Re: missing compat-ioctl for CDROM_DRIVE_STATUS + FDGETPRM

[Johannes Stezenbach <js@sig21.net>]

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