fs/fat/misc.c - LeafOS-Devices/android_kernel_samsung_universal7904 - Gitiles

 /*
  *  linux/fs/fat/misc.c
  *
  *  Written 1992,1993 by Werner Almesberger
  *  22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
  *		 and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
  */

 #include "fat.h"

 #ifdef CONFIG_FAT_UEVENT
 static struct kobject fat_uevent_kobj;

 int fat_uevent_init(struct kset *fat_kset)
 {
 	int err;
 	struct kobj_type *ktype = get_ktype(&fat_kset->kobj);

 	fat_uevent_kobj.kset = fat_kset;
 	err = kobject_init_and_add(&fat_uevent_kobj, ktype, NULL, "uevent");
 	if (err)
 		pr_err("FAT-fs Unable to create fat uevent kobj\n");

 	return err;
 }

 void fat_uevent_uninit(void)
 {
 	kobject_del(&fat_uevent_kobj);
 	memset(&fat_uevent_kobj, 0, sizeof(struct kobject));
 }

 void fat_uevent_ro_remount(struct super_block *sb)
 {
 	struct block_device *bdev = sb->s_bdev;
 	dev_t bd_dev = bdev ? bdev->bd_dev : 0;

 	char major[16], minor[16];
 	char *envp[] = { major, minor, NULL };

 	snprintf(major, sizeof(major), "MAJOR=%d", MAJOR(bd_dev));
 	snprintf(minor, sizeof(minor), "MINOR=%d", MINOR(bd_dev));

 	kobject_uevent_env(&fat_uevent_kobj, KOBJ_CHANGE, envp);

 	ST_LOG("FAT-fs (%s[%d:%d]): Uevent triggered\n",
 			sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));
 }
 #endif

 /*
  * fat_fs_error reports a file system problem that might indicate fa data
  * corruption/inconsistency. Depending on 'errors' mount option the
  * panic() is called, or error message is printed FAT and nothing is done,
  * or filesystem is remounted read-only (default behavior).
  * In case the file system is remounted read-only, it can be made writable
  * again by remounting it.
  */
 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
 {
 	struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
 	va_list args;
 	struct va_format vaf;
 	struct block_device *bdev = sb->s_bdev;
 	dev_t bd_dev = bdev ? bdev->bd_dev : 0;

 	if (report) {
 		va_start(args, fmt);
 		vaf.fmt = fmt;
 		vaf.va = &args;
 		printk(KERN_ERR "FAT-fs (%s[%d:%d]): error, %pV\n",
 				sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);

 		if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY))
 	    			ST_LOG("FAT-fs (%s[%d:%d]): error, %pV\n",
 				sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);
 		va_end(args);
 	}

 	if (opts->errors == FAT_ERRORS_PANIC)
 		panic("FAT-fs (%s[%d:%d]): fs panic from previous error\n",
 				sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));
 	else if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY)) {
 		sb->s_flags |= MS_RDONLY;
 		printk(KERN_ERR "FAT-fs (%s[%d:%d]): Filesystem has been "
 				"set read-only\n",
 				sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));

 		ST_LOG("FAT-fs (%s[%d:%d]): Filesystem has been set read-only\n",
 				sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));
 		fat_uevent_ro_remount(sb);
 	}
 }
 EXPORT_SYMBOL_GPL(__fat_fs_error);

 /**
  * fat_msg() - print preformated FAT specific messages. Every thing what is
  * not fat_fs_error() should be fat_msg().
  */
 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list args;
 	struct block_device *bdev = sb->s_bdev;
 	dev_t bd_dev = bdev ? bdev->bd_dev : 0;

 	va_start(args, fmt);
 	vaf.fmt = fmt;
 	vaf.va = &args;
 	if (!strncmp(level, KERN_ERR, sizeof(KERN_ERR)))
 		printk_ratelimited("%sFAT-fs (%s[%d:%d]): %pV\n", level,
 			sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);
 	else
 		printk("%sFAT-fs (%s[%d:%d]): %pV\n", level,
 			sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);
 	va_end(args);
 }

 /* Flushes the number of free clusters on FAT32 */
 /* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
 int fat_clusters_flush(struct super_block *sb)
 {
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	struct buffer_head *bh;
 	struct fat_boot_fsinfo *fsinfo;

 	if (sbi->fat_bits != 32)
 		return 0;

 	bh = sb_bread(sb, sbi->fsinfo_sector);
 	if (bh == NULL) {
 		fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
 		return -EIO;
 	}

