block/rnbd-clt: Check the return value of the function rtrs_clt_query

In case none of the paths are in connected state, the function
rtrs_clt_query returns an error. In such a case, error out since the
values in the rtrs_attrs structure would be garbage.

Fixes: f7a7a5c ("block/rnbd: client: main functionality")
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Guoqing Jiang <guoqing.jiang@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Link: https://lore.kernel.org/r/20210428061359.206794-4-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/rnbd/rnbd-clt.c

@@ -691,7 +691,11 @@ static void remap_devs(struct rnbd_clt_session *sess)
 		return;
 	}
 
-	rtrs_clt_query(sess->rtrs, &attrs);
+	err = rtrs_clt_query(sess->rtrs, &attrs);
+	if (err) {
+		pr_err("rtrs_clt_query(\"%s\"): %d\n", sess->sessname, err);
+		return;
+	}
 	mutex_lock(&sess->lock);
 	sess->max_io_size = attrs.max_io_size;
 
@@ -1294,7 +1298,11 @@ find_and_get_or_create_sess(const char *sessname,
 		err = PTR_ERR(sess->rtrs);
 		goto wake_up_and_put;
 	}
-	rtrs_clt_query(sess->rtrs, &attrs);
+
+	err = rtrs_clt_query(sess->rtrs, &attrs);
+	if (err)
+		goto close_rtrs;
+
 	sess->max_io_size = attrs.max_io_size;
 	sess->queue_depth = attrs.queue_depth;
 	sess->nr_poll_queues = nr_poll_queues;