static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
{
	int tot_pages = 0;
	unsigned int nr_pages;
	unsigned int i;

	/* figure out the number of pages in the vector */
	for (i = 0; i < nr_iovecs; i++) {
		nr_pages = rds_pages_in_vec(&iov[i]);
		if (nr_pages == 0)
			return -EINVAL;

		tot_pages += nr_pages;

		/*
		 * nr_pages for one entry is limited to (UINT_MAX>>PAGE_SHIFT)+1,
		 * so tot_pages cannot overflow without first going negative.
		 */
		if (tot_pages < 0)
			return -EINVAL;
	}

	return tot_pages;
}
static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs)
{
	int tot_pages = 0;
	unsigned int nr_pages;
	unsigned int i;

	 
	for (i = 0; i < nr_iovecs; i++) {
		nr_pages = rds_pages_in_vec(&iov[i]);
		if (nr_pages == 0)
			return -EINVAL;

		tot_pages += nr_pages;

		 
		if (tot_pages < 0)
			return -EINVAL;
	}

	return tot_pages;
}