fs/squashfs/squashfs_fs.h

   1 #ifndef SQUASHFS_FS
   2 #define SQUASHFS_FS
   3 /*
   4  * Squashfs
   5  *
   6  * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
   7  * Phillip Lougher <phillip@lougher.demon.co.uk>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2,
  12  * or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  *
  23  * squashfs_fs.h
  24  */
  25
  26 #define SQUASHFS_CACHED_FRAGMENTS       CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE
  27 #define SQUASHFS_MAJOR                  4
  28 #define SQUASHFS_MINOR                  0
  29 #define SQUASHFS_MAGIC                  0x73717368
  30 #define SQUASHFS_START                  0
  31
  32 /* size of metadata (inode and directory) blocks */
  33 #define SQUASHFS_METADATA_SIZE          8192
  34 #define SQUASHFS_METADATA_LOG           13
  35
  36 /* default size of data blocks */
  37 #define SQUASHFS_FILE_SIZE              131072
  38 #define SQUASHFS_FILE_LOG               17
  39
  40 #define SQUASHFS_FILE_MAX_SIZE          1048576
  41 #define SQUASHFS_FILE_MAX_LOG           20
  42
  43 /* Max number of uids and gids */
  44 #define SQUASHFS_IDS                    65536
  45
  46 /* Max length of filename (not 255) */
  47 #define SQUASHFS_NAME_LEN               256
  48
  49 #define SQUASHFS_INVALID_FRAG           (0xffffffffU)
  50 #define SQUASHFS_INVALID_BLK            (-1LL)
  51
  52 /* Filesystem flags */
  53 #define SQUASHFS_NOI                    0
  54 #define SQUASHFS_NOD                    1
  55 #define SQUASHFS_NOF                    3
  56 #define SQUASHFS_NO_FRAG                4
  57 #define SQUASHFS_ALWAYS_FRAG            5
  58 #define SQUASHFS_DUPLICATE              6
  59 #define SQUASHFS_EXPORT                 7
  60
  61 #define SQUASHFS_BIT(flag, bit)         ((flag >> bit) & 1)
  62
  63 #define SQUASHFS_UNCOMPRESSED_INODES(flags)     SQUASHFS_BIT(flags, \
  64                                                 SQUASHFS_NOI)
  65
  66 #define SQUASHFS_UNCOMPRESSED_DATA(flags)       SQUASHFS_BIT(flags, \
  67                                                 SQUASHFS_NOD)
  68
  69 #define SQUASHFS_UNCOMPRESSED_FRAGMENTS(flags)  SQUASHFS_BIT(flags, \
  70                                                 SQUASHFS_NOF)
  71
  72 #define SQUASHFS_NO_FRAGMENTS(flags)            SQUASHFS_BIT(flags, \
  73                                                 SQUASHFS_NO_FRAG)
  74
  75 #define SQUASHFS_ALWAYS_FRAGMENTS(flags)        SQUASHFS_BIT(flags, \
  76                                                 SQUASHFS_ALWAYS_FRAG)
  77
  78 #define SQUASHFS_DUPLICATES(flags)              SQUASHFS_BIT(flags, \
  79                                                 SQUASHFS_DUPLICATE)
  80
  81 #define SQUASHFS_EXPORTABLE(flags)              SQUASHFS_BIT(flags, \
  82                                                 SQUASHFS_EXPORT)
  83
  84 /* Max number of types and file types */
  85 #define SQUASHFS_DIR_TYPE               1
  86 #define SQUASHFS_REG_TYPE               2
  87 #define SQUASHFS_SYMLINK_TYPE           3
  88 #define SQUASHFS_BLKDEV_TYPE            4
  89 #define SQUASHFS_CHRDEV_TYPE            5
  90 #define SQUASHFS_FIFO_TYPE              6
  91 #define SQUASHFS_SOCKET_TYPE            7
  92 #define SQUASHFS_LDIR_TYPE              8
  93 #define SQUASHFS_LREG_TYPE              9
  94 #define SQUASHFS_LSYMLINK_TYPE          10
  95 #define SQUASHFS_LBLKDEV_TYPE           11
  96 #define SQUASHFS_LCHRDEV_TYPE           12
  97 #define SQUASHFS_LFIFO_TYPE             13
  98 #define SQUASHFS_LSOCKET_TYPE           14
  99
 100 /* Flag whether block is compressed or uncompressed, bit is set if block is
 101  * uncompressed */
 102 #define SQUASHFS_COMPRESSED_BIT         (1 << 15)
