[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 <linux/time.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, int report, const char *fmt, ...)
{
	struct fat_mount_options *opts = &MSDOS_SB(s)->options;
	va_list args;

	if (report) {
		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 "FAT: Filesystem 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 */
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) {
		printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
		return -EIO;
	}

	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);

	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;
//		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)
/* 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)
{
	struct tm tm;
	time_to_tm(ts->tv_sec, sbi->options.tz_utc ? 0 :
		   -sys_tz.tz_minuteswest * 60, &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;
}
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>
1d81a181	12	#include <linux/time.h>
9e975dae	13	#include "fat.h"
1da177e4 LT	14
1da177e4 LT	15	/*
85c78591 DK	16	* fat_fs_error reports a file system problem that might indicate fa data
	17	* corruption/inconsistency. Depending on 'errors' mount option the
	18	* panic() is called, or error message is printed FAT and nothing is done,
	19	* or filesystem is remounted read-only (default behavior).
	20	* In case the file system is remounted read-only, it can be made writable
	21	* again by remounting it.
1da177e4	22	*/
aaa04b48	23	void __fat_fs_error(struct super_block s, int report, const char fmt, ...)
1da177e4	24	{
85c78591	25	struct fat_mount_options *opts = &MSDOS_SB(s)->options;
1da177e4 LT	26	va_list args;
1da177e4 LT	27
aaa04b48 OH	28	if (report) {
aaa04b48 OH	29	printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);
1da177e4	30
aaa04b48 OH	31	printk(KERN_ERR " ");
	32	va_start(args, fmt);
	33	vprintk(fmt, args);
	34	va_end(args);
	35	printk("\n");
	36	}
1da177e4	37
85c78591	38	if (opts->errors == FAT_ERRORS_PANIC)
aaa04b48	39	panic("FAT: fs panic from previous error\n");
85c78591	40	else if (opts->errors == FAT_ERRORS_RO && !(s->s_flags & MS_RDONLY)) {
1da177e4	41	s->s_flags \|= MS_RDONLY;
aaa04b48	42	printk(KERN_ERR "FAT: Filesystem has been set read-only\n");
1da177e4 LT	43	}
1da177e4 LT	44	}
aaa04b48	45	EXPORT_SYMBOL_GPL(__fat_fs_error);
1da177e4 LT	46
	47	/* Flushes the number of free clusters on FAT32 */
	48	/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
ed248b29	49	int fat_clusters_flush(struct super_block *sb)
1da177e4 LT	50	{
	51	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	52	struct buffer_head *bh;
	53	struct fat_boot_fsinfo *fsinfo;
	54
	55	if (sbi->fat_bits != 32)
ed248b29	56	return 0;
1da177e4 LT	57
	58	bh = sb_bread(sb, sbi->fsinfo_sector);
	59	if (bh == NULL) {
	60	printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
ed248b29	61	return -EIO;
1da177e4 LT	62	}
	63
	64	fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
	65	/* Sanity check */
	66	if (!IS_FSINFO(fsinfo)) {
b4cf9c34 VN	67	printk(KERN_ERR "FAT: Invalid FSINFO signature: "
b4cf9c34 VN	68	"0x%08x, 0x%08x (sector = %lu)\n",
1da177e4 LT	69	le32_to_cpu(fsinfo->signature1),
	70	le32_to_cpu(fsinfo->signature2),
	71	sbi->fsinfo_sector);
	72	} else {
	73	if (sbi->free_clusters != -1)
	74	fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
	75	if (sbi->prev_free != -1)
	76	fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
	77	mark_buffer_dirty(bh);
1da177e4 LT	78	}
1da177e4 LT	79	brelse(bh);
ed248b29 OH	80
ed248b29 OH	81	return 0;
1da177e4 LT	82	}
	83
	84	/*
	85	* fat_chain_add() adds a new cluster to the chain of clusters represented
	86	* by inode.
	87	*/
	88	int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
	89	{
	90	struct super_block *sb = inode->i_sb;
	91	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	92	int ret, new_fclus, last;
	93
	94	/*
	95	* We must locate the last cluster of the file to add this new
	96	* one (new_dclus) to the end of the link list (the FAT).
	97	*/
	98	last = new_fclus = 0;
	99	if (MSDOS_I(inode)->i_start) {
	100	int fclus, dclus;
	101
	102	ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
	103	if (ret < 0)
	104	return ret;
	105	new_fclus = fclus + 1;
	106	last = dclus;
	107	}
	108
	109	/* add new one to the last of the cluster chain */
	110	if (last) {
	111	struct fat_entry fatent;
	112
	113	fatent_init(&fatent);
	114	ret = fat_ent_read(inode, &fatent, last);
	115	if (ret >= 0) {
	116	int wait = inode_needs_sync(inode);
	117	ret = fat_ent_write(inode, &fatent, new_dclus, wait);
	118	fatent_brelse(&fatent);
	119	}
	120	if (ret < 0)
	121	return ret;
	122	// fat_cache_add(inode, new_fclus, new_dclus);
	123	} else {
