+/* for s_flags */
+#define EXT2_FLAGS_TEST_FILESYS 0x0004
+
+/* for s_feature_compat */
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004
+
+/* for s_feature_ro_compat */
+#define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
+#define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
+#define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
+#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
+#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
+#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
+#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
+
+/* for s_feature_incompat */
+#define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002
+#define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004
+#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
+#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
+#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
+#define EXT4_FEATURE_INCOMPAT_MMP 0x0100
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
+
+#define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT2_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+ EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT2_FEATURE_INCOMPAT_UNSUPPORTED ~EXT2_FEATURE_INCOMPAT_SUPP
+#define EXT2_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT2_FEATURE_RO_COMPAT_SUPP
+
+#define EXT3_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
+ EXT2_FEATURE_RO_COMPAT_BTREE_DIR)
+#define EXT3_FEATURE_INCOMPAT_SUPP (EXT2_FEATURE_INCOMPAT_FILETYPE| \
+ EXT3_FEATURE_INCOMPAT_RECOVER| \
+ EXT2_FEATURE_INCOMPAT_META_BG)
+#define EXT3_FEATURE_INCOMPAT_UNSUPPORTED ~EXT3_FEATURE_INCOMPAT_SUPP
+#define EXT3_FEATURE_RO_COMPAT_UNSUPPORTED ~EXT3_FEATURE_RO_COMPAT_SUPP
+