++ b/libbcachefs/checksum.c
@@ -678,7 +678,7 @@ int bch2_disable_encryption(struct bch_fs *c)
 
 	mutex_lock(&c->sb_lock);
 
-	crypt = bch2_sb_get_crypt(c->disk_sb.sb);
+	crypt = bch2_sb_field_get(c->disk_sb.sb, crypt);
 	if (!crypt)
 		goto out;
 
@@ -712,7 +712,7 @@ int bch2_enable_encryption(struct bch_fs *c, bool keyed)
 	mutex_lock(&c->sb_lock);
 
 	/* Do we already have an encryption key? */
-	if (bch2_sb_get_crypt(c->disk_sb.sb))
+	if (bch2_sb_field_get(c->disk_sb.sb, crypt))
 		goto err;
 
 	ret = bch2_alloc_ciphers(c);
@@ -740,7 +740,8 @@ int bch2_enable_encryption(struct bch_fs *c, bool keyed)
 	if (ret)
 		goto err;
 
-	crypt = bch2_sb_resize_crypt(&c->disk_sb, sizeof(*crypt) / sizeof(u64));
+	crypt = bch2_sb_field_resize(&c->disk_sb, crypt,
+				     sizeof(*crypt) / sizeof(u64));
 	if (!crypt) {
 		ret = -BCH_ERR_ENOSPC_sb_crypt;
 		goto err;
@@ -781,7 +782,7 @@ int bch2_fs_encryption_init(struct bch_fs *c)
 		goto out;
 	}
 
-	crypt = bch2_sb_get_crypt(c->disk_sb.sb);
+	crypt = bch2_sb_field_get(c->disk_sb.sb, crypt);
 	if (!crypt)
 		goto out;
 
diff --git a/libbcachefs/counters.c b/libbcachefs/counters.c
index 26eb3d82..02a996e0 100644
--- a/libbcachefs/counters.c
+++ b/libbcachefs/counters.c
@@ -48,7 +48,7 @@ static void bch2_sb_counters_to_text(struct printbuf *out, struct bch_sb *sb,
 
 int bch2_sb_counters_to_cpu(struct bch_fs *c)
 {
-	struct bch_sb_field_counters *ctrs = bch2_sb_get_counters(c->disk_sb.sb);
+	struct bch_sb_field_counters *ctrs = bch2_sb_field_get(c->disk_sb.sb, counters);
 	unsigned int i;
 	unsigned int nr = bch2_sb_counter_nr_entries(ctrs);
 	u64 val = 0;
@@ -66,13 +66,13 @@ int bch2_sb_counters_to_cpu(struct bch_fs *c)
 
 int bch2_sb_counters_from_cpu(struct bch_fs *c)
 {
-	struct bch_sb_field_counters *ctrs = bch2_sb_get_counters(c->disk_sb.sb);
+	struct bch_sb_field_counters *ctrs = bch2_sb_field_get(c->disk_sb.sb, counters);
 	struct bch_sb_field_counters *ret;
 	unsigned int i;
 	unsigned int nr = bch2_sb_counter_nr_entries(ctrs);
 
 	if (nr < BCH_COUNTER_NR) {
-		ret = bch2_sb_resize_counters(&c->disk_sb,
+		ret = bch2_sb_field_resize(&c->disk_sb, counters,
 					       sizeof(*ctrs) / sizeof(u64) + BCH_COUNTER_NR);
 
 		if (ret) {
diff --git a/libbcachefs/disk_groups.c b/libbcachefs/disk_groups.c
index 43aad8ba..e00133b6 100644
--- a/libbcachefs/disk_groups.c
+++ b/libbcachefs/disk_groups.c
@@ -157,14 +157,13 @@ int bch2_sb_disk_groups_to_cpu(struct bch_fs *c)
 
 	lockdep_assert_held(&c->sb_lock);
 
-	groups		= bch2_sb_get_disk_groups(c->disk_sb.sb);
+	groups		= bch2_sb_field_get(c->disk_sb.sb, disk_groups);
 	nr_groups	= disk_groups_nr(groups);
 
 	if (!groups)
 		return 0;
 
-	cpu_g = kzalloc(sizeof(*cpu_g) +
-			sizeof(cpu_g->entries[0]) * nr_groups, GFP_KERNEL);
+	cpu_g = kzalloc(struct_size(cpu_g, entries, nr_groups), GFP_KERNEL);
 	if (!cpu_g)
 		return -BCH_ERR_ENOMEM_disk_groups_to_cpu;
 
@@ -296,7 +295,7 @@ static int __bch2_disk_group_add(struct bch_sb_handle *sb, unsigned parent,
 				 const char *name, unsigned namelen)
 {
 	struct bch_sb_field_disk_groups *groups =
-		bch2_sb_get_disk_groups(sb->sb);
+		bch2_sb_field_get(sb->sb, disk_groups);
 	unsigned i, nr_groups = disk_groups_nr(groups);
 	struct bch_disk_group *g;
 
@@ -314,7 +313,7 @@ static int __bch2_disk_group_add(struct bch_sb_handle *sb, unsigned parent,
 			 sizeof(struct bch_disk_group) * (nr_groups + 1)) /
 			sizeof(u64);
 
