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From:   Jens Axboe <axboe@kernel.dk>
To:     hch@lst.de, yukuai3@huawei.com, Yu Kuai <yukuai1@huaweicloud.com>
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        yi.zhang@huawei.com, yangerkun@huawei.com
In-Reply-To: <20230606011438.3743440-1-yukuai1@huaweicloud.com>
References: <20230606011438.3743440-1-yukuai1@huaweicloud.com>
Subject: Re: [PATCH -next] blk-ioc: fix recursive spin_lock/unlock_irq() in
 ioc_clear_queue()
Message-Id: <168614595209.134969.6798849940705397930.b4-ty@kernel.dk>
Date:   Wed, 07 Jun 2023 07:52:32 -0600
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Precedence: bulk


On Tue, 06 Jun 2023 09:14:38 +0800, Yu Kuai wrote:
> Recursive spin_lock/unlock_irq() is not safe, because spin_unlock_irq()
> will enable irq unconditionally:
> 
> spin_lock_irq	queue_lock	-> disable irq
> spin_lock_irq	ioc->lock
> spin_unlock_irq ioc->lock	-> enable irq
> /*
>  * AA dead lock will be triggered if current context is preempted by irq,
>  * and irq try to hold queue_lock again.
>  */
> spin_unlock_irq queue_lock
> 
> [...]

Applied, thanks!

[1/1] blk-ioc: fix recursive spin_lock/unlock_irq() in ioc_clear_queue()
      commit: a7cfa0af0c88353b4eb59db5a2a0fbe35329b3f9

Best regards,
-- 
Jens Axboe