fs/ubifs/ubifs-media.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * This file is part of UBIFS.
   4  *
   5  * Copyright (C) 2006-2008 Nokia Corporation.
   6  *
   7  * Authors: Artem Bityutskiy (Битюцкий Артём)
   8  *          Adrian Hunter
   9  */
  10
  11 /*
  12  * This file describes UBIFS on-flash format and contains definitions of all the
  13  * relevant data structures and constants.
  14  *
  15  * All UBIFS on-flash objects are stored in the form of nodes. All nodes start
  16  * with the UBIFS node magic number and have the same common header. Nodes
  17  * always sit at 8-byte aligned positions on the media and node header sizes are
  18  * also 8-byte aligned (except for the indexing node and the padding node).
  19  */
  20
  21 #ifndef __UBIFS_MEDIA_H__
  22 #define __UBIFS_MEDIA_H__
  23
  24 /* UBIFS node magic number (must not have the padding byte first or last) */
  25 #define UBIFS_NODE_MAGIC  0x06101831
  26
  27 /*
  28  * UBIFS on-flash format version. This version is increased when the on-flash
  29  * format is changing. If this happens, UBIFS is will support older versions as
  30  * well. But older UBIFS code will not support newer formats. Format changes
  31  * will be rare and only when absolutely necessary, e.g. to fix a bug or to add
  32  * a new feature.
  33  *
  34  * UBIFS went into mainline kernel with format version 4. The older formats
  35  * were development formats.
  36  */
  37 #define UBIFS_FORMAT_VERSION 5
  38
  39 /*
  40  * Read-only compatibility version. If the UBIFS format is changed, older UBIFS
  41  * implementations will not be able to mount newer formats in read-write mode.
  42  * However, depending on the change, it may be possible to mount newer formats
  43  * in R/O mode. This is indicated by the R/O compatibility version which is
  44  * stored in the super-block.
  45  *
  46  * This is needed to support boot-loaders which only need R/O mounting. With
  47  * this flag it is possible to do UBIFS format changes without a need to update
  48  * boot-loaders.
  49  */
  50 #define UBIFS_RO_COMPAT_VERSION 0
  51
  52 /* Minimum logical eraseblock size in bytes */
  53 #define UBIFS_MIN_LEB_SZ (15*1024)
  54
  55 /* Initial CRC32 value used when calculating CRC checksums */
  56 #define UBIFS_CRC32_INIT 0xFFFFFFFFU
  57
  58 /*
  59  * UBIFS does not try to compress data if its length is less than the below
  60  * constant.
  61  */
  62 #define UBIFS_MIN_COMPR_LEN 128
  63
  64 /*
  65  * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
  66  * shorter than uncompressed data length, UBIFS prefers to leave this data
  67  * node uncompress, because it'll be read faster.
  68  */
  69 #define UBIFS_MIN_COMPRESS_DIFF 64
  70
  71 /* Root inode number */
  72 #define UBIFS_ROOT_INO 1
  73
  74 /* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
  75 #define UBIFS_FIRST_INO 64
  76
  77 /*
  78  * Maximum file name and extended attribute length (must be a multiple of 8,
  79  * minus 1).
  80  */
  81 #define UBIFS_MAX_NLEN 255
  82
  83 /* Maximum number of data journal heads */
  84 #define UBIFS_MAX_JHEADS 1
  85
  86 /*
  87  * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
  88  * which means that it does not treat the underlying media as consisting of
  89  * blocks like in case of hard drives. Do not be confused. UBIFS block is just
  90  * the maximum amount of data which one data node can have or which can be
  91  * attached to an inode node.
