Messages in this thread | | | Date | Wed, 4 Jan 2023 11:39:47 -1000 | From | Tejun Heo <> | Subject | Re: [PATCH -next 3/4] block/rq_qos: use a global mutex to protect rq_qos apis |
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On Wed, Jan 04, 2023 at 04:53:53PM +0800, Yu Kuai wrote: > From: Yu Kuai <yukuai3@huawei.com> > > 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
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