-		groups = bch2_sb_resize_disk_groups(sb, u64s);
+		groups = bch2_sb_field_resize(sb, disk_groups, u64s);
 		if (!groups)
 			return -BCH_ERR_ENOSPC_disk_label_add;
 
@@ -338,7 +337,7 @@ static int __bch2_disk_group_add(struct bch_sb_handle *sb, unsigned parent,
 int bch2_disk_path_find(struct bch_sb_handle *sb, const char *name)
 {
 	struct bch_sb_field_disk_groups *groups =
-		bch2_sb_get_disk_groups(sb->sb);
+		bch2_sb_field_get(sb->sb, disk_groups);
 	int v = -1;
 
 	do {
@@ -368,7 +367,7 @@ int bch2_disk_path_find_or_create(struct bch_sb_handle *sb, const char *name)
 		if (*next == '.')
 			next++;
 
-		groups = bch2_sb_get_disk_groups(sb->sb);
+		groups = bch2_sb_field_get(sb->sb, disk_groups);
 
 		v = __bch2_disk_group_find(groups, parent, name, len);
 		if (v < 0)
@@ -386,7 +385,7 @@ int bch2_disk_path_find_or_create(struct bch_sb_handle *sb, const char *name)
 void bch2_disk_path_to_text(struct printbuf *out, struct bch_sb *sb, unsigned v)
 {
 	struct bch_sb_field_disk_groups *groups =
-		bch2_sb_get_disk_groups(sb);
+		bch2_sb_field_get(sb, disk_groups);
 	struct bch_disk_group *g;
 	unsigned nr = 0;
 	u16 path[32];
diff --git a/libbcachefs/extents.h b/libbcachefs/extents.h
index 7ee8d031..879e7d21 100644
--- a/libbcachefs/extents.h
+++ b/libbcachefs/extents.h
@@ -520,6 +520,7 @@ static inline bool bkey_extent_is_allocation(const struct bkey *k)
 	case KEY_TYPE_reflink_v:
 	case KEY_TYPE_inline_data:
 	case KEY_TYPE_indirect_inline_data:
+	case KEY_TYPE_error:
 		return true;
 	default:
 		return false;
@@ -632,6 +633,8 @@ void bch2_bkey_extent_entry_drop(struct bkey_i *, union bch_extent_entry *);
 
 static inline void bch2_bkey_append_ptr(struct bkey_i *k, struct bch_extent_ptr ptr)
 {
+	struct bch_extent_ptr *dest;
+
 	EBUG_ON(bch2_bkey_has_device(bkey_i_to_s(k), ptr.dev));
 
 	switch (k->k.type) {
@@ -641,10 +644,8 @@ static inline void bch2_bkey_append_ptr(struct bkey_i *k, struct bch_extent_ptr
 		EBUG_ON(bkey_val_u64s(&k->k) >= BKEY_EXTENT_VAL_U64s_MAX);
 
 		ptr.type = 1 << BCH_EXTENT_ENTRY_ptr;
-
-		memcpy((void *) &k->v + bkey_val_bytes(&k->k),
-		       &ptr,
-		       sizeof(ptr));
+		dest = (struct bch_extent_ptr *)((void *) &k->v + bkey_val_bytes(&k->k));
+		*dest = ptr;
 		k->k.u64s++;
 		break;
 	default:
diff --git a/libbcachefs/fs-ioctl.c b/libbcachefs/fs-ioctl.c
index 0679b2f7..6040bd3f 100644
--- a/libbcachefs/fs-ioctl.c
+++ b/libbcachefs/fs-ioctl.c
@@ -318,8 +318,8 @@ err:
 	return ret;
 }
 
-static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
-				struct bch_ioctl_subvolume arg)
+static long __bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
+					  struct bch_ioctl_subvolume arg)
 {
 	struct inode *dir;
 	struct bch_inode_info *inode;
@@ -440,6 +440,16 @@ err1:
 	return error;
 }
 
+static long bch2_ioctl_subvolume_create(struct bch_fs *c, struct file *filp,
+					struct bch_ioctl_subvolume arg)
+{
+	down_write(&c->snapshot_create_lock);
+	long ret = __bch2_ioctl_subvolume_create(c, filp, arg);
+	up_write(&c->snapshot_create_lock);
+
+	return ret;
+}
+
 static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp,
 				struct bch_ioctl_subvolume arg)
 {
diff --git a/libbcachefs/io_misc.c b/libbcachefs/io_misc.c
index 32432bdd..119834cb 100644
--- a/libbcachefs/io_misc.c
+++ b/libbcachefs/io_misc.c
@@ -287,9 +287,18 @@ int bch2_truncate(struct bch_fs *c, subvol_inum inum, u64 new_i_size, u64 *i_sec
 	op.v.inum	= cpu_to_le64(inum.inum);
 	op.v.new_i_size	= cpu_to_le64(new_i_size);
 
-	return bch2_trans_run(c,
+	/*
+	 * Logged ops aren't atomic w.r.t. snapshot creation: creating a
+	 * snapshot while they're in progress, then crashing, will result in the
+	 * resume only proceeding in one of the snapshots
+	 */
+	down_read(&c->snapshot_create_lock);
+	int ret = bch2_trans_run(c,
 		bch2_logged_op_start(trans, &op.k_i) ?:
 		__bch2_resume_logged_op_truncate(trans, &op.k_i, i_sectors_delta));
+	up_read(&c->snapshot_create_lock);
+
+	return ret;
 }
 
