1 files changed, 69 insertions, 14 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 3b0f62095803..b07bd1c7330f 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -434,9 +434,9 @@ unsigned long dev_trans_start(struct net_device *dev)
 		dev = vlan_dev_real_dev(dev);
 	else if (netif_is_macvlan(dev))
 		dev = macvlan_dev_real_dev(dev);
-	res = netdev_get_tx_queue(dev, 0)->trans_start;
+	res = READ_ONCE(netdev_get_tx_queue(dev, 0)->trans_start);
 	for (i = 1; i < dev->num_tx_queues; i++) {
-		val = netdev_get_tx_queue(dev, i)->trans_start;
+		val = READ_ONCE(netdev_get_tx_queue(dev, i)->trans_start);
 		if (val && time_after(val, res))
 			res = val;
 	}
@@ -445,11 +445,63 @@ unsigned long dev_trans_start(struct net_device *dev)
 }
 EXPORT_SYMBOL(dev_trans_start);
 
+static void netif_freeze_queues(struct net_device *dev)
+{
+	unsigned int i;
+	int cpu;
+
+	cpu = smp_processor_id();
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+		/* We are the only thread of execution doing a
+		 * freeze, but we have to grab the _xmit_lock in
+		 * order to synchronize with threads which are in
+		 * the ->hard_start_xmit() handler and already
+		 * checked the frozen bit.
+		 */
+		__netif_tx_lock(txq, cpu);
+		set_bit(__QUEUE_STATE_FROZEN, &txq->state);
+		__netif_tx_unlock(txq);
+	}
+}
+
+void netif_tx_lock(struct net_device *dev)
+{
+	spin_lock(&dev->tx_global_lock);
+	netif_freeze_queues(dev);
+}
+EXPORT_SYMBOL(netif_tx_lock);
+
+static void netif_unfreeze_queues(struct net_device *dev)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+		/* No need to grab the _xmit_lock here.  If the
+		 * queue is not stopped for another reason, we
+		 * force a schedule.
+		 */
+		clear_bit(__QUEUE_STATE_FROZEN, &txq->state);
+		netif_schedule_queue(txq);
+	}
+}
+
+void netif_tx_unlock(struct net_device *dev)
+{
+	netif_unfreeze_queues(dev);
+	spin_unlock(&dev->tx_global_lock);
+}
+EXPORT_SYMBOL(netif_tx_unlock);
+
 static void dev_watchdog(struct timer_list *t)
 {
 	struct net_device *dev = from_timer(dev, t, watchdog_timer);
+	bool release = true;
 
-	netif_tx_lock(dev);
+	spin_lock(&dev->tx_global_lock);
 	if (!qdisc_tx_is_noop(dev)) {
 		if (netif_device_present(dev) &&
 		    netif_running(dev) &&
@@ -462,31 +514,34 @@ static void dev_watchdog(struct timer_list *t)
 				struct netdev_queue *txq;
 
 				txq = netdev_get_tx_queue(dev, i);
-				trans_start = txq->trans_start;
+				trans_start = READ_ONCE(txq->trans_start);
 				if (netif_xmit_stopped(txq) &&
 				    time_after(jiffies, (trans_start +
 							 dev->watchdog_timeo))) {
 					some_queue_timedout = 1;
-					txq->trans_timeout++;
+					atomic_long_inc(&txq->trans_timeout);
 					break;
 				}
 			}
 
-			if (some_queue_timedout) {
+			if (unlikely(some_queue_timedout)) {
 				trace_net_dev_xmit_timeout(dev, i);
 				WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
 				       dev->name, netdev_drivername(dev), i);
+				netif_freeze_queues(dev);
 				dev->netdev_ops->ndo_tx_timeout(dev, i);
+				netif_unfreeze_queues(dev);
 			}
 			if (!mod_timer(&dev->watchdog_timer,
 				       round_jiffies(jiffies +
 						     dev->watchdog_timeo)))
-				dev_hold(dev);
+				release = false;
 		}
 	}
-	netif_tx_unlock(dev);
+	spin_unlock(&dev->tx_global_lock);
 
-	dev_put(dev);
+	if (release)
+		dev_put_track(dev, &dev->watchdog_dev_tracker);
 }
 
 void __netdev_watchdog_up(struct net_device *dev)
@@ -496,7 +551,7 @@ void __netdev_watchdog_up(struct net_device *dev)
 			dev->watchdog_timeo = 5*HZ;
 		if (!mod_timer(&dev->watchdog_timer,
 			       round_jiffies(jiffies + dev->watchdog_timeo)))
-			dev_hold(dev);
+			dev_hold_track(dev, &dev->watchdog_dev_tracker, GFP_ATOMIC);
 	}
 }
 EXPORT_SYMBOL_GPL(__netdev_watchdog_up);
@@ -510,7 +565,7 @@ static void dev_watchdog_down(struct net_device *dev)
 {
 	netif_tx_lock_bh(dev);
 	if (del_timer(&dev->watchdog_timer))
-		dev_put(dev);
+		dev_put_track(dev, &dev->watchdog_dev_tracker);
 	netif_tx_unlock_bh(dev);
 }
 
@@ -920,7 +975,7 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 	sch->enqueue = ops->enqueue;
 	sch->dequeue = ops->dequeue;
 	sch->dev_queue = dev_queue;
-	dev_hold(dev);
+	dev_hold_track(dev, &sch->dev_tracker, GFP_KERNEL);
 	refcount_set(&sch->refcnt, 1);
 
 	return sch;
@@ -1020,7 +1075,7 @@ static void qdisc_destroy(struct Qdisc *qdisc)
 		ops->destroy(qdisc);
 
 	module_put(ops->owner);
-	dev_put(qdisc_dev(qdisc));
+	dev_put_track(qdisc_dev(qdisc), &qdisc->dev_tracker);
 
 	trace_qdisc_destroy(qdisc);
 
@@ -1148,7 +1203,7 @@ static void transition_one_qdisc(struct net_device *dev,
 
 	rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
 	if (need_watchdog_p) {
-		dev_queue->trans_start = 0;
+		WRITE_ONCE(dev_queue->trans_start, 0);
 		*need_watchdog_p = 1;
 	}
 }