Merge branch 'dev-5.10' into dev-5.10-inteldev-5.10-intel

Pull 5.10.67 stable from OpenBMC upstream.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 7ee7e5e8905d..70f1d02135ed 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -263,6 +263,11 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error)
 	spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
 }
 
+bool is_flush_rq(struct request *rq)
+{
+	return rq->end_io == flush_end_io;
+}
+
 /**
  * blk_kick_flush - consider issuing flush request
  * @q: request_queue being kicked
@@ -330,6 +335,14 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
 	flush_rq->rq_flags |= RQF_FLUSH_SEQ;
 	flush_rq->rq_disk = first_rq->rq_disk;
 	flush_rq->end_io = flush_end_io;
+	/*
+	 * Order WRITE ->end_io and WRITE rq->ref, and its pair is the one
+	 * implied in refcount_inc_not_zero() called from
+	 * blk_mq_find_and_get_req(), which orders WRITE/READ flush_rq->ref
+	 * and READ flush_rq->end_io
+	 */
+	smp_wmb();
+	refcount_set(&flush_rq->ref, 1);
 
 	blk_flush_queue_rq(flush_rq, false);
 }