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

[Nick Piggin <npiggin@suse.de>]

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.

Well thanks for this. Yes it is an obviously nicer way to do it, so
tty doesn't have to know what vfs uses files list for.

 
> 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.

Why is it a mess? Just because of the conceptual nastiness of checking
a tty object via a random one of its inodes? How would be a better way
to do this?

I think for a first pass, a simple conversion for all code would be good
for me because then it stops blocking the scaling patch. (and it's
more bisectable).