Subject: re: feature request: root file system change
To: Matt Thomas <firstname.lastname@example.org>
From: matthew green <email@example.com>
Date: 04/18/2005 23:53:12
Lubomir Sedlacik wrote:
> On Sat, Apr 16, 2005 at 10:17:23PM +0200, Martin Husemann wrote:
>>On Sat, Apr 16, 2005 at 10:06:38PM +0200, Lubomir Sedlacik wrote:
>>>but at this point you already _have_ / mounted, it's the md(4) file
>>>system. you need to run cgdconfig(8) from somewhere, right?
>>Yes, just like the (temporary) read-only / in single user mode. Some
>>kernel magic would allow the update mount of the real / while the
>>pre-init script runs.
> understood, but wouldn't the "pre-init script" be even more hackish than
> pivot_root(2) at this point?
I guess I'd solve this in a few steps:
1) Add a sysctl group init:
init.rcscript=string default value would be /etc/rc
init.root=string default value would be /
init.rcaction=enum value is a comma separated list containing one or
more comma separated value of multiuser,singleuser,rcscript
Before init execs any process it will chroot to the value of
init.root. It will also open any file path by prefixing it with
When init starts up, the default rcaction is rcscript. after forking
but before execing the rcscript, init will set rcation to multiuser.
This would allow the md root to setup the new root, do
sysctl -w init.rcaction=rcscript init.root=/cgdroot
this sounds like an OK idea except that i'd like to be able to free
any memory allocated to the (first) root etc. and chroot won't do that.