s390/dasd: remove ioctl_by_bdev calls

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@lst.de>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

include/linux/dasd_mod.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef DASD_MOD_H
+#define DASD_MOD_H
+
+#include <asm/dasd.h>
+
+extern int dasd_biodasdinfo(struct gendisk *disk, dasd_information2_t *info);
+
+#endif