  92  */
  93 #define UBIFS_BLOCK_SIZE  4096
  94 #define UBIFS_BLOCK_SHIFT 12
  95
  96 /* UBIFS padding byte pattern (must not be first or last byte of node magic) */
  97 #define UBIFS_PADDING_BYTE 0xCE
  98
  99 /* Maximum possible key length */
 100 #define UBIFS_MAX_KEY_LEN 16
 101
 102 /* Key length ("simple" format) */
 103 #define UBIFS_SK_LEN 8
 104
 105 /* Minimum index tree fanout */
 106 #define UBIFS_MIN_FANOUT 3
 107
 108 /* Maximum number of levels in UBIFS indexing B-tree */
 109 #define UBIFS_MAX_LEVELS 512
 110
 111 /* Maximum amount of data attached to an inode in bytes */
 112 #define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
 113
 114 /* LEB Properties Tree fanout (must be power of 2) and fanout shift */
 115 #define UBIFS_LPT_FANOUT 4
 116 #define UBIFS_LPT_FANOUT_SHIFT 2
 117
 118 /* LEB Properties Tree bit field sizes */
 119 #define UBIFS_LPT_CRC_BITS 16
 120 #define UBIFS_LPT_CRC_BYTES 2
 121 #define UBIFS_LPT_TYPE_BITS 4
 122
 123 /* The key is always at the same position in all keyed nodes */
 124 #define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
 125
 126 /* Garbage collector journal head number */
 127 #define UBIFS_GC_HEAD   0
 128 /* Base journal head number */
 129 #define UBIFS_BASE_HEAD 1
 130 /* Data journal head number */
 131 #define UBIFS_DATA_HEAD 2
 132
 133 /*
 134  * LEB Properties Tree node types.
 135  *
 136  * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
 137  * UBIFS_LPT_NNODE: LPT internal node
 138  * UBIFS_LPT_LTAB: LPT's own lprops table
 139  * UBIFS_LPT_LSAVE: LPT's save table (big model only)
 140  * UBIFS_LPT_NODE_CNT: count of LPT node types
 141  * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
 142  */
 143 enum {
 144         UBIFS_LPT_PNODE,
 145         UBIFS_LPT_NNODE,
 146         UBIFS_LPT_LTAB,
 147         UBIFS_LPT_LSAVE,
 148         UBIFS_LPT_NODE_CNT,
 149         UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
 150 };
 151
 152 /*
 153  * UBIFS inode types.
 154  *
 155  * UBIFS_ITYPE_REG: regular file
 156  * UBIFS_ITYPE_DIR: directory
 157  * UBIFS_ITYPE_LNK: soft link
 158  * UBIFS_ITYPE_BLK: block device node
 159  * UBIFS_ITYPE_CHR: character device node
 160  * UBIFS_ITYPE_FIFO: fifo
 161  * UBIFS_ITYPE_SOCK: socket
 162  * UBIFS_ITYPES_CNT: count of supported file types
 163  */
 164 enum {
 165         UBIFS_ITYPE_REG,
 166         UBIFS_ITYPE_DIR,
 167         UBIFS_ITYPE_LNK,
 168         UBIFS_ITYPE_BLK,
 169         UBIFS_ITYPE_CHR,
 170         UBIFS_ITYPE_FIFO,
 171         UBIFS_ITYPE_SOCK,
 172         UBIFS_ITYPES_CNT,
 173 };
 174
 175 /*
 176  * Supported key hash functions.
 177  *
 178  * UBIFS_KEY_HASH_R5: R5 hash
 179  * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
 180  */
 181 enum {
 182         UBIFS_KEY_HASH_R5,
 183         UBIFS_KEY_HASH_TEST,
 184 };
 185
 186 /*
 187  * Supported key formats.
 188  *
 189  * UBIFS_SIMPLE_KEY_FMT: simple key format
 190  */
 191 enum {
 192         UBIFS_SIMPLE_KEY_FMT,
 193 };
 194
 195 /*
 196  * The simple key format uses 29 bits for storing UBIFS block number and hash
 197  * value.
 198  */
 199 #define UBIFS_S_KEY_BLOCK_BITS 29
 200 #define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
 201 #define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
 202 #define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
 203
 204 /*
 205  * Key types.
