From 4244a5984703456e3d77d1e5e734b1b430bc47a2 Mon Sep 17 00:00:00 2001
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Date: Tue, 18 Sep 2012 10:40:00 -0700
Subject: [PATCH] --- yaml --- r: 327192 b: refs/heads/master c:
 3aa62497594430ea522050b75c033f71f2c60ee6 h: refs/heads/master v: v3

---
 [refs]                   |  2 +-
 trunk/kernel/workqueue.c | 25 ++++++++++++++++++++++---
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 3bd24d37d811..939d89fa80c3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a5b4e57d7cc07cb28ccf16de0876a4770ae84920
+refs/heads/master: 3aa62497594430ea522050b75c033f71f2c60ee6
diff --git a/trunk/kernel/workqueue.c b/trunk/kernel/workqueue.c
index 48becaba1c94..d2fe8e77ceb7 100644
--- a/trunk/kernel/workqueue.c
+++ b/trunk/kernel/workqueue.c
@@ -977,10 +977,9 @@ 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);
@@ -988,6 +987,14 @@ static void cwq_activate_first_delayed(struct cpu_workqueue_struct *cwq)
 	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),