[linux-cifs-client] Re: unlocking part of a byte-range lock with, CIFS

[Jeremy Allison]

On Fri, Aug 24, 2007 at 01:07:47PM -0400, Jeff Layton wrote:
> 
> Thanks. I don't want to take up your time, but it would be good to
> settle whether this is completely unfixable...
> 
> I saw this in one of your slide decks, so I'm guessing this
> is what you mean?
> 
> Locks can't overlap, or be split or merged
>   (as they can in POSIX), but read locks can
>   be "stacked" on top of a write lock.
>   - So long as the same locking context is used.
> 
> Or is it more complicated than this? :-)

Nope - that's the issue, but that that behaviour prevents what
you're tryign to do I think. If it's a read lock you can only
delete the whole thing and race to get fragments of it, no 
way to delete part of it atomically.

Jeremy.