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From 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 Mon Sep 17 00:00:00 2001
From: Yu Kuai <yukuai3@huawei.com>
Date: Tue, 5 Mar 2024 15:23:06 +0800
Subject: [PATCH] dm-raid: fix lockdep waring in "pers->hot_add_disk"
Git-commit: 95009ae904b1e9dca8db6f649f2d7c18a6e42c75
Patch-mainline: v6.9-rc1
References: git-fixes

The lockdep assert is added by commit a448af25becf ("md/raid10: remove
rcu protection to access rdev from conf") in print_conf(). And I didn't
notice that dm-raid is calling "pers->hot_add_disk" without holding
'reconfig_mutex'.

"pers->hot_add_disk" read and write many fields that is protected by
'reconfig_mutex', and raid_resume() already grab the lock in other
contex. Hence fix this problem by protecting "pers->host_add_disk"
with the lock.

Fixes: 9092c02d9435 ("DM RAID: Add ability to restore transiently failed devices on resume")
Fixes: a448af25becf ("md/raid10: remove rcu protection to access rdev from conf")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Acked-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240305072306.2562024-10-yukuai1@huaweicloud.com
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/dm-raid.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index ea45f777691c..17e9af60bbf7 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -4091,7 +4091,9 @@ static void raid_resume(struct dm_target *ti)
 		 * Take this opportunity to check whether any failed
 		 * devices are reachable again.
 		 */
+		mddev_lock_nointr(mddev);
 		attempt_restore_of_faulty_devices(rs);
+		mddev_unlock(mddev);
 	}
 
 	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
-- 
2.35.3