/* * 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/msdos_fs.h> #include <linux/buffer_head.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: Did not find valid FSINFO signature.\n" " Found signature1 0x%08x signature2 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 != %lu)", new_fclus, 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; /* Linear day numbers of the respective 1sts in non-leap years. */ static int day_n[] = { /* Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec */ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0 }; /* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */ int date_dos2unix(unsigned short time, unsigned short date) { int month, year, secs; /* * first subtract and mask after that... Otherwise, if * date == 0, bad things happen */ month = ((date >> 5) - 1) & 15; year = date >> 9; secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400* ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 && month < 2 ? 1 : 0)+3653); /* days since 1.1.70 plus 80's leap day */ secs += sys_tz.tz_minuteswest*60; return secs; } /* Convert linear UNIX date to a MS-DOS time/date pair. */ void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date) { int day, year, nl_day, month; unix_date -= sys_tz.tz_minuteswest*60; /* Jan 1 GMT 00:00:00 1980. But what about another time zone? */ if (unix_date < 315532800) unix_date = 315532800; *time = cpu_to_le16((unix_date % 60)/2+(((unix_date/60) % 60) << 5)+ (((unix_date/3600) % 24) << 11)); day = unix_date/86400-3652; year = day/365; if ((year+3)/4+365*year > day) year--; day -= (year+3)/4+365*year; if (day == 59 && !(year & 3)) { nl_day = day; month = 2; } else { nl_day = (year & 3) || day <= 59 ? day : day-1; for (month = 0; month < 12; month++) { if (day_n[month] > nl_day) break; } } *date = cpu_to_le16(nl_day-day_n[month-1]+1+(month << 5)+(year << 9)); } EXPORT_SYMBOL_GPL(fat_date_unix2dos); 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; }