net: Introduce unregister_netdevice_queue()

This patchs adds an unreg_list anchor to struct net_device, and
introduces an unregister_netdevice_queue() function, able to queue
a net_device to a list instead of immediately unregister it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8380009..0ded0a4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -683,6 +683,7 @@
 
 	struct list_head	dev_list;
 	struct list_head	napi_list;
+	struct list_head	unreg_list;
 
 	/* Net device features */
 	unsigned long		features;
@@ -1116,7 +1117,13 @@
 extern void		dev_disable_lro(struct net_device *dev);
 extern int		dev_queue_xmit(struct sk_buff *skb);
 extern int		register_netdevice(struct net_device *dev);
-extern void		unregister_netdevice(struct net_device *dev);
+extern void		unregister_netdevice_queue(struct net_device *dev,
+						   struct list_head *head);
+static inline void unregister_netdevice(struct net_device *dev)
+{
+	unregister_netdevice_queue(dev, NULL);
+}
+
 extern void		free_netdev(struct net_device *dev);
 extern void		synchronize_net(void);
 extern int 		register_netdevice_notifier(struct notifier_block *nb);