diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9bee7ec..47a9392 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -224,6 +224,7 @@
 	pgoff_t pgoff;			/* Logical page offset based on vma */
 	void __user *virtual_address;	/* Faulting virtual address */
 
+	struct page *cow_page;		/* Handler may choose to COW */
 	struct page *page;		/* ->fault handlers should return a
 					 * page here, unless VM_FAULT_NOPAGE
 					 * is set (which is also implied by