From mboxrd@z Thu Jan  1 00:00:00 1970
To: 9fans@9fans.net
Subject: Re: [9fans] 'stuck' windows.
From: "Russ Cox" <rsc@swtch.com>
Date: Sun, 22 Jun 2008 10:22:36 -0400
In-Reply-To: <ba0d3bc70806220558k7616de29we539ffbecfdac90f@mail.gmail.com>
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> I was wondering if it would be possible to start dossrv in a new
> namespace, built from scratch, so I've been playing a bit with rfork
> (the rc builtin).
> However, when I do a 'rfork N', my namespace is empty after that (of
> course), but I'm not sure how to get it populated again? Since /bin is
> gone, I'm can't do much beside using rc's builtins, of which 'exit'
> seems to be the most useful at that point...

Rob wrote the script below, called "namespace", years ago.
It is essentially a script version of newns.
You could do

	9fs boot
	namespace /n/boot dossrv

if you really wanted to, but that seems like overkill to me.

Just FYI, you are mucking around in one of the
least satisfactory parts of the system: dossrv, 9660srv, etc.
The fact that they interpret the mount spec as a file name
in their own name space means that if you already have
dossrv running in one window and do

	import othermachine /dev/sdC0
	mount /srv/dos /n/other /dev/sdC0/dos

dossrv doesn't see othermachine's disks.  So in general
you wouldn't want dossrv itself to clear its name space,
and it is debatable whether 9fat, c:, etc. should.

Dossrv is one of those programs that it's best just to use
and not think too much about.

Russ


#!/bin/rc

rfork en

# adapted from /lib/namespace

if(~ $#* 0 || ! test -x $1/$cputype/bin/bind) {
	echo 'usage: namespace /n/foo' >[1=2]
	echo '	/n/foo/$cputype/bin/bind must exist' >[1=2]
	exit usage
}

root = $1
echo setting up $root

fn bind{
	/$cputype/bin/bind $*
}

# root
bind  $root /
bind -b '#/' /

# kernel devices
bind '#c' /dev
bind '#d' /fd
bind -c '#e' /env
bind '#p' /proc
bind -c '#s' /srv
bind -a '#S' /dev

# standard bin
bind /$cputype/bin /bin
bind -a /rc/bin /bin

ramfs
cd
prompt=(`{basename $root}^'=; ' '	')
fn cd

if(~ $#* 1)
	exec rc -i
if not{
	shift
	exec $*
}