net: remove dst gc related code
This patch removes all dst gc related code and all the dst free functions Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Wang
David S. Miller
parent
560fd93bca
commit
5b7c9a8ff8
@ -425,28 +425,9 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
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void dst_init(struct dst_entry *dst, struct dst_ops *ops,
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struct net_device *dev, int initial_ref, int initial_obsolete,
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unsigned short flags);
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void __dst_free(struct dst_entry *dst);
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struct dst_entry *dst_destroy(struct dst_entry *dst);
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void dst_dev_put(struct dst_entry *dst);
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static inline void dst_free(struct dst_entry *dst)
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{
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if (dst->obsolete > 0)
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return;
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if (!atomic_read(&dst->__refcnt)) {
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dst = dst_destroy(dst);
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if (!dst)
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return;
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}
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__dst_free(dst);
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}
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static inline void dst_rcu_free(struct rcu_head *head)
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{
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struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
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dst_free(dst);
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}
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static inline void dst_confirm(struct dst_entry *dst)
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{
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}
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@ -508,8 +489,6 @@ static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
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return dst;
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}
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void dst_subsys_init(void);
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/* Flags for xfrm_lookup flags argument. */
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enum {
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XFRM_LOOKUP_ICMP = 1 << 0,
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@ -8681,7 +8681,6 @@ static int __init net_dev_init(void)
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rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
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NULL, dev_cpu_dead);
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WARN_ON(rc < 0);
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dst_subsys_init();
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rc = 0;
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out:
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return rc;
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213
net/core/dst.c
213
net/core/dst.c
@ -42,108 +42,6 @@
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* to dirty as few cache lines as possible in __dst_free().
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* As this is not a very strong hint, we dont force an alignment on SMP.
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*/
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static struct {
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spinlock_t lock;
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struct dst_entry *list;
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unsigned long timer_inc;
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unsigned long timer_expires;
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} dst_garbage = {
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.lock = __SPIN_LOCK_UNLOCKED(dst_garbage.lock),
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.timer_inc = DST_GC_MAX,
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};
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static void dst_gc_task(struct work_struct *work);
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static void ___dst_free(struct dst_entry *dst);
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static DECLARE_DELAYED_WORK(dst_gc_work, dst_gc_task);
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static DEFINE_MUTEX(dst_gc_mutex);
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/*
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* long lived entries are maintained in this list, guarded by dst_gc_mutex
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*/
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static struct dst_entry *dst_busy_list;
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static void dst_gc_task(struct work_struct *work)
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{
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int delayed = 0;
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int work_performed = 0;
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unsigned long expires = ~0L;
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struct dst_entry *dst, *next, head;
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struct dst_entry *last = &head;
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mutex_lock(&dst_gc_mutex);
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next = dst_busy_list;
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loop:
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while ((dst = next) != NULL) {
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next = dst->next;
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prefetch(&next->next);
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cond_resched();
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if (likely(atomic_read(&dst->__refcnt))) {
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last->next = dst;
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last = dst;
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delayed++;
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continue;
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}
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work_performed++;
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dst = dst_destroy(dst);
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if (dst) {
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/* NOHASH and still referenced. Unless it is already
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* on gc list, invalidate it and add to gc list.
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*
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* Note: this is temporary. Actually, NOHASH dst's
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* must be obsoleted when parent is obsoleted.
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* But we do not have state "obsoleted, but
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* referenced by parent", so it is right.
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*/
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if (dst->obsolete > 0)
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continue;
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___dst_free(dst);
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dst->next = next;
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next = dst;
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}
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}
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spin_lock_bh(&dst_garbage.lock);
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next = dst_garbage.list;
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if (next) {
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dst_garbage.list = NULL;
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spin_unlock_bh(&dst_garbage.lock);
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goto loop;
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}
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last->next = NULL;
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dst_busy_list = head.next;
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if (!dst_busy_list)
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dst_garbage.timer_inc = DST_GC_MAX;
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else {
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/*
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* if we freed less than 1/10 of delayed entries,
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* we can sleep longer.
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*/
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if (work_performed <= delayed/10) {
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dst_garbage.timer_expires += dst_garbage.timer_inc;
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if (dst_garbage.timer_expires > DST_GC_MAX)
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dst_garbage.timer_expires = DST_GC_MAX;
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dst_garbage.timer_inc += DST_GC_INC;
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} else {
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dst_garbage.timer_inc = DST_GC_INC;
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dst_garbage.timer_expires = DST_GC_MIN;
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}
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expires = dst_garbage.timer_expires;
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/*
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* if the next desired timer is more than 4 seconds in the
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* future then round the timer to whole seconds
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*/
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if (expires > 4*HZ)
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expires = round_jiffies_relative(expires);
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schedule_delayed_work(&dst_gc_work, expires);
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}
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spin_unlock_bh(&dst_garbage.lock);
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mutex_unlock(&dst_gc_mutex);
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}
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int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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kfree_skb(skb);
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@ -216,34 +114,6 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
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}
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EXPORT_SYMBOL(dst_alloc);
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static void ___dst_free(struct dst_entry *dst)
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{
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/* The first case (dev==NULL) is required, when
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protocol module is unloaded.
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*/
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if (dst->dev == NULL || !(dst->dev->flags&IFF_UP)) {
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dst->input = dst_discard;
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dst->output = dst_discard_out;
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}
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dst->obsolete = DST_OBSOLETE_DEAD;
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}
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void __dst_free(struct dst_entry *dst)
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{
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spin_lock_bh(&dst_garbage.lock);
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___dst_free(dst);
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dst->next = dst_garbage.list;
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dst_garbage.list = dst;
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if (dst_garbage.timer_inc > DST_GC_INC) {
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dst_garbage.timer_inc = DST_GC_INC;
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dst_garbage.timer_expires = DST_GC_MIN;
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mod_delayed_work(system_wq, &dst_gc_work,
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dst_garbage.timer_expires);
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}
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spin_unlock_bh(&dst_garbage.lock);
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}
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EXPORT_SYMBOL(__dst_free);
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struct dst_entry *dst_destroy(struct dst_entry * dst)
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{
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struct dst_entry *child;
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@ -448,86 +318,3 @@ struct metadata_dst __percpu *metadata_dst_alloc_percpu(u8 optslen, gfp_t flags)
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return md_dst;
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}
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EXPORT_SYMBOL_GPL(metadata_dst_alloc_percpu);
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/* Dirty hack. We did it in 2.2 (in __dst_free),
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* we have _very_ good reasons not to repeat
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* this mistake in 2.3, but we have no choice
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* now. _It_ _is_ _explicit_ _deliberate_
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* _race_ _condition_.
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*
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* Commented and originally written by Alexey.
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*/
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static void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
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int unregister)
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{
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if (dst->ops->ifdown)
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dst->ops->ifdown(dst, dev, unregister);
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if (dev != dst->dev)
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return;
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if (!unregister) {
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dst->input = dst_discard;
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dst->output = dst_discard_out;
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} else {
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dst->dev = dev_net(dst->dev)->loopback_dev;
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dev_hold(dst->dev);
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dev_put(dev);
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}
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}
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static int dst_dev_event(struct notifier_block *this, unsigned long event,
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void *ptr)
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{
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struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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struct dst_entry *dst, *last = NULL;
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switch (event) {
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case NETDEV_UNREGISTER_FINAL:
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case NETDEV_DOWN:
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mutex_lock(&dst_gc_mutex);
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for (dst = dst_busy_list; dst; dst = dst->next) {
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last = dst;
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dst_ifdown(dst, dev, event != NETDEV_DOWN);
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}
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spin_lock_bh(&dst_garbage.lock);
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dst = dst_garbage.list;
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dst_garbage.list = NULL;
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/* The code in dst_ifdown places a hold on the loopback device.
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* If the gc entry processing is set to expire after a lengthy
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* interval, this hold can cause netdev_wait_allrefs() to hang
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* out and wait for a long time -- until the the loopback
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* interface is released. If we're really unlucky, it'll emit
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* pr_emerg messages to console too. Reset the interval here,
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* so dst cleanups occur in a more timely fashion.
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*/
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if (dst_garbage.timer_inc > DST_GC_INC) {
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dst_garbage.timer_inc = DST_GC_INC;
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dst_garbage.timer_expires = DST_GC_MIN;
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mod_delayed_work(system_wq, &dst_gc_work,
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dst_garbage.timer_expires);
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}
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spin_unlock_bh(&dst_garbage.lock);
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if (last)
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last->next = dst;
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else
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dst_busy_list = dst;
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for (; dst; dst = dst->next)
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dst_ifdown(dst, dev, event != NETDEV_DOWN);
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mutex_unlock(&dst_gc_mutex);
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break;
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}
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return NOTIFY_DONE;
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}
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static struct notifier_block dst_dev_notifier = {
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.notifier_call = dst_dev_event,
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.priority = -10, /* must be called after other network notifiers */
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};
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void __init dst_subsys_init(void)
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{
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register_netdevice_notifier(&dst_dev_notifier);
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}
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