 /* finsert/fcollapse: */
@@ -491,7 +500,16 @@ int bch2_fcollapse_finsert(struct bch_fs *c, subvol_inum inum,
 	op.v.src_offset	= cpu_to_le64(offset);
 	op.v.pos	= cpu_to_le64(insert ? U64_MAX : offset);
 
-	return bch2_trans_run(c,
+	/*
+	 * Logged ops aren't atomic w.r.t. snapshot creation: creating a
+	 * snapshot while they're in progress, then crashing, will result in the
+	 * resume only proceeding in one of the snapshots
+	 */
+	down_read(&c->snapshot_create_lock);
+	int ret = bch2_trans_run(c,
 		bch2_logged_op_start(trans, &op.k_i) ?:
 		__bch2_resume_logged_op_finsert(trans, &op.k_i, i_sectors_delta));
+	up_read(&c->snapshot_create_lock);
+
+	return ret;
 }
diff --git a/libbcachefs/journal.c b/libbcachefs/journal.c
index fc3dd5be..0e7a9ffa 100644
--- a/libbcachefs/journal.c
+++ b/libbcachefs/journal.c
@@ -1170,9 +1170,9 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 {
 	struct journal_device *ja = &ca->journal;
 	struct bch_sb_field_journal *journal_buckets =
-		bch2_sb_get_journal(sb);
+		bch2_sb_field_get(sb, journal);
 	struct bch_sb_field_journal_v2 *journal_buckets_v2 =
-		bch2_sb_get_journal_v2(sb);
+		bch2_sb_field_get(sb, journal_v2);
 	unsigned i, nr_bvecs;
 
 	ja->nr = 0;
diff --git a/libbcachefs/journal_sb.c b/libbcachefs/journal_sb.c
index 3c5a95e2..ae4fb8c3 100644
--- a/libbcachefs/journal_sb.c
+++ b/libbcachefs/journal_sb.c
@@ -194,7 +194,7 @@ int bch2_journal_buckets_to_sb(struct bch_fs *c, struct bch_dev *ca,
 		if (buckets[i] + 1 != buckets[i + 1])
 			nr_compacted++;
 
-	j = bch2_sb_resize_journal_v2(&ca->disk_sb,
+	j = bch2_sb_field_resize(&ca->disk_sb, journal_v2,
 			 (sizeof(*j) + sizeof(j->d[0]) * nr_compacted) / sizeof(u64));
 	if (!j)
 		return -BCH_ERR_ENOSPC_sb_journal;
diff --git a/libbcachefs/journal_seq_blacklist.c b/libbcachefs/journal_seq_blacklist.c
index 1e1a7940..f9d9aa95 100644
--- a/libbcachefs/journal_seq_blacklist.c
+++ b/libbcachefs/journal_seq_blacklist.c
@@ -58,8 +58,8 @@ blacklist_entry_try_merge(struct bch_fs *c,
 			&bl->start[i + 1],
 			sizeof(bl->start[0]) * (nr - i));
 
-		bl = bch2_sb_resize_journal_seq_blacklist(&c->disk_sb,
-							sb_blacklist_u64s(nr));
+		bl = bch2_sb_field_resize(&c->disk_sb, journal_seq_blacklist,
+					  sb_blacklist_u64s(nr));
 		BUG_ON(!bl);
 	}
 
@@ -79,7 +79,7 @@ int bch2_journal_seq_blacklist_add(struct bch_fs *c, u64 start, u64 end)
 	int ret = 0;
 
 	mutex_lock(&c->sb_lock);
-	bl = bch2_sb_get_journal_seq_blacklist(c->disk_sb.sb);
+	bl = bch2_sb_field_get(c->disk_sb.sb, journal_seq_blacklist);
 	nr = blacklist_nr_entries(bl);
 
 	for (i = 0; i < nr; i++) {
@@ -100,8 +100,8 @@ int bch2_journal_seq_blacklist_add(struct bch_fs *c, u64 start, u64 end)
 		}
 	}
 
-	bl = bch2_sb_resize_journal_seq_blacklist(&c->disk_sb,
-					sb_blacklist_u64s(nr + 1));
+	bl = bch2_sb_field_resize(&c->disk_sb, journal_seq_blacklist,
+				  sb_blacklist_u64s(nr + 1));
 	if (!bl) {
 		ret = -BCH_ERR_ENOSPC_sb_journal_seq_blacklist;
 		goto out;
@@ -158,7 +158,7 @@ bool bch2_journal_seq_is_blacklisted(struct bch_fs *c, u64 seq,
 int bch2_blacklist_table_initialize(struct bch_fs *c)
 {
 	struct bch_sb_field_journal_seq_blacklist *bl =
-		bch2_sb_get_journal_seq_blacklist(c->disk_sb.sb);
+		bch2_sb_field_get(c->disk_sb.sb, journal_seq_blacklist);
 	struct journal_seq_blacklist_table *t;
 	unsigned i, nr = blacklist_nr_entries(bl);
 
