Re: [PATCH V2 1/2] blk-mq: introduce blk_mq_complete_request_sync()

Keith Busch
2019-03-27T13:31:35Z

On Wed, Mar 27, 2019 at 04:51:13PM +0800, Ming Lei wrote:
> @@ -594,8 +594,11 @@ static void __blk_mq_complete_request(struct request *rq)
> /*
> * For a polled request, always complete locallly, it's pointless
> * to redirect the completion.
> + *
> + * If driver requires to complete the request synchronously,
> + * complete it locally, and it is usually done in error handler.
> */
> - if ((rq->cmd_flags & REQ_HIPRI) ||
> + if ((rq->cmd_flags & REQ_HIPRI) || sync ||
> !test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) {
> q->mq_ops->complete(rq);
> return;

I think this is fine and agree this is fixing a problem, but just
considering an alternative: would it be okay to just temporarily clear
QUEUE_FLAG_SAME_COMP in the necessary error handling that wants a sync
completion so that we're not introducing an additional parameter?