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Subject: Re: [PATCH 1/2] block: don't allow a disk link holder to itself
To:     Christoph Hellwig <hch@lst.de>, Yu Kuai <yukuai1@huaweicloud.com>
Cc:     axboe@kernel.dk, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, yi.zhang@huawei.com,
        "yukuai (C)" <yukuai3@huawei.com>
References: <20221103025541.1875809-1-yukuai1@huaweicloud.com>
 <20221103025541.1875809-2-yukuai1@huaweicloud.com>
 <20221103080628.GA3346@lst.de>
From:   Yu Kuai <yukuai1@huaweicloud.com>
Message-ID: <faabea7a-b06b-1494-59ce-e06d0a7b2882@huaweicloud.com>
Date:   Thu, 3 Nov 2022 17:17:00 +0800
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Hi,

?? 2022/11/03 16:06, Christoph Hellwig д??:
> Yes, this is a good one.  Please add a single sentence blurb explaing
> the issue before the Test prodecure?
Ok, I'll do that.
> 
> With that this looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> 
> On Thu, Nov 03, 2022 at 10:55:40AM +0800, Yu Kuai wrote:
>> From: Yu Kuai <yukuai3@huawei.com>
>>
>> Test procedures:
>>
>> 1) dmsetup create test --table "xxx sda", assume dm-0 is created
>> 2) dmsetup suspend test
>> 3) dmsetup reload test --table "xxx dm-0"
>> 4) dmsetup resume test
> 
> Can you wire this up for blocktests?

Of course I can, I'm not very familiar with how to add new test in
blktests, so I might take some time to do that.
> 
> I've also been wondering how we could wire your other two test cases
> up as I think they'be very useful.  Hopefully I can find some time
> to inject delays with eBPF or something like it.

The problem was found without the delay originally, such delay can make
sure the problem is reproduced 100%, but it's still possible without the
delay. Perhaps we can add the test without delay for now.

Thanks,
Kuai
> 
> .
>