| Message ID | 20180115165810.2515-2-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jan 15 2018 at 11:58am -0500, Ming Lei <ming.lei@redhat.com> wrote: > No functional change, just to clean up code a bit, so that the following > change of using direct issue for blk_mq_request_bypass_insert() which is > needed by DM can be easier to do. > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > 1 file changed, 27 insertions(+), 12 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index edb1291a42c5..bf8d6651f40e 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > } > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > - struct request *rq, > - blk_qc_t *cookie) > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > + struct request *rq, > + blk_qc_t *new_cookie) > { > + blk_status_t ret; > struct request_queue *q = rq->q; > struct blk_mq_queue_data bd = { > .rq = rq, > .last = true, > }; > + > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > + return BLK_STS_AGAIN; > + > + if (!blk_mq_get_dispatch_budget(hctx)) { > + blk_mq_put_driver_tag(rq); > + return BLK_STS_AGAIN; > + } > + > + *new_cookie = request_to_qc_t(hctx, rq); > + > + ret = q->mq_ops->queue_rq(hctx, &bd); > + > + return ret; > +} > + > +static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > + struct request *rq, > + blk_qc_t *cookie) > +{ > + struct request_queue *q = rq->q; > blk_qc_t new_cookie; > blk_status_t ret; > bool run_queue = true; > @@ -1718,22 +1740,15 @@ static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > if (q->elevator) > goto insert; > > - if (!blk_mq_get_driver_tag(rq, NULL, false)) > + ret = __blk_mq_issue_req(hctx, rq, &new_cookie); > + if (ret == BLK_STS_AGAIN) > goto insert; You're (ab)using BLK_STS_AGAIN as a means to an end... But what if in the future q->mq_ops->queue_rq() returns BLK_STS_AGAIN? Mike
On 1/15/18 9:58 AM, Ming Lei wrote: > No functional change, just to clean up code a bit, so that the following > change of using direct issue for blk_mq_request_bypass_insert() which is > needed by DM can be easier to do. > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > 1 file changed, 27 insertions(+), 12 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index edb1291a42c5..bf8d6651f40e 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > } > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > - struct request *rq, > - blk_qc_t *cookie) > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > + struct request *rq, > + blk_qc_t *new_cookie) > { > + blk_status_t ret; > struct request_queue *q = rq->q; > struct blk_mq_queue_data bd = { > .rq = rq, > .last = true, > }; > + > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > + return BLK_STS_AGAIN; > + > + if (!blk_mq_get_dispatch_budget(hctx)) { > + blk_mq_put_driver_tag(rq); > + return BLK_STS_AGAIN; > + } > + > + *new_cookie = request_to_qc_t(hctx, rq); > + > + ret = q->mq_ops->queue_rq(hctx, &bd); > + > + return ret; return q->mq_ops->queue_rq(hctx, &bd); and kill 'ret', it's not used. But more importantly, who puts the driver tag and the budget if we get != OK for ->queue_rq()?
