From: Yu Kuai <yukuai3@huawei.com>
To: <agk@redhat.com>, <snitzer@kernel.org>, <mpatocka@redhat.com>,
<dm-devel@lists.linux.dev>, <xni@redhat.com>, <song@kernel.org>,
<yukuai3@huawei.com>, <jbrassow@f14.redhat.com>, <neilb@suse.de>,
<heinzm@redhat.com>, <shli@fb.com>, <akpm@osdl.org>
Cc: <linux-kernel@vger.kernel.org>, <linux-raid@vger.kernel.org>,
<yukuai1@huaweicloud.com>, <yi.zhang@huawei.com>,
<yangerkun@huawei.com>
Subject: [PATCH v2 01/11] md: don't ignore suspended array in md_check_recovery()
Date: Wed, 24 Jan 2024 17:14:11 +0800 [thread overview]
Message-ID: <20240124091421.1261579-2-yukuai3@huawei.com> (raw)
In-Reply-To: <20240124091421.1261579-1-yukuai3@huawei.com>
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")
Signed-off-by: Yu Kuai <yukuai3@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 2266358d8074..07b80278eaa5 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -9469,9 +9469,6 @@ 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
next prev parent reply other threads:[~2024-01-24 9:18 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-24 9:14 [PATCH v2 00/11] dm-raid: fix v6.7 regressions Yu Kuai
2024-01-24 9:14 ` Yu Kuai [this message]
2024-01-24 9:14 ` [PATCH v2 02/11] md: don't ignore read-only array in md_check_recovery() Yu Kuai
2024-01-24 9:14 ` [PATCH v2 03/11] md: make sure md_do_sync() will set MD_RECOVERY_DONE Yu Kuai
2024-01-24 9:14 ` [PATCH v2 04/11] md: don't register sync_thread for reshape directly Yu Kuai
2024-01-24 9:14 ` [PATCH v2 05/11] md: export helpers to stop sync_thread Yu Kuai
2024-01-25 7:51 ` Xiao Ni
2024-01-25 7:57 ` Yu Kuai
2024-01-26 2:38 ` Yu Kuai
2024-01-25 11:35 ` Xiao Ni
2024-01-25 11:42 ` Yu Kuai
2024-01-25 11:52 ` Xiao Ni
2024-01-25 11:56 ` Yu Kuai
2024-01-25 11:45 ` Yu Kuai
2024-01-25 13:33 ` Xiao Ni
2024-01-26 0:14 ` Song Liu
2024-01-26 6:54 ` Xiao Ni
2024-01-24 9:14 ` [PATCH v2 06/11] dm-raid: really frozen sync_thread during suspend Yu Kuai
2024-01-24 9:14 ` [PATCH v2 07/11] md/dm-raid: don't call md_reap_sync_thread() directly Yu Kuai
2024-01-24 9:14 ` [PATCH v2 08/11] dm-raid: remove mddev_suspend/resume() Yu Kuai
2024-01-24 9:14 ` [PATCH v2 09/11] dm-raid: add a new helper prepare_suspend() in md_personality Yu Kuai
2024-01-24 9:14 ` [PATCH v2 10/11] md: export helper md_is_rdwr() Yu Kuai
2024-01-24 9:14 ` [PATCH v2 11/11] md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape Yu Kuai
2024-01-24 12:19 ` [PATCH v2 00/11] dm-raid: fix v6.7 regressions Xiao Ni
2024-01-25 0:50 ` Xiao Ni
2024-01-25 1:40 ` Yu Kuai
2024-01-25 0:46 ` Song Liu
2024-01-25 1:08 ` Yu Kuai
2024-01-25 1:51 ` Song Liu
2024-01-25 2:36 ` Yu Kuai
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