Re: [PATCH v2 2/2] block: cancel all throttled bios in del_gendisk()

[yukuai (C)]

在 2021/12/01 0:26, Tejun Heo 写道:
> Hello,
>
> On Tue, Nov 30, 2021 at 09:17:30AM +0800, Yu Kuai wrote:
> > +void blk_throtl_cancel_bios(struct request_queue *q)
> > +{
> > +	struct throtl_data *td = q->td;
> > +	struct blkcg_gq *blkg;
> > +	struct cgroup_subsys_state *pos_css;
> > +	struct bio *bio;
> > +	int rw;
> > +
> > +	rcu_read_lock();
>
> So, all of the draining is being performed without holding the q lock, which
> *might* be okay given that we're in the del_gendisk path but is likely risky
> - ie. there can still be timers or whatever racing against it.

I'll hold queue_lock to draining bios in next iteration,

Thanks,
Kuai
> Thanks.