Re: [PATCH] exfat: use local UTC offset when EXFAT_TZ_VALID isn't set

From: Namjae Jeon
Date: Fri Oct 01 2021 - 10:40:16 EST


2021-10-01 22:19 GMT+09:00, Sungjong Seo <sj1557.seo@xxxxxxxxxxx>:
> Hello, Namjae,
Hi Sungjong,
>
> I found an important difference between the code we first wrote and the code
> that has changed since our initial patch review. This difference seems to
> cause compatibility issues when reading saved timestamps without timezone.
> (In our initial patch review, there were concerns about possible
> compatibility issues.)
> I think the code that reads timestamps without timezone should go back to
> the concept we wrote in the first place like reported patch.
Are you talking about using sys_tz?

> It could be an answer of another timestamp issue.
What is another timestamp issue ?

>
> Could you please let me know what you think?
>
> Thanks.
>> -----Original Message-----
>> From: Namjae Jeon [mailto:linkinjeon@xxxxxxxxxx]
>> Sent: Friday, September 10, 2021 10:01 AM
>> To: Chung-Chiang Cheng <cccheng@xxxxxxxxxxxx>
>> Cc: sj1557.seo@xxxxxxxxxxx; linux-fsdevel@xxxxxxxxxxxxxxx; linux-
>> kernel@xxxxxxxxxxxxxxx; shepjeng@xxxxxxxxx
>> Subject: Re: [PATCH] exfat: use local UTC offset when EXFAT_TZ_VALID
>> isn't
>> set
>>
>> 2021-09-09 15:55 GMT+09:00, Chung-Chiang Cheng <cccheng@xxxxxxxxxxxx>:
>> > EXFAT_TZ_VALID is corresponding to OffsetValid field in exfat
>> > specification [1]. If this bit isn't set, timestamps should be treated
>> > as having the same UTC offset as the current local time.
>> >
>> > This patch uses the existing mount option 'time_offset' as fat does.
>> > If time_offset isn't set, local UTC offset in sys_tz will be used as
>> > the default value.
>> >
>> > Link: [1]
>> > https://protect2.fireeye.com/v1/url?k=cba4edf5-943fd4c8-cba566ba-0cc47
>> > a31309a-e70aa065be678729&q=1&e=225feff2-841f-404c-9a2e-c12064b232d0&u=
>> > https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fwindows%2Fwin32%2Ffileio%2F
>> > exfat-specification%2374102-offsetvalid-field
>> > Signed-off-by: Chung-Chiang Cheng <cccheng@xxxxxxxxxxxx>
>> Please read this discussion:
>> https://patchwork.kernel.org/project/linux-
>> fsdevel/patch/20200115082447.19520-10-namjae.jeon@xxxxxxxxxxx/
>>
>> Thanks!
>
>