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Diffstat (limited to 'net/core/dst.c')
-rw-r--r--net/core/dst.c174
1 files changed, 108 insertions, 66 deletions
diff --git a/net/core/dst.c b/net/core/dst.c
index b99c7c7ffce..a028409ee43 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -19,6 +19,7 @@
#include <linux/types.h>
#include <net/net_namespace.h>
#include <linux/sched.h>
+#include <linux/prefetch.h>
#include <net/dst.h>
@@ -33,9 +34,6 @@
* 3) This list is guarded by a mutex,
* so that the gc_task and dst_dev_event() can be synchronized.
*/
-#if RT_CACHE_DEBUG >= 2
-static atomic_t dst_total = ATOMIC_INIT(0);
-#endif
/*
* We want to keep lock & list close together
@@ -69,10 +67,6 @@ static void dst_gc_task(struct work_struct *work)
unsigned long expires = ~0L;
struct dst_entry *dst, *next, head;
struct dst_entry *last = &head;
-#if RT_CACHE_DEBUG >= 2
- ktime_t time_start = ktime_get();
- struct timespec elapsed;
-#endif
mutex_lock(&dst_gc_mutex);
next = dst_busy_list;
@@ -100,7 +94,7 @@ loop:
* But we do not have state "obsoleted, but
* referenced by parent", so it is right.
*/
- if (dst->obsolete > 1)
+ if (dst->obsolete > 0)
continue;
___dst_free(dst);
@@ -146,25 +140,27 @@ loop:
spin_unlock_bh(&dst_garbage.lock);
mutex_unlock(&dst_gc_mutex);
-#if RT_CACHE_DEBUG >= 2
- elapsed = ktime_to_timespec(ktime_sub(ktime_get(), time_start));
- printk(KERN_DEBUG "dst_total: %d delayed: %d work_perf: %d"
- " expires: %lu elapsed: %lu us\n",
- atomic_read(&dst_total), delayed, work_performed,
- expires,
- elapsed.tv_sec * USEC_PER_SEC +
- elapsed.tv_nsec / NSEC_PER_USEC);
-#endif
}
-int dst_discard(struct sk_buff *skb)
+int dst_discard_sk(struct sock *sk, struct sk_buff *skb)
{
kfree_skb(skb);
return 0;
}
-EXPORT_SYMBOL(dst_discard);
+EXPORT_SYMBOL(dst_discard_sk);
-void *dst_alloc(struct dst_ops *ops)
+const u32 dst_default_metrics[RTAX_MAX + 1] = {
+ /* This initializer is needed to force linker to place this variable
+ * into const section. Otherwise it might end into bss section.
+ * We really want to avoid false sharing on this variable, and catch
+ * any writes on it.
+ */
+ [RTAX_MAX] = 0xdeadbeef,
+};
+
+
+void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
+ int initial_ref, int initial_obsolete, unsigned short flags)
{
struct dst_entry *dst;
@@ -172,18 +168,38 @@ void *dst_alloc(struct dst_ops *ops)
if (ops->gc(ops))
return NULL;
}
- dst = kmem_cache_zalloc(ops->kmem_cachep, GFP_ATOMIC);
+ dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC);
if (!dst)
return NULL;
- atomic_set(&dst->__refcnt, 0);
+ dst->child = NULL;
+ dst->dev = dev;
+ if (dev)
+ dev_hold(dev);
dst->ops = ops;
- dst->lastuse = jiffies;
+ dst_init_metrics(dst, dst_default_metrics, true);
+ dst->expires = 0UL;
dst->path = dst;
- dst->input = dst->output = dst_discard;
-#if RT_CACHE_DEBUG >= 2
- atomic_inc(&dst_total);
+ dst->from = NULL;
+#ifdef CONFIG_XFRM
+ dst->xfrm = NULL;
+#endif
+ dst->input = dst_discard;
+ dst->output = dst_discard_sk;
+ dst->error = 0;
+ dst->obsolete = initial_obsolete;
+ dst->header_len = 0;
+ dst->trailer_len = 0;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ dst->tclassid = 0;
#endif
- dst_entries_add(ops, 1);
+ atomic_set(&dst->__refcnt, initial_ref);
+ dst->__use = 0;
+ dst->lastuse = jiffies;
+ dst->flags = flags;
+ dst->pending_confirm = 0;
+ dst->next = NULL;
+ if (!(flags & DST_NOCOUNT))
+ dst_entries_add(ops, 1);
return dst;
}
EXPORT_SYMBOL(dst_alloc);
@@ -193,9 +209,11 @@ static void ___dst_free(struct dst_entry *dst)
/* The first case (dev==NULL) is required, when
protocol module is unloaded.
