diff -Nurp linux-3.6-rc1-orig/fs/ext3/ext3.h linux-3.6-rc1/fs/ext3/ext3.h
--- linux-3.6-rc1-orig/fs/ext3/ext3.h	2012-08-16 09:37:31.000000000 +0200
+++ linux-3.6-rc1/fs/ext3/ext3.h	2012-08-16 09:46:39.000000000 +0200
@@ -672,6 +672,7 @@ struct ext3_sb_info {
 	char *s_qf_names[MAXQUOTAS];		/* Names of quota files with journalled quota */
 	int s_jquota_fmt;			/* Format of quota to use */
 #endif
+	struct mutex s_lock;
 };
  static inline spinlock_t *
diff -Nurp linux-3.6-rc1-orig/fs/ext3/super.c linux-3.6-rc1/fs/ext3/super.c
--- linux-3.6-rc1-orig/fs/ext3/super.c	2012-08-16 09:37:31.000000000 +0200
+++ linux-3.6-rc1/fs/ext3/super.c	2012-08-16 09:49:11.000000000 +0200
@@ -1939,6 +1939,7 @@ static int ext3_fill_super (struct super
 	sbi->s_gdb_count = db_count;
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 	spin_lock_init(&sbi->s_next_gen_lock);
+	mutex_init(&sbi->s_lock);
  	/* per fileystem reservation list head & lock */
 	spin_lock_init(&sbi->s_rsv_window_lock);
@@ -2582,11 +2583,11 @@ out: