From: Xueshi Hu <redacted>

Raid reshape changes the r1conf::raid_disks and mempool. Keep holding the
barrier in handle_read_error() to avoid raid reshape.

Signed-off-by: Xueshi Hu <redacted>
---
  drivers/md/raid1.c | 25 ++++++++++++-------------
  1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 6c54786067b4..43a9c095f94d 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c

@@ -1240,20 +1240,20 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
  		rcu_read_unlock();
  	}
  
-	/*
-	 * Still need barrier for READ in case that whole
-	 * array is frozen.
-	 */
-	if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
-				bio->bi_opf & REQ_NOWAIT)) {
-		bio_wouldblock_error(bio);
-		return;
-	}
-
-	if (!r1_bio)
+	if (!r1_bio) {
+		/*
+		 * Still need barrier for READ in case that whole
+		 * array is frozen.
+		 */
+		if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
+					bio->bi_opf & REQ_NOWAIT)) {
+			bio_wouldblock_error(bio);
+			return;
+		}
  		r1_bio = alloc_r1bio(mddev, bio);
-	else
+	} else
  		init_r1bio(r1_bio, mddev, bio);
+
  	r1_bio->sectors = max_read_sectors;
  
  	/*

@@ -2527,7 +2527,6 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
  	}
  
  	rdev_dec_pending(rdev, conf->mddev);
-	allow_barrier(conf, r1_bio->sector);