Re: file as a directory

[Helge Hafting <helgehaf@aitel.hist.no>]

On Tue, May 10, 2005 at 04:38:48PM +0100, Peter Foldiak wrote:
> On Tue, 2005-05-10 at 16:14, Valdis.Kletnieks@vt.edu wrote:
> > On Tue, 10 May 2005 10:39:23 BST, Peter Foldiak said:
> > > Back in November 2004, I suggested on the linux-kernel and reiserfs
> > > lists that the Reiser4 architecture could allow us to abolish the
> > > unnatural naming distinction between directories/files/parts-of-file
> > > (i.e. to unify naming within-file-system and within-file naming) in an
> > > efficient way.
> > > I suggested that one way of doing that would be to extend XPath-like
> > > selection syntax above the (XML) file level.
> > 
> > I believe the consensus was that this needs to happen at the VFS layer, not
> > the FS level.  The next step would be designing an API for this - what would
> > the VFS present to userspace, and in what way, and how would backward
> > combatability be maintained?
> 
> But can it be done efficiently above the file system level??
> 
Anything that can be done at the fs level should be doable on the vfs level too.
That is simple to show in theory: You could make the VFS api identical to
the reiser4 api, and reiser4 should continue to work as efficiently as before.

> As far as I understand, Reiser4 has this nice tree structure, which
> means that the part of file selection could be done with almost no extra
> effort, you just attach additional names to inside nodes of the tree, so
> the same tree can be used to store the whole object, and part of the
> same tree can be used to select the object part. Right?
> If you do this above the file system level, I don't think it would have
> such an efficient implementation. Or would it?  Peter

I cannot see why reiser4 should suffer - but of course this might be hard to
implement for other filesystems.

Helge Hafting