 206  *
 207  * UBIFS_INO_KEY: inode node key
 208  * UBIFS_DATA_KEY: data node key
 209  * UBIFS_DENT_KEY: directory entry node key
 210  * UBIFS_XENT_KEY: extended attribute entry key
 211  * UBIFS_KEY_TYPES_CNT: number of supported key types
 212  */
 213 enum {
 214         UBIFS_INO_KEY,
 215         UBIFS_DATA_KEY,
 216         UBIFS_DENT_KEY,
 217         UBIFS_XENT_KEY,
 218         UBIFS_KEY_TYPES_CNT,
 219 };
 220
 221 /* Count of LEBs reserved for the superblock area */
 222 #define UBIFS_SB_LEBS 1
 223 /* Count of LEBs reserved for the master area */
 224 #define UBIFS_MST_LEBS 2
 225
 226 /* First LEB of the superblock area */
 227 #define UBIFS_SB_LNUM 0
 228 /* First LEB of the master area */
 229 #define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
 230 /* First LEB of the log area */
 231 #define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
 232
 233 /*
 234  * The below constants define the absolute minimum values for various UBIFS
 235  * media areas. Many of them actually depend of flash geometry and the FS
 236  * configuration (number of journal heads, orphan LEBs, etc). This means that
 237  * the smallest volume size which can be used for UBIFS cannot be pre-defined
 238  * by these constants. The file-system that meets the below limitation will not
 239  * necessarily mount. UBIFS does run-time calculations and validates the FS
 240  * size.
 241  */
 242
 243 /* Minimum number of logical eraseblocks in the log */
 244 #define UBIFS_MIN_LOG_LEBS 2
 245 /* Minimum number of bud logical eraseblocks (one for each head) */
 246 #define UBIFS_MIN_BUD_LEBS 3
 247 /* Minimum number of journal logical eraseblocks */
 248 #define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
 249 /* Minimum number of LPT area logical eraseblocks */
 250 #define UBIFS_MIN_LPT_LEBS 2
 251 /* Minimum number of orphan area logical eraseblocks */
 252 #define UBIFS_MIN_ORPH_LEBS 1
 253 /*
 254  * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
 255  * for GC, 1 for deletions, and at least 1 for committed data).
 256  */
 257 #define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
 258
 259 /* Minimum number of logical eraseblocks */
 260 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
 261                            UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
 262                            UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
 263
 264 /* Node sizes (N.B. these are guaranteed to be multiples of 8) */
 265 #define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
 266 #define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
 267 #define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
 268 #define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
 269 #define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
 270 #define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
 271 #define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
 272 #define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
 273 #define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
 274 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
 275 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
 276 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
 277 #define UBIFS_AUTH_NODE_SZ sizeof(struct ubifs_auth_node)
 278 #define UBIFS_SIG_NODE_SZ  sizeof(struct ubifs_sig_node)
 279
 280 /* Extended attribute entry nodes are identical to directory entry nodes */
 281 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
 282 /* Only this does not have to be multiple of 8 bytes */
 283 #define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
 284
 285 /* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
 286 #define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
 287 #define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
 288 #define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
 289 #define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
 290
 291 /* The largest UBIFS node */
 292 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
 293
 294 /* The maxmimum size of a hash, enough for sha512 */
 295 #define UBIFS_MAX_HASH_LEN 64
 296
 297 /* The maxmimum size of a hmac, enough for hmac(sha512) */
 298 #define UBIFS_MAX_HMAC_LEN 64
 299
 300 /*
 301  * xattr name of UBIFS encryption context, we don't use a prefix
 302  * nor a long name to not waste space on the flash.
 303  */
 304 #define UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT "c"
 305
 306 /* Type field in ubifs_sig_node */
 307 #define UBIFS_SIGNATURE_TYPE_PKCS7      1
 308
 309 /*
 310  * On-flash inode flags.
 311  *
 312  * UBIFS_COMPR_FL: use compression for this inode
 313  * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
 314  * UBIFS_IMMUTABLE_FL: inode is immutable
 315  * UBIFS_APPEND_FL: writes to the inode may only append data
 316  * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
 317  * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
 318  * UBIFS_CRYPT_FL: use encryption for this inode
 319  *
 320  * Note, these are on-flash flags which correspond to ioctl flags
 321  * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
 322  * have to be the same.
