fs/ubifs/ubifs-media.h

   1 /*
   2  * This file is part of UBIFS.
   3  *
   4  * Copyright (C) 2006-2008 Nokia Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published by
   8  * the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  *
  19  * Authors: Artem Bityutskiy (Битюцкий Артём)
  20  *          Adrian Hunter
  21  */
  22
  23 /*
  24  * This file describes UBIFS on-flash format and contains definitions of all the
  25  * relevant data structures and constants.
  26  *
  27  * All UBIFS on-flash objects are stored in the form of nodes. All nodes start
  28  * with the UBIFS node magic number and have the same common header. Nodes
  29  * always sit at 8-byte aligned positions on the media and node header sizes are
  30  * also 8-byte aligned (except for the indexing node and the padding node).
  31  */
  32
  33 #ifndef __UBIFS_MEDIA_H__
  34 #define __UBIFS_MEDIA_H__
  35
  36 /* UBIFS node magic number (must not have the padding byte first or last) */
  37 #define UBIFS_NODE_MAGIC  0x06101831
  38
  39 /*
  40  * UBIFS on-flash format version. This version is increased when the on-flash
  41  * format is changing. If this happens, UBIFS is will support older versions as
  42  * well. But older UBIFS code will not support newer formats. Format changes
  43  * will be rare and only when absolutely necessary, e.g. to fix a bug or to add
  44  * a new feature.
  45  *
  46  * UBIFS went into mainline kernel with format version 4. The older formats
  47  * were development formats.
  48  */
  49 #define UBIFS_FORMAT_VERSION 5
  50
  51 /*
  52  * Read-only compatibility version. If the UBIFS format is changed, older UBIFS
  53  * implementations will not be able to mount newer formats in read-write mode.
  54  * However, depending on the change, it may be possible to mount newer formats
  55  * in R/O mode. This is indicated by the R/O compatibility version which is
  56  * stored in the super-block.
  57  *
  58  * This is needed to support boot-loaders which only need R/O mounting. With
  59  * this flag it is possible to do UBIFS format changes without a need to update
  60  * boot-loaders.
  61  */
  62 #define UBIFS_RO_COMPAT_VERSION 0
  63
  64 /* Minimum logical eraseblock size in bytes */
  65 #define UBIFS_MIN_LEB_SZ (15*1024)
  66
  67 /* Initial CRC32 value used when calculating CRC checksums */
  68 #define UBIFS_CRC32_INIT 0xFFFFFFFFU
  69
  70 /*
  71  * UBIFS does not try to compress data if its length is less than the below
  72  * constant.
  73  */
  74 #define UBIFS_MIN_COMPR_LEN 128
  75
  76 /*
  77  * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
  78  * shorter than uncompressed data length, UBIFS prefers to leave this data
  79  * node uncompress, because it'll be read faster.
  80  */
  81 #define UBIFS_MIN_COMPRESS_DIFF 64
  82
  83 /* Root inode number */
  84 #define UBIFS_ROOT_INO 1
  85
  86 /* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
  87 #define UBIFS_FIRST_INO 64
  88
  89 /*
  90  * Maximum file name and extended attribute length (must be a multiple of 8,
  91  * minus 1).
  92  */
  93 #define UBIFS_MAX_NLEN 255
  94
  95 /* Maximum number of data journal heads */
  96 #define UBIFS_MAX_JHEADS 1
  97
  98 /*
  99  * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
 100  * which means that it does not treat the underlying media as consisting of
 101  * blocks like in case of hard drives. Do not be confused. UBIFS block is just
 102  * the maximum amount of data which one data node can have or which can be
 103  * attached to an inode node.
