extern struct block_device *bdget(dev_t);
extern struct block_device *bdgrab(struct block_device *bdev);
extern void bd_set_size(struct block_device *, loff_t size);
+extern sector_t blkdev_max_block(struct block_device *bdev);
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
extern void invalidate_bdev(struct block_device *);