iov_iter_get_pages_alloc2
err = iov_iter_get_pages_alloc2(&subreq->io_iter, &pages, len, &page_off);
result = iov_iter_get_pages_alloc2(iter, &pagevec,
result = iov_iter_get_pages_alloc2(iter, &pagevec,
ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages,
EXPORT_SYMBOL(iov_iter_get_pages_alloc2);
n = iov_iter_get_pages_alloc2(data, pages, count, offs);