On Fri, May 21, 2021 at 02:15:32PM +0800, Coly Li wrote: > The above 2 lines are added on purpose to prevent an refcount > underflow. It is from commit 86da9f736740 ("bcache: fix refcount > underflow in bcache_device_free()"). > > Maybe add a parameter to blk_cleanup_disk() or checking (disk->flags & > GENHD_FL_UP) inside blk_cleanup_disk() ? Please take a look at patch 4 in the series.