On Mon, Nov 26, 2018 at 09:35:55AM -0700, Jens Axboe wrote: > If we are issuing a list of requests, we know if we're at the last one. > If we fail issuing, ensure that we call ->commits_rqs() to flush any > potential previous requests.
One comment below, otherwise Reviewed-by: Omar Sandoval <[email protected]> > Signed-off-by: Jens Axboe <[email protected]> > --- > block/blk-core.c | 2 +- > block/blk-mq.c | 32 ++++++++++++++++++++++++-------- > block/blk-mq.h | 2 +- > 3 files changed, 26 insertions(+), 10 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index c9758d185357..808a65d23f1a 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1334,7 +1334,7 @@ blk_status_t blk_insert_cloned_request(struct > request_queue *q, struct request * > * bypass a potential scheduler on the bottom device for > * insert. > */ > - return blk_mq_request_issue_directly(rq); > + return blk_mq_request_issue_directly(rq, true); > } > EXPORT_SYMBOL_GPL(blk_insert_cloned_request); > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 6a249bf6ed00..0a12cec0b426 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1260,6 +1260,14 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, > struct list_head *list, > if (!list_empty(list)) { > bool needs_restart; > > + /* > + * If we didn't flush the entire list, we could have told > + * the driver there was more coming, but that turned out to > + * be a lie. > + */ > + if (q->mq_ops->commit_rqs) > + q->mq_ops->commit_rqs(hctx); > + This hunk seems like it should go with the patch adding commit_rqs. > spin_lock(&hctx->lock); > list_splice_init(list, &hctx->dispatch); > spin_unlock(&hctx->lock); > @@ -1736,12 +1744,12 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx > *hctx, struct request *rq) > > static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, > struct request *rq, > - blk_qc_t *cookie) > + blk_qc_t *cookie, bool last) > { > struct request_queue *q = rq->q; > struct blk_mq_queue_data bd = { > .rq = rq, > - .last = true, > + .last = last, > }; > blk_qc_t new_cookie; > blk_status_t ret; > @@ -1776,7 +1784,7 @@ static blk_status_t __blk_mq_issue_directly(struct > blk_mq_hw_ctx *hctx, > static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > struct request *rq, > blk_qc_t *cookie, > - bool bypass_insert) > + bool bypass_insert, bool last) > { > struct request_queue *q = rq->q; > bool run_queue = true; > @@ -1805,7 +1813,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct > blk_mq_hw_ctx *hctx, > goto insert; > } > > - return __blk_mq_issue_directly(hctx, rq, cookie); > + return __blk_mq_issue_directly(hctx, rq, cookie, last); > insert: > if (bypass_insert) > return BLK_STS_RESOURCE; > @@ -1824,7 +1832,7 @@ static void blk_mq_try_issue_directly(struct > blk_mq_hw_ctx *hctx, > > hctx_lock(hctx, &srcu_idx); > > - ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false); > + ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true); > if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) > blk_mq_sched_insert_request(rq, false, true, false); > else if (ret != BLK_STS_OK) > @@ -1833,7 +1841,7 @@ static void blk_mq_try_issue_directly(struct > blk_mq_hw_ctx *hctx, > hctx_unlock(hctx, srcu_idx); > } > > -blk_status_t blk_mq_request_issue_directly(struct request *rq) > +blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) > { > blk_status_t ret; > int srcu_idx; > @@ -1841,7 +1849,7 @@ blk_status_t blk_mq_request_issue_directly(struct > request *rq) > struct blk_mq_hw_ctx *hctx = rq->mq_hctx; > > hctx_lock(hctx, &srcu_idx); > - ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true); > + ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last); > hctx_unlock(hctx, srcu_idx); > > return ret; > @@ -1856,7 +1864,7 @@ void blk_mq_try_issue_list_directly(struct > blk_mq_hw_ctx *hctx, > queuelist); > > list_del_init(&rq->queuelist); > - ret = blk_mq_request_issue_directly(rq); > + ret = blk_mq_request_issue_directly(rq, list_empty(list)); > if (ret != BLK_STS_OK) { > if (ret == BLK_STS_RESOURCE || > ret == BLK_STS_DEV_RESOURCE) { > @@ -1866,6 +1874,14 @@ void blk_mq_try_issue_list_directly(struct > blk_mq_hw_ctx *hctx, > blk_mq_end_request(rq, ret); > } > } > + > + /* > + * If we didn't flush the entire list, we could have told > + * the driver there was more coming, but that turned out to > + * be a lie. > + */ > + if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs) > + hctx->queue->mq_ops->commit_rqs(hctx); > } > > static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) > diff --git a/block/blk-mq.h b/block/blk-mq.h > index 9ae8e9f8f8b1..7291e5379358 100644 > --- a/block/blk-mq.h > +++ b/block/blk-mq.h > @@ -69,7 +69,7 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, > struct blk_mq_ctx *ctx, > struct list_head *list); > > /* Used by blk_insert_cloned_request() to issue request directly */ > -blk_status_t blk_mq_request_issue_directly(struct request *rq); > +blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last); > void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, > struct list_head *list); > > -- > 2.17.1 >
