From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 25 Oct 2021 09:06:57 +0200
Subject: [PATCH] blk-mq: Add blk_mq_complete_request_direct()
Git-commit: e8dc17e2893b4107366004810ca2a4acf1fc8563
Patch-mainline: v5.17-rc1
References: jsc#PED-1183

Add blk_mq_complete_request_direct() which completes the block request
directly instead deferring it to softirq for single queue devices.

This is useful for devices which complete the requests in preemptible
context and raising softirq from means scheduling ksoftirqd.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211025070658.1565848-2-bigeasy@linutronix.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 include/linux/blk-mq.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 308edc2a4925..d952c3442261 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -752,6 +752,17 @@ static inline void blk_mq_set_request_complete(struct request *rq)
 	WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
 }
 
+/*
+ * Complete the request directly instead of deferring it to softirq or
+ * completing it another CPU. Useful in preemptible instead of an interrupt.
+ */
+static inline void blk_mq_complete_request_direct(struct request *rq,
+		   void (*complete)(struct request *rq))
+{
+	WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
+	complete(rq);
+}
+
 void blk_mq_start_request(struct request *rq);
 void blk_mq_end_request(struct request *rq, blk_status_t error);
 void __blk_mq_end_request(struct request *rq, blk_status_t error);
-- 
2.35.3