SUNRPC: Fail over more quickly on connect errors

[safe/jmp/linux-2.6] / net / sched / sch_generic.c

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 6128e6f..ff4dd53 100644 (file)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -24,6 +24,7 @@
 #include <linux/init.h>
 #include <linux/rcupdate.h>
 #include <linux/list.h>
+#include <linux/slab.h>
 #include <net/pkt_sched.h>
 
 /* Main transmission queue. */
@@ -119,32 +120,26 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
        spin_unlock(root_lock);
 
        HARD_TX_LOCK(dev, txq, smp_processor_id());
-       if (!netif_tx_queue_stopped(txq) &&
-           !netif_tx_queue_frozen(txq))
+       if (!netif_tx_queue_stopped(txq) && !netif_tx_queue_frozen(txq))
                ret = dev_hard_start_xmit(skb, dev, txq);
+
        HARD_TX_UNLOCK(dev, txq);
 
        spin_lock(root_lock);
 
-       switch (ret) {
-       case NETDEV_TX_OK:
-               /* Driver sent out skb successfully */
+       if (dev_xmit_complete(ret)) {
+               /* Driver sent out skb successfully or skb was consumed */
                ret = qdisc_qlen(q);
-               break;
-
-       case NETDEV_TX_LOCKED:
+       } else if (ret == NETDEV_TX_LOCKED) {
                /* Driver try lock failed */
                ret = handle_dev_cpu_collision(skb, txq, q);
-               break;
-
-       default:
+       } else {
                /* Driver returned NETDEV_TX_BUSY - requeue skb */
                if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit()))
                        printk(KERN_WARNING "BUG %s code %d qlen %d\n",
                               dev->name, ret, q->q.qlen);
 
                ret = dev_requeue_skb(skb, q);
-               break;
        }
 
        if (ret && (netif_tx_queue_stopped(txq) ||
@@ -514,7 +509,7 @@ static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
        return 0;
 }
 
-static struct Qdisc_ops pfifo_fast_ops __read_mostly = {
+struct Qdisc_ops pfifo_fast_ops __read_mostly = {
        .id             =       "pfifo_fast",
        .priv_size      =       sizeof(struct pfifo_fast_priv),
        .enqueue        =       pfifo_fast_enqueue,
@@ -623,17 +618,29 @@ void qdisc_destroy(struct Qdisc *qdisc)
 }
 EXPORT_SYMBOL(qdisc_destroy);
 
-static bool dev_all_qdisc_sleeping_noop(struct net_device *dev)
+/* Attach toplevel qdisc to device queue. */
+struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
+                             struct Qdisc *qdisc)
 {
-       unsigned int i;
+       struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
+       spinlock_t *root_lock;
 
-       for (i = 0; i < dev->num_tx_queues; i++) {
-               struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+       root_lock = qdisc_lock(oqdisc);
+       spin_lock_bh(root_lock);
 
-               if (txq->qdisc_sleeping != &noop_qdisc)
-                       return false;
-       }
-       return true;
+       /* Prune old scheduler */
+       if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
+               qdisc_reset(oqdisc);
+
+       /* ... and graft new one */
+       if (qdisc == NULL)
+               qdisc = &noop_qdisc;
+       dev_queue->qdisc_sleeping = qdisc;
+       rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
+
+       spin_unlock_bh(root_lock);
+
+       return oqdisc;
 }
 
 static void attach_one_default_qdisc(struct net_device *dev,
@@ -658,6 +665,26 @@ static void attach_one_default_qdisc(struct net_device *dev,
        dev_queue->qdisc_sleeping = qdisc;
 }
 
+static void attach_default_qdiscs(struct net_device *dev)
+{
+       struct netdev_queue *txq;
+       struct Qdisc *qdisc;
+
+       txq = netdev_get_tx_queue(dev, 0);
+
+       if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) {
+               netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
+               dev->qdisc = txq->qdisc_sleeping;
+               atomic_inc(&dev->qdisc->refcnt);
+       } else {
+               qdisc = qdisc_create_dflt(dev, txq, &mq_qdisc_ops, TC_H_ROOT);
+               if (qdisc) {
+                       qdisc->ops->attach(qdisc);
+                       dev->qdisc = qdisc;
+               }
+       }
+}
+
 static void transition_one_qdisc(struct net_device *dev,
                                 struct netdev_queue *dev_queue,
                                 void *_need_watchdog)
@@ -685,8 +712,8 @@ void dev_activate(struct net_device *dev)
           virtual interfaces
         */
 
-       if (dev_all_qdisc_sleeping_noop(dev))
-               netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
+       if (dev->qdisc == &noop_qdisc)
+               attach_default_qdiscs(dev);
 
        if (!netif_carrier_ok(dev))
                /* Delay activation until next carrier-on event */
@@ -777,6 +804,7 @@ static void dev_init_scheduler_queue(struct net_device *dev,
 
 void dev_init_scheduler(struct net_device *dev)
 {
+       dev->qdisc = &noop_qdisc;
        netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
        dev_init_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
 
@@ -802,5 +830,8 @@ void dev_shutdown(struct net_device *dev)
 {
        netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
        shutdown_scheduler_queue(dev, &dev->rx_queue, &noop_qdisc);
+       qdisc_destroy(dev->qdisc);
+       dev->qdisc = &noop_qdisc;
+
        WARN_ON(timer_pending(&dev->watchdog_timer));
 }