 323  */
 324 enum {
 325         UBIFS_COMPR_FL     = 0x01,
 326         UBIFS_SYNC_FL      = 0x02,
 327         UBIFS_IMMUTABLE_FL = 0x04,
 328         UBIFS_APPEND_FL    = 0x08,
 329         UBIFS_DIRSYNC_FL   = 0x10,
 330         UBIFS_XATTR_FL     = 0x20,
 331         UBIFS_CRYPT_FL     = 0x40,
 332 };
 333
 334 /* Inode flag bits used by UBIFS */
 335 #define UBIFS_FL_MASK 0x0000001F
 336
 337 /*
 338  * UBIFS compression algorithms.
 339  *
 340  * UBIFS_COMPR_NONE: no compression
 341  * UBIFS_COMPR_LZO: LZO compression
 342  * UBIFS_COMPR_ZLIB: ZLIB compression
 343  * UBIFS_COMPR_ZSTD: ZSTD 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_ZSTD,
 351         UBIFS_COMPR_TYPES_CNT,
 352 };
 353
 354 /*
 355  * UBIFS node types.
 356  *
 357  * UBIFS_INO_NODE: inode node
 358  * UBIFS_DATA_NODE: data node
 359  * UBIFS_DENT_NODE: directory entry node
 360  * UBIFS_XENT_NODE: extended attribute node
 361  * UBIFS_TRUN_NODE: truncation node
 362  * UBIFS_PAD_NODE: padding node
 363  * UBIFS_SB_NODE: superblock node
 364  * UBIFS_MST_NODE: master node
 365  * UBIFS_REF_NODE: LEB reference node
 366  * UBIFS_IDX_NODE: index node
 367  * UBIFS_CS_NODE: commit start node
 368  * UBIFS_ORPH_NODE: orphan node
 369  * UBIFS_AUTH_NODE: authentication node
 370  * UBIFS_SIG_NODE: signature node
 371  * UBIFS_NODE_TYPES_CNT: count of supported node types
 372  *
 373  * Note, we index arrays by these numbers, so keep them low and contiguous.
 374  * Node type constants for inodes, direntries and so on have to be the same as
 375  * corresponding key type constants.
 376  */
 377 enum {
 378         UBIFS_INO_NODE,
 379         UBIFS_DATA_NODE,
 380         UBIFS_DENT_NODE,
 381         UBIFS_XENT_NODE,
 382         UBIFS_TRUN_NODE,
 383         UBIFS_PAD_NODE,
 384         UBIFS_SB_NODE,
 385         UBIFS_MST_NODE,
 386         UBIFS_REF_NODE,
 387         UBIFS_IDX_NODE,
 388         UBIFS_CS_NODE,
 389         UBIFS_ORPH_NODE,
 390         UBIFS_AUTH_NODE,
 391         UBIFS_SIG_NODE,
 392         UBIFS_NODE_TYPES_CNT,
 393 };
 394
 395 /*
 396  * Master node flags.
 397  *
 398  * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
 399  * UBIFS_MST_NO_ORPHS: no orphan inodes present
 400  * UBIFS_MST_RCVRY: written by recovery
 401  */
 402 enum {
 403         UBIFS_MST_DIRTY = 1,
 404         UBIFS_MST_NO_ORPHS = 2,
 405         UBIFS_MST_RCVRY = 4,
 406 };
 407
 408 /*
 409  * Node group type (used by recovery to recover whole group or none).
 410  *
 411  * UBIFS_NO_NODE_GROUP: this node is not part of a group
 412  * UBIFS_IN_NODE_GROUP: this node is a part of a group
 413  * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
 414  */
 415 enum {
 416         UBIFS_NO_NODE_GROUP = 0,
 417         UBIFS_IN_NODE_GROUP,
 418         UBIFS_LAST_OF_NODE_GROUP,
 419 };
 420
 421 /*
 422  * Superblock flags.
