On Mon, Apr 26, 2021 at 07:28:18PM -0700, Bart Van Assche wrote:
> On 4/26/21 6:45 PM, Ming Lei wrote:
> > + * We grab one request reference before calling @fn and release it after
> > + * @fn returns. So far we don't support to pass the request reference to
> > + * one new conetxt in @fn.
> ^^^^^^^
> context?
>
> > +void blk_mq_put_rq_ref(struct request *rq)
> > +{
> > + if (is_flush_rq(rq, rq->mq_hctx))
> > + rq->end_io(rq, 0);
> > + else if (refcount_dec_and_test(&rq->ref))
> > + __blk_mq_free_request(rq);
> > +}
>
> Will rq->end_io() be called twice when a tag iteration function
> encounters a flush request?
It could be, see flush_end_io():
static void flush_end_io(struct request *flush_rq, blk_status_t error)
{
...
spin_lock_irqsave(&fq->mq_flush_lock, flags);
if (!refcount_dec_and_test(&flush_rq->ref)) {
fq->rq_status = error;
spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
return;
}
...
Thanks,
Ming
