Re: [PATCH] net: skip genenerating uevents for network namespaces that are exiting

From: Cong Wang
Date: Mon Oct 24 2016 - 13:17:44 EST


On Sat, Oct 22, 2016 at 12:37 AM, Andrey Vagin <avagin@xxxxxxxxxx> wrote:
> Hi Cong,
>
> On Thu, Oct 20, 2016 at 10:25 PM, Andrey Vagin <avagin@xxxxxxxxxx> wrote:
>> On Thu, Oct 20, 2016 at 8:10 PM, Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote:
>>> On Thu, Oct 20, 2016 at 7:46 PM, Andrei Vagin <avagin@xxxxxxxxxx> wrote:
>>>> No one can see these events, because a network namespace can not be
>>>> destroyed, if it has sockets.
>>>>
>>>
>>> Are you sure? kobject_uevent_env() seems sending uevents to all
>>> network namespaces.
>>
>> kobj_bcast_filter() checks that a kobject namespace is equal to a
>> socket namespace.
>
> Today I've checked that it really works as I read from the source code.
> I use this tool to read events:
> https://gist.github.com/avagin/430ba431fc2972002df40ebe6a048b36
>
> And I see that events from non-network devices are delivered to all sockets,
> but events from network devices are delivered only to sockets from
> a network namespace where a device is operated.

I missed it, it makes sense now. Please consider adding a comment in
the code or expanding your changelog for reference.

Thanks!