X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Fbkey_methods.c;h=1381166bfc55b7cad8600a1d313ed267f95dfa27;hb=5d507f795b0b679a67e972a48cbd0854c4ad0f02;hp=27f196ef0b186963df59c6523479db6593e11eee;hpb=f96ba8e0aac91f2650270e9639359243cb9ac2d1;p=bcachefs-tools-debian

diff --git a/libbcachefs/bkey_methods.c b/libbcachefs/bkey_methods.c
index 27f196e..1381166 100644
--- a/libbcachefs/bkey_methods.c
+++ b/libbcachefs/bkey_methods.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include "bcachefs.h"
+#include "backpointers.h"
 #include "bkey_methods.h"
 #include "btree_types.h"
 #include "alloc_background.h"
@@ -9,221 +10,382 @@
 #include "error.h"
 #include "extents.h"
 #include "inode.h"
+#include "lru.h"
 #include "quota.h"
+#include "reflink.h"
+#include "subvolume.h"
 #include "xattr.h"
 
-const char * const bch_bkey_types[] = {
+const char * const bch2_bkey_types[] = {
 #define x(name, nr) #name,
 	BCH_BKEY_TYPES()
 #undef x
 	NULL
 };
 
-static const char *deleted_key_invalid(const struct bch_fs *c,
-					struct bkey_s_c k)
+static int deleted_key_invalid(const struct bch_fs *c, struct bkey_s_c k,
+			       unsigned flags, struct printbuf *err)
 {
-	return NULL;
+	return 0;
 }
 
-#define bch2_bkey_ops_deleted (struct bkey_ops) {	\
+#define bch2_bkey_ops_deleted ((struct bkey_ops) {	\
 	.key_invalid = deleted_key_invalid,		\
-}
+})
 
-#define bch2_bkey_ops_discard (struct bkey_ops) {	\
+#define bch2_bkey_ops_whiteout ((struct bkey_ops) {	\
 	.key_invalid = deleted_key_invalid,		\
-}
+})
 
-static const char *empty_val_key_invalid(const struct bch_fs *c, struct bkey_s_c k)
+static int empty_val_key_invalid(const struct bch_fs *c, struct bkey_s_c k,
+				 unsigned flags, struct printbuf *err)
 {
-	if (bkey_val_bytes(k.k))
-		return "value size should be zero";
+	if (bkey_val_bytes(k.k)) {
+		prt_printf(err, "incorrect value size (%zu != 0)",
+		       bkey_val_bytes(k.k));
+		return -BCH_ERR_invalid_bkey;
+	}
+
+	return 0;
+}
+
+#define bch2_bkey_ops_error ((struct bkey_ops) {	\
+	.key_invalid = empty_val_key_invalid,		\
+})
 
-	return NULL;
+static int key_type_cookie_invalid(const struct bch_fs *c, struct bkey_s_c k,
+				   unsigned flags, struct printbuf *err)
+{
+	return 0;
 }
 
-#define bch2_bkey_ops_error (struct bkey_ops) {		\
+#define bch2_bkey_ops_cookie ((struct bkey_ops) {	\
+	.key_invalid	= key_type_cookie_invalid,	\
+	.min_val_size	= 8,				\
+})
+
+#define bch2_bkey_ops_hash_whiteout ((struct bkey_ops) {\
 	.key_invalid = empty_val_key_invalid,		\
+})
+
+static int key_type_inline_data_invalid(const struct bch_fs *c, struct bkey_s_c k,
+					unsigned flags, struct printbuf *err)
+{
+	return 0;
 }
 
-static const char *key_type_cookie_invalid(const struct bch_fs *c,
-					   struct bkey_s_c k)
+static void key_type_inline_data_to_text(struct printbuf *out, struct bch_fs *c,
+					 struct bkey_s_c k)
 {
-	if (bkey_val_bytes(k.k) != sizeof(struct bch_cookie))
-		return "incorrect value size";
+	struct bkey_s_c_inline_data d = bkey_s_c_to_inline_data(k);
+	unsigned datalen = bkey_inline_data_bytes(k.k);
 
-	return NULL;
+	prt_printf(out, "datalen %u: %*phN",
+	       datalen, min(datalen, 32U), d.v->data);
 }
 
