[-next,9/9] dm-raid: fix lockdep waring in "pers->hot_add_disk"

Message ID 20240301095657.662111-10-yukuai1@huaweicloud.com
State New
Headers
Series dm-raid, md/raid: fix v6.7 regressions part2 |

Commit Message

Yu Kuai March 1, 2024, 9:56 a.m. UTC
  From: Yu Kuai <yukuai3@huawei.com>

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")

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/md/dm-raid.c | 2 ++
 1 file changed, 2 insertions(+)
  

Patch

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 64d381123ce3..97ad4a8582c4 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)) {