~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/fs/fat/misc.c

Version: ~ [ linux-5.6-rc1 ] ~ [ linux-5.5.2 ] ~ [ linux-5.4.17 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.102 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.170 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.213 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.213 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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>
 11 #include <linux/buffer_head.h>
 12 #include <linux/time.h>
 13 #include "fat.h"
 14 
 15 /*
 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.
 22  */
 23 void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
 24 {
 25         struct fat_mount_options *opts = &MSDOS_SB(sb)->options;
 26         va_list args;
 27         struct va_format vaf;
 28 
 29         if (report) {
 30                 va_start(args, fmt);
 31                 vaf.fmt = fmt;
 32                 vaf.va = &args;
 33                 fat_msg(sb, KERN_ERR, "error, %pV", &vaf);
 34                 va_end(args);
 35         }
 36 
 37         if (opts->errors == FAT_ERRORS_PANIC)
 38                 panic("FAT-fs (%s): fs panic from previous error\n", sb->s_id);
 39         else if (opts->errors == FAT_ERRORS_RO && !(sb->s_flags & MS_RDONLY)) {
 40                 sb->s_flags |= MS_RDONLY;
 41                 fat_msg(sb, KERN_ERR, "Filesystem has been set read-only");
 42         }
 43 }
 44 EXPORT_SYMBOL_GPL(__fat_fs_error);
 45 
 46 /**
 47  * fat_msg() - print preformated FAT specific messages. Every thing what is
 48  * not fat_fs_error() should be fat_msg().
 49  */
 50 void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...)
 51 {
 52         struct va_format vaf;
 53         va_list args;
 54 
 55         va_start(args, fmt);
 56         vaf.fmt = fmt;
 57         vaf.va = &args;
 58         printk("%sFAT-fs (%s): %pV\n", level, sb->s_id, &vaf);
 59         va_end(args);
 60 }
 61 
 62 /* Flushes the number of free clusters on FAT32 */
 63 /* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
 64 int fat_clusters_flush(struct super_block *sb)
 65 {
 66         struct msdos_sb_info *sbi = MSDOS_SB(sb);
 67         struct buffer_head *bh;
 68         struct fat_boot_fsinfo *fsinfo;
 69 
 70         if (sbi->fat_bits != 32)
 71                 return 0;
 72 
 73         bh = sb_bread(sb, sbi->fsinfo_sector);
 74         if (bh == NULL) {
 75                 fat_msg(sb, KERN_ERR, "bread failed in fat_clusters_flush");
 76                 return -EIO;
 77         }
 78 
 79         fsinfo = (struct fat_boot_fsinfo *)bh->b_data;
 80         /* Sanity check */
 81         if (!IS_FSINFO(fsinfo)) {
 82                 fat_msg(sb, KERN_ERR, "Invalid FSINFO signature: "
 83                        "0x%08x, 0x%08x (sector = %lu)",
 84                        le32_to_cpu(fsinfo->signature1),
 85                        le32_to_cpu(fsinfo->signature2),
 86                        sbi->fsinfo_sector);
 87         } else {
 88                 if (sbi->free_clusters != -1)
 89                         fsinfo->free_clusters = cpu_to_le32(sbi->free_clusters);
 90                 if (sbi->prev_free != -1)
 91                         fsinfo->next_cluster = cpu_to_le32(sbi->prev_free);
 92                 mark_buffer_dirty(bh);
 93         }
 94         brelse(bh);
 95 
 96         return 0;
 97 }
 98 
 99 /*
100  * fat_chain_add() adds a new cluster to the chain of clusters represented
101  * by inode.
102  */
103 int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
104 {
105         struct super_block *sb = inode->i_sb;
106         struct msdos_sb_info *sbi = MSDOS_SB(sb);
107         int ret, new_fclus, last;
108 
109         /*
110          * We must locate the last cluster of the file to add this new
111          * one (new_dclus) to the end of the link list (the FAT).
112          */
113         last = new_fclus = 0;
114         if (MSDOS_I(inode)->i_start) {
115                 int fclus, dclus;
116 
117                 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
118                 if (ret < 0)
119                         return ret;
120                 new_fclus = fclus + 1;
121                 last = dclus;
122         }
123 
124         /* add new one to the last of the cluster chain */
125         if (last) {
126                 struct fat_entry fatent;
127 
128                 fatent_init(&fatent);
129                 ret = fat_ent_read(inode, &fatent, last);
130                 if (ret >= 0) {
131                         int wait = inode_needs_sync(inode);
132                         ret = fat_ent_write(inode, &fatent, new_dclus, wait);
133                         fatent_brelse(&fatent);
134                 }
135                 if (ret < 0)
136                         return ret;
137                 /*
138                  * FIXME:Although we can add this cache, fat_cache_add() is
139                  * assuming to be called after linear search with fat_cache_id.
140                  */
141 //              fat_cache_add(inode, new_fclus, new_dclus);
142         } else {
143                 MSDOS_I(inode)->i_start = new_dclus;
144                 MSDOS_I(inode)->i_logstart = new_dclus;
145                 /*
146                  * Since generic_write_sync() synchronizes regular files later,
147                  * we sync here only directories.
