1 files changed, 225 insertions, 0 deletions
diff --git a/fs/fat/misc.c b/fs/fat/misc.c
new file mode 100644
index 00000000000..2a0df2122f5
--- /dev/null
+++ b/fs/fat/misc.c
@@ -0,0 +1,225 @@
+/*
+ *  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(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);
+		if (sb->s_flags & MS_SYNCHRONOUS)
+			sync_dirty_buffer(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(fat_date_unix2dos);
+
+int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs)
+{
+	int i, e, err = 0;
+
+	for (i = 0; i < nr_bhs; i++) {
+		lock_buffer(bhs[i]);
+		if (test_clear_buffer_dirty(bhs[i])) {
+			get_bh(bhs[i]);
+			bhs[i]->b_end_io = end_buffer_write_sync;
+			e = submit_bh(WRITE, bhs[i]);
+			if (!err && e)
+				err = e;
+		} else
+			unlock_buffer(bhs[i]);
+	}
+	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;
+}
+
+EXPORT_SYMBOL(fat_sync_bhs);