netlink: constify nlmsghdr arguments
[safe/jmp/linux-2.6] / net / sched / sch_generic.c
index 4685746..693df7a 100644 (file)
  * - updates to tree and tree walking are only done under the rtnl mutex.
  */
 
-static inline int qdisc_qlen(struct Qdisc *q)
-{
-       return q->q.qlen;
-}
-
 static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
 {
-       if (unlikely(skb->next))
-               q->gso_skb = skb;
-       else
-               q->ops->requeue(skb, q);
-
+       q->gso_skb = skb;
+       q->qstats.requeues++;
+       q->q.qlen++;    /* it's still part of the queue */
        __netif_schedule(q);
+
        return 0;
 }
 
 static inline struct sk_buff *dequeue_skb(struct Qdisc *q)
 {
-       struct sk_buff *skb;
+       struct sk_buff *skb = q->gso_skb;
+
+       if (unlikely(skb)) {
+               struct net_device *dev = qdisc_dev(q);
+               struct netdev_queue *txq;
 
-       if ((skb = q->gso_skb))
-               q->gso_skb = NULL;
-       else
+               /* check the reason of requeuing without tx lock first */
+               txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
+               if (!netif_tx_queue_stopped(txq) &&
+                   !netif_tx_queue_frozen(txq)) {
+                       q->gso_skb = NULL;
+                       q->q.qlen--;
+               } else
+                       skb = NULL;
+       } else {
                skb = q->dequeue(q);
+       }
 
        return skb;
 }
@@ -96,44 +101,23 @@ static inline int handle_dev_cpu_collision(struct sk_buff *skb,
 }
 
 /*
- * NOTE: Called under qdisc_lock(q) with locally disabled BH.
- *
- * __QDISC_STATE_RUNNING guarantees only one CPU can process
- * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
- * this queue.
- *
- *  netif_tx_lock serializes accesses to device driver.
- *
- *  qdisc_lock(q) and netif_tx_lock are mutually exclusive,
- *  if one is grabbed, another must be free.
- *
- * Note, that this procedure can be called by a watchdog timer
+ * Transmit one skb, and handle the return status as required. Holding the
+ * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this
+ * function.
  *
  * Returns to the caller:
  *                             0  - queue is empty or throttled.
  *                             >0 - queue is not empty.
- *
  */
-static inline int qdisc_restart(struct Qdisc *q)
+int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
+                   struct net_device *dev, struct netdev_queue *txq,
+                   spinlock_t *root_lock)
 {
-       struct netdev_queue *txq;
        int ret = NETDEV_TX_BUSY;
-       struct net_device *dev;
-       spinlock_t *root_lock;
-       struct sk_buff *skb;
-
-       /* Dequeue packet */
-       if (unlikely((skb = dequeue_skb(q)) == NULL))
-               return 0;
-
-       root_lock = qdisc_lock(q);
 
        /* And release qdisc */
        spin_unlock(root_lock);
 
-       dev = qdisc_dev(q);
-       txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
-
        HARD_TX_LOCK(dev, txq, smp_processor_id());
        if (!netif_tx_queue_stopped(txq) &&
            !netif_tx_queue_frozen(txq))
@@ -170,6 +154,44 @@ static inline int qdisc_restart(struct Qdisc *q)
        return ret;
 }
 
+/*
+ * NOTE: Called under qdisc_lock(q) with locally disabled BH.
+ *
+ * __QDISC_STATE_RUNNING guarantees only one CPU can process
+ * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
+ * this queue.
+ *
+ *  netif_tx_lock serializes accesses to device driver.
+ *
+ *  qdisc_lock(q) and netif_tx_lock are mutually exclusive,
+ *  if one is grabbed, another must be free.
+ *
+ * Note, that this procedure can be called by a watchdog timer
+ *
+ * Returns to the caller:
+ *                             0  - queue is empty or throttled.
+ *                             >0 - queue is not empty.
+ *
+ */
+static inline int qdisc_restart(struct Qdisc *q)
+{
+       struct netdev_queue *txq;
+       struct net_device *dev;
+       spinlock_t *root_lock;
+       struct sk_buff *skb;
+
+       /* Dequeue packet */
+       skb = dequeue_skb(q);
+       if (unlikely(!skb))
+               return 0;
+
+       root_lock = qdisc_lock(q);
+       dev = qdisc_dev(q);
+       txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
+
+       return sch_direct_xmit(skb, q, dev, txq, root_lock);
+}
+
 void __qdisc_run(struct Qdisc *q)
 {
        unsigned long start_time = jiffies;
@@ -189,6 +211,21 @@ void __qdisc_run(struct Qdisc *q)
        clear_bit(__QDISC_STATE_RUNNING, &q->state);
 }
 
