diff -up drbd-8.4.2_new/drbd/drbd_interval.c.unused drbd-8.4.2_new/drbd/drbd_interval.c
--- drbd-8.4.2_new/drbd/drbd_interval.c.unused	2013-03-11 16:56:20.223046627 +0100
+++ drbd-8.4.2_new/drbd/drbd_interval.c	2013-03-11 15:42:57.180316557 +0100
@@ -19,7 +19,7 @@ sector_t interval_end(struct rb_node *no
  * may have changed.
  */
 static void
-update_interval_end(struct rb_node *node, void *__unused)
+update_interval_end(struct rb_node *node, void *v__unused)
 {
 	struct drbd_interval *this = rb_entry(node, struct drbd_interval, rb);
 	sector_t end;
diff -up drbd-8.4.2_new/user/libgenl.h.unused drbd-8.4.2_new/user/libgenl.h
--- drbd-8.4.2_new/user/libgenl.h.unused	2013-03-11 16:56:41.103106379 +0100
+++ drbd-8.4.2_new/user/libgenl.h	2013-03-11 15:42:32.180242889 +0100
@@ -48,8 +48,8 @@ do {							\
         type __min2 = (y);                      \
         __min1 < __min2 ? __min1: __min2; })
 
-#ifndef __unused
-#define __unused __attribute((unused))
+#ifndef v__unused
+#define v__unused __attribute((unused))
 #endif
 
 #ifndef __read_mostly