diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h
index 3247983..94b3c05 100644
--- a/fs/bcachefs/alloc_background.h
+++ b/fs/bcachefs/alloc_background.h
@@ -159,6 +159,7 @@ void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.val_to_text	= bch2_alloc_to_text,		\
 	.trans_trigger	= bch2_trans_mark_alloc,	\
 	.atomic_trigger	= bch2_mark_alloc,		\
+	.min_val_size	= 8,				\
 })
 
 #define bch2_bkey_ops_alloc_v2 ((struct bkey_ops) {	\
@@ -166,6 +167,7 @@ void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.val_to_text	= bch2_alloc_to_text,		\
 	.trans_trigger	= bch2_trans_mark_alloc,	\
 	.atomic_trigger	= bch2_mark_alloc,		\
+	.min_val_size	= 8,				\
 })
 
 #define bch2_bkey_ops_alloc_v3 ((struct bkey_ops) {	\
@@ -173,6 +175,7 @@ void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.val_to_text	= bch2_alloc_to_text,		\
 	.trans_trigger	= bch2_trans_mark_alloc,	\
 	.atomic_trigger	= bch2_mark_alloc,		\
+	.min_val_size	= 16,				\
 })
 
 #define bch2_bkey_ops_alloc_v4 ((struct bkey_ops) {	\
@@ -181,6 +184,7 @@ void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.swab		= bch2_alloc_v4_swab,		\
 	.trans_trigger	= bch2_trans_mark_alloc,	\
 	.atomic_trigger	= bch2_mark_alloc,		\
+	.min_val_size	= 48,				\
 })
 
 int bch2_bucket_gens_invalid(const struct bch_fs *, struct bkey_s_c, unsigned, struct printbuf *);
diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c
index a3a1ed6..e8666c3 100644
--- a/fs/bcachefs/backpointers.c
+++ b/fs/bcachefs/backpointers.c
@@ -43,11 +43,6 @@ int bch2_backpointer_invalid(const struct bch_fs *c, struct bkey_s_c k,
 	struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(k);
 	struct bpos bucket = bp_pos_to_bucket(c, bp.k->p);
 
-	if (bkey_val_bytes(bp.k) < sizeof(*bp.v)) {
-		prt_str(err, "incorrect value size");
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (!bpos_eq(bp.k->p, bucket_pos_to_bp(c, bucket, bp.v->bucket_offset))) {
 		prt_str(err, "backpointer at wrong pos");
 		return -BCH_ERR_invalid_bkey;
diff --git a/fs/bcachefs/backpointers.h b/fs/bcachefs/backpointers.h
index 9c03709..3994bc8 100644
--- a/fs/bcachefs/backpointers.h
+++ b/fs/bcachefs/backpointers.h
@@ -17,6 +17,7 @@ void bch2_backpointer_swab(struct bkey_s);
 	.key_invalid	= bch2_backpointer_invalid,	\
 	.val_to_text	= bch2_backpointer_k_to_text,	\
 	.swab		= bch2_backpointer_swab,	\
+	.min_val_size	= 32,				\
 })
 
 #define MAX_EXTENT_COMPRESS_RATIO_SHIFT		10
diff --git a/fs/bcachefs/bkey_methods.c b/fs/bcachefs/bkey_methods.c
index 72d9583..47f0ab0 100644
--- a/fs/bcachefs/bkey_methods.c
+++ b/fs/bcachefs/bkey_methods.c
@@ -56,17 +56,12 @@ static int empty_val_key_invalid(const struct bch_fs *c, struct bkey_s_c k,
 static int key_type_cookie_invalid(const struct bch_fs *c, struct bkey_s_c k,
 				   unsigned flags, struct printbuf *err)
 {
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_cookie)) {
-		prt_printf(err, "incorrect value size (%zu != %zu)",
-		       bkey_val_bytes(k.k), sizeof(struct bch_cookie));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	return 0;
 }
 
 #define bch2_bkey_ops_cookie ((struct bkey_ops) {	\
-	.key_invalid = key_type_cookie_invalid,		\
+	.key_invalid	= key_type_cookie_invalid,	\
+	.min_val_size	= 8,				\
 })
 
