[mirror_ubuntu-artful-kernel.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_panic reports a severe file system problem and sets the file system
 * read-only. The file system can be made writable again by remounting it.
 */
void fat_fs_panic(struct super_block *s, const char *fmt, ...)
{
	va_list args;

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

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

	if (!(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_panic);

/* 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_osync_inode() synchronize later if
		 * this is not directory, we don't here.
		 */
		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_panic(sb, "clusters badly computed (%d != %lu)",
			new_fclus, 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
	14	/*
	15	* fat_fs_panic reports a severe file system problem and sets the file system
	16	* read-only. The file system can be made writable again by remounting it.
	17	*/
	18	void fat_fs_panic(struct super_block s, const char fmt, ...)
	19	{
	20	va_list args;
	21
	22	printk(KERN_ERR "FAT: Filesystem panic (dev %s)\n", s->s_id);
	23
	24	printk(KERN_ERR " ");
	25	va_start(args, fmt);
	26	vprintk(fmt, args);
	27	va_end(args);
	28	printk("\n");
	29
	30	if (!(s->s_flags & MS_RDONLY)) {
	31	s->s_flags \|= MS_RDONLY;
	32	printk(KERN_ERR " File system has been set read-only\n");
	33	}
	34	}
	35
7c709d00	36	EXPORT_SYMBOL_GPL(fat_fs_panic);
1da177e4 LT	37
	38	/* Flushes the number of free clusters on FAT32 */
	39	/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
	40	void fat_clusters_flush(struct super_block *sb)
	41	{
	42	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	43	struct buffer_head *bh;
	44	struct fat_boot_fsinfo *fsinfo;
	45
	46	if (sbi->fat_bits != 32)
	47	return;
	48
	49	bh = sb_bread(sb, sbi->fsinfo_sector);
	50	if (bh == NULL) {
	51	printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
	52	return;
	53	}
	54
	55	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	56	/* Sanity check */
	57	if (!IS_FSINFO(fsinfo)) {
b4cf9c34 VN	58	printk(KERN_ERR "FAT: Invalid FSINFO signature: "
b4cf9c34 VN	59	"0x%08x, 0x%08x (sector = %lu)\n",
1da177e4 LT	60	le32_to_cpu(fsinfo->signature1),
	61	le32_to_cpu(fsinfo->signature2),
	62	sbi->fsinfo_sector);
	63	} else {
	64	if (sbi->free_clusters != -1)
	65	fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
	66	if (sbi->prev_free != -1)
	67	fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
	68	mark_buffer_dirty(bh);
1da177e4 LT	69	}
	70	brelse(bh);
	71	}
	72
	73	/*
	74	* fat_chain_add() adds a new cluster to the chain of clusters represented
	75	* by inode.
	76	*/
	77	int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
	78	{
	79	struct super_block *sb = inode->i_sb;
	80	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	81	int ret, new_fclus, last;
	82
	83	/*
	84	* We must locate the last cluster of the file to add this new
	85	* one (new_dclus) to the end of the link list (the FAT).
	86	*/
	87	last = new_fclus = 0;
	88	if (MSDOS_I(inode)->i_start) {
	89	int fclus, dclus;
	90
	91	ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
	92	if (ret < 0)
	93	return ret;
	94	new_fclus = fclus + 1;
	95	last = dclus;
	96	}
	97
	98	/* add new one to the last of the cluster chain */
	99	if (last) {
	100	struct fat_entry fatent;
	101
	102	fatent_init(&fatent);
	103	ret = fat_ent_read(inode, &fatent, last);
	104	if (ret >= 0) {
	105	int wait = inode_needs_sync(inode);
	106	ret = fat_ent_write(inode, &fatent, new_dclus, wait);
	107	fatent_brelse(&fatent);
	108	}
	109	if (ret < 0)
	110	return ret;
	111	// fat_cache_add(inode, new_fclus, new_dclus);
	112	} else {
	113	MSDOS_I(inode)->i_start = new_dclus;
	114	MSDOS_I(inode)->i_logstart = new_dclus;
	115	/*
	116	* Since generic_osync_inode() synchronize later if
	117	* this is not directory, we don't here.
	118	*/
	119	if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
	120	ret = fat_sync_inode(inode);
	121	if (ret)
	122	return ret;
	123	} else
	124	mark_inode_dirty(inode);
	125	}
	126	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
	127	fat_fs_panic(sb, "clusters badly computed (%d != %lu)",
	128	new_fclus, inode->i_blocks >> (sbi->cluster_bits - 9));
	129	fat_cache_inval_inode(inode);
	130	}
	131	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
	132
133	return 0;
134	}
135
136	extern struct timezone sys_tz;
137
7decd1cb OH	138	/*
	139	* The epoch of FAT timestamp is 1980.
	140	* : bits : value
	141	* date: 0 - 4: day (1 - 31)
	142	* date: 5 - 8: month (1 - 12)