-#define bch2_bkey_ops_cookie (struct bkey_ops) {	\
-	.key_invalid = key_type_cookie_invalid,		\
+#define bch2_bkey_ops_inline_data ((struct bkey_ops) {	\
+	.key_invalid	= key_type_inline_data_invalid,	\
+	.val_to_text	= key_type_inline_data_to_text,	\
+})
+
+static int key_type_set_invalid(const struct bch_fs *c, struct bkey_s_c k,
+				unsigned flags, struct printbuf *err)
+{
+	if (bkey_val_bytes(k.k)) {
+		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_whiteout (struct bkey_ops) {	\
-	.key_invalid = empty_val_key_invalid,		\
+static bool key_type_set_merge(struct bch_fs *c, struct bkey_s l, struct bkey_s_c r)
+{
+	bch2_key_resize(l.k, l.k->size + r.k->size);
+	return true;
 }
 
-static const struct bkey_ops bch2_bkey_ops[] = {
+#define bch2_bkey_ops_set ((struct bkey_ops) {		\
+	.key_invalid	= key_type_set_invalid,		\
+	.key_merge	= key_type_set_merge,		\
+})
+
+const struct bkey_ops bch2_bkey_ops[] = {
 #define x(name, nr) [KEY_TYPE_##name]	= bch2_bkey_ops_##name,
 	BCH_BKEY_TYPES()
 #undef x
 };
 
-const char *bch2_bkey_val_invalid(struct bch_fs *c, struct bkey_s_c k)
+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,
+			  enum bkey_invalid_flags flags,
+			  struct printbuf *err)
 {
-	if (k.k->type >= KEY_TYPE_MAX)
-		return "invalid type";
+	const struct bkey_ops *ops = bch2_bkey_type_ops(k.k->type);
 
-	return bch2_bkey_ops[k.k->type].key_invalid(c, k);
+	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;
+	}
+
+	if (!ops->key_invalid)
+		return 0;
+
+	return ops->key_invalid(c, k, flags, err);
 }
 
-const char *__bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
-				enum btree_node_type type)
+static unsigned bch2_key_types_allowed[] = {
+	[BKEY_TYPE_extents] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_whiteout)|
+		(1U << KEY_TYPE_error)|
+		(1U << KEY_TYPE_cookie)|
+		(1U << KEY_TYPE_extent)|
+		(1U << KEY_TYPE_reservation)|
+		(1U << KEY_TYPE_reflink_p)|
+		(1U << KEY_TYPE_inline_data),
+	[BKEY_TYPE_inodes] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_whiteout)|
+		(1U << KEY_TYPE_inode)|
+		(1U << KEY_TYPE_inode_v2)|
+		(1U << KEY_TYPE_inode_v3)|
+		(1U << KEY_TYPE_inode_generation),
+	[BKEY_TYPE_dirents] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_whiteout)|
+		(1U << KEY_TYPE_hash_whiteout)|
+		(1U << KEY_TYPE_dirent),
+	[BKEY_TYPE_xattrs] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_whiteout)|
+		(1U << KEY_TYPE_cookie)|
+		(1U << KEY_TYPE_hash_whiteout)|
+		(1U << KEY_TYPE_xattr),
+	[BKEY_TYPE_alloc] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_alloc)|
+		(1U << KEY_TYPE_alloc_v2)|
+		(1U << KEY_TYPE_alloc_v3)|
+		(1U << KEY_TYPE_alloc_v4),
+	[BKEY_TYPE_quotas] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_quota),
+	[BKEY_TYPE_stripes] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_stripe),
+	[BKEY_TYPE_reflink] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_reflink_v)|
+		(1U << KEY_TYPE_indirect_inline_data),
+	[BKEY_TYPE_subvolumes] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_subvolume),
+	[BKEY_TYPE_snapshots] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_snapshot),
+	[BKEY_TYPE_lru] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_set),
+	[BKEY_TYPE_freespace] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_set),
+	[BKEY_TYPE_need_discard] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_set),
+	[BKEY_TYPE_backpointers] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_backpointer),
+	[BKEY_TYPE_bucket_gens] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_bucket_gens),
+	[BKEY_TYPE_snapshot_trees] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_snapshot_tree),
+	[BKEY_TYPE_btree] =
+		(1U << KEY_TYPE_deleted)|
+		(1U << KEY_TYPE_btree_ptr)|
+		(1U << KEY_TYPE_btree_ptr_v2),
+};
+
+int __bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
+			enum btree_node_type type,
+			enum bkey_invalid_flags flags,
+			struct printbuf *err)
 {
-	if (k.k->u64s < BKEY_U64s)
-		return "u64s too small";
+	if (k.k->u64s < BKEY_U64s) {
+		prt_printf(err, "u64s too small (%u < %zu)", k.k->u64s, BKEY_U64s);
+		return -BCH_ERR_invalid_bkey;
+	}
 
