From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH resend] compat_ioctl: fix warning caused by qemu
Date: Fri, 1 Jul 2011 16:46:28 +0200
Message-ID: <201107011646.28918.arnd@arndb.de>
References: <20110701093336.GA9582@sig21.net>
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Cc: Kevin Wolf <kwolf@redhat.com>, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Jens Axboe <axboe@kernel.dk>,
	Alexander Viro <viro@zeniv.linux.org.uk>
To: Johannes Stezenbach <js@sig21.net>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20110701093336.GA9582@sig21.net>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: kvm.vger.kernel.org

On Friday 01 July 2011, Johannes Stezenbach wrote:
> 
> On Linux x86_64 host with 32bit userspace, running
> qemu or even just "qemu-img create -f qcow2 some.img 1G"
> causes a kernel warning:
> 
> ioctl32(qemu-img:5296): Unknown cmd fd(3) cmd(00005326){t:'S';sz:0} arg(7fffffff) on some.img
> ioctl32(qemu-img:5296): Unknown cmd fd(3) cmd(801c0204){t:02;sz:28} arg(fff77350) on some.img
> 
> ioctl 00005326 is CDROM_DRIVE_STATUS,
> ioctl 801c0204 is FDGETPRM.
> 
> The warning appears because the Linux compat-ioctl handler for these
> ioctls only applies to block devices, while qemu also uses the ioctls on
> plain files.
> 
> Signed-off-by: Johannes Stezenbach <js@sig21.net>

Acked-by: Arnd Bergmann <arnd@arndb.de>

> ---
> (resend with Cc: suggested by get_maintainer.pl)
> 
> discussed in http://lkml.kernel.org/r/20110617090424.GA19345@sig21.net
> 
> Arnd, is this what you had in mind, or did you mean to move
> all floppy compat definitions?  I decided to go with the
> minimal change.  Tested on both 2.6.39.2 and 3.0-rc5-63-g0d72c6f.

Yes, that should be fine, unless Jens would like to see a different
solution for the struct definitions, e.g. moving all of the floppy
compat ioctl numbers to fd.h. I'm fine with it either way.

	Arnd