Re: [fuse-devel] [PATCH] FUSE/CUSE: implement direct mmap support

[Miklos Szeredi]

On Thu, 11 Feb 2010, Tejun Heo wrote:
> Hello,
> 
> On 02/11/2010 09:46 PM, Miklos Szeredi wrote:
> > The problem with that is you simply can't determine in advance where
> > the region will grow.  Okay, you can leave space according to the size
> > of the file, but the size of the file can grow too.
> > 
> > *This* is the complexity that I want to get rid of.
> 
> Alright, then let's talk about that, not SHMLBA which doesn't really
> have much to do with this.  So, you're basically saying that you want
> multiple address spaces.  In that case, the only logical abstraction
> for that are files.  ie. We need to be passing file descriptors to the
> server and asking the server which descriptor it would want to use,
> which was the previous implementation, which you objected mentioning
> that this type of direct mmap would probably be useful only for device
> mmap implementations.

No, I don't want to pass file descriptors (early fuse did use that for
readdir and it was a mistake).

Global address space for server side maps are OK.  What I mind is that
in the *absence* of server side maps the filesystem still has to deal
with the global address space (with all its quirks).  This is totally
unnecessary.

Thanks,
Miklos
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/