[OpenAFS] dropbox semantics ("irl")

[Derrick J Brashear]

On Wed, 30 May 2007, Christopher D. Clausen wrote:

> Derrick J Brashear <shadow@dementia.org> wrote:
>> On Wed, 30 May 2007, Russ Allbery wrote:
>>
>>> Derrick J Brashear <shadow@dementia.org> writes:
>>>
>>>> It's enforced in the fileserver. The logic is weird and i don't
>>>> remember it, It may be that you can only extend the file.
>>>
>>> Oh, okay, I'm wrong then.  I must be remembering something different.
>>
>> I could just as easily be wrong. I don't remember anymore. The key is
>> "it's a hack"
>
> I think this previous thread still applies:
> http://www.openafs.org/pipermail/openafs-info/2005-December/020826.html
>
> And I'm pretty sure it is indeed client enforced.  Try using arla and
> see if it works differently.

I just went and read server code. Yeah, that thread is basically right.

We could make it so it effectively became create+append, but there are 
some tweaks which would need to be done.

The relevant check is src/viced/afsfileprocs.c in Check_PermissionRights