Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / net / core / dst.c

diff --git a/net/core/dst.c b/net/core/dst.c
index 571ef1f..470c05b 100644 (file)
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -32,19 +32,19 @@ static struct dst_entry     *dst_garbage_list;
 #if RT_CACHE_DEBUG >= 2 
 static atomic_t                         dst_total = ATOMIC_INIT(0);
 #endif
-static spinlock_t               dst_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(dst_lock);
 
 static unsigned long dst_gc_timer_expires;
 static unsigned long dst_gc_timer_inc = DST_GC_MAX;
 static void dst_run_gc(unsigned long);
 static void ___dst_free(struct dst_entry * dst);
 
-static struct timer_list dst_gc_timer =
-       TIMER_INITIALIZER(dst_run_gc, DST_GC_MIN, 0);
+static DEFINE_TIMER(dst_gc_timer, dst_run_gc, DST_GC_MIN, 0);
 
 static void dst_run_gc(unsigned long dummy)
 {
        int    delayed = 0;
+       int    work_performed;
        struct dst_entry * dst, **dstp;
 
        if (!spin_trylock(&dst_lock)) {
@@ -52,9 +52,9 @@ static void dst_run_gc(unsigned long dummy)
                return;
        }
 
-
        del_timer(&dst_gc_timer);
        dstp = &dst_garbage_list;
+       work_performed = 0;
        while ((dst = *dstp) != NULL) {
                if (atomic_read(&dst->__refcnt)) {
                        dstp = &dst->next;
@@ -62,6 +62,7 @@ static void dst_run_gc(unsigned long dummy)
                        continue;
                }
                *dstp = dst->next;
+               work_performed = 1;
 
                dst = dst_destroy(dst);
                if (dst) {
@@ -86,9 +87,14 @@ static void dst_run_gc(unsigned long dummy)
                dst_gc_timer_inc = DST_GC_MAX;
                goto out;
        }
-       if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX)
-               dst_gc_timer_expires = DST_GC_MAX;
-       dst_gc_timer_inc += DST_GC_INC;
+       if (!work_performed) {
+               if ((dst_gc_timer_expires += dst_gc_timer_inc) > DST_GC_MAX)
+                       dst_gc_timer_expires = DST_GC_MAX;
+               dst_gc_timer_inc += DST_GC_INC;
+       } else {
+               dst_gc_timer_inc = DST_GC_INC;
+               dst_gc_timer_expires = DST_GC_MIN;
+       }
        dst_gc_timer.expires = jiffies + dst_gc_timer_expires;
 #if RT_CACHE_DEBUG >= 2
        printk("dst_total: %d/%d %ld\n",
@@ -106,9 +112,9 @@ static int dst_discard_in(struct sk_buff *skb)
        return 0;
 }
 
-static int dst_discard_out(struct sk_buff **pskb)
+static int dst_discard_out(struct sk_buff *skb)
 {
-       kfree_skb(*pskb);
+       kfree_skb(skb);
        return 0;
 }
 
@@ -169,6 +175,8 @@ struct dst_entry *dst_destroy(struct dst_entry * dst)
        struct neighbour *neigh;
        struct hh_cache *hh;
 
+       smp_rmb();
+
 again:
        neigh = dst->neighbour;
        hh = dst->hh;
@@ -196,13 +204,15 @@ again:
 
        dst = child;
        if (dst) {
+               int nohash = dst->flags & DST_NOHASH;
+
                if (atomic_dec_and_test(&dst->__refcnt)) {
                        /* We were real parent of this dst, so kill child. */
-                       if (dst->flags&DST_NOHASH)
+                       if (nohash)
                                goto again;
                } else {
                        /* Child is still referenced, return it for freeing. */
-                       if (dst->flags&DST_NOHASH)
+                       if (nohash)
                                return dst;
                        /* Child is still in his hash table */
                }
@@ -210,6 +220,38 @@ again:
        return NULL;
 }
 
+/* Dirty hack. We did it in 2.2 (in __dst_free),
+ * we have _very_ good reasons not to repeat
+ * this mistake in 2.3, but we have no choice
+ * now. _It_ _is_ _explicit_ _deliberate_
+ * _race_ _condition_.
+ *
+ * Commented and originally written by Alexey.
+ */
+static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+                             int unregister)
+{
+       if (dst->ops->ifdown)
+               dst->ops->ifdown(dst, dev, unregister);
+
+       if (dev != dst->dev)
+               return;
+
+       if (!unregister) {
+               dst->input = dst_discard_in;
+               dst->output = dst_discard_out;
+       } else {
+               dst->dev = &loopback_dev;
+               dev_hold(&loopback_dev);
+               dev_put(dev);
+               if (dst->neighbour && dst->neighbour->dev == dev) {
+                       dst->neighbour->dev = &loopback_dev;
+                       dev_put(dev);
+                       dev_hold(&loopback_dev);
+               }
+       }
+}
+
 static int dst_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
 {
        struct net_device *dev = ptr;
@@ -220,31 +262,7 @@ static int dst_dev_event(struct notifier_block *this, unsigned long event, void
        case NETDEV_DOWN:
                spin_lock_bh(&dst_lock);
                for (dst = dst_garbage_list; dst; dst = dst->next) {
-                       if (dst->dev == dev) {
-                               /* Dirty hack. We did it in 2.2 (in __dst_free),
-                                  we have _very_ good reasons not to repeat
-                                  this mistake in 2.3, but we have no choice
-                                  now. _It_ _is_ _explicit_ _deliberate_
-                                  _race_ _condition_.
-                                */
-                               if (event!=NETDEV_DOWN &&
-                                   dst->output == dst_discard_out) {
-                                       dst->dev = &loopback_dev;
-                                       dev_hold(&loopback_dev);
-                                       dev_put(dev);
-                                       dst->output = dst_discard_out;
-                                       if (dst->neighbour && dst->neighbour->dev == dev) {
-                                               dst->neighbour->dev = &loopback_dev;
-                                               dev_put(dev);
-                                               dev_hold(&loopback_dev);
-                                       }
-                               } else {
-                                       dst->input = dst_discard_in;
-                                       dst->output = dst_discard_out;
-                               }
-                               if (dst->ops->ifdown)
-                                       dst->ops->ifdown(dst, event != NETDEV_DOWN);
-                       }
+                       dst_ifdown(dst, dev, event != NETDEV_DOWN);
                }
                spin_unlock_bh(&dst_lock);
                break;
@@ -252,7 +270,7 @@ static int dst_dev_event(struct notifier_block *this, unsigned long event, void
        return NOTIFY_DONE;
 }
 
-struct notifier_block dst_dev_notifier = {
+static struct notifier_block dst_dev_notifier = {
        .notifier_call  = dst_dev_event,
 };