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://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification#74102-offsetvalid-field Signed-off-by: Chung-Chiang Cheng <cccheng@xxxxxxxxxxxx> --- fs/exfat/exfat_fs.h | 1 + fs/exfat/misc.c | 8 +++++++- fs/exfat/super.c | 3 ++- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h index 1d6da61157c9..b57fdd94ad01 100644 --- a/fs/exfat/exfat_fs.h +++ b/fs/exfat/exfat_fs.h @@ -204,6 +204,7 @@ struct exfat_mount_options { /* on error: continue, panic, remount-ro */ enum exfat_error_mode errors; unsigned utf8:1, /* Use of UTF-8 character set */ + tz_set:1, /* Filesystem timestamps' offset set */ discard:1; /* Issue discard requests on deletions */ int time_offset; /* Offset of timestamps from UTC (in minutes) */ }; diff --git a/fs/exfat/misc.c b/fs/exfat/misc.c index d34e6193258d..349e3fe64ea2 100644 --- a/fs/exfat/misc.c +++ b/fs/exfat/misc.c @@ -73,6 +73,12 @@ static void exfat_adjust_tz(struct timespec64 *ts, u8 tz_off) ts->tv_sec += TIMEZONE_SEC(0x80 - tz_off); } +static inline int exfat_tz_offset(struct exfat_sb_info *sbi) +{ + return (sbi->options.tz_set ? -sbi->options.time_offset : + sys_tz.tz_minuteswest) * SECS_PER_MIN; +} + /* Convert a EXFAT time/date pair to a UNIX date (seconds since 1 1 70). */ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts, u8 tz, __le16 time, __le16 date, u8 time_cs) @@ -96,7 +102,7 @@ void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts, exfat_adjust_tz(ts, tz & ~EXFAT_TZ_VALID); else /* Convert from local time to UTC using time_offset. */ - ts->tv_sec -= sbi->options.time_offset * SECS_PER_MIN; + ts->tv_sec += exfat_tz_offset(sbi); } /* Convert linear UNIX date to a EXFAT time/date pair. */ diff --git a/fs/exfat/super.c b/fs/exfat/super.c index 5539ffc20d16..caeea375e4fa 100644 --- a/fs/exfat/super.c +++ b/fs/exfat/super.c @@ -173,7 +173,7 @@ static int exfat_show_options(struct seq_file *m, struct dentry *root) seq_puts(m, ",errors=remount-ro"); if (opts->discard) seq_puts(m, ",discard"); - if (opts->time_offset) + if (opts->tz_set) seq_printf(m, ",time_offset=%d", opts->time_offset); return 0; } @@ -303,6 +303,7 @@ static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param) */ if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60) return -EINVAL; + opts->tz_set = 1; opts->time_offset = result.int_32; break; case Opt_utf8: -- 2.25.1
