[PATCH v2] kthread: work could not be queued when worker being destroyed

From: <qiang.zhang@windriver.com>
To: <ben.dooks@codethink.co.uk>, <bfields@redhat.com>,
	<cl@rock-chips.com>, <peterz@infradead.org>, <pmladek@suse.com>,
	<tj@kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Subject: [PATCH v2] kthread: work could not be queued when worker being destroyed
Date: Thu, 2 Jul 2020 15:01:56 +0800	[thread overview]
Message-ID: <20200702070156.5862-1-qiang.zhang@windriver.com> (raw)

From: Zhang Qiang <qiang.zhang@windriver.com>

The "queuing_blocked" func should print warning message and
returns true when the worker being destroyed.

Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Zhang Qiang <qiang.zhang@windriver.com>
---
 v1->v2:
 Add warning information for condition "!worker->task"	

 kernel/kthread.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/kthread.c b/kernel/kthread.c
index bfbfa481be3a..cac5184ffd86 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -791,6 +791,9 @@ static inline bool queuing_blocked(struct kthread_worker *worker,
 {
 	lockdep_assert_held(&worker->lock);
 
+	if (WARN_ON(!worker->task))
+		return true;
+
 	return !list_empty(&work->node) || work->canceling;
 }
 
-- 
2.24.1

