net/sched: Change behavior of mq select_queue()

Currently, the class_ops select_queue() implementation on sch_mq
returns a pointer to netdev_queue #0 when it receives and invalid
qdisc id. That can be misleading since all of mq's inner qdiscs are
attached to a valid netdev_queue.

Here we fix that by returning NULL when a qdisc id is invalid. This is
aligned with how select_queue() is implemented for sch_mqprio in the
next patch on this series, keeping a consistent behavior between these
two qdiscs.

Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Tested-by: Henrik Austad <henrik@austad.us>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index f3a3e507422bff4eabda205b9d2f8deea82b1b8e..213b586a06a0ff4c35f668a42f9217522cc29b5a 100644 (file)
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -130,15 +130,7 @@ static struct netdev_queue *mq_queue_get(struct Qdisc *sch, unsigned long cl)
 static struct netdev_queue *mq_select_queue(struct Qdisc *sch,
                                            struct tcmsg *tcm)
 {
-       unsigned int ntx = TC_H_MIN(tcm->tcm_parent);
-       struct netdev_queue *dev_queue = mq_queue_get(sch, ntx);
-
-       if (!dev_queue) {
-               struct net_device *dev = qdisc_dev(sch);
-
-               return netdev_get_tx_queue(dev, 0);
-       }
-       return dev_queue;
+       return mq_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
 }
 
 static int mq_graft(struct Qdisc *sch, unsigned long cl, struct Qdisc *new,