Re: Support for VRF in NFS?

[Ben Greear <greearb@candelatech.com>]

On 11/09/2018 01:59 AM, Steven Whitehouse wrote:
> Hi,
>
>
> On 08/11/18 16:35, Ben Greear wrote:
>>
>>
>> On 11/08/2018 07:31 AM, J. Bruce Fields wrote:
>>> On Wed, Nov 07, 2018 at 09:08:16PM -0800, Ben Greear wrote:
>>>>
>>>>
>>>> On 11/07/2018 05:14 PM, J. Bruce Fields wrote:
>>>>> On Tue, Nov 06, 2018 at 01:03:54PM -0800, Ben Greear wrote:
>>>>>> Hello,
>>>>>>
>>>>>> I made a stab at implementing VRF support in NFS, but it appears
>>>>>> fairly complicated and I ended up reverting my changes....
>>>>>>
>>>>>> Is anyone working on this?
>>>>>>
>>>>>> And, if not, if anyone would like to be sponsored to work on this, please
>>>>>> let me know.
>>>>>
>>>>> Um, sorry--what's VRF?
>>>>
>>>> Virtual Router logic.  It is sort of like network stack containers,
>>>> and has been solid and fully featured in the kernel since 4.16 or so.
>>>>
>>>> In the end, you effectively need to call the logic that SO_BINDTODEVICE
>>>> calls on the socket before binding to an IP.
>>>>
>>>> The NFS and RPC logic is a giant tangled mess to my eyes, so
>>>> hoping I could bribe someone else to do it :)
>>>
>>> So it's not enough to support network namespaces?
>>>
>>> What's your motivation for this?
>>
>> Network namespaces are difficult to uses for lots of use cases, and thus VRF
>> was born.
>>
>> My own motivation is that it allows me to make hundreds or thousands
>> of individual NFS mounts from local mac-vlan (or other virtual/physical interfaces),
>> for testing purposes.
>>
>> Similar to my patch set that binds to local IP address, which gives similar feature
>> set for non-VRF configurations.  These bind-local-IP patches are not upstream and were rejected in
>> the past as un-wanted.  I'm hoping VRF support would be more acceptable.
>>
>> Thanks,
>> Ben
>>
>
> For similar reasons David Windsor has been looking at some extensions for DLM along these lines. Improving our ability to test seems to me like it should be a good thing to do - in both cases. Likewise VRF support seems also like it should be useful in a number of contexts.
>
> Do you have a reference to your past work? I think it would be interesting to get some discussion going here - maybe it would be possible to have some common approach between kernel-side socket users, and/or bounce some ideas around,
>
> Steve.

Here is an old thread on the topic.

https://www.spinics.net/lists/linux-nfs/msg34811.html

My patches are in all my 'ct' kernels, and the needed patches are also in my nfs-utils repo.

My 4.19 tree has just been ported, so no idea if it works or not.

https://github.com/greearb?tab=repositories

My patch work fine using routing table rules without VRF, but they will not work with VRF.


Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com