1 files changed, 15 insertions, 35 deletions

diff --git a/net/core/link_watch.c b/net/core/link_watch.c
index e3c26a9ccad6..71a35da275d4 100644
--- a/net/core/link_watch.c
+++ b/net/core/link_watch.c
@@ -19,7 +19,6 @@
 #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>
@@ -28,7 +27,6 @@
 
 enum lw_bits {
         LW_RUNNING = 0,
-        LW_SE_USED
 };
 
 static unsigned long linkwatch_flags;
@@ -37,17 +35,9 @@ static unsigned long linkwatch_nextevent;
 static void linkwatch_event(struct work_struct *dummy);
 static DECLARE_DELAYED_WORK(linkwatch_work, linkwatch_event);
 
-static LIST_HEAD(lweventlist);
+static struct net_device *lweventlist;
 static DEFINE_SPINLOCK(lweventlist_lock);
 
-struct lw_event {
-        struct list_head list;
-        struct net_device *dev;
-};
-
-/* Avoid kmalloc() for most systems */
-static struct lw_event singleevent;
-
 static unsigned char default_operstate(const struct net_device *dev)
 {
         if (!netif_carrier_ok(dev))
@@ -90,21 +80,23 @@ static void rfc2863_policy(struct net_device *dev)
 /* Must be called with the rtnl semaphore held */
 void linkwatch_run_queue(void)
 {
-        struct list_head head, *n, *next;
+        struct net_device *next;
 
         spin_lock_irq(&lweventlist_lock);
-        list_replace_init(&lweventlist, &head);
+        next = lweventlist;
+        lweventlist = NULL;
         spin_unlock_irq(&lweventlist_lock);
 
-        list_for_each_safe(n, next, &head) {
-                struct lw_event *event = list_entry(n, struct lw_event, list);
-                struct net_device *dev = event->dev;
+        while (next) {
+                struct net_device *dev = next;
 
-                if (event == &singleevent) {
-                        clear_bit(LW_SE_USED, &linkwatch_flags);
-                } else {
-                        kfree(event);
-                }
+                next = dev->link_watch_next;
+
+                /*
+                 * Make sure the above read is complete since it can be
+                 * rewritten as soon as we clear the bit below.
+                 */
+                smp_mb__before_clear_bit();
 
                 /* We are about to handle this device,
                  * so new events can be accepted
@@ -147,24 +139,12 @@ void linkwatch_fire_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;
-                }
 
                 dev_hold(dev);
-                event->dev = dev;
 
                 spin_lock_irqsave(&lweventlist_lock, flags);
-                list_add_tail(&event->list, &lweventlist);
+                dev->link_watch_next = lweventlist;
+                lweventlist = dev;
                 spin_unlock_irqrestore(&lweventlist_lock, flags);
 
                 if (!test_and_set_bit(LW_RUNNING, &linkwatch_flags)) {