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