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Subject: Re: [PATCH 2/2] f2fs: Add f2fs stats to sysfs
To:     Jaegeuk Kim <jaegeuk@kernel.org>
CC:     Hridya Valsaraju <hridya@google.com>,
        <linux-f2fs-devel@lists.sourceforge.net>,
        LKML <linux-kernel@vger.kernel.org>,
        Android Kernel Team <kernel-team@android.com>
References: <20191023214821.107615-1-hridya@google.com>
 <20191023214821.107615-2-hridya@google.com>
 <e61510b8-c8d7-349f-b297-9df367c26a9f@huawei.com>
 <CA+wgaPNas7ixNtepJE_6e7b6Dcutb9a1Who4WrUfKSw1ZnQhTA@mail.gmail.com>
 <96f89e7c-d91e-e263-99f7-16998cc443a7@huawei.com>
 <20191025182229.GB24183@jaegeuk-macbookpro.roam.corp.google.com>
From:   Chao Yu <yuchao0@huawei.com>
Message-ID: <eb08716f-2f56-30bb-d71d-28125b3b0608@huawei.com>
Date:   Sat, 26 Oct 2019 09:37:57 +0800
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On 2019/10/26 2:22, Jaegeuk Kim wrote:
> On 10/25, Chao Yu wrote:
>> On 2019/10/25 11:51, Hridya Valsaraju wrote:
>>> On Thu, Oct 24, 2019 at 2:26 AM Chao Yu <yuchao0@huawei.com> wrote:
>>>>
>>>> On 2019/10/24 5:48, Hridya Valsaraju wrote:
>>>>> Currently f2fs stats are only available from /d/f2fs/status. This patch
>>>>> adds some of the f2fs stats to sysfs so that they are accessible even
>>>>> when debugfs is not mounted.
>>>>
>>>> Why don't we mount debugfs first?
>>>
>>> Thank you for taking a look at the patch Chao. We will not be mounting
>>> debugfs for security reasons.
>>
>> Hi, Hridya,
>>
>> May I ask is there any use case for those new entries?
>>
>> So many sysfs entries exist, if there is real use case, how about backuping
>> entire /d/f2fs/status entry into /proc/fs/f2fs/<dev>/ directory rather than
>> adding some of stats as a single entry in sysfs directory?
> 
> These will be useful to keep a track on f2fs health status by one value
> per entry, which doesn't require user-land parsing stuff. Of course, Android
> can exploit them by IdleMaint, rollback feature, and so on.

Alright, I suggest to add a sub-directory for those statistic entries, we can
manage them more easily isolated from those existed switch entries.

Thanks,

> 
>>
>> Thanks,
>>
>>>
>>> Regards,
>>> Hridya
>>>
>>>>
>>>> Thanks,
>>> .
>>>
> .
>