*/
- if (dst->dev == NULL || !(dst->dev->flags&IFF_UP))
- dst->input = dst->output = dst_discard;
- dst->obsolete = 2;
+ if (dst->dev == NULL || !(dst->dev->flags&IFF_UP)) {
+ dst->input = dst_discard;
+ dst->output = dst_discard_sk;
+ }
+ dst->obsolete = DST_OBSOLETE_DEAD;
}
void __dst_free(struct dst_entry *dst)
@@ -207,8 +225,8 @@ void __dst_free(struct dst_entry *dst)
if (dst_garbage.timer_inc > DST_GC_INC) {
dst_garbage.timer_inc = DST_GC_INC;
dst_garbage.timer_expires = DST_GC_MIN;
- cancel_delayed_work(&dst_gc_work);
- schedule_delayed_work(&dst_gc_work, dst_garbage.timer_expires);
+ mod_delayed_work(system_wq, &dst_gc_work,
+ dst_garbage.timer_expires);
}
spin_unlock_bh(&dst_garbage.lock);
}
@@ -217,34 +235,19 @@ EXPORT_SYMBOL(__dst_free);
struct dst_entry *dst_destroy(struct dst_entry * dst)
{
struct dst_entry *child;
- struct neighbour *neigh;
- struct hh_cache *hh;
smp_rmb();
again:
- neigh = dst->neighbour;
- hh = dst->hh;
child = dst->child;
- dst->hh = NULL;
- if (hh)
- hh_cache_put(hh);
-
- if (neigh) {
- dst->neighbour = NULL;
- neigh_release(neigh);
- }
-
- dst_entries_add(dst->ops, -1);
+ if (!(dst->flags & DST_NOCOUNT))
+ dst_entries_add(dst->ops, -1);
if (dst->ops->destroy)
dst->ops->destroy(dst);
if (dst->dev)
dev_put(dst->dev);
-#if RT_CACHE_DEBUG >= 2
- atomic_dec(&dst_total);
-#endif
kmem_cache_free(dst->ops->kmem_cachep, dst);
dst = child;
@@ -266,6 +269,15 @@ again:
}
EXPORT_SYMBOL(dst_destroy);
+static void dst_destroy_rcu(struct rcu_head *head)
+{
+ struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
+
+ dst = dst_destroy(dst);
+ if (dst)
+ __dst_free(dst);
+}
+
void dst_release(struct dst_entry *dst)
{
if (dst) {
@@ -273,37 +285,71 @@ void dst_release(struct dst_entry *dst)
newrefcnt = atomic_dec_return(&dst->__refcnt);
WARN_ON(newrefcnt < 0);
- if (unlikely(dst->flags & DST_NOCACHE) && !newrefcnt) {
- dst = dst_destroy(dst);
- if (dst)
- __dst_free(dst);
- }
+ if (unlikely(dst->flags & DST_NOCACHE) && !newrefcnt)
+ call_rcu(&dst->rcu_head, dst_destroy_rcu);
}
}
EXPORT_SYMBOL(dst_release);
+u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old)
+{
+ u32 *p = kmalloc(sizeof(u32) * RTAX_MAX, GFP_ATOMIC);
+
+ if (p) {
+ u32 *old_p = __DST_METRICS_PTR(old);
+ unsigned long prev, new;
+
+ memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
+
+ new = (unsigned long) p;
+ prev = cmpxchg(&dst->_metrics, old, new);
+
+ if (prev != old) {
+ kfree(p);
+ p = __DST_METRICS_PTR(prev);
+ if (prev & DST_METRICS_READ_ONLY)
+ p = NULL;
+ }
+ }
+ return p;
+}
+EXPORT_SYMBOL(dst_cow_metrics_generic);
+
+/* Caller asserts that dst_metrics_read_only(dst) is false. */
+void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
+{
+ unsigned long prev, new;
+
+ new = ((unsigned long) dst_default_metrics) | DST_METRICS_READ_ONLY;
+ prev = cmpxchg(&dst->_metrics, old, new);
+ if (prev == old)
+ kfree(__DST_METRICS_PTR(old));
+}
+EXPORT_SYMBOL(__dst_destroy_metrics_generic);
+
/**
- * skb_dst_set_noref - sets skb dst, without a reference
+ * __skb_dst_set_noref - sets skb dst, without a reference
* @skb: buffer
* @dst: dst entry
+ * @force: if force is set, use noref version even for DST_NOCACHE entries
*
* Sets skb dst, assuming a reference was not taken on dst
* skb_dst_drop() should not dst_release() this dst
*/
-void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
+void __skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst, bool force)
{
WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
/* If dst not in cache, we must take a reference, because
* dst_release() will destroy dst as soon as its refcount becomes zero
*/
- if (unlikely(dst->flags & DST_NOCACHE)) {
+ if (unlikely((dst->flags & DST_NOCACHE) && !force)) {
dst_hold(dst);
skb_dst_set(skb, dst);
} else {
skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
}
}
-EXPORT_SYMBOL(skb_dst_set_noref);
+EXPORT_SYMBOL(__skb_dst_set_noref);
/* Dirty hack. We did it in 2.2 (in __dst_free),
* we have _very_ good reasons not to repeat
@@ -323,27 +369,23 @@ static void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
return;
if (!unregister) {
- dst->input = dst->output = dst_discard;
+ dst->input = dst_discard;
+ dst->output = dst_discard_sk;
} else {
dst->dev = dev_net(dst->dev)->loopback_dev;
dev_hold(dst->dev);
dev_put(dev);
- if (dst->neighbour && dst->neighbour->dev == dev) {
- dst->neighbour->dev = dst->dev;
- dev_hold(dst->dev);
- dev_put(dev);
- }
}
}
static int dst_dev_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
- struct net_device *dev = ptr;
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct dst_entry *dst, *last = NULL;
switch (event) {
- case NETDEV_UNREGISTER:
+ case NETDEV_UNREGISTER_FINAL:
case NETDEV_DOWN:
mutex_lock(&dst_gc_mutex);
for (dst = dst_busy_list; dst; dst = dst->next) {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-05 00:25:48 +0000