net: In unregister_netdevice_notifier unregister the netdevices.

We already synthesize events in register_netdevice_notifier and synthesizing
events in unregister_netdevice_notifier allows to us remove the need for
special case cleanup code.

This change should be safe as it adds no new cases for existing callers
of unregiser_netdevice_notifier to handle.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index c25d453..9bb8f87 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1409,14 +1409,34 @@ EXPORT_SYMBOL(register_netdevice_notifier);
  *     register_netdevice_notifier(). The notifier is unlinked into the
  *     kernel structures and may then be reused. A negative errno code
  *     is returned on a failure.
+ *
+ *     After unregistering unregister and down device events are synthesized
+ *     for all devices on the device list to the removed notifier to remove
+ *     the need for special case cleanup code.
  */
 
 int unregister_netdevice_notifier(struct notifier_block *nb)
 {
+       struct net_device *dev;
+       struct net *net;
        int err;
 
        rtnl_lock();
        err = raw_notifier_chain_unregister(&netdev_chain, nb);
+       if (err)
+               goto unlock;
+
+       for_each_net(net) {
+               for_each_netdev(net, dev) {
+                       if (dev->flags & IFF_UP) {
+                               nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
+                               nb->notifier_call(nb, NETDEV_DOWN, dev);
+                       }
+                       nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
+                       nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
+               }
+       }
+unlock:
        rtnl_unlock();
        return err;
 }