[net-next-2.6.git] / fs / fat / misc.c

/*
 *  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 <linux/module.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include "fat.h"

/*
 * 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 *s, const char *fmt, ...)
{
	struct fat_mount_options *opts = &MSDOS_SB(s)->options;
	va_list args;

	printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);

	printk(KERN_ERR "    ");
	va_start(args, fmt);
	vprintk(fmt, args);
	va_end(args);
	printk("\n");

	if (opts->errors == FAT_ERRORS_PANIC)
		panic("    FAT fs panic from previous error\n");
	else if (opts->errors == FAT_ERRORS_RO && !(s->s_flags & MS_RDONLY)) {
		s->s_flags |= MS_RDONLY;
		printk(KERN_ERR "    File system has been set read-only\n");
	}
}
EXPORT_SYMBOL_GPL(fat_fs_error);

/* Flushes the number of free clusters on FAT32 */
/* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
void 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;

	bh = sb_bread(sb, sbi->fsinfo_sector);
	if (bh == NULL) {
		printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
		return;
	}

	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	/* Sanity check */
	if (!IS_FSINFO(fsinfo)) {
		printk(KERN_ERR "FAT: Invalid FSINFO signature: "
		       "0x%08x, 0x%08x (sector = %lu)\n",
		       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(bh);
	}
	brelse(bh);
}

/*
 * 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;
//		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;
}

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 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_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 FAT time/date pair. */
void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
		       __le16 *time, __le16 *date, u8 *time_cs)
{
	time_t second = ts->tv_sec;
	time_t day, leap_day, month, year;

	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 (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

	day = second / SECS_PER_DAY - DAYS_DELTA;
	year = day / 365;
	leap_day = (year + 3) / 4;
	if (year > YEAR_2100)		/* 2100 isn't leap year */
		leap_day--;
	if (year * 365 + leap_day > day)
		year--;
	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 {
		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;
		}
	}
	day -= days_in_year[month];

	*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)
{
	int i, err = 0;

