Re: metadata plugins (was Re: the " 'official' point of view" expressed by regarding reiser4 inclusion)

From: Horst H. von Brand
Date: Wed Aug 02 2006 - 14:43:18 EST

Vladimir V. Saveliev <vs@xxxxxxxxxxx> wrote:
> On Tue, 2006-08-01 at 17:32 +0200, Å?ukasz Mierzwa wrote:
> > Dnia Fri, 28 Jul 2006 18:33:56 +0200, Linus Torvalds <torvalds@xxxxxxxx>
> > napisaÅ?:
> > > In other words, if a filesystem wants to do something fancy, it needs to
> > > do so WITH THE VFS LAYER, not as some plugin architecture of its own. We
> > > already have exactly the plugin interface we need, and it literally _is_
> > > the VFS interfaces - you can plug in your own filesystems with
> > > "register_filesystem()", which in turn indirectly allows you to plug in
> > > your per-file and per-directory operations for things like lookup etc.

> > What fancy (beside cryptocompress) does reiser4 do now?
> it is supposed to provide an ability to easy modify filesystem behaviour
> in various aspects without breaking compatibility.

If it just modifies /behaviour/ it can't really do much. And what can be
done here is more the job of the scheduler, not of the filesystem. Keep your
hands off it!

If it somehow modifies /on disk format/, it (by *definition*) isn't
compatible. Ditto.

> > Can someone point me to a list of things that are required by kernel
> > mainteiners to merge reiser4 into vanilla?
> list of features reiser4 does not have now:
> O_DIRECT support - we are working on it now
> various block size support

Is this required?

> quota support
> xattrs and acls

Without those, it is next to useless anyway.
Dr. Horst H. von Brand User #22616
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