blk-mq: Export freeze/unfreeze functions

Let drivers prevent entering a queue that isn't available.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index bfe0f1f..97ebb84 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -107,7 +107,7 @@ static void blk_mq_usage_counter_release(struct percpu_ref *ref)
        wake_up_all(&q->mq_freeze_wq);
 }
 
-static void blk_mq_freeze_queue_start(struct request_queue *q)
+void blk_mq_freeze_queue_start(struct request_queue *q)
 {
        bool freeze;
 
@@ -120,6 +120,7 @@ static void blk_mq_freeze_queue_start(struct request_queue *q)
                blk_mq_run_queues(q, false);
        }
 }
+EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
 
 static void blk_mq_freeze_queue_wait(struct request_queue *q)
 {
@@ -136,7 +137,7 @@ void blk_mq_freeze_queue(struct request_queue *q)
        blk_mq_freeze_queue_wait(q);
 }
 
-static void blk_mq_unfreeze_queue(struct request_queue *q)
+void blk_mq_unfreeze_queue(struct request_queue *q)
 {
        bool wake;
 
@@ -149,6 +150,7 @@ static void blk_mq_unfreeze_queue(struct request_queue *q)
                wake_up_all(&q->mq_freeze_wq);
        }
 }
+EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
 
 bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
 {

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 8aded9a..3b43f50 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -212,6 +212,8 @@ void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
 void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
 void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
                void *priv);
+void blk_mq_unfreeze_queue(struct request_queue *q);
+void blk_mq_freeze_queue_start(struct request_queue *q);
 
 /*
  * Driver command data is immediately after the request. So subtract request