-	if ((btree_node_type_is_extents(type) ||
-	     type == BKEY_TYPE_BTREE) &&
-	    bkey_val_u64s(k.k) > BKEY_EXTENT_VAL_U64s_MAX)
-		return "value too big";
+	if (flags & BKEY_INVALID_COMMIT	 &&
+	    !(bch2_key_types_allowed[type] & (1U << k.k->type))) {
+		prt_printf(err, "invalid key type for btree %s (%s)",
+			   bch2_btree_ids[type], bch2_bkey_types[k.k->type]);
+		return -BCH_ERR_invalid_bkey;
+	}
 
-	if (btree_node_type_is_extents(type)) {
-		if ((k.k->size == 0) != bkey_deleted(k.k))
-			return "bad size field";
+	if (btree_node_type_is_extents(type) && !bkey_whiteout(k.k)) {
+		if (k.k->size == 0) {
+			prt_printf(err, "size == 0");
+			return -BCH_ERR_invalid_bkey;
+		}
 
-		if (k.k->size > k.k->p.offset)
-			return "size greater than offset";
+		if (k.k->size > k.k->p.offset) {
+			prt_printf(err, "size greater than offset (%u > %llu)",
+			       k.k->size, k.k->p.offset);
+			return -BCH_ERR_invalid_bkey;
+		}
 	} else {
-		if (k.k->size)
-			return "nonzero size field";
+		if (k.k->size) {
+			prt_printf(err, "size != 0");
+			return -BCH_ERR_invalid_bkey;
+		}
 	}
 
-	if (k.k->p.snapshot)
-		return "nonzero snapshot";
+	if (type != BKEY_TYPE_btree) {
+		if (!btree_type_has_snapshots((enum btree_id) type) &&
+		    k.k->p.snapshot) {
+			prt_printf(err, "nonzero snapshot");
+			return -BCH_ERR_invalid_bkey;
+		}
 
-	if (type != BKEY_TYPE_BTREE &&
-	    !bkey_cmp(k.k->p, POS_MAX))
-		return "POS_MAX key";
+		if (btree_type_has_snapshots((enum btree_id) type) &&
+		    !k.k->p.snapshot) {
+			prt_printf(err, "snapshot == 0");
+			return -BCH_ERR_invalid_bkey;
+		}
 
-	return NULL;
-}
+		if (bkey_eq(k.k->p, POS_MAX)) {
+			prt_printf(err, "key at POS_MAX");
+			return -BCH_ERR_invalid_bkey;
+		}
+	}
 
-const char *bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
-			      enum btree_node_type type)
-{
-	return __bch2_bkey_invalid(c, k, type) ?:
-		bch2_bkey_val_invalid(c, k);
+	return 0;
 }
 
-const char *bch2_bkey_in_btree_node(struct btree *b, struct bkey_s_c k)
+int bch2_bkey_invalid(struct bch_fs *c, struct bkey_s_c k,
+		      enum btree_node_type type,
+		      enum bkey_invalid_flags flags,
+		      struct printbuf *err)
 {
-	if (bkey_cmp(bkey_start_pos(k.k), b->data->min_key) < 0)
-		return "key before start of btree node";
-
-	if (bkey_cmp(k.k->p, b->data->max_key) > 0)
-		return "key past end of btree node";
-
-	return NULL;
+	return __bch2_bkey_invalid(c, k, type, flags, err) ?:
+		bch2_bkey_val_invalid(c, k, flags, err);
 }
 