@@ -281,7 +281,7 @@ retry:
 		return;
 
 	mutex_lock(&c->sb_lock);
-	bl = bch2_sb_get_journal_seq_blacklist(c->disk_sb.sb);
+	bl = bch2_sb_field_get(c->disk_sb.sb, journal_seq_blacklist);
 	if (!bl)
 		goto out;
 
@@ -306,7 +306,7 @@ retry:
 	bch_info(c, "nr blacklist entries was %u, now %u", nr, new_nr);
 
 	if (new_nr != nr) {
-		bl = bch2_sb_resize_journal_seq_blacklist(&c->disk_sb,
+		bl = bch2_sb_field_resize(&c->disk_sb, journal_seq_blacklist,
 				new_nr ? sb_blacklist_u64s(new_nr) : 0);
 		BUG_ON(new_nr && !bl);
 
diff --git a/libbcachefs/quota.c b/libbcachefs/quota.c
index 36de2f07..cb68ae44 100644
--- a/libbcachefs/quota.c
+++ b/libbcachefs/quota.c
@@ -513,12 +513,12 @@ void bch2_fs_quota_init(struct bch_fs *c)
 
 static struct bch_sb_field_quota *bch2_sb_get_or_create_quota(struct bch_sb_handle *sb)
 {
-	struct bch_sb_field_quota *sb_quota = bch2_sb_get_quota(sb->sb);
+	struct bch_sb_field_quota *sb_quota = bch2_sb_field_get(sb->sb, quota);
 
 	if (sb_quota)
 		return sb_quota;
 
-	sb_quota = bch2_sb_resize_quota(sb, sizeof(*sb_quota) / sizeof(u64));
+	sb_quota = bch2_sb_field_resize(sb, quota, sizeof(*sb_quota) / sizeof(u64));
 	if (sb_quota) {
 		unsigned qtype, qc;
 
@@ -536,7 +536,7 @@ static void bch2_sb_quota_read(struct bch_fs *c)
 	struct bch_sb_field_quota *sb_quota;
 	unsigned i, j;
 
-	sb_quota = bch2_sb_get_quota(c->disk_sb.sb);
+	sb_quota = bch2_sb_field_get(c->disk_sb.sb, quota);
 	if (!sb_quota)
 		return;
 
diff --git a/libbcachefs/recovery.c b/libbcachefs/recovery.c
index cd037f2e..4cd66065 100644
--- a/libbcachefs/recovery.c
+++ b/libbcachefs/recovery.c
@@ -35,13 +35,27 @@
 
 #define QSTR(n) { { { .len = strlen(n) } }, .name = n }
 
+static bool btree_id_is_alloc(enum btree_id id)
+{
+	switch (id) {
+	case BTREE_ID_alloc:
+	case BTREE_ID_backpointers:
+	case BTREE_ID_need_discard:
+	case BTREE_ID_freespace:
+	case BTREE_ID_bucket_gens:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /* for -o reconstruct_alloc: */
 static void drop_alloc_keys(struct journal_keys *keys)
 {
 	size_t src, dst;
 
 	for (src = 0, dst = 0; src < keys->nr; src++)
-		if (keys->d[src].btree_id != BTREE_ID_alloc)
+		if (!btree_id_is_alloc(keys->d[src].btree_id))
 			keys->d[dst++] = keys->d[src];
 
 	keys->nr = dst;
@@ -332,20 +346,6 @@ static int journal_replay_early(struct bch_fs *c,
 
 /* sb clean section: */
 
-static bool btree_id_is_alloc(enum btree_id id)
-{
-	switch (id) {
-	case BTREE_ID_alloc:
-	case BTREE_ID_backpointers:
-	case BTREE_ID_need_discard:
-	case BTREE_ID_freespace:
-	case BTREE_ID_bucket_gens:
-		return true;
-	default:
-		return false;
-	}
-}
-
 static int read_btree_roots(struct bch_fs *c)
 {
 	unsigned i;
diff --git a/libbcachefs/replicas.c b/libbcachefs/replicas.c
index a9a694fb..cef2a044 100644
--- a/libbcachefs/replicas.c
+++ b/libbcachefs/replicas.c
@@ -700,9 +700,9 @@ int bch2_sb_replicas_to_cpu_replicas(struct bch_fs *c)
 	struct bch_replicas_cpu new_r = { 0, 0, NULL };
 	int ret = 0;
 
-	if ((sb_v1 = bch2_sb_get_replicas(c->disk_sb.sb)))
+	if ((sb_v1 = bch2_sb_field_get(c->disk_sb.sb, replicas)))
 		ret = __bch2_sb_replicas_to_cpu_replicas(sb_v1, &new_r);
-	else if ((sb_v0 = bch2_sb_get_replicas_v0(c->disk_sb.sb)))
+	else if ((sb_v0 = bch2_sb_field_get(c->disk_sb.sb, replicas_v0)))
 		ret = __bch2_sb_replicas_v0_to_cpu_replicas(sb_v0, &new_r);
 	if (ret)
 		return ret;
@@ -732,13 +732,13 @@ static int bch2_cpu_replicas_to_sb_replicas_v0(struct bch_fs *c,
 	for_each_cpu_replicas_entry(r, src)
 		bytes += replicas_entry_bytes(src) - 1;
 
