[PATCH] kthread_worker: Add flush delayed work func

[qiang.zhang@windriver.com]

From: Zqiang <qiang.zhang@windriver.com>

Add 'kthread_flush_delayed_work' func, the principle of
this func is wait for a dwork to finish executing the
last queueing.

Signed-off-by: Zqiang <qiang.zhang@windriver.com>
---
 kernel/kthread.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index a5eceecd4513..1afe399ccd02 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -1045,6 +1045,30 @@ void kthread_flush_work(struct kthread_work *work)
 }
 EXPORT_SYMBOL_GPL(kthread_flush_work);
 
+/*
+ * kthread_flush_delayed_work - flush a kthread_delayed_work
+ * @dwork: dwork to flush
+ *
+ * wait for a dwork to finish executing the last queueing
+ */
+void kthread_flush_delayed_work(struct kthread_delayed_work *dwork)
+{
+	struct kthread_work *work = &dwork->work;
+	struct kthread_worker *worker = work->worker;
+	unsigned long flags;
+
+	if (del_timer_sync(&dwork->timer)) {
+		raw_spin_lock_irqsave(&worker->lock, flags);
+		list_del_init(&work->node);
+		if (!work->canceling)
+			kthread_insert_work(worker, work, &worker->work_list);
+
+		raw_spin_unlock_irqrestore(&worker->lock, flags);
+	}
+	kthread_flush_work(work);
+}
+EXPORT_SYMBOL_GPL(kthread_flush_delayed_work);
+
 /*
  * This function removes the work from the worker queue. Also it makes sure
  * that it won't get queued later via the delayed work's timer.
-- 
2.17.1