 	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
 	/* Sanity check */
 	if (!IS_FSINFO(fsinfo)) {
 		fat_msg(sb, KERN_ERR, "Invalid FSINFO signature: "
 		       "0x%08x, 0x%08x (sector = %lu)",
 		       le32_to_cpu(fsinfo->signature1),
 		       le32_to_cpu(fsinfo->signature2),
 		       sbi->fsinfo_sector);
 	} else {
 		if (sbi->free_clusters != -1)
 			fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
 		if (sbi->prev_free != -1)
 			fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
 		mark_buffer_dirty_sync(bh);
 	}
 	brelse(bh);

 	return 0;
 }

 /*
  * fat_chain_add() adds a new cluster to the chain of clusters represented
  * by inode.
  */
 int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
 {
 	struct super_block *sb = inode->i_sb;
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	int ret, new_fclus, last;

 	/*
 	 * We must locate the last cluster of the file to add this new
 	 * one (new_dclus) to the end of the link list (the FAT).
 	 */
 	last = new_fclus = 0;
 	if (MSDOS_I(inode)->i_start) {
 		int fclus, dclus;

 		ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
 		if (ret < 0)
 			return ret;
 		new_fclus = fclus + 1;
 		last = dclus;
 	}

 	/* add new one to the last of the cluster chain */
 	if (last) {
 		struct fat_entry fatent;

 		fatent_init(&fatent);
 		ret = fat_ent_read(inode, &fatent, last);
 		if (ret >= 0) {
 			int wait = inode_needs_sync(inode);
 			ret = fat_ent_write(inode, &fatent, new_dclus, wait);
 			fatent_brelse(&fatent);
 		}
 		if (ret < 0)
 			return ret;
 		/*
 		 * FIXME:Although we can add this cache, fat_cache_add() is
 		 * assuming to be called after linear search with fat_cache_id.
 		 */
 //		fat_cache_add(inode, new_fclus, new_dclus);
 	} else {
 		MSDOS_I(inode)->i_start = new_dclus;
 		MSDOS_I(inode)->i_logstart = new_dclus;
 		/*
 		 * Since generic_write_sync() synchronizes regular files later,
 		 * we sync here only directories.
 		 */
 		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
 			ret = fat_sync_inode(inode);
 			if (ret)
 				return ret;
 		} else
 			mark_inode_dirty(inode);
 	}
 	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
 		fat_fs_error(sb, "clusters badly computed (%d != %llu)",
 			     new_fclus,
 			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
 		fat_cache_inval_inode(inode);
 	}
 	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);

 	return 0;
 }

 /*
  * 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)
 /* 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 time_t days_in_year[] = {
 	/* Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
 	0,   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
 };

 /* 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)
 {
 	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
 	time_t second, day, leap_day, month, year;

 	year  = date >> 9;
 	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_set)
 		second += sys_tz.tz_minuteswest * SECS_PER_MIN;
 	else
 		second -= sbi->options.time_offset * 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 FAT time/date pair. */
 void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
 		       __le16 *time, __le16 *date, u8 *time_cs)
 {
 	struct tm tm;
 	time_to_tm(ts->tv_sec,
 		   (sbi->options.tz_set ? sbi->options.time_offset :
 		   -sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm);

 	/*  FAT can only support year between 1980 to 2107 */
 	if (tm.tm_year < 1980 - 1900) {
 		*time = 0;
 		*date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
 		if (time_cs)
 			*time_cs = 0;
 		return;
 	}
 	if (tm.tm_year > 2107 - 1900) {
 		*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;
 	}

 	/* from 1900 -> from 1980 */
 	tm.tm_year -= 80;
 	/* 0~11 -> 1~12 */
 	tm.tm_mon++;
 	/* 0~59 -> 0~29(2sec counts) */
 	tm.tm_sec >>= 1;

 	*time = cpu_to_le16(tm.tm_hour << 11 | tm.tm_min << 5 | tm.tm_sec);
 	*date = cpu_to_le16(tm.tm_year << 9 | tm.tm_mon << 5 | tm.tm_mday);
 	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)
 {
 	int i, err = 0;

 	for (i = 0; i < nr_bhs; i++)
 		write_dirty_buffer(bhs[i], WRITE);

 	for (i = 0; i < nr_bhs; i++) {
 		wait_on_buffer(bhs[i]);
 		if (!err && !buffer_uptodate(bhs[i]))
 			err = -EIO;
 	}
 	return err;
 }
	/*
	* linux/fs/fat/misc.c
	*
	* Written 1992,1993 by Werner Almesberger
	* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
	* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
	*/

