net: sched: simplify attach_one_default_qdisc()

Now that noqueue qdisc can be attached just like any other qdisc, no
special treatment is necessary anymore when attaching it as default
qdisc.

This change has the added benefit that 'tc qdisc show' prints noqueue
instead of nothing for devices defaulting to noqueue.
Signed-off-by: NPhil Sutter <phil@nwl.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_generic.c

@@ -435,24 +435,6 @@ struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
 	.owner		=	THIS_MODULE,
 };
 
-static struct Qdisc noqueue_qdisc;
-static struct netdev_queue noqueue_netdev_queue = {
-	.qdisc		=	&noqueue_qdisc,
-	.qdisc_sleeping	=	&noqueue_qdisc,
-};
-
-static struct Qdisc noqueue_qdisc = {
-	.enqueue	=	NULL,
-	.dequeue	=	noop_dequeue,
-	.flags		=	TCQ_F_BUILTIN,
-	.ops		=	&noqueue_qdisc_ops,
-	.list		=	LIST_HEAD_INIT(noqueue_qdisc.list),
-	.q.lock		=	__SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
-	.dev_queue	=	&noqueue_netdev_queue,
-	.busylock	=	__SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock),
-};
-
-
 static const u8 prio2band[TC_PRIO_MAX + 1] = {
 	1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
 };
@@ -743,18 +725,19 @@ static void attach_one_default_qdisc(struct net_device *dev,
 				     struct netdev_queue *dev_queue,
 				     void *_unused)
 {
-	struct Qdisc *qdisc = &noqueue_qdisc;
+	struct Qdisc *qdisc;
+	const struct Qdisc_ops *ops = default_qdisc_ops;
 
-	if (!(dev->priv_flags & IFF_NO_QUEUE)) {
-		qdisc = qdisc_create_dflt(dev_queue,
-					  default_qdisc_ops, TC_H_ROOT);
-		if (!qdisc) {
-			netdev_info(dev, "activation failed\n");
-			return;
-		}
-		if (!netif_is_multiqueue(dev))
-			qdisc->flags |= TCQ_F_ONETXQUEUE;
+	if (dev->priv_flags & IFF_NO_QUEUE)
+		ops = &noqueue_qdisc_ops;
+
+	qdisc = qdisc_create_dflt(dev_queue, ops, TC_H_ROOT);
+	if (!qdisc) {
+		netdev_info(dev, "activation failed\n");
+		return;
 	}
+	if (!netif_is_multiqueue(dev))
+		qdisc->flags |= TCQ_F_ONETXQUEUE;
 	dev_queue->qdisc_sleeping = qdisc;
 }
 
@@ -790,7 +773,7 @@ static void transition_one_qdisc(struct net_device *dev,
 		clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
 
 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
-	if (need_watchdog_p && new_qdisc != &noqueue_qdisc) {
+	if (need_watchdog_p) {
 		dev_queue->trans_start = 0;
 		*need_watchdog_p = 1;
 	}