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Date:   Fri, 25 Oct 2019 11:22:29 -0700
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Chao Yu <yuchao0@huawei.com>
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>
Subject: Re: [PATCH 2/2] f2fs: Add f2fs stats to sysfs
Message-ID: <20191025182229.GB24183@jaegeuk-macbookpro.roam.corp.google.com>
References: <20191023214821.107615-1-hridya@google.com>
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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.

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