-void bch2_bkey_debugcheck(struct bch_fs *c, struct btree *b, struct bkey_s_c k)
+int bch2_bkey_in_btree_node(struct btree *b, struct bkey_s_c k,
+			    struct printbuf *err)
 {
-	const struct bkey_ops *ops = &bch2_bkey_ops[k.k->type];
-	const char *invalid;
-
-	BUG_ON(!k.k->u64s);
-
-	invalid = bch2_bkey_invalid(c, k, btree_node_type(b)) ?:
-		bch2_bkey_in_btree_node(b, k);
-	if (invalid) {
-		char buf[160];
+	if (bpos_lt(k.k->p, b->data->min_key)) {
+		prt_printf(err, "key before start of btree node");
+		return -BCH_ERR_invalid_bkey;
+	}
 
-		bch2_bkey_val_to_text(&PBUF(buf), c, k);
-		bch2_fs_bug(c, "invalid bkey %s: %s", buf, invalid);
-		return;
+	if (bpos_gt(k.k->p, b->data->max_key)) {
+		prt_printf(err, "key past end of btree node");
+		return -BCH_ERR_invalid_bkey;
 	}
 
-	if (ops->key_debugcheck)
-		ops->key_debugcheck(c, b, k);
+	return 0;
 }
 
 void bch2_bpos_to_text(struct printbuf *out, struct bpos pos)
 {
-	if (!bkey_cmp(pos, POS_MIN))
-		pr_buf(out, "POS_MIN");
-	else if (!bkey_cmp(pos, POS_MAX))
-		pr_buf(out, "POS_MAX");
-	else
-		pr_buf(out, "%llu:%llu", pos.inode, pos.offset);
+	if (bpos_eq(pos, POS_MIN))
+		prt_printf(out, "POS_MIN");
+	else if (bpos_eq(pos, POS_MAX))
+		prt_printf(out, "POS_MAX");
+	else if (bpos_eq(pos, SPOS_MAX))
+		prt_printf(out, "SPOS_MAX");
+	else {
+		if (pos.inode == U64_MAX)
+			prt_printf(out, "U64_MAX");
+		else
+			prt_printf(out, "%llu", pos.inode);
+		prt_printf(out, ":");
+		if (pos.offset == U64_MAX)
+			prt_printf(out, "U64_MAX");
+		else
+			prt_printf(out, "%llu", pos.offset);
+		prt_printf(out, ":");
+		if (pos.snapshot == U32_MAX)
+			prt_printf(out, "U32_MAX");
+		else
+			prt_printf(out, "%u", pos.snapshot);
+	}
 }
 
 void bch2_bkey_to_text(struct printbuf *out, const struct bkey *k)
 {
-	pr_buf(out, "u64s %u type %u ", k->u64s, k->type);
+	if (k) {
+		prt_printf(out, "u64s %u type ", k->u64s);
+
+		if (k->type < KEY_TYPE_MAX)
+			prt_printf(out, "%s ", bch2_bkey_types[k->type]);
+		else
+			prt_printf(out, "%u ", k->type);
 
-	bch2_bpos_to_text(out, k->p);
+		bch2_bpos_to_text(out, k->p);
 
-	pr_buf(out, " snap %u len %u ver %llu",
-	       k->p.snapshot, k->size, k->version.lo);
+		prt_printf(out, " len %u ver %llu", k->size, k->version.lo);
+	} else {
+		prt_printf(out, "(null)");
+	}
 }
 
 void bch2_val_to_text(struct printbuf *out, struct bch_fs *c,
 		      struct bkey_s_c k)
 {
-	const struct bkey_ops *ops = &bch2_bkey_ops[k.k->type];
+	const struct bkey_ops *ops = bch2_bkey_type_ops(k.k->type);
 
 	if (likely(ops->val_to_text))
 		ops->val_to_text(out, c, k);
-	else
-		pr_buf(out, " %s", bch_bkey_types[k.k->type]);
 }
 
 void bch2_bkey_val_to_text(struct printbuf *out, struct bch_fs *c,
 			   struct bkey_s_c k)
 {
 	bch2_bkey_to_text(out, k.k);
-	pr_buf(out, ": ");
-	bch2_val_to_text(out, c, k);
+
+	if (bkey_val_bytes(k.k)) {
+		prt_printf(out, ": ");
+		bch2_val_to_text(out, c, k);
+	}
 }
 