	#include "fat.h"

	#ifdef CONFIG_FAT_UEVENT
	static struct kobject fat_uevent_kobj;

	int fat_uevent_init(struct kset *fat_kset)
	{
	int err;
	struct kobj_type *ktype = get_ktype(&fat_kset->kobj);

	fat_uevent_kobj.kset = fat_kset;
	err = kobject_init_and_add(&fat_uevent_kobj, ktype, NULL, "uevent");
	if (err)
	pr_err("FAT-fs Unable to create fat uevent kobj\n");

	return err;
	}

	void fat_uevent_uninit(void)
	{
	kobject_del(&fat_uevent_kobj);
	memset(&fat_uevent_kobj, 0, sizeof(struct kobject));
	}

	void fat_uevent_ro_remount(struct super_block *sb)
	{
	struct block_device *bdev = sb->s_bdev;
	dev_t bd_dev = bdev ? bdev->bd_dev : 0;

	char major[16], minor[16];
	char *envp[] = { major, minor, NULL };

	snprintf(major, sizeof(major), "MAJOR=%d", MAJOR(bd_dev));
	snprintf(minor, sizeof(minor), "MINOR=%d", MINOR(bd_dev));

	kobject_uevent_env(&fat_uevent_kobj, KOBJ_CHANGE, envp);

	ST_LOG("FAT-fs (%s[%d:%d]): Uevent triggered\n",
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));
	}
	#endif

	/*
	* fat_fs_error reports a file system problem that might indicate fa data
	* corruption/inconsistency. Depending on 'errors' mount option the
	* panic() is called, or error message is printed FAT and nothing is done,
	* or filesystem is remounted read-only (default behavior).
	* In case the file system is remounted read-only, it can be made writable
	* again by remounting it.
	*/
	void __fat_fs_error(struct super_block sb, int report, const char fmt, ...)
	{
	struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
	va_list args;
	struct va_format vaf;
	struct block_device *bdev = sb->s_bdev;
	dev_t bd_dev = bdev ? bdev->bd_dev : 0;

	if (report) {
	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	printk(KERN_ERR "FAT-fs (%s[%d:%d]): error, %pV\n",
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);

	if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY))
	ST_LOG("FAT-fs (%s[%d:%d]): error, %pV\n",
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);
	va_end(args);
	}

	if (opts->errors == FAT_ERRORS_PANIC)
	panic("FAT-fs (%s[%d:%d]): fs panic from previous error\n",
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));
	else if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY)) {
	sb->s_flags \|= MS_RDONLY;
	printk(KERN_ERR "FAT-fs (%s[%d:%d]): Filesystem has been "
	"set read-only\n",
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));

	ST_LOG("FAT-fs (%s[%d:%d]): Filesystem has been set read-only\n",
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev));
	fat_uevent_ro_remount(sb);
	}
	}
	EXPORT_SYMBOL_GPL(__fat_fs_error);

	/**
	* fat_msg() - print preformated FAT specific messages. Every thing what is
	* not fat_fs_error() should be fat_msg().
	*/
	void fat_msg(struct super_block sb, const char level, const char *fmt, ...)
	{
	struct va_format vaf;
	va_list args;
	struct block_device *bdev = sb->s_bdev;
	dev_t bd_dev = bdev ? bdev->bd_dev : 0;

	va_start(args, fmt);
	vaf.fmt = fmt;
	vaf.va = &args;
	if (!strncmp(level, KERN_ERR, sizeof(KERN_ERR)))
	printk_ratelimited("%sFAT-fs (%s[%d:%d]): %pV\n", level,
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);
	else
	printk("%sFAT-fs (%s[%d:%d]): %pV\n", level,
	sb->s_id, MAJOR(bd_dev), MINOR(bd_dev), &vaf);
	va_end(args);
	}

	/* Flushes the number of free clusters on FAT32 */
	/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
	int fat_clusters_flush(struct super_block *sb)
	{
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	struct buffer_head *bh;
	struct fat_boot_fsinfo *fsinfo;

	if (sbi->fat_bits != 32)
	return 0;

	bh = sb_bread(sb, sbi->fsinfo_sector);
	if (bh == NULL) {
	fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
	return -EIO;
	}