 104  */
 105 #define UBIFS_BLOCK_SIZE  4096
 106 #define UBIFS_BLOCK_SHIFT 12
 107
 108 /* UBIFS padding byte pattern (must not be first or last byte of node magic) */
 109 #define UBIFS_PADDING_BYTE 0xCE
 110
 111 /* Maximum possible key length */
 112 #define UBIFS_MAX_KEY_LEN 16
 113
 114 /* Key length ("simple" format) */
 115 #define UBIFS_SK_LEN 8
 116
 117 /* Minimum index tree fanout */
 118 #define UBIFS_MIN_FANOUT 3
 119
 120 /* Maximum number of levels in UBIFS indexing B-tree */
 121 #define UBIFS_MAX_LEVELS 512
 122
 123 /* Maximum amount of data attached to an inode in bytes */
 124 #define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
 125
 126 /* LEB Properties Tree fanout (must be power of 2) and fanout shift */
 127 #define UBIFS_LPT_FANOUT 4
 128 #define UBIFS_LPT_FANOUT_SHIFT 2
 129
 130 /* LEB Properties Tree bit field sizes */
 131 #define UBIFS_LPT_CRC_BITS 16
 132 #define UBIFS_LPT_CRC_BYTES 2
 133 #define UBIFS_LPT_TYPE_BITS 4
 134
 135 /* The key is always at the same position in all keyed nodes */
 136 #define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
 137
 138 /* Garbage collector journal head number */
 139 #define UBIFS_GC_HEAD   0
 140 /* Base journal head number */
 141 #define UBIFS_BASE_HEAD 1
 142 /* Data journal head number */
 143 #define UBIFS_DATA_HEAD 2
 144
 145 /*
 146  * LEB Properties Tree node types.
 147  *
 148  * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
 149  * UBIFS_LPT_NNODE: LPT internal node
 150  * UBIFS_LPT_LTAB: LPT's own lprops table
 151  * UBIFS_LPT_LSAVE: LPT's save table (big model only)
 152  * UBIFS_LPT_NODE_CNT: count of LPT node types
 153  * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
 154  */
 155 enum {
 156         UBIFS_LPT_PNODE,
 157         UBIFS_LPT_NNODE,
 158         UBIFS_LPT_LTAB,
 159         UBIFS_LPT_LSAVE,
 160         UBIFS_LPT_NODE_CNT,
 161         UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
 162 };
 163
 164 /*
 165  * UBIFS inode types.
 166  *
 167  * UBIFS_ITYPE_REG: regular file
 168  * UBIFS_ITYPE_DIR: directory
 169  * UBIFS_ITYPE_LNK: soft link
 170  * UBIFS_ITYPE_BLK: block device node
 171  * UBIFS_ITYPE_CHR: character device node
 172  * UBIFS_ITYPE_FIFO: fifo
 173  * UBIFS_ITYPE_SOCK: socket
 174  * UBIFS_ITYPES_CNT: count of supported file types
 175  */
 176 enum {
 177         UBIFS_ITYPE_REG,
 178         UBIFS_ITYPE_DIR,
 179         UBIFS_ITYPE_LNK,
 180         UBIFS_ITYPE_BLK,
 181         UBIFS_ITYPE_CHR,
 182         UBIFS_ITYPE_FIFO,
 183         UBIFS_ITYPE_SOCK,
 184         UBIFS_ITYPES_CNT,
 185 };
 186
 187 /*
 188  * Supported key hash functions.
 189  *
 190  * UBIFS_KEY_HASH_R5: R5 hash
 191  * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
 192  */
 193 enum {
 194         UBIFS_KEY_HASH_R5,
 195         UBIFS_KEY_HASH_TEST,
 196 };
 197
 198 /*
 199  * Supported key formats.
 200  *
 201  * UBIFS_SIMPLE_KEY_FMT: simple key format
 202  */
 203 enum {
 204         UBIFS_SIMPLE_KEY_FMT,
 205 };
 206
 207 /*
 208  * The simple key format uses 29 bits for storing UBIFS block number and hash
 209  * value.
 210  */
 211 #define UBIFS_S_KEY_BLOCK_BITS 29
 212 #define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
 213 #define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
 214 #define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
 215
 216 /*
 217  * Key types.
