From 43046b606673c9c991919ff75b980b72541e9ede Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed, 14 Oct 2009 09:16:42 -0700
Subject: [PATCH] workqueue: add 'flush_delayed_work()' to run and wait for
 delayed work

It basically turns a delayed work into an immediate work, and then waits
for it to finish.
---
 include/linux/workqueue.h |  1 +
 kernel/workqueue.c        | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 7ef0c7b94f31..cf24c20de9e4 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -207,6 +207,7 @@ extern int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
 
 extern void flush_workqueue(struct workqueue_struct *wq);
 extern void flush_scheduled_work(void);
+extern void flush_delayed_work(struct delayed_work *work);
 
 extern int schedule_work(struct work_struct *work);
 extern int schedule_work_on(int cpu, struct work_struct *work);
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index addfe2df93b1..ccefe574dcf7 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -639,6 +639,24 @@ int schedule_delayed_work(struct delayed_work *dwork,
 }
 EXPORT_SYMBOL(schedule_delayed_work);
 
+/**
+ * flush_delayed_work - block until a dwork_struct's callback has terminated
+ * @dwork: the delayed work which is to be flushed
+ *
+ * Any timeout is cancelled, and any pending work is run immediately.
+ */
+void flush_delayed_work(struct delayed_work *dwork)
+{
+	if (del_timer(&dwork->timer)) {
+		struct cpu_workqueue_struct *cwq;
+		cwq = wq_per_cpu(keventd_wq, get_cpu());
+		__queue_work(cwq, &dwork->work);
+		put_cpu();
+	}
+	flush_work(&dwork->work);
+}
+EXPORT_SYMBOL(flush_delayed_work);
+
 /**
  * schedule_delayed_work_on - queue work in global workqueue on CPU after delay
  * @cpu: cpu to use
-- 
2.34.1