[PATCH 1/7] blk-mq: factor out a blk_rq_init_flush helper

[Christoph Hellwig <hch@lst.de>]

Factor out a helper from blk_insert_flush that initializes the flush
machine related fields in struct request, and don't bother with the
full memset as there's just a few fields to initialize, and all but
one already have explicit initializers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
---
 block/blk-flush.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 04698ed9bcd4a9..ed37d272f787eb 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -376,6 +376,15 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq,
 	return RQ_END_IO_NONE;
 }
 
+static void blk_rq_init_flush(struct request *rq)
+{
+	rq->flush.seq = 0;
+	INIT_LIST_HEAD(&rq->flush.list);
+	rq->rq_flags |= RQF_FLUSH_SEQ;
+	rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
+	rq->end_io = mq_flush_data_end_io;
+}
+
 /**
  * blk_insert_flush - insert a new PREFLUSH/FUA request
  * @rq: request to insert
@@ -437,13 +446,7 @@ void blk_insert_flush(struct request *rq)
 	 * @rq should go through flush machinery.  Mark it part of flush
 	 * sequence and submit for further processing.
 	 */
-	memset(&rq->flush, 0, sizeof(rq->flush));
-	INIT_LIST_HEAD(&rq->flush.list);
-	rq->rq_flags |= RQF_FLUSH_SEQ;
-	rq->flush.saved_end_io = rq->end_io; /* Usually NULL */
-
-	rq->end_io = mq_flush_data_end_io;
-
+	blk_rq_init_flush(rq);
 	spin_lock_irq(&fq->mq_flush_lock);
 	blk_flush_complete_seq(rq, fq, REQ_FSEQ_ACTIONS & ~policy, 0);
 	spin_unlock_irq(&fq->mq_flush_lock);
-- 
2.39.2