Update bcachefs sources to 254510a1c269 bcachefs: btree_ptr_sectors_written() now takes bkey_s_c

22 files changed, 203 insertions, 124 deletions

diff --git a/.bcachefs_revision b/.bcachefs_revision
index 3ab5aa28..d5cdc669 100644
--- a/.bcachefs_revision
+++ b/.bcachefs_revision
@@ -1 +1 @@
-07f9a27f1969764d11374942961d51fee0ab628f
+254510a1c2691db5fdaccbafe0e1872fd7a2e4e6
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 6dad5653..c17fb5d5 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -20,6 +20,8 @@
 #define ARCH_KMALLOC_MINALIGN		16
 #define KMALLOC_MAX_SIZE		SIZE_MAX
 
+#define MAX_PAGE_ORDER			10
+
 static inline size_t kmalloc_size_roundup(size_t s)
 {
 	return roundup_pow_of_two(s);
diff --git a/libbcachefs/bcachefs_format.h b/libbcachefs/bcachefs_format.h
index 1bebba88..d801e19c 100644
--- a/libbcachefs/bcachefs_format.h
+++ b/libbcachefs/bcachefs_format.h
@@ -1555,6 +1555,12 @@ enum btree_id {
 	BTREE_ID_NR
 };
 
+/*
+ * Maximum number of btrees that we will _ever_ have under the current scheme,
+ * where we refer to them with bitfields
+ */
+#define BTREE_ID_NR_MAX		64
+
 static inline bool btree_id_is_alloc(enum btree_id id)
 {
 	switch (id) {
diff --git a/libbcachefs/btree_io.c b/libbcachefs/btree_io.c
index cbf8f5d9..0b176d4c 100644
--- a/libbcachefs/btree_io.c
+++ b/libbcachefs/btree_io.c
@@ -519,7 +519,7 @@ void bch2_btree_init_next(struct btree_trans *trans, struct btree *b)
 
 static void btree_err_msg(struct printbuf *out, struct bch_fs *c,
 			  struct bch_dev *ca,
-			  struct btree *b, struct bset *i,
+			  struct btree *b, struct bset *i, struct bkey_packed *k,
 			  unsigned offset, int write)
 {
 	prt_printf(out, bch2_log_msg(c, "%s"),
@@ -534,18 +534,23 @@ static void btree_err_msg(struct printbuf *out, struct bch_fs *c,
 	printbuf_indent_add(out, 2);
 
 	prt_printf(out, "\nnode offset %u/%u",
-		   b->written, btree_ptr_sectors_written(&b->key));
+		   b->written, btree_ptr_sectors_written(bkey_i_to_s_c(&b->key)));
 	if (i)
 		prt_printf(out, " bset u64s %u", le16_to_cpu(i->u64s));
+	if (k)
+		prt_printf(out, " bset byte offset %zu",
+			   (unsigned long)(void *)k -
+			   ((unsigned long)(void *)i & ~511UL));
 	prt_str(out, ": ");
 }
 
-__printf(9, 10)
+__printf(10, 11)
 static int __btree_err(int ret,
 		       struct bch_fs *c,
 		       struct bch_dev *ca,
 		       struct btree *b,
 		       struct bset *i,
+		       struct bkey_packed *k,
 		       int write,
 		       bool have_retry,
 		       enum bch_sb_error_id err_type,
@@ -555,7 +560,7 @@ static int __btree_err(int ret,
 	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);
+	btree_err_msg(&out, c, ca, b, i, k, b->written, write);
 
 	va_start(args, fmt);
 	prt_vprintf(&out, fmt, args);
@@ -611,9 +616,9 @@ fsck_err:
 	return ret;
 }
 
-#define btree_err(type, c, ca, b, i, _err_type, msg, ...)		\
+#define btree_err(type, c, ca, b, i, k, _err_type, msg, ...)		\
 ({									\
-	int _ret = __btree_err(type, c, ca, b, i, write, have_retry,	\
+	int _ret = __btree_err(type, c, ca, b, i, k, write, have_retry,	\
 			       BCH_FSCK_ERR_##_err_type,		\
 			       msg, ##__VA_ARGS__);			\
 									\
@@ -684,13 +689,14 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 			 int write, bool have_retry, bool *saw_error)
 {
 	unsigned version = le16_to_cpu(i->version);
+	unsigned ptr_written = btree_ptr_sectors_written(bkey_i_to_s_c(&b->key));
 	struct printbuf buf1 = PRINTBUF;
 	struct printbuf buf2 = PRINTBUF;
 	int ret = 0;
 
 	btree_err_on(!bch2_version_compatible(version),
 		     -BCH_ERR_btree_node_read_err_incompatible,
-		     c, ca, b, i,
+		     c, ca, b, i, NULL,
 		     btree_node_unsupported_version,
 		     "unsupported bset version %u.%u",
 		     BCH_VERSION_MAJOR(version),
@@ -698,7 +704,7 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 
 	if (btree_err_on(version < c->sb.version_min,
 			 -BCH_ERR_btree_node_read_err_fixable,
-			 c, NULL, b, i,
+			 c, NULL, b, i, NULL,
 			 btree_node_bset_older_than_sb_min,
 			 "bset version %u older than superblock version_min %u",
 			 version, c->sb.version_min)) {
@@ -711,7 +717,7 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 	if (btree_err_on(BCH_VERSION_MAJOR(version) >
 			 BCH_VERSION_MAJOR(c->sb.version),
 			 -BCH_ERR_btree_node_read_err_fixable,
-			 c, NULL, b, i,
+			 c, NULL, b, i, NULL,
 			 btree_node_bset_newer_than_sb,
 			 "bset version %u newer than superblock version %u",
 			 version, c->sb.version)) {
@@ -723,15 +729,17 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 
 	btree_err_on(BSET_SEPARATE_WHITEOUTS(i),
 		     -BCH_ERR_btree_node_read_err_incompatible,
-		     c, ca, b, i,
+		     c, ca, b, i, NULL,
 		     btree_node_unsupported_version,
 		     "BSET_SEPARATE_WHITEOUTS no longer supported");
 