148                  */
149                 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) {
150                         ret = fat_sync_inode(inode);
151                         if (ret)
152                                 return ret;
153                 } else
154                         mark_inode_dirty(inode);
155         }
156         if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
157                 fat_fs_error(sb, "clusters badly computed (%d != %llu)",
158                              new_fclus,
159                              (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
160                 fat_cache_inval_inode(inode);
161         }
162         inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);
163 
164         return 0;
165 }
166 
167 extern struct timezone sys_tz;
168 
169 /*
170  * The epoch of FAT timestamp is 1980.
171  *     :  bits :     value
172  * date:  0 -  4: day   (1 -  31)
173  * date:  5 -  8: month (1 -  12)
174  * date:  9 - 15: year  (0 - 127) from 1980
175  * time:  0 -  4: sec   (0 -  29) 2sec counts
176  * time:  5 - 10: min   (0 -  59)
177  * time: 11 - 15: hour  (0 -  23)
178  */
179 #define SECS_PER_MIN    60
180 #define SECS_PER_HOUR   (60 * 60)
181 #define SECS_PER_DAY    (SECS_PER_HOUR * 24)
182 /* days between 1.1.70 and 1.1.80 (2 leap days) */
183 #define DAYS_DELTA      (365 * 10 + 2)
184 /* 120 (2100 - 1980) isn't leap year */
185 #define YEAR_2100       120
186 #define IS_LEAP_YEAR(y) (!((y) & 3) && (y) != YEAR_2100)
187 
188 /* Linear day numbers of the respective 1sts in non-leap years. */
189 static time_t days_in_year[] = {
190         /* Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec */
191         0,   0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0,
192 };
193 
194 /* Convert a FAT time/date pair to a UNIX date (seconds since 1 1 70). */
195 void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec *ts,
196                        __le16 __time, __le16 __date, u8 time_cs)
197 {
198         u16 time = le16_to_cpu(__time), date = le16_to_cpu(__date);
199         time_t second, day, leap_day, month, year;
200 
201         year  = date >> 9;
202         month = max(1, (date >> 5) & 0xf);
203         day   = max(1, date & 0x1f) - 1;
204 
205         leap_day = (year + 3) / 4;
206         if (year > YEAR_2100)           /* 2100 isn't leap year */
207                 leap_day--;
208         if (IS_LEAP_YEAR(year) && month > 2)
209                 leap_day++;
210 
211         second =  (time & 0x1f) << 1;
212         second += ((time >> 5) & 0x3f) * SECS_PER_MIN;
213         second += (time >> 11) * SECS_PER_HOUR;
214         second += (year * 365 + leap_day
215                    + days_in_year[month] + day
216                    + DAYS_DELTA) * SECS_PER_DAY;
217 
218         if (!sbi->options.tz_set)
219                 second += sys_tz.tz_minuteswest * SECS_PER_MIN;
220         else
221                 second -= sbi->options.time_offset * SECS_PER_MIN;
222 
223         if (time_cs) {
224                 ts->tv_sec = second + (time_cs / 100);
225                 ts->tv_nsec = (time_cs % 100) * 10000000;
226         } else {
227                 ts->tv_sec = second;
228                 ts->tv_nsec = 0;
229         }
230 }
231 
232 /* Convert linear UNIX date to a FAT time/date pair. */
233 void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec *ts,
234                        __le16 *time, __le16 *date, u8 *time_cs)
235 {
236         struct tm tm;
237         time_to_tm(ts->tv_sec,
238                    (sbi->options.tz_set ? sbi->options.time_offset :
239                    -sys_tz.tz_minuteswest) * SECS_PER_MIN, &tm);
240 
241         /*  FAT can only support year between 1980 to 2107 */
242         if (tm.tm_year < 1980 - 1900) {
243                 *time = 0;
244                 *date = cpu_to_le16((0 << 9) | (1 << 5) | 1);
245                 if (time_cs)
246                         *time_cs = 0;
247                 return;
248         }
249         if (tm.tm_year > 2107 - 1900) {
250                 *time = cpu_to_le16((23 << 11) | (59 << 5) | 29);
251                 *date = cpu_to_le16((127 << 9) | (12 << 5) | 31);
252                 if (time_cs)
253                         *time_cs = 199;
254                 return;
255         }
256 
257         /* from 1900 -> from 1980 */
258         tm.tm_year -= 80;
259         /* 0~11 -> 1~12 */
260         tm.tm_mon++;
261         /* 0~59 -> 0~29(2sec counts) */
262         tm.tm_sec >>= 1;
263 
264         *time = cpu_to_le16(tm.tm_hour << 11 | tm.tm_min << 5 | tm.tm_sec);
265         *date = cpu_to_le16(tm.tm_year << 9 | tm.tm_mon << 5 | tm.tm_mday);
266         if (time_cs)
267                 *time_cs = (ts->tv_sec & 1) * 100 + ts->tv_nsec / 10000000;
268 }
269 EXPORT_SYMBOL_GPL(fat_time_unix2fat);
270 
271 int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
272 {
273         int i, err = 0;
274 
275         for (i = 0; i < nr_bhs; i++)
276                 write_dirty_buffer(bhs[i], WRITE);
277 
278         for (i = 0; i < nr_bhs; i++) {
279                 wait_on_buffer(bhs[i]);
280                 if (!err && !buffer_uptodate(bhs[i]))
281                         err = -EIO;
282         }
283         return err;
284 }
285 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp