Commit | Line | Data |
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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: " |
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))) { | |
c3302931 OH |
127 | fat_fs_panic(sb, "clusters badly computed (%d != %llu)", |
128 | new_fclus, | |
129 | (llu)(inode->i_blocks >> (sbi->cluster_bits - 9))); | |
1da177e4 LT |
130 | fat_cache_inval_inode(inode); |
131 | } | |
132 | inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9); | |
133 | ||
134 | return 0; | |
135 | } | |
136 | ||
137 | extern struct timezone sys_tz; | |
138 | ||
7decd1cb OH |
139 | /* |
140 | * The epoch of FAT timestamp is 1980. | |
141 | * : bits : value | |
142 | * date: 0 - 4: day (1 - 31) | |
143 | * date: 5 - 8: month (1 - 12) | |
144 | * date: 9 - 15: year (0 - 127) from 1980 | |
145 | * time: 0 - 4: sec (0 - 29) 2sec counts | |
146 | * time: 5 - 10: min (0 - 59) | |
147 | * time: 11 - 15: hour (0 - 23) | |
148 | */ | |
149 | #define SECS_PER_MIN 60 | |
150 | #define SECS_PER_HOUR (60 * 60) | |
151 | #define SECS_PER_DAY (SECS_PER_HOUR * 24) | |
152 | #define UNIX_SECS_1980 315532800L | |
153 | #if BITS_PER_LONG == 64 | |
154 | #define UNIX_SECS_2108 4354819200L | |
155 | #endif | |
156 | /* days between 1.1.70 and 1.1.80 (2 leap days) */ | |
157 | #define DAYS_DELTA (365 * 10 + 2) | |
158 | /* 120 (2100 - 1980) isn't leap year */ | |
159 | #define YEAR_2100 120 | |
160 | #define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100) | |
161 | ||
1da177e4 | 162 | /* Linear day numbers of the respective 1sts in non-leap years. */ |
7decd1cb OH |
163 | static time_t days_in_year[] = { |
164 | /* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */ | |
165 | 0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, | |
1da177e4 LT |
166 | }; |
167 | ||
7decd1cb OH |
168 | /* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */ |
169 | void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts, | |
170 | __le16 __time, __le16 __date, u8 time_cs) | |
1da177e4 | 171 | { |
7decd1cb OH |
172 | u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date); |
173 | time_t second, day, leap_day, month, year; | |
1da177e4 | 174 | |
7decd1cb OH |
175 | year = date >> 9; |
176 | month = max(1, (date >> 5) & 0xf); | |
177 | day = max(1, date & 0x1f) - 1; | |
178 | ||
179 | leap_day = (year + 3) / 4; | |
180 | if (year > YEAR_2100) /* 2100 isn't leap year */ | |
181 | leap_day--; | |
182 | if (IS_LEAP_YEAR(year) && month > 2) | |
183 | leap_day++; | |
184 | ||
185 | second = (time & 0x1f) << 1; | |
186 | second += ((time >> 5) & 0x3f) * SECS_PER_MIN; | |
187 | second += (time >> 11) * SECS_PER_HOUR; | |
188 | second += (year * 365 + leap_day | |
189 | + days_in_year[month] + day | |
190 | + DAYS_DELTA) * SECS_PER_DAY; | |
191 | ||
192 | if (!sbi->options.tz_utc) | |
193 | second += sys_tz.tz_minuteswest * SECS_PER_MIN; | |
194 | ||
195 | if (time_cs) { | |
196 | ts->tv_sec = second + (time_cs / 100); | |
197 | ts->tv_nsec = (time_cs % 100) * 10000000; | |
198 | } else { | |
199 | ts->tv_sec = second; | |
200 | ts->tv_nsec = 0; | |
201 | } | |
1da177e4 LT |
202 | } |
203 | ||
7decd1cb OH |
204 | /* Convert linear UNIX date to a FAT time/date pair. */ |
205 | void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts, | |
206 | __le16 *time, __le16 *date, u8 *time_cs) | |
1da177e4 | 207 | { |
7decd1cb OH |
208 | time_t second = ts->tv_sec; |
209 | time_t day, leap_day, month, year; | |
1da177e4 | 210 | |
7decd1cb OH |
211 | if (!sbi->options.tz_utc) |
212 | second -= sys_tz.tz_minuteswest * SECS_PER_MIN; | |
1da177e4 LT |
213 | |
214 | /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */ | |
7decd1cb OH |
215 | if (second < UNIX_SECS_1980) { |
216 | *time = 0; | |
217 | *date = cpu_to_le16((0 << 9) | (1 << 5) | 1); | |
218 | if (time_cs) | |
219 | *time_cs = 0; | |
220 | return; | |
221 | } | |
222 | #if BITS_PER_LONG == 64 | |
223 | if (second >= UNIX_SECS_2108) { | |
224 | *time = cpu_to_le16((23 << 11) | (59 << 5) | 29); | |
225 | *date = cpu_to_le16((127 << 9) | (12 << 5) | 31); | |
226 | if (time_cs) | |
227 | *time_cs = 199; | |
228 | return; | |
229 | } | |
230 | #endif | |
231 | ||
232 | day = second / SECS_PER_DAY - DAYS_DELTA; | |
233 | year = day / 365; | |
234 | leap_day = (year + 3) / 4; | |
235 | if (year > YEAR_2100) /* 2100 isn't leap year */ | |
236 | leap_day--; | |
237 | if (year * 365 + leap_day > day) | |
1da177e4 | 238 | year--; |
7decd1cb OH |
239 | leap_day = (year + 3) / 4; |
240 | if (year > YEAR_2100) /* 2100 isn't leap year */ | |
241 | leap_day--; | |
242 | day -= year * 365 + leap_day; | |
243 | ||
244 | if (IS_LEAP_YEAR(year) && day == days_in_year[3]) { | |
1da177e4 LT |
245 | month = 2; |
246 | } else { | |
7decd1cb OH |
247 | if (IS_LEAP_YEAR(year) && day > days_in_year[3]) |
248 | day--; | |
249 | for (month = 1; month < 12; month++) { | |
250 | if (days_in_year[month + 1] > day) | |
1da177e4 LT |
251 | break; |
252 | } | |
253 | } | |
7decd1cb | 254 | day -= days_in_year[month]; |
1da177e4 | 255 | |
7decd1cb OH |
256 | *time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11 |
257 | | ((second / SECS_PER_MIN) % 60) << 5 | |
258 | | (second % SECS_PER_MIN) >> 1); | |
259 | *date = cpu_to_le16((year << 9) | (month << 5) | (day + 1)); | |
260 | if (time_cs) | |
261 | *time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000; | |
262 | } | |
263 | EXPORT_SYMBOL_GPL(fat_time_unix2fat); | |
1da177e4 LT |
264 | |
265 | int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs) | |
266 | { | |
5b00226d | 267 | int i, err = 0; |
1da177e4 | 268 | |
5b00226d | 269 | ll_rw_block(SWRITE, nr_bhs, bhs); |
1da177e4 LT |
270 | for (i = 0; i < nr_bhs; i++) { |
271 | wait_on_buffer(bhs[i]); | |
272 | if (buffer_eopnotsupp(bhs[i])) { | |
273 | clear_buffer_eopnotsupp(bhs[i]); | |
274 | err = -EOPNOTSUPP; | |
275 | } else if (!err && !buffer_uptodate(bhs[i])) | |
276 | err = -EIO; | |
277 | } | |
278 | return err; | |
279 | } | |
280 |