-	if (btree_err_on(offset + sectors > btree_sectors(c),
+	if (!write &&
+	    btree_err_on(offset + sectors > (ptr_written ?: btree_sectors(c)),
 			 -BCH_ERR_btree_node_read_err_fixable,
-			 c, ca, b, i,
+			 c, ca, b, i, NULL,
 			 bset_past_end_of_btree_node,
-			 "bset past end of btree node")) {
+			 "bset past end of btree node (offset %u len %u but written %zu)",
+			 offset, sectors, ptr_written ?: btree_sectors(c))) {
 		i->u64s = 0;
 		ret = 0;
 		goto out;
@@ -739,13 +747,13 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 
 	btree_err_on(offset && !i->u64s,
 		     -BCH_ERR_btree_node_read_err_fixable,
-		     c, ca, b, i,
+		     c, ca, b, i, NULL,
 		     bset_empty,
 		     "empty bset");
 
 	btree_err_on(BSET_OFFSET(i) && BSET_OFFSET(i) != offset,
 		     -BCH_ERR_btree_node_read_err_want_retry,
-		     c, ca, b, i,
+		     c, ca, b, i, NULL,
 		     bset_wrong_sector_offset,
 		     "bset at wrong sector offset");
 
@@ -761,20 +769,20 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 			/* XXX endianness */
 			btree_err_on(bp->seq != bn->keys.seq,
 				     -BCH_ERR_btree_node_read_err_must_retry,
-				     c, ca, b, NULL,
+				     c, ca, b, NULL, NULL,
 				     bset_bad_seq,
 				     "incorrect sequence number (wrong btree node)");
 		}
 
 		btree_err_on(BTREE_NODE_ID(bn) != b->c.btree_id,
 			     -BCH_ERR_btree_node_read_err_must_retry,
-			     c, ca, b, i,
+			     c, ca, b, i, NULL,
 			     btree_node_bad_btree,
 			     "incorrect btree id");
 
 		btree_err_on(BTREE_NODE_LEVEL(bn) != b->c.level,
 			     -BCH_ERR_btree_node_read_err_must_retry,
-			     c, ca, b, i,
+			     c, ca, b, i, NULL,
 			     btree_node_bad_level,
 			     "incorrect level");
 
@@ -793,7 +801,7 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 
 			btree_err_on(!bpos_eq(b->data->min_key, bp->min_key),
 				     -BCH_ERR_btree_node_read_err_must_retry,
-				     c, ca, b, NULL,
+				     c, ca, b, NULL, NULL,
 				     btree_node_bad_min_key,
 				     "incorrect min_key: got %s should be %s",
 				     (printbuf_reset(&buf1),
@@ -804,7 +812,7 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 
 		btree_err_on(!bpos_eq(bn->max_key, b->key.k.p),
 			     -BCH_ERR_btree_node_read_err_must_retry,
-			     c, ca, b, i,
+			     c, ca, b, i, NULL,
 			     btree_node_bad_max_key,
 			     "incorrect max key %s",
 			     (printbuf_reset(&buf1),
@@ -816,7 +824,7 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 
 		btree_err_on(bch2_bkey_format_invalid(c, &bn->format, write, &buf1),
 			     -BCH_ERR_btree_node_read_err_bad_node,
-			     c, ca, b, i,
+			     c, ca, b, i, NULL,
 			     btree_node_bad_format,
 			     "invalid bkey format: %s\n  %s", buf1.buf,
 			     (printbuf_reset(&buf2),
@@ -883,7 +891,7 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
 
 		if (btree_err_on(bkey_p_next(k) > vstruct_last(i),
 				 -BCH_ERR_btree_node_read_err_fixable,
-				 c, NULL, b, i,
+				 c, NULL, b, i, k,
 				 btree_node_bkey_past_bset_end,
 				 "key extends past end of bset")) {
 			i->u64s = cpu_to_le16((u64 *) k - i->_data);
@@ -892,14 +900,14 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
 
 		if (btree_err_on(k->format > KEY_FORMAT_CURRENT,
 				 -BCH_ERR_btree_node_read_err_fixable,
-				 c, NULL, b, i,
+				 c, NULL, b, i, k,
 				 btree_node_bkey_bad_format,
 				 "invalid bkey format %u", k->format))
 			goto drop_this_key;
 
 		if (btree_err_on(!bkeyp_u64s_valid(&b->format, k),
 				 -BCH_ERR_btree_node_read_err_fixable,
-				 c, NULL, b, i,
+				 c, NULL, b, i, k,
 				 btree_node_bkey_bad_u64s,
 				 "bad k->u64s %u (min %u max %zu)", k->u64s,
 				 bkeyp_key_u64s(&b->format, k),
@@ -921,7 +929,7 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
 			bch2_bkey_val_to_text(&buf, c, u.s_c);
 
 			btree_err(-BCH_ERR_btree_node_read_err_fixable,
-				  c, NULL, b, i,
+				  c, NULL, b, i, k,
 				  btree_node_bad_bkey,
 				  "invalid bkey: %s", buf.buf);
 			goto drop_this_key;
@@ -942,7 +950,7 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
 			bch2_bkey_to_text(&buf, u.k);
 
 			if (btree_err(-BCH_ERR_btree_node_read_err_fixable,
-				      c, NULL, b, i,
+				      c, NULL, b, i, k,
 				      btree_node_bkey_out_of_order,
 				      "%s", buf.buf))
 				goto drop_this_key;
@@ -997,7 +1005,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 	bool updated_range = b->key.k.type == KEY_TYPE_btree_ptr_v2 &&
 		BTREE_PTR_RANGE_UPDATED(&bkey_i_to_btree_ptr_v2(&b->key)->v);
 	unsigned u64s;
-	unsigned ptr_written = btree_ptr_sectors_written(&b->key);
+	unsigned ptr_written = btree_ptr_sectors_written(bkey_i_to_s_c(&b->key));
 	struct printbuf buf = PRINTBUF;
 	int ret = 0, retry_read = 0, write = READ;
 	u64 start_time = local_clock();
@@ -1011,13 +1019,13 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 	if (bch2_meta_read_fault("btree"))
 		btree_err(-BCH_ERR_btree_node_read_err_must_retry,
-			  c, ca, b, NULL,
+			  c, ca, b, NULL, NULL,
 			  btree_node_fault_injected,
 			  "dynamic fault");
 
