Hello, On Wed, Mar 08, 2017 at 05:48:31PM +0100, Jan Kara wrote: > @@ -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); So, this is more re-initializing the ref to the initial state so that it can be re-used, right? Maybe ATOMIC_INIT() is a better choice here just to clarify what's going on? Thanks. -- tejun