Re: [PATCH 5/8] blk-mq: make blk_abort_request() trigger timeout path

[Bart Van Assche]

On Mon, 2018-01-08 at 11:15 -0800, Tejun Heo wrote:
> @@ -156,12 +156,12 @@ void blk_timeout_work(struct work_struct *work)
>   */
>  void blk_abort_request(struct request *req)
>  {
> -	if (blk_mark_rq_complete(req))
> -		return;
> -
>  	if (req->q->mq_ops) {
> -		blk_mq_rq_timed_out(req, false);
> +		req->deadline = jiffies;
> +		mod_timer(&req->q->timeout, 0);
>  	} else {
> +		if (blk_mark_rq_complete(req))
> +			return;
>  		blk_delete_timer(req);
>  		blk_rq_timed_out(req);
>  	}

Other req->deadline writes are protected by preempt_disable(),
write_seqcount_begin(&rq->gstate_seq), write_seqcount_end(&rq->gstate_seq)
and preempt_enable(). I think it's fine that the above req->deadline store
does not have that protection but I also think that that deserves a comment.

Thanks,

Bart.