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.

Signed-off-by: Nikolay Borisov nborisov@suse.com ---

Here is the 4.4 backport for upstream commit f3038ee3a3f1017a1cbe9907e31fa12d366c5dcb

fs/btrfs/inode.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index af1da85da509..86d209fc4992 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -2015,7 +2015,15 @@ static void btrfs_writepage_fixup_worker(struct btrfs_work *work) goto out; }

- btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); + ret = btrfs_set_extent_delalloc(inode, page_start, page_end, + &cached_state); + if (ret) { + mapping_set_error(page->mapping, ret); + end_extent_writepage(page, ret, page_start, page_end); + ClearPageChecked(page); + goto out; + } + ClearPageChecked(page); set_page_dirty(page); out: