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Commit 6561a3b1 authored by David S. Miller's avatar David S. Miller
Browse files

ipv4: Flush per-ns routing cache more sanely. 



Flush the routing cache only of entries that match the
network namespace in which the purge event occurred.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
parent 782615ae

include/net/route.h

+1 −1
Original line number Diff line number Diff line
@@ -114,7 +114,7 @@ extern int ip_rt_init(void); 
extern void		ip_rt_redirect(__be32 old_gw, __be32 dst, __be32 new_gw,

				       __be32 src, struct net_device *dev);

extern void		rt_cache_flush(struct net *net, int how);

extern void		rt_cache_flush_batch(void);

extern void		rt_cache_flush_batch(struct net *net);

extern int		__ip_route_output_key(struct net *, struct rtable **, const struct flowi *flp);

extern int		ip_route_output_key(struct net *, struct rtable **, struct flowi *flp);

extern int		ip_route_output_flow(struct net *, struct rtable **rp, struct flowi *flp, struct sock *sk, int flags);

net/ipv4/fib_frontend.c

+5 −1
Original line number Diff line number Diff line
@@ -987,7 +987,11 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo 
		rt_cache_flush(dev_net(dev), 0);

		break;

	case NETDEV_UNREGISTER_BATCH:

		rt_cache_flush_batch();

		/* The batch unregister is only called on the first

		 * device in the list of devices being unregistered.

		 * Therefore we should not pass dev_net(dev) in here.

		 */

		rt_cache_flush_batch(NULL);

		break;

	}

	return NOTIFY_DONE;

net/ipv4/route.c

+24 −40
Original line number Diff line number Diff line
@@ -717,13 +717,15 @@ static inline int rt_is_expired(struct rtable *rth) 
 * Can be called by a softirq or a process.

 * In the later case, we want to be reschedule if necessary

 */

static void rt_do_flush(int process_context)

static void rt_do_flush(struct net *net, int process_context)

{

	unsigned int i;

	struct rtable *rth, *next;

	struct rtable * tail;



	for (i = 0; i <= rt_hash_mask; i++) {

		struct rtable __rcu **pprev;

		struct rtable *list;



		if (process_context && need_resched())

			cond_resched();

		rth = rcu_dereference_raw(rt_hash_table[i].chain);
@@ -731,50 +733,32 @@ static void rt_do_flush(int process_context) 
			continue;



		spin_lock_bh(rt_hash_lock_addr(i));

#ifdef CONFIG_NET_NS

		{

		struct rtable __rcu **prev;

		struct rtable *p;



		rth = rcu_dereference_protected(rt_hash_table[i].chain,

		list = NULL;

		pprev = &rt_hash_table[i].chain;

		rth = rcu_dereference_protected(*pprev,

			lockdep_is_held(rt_hash_lock_addr(i)));



		/* defer releasing the head of the list after spin_unlock */

		for (tail = rth; tail;

		     tail = rcu_dereference_protected(tail->dst.rt_next,

				lockdep_is_held(rt_hash_lock_addr(i))))

			if (!rt_is_expired(tail))

				break;

		if (rth != tail)

			rt_hash_table[i].chain = tail;



		/* call rt_free on entries after the tail requiring flush */

		prev = &rt_hash_table[i].chain;

		for (p = rcu_dereference_protected(*prev,

				lockdep_is_held(rt_hash_lock_addr(i)));

		     p != NULL;

		     p = next) {

			next = rcu_dereference_protected(p->dst.rt_next,

		while (rth) {

			next = rcu_dereference_protected(rth->dst.rt_next,

				lockdep_is_held(rt_hash_lock_addr(i)));

			if (!rt_is_expired(p)) {

				prev = &p->dst.rt_next;



			if (!net ||

			    net_eq(dev_net(rth->dst.dev), net)) {

				rcu_assign_pointer(*pprev, next);

				rcu_assign_pointer(rth->dst.rt_next, list);

				list = rth;

			} else {

				*prev = next;

				rt_free(p);

				pprev = &rth->dst.rt_next;

			}

			rth = next;

		}

		}

#else

		rth = rcu_dereference_protected(rt_hash_table[i].chain,

			lockdep_is_held(rt_hash_lock_addr(i)));

		rcu_assign_pointer(rt_hash_table[i].chain, NULL);

		tail = NULL;

#endif



		spin_unlock_bh(rt_hash_lock_addr(i));



		for (; rth != tail; rth = next) {

			next = rcu_dereference_protected(rth->dst.rt_next, 1);

			rt_free(rth);

		for (; list; list = next) {

			next = rcu_dereference_protected(list->dst.rt_next, 1);

			rt_free(list);

		}

	}

}
@@ -922,13 +906,13 @@ void rt_cache_flush(struct net *net, int delay) 
{

	rt_cache_invalidate(net);

	if (delay >= 0)

		rt_do_flush(!in_softirq());

		rt_do_flush(net, !in_softirq());

}



/* Flush previous cache invalidated entries from the cache */

void rt_cache_flush_batch(void)

void rt_cache_flush_batch(struct net *net)

{

	rt_do_flush(!in_softirq());

	rt_do_flush(net, !in_softirq());

}



static void rt_emergency_hash_rebuild(struct net *net)