* switched to private queue
	* got ->queue set
	* ->open() and friends are using ->bd_disk->private_data instead of
	  messing with DEVICE_NR(inode->i_rdev)
	* request handler uses ->rq_disk->private_data instead of DEVICE_NR(...)
	* DEVICE_NR() removed.
	* switched to new methods.
	* got rid of CURRENT