From: Yu Kuai <yukuai3@huawei.com> mainline inclusion from mainline-v6.8-rc6 commit 1baae052cccd08daf9a9d64c3f959d8cdb689757 category: bugfix bugzilla: 190197 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- mddev_suspend() never stop sync_thread, hence it doesn't make sense to ignore suspended array in md_check_recovery(), which might cause sync_thread can't be unregistered. After commit f52f5c71f3d4 ("md: fix stopping sync thread"), following hang can be triggered by test shell/integrity-caching.sh: 1) suspend the array: raid_postsuspend mddev_suspend 2) stop the array: raid_dtr md_stop __md_stop_writes stop_sync_thread set_bit(MD_RECOVERY_INTR, &mddev->recovery); md_wakeup_thread_directly(mddev->sync_thread); wait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) 3) sync thread done: md_do_sync set_bit(MD_RECOVERY_DONE, &mddev->recovery); md_wakeup_thread(mddev->thread); 4) daemon thread can't unregister sync thread: md_check_recovery if (mddev->suspended) return; -> return directly md_read_sync_thread clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery); -> MD_RECOVERY_RUNNING can't be cleared, hence step 2 hang; This problem is not just related to dm-raid, fix it by ignoring suspended array in md_check_recovery(). And follow up patches will improve dm-raid better to frozen sync thread during suspend. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Closes: https://lore.kernel.org/all/8fb335e-6d2c-dbb5-d7-ded8db5145a@redhat.com/ Fixes: 68866e425be2 ("MD: no sync IO while suspended") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20240201092559.910982-2-yukuai1@huaweicloud.com Signed-off-by: Li Nan <linan122@huawei.com> --- drivers/md/md.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index beea5bf9f084..2de87f4cf94d 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -9548,9 +9548,6 @@ static void md_start_sync(struct work_struct *ws) */ void md_check_recovery(struct mddev *mddev) { - if (READ_ONCE(mddev->suspended)) - return; - if (mddev->bitmap) md_bitmap_daemon_work(mddev); -- 2.39.2