blk-mq: blk-mq: provide forced completion method

Drivers may need to bypass error injection for error recovery. Rename
__blk_mq_complete_request() to blk_mq_force_complete_rq() and export
that function so drivers may skip potential fake timeouts after they've
reclaimed lost requests.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index c606c74..c6dcd39 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -556,7 +556,17 @@ static void __blk_mq_complete_request_remote(void *data)
        q->mq_ops->complete(rq);
 }
 
-static void __blk_mq_complete_request(struct request *rq)
+/**
+ * blk_mq_force_complete_rq() - Force complete the request, bypassing any error
+ *                             injection that could drop the completion.
+ * @rq: Request to be force completed
+ *
+ * Drivers should use blk_mq_complete_request() to complete requests in their
+ * normal IO path. For timeout error recovery, drivers may call this forced
+ * completion routine after they've reclaimed timed out requests to bypass
+ * potentially subsequent fake timeouts.
+ */
+void blk_mq_force_complete_rq(struct request *rq)
 {
        struct blk_mq_ctx *ctx = rq->mq_ctx;
        struct request_queue *q = rq->q;
@@ -602,6 +612,7 @@ static void __blk_mq_complete_request(struct request *rq)
        }
        put_cpu();
 }
+EXPORT_SYMBOL_GPL(blk_mq_force_complete_rq);
 
 static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
        __releases(hctx->srcu)
@@ -635,7 +646,7 @@ bool blk_mq_complete_request(struct request *rq)
 {
        if (unlikely(blk_should_fake_timeout(rq->q)))
                return false;
-       __blk_mq_complete_request(rq);
+       blk_mq_force_complete_rq(rq);
        return true;
 }
 EXPORT_SYMBOL(blk_mq_complete_request);

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index d730779..856bb10 100644 (file)
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -494,6 +494,7 @@ void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
 void blk_mq_kick_requeue_list(struct request_queue *q);
 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
 bool blk_mq_complete_request(struct request *rq);
+void blk_mq_force_complete_rq(struct request *rq);
 bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
                           struct bio *bio, unsigned int nr_segs);
 bool blk_mq_queue_stopped(struct request_queue *q);