-	sb_r = bch2_sb_resize_replicas_v0(&c->disk_sb,
+	sb_r = bch2_sb_field_resize(&c->disk_sb, replicas_v0,
 			DIV_ROUND_UP(bytes, sizeof(u64)));
 	if (!sb_r)
 		return -BCH_ERR_ENOSPC_sb_replicas;
 
 	bch2_sb_field_delete(&c->disk_sb, BCH_SB_FIELD_replicas);
-	sb_r = bch2_sb_get_replicas_v0(c->disk_sb.sb);
+	sb_r = bch2_sb_field_get(c->disk_sb.sb, replicas_v0);
 
 	memset(&sb_r->entries, 0,
 	       vstruct_end(&sb_r->field) -
@@ -777,13 +777,13 @@ static int bch2_cpu_replicas_to_sb_replicas(struct bch_fs *c,
 	if (!need_v1)
 		return bch2_cpu_replicas_to_sb_replicas_v0(c, r);
 
-	sb_r = bch2_sb_resize_replicas(&c->disk_sb,
+	sb_r = bch2_sb_field_resize(&c->disk_sb, replicas,
 			DIV_ROUND_UP(bytes, sizeof(u64)));
 	if (!sb_r)
 		return -BCH_ERR_ENOSPC_sb_replicas;
 
 	bch2_sb_field_delete(&c->disk_sb, BCH_SB_FIELD_replicas_v0);
-	sb_r = bch2_sb_get_replicas(c->disk_sb.sb);
+	sb_r = bch2_sb_field_get(c->disk_sb.sb, replicas);
 
 	memset(&sb_r->entries, 0,
 	       vstruct_end(&sb_r->field) -
@@ -998,8 +998,8 @@ unsigned bch2_sb_dev_has_data(struct bch_sb *sb, unsigned dev)
 	struct bch_sb_field_replicas_v0 *replicas_v0;
 	unsigned i, data_has = 0;
 
-	replicas = bch2_sb_get_replicas(sb);
-	replicas_v0 = bch2_sb_get_replicas_v0(sb);
+	replicas = bch2_sb_field_get(sb, replicas);
+	replicas_v0 = bch2_sb_field_get(sb, replicas_v0);
 
 	if (replicas) {
 		struct bch_replicas_entry *r;
diff --git a/libbcachefs/sb-clean.c b/libbcachefs/sb-clean.c
index a3695e56..61203d7c 100644
--- a/libbcachefs/sb-clean.c
+++ b/libbcachefs/sb-clean.c
@@ -137,7 +137,7 @@ struct bch_sb_field_clean *bch2_read_superblock_clean(struct bch_fs *c)
 	int ret;
 
 	mutex_lock(&c->sb_lock);
-	sb_clean = bch2_sb_get_clean(c->disk_sb.sb);
+	sb_clean = bch2_sb_field_get(c->disk_sb.sb, clean);
 
 	if (fsck_err_on(!sb_clean, c,
 			"superblock marked clean but clean section not present")) {
@@ -359,7 +359,7 @@ void bch2_fs_mark_clean(struct bch_fs *c)
 
 	u64s = sizeof(*sb_clean) / sizeof(u64) + c->journal.entry_u64s_reserved;
 
-	sb_clean = bch2_sb_resize_clean(&c->disk_sb, u64s);
+	sb_clean = bch2_sb_field_resize(&c->disk_sb, clean, u64s);
 	if (!sb_clean) {
 		bch_err(c, "error resizing superblock while setting filesystem clean");
 		goto out;
diff --git a/libbcachefs/sb-members.c b/libbcachefs/sb-members.c
index 04bde1aa..6dd85bb9 100644
--- a/libbcachefs/sb-members.c
+++ b/libbcachefs/sb-members.c
@@ -16,7 +16,7 @@ static struct bch_member *members_v2_get_mut(struct bch_sb_field_members_v2 *mi,
 
 struct bch_member *bch2_members_v2_get_mut(struct bch_sb *sb, int i)
 {
-	return members_v2_get_mut(bch2_sb_get_members_v2(sb), i);
+	return members_v2_get_mut(bch2_sb_field_get(sb, members_v2), i);
 }
 
 static struct bch_member members_v2_get(struct bch_sb_field_members_v2 *mi, int i)
@@ -41,22 +41,22 @@ static struct bch_member members_v1_get(struct bch_sb_field_members_v1 *mi, int
 
 struct bch_member bch2_sb_member_get(struct bch_sb *sb, int i)
 {
-	struct bch_sb_field_members_v2 *mi2 = bch2_sb_get_members_v2(sb);
+	struct bch_sb_field_members_v2 *mi2 = bch2_sb_field_get(sb, members_v2);
 	if (mi2)
 		return members_v2_get(mi2, i);
-	struct bch_sb_field_members_v1 *mi1 = bch2_sb_get_members_v1(sb);
+	struct bch_sb_field_members_v1 *mi1 = bch2_sb_field_get(sb, members_v1);
 	return members_v1_get(mi1, i);
 }
 
 static int sb_members_v2_resize_entries(struct bch_fs *c)
 {
-	struct bch_sb_field_members_v2 *mi = bch2_sb_get_members_v2(c->disk_sb.sb);
+	struct bch_sb_field_members_v2 *mi = bch2_sb_field_get(c->disk_sb.sb, members_v2);
 
 	if (le16_to_cpu(mi->member_bytes) < sizeof(struct bch_member)) {
 		unsigned u64s = DIV_ROUND_UP((sizeof(*mi) + sizeof(mi->_members[0]) *
 					      c->disk_sb.sb->nr_devices), 8);
 
