From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johannes Stezenbach <js@sig21.net>
Subject: Re: missing compat-ioctl for CDROM_DRIVE_STATUS + FDGETPRM
Date: Wed, 29 Jun 2011 14:51:17 +0200
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Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
To: Arnd Bergmann <arnd@arndb.de>
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On Wed, Jun 29, 2011 at 02:30:42PM +0200, Arnd Bergmann wrote:
> On Wednesday 29 June 2011, Johannes Stezenbach wrote:
> > Sorry for very slow reply.  I think qemu's use of these ioctls
> > to probe if the device is a cdrom or floppy is valid, so instead
> > of adding a stat() call to check for block device in qemu, I think
> > it is better to silence the warning in the kernel.
> 
> Well, correct or not, it will keep causing annoying messages on
> old kernels, so why not do both?

OK, I'll send a patch for qemu, too.

> > Do I get it right that just adding two IGNORE_IOCTL() to
> > the ioctl_pointer array in linux/fs/compat_ioctl.c is sufficient,
> > like in commit 3f001711?
> 
> Yes.
> 
> > I.e. these ioctls are handled for block devices earlier
> > in compat_sys_ioctl()?
> 
> Right. We always first ask the driver, and then search the lookup table
> when the driver does not know how to handle it in compat mode.

Good, I'll send a patch soon.


Thanks,
Johannes