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_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
 193 struct meta_entry {
 194         u64                     data_block;
 195         unsigned int            index_block;
 196         unsigned short          offset;
 197         unsigned short          pad;
 198 };
 199
 200 struct 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
 216 struct 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
 238 struct squashfs_dir_index {
 239         __le32                  index;
 240         __le32                  start_block;
 241         __le32                  size;
 242         unsigned char           name[0];
 243 };
 244
 245 struct 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
 254 struct 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
 264 struct 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
 275 struct 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
 287 struct 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
 301 struct 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
 318 struct 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
 332 struct 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
 349 union 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
 360 struct squashfs_dir_entry {
 361         __le16                  offset;
 362         __le16                  inode_number;
 363         __le16                  type;
 364         __le16                  size;
 365         char                    name[0];
 366 };
 367
 368 struct squashfs_dir_header {
 369         __le32                  count;
 370         __le32                  start_block;
 371         __le32                  inode_number;
 372 };
 373
 374 struct squashfs_fragment_entry {
 375         __le64                  start_block;
 376         __le32                  size;
 377         unsigned int            unused;
 378 };
 379
 380 #endif