nilfs2: add helper to find existent block on metadata file
Add a new metadata file function, nilfs_mdt_find_block(), which finds
an existent block on a metadata file in a given range of blocks. This
function skips continuous hole blocks efficiently by using
nilfs_bmap_seek_key().
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h
index a294ea3..fe529a8 100644
--- a/fs/nilfs2/mdt.h
+++ b/fs/nilfs2/mdt.h
@@ -78,6 +78,9 @@
void (*init_block)(struct inode *,
struct buffer_head *, void *),
struct buffer_head **);
+int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
+ unsigned long end, unsigned long *blkoff,
+ struct buffer_head **out_bh);
int nilfs_mdt_delete_block(struct inode *, unsigned long);
int nilfs_mdt_forget_block(struct inode *, unsigned long);
int nilfs_mdt_mark_block_dirty(struct inode *, unsigned long);