On Mon, Jan 15 2018 at 12:29pm -0500, Jens Axboe <axboe@kernel.dk> wrote: > On 1/15/18 9:58 AM, Ming Lei wrote: > > No functional change, just to clean up code a bit, so that the following > > change of using direct issue for blk_mq_request_bypass_insert() which is > > needed by DM can be easier to do. > > > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > --- > > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > > 1 file changed, 27 insertions(+), 12 deletions(-) > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > index edb1291a42c5..bf8d6651f40e 100644 > > --- a/block/blk-mq.c > > +++ b/block/blk-mq.c > > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > > } > > > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > - struct request *rq, > > - blk_qc_t *cookie) > > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > > + struct request *rq, > > + blk_qc_t *new_cookie) > > { > > + blk_status_t ret; > > struct request_queue *q = rq->q; > > struct blk_mq_queue_data bd = { > > .rq = rq, > > .last = true, > > }; > > + > > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > > + return BLK_STS_AGAIN; > > + > > + if (!blk_mq_get_dispatch_budget(hctx)) { > > + blk_mq_put_driver_tag(rq); > > + return BLK_STS_AGAIN; > > + } > > + > > + *new_cookie = request_to_qc_t(hctx, rq); > > + > > + ret = q->mq_ops->queue_rq(hctx, &bd); > > + > > + return ret; > > return q->mq_ops->queue_rq(hctx, &bd); > > and kill 'ret', it's not used. Yeap, good point. > But more importantly, who puts the > driver tag and the budget if we get != OK for ->queue_rq()? __blk_mq_try_issue_directly() processes the returned value same as before this patch. Means this patch isn't making any functional change: If BLK_STS_RESOURCE: __blk_mq_requeue_request() is called. __blk_mq_requeue_request() will blk_mq_put_driver_tag(). Otherwise, all other errors result in blk_mq_end_request(rq, ret); So ignoring this patch, are you concerned that: 1) Does blk_mq_end_request() put both? Looks like blk_mq_free_request() handles rq->tag != -1 but why not have it use __blk_mq_put_driver_tag()? I'm not seeing where the budget is put from blk_mq_end_request()... 2) Nothing seems to be putting the budget in __blk_mq_try_issue_directly()'s BLK_STS_RESOURCE error path? I share your concern now (for drivers who set {get,put}_budget in mq_ops). Should __blk_mq_requeue_request() be updated to also blk_mq_put_dispatch_budget()? Mike
On Mon, Jan 15, 2018 at 12:15:47PM -0500, Mike Snitzer wrote: > On Mon, Jan 15 2018 at 11:58am -0500, > Ming Lei <ming.lei@redhat.com> wrote: > > > No functional change, just to clean up code a bit, so that the following > > change of using direct issue for blk_mq_request_bypass_insert() which is > > needed by DM can be easier to do. > > > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > --- > > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > > 1 file changed, 27 insertions(+), 12 deletions(-) > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > index edb1291a42c5..bf8d6651f40e 100644 > > --- a/block/blk-mq.c > > +++ b/block/blk-mq.c > > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > > } > > > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > - struct request *rq, > > - blk_qc_t *cookie) > > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > > + struct request *rq, > > + blk_qc_t *new_cookie) > > { > > + blk_status_t ret; > > struct request_queue *q = rq->q; > > struct blk_mq_queue_data bd = { > > .rq = rq, > > .last = true, > > }; > > + > > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > > + return BLK_STS_AGAIN; > > + > > + if (!blk_mq_get_dispatch_budget(hctx)) { > > + blk_mq_put_driver_tag(rq); > > + return BLK_STS_AGAIN; > > + } > > + > > + *new_cookie = request_to_qc_t(hctx, rq); > > + > > + ret = q->mq_ops->queue_rq(hctx, &bd); > > + > > + return ret; > > +} > > + > > +static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > + struct request *rq, > > + blk_qc_t *cookie) > > +{ > > + struct request_queue *q = rq->q; > > blk_qc_t new_cookie; > > blk_status_t ret; > > bool run_queue = true; > > @@ -1718,22 +1740,15 @@ static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > if (q->elevator) > > goto insert; > > > > - if (!blk_mq_get_driver_tag(rq, NULL, false)) > > + ret = __blk_mq_issue_req(hctx, rq, &new_cookie); > > + if (ret == BLK_STS_AGAIN) > > goto insert; > > You're (ab)using BLK_STS_AGAIN as a means to an end... > But what if in the future q->mq_ops->queue_rq() returns BLK_STS_AGAIN? Yeah, but now only dio uses that, so I let Jens decide it.
