From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Chung-Chiang Cheng <shepjeng@gmail.com>
Cc: Chung-Chiang Cheng <cccheng@synology.com>,
linux-fsdevel@vger.kernel.org, kernel@cccheng.net
Subject: Re: [PATCH 2/2] fat: introduce creation time
Date: Fri, 25 Mar 2022 19:36:16 +0900 [thread overview]
Message-ID: <87cziapbdr.fsf@mail.parknet.co.jp> (raw)
In-Reply-To: <CAHuHWtm5qdJm0wmjMbauRERg4hJYv7EWTtA6-0n9Ss9p=OtOqw@mail.gmail.com> (Chung-Chiang Cheng's message of "Fri, 25 Mar 2022 15:38:29 +0800")
Chung-Chiang Cheng <shepjeng@gmail.com> writes:
> On Wed, Mar 23, 2022 at 6:57 PM OGAWA Hirofumi
> <hirofumi@mail.parknet.co.jp> wrote:
>>
>> No, a user can change the ctime to arbitrary time, and after the your
>> patch, the changed ctime only hold on a memory inode. So a user sees
>> ctime jump backward and forward when a memory inode is expired. (Of
>> course, this happens just by "cp -a" in real world use case.)
>>
>> I'm pointing about this introduced new behavior by your patch.
>>
>
> As you mentioned, there are still some cases to consider that ctime
> isn't identical to mtime. If so, ctime won't be consistent after
> inode is expired because it will be filled with the value of on-disk
> mtime, which is weird and confusing.
>
> To solve the issue, I propose to keep ctime and mtime always the same
> in memory. If you agree with this approach, I'll send a v2 patch for
> it.
Yes, exactly.
Although I think it is better, in real world userspace, it may got
actual compatibility issue and reported, then we may have to revert even
if I personally think new is better.
Thanks.
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
prev parent reply other threads:[~2022-03-25 10:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-21 9:58 [PATCH 1/2] fat: split fat_truncate_time() into separate functions Chung-Chiang Cheng
2022-03-21 9:58 ` [PATCH 2/2] fat: introduce creation time Chung-Chiang Cheng
2022-03-22 7:33 ` OGAWA Hirofumi
2022-03-23 2:14 ` Chung-Chiang Cheng
2022-03-23 6:57 ` OGAWA Hirofumi
2022-03-23 10:27 ` Chung-Chiang Cheng
2022-03-23 10:57 ` OGAWA Hirofumi
2022-03-25 7:38 ` Chung-Chiang Cheng
2022-03-25 10:36 ` OGAWA Hirofumi [this message]
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