rem: file_cookie cookie;
add: fs_cookie cookie;
context: open_vnode(struct vnode *vnode, int omode, bool kernel){	file_cookie cookie;	int status;	status = FS_CALL(vnode,fs_open)(vnode->mount->cookie, vnode->private_node, omode, &cookie);	if (status < 0)		return status;	status = new_file_fd(vnode, cookie, omode, kernel);	if (status < 0) {		FS_CALL(vnode,fs_close)(vnode->mount->cookie, vnode->private_node, cookie);		FS_CALL(vnode,fs_free_cookie)(vnode->mount->cookie, vnode->private_node, cookie);	}	return status;}