Re: network-namespace-aware nfsd

[Stanislav Kinsbursky <skinsbursky@parallels.com>]

06.10.2011 17:14, Pavel Emelyanov пишет:
> On 10/06/2011 05:11 PM, J. Bruce Fields wrote:
>> On Thu, Oct 06, 2011 at 04:29:51PM +0400, Pavel Emelyanov wrote:
>>>>> Also, do you think per-namespace version support is important?
>>>>>
>>>>
>>>> Actually, yes, I do.
>>>> As I see it, nfsd filesystem have to virtualized to provide flexible control for
>>>> server features. If so, then we need to virtualize program as well.
>>>
>>> ACK - per namespace version control is required as well.
>>>
>>> AFAIK it's performed via sysctl-s and this part (sysctls engine I mean) is already
>>> namespaces aware, thus it will not be the hard part of the implementation :)
>>
>> It's a special file in the nfsd filesystem.  But I assume that won't be
>> a big deal either.
>
> Well, yes, you're right :)
>
>> By the way, I'm curious: as we do this virtualization step-by-step, is
>> there any way for userspace to tell how far we've gotten?
>>
>> So for example if you have a system that's configured to use some new
>> namespace-based feature, and you boot it to an old kernel, is there some
>> way for it to check at the start and say "sorry, this isn't going to
>> work"?
>
> M-m... I'd say - there's no automatic way for doing this. What we can (and probably
> should) do is - audit the nfs/nfsd subsystems and mark places with
>     if (ns !=&init_net_ns)
>            return -EOPNOTSUPP
> and remove these parts eventually.
>

Or just use init_net instead of current network namespace (is possible, of 
course). At least I'm trying to do so.

>> --b.
>> .
>>
>


-- 
Best regards,
Stanislav Kinsbursky