-void bch2_bkey_swab(const struct bkey_format *f,
-		    struct bkey_packed *k)
+void bch2_bkey_swab_val(struct bkey_s k)
 {
-	const struct bkey_ops *ops = &bch2_bkey_ops[k->type];
-
-	bch2_bkey_swab_key(f, k);
+	const struct bkey_ops *ops = bch2_bkey_type_ops(k.k->type);
 
 	if (ops->swab)
-		ops->swab(f, k);
+		ops->swab(k);
 }
 
 bool bch2_bkey_normalize(struct bch_fs *c, struct bkey_s k)
 {
-	const struct bkey_ops *ops = &bch2_bkey_ops[k.k->type];
+	const struct bkey_ops *ops = bch2_bkey_type_ops(k.k->type);
 
 	return ops->key_normalize
 		? ops->key_normalize(c, k)
 		: false;
 }
 
-enum merge_result bch2_bkey_merge(struct bch_fs *c,
-				  struct bkey_s l, struct bkey_s r)
+bool bch2_bkey_merge(struct bch_fs *c, struct bkey_s l, struct bkey_s_c r)
 {
-	const struct bkey_ops *ops = &bch2_bkey_ops[l.k->type];
-	enum merge_result ret;
-
-	if (key_merging_disabled(c) ||
-	    !ops->key_merge ||
-	    l.k->type != r.k->type ||
-	    bversion_cmp(l.k->version, r.k->version) ||
-	    bkey_cmp(l.k->p, bkey_start_pos(r.k)))
-		return BCH_MERGE_NOMERGE;
-
-	ret = ops->key_merge(c, l, r);
+	const struct bkey_ops *ops = bch2_bkey_type_ops(l.k->type);
 
-	if (ret != BCH_MERGE_NOMERGE)
-		l.k->needs_whiteout |= r.k->needs_whiteout;
-	return ret;
+	return ops->key_merge &&
+		bch2_bkey_maybe_mergable(l.k, r.k) &&
+		(u64) l.k->size + r.k->size <= KEY_SIZE_MAX &&
+		!bch2_key_merging_disabled &&
+		ops->key_merge(c, l, r);
 }
 
 static const struct old_bkey_type {
@@ -231,18 +393,18 @@ static const struct old_bkey_type {
 	u8		old;
 	u8		new;
 } bkey_renumber_table[] = {
-	{BKEY_TYPE_BTREE,	128, KEY_TYPE_btree_ptr		},
-	{BKEY_TYPE_EXTENTS,	128, KEY_TYPE_extent		},
-	{BKEY_TYPE_EXTENTS,	129, KEY_TYPE_extent		},
-	{BKEY_TYPE_EXTENTS,	130, KEY_TYPE_reservation	},
-	{BKEY_TYPE_INODES,	128, KEY_TYPE_inode		},
-	{BKEY_TYPE_INODES,	130, KEY_TYPE_inode_generation	},
-	{BKEY_TYPE_DIRENTS,	128, KEY_TYPE_dirent		},
-	{BKEY_TYPE_DIRENTS,	129, KEY_TYPE_whiteout		},
-	{BKEY_TYPE_XATTRS,	128, KEY_TYPE_xattr		},
-	{BKEY_TYPE_XATTRS,	129, KEY_TYPE_whiteout		},
-	{BKEY_TYPE_ALLOC,	128, KEY_TYPE_alloc		},
-	{BKEY_TYPE_QUOTAS,	128, KEY_TYPE_quota		},
+	{BKEY_TYPE_btree,	128, KEY_TYPE_btree_ptr		},
+	{BKEY_TYPE_extents,	128, KEY_TYPE_extent		},
+	{BKEY_TYPE_extents,	129, KEY_TYPE_extent		},
+	{BKEY_TYPE_extents,	130, KEY_TYPE_reservation	},
+	{BKEY_TYPE_inodes,	128, KEY_TYPE_inode		},
+	{BKEY_TYPE_inodes,	130, KEY_TYPE_inode_generation	},
+	{BKEY_TYPE_dirents,	128, KEY_TYPE_dirent		},
+	{BKEY_TYPE_dirents,	129, KEY_TYPE_hash_whiteout	},
+	{BKEY_TYPE_xattrs,	128, KEY_TYPE_xattr		},
+	{BKEY_TYPE_xattrs,	129, KEY_TYPE_hash_whiteout	},
+	{BKEY_TYPE_alloc,	128, KEY_TYPE_alloc		},
+	{BKEY_TYPE_quotas,	128, KEY_TYPE_quota		},
 };
 
