ÔÚ 2021/12/01 0:26, Tejun Heo дµÀ:

Hello,

On Tue, Nov 30, 2021 at 09:17:30AM +0800, Yu Kuai wrote:

quoted

+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.