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

--
diff -rupN linux-2.6.18-164.6.1_1/fs/ext4/super.c linux-2.6.18-164.6.1_2/fs/ext4/super.c
--- linux-2.6.18-164.6.1_1/fs/ext4/super.c	2010-08-05 13:44:07.000000000 +0530
+++ linux-2.6.18-164.6.1_2/fs/ext4/super.c	2010-08-05 13:46:29.000000000 +0530
@@ -2091,12 +2091,6 @@ 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;