From 9d74e25737d73e93ccddeb5a61bcd56b7b8eb57b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 14 Apr 2014 10:30:07 +0200 Subject: [PATCH] blk-mq: do not initialize req->special Drivers can reach their private data easily using the blk_mq_rq_to_pdu helper and don't need req->special. By not initializing it code can be simplified nicely, and we also shave off a few more instructions from the I/O path. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-flush.c | 10 ++-------- block/blk-mq.c | 15 ++------------- block/blk-mq.h | 1 - drivers/block/null_blk.c | 4 ++-- drivers/block/virtio_blk.c | 6 +++--- 5 files changed, 9 insertions(+), 27 deletions(-) diff --git a/block/blk-flush.c b/block/blk-flush.c index 77f20458910c..0e42adcfb55e 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -306,22 +306,16 @@ 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) { - struct blk_mq_ctx *ctx = first_rq->mq_ctx; - struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu); - - blk_mq_rq_init(hctx, q->flush_rq); - q->flush_rq->mq_ctx = ctx; - /* * 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; - } else { - blk_rq_init(q, q->flush_rq); } q->flush_rq->cmd_type = REQ_TYPE_FS; diff --git a/block/blk-mq.c b/block/blk-mq.c index 658428a28faf..d9d0984d2f01 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -251,24 +251,13 @@ struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, } EXPORT_SYMBOL(blk_mq_alloc_reserved_request); -/* - * Re-init and set pdu, if we have it - */ -void blk_mq_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq) -{ - blk_rq_init(hctx->queue, rq); - - if (hctx->cmd_size) - rq->special = blk_mq_rq_to_pdu(rq); -} - static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct request *rq) { const int tag = rq->tag; struct request_queue *q = rq->q; - blk_mq_rq_init(hctx, rq); + blk_rq_init(hctx->queue, rq); blk_mq_put_tag(hctx->tags, tag); blk_mq_queue_exit(q); @@ -1165,7 +1154,7 @@ static int blk_mq_init_rq_map(struct blk_mq_hw_ctx *hctx, left -= to_do * rq_size; for (j = 0; j < to_do; j++) { hctx->rqs[i] = p; - blk_mq_rq_init(hctx, hctx->rqs[i]); + blk_rq_init(hctx->queue, hctx->rqs[i]); p += rq_size; i++; } diff --git a/block/blk-mq.h b/block/blk-mq.h index ebbe6bac9d61..238379a612e4 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -27,7 +27,6 @@ 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_rq_init(struct blk_mq_hw_ctx *hctx, struct request *rq); /* * CPU hotplug helpers diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 091b9ea14feb..71df69d90900 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -226,7 +226,7 @@ static void null_cmd_end_timer(struct nullb_cmd *cmd) static void null_softirq_done_fn(struct request *rq) { - end_cmd(rq->special); + end_cmd(blk_mq_rq_to_pdu(rq)); } static inline void null_handle_cmd(struct nullb_cmd *cmd) @@ -311,7 +311,7 @@ static void null_request_fn(struct request_queue *q) static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) { - struct nullb_cmd *cmd = rq->special; + struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq); cmd->rq = rq; cmd->nq = hctx->driver_data; diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 6d8a87f252de..c7d02bc9d945 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -112,7 +112,7 @@ static int __virtblk_add_req(struct virtqueue *vq, static inline void virtblk_request_done(struct request *req) { - struct virtblk_req *vbr = req->special; + struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); int error = virtblk_result(vbr); if (req->cmd_type == REQ_TYPE_BLOCK_PC) { @@ -154,7 +154,7 @@ static void virtblk_done(struct virtqueue *vq) static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) { struct virtio_blk *vblk = hctx->queue->queuedata; - struct virtblk_req *vbr = req->special; + struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); unsigned long flags; unsigned int num; const bool last = (req->cmd_flags & REQ_END) != 0; @@ -501,7 +501,7 @@ static int virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx, struct request *rq, unsigned int nr) { struct virtio_blk *vblk = data; - struct virtblk_req *vbr = rq->special; + struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq); sg_init_table(vbr->sg, vblk->sg_elems); return 0; -- 2.30.2