| Message ID | 20180821120555.11941-1-adrian.hunter@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: block: Fix unsupported parallel dispatch of requests | expand |
On 21 August 2018 at 14:05, Adrian Hunter <adrian.hunter@intel.com> wrote: > The mmc block driver does not support parallel dispatch of requests. In > normal circumstances, all requests are anyway funneled through a single > work item, so parallel dispatch never happens. However it can happen if > there is no elevator. > > Fix that by detecting if a dispatch is in progress and returning busy > (BLK_STS_RESOURCE) in that case > > Fixes: 81196976ed94 ("mmc: block: Add blk-mq support") > Cc: stable@vger.kernel.org > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Thanks, applied for fixes! Kind regards Uffe > --- > drivers/mmc/core/queue.c | 12 +++++++----- > drivers/mmc/core/queue.h | 1 + > 2 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c > index 648eb6743ed5..6edffeed9953 100644 > --- a/drivers/mmc/core/queue.c > +++ b/drivers/mmc/core/queue.c > @@ -238,10 +238,6 @@ static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req, > mmc_exit_request(mq->queue, req); > } > > -/* > - * We use BLK_MQ_F_BLOCKING and have only 1 hardware queue, which means requests > - * will not be dispatched in parallel. > - */ > static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, > const struct blk_mq_queue_data *bd) > { > @@ -264,7 +260,7 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, > > spin_lock_irq(q->queue_lock); > > - if (mq->recovery_needed) { > + if (mq->recovery_needed || mq->busy) { > spin_unlock_irq(q->queue_lock); > return BLK_STS_RESOURCE; > } > @@ -291,6 +287,9 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, > break; > } > > + /* Parallel dispatch of requests is not supported at the moment */ > + mq->busy = true; > + > mq->in_flight[issue_type] += 1; > get_card = (mmc_tot_in_flight(mq) == 1); > cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1); > @@ -333,9 +332,12 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, > mq->in_flight[issue_type] -= 1; > if (mmc_tot_in_flight(mq) == 0) > put_card = true; > + mq->busy = false; > spin_unlock_irq(q->queue_lock); > if (put_card) > mmc_put_card(card, &mq->ctx); > + } else { > + WRITE_ONCE(mq->busy, false); > } > > return ret; > diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h > index 17e59d50b496..9bf3c9245075 100644 > --- a/drivers/mmc/core/queue.h > +++ b/drivers/mmc/core/queue.h > @@ -81,6 +81,7 @@ struct mmc_queue { > unsigned int cqe_busy; > #define MMC_CQE_DCMD_BUSY BIT(0) > #define MMC_CQE_QUEUE_FULL BIT(1) > + bool busy; > bool use_cqe; > bool recovery_needed; > bool in_recovery; > -- > 2.17.1 >
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 648eb6743ed5..6edffeed9953 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -238,10 +238,6 @@ static void mmc_mq_exit_request(struct blk_mq_tag_set *set, struct request *req, mmc_exit_request(mq->queue, req); } -/* - * We use BLK_MQ_F_BLOCKING and have only 1 hardware queue, which means requests - * will not be dispatched in parallel. - */ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, const struct blk_mq_queue_data *bd) { @@ -264,7 +260,7 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, spin_lock_irq(q->queue_lock); - if (mq->recovery_needed) { + if (mq->recovery_needed || mq->busy) { spin_unlock_irq(q->queue_lock); return BLK_STS_RESOURCE; } @@ -291,6 +287,9 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, break; } + /* Parallel dispatch of requests is not supported at the moment */ + mq->busy = true; + mq->in_flight[issue_type] += 1; get_card = (mmc_tot_in_flight(mq) == 1); cqe_retune_ok = (mmc_cqe_qcnt(mq) == 1); @@ -333,9 +332,12 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, mq->in_flight[issue_type] -= 1; if (mmc_tot_in_flight(mq) == 0) put_card = true; + mq->busy = false; spin_unlock_irq(q->queue_lock); if (put_card) mmc_put_card(card, &mq->ctx); + } else { + WRITE_ONCE(mq->busy, false); } return ret; diff --git a/drivers/mmc/core/queue.h b/drivers/mmc/core/queue.h index 17e59d50b496..9bf3c9245075 100644 --- a/drivers/mmc/core/queue.h +++ b/drivers/mmc/core/queue.h @@ -81,6 +81,7 @@ struct mmc_queue { unsigned int cqe_busy; #define MMC_CQE_DCMD_BUSY BIT(0) #define MMC_CQE_QUEUE_FULL BIT(1) + bool busy; bool use_cqe; bool recovery_needed; bool in_recovery;
The mmc block driver does not support parallel dispatch of requests. In normal circumstances, all requests are anyway funneled through a single work item, so parallel dispatch never happens. However it can happen if there is no elevator. Fix that by detecting if a dispatch is in progress and returning busy (BLK_STS_RESOURCE) in that case Fixes: 81196976ed94 ("mmc: block: Add blk-mq support") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- drivers/mmc/core/queue.c | 12 +++++++----- drivers/mmc/core/queue.h | 1 + 2 files changed, 8 insertions(+), 5 deletions(-)