Subject: Re: 4.4-rc7 failure report

From: Doug Ledford <[email-masked]>
Date: Tue, 29 Dec 2015 22:44:31 -0500

On 12/29/2015 10:43 PM, Alexei Starovoitov wrote:
> On Mon, Dec 28, 2015 at 08:26:44PM -0500, Doug Ledford wrote:
>> On 12/28/2015 05:20 PM, Daniel Borkmann wrote:
>>> On 12/28/2015 10:53 PM, Doug Ledford wrote:
>>>> The 4.4-rc7 kernel is failing for me.  In my case, all of my vlan
>>>> interfaces are failing to obtain a dhcp address using dhclient.  I've
>>>> tried a hand built 4.4-rc7, and the Fedora rawhide 4.4-rc7 kernel, both
>>>> failed.  I've tried NetworkManager and the old SysV network service,
>>>> both fail.  I tried a working dhclient from rhel7 on the Fedora rawhide
>>>> install and it failed too.  Running tcpdump on the interface shows the
>>>> dhcp request going out, and a dhcp response coming back in.  Running
>>>> strace on dhclient shows that it writes the dhcp request, but it never
>>>> recvs a dhcp response.  If I manually bring the interface up with a
>>>> static IP address then I'm able to run typical IP traffic across the
>>>> link (aka, ping).  It would seem that when dhclient registers a packet
>>>> filter on the socket, that filter is preventing it from ever getting the
>>>> dhcp response.  The same dhclient works on any non-vlan interfaces in
>>>> the system, so the filter must work for non-vlan interfaces.  Aside from
>>>> the fact that the interface is a vlan, we also use a priority egress map
>>>> on the interface, and we use PFC flow control.  Let me know if you need
>>>> anymore to debug the issue, or email me off list and I can get you
>>>> logins to my reproducer machines.
>>>
>>> When you say 4.4-rc7 kernel is failing for you, what latest kernel version
>>> was working, where the socket filter was properly receiving the response on
>>> your vlan iface?
>>
>> v4.3 final works.  I haven't bisected where in the 4.4 series it quits
>> working.  I can do that tomorrow.
> 
> I've tried to reproduce, but cannot seem to make dnsmasq work properly
> over vlan, so bisect would be great.
> 

Yeah, I've been working on it.  Issues with available machines that
reproduce combined with what hardware they have and whether or not that
hardware works at various steps in the bisection :-/

-- 
Doug Ledford <[email-masked]>
              GPG KeyID: 0E572FDD