On Mon, Jan 15, 2018 at 10:29:46AM -0700, Jens Axboe wrote: > On 1/15/18 9:58 AM, Ming Lei wrote: > > No functional change, just to clean up code a bit, so that the following > > change of using direct issue for blk_mq_request_bypass_insert() which is > > needed by DM can be easier to do. > > > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > --- > > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > > 1 file changed, 27 insertions(+), 12 deletions(-) > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > index edb1291a42c5..bf8d6651f40e 100644 > > --- a/block/blk-mq.c > > +++ b/block/blk-mq.c > > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > > } > > > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > - struct request *rq, > > - blk_qc_t *cookie) > > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > > + struct request *rq, > > + blk_qc_t *new_cookie) > > { > > + blk_status_t ret; > > struct request_queue *q = rq->q; > > struct blk_mq_queue_data bd = { > > .rq = rq, > > .last = true, > > }; > > + > > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > > + return BLK_STS_AGAIN; > > + > > + if (!blk_mq_get_dispatch_budget(hctx)) { > > + blk_mq_put_driver_tag(rq); > > + return BLK_STS_AGAIN; > > + } > > + > > + *new_cookie = request_to_qc_t(hctx, rq); > > + > > + ret = q->mq_ops->queue_rq(hctx, &bd); > > + > > + return ret; > > return q->mq_ops->queue_rq(hctx, &bd); > > and kill 'ret', it's not used. But more importantly, who puts the OK. > driver tag and the budget if we get != OK for ->queue_rq()? For the budget, the current protocol is that driver is responsible for the release once .queue_rq is called, see scsi_mq_queue_rq() and comment in blk_mq_do_dispatch_sched(). For driver tag, it is released in blk_mq_free_request(), which is done in failure handling of != OK.
On Mon, Jan 15, 2018 at 02:41:12PM -0500, Mike Snitzer wrote: > On Mon, Jan 15 2018 at 12:29pm -0500, > Jens Axboe <axboe@kernel.dk> wrote: > > > On 1/15/18 9:58 AM, Ming Lei wrote: > > > No functional change, just to clean up code a bit, so that the following > > > change of using direct issue for blk_mq_request_bypass_insert() which is > > > needed by DM can be easier to do. > > > > > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > > --- > > > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > > > 1 file changed, 27 insertions(+), 12 deletions(-) > > > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > > index edb1291a42c5..bf8d6651f40e 100644 > > > --- a/block/blk-mq.c > > > +++ b/block/blk-mq.c > > > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > > > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > > > } > > > > > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > > - struct request *rq, > > > - blk_qc_t *cookie) > > > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > > > + struct request *rq, > > > + blk_qc_t *new_cookie) > > > { > > > + blk_status_t ret; > > > struct request_queue *q = rq->q; > > > struct blk_mq_queue_data bd = { > > > .rq = rq, > > > .last = true, > > > }; > > > + > > > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > > > + return BLK_STS_AGAIN; > > > + > > > + if (!blk_mq_get_dispatch_budget(hctx)) { > > > + blk_mq_put_driver_tag(rq); > > > + return BLK_STS_AGAIN; > > > + } > > > + > > > + *new_cookie = request_to_qc_t(hctx, rq); > > > + > > > + ret = q->mq_ops->queue_rq(hctx, &bd); > > > + > > > + return ret; > > > > return q->mq_ops->queue_rq(hctx, &bd); > > > > and kill 'ret', it's not used. > > Yeap, good point. > > > But more importantly, who puts the > > driver tag and the budget if we get != OK for ->queue_rq()? > > __blk_mq_try_issue_directly() processes the returned value same as before > this patch. Means this patch isn't making any functional change: > If BLK_STS_RESOURCE: __blk_mq_requeue_request() is called. > __blk_mq_requeue_request() will blk_mq_put_driver_tag(). > Otherwise, all other errors result in blk_mq_end_request(rq, ret); > > So ignoring this patch, are you concerned that: > 1) Does blk_mq_end_request() put both? Looks like blk_mq_free_request() > handles rq->tag != -1 but why not have it use __blk_mq_put_driver_tag()? > I'm not seeing where the budget is put from blk_mq_end_request()... blk_mq_free_request() releases driver tag, and budget is owned by driver once .queue_rq is called. > > 2) Nothing seems to be putting the budget in > __blk_mq_try_issue_directly()'s BLK_STS_RESOURCE error path? I share > your concern now (for drivers who set {get,put}_budget in mq_ops). > Should __blk_mq_requeue_request() be updated to also > blk_mq_put_dispatch_budget()? No, at least it is current protocol of using budget, please see scsi_mq_queue_rq() and comment of blk_mq_do_dispatch_sched().
