1 files changed, 190 insertions, 81 deletions

diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index d43d1201275..bd0767e6b2b 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -11,7 +11,6 @@
  *
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/if.h>
@@ -20,125 +19,235 @@
 #include <linux/rtnetlink.h>
 #include <linux/jiffies.h>
 #include <linux/spinlock.h>
-#include <linux/list.h>
-#include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/bitops.h>
 #include <asm/types.h>
 
 
 enum lw_bits {
-	LW_RUNNING = 0,
-	LW_SE_USED
+	LW_URGENT = 0,
 };
 
 static unsigned long linkwatch_flags;
 static unsigned long linkwatch_nextevent;
 
-static void linkwatch_event(void *dummy);
-static DECLARE_WORK(linkwatch_work, linkwatch_event, NULL);
+static void linkwatch_event(struct work_struct *dummy);
+static DECLARE_DELAYED_WORK(linkwatch_work, linkwatch_event);
 
 static LIST_HEAD(lweventlist);
 static DEFINE_SPINLOCK(lweventlist_lock);
 
-struct lw_event {
-	struct list_head list;
-	struct net_device *dev;
-};
+static unsigned char default_operstate(const struct net_device *dev)
+{
+	if (!netif_carrier_ok(dev))
+		return (dev->ifindex != dev->iflink ?
+			IF_OPER_LOWERLAYERDOWN : IF_OPER_DOWN);
 
-/* Avoid kmalloc() for most systems */
-static struct lw_event singleevent;
+	if (netif_dormant(dev))
+		return IF_OPER_DORMANT;
 
-/* Must be called with the rtnl semaphore held */
-void linkwatch_run_queue(void)
+	return IF_OPER_UP;
+}
+
+
+static void rfc2863_policy(struct net_device *dev)
 {
-	LIST_HEAD(head);
-	struct list_head *n, *next;
+	unsigned char operstate = default_operstate(dev);
 
-	spin_lock_irq(&lweventlist_lock);
-	list_splice_init(&lweventlist, &head);
-	spin_unlock_irq(&lweventlist_lock);
+	if (operstate == dev->operstate)
+		return;
 
-	list_for_each_safe(n, next, &head) {
-		struct lw_event *event = list_entry(n, struct lw_event, list);
-		struct net_device *dev = event->dev;
+	write_lock_bh(&dev_base_lock);
 
-		if (event == &singleevent) {
-			clear_bit(LW_SE_USED, &linkwatch_flags);
-		} else {
-			kfree(event);
-		}
+	switch(dev->link_mode) {
+	case IF_LINK_MODE_DORMANT:
+		if (operstate == IF_OPER_UP)
+			operstate = IF_OPER_DORMANT;
+		break;
 
-		/* We are about to handle this device,
-		 * so new events can be accepted
-		 */
-		clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state);
+	case IF_LINK_MODE_DEFAULT:
+	default:
+		break;
+	}
 
-		if (dev->flags & IFF_UP) {
-			if (netif_carrier_ok(dev)) {
-				WARN_ON(dev->qdisc_sleeping == &noop_qdisc);
-				dev_activate(dev);
-			} else
-				dev_deactivate(dev);
+	dev->operstate = operstate;
 
-			netdev_state_change(dev);
-		}
+	write_unlock_bh(&dev_base_lock);
+}
 
-		dev_put(dev);
-	}
-}       
 
+void linkwatch_init_dev(struct net_device *dev)
+{
+	/* Handle pre-registration link state changes */
+	if (!netif_carrier_ok(dev) || netif_dormant(dev))
+		rfc2863_policy(dev);
+}
 
-static void linkwatch_event(void *dummy)
+
+static bool linkwatch_urgent_event(struct net_device *dev)
 {
-	/* Limit the number of linkwatch events to one
-	 * per second so that a runaway driver does not
-	 * cause a storm of messages on the netlink
-	 * socket
-	 */	
-	linkwatch_nextevent = jiffies + HZ;
-	clear_bit(LW_RUNNING, &linkwatch_flags);
-
-	rtnl_shlock();
-	linkwatch_run_queue();
-	rtnl_shunlock();
+	if (!netif_running(dev))
+		return false;
+
+	if (dev->ifindex != dev->iflink)
+		return true;
+
+	if (dev->priv_flags & IFF_TEAM_PORT)
+		return true;
+
+	return netif_carrier_ok(dev) &&	qdisc_tx_changing(dev);
 }
 
 
-void linkwatch_fire_event(struct net_device *dev)
+static void linkwatch_add_event(struct net_device *dev)
 {
-	if (!test_and_set_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) {
-		unsigned long flags;
-		struct lw_event *event;
-
-		if (test_and_set_bit(LW_SE_USED, &linkwatch_flags)) {
-			event = kmalloc(sizeof(struct lw_event), GFP_ATOMIC);
-
-			if (unlikely(event == NULL)) {
-				clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state);
-				return;
-			}
-		} else {
-			event = &singleevent;
-		}
+	unsigned long flags;
 