 	btree_err_on(le64_to_cpu(b->data->magic) != bset_magic(c),
 		     -BCH_ERR_btree_node_read_err_must_retry,
-		     c, ca, b, NULL,
+		     c, ca, b, NULL, NULL,
 		     btree_node_bad_magic,
 		     "bad magic: want %llx, got %llx",
 		     bset_magic(c), le64_to_cpu(b->data->magic));
@@ -1032,7 +1040,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 		btree_err_on(b->data->keys.seq != bp->seq,
 			     -BCH_ERR_btree_node_read_err_must_retry,
-			     c, ca, b, NULL,
+			     c, ca, b, NULL, NULL,
 			     btree_node_bad_seq,
 			     "got wrong btree node: got\n%s",
 			     (printbuf_reset(&buf),
@@ -1041,7 +1049,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 	} else {
 		btree_err_on(!b->data->keys.seq,
 			     -BCH_ERR_btree_node_read_err_must_retry,
-			     c, ca, b, NULL,
+			     c, ca, b, NULL, NULL,
 			     btree_node_bad_seq,
 			     "bad btree header: seq 0\n%s",
 			     (printbuf_reset(&buf),
@@ -1060,7 +1068,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 			btree_err_on(!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i)),
 				     -BCH_ERR_btree_node_read_err_want_retry,
-				     c, ca, b, i,
+				     c, ca, b, i, NULL,
 				     bset_unknown_csum,
 				     "unknown checksum type %llu", BSET_CSUM_TYPE(i));
 
@@ -1073,7 +1081,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 			btree_err_on(csum_bad,
 				     -BCH_ERR_btree_node_read_err_want_retry,
-				     c, ca, b, i,
+				     c, ca, b, i, NULL,
 				     bset_bad_csum,
 				     "%s",
 				     (printbuf_reset(&buf),
@@ -1088,7 +1096,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 			btree_err_on(btree_node_type_is_extents(btree_node_type(b)) &&
 				     !BTREE_NODE_NEW_EXTENT_OVERWRITE(b->data),
 				     -BCH_ERR_btree_node_read_err_incompatible,
-				     c, NULL, b, NULL,
+				     c, NULL, b, NULL, NULL,
 				     btree_node_unsupported_version,
 				     "btree node does not have NEW_EXTENT_OVERWRITE set");
 
@@ -1102,7 +1110,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 			btree_err_on(!bch2_checksum_type_valid(c, BSET_CSUM_TYPE(i)),
 				     -BCH_ERR_btree_node_read_err_want_retry,
-				     c, ca, b, i,
+				     c, ca, b, i, NULL,
 				     bset_unknown_csum,
 				     "unknown checksum type %llu", BSET_CSUM_TYPE(i));
 
@@ -1114,7 +1122,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 			btree_err_on(csum_bad,
 				     -BCH_ERR_btree_node_read_err_want_retry,
-				     c, ca, b, i,
+				     c, ca, b, i, NULL,
 				     bset_bad_csum,
 				     "%s",
 				     (printbuf_reset(&buf),
@@ -1152,14 +1160,14 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 
 		btree_err_on(blacklisted && first,
 			     -BCH_ERR_btree_node_read_err_fixable,
-			     c, ca, b, i,
+			     c, ca, b, i, NULL,
 			     bset_blacklisted_journal_seq,
 			     "first btree node bset has blacklisted journal seq (%llu)",
 			     le64_to_cpu(i->journal_seq));
 
 		btree_err_on(blacklisted && ptr_written,
 			     -BCH_ERR_btree_node_read_err_fixable,
-			     c, ca, b, i,
+			     c, ca, b, i, NULL,
 			     first_bset_blacklisted_journal_seq,
 			     "found blacklisted bset (journal seq %llu) in btree node at offset %u-%u/%u",
 			     le64_to_cpu(i->journal_seq),
@@ -1178,7 +1186,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 	if (ptr_written) {
 		btree_err_on(b->written < ptr_written,
 			     -BCH_ERR_btree_node_read_err_want_retry,
-			     c, ca, b, NULL,
+			     c, ca, b, NULL, NULL,
 			     btree_node_data_missing,
 			     "btree node data missing: expected %u sectors, found %u",
 			     ptr_written, b->written);
@@ -1191,7 +1199,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 								      le64_to_cpu(bne->keys.journal_seq),
 								      true),
 				     -BCH_ERR_btree_node_read_err_want_retry,
-				     c, ca, b, NULL,
+				     c, ca, b, NULL, NULL,
 				     btree_node_bset_after_end,
 				     "found bset signature after last bset");
 	}
@@ -1235,7 +1243,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca,
 			bch2_bkey_val_to_text(&buf, c, u.s_c);
 
 			btree_err(-BCH_ERR_btree_node_read_err_fixable,
-				  c, NULL, b, i,
+				  c, NULL, b, i, k,
 				  btree_node_bad_bkey,
 				  "%s", buf.buf);
 
@@ -1471,18 +1479,18 @@ static CLOSURE_CALLBACK(btree_node_read_all_replicas_done)
 
 		written2 = btree_node_sectors_written(c, ra->buf[i]);
 		if (btree_err_on(written2 != written, -BCH_ERR_btree_node_read_err_fixable,
-				 c, NULL, b, NULL,
+				 c, NULL, b, NULL, NULL,
 				 btree_node_replicas_sectors_written_mismatch,
 				 "btree node sectors written mismatch: %u != %u",
 				 written, written2) ||
 		    btree_err_on(btree_node_has_extra_bsets(c, written2, ra->buf[i]),
 				 -BCH_ERR_btree_node_read_err_fixable,
-				 c, NULL, b, NULL,
+				 c, NULL, b, NULL, NULL,
 				 btree_node_bset_after_end,
 				 "found bset signature after last bset") ||
 		    btree_err_on(memcmp(ra->buf[best], ra->buf[i], written << 9),
 				 -BCH_ERR_btree_node_read_err_fixable,
-				 c, NULL, b, NULL,
+				 c, NULL, b, NULL, NULL,
 				 btree_node_replicas_data_mismatch,
 				 "btree node replicas content mismatch"))
 			dump_bset_maps = true;
@@ -2128,7 +2136,7 @@ do_write:
 
 	if (!b->written &&
 	    b->key.k.type == KEY_TYPE_btree_ptr_v2)
-		BUG_ON(btree_ptr_sectors_written(&b->key) != sectors_to_write);
+		BUG_ON(btree_ptr_sectors_written(bkey_i_to_s_c(&b->key)) != sectors_to_write);
 
 	memset(data + bytes_to_write, 0,
 	       (sectors_to_write << 9) - bytes_to_write);
diff --git a/libbcachefs/btree_io.h b/libbcachefs/btree_io.h
index 2b8b564f..63d76f5c 100644
--- a/libbcachefs/btree_io.h
+++ b/libbcachefs/btree_io.h
@@ -27,10 +27,10 @@ static inline void clear_btree_node_dirty_acct(struct bch_fs *c, struct btree *b
 		atomic_dec(&c->btree_cache.dirty);
 }
 