On Mon, Jan 15 2018 at 8:43pm -0500, Ming Lei <ming.lei@redhat.com> wrote: > On Mon, Jan 15, 2018 at 02:41:12PM -0500, Mike Snitzer wrote: > > On Mon, Jan 15 2018 at 12:29pm -0500, > > Jens Axboe <axboe@kernel.dk> wrote: > > > > > On 1/15/18 9:58 AM, Ming Lei wrote: > > > > No functional change, just to clean up code a bit, so that the following > > > > change of using direct issue for blk_mq_request_bypass_insert() which is > > > > needed by DM can be easier to do. > > > > > > > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > > > > --- > > > > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ > > > > 1 file changed, 27 insertions(+), 12 deletions(-) > > > > > > > > diff --git a/block/blk-mq.c b/block/blk-mq.c > > > > index edb1291a42c5..bf8d6651f40e 100644 > > > > --- a/block/blk-mq.c > > > > +++ b/block/blk-mq.c > > > > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) > > > > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); > > > > } > > > > > > > > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, > > > > - struct request *rq, > > > > - blk_qc_t *cookie) > > > > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, > > > > + struct request *rq, > > > > + blk_qc_t *new_cookie) > > > > { > > > > + blk_status_t ret; > > > > struct request_queue *q = rq->q; > > > > struct blk_mq_queue_data bd = { > > > > .rq = rq, > > > > .last = true, > > > > }; > > > > + > > > > + if (!blk_mq_get_driver_tag(rq, NULL, false)) > > > > + return BLK_STS_AGAIN; > > > > + > > > > + if (!blk_mq_get_dispatch_budget(hctx)) { > > > > + blk_mq_put_driver_tag(rq); > > > > + return BLK_STS_AGAIN; > > > > + } > > > > + > > > > + *new_cookie = request_to_qc_t(hctx, rq); > > > > + > > > > + ret = q->mq_ops->queue_rq(hctx, &bd); > > > > + > > > > + return ret; > > > > > > return q->mq_ops->queue_rq(hctx, &bd); > > > > > > and kill 'ret', it's not used. > > > > Yeap, good point. > > > > > But more importantly, who puts the > > > driver tag and the budget if we get != OK for ->queue_rq()? > > > > __blk_mq_try_issue_directly() processes the returned value same as before > > this patch. Means this patch isn't making any functional change: > > If BLK_STS_RESOURCE: __blk_mq_requeue_request() is called. > > __blk_mq_requeue_request() will blk_mq_put_driver_tag(). > > Otherwise, all other errors result in blk_mq_end_request(rq, ret); > > > > So ignoring this patch, are you concerned that: > > 1) Does blk_mq_end_request() put both? Looks like blk_mq_free_request() > > handles rq->tag != -1 but why not have it use __blk_mq_put_driver_tag()? > > I'm not seeing where the budget is put from blk_mq_end_request()... > > blk_mq_free_request() releases driver tag, and budget is owned by driver > once .queue_rq is called. > > > > > 2) Nothing seems to be putting the budget in > > __blk_mq_try_issue_directly()'s BLK_STS_RESOURCE error path? I share > > your concern now (for drivers who set {get,put}_budget in mq_ops). > > Should __blk_mq_requeue_request() be updated to also > > blk_mq_put_dispatch_budget()? > > No, at least it is current protocol of using budget, please see > scsi_mq_queue_rq() and comment of blk_mq_do_dispatch_sched(). Yeap, thanks for clarifying.
