It is enough to just check if we can get the budget via .get_budget(). And we don't need to deal with device state change in .get_budget().
For SCSI, one issue to be fixed is that we have to call scsi_mq_uninit_cmd() to free allocated ressources if SCSI device fails to handle the request. And it isn't enough to simply call blk_mq_end_request() to do that if this request is marked as RQF_DONTPREP. Fixes: 0df21c86bdbf(scsi: implement .get_budget and .put_budget for blk-mq) Signed-off-by: Ming Lei <[email protected]> --- block/blk-mq-sched.c | 14 ++------------ block/blk-mq.c | 17 ++++------------- block/blk-mq.h | 5 ++--- drivers/scsi/scsi_lib.c | 11 +++-------- include/linux/blk-mq.h | 2 +- 5 files changed, 12 insertions(+), 37 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 7775f6b12fa9..13a27d4d1671 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -94,23 +94,18 @@ static void blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx) do { struct request *rq; - blk_status_t ret; if (e->type->ops.mq.has_work && !e->type->ops.mq.has_work(hctx)) break; - ret = blk_mq_get_dispatch_budget(hctx); - if (ret == BLK_STS_RESOURCE) + if (!blk_mq_get_dispatch_budget(hctx)) break; rq = e->type->ops.mq.dispatch_request(hctx); if (!rq) { blk_mq_put_dispatch_budget(hctx); break; - } else if (ret != BLK_STS_OK) { - blk_mq_end_request(rq, ret); - continue; } /* @@ -146,22 +141,17 @@ static void blk_mq_do_dispatch_ctx(struct blk_mq_hw_ctx *hctx) do { struct request *rq; - blk_status_t ret; if (!sbitmap_any_bit_set(&hctx->ctx_map)) break; - ret = blk_mq_get_dispatch_budget(hctx); - if (ret == BLK_STS_RESOURCE) + if (!blk_mq_get_dispatch_budget(hctx)) break; rq = blk_mq_dequeue_from_ctx(hctx, ctx); if (!rq) { blk_mq_put_dispatch_budget(hctx); break; - } else if (ret != BLK_STS_OK) { - blk_mq_end_request(rq, ret); - continue; } /* diff --git a/block/blk-mq.c b/block/blk-mq.c index e4d2490f4e7e..f4e1d8447b5d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1134,13 +1134,8 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, } } - if (!got_budget) { - ret = blk_mq_get_dispatch_budget(hctx); - if (ret == BLK_STS_RESOURCE) - break; - if (ret != BLK_STS_OK) - goto fail_rq; - } + if (!got_budget && !blk_mq_get_dispatch_budget(hctx)) + break; list_del_init(&rq->queuelist); @@ -1167,7 +1162,6 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, break; } - fail_rq: if (unlikely(ret != BLK_STS_OK)) { errors++; blk_mq_end_request(rq, BLK_STS_IOERR); @@ -1639,12 +1633,10 @@ static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, if (!blk_mq_get_driver_tag(rq, NULL, false)) goto insert; - ret = blk_mq_get_dispatch_budget(hctx); - if (ret == BLK_STS_RESOURCE) { + if (!blk_mq_get_dispatch_budget(hctx)) { blk_mq_put_driver_tag(rq); goto insert; - } else if (ret != BLK_STS_OK) - goto fail_rq; + } new_cookie = request_to_qc_t(hctx, rq); @@ -1662,7 +1654,6 @@ static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, __blk_mq_requeue_request(rq); goto insert; default: - fail_rq: *cookie = BLK_QC_T_NONE; blk_mq_end_request(rq, ret); return; diff --git a/block/blk-mq.h b/block/blk-mq.h index 522b420dedc0..f97aceff76e9 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -147,14 +147,13 @@ static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx) q->mq_ops->put_budget(hctx); } -static inline blk_status_t blk_mq_get_dispatch_budget( - struct blk_mq_hw_ctx *hctx) +static inline bool blk_mq_get_dispatch_budget(struct blk_mq_hw_ctx *hctx) { struct request_queue *q = hctx->queue; if (q->mq_ops->get_budget) return q->mq_ops->get_budget(hctx); - return BLK_STS_OK; + return true; } #endif diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 7f218ef61900..c537c4d768c1 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1949,27 +1949,22 @@ static void scsi_mq_put_budget(struct blk_mq_hw_ctx *hctx) put_device(&sdev->sdev_gendev); } -static blk_status_t scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx) +static bool scsi_mq_get_budget(struct blk_mq_hw_ctx *hctx) { struct request_queue *q = hctx->queue; struct scsi_device *sdev = q->queuedata; - blk_status_t ret; - - ret = prep_to_mq(scsi_prep_state_check(sdev, NULL)); - if (ret == BLK_STS_RESOURCE || ret != BLK_STS_OK) - return ret; if (!get_device(&sdev->sdev_gendev)) goto out; if (!scsi_dev_queue_ready(q, sdev)) goto out_put_device; - return BLK_STS_OK; + return true; out_put_device: put_device(&sdev->sdev_gendev); out: - return BLK_STS_RESOURCE; + return false; } static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index e5e6becd57d3..439a7970ed5d 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -92,7 +92,7 @@ struct blk_mq_queue_data { typedef blk_status_t (queue_rq_fn)(struct blk_mq_hw_ctx *, const struct blk_mq_queue_data *); -typedef blk_status_t (get_budget_fn)(struct blk_mq_hw_ctx *); +typedef bool (get_budget_fn)(struct blk_mq_hw_ctx *); typedef void (put_budget_fn)(struct blk_mq_hw_ctx *); typedef enum blk_eh_timer_return (timeout_fn)(struct request *, bool); typedef int (init_hctx_fn)(struct blk_mq_hw_ctx *, void *, unsigned int); -- 2.9.5