 218  *
 219  * UBIFS_INO_KEY: inode node key
 220  * UBIFS_DATA_KEY: data node key
 221  * UBIFS_DENT_KEY: directory entry node key
 222  * UBIFS_XENT_KEY: extended attribute entry key
 223  * UBIFS_KEY_TYPES_CNT: number of supported key types
 224  */
 225 enum {
 226         UBIFS_INO_KEY,
 227         UBIFS_DATA_KEY,
 228         UBIFS_DENT_KEY,
 229         UBIFS_XENT_KEY,
 230         UBIFS_KEY_TYPES_CNT,
 231 };
 232
 233 /* Count of LEBs reserved for the superblock area */
 234 #define UBIFS_SB_LEBS 1
 235 /* Count of LEBs reserved for the master area */
 236 #define UBIFS_MST_LEBS 2
 237
 238 /* First LEB of the superblock area */
 239 #define UBIFS_SB_LNUM 0
 240 /* First LEB of the master area */
 241 #define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
 242 /* First LEB of the log area */
 243 #define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
 244
 245 /*
 246  * The below constants define the absolute minimum values for various UBIFS
 247  * media areas. Many of them actually depend of flash geometry and the FS
 248  * configuration (number of journal heads, orphan LEBs, etc). This means that
 249  * the smallest volume size which can be used for UBIFS cannot be pre-defined
 250  * by these constants. The file-system that meets the below limitation will not
 251  * necessarily mount. UBIFS does run-time calculations and validates the FS
 252  * size.
 253  */
 254
 255 /* Minimum number of logical eraseblocks in the log */
 256 #define UBIFS_MIN_LOG_LEBS 2
 257 /* Minimum number of bud logical eraseblocks (one for each head) */
 258 #define UBIFS_MIN_BUD_LEBS 3
 259 /* Minimum number of journal logical eraseblocks */
 260 #define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
 261 /* Minimum number of LPT area logical eraseblocks */
 262 #define UBIFS_MIN_LPT_LEBS 2
 263 /* Minimum number of orphan area logical eraseblocks */
 264 #define UBIFS_MIN_ORPH_LEBS 1
 265 /*
 266  * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
 267  * for GC, 1 for deletions, and at least 1 for committed data).
 268  */
 269 #define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
 270
 271 /* Minimum number of logical eraseblocks */
 272 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
 273                            UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
 274                            UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
 275
 276 /* Node sizes (N.B. these are guaranteed to be multiples of 8) */
 277 #define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
 278 #define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
 279 #define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
 280 #define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
 281 #define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
 282 #define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
 283 #define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
 284 #define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
 285 #define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
 286 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
 287 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
 288 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
 289 /* Extended attribute entry nodes are identical to directory entry nodes */
 290 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
 291 /* Only this does not have to be multiple of 8 bytes */
 292 #define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
 293
 294 /* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
 295 #define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
 296 #define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
 297 #define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
 298 #define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
 299
 300 /* The largest UBIFS node */
 301 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
 302
 303 /*
 304  * xattr name of UBIFS encryption context, we don't use a prefix
 305  * nor a long name to not waste space on the flash.
 306  */
 307 #define UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT "c"
 308
 309
 310 /*
 311  * On-flash inode flags.
 312  *
 313  * UBIFS_COMPR_FL: use compression for this inode
 314  * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
 315  * UBIFS_IMMUTABLE_FL: inode is immutable
 316  * UBIFS_APPEND_FL: writes to the inode may only append data
 317  * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
 318  * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
 319  * UBIFS_CRYPT_FL: use encryption for this inode
 320  *
 321  * Note, these are on-flash flags which correspond to ioctl flags
 322  * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
 323  * have to be the same.
 324  */
 325 enum {
 326         UBIFS_COMPR_FL     = 0x01,
 327         UBIFS_SYNC_FL      = 0x02,
 328         UBIFS_IMMUTABLE_FL = 0x04,
 329         UBIFS_APPEND_FL    = 0x08,
 330         UBIFS_DIRSYNC_FL   = 0x10,
 331         UBIFS_XATTR_FL     = 0x20,
 332         UBIFS_CRYPT_FL     = 0x40,
 333 };
 334
 335 /* Inode flag bits used by UBIFS */
 336 #define UBIFS_FL_MASK 0x0000001F
 337
 338 /*
 339  * UBIFS compression algorithms.
 340  *
 341  * UBIFS_COMPR_NONE: no compression
 342  * UBIFS_COMPR_LZO: LZO compression
 343  * UBIFS_COMPR_ZLIB: ZLIB compression
 344  * UBIFS_COMPR_TYPES_CNT: count of supported compression types
 345  */
 346 enum {
 347         UBIFS_COMPR_NONE,
 348         UBIFS_COMPR_LZO,
 349         UBIFS_COMPR_ZLIB,
 350         UBIFS_COMPR_TYPES_CNT,
 351 };
 352
 353 /*
 354  * UBIFS node types.
