Commit c757faa8 authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

ipv6: prepare fib6_age() for exception table 



If all dst cache entries are stored in the exception table under the
main route, we have to go through them during fib6_age() when doing
garbage collecting.
Introduce a new function rt6_age_exception() which goes through all dst
entries in the exception table and remove those entries that are expired.
This function is called in fib6_age() so that all dst caches are also
garbage collected.

Signed-off-by: default avatarWei Wang <weiwan@google.com>
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b16cb459

include/net/ip6_fib.h

+13 −0
Original line number Diff line number Diff line
@@ -29,6 +29,14 @@ 
#define FIB6_TABLE_HASHSZ 1

#endif



#define RT6_DEBUG 2



#if RT6_DEBUG >= 3

#define RT6_TRACE(x...) pr_debug(x)

#else

#define RT6_TRACE(x...) do { ; } while (0)

#endif



struct rt6_info;



struct fib6_config {
@@ -75,6 +83,11 @@ struct fib6_node { 
	struct rcu_head		rcu;

};



struct fib6_gc_args {

	int			timeout;

	int			more;

};



#ifndef CONFIG_IPV6_SUBTREES

#define FIB6_SUBTREE(fn)	NULL

#else

include/net/ip6_route.h

+2 −0
Original line number Diff line number Diff line
@@ -97,6 +97,8 @@ int ip6_del_rt(struct rt6_info *); 


void rt6_flush_exceptions(struct rt6_info *rt);

int rt6_remove_exception_rt(struct rt6_info *rt);

void rt6_age_exceptions(struct rt6_info *rt, struct fib6_gc_args *gc_args,

			unsigned long now);



static inline int ip6_route_get_saddr(struct net *net, struct rt6_info *rt,

				      const struct in6_addr *daddr,

net/ipv6/ip6_fib.c

+9 −17
Original line number Diff line number Diff line
@@ -38,14 +38,6 @@ 
#include <net/ip6_fib.h>

#include <net/ip6_route.h>



#define RT6_DEBUG 2



#if RT6_DEBUG >= 3

#define RT6_TRACE(x...) pr_debug(x)

#else

#define RT6_TRACE(x...) do { ; } while (0)

#endif



static struct kmem_cache *fib6_node_kmem __read_mostly;



struct fib6_cleaner {
@@ -1890,12 +1882,6 @@ static void fib6_flush_trees(struct net *net) 
 *	Garbage collection

 */



struct fib6_gc_args

{

	int			timeout;

	int			more;

};



static int fib6_age(struct rt6_info *rt, void *arg)

{

	struct fib6_gc_args *gc_args = arg;
@@ -1904,9 +1890,6 @@ static int fib6_age(struct rt6_info *rt, void *arg) 
	/*

	 *	check addrconf expiration here.

	 *	Routes are expired even if they are in use.

	 *

	 *	Also age clones. Note, that clones are aged out

	 *	only if they are not in use now.

	 */



	if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
@@ -1915,6 +1898,9 @@ static int fib6_age(struct rt6_info *rt, void *arg) 
			return -1;

		}

		gc_args->more++;

	/* The following part will soon be removed when the exception

	 * table is hooked up to store all cached routes.

	 */

	} else if (rt->rt6i_flags & RTF_CACHE) {

		if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout))

			rt->dst.obsolete = DST_OBSOLETE_KILL;
@@ -1940,6 +1926,12 @@ static int fib6_age(struct rt6_info *rt, void *arg) 
		gc_args->more++;

	}



	/*	Also age clones in the exception table.

	 *	Note, that clones are aged out

	 *	only if they are not in use now.

	 */

	rt6_age_exceptions(rt, gc_args, now);



	return 0;

}

net/ipv6/route.c

+60 −0
Original line number Diff line number Diff line
@@ -1528,6 +1528,66 @@ static void rt6_exceptions_clean_tohost(struct rt6_info *rt, 
	spin_unlock_bh(&rt6_exception_lock);

}



static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,

				      struct rt6_exception *rt6_ex,

				      struct fib6_gc_args *gc_args,

				      unsigned long now)

{

	struct rt6_info *rt = rt6_ex->rt6i;



	if (atomic_read(&rt->dst.__refcnt) == 1 &&

	    time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {

		RT6_TRACE("aging clone %p\n", rt);

		rt6_remove_exception(bucket, rt6_ex);

		return;

	} else if (rt->rt6i_flags & RTF_GATEWAY) {

		struct neighbour *neigh;

		__u8 neigh_flags = 0;



		neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);

		if (neigh) {

			neigh_flags = neigh->flags;

			neigh_release(neigh);

		}

		if (!(neigh_flags & NTF_ROUTER)) {

			RT6_TRACE("purging route %p via non-router but gateway\n",

				  rt);

			rt6_remove_exception(bucket, rt6_ex);

			return;

		}

	}

	gc_args->more++;

}



void rt6_age_exceptions(struct rt6_info *rt,

			struct fib6_gc_args *gc_args,

			unsigned long now)

{

	struct rt6_exception_bucket *bucket;

	struct rt6_exception *rt6_ex;

	struct hlist_node *tmp;

	int i;



	if (!rcu_access_pointer(rt->rt6i_exception_bucket))

		return;



	spin_lock_bh(&rt6_exception_lock);

	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,

				    lockdep_is_held(&rt6_exception_lock));



	if (bucket) {

		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {

			hlist_for_each_entry_safe(rt6_ex, tmp,

						  &bucket->chain, hlist) {

				rt6_age_examine_exception(bucket, rt6_ex,

							  gc_args, now);

			}

			bucket++;

		}

	}

	spin_unlock_bh(&rt6_exception_lock);

}



struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,

			       int oif, struct flowi6 *fl6, int flags)

{

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