block/raw-posix: avoid bogus fixup for cylinders on DASD disks

large volume DASD that have > 64k cylinders do claim to have
0xFFFE cylinders as special value in the old 16 bit field. We
want to pass this "token" along to the guest, instead of
calculating the real number. Otherwise qemu might fail with
"cyls must be between 1 and 65535"

Cc: qemu-stable@nongnu.org
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block/raw-posix.c

@@ -779,7 +779,6 @@ static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
 {
     BDRVRawState *s = bs->opaque;
     struct hd_geometry ioctl_geo = {0};
-    uint32_t blksize;
 
     /* If DASD, get its geometry */
     if (check_for_dasd(s->fd) < 0) {
@@ -799,12 +798,6 @@ static int hdev_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
     }
     geo->heads = ioctl_geo.heads;
     geo->sectors = ioctl_geo.sectors;
-    if (!probe_physical_blocksize(s->fd, &blksize)) {
-        /* overwrite cyls: HDIO_GETGEO result is incorrect for big drives */
-        geo->cylinders = bdrv_nb_sectors(bs) / (blksize / BDRV_SECTOR_SIZE)
-                                             / (geo->heads * geo->sectors);
-        return 0;
-    }
     geo->cylinders = ioctl_geo.cylinders;
 
     return 0;