-static inline unsigned btree_ptr_sectors_written(struct bkey_i *k)
+static inline unsigned btree_ptr_sectors_written(struct bkey_s_c k)
 {
-	return k->k.type == KEY_TYPE_btree_ptr_v2
-		? le16_to_cpu(bkey_i_to_btree_ptr_v2(k)->v.sectors_written)
+	return k.k->type == KEY_TYPE_btree_ptr_v2
+		? le16_to_cpu(bkey_s_c_to_btree_ptr_v2(k).v->sectors_written)
 		: 0;
 }
 
diff --git a/libbcachefs/btree_iter.c b/libbcachefs/btree_iter.c
index 5bf98cb8..d3bcb4e4 100644
--- a/libbcachefs/btree_iter.c
+++ b/libbcachefs/btree_iter.c
@@ -332,6 +332,8 @@ out:
 void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
 			    struct bpos pos, bool key_cache)
 {
+	bch2_trans_verify_not_unlocked(trans);
+
 	struct btree_path *path;
 	struct trans_for_each_path_inorder_iter iter;
 	struct printbuf buf = PRINTBUF;
diff --git a/libbcachefs/btree_iter.h b/libbcachefs/btree_iter.h
index eab2a25b..798eb1c4 100644
--- a/libbcachefs/btree_iter.h
+++ b/libbcachefs/btree_iter.h
@@ -838,7 +838,7 @@ __bch2_btree_iter_peek_and_restart(struct btree_trans *trans,
 #define drop_locks_do(_trans, _do)					\
 ({									\
 	bch2_trans_unlock(_trans);					\
-	_do ?: bch2_trans_relock(_trans);				\
+	(_do) ?: bch2_trans_relock(_trans);				\
 })
 
 #define allocate_dropping_locks_errcode(_trans, _do)			\
diff --git a/libbcachefs/btree_update_interior.c b/libbcachefs/btree_update_interior.c
index 60b8544c..7647ccdc 100644
--- a/libbcachefs/btree_update_interior.c
+++ b/libbcachefs/btree_update_interior.c
@@ -1359,7 +1359,7 @@ static void bch2_insert_fixup_btree_ptr(struct btree_update *as,
 	unsigned long old, new, v;
 
 	BUG_ON(insert->k.type == KEY_TYPE_btree_ptr_v2 &&
-	       !btree_ptr_sectors_written(insert));
+	       !btree_ptr_sectors_written(bkey_i_to_s_c(insert)));
 
 	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);
diff --git a/libbcachefs/buckets.c b/libbcachefs/buckets.c
index e28d28ac..b4695865 100644
--- a/libbcachefs/buckets.c
+++ b/libbcachefs/buckets.c
@@ -479,9 +479,8 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
 
 	percpu_down_read(&c->mark_lock);
 
-	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);
+		struct bch_dev *ca = bch2_dev_tryget(c, p.ptr.dev);
 		if (!ca) {
 			if (fsck_err(c, ptr_to_invalid_device,
 				     "pointer to missing device %u\n"
@@ -558,7 +557,7 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
 			do_update = true;
 
 		if (data_type != BCH_DATA_btree && p.ptr.gen != g->gen)
-			continue;
+			goto next;
 
 		if (fsck_err_on(bucket_data_type_mismatch(g->data_type, data_type),
 				c, ptr_bucket_data_type_mismatch,
@@ -601,8 +600,9 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
 					 bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
 				do_update = true;
 		}
+next:
+		bch2_dev_put(ca);
 	}
-	rcu_read_unlock();
 
 	if (do_update) {
 		if (flags & BTREE_TRIGGER_is_root) {
@@ -638,9 +638,10 @@ int bch2_check_fix_ptrs(struct btree_trans *trans,
 		} else {
 			struct bkey_ptrs ptrs;
 			union bch_extent_entry *entry;
+
+			rcu_read_lock();
 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);
@@ -1464,7 +1465,7 @@ int bch2_trans_mark_dev_sbs_flags(struct bch_fs *c,
 	for_each_online_member(c, ca) {
 		int ret = bch2_trans_mark_dev_sb(c, ca, flags);
 		if (ret) {
-			bch2_dev_put(ca);
+			percpu_ref_put(&ca->io_ref);
 			return ret;
 		}
 	}
diff --git a/libbcachefs/checksum.c b/libbcachefs/checksum.c
index 85198f39..3bd3aba9 100644
--- a/libbcachefs/checksum.c
+++ b/libbcachefs/checksum.c
@@ -233,7 +233,7 @@ struct bch_csum bch2_checksum(struct bch_fs *c, unsigned type,
 		return ret;
 	}
 	default:
-		BUG();
+		return (struct bch_csum) {};
 	}
 }
 
@@ -307,7 +307,7 @@ static struct bch_csum __bch2_checksum_bio(struct bch_fs *c, unsigned type,
 		return ret;
 	}
 	default:
-		BUG();
+		return (struct bch_csum) {};
 	}
 }
 
@@ -352,8 +352,12 @@ int __bch2_encrypt_bio(struct bch_fs *c, unsigned type,
 		bytes += bv.bv_len;
 	}
 
-	sg_mark_end(sg - 1);
-	return do_encrypt_sg(c->chacha20, nonce, sgl, bytes);
+	if (sg != sgl) {
+		sg_mark_end(sg - 1);
+		return do_encrypt_sg(c->chacha20, nonce, sgl, bytes);
+	}
+
+	return ret;
 }
 
 struct bch_csum bch2_checksum_merge(unsigned type, struct bch_csum a,
@@ -648,26 +652,26 @@ err:
 
 static int bch2_alloc_ciphers(struct bch_fs *c)
 {
-	int ret;
-
-	if (!c->chacha20)
-		c->chacha20 = crypto_alloc_sync_skcipher("chacha20", 0, 0);
-	ret = PTR_ERR_OR_ZERO(c->chacha20);
+	if (c->chacha20)
+		return 0;
 
