On Wed, Jan 04, 2023 at 04:53:53PM +0800, Yu Kuai wrote: > From: Yu Kuai <yukuai3@xxxxxxxxxx> > > This patch fix following problems: > > 1) rq_qos_add() and rq_qos_del() is protected, while rq_qos_exit() is > not. This part makes sense. > 2) rq_qos_add() and blkcg_activate_policy() is not atomic, if > rq_qos_exit() is done before blkcg_activate_policy(), > null-ptr-deference can be triggered. I'm not sure this part does. I think it'd be better to guarantee that device destruction is blocked while these configuration operations are in progress which can be built into blkg_conf helpers. Thanks. -- tejun
