[PATCH] Btrfs: report errors when checksum is not found

[Liu Bo <bo.li.liu@oracle.com>]

When btrfs fails the checksum check, it'll fill the whole page with
"1".

However, if %csum_expected is 0 (which means there is no checksum), then
for some unknown reason, we just pretend that the read is correct, so
userspace would be confused about the dilemma that read is successful but
getting a page with all content being "1".

This can happen due to a bug in btrfs-convert.

This fixes it by always returning errors if checksum doesn't match.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/inode.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ef3c98c..8a4d8ee 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3151,8 +3151,6 @@ static int __readpage_endio_check(struct inode *inode,
 	memset(kaddr + pgoff, 1, len);
 	flush_dcache_page(page);
 	kunmap_atomic(kaddr);
-	if (csum_expected == 0)
-		return 0;
 	return -EIO;
 }
 
-- 
2.9.4