[PATCHv3,1/2] blk-mq: export blk_mq_force_complete_rq

Commit Message

Keith Busch May 29, 2020, 2:37 p.m. UTC

For when drivers have a need to bypass error injection.

Signed-off-by: Keith Busch <[e-mail]>
---
 block/blk-mq.c         | 15 +++++++++++++--
 include/linux/blk-mq.h |  1 +
 2 files changed, 14 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig May 29, 2020, 2:41 p.m. UTC | #1

On Fri, May 29, 2020 at 07:37:43AM -0700, Keith Busch wrote:
> For when drivers have a need to bypass error injection.

The subject doesn't quite match the content, and the commit log in
general could be a little more verbose.  The changes itself look
fine to me.

Patch

diff --git a/block/blk-mq.c b/block/blk-mq.c
index cac11945f602..560a114a82f8 100644
--- 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 d7307795439a..856bb10993cf 100644
--- 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);