/* * 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 "fat.h" /* * fat_fs_panic reports a severe file system problem and sets the file system * read-only. The file system can be made writable again by remounting it. */ void fat_fs_panic(struct super_block *s, const char *fmt, ...) { va_list args; printk(KERN_ERR "FAT: Filesystem panic (dev %s)\n", s->s_id); printk(KERN_ERR " "); va_start(args, fmt); vprintk(fmt, args); va_end(args); printk("\n"); if (!(s->s_flags & MS_RDONLY)) { s->s_flags |= MS_RDONLY; printk(KERN_ERR " File system has been set read-only\n"); } } EXPORT_SYMBOL_GPL(fat_fs_panic); /* Flushes the number of free clusters on FAT32 */ /* XXX: Need to write one per FSINFO block. Currently only writes 1 */ void 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; bh = sb_bread(sb, sbi->fsinfo_sector); if (bh == NULL) { printk(KERN_ERR "FAT: bread failed in fat_clusters_flush\n"); return; } 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); } /* * 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_osync_inode() synchronize later if * this is not directory, we don't here. */ 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_panic(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) #define UNIX_SECS_1980 315532800L #if BITS_PER_LONG == 64 #define UNIX_SECS_2108 4354819200L #endif /* 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) { time_t second = ts->tv_sec; time_t day, leap_day, month, year; if (!sbi->options.tz_utc) second -= sys_tz.tz_minuteswest * SECS_PER_MIN; /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */ if (second < UNIX_SECS_1980) { *time = 0; *date = cpu_to_le16((0 << 9) | (1 << 5) | 1); if (time_cs) *time_cs = 0; return; } #if BITS_PER_LONG == 64 if (second >= UNIX_SECS_2108) { *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; } #endif day = second / SECS_PER_DAY - DAYS_DELTA; year = day / 365; leap_day = (year + 3) / 4; if (year > YEAR_2100) /* 2100 isn't leap year */ leap_day--; if (year * 365 + leap_day > day) year--; leap_day = (year + 3) / 4; if (year > YEAR_2100) /* 2100 isn't leap year */ leap_day--; day -= year * 365 + leap_day; if (IS_LEAP_YEAR(year) && day == days_in_year[3]) { month = 2; } else { if (IS_LEAP_YEAR(year) && day > days_in_year[3]) day--; for (month = 1; month < 12; month++) { if (days_in_year[month + 1] > day) break; } } day -= days_in_year[month]; *time = cpu_to_le16(((second / SECS_PER_HOUR) % 24) << 11 | ((second / SECS_PER_MIN) % 60) << 5 | (second % SECS_PER_MIN) >> 1); *date = cpu_to_le16((year << 9) | (month << 5) | (day + 1)); 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; ll_rw_block(SWRITE, nr_bhs, bhs); for (i = 0; i < nr_bhs; i++) { wait_on_buffer(bhs[i]); if (buffer_eopnotsupp(bhs[i])) { clear_buffer_eopnotsupp(bhs[i]); err = -EOPNOTSUPP; } else if (!err && !buffer_uptodate(bhs[i])) err = -EIO; } return err; }