Re: [GSoC Project] Implementing NFS v4.2

[David Quigley <dpquigl@davequigley.com>]

On 04/09/2012 20:27, Calvin Owens wrote:
> On 04/05/2012 10:17 PM, Myklebust, Trond wrote:
>> On Thu, 2012-04-05 at 19:03 -0500, Calvin Owens wrote:
>>> Hello all,
>>>
>>> I'm interested in implementing the draft specification for NFS v4.2 
>>> as a
>>> Google Summer of Code project. That includes server-side copying, 
>>> sparse
>>> files, and carrying fadvise() calls through to the server, among 
>>> other
>>> things.
>>>
>>> The current document can be found here:
>>> http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion2-07
>>>
>>> Is this something that you need to be done? If so, I'd very much 
>>> like to
>>> be involved. :)
>>
>> Hi Calvin,
>>
>> Labelled NFS is likely to be merged into 3.5 (if Dave Q finds the 
>> time
>> to port his existing code).
>>
>> Copy offload already exists in prototype form. The main remaining 
>> issue
>> is working out the user syscall interface, which really requires 
>> getting
>> all the interested filesystem maintainers to agree (we've started on
>> doing that).
>>
>> If you'd like to contribute, then I'd suggest looking into SEEK (for
>> providing lseek(SEEK_HOLE/SEEK_DATA) support. There is also the hole
>> punching/space reservation, that should fit nicely into the 
>> fallocate()
>> system call.
>
> Yes, that sounds good. I'll start looking into that.
>
>> The efficient sparse file read and fadvise support might be nice 
>> too,
>> but I'd like to see numbers for how they improve matters before I 
>> feel
>> comfortable saying yea or nay to adding those specific features.
>
> I definitely see your point. It does seem to be a lot of added
> complexity for a negligible benefit.
>
>> Note that there are also a bunch of NFSv4.1 features that have yet 
>> to be
>> implemented, so the above list of tasks is not exhaustive. I'd be 
>> happy
>> to work with you to find something...
>
> What else, precisely, would you like to get done? I need to get some
> more detailed objectives to put into my application. (Forgive me for
> so blatantly not looking myself, but it seems more efficient than me
> digging through the code finding missing features and lobbing them at
> you for approval, when I'm sure you know exactly where your 
> priorities
> are...)
>
> Thanks very much,
> Calvin Owens
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Finishing up the port of Labeled NFS would be some low hanging fruit if 
someone wants to help tackle it. I'll be trying to find time to work on 
it but its unclear how soon I'll be able to get around to it.

Dave