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From:   <qiang.zhang@windriver.com>
To:     <ben.dooks@codethink.co.uk>, <bfields@redhat.com>,
        <cl@rock-chips.com>, <peterz@infradead.org>
CC:     <linux-kernel@vger.kernel.org>
Subject: [PATCH] kthread: Don't cancel a work that is being cancelled
Date:   Thu, 2 Jul 2020 09:13:50 +0800
Message-ID: <20200702011350.32125-1-qiang.zhang@windriver.com>
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From: Zhang Qiang <qiang.zhang@windriver.com>

When canceling a work, if it is found that the work is in
the cancelling state, we should directly exit the cancelled
operation.

Signed-off-by: Zhang Qiang <qiang.zhang@windriver.com>
---
 kernel/kthread.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index bfbfa481be3a..1166f2043e67 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -1103,6 +1103,9 @@ static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork)
 	/* Work must not be used with >1 worker, see kthread_queue_work(). */
 	WARN_ON_ONCE(work->worker != worker);
 
+	if (work->canceling)
+		goto out_fast;
+
 	ret = __kthread_cancel_work(work, is_dwork, &flags);
 
 	if (worker->current_work != work)
-- 
2.24.1