+	struct crypto_sync_skcipher *chacha20 = crypto_alloc_sync_skcipher("chacha20", 0, 0);
+	int ret = PTR_ERR_OR_ZERO(chacha20);
 	if (ret) {
 		bch_err(c, "error requesting chacha20 module: %s", bch2_err_str(ret));
 		return ret;
 	}
 
-	if (!c->poly1305)
-		c->poly1305 = crypto_alloc_shash("poly1305", 0, 0);
-	ret = PTR_ERR_OR_ZERO(c->poly1305);
-
+	struct crypto_shash *poly1305 = crypto_alloc_shash("poly1305", 0, 0);
+	ret = PTR_ERR_OR_ZERO(poly1305);
 	if (ret) {
 		bch_err(c, "error requesting poly1305 module: %s", bch2_err_str(ret));
+		crypto_free_sync_skcipher(chacha20);
 		return ret;
 	}
 
+	c->chacha20	= chacha20;
+	c->poly1305	= poly1305;
 	return 0;
 }
 
@@ -762,11 +766,11 @@ err:
 
 void bch2_fs_encryption_exit(struct bch_fs *c)
 {
-	if (!IS_ERR_OR_NULL(c->poly1305))
+	if (c->poly1305)
 		crypto_free_shash(c->poly1305);
-	if (!IS_ERR_OR_NULL(c->chacha20))
+	if (c->chacha20)
 		crypto_free_sync_skcipher(c->chacha20);
-	if (!IS_ERR_OR_NULL(c->sha256))
+	if (c->sha256)
 		crypto_free_shash(c->sha256);
 }
 
@@ -779,6 +783,7 @@ int bch2_fs_encryption_init(struct bch_fs *c)
 	c->sha256 = crypto_alloc_shash("sha256", 0, 0);
 	ret = PTR_ERR_OR_ZERO(c->sha256);
 	if (ret) {
+		c->sha256 = NULL;
 		bch_err(c, "error requesting sha256 module: %s", bch2_err_str(ret));
 		goto out;
 	}
diff --git a/libbcachefs/dirent.c b/libbcachefs/dirent.c
index 6bbf9a7d..c67460d8 100644
--- a/libbcachefs/dirent.c
+++ b/libbcachefs/dirent.c
@@ -15,6 +15,9 @@
 
 static unsigned bch2_dirent_name_bytes(struct bkey_s_c_dirent d)
 {
+	if (bkey_val_bytes(d.k) < offsetof(struct bch_dirent, d_name))
+		return 0;
+
 	unsigned bkey_u64s = bkey_val_u64s(d.k);
 	unsigned bkey_bytes = bkey_u64s * sizeof(u64);
 	u64 last_u64 = ((u64*)d.v)[bkey_u64s - 1];
diff --git a/libbcachefs/fs-io-buffered.c b/libbcachefs/fs-io-buffered.c
index b0a33fab..54873ecc 100644
--- a/libbcachefs/fs-io-buffered.c
+++ b/libbcachefs/fs-io-buffered.c
@@ -257,7 +257,6 @@ void bch2_readahead(struct readahead_control *ractl)
 	struct bch_inode_info *inode = to_bch_ei(ractl->mapping->host);
 	struct bch_fs *c = inode->v.i_sb->s_fs_info;
 	struct bch_io_opts opts;
-	struct btree_trans *trans = bch2_trans_get(c);
 	struct folio *folio;
 	struct readpages_iter readpages_iter;
 
@@ -269,6 +268,7 @@ void bch2_readahead(struct readahead_control *ractl)
 
 	bch2_pagecache_add_get(inode);
 
+	struct btree_trans *trans = bch2_trans_get(c);
 	while ((folio = readpage_iter_peek(&readpages_iter))) {
 		unsigned n = min_t(unsigned,
 				   readpages_iter.folios.nr -
@@ -289,10 +289,10 @@ void bch2_readahead(struct readahead_control *ractl)
 			   &readpages_iter);
 		bch2_trans_unlock(trans);
 	}
+	bch2_trans_put(trans);
 
 	bch2_pagecache_add_put(inode);
 
-	bch2_trans_put(trans);
 	darray_exit(&readpages_iter.folios);
 }
 
@@ -437,8 +437,8 @@ static void bch2_writepage_io_done(struct bch_write_op *op)
 	 */
 
 	/*
-	 * PageWriteback is effectively our ref on the inode - fixup i_blocks
-	 * before calling end_page_writeback:
+	 * The writeback flag is effectively our ref on the inode -
+	 * fixup i_blocks before calling folio_end_writeback:
 	 */
 	bch2_i_sectors_acct(c, io->inode, NULL, io->op.i_sectors_delta);
 
@@ -898,7 +898,7 @@ static int __bch2_buffered_write(struct bch_inode_info *inode,
 	darray_for_each(fs, fi) {
 		f = *fi;
 		f_len = min(end, folio_end_pos(f)) - f_pos;
-		f_copied = copy_page_from_iter_atomic(&f->page, f_offset, f_len, iter);
+		f_copied = copy_folio_from_iter_atomic(f, f_offset, f_len, iter);
 		if (!f_copied) {
 			folios_trunc(&fs, fi);
 			break;
diff --git a/libbcachefs/fs.c b/libbcachefs/fs.c
index a8d71cec..96040a95 100644
--- a/libbcachefs/fs.c
+++ b/libbcachefs/fs.c
@@ -188,8 +188,7 @@ static struct bch_inode_info *bch2_inode_insert(struct bch_fs *c, struct bch_ino
 	BUG_ON(!old);
 
 	if (unlikely(old != inode)) {
-		__destroy_inode(&inode->v);
-		kmem_cache_free(bch2_inode_cache, inode);
+		discard_new_inode(&inode->v);
 		inode = old;
 	} else {
 		mutex_lock(&c->vfs_inodes_lock);
@@ -876,6 +875,9 @@ static int bch2_getattr(struct mnt_idmap *idmap,
 	stat->blksize	= block_bytes(c);
 	stat->blocks	= inode->v.i_blocks;
 