 #define bch2_bkey_ops_hash_whiteout ((struct bkey_ops) {\
@@ -126,12 +121,22 @@ const struct bkey_ops bch2_bkey_ops[] = {
 int bch2_bkey_val_invalid(struct bch_fs *c, struct bkey_s_c k,
 			  unsigned flags, struct printbuf *err)
 {
+	const struct bkey_ops *ops;
+
 	if (k.k->type >= KEY_TYPE_MAX) {
 		prt_printf(err, "invalid type (%u >= %u)", k.k->type, KEY_TYPE_MAX);
 		return -BCH_ERR_invalid_bkey;
 	}
 
-	return bch2_bkey_ops[k.k->type].key_invalid(c, k, flags, err);
+	ops = &bch2_bkey_ops[k.k->type];
+
+	if (bkey_val_bytes(k.k) < ops->min_val_size) {
+		prt_printf(err, "bad val size (%zu < %u)",
+			   bkey_val_bytes(k.k), ops->min_val_size);
+		return -BCH_ERR_invalid_bkey;
+	}
+
+	return ops->key_invalid(c, k, flags, err);
 }
 
 static unsigned bch2_key_types_allowed[] = {
diff --git a/fs/bcachefs/bkey_methods.h b/fs/bcachefs/bkey_methods.h
index ec46381..a65756e 100644
--- a/fs/bcachefs/bkey_methods.h
+++ b/fs/bcachefs/bkey_methods.h
@@ -34,6 +34,9 @@ struct bkey_ops {
 	void		(*compat)(enum btree_id id, unsigned version,
 				  unsigned big_endian, int write,
 				  struct bkey_s);
+
+	/* Size of value type when first created: */
+	unsigned	min_val_size;
 };
 
 extern const struct bkey_ops bch2_bkey_ops[];
diff --git a/fs/bcachefs/dirent.c b/fs/bcachefs/dirent.c
index 4c85d33..1544fc5 100644
--- a/fs/bcachefs/dirent.c
+++ b/fs/bcachefs/dirent.c
@@ -89,12 +89,6 @@ int bch2_dirent_invalid(const struct bch_fs *c, struct bkey_s_c k,
 	struct bkey_s_c_dirent d = bkey_s_c_to_dirent(k);
 	unsigned len;
 
-	if (bkey_val_bytes(k.k) < sizeof(struct bch_dirent)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*d.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	len = bch2_dirent_name_bytes(d);
 	if (!len) {
 		prt_printf(err, "empty name");
diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
index ad131e8..bf9ea2e 100644
--- a/fs/bcachefs/dirent.h
+++ b/fs/bcachefs/dirent.h
@@ -12,6 +12,7 @@ void bch2_dirent_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 #define bch2_bkey_ops_dirent ((struct bkey_ops) {	\
 	.key_invalid	= bch2_dirent_invalid,		\
 	.val_to_text	= bch2_dirent_to_text,		\
+	.min_val_size	= 16,				\
 })
 
 struct qstr;
diff --git a/fs/bcachefs/ec.c b/fs/bcachefs/ec.c
index 1855d08..cf9f8c0 100644
--- a/fs/bcachefs/ec.c
+++ b/fs/bcachefs/ec.c
@@ -119,12 +119,6 @@ int bch2_stripe_invalid(const struct bch_fs *c, struct bkey_s_c k,
 		return -BCH_ERR_invalid_bkey;
 	}
 
-	if (bkey_val_bytes(k.k) < sizeof(*s)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*s));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (bkey_val_u64s(k.k) < stripe_val_u64s(s)) {
 		prt_printf(err, "incorrect value size (%zu < %u)",
 		       bkey_val_u64s(k.k), stripe_val_u64s(s));
diff --git a/fs/bcachefs/ec.h b/fs/bcachefs/ec.h
index 7c08a49d..3995b70 100644
--- a/fs/bcachefs/ec.h
+++ b/fs/bcachefs/ec.h
@@ -17,6 +17,7 @@ void bch2_stripe_to_text(struct printbuf *, struct bch_fs *,
 	.swab		= bch2_ptr_swab,		\
 	.trans_trigger	= bch2_trans_mark_stripe,	\
 	.atomic_trigger	= bch2_mark_stripe,		\
+	.min_val_size	= 8,				\
 })
 
