Re: A bad loop in settrans

[Marcus Brinkmann]

On Fri, Jun 29, 2001 at 09:31:08PM +0200, Maurizio Boriani wrote:
> Hi all,
>       for a mistake I launched this on command line:
> elisia# settrans -a /home /hurd/ext2fs /home
>
> and then try to enter in /home using cd. I looped out.

Funny, isn't it ;)

> I think this could be a bug,

Yes, but maybe a different one than you think.  What about the following:

$ dd if=/dev/zero of=/image bs=1024k count=10
$ mke2fs /image
$ settrans -a /home /hurd/ext2fs /image

The purpose would be to use the underlying file as the store.  It would be
hidden by the actual content of the filesystem, quite convenient ;)

You can even implement that in this case, "cat /image" does not return the
binary representation of the root directory, but the underlying file
itself!  Break the chains of Unix, this is the Hurd (but be careful not to
confuse users too much by inconsistencies or levels of redirection).

Also, for a tarfs:

$ settrans -a /gnu.tar.gz /hurd/tarfs /gnu.tar.tz
$ cd /gnu; ls
some_file
some_other_file
$ cat /gnu > /tmp/gnu.tar.gz
# (/tmp/gnu.tar.gz is now a copy of the original tar file).

Other translators would just forward the accesses to the underlying
directory hierarchy, but would maybe filter or log them somewhere.  For
example shadowfs.

What do you think?

Thanks,
Marcus


-- 
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Marcus Brinkmann              GNU    http://www.gnu.org    marcus@gnu.org
Marcus.Brinkmann@ruhr-uni-bochum.de
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