+	stat->subvol	= inode->ei_subvol;
+	stat->result_mask |= STATX_SUBVOL;
+
 	if (request_mask & STATX_BTIME) {
 		stat->result_mask |= STATX_BTIME;
 		stat->btime = bch2_time_to_timespec(c, inode->ei_inode.bi_otime);
@@ -1142,6 +1144,8 @@ static int bch2_open(struct inode *vinode, struct file *file)
 			return ret;
 	}
 
+	file->f_mode |= FMODE_CAN_ODIRECT;
+
 	return generic_file_open(vinode, file);
 }
 
@@ -1234,7 +1238,6 @@ static const struct address_space_operations bch_address_space_operations = {
 	.write_end	= bch2_write_end,
 	.invalidate_folio = bch2_invalidate_folio,
 	.release_folio	= bch2_release_folio,
-	.direct_IO	= noop_direct_IO,
 #ifdef CONFIG_MIGRATION
 	.migrate_folio	= filemap_migrate_folio,
 #endif
diff --git a/libbcachefs/move.c b/libbcachefs/move.c
index 8171f947..0e587916 100644
--- a/libbcachefs/move.c
+++ b/libbcachefs/move.c
@@ -804,7 +804,7 @@ int bch2_evacuate_bucket(struct moving_context *ctxt,
 			if (!b)
 				goto next;
 
-			unsigned sectors = btree_ptr_sectors_written(&b->key);
+			unsigned sectors = btree_ptr_sectors_written(bkey_i_to_s_c(&b->key));
 
 			ret = bch2_btree_node_rewrite(trans, &iter, b, 0);
 			bch2_trans_iter_exit(trans, &iter);
diff --git a/libbcachefs/printbuf.c b/libbcachefs/printbuf.c
index 8b036918..9f529e4c 100644
--- a/libbcachefs/printbuf.c
+++ b/libbcachefs/printbuf.c
@@ -45,6 +45,13 @@ int bch2_printbuf_make_room(struct printbuf *out, unsigned extra)
 
 	unsigned new_size = roundup_pow_of_two(out->size + extra);
 
+	/* Sanity check... */
+	if (new_size > PAGE_SIZE << MAX_PAGE_ORDER) {
+		out->allocation_failure = true;
+		out->overflow = true;
+		return -ENOMEM;
+	}
+
 	/*
 	 * Note: output buffer must be freeable with kfree(), it's not required
 	 * that the user use printbuf_exit().
diff --git a/libbcachefs/recovery.c b/libbcachefs/recovery.c
index 1266916a..cf513fc7 100644
--- a/libbcachefs/recovery.c
+++ b/libbcachefs/recovery.c
@@ -35,6 +35,9 @@
 
 void bch2_btree_lost_data(struct bch_fs *c, enum btree_id btree)
 {
+	if (btree >= BTREE_ID_NR_MAX)
+		return;
+
 	u64 b = BIT_ULL(btree);
 
 	if (!(c->sb.btrees_lost_data & b)) {
@@ -808,9 +811,11 @@ use_clean:
 	clear_bit(BCH_FS_fsck_running, &c->flags);
 
 	/* fsync if we fixed errors */
-	if (test_bit(BCH_FS_errors_fixed, &c->flags)) {
+	if (test_bit(BCH_FS_errors_fixed, &c->flags) &&
+	    bch2_write_ref_tryget(c, BCH_WRITE_REF_fsync)) {
 		bch2_journal_flush_all_pins(&c->journal);
 		bch2_journal_meta(&c->journal);
+		bch2_write_ref_put(c, BCH_WRITE_REF_fsync);
 	}
 
 	/* If we fixed errors, verify that fs is actually clean now: */
diff --git a/libbcachefs/replicas.c b/libbcachefs/replicas.c
index bd1d5d08..57a1f09c 100644
--- a/libbcachefs/replicas.c
+++ b/libbcachefs/replicas.c
@@ -23,14 +23,12 @@ static int bch2_memcmp(const void *l, const void *r,  const void *priv)
 static void verify_replicas_entry(struct bch_replicas_entry_v1 *e)
 {
 #ifdef CONFIG_BCACHEFS_DEBUG
-	unsigned i;
-
 	BUG_ON(e->data_type >= BCH_DATA_NR);
 	BUG_ON(!e->nr_devs);
 	BUG_ON(e->nr_required > 1 &&
 	       e->nr_required >= e->nr_devs);
 
-	for (i = 0; i + 1 < e->nr_devs; i++)
+	for (unsigned i = 0; i + 1 < e->nr_devs; i++)
 		BUG_ON(e->devs[i] >= e->devs[i + 1]);
 #endif
 }
@@ -192,24 +190,17 @@ cpu_replicas_add_entry(struct bch_fs *c,
 		       struct bch_replicas_cpu *old,
 		       struct bch_replicas_entry_v1 *new_entry)
 {
-	unsigned i;
 	struct bch_replicas_cpu new = {
 		.nr		= old->nr + 1,
 		.entry_size	= max_t(unsigned, old->entry_size,
 					replicas_entry_bytes(new_entry)),
 	};
 
-	for (i = 0; i < new_entry->nr_devs; i++)
-		BUG_ON(!bch2_dev_exists(c, new_entry->devs[i]));
-
-	BUG_ON(!new_entry->data_type);
-	verify_replicas_entry(new_entry);
-
 	new.entries = kcalloc(new.nr, new.entry_size, GFP_KERNEL);
 	if (!new.entries)
 		return new;
 
-	for (i = 0; i < old->nr; i++)
+	for (unsigned i = 0; i < old->nr; i++)
 		memcpy(cpu_replicas_entry(&new, i),
 		       cpu_replicas_entry(old, i),
 		       old->entry_size);
@@ -230,8 +221,6 @@ static inline int __replicas_entry_idx(struct bch_replicas_cpu *r,
 	if (unlikely(entry_size > r->entry_size))
 		return -1;
 
-	verify_replicas_entry(search);
-
 #define entry_cmp(_l, _r)	memcmp(_l, _r, entry_size)
 	idx = eytzinger0_find(r->entries, r->nr, r->entry_size,
 			      entry_cmp, search);
@@ -524,13 +513,16 @@ int bch2_replicas_gc_start(struct bch_fs *c, unsigned typemask)
 	c->replicas_gc.nr		= 0;
 	c->replicas_gc.entry_size	= 0;
 