 static inline unsigned stripe_csums_per_device(const struct bch_stripe *s)
diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index ccefacd..e2b126a 100644
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -183,14 +183,6 @@ void bch2_btree_ptr_to_text(struct printbuf *out, struct bch_fs *c,
 int bch2_btree_ptr_v2_invalid(const struct bch_fs *c, struct bkey_s_c k,
 			      unsigned flags, struct printbuf *err)
 {
-	struct bkey_s_c_btree_ptr_v2 bp = bkey_s_c_to_btree_ptr_v2(k);
-
-	if (bkey_val_bytes(k.k) <= sizeof(*bp.v)) {
-		prt_printf(err, "value too small (%zu <= %zu)",
-		       bkey_val_bytes(k.k), sizeof(*bp.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (bkey_val_u64s(k.k) > BKEY_BTREE_PTR_VAL_U64s_MAX) {
 		prt_printf(err, "value too big (%zu > %zu)",
 		       bkey_val_u64s(k.k), BKEY_BTREE_PTR_VAL_U64s_MAX);
@@ -383,12 +375,6 @@ int bch2_reservation_invalid(const struct bch_fs *c, struct bkey_s_c k,
 {
 	struct bkey_s_c_reservation r = bkey_s_c_to_reservation(k);
 
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_reservation)) {
-		prt_printf(err, "incorrect value size (%zu != %zu)",
-		       bkey_val_bytes(k.k), sizeof(*r.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (!r.v->nr_replicas || r.v->nr_replicas > BCH_REPLICAS_MAX) {
 		prt_printf(err, "invalid nr_replicas (%u)",
 		       r.v->nr_replicas);
diff --git a/fs/bcachefs/extents.h b/fs/bcachefs/extents.h
index 9b026ae..31c8140 100644
--- a/fs/bcachefs/extents.h
+++ b/fs/bcachefs/extents.h
@@ -407,6 +407,7 @@ void bch2_btree_ptr_v2_compat(enum btree_id, unsigned, unsigned,
 	.compat		= bch2_btree_ptr_v2_compat,		\
 	.trans_trigger	= bch2_trans_mark_extent,		\
 	.atomic_trigger	= bch2_mark_extent,			\
+	.min_val_size	= 40,					\
 })
 
 /* KEY_TYPE_extent: */
@@ -436,6 +437,7 @@ bool bch2_reservation_merge(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 	.key_merge	= bch2_reservation_merge,		\
 	.trans_trigger	= bch2_trans_mark_reservation,		\
 	.atomic_trigger	= bch2_mark_reservation,		\
+	.min_val_size	= 8,					\
 })
 
 /* Extent checksum entries: */
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 7ccbc00..107210d 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -437,12 +437,6 @@ int bch2_inode_invalid(const struct bch_fs *c, struct bkey_s_c k,
 {
 	struct bkey_s_c_inode inode = bkey_s_c_to_inode(k);
 
-	if (bkey_val_bytes(k.k) < sizeof(*inode.v)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*inode.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (INODE_STR_HASH(inode.v) >= BCH_STR_HASH_NR) {
 		prt_printf(err, "invalid str hash type (%llu >= %u)",
 		       INODE_STR_HASH(inode.v), BCH_STR_HASH_NR);
@@ -457,12 +451,6 @@ int bch2_inode_v2_invalid(const struct bch_fs *c, struct bkey_s_c k,
 {
 	struct bkey_s_c_inode_v2 inode = bkey_s_c_to_inode_v2(k);
 
-	if (bkey_val_bytes(k.k) < sizeof(*inode.v)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*inode.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (INODEv2_STR_HASH(inode.v) >= BCH_STR_HASH_NR) {
 		prt_printf(err, "invalid str hash type (%llu >= %u)",
 		       INODEv2_STR_HASH(inode.v), BCH_STR_HASH_NR);
@@ -477,12 +465,6 @@ int bch2_inode_v3_invalid(const struct bch_fs *c, struct bkey_s_c k,
 {
 	struct bkey_s_c_inode_v3 inode = bkey_s_c_to_inode_v3(k);
 
