+static int slow_work_wait(void *word)
+{
+ schedule();
+ return 0;
+}
+
+/**
+ * slow_work_cancel - Cancel a slow work item
+ * @work: The work item to cancel
+ *
+ * This function will cancel a previously enqueued work item. If we cannot
+ * cancel the work item, it is guarenteed to have run when this function
+ * returns.
+ */
+void slow_work_cancel(struct slow_work *work)
+{
+ bool wait = true, put = false;
+
+ set_bit(SLOW_WORK_CANCELLING, &work->flags);
+
+ spin_lock_irq(&slow_work_queue_lock);
+
+ if (test_bit(SLOW_WORK_PENDING, &work->flags) &&
+ !list_empty(&work->link)) {
+ /* the link in the pending queue holds a reference on the item
+ * that we will need to release */
+ list_del_init(&work->link);
+ wait = false;
+ put = true;
+ clear_bit(SLOW_WORK_PENDING, &work->flags);
+
+ } else if (test_and_clear_bit(SLOW_WORK_ENQ_DEFERRED, &work->flags)) {
+ /* the executor is holding our only reference on the item, so
+ * we merely need to wait for it to finish executing */
+ clear_bit(SLOW_WORK_PENDING, &work->flags);
+ }
+
+ spin_unlock_irq(&slow_work_queue_lock);
+
+ /* the EXECUTING flag is set by the executor whilst the spinlock is set
+ * and before the item is dequeued - so assuming the above doesn't
+ * actually dequeue it, simply waiting for the EXECUTING flag to be
+ * released here should be sufficient */
+ if (wait)
+ wait_on_bit(&work->flags, SLOW_WORK_EXECUTING, slow_work_wait,
+ TASK_UNINTERRUPTIBLE);
+
+ clear_bit(SLOW_WORK_CANCELLING, &work->flags);
+ if (put)
+ slow_work_put_ref(work);
+}
+EXPORT_SYMBOL(slow_work_cancel);
+