[PATCH 2/2] nvme-rdma: move admin queue cleanup to nvme_rdma_free_ctrl

Ming Lin mlin at kernel.org
Wed Jul 13 23:39:06 PDT 2016


On Wed, 2016-07-13 at 16:59 -0700, J Freyensee wrote:
> On Wed, 2016-07-13 at 16:36 -0700, Ming Lin wrote:
> > On Wed, Jul 13, 2016 at 4:19 PM, J Freyensee
> > <james_p_freyensee at linux.intel.com> wrote:
> > > 
> > > >  static void nvme_rdma_free_ctrl(struct nvme_ctrl *nctrl)
> > > > @@ -687,6 +684,10 @@ static void nvme_rdma_free_ctrl(struct
> > > > nvme_ctrl
> > > > *nctrl)
> > > >       list_del(&ctrl->list);
> > > >       mutex_unlock(&nvme_rdma_ctrl_mutex);
> > > > 
> > > > +     blk_cleanup_queue(ctrl->ctrl.admin_q);
> > > > +     blk_mq_free_tag_set(&ctrl->admin_tag_set);
> > > > +     nvme_rdma_dev_put(ctrl->device);
> > > > +
> > > >       if (ctrl->ctrl.tagset) {
> > > >               blk_cleanup_queue(ctrl->ctrl.connect_q);
> > > >               blk_mq_free_tag_set(&ctrl->tag_set);
> > > 
> > > This patch does not remove the second
> > > 
> > > nvme_rdma_dev_put(ctrl->device);
> > > 
> > > call that happens within the if() statement above if it evaluates
> > > to
> > > TRUE.  Should that have been removed or moved elsewhere?
> > 
> > Not sure I understand your question.
> > Did you mean line 694?
> 
> Yes I mean line 694.
> 
> > 
> > For discovery controller, there is no IO queues. So ctrl-
> > >ctrl.tagset
> > is NULL.
> > 
> > The first bulk of
> > "blk_cleanup_queue/blk_mq_free_tag_set/nvme_rdma_dev_put" is for
> > admin
> > queue.
> > And the second is for IO queues.
> 
> I'm just confused when nvme_free_ctrl() in core.c calls:
> 
> ctrl->ops->free_ctrl(ctrl);
> 
> which looks like would be the only call that would free both the
> admin
> and I/O rdma queues, why there would be the potential to do a _put()
> twice in nvme_rdma_free_ctrl() via:
> 
> nvme_rdma_dev_put(ctrl->device);
> 
> one for the admin section:
> 
> 687         blk_cleanup_queue(ctrl>ctrl.admin_q);
> 688         blk_mq_free_tag_set(&ctrl->admin_tag_set);
> 689         nvme_rdma_dev_put(ctrl->device);

This put paired with the get in nvme_rdma_configure_admin_queue()

> 
> and one for the I/O section (assuming "if (ctrl->ctrl.tagset)"
> evaluate
> s to TRUE in that call):
> 
> 691         if (ctrl->ctrl.tagset) {
> 692                 blk_cleanup_queue(ctrl->ctrl.connect_q);
> 693                 blk_mq_free_tag_set(&ctrl->tag_set);
> 694                 nvme_rdma_dev_put(ctrl->device);

This put paired with the get in nvme_rdma_create_io_queues()

> 695         }
> 
> 
> My assumption would be that the correct path for this case would be
> such that 
> 
> nvme_rdma_dev_put(ctrl->device); 
> 
> would only be called one time, for a single device.

As above, need put for each get.



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