On Thu, Aug 02, 2018 at 11:29:43AM -0700, Bart Van Assche wrote: > Make sure that blk_pm_add_request() is called exactly once before > a request is added to a software queue, to the scheduler and also > before .queue_rq() is called directly. Call blk_pm_put_request() > after a request has finished. > > Signed-off-by: Bart Van Assche <[email protected]> > Cc: Christoph Hellwig <[email protected]> > Cc: Jianchao Wang <[email protected]> > Cc: Ming Lei <[email protected]> > Cc: Alan Stern <[email protected]> > Cc: Johannes Thumshirn <[email protected]> > --- > block/blk-mq-sched.c | 13 +++++++++++-- > block/blk-mq.c | 8 ++++++++ > 2 files changed, 19 insertions(+), 2 deletions(-) > > diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c > index cf9c66c6d35a..d87839b31d56 100644 > --- a/block/blk-mq-sched.c > +++ b/block/blk-mq-sched.c > @@ -14,6 +14,7 @@ > #include "blk-mq-debugfs.h" > #include "blk-mq-sched.h" > #include "blk-mq-tag.h" > +#include "blk-pm.h" > #include "blk-wbt.h" > > void blk_mq_sched_free_hctx_data(struct request_queue *q, > @@ -349,6 +350,8 @@ static bool blk_mq_sched_bypass_insert(struct > blk_mq_hw_ctx *hctx, > { > /* dispatch flush rq directly */ > if (rq->rq_flags & RQF_FLUSH_SEQ) { > + blk_pm_add_request(rq->q, rq); > + > spin_lock(&hctx->lock); > list_add(&rq->queuelist, &hctx->dispatch); > spin_unlock(&hctx->lock); > @@ -380,6 +383,8 @@ void blk_mq_sched_insert_request(struct request *rq, bool > at_head, > if (blk_mq_sched_bypass_insert(hctx, !!e, rq)) > goto run; > > + blk_pm_add_request(q, rq); > + > if (e && e->type->ops.mq.insert_requests) { > LIST_HEAD(list); > > @@ -402,10 +407,14 @@ void blk_mq_sched_insert_requests(struct request_queue > *q, > { > struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); > struct elevator_queue *e = hctx->queue->elevator; > + struct request *rq; > + > + if (e && e->type->ops.mq.insert_requests) { > + list_for_each_entry(rq, list, queuelist) > + blk_pm_add_request(q, rq); > > - if (e && e->type->ops.mq.insert_requests) > e->type->ops.mq.insert_requests(hctx, list, false); > - else { > + } else { > /* > * try to issue requests directly if the hw queue isn't > * busy in case of 'none' scheduler, and this way may save > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 8d845872ea02..592d81c37b07 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -36,6 +36,7 @@ > #include "blk-mq-tag.h" > #include "blk-stat.h" > #include "blk-mq-sched.h" > +#include "blk-pm.h" > #include "blk-rq-qos.h" > > static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie); > @@ -476,6 +477,8 @@ static void __blk_mq_free_request(struct request *rq) > struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); > const int sched_tag = rq->internal_tag; > > + blk_pm_put_request(rq); > + > if (rq->tag != -1) > blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); > if (sched_tag != -1) > @@ -1565,6 +1568,8 @@ void blk_mq_request_bypass_insert(struct request *rq, > bool run_queue) > struct blk_mq_ctx *ctx = rq->mq_ctx; > struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(rq->q, ctx->cpu); > > + blk_pm_add_request(rq->q, rq); > + > spin_lock(&hctx->lock); > list_add_tail(&rq->queuelist, &hctx->dispatch); > spin_unlock(&hctx->lock); > @@ -1586,6 +1591,7 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, > struct blk_mq_ctx *ctx, > list_for_each_entry(rq, list, queuelist) { > BUG_ON(rq->mq_ctx != ctx); > trace_block_rq_insert(hctx->queue, rq); > + blk_pm_add_request(rq->q, rq); > } > > spin_lock(&ctx->lock); > @@ -1682,6 +1688,8 @@ static blk_status_t __blk_mq_issue_directly(struct > blk_mq_hw_ctx *hctx, > blk_qc_t new_cookie; > blk_status_t ret; > > + blk_pm_add_request(q, rq); > + > new_cookie = request_to_qc_t(hctx, rq); >
blk_pm_add_request() calls pm_request_resume() for waking up device, but it is wrong because it is async request, which can't guarantee device will be ready before calling .queue_rq(). Thanks, Ming