+unsigned long dev_trans_start(struct net_device *dev)
+{
+       unsigned long val, res = dev->trans_start;
+       unsigned int i;
+
+       for (i = 0; i < dev->num_tx_queues; i++) {
+               val = netdev_get_tx_queue(dev, i)->trans_start;
+               if (val && time_after(val, res))
+                       res = val;
+       }
+       dev->trans_start = res;
+       return res;
+}
+EXPORT_SYMBOL(dev_trans_start);
+
 static void dev_watchdog(unsigned long arg)
 {
        struct net_device *dev = (struct net_device *)arg;
@@ -198,27 +235,31 @@ static void dev_watchdog(unsigned long arg)
                if (netif_device_present(dev) &&
                    netif_running(dev) &&
                    netif_carrier_ok(dev)) {
-                       int some_queue_stopped = 0;
+                       int some_queue_timedout = 0;
                        unsigned int i;
+                       unsigned long trans_start;
 
                        for (i = 0; i < dev->num_tx_queues; i++) {
                                struct netdev_queue *txq;
 
                                txq = netdev_get_tx_queue(dev, i);
-                               if (netif_tx_queue_stopped(txq)) {
-                                       some_queue_stopped = 1;
+                               /*
+                                * old device drivers set dev->trans_start
+                                */
+                               trans_start = txq->trans_start ? : dev->trans_start;
+                               if (netif_tx_queue_stopped(txq) &&
+                                   time_after(jiffies, (trans_start +
+                                                        dev->watchdog_timeo))) {
+                                       some_queue_timedout = 1;
                                        break;
                                }
                        }
 
-                       if (some_queue_stopped &&
-                           time_after(jiffies, (dev->trans_start +
-                                                dev->watchdog_timeo))) {
+                       if (some_queue_timedout) {
                                char drivername[64];
-                               printk(KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n",
-                                      dev->name, netdev_drivername(dev, drivername, 64));
-                               dev->tx_timeout(dev);
-                               WARN_ON_ONCE(1);
+                               WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
+                                      dev->name, netdev_drivername(dev, drivername, 64), i);
+                               dev->netdev_ops->ndo_tx_timeout(dev);
                        }
                        if (!mod_timer(&dev->watchdog_timer,
                                       round_jiffies(jiffies +
@@ -233,7 +274,7 @@ static void dev_watchdog(unsigned long arg)
 
 void __netdev_watchdog_up(struct net_device *dev)
 {
-       if (dev->tx_timeout) {
+       if (dev->netdev_ops->ndo_tx_timeout) {
                if (dev->watchdog_timeo <= 0)
                        dev->watchdog_timeo = 5*HZ;
                if (!mod_timer(&dev->watchdog_timer,
@@ -264,6 +305,8 @@ static void dev_watchdog_down(struct net_device *dev)
 void netif_carrier_on(struct net_device *dev)
 {
        if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
+               if (dev->reg_state == NETREG_UNINITIALIZED)
+                       return;
                linkwatch_fire_event(dev);
                if (netif_running(dev))
                        __netdev_watchdog_up(dev);
@@ -279,8 +322,11 @@ EXPORT_SYMBOL(netif_carrier_on);
  */
 void netif_carrier_off(struct net_device *dev)
 {
-       if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state))
+       if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
+               if (dev->reg_state == NETREG_UNINITIALIZED)
+                       return;
                linkwatch_fire_event(dev);
+       }
 }
 EXPORT_SYMBOL(netif_carrier_off);
 