	ll_rw_block(SWRITE, nr_bhs, bhs);
	for (i = 0; i < nr_bhs; i++) {
		wait_on_buffer(bhs[i]);
		if (buffer_eopnotsupp(bhs[i])) {
			clear_buffer_eopnotsupp(bhs[i]);
			err = -EOPNOTSUPP;
		} else if (!err && !buffer_uptodate(bhs[i]))
			err = -EIO;
	}
	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/fat/misc.c
	3	*
	4	* Written 1992,1993 by Werner Almesberger
	5	* 22/11/2000 - Fixed fat_date_unix2dos for dates earlier than 01/01/1980
	6	* and date_dos2unix for date==0 by Igor Zhbanov(bsg@uniyar.ac.ru)
	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/fs.h>
1da177e4	11	#include <linux/buffer_head.h>
9e975dae	12	#include "fat.h"
1da177e4 LT	13
1da177e4 LT	14	/*
85c78591 DK	15	* fat_fs_error reports a file system problem that might indicate fa data
	16	* corruption/inconsistency. Depending on 'errors' mount option the
	17	* panic() is called, or error message is printed FAT and nothing is done,
	18	* or filesystem is remounted read-only (default behavior).
	19	* In case the file system is remounted read-only, it can be made writable
	20	* again by remounting it.
1da177e4	21	*/
85c78591	22	void fat_fs_error(struct super_block s, const char fmt, ...)
1da177e4	23	{
85c78591	24	struct fat_mount_options *opts = &MSDOS_SB(s)->options;
1da177e4 LT	25	va_list args;
1da177e4 LT	26
85c78591	27	printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);
1da177e4 LT	28
	29	printk(KERN_ERR " ");
	30	va_start(args, fmt);
	31	vprintk(fmt, args);
	32	va_end(args);
	33	printk("\n");
	34
85c78591 DK	35	if (opts->errors == FAT_ERRORS_PANIC)
	36	panic(" FAT fs panic from previous error\n");
	37	else if (opts->errors == FAT_ERRORS_RO && !(s->s_flags & MS_RDONLY)) {
1da177e4 LT	38	s->s_flags \|= MS_RDONLY;
	39	printk(KERN_ERR " File system has been set read-only\n");
	40	}
	41	}
85c78591	42	EXPORT_SYMBOL_GPL(fat_fs_error);
1da177e4 LT	43
	44	/* Flushes the number of free clusters on FAT32 */
	45	/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
	46	void fat_clusters_flush(struct super_block *sb)
	47	{
	48	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	49	struct buffer_head *bh;
	50	struct fat_boot_fsinfo *fsinfo;
	51
	52	if (sbi->fat_bits != 32)
	53	return;
	54
	55	bh = sb_bread(sb, sbi->fsinfo_sector);
	56	if (bh == NULL) {
	57	printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
	58	return;
	59	}
	60
	61	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	62	/* Sanity check */
	63	if (!IS_FSINFO(fsinfo)) {
b4cf9c34 VN	64	printk(KERN_ERR "FAT: Invalid FSINFO signature: "
b4cf9c34 VN	65	"0x%08x, 0x%08x (sector = %lu)\n",
1da177e4 LT	66	le32_to_cpu(fsinfo->signature1),
	67	le32_to_cpu(fsinfo->signature2),
	68	sbi->fsinfo_sector);
	69	} else {
	70	if (sbi->free_clusters != -1)
	71	fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
	72	if (sbi->prev_free != -1)
	73	fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
	74	mark_buffer_dirty(bh);
1da177e4 LT	75	}
	76	brelse(bh);
	77	}
	78
	79	/*
	80	* fat_chain_add() adds a new cluster to the chain of clusters represented
	81	* by inode.
	82	*/
	83	int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
	84	{
	85	struct super_block *sb = inode->i_sb;
	86	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	87	int ret, new_fclus, last;
	88
	89	/*
	90	* We must locate the last cluster of the file to add this new
	91	* one (new_dclus) to the end of the link list (the FAT).
	92	*/
	93	last = new_fclus = 0;
	94	if (MSDOS_I(inode)->i_start) {
	95	int fclus, dclus;
	96
	97	ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
	98	if (ret < 0)
	99	return ret;
	100	new_fclus = fclus + 1;
	101	last = dclus;
	102	}
	103
	104	/* add new one to the last of the cluster chain */
	105	if (last) {
	106	struct fat_entry fatent;
	107
	108	fatent_init(&fatent);
	109	ret = fat_ent_read(inode, &fatent, last);
	110	if (ret >= 0) {
	111	int wait = inode_needs_sync(inode);
	112	ret = fat_ent_write(inode, &fatent, new_dclus, wait);
	113	fatent_brelse(&fatent);
	114	}
	115	if (ret < 0)
	116	return ret;
	117	// fat_cache_add(inode, new_fclus, new_dclus);
	118	} else {
	119	MSDOS_I(inode)->i_start = new_dclus;
	120	MSDOS_I(inode)->i_logstart = new_dclus;
	121	/*
2f3d675b JK	122	* Since generic_write_sync() synchronizes regular files later,
2f3d675b JK	123	* we sync here only directories.
1da177e4 LT	124	*/
	125	if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
	126	ret = fat_sync_inode(inode);
	127	if (ret)
	128	return ret;
	129	} else
	130	mark_inode_dirty(inode);
	131	}
	132	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
85c78591	133	fat_fs_error(sb, "clusters badly computed (%d != %llu)",
c3302931 OH	134	new_fclus,
c3302931 OH	135	(llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
1da177e4 LT	136	fat_cache_inval_inode(inode);
	137	}
	138	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