	143	* date: 9 - 15: year (0 - 127) from 1980
	144	* time: 0 - 4: sec (0 - 29) 2sec counts
	145	* time: 5 - 10: min (0 - 59)
	146	* time: 11 - 15: hour (0 - 23)
	147	*/
	148	#define SECS_PER_MIN 60
	149	#define SECS_PER_HOUR (60 * 60)
	150	#define SECS_PER_DAY (SECS_PER_HOUR * 24)
	151	#define UNIX_SECS_1980 315532800L
	152	#if BITS_PER_LONG == 64
	153	#define UNIX_SECS_2108 4354819200L
	154	#endif
	155	/* days between 1.1.70 and 1.1.80 (2 leap days) */
	156	#define DAYS_DELTA (365 * 10 + 2)
	157	/* 120 (2100 - 1980) isn't leap year */
	158	#define YEAR_2100 120
	159	#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
	160
1da177e4	161	/* Linear day numbers of the respective 1sts in non-leap years. */
7decd1cb OH	162	static time_t days_in_year[] = {
	163	/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
	164	0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
1da177e4 LT	165	};
1da177e4 LT	166
7decd1cb OH	167	/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
	168	void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec ts,
	169	__le16 __time, __le16 __date, u8 time_cs)
1da177e4	170	{
7decd1cb OH	171	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
7decd1cb OH	172	time_t second, day, leap_day, month, year;
1da177e4	173
7decd1cb OH	174	year = date >> 9;
	175	month = max(1, (date >> 5) & 0xf);
	176	day = max(1, date & 0x1f) - 1;
	177
	178	leap_day = (year + 3) / 4;
	179	if (year > YEAR_2100) /* 2100 isn't leap year */
	180	leap_day--;
	181	if (IS_LEAP_YEAR(year) && month > 2)
	182	leap_day++;
	183
	184	second = (time & 0x1f) << 1;
	185	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
	186	second += (time >> 11) * SECS_PER_HOUR;
	187	second += (year * 365 + leap_day
	188	+ days_in_year[month] + day
	189	+ DAYS_DELTA) * SECS_PER_DAY;
	190
	191	if (!sbi->options.tz_utc)
	192	second += sys_tz.tz_minuteswest * SECS_PER_MIN;
	193
	194	if (time_cs) {
	195	ts->tv_sec = second + (time_cs / 100);
	196	ts->tv_nsec = (time_cs % 100) * 10000000;
	197	} else {
	198	ts->tv_sec = second;
	199	ts->tv_nsec = 0;
	200	}
1da177e4 LT	201	}
1da177e4 LT	202
7decd1cb OH	203	/* Convert linear UNIX date to a FAT time/date pair. */
	204	void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
	205	__le16 time, __le16 date, u8 *time_cs)
1da177e4	206	{
7decd1cb OH	207	time_t second = ts->tv_sec;
7decd1cb OH	208	time_t day, leap_day, month, year;
1da177e4	209
7decd1cb OH	210	if (!sbi->options.tz_utc)
7decd1cb OH	211	second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
1da177e4 LT	212
1da177e4 LT	213	/* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
7decd1cb OH	214	if (second < UNIX_SECS_1980) {
	215	*time = 0;
	216	*date = cpu_to_le16((0 << 9) \| (1 << 5) \| 1);
	217	if (time_cs)
	218	*time_cs = 0;
	219	return;
	220	}
	221	#if BITS_PER_LONG == 64
	222	if (second >= UNIX_SECS_2108) {
	223	*time = cpu_to_le16((23 << 11) \| (59 << 5) \| 29);
	224	*date = cpu_to_le16((127 << 9) \| (12 << 5) \| 31);
	225	if (time_cs)
	226	*time_cs = 199;
	227	return;
	228	}
	229	#endif
	230
	231	day = second / SECS_PER_DAY - DAYS_DELTA;
	232	year = day / 365;
	233	leap_day = (year + 3) / 4;
	234	if (year > YEAR_2100) /* 2100 isn't leap year */
	235	leap_day--;
	236	if (year * 365 + leap_day > day)
1da177e4	237	year--;
7decd1cb OH	238	leap_day = (year + 3) / 4;
	239	if (year > YEAR_2100) /* 2100 isn't leap year */
	240	leap_day--;
	241	day -= year * 365 + leap_day;
	242
	243	if (IS_LEAP_YEAR(year) && day == days_in_year[3]) {
1da177e4 LT	244	month = 2;
1da177e4 LT	245	} else {
7decd1cb OH	246	if (IS_LEAP_YEAR(year) && day > days_in_year[3])
	247	day--;
	248	for (month = 1; month < 12; month++) {
	249	if (days_in_year[month + 1] > day)
1da177e4 LT	250	break;
	251	}
	252	}
7decd1cb	253	day -= days_in_year[month];
1da177e4	254
7decd1cb OH	255	*time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11
	256	\| ((second / SECS_PER_MIN) % 60) << 5
	257	\| (second % SECS_PER_MIN) >> 1);
	258	*date = cpu_to_le16((year << 9) \| (month << 5) \| (day + 1));
	259	if (time_cs)
	260	time_cs = (ts->tv_sec & 1) 100 + ts->tv_nsec / 10000000;
	261	}
	262	EXPORT_SYMBOL_GPL(fat_time_unix2fat);
1da177e4 LT	263
	264	int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
	265	{
5b00226d	266	int i, err = 0;
1da177e4	267
5b00226d	268	ll_rw_block(SWRITE, nr_bhs, bhs);
1da177e4 LT	269	for (i = 0; i < nr_bhs; i++) {
	270	wait_on_buffer(bhs[i]);
	271	if (buffer_eopnotsupp(bhs[i])) {
	272	clear_buffer_eopnotsupp(bhs[i]);
	273	err = -EOPNOTSUPP;
	274	} else if (!err && !buffer_uptodate(bhs[i]))
	275	err = -EIO;
	276	}
	277	return err;
	278	}
	279