RE: [PATCH v9 09/13] exfat: add misc operations

["Namjae Jeon" <namjae.jeon@samsung.com>]

> On Wed, Jan 8, 2020 at 7:03 PM Christoph Hellwig <hch@lst.de> wrote:
> >
> > Arnd, can you review the exfat time handling, especially vs y2038
> > related issues?
> 
> Sure, thanks for adding me to the loop
> 
> > On Thu, Jan 02, 2020 at 10:19:02AM +0100, Pali Rohár wrote:
> > > On Thursday 02 January 2020 16:20:32 Namjae Jeon wrote:
> > > > +#define TIMEZONE_CUR_OFFSET()      ((sys_tz.tz_minuteswest / (-15))
> & 0x7F)
> > > > +/* Convert linear UNIX date to a FAT time/date pair. */ void
> > > > +exfat_time_unix2fat(struct exfat_sb_info *sbi, struct timespec64
> *ts,
> > > > +           struct exfat_date_time *tp) {
> > > > +   time_t second = ts->tv_sec;
> > > > +   time_t day, month, year;
> > > > +   time_t ld; /* leap day */
> > >
> > > Question for other maintainers: Has kernel code already time_t
> > > defined as 64bit? Or it is still just 32bit and 32bit systems and
> > > some time64_t needs to be used? I remember that there was discussion
> > > about these problems, but do not know if it was changed/fixed or
> > > not... Just a pointer for possible Y2038 problem. As "ts" is of type
> > > timespec64, but "second" of type time_t.
> 
> I am actually very close to sending the patches to remove the time_t
> definition from the kernel, at least in yesterday's version there were no
> users.
> 
> exfat_time_unix2fat() seems to be a copy of the old fat_time_unix2fat()
> that we fixed a while ago, please have a look at that implementation based
> on time64_to_tm(), which avoids time_t.
Okay, Pali reported it and suggested to check your patch in staging/exfat.
I will fix it on v10.

Thanks for your review!
> 
>       Arnd