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From:   OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To:     Chung-Chiang Cheng <shepjeng@gmail.com>
Cc:     Chung-Chiang Cheng <cccheng@synology.com>,
        linux-kernel@vger.kernel.org, kernel@cccheng.net
Subject: Re: [PATCH v3 3/3] fat: report creation time in statx
References: <20220415094518.380543-1-cccheng@synology.com>
        <20220415094518.380543-3-cccheng@synology.com>
        <87h76utrj2.fsf@mail.parknet.co.jp>
        <CAHuHWt=xYOBhRp_KJrSF5-xDBW+x_O4gnQSsX2M5u2D8zSXwTg@mail.gmail.com>
Date:   Fri, 22 Apr 2022 21:06:42 +0900
In-Reply-To: <CAHuHWt=xYOBhRp_KJrSF5-xDBW+x_O4gnQSsX2M5u2D8zSXwTg@mail.gmail.com>
        (Chung-Chiang Cheng's message of "Fri, 22 Apr 2022 16:20:06 +0800")
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Chung-Chiang Cheng <shepjeng@gmail.com> writes:

>
> I also have a question. If msdos doesn't support create-time, why does the
> original fat_truncate_time() truncate it to a 2-sec granularity?
>
> if (flags & S_CTIME) {
>         if (sbi->options.isvfat)
>                 inode->i_ctime = fat_timespec64_trunc_10ms(*now);
>         else
>                 inode->i_ctime = fat_timespec64_trunc_2secs(*now);
> }
>
> This logic was introduced in 6bb885ecd746 (fat: add functions to update
> and truncate timestamps appropriately"), and seems not for change-time.
> Should I remove it?

Hm, not sure.

However, ctime/atime is not stored into backing storage in
__fat_write_inode() and loaded if !isvfat (if I'm not missing
something).  So I think we don't need it for creation time.

Thanks.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>