f2fs_parent_dir
struct f2fs_dir_entry *f2fs_parent_dir(struct inode *dir, struct folio **f);
old_dir_entry = f2fs_parent_dir(old_inode,
new_dir_entry = f2fs_parent_dir(new_inode,
old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_folio);