Index: linux-2.6.22.14/fs/ext3/super.c
===================================================================
--- linux-2.6.22.14.orig/fs/ext3/super.c
+++ linux-2.6.22.14/fs/ext3/super.c
@@ -71,6 +71,8 @@ static void ext3_unlockfs(struct super_b
 static void ext3_write_super (struct super_block * sb);
 static void ext3_write_super_lockfs(struct super_block *sb);
 
+static int bigendian_extents;
+
 /*
  * Wrappers for journal_start/end.
  *
@@ -700,7 +702,7 @@ enum {
 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 	Opt_iopen, Opt_noiopen, Opt_iopen_nopriv,
 	Opt_grpquota,
-	Opt_extents, Opt_noextents, Opt_extdebug,
+	Opt_extents, Opt_noextents, Opt_bigendian_extents, Opt_extdebug,
 	Opt_mballoc, Opt_nomballoc, Opt_stripe,
 };
 
@@ -756,6 +758,7 @@ static match_table_t tokens = {
 	{Opt_barrier, "barrier=%u"},
 	{Opt_extents, "extents"},
 	{Opt_noextents, "noextents"},
+	{Opt_bigendian_extents, "bigendian_extents"},
 	{Opt_extdebug, "extdebug"},
 	{Opt_mballoc, "mballoc"},
 	{Opt_nomballoc, "nomballoc"},
@@ -1110,6 +1113,9 @@ clear_qf_name:
 		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;
@@ -2208,6 +2214,15 @@ static int ext3_fill_super (struct super
 		goto failed_mount;
 	}
 
+#ifdef __BIG_ENDIAN
+	if (bigendian_extents == 0) {
+		printk(KERN_ERR "EXT3-fs: extents feature is not guaranteed to "
+		       "work on big-endian systems. Use \"bigendian_extents\" "
+		       "mount option to override.\n");
+		goto failed_mount;
+	}
+#endif
+
 	bgl_lock_init(&sbi->s_blockgroup_lock);
 
 	sbi->s_last_alloc_group = -1;