diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 38d45d8..a4d0cee 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -445,17 +445,12 @@
 	return cur_time;
 }
 
-/*
- * Increment the wb's writeout completion count and the global writeout
- * completion count. Called from test_clear_page_writeback().
- */
-static inline void __wb_writeout_inc(struct bdi_writeback *wb)
+static void wb_domain_writeout_inc(struct wb_domain *dom,
+				   struct fprop_local_percpu *completions,
+				   unsigned int max_prop_frac)
 {
-	struct wb_domain *dom = &global_wb_domain;
-
-	__inc_wb_stat(wb, WB_WRITTEN);
-	__fprop_inc_percpu_max(&dom->completions, &wb->completions,
-			       wb->bdi->max_prop_frac);
+	__fprop_inc_percpu_max(&dom->completions, completions,
+			       max_prop_frac);
 	/* First event after period switching was turned off? */
 	if (!unlikely(dom->period_time)) {
 		/*
@@ -469,6 +464,17 @@
 	}
 }
 
+/*
+ * Increment @wb's writeout completion count and the global writeout
+ * completion count. Called from test_clear_page_writeback().
+ */
+static inline void __wb_writeout_inc(struct bdi_writeback *wb)
+{
+	__inc_wb_stat(wb, WB_WRITTEN);
+	wb_domain_writeout_inc(&global_wb_domain, &wb->completions,
+			       wb->bdi->max_prop_frac);
+}
+
 void wb_writeout_inc(struct bdi_writeback *wb)
 {
 	unsigned long flags;
@@ -571,10 +577,9 @@
 	return (thresh + bg_thresh) / 2;
 }
 
-static unsigned long hard_dirty_limit(unsigned long thresh)
+static unsigned long hard_dirty_limit(struct wb_domain *dom,
+				      unsigned long thresh)
 {
-	struct wb_domain *dom = &global_wb_domain;
-
 	return max(thresh, dom->dirty_limit);
 }
 
@@ -744,7 +749,7 @@
 	struct bdi_writeback *wb = dtc->wb;
 	unsigned long write_bw = wb->avg_write_bandwidth;
 	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);
-	unsigned long limit = hard_dirty_limit(dtc->thresh);
+	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);
 	unsigned long wb_thresh = dtc->wb_thresh;
 	unsigned long x_intercept;
 	unsigned long setpoint;		/* dirty pages' target balance point */
@@ -1029,7 +1034,7 @@
 	struct bdi_writeback *wb = dtc->wb;
 	unsigned long dirty = dtc->dirty;
 	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);
-	unsigned long limit = hard_dirty_limit(dtc->thresh);
+	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);
 	unsigned long setpoint = (freerun + limit) / 2;
 	unsigned long write_bw = wb->avg_write_bandwidth;
 	unsigned long dirty_ratelimit = wb->dirty_ratelimit;
@@ -1681,7 +1686,7 @@
 
         for ( ; ; ) {
 		global_dirty_limits(&background_thresh, &dirty_thresh);
-		dirty_thresh = hard_dirty_limit(dirty_thresh);
+		dirty_thresh = hard_dirty_limit(&global_wb_domain, dirty_thresh);
 
                 /*
                  * Boost the allowable dirty threshold a bit for page