diff --git a/ChangeLog b/ChangeLog
index 1fdf98bf1..844d9f181 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-07-13  Jiro SEKIBA <jir@unicus.jp>
+
+	* fs/nilfs2.c: fix macro NILFS_2ND_SUPER_BLOCK to calculate
+	2nd superblock position from partition size.
+
 2010-07-10  Colin Watson  <cjwatson@ubuntu.com>
 
 	* Makefile.in (MAINTAINER_CLEANFILES): Remove
diff --git a/fs/nilfs2.c b/fs/nilfs2.c
index 5d32f5f88..8329c01a1 100644
--- a/fs/nilfs2.c
+++ b/fs/nilfs2.c
@@ -52,9 +52,9 @@
 /* nilfs 1st super block posission from beginning of the partition
    in 512 block size */
 #define NILFS_1ST_SUPER_BLOCK	2
-/* nilfs 2nd super block posission from end of the partition
+/* nilfs 2nd super block posission from beginning of the partition
    in 512 block size */
-#define NILFS_2ND_SUPER_BLOCK	8
+#define NILFS_2ND_SUPER_BLOCK(devsize)	(((devsize >> 3) - 1) << 3)
 
 struct grub_nilfs2_inode
 {
@@ -729,7 +729,7 @@ grub_nilfs2_load_sb (struct grub_nilfs2_data *data)
   if (partition_size != GRUB_DISK_SIZE_UNKNOWN)
     {
       /* Read second super block. */
-      grub_disk_read (disk, partition_size - NILFS_2ND_SUPER_BLOCK, 0,
+      grub_disk_read (disk, NILFS_2ND_SUPER_BLOCK (partition_size), 0,
 		      sizeof (struct grub_nilfs2_super_block), &sb2);
       /* Make sure if 2nd super block is valid.  */
       valid[1] = grub_nilfs2_valid_sb (&sb2);