Date: Thu, 13 Jul 2000 19:27:55 -0400
From: Olivier Galibert <[EMAIL PROTECTED]>
On Fri, Jul 14, 2000 at 01:07:38AM +0200, Marcus Brinkmann wrote:
> On Thu, Jul 13, 2000 at 07:01:28PM -0400, Olivier Galibert wrote:
> > Currently the on-disk structures for translators in ext2 allow for an
> > inode to be both a passive translator and a file (or directory) with
> > actual contents. AFAICT, this capability is not used anywhere for
> > now. I'm not even sure it is accessible from the filesystem
> > interface.
>
> The underlying node is accessible to the translator, and this can and will
> be used for example for filter (or for example for activity logging etc).
But only the translator has access to it? That's yucky. This means
that things can be hidden behind a translator and the only way for
both yourself and the sysadmin to know what's there is to remove it?
That's why we have O_NOTRANS, i.e. you can do
fd = open (..., O_READ | O_NOTRANS);
and use the file descriptor to read from the actual file.
It's probably even too magic for the translator itself. This does not
work:
dd if=/dev/zero of=dummy bs=1024k count=8
mke2fs dummy
settrans -c dummy /hurd/ext2fs `pwd`/dummy
...because the translator will end up looping on itself.
Did you check that? If it really does that, I'd consider it a bug,
and I might try to fix it :-).
Anyway, I agree with Marcus that it's useful to have this feature, and
it's probably how Thomas designed it.
Mark