 355  *
 356  * UBIFS_INO_NODE: inode node
 357  * UBIFS_DATA_NODE: data node
 358  * UBIFS_DENT_NODE: directory entry node
 359  * UBIFS_XENT_NODE: extended attribute node
 360  * UBIFS_TRUN_NODE: truncation node
 361  * UBIFS_PAD_NODE: padding node
 362  * UBIFS_SB_NODE: superblock node
 363  * UBIFS_MST_NODE: master node
 364  * UBIFS_REF_NODE: LEB reference node
 365  * UBIFS_IDX_NODE: index node
 366  * UBIFS_CS_NODE: commit start node
 367  * UBIFS_ORPH_NODE: orphan node
 368  * UBIFS_NODE_TYPES_CNT: count of supported node types
 369  *
 370  * Note, we index arrays by these numbers, so keep them low and contiguous.
 371  * Node type constants for inodes, direntries and so on have to be the same as
 372  * corresponding key type constants.
 373  */
 374 enum {
 375         UBIFS_INO_NODE,
 376         UBIFS_DATA_NODE,
 377         UBIFS_DENT_NODE,
 378         UBIFS_XENT_NODE,
 379         UBIFS_TRUN_NODE,
 380         UBIFS_PAD_NODE,
 381         UBIFS_SB_NODE,
 382         UBIFS_MST_NODE,
 383         UBIFS_REF_NODE,
 384         UBIFS_IDX_NODE,
 385         UBIFS_CS_NODE,
 386         UBIFS_ORPH_NODE,
 387         UBIFS_NODE_TYPES_CNT,
 388 };
 389
 390 /*
 391  * Master node flags.
 392  *
 393  * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
 394  * UBIFS_MST_NO_ORPHS: no orphan inodes present
 395  * UBIFS_MST_RCVRY: written by recovery
 396  */
 397 enum {
 398         UBIFS_MST_DIRTY = 1,
 399         UBIFS_MST_NO_ORPHS = 2,
 400         UBIFS_MST_RCVRY = 4,
 401 };
 402
 403 /*
 404  * Node group type (used by recovery to recover whole group or none).
 405  *
 406  * UBIFS_NO_NODE_GROUP: this node is not part of a group
 407  * UBIFS_IN_NODE_GROUP: this node is a part of a group
 408  * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
 409  */
 410 enum {
 411         UBIFS_NO_NODE_GROUP = 0,
 412         UBIFS_IN_NODE_GROUP,
 413         UBIFS_LAST_OF_NODE_GROUP,
 414 };
 415
 416 /*
 417  * Superblock flags.
 418  *
 419  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
 420  * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
 421  * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to
 422  *                        support 64bit cookies for lookups by hash
 423  * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files
 424  */
 425 enum {
 426         UBIFS_FLG_BIGLPT = 0x02,
 427         UBIFS_FLG_SPACE_FIXUP = 0x04,
 428         UBIFS_FLG_DOUBLE_HASH = 0x08,
 429         UBIFS_FLG_ENCRYPTION = 0x10,
 430 };
 431
 432 #define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT|UBIFS_FLG_SPACE_FIXUP|UBIFS_FLG_DOUBLE_HASH|UBIFS_FLG_ENCRYPTION)
 433
 434 /**
 435  * struct ubifs_ch - common header node.
 436  * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
 437  * @crc: CRC-32 checksum of the node header
 438  * @sqnum: sequence number
 439  * @len: full node length
 440  * @node_type: node type
 441  * @group_type: node group type
 442  * @padding: reserved for future, zeroes
 443  *
 444  * Every UBIFS node starts with this common part. If the node has a key, the
 445  * key always goes next.
 446  */
 447 struct ubifs_ch {
 448         __le32 magic;
 449         __le32 crc;
 450         __le64 sqnum;
 451         __le32 len;
 452         __u8 node_type;
 453         __u8 group_type;
 454         __u8 padding[2];
 455 } __packed;
 456
 457 /**
 458  * union ubifs_dev_desc - device node descriptor.
