[NET]: Add netdev argument to dst ifdown.

This patch adds a net_device argument to ifdown.  After all,
it's a bit silly to notify someone of an ifdown event without
telling them what which device it was for :)
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dst.h

@@ -89,7 +89,8 @@ struct dst_ops
 	int			(*gc)(void);
 	struct dst_entry *	(*check)(struct dst_entry *, __u32 cookie);
 	void			(*destroy)(struct dst_entry *);
-	void			(*ifdown)(struct dst_entry *, int how);
+	void			(*ifdown)(struct dst_entry *,
+					  struct net_device *dev, int how);
 	struct dst_entry *	(*negative_advice)(struct dst_entry *);
 	void			(*link_failure)(struct sk_buff *);
 	void			(*update_pmtu)(struct dst_entry *dst, u32 mtu);

net/core/dst.c

@@ -220,12 +220,14 @@ struct dst_entry *dst_destroy(struct dst_entry * dst)
  *
  * Commented and originally written by Alexey.
  */
-static inline void dst_ifdown(struct dst_entry *dst, int unregister)
+static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			      int unregister)
 {
-	struct net_device *dev = dst->dev;
-
 	if (dst->ops->ifdown)
-		dst->ops->ifdown(dst, unregister);
+		dst->ops->ifdown(dst, dev, unregister);
+
+	if (dev != dst->dev)
+		return;
 
 	if (!unregister) {
 		dst->input = dst_discard_in;
@@ -252,8 +254,7 @@ static int dst_dev_event(struct notifier_block *this, unsigned long event, void
 	case NETDEV_DOWN:
 		spin_lock_bh(&dst_lock);
 		for (dst = dst_garbage_list; dst; dst = dst->next) {
-			if (dst->dev == dev)
-				dst_ifdown(dst, event != NETDEV_DOWN);
+			dst_ifdown(dst, dev, event != NETDEV_DOWN);
 		}
 		spin_unlock_bh(&dst_lock);
 		break;

net/ipv4/route.c

@@ -138,7 +138,8 @@ static struct timer_list rt_secret_timer;
 
 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
 static void		 ipv4_dst_destroy(struct dst_entry *dst);
-static void		 ipv4_dst_ifdown(struct dst_entry *dst, int how);
+static void		 ipv4_dst_ifdown(struct dst_entry *dst,
+					 struct net_device *dev, int how);
 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);
@@ -1342,11 +1343,12 @@ static void ipv4_dst_destroy(struct dst_entry *dst)
 	}
 }
 
-static void ipv4_dst_ifdown(struct dst_entry *dst, int how)
+static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			    int how)
 {
 	struct rtable *rt = (struct rtable *) dst;
 	struct in_device *idev = rt->idev;
-	if (idev && idev->dev != &loopback_dev) {
+	if (dev != &loopback_dev && idev && idev->dev == dev) {
 		struct in_device *loopback_idev = in_dev_get(&loopback_dev);
 		if (loopback_idev) {
 			rt->idev = loopback_idev;

net/ipv6/route.c

@@ -84,7 +84,8 @@ static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);
 static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
 static struct dst_entry *ip6_negative_advice(struct dst_entry *);
 static void		ip6_dst_destroy(struct dst_entry *);
-static void		ip6_dst_ifdown(struct dst_entry *, int how);
+static void		ip6_dst_ifdown(struct dst_entry *,
+				       struct net_device *dev, int how);
 static int		 ip6_dst_gc(void);
 
 static int		ip6_pkt_discard(struct sk_buff *skb);
@@ -153,12 +154,13 @@ static void ip6_dst_destroy(struct dst_entry *dst)
 	}	
 }
 
-static void ip6_dst_ifdown(struct dst_entry *dst, int how)
+static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			   int how)
 {
 	struct rt6_info *rt = (struct rt6_info *)dst;
 	struct inet6_dev *idev = rt->rt6i_idev;
 
-	if (idev != NULL && idev->dev != &loopback_dev) {
+	if (dev != &loopback_dev && idev != NULL && idev->dev == dev) {
 		struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
 		if (loopback_idev != NULL) {
 			rt->rt6i_idev = loopback_idev;

net/xfrm/xfrm_policy.c

@@ -1043,10 +1043,9 @@ static void xfrm_dst_destroy(struct dst_entry *dst)
 	dst->xfrm = NULL;
 }
 
-static void xfrm_dst_ifdown(struct dst_entry *dst, int unregister)
+static void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			    int unregister)
 {
-	struct net_device *dev = dst->dev;
-
 	if (!unregister)
 		return;