From 3ca15aebf027feb269065547179fa5d1350085c5 Mon Sep 17 00:00:00 2001
From: Guoqing Jiang <gqjiang@suse.com>
Date: Mon, 24 Apr 2017 17:09:00 +0800
Subject: [PATCH 1/5] md-cluster/raid10: set "do_balance = 0" if area is
 resyncing
Patch-mainline: v4.15-rc1
Git-commit: d4098c7262a47f529765d89614484a957363d623
References: fate#323171

Just like clustered raid1, it is impossible for cluster raid10
to choose the best device for read balance when the area of
array is resyncing. Because we cannot trust the data to be the
same on all devices at that time, so we choose just the first
one to use, so set do_balance to 0.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
---
 drivers/md/raid10.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index d51ac02e98ef..b1de089cef9f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -761,8 +761,11 @@ static struct md_rdev *read_balance(struct r10conf *conf,
 	 * the resync window. We take the first readable disk when
 	 * above the resync window.
 	 */
-	if (conf->mddev->recovery_cp < MaxSector
-	    && (this_sector + sectors >= conf->next_resync))
+	if ((conf->mddev->recovery_cp < MaxSector
+	     && (this_sector + sectors >= conf->next_resync)) ||
+	    (mddev_is_clustered(conf->mddev) &&
+	     md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
+					    this_sector + sectors)))
 		do_balance = 0;
 
 	for (slot = 0; slot < conf->copies ; slot++) {
-- 
2.10.0