@@ -300,26 +346,18 @@ static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
        return NULL;
 }
 
-static int noop_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
-{
-       if (net_ratelimit())
-               printk(KERN_DEBUG "%s deferred output. It is buggy.\n",
-                      skb->dev->name);
-       kfree_skb(skb);
-       return NET_XMIT_CN;
-}
-
 struct Qdisc_ops noop_qdisc_ops __read_mostly = {
        .id             =       "noop",
        .priv_size      =       0,
        .enqueue        =       noop_enqueue,
        .dequeue        =       noop_dequeue,
-       .requeue        =       noop_requeue,
+       .peek           =       noop_dequeue,
        .owner          =       THIS_MODULE,
 };
 
 static struct netdev_queue noop_netdev_queue = {
        .qdisc          =       &noop_qdisc,
+       .qdisc_sleeping =       &noop_qdisc,
 };
 
 struct Qdisc noop_qdisc = {
@@ -338,13 +376,14 @@ static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
        .priv_size      =       0,
        .enqueue        =       noop_enqueue,
        .dequeue        =       noop_dequeue,
-       .requeue        =       noop_requeue,
+       .peek           =       noop_dequeue,
        .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 = {
@@ -401,10 +440,17 @@ static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc)
        return NULL;
 }
 
-static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc)
+static struct sk_buff *pfifo_fast_peek(struct Qdisc* qdisc)
 {
-       qdisc->q.qlen++;
-       return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc));
+       int prio;
+       struct sk_buff_head *list = qdisc_priv(qdisc);
+
+       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
+               if (!skb_queue_empty(list + prio))
+                       return skb_peek(list + prio);
+       }
+
+       return NULL;
 }
 
 static void pfifo_fast_reset(struct Qdisc* qdisc)
@@ -447,7 +493,7 @@ static struct Qdisc_ops pfifo_fast_ops __read_mostly = {
        .priv_size      =       PFIFO_FAST_BANDS * sizeof(struct sk_buff_head),
        .enqueue        =       pfifo_fast_enqueue,
        .dequeue        =       pfifo_fast_dequeue,
-       .requeue        =       pfifo_fast_requeue,
+       .peek           =       pfifo_fast_peek,
        .init           =       pfifo_fast_init,
        .reset          =       pfifo_fast_reset,
        .dump           =       pfifo_fast_dump,
@@ -515,18 +561,26 @@ void qdisc_reset(struct Qdisc *qdisc)
 
        if (ops->reset)
                ops->reset(qdisc);
+
+       if (qdisc->gso_skb) {
+               kfree_skb(qdisc->gso_skb);
+               qdisc->gso_skb = NULL;
+               qdisc->q.qlen = 0;
+       }
 }
 EXPORT_SYMBOL(qdisc_reset);
 
-/* this is the rcu callback function to clean up a qdisc when there
- * are no further references to it */
-
-static void __qdisc_destroy(struct rcu_head *head)
+void qdisc_destroy(struct Qdisc *qdisc)
 {
-       struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu);
        const struct Qdisc_ops  *ops = qdisc->ops;
 
+       if (qdisc->flags & TCQ_F_BUILTIN ||
+           !atomic_dec_and_test(&qdisc->refcnt))
+               return;
+
 #ifdef CONFIG_NET_SCHED
+       qdisc_list_del(qdisc);
+
        qdisc_put_stab(qdisc->stab);
 #endif
        gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
@@ -539,23 +593,8 @@ static void __qdisc_destroy(struct rcu_head *head)
        dev_put(qdisc_dev(qdisc));
 
        kfree_skb(qdisc->gso_skb);
-
        kfree((char *) qdisc - qdisc->padded);
 }
-
-/* Under qdisc_lock(qdisc) and BH! */
-
-void qdisc_destroy(struct Qdisc *qdisc)
-{
-       if (qdisc->flags & TCQ_F_BUILTIN ||
-           !atomic_dec_and_test(&qdisc->refcnt))
-               return;
-
-       if (qdisc->parent)
-               list_del(&qdisc->list);
-
-       call_rcu(&qdisc->q_rcu, __qdisc_destroy);
-}
 EXPORT_SYMBOL(qdisc_destroy);
 
