On Thursday 02 January 2020 16:20:32 Namjae Jeon wrote:
> This adds the implementation of misc operations for exfat.
>
> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
> Signed-off-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx>
> ---
> fs/exfat/misc.c | 253 ++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 253 insertions(+)
> create mode 100644 fs/exfat/misc.c
>
> diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c
> new file mode 100644
> index 000000000000..7f533bcb3b3f
> --- /dev/null
> +++ b/fs/exfat/misc.c
...
> +/* <linux/time.h> externs sys_tz
> + * extern struct timezone sys_tz;
> + */
> +#define UNIX_SECS_1980 315532800L
> +
> +#if BITS_PER_LONG == 64
> +#define UNIX_SECS_2108 4354819200L
> +#endif
...
> +#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.
> +
> + /* Treats as local time with proper time */
> + second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
> + tp->timezone.valid = 1;
> + tp->timezone.off = TIMEZONE_CUR_OFFSET();
> +
> + /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
> + if (second < UNIX_SECS_1980) {
> + tp->second = 0;
> + tp->minute = 0;
> + tp->hour = 0;
> + tp->day = 1;
> + tp->month = 1;
> + tp->year = 0;
> + return;
> + }
> +
> + if (second >= UNIX_SECS_2108) {
Hello, this code cause compile errors on 32bit systems as UNIX_SECS_2108
macro is not defined when BITS_PER_LONG == 32.
Value 4354819200 really cannot fit into 32bit signed integer, so you
should use 64bit signed integer. I would suggest to define this macro
value via LL not just L suffix (and it would work on both 32 and 64bit)
#define UNIX_SECS_2108 4354819200LL
> + tp->second = 59;
> + tp->minute = 59;
> + tp->hour = 23;
> + tp->day = 31;
> + tp->month = 12;
> + tp->year = 127;
> + return;
> + }
--
Pali Rohár
pali.rohar@xxxxxxxxx
