2 files changed, 31 insertions, 16 deletions

diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index d86b320319e0..4898289564ab 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -420,6 +420,7 @@ extern bool flush_work(struct work_struct *work);
 extern bool cancel_work_sync(struct work_struct *work);
 
 extern bool flush_delayed_work(struct delayed_work *dwork);
+extern bool cancel_delayed_work(struct delayed_work *dwork);
 extern bool cancel_delayed_work_sync(struct delayed_work *dwork);
 
 extern void workqueue_set_max_active(struct workqueue_struct *wq,
@@ -429,22 +430,6 @@ extern unsigned int work_cpu(struct work_struct *work);
 extern unsigned int work_busy(struct work_struct *work);
 
 /*
- * Kill off a pending schedule_delayed_work().  Note that the work callback
- * function may still be running on return from cancel_delayed_work(), unless
- * it returns 1 and the work doesn't re-arm itself. Run flush_workqueue() or
- * cancel_work_sync() to wait on it.
- */
-static inline bool cancel_delayed_work(struct delayed_work *work)
-{
-        bool ret;
-
-        ret = del_timer_sync(&work->timer);
-        if (ret)
-                work_clear_pending(&work->work);
-        return ret;
-}
-
-/*
  * Like above, but uses del_timer() instead of del_timer_sync(). This means,
  * if it returns 0 the timer function may be running and the queueing is in
  * progress.
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index b394df8beaee..039d0fae171a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2949,6 +2949,36 @@ bool flush_delayed_work(struct delayed_work *dwork)
 EXPORT_SYMBOL(flush_delayed_work);
 
 /**
+ * cancel_delayed_work - cancel a delayed work
+ * @dwork: delayed_work to cancel
+ *
+ * Kill off a pending delayed_work.  Returns %true if @dwork was pending
+ * and canceled; %false if wasn't pending.  Note that the work callback
+ * function may still be running on return, unless it returns %true and the
+ * work doesn't re-arm itself.  Explicitly flush or use
+ * cancel_delayed_work_sync() to wait on it.
+ *
+ * This function is safe to call from any context including IRQ handler.
+ */
+bool cancel_delayed_work(struct delayed_work *dwork)
+{
+        unsigned long flags;
+        int ret;
+
+        do {
+                ret = try_to_grab_pending(&dwork->work, true, &flags);
+        } while (unlikely(ret == -EAGAIN));
+
+        if (unlikely(ret < 0))
+                return false;
+
+        set_work_cpu_and_clear_pending(&dwork->work, work_cpu(&dwork->work));
+        local_irq_restore(flags);
+        return true;
+}
+EXPORT_SYMBOL(cancel_delayed_work);
+
+/**
  * cancel_delayed_work_sync - cancel a delayed work and wait for it to finish
  * @dwork: the delayed work cancel
  *