dcache: close d_move race in d_splice_alias

[mirror_ubuntu-artful-kernel.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 518e2c3f4c75f0014a03817b4910cf4050a2f480..e0c943014eb74ce3d4cb4c021d6f896740386d6d 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1306,9 +1306,9 @@ static inline void bdi_dirty_limits(struct backing_dev_info *bdi,
        *bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh);
 
        if (bdi_bg_thresh)
-               *bdi_bg_thresh = div_u64((u64)*bdi_thresh *
-                                        background_thresh,
-                                        dirty_thresh);
+               *bdi_bg_thresh = dirty_thresh ? div_u64((u64)*bdi_thresh *
+                                                       background_thresh,
+                                                       dirty_thresh) : 0;
 
        /*
         * In order to avoid the stacked BDI deadlock we need