diff --git a/block/blk-flush.c b/block/blk-flush.c index 0e42adcfb55e..c41fc19f75d1 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -307,16 +307,8 @@ static bool blk_kick_flush(struct request_queue *q) q->flush_pending_idx ^= 1; blk_rq_init(q, q->flush_rq); - if (q->mq_ops) { - /* - * Reuse the tag value from the fist waiting request, - * with blk-mq the tag is generated during request - * allocation and drivers can rely on it being inside - * the range they asked for. - */ - q->flush_rq->mq_ctx = first_rq->mq_ctx; - q->flush_rq->tag = first_rq->tag; - } + if (q->mq_ops) + blk_mq_clone_flush_request(q->flush_rq, first_rq); q->flush_rq->cmd_type = REQ_TYPE_FS; q->flush_rq->cmd_flags = WRITE_FLUSH | REQ_FLUSH_SEQ; diff --git a/block/blk-mq.c b/block/blk-mq.c index d9d0984d2f01..e644feec068c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -275,6 +275,26 @@ void blk_mq_free_request(struct request *rq) __blk_mq_free_request(hctx, ctx, rq); } +/* + * Clone all relevant state from a request that has been put on hold in + * the flush state machine into the preallocated flush request that hangs + * off the request queue. + * + * For a driver the flush request should be invisible, that's why we are + * impersonating the original request here. + */ +void blk_mq_clone_flush_request(struct request *flush_rq, + struct request *orig_rq) +{ + struct blk_mq_hw_ctx *hctx = + orig_rq->q->mq_ops->map_queue(orig_rq->q, orig_rq->mq_ctx->cpu); + + flush_rq->mq_ctx = orig_rq->mq_ctx; + flush_rq->tag = orig_rq->tag; + memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), + hctx->cmd_size); +} + bool blk_mq_end_io_partial(struct request *rq, int error, unsigned int nr_bytes) { if (blk_update_request(rq, error, blk_rq_bytes(rq))) diff --git a/block/blk-mq.h b/block/blk-mq.h index 238379a612e4..7964dadb7d64 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -27,6 +27,8 @@ void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async); void blk_mq_init_flush(struct request_queue *q); void blk_mq_drain_queue(struct request_queue *q); void blk_mq_free_queue(struct request_queue *q); +void blk_mq_clone_flush_request(struct request *flush_rq, + struct request *orig_rq); /* * CPU hotplug helpers