From e6ada46ff8b4b3fc3b032699dfbd1c9688162831 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 22 Jan 2014 21:07:53 +0100 Subject: [PATCH] net: vxlan: convert to act as a pernet subsystem As per suggestion from Eric W. Biederman, vxlan should be using {un,}register_pernet_subsys() instead of {un,}register_pernet_device() to ensure the vxlan_net structure is initialized before and cleaned up after all network devices in a given network namespace i.e. when dealing with network notifiers. This is similarly handeled already in commit 83a66f65b189 ("net: Teach vlans to cleanup as a pernet subsystem") and, thus, improves upon 2d516d587245 ("net: vxlan: do not use vxlan_net before checking event type"). Just as in 83a66f65b189, we do not need to explicitly handle deletion of vxlan devices as network namespace exit calls dellink on all remaining virtual devices, and rtnl_link_unregister() calls dellink on all outstanding devices in that network namespace, so we can entirely drop the pernet exit operation as well. Moreover, on vxlan module exit, rcu_barrier() is called by netns since commit 1c43004195b6 ("netns: Add an explicit rcu_barrier to unregister_pernet_{device|subsys}"), so this may be omitted. Tested with various scenarios and works well on my side. Suggested-by: Eric W. Biederman Cc: Jesse Brandeburg Cc: Eric W. Biederman Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 942acc20d3940..e1bc9252e3f43 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -2784,12 +2784,10 @@ static int vxlan_lowerdev_event(struct notifier_block *unused, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); - struct vxlan_net *vn; + struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id); - if (event == NETDEV_UNREGISTER) { - vn = net_generic(dev_net(dev), vxlan_net_id); + if (event == NETDEV_UNREGISTER) vxlan_handle_lowerdev_unregister(vn, dev); - } return NOTIFY_DONE; } @@ -2812,22 +2810,8 @@ static __net_init int vxlan_init_net(struct net *net) return 0; } -static __net_exit void vxlan_exit_net(struct net *net) -{ - struct vxlan_net *vn = net_generic(net, vxlan_net_id); - struct vxlan_dev *vxlan, *next; - LIST_HEAD(list_kill); - - rtnl_lock(); - list_for_each_entry_safe(vxlan, next, &vn->vxlan_list, next) - vxlan_dellink(vxlan->dev, &list_kill); - unregister_netdevice_many(&list_kill); - rtnl_unlock(); -} - static struct pernet_operations vxlan_net_ops = { .init = vxlan_init_net, - .exit = vxlan_exit_net, .id = &vxlan_net_id, .size = sizeof(struct vxlan_net), }; @@ -2842,7 +2826,7 @@ static int __init vxlan_init_module(void) get_random_bytes(&vxlan_salt, sizeof(vxlan_salt)); - rc = register_pernet_device(&vxlan_net_ops); + rc = register_pernet_subsys(&vxlan_net_ops); if (rc) goto out1; @@ -2858,7 +2842,7 @@ static int __init vxlan_init_module(void) out3: unregister_netdevice_notifier(&vxlan_notifier_block); out2: - unregister_pernet_device(&vxlan_net_ops); + unregister_pernet_subsys(&vxlan_net_ops); out1: destroy_workqueue(vxlan_wq); return rc; @@ -2870,8 +2854,8 @@ static void __exit vxlan_cleanup_module(void) rtnl_link_unregister(&vxlan_link_ops); unregister_netdevice_notifier(&vxlan_notifier_block); destroy_workqueue(vxlan_wq); - unregister_pernet_device(&vxlan_net_ops); - rcu_barrier(); + unregister_pernet_subsys(&vxlan_net_ops); + /* rcu_barrier() is called by netns */ } module_exit(vxlan_cleanup_module); -- 2.39.5