disk_sector_no disk_size (struct disk *);
void disk_read (struct disk *, disk_sector_no, void *);
void disk_write (struct disk *, disk_sector_no, const void *);
disk_sector_no disk_size (struct disk *);
void disk_read (struct disk *, disk_sector_no, void *);
void disk_write (struct disk *, disk_sector_no, const void *);