Index: linux-2.6.5-7.312/fs/ext3/super.c
===================================================================
--- linux-2.6.5-7.312.orig/fs/ext3/super.c
+++ linux-2.6.5-7.312/fs/ext3/super.c
@@ -84,6 +84,8 @@ handle_t *ext3_journal_start(struct inod
 	return journal_start(journal, nblocks);
 }
 
+static int bigendian_extents;
+
 /* 
  * The only special thing we need to do here is to make sure that all
  * journal_stop calls result in the superblock being marked dirty, so
@@ -601,7 +603,7 @@ enum {
 	Opt_ignore, Opt_barrier,
 	Opt_err,
 	Opt_iopen, Opt_noiopen, Opt_iopen_nopriv,
-	Opt_extents, Opt_noextents, Opt_extdebug,
+	Opt_extents, Opt_noextents, Opt_bigendian_extents, Opt_extdebug,
 	Opt_mballoc, Opt_nomballoc, Opt_stripe,
 };
 
@@ -649,6 +651,7 @@ static match_table_t tokens = {
 	{Opt_iopen_nopriv, "iopen_nopriv"},
 	{Opt_extents, "extents"},
 	{Opt_noextents, "noextents"},
+	{Opt_bigendian_extents, "bigendian_extents"},
 	{Opt_extdebug, "extdebug"},
 	{Opt_barrier, "barrier=%u"},
 	{Opt_mballoc, "mballoc"},
@@ -886,6 +889,9 @@ static int parse_options (char * options
 		case Opt_noextents:
 			clear_opt (sbi->s_mount_opt, EXTENTS);
 			break;
+		case Opt_bigendian_extents:
+			bigendian_extents = 1;
+			break;
 		case Opt_extdebug:
 			set_opt (sbi->s_mount_opt, EXTDEBUG);
 			break;
@@ -1450,6 +1456,16 @@ static int ext3_fill_super (struct super
 			    0))
 		goto failed_mount;
 
+#ifdef __BIG_ENDIAN
+	if (bigendian_extents == 0) {
+		printk(KERN_ERR "EXT3-fs: e2fsck is not guaranteed to work "
+		       "correctly on the filesystem if EXTENTS feature is "
+		       "used on big-endian systems. Use \"bigendian_extents\" "
+		       "mount option to override.\n");
+		goto failed_mount;
+	}
+#endif
+
 	sb->s_flags |= MS_ONE_SECOND;
 	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
 		((sbi->s_mount_opt & EXT3_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);