smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
{
	int rc;
	struct kvec *iov = rqst->rq_iov;
	int n_vec = rqst->rq_nvec;
	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
	unsigned int i;
	size_t total_len = 0, sent;
	struct socket *ssocket = server->ssocket;
	int val = 1;

	if (ssocket == NULL)
		return -ENOTSOCK;

	cFYI(1, "Sending smb: smb_len=%u", smb_buf_length);
	dump_smb(iov[0].iov_base, iov[0].iov_len);

	/* cork the socket */
	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
				(char *)&val, sizeof(val));

	rc = smb_send_kvec(server, iov, n_vec, &sent);
	if (rc < 0)
		goto uncork;

	total_len += sent;

	/* now walk the page array and send each page in it */
	for (i = 0; i < rqst->rq_npages; i++) {
		struct kvec p_iov;

		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
		rc = smb_send_kvec(server, &p_iov, 1, &sent);
		kunmap(rqst->rq_pages[i]);
		if (rc < 0)
			break;

		total_len += sent;
	}

uncork:
	/* uncork it */
	val = 0;
	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
				(char *)&val, sizeof(val));

	if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
		cFYI(1, "partial send (wanted=%u sent=%zu): terminating "
			"session", smb_buf_length + 4, total_len);
		/*
		 * If we have only sent part of an SMB then the next SMB could
		 * be taken as the remainder of this one. We need to kill the
		 * socket so the server throws away the partial SMB
		 */
		server->tcpStatus = CifsNeedReconnect;
	}

	if (rc < 0 && rc != -EINTR)
		cERROR(1, "Error %d sending data on socket to server", rc);
	else
		rc = 0;

	return rc;
}
The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.