diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c
index cf045f5..be1e2ed 100644
--- a/arch/s390/mm/gup.c
+++ b/arch/s390/mm/gup.c
@@ -261,7 +261,14 @@
 
 	might_sleep();
 	start &= PAGE_MASK;
-	nr = __get_user_pages_fast(start, nr_pages, write, pages);
+	/*
+	 * The FAST_GUP case requires FOLL_WRITE even for pure reads,
+	 * because get_user_pages() may need to cause an early COW in
+	 * order to avoid confusing the normal COW routines. So only
+	 * targets that are already writable are safe to do by just
+	 * looking at the page tables.
+	 */
+	nr = __get_user_pages_fast(start, nr_pages, 1, pages);
 	if (nr == nr_pages)
 		return nr;