1 files changed, 14 insertions, 0 deletions

diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c
index a10e7107bd89..7758fbdb1a27 100644
--- a/sys/kern/subr_taskqueue.c
+++ b/sys/kern/subr_taskqueue.c
@@ -186,11 +186,14 @@ taskqueue_run(struct taskqueue *queue)
 		STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
 		pending = task->ta_pending;
 		task->ta_pending = 0;
+		task->ta_flags |= TAF_PENDING;
 		mtx_unlock(&queue->tq_mutex);
 
 		task->ta_func(task->ta_context, pending);
 
 		mtx_lock(&queue->tq_mutex);
+		task->ta_flags &= ~TAF_PENDING;
+		wakeup(task);
 	}
 
 	/*
@@ -201,6 +204,17 @@ taskqueue_run(struct taskqueue *queue)
 		mtx_unlock(&queue->tq_mutex);
 }
 
+void
+taskqueue_drain(struct taskqueue *queue, struct task *task)
+{
+	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "taskqueue_drain");
+	mtx_lock(&queue->tq_mutex);
+	while (task->ta_pending != 0 || (task->ta_flags & TAF_PENDING)) {
+		msleep(task, &queue->tq_mutex, PWAIT, "-", 0);
+	}
+	mtx_unlock(&queue->tq_mutex);
+}
+
 static void
 taskqueue_swi_enqueue(void *context)
 {