This patch moves synchronization on mq->delay_work
from blk_mq_free_queue() to blk_sync_queue(), so that
blk_sync_queue can work on mq.
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
 void blk_sync_queue(struct request_queue *q)
 {
        del_timer_sync(&q->timeout);
-       cancel_delayed_work_sync(&q->delay_work);
+
+       if (q->mq_ops) {
+               struct blk_mq_hw_ctx *hctx;
+               int i;
+
+               queue_for_each_hw_ctx(q, hctx, i)
+                       cancel_delayed_work_sync(&hctx->delayed_work);
+       } else {
+               cancel_delayed_work_sync(&q->delay_work);
+       }
 }
 EXPORT_SYMBOL(blk_sync_queue);
 
 
        int i;
 
        queue_for_each_hw_ctx(q, hctx, i) {
-               cancel_delayed_work_sync(&hctx->delayed_work);
                kfree(hctx->ctx_map);
                kfree(hctx->ctxs);
                blk_mq_free_rq_map(hctx);