---

yaml
---
r: 327192
b: refs/heads/master
c: 3aa6249
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a5b4e57d7cc07cb28ccf16de0876a4770ae84920
+refs/heads/master: 3aa62497594430ea522050b75c033f71f2c60ee6

trunk/kernel/workqueue.c

@@ -977,17 +977,24 @@ static void move_linked_works(struct work_struct *work, struct list_head *head,
 		*nextp = n;
 }
 
-static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
+static void cwq_activate_delayed_work(struct work_struct *work)
 {
-	struct work_struct *work = list_first_entry(&cwq->delayed_works,
-						    struct work_struct, entry);
+	struct cpu_workqueue_struct *cwq = get_work_cwq(work);
 
 	trace_workqueue_activate_work(work);
 	move_linked_works(work, &cwq->pool->worklist, NULL);
 	__clear_bit(WORK_STRUCT_DELAYED_BIT, work_data_bits(work));
 	cwq->nr_active++;
 }
 
+static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
+{
+	struct work_struct *work = list_first_entry(&cwq->delayed_works,
+						    struct work_struct, entry);
+
+	cwq_activate_delayed_work(work);
+}
+
 /**
  * cwq_dec_nr_in_flight - decrement cwq's nr_in_flight
  * @cwq: cwq of interest
@@ -1106,6 +1113,18 @@ static int try_to_grab_pending(struct work_struct *work, bool is_dwork,
 		smp_rmb();
 		if (gcwq == get_work_gcwq(work)) {
 			debug_work_deactivate(work);
+
+			/*
+			 * A delayed work item cannot be grabbed directly
+			 * because it might have linked NO_COLOR work items
+			 * which, if left on the delayed_list, will confuse
+			 * cwq->nr_active management later on and cause
+			 * stall.  Make sure the work item is activated
+			 * before grabbing.
+			 */
+			if (*work_data_bits(work) & WORK_STRUCT_DELAYED)
+				cwq_activate_delayed_work(work);
+
 			list_del_init(&work->entry);
 			cwq_dec_nr_in_flight(get_work_cwq(work),
 				get_work_color(work),