btrfs: fix use of uninit "ret" in end_extent_writepage()
commit 3e2426bd0eb980648449e7a2f5a23e3cd3c7725c upstream.
If this condition in end_extent_writepage() is false:
if (tree->ops && tree->ops->writepage_end_io_hook)
we will then test an uninitialized "ret" at:
ret = ret < 0 ? ret : -EIO;
The test for ret is for the case where ->writepage_end_io_hook
failed, and we'd choose that ret as the error; but if
there is no ->writepage_end_io_hook, nothing sets ret.
Initializing ret to 0 should be sufficient; if
writepage_end_io_hook wasn't set, (!uptodate) means
non-zero err was passed in, so we choose -EIO in that case.
Signed-of-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 57484d2..24b58c7 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2245,7 +2245,7 @@
{
int uptodate = (err == 0);
struct extent_io_tree *tree;
- int ret;
+ int ret = 0;
tree = &BTRFS_I(page->mapping->host)->io_tree;