	139
	140	return 0;
	141	}
	142
	143	extern struct timezone sys_tz;
	144
7decd1cb OH	145	/*
	146	* The epoch of FAT timestamp is 1980.
	147	* : bits : value
	148	* date: 0 - 4: day (1 - 31)
	149	* date: 5 - 8: month (1 - 12)
	150	* date: 9 - 15: year (0 - 127) from 1980
	151	* time: 0 - 4: sec (0 - 29) 2sec counts
	152	* time: 5 - 10: min (0 - 59)
	153	* time: 11 - 15: hour (0 - 23)
	154	*/
	155	#define SECS_PER_MIN 60
	156	#define SECS_PER_HOUR (60 * 60)
	157	#define SECS_PER_DAY (SECS_PER_HOUR * 24)
	158	#define UNIX_SECS_1980 315532800L
	159	#if BITS_PER_LONG == 64
	160	#define UNIX_SECS_2108 4354819200L
	161	#endif
	162	/* days between 1.1.70 and 1.1.80 (2 leap days) */
	163	#define DAYS_DELTA (365 * 10 + 2)
	164	/* 120 (2100 - 1980) isn't leap year */
	165	#define YEAR_2100 120
	166	#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
	167
1da177e4	168	/* Linear day numbers of the respective 1sts in non-leap years. */
7decd1cb OH	169	static time_t days_in_year[] = {
	170	/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
	171	0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
1da177e4 LT	172	};
1da177e4 LT	173
7decd1cb OH	174	/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
	175	void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec ts,
	176	__le16 __time, __le16 __date, u8 time_cs)
1da177e4	177	{
7decd1cb OH	178	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
7decd1cb OH	179	time_t second, day, leap_day, month, year;
1da177e4	180
7decd1cb OH	181	year = date >> 9;
	182	month = max(1, (date >> 5) & 0xf);
	183	day = max(1, date & 0x1f) - 1;
	184
	185	leap_day = (year + 3) / 4;
	186	if (year > YEAR_2100) /* 2100 isn't leap year */
	187	leap_day--;
	188	if (IS_LEAP_YEAR(year) && month > 2)
	189	leap_day++;
	190
	191	second = (time & 0x1f) << 1;
	192	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
	193	second += (time >> 11) * SECS_PER_HOUR;
	194	second += (year * 365 + leap_day
	195	+ days_in_year[month] + day
	196	+ DAYS_DELTA) * SECS_PER_DAY;
	197
	198	if (!sbi->options.tz_utc)
	199	second += sys_tz.tz_minuteswest * SECS_PER_MIN;
	200
	201	if (time_cs) {
	202	ts->tv_sec = second + (time_cs / 100);
	203	ts->tv_nsec = (time_cs % 100) * 10000000;
	204	} else {
	205	ts->tv_sec = second;
	206	ts->tv_nsec = 0;
	207	}
1da177e4 LT	208	}
1da177e4 LT	209
7decd1cb OH	210	/* Convert linear UNIX date to a FAT time/date pair. */
	211	void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
	212	__le16 time, __le16 date, u8 *time_cs)
1da177e4	213	{
7decd1cb OH	214	time_t second = ts->tv_sec;
7decd1cb OH	215	time_t day, leap_day, month, year;
1da177e4	216
7decd1cb OH	217	if (!sbi->options.tz_utc)
7decd1cb OH	218	second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
1da177e4 LT	219
1da177e4 LT	220	/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
7decd1cb OH	221	if (second < UNIX_SECS_1980) {
	222	*time = 0;
	223	*date = cpu_to_le16((0 << 9) \| (1 << 5) \| 1);
	224	if (time_cs)
	225	*time_cs = 0;
	226	return;
	227	}
	228	#if BITS_PER_LONG == 64
	229	if (second >= UNIX_SECS_2108) {
	230	*time = cpu_to_le16((23 << 11) \| (59 << 5) \| 29);
	231	*date = cpu_to_le16((127 << 9) \| (12 << 5) \| 31);
	232	if (time_cs)
	233	*time_cs = 199;
	234	return;
	235	}
	236	#endif
	237
	238	day = second / SECS_PER_DAY - DAYS_DELTA;
	239	year = day / 365;
	240	leap_day = (year + 3) / 4;
	241	if (year > YEAR_2100) /* 2100 isn't leap year */
	242	leap_day--;
	243	if (year * 365 + leap_day > day)
1da177e4	244	year--;
7decd1cb OH	245	leap_day = (year + 3) / 4;
	246	if (year > YEAR_2100) /* 2100 isn't leap year */
	247	leap_day--;
	248	day -= year * 365 + leap_day;
	249
	250	if (IS_LEAP_YEAR(year) && day == days_in_year[3]) {
1da177e4 LT	251	month = 2;
1da177e4 LT	252	} else {
7decd1cb OH	253	if (IS_LEAP_YEAR(year) && day > days_in_year[3])
	254	day--;
	255	for (month = 1; month < 12; month++) {
	256	if (days_in_year[month + 1] > day)
1da177e4 LT	257	break;
	258	}
	259	}
7decd1cb	260	day -= days_in_year[month];
1da177e4	261
7decd1cb OH	262	*time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11
	263	\| ((second / SECS_PER_MIN) % 60) << 5
	264	\| (second % SECS_PER_MIN) >> 1);
	265	*date = cpu_to_le16((year << 9) \| (month << 5) \| (day + 1));
	266	if (time_cs)
	267	time_cs = (ts->tv_sec & 1) 100 + ts->tv_nsec / 10000000;
	268	}
	269	EXPORT_SYMBOL_GPL(fat_time_unix2fat);
1da177e4 LT	270
	271	int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
	272	{
5b00226d	273	int i, err = 0;
1da177e4	274
5b00226d	275	ll_rw_block(SWRITE, nr_bhs, bhs);
1da177e4 LT	276	for (i = 0; i < nr_bhs; i++) {
	277	wait_on_buffer(bhs[i]);
	278	if (buffer_eopnotsupp(bhs[i])) {
	279	clear_buffer_eopnotsupp(bhs[i]);
	280	err = -EOPNOTSUPP;
	281	} else if (!err && !buffer_uptodate(bhs[i]))
	282	err = -EIO;
	283	}
	284	return err;
	285	}
	286