netdev - Re: [PATCH 0/5] Make /sys/class/net per net namespace objects belong to container

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Message-ID: <87zinvpx5s.fsf@x220.int.ebiederm.org>
Date:   Mon, 29 Aug 2016 07:38:55 -0500
From:   ebiederm@...ssion.com (Eric W. Biederman)
To:     David Miller <davem@...emloft.net>
Cc:     dmitry.torokhov@...il.com, tj@...nel.org,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH 0/5] Make /sys/class/net per net namespace objects belong to container

David Miller <davem@...emloft.net> writes:

> From: Dmitry Torokhov <dmitry.torokhov@...il.com>
> Date: Tue, 16 Aug 2016 15:33:10 -0700
>
>> There are objects in /sys hierarchy (/sys/class/net/) that logically belong
>> to a namespace/container. Unfortunately all sysfs objects start their life
>> belonging to global root, and while we could change ownership manually,
>> keeping tracks of all objects that come and go is cumbersome. It would
>> be better if kernel created them using correct uid/gid from the beginning.
>> 
>> This series changes kernfs to allow creating object's with arbitrary
>> uid/gid, adds get_ownership() callback to ktype structure so subsystems
>> could supply their own logic (likely tied to namespace support) for
>> determining ownership of kobjects, and adjusts sysfs code to make use of
>> this information. Lastly net-sysfs is adjusted to make sure that objects in
>> net namespace are owned by the root user from the owning user namespace.
>> 
>> Note that we do not adjust ownership of objects moved into a new namespace
>> (as when moving a network device into a container) as userspace can easily
>> do it.
>
> I need some domain experts to review this series please.

I just came back from vacation and I will aim to take a look shortly.

The big picture idea seems sensible.  Having a better ownship of sysfs
files that are part of a network namespace.  I will have to look at the
details to see if the implementation is similarly sensible.

Eric