btrfs: remove btrfs_find_ordered_sum call from btrfs_lookup_bio_sums

The function btrfs_lookup_bio_sums() is only called for read bios.
While btrfs_find_ordered_sum() is to search ordered extent sums, which
is only for write path.

This means to read a page we either:

- Submit read bio if it's not uptodate
  This means we only need to search csum tree for checksums.

- The page is already uptodate
  It can be marked uptodate for previous read, or being marked dirty.
  As we always mark page uptodate for dirty page.
  In that case, we don't need to submit read bio at all, thus no need
  to search any checksums.

Remove the btrfs_find_ordered_sum() call in btrfs_lookup_bio_sums().
And since btrfs_lookup_bio_sums() is the only caller for
btrfs_find_ordered_sum(), also remove the implementation.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
index 367269effd6a..0bfa82b58e23 100644
--- a/fs/btrfs/ordered-data.h
+++ b/fs/btrfs/ordered-data.h
@@ -183,8 +183,6 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 		u64 len);
 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 					   struct list_head *list);
-int btrfs_find_ordered_sum(struct btrfs_inode *inode, u64 offset,
-			   u64 disk_bytenr, u8 *sum, int len);
 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 			       const u64 range_start, const u64 range_len);
 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,