-		mi = bch2_sb_resize_members_v2(&c->disk_sb, u64s);
+		mi = bch2_sb_field_resize(&c->disk_sb, members_v2, u64s);
 		if (!mi)
 			return -BCH_ERR_ENOSPC_sb_members_v2;
 
@@ -76,12 +76,12 @@ int bch2_members_v2_init(struct bch_fs *c)
 	struct bch_sb_field_members_v1 *mi1;
 	struct bch_sb_field_members_v2 *mi2;
 
-	if (!bch2_sb_get_members_v2(c->disk_sb.sb)) {
-		mi2 = bch2_sb_resize_members_v2(&c->disk_sb,
+	if (!bch2_sb_field_get(c->disk_sb.sb, members_v2)) {
+		mi2 = bch2_sb_field_resize(&c->disk_sb, members_v2,
 				DIV_ROUND_UP(sizeof(*mi2) +
 					     sizeof(struct bch_member) * c->sb.nr_devices,
 					     sizeof(u64)));
-		mi1 = bch2_sb_get_members_v1(c->disk_sb.sb);
+		mi1 = bch2_sb_field_get(c->disk_sb.sb, members_v1);
 		memcpy(&mi2->_members[0], &mi1->_members[0],
 		       BCH_MEMBER_V1_BYTES * c->sb.nr_devices);
 		memset(&mi2->pad[0], 0, sizeof(mi2->pad));
@@ -96,13 +96,13 @@ int bch_members_cpy_v2_v1(struct bch_sb_handle *disk_sb)
 	struct bch_sb_field_members_v1 *mi1;
 	struct bch_sb_field_members_v2 *mi2;
 
-	mi1 = bch2_sb_resize_members_v1(disk_sb,
+	mi1 = bch2_sb_field_resize(disk_sb, members_v1,
 			DIV_ROUND_UP(sizeof(*mi1) + BCH_MEMBER_V1_BYTES *
 				     disk_sb->sb->nr_devices, sizeof(u64)));
 	if (!mi1)
 		return -BCH_ERR_ENOSPC_sb_members;
 
-	mi2 = bch2_sb_get_members_v2(disk_sb->sb);
+	mi2 = bch2_sb_field_get(disk_sb->sb, members_v2);
 
 	for (unsigned i = 0; i < disk_sb->sb->nr_devices; i++)
 		memcpy(members_v1_get_mut(mi1, i), members_v2_get_mut(mi2, i), BCH_MEMBER_V1_BYTES);
@@ -283,7 +283,7 @@ static void bch2_sb_members_v1_to_text(struct printbuf *out, struct bch_sb *sb,
 				       struct bch_sb_field *f)
 {
 	struct bch_sb_field_members_v1 *mi = field_to_type(f, members_v1);
-	struct bch_sb_field_disk_groups *gi = bch2_sb_get_disk_groups(sb);
+	struct bch_sb_field_disk_groups *gi = bch2_sb_field_get(sb, disk_groups);
 	unsigned i;
 
 	for (i = 0; i < sb->nr_devices; i++) {
@@ -301,7 +301,7 @@ static void bch2_sb_members_v2_to_text(struct printbuf *out, struct bch_sb *sb,
 				       struct bch_sb_field *f)
 {
 	struct bch_sb_field_members_v2 *mi = field_to_type(f, members_v2);
-	struct bch_sb_field_disk_groups *gi = bch2_sb_get_disk_groups(sb);
+	struct bch_sb_field_disk_groups *gi = bch2_sb_field_get(sb, disk_groups);
 	unsigned i;
 
 	for (i = 0; i < sb->nr_devices; i++) {
diff --git a/libbcachefs/snapshot.c b/libbcachefs/snapshot.c
index 3ecc17b8..4982468b 100644
--- a/libbcachefs/snapshot.c
+++ b/libbcachefs/snapshot.c
@@ -1288,6 +1288,9 @@ static inline u32 bch2_snapshot_nth_parent_skip(struct bch_fs *c, u32 id, u32 n,
 						snapshot_id_list *skip)
 {
 	rcu_read_lock();
+	while (snapshot_list_has_id(skip, id))
+		id = __bch2_snapshot_parent(c, id);
+
 	while (n--) {
 		do {
 			id = __bch2_snapshot_parent(c, id);
@@ -1444,6 +1447,8 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 		}
 	}
 
+	down_write(&c->snapshot_create_lock);
+
 	for_each_btree_key(trans, iter, BTREE_ID_snapshots,
 			   POS_MIN, 0, k, ret) {
 		u32 snapshot = k.k->p.offset;
@@ -1454,6 +1459,9 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 	}
 	bch2_trans_iter_exit(trans, &iter);
 
