[PATCH v5 2/6] block: add blk_mq_is_queue_frozen()
From: Sergei Shtepa <hidden>
Date: 2021-02-09 14:32:21
Also in:
dm-devel, linux-doc, 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 f285a9123a8b..924ec26fae5f 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 ret; + + mutex_lock(&q->mq_freeze_lock); + ret = percpu_ref_is_dying(&q->q_usage_counter) && percpu_ref_is_zero(&q->q_usage_counter); + mutex_unlock(&q->mq_freeze_lock); + + return ret; +} +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 d705b174d346..9d1e8c4e922e 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h@@ -525,6 +525,7 @@ 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