-	for_each_cpu_replicas_entry(&c->replicas, e)
-		if (!((1 << e->data_type) & typemask)) {
+	for_each_cpu_replicas_entry(&c->replicas, e) {
+		/* Preserve unknown data types */
+		if (e->data_type >= BCH_DATA_NR ||
+		    !((1 << e->data_type) & typemask)) {
 			c->replicas_gc.nr++;
 			c->replicas_gc.entry_size =
 				max_t(unsigned, c->replicas_gc.entry_size,
 				      replicas_entry_bytes(e));
 		}
+	}
 
 	c->replicas_gc.entries = kcalloc(c->replicas_gc.nr,
 					 c->replicas_gc.entry_size,
@@ -542,7 +534,8 @@ int bch2_replicas_gc_start(struct bch_fs *c, unsigned typemask)
 	}
 
 	for_each_cpu_replicas_entry(&c->replicas, e)
-		if (!((1 << e->data_type) & typemask))
+		if (e->data_type >= BCH_DATA_NR ||
+		    !((1 << e->data_type) & typemask))
 			memcpy(cpu_replicas_entry(&c->replicas_gc, i++),
 			       e, c->replicas_gc.entry_size);
 
@@ -998,7 +991,7 @@ unsigned bch2_sb_dev_has_data(struct bch_sb *sb, unsigned dev)
 {
 	struct bch_sb_field_replicas *replicas;
 	struct bch_sb_field_replicas_v0 *replicas_v0;
-	unsigned i, data_has = 0;
+	unsigned data_has = 0;
 
 	replicas = bch2_sb_field_get(sb, replicas);
 	replicas_v0 = bch2_sb_field_get(sb, replicas_v0);
@@ -1006,17 +999,26 @@ unsigned bch2_sb_dev_has_data(struct bch_sb *sb, unsigned dev)
 	if (replicas) {
 		struct bch_replicas_entry_v1 *r;
 
-		for_each_replicas_entry(replicas, r)
-			for (i = 0; i < r->nr_devs; i++)
+		for_each_replicas_entry(replicas, r) {
+			if (r->data_type >= sizeof(data_has) * 8)
+				continue;
+
+			for (unsigned i = 0; i < r->nr_devs; i++)
 				if (r->devs[i] == dev)
 					data_has |= 1 << r->data_type;
+		}
+
 	} else if (replicas_v0) {
 		struct bch_replicas_entry_v0 *r;
 
-		for_each_replicas_entry_v0(replicas_v0, r)
-			for (i = 0; i < r->nr_devs; i++)
+		for_each_replicas_entry_v0(replicas_v0, r) {
+			if (r->data_type >= sizeof(data_has) * 8)
+				continue;
+
+			for (unsigned i = 0; i < r->nr_devs; i++)
 				if (r->devs[i] == dev)
 					data_has |= 1 << r->data_type;
+		}
 	}
 
 
diff --git a/libbcachefs/sb-errors_types.h b/libbcachefs/sb-errors_types.h
index 87324747..666599d3 100644
--- a/libbcachefs/sb-errors_types.h
+++ b/libbcachefs/sb-errors_types.h
@@ -273,7 +273,9 @@
 	x(dup_backpointer_to_bad_csum_extent,			265)	\
 	x(btree_bitmap_not_marked,				266)	\
 	x(sb_clean_entry_overrun,				267)	\
-	x(btree_ptr_v2_written_0,				268)
+	x(btree_ptr_v2_written_0,				268)	\
+	x(subvol_snapshot_bad,					269)	\
+	x(subvol_inode_bad,					270)
 
 enum bch_sb_error_id {
 #define x(t, n) BCH_FSCK_ERR_##t = n,
diff --git a/libbcachefs/snapshot.c b/libbcachefs/snapshot.c
index 629900a5..720c4080 100644
--- a/libbcachefs/snapshot.c
+++ b/libbcachefs/snapshot.c
@@ -92,10 +92,19 @@ static int bch2_snapshot_tree_create(struct btree_trans *trans,
 
 /* Snapshot nodes: */
 
-static bool __bch2_snapshot_is_ancestor_early(struct snapshot_table *t, u32 id, u32 ancestor)
+void bch2_invalid_snapshot_id(struct bch_fs *c, u32 id)
+{
+	bch_err(c, "reference to invalid snapshot ID %u", id);
+
+	if (c->curr_recovery_pass == BCH_RECOVERY_PASS_NR)
+		bch2_inconsistent_error(c);
+}
+
+static bool __bch2_snapshot_is_ancestor_early(struct bch_fs *c, struct snapshot_table *t,
+					      u32 id, u32 ancestor)
 {
 	while (id && id < ancestor) {
-		const struct snapshot_t *s = __snapshot_t(t, id);
+		const struct snapshot_t *s = __snapshot_t(c, t, id);
 		id = s ? s->parent : 0;
 	}
 	return id == ancestor;
@@ -104,15 +113,15 @@ static bool __bch2_snapshot_is_ancestor_early(struct snapshot_table *t, u32 id,
 static bool bch2_snapshot_is_ancestor_early(struct bch_fs *c, u32 id, u32 ancestor)
 {
 	rcu_read_lock();
-	bool ret = __bch2_snapshot_is_ancestor_early(rcu_dereference(c->snapshots), id, ancestor);
+	bool ret = __bch2_snapshot_is_ancestor_early(c, rcu_dereference(c->snapshots), id, ancestor);
 	rcu_read_unlock();
 
 	return ret;
 }
 
-static inline u32 get_ancestor_below(struct snapshot_table *t, u32 id, u32 ancestor)
+static inline u32 get_ancestor_below(struct bch_fs *c, struct snapshot_table *t, u32 id, u32 ancestor)
 {
-	const struct snapshot_t *s = __snapshot_t(t, id);
+	const struct snapshot_t *s = __snapshot_t(c, t, id);
 	if (!s)
 		return 0;
 
@@ -125,9 +134,9 @@ static inline u32 get_ancestor_below(struct snapshot_table *t, u32 id, u32 ances
 	return s->parent;
 }
 