 static bool dev_all_qdisc_sleeping_noop(struct net_device *dev)
@@ -584,6 +623,9 @@ static void attach_one_default_qdisc(struct net_device *dev,
                        printk(KERN_INFO "%s: activation failed\n", dev->name);
                        return;
                }
+
+               /* Can by-pass the queue discipline for default qdisc */
+               qdisc->flags |= TCQ_F_CAN_BYPASS;
        } else {
                qdisc =  &noqueue_qdisc;
        }
@@ -597,9 +639,14 @@ static void transition_one_qdisc(struct net_device *dev,
        struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
        int *need_watchdog_p = _need_watchdog;
 
+       if (!(new_qdisc->flags & TCQ_F_BUILTIN))
+               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 && new_qdisc != &noqueue_qdisc) {
+               dev_queue->trans_start = 0;
                *need_watchdog_p = 1;
+       }
 }
 
 void dev_activate(struct net_device *dev)
@@ -640,14 +687,17 @@ static void dev_deactivate_queue(struct net_device *dev,
        if (qdisc) {
                spin_lock_bh(qdisc_lock(qdisc));
 
-               dev_queue->qdisc = qdisc_default;
+               if (!(qdisc->flags & TCQ_F_BUILTIN))
+                       set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
+
+               rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
                qdisc_reset(qdisc);
 
                spin_unlock_bh(qdisc_lock(qdisc));
        }
 }
 
-static bool some_qdisc_is_busy(struct net_device *dev, int lock)
+static bool some_qdisc_is_busy(struct net_device *dev)
 {
        unsigned int i;
 
@@ -661,14 +711,12 @@ static bool some_qdisc_is_busy(struct net_device *dev, int lock)
                q = dev_queue->qdisc_sleeping;
                root_lock = qdisc_lock(q);
 
-               if (lock)
-                       spin_lock_bh(root_lock);
+               spin_lock_bh(root_lock);
 
                val = (test_bit(__QDISC_STATE_RUNNING, &q->state) ||
                       test_bit(__QDISC_STATE_SCHED, &q->state));
 
-               if (lock)
-                       spin_unlock_bh(root_lock);
+               spin_unlock_bh(root_lock);
 
                if (val)
                        return true;
@@ -678,8 +726,6 @@ static bool some_qdisc_is_busy(struct net_device *dev, int lock)
 
 void dev_deactivate(struct net_device *dev)
 {
-       bool running;
-
        netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc);
        dev_deactivate_queue(dev, &dev->rx_queue, &noop_qdisc);
 
@@ -689,25 +735,8 @@ void dev_deactivate(struct net_device *dev)
        synchronize_rcu();
 
        /* Wait for outstanding qdisc_run calls. */
-       do {
-               while (some_qdisc_is_busy(dev, 0))
-                       yield();
-
-               /*
-                * Double-check inside queue lock to ensure that all effects
-                * of the queue run are visible when we return.
-                */
-               running = some_qdisc_is_busy(dev, 1);
-
-               /*
-                * The running flag should never be set at this point because
-                * we've already set dev->qdisc to noop_qdisc *inside* the same
-                * pair of spin locks.  That is, if any qdisc_run starts after
-                * our initial test it should see the noop_qdisc and then
-                * clear the RUNNING bit before dropping the queue lock.  So
-                * if it is set here then we've found a bug.
-                */
-       } while (WARN_ON_ONCE(running));
+       while (some_qdisc_is_busy(dev))
+               yield();
 }
 
 static void dev_init_scheduler_queue(struct net_device *dev,
@@ -736,14 +765,10 @@ static void shutdown_scheduler_queue(struct net_device *dev,
        struct Qdisc *qdisc_default = _qdisc_default;
 
        if (qdisc) {
-               spinlock_t *root_lock = qdisc_lock(qdisc);
-
-               dev_queue->qdisc = qdisc_default;
+               rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
                dev_queue->qdisc_sleeping = qdisc_default;
 
-               spin_lock_bh(root_lock);
                qdisc_destroy(qdisc);
-               spin_unlock_bh(root_lock);
        }
 }