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Message-ID: <6ed5b778-24f6-25c2-7689-113bb0297847@huaweicloud.com>
Date:   Sun, 14 May 2023 19:08:03 +0800
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Subject: Re: [PATCH v2 3/4] md/raid10: fix wrong setting of
 max_corr_read_errors
To:     Yu Kuai <yukuai1@huaweicloud.com>, Song Liu <song@kernel.org>
Cc:     linan666@huaweicloud.com, neilb@suse.de, Rob.Becker@riverbed.com,
        linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
        yi.zhang@huawei.com, houtao1@huawei.com, yangerkun@huawei.com,
        "yukuai (C)" <yukuai3@huawei.com>
References: <20230506012315.3370489-1-linan666@huaweicloud.com>
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 <5db8b619-7eac-79be-10e4-1292a44b943b@huaweicloud.com>
From:   Li Nan <linan666@huaweicloud.com>
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在 2023/5/13 10:21, Yu Kuai 写道:
> Hi,
> 
> 在 2023/05/13 9:08, Song Liu 写道:
>> On Fri, May 5, 2023 at 7:02 PM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>>>
>>> Hi,
>>>
>>> 在 2023/05/06 9:23, linan666@huaweicloud.com 写道:
>>>> From: Li Nan <linan122@huawei.com>
>>>>
>>>> max_corr_read_errors should not be negative number. Change it to
>>>> unsigned int where use it.
>>>>
>>>
>>> Looks good, feel free to add:
>>>
>>> Reviewed-by: Yu Kuai <yukuai3@huawei.com>
>>>
>>>> Fixes: 1e50915fe0bb ("raid: improve MD/raid10 handling of 
>>>> correctable read errors.")
>>>> Signed-off-by: Li Nan <linan122@huawei.com>
>>
>> Hmm.. Does the current code break in any cases?
> 
> The problem is that somewhere use unsigned value, and somewhere use
> signed value, and I thinsk the only functional change is in
> fix_read_error(), if max_read_errors is negative, the judgement will
> always pass before this patch:
> 
> if (atomic_read(&rdev->read_errors) > max_read_errors)
> 

In addition, it is confusing for users after setting a huge number to it.
   # echo 4294967295 > /sys/block/$disk/md/max_read_errors
   # cat /sys/block/$disk/md/max_read_errors
     -1

-- 
Thanks,
Nan