 459  * @new: new type device descriptor
 460  * @huge: huge type device descriptor
 461  *
 462  * This data structure describes major/minor numbers of a device node. In an
 463  * inode is a device node then its data contains an object of this type. UBIFS
 464  * uses standard Linux "new" and "huge" device node encodings.
 465  */
 466 union ubifs_dev_desc {
 467         __le32 new;
 468         __le64 huge;
 469 } __packed;
 470
 471 /**
 472  * struct ubifs_ino_node - inode node.
 473  * @ch: common header
 474  * @key: node key
 475  * @creat_sqnum: sequence number at time of creation
 476  * @size: inode size in bytes (amount of uncompressed data)
 477  * @atime_sec: access time seconds
 478  * @ctime_sec: creation time seconds
 479  * @mtime_sec: modification time seconds
 480  * @atime_nsec: access time nanoseconds
 481  * @ctime_nsec: creation time nanoseconds
 482  * @mtime_nsec: modification time nanoseconds
 483  * @nlink: number of hard links
 484  * @uid: owner ID
 485  * @gid: group ID
 486  * @mode: access flags
 487  * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
 488  * @data_len: inode data length
 489  * @xattr_cnt: count of extended attributes this inode has
 490  * @xattr_size: summarized size of all extended attributes in bytes
 491  * @padding1: reserved for future, zeroes
 492  * @xattr_names: sum of lengths of all extended attribute names belonging to
 493  *               this inode
 494  * @compr_type: compression type used for this inode
 495  * @padding2: reserved for future, zeroes
 496  * @data: data attached to the inode
 497  *
 498  * Note, even though inode compression type is defined by @compr_type, some
 499  * nodes of this inode may be compressed with different compressor - this
 500  * happens if compression type is changed while the inode already has data
 501  * nodes. But @compr_type will be use for further writes to the inode.
 502  *
 503  * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
 504  * the padding fields.
 505  */
 506 struct ubifs_ino_node {
 507         struct ubifs_ch ch;
 508         __u8 key[UBIFS_MAX_KEY_LEN];
 509         __le64 creat_sqnum;
 510         __le64 size;
 511         __le64 atime_sec;
 512         __le64 ctime_sec;
 513         __le64 mtime_sec;
 514         __le32 atime_nsec;
 515         __le32 ctime_nsec;
 516         __le32 mtime_nsec;
 517         __le32 nlink;
 518         __le32 uid;
 519         __le32 gid;
 520         __le32 mode;
 521         __le32 flags;
 522         __le32 data_len;
 523         __le32 xattr_cnt;
 524         __le32 xattr_size;
 525         __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
 526         __le32 xattr_names;
 527         __le16 compr_type;
 528         __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
 529         __u8 data[];
 530 } __packed;
 531
 532 /**
 533  * struct ubifs_dent_node - directory entry node.
 534  * @ch: common header
 535  * @key: node key
 536  * @inum: target inode number
 537  * @padding1: reserved for future, zeroes
 538  * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
 539  * @nlen: name length
 540  * @cookie: A 32bits random number, used to construct a 64bits
 541  *          identifier.
 542  * @name: zero-terminated name
 543  *
 544  * Note, do not forget to amend 'zero_dent_node_unused()' function when
 545  * changing the padding fields.
 546  */
 547 struct ubifs_dent_node {
 548         struct ubifs_ch ch;
 549         __u8 key[UBIFS_MAX_KEY_LEN];
 550         __le64 inum;
 551         __u8 padding1;
 552         __u8 type;
 553         __le16 nlen;
 554         __le32 cookie;
 555         __u8 name[];
 556 } __packed;
 557
 558 /**
 559  * struct ubifs_data_node - data node.
 560  * @ch: common header
 561  * @key: node key
 562  * @size: uncompressed data size in bytes
 563  * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
 564  * @compr_size: compressed data size in bytes, only valid when data is encrypted
 565  * @data: data
 566  *
 567  */
 568 struct ubifs_data_node {
 569         struct ubifs_ch ch;
 570         __u8 key[UBIFS_MAX_KEY_LEN];
 571         __le32 size;
 572         __le16 compr_type;
 573         __le16 compr_size;
 574         __u8 data[];
 575 } __packed;
 576
 577 /**
 578  * struct ubifs_trun_node - truncation node.
