blk-mq: Add helper to abort requeued requests

Adds a helper function a driver can use to abort requeued requests in
case any are pending when h/w queues are being removed.

Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e73a5dd89fc4..261ccd89e15d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -539,6 +539,26 @@ void blk_mq_kick_requeue_list(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_mq_kick_requeue_list);
 
+void blk_mq_abort_requeue_list(struct request_queue *q)
+{
+        unsigned long flags;
+        LIST_HEAD(rq_list);
+
+        spin_lock_irqsave(&q->requeue_lock, flags);
+        list_splice_init(&q->requeue_list, &rq_list);
+        spin_unlock_irqrestore(&q->requeue_lock, flags);
+
+        while (!list_empty(&rq_list)) {
+                struct request *rq;
+
+                rq = list_first_entry(&rq_list, struct request, queuelist);
+                list_del_init(&rq->queuelist);
+                rq->errors = -EIO;
+                blk_mq_end_request(rq, rq->errors);
+        }
+}
+EXPORT_SYMBOL(blk_mq_abort_requeue_list);
+
 static inline bool is_flush_request(struct request *rq,
                 struct blk_flush_queue *fq, unsigned int tag)
 {