diff --git a/[refs] b/[refs]
index 96b19677e07f..5a7b868b4487 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a0acd820807680d2ccc4ef3448387fcdbf152c73
+refs/heads/master: b5fab14e5d87df4d94161ae5f5e0c8625f9ffda2
diff --git a/trunk/include/linux/mm.h b/trunk/include/linux/mm.h
index 4c482a3ee870..a5c451816fdc 100644
--- a/trunk/include/linux/mm.h
+++ b/trunk/include/linux/mm.h
@@ -599,6 +599,7 @@ static inline struct address_space *page_mapping(struct page *page)
 {
 	struct address_space *mapping = page->mapping;
 
+	VM_BUG_ON(PageSlab(page));
 	if (unlikely(PageSwapCache(page)))
 		mapping = &swapper_space;
 #ifdef CONFIG_SLUB