From af147b740f111730c2e387ee6c0ac3ada7d51117 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <dlemoal@kernel.org>
Date: Wed, 1 May 2024 20:09:01 +0900
Subject: [PATCH] block: Fix flush request sector restore

Make sure that a request bio is not NULL before trying to restore the
request start sector.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Fixes: 6f8fd758de63 ("block: Restore sector of flush requests")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240501110907.96950-9-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 block/blk-flush.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blk-flush.c b/block/blk-flush.c
index 2f58ae018464..c17cf8ed8113 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -130,7 +130,8 @@ static void blk_flush_restore_request(struct request *rq)
 	 * original @rq->bio.  Restore it.
 	 */
 	rq->bio = rq->biotail;
-	rq->__sector = rq->bio->bi_iter.bi_sector;
+	if (rq->bio)
+		rq->__sector = rq->bio->bi_iter.bi_sector;
 
 	/* make @rq a normal request */
 	rq->rq_flags &= ~RQF_FLUSH_SEQ;