| Message ID | 20201130024615.29171-10-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Rework runtime suspend and SPI domain validation | expand |
On 11/30/20 3:46 AM, Bart Van Assche wrote: > From: Alan Stern <stern@rowland.harvard.edu> > > blk_queue_enter() accepts BLK_MQ_REQ_PM requests independent of the runtime > power management state. Now that SCSI domain validation no longer depends > on this behavior, modify the behavior of blk_queue_enter() as follows: > - Do not accept any requests while suspended. > - Only process power management requests while suspending or resuming. > > Submitting BLK_MQ_REQ_PM requests to a device that is runtime suspended > causes runtime-suspended devices not to resume as they should. The request > which should cause a runtime resume instead gets issued directly, without > resuming the device first. Of course the device can't handle it properly, > the I/O fails, and the device remains suspended. > > The problem is fixed by checking that the queue's runtime-PM status > isn't RPM_SUSPENDED before allowing a request to be issued, and > queuing a runtime-resume request if it is. In particular, the inline > blk_pm_request_resume() routine is renamed blk_pm_resume_queue() and > the code is unified by merging the surrounding checks into the > routine. If the queue isn't set up for runtime PM, or there currently > is no restriction on allowed requests, the request is allowed. > Likewise if the BLK_MQ_REQ_PM flag is set and the status isn't > RPM_SUSPENDED. Otherwise a runtime resume is queued and the request > is blocked until conditions are more suitable. > > Reviewed-by: Christoph Hellwig <hch@lst.de> > Reviewed-by: Can Guo <cang@codeaurora.org> > Reviewed-by: Stanley Chu <stanley.chu@mediatek.com> > Cc: Ming Lei <ming.lei@redhat.com> > Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > Reported-and-tested-by: Martin Kepplinger <martin.kepplinger@puri.sm> > Signed-off-by: Alan Stern <stern@rowland.harvard.edu> > Signed-off-by: Bart Van Assche <bvanassche@acm.org> > [ bvanassche: modified commit message and removed Cc: stable because without > the previous patches from this series this patch would break parallel SCSI > domain validation ] > --- > block/blk-core.c | 6 +++--- > block/blk-pm.h | 14 +++++++++----- > 2 files changed, 12 insertions(+), 8 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
diff --git a/block/blk-core.c b/block/blk-core.c index a00bce9f46d8..230880cbf8c8 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -440,7 +440,8 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) * responsible for ensuring that that counter is * globally visible before the queue is unfrozen. */ - if (pm || !blk_queue_pm_only(q)) { + if ((pm && q->rpm_status != RPM_SUSPENDED) || + !blk_queue_pm_only(q)) { success = true; } else { percpu_ref_put(&q->q_usage_counter); @@ -465,8 +466,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) wait_event(q->mq_freeze_wq, (!q->mq_freeze_depth && - (pm || (blk_pm_request_resume(q), - !blk_queue_pm_only(q)))) || + blk_pm_resume_queue(pm, q)) || blk_queue_dying(q)); if (blk_queue_dying(q)) return -ENODEV; diff --git a/block/blk-pm.h b/block/blk-pm.h index ea5507d23e75..a2283cc9f716 100644 --- a/block/blk-pm.h +++ b/block/blk-pm.h @@ -6,11 +6,14 @@ #include <linux/pm_runtime.h> #ifdef CONFIG_PM -static inline void blk_pm_request_resume(struct request_queue *q) +static inline int blk_pm_resume_queue(const bool pm, struct request_queue *q) { - if (q->dev && (q->rpm_status == RPM_SUSPENDED || - q->rpm_status == RPM_SUSPENDING)) - pm_request_resume(q->dev); + if (!q->dev || !blk_queue_pm_only(q)) + return 1; /* Nothing to do */ + if (pm && q->rpm_status != RPM_SUSPENDED) + return 1; /* Request allowed */ + pm_request_resume(q->dev); + return 0; } static inline void blk_pm_mark_last_busy(struct request *rq) @@ -44,8 +47,9 @@ static inline void blk_pm_put_request(struct request *rq) --rq->q->nr_pending; } #else -static inline void blk_pm_request_resume(struct request_queue *q) +static inline int blk_pm_resume_queue(const bool pm, struct request_queue *q) { + return 1; } static inline void blk_pm_mark_last_busy(struct request *rq)