[Unionfs] UNIONFS_MMAP (was: rw nfs branch ...)

[Erez Zadok]

In message <200603071424.07490.hpj at urpla.net>, Hans-Peter Jansen writes:

> > About /proc soft link problem, I guess Shaya Potter's mmap patch is
> > the answer. But I didn't try it and it seems to be needed some
> > fixing, for example lseek at readdir.
> 
> Yeah, Shaya's mmap support patch sounds very promising, and I'm going to 
> try it as soon as my time window will allow more experiments. But 
> pressure is high currently to deploy the stuff..

We've begun the long journey to get full mmap support working.  Just in the
past day or so we've applied Shaya's patch, slightly modified to the CVS
tree.  It is NOT on by default: you'll have to compile unionfs with
UNIONFS_MMAP.

We have done very little testing on it; it's highly experimental, but looks
promising as a starting point.  So I preferred to have at least _something_
available for people to try, and hopefully help us enhance and fix it (while
we're continuing to stabilize the rest of the code in preparation for a
first release).

So, consider this a request for testing from those of you who feel
comfortable enough with the unionfs code, to try out UNIONFS_MMAP, find
what's missing/broken, and give us feedback (or patches :-)

Thanks,
Erez.