diff --git a/[refs] b/[refs]
index 958634c080c8..d758c0fe0238 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6cda9fa2575ec0869fe77b0bdf295c0e51868cab
+refs/heads/master: 89c0fd014d34d409a7b196667c2b9a4813b6c968
diff --git a/trunk/fs/nilfs2/the_nilfs.c b/trunk/fs/nilfs2/the_nilfs.c
index da67b560f3c3..37de1f062d81 100644
--- a/trunk/fs/nilfs2/the_nilfs.c
+++ b/trunk/fs/nilfs2/the_nilfs.c
@@ -671,7 +671,7 @@ int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
 		goto out;
 	}
 
-	blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
+	blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
 	if (!blocksize) {
 		printk(KERN_ERR "NILFS: unable to set blocksize\n");
 		err = -EINVAL;
@@ -690,6 +690,13 @@ int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
 		goto failed_sbh;
 
 	blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
+	if (blocksize < NILFS_MIN_BLOCK_SIZE ||
+	    blocksize > NILFS_MAX_BLOCK_SIZE) {
+		printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
+		       "filesystem blocksize %d\n", blocksize);
+		err = -EINVAL;
+		goto failed_sbh;
+	}
 	if (sb->s_blocksize != blocksize) {
 		int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
 
diff --git a/trunk/include/linux/nilfs2_fs.h b/trunk/include/linux/nilfs2_fs.h
index 970828a5ffc5..f5487b6f91ed 100644
--- a/trunk/include/linux/nilfs2_fs.h
+++ b/trunk/include/linux/nilfs2_fs.h
@@ -286,6 +286,12 @@ struct nilfs_super_block {
 
 #define NILFS_NAME_LEN 255
 
+/*
+ * Block size limitations
+ */
+#define NILFS_MIN_BLOCK_SIZE		1024
+#define NILFS_MAX_BLOCK_SIZE		65536
+
 /*
  * The new version of the directory entry.  Since V0 structures are
  * stored in intel byte order, and the name_len field could never be