-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- page_head = page;
- if (unlikely(PageTail(page))) {
- put_page(page);
- /* serialize against __split_huge_page_splitting() */
- local_irq_disable();
- if (likely(__get_user_pages_fast(address, 1, !ro, &page) == 1)) {
- page_head = compound_head(page);
- /*
- * page_head is valid pointer but we must pin
- * it before taking the PG_lock and/or
- * PG_compound_lock. The moment we re-enable
- * irqs __split_huge_page_splitting() can
- * return and the head page can be freed from
- * under us. We can't take the PG_lock and/or
- * PG_compound_lock on a page that could be
- * freed from under us.
- */
- if (page != page_head) {
- get_page(page_head);
- put_page(page);
- }
- local_irq_enable();
- } else {
- local_irq_enable();
- goto again;
- }
- }
-#else
- page_head = compound_head(page);
- if (page != page_head) {
- get_page(page_head);
- put_page(page);
- }
-#endif
-
- lock_page(page_head);
-