1 /* mke2fs.h - Headers for ext2
2  *
3  * Copyright 2006 Rob Landley <rob@landley.net>
4  */
5 
6 // Stuff defined in linux/ext2_fs.h
7 
8 #define EXT2_SUPER_MAGIC  0xEF53
9 
10 struct ext2_superblock {
11   uint32_t inodes_count;      // Inodes count
12   uint32_t blocks_count;      // Blocks count
13   uint32_t r_blocks_count;    // Reserved blocks count
14   uint32_t free_blocks_count; // Free blocks count
15   uint32_t free_inodes_count; // Free inodes count
16   uint32_t first_data_block;  // First Data Block
17   uint32_t log_block_size;    // Block size
18   uint32_t log_frag_size;     // Fragment size
19   uint32_t blocks_per_group;  // Blocks per group
20   uint32_t frags_per_group;   // Fragments per group
21   uint32_t inodes_per_group;  // Inodes per group
22   uint32_t mtime;             // Mount time
23   uint32_t wtime;             // Write time
24   uint16_t mnt_count;         // Mount count
25   uint16_t max_mnt_count;     // Maximal mount count
26   uint16_t magic;             // Magic signature
27   uint16_t state;             // File system state
28   uint16_t errors;            // Behaviour when detecting errors
29   uint16_t minor_rev_level;   // minor revision level
30   uint32_t lastcheck;         // time of last check
31   uint32_t checkinterval;     // max. time between checks
32   uint32_t creator_os;        // OS
33   uint32_t rev_level;         // Revision level
34   uint16_t def_resuid;        // Default uid for reserved blocks
35   uint16_t def_resgid;        // Default gid for reserved blocks
36   uint32_t first_ino;         // First non-reserved inode
37   uint16_t inode_size;        // size of inode structure
38   uint16_t block_group_nr;    // block group # of this superblock
39   uint32_t feature_compat;    // compatible feature set
40   uint32_t feature_incompat;  // incompatible feature set
41   uint32_t feature_ro_compat; // readonly-compatible feature set
42   char     uuid[16];          // 128-bit uuid for volume
43   char     volume_name[16];   // volume name
44   char     last_mounted[64];  // directory where last mounted
45   uint32_t alg_usage_bitmap;  // For compression
46   // For EXT2_COMPAT_PREALLOC
47   uint8_t  prealloc_blocks;   // Nr of blocks to try to preallocate
48   uint8_t  prealloc_dir_blocks; //Nr to preallocate for dirs
49   uint16_t padding1;
50   // For EXT3_FEATURE_COMPAT_HAS_JOURNAL
51   uint8_t  journal_uuid[16];   // uuid of journal superblock
52   uint32_t journal_inum;       // inode number of journal file
53   uint32_t journal_dev;        // device number of journal file
54   uint32_t last_orphan;        // start of list of inodes to delete
55   uint32_t hash_seed[4];       // HTREE hash seed
56   uint8_t  def_hash_version;   // Default hash version to use
57   uint8_t  padding2[3];
58   uint32_t default_mount_opts;
59   uint32_t first_meta_bg;      // First metablock block group
60   uint32_t mkfs_time;          // Creation timestamp
61   uint32_t jnl_blocks[17];     // Backup of journal inode
62   // uint32_t reserved[172];      // Padding to the end of the block
63 };
64 
65 struct ext2_group
66 {
67   uint32_t block_bitmap;       // Block number of block bitmap
68   uint32_t inode_bitmap;       // Block number of inode bitmap
69   uint32_t inode_table;        // Block number of inode table
70   uint16_t free_blocks_count;  // How many free blocks in this group?
71   uint16_t free_inodes_count;  // How many free inodes in this group?
72   uint16_t used_dirs_count;    // How many directories?
73   uint16_t reserved[7];        // pad to 32 bytes
74 };
75 
76 struct ext2_dentry {
77   uint32_t inode;         // Inode number
78   uint16_t rec_len;       // Directory entry length
79   uint8_t  name_len;      // Name length
80   uint8_t  file_type;
81   char     name[0];     // File name
82 };
83 
84 struct ext2_inode {
85   uint16_t mode;        // File mode
86   uint16_t uid;         // Low 16 bits of Owner Uid
87   uint32_t size;        // Size in bytes
88   uint32_t atime;       // Access time
89   uint32_t ctime;       // Creation time
90   uint32_t mtime;       // Modification time
91   uint32_t dtime;       // Deletion Time
92   uint16_t gid;         // Low 16 bits of Group Id
93   uint16_t links_count; // Links count
94   uint32_t blocks;      // Blocks count
95   uint32_t flags;       // File flags
96   uint32_t reserved1;
97   uint32_t block[15];   // Pointers to blocks
98   uint32_t generation;  // File version (for NFS)
99   uint32_t file_acl;    // File ACL
100   uint32_t dir_acl;     // Directory ACL (or top bits of file length)
101   uint32_t faddr;       // Last block in file
102   uint8_t  frag;        // Fragment number
103   uint8_t  fsize;       // Fragment size
104   uint16_t pad1;
105   uint16_t uid_high;    // High bits of uid
106   uint16_t gid_high;    // High bits of gid
107   uint32_t reserved2;
108 };
109 
110 #define EXT2_FEATURE_COMPAT_DIR_PREALLOC	0x0001
111 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES	0x0002
112 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL		0x0004
113 #define EXT2_FEATURE_COMPAT_EXT_ATTR		0x0008
114 #define EXT2_FEATURE_COMPAT_RESIZE_INO		0x0010
115 #define EXT2_FEATURE_COMPAT_DIR_INDEX		0x0020
116 
117 #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
118 #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
119 #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004
120 
121 #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
122 #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002
123 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
124 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
125 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
126 
127 #define EXT2_NAME_LEN 255
128 
129 // Ext2 directory file types.  Only the low 3 bits are used.  The
130 // other bits are reserved for now.
131 
132 enum {
133   EXT2_FT_UNKNOWN,
134   EXT2_FT_REG_FILE,
135   EXT2_FT_DIR,
136   EXT2_FT_CHRDEV,
137   EXT2_FT_BLKDEV,
138   EXT2_FT_FIFO,
139   EXT2_FT_SOCK,
140   EXT2_FT_SYMLINK,
141   EXT2_FT_MAX
142 };
143