 423  *
 424  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
 425  * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
 426  * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to
 427  *                        support 64bit cookies for lookups by hash
 428  * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files
 429  * UBIFS_FLG_AUTHENTICATION: this filesystem contains hashes for authentication
 430  */
 431 enum {
 432         UBIFS_FLG_BIGLPT = 0x02,
 433         UBIFS_FLG_SPACE_FIXUP = 0x04,
 434         UBIFS_FLG_DOUBLE_HASH = 0x08,
 435         UBIFS_FLG_ENCRYPTION = 0x10,
 436         UBIFS_FLG_AUTHENTICATION = 0x20,
 437 };
 438
 439 #define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT | UBIFS_FLG_SPACE_FIXUP | \
 440                 UBIFS_FLG_DOUBLE_HASH | UBIFS_FLG_ENCRYPTION | \
 441                 UBIFS_FLG_AUTHENTICATION)
 442
 443 /**
 444  * struct ubifs_ch - common header node.
 445  * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
 446  * @crc: CRC-32 checksum of the node header
 447  * @sqnum: sequence number
 448  * @len: full node length
 449  * @node_type: node type
 450  * @group_type: node group type
 451  * @padding: reserved for future, zeroes
 452  *
 453  * Every UBIFS node starts with this common part. If the node has a key, the
 454  * key always goes next.
 455  */
 456 struct ubifs_ch {
 457         __le32 magic;
 458         __le32 crc;
 459         __le64 sqnum;
 460         __le32 len;
 461         __u8 node_type;
 462         __u8 group_type;
 463         __u8 padding[2];
 464 } __packed;
 465
 466 /**
 467  * union ubifs_dev_desc - device node descriptor.
 468  * @new: new type device descriptor
 469  * @huge: huge type device descriptor
 470  *
 471  * This data structure describes major/minor numbers of a device node. In an
 472  * inode is a device node then its data contains an object of this type. UBIFS
 473  * uses standard Linux "new" and "huge" device node encodings.
 474  */
 475 union ubifs_dev_desc {
 476         __le32 new;
 477         __le64 huge;
 478 } __packed;
 479
 480 /**
 481  * struct ubifs_ino_node - inode node.
 482  * @ch: common header
 483  * @key: node key
 484  * @creat_sqnum: sequence number at time of creation
 485  * @size: inode size in bytes (amount of uncompressed data)
 486  * @atime_sec: access time seconds
 487  * @ctime_sec: creation time seconds
 488  * @mtime_sec: modification time seconds
 489  * @atime_nsec: access time nanoseconds
 490  * @ctime_nsec: creation time nanoseconds
 491  * @mtime_nsec: modification time nanoseconds
 492  * @nlink: number of hard links
 493  * @uid: owner ID
 494  * @gid: group ID
 495  * @mode: access flags
 496  * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
 497  * @data_len: inode data length
 498  * @xattr_cnt: count of extended attributes this inode has
 499  * @xattr_size: summarized size of all extended attributes in bytes
 500  * @padding1: reserved for future, zeroes
 501  * @xattr_names: sum of lengths of all extended attribute names belonging to
 502  *               this inode
 503  * @compr_type: compression type used for this inode
 504  * @padding2: reserved for future, zeroes
 505  * @data: data attached to the inode
 506  *
 507  * Note, even though inode compression type is defined by @compr_type, some
 508  * nodes of this inode may be compressed with different compressor - this
 509  * happens if compression type is changed while the inode already has data
 510  * nodes. But @compr_type will be use for further writes to the inode.
 511  *
 512  * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
 513  * the padding fields.
 514  */
 515 struct ubifs_ino_node {
 516         struct ubifs_ch ch;
 517         __u8 key[UBIFS_MAX_KEY_LEN];
 518         __le64 creat_sqnum;
 519         __le64 size;
 520         __le64 atime_sec;
 521         __le64 ctime_sec;
 522         __le64 mtime_sec;
 523         __le32 atime_nsec;
 524         __le32 ctime_nsec;
 525         __le32 mtime_nsec;
 526         __le32 nlink;
 527         __le32 uid;
 528         __le32 gid;
 529         __le32 mode;
 530         __le32 flags;
 531         __le32 data_len;
 532         __le32 xattr_cnt;
 533         __le32 xattr_size;
 534         __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
 535         __le32 xattr_names;
 536         __le16 compr_type;
 537         __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
 538         __u8 data[];
 539 } __packed;
 540
 541 /**
 542  * struct ubifs_dent_node - directory entry node.
 543  * @ch: common header
 544  * @key: node key
 545  * @inum: target inode number
 546  * @padding1: reserved for future, zeroes
 547  * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
 548  * @nlen: name length
 549  * @cookie: A 32bits random number, used to construct a 64bits
 550  *          identifier.
 551  * @name: zero-terminated name
 552  *
 553  * Note, do not forget to amend 'zero_dent_node_unused()' function when
 554  * changing the padding fields.
 555  */
 556 struct ubifs_dent_node {
 557         struct ubifs_ch ch;
 558         __u8 key[UBIFS_MAX_KEY_LEN];
 559         __le64 inum;
 560         __u8 padding1;
 561         __u8 type;
 562         __le16 nlen;
 563         __le32 cookie;
 564         __u8 name[];
 565 } __packed;
 566
 567 /**
 568  * struct ubifs_data_node - data node.
 569  * @ch: common header
 570  * @key: node key
 571  * @size: uncompressed data size in bytes
 572  * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
 573  * @compr_size: compressed data size in bytes, only valid when data is encrypted
 574  * @data: data
 575  *
 576  */
 577 struct ubifs_data_node {
 578         struct ubifs_ch ch;
 579         __u8 key[UBIFS_MAX_KEY_LEN];
 580         __le32 size;
 581         __le16 compr_type;
 582         __le16 compr_size;
 583         __u8 data[];
 584 } __packed;
 585
 586 /**
 587  * struct ubifs_trun_node - truncation node.
 588  * @ch: common header
 589  * @inum: truncated inode number
 590  * @padding: reserved for future, zeroes
 591  * @old_size: size before truncation
 592  * @new_size: size after truncation
 593  *
 594  * This node exists only in the journal and never goes to the main area. Note,
 595  * do not forget to amend 'zero_trun_node_unused()' function when changing the
 596  * padding fields.
 597  */
 598 struct ubifs_trun_node {
 599         struct ubifs_ch ch;
 600         __le32 inum;
 601         __u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
 602         __le64 old_size;
 603         __le64 new_size;
 604 } __packed;
 605
 606 /**
 607  * struct ubifs_pad_node - padding node.
 608  * @ch: common header
 609  * @pad_len: how many bytes after this node are unused (because padded)
 610  * @padding: reserved for future, zeroes
 611  */
 612 struct ubifs_pad_node {
 613         struct ubifs_ch ch;
 614         __le32 pad_len;
 615 } __packed;
 616
 617 /**
 618  * struct ubifs_sb_node - superblock node.
 619  * @ch: common header
 620  * @padding: reserved for future, zeroes
 621  * @key_hash: type of hash function used in keys
 622  * @key_fmt: format of the key
 623  * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
 624  * @min_io_size: minimal input/output unit size
 625  * @leb_size: logical eraseblock size in bytes
 626  * @leb_cnt: count of LEBs used by file-system
 627  * @max_leb_cnt: maximum count of LEBs used by file-system
 628  * @max_bud_bytes: maximum amount of data stored in buds
 629  * @log_lebs: log size in logical eraseblocks
 630  * @lpt_lebs: number of LEBs used for lprops table
 631  * @orph_lebs: number of LEBs used for recording orphans
 632  * @jhead_cnt: count of journal heads
 633  * @fanout: tree fanout (max. number of links per indexing node)
 634  * @lsave_cnt: number of LEB numbers in LPT's save table
 635  * @fmt_version: UBIFS on-flash format version
 636  * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
 637  * @padding1: reserved for future, zeroes
 638  * @rp_uid: reserve pool UID
 639  * @rp_gid: reserve pool GID
 640  * @rp_size: size of the reserved pool in bytes
 641  * @padding2: reserved for future, zeroes
 642  * @time_gran: time granularity in nanoseconds
 643  * @uuid: UUID generated when the file system image was created
 644  * @ro_compat_version: UBIFS R/O compatibility version
 645  * @hmac: HMAC to authenticate the superblock node
 646  * @hmac_wkm: HMAC of a well known message (the string "UBIFS") as a convenience
 647  *            to the user to check if the correct key is passed.
