Patch "dm-raid: fix lockdep waring in "pers->hot_add_disk"" has been added to the 6.7-stable tree

Patch "dm-raid: fix lockdep waring in "pers->hot_add_disk"" has been added to the 6.7-stable tree

[Sasha Levin]

This is a note to let you know that I've just added the patch titled

    dm-raid: fix lockdep waring in "pers->hot_add_disk"

to the 6.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     dm-raid-fix-lockdep-waring-in-pers-hot_add_disk.patch
and it can be found in the queue-6.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.



commit 319d615c8b877a8c284797811fcfedf1e2e9b023
Author: Yu Kuai <yukuai3@huawei.com>
Date:   Tue Mar 5 15:23:06 2024 +0800

    dm-raid: fix lockdep waring in "pers->hot_add_disk"
    
    [ Upstream commit 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 ]
    
    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: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 063f1266ec462..d97355e9b9a6e 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)) {