 void bch2_bkey_renumber(enum btree_node_type btree_node_type,
@@ -260,3 +422,98 @@ void bch2_bkey_renumber(enum btree_node_type btree_node_type,
 			break;
 		}
 }
+
+void __bch2_bkey_compat(unsigned level, enum btree_id btree_id,
+			unsigned version, unsigned big_endian,
+			int write,
+			struct bkey_format *f,
+			struct bkey_packed *k)
+{
+	const struct bkey_ops *ops;
+	struct bkey uk;
+	struct bkey_s u;
+	unsigned nr_compat = 5;
+	int i;
+
+	/*
+	 * Do these operations in reverse order in the write path:
+	 */
+
+	for (i = 0; i < nr_compat; i++)
+	switch (!write ? i : nr_compat - 1 - i) {
+	case 0:
+		if (big_endian != CPU_BIG_ENDIAN)
+			bch2_bkey_swab_key(f, k);
+		break;
+	case 1:
+		if (version < bcachefs_metadata_version_bkey_renumber)
+			bch2_bkey_renumber(__btree_node_type(level, btree_id), k, write);
+		break;
+	case 2:
+		if (version < bcachefs_metadata_version_inode_btree_change &&
+		    btree_id == BTREE_ID_inodes) {
+			if (!bkey_packed(k)) {
+				struct bkey_i *u = packed_to_bkey(k);
+
+				swap(u->k.p.inode, u->k.p.offset);
+			} else if (f->bits_per_field[BKEY_FIELD_INODE] &&
+				   f->bits_per_field[BKEY_FIELD_OFFSET]) {
+				struct bkey_format tmp = *f, *in = f, *out = &tmp;
+
+				swap(tmp.bits_per_field[BKEY_FIELD_INODE],
+				     tmp.bits_per_field[BKEY_FIELD_OFFSET]);
+				swap(tmp.field_offset[BKEY_FIELD_INODE],
+				     tmp.field_offset[BKEY_FIELD_OFFSET]);
+
+				if (!write)
+					swap(in, out);
+
+				uk = __bch2_bkey_unpack_key(in, k);
+				swap(uk.p.inode, uk.p.offset);
+				BUG_ON(!bch2_bkey_pack_key(k, &uk, out));
+			}
+		}
+		break;
+	case 3:
+		if (version < bcachefs_metadata_version_snapshot &&
+		    (level || btree_type_has_snapshots(btree_id))) {
+			struct bkey_i *u = packed_to_bkey(k);
+
+			if (u) {
+				u->k.p.snapshot = write
+					? 0 : U32_MAX;
+			} else {
+				u64 min_packed = le64_to_cpu(f->field_offset[BKEY_FIELD_SNAPSHOT]);
+				u64 max_packed = min_packed +
+					~(~0ULL << f->bits_per_field[BKEY_FIELD_SNAPSHOT]);
+
+				uk = __bch2_bkey_unpack_key(f, k);
+				uk.p.snapshot = write
+					? min_packed : min_t(u64, U32_MAX, max_packed);
+
+				BUG_ON(!bch2_bkey_pack_key(k, &uk, f));
+			}
+		}
+
+		break;
+	case 4:
+		if (!bkey_packed(k)) {
+			u = bkey_i_to_s(packed_to_bkey(k));
+		} else {
+			uk = __bch2_bkey_unpack_key(f, k);
+			u.k = &uk;
+			u.v = bkeyp_val(f, k);
+		}
+
+		if (big_endian != CPU_BIG_ENDIAN)
+			bch2_bkey_swab_val(u);
+
+		ops = bch2_bkey_type_ops(k->type);
+
+		if (ops->compat)
+			ops->compat(btree_id, version, big_endian, write, u);
+		break;
+	default:
+		BUG();
+	}
+}