 648  * @hash_algo: The hash algo used for this filesystem (one of enum hash_algo)
 649  * @hash_mst: hash of the master node, only valid for signed images in which the
 650  *            master node does not contain a hmac
 651  */
 652 struct ubifs_sb_node {
 653         struct ubifs_ch ch;
 654         __u8 padding[2];
 655         __u8 key_hash;
 656         __u8 key_fmt;
 657         __le32 flags;
 658         __le32 min_io_size;
 659         __le32 leb_size;
 660         __le32 leb_cnt;
 661         __le32 max_leb_cnt;
 662         __le64 max_bud_bytes;
 663         __le32 log_lebs;
 664         __le32 lpt_lebs;
 665         __le32 orph_lebs;
 666         __le32 jhead_cnt;
 667         __le32 fanout;
 668         __le32 lsave_cnt;
 669         __le32 fmt_version;
 670         __le16 default_compr;
 671         __u8 padding1[2];
 672         __le32 rp_uid;
 673         __le32 rp_gid;
 674         __le64 rp_size;
 675         __le32 time_gran;
 676         __u8 uuid[16];
 677         __le32 ro_compat_version;
 678         __u8 hmac[UBIFS_MAX_HMAC_LEN];
 679         __u8 hmac_wkm[UBIFS_MAX_HMAC_LEN];
 680         __le16 hash_algo;
 681         __u8 hash_mst[UBIFS_MAX_HASH_LEN];
 682         __u8 padding2[3774];
 683 } __packed;
 684
 685 /**
 686  * struct ubifs_mst_node - master node.
 687  * @ch: common header
 688  * @highest_inum: highest inode number in the committed index
 689  * @cmt_no: commit number
 690  * @flags: various flags (%UBIFS_MST_DIRTY, etc)
 691  * @log_lnum: start of the log
 692  * @root_lnum: LEB number of the root indexing node
 693  * @root_offs: offset within @root_lnum
 694  * @root_len: root indexing node length
 695  * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
 696  * not reserved and should be reserved on mount)
 697  * @ihead_lnum: LEB number of index head
 698  * @ihead_offs: offset of index head
 699  * @index_size: size of index on flash
 700  * @total_free: total free space in bytes
 701  * @total_dirty: total dirty space in bytes
 702  * @total_used: total used space in bytes (includes only data LEBs)
 703  * @total_dead: total dead space in bytes (includes only data LEBs)
 704  * @total_dark: total dark space in bytes (includes only data LEBs)
 705  * @lpt_lnum: LEB number of LPT root nnode
 706  * @lpt_offs: offset of LPT root nnode
 707  * @nhead_lnum: LEB number of LPT head
 708  * @nhead_offs: offset of LPT head
 709  * @ltab_lnum: LEB number of LPT's own lprops table
 710  * @ltab_offs: offset of LPT's own lprops table
 711  * @lsave_lnum: LEB number of LPT's save table (big model only)
 712  * @lsave_offs: offset of LPT's save table (big model only)
 713  * @lscan_lnum: LEB number of last LPT scan
 714  * @empty_lebs: number of empty logical eraseblocks
 715  * @idx_lebs: number of indexing logical eraseblocks
 716  * @leb_cnt: count of LEBs used by file-system
 717  * @hash_root_idx: the hash of the root index node
 718  * @hash_lpt: the hash of the LPT
 719  * @hmac: HMAC to authenticate the master node
 720  * @padding: reserved for future, zeroes
 721  */
 722 struct ubifs_mst_node {
 723         struct ubifs_ch ch;
 724         __le64 highest_inum;
 725         __le64 cmt_no;
 726         __le32 flags;
 727         __le32 log_lnum;
 728         __le32 root_lnum;
 729         __le32 root_offs;
 730         __le32 root_len;
 731         __le32 gc_lnum;
 732         __le32 ihead_lnum;
 733         __le32 ihead_offs;
 734         __le64 index_size;
 735         __le64 total_free;
 736         __le64 total_dirty;
 737         __le64 total_used;
 738         __le64 total_dead;
 739         __le64 total_dark;
 740         __le32 lpt_lnum;
 741         __le32 lpt_offs;
 742         __le32 nhead_lnum;
 743         __le32 nhead_offs;
 744         __le32 ltab_lnum;
 745         __le32 ltab_offs;
 746         __le32 lsave_lnum;
 747         __le32 lsave_offs;
 748         __le32 lscan_lnum;
 749         __le32 empty_lebs;
 750         __le32 idx_lebs;
 751         __le32 leb_cnt;
 752         __u8 hash_root_idx[UBIFS_MAX_HASH_LEN];
 753         __u8 hash_lpt[UBIFS_MAX_HASH_LEN];
 754         __u8 hmac[UBIFS_MAX_HMAC_LEN];
 755         __u8 padding[152];
 756 } __packed;
 757
 758 /**
 759  * struct ubifs_ref_node - logical eraseblock reference node.
