#ifdef CONFIG_BLOCK
extern int register_blkdev(unsigned int, const char *);
-extern int unregister_blkdev(unsigned int, const char *);
+extern void unregister_blkdev(unsigned int, const char *);
extern struct block_device *bdget(dev_t);
extern void bd_set_size(struct block_device *, loff_t size);
extern void bd_forget(struct inode *inode);