A common VFS and a Common conf-system (Was: namespacing)

[Sean Middleditch]

On Tue, 2005-03-01 at 11:25 -0500, Avery Pennarun wrote:
>On Mon, Feb 28, 2005 at 11:45:59PM -0500, Sean Middleditch wrote:
>
>> On Tue, 2005-03-01 at 01:05 +0000, Jamie McCracken wrote:
>> 
>> >If you want something thats fast, easy to use and KISS that could take 
>> >advantage of this then look at FUSE (http://fuse.sourceforge.net/) - it 
>> >rocks!.
>> 
>> Unfortunately, it's Linux only, and has an incredibly brain-dead design
>> where you have to utilize "round-trips" through the kernel for something
>> that essentially happens entirely in user-space,
>
>This is not entirely true: thanks to some contributions by my company, FUSE
>has extensions that allow the kernel to *cache* your stuff in the normal
>page cache, so after the first access, files can be retrieved as quickly as
>from a normal filesystem, even across processes, and with a high level of
>reliability.  That's a very big advantage that you will simply never achieve
>in a 100% userspace solution.

Why can't it be done in userspace?

>
>This allowed us to make a network file sharing client (FunFS) using FUSE
>that runs faster than the NFS client even though 99% of the client is in
>userspace.

And what stops that from running 100% in userspace?

>
>> and forces a superbly poor API (POSIX) onto all its file systems,
>> including those where POSIX makes absolutely no sense whatsoever.
>
>This, however, is true.  Once you've made a good VFS layer, connect it to
>FUSE and get the advantages of FUSE.  Don't do it the other way around, or
>you get the *disadvantages* of FUSE.

That is certainly possible.  I rather expect FUSE, KIO, and Gnome-Vfs
backends to exist, at least until "native" backends for all the
interesting protocols exist.

>
>Have fun,
>
>Avery
>
-- 
Sean Middleditch <elanthis at awesomeplay.com>