[NETNS][DST] dst: pass the dst_ops as parameter to the gc functions

The garbage collection function receive the dst_ops structure as
parameter. This is useful for the next incoming patchset because it
will need the dst_ops (there will be several instances) and the
network namespace pointer (contained in the dst_ops).

The protocols which do not take care of the namespaces will not be
impacted by this change (expect for the function signature), they do
just ignore the parameter.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -154,7 +154,7 @@ static void		 ipv4_dst_ifdown(struct dst_entry *dst,
 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
 static void		 ipv4_link_failure(struct sk_buff *skb);
 static void		 ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
-static int rt_garbage_collect(void);
+static int rt_garbage_collect(struct dst_ops *ops);
 
 
 static struct dst_ops ipv4_dst_ops = {
@@ -820,7 +820,7 @@ static void rt_secret_rebuild(unsigned long dummy)
    and when load increases it reduces to limit cache size.
  */
 
-static int rt_garbage_collect(void)
+static int rt_garbage_collect(struct dst_ops *ops)
 {
 	static unsigned long expire = RT_GC_TIMEOUT;
 	static unsigned long last_gc;
@@ -1035,7 +1035,7 @@ restart:
 				int saved_int = ip_rt_gc_min_interval;
 				ip_rt_gc_elasticity	= 1;
 				ip_rt_gc_min_interval	= 0;
-				rt_garbage_collect();
+				rt_garbage_collect(&ipv4_dst_ops);
 				ip_rt_gc_min_interval	= saved_int;
 				ip_rt_gc_elasticity	= saved_elasticity;
 				goto restart;