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Diffstat (limited to 'block/blk-rq-qos.h')
-rw-r--r--block/blk-rq-qos.h11
1 files changed, 10 insertions, 1 deletions
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 0e46052b018a..08b856570ad1 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -86,7 +86,7 @@ static inline void rq_wait_init(struct rq_wait *rq_wait)
init_waitqueue_head(&rq_wait->wait);
}
-static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
+static inline int rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
{
/*
* No IO can be in-flight when adding rqos, so freeze queue, which
@@ -98,6 +98,8 @@ static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
blk_mq_freeze_queue(q);
spin_lock_irq(&q->queue_lock);
+ if (rq_qos_id(q, rqos->id))
+ goto ebusy;
rqos->next = q->rq_qos;
q->rq_qos = rqos;
spin_unlock_irq(&q->queue_lock);
@@ -109,6 +111,13 @@ static inline void rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
blk_mq_debugfs_register_rqos(rqos);
mutex_unlock(&q->debugfs_mutex);
}
+
+ return 0;
+ebusy:
+ spin_unlock_irq(&q->queue_lock);
+ blk_mq_unfreeze_queue(q);
+ return -EBUSY;
+
}
static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)