 103
 104 #define SQUASHFS_COMPRESSED_SIZE(B)     (((B) & ~SQUASHFS_COMPRESSED_BIT) ? \
 105                 (B) & ~SQUASHFS_COMPRESSED_BIT :  SQUASHFS_COMPRESSED_BIT)
 106
 107 #define SQUASHFS_COMPRESSED(B)          (!((B) & SQUASHFS_COMPRESSED_BIT))
 108
 109 #define SQUASHFS_COMPRESSED_BIT_BLOCK   (1 << 24)
 110
 111 #define SQUASHFS_COMPRESSED_SIZE_BLOCK(B)       ((B) & \
 112                                                 ~SQUASHFS_COMPRESSED_BIT_BLOCK)
 113
 114 #define SQUASHFS_COMPRESSED_BLOCK(B)    (!((B) & SQUASHFS_COMPRESSED_BIT_BLOCK))
 115
 116 /*
 117  * Inode number ops.  Inodes consist of a compressed block number, and an
 118  * uncompressed offset within that block
 119  */
 120 #define SQUASHFS_INODE_BLK(A)           ((unsigned int) ((A) >> 16))
 121
 122 #define SQUASHFS_INODE_OFFSET(A)        ((unsigned int) ((A) & 0xffff))
 123
 124 #define SQUASHFS_MKINODE(A, B)          ((long long)(((long long) (A)\
 125                                         << 16) + (B)))
 126
 127 /* Translate between VFS mode and squashfs mode */
 128 #define SQUASHFS_MODE(A)                ((A) & 0xfff)
 129
 130 /* fragment and fragment table defines */
 131 #define SQUASHFS_FRAGMENT_BYTES(A)      \
 132                                 ((A) * sizeof(struct squashfs_fragment_entry))
 133
 134 #define SQUASHFS_FRAGMENT_INDEX(A)      (SQUASHFS_FRAGMENT_BYTES(A) / \
 135                                         SQUASHFS_METADATA_SIZE)
 136
 137 #define SQUASHFS_FRAGMENT_INDEX_OFFSET(A)       (SQUASHFS_FRAGMENT_BYTES(A) % \
 138                                                 SQUASHFS_METADATA_SIZE)
 139
 140 #define SQUASHFS_FRAGMENT_INDEXES(A)    ((SQUASHFS_FRAGMENT_BYTES(A) + \
 141                                         SQUASHFS_METADATA_SIZE - 1) / \
 142                                         SQUASHFS_METADATA_SIZE)
 143
 144 #define SQUASHFS_FRAGMENT_INDEX_BYTES(A)        (SQUASHFS_FRAGMENT_INDEXES(A) *\
 145                                                 sizeof(u64))
 146
 147 /* inode lookup table defines */
 148 #define SQUASHFS_LOOKUP_BYTES(A)        ((A) * sizeof(u64))
 149
 150 #define SQUASHFS_LOOKUP_BLOCK(A)        (SQUASHFS_LOOKUP_BYTES(A) / \
 151                                         SQUASHFS_METADATA_SIZE)
 152
 153 #define SQUASHFS_LOOKUP_BLOCK_OFFSET(A) (SQUASHFS_LOOKUP_BYTES(A) % \
 154                                         SQUASHFS_METADATA_SIZE)
 155
 156 #define SQUASHFS_LOOKUP_BLOCKS(A)       ((SQUASHFS_LOOKUP_BYTES(A) + \
 157                                         SQUASHFS_METADATA_SIZE - 1) / \
 158                                         SQUASHFS_METADATA_SIZE)
 159
 160 #define SQUASHFS_LOOKUP_BLOCK_BYTES(A)  (SQUASHFS_LOOKUP_BLOCKS(A) *\
 161                                         sizeof(u64))
 162
 163 /* uid/gid lookup table defines */
 164 #define SQUASHFS_ID_BYTES(A)            ((A) * sizeof(unsigned int))
 165
 166 #define SQUASHFS_ID_BLOCK(A)            (SQUASHFS_ID_BYTES(A) / \
 167                                         SQUASHFS_METADATA_SIZE)
 168
 169 #define SQUASHFS_ID_BLOCK_OFFSET(A)     (SQUASHFS_ID_BYTES(A) % \
 170                                         SQUASHFS_METADATA_SIZE)
 171
 172 #define SQUASHFS_ID_BLOCKS(A)           ((SQUASHFS_ID_BYTES(A) + \
 173                                         SQUASHFS_METADATA_SIZE - 1) / \
 174                                         SQUASHFS_METADATA_SIZE)
 175
 176 #define SQUASHFS_ID_BLOCK_BYTES(A)      (SQUASHFS_ID_BLOCKS(A) *\
 177                                         sizeof(u64))
 178
 179 /* cached data constants for filesystem */
 180 #define SQUASHFS_CACHED_BLKS            8
 181
 182 #define SQUASHFS_MAX_FILE_SIZE_LOG      64
 183
 184 #define SQUASHFS_MAX_FILE_SIZE          (1LL << \