	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	/* Sanity check */
	if (!IS_FSINFO(fsinfo)) {
	fat_msg(sb, KERN_ERR, "Invalid FSINFO signature: "
	"0x%08x, 0x%08x (sector = %lu)",
	le32_to_cpu(fsinfo->signature1),
	le32_to_cpu(fsinfo->signature2),
	sbi->fsinfo_sector);
	} else {
	if (sbi->free_clusters != -1)
	fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
	if (sbi->prev_free != -1)
	fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
	mark_buffer_dirty_sync(bh);
	}
	brelse(bh);

	return 0;
	}

	/*
	* fat_chain_add() adds a new cluster to the chain of clusters represented
	* by inode.
	*/
	int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
	{
	struct super_block *sb = inode->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	int ret, new_fclus, last;

	/*
	* We must locate the last cluster of the file to add this new
	* one (new_dclus) to the end of the link list (the FAT).
	*/
	last = new_fclus = 0;
	if (MSDOS_I(inode)->i_start) {
	int fclus, dclus;

	ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
	if (ret < 0)
	return ret;
	new_fclus = fclus + 1;
	last = dclus;
	}

	/* add new one to the last of the cluster chain */
	if (last) {
	struct fat_entry fatent;

	fatent_init(&fatent);
	ret = fat_ent_read(inode, &fatent, last);
	if (ret >= 0) {
	int wait = inode_needs_sync(inode);
	ret = fat_ent_write(inode, &fatent, new_dclus, wait);
	fatent_brelse(&fatent);
	}
	if (ret < 0)
	return ret;
	/*
	* FIXME:Although we can add this cache, fat_cache_add() is
	* assuming to be called after linear search with fat_cache_id.
	*/
	// fat_cache_add(inode, new_fclus, new_dclus);
	} else {
	MSDOS_I(inode)->i_start = new_dclus;
	MSDOS_I(inode)->i_logstart = new_dclus;
	/*
	* Since generic_write_sync() synchronizes regular files later,
	* we sync here only directories.
	*/
	if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
	ret = fat_sync_inode(inode);
	if (ret)
	return ret;
	} else
	mark_inode_dirty(inode);
	}
	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
	fat_fs_error(sb, "clusters badly computed (%d != %llu)",
	new_fclus,
	(llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
	fat_cache_inval_inode(inode);
	}
	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);

	return 0;
	}

	/*
	* 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)
	/* 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 time_t days_in_year[] = {
	/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
	0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
	};

	/* 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)
	{
	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
	time_t second, day, leap_day, month, year;

	year = date >> 9;
	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_set)
	second += sys_tz.tz_minuteswest * SECS_PER_MIN;
	else
	second -= sbi->options.time_offset * 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 FAT time/date pair. */
	void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
	__le16 time, __le16 date, u8 *time_cs)
	{
	struct tm tm;
	time_to_tm(ts->tv_sec,
	(sbi->options.tz_set ? sbi->options.time_offset :
	-sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm);

	/* FAT can only support year between 1980 to 2107 */
	if (tm.tm_year < 1980 - 1900) {
	*time = 0;
	*date = cpu_to_le16((0 << 9) \| (1 << 5) \| 1);
	if (time_cs)
	*time_cs = 0;
	return;
	}
	if (tm.tm_year > 2107 - 1900) {
	*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;
	}

	/* from 1900 -> from 1980 */
	tm.tm_year -= 80;
	/* 0~11 -> 1~12 */
	tm.tm_mon++;
	/* 0~59 -> 0~29(2sec counts) */
	tm.tm_sec >>= 1;

	*time = cpu_to_le16(tm.tm_hour << 11 \| tm.tm_min << 5 \| tm.tm_sec);
	*date = cpu_to_le16(tm.tm_year << 9 \| tm.tm_mon << 5 \| tm.tm_mday);
	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)
	{
	int i, err = 0;

	for (i = 0; i < nr_bhs; i++)
	write_dirty_buffer(bhs[i], WRITE);

	for (i = 0; i < nr_bhs; i++) {
	wait_on_buffer(bhs[i]);
	if (!err && !buffer_uptodate(bhs[i]))
	err = -EIO;
	}
	return err;
	}