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 | 12 ++++++++++++
include/linux/blk-mq.h | 1 +
2 files changed, 13 insertions(+)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index d4d7c1caa439..d5e7122789fc 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -161,6 +161,18 @@ 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 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);
--
2.20.1
