Index: linux-2.6.18-194.17.1-ext3/fs/ext3/dir.c
===================================================================
--- linux-2.6.18-194.17.1-ext3.orig/fs/ext3/dir.c	2010-11-30 22:46:09.000000000 +0300
+++ linux-2.6.18-194.17.1-ext3/fs/ext3/dir.c	2010-12-16 00:10:12.000000000 +0300
@@ -240,19 +240,34 @@ out:
 /*
  * These functions convert from the major/minor hash to an f_pos
  * value.
- * 
- * Currently we only use major hash numer.  This is unfortunate, but
- * on 32-bit machines, the same VFS interface is used for lseek and
- * llseek, so if we use the 64 bit offset, then the 32-bit versions of
- * lseek/telldir/seekdir will blow out spectacularly, and from within
- * the ext2 low-level routine, we don't know if we're being called by
- * a 64-bit version of the system call or the 32-bit version of the
- * system call.  Worse yet, NFSv2 only allows for a 32-bit readdir
- * cookie.  Sigh.
+ *
+ * Whether 64-bit or 32-bit hash value is exported as file pos is
+ * controlled by "64bithash" mount option.
  */
-#define hash2pos(major, minor)	(major >> 1)
-#define pos2maj_hash(pos)	((pos << 1) & 0xffffffff)
-#define pos2min_hash(pos)	(0)
+
+static inline loff_t hash2pos(struct super_block *sb, __u32 major, __u32 minor)
+{
+	if (test_opt(sb, 64BITHASH))
+		return (((__u64)(major >> 1) << 32) | (__u64)minor);
+	else
+		return (major >> 1);
+}
+
+static inline __u32 pos2maj_hash(struct super_block *sb, loff_t pos)
+{
+	if (test_opt(sb, 64BITHASH))
+		return (((pos >> 32) << 1) & 0xffffffff);
+	else
+		return ((pos << 1) & 0xffffffff);
+}
+
+static inline __u32 pos2min_hash(struct super_block *sb, loff_t pos)
+{
+	if (test_opt(sb, 64BITHASH))
+		return (pos & 0xffffffff);
+	else
+		return (0);
+}
 
 /*
  * This structure holds the nodes of the red-black tree used to store
@@ -314,7 +329,7 @@ static void free_rb_tree_fname(struct rb
 }
 
 
-static struct dir_private_info *create_dir_info(loff_t pos)
+static struct dir_private_info *create_dir_info(struct super_block *sb, loff_t pos)
 {
 	struct dir_private_info *p;
 
@@ -325,8 +340,8 @@ static struct dir_private_info *create_d
 	p->curr_node = NULL;
 	p->extra_fname = NULL;
 	p->last_pos = 0;
-	p->curr_hash = pos2maj_hash(pos);
-	p->curr_minor_hash = pos2min_hash(pos);
+	p->curr_hash = pos2maj_hash(sb, pos);
+	p->curr_minor_hash = pos2min_hash(sb, pos);
 	p->next_hash = 0;
 	return p;
 }
@@ -422,7 +437,7 @@ static int call_filldir(struct file * fi
 		printk("call_filldir: called with null fname?!?\n");
 		return 0;
 	}
-	curr_pos = hash2pos(fname->hash, fname->minor_hash);
+	curr_pos = hash2pos(sb, fname->hash, fname->minor_hash);
 	while (fname) {
 		error = filldir(dirent, fname->name,
 				fname->name_len, curr_pos, 
@@ -447,7 +462,7 @@ static int ext3_dx_readdir(struct file *
 	int	ret;
 
 	if (!info) {
-		info = create_dir_info(filp->f_pos);
+		info = create_dir_info(inode->i_sb, filp->f_pos);
 		if (!info)
 			return -ENOMEM;
 		filp->private_data = info;
@@ -461,8 +476,8 @@ static int ext3_dx_readdir(struct file *
 		free_rb_tree_fname(&info->root);
 		info->curr_node = NULL;
 		info->extra_fname = NULL;
-		info->curr_hash = pos2maj_hash(filp->f_pos);
-		info->curr_minor_hash = pos2min_hash(filp->f_pos);
+		info->curr_hash = pos2maj_hash(inode->i_sb, filp->f_pos);
+		info->curr_minor_hash = pos2min_hash(inode->i_sb, filp->f_pos);
 	}
 
 	/*
Index: linux-2.6.18-194.17.1-ext3/fs/ext3/super.c
===================================================================
--- linux-2.6.18-194.17.1-ext3.orig/fs/ext3/super.c	2010-11-30 22:48:01.000000000 +0300
+++ linux-2.6.18-194.17.1-ext3/fs/ext3/super.c	2010-12-16 00:11:59.000000000 +0300
@@ -742,6 +742,7 @@ enum {
 	Opt_grpquota,
 	Opt_extents, Opt_noextents, Opt_bigendian_extents, Opt_extdebug,
 	Opt_mballoc, Opt_nomballoc, Opt_stripe, Opt_maxdirsize, Opt_force_over_8tb,
+	Opt_64bithash,
 };
 
 static match_table_t tokens = {
@@ -808,6 +809,7 @@ static match_table_t tokens = {
 	{Opt_force_over_8tb, "force_over_8tb"},
 	{Opt_resize, "resize"},
 	{Opt_maxdirsize, "maxdirsize=%u"},
+	{Opt_64bithash, "64bithash"},
 	{Opt_err, NULL}
 };
 
@@ -1195,6 +1197,9 @@ clear_qf_name:
 		case Opt_force_over_8tb:
 			force_over_8tb = 1;
 			break;
+		case Opt_64bithash:
+			set_opt(sbi->s_mount_opt, 64BITHASH);
+			break;
 		default:
 			printk (KERN_ERR
 				"EXT3-fs: Unrecognized mount option \"%s\" "
Index: linux-2.6.18-194.17.1-ext3/include/linux/ext3_fs.h
===================================================================
--- linux-2.6.18-194.17.1-ext3.orig/include/linux/ext3_fs.h	2010-11-30 22:52:58.000000000 +0300
+++ linux-2.6.18-194.17.1-ext3/include/linux/ext3_fs.h	2010-12-16 00:12:45.000000000 +0300
@@ -483,6 +483,8 @@ do {									       \
 #define EXT3_MOUNT_JOURNAL_ASYNC_COMMIT 0x20000000 /* Journal Async Commit */
 #endif
 
+#define EXT3_MOUNT_64BITHASH            0x40000000 /* export 64-bit name hash */
+
 /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
 #ifndef clear_opt
 #define clear_opt(o, opt)		o &= ~EXT3_MOUNT_##opt