diff --git a/include/ext4fs.h b/include/ext4fs.h
index cb5d9cc..dd66d27 100644
--- a/include/ext4fs.h
+++ b/include/ext4fs.h
@@ -31,6 +31,7 @@
 struct disk_partition;
 
 #define EXT4_INDEX_FL		0x00001000 /* Inode uses hash tree index */
+#define EXT4_TOPDIR_FL		0x00020000 /* Top of directory hierarchies*/
 #define EXT4_EXTENTS_FL		0x00080000 /* Inode uses extents */
 #define EXT4_EXT_MAGIC			0xf30a
 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM	0x0010
diff --git a/include/ext_common.h b/include/ext_common.h
index 30a0c24..b09bbde 100644
--- a/include/ext_common.h
+++ b/include/ext_common.h
@@ -35,6 +35,16 @@
 #define EXT2_PATH_MAX				4096
 /* Maximum nesting of symlinks, used to prevent a loop.  */
 #define	EXT2_MAX_SYMLINKCNT		8
+/* Maximum file name length */
+#define EXT2_NAME_LEN 255
+
+/*
+ * Revision levels
+ */
+#define EXT2_GOOD_OLD_REV	0	/* The good old (original) format */
+#define EXT2_DYNAMIC_REV	1	/* V2 format w/ dynamic inode sizes */
+
+#define EXT2_GOOD_OLD_INODE_SIZE 128
 
 /* Filetype used in directory entry.  */
 #define	FILETYPE_UNKNOWN		0
@@ -48,6 +58,10 @@
 #define FILETYPE_INO_DIRECTORY		0040000
 #define FILETYPE_INO_SYMLINK		0120000
 #define EXT2_ROOT_INO			2 /* Root inode */
+#define EXT2_BOOT_LOADER_INO		5 /* Boot loader inode */
+
+/* First non-reserved inode for old ext2 filesystems */
+#define EXT2_GOOD_OLD_FIRST_INO	11
 
 /* The size of an ext2 block in bytes.  */
 #define EXT2_BLOCK_SIZE(data)	   (1 << LOG2_BLOCK_SIZE(data))