diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 5fdd4e1..b57c2786 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -207,6 +207,7 @@
 void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time);
 void page_writeback_init(void);
 void balance_dirty_pages_ratelimited(struct address_space *mapping);
+bool wb_over_bg_thresh(struct bdi_writeback *wb);
 
 typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
 				void *data);