Re: [Patch net] rtnetlink: call rtnl_lock_unregistering() in rtnl_link_unregister()

[ebiederm@xmission.com (Eric W. Biederman)]

Cong Wang <xiyou.wangcong@gmail.com> writes:

> On Fri, May 9, 2014 at 12:02 PM, Stephen Hemminger
> <stephen@networkplumber.org> wrote:
>> On Fri, 9 May 2014 11:10:36 -0700
>> Cong Wang <xiyou.wangcong@gmail.com> wrote:
>>
>>>
>>> This can't be done without a macro (at least for me). Or
>>> we have to duplicate the code.
>>
>> macro method is too ugly, figure out a better way.
>
> That's what I am going to do for -net-next. This patch is for -net,
> it's an ugly but minimum change I can find.
>
> Of course, if you insist we should clean up it for -net as well,
> I can do that.

It would be no worse to rename the existing function
rtnl_lock_unregistering_list

And add a second function rtnl_lock_unregistering that does
the same thing but uses the global list.

Of course this begs the question what happens if the network
device we want to destroy is a network namespace that is currently
exiting and not on the global list.

It looks like we need to grab the net_mutex to get a state where network
namespaces are not exiting...

Eric