-	if (bkey_val_bytes(k.k) < sizeof(*inode.v)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*inode.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (INODEv3_FIELDS_START(inode.v) < INODEv3_FIELDS_START_INITIAL ||
 	    INODEv3_FIELDS_START(inode.v) > bkey_val_u64s(inode.k)) {
 		prt_printf(err, "invalid fields_start (got %llu, min %u max %zu)",
@@ -543,12 +525,6 @@ int bch2_inode_generation_invalid(const struct bch_fs *c, struct bkey_s_c k,
 		return -BCH_ERR_invalid_bkey;
 	}
 
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_inode_generation)) {
-		prt_printf(err, "incorrect value size (%zu != %zu)",
-		       bkey_val_bytes(k.k), sizeof(struct bch_inode_generation));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	return 0;
 }
 
diff --git a/fs/bcachefs/inode.h b/fs/bcachefs/inode.h
index f5066af..0c3022d 100644
--- a/fs/bcachefs/inode.h
+++ b/fs/bcachefs/inode.h
@@ -17,6 +17,7 @@ void bch2_inode_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.val_to_text	= bch2_inode_to_text,		\
 	.trans_trigger	= bch2_trans_mark_inode,	\
 	.atomic_trigger	= bch2_mark_inode,		\
+	.min_val_size	= 16,				\
 })
 
 #define bch2_bkey_ops_inode_v2 ((struct bkey_ops) {	\
@@ -24,6 +25,7 @@ void bch2_inode_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.val_to_text	= bch2_inode_to_text,		\
 	.trans_trigger	= bch2_trans_mark_inode,	\
 	.atomic_trigger	= bch2_mark_inode,		\
+	.min_val_size	= 32,				\
 })
 
 #define bch2_bkey_ops_inode_v3 ((struct bkey_ops) {	\
@@ -31,6 +33,7 @@ void bch2_inode_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 	.val_to_text	= bch2_inode_to_text,		\
 	.trans_trigger	= bch2_trans_mark_inode,	\
 	.atomic_trigger	= bch2_mark_inode,		\
+	.min_val_size	= 48,				\
 })
 
 static inline bool bkey_is_inode(const struct bkey *k)
@@ -47,6 +50,7 @@ void bch2_inode_generation_to_text(struct printbuf *, struct bch_fs *, struct bk
 #define bch2_bkey_ops_inode_generation ((struct bkey_ops) {	\
 	.key_invalid	= bch2_inode_generation_invalid,	\
 	.val_to_text	= bch2_inode_generation_to_text,	\
+	.min_val_size	= 8,					\
 })
 
 #if 0
diff --git a/fs/bcachefs/lru.c b/fs/bcachefs/lru.c
index c2dece2..0e6193d 100644
--- a/fs/bcachefs/lru.c
+++ b/fs/bcachefs/lru.c
@@ -13,14 +13,6 @@
 int bch2_lru_invalid(const struct bch_fs *c, struct bkey_s_c k,
 		     unsigned flags, struct printbuf *err)
 {
-	const struct bch_lru *lru = bkey_s_c_to_lru(k).v;
-
-	if (bkey_val_bytes(k.k) < sizeof(*lru)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*lru));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (!lru_pos_time(k.k->p)) {
 		prt_printf(err, "lru entry at time=0");
 		return -BCH_ERR_invalid_bkey;
diff --git a/fs/bcachefs/lru.h b/fs/bcachefs/lru.h
index 78a6076..adb9842 100644
--- a/fs/bcachefs/lru.h
+++ b/fs/bcachefs/lru.h
@@ -51,6 +51,7 @@ void bch2_lru_pos_to_text(struct printbuf *, struct bpos);
 #define bch2_bkey_ops_lru ((struct bkey_ops) {	\
 	.key_invalid	= bch2_lru_invalid,	\
 	.val_to_text	= bch2_lru_to_text,	\
+	.min_val_size	= 8,			\
 })
 
 int bch2_lru_del(struct btree_trans *, u16, u64, u64);
diff --git a/fs/bcachefs/quota.c b/fs/bcachefs/quota.c
index 331f228..22cd662 100644
--- a/fs/bcachefs/quota.c
+++ b/fs/bcachefs/quota.c
@@ -67,12 +67,6 @@ int bch2_quota_invalid(const struct bch_fs *c, struct bkey_s_c k,
 		return -BCH_ERR_invalid_bkey;
 	}
 
