1 files changed, 7 insertions, 0 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 6d861d090e9f..6ac932210f56 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -710,6 +710,11 @@ static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
          */
         atomic_dec(&bdi->usage_cnt);
         wait_event(cgwb_release_wait, !atomic_read(&bdi->usage_cnt));
+        /*
+         * Grab back our reference so that we hold it when @bdi gets
+         * re-registered.
+         */
+        atomic_inc(&bdi->usage_cnt);
 }
 
 /**
@@ -857,6 +862,8 @@ int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner)
                         MINOR(owner->devt));
         if (rc)
                 return rc;
+        /* Leaking owner reference... */
+        WARN_ON(bdi->owner);
         bdi->owner = owner;
         get_device(owner);
         return 0;