Merge tag 'dm-3.17-fix2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fix from Mike Snitzer:
 "Fix a race in the DM cache target that caused dirty blocks to be
  marked as clean.  This could cause no writeback to occur or spurious
  dirty block counts"

* tag 'dm-3.17-fix2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache: fix race causing dirty blocks to be marked as clean

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 1af40ee209e2..7130505c2425 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -895,8 +895,8 @@ static void migration_success_pre_commit(struct dm_cache_migration *mg)
         struct cache *cache = mg->cache;
 
         if (mg->writeback) {
-                cell_defer(cache, mg->old_ocell, false);
                 clear_dirty(cache, mg->old_oblock, mg->cblock);
+                cell_defer(cache, mg->old_ocell, false);
                 cleanup_migration(mg);
                 return;
 
@@ -951,13 +951,13 @@ static void migration_success_post_commit(struct dm_cache_migration *mg)
                 }
 
         } else {
+                clear_dirty(cache, mg->new_oblock, mg->cblock);
                 if (mg->requeue_holder)
                         cell_defer(cache, mg->new_ocell, true);
                 else {
                         bio_endio(mg->new_ocell->holder, 0);
                         cell_defer(cache, mg->new_ocell, false);
                 }
-                clear_dirty(cache, mg->new_oblock, mg->cblock);
                 cleanup_migration(mg);
         }
 }