Re: [PATCH, RFC] tty: stop abusing file->f_u.fu_list

[Al Viro <viro@ZenIV.linux.org.uk>]

On Fri, Jun 04, 2010 at 02:39:34PM -0400, Christoph Hellwig wrote:
> The ttry code currently abuses the file anchor for the per-sb file list
> to track instances of a given tty.  But there's no good reason for
> that, we can just install a proxy object in file->private that gets
> added to the list and points to the tty and keep the list away from
> VFS internals.
> 
> Note that I've just if 0'd the selinux mess poking into it.  While we
> could trivially port it to the new code by making the tty_private
> structure public this code is just too revolting to be kept around.
> It would never have been there anyway if a person with some amount of
> clue had ever reviewed the selinux code.  And no, it's not just the
> tty portion, the rest of that function is just as bad.

This is disgusting, as much as selinux code you've mentioned ;-/

FWIW, selinux problem here is interesting - essentially, it violates its
own rules since the real object here is not an inode.  It's tty.  And
inode pretty much serves as a name - potentially one of many.  So the
policy should've been associated with tty instead...