Re: ext2 in a dos file/partition

Linus Torvalds (
Sat, 9 Mar 1996 15:32:15 +0200

Bryn Paul Arnold Jones: "Re: ext2 in a dos file/partition" (Mar 8, 20:44):
> On Fri, 8 Mar 1996, John Henders wrote:
> > In <01I216H7NG2Q003OFI@VAX1.ROCKHURST.EDU> (Aaron Ucko) writes:
> >
> > >cpmfs?! Now I've heard everything! What's next, punch card reader
> > >support? :-)
> >
> > On a more serious note, is anyone working on a union fs?
> >
> What do you mean, like the ifs (i think that's what it's called), where
> you can mount one fs over annother, and you see all files in the trees
> (you could, say mount a read-write fs over a cdrom, and see the cdrom
> files, mess about, whatever).
> Bryn
> PS The person working on it stoped some time ago as whilst the consept is
> simple, the implanation is not :(

While at USENIX, I saw the _correct_ way to do a union FS. It was done
as a pre-loaded shared library, and because of that it was a lot more
flexible than any kernel implementation would ever be (it was not
limited to the unix mount global state: it was used more like Plan-9's
dynamic per-process mounting).

After having seen that, I don't think I necessarily would even want a
kernel implementation. It simply was so much better done in user

The stuff had been done by Dave Korn (or Korn shell fame (and don't
flame me if his first name isn't "Dave", my mind is going)) at AT&T.
Damn, but I can't remember his email address..