fat: Fix and cleanup timestamp conversion (7decd1cb) · Commits · 戴 / test

fs/fat/dir.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -1089,6 +1089,7 @@ int fat_alloc_new_dir(struct inode dir, struct timespec ts)
		struct msdos_dir_entry *de;
		sector_t blknr;
		__le16 date, time;
		u8 time_cs;
		int err, cluster;

		err = fat_alloc_clusters(dir, &cluster, 1);
		@@ -1102,7 +1103,7 @@ int fat_alloc_new_dir(struct inode dir, struct timespec ts)
		goto error_free;
		}

		fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
		fat_time_unix2fat(sbi, ts, &time, &date, &time_cs);

		de = (struct msdos_dir_entry *)bhs[0]->b_data;
		/* filling the new directory slots ("." and ".." entries) */
		@@ -1112,13 +1113,14 @@ int fat_alloc_new_dir(struct inode dir, struct timespec ts)
		de[0].lcase = de[1].lcase = 0;
		de[0].time = de[1].time = time;
		de[0].date = de[1].date = date;
		de[0].ctime_cs = de[1].ctime_cs = 0;
		if (sbi->options.isvfat) {
		/* extra timestamps */
		de[0].ctime = de[1].ctime = time;
		de[0].ctime_cs = de[1].ctime_cs = time_cs;
		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
		} else {
		de[0].ctime = de[1].ctime = 0;
		de[0].ctime_cs = de[1].ctime_cs = 0;
		de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
		}
		de[0].start = cpu_to_le16(cluster);

fs/fat/fat.h

+4 −3

Original line number	Diff line number	Diff line
		@@ -263,9 +263,10 @@ extern int fat_flush_inodes(struct super_block sb, struct inode i1,
		extern void fat_fs_panic(struct super_block s, const char fmt, ...);
		extern void fat_clusters_flush(struct super_block *sb);
		extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);
		extern int date_dos2unix(unsigned short time, unsigned short date, int tz_utc);
		extern void fat_date_unix2dos(int unix_date, __le16 time, __le16 date,
		int tz_utc);
		extern void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec ts,
		__le16 __time, __le16 __date, u8 time_cs);
		extern void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
		__le16 time, __le16 date, u8 *time_cs);
		extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs);

		int fat_cache_init(void);

fs/fat/inode.c

+11 −23

Original line number	Diff line number	Diff line
		@@ -381,22 +381,12 @@ static int fat_fill_inode(struct inode inode, struct msdos_dir_entry de)
		MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
		inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
		& ~((loff_t)sbi->cluster_size - 1)) >> 9;
		inode->i_mtime.tv_sec =
		date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date),
		sbi->options.tz_utc);
		inode->i_mtime.tv_nsec = 0;

		fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
		if (sbi->options.isvfat) {
		int secs = de->ctime_cs / 100;
		int csecs = de->ctime_cs % 100;
		inode->i_ctime.tv_sec =
		date_dos2unix(le16_to_cpu(de->ctime),
		le16_to_cpu(de->cdate),
		sbi->options.tz_utc) + secs;
		inode->i_ctime.tv_nsec = csecs * 10000000;
		inode->i_atime.tv_sec =
		date_dos2unix(0, le16_to_cpu(de->adate),
		sbi->options.tz_utc);
		inode->i_atime.tv_nsec = 0;
		fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
		de->cdate, de->ctime_cs);
		fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
		} else
		inode->i_ctime = inode->i_atime = inode->i_mtime;

		@@ -591,16 +581,14 @@ retry:
		raw_entry->attr = fat_attr(inode);
		raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
		raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
		fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time,
		&raw_entry->date, sbi->options.tz_utc);
		fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
		&raw_entry->date, NULL);
		if (sbi->options.isvfat) {
		__le16 atime;
		fat_date_unix2dos(inode->i_ctime.tv_sec, &raw_entry->ctime,
		&raw_entry->cdate, sbi->options.tz_utc);
		fat_date_unix2dos(inode->i_atime.tv_sec, &atime,
		&raw_entry->adate, sbi->options.tz_utc);
		raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
		inode->i_ctime.tv_nsec / 10000000;
		fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
		&raw_entry->cdate, &raw_entry->ctime_cs);
		fat_time_unix2fat(sbi, &inode->i_atime, &atime,
		&raw_entry->adate, NULL);
		}
		spin_unlock(&sbi->inode_hash_lock);
		mark_buffer_dirty(bh);

fs/fat/misc.c

+107 −41

Original line number	Diff line number	Diff line
		@@ -135,65 +135,131 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)

		extern struct timezone sys_tz;

		/*
		* The epoch of FAT timestamp is 1980.
		* : bits : value
		* date: 0 - 4: day (1 - 31)
		* date: 5 - 8: month (1 - 12)
		* date: 9 - 15: year (0 - 127) from 1980
		* time: 0 - 4: sec (0 - 29) 2sec counts
		* time: 5 - 10: min (0 - 59)
		* time: 11 - 15: hour (0 - 23)
		*/
		#define SECS_PER_MIN 60
		#define SECS_PER_HOUR (60 * 60)
		#define SECS_PER_DAY (SECS_PER_HOUR * 24)
		#define UNIX_SECS_1980 315532800L
		#if BITS_PER_LONG == 64
		#define UNIX_SECS_2108 4354819200L
		#endif
		/* days between 1.1.70 and 1.1.80 (2 leap days) */
		#define DAYS_DELTA (365 * 10 + 2)
		/* 120 (2100 - 1980) isn't leap year */
		#define YEAR_2100 120
		#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)

