From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <amwang@redhat.com>
Subject: Re: [Patch net-next v3] netpoll: fix a rtnl lock assertion failure
Date: Tue, 15 Jan 2013 10:23:45 +0800
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Cc: netdev@vger.kernel.org, Jiri Pirko <jiri@resnulli.us>,
	"David S. Miller" <davem@davemloft.net>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Mon, 2013-01-14 at 09:09 -0800, Eric Dumazet wrote:
> On Mon, 2013-01-14 at 09:07 -0800, Eric Dumazet wrote:
> 
> > Strange, why dont we call netdev_master_upper_dev_get() instead ?
> > 
> > 
> 
> What I meant is : the result of this check might be of little use, if we
> don't hold any lock preventing another thread to change things behind
> us.
> 
> 

Even if so, enslaving this device can still happen after we release the
rtnl lock, unless we take this lock for the whole netpoll_setup().

Am I missing anything?