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Sender: Tejun Heo <htejun@gmail.com>
Date:   Thu, 5 Aug 2021 07:17:24 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Yu Kuai <yukuai3@huawei.com>
Cc:     axboe@kernel.dk, bo.liu@linux.alibaba.com, cgroups@vger.kernel.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        yi.zhang@huawei.com
Subject: Re: [PATCH] blk-iolatency: error out if blk_get_queue() failed in
 iolatency_set_limit()
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References: <20210805124645.543797-1-yukuai3@huawei.com>
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On Thu, Aug 05, 2021 at 08:46:45PM +0800, Yu Kuai wrote:
> If queue is dying while iolatency_set_limit() is in progress,
> blk_get_queue() won't increment the refcount of the queue. However,
> blk_put_queue() will still decrement the refcount later, which will
> cause the refcout to be unbalanced.
> 
> Thus error out in such case to fix the problem.
> 
> Fixes: 8c772a9bfc7c ("blk-iolatency: fix IO hang due to negative inflight counter")
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun