f946e0d22e22 ("writeback: rework the loop termination condition in write_cache_pages")
5d899d43ed29 ("writeback: only update ->writeback_index for range_cyclic writeback")
9810325854a3 ("writeback: also update wbc->nr_to_write on writeback failure")
a02829f011b6 ("writeback: fix done_index when hitting the wbc->nr_to_write")