 579  * @ch: common header
 580  * @inum: truncated inode number
 581  * @padding: reserved for future, zeroes
 582  * @old_size: size before truncation
 583  * @new_size: size after truncation
 584  *
 585  * This node exists only in the journal and never goes to the main area. Note,
 586  * do not forget to amend 'zero_trun_node_unused()' function when changing the
 587  * padding fields.
 588  */
 589 struct ubifs_trun_node {
 590         struct ubifs_ch ch;
 591         __le32 inum;
 592         __u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
 593         __le64 old_size;
 594         __le64 new_size;
 595 } __packed;
 596
 597 /**
 598  * struct ubifs_pad_node - padding node.
 599  * @ch: common header
 600  * @pad_len: how many bytes after this node are unused (because padded)
 601  * @padding: reserved for future, zeroes
 602  */
 603 struct ubifs_pad_node {
 604         struct ubifs_ch ch;
 605         __le32 pad_len;
 606 } __packed;
 607
 608 /**
 609  * struct ubifs_sb_node - superblock node.
 610  * @ch: common header
 611  * @padding: reserved for future, zeroes
 612  * @key_hash: type of hash function used in keys
 613  * @key_fmt: format of the key
 614  * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
 615  * @min_io_size: minimal input/output unit size
 616  * @leb_size: logical eraseblock size in bytes
 617  * @leb_cnt: count of LEBs used by file-system
 618  * @max_leb_cnt: maximum count of LEBs used by file-system
 619  * @max_bud_bytes: maximum amount of data stored in buds
 620  * @log_lebs: log size in logical eraseblocks
 621  * @lpt_lebs: number of LEBs used for lprops table
 622  * @orph_lebs: number of LEBs used for recording orphans
 623  * @jhead_cnt: count of journal heads
 624  * @fanout: tree fanout (max. number of links per indexing node)
 625  * @lsave_cnt: number of LEB numbers in LPT's save table
 626  * @fmt_version: UBIFS on-flash format version
 627  * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
 628  * @padding1: reserved for future, zeroes
 629  * @rp_uid: reserve pool UID
 630  * @rp_gid: reserve pool GID
 631  * @rp_size: size of the reserved pool in bytes
 632  * @padding2: reserved for future, zeroes
 633  * @time_gran: time granularity in nanoseconds
 634  * @uuid: UUID generated when the file system image was created
 635  * @ro_compat_version: UBIFS R/O compatibility version
 636  */
 637 struct ubifs_sb_node {
 638         struct ubifs_ch ch;
 639         __u8 padding[2];
 640         __u8 key_hash;
 641         __u8 key_fmt;
 642         __le32 flags;
 643         __le32 min_io_size;
 644         __le32 leb_size;
 645         __le32 leb_cnt;
 646         __le32 max_leb_cnt;
 647         __le64 max_bud_bytes;
 648         __le32 log_lebs;
 649         __le32 lpt_lebs;
 650         __le32 orph_lebs;
 651         __le32 jhead_cnt;
 652         __le32 fanout;
 653         __le32 lsave_cnt;
 654         __le32 fmt_version;
 655         __le16 default_compr;
 656         __u8 padding1[2];
 657         __le32 rp_uid;
 658         __le32 rp_gid;
 659         __le64 rp_size;
 660         __le32 time_gran;
 661         __u8 uuid[16];
 662         __le32 ro_compat_version;
 663         __u8 padding2[3968];
 664 } __packed;
 665
 666 /**
 667  * struct ubifs_mst_node - master node.
