5.3.1.3.1. EXT2 Inode Structure
struct ext2_inode {
  __u16  i_mode;			/* File mode */
  __u16  i_uid;                         /* Owner ID */
  __u32  i_size;                        /* Size in bytes */
  __u32  i_atime;                       /* Access time */
  __u32  i_ctime;                       /* Creation time */
  __u32  i_mtime;                       /* Modification time */
  __u32  i_dtime;                       /* Deletion Time */
  __u16  i_gid;                         /* Group ID */
  __u16  i_links_count;                 /* Links count */
  __u32  i_blocks;                      /* Blocks count */
  __u32  i_flags;                       /* File flags */
  __u32  i_block [EXT2_N_BLOCKS];       /* Ptrs to blocks */
  __u32  i_version;                     /* File version for NFS */
  __u32  i_file_acl;                    /* File ACL */
  __u32  i_dir_acl;                     /* Directory ACL */
  __u32  i_faddr;                       /* Fragment address */
  __u8   l_i_frag;                      /* Fragment number */
  __u8   l_i_fsize;                     /* Fragment size */
};

#define EXT2_DIR_BLOCKS		12
#define EXT2_IND_BLOCK          EXT2_DIR_BLOCKS
#define EXT2_DIND_BLOCK		(EXT2_IND_BLOCK + 1)
#define EXT2_TIND_BLOCK		(EXT2_DIND_BLOCK + 1)
#define EXT2_N_BLOCKS           (EXT2_TIND_BLOCK + 1)

#define EXT2_SECRM_FL   	0x00000001      /* Secure del */
#define EXT2_SYNC_FL    	0x00000008      /* Sync update */
#define EXT2_IMMUTABLE_FL       0x00000010      /* Immutable */
#define EXT2_APPEND_FL          0x00000020      /* Only ap */