#define dev_to_disk(device) container_of(device, struct gendisk, dev)
#define dev_to_part(device) container_of(device, struct hd_struct, dev)
-extern struct device_type disk_type;
extern struct device_type part_type;
extern struct kobject *block_depr;
extern struct class block_class;
extern struct gendisk *alloc_disk(int minors);
extern struct kobject *get_disk(struct gendisk *disk);
extern void put_disk(struct gendisk *disk);
-extern void genhd_media_change_notify(struct gendisk *disk);
extern void blk_register_region(dev_t devt, unsigned long range,
struct module *module,
struct kobject *(*probe)(dev_t, int *, void *),