netdev - Re: kernel panic receiving flooded VXLAN traffic with OVS

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Date:	Fri, 7 Nov 2014 14:29:09 -0800
From:	Jesse Gross <jesse@...ira.com>
To:	Jay Vosburgh <jay.vosburgh@...onical.com>
Cc:	Pravin Shelar <pshelar@...ira.com>,
	netdev <netdev@...r.kernel.org>,
	"discuss@...nvswitch.org" <discuss@...nvswitch.org>
Subject: Re: kernel panic receiving flooded VXLAN traffic with OVS

On Fri, Nov 7, 2014 at 1:13 PM, Jay Vosburgh <jay.vosburgh@...onical.com> wrote:
> Jesse Gross <jesse@...ira.com> wrote:
>
>>On Fri, Nov 7, 2014 at 10:34 AM, Jesse Gross <jesse@...ira.com> wrote:
>>> On Fri, Nov 7, 2014 at 9:40 AM, Pravin Shelar <pshelar@...ira.com> wrote:
>>>> On Thu, Nov 6, 2014 at 5:58 PM, Jay Vosburgh <jay.vosburgh@...onical.com> wrote:
> [...]
>>>>>         I'm not sure if this is an error on the part of the RX / GRO
>>>>> processing in assembling the GRO skb, or in how OVS calls skb_segment.
>>>>>
>>>>
>>>> I think this is related skb_segment() issue where it is not able to
>>>> handle this type of skb geometry. We need to fix skb-segmentation. I
>>>> will investigate it more.
>>>
>>> One problem that I see is that vxlan_gro_complete() doesn't add
>>> SKB_GSO_UDP_TUNNEL to gso_type. This causes us to attempt
>>> fragmentation as UDP rather than continuing down to do TCP
>>> segmentation. That probably screws up the skb geometry.
>>
>>I sent out a patch to fix this issue. I'm pretty sure that it is the
>>root cause of the originally reported case but I don't have a good way
>>to reproduce it so it would be great if you could test it Jay.
>
>         I'm having an issue there; when I set up my recreation on
> current net-next (3.18-rc2) without your new patch, I get the following
> oops when my ovs script does "ovs-vsctl --if-exists del-br br-ex":

Hmm, that looks like a totally different problem. Pravin - any ideas?
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