RE: [PATCH 4/5] nvmet-rdma: add a NVMe over Fabrics RDMA target driver

From: "Steve Wise" <swise@opengridcomputing.com>
To: "'Sagi Grimberg'" <sagi@lightbits.io>,
	"'Christoph Hellwig'" <hch@lst.de>, <axboe@kernel.dk>,
	<keith.busch@intel.com>
Cc: <linux-nvme@lists.infradead.org>, <linux-block@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	"'Armen Baloyan'" <armenx.baloyan@intel.com>,
	"'Jay Freyensee'" <james.p.freyensee@intel.com>,
	"'Ming Lin'" <ming.l@ssi.samsung.com>,
	<linux-rdma@vger.kernel.org>
Subject: RE: [PATCH 4/5] nvmet-rdma: add a NVMe over Fabrics RDMA target driver
Date: Thu, 9 Jun 2016 18:03:51 -0500	[thread overview]
Message-ID: <057a01d1c2a3$3082eec0$9188cc40$@opengridcomputing.com> (raw)
In-Reply-To: <5756B75C.9000409@lightbits.io>

<snip>

> > +
> > +static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
> > +		struct rdma_cm_event *event)
> > +{
> > +	struct nvmet_rdma_queue *queue = NULL;
> > +	int ret = 0;
> > +
> > +	if (cm_id->qp)
> > +		queue = cm_id->qp->qp_context;
> > +
> > +	pr_debug("%s (%d): status %d id %p\n",
> > +		rdma_event_msg(event->event), event->event,
> > +		event->status, cm_id);
> > +
> > +	switch (event->event) {
> > +	case RDMA_CM_EVENT_CONNECT_REQUEST:
> > +		ret = nvmet_rdma_queue_connect(cm_id, event);

The above nvmet cm event handler, nvmet_rdma_cm_handler(), calls
nvmet_rdma_queue_connect() for CONNECT_REQUEST events, which calls
nvmet_rdma_alloc_queue (), which, if it encounters a failure (like creating
the qp), calls nvmet_rdma_cm_reject () which calls rdma_reject().  The
non-zero error, however, gets returned back here and this function returns
the error to the RDMA_CM which will also reject the connection as well as
destroy the cm_id.  So there are two rejects happening, I think.  Either
nvmet should reject and destroy the cm_id, or it should do neither and
return non-zero to the RDMA_CM to reject/destroy.

Steve.