blk_mq_is_queue_frozen() allow to assert that the queue is frozen.
Signed-off-by: Sergei Shtepa <sergei.shtepa@xxxxxxxxx>
---
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);
--
2.20.1
