[IPV4]: fib_sync_down rework.

fib_sync_down can be called with an address and with a device. In
reality it is called either with address OR with a device. The
codepath inside is completely different, so lets separate it into two
calls for these two cases.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_fib.h

@@ -218,7 +218,8 @@ extern void fib_select_default(struct net *net, const struct flowi *flp,
 
 /* Exported by fib_semantics.c */
 extern int ip_fib_check_default(__be32 gw, struct net_device *dev);
-extern int fib_sync_down(__be32 local, struct net_device *dev, int force);
+extern int fib_sync_down_dev(struct net_device *dev, int force);
+extern int fib_sync_down_addr(__be32 local);
 extern int fib_sync_up(struct net_device *dev);
 extern __be32  __fib_res_prefsrc(struct fib_result *res);
 extern void fib_select_multipath(const struct flowi *flp, struct fib_result *res);

net/ipv4/fib_frontend.c

@@ -808,7 +808,7 @@ static void fib_del_ifaddr(struct in_ifaddr *ifa)
 			   First of all, we scan fib_info list searching
 			   for stray nexthop entries, then ignite fib_flush.
 			*/
-			if (fib_sync_down(ifa->ifa_local, NULL, 0))
+			if (fib_sync_down_addr(ifa->ifa_local))
 				fib_flush(dev->nd_net);
 		}
 	}
@@ -898,7 +898,7 @@ static void nl_fib_lookup_exit(struct net *net)
 
 static void fib_disable_ip(struct net_device *dev, int force)
 {
-	if (fib_sync_down(0, dev, force))
+	if (fib_sync_down_dev(dev, force))
 		fib_flush(dev->nd_net);
 	rt_cache_flush(0);
 	arp_ifdown(dev);

net/ipv4/fib_semantics.c

@@ -1031,36 +1031,39 @@ nla_put_failure:
      referring to it.
    - device went down -> we must shutdown all nexthops going via it.
  */
-
-int fib_sync_down(__be32 local, struct net_device *dev, int force)
+int fib_sync_down_addr(__be32 local)
 {
 	int ret = 0;
-	int scope = RT_SCOPE_NOWHERE;
-
-	if (force)
-		scope = -1;
-
-	if (local && fib_info_laddrhash) {
 	unsigned int hash = fib_laddr_hashfn(local);
 	struct hlist_head *head = &fib_info_laddrhash[hash];
 	struct hlist_node *node;
 	struct fib_info *fi;
 
+	if (fib_info_laddrhash == NULL || local == 0)
+		return 0;
+
 	hlist_for_each_entry(fi, node, head, fib_lhash) {
 		if (fi->fib_prefsrc == local) {
 			fi->fib_flags |= RTNH_F_DEAD;
 			ret++;
 		}
 	}
-	}
+	return ret;
+}
 
-	if (dev) {
+int fib_sync_down_dev(struct net_device *dev, int force)
+{
+	int ret = 0;
+	int scope = RT_SCOPE_NOWHERE;
 	struct fib_info *prev_fi = NULL;
 	unsigned int hash = fib_devindex_hashfn(dev->ifindex);
 	struct hlist_head *head = &fib_info_devhash[hash];
 	struct hlist_node *node;
 	struct fib_nh *nh;
 
+	if (force)
+		scope = -1;
+
 	hlist_for_each_entry(nh, node, head, nh_hash) {
 		struct fib_info *fi = nh->nh_parent;
 		int dead;
@@ -1096,7 +1099,6 @@ int fib_sync_down(__be32 local, struct net_device *dev, int force)
 			ret++;
 		}
 	}
-	}
 
 	return ret;
 }