+	if (ret)
+		goto err_create_lock;
+
 	/*
 	 * Fixing children of deleted snapshots can't be done completely
 	 * atomically, if we crash between here and when we delete the interior
@@ -1464,14 +1472,14 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 				  NULL, NULL, BTREE_INSERT_NOFAIL,
 		bch2_fix_child_of_deleted_snapshot(trans, &iter, k, &deleted_interior));
 	if (ret)
-		goto err;
+		goto err_create_lock;
 
 	darray_for_each(deleted, i) {
 		ret = commit_do(trans, NULL, NULL, 0,
 			bch2_snapshot_node_delete(trans, *i));
 		if (ret) {
 			bch_err_msg(c, ret, "deleting snapshot %u", *i);
-			goto err;
+			goto err_create_lock;
 		}
 	}
 
@@ -1480,11 +1488,13 @@ int bch2_delete_dead_snapshots(struct bch_fs *c)
 			bch2_snapshot_node_delete(trans, *i));
 		if (ret) {
 			bch_err_msg(c, ret, "deleting snapshot %u", *i);
-			goto err;
+			goto err_create_lock;
 		}
 	}
 
 	clear_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags);
+err_create_lock:
+	up_write(&c->snapshot_create_lock);
 err:
 	darray_exit(&deleted_interior);
 	darray_exit(&deleted);
diff --git a/libbcachefs/super-io.c b/libbcachefs/super-io.c
index 4498e24d..332d41e1 100644
--- a/libbcachefs/super-io.c
+++ b/libbcachefs/super-io.c
@@ -96,7 +96,7 @@ const char * const bch2_sb_fields[] = {
 static int bch2_sb_field_validate(struct bch_sb *, struct bch_sb_field *,
 				  struct printbuf *);
 
-struct bch_sb_field *bch2_sb_field_get(struct bch_sb *sb,
+struct bch_sb_field *bch2_sb_field_get_id(struct bch_sb *sb,
 				      enum bch_sb_field_type type)
 {
 	struct bch_sb_field *f;
@@ -151,7 +151,7 @@ static struct bch_sb_field *__bch2_sb_field_resize(struct bch_sb_handle *sb,
 void bch2_sb_field_delete(struct bch_sb_handle *sb,
 			  enum bch_sb_field_type type)
 {
-	struct bch_sb_field *f = bch2_sb_field_get(sb->sb, type);
+	struct bch_sb_field *f = bch2_sb_field_get_id(sb->sb, type);
 
 	if (f)
 		__bch2_sb_field_resize(sb, f, 0);
@@ -225,11 +225,11 @@ int bch2_sb_realloc(struct bch_sb_handle *sb, unsigned u64s)
 	return 0;
 }
 
-struct bch_sb_field *bch2_sb_field_resize(struct bch_sb_handle *sb,
+struct bch_sb_field *bch2_sb_field_resize_id(struct bch_sb_handle *sb,
 					  enum bch_sb_field_type type,
 					  unsigned u64s)
 {
-	struct bch_sb_field *f = bch2_sb_field_get(sb->sb, type);
+	struct bch_sb_field *f = bch2_sb_field_get_id(sb->sb, type);
 	ssize_t old_u64s = f ? le32_to_cpu(f->u64s) : 0;
 	ssize_t d = -old_u64s + u64s;
 
@@ -255,7 +255,7 @@ struct bch_sb_field *bch2_sb_field_resize(struct bch_sb_handle *sb,
 		}
 	}
 
-	f = bch2_sb_field_get(sb->sb, type);
+	f = bch2_sb_field_get_id(sb->sb, type);
 	f = __bch2_sb_field_resize(sb, f, u64s);
 	if (f)
 		f->type = cpu_to_le32(type);
@@ -458,7 +458,7 @@ static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
 	}
 
 	/* members must be validated first: */
-	mi = bch2_sb_get_members_v1(sb);
+	mi = bch2_sb_field_get(sb, members_v1);
 	if (!mi) {
 		prt_printf(out, "Invalid superblock: member info area missing");
 		return -BCH_ERR_invalid_sb_members_missing;
@@ -546,8 +546,8 @@ static int __copy_super(struct bch_sb_handle *dst_handle, struct bch_sb *src)
 		if ((1U << i) & BCH_SINGLE_DEVICE_SB_FIELDS)
 			continue;
 
-		src_f = bch2_sb_field_get(src, i);
-		dst_f = bch2_sb_field_get(dst, i);
+		src_f = bch2_sb_field_get_id(src, i);
+		dst_f = bch2_sb_field_get_id(dst, i);
 
 		d = (src_f ? le32_to_cpu(src_f->u64s) : 0) -
 		    (dst_f ? le32_to_cpu(dst_f->u64s) : 0);
@@ -559,7 +559,7 @@ static int __copy_super(struct bch_sb_handle *dst_handle, struct bch_sb *src)
 				return ret;
 
 			dst = dst_handle->sb;
-			dst_f = bch2_sb_field_get(dst, i);
+			dst_f = bch2_sb_field_get_id(dst, i);
 		}
 
 		dst_f = __bch2_sb_field_resize(dst_handle, dst_f,
diff --git a/libbcachefs/super-io.h b/libbcachefs/super-io.h
index f7e90999..b0d8584f 100644
--- a/libbcachefs/super-io.h
+++ b/libbcachefs/super-io.h
@@ -23,31 +23,19 @@ u64 bch2_upgrade_recovery_passes(struct bch_fs *c,
 				 unsigned,
 				 unsigned);
 
