Disable the DELALLOC feature because it is not robust in ext4 versions < 2.6.31.

--
Index: linux-2.6.27.21-0.1/fs/ext4/super.c
===================================================================
--- linux-2.6.27.21-0.1.orig/fs/ext4/super.c	2009-06-15 05:36:44.000000000 -0400
+++ linux-2.6.27.21-0.1/fs/ext4/super.c	2009-06-15 05:40:38.000000000 -0400
@@ -2462,12 +2462,6 @@ static int ext4_fill_super(struct super_

	set_opt(sbi->s_mount_opt, BARRIER);

-	/*
-	 * enable delayed allocation by default
-	 * Use -o nodelalloc to turn it off
-	 */
-	set_opt(sbi->s_mount_opt, DELALLOC);
-
	if (!parse_options((char *) data, sb, &journal_devnum,
			   &journal_ioprio, NULL, 0))
		goto failed_mount;