net: Move network device exit batching

Move network device exit batching from a special case in
net_namespace.c to using common mechanisms in dev.c

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

1 files changed, 25 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index e3e18dee0bd3..0913a08a87d6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5766,8 +5766,33 @@ static void __net_exit default_device_exit(struct net *net)
         rtnl_unlock();
 }
 
+static void __net_exit default_device_exit_batch(struct list_head *net_list)
+{
+        /* At exit all network devices most be removed from a network
+         * namespace.  Do this in the reverse order of registeration.
+         * Do this across as many network namespaces as possible to
+         * improve batching efficiency.
+         */
+        struct net_device *dev;
+        struct net *net;
+        LIST_HEAD(dev_kill_list);
+
+        rtnl_lock();
+        list_for_each_entry(net, net_list, exit_list) {
+                for_each_netdev_reverse(net, dev) {
+                        if (dev->rtnl_link_ops)
+                                dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
+                        else
+                                unregister_netdevice_queue(dev, &dev_kill_list);
+                }
+        }
+        unregister_netdevice_many(&dev_kill_list);
+        rtnl_unlock();
+}
+
 static struct pernet_operations __net_initdata default_device_ops = {
         .exit = default_device_exit,
+        .exit_batch = default_device_exit_batch,
 };
 
 /*