-static bool test_ancestor_bitmap(struct snapshot_table *t, u32 id, u32 ancestor)
+static bool test_ancestor_bitmap(struct bch_fs *c, struct snapshot_table *t, u32 id, u32 ancestor)
 {
-	const struct snapshot_t *s = __snapshot_t(t, id);
+	const struct snapshot_t *s = __snapshot_t(c, t, id);
 	if (!s)
 		return false;
 
@@ -142,18 +151,18 @@ bool __bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
 	struct snapshot_table *t = rcu_dereference(c->snapshots);
 
 	if (unlikely(c->recovery_pass_done < BCH_RECOVERY_PASS_check_snapshots)) {
-		ret = __bch2_snapshot_is_ancestor_early(t, id, ancestor);
+		ret = __bch2_snapshot_is_ancestor_early(c, t, id, ancestor);
 		goto out;
 	}
 
 	while (id && id < ancestor - IS_ANCESTOR_BITMAP)
-		id = get_ancestor_below(t, id, ancestor);
+		id = get_ancestor_below(c, t, id, ancestor);
 
 	ret = id && id < ancestor
-		? test_ancestor_bitmap(t, id, ancestor)
+		? test_ancestor_bitmap(c, t, id, ancestor)
 		: id == ancestor;
 
-	EBUG_ON(ret != __bch2_snapshot_is_ancestor_early(t, id, ancestor));
+	EBUG_ON(ret != __bch2_snapshot_is_ancestor_early(c, t, id, ancestor));
 out:
 	rcu_read_unlock();
 
@@ -321,6 +330,7 @@ static int __bch2_mark_snapshot(struct btree_trans *trans,
 		t->children[1]	= le32_to_cpu(s.v->children[1]);
 		t->subvol	= BCH_SNAPSHOT_SUBVOL(s.v) ? le32_to_cpu(s.v->subvol) : 0;
 		t->tree		= le32_to_cpu(s.v->tree);
+		t->equiv	= id;
 
 		if (bkey_val_bytes(s.k) > offsetof(struct bch_snapshot, depth)) {
 			t->depth	= le32_to_cpu(s.v->depth);
diff --git a/libbcachefs/snapshot.h b/libbcachefs/snapshot.h
index bd5d7426..29e1c5a6 100644
--- a/libbcachefs/snapshot.h
+++ b/libbcachefs/snapshot.h
@@ -32,7 +32,7 @@ int bch2_mark_snapshot(struct btree_trans *, enum btree_id, unsigned,
 	.min_val_size	= 24,					\
 })
 
-static inline struct snapshot_t *__snapshot_t(struct snapshot_table *t, u32 id)
+static inline struct snapshot_t *__snapshot_t_noerror(struct snapshot_table *t, u32 id)
 {
 	u32 idx = U32_MAX - id;
 
@@ -41,9 +41,26 @@ static inline struct snapshot_t *__snapshot_t(struct snapshot_table *t, u32 id)
 		: NULL;
 }
 
+void bch2_invalid_snapshot_id(struct bch_fs *, u32);
+
+static inline struct snapshot_t *__snapshot_t(struct bch_fs *c, struct snapshot_table *t, u32 id)
+{
+	struct snapshot_t *s = __snapshot_t_noerror(t, id);
+	if (unlikely(!s || !s->equiv)) {
+		bch2_invalid_snapshot_id(c, id);
+		s = NULL;
+	}
+	return s;
+}
+
+static inline const struct snapshot_t *snapshot_t_noerror(struct bch_fs *c, u32 id)
+{
+	return __snapshot_t_noerror(rcu_dereference(c->snapshots), id);
+}
+
 static inline const struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
 {
-	return __snapshot_t(rcu_dereference(c->snapshots), id);
+	return __snapshot_t(c, rcu_dereference(c->snapshots), id);
 }
 
 static inline u32 bch2_snapshot_tree(struct bch_fs *c, u32 id)
@@ -176,12 +193,9 @@ static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ances
 
 static inline bool bch2_snapshot_has_children(struct bch_fs *c, u32 id)
 {
-	const struct snapshot_t *t;
-	bool ret;
-
 	rcu_read_lock();
-	t = snapshot_t(c, id);
-	ret = (t->children[0]|t->children[1]) != 0;
+	const struct snapshot_t *t = snapshot_t(c, id);
+	bool ret = t && (t->children[0]|t->children[1]) != 0;
 	rcu_read_unlock();
 
 	return ret;
diff --git a/libbcachefs/subvolume.c b/libbcachefs/subvolume.c
index 13221376..dfc9cf30 100644
--- a/libbcachefs/subvolume.c
+++ b/libbcachefs/subvolume.c
@@ -210,12 +210,21 @@ int bch2_check_subvol_children(struct bch_fs *c)
 int bch2_subvolume_invalid(struct bch_fs *c, struct bkey_s_c k,
 			   enum bch_validate_flags flags, struct printbuf *err)
 {
+	struct bkey_s_c_subvolume subvol = bkey_s_c_to_subvolume(k);
 	int ret = 0;
 
 	bkey_fsck_err_on(bkey_lt(k.k->p, SUBVOL_POS_MIN) ||
 			 bkey_gt(k.k->p, SUBVOL_POS_MAX), c, err,
 			 subvol_pos_bad,
 			 "invalid pos");
+
+	bkey_fsck_err_on(!subvol.v->snapshot, c, err,
+			 subvol_snapshot_bad,
+			 "invalid snapshot");
+
+	bkey_fsck_err_on(!subvol.v->inode, c, err,
+			 subvol_inode_bad,
+			 "invalid inode");
 fsck_err:
 	return ret;
 }
diff --git a/libbcachefs/super.c b/libbcachefs/super.c
index 294a9d35..2206a8de 100644
--- a/libbcachefs/super.c
+++ b/libbcachefs/super.c
@@ -551,9 +551,9 @@ static void __bch2_fs_free(struct bch_fs *c)
 	bch2_fs_io_read_exit(c);
 	bch2_fs_buckets_waiting_for_journal_exit(c);
 	bch2_fs_btree_interior_update_exit(c);
-	bch2_fs_btree_iter_exit(c);
 	bch2_fs_btree_key_cache_exit(&c->btree_key_cache);
 	bch2_fs_btree_cache_exit(c);
+	bch2_fs_btree_iter_exit(c);
 	bch2_fs_replicas_exit(c);
 	bch2_fs_journal_exit(&c->journal);
 	bch2_io_clock_exit(&c->io_clock[WRITE]);