From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [Patch net-next v4] netpoll: fix a rtnl lock assertion failure
Date: Wed, 16 Jan 2013 22:54:13 -0500 (EST)
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From: Cong Wang <amwang@redhat.com>
Date: Thu, 17 Jan 2013 11:30:18 +0800

> On Wed, 2013-01-16 at 17:24 -0800, Eric Dumazet wrote:
>> On Tue, 2013-01-15 at 17:34 +0800, Cong Wang wrote:
>> >  	if (np->dev_name)
>> > -		ndev = dev_get_by_name(&init_net, np->dev_name);
>> > +		ndev = __dev_get_by_name(&init_net, np->dev_name);
>> 
>> This change brings interesting bugs.
> 
> Hmm, I didn't realize __dev_get_by_name() doesn't hold the device, so
> just call dev_hold() after this?

Why not just... call dev_get_by_name()?  It doesn't hurt to over-RCU
lock.