Re: [PATCH 06/11] sysfs: Implement sysfs tagged directory support.

[Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>]

Eric W. Biederman wrote:
> Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org> writes:
> 
>> The kobject events are sent through a netlink message which is not currently per
>> network namespace. Shouldn't be useful to have a way to retrieve from the
>> kobject the network namespace or the uevent socket associated with it ? IMHO
>> having idr in the kobject + netns pointer associated may help to handle the
>> sysfs isolation and makes the uevent per namespace trivial, no ?
> 
> Grumble.  I have been conveniently been forgetting about that socket.
> Similarly we have the user mode helpers to deal with.
> 
> For this conversation there is a simple answer.  All of that is in the
> kobject layer, and works even when you compile sysfs out of your kernel.
> Therefore it is a separate problem.  And sysfs idr tags have nothing
> to do with it.

Ah Ok, I am not really familiar with kobject/sysfs so I thought there 
was a proposition to store the id in the kobject instead of using the 
tag callbacks, so I figured, perhaps, the idr could have been used in 
the kobject layer and the sysfs being built upon that.

> It is most definitely something we need to come back to.  I bet there
> are some interesting interactions when you have multiple network devices
> with the same name generating events.

Yes as mentionned Benjamin, we have the eth0 in the init_net which is 
shut down when a network namespace with a netdev with the same name 
exits. There is a udev rule which ifdown eth0 :)