Subject: Re: [PATCH v3 net-next] net: vxlan: when lower dev unregisters remove vxlan dev as well

From: Daniel Borkmann <[email-masked]>
Date: Sat, 11 Jan 2014 09:46:58 +0100

On 01/11/2014 01:49 AM, Cong Wang wrote:
> On Fri, Jan 10, 2014 at 2:35 PM, Daniel Borkmann <[email-masked]> wrote:
>> @@ -2673,13 +2712,14 @@ static __net_init int vxlan_init_net(struct net *net)
>>   static __net_exit void vxlan_exit_net(struct net *net)
>>   {
>>          struct vxlan_net *vn = net_generic(net, vxlan_net_id);
>> -       struct vxlan_dev *vxlan;
>> -       LIST_HEAD(list);
>> +       struct vxlan_dev *vxlan, *next;
>> +       LIST_HEAD(list_kill);
>>
>>          rtnl_lock();
>> -       list_for_each_entry(vxlan, &vn->vxlan_list, next)
>> -               unregister_netdevice_queue(vxlan->dev, &list);
>> -       unregister_netdevice_many(&list);
>> +       list_for_each_entry_safe(vxlan, next, &vn->vxlan_list, next)
>> +               vxlan_dellink(vxlan->dev, &list_kill);
>> +       unregister_netdevice_many(&list_kill);
>> +       list_del(&list_kill);
>
> The last list_del() looks suspicous... Since list_kill is a local list head,
> why do we need to delete the head at the end??

Cong, maybe I'm missing something, but we're doing this rtnl_dellink()
and elsewehere, e.g. commit 226bd341147 ("net: use batched device unregister
in veth and macvlan").