On Tue, Jan 16, 2018 at 9:40 AM, Ming Lei <ming.lei@redhat.com> wrote: > On Mon, Jan 15, 2018 at 10:29:46AM -0700, Jens Axboe wrote: >> On 1/15/18 9:58 AM, Ming Lei wrote: >> > No functional change, just to clean up code a bit, so that the following >> > change of using direct issue for blk_mq_request_bypass_insert() which is >> > needed by DM can be easier to do. >> > >> > Signed-off-by: Ming Lei <ming.lei@redhat.com> >> > --- >> > block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ >> > 1 file changed, 27 insertions(+), 12 deletions(-) >> > >> > diff --git a/block/blk-mq.c b/block/blk-mq.c >> > index edb1291a42c5..bf8d6651f40e 100644 >> > --- a/block/blk-mq.c >> > +++ b/block/blk-mq.c >> > @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) >> > return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); >> > } >> > >> > -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, >> > - struct request *rq, >> > - blk_qc_t *cookie) >> > +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, >> > + struct request *rq, >> > + blk_qc_t *new_cookie) >> > { >> > + blk_status_t ret; >> > struct request_queue *q = rq->q; >> > struct blk_mq_queue_data bd = { >> > .rq = rq, >> > .last = true, >> > }; >> > + >> > + if (!blk_mq_get_driver_tag(rq, NULL, false)) >> > + return BLK_STS_AGAIN; >> > + >> > + if (!blk_mq_get_dispatch_budget(hctx)) { >> > + blk_mq_put_driver_tag(rq); >> > + return BLK_STS_AGAIN; >> > + } >> > + >> > + *new_cookie = request_to_qc_t(hctx, rq); >> > + >> > + ret = q->mq_ops->queue_rq(hctx, &bd); >> > + >> > + return ret; >> >> return q->mq_ops->queue_rq(hctx, &bd); >> >> and kill 'ret', it's not used. But more importantly, who puts the > > OK. > >> driver tag and the budget if we get != OK for ->queue_rq()? > > For the budget, the current protocol is that driver is responsible for the > release once .queue_rq is called, see scsi_mq_queue_rq() and comment in > blk_mq_do_dispatch_sched(). > > For driver tag, it is released in blk_mq_free_request(), which is done > in failure handling of != OK. Actually the driver tag should be released here when .queue_rq() returns !OK, and this patch does follow the current logic: - call __blk_mq_requeue_request() to release tag and make it ready for requeue if STS_RESOURCE is returned. - For other !OK cases, let driver free the request.
diff --git a/block/blk-mq.c b/block/blk-mq.c index edb1291a42c5..bf8d6651f40e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1696,15 +1696,37 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); } -static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, - struct request *rq, - blk_qc_t *cookie) +static blk_status_t __blk_mq_issue_req(struct blk_mq_hw_ctx *hctx, + struct request *rq, + blk_qc_t *new_cookie) { + blk_status_t ret; struct request_queue *q = rq->q; struct blk_mq_queue_data bd = { .rq = rq, .last = true, }; + + if (!blk_mq_get_driver_tag(rq, NULL, false)) + return BLK_STS_AGAIN; + + if (!blk_mq_get_dispatch_budget(hctx)) { + blk_mq_put_driver_tag(rq); + return BLK_STS_AGAIN; + } + + *new_cookie = request_to_qc_t(hctx, rq); + + ret = q->mq_ops->queue_rq(hctx, &bd); + + return ret; +} + +static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, + struct request *rq, + blk_qc_t *cookie) +{ + struct request_queue *q = rq->q; blk_qc_t new_cookie; blk_status_t ret; bool run_queue = true; @@ -1718,22 +1740,15 @@ static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, if (q->elevator) goto insert; - if (!blk_mq_get_driver_tag(rq, NULL, false)) + ret = __blk_mq_issue_req(hctx, rq, &new_cookie); + if (ret == BLK_STS_AGAIN) goto insert; - if (!blk_mq_get_dispatch_budget(hctx)) { - blk_mq_put_driver_tag(rq); - goto insert; - } - - new_cookie = request_to_qc_t(hctx, 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(hctx, &bd); switch (ret) { case BLK_STS_OK: *cookie = new_cookie;
No functional change, just to clean up code a bit, so that the following change of using direct issue for blk_mq_request_bypass_insert() which is needed by DM can be easier to do. Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/blk-mq.c | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-)