		/* Linear day numbers of the respective 1sts in non-leap years. */
		static int day_n[] = {
		static time_t days_in_year[] = {
		/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
		0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0
		0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
		};

		/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */
		int date_dos2unix(unsigned short time, unsigned short date, int tz_utc)
		/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
		void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec ts,
		__le16 __time, __le16 __date, u8 time_cs)
		{
		int month, year, secs;
		u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
		time_t second, day, leap_day, month, year;

		/*
		* first subtract and mask after that... Otherwise, if
		* date == 0, bad things happen
		*/
		month = ((date >> 5) - 1) & 15;
		year = date >> 9;
		secs = (time & 31)2+60((time >> 5) & 63)+(time >> 11)3600+86400
		((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
		month < 2 ? 1 : 0)+3653);
		/* days since 1.1.70 plus 80's leap day */
		if (!tz_utc)
		secs += sys_tz.tz_minuteswest*60;
		return secs;
		month = max(1, (date >> 5) & 0xf);
		day = max(1, date & 0x1f) - 1;

		leap_day = (year + 3) / 4;
		if (year > YEAR_2100) /* 2100 isn't leap year */
		leap_day--;
		if (IS_LEAP_YEAR(year) && month > 2)
		leap_day++;

		second = (time & 0x1f) << 1;
		second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
		second += (time >> 11) * SECS_PER_HOUR;
		second += (year * 365 + leap_day
		+ days_in_year[month] + day
		+ DAYS_DELTA) * SECS_PER_DAY;

		if (!sbi->options.tz_utc)
		second += sys_tz.tz_minuteswest * SECS_PER_MIN;

		if (time_cs) {
		ts->tv_sec = second + (time_cs / 100);
		ts->tv_nsec = (time_cs % 100) * 10000000;
		} else {
		ts->tv_sec = second;
		ts->tv_nsec = 0;
		}
		}

		/* Convert linear UNIX date to a MS-DOS time/date pair. */
		void fat_date_unix2dos(int unix_date, __le16 time, __le16 date, int tz_utc)
		/* Convert linear UNIX date to a FAT time/date pair. */
		void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
		__le16 time, __le16 date, u8 *time_cs)
		{
		int day, year, nl_day, month;
		time_t second = ts->tv_sec;
		time_t day, leap_day, month, year;

		if (!tz_utc)
		unix_date -= sys_tz.tz_minuteswest*60;
		if (!sbi->options.tz_utc)
		second -= sys_tz.tz_minuteswest * SECS_PER_MIN;

		/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
		if (unix_date < 315532800)
		unix_date = 315532800;
		if (second < UNIX_SECS_1980) {
		*time = 0;
		*date = cpu_to_le16((0 << 9) \| (1 << 5) \| 1);
		if (time_cs)
		*time_cs = 0;
		return;
		}
		#if BITS_PER_LONG == 64
		if (second >= UNIX_SECS_2108) {
		*time = cpu_to_le16((23 << 11) \| (59 << 5) \| 29);
		*date = cpu_to_le16((127 << 9) \| (12 << 5) \| 31);
		if (time_cs)
		*time_cs = 199;
		return;
		}
		#endif

		*time = cpu_to_le16((unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
		(((unix_date/3600) % 24) << 11));
		day = unix_date/86400-3652;
		day = second / SECS_PER_DAY - DAYS_DELTA;
		year = day / 365;
		if ((year+3)/4+365*year > day)
		leap_day = (year + 3) / 4;
		if (year > YEAR_2100) /* 2100 isn't leap year */
		leap_day--;
		if (year * 365 + leap_day > day)
		year--;
		day -= (year+3)/4+365*year;
		if (day == 59 && !(year & 3)) {
		nl_day = day;
		leap_day = (year + 3) / 4;
		if (year > YEAR_2100) /* 2100 isn't leap year */
		leap_day--;
		day -= year * 365 + leap_day;

		if (IS_LEAP_YEAR(year) && day == days_in_year[3]) {
		month = 2;
		} else {
		nl_day = (year & 3) \|\| day <= 59 ? day : day-1;
		for (month = 0; month < 12; month++) {
		if (day_n[month] > nl_day)
		if (IS_LEAP_YEAR(year) && day > days_in_year[3])
		day--;
		for (month = 1; month < 12; month++) {
		if (days_in_year[month + 1] > day)
		break;
		}
		}
		*date = cpu_to_le16(nl_day-day_n[month-1]+1+(month << 5)+(year << 9));
		}
		day -= days_in_year[month];

		EXPORT_SYMBOL_GPL(fat_date_unix2dos);
		*time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11
		\| ((second / SECS_PER_MIN) % 60) << 5
		\| (second % SECS_PER_MIN) >> 1);
		*date = cpu_to_le16((year << 9) \| (month << 5) \| (day + 1));
		if (time_cs)
		time_cs = (ts->tv_sec & 1) 100 + ts->tv_nsec / 10000000;
		}
		EXPORT_SYMBOL_GPL(fat_time_unix2fat);

		int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
		{

fs/fat/namei_msdos.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -247,7 +247,7 @@ static int msdos_add_entry(struct inode dir, const unsigned char name,
		if (is_hid)
		de.attr \|= ATTR_HIDDEN;
		de.lcase = 0;
		fat_date_unix2dos(ts->tv_sec, &time, &date, sbi->options.tz_utc);
		fat_time_unix2fat(sbi, ts, &time, &date, NULL);
		de.cdate = de.adate = 0;
		de.ctime = 0;
		de.ctime_cs = 0;

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