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Subject: Re: [PATCH V1] block: Fix null pointer dereference issue on struct
 io_cq
To:     Pradeep Pragallapati <quic_pragalla@quicinc.com>,
        Yu Kuai <yukuai1@huaweicloud.com>, axboe@kernel.dk
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        "yukuai (C)" <yukuai3@huawei.com>
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 <00eefae6-8db4-139b-9f8a-9ed326817561@quicinc.com>
From:   Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <b7d92802-8403-874d-0cf5-d492e3ea96ae@huaweicloud.com>
Date:   Tue, 30 May 2023 21:24:36 +0800
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Hi,

在 2023/05/30 21:15, Pradeep Pragallapati 写道:
> Hi,
> 
> On 5/22/2023 11:49 AM, Pradeep Pragallapati wrote:
>>
>> On 5/18/2023 6:14 PM, Yu Kuai wrote:
>>> Hi,
>>>
>>> 在 2023/05/18 20:16, Yu Kuai 写道:
>>>
>>>> @@ -173,18 +171,17 @@ void ioc_clear_queue(struct request_queue *q)
>>>>   {
>>>>          LIST_HEAD(icq_list);
>>>>
>>>> +       rcu_read_lock();
>>>
>>> Sorry that I realized this is still not enough, following list_empty()
>>> and list_entry() can still concurrent with list_del(). Please try the
>>> following patch:
>> sure will try and update the results.
> 
> 
> At least for 80+hrs of testing, i didn't see the issue reproduced. seems 
> like it is helping my case.

Thanks for the test, I'll send a patch soon.

Kuai