diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index c68bdf58c9a6..54fbe1e80cc4 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -849,6 +849,7 @@ static void blkcg_fill_root_iostats(void)
 			blkg_iostat_set(&blkg->iostat.cur, &tmp);
 			u64_stats_update_end(&blkg->iostat.sync);
 		}
+		disk_put_part(part);
 	}
 }