[NET]: Move dst_release out of dst->ops->check

As promised here is the patch that moves dst_release out of
dst->ops->check.  It bloats sk_dst_check/__sk_dst_check slightly
but they're only used in a handful of places so it isn't too bad.
I actually counted, it's about a few hundred bytes.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dst.h

@@ -270,10 +270,8 @@ static inline int dst_input(struct sk_buff *skb)
 
 static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
 {
-	dst_hold(dst);
 	if (dst->obsolete)
 		dst = dst->ops->check(dst, cookie);
-	dst_release(dst);
 	return dst;
 }
 

include/net/sock.h

@@ -983,6 +983,7 @@ __sk_dst_check(struct sock *sk, u32 cookie)
 
 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
 		sk->sk_dst_cache = NULL;
+		dst_release(dst);
 		return NULL;
 	}
 
@@ -996,6 +997,7 @@ sk_dst_check(struct sock *sk, u32 cookie)
 
 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
 		sk_dst_reset(sk);
+		dst_release(dst);
 		return NULL;
 	}
 

net/decnet/dn_route.c

@@ -253,7 +253,6 @@ static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu)
  */
 static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie)
 {
-	dst_release(dst);
 	return NULL;
 }
 

net/ipv4/ipvs/ip_vs_xmit.c

@@ -52,6 +52,7 @@ __ip_vs_dst_check(struct ip_vs_dest *dest, u32 rtos, u32 cookie)
 	if ((dst->obsolete || rtos != dest->dst_rtos) &&
 	    dst->ops->check(dst, cookie) == NULL) {
 		dest->dst_cache = NULL;
+		dst_release(dst);
 		return NULL;
 	}
 	dst_hold(dst);

net/ipv4/route.c

@@ -1326,7 +1326,6 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
 
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
 {
-	dst_release(dst);
 	return NULL;
 }
 

net/ipv6/ip6_tunnel.c

@@ -94,6 +94,7 @@ static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
 	if (dst && dst->obsolete && 
 	    dst->ops->check(dst, t->dst_cookie) == NULL) {
 		t->dst_cache = NULL;
+		dst_release(dst);
 		return NULL;
 	}
 

net/ipv6/route.c

@@ -589,7 +589,6 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
 	if (rt && rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie))
 		return dst;
 
-	dst_release(dst);
 	return NULL;
 }
 

net/xfrm/xfrm_policy.c

@@ -1015,7 +1015,6 @@ static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie)
 	if (!stale_bundle(dst))
 		return dst;
 
-	dst_release(dst);
 	return NULL;
 }