iser-target: Handle DEVICE_REMOVAL event on network portal listener correctly

In this case the cm_id->context is the isert_np, and the cm_id->qp
is NULL, so use that to distinct the cases.

Since we don't expect any other events on this cm_id we can
just return -1 for explicit termination of the cm_id by the
cma layer.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/infiniband/ulp/isert/ib_isert.c

@@ -806,14 +806,25 @@ isert_disconnect_work(struct work_struct *work)
 	complete(&isert_conn->conn_wait);
 }
 
-static void
+static int
 isert_disconnected_handler(struct rdma_cm_id *cma_id, bool disconnect)
 {
-	struct isert_conn *isert_conn = (struct isert_conn *)cma_id->context;
+	struct isert_conn *isert_conn;
+
+	if (!cma_id->qp) {
+		struct isert_np *isert_np = cma_id->context;
+
+		isert_np->np_cm_id = NULL;
+		return -1;
+	}
+
+	isert_conn = (struct isert_conn *)cma_id->context;
 
 	isert_conn->disconnect = disconnect;
 	INIT_WORK(&isert_conn->conn_logout_work, isert_disconnect_work);
 	schedule_work(&isert_conn->conn_logout_work);
+
+	return 0;
 }
 
 static int
@@ -828,6 +839,9 @@ isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 	switch (event->event) {
 	case RDMA_CM_EVENT_CONNECT_REQUEST:
 		ret = isert_connect_request(cma_id, event);
+		if (ret)
+			pr_err("isert_cma_handler failed RDMA_CM_EVENT: 0x%08x %d\n",
+				event->event, ret);
 		break;
 	case RDMA_CM_EVENT_ESTABLISHED:
 		isert_connected_handler(cma_id);
@@ -837,7 +851,7 @@ isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 	case RDMA_CM_EVENT_DEVICE_REMOVAL: /* FALLTHRU */
 		disconnect = true;
 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:  /* FALLTHRU */
-		isert_disconnected_handler(cma_id, disconnect);
+		ret = isert_disconnected_handler(cma_id, disconnect);
 		break;
 	case RDMA_CM_EVENT_CONNECT_ERROR:
 	default:
@@ -845,12 +859,6 @@ isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
 		break;
 	}
 
-	if (ret != 0) {
-		pr_err("isert_cma_handler failed RDMA_CM_EVENT: 0x%08x %d\n",
-		       event->event, ret);
-		dump_stack();
-	}
-
 	return ret;
 }
 
@@ -3193,7 +3201,8 @@ isert_free_np(struct iscsi_np *np)
 {
 	struct isert_np *isert_np = (struct isert_np *)np->np_context;
 
-	rdma_destroy_id(isert_np->np_cm_id);
+	if (isert_np->np_cm_id)
+		rdma_destroy_id(isert_np->np_cm_id);
 
 	np->np_context = NULL;
 	kfree(isert_np);