diff options
| -rw-r--r-- | block/blk-core.c | 37 | ||||
| -rw-r--r-- | block/blk-pm.c | 44 |
2 files changed, 47 insertions, 34 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index fec135ae52cf..16dd3a989753 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2746,30 +2746,6 @@ void blk_account_io_done(struct request *req, u64 now) } } -#ifdef CONFIG_PM -/* - * Don't process normal requests when queue is suspended - * or in the process of suspending/resuming - */ -static bool blk_pm_allow_request(struct request *rq) -{ - switch (rq->q->rpm_status) { - case RPM_RESUMING: - case RPM_SUSPENDING: - return rq->rq_flags & RQF_PM; - case RPM_SUSPENDED: - return false; - default: - return true; - } -} -#else -static bool blk_pm_allow_request(struct request *rq) -{ - return true; -} -#endif - void blk_account_io_start(struct request *rq, bool new_io) { struct hd_struct *part; @@ -2815,11 +2791,14 @@ static struct request *elv_next_request(struct request_queue *q) while (1) { list_for_each_entry(rq, &q->queue_head, queuelist) { - if (blk_pm_allow_request(rq)) - return rq; - - if (rq->rq_flags & RQF_SOFTBARRIER) - break; +#ifdef CONFIG_PM + /* + * If a request gets queued in state RPM_SUSPENDED + * then that's a kernel bug. + */ + WARN_ON_ONCE(q->rpm_status == RPM_SUSPENDED); +#endif + return rq; } /* diff --git a/block/blk-pm.c b/block/blk-pm.c index 9b636960d285..972fbc656846 100644 --- a/block/blk-pm.c +++ b/block/blk-pm.c @@ -1,8 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 +#include <linux/blk-mq.h> #include <linux/blk-pm.h> #include <linux/blkdev.h> #include <linux/pm_runtime.h> +#include "blk-mq.h" +#include "blk-mq-tag.h" /** * blk_pm_runtime_init - Block layer runtime PM initialization routine @@ -68,14 +71,40 @@ int blk_pre_runtime_suspend(struct request_queue *q) if (!q->dev) return ret; + WARN_ON_ONCE(q->rpm_status != RPM_ACTIVE); + + /* + * Increase the pm_only counter before checking whether any + * non-PM blk_queue_enter() calls are in progress to avoid that any + * new non-PM blk_queue_enter() calls succeed before the pm_only + * counter is decreased again. + */ + blk_set_pm_only(q); + ret = -EBUSY; + /* Switch q_usage_counter from per-cpu to atomic mode. */ + blk_freeze_queue_start(q); + /* + * Wait until atomic mode has been reached. Since that + * involves calling call_rcu(), it is guaranteed that later + * blk_queue_enter() calls see the pm-only state. See also + * http://lwn.net/Articles/573497/. + */ + percpu_ref_switch_to_atomic_sync(&q->q_usage_counter); + if (percpu_ref_is_zero(&q->q_usage_counter)) + ret = 0; + /* Switch q_usage_counter back to per-cpu mode. */ + blk_mq_unfreeze_queue(q); + spin_lock_irq(q->queue_lock); - if (q->nr_pending) { - ret = -EBUSY; + if (ret < 0) pm_runtime_mark_last_busy(q->dev); - } else { + else q->rpm_status = RPM_SUSPENDING; - } spin_unlock_irq(q->queue_lock); + + if (ret) + blk_clear_pm_only(q); + return ret; } EXPORT_SYMBOL(blk_pre_runtime_suspend); @@ -106,6 +135,9 @@ void blk_post_runtime_suspend(struct request_queue *q, int err) pm_runtime_mark_last_busy(q->dev); } spin_unlock_irq(q->queue_lock); + + if (err) + blk_clear_pm_only(q); } EXPORT_SYMBOL(blk_post_runtime_suspend); @@ -153,13 +185,15 @@ void blk_post_runtime_resume(struct request_queue *q, int err) spin_lock_irq(q->queue_lock); if (!err) { q->rpm_status = RPM_ACTIVE; - __blk_run_queue(q); pm_runtime_mark_last_busy(q->dev); pm_request_autosuspend(q->dev); } else { q->rpm_status = RPM_SUSPENDED; } spin_unlock_irq(q->queue_lock); + + if (!err) + blk_clear_pm_only(q); } EXPORT_SYMBOL(blk_post_runtime_resume); |