diff --git a/block/blk-mq.c b/block/blk-mq.c index c9306e3403fe28c61f17e0d5983002ee3e9fbfaf..a99bea4554529bc2c00f5a6f642687715625d490 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -582,6 +582,16 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) list_del_init(&rq->queuelist); blk_mq_start_request(rq); + if (q->dma_drain_size && blk_rq_bytes(rq)) { + /* + * make sure space for the drain appears we + * know we can do this because max_hw_segments + * has been adjusted to be one fewer than the + * device can handle + */ + rq->nr_phys_segments++; + } + /* * Last request in the series. Flag it as such, this * enables drivers to know when IO should be kicked off,