[PATCH v7 1/3] block: add blk_mq_is_queue_frozen()
From: Sergei Shtepa <hidden>
Date: 2021-03-12 15:46:11
Also in:
dm-devel, linux-block, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
blk_mq_is_queue_frozen() allow to assert that the queue is frozen. Signed-off-by: Sergei Shtepa <redacted> --- block/blk-mq.c | 13 +++++++++++++ include/linux/blk-mq.h | 1 + 2 files changed, 14 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index d4d7c1caa439..2f188a865024 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c@@ -161,6 +161,19 @@ int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, } EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); +bool blk_mq_is_queue_frozen(struct request_queue *q) +{ + bool frozen; + + mutex_lock(&q->mq_freeze_lock); + frozen = percpu_ref_is_dying(&q->q_usage_counter) && + percpu_ref_is_zero(&q->q_usage_counter); + mutex_unlock(&q->mq_freeze_lock); + + return frozen; +} +EXPORT_SYMBOL_GPL(blk_mq_is_queue_frozen); + /* * Guarantee no request is in use, so we can change any data structure of * the queue afterward.
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 2c473c9b8990..6f01971abf7b 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -533,6 +533,7 @@ void blk_freeze_queue_start(struct request_queue *q); void blk_mq_freeze_queue_wait(struct request_queue *q); int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, unsigned long timeout); +bool blk_mq_is_queue_frozen(struct request_queue *q); int blk_mq_map_queues(struct blk_mq_queue_map *qmap); void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
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2.20.1