[OpenAFS-devel] convergence of RxOSD, Extended Call Backs, Byte Range Locking, etc.

[Jeffrey Hutzelman]

--On Thursday, July 23, 2009 09:17:19 AM +0200 Felix Frank 
<Felix.Frank@Desy.de> wrote:

> Hi,
>
> I want to comment on what I'm sure has been fixed since the 1.4.8 times.
> Also I apparently don't understand some of the points you make.
>
>> 2) mandatory locking semantics cannot be implemented
>
> What are these? Access to object storage does not bypass the fileserver
> (except for actual data transfer). Regular AFS semantics apply, no?

Mandatory locking means that you cannot read or write while someone else 
holds a conflicting lock, or more restrictively, that you cannot read or 
write without holding the corresponding lock.  AFS does not currently 
provide this functionality, but many filesystems do, and it's a feature 
that we might wish to add.  I think Tom's point is that the proposed design 
would make it difficult to implement mandatory locking, because the 
fileserver (which manages locks) no longer mediates all read/write 
operations.


-- Jeff