 185                                         (SQUASHFS_MAX_FILE_SIZE_LOG - 2))
 186
 187 #define SQUASHFS_MARKER_BYTE            0xff
 188
 189 /* meta index cache */
 190 #define SQUASHFS_META_INDEXES   (SQUASHFS_METADATA_SIZE / sizeof(unsigned int))
 191 #define SQUASHFS_META_ENTRIES   127
 192 #define SQUASHFS_META_SLOTS     8
 193
 194 struct meta_entry {
 195         u64                     data_block;
 196         unsigned int            index_block;
 197         unsigned short          offset;
 198         unsigned short          pad;
 199 };
 200
 201 struct meta_index {
 202         unsigned int            inode_number;
 203         unsigned int            offset;
 204         unsigned short          entries;
 205         unsigned short          skip;
 206         unsigned short          locked;
 207         unsigned short          pad;
 208         struct meta_entry       meta_entry[SQUASHFS_META_ENTRIES];
 209 };
 210
 211
 212 /*
 213  * definitions for structures on disk
 214  */
 215 #define ZLIB_COMPRESSION         1
 216
 217 struct squashfs_super_block {
 218         __le32                  s_magic;
 219         __le32                  inodes;
 220         __le32                  mkfs_time;
 221         __le32                  block_size;
 222         __le32                  fragments;
 223         __le16                  compression;
 224         __le16                  block_log;
 225         __le16                  flags;
 226         __le16                  no_ids;
 227         __le16                  s_major;
 228         __le16                  s_minor;
 229         __le64                  root_inode;
 230         __le64                  bytes_used;
 231         __le64                  id_table_start;
 232         __le64                  xattr_table_start;
 233         __le64                  inode_table_start;
 234         __le64                  directory_table_start;
 235         __le64                  fragment_table_start;
 236         __le64                  lookup_table_start;
 237 };
 238
 239 struct squashfs_dir_index {
 240         __le32                  index;
 241         __le32                  start_block;
 242         __le32                  size;
 243         unsigned char           name[0];
 244 };
 245
 246 struct squashfs_base_inode {
 247         __le16                  inode_type;
 248         __le16                  mode;
 249         __le16                  uid;
 250         __le16                  guid;
 251         __le32                  mtime;
 252         __le32                  inode_number;
 253 };
 254
 255 struct squashfs_ipc_inode {
 256         __le16                  inode_type;
 257         __le16                  mode;
 258         __le16                  uid;
 259         __le16                  guid;
 260         __le32                  mtime;
 261         __le32                  inode_number;
 262         __le32                  nlink;
 263 };
 264
 265 struct squashfs_dev_inode {
 266         __le16                  inode_type;
 267         __le16                  mode;
 268         __le16                  uid;
 269         __le16                  guid;
 270         __le32                  mtime;
 271         __le32                  inode_number;
 272         __le32                  nlink;
 273         __le32                  rdev;
 274 };
 275
 276 struct squashfs_symlink_inode {
 277         __le16                  inode_type;
 278         __le16                  mode;
 279         __le16                  uid;
 280         __le16                  guid;
 281         __le32                  mtime;
 282         __le32                  inode_number;
 283         __le32                  nlink;
 284         __le32                  symlink_size;
