net: Change handling of the __QDISC_STATE_SCHED flag in net_tx_action().

Change handling of the __QDISC_STATE_SCHED flag in net_tx_action() to
enable proper control in dev_deactivate(). Now, if this flag is seen
as unset under root_lock means a qdisc can't be netif_scheduled.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index d9e31f6..819f017 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1339,19 +1339,23 @@ static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
 }
 
 
-void __netif_schedule(struct Qdisc *q)
+static inline void __netif_reschedule(struct Qdisc *q)
 {
-       if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state)) {
-               struct softnet_data *sd;
-               unsigned long flags;
+       struct softnet_data *sd;
+       unsigned long flags;
 
-               local_irq_save(flags);
-               sd = &__get_cpu_var(softnet_data);
-               q->next_sched = sd->output_queue;
-               sd->output_queue = q;
-               raise_softirq_irqoff(NET_TX_SOFTIRQ);
-               local_irq_restore(flags);
-       }
+       local_irq_save(flags);
+       sd = &__get_cpu_var(softnet_data);
+       q->next_sched = sd->output_queue;
+       sd->output_queue = q;
+       raise_softirq_irqoff(NET_TX_SOFTIRQ);
+       local_irq_restore(flags);
+}
+
+void __netif_schedule(struct Qdisc *q)
+{
+       if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
+               __netif_reschedule(q);
 }
 EXPORT_SYMBOL(__netif_schedule);
 
@@ -1980,15 +1984,15 @@ static void net_tx_action(struct softirq_action *h)
 
                        head = head->next_sched;
 
-                       smp_mb__before_clear_bit();
-                       clear_bit(__QDISC_STATE_SCHED, &q->state);
-
                        root_lock = qdisc_lock(q);
                        if (spin_trylock(root_lock)) {
+                               smp_mb__before_clear_bit();
+                               clear_bit(__QDISC_STATE_SCHED,
+                                         &q->state);
                                qdisc_run(q);
                                spin_unlock(root_lock);
                        } else {
-                               __netif_schedule(q);
+                               __netif_reschedule(q);
                        }
                }
        }