Re: Symlink, chrdev, blkdev translators

[Marcus Brinkmann]

On Mon, Aug 19, 2002 at 10:42:45PM +0200, Ludovic Courtès wrote:
> On Mon, Aug 19, 2002 at 07:37:02PM +0200, Marcus Brinkmann wrote:
> > Let me counter with a question:  Where do you expect device nodes, fifos and
> > symlinks to come from if not from translator settings?
> > [snip]
> > This is similar for other special files, like character and block devices. 
> > But we don't use those special files at all, so we don't have support for
> > them (that explains why there is no /hurd/chrdev and /hurd/blkdev).  Maybe
> > at some time we will.
> 
> Actually, what makes a file "look like" a symlink or a character/block device
> is just its st_mode field in struct stat. So why do we need a special case
> that will make these kind of files "look like translators" for filesystems
> that support them natively -- beside the fact that it's conceptually
> equivalent?

So you are saying that showtrans should not give us anything on special
nodes?  What advantage does it give you to be inconsistent on purpose?

> > > However, it seems that a fifo translator was started (how?)
> > Although a fifo is short-circuited by the filesystem, it will be set, 
> > reported
> > and treated like a real translator.
> 
> But it seems that the fs on which it was started isn't aware of it: this fs is
> doesn't allow to set translators on it. So "who" knows that a fifo translator
> is running there?

You are confusing passive with active translators, and the filesystem as on
disk with the filesystem server as process.

marcus@ajax:~$ showtrans hurd
/hurd/ext2fs /dev/hd3s3
marcus@ajax:~$ settrans -ag hurd
marcus@ajax:~$ /sbin/e2os /dev/hd3s3 linux
marcus@ajax:~$ cd hurd
marcus@ajax:~/hurd$ settrans foo /hurd/hello
settrans: foo: Operation not supported
marcus@ajax:~/hurd$ settrans -a foo /hurd/hello
marcus@ajax:~/hurd$ cat foo
Hello, world!

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' GNU      http://www.gnu.org    marcus@gnu.org
Marcus Brinkmann              The Hurd http://www.gnu.org/software/hurd/
Marcus.Brinkmann@ruhr-uni-bochum.de
http://www.marcus-brinkmann.de/