 285         char                    symlink[0];
 286 };
 287
 288 struct squashfs_reg_inode {
 289         __le16                  inode_type;
 290         __le16                  mode;
 291         __le16                  uid;
 292         __le16                  guid;
 293         __le32                  mtime;
 294         __le32                  inode_number;
 295         __le32                  start_block;
 296         __le32                  fragment;
 297         __le32                  offset;
 298         __le32                  file_size;
 299         __le16                  block_list[0];
 300 };
 301
 302 struct squashfs_lreg_inode {
 303         __le16                  inode_type;
 304         __le16                  mode;
 305         __le16                  uid;
 306         __le16                  guid;
 307         __le32                  mtime;
 308         __le32                  inode_number;
 309         __le64                  start_block;
 310         __le64                  file_size;
 311         __le64                  sparse;
 312         __le32                  nlink;
 313         __le32                  fragment;
 314         __le32                  offset;
 315         __le32                  xattr;
 316         __le16                  block_list[0];
 317 };
 318
 319 struct squashfs_dir_inode {
 320         __le16                  inode_type;
 321         __le16                  mode;
 322         __le16                  uid;
 323         __le16                  guid;
 324         __le32                  mtime;
 325         __le32                  inode_number;
 326         __le32                  start_block;
 327         __le32                  nlink;
 328         __le16                  file_size;
 329         __le16                  offset;
 330         __le32                  parent_inode;
 331 };
 332
 333 struct squashfs_ldir_inode {
 334         __le16                  inode_type;
 335         __le16                  mode;
 336         __le16                  uid;
 337         __le16                  guid;
 338         __le32                  mtime;
 339         __le32                  inode_number;
 340         __le32                  nlink;
 341         __le32                  file_size;
 342         __le32                  start_block;
 343         __le32                  parent_inode;
 344         __le16                  i_count;
 345         __le16                  offset;
 346         __le32                  xattr;
 347         struct squashfs_dir_index       index[0];
 348 };
 349
 350 union squashfs_inode {
 351         struct squashfs_base_inode              base;
 352         struct squashfs_dev_inode               dev;
 353         struct squashfs_symlink_inode           symlink;
 354         struct squashfs_reg_inode               reg;
 355         struct squashfs_lreg_inode              lreg;
 356         struct squashfs_dir_inode               dir;
 357         struct squashfs_ldir_inode              ldir;
 358         struct squashfs_ipc_inode               ipc;
 359 };
 360
 361 struct squashfs_dir_entry {
 362         __le16                  offset;
 363         __le16                  inode_number;
 364         __le16                  type;
 365         __le16                  size;
 366         char                    name[0];
 367 };
 368
 369 struct squashfs_dir_header {
 370         __le32                  count;
 371         __le32                  start_block;
 372         __le32                  inode_number;
 373 };
 374
 375 struct squashfs_fragment_entry {
 376         __le64                  start_block;
 377         __le32                  size;
 378         unsigned int            unused;
 379 };
 380
 381 #endif