blob: 0f55f5cb732f24078af99a605e4fa764eabad6bf [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/buffer_head.h>
OGAWA Hirofumi9e975da2008-11-06 12:53:46 -080012#include "fat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
14/*
Denis Karpov85c78592009-06-04 02:34:22 +090015 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 */
Denis Karpov85c78592009-06-04 02:34:22 +090022void fat_fs_error(struct super_block *s, const char *fmt, ...)
Linus Torvalds1da177e2005-04-16 15:20:36 -070023{
Denis Karpov85c78592009-06-04 02:34:22 +090024 struct fat_mount_options *opts = &MSDOS_SB(s)->options;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025 va_list args;
26
Denis Karpov85c78592009-06-04 02:34:22 +090027 printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29 printk(KERN_ERR " ");
30 va_start(args, fmt);
31 vprintk(fmt, args);
32 va_end(args);
33 printk("\n");
34
Denis Karpov85c78592009-06-04 02:34:22 +090035 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)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 s->s_flags |= MS_RDONLY;
39 printk(KERN_ERR " File system has been set read-only\n");
40 }
41}
Denis Karpov85c78592009-06-04 02:34:22 +090042EXPORT_SYMBOL_GPL(fat_fs_error);
Linus Torvalds1da177e2005-04-16 15:20:36 -070043
44/* Flushes the number of free clusters on FAT32 */
45/* XXX: Need to write one per FSINFO block. Currently only writes 1 */
OGAWA Hirofumied248b22009-09-20 01:31:58 +090046int fat_clusters_flush(struct super_block *sb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070047{
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)
OGAWA Hirofumied248b22009-09-20 01:31:58 +090053 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55 bh = sb_bread(sb, sbi->fsinfo_sector);
56 if (bh == NULL) {
57 printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n");
OGAWA Hirofumied248b22009-09-20 01:31:58 +090058 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 }
60
61 fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
62 /* Sanity check */
63 if (!IS_FSINFO(fsinfo)) {
Vegard Nossumb4cf9c32008-02-06 01:36:36 -080064 printk(KERN_ERR "FAT: Invalid FSINFO signature: "
65 "0x%08x, 0x%08x (sector = %lu)\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 }
76 brelse(bh);
OGAWA Hirofumied248b22009-09-20 01:31:58 +090077
78 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079}
80
81/*
82 * fat_chain_add() adds a new cluster to the chain of clusters represented
83 * by inode.
84 */
85int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
86{
87 struct super_block *sb = inode->i_sb;
88 struct msdos_sb_info *sbi = MSDOS_SB(sb);
89 int ret, new_fclus, last;
90
91 /*
92 * We must locate the last cluster of the file to add this new
93 * one (new_dclus) to the end of the link list (the FAT).
94 */
95 last = new_fclus = 0;
96 if (MSDOS_I(inode)->i_start) {
97 int fclus, dclus;
98
99 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
100 if (ret < 0)
101 return ret;
102 new_fclus = fclus + 1;
103 last = dclus;
104 }
105
106 /* add new one to the last of the cluster chain */
107 if (last) {
108 struct fat_entry fatent;
109
110 fatent_init(&fatent);
111 ret = fat_ent_read(inode, &fatent, last);
112 if (ret >= 0) {
113 int wait = inode_needs_sync(inode);
114 ret = fat_ent_write(inode, &fatent, new_dclus, wait);
115 fatent_brelse(&fatent);
116 }
117 if (ret < 0)
118 return ret;
119// fat_cache_add(inode, new_fclus, new_dclus);
120 } else {
121 MSDOS_I(inode)->i_start = new_dclus;
122 MSDOS_I(inode)->i_logstart = new_dclus;
123 /*
Jan Kara2f3d6752009-08-17 17:00:02 +0200124 * Since generic_write_sync() synchronizes regular files later,
125 * we sync here only directories.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 */
127 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
128 ret = fat_sync_inode(inode);
129 if (ret)
130 return ret;
131 } else
132 mark_inode_dirty(inode);
133 }
134 if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
Denis Karpov85c78592009-06-04 02:34:22 +0900135 fat_fs_error(sb, "clusters badly computed (%d != %llu)",
OGAWA Hirofumic3302932008-11-06 12:53:58 -0800136 new_fclus,
137 (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 fat_cache_inval_inode(inode);
139 }
140 inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
141
142 return 0;
143}
144
145extern struct timezone sys_tz;
146
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800147/*
148 * The epoch of FAT timestamp is 1980.
