JFS: Don't do filename translation by default

Due to its roots in OS/2, JFS has always tried to convert pathnames
into unicode.  Unfortunately, it never had a reliable idea of what
the incoming character set was, so it defaulted to CONFIG_NLS_DEFAULT.

This behavior was confusing and many users have requested that JFS
have a more sane behavior.   This patch changes the default behavior
to store the incoming bytes directly without translation.  This is
consistent with the behavior when the default value of
CONFIG_NLS_DEFAULT (iso8859-1) was defined.  The default behavior
can be overridden by using the iocharset mount option.

Documentation/filesystems/jfs.txt

@@ -12,10 +12,9 @@ Barry Arndt        barndt@us.ibm.com
 The following mount options are supported:
 
 iocharset=name	Character set to use for converting from Unicode to
-		ASCII.  The default is compiled into the kernel as
-		CONFIG_NLS_DEFAULT.  Use iocharset=utf8 for UTF8
-		translations.  This requires CONFIG_NLS_UTF8 to be set
-		in the kernel .config file.
+		ASCII.  The default is to do no conversion.  Use
+		iocharset=utf8 for UTF8 translations.  This requires
+		CONFIG_NLS_UTF8 to be set in the kernel .config file.
 
 resize=value	Resize the volume to <value> blocks.  JFS only supports
 		growing a volume, not shrinking it.  This option is only
@@ -36,18 +35,6 @@ errors=continue		Keep going on a filesystem error.
 errors=remount-ro	Default. Remount the filesystem read-only on an error.
 errors=panic		Panic and halt the machine if an error occurs.
 
-JFS TODO list:
-
-Plans for our near term development items
-
-   - enhance support for logfile on dedicated partition
-
-Longer term work items
-
-   - implement defrag utility, for online defragmenting
-   - add quota support
-   - add support for block sizes (512,1024,2048)
-
 Please send bugs, comments, cards and letters to shaggy@austin.ibm.com.
 
 The JFS mailing list can be subscribed to by using the link labeled

fs/jfs/jfs_unicode.c

 /*
- *   Copyright (c) International Business Machines Corp., 2000-2002
+ *   Copyright (C) International Business Machines Corp., 2000-2004
  *
  *   This program is free software;  you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -35,16 +35,22 @@ int jfs_strfromUCS_le(char *to, const wchar_t * from,	/* LITTLE ENDIAN */
 	int i;
 	int outlen = 0;
 
-	for (i = 0; (i < len) && from[i]; i++) {
-		int charlen;
-		charlen =
-		    codepage->uni2char(le16_to_cpu(from[i]), &to[outlen],
-				       NLS_MAX_CHARSET_SIZE);
-		if (charlen > 0) {
-			outlen += charlen;
-		} else {
-			to[outlen++] = '?';
+	if (codepage) {
+		for (i = 0; (i < len) && from[i]; i++) {
+			int charlen;
+			charlen =
+			    codepage->uni2char(le16_to_cpu(from[i]),
+					       &to[outlen],
+					       NLS_MAX_CHARSET_SIZE);
+			if (charlen > 0)
+				outlen += charlen;
+			else
+				to[outlen++] = '?';
 		}
+	} else {
+		for (i = 0; (i < len) && from[i]; i++)
+			to[i] = (char) (le16_to_cpu(from[i]));
+		outlen = i;
 	}
 	to[outlen] = 0;
 	return outlen;
@@ -62,14 +68,22 @@ int jfs_strtoUCS(wchar_t * to,
 	int charlen;
 	int i;
 
-	for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
-		charlen = codepage->char2uni(from, len, &to[i]);
-		if (charlen < 1) {
-			jfs_err("jfs_strtoUCS: char2uni returned %d.", charlen);
-			jfs_err("charset = %s, char = 0x%x",
-				codepage->charset, (unsigned char) *from);
-			return charlen;
+	if (codepage) {
+		for (i = 0; len && *from; i++, from += charlen, len -= charlen)
+		{
+			charlen = codepage->char2uni(from, len, &to[i]);
+			if (charlen < 1) {
+				jfs_err("jfs_strtoUCS: char2uni returned %d.",
+					charlen);
+				jfs_err("charset = %s, char = 0x%x",
+					codepage->charset,
+					(unsigned char) *from);
+				return charlen;
+			}
 		}
+	} else {
+		for (i = 0; (i < len) && from[i]; i++)
+			to[i] = (wchar_t) from[i];
 	}
 
 	to[i] = 0;

fs/jfs/super.c

@@ -195,7 +195,8 @@ static void jfs_put_super(struct super_block *sb)
 	rc = jfs_umount(sb);
 	if (rc)
 		jfs_err("jfs_umount failed with return code %d", rc);
-	unload_nls(sbi->nls_tab);
+	if (sbi->nls_tab)
+		unload_nls(sbi->nls_tab);
 	sbi->nls_tab = NULL;
 
 	kfree(sbi);
@@ -435,9 +436,6 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 	if (!sb->s_root)
 		goto out_no_root;
 
-	if (!sbi->nls_tab)
-		sbi->nls_tab = load_nls_default();
-
 	/* logical blocks are represented by 40 bits in pxd_t, etc. */
 	sb->s_maxbytes = ((u64) sb->s_blocksize) << 40;
 #if BITS_PER_LONG == 32