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_quota)) {
-		prt_printf(err, "incorrect value size (%zu != %zu)",
-		       bkey_val_bytes(k.k), sizeof(struct bch_quota));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	return 0;
 }
 
diff --git a/fs/bcachefs/quota.h b/fs/bcachefs/quota.h
index 146264f..b0f7d4e 100644
--- a/fs/bcachefs/quota.h
+++ b/fs/bcachefs/quota.h
@@ -13,6 +13,7 @@ void bch2_quota_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 #define bch2_bkey_ops_quota ((struct bkey_ops) {	\
 	.key_invalid	= bch2_quota_invalid,		\
 	.val_to_text	= bch2_quota_to_text,		\
+	.min_val_size	= 32,				\
 })
 
 static inline struct bch_qid bch_qid(struct bch_inode_unpacked *u)
diff --git a/fs/bcachefs/reflink.c b/fs/bcachefs/reflink.c
index d8426e7..9430899 100644
--- a/fs/bcachefs/reflink.c
+++ b/fs/bcachefs/reflink.c
@@ -30,12 +30,6 @@ int bch2_reflink_p_invalid(const struct bch_fs *c, struct bkey_s_c k,
 {
 	struct bkey_s_c_reflink_p p = bkey_s_c_to_reflink_p(k);
 
-	if (bkey_val_bytes(p.k) != sizeof(*p.v)) {
-		prt_printf(err, "incorrect value size (%zu != %zu)",
-		       bkey_val_bytes(p.k), sizeof(*p.v));
-		return -EINVAL;
-	}
-
 	if (c->sb.version >= bcachefs_metadata_version_reflink_p_fix &&
 	    le64_to_cpu(p.v->idx) < le32_to_cpu(p.v->front_pad)) {
 		prt_printf(err, "idx < front_pad (%llu < %u)",
@@ -80,14 +74,6 @@ bool bch2_reflink_p_merge(struct bch_fs *c, struct bkey_s _l, struct bkey_s_c _r
 int bch2_reflink_v_invalid(const struct bch_fs *c, struct bkey_s_c k,
 			   unsigned flags, struct printbuf *err)
 {
-	struct bkey_s_c_reflink_v r = bkey_s_c_to_reflink_v(k);
-
-	if (bkey_val_bytes(r.k) < sizeof(*r.v)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(r.k), sizeof(*r.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	return bch2_bkey_ptrs_invalid(c, k, flags, err);
 }
 
@@ -133,12 +119,6 @@ int bch2_trans_mark_reflink_v(struct btree_trans *trans,
 int bch2_indirect_inline_data_invalid(const struct bch_fs *c, struct bkey_s_c k,
 				      unsigned flags, struct printbuf *err)
 {
-	if (bkey_val_bytes(k.k) < sizeof(struct bch_indirect_inline_data)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(struct bch_indirect_inline_data));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	return 0;
 }
 
diff --git a/fs/bcachefs/reflink.h b/fs/bcachefs/reflink.h
index 2391037..ba40018 100644
--- a/fs/bcachefs/reflink.h
+++ b/fs/bcachefs/reflink.h
@@ -14,6 +14,7 @@ bool bch2_reflink_p_merge(struct bch_fs *, struct bkey_s, struct bkey_s_c);
 	.key_merge	= bch2_reflink_p_merge,			\
 	.trans_trigger	= bch2_trans_mark_reflink_p,		\
 	.atomic_trigger	= bch2_mark_reflink_p,			\
+	.min_val_size	= 16,					\
 })
 
 int bch2_reflink_v_invalid(const struct bch_fs *, struct bkey_s_c,
@@ -29,6 +30,7 @@ int bch2_trans_mark_reflink_v(struct btree_trans *, enum btree_id, unsigned,
 	.swab		= bch2_ptr_swab,			\
 	.trans_trigger	= bch2_trans_mark_reflink_v,		\
 	.atomic_trigger	= bch2_mark_extent,			\
+	.min_val_size	= 8,					\
 })
 
 int bch2_indirect_inline_data_invalid(const struct bch_fs *, struct bkey_s_c,
@@ -44,6 +46,7 @@ int bch2_trans_mark_indirect_inline_data(struct btree_trans *,
 	.key_invalid	= bch2_indirect_inline_data_invalid,	\
 	.val_to_text	= bch2_indirect_inline_data_to_text,	\
 	.trans_trigger	= bch2_trans_mark_indirect_inline_data,	\
+	.min_val_size	= 8,					\
 })
 
 static inline const __le64 *bkey_refcount_c(struct bkey_s_c k)
diff --git a/fs/bcachefs/subvolume.c b/fs/bcachefs/subvolume.c
index 6407d19..31af41d 100644
--- a/fs/bcachefs/subvolume.c
+++ b/fs/bcachefs/subvolume.c
@@ -36,12 +36,6 @@ int bch2_snapshot_invalid(const struct bch_fs *c, struct bkey_s_c k,
 		return -BCH_ERR_invalid_bkey;
 	}
 
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_snapshot)) {
-		prt_printf(err, "bad val size (%zu != %zu)",
-		       bkey_val_bytes(k.k), sizeof(struct bch_snapshot));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	s = bkey_s_c_to_snapshot(k);
 
 	id = le32_to_cpu(s.v->parent);
@@ -743,12 +737,6 @@ int bch2_subvolume_invalid(const struct bch_fs *c, struct bkey_s_c k,
 		return -BCH_ERR_invalid_bkey;
 	}
 
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_subvolume)) {
-		prt_printf(err, "incorrect value size (%zu != %zu)",
-		       bkey_val_bytes(k.k), sizeof(struct bch_subvolume));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	return 0;
 }
 
diff --git a/fs/bcachefs/subvolume.h b/fs/bcachefs/subvolume.h
index df66579..1f6f786 100644
--- a/fs/bcachefs/subvolume.h
+++ b/fs/bcachefs/subvolume.h
@@ -15,6 +15,7 @@ int bch2_mark_snapshot(struct btree_trans *, enum btree_id, unsigned,
 	.key_invalid	= bch2_snapshot_invalid,		\
 	.val_to_text	= bch2_snapshot_to_text,		\
 	.atomic_trigger	= bch2_mark_snapshot,			\
+	.min_val_size	= 24,					\
 })
 
 static inline struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
@@ -119,6 +120,7 @@ void bch2_subvolume_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c)
 #define bch2_bkey_ops_subvolume ((struct bkey_ops) {		\
 	.key_invalid	= bch2_subvolume_invalid,		\
 	.val_to_text	= bch2_subvolume_to_text,		\
+	.min_val_size	= 16,					\
 })
 
 int bch2_subvolume_get(struct btree_trans *, unsigned,
diff --git a/fs/bcachefs/xattr.c b/fs/bcachefs/xattr.c
index 4c86878..448eb44 100644
--- a/fs/bcachefs/xattr.c
+++ b/fs/bcachefs/xattr.c
@@ -75,12 +75,6 @@ int bch2_xattr_invalid(const struct bch_fs *c, struct bkey_s_c k,
 	const struct xattr_handler *handler;
 	struct bkey_s_c_xattr xattr = bkey_s_c_to_xattr(k);
 
-	if (bkey_val_bytes(k.k) < sizeof(struct bch_xattr)) {
-		prt_printf(err, "incorrect value size (%zu < %zu)",
-		       bkey_val_bytes(k.k), sizeof(*xattr.v));
-		return -BCH_ERR_invalid_bkey;
-	}
-
 	if (bkey_val_u64s(k.k) <
 	    xattr_val_u64s(xattr.v->x_name_len,
 			   le16_to_cpu(xattr.v->x_val_len))) {
diff --git a/fs/bcachefs/xattr.h b/fs/bcachefs/xattr.h
index 1a4cff3..b3e1672 100644
--- a/fs/bcachefs/xattr.h
+++ b/fs/bcachefs/xattr.h
@@ -12,6 +12,7 @@ void bch2_xattr_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 #define bch2_bkey_ops_xattr ((struct bkey_ops) {	\
 	.key_invalid	= bch2_xattr_invalid,		\
 	.val_to_text	= bch2_xattr_to_text,		\
+	.min_val_size	= 8,				\
 })
 
 static inline unsigned xattr_val_u64s(unsigned name_len, unsigned val_len)