bool dir_create (disk_sector_t sector, size_t entry_cnt);
struct dir *dir_open (struct inode *);
struct dir *dir_open_root (void);
struct dir *dir_reopen (struct dir *);
void dir_close (struct dir *);
struct inode *dir_get_inode (struct dir *);
bool dir_create (disk_sector_t sector, size_t entry_cnt);
struct dir *dir_open (struct inode *);
struct dir *dir_open_root (void);
struct dir *dir_reopen (struct dir *);
void dir_close (struct dir *);
struct inode *dir_get_inode (struct dir *);