niu_next_page
for (; (p = *pp) != NULL; pp = &niu_next_page(p)) {
niu_next_page(page) = rp->rxhash[h];
*link = niu_next_page(page);
niu_next_page(page) = NULL;
*link = niu_next_page(page);
niu_next_page(page) = NULL;
struct page *next = niu_next_page(page);
niu_next_page(page) = NULL;
struct page *next = niu_next_page(page);