From bf57229745f849e500ba69ff91e35bc8160a7373 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 13 Sep 2014 16:40:08 -0700 Subject: [PATCH] blk-mq: remove REQ_END Pass an explicit parameter for the last request in a batch to ->queue_rq instead of using a request flag. Besides being a cleaner and non-stateful interface this is also required for the next patch, which fixes the blk-mq I/O submission code to not start a time too early. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-mq.c | 22 +++++----------------- drivers/block/mtip32xx/mtip32xx.c | 3 ++- drivers/block/null_blk.c | 3 ++- drivers/block/virtio_blk.c | 4 ++-- drivers/scsi/scsi_lib.c | 3 ++- include/linux/blk-mq.h | 2 +- include/linux/blk_types.h | 2 -- 7 files changed, 14 insertions(+), 25 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index e743d28620b2..32b4797f4186 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -384,7 +384,7 @@ void blk_mq_complete_request(struct request *rq) } EXPORT_SYMBOL(blk_mq_complete_request); -static void blk_mq_start_request(struct request *rq, bool last) +static void blk_mq_start_request(struct request *rq) { struct request_queue *q = rq->q; @@ -421,16 +421,6 @@ static void blk_mq_start_request(struct request *rq, bool last) */ rq->nr_phys_segments++; } - - /* - * Flag the last request in the series so that drivers know when IO - * should be kicked off, if they don't do it on a per-request basis. - * - * Note: the flag isn't the only condition drivers should do kick off. - * If drive is busy, the last request might not have the bit set. - */ - if (last) - rq->cmd_flags |= REQ_END; } static void __blk_mq_requeue_request(struct request *rq) @@ -440,8 +430,6 @@ static void __blk_mq_requeue_request(struct request *rq) trace_block_rq_requeue(q, rq); clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); - rq->cmd_flags &= ~REQ_END; - if (q->dma_drain_size && blk_rq_bytes(rq)) rq->nr_phys_segments--; } @@ -755,9 +743,9 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) rq = list_first_entry(&rq_list, struct request, queuelist); list_del_init(&rq->queuelist); - blk_mq_start_request(rq, list_empty(&rq_list)); + blk_mq_start_request(rq); - ret = q->mq_ops->queue_rq(hctx, rq); + ret = q->mq_ops->queue_rq(hctx, rq, list_empty(&rq_list)); switch (ret) { case BLK_MQ_RQ_QUEUE_OK: queued++; @@ -1198,14 +1186,14 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) int ret; blk_mq_bio_to_request(rq, bio); - blk_mq_start_request(rq, true); + blk_mq_start_request(rq); /* * For OK queue, we are done. For error, kill it. Any other * error (busy), just add it to our list as we previously * would have done */ - ret = q->mq_ops->queue_rq(data.hctx, rq); + ret = q->mq_ops->queue_rq(data.hctx, rq, true); if (ret == BLK_MQ_RQ_QUEUE_OK) goto done; else { diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c index 5c8e7fe07745..0e2084f37c67 100644 --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -3775,7 +3775,8 @@ static bool mtip_check_unal_depth(struct blk_mq_hw_ctx *hctx, return false; } -static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) +static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq, + bool last) { int ret; diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 00d469c7f9f7..c5b7315c2c13 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -313,7 +313,8 @@ static void null_request_fn(struct request_queue *q) } } -static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq) +static int null_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *rq, + bool last) { struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq); diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 0a581400de0f..13756e016797 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -164,14 +164,14 @@ static void virtblk_done(struct virtqueue *vq) spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); } -static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) +static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req, + bool last) { struct virtio_blk *vblk = hctx->queue->queuedata; struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); unsigned long flags; unsigned int num; int qid = hctx->queue_num; - const bool last = (req->cmd_flags & REQ_END) != 0; int err; bool notify = false; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 1f2bae475cb7..f1df41168391 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1855,7 +1855,8 @@ static void scsi_mq_done(struct scsi_cmnd *cmd) blk_mq_complete_request(cmd->request); } -static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) +static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req, + bool last) { struct request_queue *q = req->q; struct scsi_device *sdev = q->queuedata; diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index a1e31f274fcd..9c4e306a9217 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -77,7 +77,7 @@ struct blk_mq_tag_set { struct list_head tag_list; }; -typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *); +typedef int (queue_rq_fn)(struct blk_mq_hw_ctx *, struct request *, bool); typedef struct blk_mq_hw_ctx *(map_queue_fn)(struct request_queue *, const int); typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int); typedef void (exit_hctx_fn)(struct blk_mq_hw_ctx *, unsigned int); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 66c2167f04a9..bb7d66460e7a 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -188,7 +188,6 @@ enum rq_flag_bits { __REQ_MIXED_MERGE, /* merge of different types, fail separately */ __REQ_KERNEL, /* direct IO to kernel pages */ __REQ_PM, /* runtime pm request */ - __REQ_END, /* last of chain of requests */ __REQ_HASHED, /* on IO scheduler merge hash */ __REQ_MQ_INFLIGHT, /* track inflight for MQ */ __REQ_NR_BITS, /* stops here */ @@ -242,7 +241,6 @@ enum rq_flag_bits { #define REQ_SECURE (1ULL << __REQ_SECURE) #define REQ_KERNEL (1ULL << __REQ_KERNEL) #define REQ_PM (1ULL << __REQ_PM) -#define REQ_END (1ULL << __REQ_END) #define REQ_HASHED (1ULL << __REQ_HASHED) #define REQ_MQ_INFLIGHT (1ULL << __REQ_MQ_INFLIGHT)