PM / yenta: Split resume into early and late parts (rev. 4)
[linux/fpc-iii.git] / fs / fat / misc.c
bloba6c20473dfd75bd83d2d6caf1d4685078c687fb4
1 /*
2 * linux/fs/fat/misc.c
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 */
9 #include <linux/module.h>
10 #include <linux/fs.h>
11 #include <linux/buffer_head.h>
12 #include "fat.h"
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.
22 void fat_fs_error(struct super_block *s, const char *fmt, ...)
24 struct fat_mount_options *opts = &MSDOS_SB(s)->options;
25 va_list args;
27 printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);
29 printk(KERN_ERR " ");
30 va_start(args, fmt);
31 vprintk(fmt, args);
32 va_end(args);
33 printk("\n");
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)) {
38 s->s_flags |= MS_RDONLY;
39 printk(KERN_ERR " File system has been set read-only\n");
42 EXPORT_SYMBOL_GPL(fat_fs_error);
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)
48 struct msdos_sb_info *sbi = MSDOS_SB(sb);
49 struct buffer_head *bh;
50 struct fat_boot_fsinfo *fsinfo;
52 if (sbi->fat_bits != 32)
53 return;
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;
61 fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
62 /* Sanity check */
63 if (!IS_FSINFO(fsinfo)) {
64 printk(KERN_ERR "FAT: Invalid FSINFO signature: "
65 "0x%08x, 0x%08x (sector = %lu)\n",
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);
76 brelse(bh);
80 * fat_chain_add() adds a new cluster to the chain of clusters represented
81 * by inode.
83 int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
85 struct super_block *sb = inode->i_sb;
86 struct msdos_sb_info *sbi = MSDOS_SB(sb);
87 int ret, new_fclus, last;
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).
93 last = new_fclus = 0;
94 if (MSDOS_I(inode)->i_start) {
95 int fclus, dclus;
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;
104 /* add new one to the last of the cluster chain */
105 if (last) {
106 struct fat_entry fatent;
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);
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;
122 * Since generic_osync_inode() synchronize later if
123 * this is not directory, we don't here.
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);
132 if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
133 fat_fs_error(sb, "clusters badly computed (%d != %llu)",
134 new_fclus,
135 (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
136 fat_cache_inval_inode(inode);
138 inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
140 return 0;
143 extern struct timezone sys_tz;
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)
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)
168 /* Linear day numbers of the respective 1sts in non-leap years. */
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,
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)
178 u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
179 time_t second, day, leap_day, month, year;
181 year = date >> 9;
182 month = max(1, (date >> 5) & 0xf);
183 day = max(1, date & 0x1f) - 1;
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++;
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;
198 if (!sbi->options.tz_utc)
199 second += sys_tz.tz_minuteswest * SECS_PER_MIN;
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;
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)
214 time_t second = ts->tv_sec;
215 time_t day, leap_day, month, year;
217 if (!sbi->options.tz_utc)
218 second -= sys_tz.tz_minuteswest * SECS_PER_MIN;
220 /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */
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;
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;
236 #endif
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)
244 year--;
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;
250 if (IS_LEAP_YEAR(year) && day == days_in_year[3]) {
251 month = 2;
252 } else {
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)
257 break;
260 day -= days_in_year[month];
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;
269 EXPORT_SYMBOL_GPL(fat_time_unix2fat);
271 int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
273 int i, err = 0;
275 ll_rw_block(SWRITE, nr_bhs, bhs);
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;
284 return err;