Re: [PATCH v4 2/2] s390/dasd: remove ioctl_by_bdev calls

[Christoph Hellwig]

On Wed, Oct 07, 2020 at 11:34:17AM +0200, Christian Borntraeger wrote:
> 
> On 19.05.20 16:22, Stefan Haberland wrote:
> > The IBM partition parser requires device type specific information only
> > available to the DASD driver to correctly register partitions. The
> > current approach of using ioctl_by_bdev with a fake user space pointer
> > is discouraged.
> > 
> > Fix this by replacing IOCTL calls with direct in-kernel function calls.
> > 
> > Suggested-by: Christoph Hellwig <hch@xxxxxx>
> > Signed-off-by: Stefan Haberland <sth@xxxxxxxxxxxxx>
> > Reviewed-by: Jan Hoeppner <hoeppner@xxxxxxxxxxxxx>
> > Reviewed-by: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
> 
> FWIW, this broken the ibm-partition code for virtio-blk, when CONFIG_DASD=m.

What are the symptoms?