diff --git a/[refs] b/[refs]
index dde0889bc0bc..0f8950a587ac 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 10ee27a06cc8eb57f83342a8eabcb75deb872d52
+refs/heads/master: ed84825b785ceb932af7dd5aa08614801721320b
diff --git a/trunk/mm/page-writeback.c b/trunk/mm/page-writeback.c
index 0713bfbf0954..1534ebd6e70f 100644
--- a/trunk/mm/page-writeback.c
+++ b/trunk/mm/page-writeback.c
@@ -692,7 +692,7 @@ static unsigned long bdi_position_ratio(struct backing_dev_info *bdi,
 	 *     => fast response on large errors; small oscillation near setpoint
 	 */
 	setpoint = (freerun + limit) / 2;
-	x = div_s64((setpoint - dirty) << RATELIMIT_CALC_SHIFT,
+	x = div_s64(((s64)setpoint - (s64)dirty) << RATELIMIT_CALC_SHIFT,
 		    limit - setpoint + 1);
 	pos_ratio = x;
 	pos_ratio = pos_ratio * x >> RATELIMIT_CALC_SHIFT;