[PATCH AUTOSEL for 4.9 059/281] btrfs: fix incorrect error return ret being passed to mapping_set_error

[Sasha Levin]

From: Colin Ian King <colin.k...@canonical.com>

[ Upstream commit bff5baf8aa37a97293725a16c03f49872249c07e ]

The setting of return code ret should be based on the error code
passed into function end_extent_writepage and not on ret. Thanks
to Liu Bo for spotting this mistake in the original fix I submitted.

Detected by CoverityScan, CID#1414312 ("Logically dead code")

Fixes: 5dca6eea91653e ("Btrfs: mark mapping with error flag to report errors to 
userspace")
Signed-off-by: Colin Ian King <colin.k...@canonical.com>
Reviewed-by: Liu Bo <bo.li....@oracle.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
---
 fs/btrfs/extent_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8ed05d95584a..03ac3ab4b3b4 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2453,7 +2453,7 @@ void end_extent_writepage(struct page *page, int err, u64 
start, u64 end)
        if (!uptodate) {
                ClearPageUptodate(page);
                SetPageError(page);
-               ret = ret < 0 ? ret : -EIO;
+               ret = err < 0 ? err : -EIO;
                mapping_set_error(page->mapping, ret);
        }
 }
-- 
2.14.1