bcachefs: bcachefs_metadata_version_persistent_inode_cursors

Persistent cursors for inode allocation.

A free inodes btree would add substantial overhead to inode allocation
and freeing - a "next num to allocate" cursor is always going to be
faster.

We just need it to be persistent, to avoid scanning the inodes btree
from the start on startup.

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

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/bcachefs/inode.h b/fs/bcachefs/inode.h
index 5bca6950f20e..d2e134528f0e 100644
--- a/fs/bcachefs/inode.h
+++ b/fs/bcachefs/inode.h
@@ -68,6 +68,16 @@ void bch2_inode_generation_to_text(struct printbuf *, struct bch_fs *, struct bk
 	.min_val_size	= 8,					\
 })
 
+int bch2_inode_alloc_cursor_validate(struct bch_fs *, struct bkey_s_c,
+				     struct bkey_validate_context);
+void bch2_inode_alloc_cursor_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
+
+#define bch2_bkey_ops_inode_alloc_cursor ((struct bkey_ops) {	\
+	.key_validate	= bch2_inode_alloc_cursor_validate,	\
+	.val_to_text	= bch2_inode_alloc_cursor_to_text,	\
+	.min_val_size	= 16,					\
+})
+
 #if 0
 typedef struct {
 	u64			lo;