[PATCH 9/9] nvme: implement multipath access to nvme subsystems

[Christoph Hellwig]

On Fri, Sep 22, 2017 at 11:09:16AM -0400, Keith Busch wrote:
> On Mon, Sep 18, 2017 at 04:14:53PM -0700, Christoph Hellwig wrote:
> > +static void nvme_failover_req(struct request *req)
> > +{
> > +	struct nvme_ns *ns = req->q->queuedata;
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&ns->head->requeue_lock, flags);
> > +	blk_steal_bios(&ns->head->requeue_list, req);
> > +	spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
> > +
> > +	nvme_reset_ctrl(ns->ctrl);
> > +	kblockd_schedule_work(&ns->head->requeue_work);
> > +}
> 
> Need to call blk_mq_free_req after stealing all its bios to prevent
> leaking that entered request.

I think this should be a blk_mq_end_request actually.  The difference
is that blk_mq_end_request will get the I/O accounting right, and
treats the case of having and ->end_io handler correctly as well.