Re: [PATCH 1/4] add compat_ioctl methods to dasd

[Christoph Hellwig <hch@lst.de>]

On Tue, Nov 15, 2005 at 03:51:17PM +0100, Martin Schwidefsky wrote:
> On Sat, 2005-11-12 at 10:33 +0100, Christoph Hellwig wrote:
> > On Fri, Nov 04, 2005 at 11:16:52PM +0100, Christoph Hellwig wrote:
> > > all dasd ioctls are directly useable from 32bit process, thus switch
> > > the dasd driver to unlocked_ioctl/compat_ioctl and get rid of the
> > > translations in the global table.
> > 
> > ping on all the four s390 compat_ioctl patches.  These are few of the
> > remaining arch compat_ioctl bits and I'd really really like to get rid
> > of them soonish.
> 
> Current status on the four patches:
> 1) dasd ioctl patch didn't compile (missing semicolon after
> lock_kernel())

oops.

> and doesn't work after fixing the compile problem. It's a
> problem with the bdev->bd_disk->private_data which is NULL at the time
> the partition detection code calls the BIODASDINFO and HDIO_GETGEO ioctl
> with ioctl_by_bdev. I don't see an easy way to fix this right now.

my patch doesn't change anything related to dereferencing those fields.

I see the problem that you're probably having: ioctl_by_bdev calls
->ioctl without ensuring ->open has been called previously.  But I don't
see why this couldn't have happened previously.