diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 5c76737..2aaf72f 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -495,6 +495,10 @@
 	ZONE_CONGESTED,			/* zone has many dirty pages backed by
 					 * a congested BDI
 					 */
+	ZONE_TAIL_LRU_DIRTY,		/* reclaim scanning has recently found
+					 * many dirty file pages at the tail
+					 * of the LRU.
+					 */
 } zone_flags_t;
 
 static inline void zone_set_flag(struct zone *zone, zone_flags_t flag)
@@ -517,6 +521,11 @@
 	return test_bit(ZONE_CONGESTED, &zone->flags);
 }
 
+static inline int zone_is_reclaim_dirty(const struct zone *zone)
+{
+	return test_bit(ZONE_TAIL_LRU_DIRTY, &zone->flags);
+}
+
 static inline int zone_is_reclaim_locked(const struct zone *zone)
 {
 	return test_bit(ZONE_RECLAIM_LOCKED, &zone->flags);