 760  * @ch: common header
 761  * @lnum: the referred logical eraseblock number
 762  * @offs: start offset in the referred LEB
 763  * @jhead: journal head number
 764  * @padding: reserved for future, zeroes
 765  */
 766 struct ubifs_ref_node {
 767         struct ubifs_ch ch;
 768         __le32 lnum;
 769         __le32 offs;
 770         __le32 jhead;
 771         __u8 padding[28];
 772 } __packed;
 773
 774 /**
 775  * struct ubifs_auth_node - node for authenticating other nodes
 776  * @ch: common header
 777  * @hmac: The HMAC
 778  */
 779 struct ubifs_auth_node {
 780         struct ubifs_ch ch;
 781         __u8 hmac[];
 782 } __packed;
 783
 784 /**
 785  * struct ubifs_sig_node - node for signing other nodes
 786  * @ch: common header
 787  * @type: type of the signature, currently only UBIFS_SIGNATURE_TYPE_PKCS7
 788  * supported
 789  * @len: The length of the signature data
 790  * @padding: reserved for future, zeroes
 791  * @sig: The signature data
 792  */
 793 struct ubifs_sig_node {
 794         struct ubifs_ch ch;
 795         __le32 type;
 796         __le32 len;
 797         __u8 padding[32];
 798         __u8 sig[];
 799 } __packed;
 800
 801 /**
 802  * struct ubifs_branch - key/reference/length branch
 803  * @lnum: LEB number of the target node
 804  * @offs: offset within @lnum
 805  * @len: target node length
 806  * @key: key
 807  *
 808  * In an authenticated UBIFS we have the hash of the referenced node after @key.
 809  * This can't be added to the struct type definition because @key is a
 810  * dynamically sized element already.
 811  */
 812 struct ubifs_branch {
 813         __le32 lnum;
 814         __le32 offs;
 815         __le32 len;
 816         __u8 key[];
 817 } __packed;
 818
 819 /**
 820  * struct ubifs_idx_node - indexing node.
 821  * @ch: common header
 822  * @child_cnt: number of child index nodes
 823  * @level: tree level
 824  * @branches: LEB number / offset / length / key branches
 825  */
 826 struct ubifs_idx_node {
 827         struct ubifs_ch ch;
 828         __le16 child_cnt;
 829         __le16 level;
 830         __u8 branches[];
 831 } __packed;
 832
 833 /**
 834  * struct ubifs_cs_node - commit start node.
 835  * @ch: common header
 836  * @cmt_no: commit number
 837  */
 838 struct ubifs_cs_node {
 839         struct ubifs_ch ch;
 840         __le64 cmt_no;
 841 } __packed;
 842
 843 /**
 844  * struct ubifs_orph_node - orphan node.
 845  * @ch: common header
 846  * @cmt_no: commit number (also top bit is set on the last node of the commit)
 847  * @inos: inode numbers of orphans
 848  */
 849 struct ubifs_orph_node {
 850         struct ubifs_ch ch;
 851         __le64 cmt_no;
 852         __le64 inos[];
 853 } __packed;
 854
 855 #endif /* __UBIFS_MEDIA_H__ */