Hi Jens, except for the DASD case under discussion the last users of ioctl_by_bdev are the file system drivers that want to query CDROM information using ioctls. This series switches them to use function calls directly into the CDROM midlayer instead, which implies: - adding a cdrom_device_info pointer to the gendisk, so that file systems can find it without going to the low-level driver first - ensuring that the CDROM midlayer (which isn't a lot of code) is built in if the file systems are built in so that they can actually call the exported functions Changes since v1: - fix up the no-CDROM error case in isofs_get_last_session to return 0 instead of -EINVAL.