RDMA/rtrs: Fix warning when use poll mode on client side.

[ Upstream commit 4b6afe9bc9 ]

When testing with poll mode, it will fail and lead to warning below on
client side:

$ echo "sessname=bla path=gid:fe80::2:c903:4e:d0b3@gid:fe80::2:c903:8:ca17 device_path=/dev/nullb2 nr_poll_queues=-1" | \
  sudo tee /sys/devices/virtual/rnbd-client/ctl/map_device

rnbd_client L597: Mapping device /dev/nullb2 on session bla, (access_mode: rw, nr_poll_queues: 8)
WARNING: CPU: 3 PID: 9886 at drivers/infiniband/core/cq.c:447 ib_cq_pool_get+0x26f/0x2a0 [ib_core]

The problem is in case of poll queue, we need to still call
ib_alloc_cq/ib_free_cq, we can't use cq_poll api for poll queue.

As both client and server use shared function from rtrs, set irq_con_num
to con_num on server side, which is number of total connection of the
session, this way we can differ if the rtrs_con requires pollqueue.

Following up patches will replace the duplicate code with helpers.

Link: https://lore.kernel.org/r/20210922125333.351454-4-haris.iqbal@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Reviewed-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/infiniband/ulp/rtrs/rtrs-srv.c

@@ -1766,6 +1766,7 @@ static struct rtrs_srv_sess *__alloc_sess(struct rtrs_srv *srv,
 	strscpy(sess->s.sessname, str, sizeof(sess->s.sessname));
 
 	sess->s.con_num = con_num;
+	sess->s.irq_con_num = con_num;
 	sess->s.recon_cnt = recon_cnt;
 	uuid_copy(&sess->s.uuid, uuid);
 	spin_lock_init(&sess->state_lock);

drivers/infiniband/ulp/rtrs/rtrs.c

@@ -228,7 +228,12 @@ static int create_cq(struct rtrs_con *con, int cq_vector, int nr_cqe,
 	struct rdma_cm_id *cm_id = con->cm_id;
 	struct ib_cq *cq;
 
-	cq = ib_cq_pool_get(cm_id->device, nr_cqe, cq_vector, poll_ctx);
+	if (con->cid >= con->sess->irq_con_num)
+		cq = ib_alloc_cq(cm_id->device, con, nr_cqe, cq_vector,
+				 poll_ctx);
+	else
+		cq = ib_cq_pool_get(cm_id->device, nr_cqe, cq_vector, poll_ctx);
+
 	if (IS_ERR(cq)) {
 		rtrs_err(con->sess, "Creating completion queue failed, errno: %ld\n",
 			  PTR_ERR(cq));
@@ -283,7 +288,10 @@ int rtrs_cq_qp_create(struct rtrs_sess *sess, struct rtrs_con *con,
 	err = create_qp(con, sess->dev->ib_pd, max_send_wr, max_recv_wr,
 			max_send_sge);
 	if (err) {
-		ib_cq_pool_put(con->cq, con->nr_cqe);
+		if (con->cid >= con->sess->irq_con_num)
+			ib_free_cq(con->cq);
+		else
+			ib_cq_pool_put(con->cq, con->nr_cqe);
 		con->cq = NULL;
 		return err;
 	}
@@ -300,7 +308,10 @@ void rtrs_cq_qp_destroy(struct rtrs_con *con)
 		con->qp = NULL;
 	}
 	if (con->cq) {
-		ib_cq_pool_put(con->cq, con->nr_cqe);
+		if (con->cid >= con->sess->irq_con_num)
+			ib_free_cq(con->cq);
+		else
+			ib_cq_pool_put(con->cq, con->nr_cqe);
 		con->cq = NULL;
 	}
 }