On Tue, Jun 30, 2020 at 06:05:57AM +0100, Christoph Hellwig wrote:
> > index 21108a550fbf..3b0c5cfe922a 100644
> > --- a/block/blk-flush.c
> > +++ b/block/blk-flush.c
> > @@ -236,12 +236,10 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error)
> > error = fq->rq_status;
> >
> > hctx = flush_rq->mq_hctx;
> > + if (!q->elevator)
> > flush_rq->tag = -1;
> > + else
> > flush_rq->internal_tag = -1;
>
> These should switch to BLK_MQ_NO_TAG which you're at it.
OK, we can do that in this patch.
>
> > - if (!(data->flags & BLK_MQ_REQ_INTERNAL))
> > - blk_mq_tag_busy(data->hctx);
>
> BLK_MQ_REQ_INTERNAL is gone now, so this won't apply.
blk_mq_tag_busy() is needed for either none and io scheduler, so it
is moved into blk_mq_get_driver_tag(), then check on BLK_MQ_REQ_INTERNAL
is gone.
>
> > static bool blk_mq_get_driver_tag(struct request *rq)
> > {
> > + struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
> > + bool shared = blk_mq_tag_busy(rq->mq_hctx);
> > +
> > + if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_get_driver_tag(rq))
> > + return false;
> > +
> > + if (shared) {
> > + rq->rq_flags |= RQF_MQ_INFLIGHT;
> > + atomic_inc(&hctx->nr_active);
> > + }
> > + hctx->tags->rqs[rq->tag] = rq;
> > + return true;
> > }
>
> The function seems a bit misnamed now, although I don't have a good
> suggestion for a better name.
I think it is fine to leave it as-is, since what the patch does is just
to move blk_mq_tag_busy() & the RQF_MQ_INFLIGHT part from __blk_mq_get_driver_tag
to blk_mq_get_driver_tag().
Thanks,
Ming
