Subject: Re: devfs, was Re: ptyfs fully working now...
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Eric Haszlakiewicz <erh@nimenees.com>
List: tech-kern
Date: 11/13/2004 21:48:23
On Fri, Nov 12, 2004 at 10:42:25PM -0500, der Mouse wrote:
> Right - but now the admin does "chown uucp:uucp /dev/tty02" or
> "ln -s lpt1 /dev/scanner".  How do you make the results of such
> commands persist across reboots?  That problem is introduced by a devfs
> that has no permanent storage backing it, and _that_ is the problem the
> config file solves.

	I was thinking that a better way to do this would be a devfs as a
slightly twisted unionfs style layer. The changes in permissions (if any)
would be stored in the filesystem as permissions on a symlink in the underlying
filestore.  e.g.:
	Filestore         device       Visible
    ----------        ------       -------
foo -> .../dev/audio  audio        foo as an actual device node
(nothing)             mixerctl     mixerctl as dev node
fd0a -> .../deleted   fd0a         nothing visible
  (or perhaps a whiteout)
bar -> blah           (anything)   normal symlink to blah
xxx -> .../dev/aaa    (no aaa)     normal symlink

eric