From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1752270Ab2BVMkE (ORCPT <rfc822;w@1wt.eu>);
	Wed, 22 Feb 2012 07:40:04 -0500
Received: from out5-smtp.messagingengine.com ([66.111.4.29]:43240 "EHLO
	out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK)
	by vger.kernel.org with ESMTP id S1751871Ab2BVMkC (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 22 Feb 2012 07:40:02 -0500
X-Sasl-enc: SBdlNZuKCDhAsPLN/KRQcAg65HTa7IxbTReyyUV9fopBNrttq6FRQGVy1w 1329914401
Message-ID: <1329914392.2193.71.camel@perseus.themaw.net>
Subject: Re: compat: autofs v5 packet size ambiguity - update
From: Ian Kent <raven@themaw.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Miller <davem@davemloft.net>, linux-kernel@vger.kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, autofs@vger.kernel.org,
        Thomas Meyer <thomas@m3y3r.de>, Al Viro <viro@zeniv.linux.org.uk>
Date: Wed, 22 Feb 2012 20:39:52 +0800
In-Reply-To: <1329912927.2193.68.camel@perseus.themaw.net>
References: <CA+55aFzhS69QSoN1j+Z2md116u+3OfniAoE0QMo6xyBjDyjbEw@mail.gmail.com>
	 <20120221.221609.218135609185671883.davem@davemloft.net>
	 <CA+55aFwvmZGDzO_8wwYfH8HsLE=qCmLkJfeMyCe4PVvOYbDMHQ@mail.gmail.com>
	 <CA+55aFzv3X3yW8WZGMZO+aKa=qWi2w8=zn2DP-Q3jRry8Ermyw@mail.gmail.com>
	 <CA+55aFyh1NmBt0LwR3+iD6B-Xa8wAs-nGJ0MBouPhTzWUi8W5g@mail.gmail.com>
	 <1329889428.2193.45.camel@perseus.themaw.net>
	 <1329890027.2193.48.camel@perseus.themaw.net>
	 <1329890251.2193.50.camel@perseus.themaw.net>
	 <1329903139.2193.66.camel@perseus.themaw.net>
	 <1329912927.2193.68.camel@perseus.themaw.net>
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.2.3 (3.2.3-1.fc16) 
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Wed, 2012-02-22 at 20:15 +0800, Ian Kent wrote:
> On Wed, 2012-02-22 at 17:32 +0800, Ian Kent wrote:
> > On Wed, 2012-02-22 at 13:57 +0800, Ian Kent wrote:
> > > On Wed, 2012-02-22 at 13:53 +0800, Ian Kent wrote:
> > > > On Wed, 2012-02-22 at 13:43 +0800, Ian Kent wrote:
> > > > > On Tue, 2012-02-21 at 20:56 -0800, Linus Torvalds wrote:
> > > > 
> > > > Ahh ... forgot to set the file_operations structure member .. oops
> > > > 
> > > > >  
> > > > > +static int autofs4_root_dir_open(struct inode *inode, struct file *file)
> > > > > +{
> > > > > +	struct autofs_sb_info *sbi= autofs4_sbi(file->f_path.dentry->d_sb);
> > > > > +	if (sbi->compat_daemon < 0)
> > > > > +		sbi->compat_daemon = is_compat_task();
> > > > > +	return dcache_dir_open(inode, file);
> > > > > +}
> > > > > +
> > > > 
> > > 
> > > Lets try that again.
> > 
> > Oh, DOH ... 
> > 
> > The process mounting the autofs mount is passing the pipe it will use
> > for communication via a mount option so we can do this right in
> > fill_super.
> > 
> > I'm out for a while, I'll update the patch when I'm back.

This is *still* not right.

The daemon could be SIGKILLed and then re-connect to the existing mounts
and set a new pipe file handle. But that new task may or may not be a
compat task.

Let me fix that too.