rem: if (descriptor->ops->fd_close) retval = descriptor->ops->fd_close(descriptor, fd, ioContext); else retval = EOPNOTSUPP;
add: TRACE(("user_close(descriptor = %p)\n",descriptor));  remove_fd(io, fd);
context: user_close(int fd){	struct io_context *ioContext = get_current_io_context(false);	struct file_descriptor *descriptor = get_fd(ioContext, fd);	int retval;	if (descriptor == NULL)		return EBADF;	if (descriptor->ops->fd_close)		retval = descriptor->ops->fd_close(descriptor, fd, ioContext);	else		retval = EOPNOTSUPP;	put_fd(descriptor);	return retval;}