[NET]: Rework dev_base via list_head (v3)

Cleanup of dev_base list use, with the aim to simplify making device
list per-namespace. In almost every occasion, use of dev_base variable
and dev->next pointer could be easily replaced by for_each_netdev
loop. A few most complicated places were converted to using
first_netdev()/next_netdev().

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 09117d6..9b81264 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -423,14 +423,18 @@
  */
 int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
 {
+	int found = 0;
+
 	if (dev)
 		return ipv6_chk_acast_dev(dev, addr);
 	read_lock(&dev_base_lock);
-	for (dev=dev_base; dev; dev=dev->next)
-		if (ipv6_chk_acast_dev(dev, addr))
+	for_each_netdev(dev)
+		if (ipv6_chk_acast_dev(dev, addr)) {
+			found = 1;
 			break;
+		}
 	read_unlock(&dev_base_lock);
-	return dev != 0;
+	return found;
 }
 
 
@@ -447,9 +451,8 @@
 	struct ifacaddr6 *im = NULL;
 	struct ac6_iter_state *state = ac6_seq_private(seq);
 
-	for (state->dev = dev_base, state->idev = NULL;
-	     state->dev;
-	     state->dev = state->dev->next) {
+	state->idev = NULL;
+	for_each_netdev(state->dev) {
 		struct inet6_dev *idev;
 		idev = in6_dev_get(state->dev);
 		if (!idev)
@@ -476,7 +479,7 @@
 			read_unlock_bh(&state->idev->lock);
 			in6_dev_put(state->idev);
 		}
-		state->dev = state->dev->next;
+		state->dev = next_net_device(state->dev);
 		if (!state->dev) {
 			state->idev = NULL;
 			break;