Subject: Re: RTNL: assertion failed at net/ipv6/addrconf.c (1699)

From: Vlad Yasevich <[email-masked]>
Date: Tue, 02 Sep 2014 15:08:21 -0400

On 09/02/2014 02:15 PM, Cong Wang wrote:
> On Tue, Sep 2, 2014 at 11:11 AM, Eric Dumazet <[email-masked]> wrote:
>> On Tue, 2014-09-02 at 11:04 -0700, Cong Wang wrote:
>>> On Tue, Sep 2, 2014 at 10:58 AM, Hannes Frederic Sowa
>>
>>>> I definitely don't have a problem cleaning this up in net-next. I wanted
>>>> a minimal patch for stable because I didn't check history where and when
>>>> additional users of dev_get_by_flags_rcu were removed.
>>>
>>> `git grep` should show you we only have one caller. Apparently we don't
>>> care about any out-of-tree module.
>>
>> Point is : you did not check if some stable versions had more callers.
>>
>> Its very nice you checked current version, but it is not enough for a
>> stable candidate.
> 
> That is what we do when backporting patches, I can do that if David asks
> me to backport it, but you know for netdev that is David's work.
> 
> (I am not saying I don't want to help him, I just want to point out the fact.
> I am very pleased to help David for stable backports as long as he asks)

Instead of helping after the fact, why not arrange the patches so that it's
not such a big issue.  Leave the _rcu variant alone.  Add an _rtnl variant
of the function and use that in the patch.  Have a follow-on patch that
removes the _rcu variant all by itself.  This way backports become easier,
and if anyone wants the _rcu variant back, all they have to do is revert
a very simple commit.

-vlad