block: Enhance new plugging support to support general callbacks
[firefly-linux-kernel-4.4.55.git] / block / blk-core.c
index 78b7b0cb7216ec1c3a86545ad86ece5cd85a24da..77edf051233868c50f26c4130549888dd88b5ca0 100644 (file)
@@ -2638,6 +2638,7 @@ void blk_start_plug(struct blk_plug *plug)
 
        plug->magic = PLUG_MAGIC;
        INIT_LIST_HEAD(&plug->list);
+       INIT_LIST_HEAD(&plug->cb_list);
        plug->should_sort = 0;
 
        /*
@@ -2678,6 +2679,24 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
                q->unplugged_fn(q);
 }
 
+static void flush_plug_callbacks(struct blk_plug *plug)
+{
+       LIST_HEAD(callbacks);
+
+       if (list_empty(&plug->cb_list))
+               return;
+
+       list_splice_init(&plug->cb_list, &callbacks);
+
+       while (!list_empty(&callbacks)) {
+               struct blk_plug_cb *cb = list_first_entry(&callbacks,
+                                                         struct blk_plug_cb,
+                                                         list);
+               list_del(&cb->list);
+               cb->callback(cb);
+       }
+}
+
 void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
        struct request_queue *q;
@@ -2688,6 +2707,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 
        BUG_ON(plug->magic != PLUG_MAGIC);
 
+       flush_plug_callbacks(plug);
        if (list_empty(&plug->list))
                return;