	124	MSDOS_I(inode)->i_start = new_dclus;
	125	MSDOS_I(inode)->i_logstart = new_dclus;
	126	/*
2f3d675b JK	127	* Since generic_write_sync() synchronizes regular files later,
2f3d675b JK	128	* we sync here only directories.
1da177e4 LT	129	*/
	130	if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
	131	ret = fat_sync_inode(inode);
	132	if (ret)
	133	return ret;
	134	} else
	135	mark_inode_dirty(inode);
	136	}
	137	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
85c78591	138	fat_fs_error(sb, "clusters badly computed (%d != %llu)",
c3302931 OH	139	new_fclus,
c3302931 OH	140	(llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
1da177e4 LT	141	fat_cache_inval_inode(inode);
	142	}
	143	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
	144
	145	return 0;
	146	}
	147
	148	extern struct timezone sys_tz;
	149
7decd1cb OH	150	/*
	151	* The epoch of FAT timestamp is 1980.
	152	* : bits : value
	153	* date: 0 - 4: day (1 - 31)
	154	* date: 5 - 8: month (1 - 12)
	155	* date: 9 - 15: year (0 - 127) from 1980
	156	* time: 0 - 4: sec (0 - 29) 2sec counts
	157	* time: 5 - 10: min (0 - 59)
	158	* time: 11 - 15: hour (0 - 23)
	159	*/
	160	#define SECS_PER_MIN 60
	161	#define SECS_PER_HOUR (60 * 60)
	162	#define SECS_PER_DAY (SECS_PER_HOUR * 24)
7decd1cb OH	163	/* days between 1.1.70 and 1.1.80 (2 leap days) */
	164	#define DAYS_DELTA (365 * 10 + 2)
	165	/* 120 (2100 - 1980) isn't leap year */
	166	#define YEAR_2100 120
	167	#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
	168
1da177e4	169	/* Linear day numbers of the respective 1sts in non-leap years. */
7decd1cb OH	170	static time_t days_in_year[] = {
	171	/* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
	172	0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
1da177e4 LT	173	};
1da177e4 LT	174
7decd1cb OH	175	/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
	176	void fat_time_fat2unix(struct msdos_sb_info sbi, struct timespec ts,
	177	__le16 __time, __le16 __date, u8 time_cs)
1da177e4	178	{
7decd1cb OH	179	u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
7decd1cb OH	180	time_t second, day, leap_day, month, year;
1da177e4	181
7decd1cb OH	182	year = date >> 9;
	183	month = max(1, (date >> 5) & 0xf);
	184	day = max(1, date & 0x1f) - 1;
	185
	186	leap_day = (year + 3) / 4;
	187	if (year > YEAR_2100) /* 2100 isn't leap year */
	188	leap_day--;
	189	if (IS_LEAP_YEAR(year) && month > 2)
	190	leap_day++;
	191
	192	second = (time & 0x1f) << 1;
	193	second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
	194	second += (time >> 11) * SECS_PER_HOUR;
	195	second += (year * 365 + leap_day
	196	+ days_in_year[month] + day
	197	+ DAYS_DELTA) * SECS_PER_DAY;
	198
	199	if (!sbi->options.tz_utc)
	200	second += sys_tz.tz_minuteswest * SECS_PER_MIN;
	201
	202	if (time_cs) {
	203	ts->tv_sec = second + (time_cs / 100);
	204	ts->tv_nsec = (time_cs % 100) * 10000000;
	205	} else {
	206	ts->tv_sec = second;
	207	ts->tv_nsec = 0;
	208	}
1da177e4 LT	209	}
1da177e4 LT	210
7decd1cb OH	211	/* Convert linear UNIX date to a FAT time/date pair. */
	212	void fat_time_unix2fat(struct msdos_sb_info sbi, struct timespec ts,
	213	__le16 time, __le16 date, u8 *time_cs)
1da177e4	214	{
1d81a181 Z	215	struct tm tm;
	216	time_to_tm(ts->tv_sec, sbi->options.tz_utc ? 0 :
	217	-sys_tz.tz_minuteswest * 60, &tm);
1da177e4	218
1d81a181 Z	219	/* FAT can only support year between 1980 to 2107 */
1d81a181 Z	220	if (tm.tm_year < 1980 - 1900) {
7decd1cb OH	221	*time = 0;
	222	*date = cpu_to_le16((0 << 9) \| (1 << 5) \| 1);
	223	if (time_cs)
	224	*time_cs = 0;
	225	return;
	226	}
1d81a181	227	if (tm.tm_year > 2107 - 1900) {
7decd1cb OH	228	*time = cpu_to_le16((23 << 11) \| (59 << 5) \| 29);
	229	*date = cpu_to_le16((127 << 9) \| (12 << 5) \| 31);
	230	if (time_cs)
	231	*time_cs = 199;
	232	return;
	233	}
7decd1cb	234
1d81a181 Z	235	/* from 1900 -> from 1980 */
	236	tm.tm_year -= 80;
	237	/* 0~11 -> 1~12 */
	238	tm.tm_mon++;
	239	/* 0~59 -> 0~29(2sec counts) */
	240	tm.tm_sec >>= 1;
1da177e4	241
1d81a181 Z	242	*time = cpu_to_le16(tm.tm_hour << 11 \| tm.tm_min << 5 \| tm.tm_sec);
1d81a181 Z	243	*date = cpu_to_le16(tm.tm_year << 9 \| tm.tm_mon << 5 \| tm.tm_mday);
7decd1cb OH	244	if (time_cs)
	245	time_cs = (ts->tv_sec & 1) 100 + ts->tv_nsec / 10000000;
	246	}
	247	EXPORT_SYMBOL_GPL(fat_time_unix2fat);
1da177e4 LT	248
	249	int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
	250	{
5b00226d	251	int i, err = 0;
1da177e4	252
9cb569d6 CH	253	for (i = 0; i < nr_bhs; i++)
	254	write_dirty_buffer(bhs[i], WRITE);
	255
1da177e4 LT	256	for (i = 0; i < nr_bhs; i++) {
1da177e4 LT	257	wait_on_buffer(bhs[i]);
0edd55fa	258	if (!err && !buffer_uptodate(bhs[i]))
1da177e4 LT	259	err = -EIO;
	260	}
	261	return err;
	262	}