On Tue, Dec 05, 2017 at 09:29:19AM +0200, Nikolay Borisov wrote:
This function was introduced by 247e743cbe6e ("Btrfs: Use async helpers to deal with pages that have been improperly dirtied") and it didn't do any error handling then. This function might very well fail in ENOMEM situation, yet it's not handled, this could lead to inconsistent state. So let's handle the failure by setting the mapping error bit.
In current code the ENOMEM cannot happen (returned by __set_extent_bit), but EEXIST could, so there's a possibility of an unhandled error.
Signed-off-by: Nikolay Borisov nborisov@suse.com Cc: stable@vger.kernel.org
fs/btrfs/inode.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 993061f83067..7a5a46fefdb4 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2098,8 +2098,15 @@ static void btrfs_writepage_fixup_worker(struct btrfs_work *work) goto out; }
- btrfs_set_extent_delalloc(inode, page_start, page_end, 0, &cached_state,
0);
- ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
&cached_state, 0);- if (ret) {
mapping_set_error(page->mapping, ret);end_extent_writepage(page, ret, page_start, page_end);ClearPageChecked(page);
So this repeats the cleanup code after the preceding call to btrfs_delalloc_reserve_space fails, I don't see a better way how to get out of that so it's probably ok.