[PATCH] dlm: use kern_recvmsg()

static int receive_from_sock(struct connection *con)

{

	int ret = 0;

	struct msghdr msg;

	struct iovec iov[2];

	mm_segment_t fs;

	struct msghdr msg = {};

	struct kvec iov[2];

	unsigned len;

	int r;

	int call_again_soon = 0;

	int nvec;

	mutex_lock(&con->sock_mutex);

		cbuf_init(&con->cb, PAGE_CACHE_SIZE);

	}

	msg.msg_control = NULL;

	msg.msg_controllen = 0;

	msg.msg_iovlen = 1;

	msg.msg_iov = iov;

	msg.msg_name = NULL;

	msg.msg_namelen = 0;

	msg.msg_flags = 0;

	/*

	 * iov[0] is the bit of the circular buffer between the current end

	 * point (cb.base + cb.len) and the end of the buffer.

	 */

	iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);

	iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);

	iov[1].iov_len = 0;

	nvec = 1;

	/*

	 * iov[1] is the bit of the circular buffer between the start of the

		iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);

		iov[1].iov_len = con->cb.base;

		iov[1].iov_base = page_address(con->rx_page);

		msg.msg_iovlen = 2;

		nvec = 2;

	}

	len = iov[0].iov_len + iov[1].iov_len;

	fs = get_fs();

	set_fs(get_ds());

	r = ret = sock_recvmsg(con->sock, &msg, len,

	r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,

			       MSG_DONTWAIT | MSG_NOSIGNAL);

	set_fs(fs);

	if (ret <= 0)

		goto out_close;