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Sender: Tejun Heo <htejun@gmail.com>
Date:   Sun, 13 Feb 2022 17:44:25 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc:     Bart Van Assche <bvanassche@acm.org>,
        syzbot <syzbot+831661966588c802aae9@syzkaller.appspotmail.com>,
        jgg@ziepe.ca, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [syzbot] possible deadlock in worker_thread
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Hello,

On Mon, Feb 14, 2022 at 10:08:00AM +0900, Tetsuo Handa wrote:
> +	destroy_workqueue(srp_tl_err_wq);
> 
> Then, we can call WARN_ON() if e.g. flush_workqueue() is called on system-wide workqueues.

Yeah, this is the right thing to do. It makes no sense at all to call
flush_workqueue() on the shared workqueues as the caller has no idea what
it's gonna end up waiting for. It was on my todo list a long while ago but
slipped through the crack. If anyone wanna take a stab at it (including
scrubbing the existing users, of course), please be my guest.

Thanks.

-- 
tejun