netdev - more troubles with bridge in netns

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Message-Id: <200909141419.12330.atis@mikrotik.com>
Date:	Mon, 14 Sep 2009 14:19:12 +0300
From:	Atis Elsts <atis@...rotik.com>
To:	Daniel Lezcano <daniel.lezcano@...e.fr>
Cc:	netdev@...r.kernel.org
Subject: more troubles with bridge in netns

On Tuesday 08 September 2009 11:40:44 Daniel Lezcano wrote:
> Atis Elsts wrote:
> > Trying to add bridge interface from userspace program, after moving the
> > program to a new network namespace, causes kernel to crash. I am using
> > latest kernel version from git (2.6.31-rc9).
> > The bug is easy to reproduce - just compile and run the attached C
> > program.
> >
> > I see that bridge interface has NETIF_F_NETNS_LOCAL flag, but as I
> > understand, this flag simply means that a device cannot be *moved* across
> > network namespaces, not that it cannot be *created* in other namespaces.
>
> Yep, very easy to reproduce :/
> The sysfs has not been disabled for the bridge. I will try to fix it as
> soon as I can.
>
> Thanks
>   -- Daniel

Hello,

please let me know when the sysfs patch for bridge is available. At the moment 
I managed to get it to work by just commenting out all sysfs stuff for bridge 
module. However, a new problem appears now. After running C program 
(attached) that creates a bridge in network namespace and attaches an 
interface to it, I got this message repeatedly:
 kernel:[  466.758908] unregister_netdevice: waiting for lo to become free. 
Usage count = 2

It sems pretty unlikely that my kernel changes could have caused this?

The unregister_netdevice message does not appear, however, if I uncomment this 
line in child.c:
    system("brctl setfd sim_br0 0");

--Atis

Download attachment "brtest.tgz" of type "application/x-tgz" (10767 bytes)