mm: memory: use a folio in validate_page_before_insert()

Use a folio in validate_page_before_insert() to save two compound_head()
calls.

Link: https://lkml.kernel.org/r/20231118023232.1409103-3-wangkefeng.wang@huawei.comSigned-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory.c

@@ -1842,9 +1842,12 @@ pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
 
 static int validate_page_before_insert(struct page *page)
 {
-	if (PageAnon(page) || PageSlab(page) || page_has_type(page))
+	struct folio *folio = page_folio(page);
+
+	if (folio_test_anon(folio) || folio_test_slab(folio) ||
+	    page_has_type(page))
 		return -EINVAL;
-	flush_dcache_page(page);
+	flush_dcache_folio(folio);
 	return 0;
 }