149 * : bits : value
150 * date: 0 - 4: day (1 - 31)
151 * date: 5 - 8: month (1 - 12)
152 * date: 9 - 15: year (0 - 127) from 1980
153 * time: 0 - 4: sec (0 - 29) 2sec counts
154 * time: 5 - 10: min (0 - 59)
155 * time: 11 - 15: hour (0 - 23)
156 */
157#define SECS_PER_MIN 60
158#define SECS_PER_HOUR (60 * 60)
159#define SECS_PER_DAY (SECS_PER_HOUR * 24)
160#define UNIX_SECS_1980 315532800L
161#if BITS_PER_LONG == 64
162#define UNIX_SECS_2108 4354819200L
163#endif
164/* days between 1.1.70 and 1.1.80 (2 leap days) */
165#define DAYS_DELTA (365 * 10 + 2)
166/* 120 (2100 - 1980) isn't leap year */
167#define YEAR_2100 120
168#define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170/* Linear day numbers of the respective 1sts in non-leap years. */
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800171static time_t days_in_year[] = {
172 /* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */
173 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174};
175
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800176/* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
177void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
178 __le16 __time, __le16 __date, u8 time_cs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800180 u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
181 time_t second, day, leap_day, month, year;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800183 year = date >> 9;
184 month = max(1, (date >> 5) & 0xf);
185 day = max(1, date & 0x1f) - 1;
186
187 leap_day = (year + 3) / 4;
188 if (year > YEAR_2100) /* 2100 isn't leap year */
189 leap_day--;
190 if (IS_LEAP_YEAR(year) && month > 2)
191 leap_day++;
192
193 second = (time & 0x1f) << 1;
194 second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
195 second += (time >> 11) * SECS_PER_HOUR;
196 second += (year * 365 + leap_day
197 + days_in_year[month] + day
198 + DAYS_DELTA) * SECS_PER_DAY;
199
200 if (!sbi->options.tz_utc)
201 second += sys_tz.tz_minuteswest * SECS_PER_MIN;
202
203 if (time_cs) {
204 ts->tv_sec = second + (time_cs / 100);
205 ts->tv_nsec = (time_cs % 100) * 10000000;
206 } else {
207 ts->tv_sec = second;
208 ts->tv_nsec = 0;
209 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210}
211
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800212/* Convert linear UNIX date to a FAT time/date pair. */
213void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
214 __le16 *time, __le16 *date, u8 *time_cs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215{
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800216 time_t second = ts->tv_sec;
217 time_t day, leap_day, month, year;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800219 if (!sbi->options.tz_utc)
220 second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222 /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800223 if (second < UNIX_SECS_1980) {
224 *time = 0;
225 *date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
226 if (time_cs)
227 *time_cs = 0;
228 return;
229 }
230#if BITS_PER_LONG == 64
231 if (second >= UNIX_SECS_2108) {
232 *time = cpu_to_le16((23 << 11) | (59 << 5) | 29);
233 *date = cpu_to_le16((127 << 9) | (12 << 5) | 31);
234 if (time_cs)
235 *time_cs = 199;
236 return;
237 }
238#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800240 day = second / SECS_PER_DAY - DAYS_DELTA;
241 year = day / 365;
242 leap_day = (year + 3) / 4;
243 if (year > YEAR_2100) /* 2100 isn't leap year */
244 leap_day--;
245 if (year * 365 + leap_day > day)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 year--;
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800247 leap_day = (year + 3) / 4;
248 if (year > YEAR_2100) /* 2100 isn't leap year */
249 leap_day--;
250 day -= year * 365 + leap_day;
251
252 if (IS_LEAP_YEAR(year) && day == days_in_year[3]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 month = 2;
254 } else {
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800255 if (IS_LEAP_YEAR(year) && day > days_in_year[3])
256 day--;
257 for (month = 1; month < 12; month++) {
258 if (days_in_year[month + 1] > day)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 break;
260 }
261 }
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800262 day -= days_in_year[month];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
OGAWA Hirofumi7decd1c2008-11-06 12:53:47 -0800264 *time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11
265 | ((second / SECS_PER_MIN) % 60) << 5
266 | (second % SECS_PER_MIN) >> 1);
267 *date = cpu_to_le16((year << 9) | (month << 5) | (day + 1));
268 if (time_cs)
269 *time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000;
270}
271EXPORT_SYMBOL_GPL(fat_time_unix2fat);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
274{
OGAWA Hirofumi5b002262006-02-03 03:04:42 -0800275 int i, err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
OGAWA Hirofumi5b002262006-02-03 03:04:42 -0800277 ll_rw_block(SWRITE, nr_bhs, bhs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 for (i = 0; i < nr_bhs; i++) {
279 wait_on_buffer(bhs[i]);
280 if (buffer_eopnotsupp(bhs[i])) {
281 clear_buffer_eopnotsupp(bhs[i]);
282 err = -EOPNOTSUPP;
283 } else if (!err && !buffer_uptodate(bhs[i]))
284 err = -EIO;
285 }
286 return err;
287}
288