-struct bch_sb_field *bch2_sb_field_get(struct bch_sb *, enum bch_sb_field_type);
-struct bch_sb_field *bch2_sb_field_resize(struct bch_sb_handle *,
-					  enum bch_sb_field_type, unsigned);
-void bch2_sb_field_delete(struct bch_sb_handle *, enum bch_sb_field_type);
-
 #define field_to_type(_f, _name)					\
 	container_of_or_null(_f, struct bch_sb_field_##_name, field)
 
-#define x(_name, _nr)							\
-static inline struct bch_sb_field_##_name *				\
-bch2_sb_get_##_name(struct bch_sb *sb)					\
-{									\
-	return field_to_type(bch2_sb_field_get(sb,			\
-				BCH_SB_FIELD_##_name), _name);		\
-}									\
-									\
-static inline struct bch_sb_field_##_name *				\
-bch2_sb_resize_##_name(struct bch_sb_handle *sb, unsigned u64s)	\
-{									\
-	return field_to_type(bch2_sb_field_resize(sb,			\
-				BCH_SB_FIELD_##_name, u64s), _name);	\
-}
+struct bch_sb_field *bch2_sb_field_get_id(struct bch_sb *, enum bch_sb_field_type);
+#define bch2_sb_field_get(_sb, _name)					\
+	field_to_type(bch2_sb_field_get_id(_sb, BCH_SB_FIELD_##_name), _name)
 
-BCH_SB_FIELDS()
-#undef x
+struct bch_sb_field *bch2_sb_field_resize_id(struct bch_sb_handle *,
+					     enum bch_sb_field_type, unsigned);
+#define bch2_sb_field_resize(_sb, _name, _u64s)				\
+	field_to_type(bch2_sb_field_resize_id(_sb, BCH_SB_FIELD_##_name, _u64s), _name)
+
+void bch2_sb_field_delete(struct bch_sb_handle *, enum bch_sb_field_type);
 
 extern const char * const bch2_sb_fields[];
 
diff --git a/libbcachefs/super.c b/libbcachefs/super.c
index 2014f781..0e85c226 100644
--- a/libbcachefs/super.c
+++ b/libbcachefs/super.c
@@ -720,6 +720,7 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
 	mutex_init(&c->bio_bounce_pages_lock);
 	mutex_init(&c->snapshot_table_lock);
+	init_rwsem(&c->snapshot_create_lock);
 
 	spin_lock_init(&c->btree_write_error_lock);
 
@@ -1630,9 +1631,9 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
 		goto err_unlock;
 	}
 
-	mi = bch2_sb_get_members_v2(ca->disk_sb.sb);
+	mi = bch2_sb_field_get(ca->disk_sb.sb, members_v2);
 
-	if (!bch2_sb_resize_members_v2(&ca->disk_sb,
+	if (!bch2_sb_field_resize(&ca->disk_sb, members_v2,
 				le32_to_cpu(mi->field.u64s) +
 				sizeof(dev_mi) / sizeof(u64))) {
 		ret = -BCH_ERR_ENOSPC_sb_members;
@@ -1656,7 +1657,7 @@ have_slot:
 	u64s = DIV_ROUND_UP(sizeof(struct bch_sb_field_members_v2) +
 			    le16_to_cpu(mi->member_bytes) * nr_devices, sizeof(u64));
 
-	mi = bch2_sb_resize_members_v2(&c->disk_sb, u64s);
+	mi = bch2_sb_field_resize(&c->disk_sb, members_v2, u64s);
 	if (!mi) {
 		ret = -BCH_ERR_ENOSPC_sb_members;
 		bch_err_msg(c, ret, "setting up new superblock");
diff --git a/libbcachefs/super_types.h b/libbcachefs/super_types.h
index 597a8db7..78d6138d 100644
--- a/libbcachefs/super_types.h
+++ b/libbcachefs/super_types.h
@@ -46,7 +46,7 @@ struct bch_disk_group_cpu {
 struct bch_disk_groups_cpu {
 	struct rcu_head			rcu;
 	unsigned			nr;
-	struct bch_disk_group_cpu	entries[];
+	struct bch_disk_group_cpu	entries[] __counted_by(nr);
 };
 
 #endif /* _BCACHEFS_SUPER_TYPES_H */
diff --git a/rust-src/bch_bindgen/src/bcachefs.rs b/rust-src/bch_bindgen/src/bcachefs.rs
index fa8dbdeb..8e897c08 100644
--- a/rust-src/bch_bindgen/src/bcachefs.rs
+++ b/rust-src/bch_bindgen/src/bcachefs.rs
@@ -43,7 +43,7 @@ impl PartialEq for bch_sb {
 impl bch_sb {
     pub fn crypt(&self) -> Option<&bch_sb_field_crypt> {
         unsafe {
-            let ptr = bch2_sb_field_get(
+            let ptr = bch2_sb_field_get_id(
                 self as *const _ as *mut _,
                 bch_sb_field_type::BCH_SB_FIELD_crypt,
             ) as *const u8;