bcachefs: Kill bkey_type_successor

Previously, BTREE_ID_INODES was special - inodes were indexed by the
inode field, which meant the offset field of struct bpos wasn't used,
which led to special cases in e.g. the btree iterator code.

Now, inodes in the inodes btree are indexed by the offset field.

Also: prevously min_key was special for extents btrees, min_key for
extents would equal max_key for the previous node. Now, min_key =
bkey_successor() of the previous node, same as non extent btrees.

This means we can completely get rid of
btree_type_sucessor/predecessor.

Also make some improvements to the metadata IO validate/compat code.

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

1 files changed, 19 insertions, 0 deletions

diff --git a/fs/bcachefs/bkey_methods.h b/fs/bcachefs/bkey_methods.h
index d36468b75223..0bca725ae3b8 100644
--- a/fs/bcachefs/bkey_methods.h
+++ b/fs/bcachefs/bkey_methods.h
@@ -33,6 +33,9 @@ struct bkey_ops {
 	bool		(*key_normalize)(struct bch_fs *, struct bkey_s);
 	enum merge_result (*key_merge)(struct bch_fs *,
 				       struct bkey_s, struct bkey_s);
+	void		(*compat)(enum btree_id id, unsigned version,
+				  unsigned big_endian, int write,
+				  struct bkey_s);
 };
 
 const char *bch2_bkey_val_invalid(struct bch_fs *, struct bkey_s_c);
@@ -60,4 +63,20 @@ enum merge_result bch2_bkey_merge(struct bch_fs *,
 
 void bch2_bkey_renumber(enum btree_node_type, struct bkey_packed *, int);
 
+void __bch2_bkey_compat(unsigned, enum btree_id, unsigned, unsigned,
+			int, struct bkey_format *, struct bkey_packed *);
+
+static inline 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)
+{
+	if (version < bcachefs_metadata_version_current ||
+	    big_endian != CPU_BIG_ENDIAN)
+		__bch2_bkey_compat(level, btree_id, version,
+				   big_endian, write, f, k);
+
+}
+
 #endif /* _BCACHEFS_BKEY_METHODS_H */