6.7-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yu Kuai <yukuai3@xxxxxxxxxx>
commit 1baae052cccd08daf9a9d64c3f959d8cdb689757 upstream.
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@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/8fb335e-6d2c-dbb5-d7-ded8db5145a@xxxxxxxxxx/
Fixes: 68866e425be2 ("MD: no sync IO while suspended")
Fixes: f52f5c71f3d4 ("md: fix stopping sync thread")
Cc: stable@xxxxxxxxxxxxxxx # v6.7+
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240201092559.910982-2-yukuai1@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/md.c | 3 ---
1 file changed, 3 deletions(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9519,9 +9519,6 @@ not_running:
*/
void md_check_recovery(struct mddev *mddev)
{
- if (READ_ONCE(mddev->suspended))
- return;
-
if (mddev->bitmap)
md_bitmap_daemon_work(mddev);
