Index: linux-2.6.27.21-0.1/fs/ext4/super.c
===================================================================
--- linux-2.6.27.21-0.1.orig/fs/ext4/super.c	2009-07-07 15:00:32.000000000 +0530
+++ linux-2.6.27.21-0.1/fs/ext4/super.c	2009-07-07 15:01:30.000000000 +0530
@@ -52,6 +52,8 @@
 
 struct proc_dir_entry *ext4_proc_root;
 
+static int force_over_8tb;
+
 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
 			     unsigned long journal_devnum);
 static int ext4_create_journal(struct super_block *, struct ext4_super_block *,
@@ -1287,7 +1289,7 @@
 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
 	Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
-	Opt_mballoc,
+	Opt_mballoc, Opt_force_over_8tb,
 	Opt_stripe, Opt_delalloc, Opt_nodelalloc,
 	Opt_inode_readahead_blks, Opt_bigendian_extents,
 	Opt_iopen, Opt_noiopen, Opt_iopen_nopriv,
@@ -1349,6 +1351,7 @@
 	{Opt_stripe, "stripe=%u"},
 	{Opt_resize, "resize"},
 	{Opt_mballoc, "mballoc"},
+	{Opt_force_over_8tb, "force_over_8tb"},
 	{Opt_delalloc, "delalloc"},
 	{Opt_nodelalloc, "nodelalloc"},
 	{Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
@@ -1773,6 +1776,9 @@
 			break;
 		case Opt_mballoc:
 			break;
+		case Opt_force_over_8tb:
+			force_over_8tb = 1;
+			break;
 		default:
 			printk(KERN_ERR
 			       "EXT4-fs: Unrecognized mount option \"%s\" "
@@ -2634,6 +2640,17 @@
 		goto failed_mount;
 	}
 
+	if (ext4_blocks_count(es) >
+	    ((0x80000000000ULL >> sb->s_blocksize_bits) - 1)) {
+		if (force_over_8tb == 0) {
+			printk(KERN_ERR "EXT4-fs does not support filesystems "
+			       "greater than 8TB and can cause data corruption."
+			       "Use \"force_over_8tb\" mount option to override."
+			       "\n");
+			goto failed_mount;
+		}
+	}
+
 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
 		goto cantfind_ext4;