+	spin_lock_irqsave(&lweventlist_lock, flags);
+	if (list_empty(&dev->link_watch_list)) {
+		list_add_tail(&dev->link_watch_list, &lweventlist);
 		dev_hold(dev);
-		event->dev = dev;
+	}
+	spin_unlock_irqrestore(&lweventlist_lock, flags);
+}
+
+
+static void linkwatch_schedule_work(int urgent)
+{
+	unsigned long delay = linkwatch_nextevent - jiffies;
+
+	if (test_bit(LW_URGENT, &linkwatch_flags))
+		return;
+
+	/* Minimise down-time: drop delay for up event. */
+	if (urgent) {
+		if (test_and_set_bit(LW_URGENT, &linkwatch_flags))
+			return;
+		delay = 0;
+	}
+
+	/* If we wrap around we'll delay it by at most HZ. */
+	if (delay > HZ)
+		delay = 0;
+
+	/*
+	 * If urgent, schedule immediate execution; otherwise, don't
+	 * override the existing timer.
+	 */
+	if (test_bit(LW_URGENT, &linkwatch_flags))
+		mod_delayed_work(system_wq, &linkwatch_work, 0);
+	else
+		schedule_delayed_work(&linkwatch_work, delay);
+}
+
 
-		spin_lock_irqsave(&lweventlist_lock, flags);
-		list_add_tail(&event->list, &lweventlist);
-		spin_unlock_irqrestore(&lweventlist_lock, flags);
+static void linkwatch_do_dev(struct net_device *dev)
+{
+	/*
+	 * Make sure the above read is complete since it can be
+	 * rewritten as soon as we clear the bit below.
+	 */
+	smp_mb__before_atomic();
+
+	/* We are about to handle this device,
+	 * so new events can be accepted
+	 */
+	clear_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state);
+
+	rfc2863_policy(dev);
+	if (dev->flags & IFF_UP) {
+		if (netif_carrier_ok(dev))
+			dev_activate(dev);
+		else
+			dev_deactivate(dev);
+
+		netdev_state_change(dev);
+	}
+	dev_put(dev);
+}
+
+static void __linkwatch_run_queue(int urgent_only)
+{
+	struct net_device *dev;
+	LIST_HEAD(wrk);
 
-		if (!test_and_set_bit(LW_RUNNING, &linkwatch_flags)) {
-			unsigned long thisevent = jiffies;
+	/*
+	 * Limit the number of linkwatch events to one
+	 * per second so that a runaway driver does not
+	 * cause a storm of messages on the netlink
+	 * socket.  This limit does not apply to up events
+	 * while the device qdisc is down.
+	 */
+	if (!urgent_only)
+		linkwatch_nextevent = jiffies + HZ;
+	/* Limit wrap-around effect on delay. */
+	else if (time_after(linkwatch_nextevent, jiffies + HZ))
+		linkwatch_nextevent = jiffies;
 
-			if (thisevent >= linkwatch_nextevent) {
-				schedule_work(&linkwatch_work);
-			} else {
-				schedule_delayed_work(&linkwatch_work, linkwatch_nextevent - thisevent);
-			}
+	clear_bit(LW_URGENT, &linkwatch_flags);
+
+	spin_lock_irq(&lweventlist_lock);
+	list_splice_init(&lweventlist, &wrk);
+
+	while (!list_empty(&wrk)) {
+
+		dev = list_first_entry(&wrk, struct net_device, link_watch_list);
+		list_del_init(&dev->link_watch_list);
+
+		if (urgent_only && !linkwatch_urgent_event(dev)) {
+			list_add_tail(&dev->link_watch_list, &lweventlist);
+			continue;
 		}
+		spin_unlock_irq(&lweventlist_lock);
+		linkwatch_do_dev(dev);
+		spin_lock_irq(&lweventlist_lock);
 	}
+
+	if (!list_empty(&lweventlist))
+		linkwatch_schedule_work(0);
+	spin_unlock_irq(&lweventlist_lock);
 }
 
+void linkwatch_forget_dev(struct net_device *dev)
+{
+	unsigned long flags;
+	int clean = 0;
+
+	spin_lock_irqsave(&lweventlist_lock, flags);
+	if (!list_empty(&dev->link_watch_list)) {
+		list_del_init(&dev->link_watch_list);
+		clean = 1;
+	}
+	spin_unlock_irqrestore(&lweventlist_lock, flags);
+	if (clean)
+		linkwatch_do_dev(dev);
+}
+
+
+/* Must be called with the rtnl semaphore held */
+void linkwatch_run_queue(void)
+{
+	__linkwatch_run_queue(0);
+}
+
+
+static void linkwatch_event(struct work_struct *dummy)
+{
+	rtnl_lock();
+	__linkwatch_run_queue(time_after(linkwatch_nextevent, jiffies));
+	rtnl_unlock();
+}
+
+
+void linkwatch_fire_event(struct net_device *dev)
+{
+	bool urgent = linkwatch_urgent_event(dev);
+
+	if (!test_and_set_bit(__LINK_STATE_LINKWATCH_PENDING, &dev->state)) {
+		linkwatch_add_event(dev);
+	} else if (!urgent)
+		return;
+
+	linkwatch_schedule_work(urgent);
+}
 EXPORT_SYMBOL(linkwatch_fire_event);