Btrfs: create a logical->phsyical block number mapping scheme

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 0ef6e6f714af..46cc5dc9d572 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -41,4 +41,5 @@ int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
                     char *result);
 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
                                       struct btrfs_key *location);
+u64 bh_blocknr(struct buffer_head *bh);
 #endif