 668  * @ch: common header
 669  * @highest_inum: highest inode number in the committed index
 670  * @cmt_no: commit number
 671  * @flags: various flags (%UBIFS_MST_DIRTY, etc)
 672  * @log_lnum: start of the log
 673  * @root_lnum: LEB number of the root indexing node
 674  * @root_offs: offset within @root_lnum
 675  * @root_len: root indexing node length
 676  * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
 677  * not reserved and should be reserved on mount)
 678  * @ihead_lnum: LEB number of index head
 679  * @ihead_offs: offset of index head
 680  * @index_size: size of index on flash
 681  * @total_free: total free space in bytes
 682  * @total_dirty: total dirty space in bytes
 683  * @total_used: total used space in bytes (includes only data LEBs)
 684  * @total_dead: total dead space in bytes (includes only data LEBs)
 685  * @total_dark: total dark space in bytes (includes only data LEBs)
 686  * @lpt_lnum: LEB number of LPT root nnode
 687  * @lpt_offs: offset of LPT root nnode
 688  * @nhead_lnum: LEB number of LPT head
 689  * @nhead_offs: offset of LPT head
 690  * @ltab_lnum: LEB number of LPT's own lprops table
 691  * @ltab_offs: offset of LPT's own lprops table
 692  * @lsave_lnum: LEB number of LPT's save table (big model only)
 693  * @lsave_offs: offset of LPT's save table (big model only)
 694  * @lscan_lnum: LEB number of last LPT scan
 695  * @empty_lebs: number of empty logical eraseblocks
 696  * @idx_lebs: number of indexing logical eraseblocks
 697  * @leb_cnt: count of LEBs used by file-system
 698  * @padding: reserved for future, zeroes
 699  */
 700 struct ubifs_mst_node {
 701         struct ubifs_ch ch;
 702         __le64 highest_inum;
 703         __le64 cmt_no;
 704         __le32 flags;
 705         __le32 log_lnum;
 706         __le32 root_lnum;
 707         __le32 root_offs;
 708         __le32 root_len;
 709         __le32 gc_lnum;
 710         __le32 ihead_lnum;
 711         __le32 ihead_offs;
 712         __le64 index_size;
 713         __le64 total_free;
 714         __le64 total_dirty;
 715         __le64 total_used;
 716         __le64 total_dead;
 717         __le64 total_dark;
 718         __le32 lpt_lnum;
 719         __le32 lpt_offs;
 720         __le32 nhead_lnum;
 721         __le32 nhead_offs;
 722         __le32 ltab_lnum;
 723         __le32 ltab_offs;
 724         __le32 lsave_lnum;
 725         __le32 lsave_offs;
 726         __le32 lscan_lnum;
 727         __le32 empty_lebs;
 728         __le32 idx_lebs;
 729         __le32 leb_cnt;
 730         __u8 padding[344];
 731 } __packed;
 732
 733 /**
 734  * struct ubifs_ref_node - logical eraseblock reference node.
 735  * @ch: common header
 736  * @lnum: the referred logical eraseblock number
 737  * @offs: start offset in the referred LEB
 738  * @jhead: journal head number
 739  * @padding: reserved for future, zeroes
 740  */
 741 struct ubifs_ref_node {
 742         struct ubifs_ch ch;
 743         __le32 lnum;
 744         __le32 offs;
 745         __le32 jhead;
 746         __u8 padding[28];
 747 } __packed;
 748
 749 /**
 750  * struct ubifs_branch - key/reference/length branch
 751  * @lnum: LEB number of the target node
 752  * @offs: offset within @lnum
 753  * @len: target node length
 754  * @key: key
 755  */
 756 struct ubifs_branch {
 757         __le32 lnum;
 758         __le32 offs;
 759         __le32 len;
 760         __u8 key[];
 761 } __packed;
 762
 763 /**
 764  * struct ubifs_idx_node - indexing node.
 765  * @ch: common header
 766  * @child_cnt: number of child index nodes
 767  * @level: tree level
 768  * @branches: LEB number / offset / length / key branches
 769  */
 770 struct ubifs_idx_node {
 771         struct ubifs_ch ch;
 772         __le16 child_cnt;
 773         __le16 level;
 774         __u8 branches[];
 775 } __packed;
 776
 777 /**
 778  * struct ubifs_cs_node - commit start node.
 779  * @ch: common header
 780  * @cmt_no: commit number
 781  */
 782 struct ubifs_cs_node {
 783         struct ubifs_ch ch;
 784         __le64 cmt_no;
 785 } __packed;
 786
 787 /**
 788  * struct ubifs_orph_node - orphan node.
 789  * @ch: common header
 790  * @cmt_no: commit number (also top bit is set on the last node of the commit)
 791  * @inos: inode numbers of orphans
 792  */
 793 struct ubifs_orph_node {
 794         struct ubifs_ch ch;
 795         __le64 cmt_no;
 796         __le64 inos[];
 797 } __packed;
 798
 799 #endif /* __UBIFS_MEDIA_H__ */