linux/fs/ubifs/ubifs-media.h
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   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 4
  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 */
 155enum {
 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 */
 176enum {
 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 */
 193enum {
 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 */
 203enum {
 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 */
 225enum {
 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 * On-flash inode flags.
 305 *
 306 * UBIFS_COMPR_FL: use compression for this inode
 307 * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
 308 * UBIFS_IMMUTABLE_FL: inode is immutable
 309 * UBIFS_APPEND_FL: writes to the inode may only append data
 310 * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
 311 * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
 312 *
 313 * Note, these are on-flash flags which correspond to ioctl flags
 314 * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
 315 * have to be the same.
 316 */
 317enum {
 318        UBIFS_COMPR_FL     = 0x01,
 319        UBIFS_SYNC_FL      = 0x02,
 320        UBIFS_IMMUTABLE_FL = 0x04,
 321        UBIFS_APPEND_FL    = 0x08,
 322        UBIFS_DIRSYNC_FL   = 0x10,
 323        UBIFS_XATTR_FL     = 0x20,
 324};
 325
 326/* Inode flag bits used by UBIFS */
 327#define UBIFS_FL_MASK 0x0000001F
 328
 329/*
 330 * UBIFS compression algorithms.
 331 *
 332 * UBIFS_COMPR_NONE: no compression
 333 * UBIFS_COMPR_LZO: LZO compression
 334 * UBIFS_COMPR_ZLIB: ZLIB compression
 335 * UBIFS_COMPR_TYPES_CNT: count of supported compression types
 336 */
 337enum {
 338        UBIFS_COMPR_NONE,
 339        UBIFS_COMPR_LZO,
 340        UBIFS_COMPR_ZLIB,
 341        UBIFS_COMPR_TYPES_CNT,
 342};
 343
 344/*
 345 * UBIFS node types.
 346 *
 347 * UBIFS_INO_NODE: inode node
 348 * UBIFS_DATA_NODE: data node
 349 * UBIFS_DENT_NODE: directory entry node
 350 * UBIFS_XENT_NODE: extended attribute node
 351 * UBIFS_TRUN_NODE: truncation node
 352 * UBIFS_PAD_NODE: padding node
 353 * UBIFS_SB_NODE: superblock node
 354 * UBIFS_MST_NODE: master node
 355 * UBIFS_REF_NODE: LEB reference node
 356 * UBIFS_IDX_NODE: index node
 357 * UBIFS_CS_NODE: commit start node
 358 * UBIFS_ORPH_NODE: orphan node
 359 * UBIFS_NODE_TYPES_CNT: count of supported node types
 360 *
 361 * Note, we index arrays by these numbers, so keep them low and contiguous.
 362 * Node type constants for inodes, direntries and so on have to be the same as
 363 * corresponding key type constants.
 364 */
 365enum {
 366        UBIFS_INO_NODE,
 367        UBIFS_DATA_NODE,
 368        UBIFS_DENT_NODE,
 369        UBIFS_XENT_NODE,
 370        UBIFS_TRUN_NODE,
 371        UBIFS_PAD_NODE,
 372        UBIFS_SB_NODE,
 373        UBIFS_MST_NODE,
 374        UBIFS_REF_NODE,
 375        UBIFS_IDX_NODE,
 376        UBIFS_CS_NODE,
 377        UBIFS_ORPH_NODE,
 378        UBIFS_NODE_TYPES_CNT,
 379};
 380
 381/*
 382 * Master node flags.
 383 *
 384 * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
 385 * UBIFS_MST_NO_ORPHS: no orphan inodes present
 386 * UBIFS_MST_RCVRY: written by recovery
 387 */
 388enum {
 389        UBIFS_MST_DIRTY = 1,
 390        UBIFS_MST_NO_ORPHS = 2,
 391        UBIFS_MST_RCVRY = 4,
 392};
 393
 394/*
 395 * Node group type (used by recovery to recover whole group or none).
 396 *
 397 * UBIFS_NO_NODE_GROUP: this node is not part of a group
 398 * UBIFS_IN_NODE_GROUP: this node is a part of a group
 399 * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
 400 */
 401enum {
 402        UBIFS_NO_NODE_GROUP = 0,
 403        UBIFS_IN_NODE_GROUP,
 404        UBIFS_LAST_OF_NODE_GROUP,
 405};
 406
 407/*
 408 * Superblock flags.
 409 *
 410 * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
 411 * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
 412 */
 413enum {
 414        UBIFS_FLG_BIGLPT = 0x02,
 415        UBIFS_FLG_SPACE_FIXUP = 0x04,
 416};
 417
 418/**
 419 * struct ubifs_ch - common header node.
 420 * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
 421 * @crc: CRC-32 checksum of the node header
 422 * @sqnum: sequence number
 423 * @len: full node length
 424 * @node_type: node type
 425 * @group_type: node group type
 426 * @padding: reserved for future, zeroes
 427 *
 428 * Every UBIFS node starts with this common part. If the node has a key, the
 429 * key always goes next.
 430 */
 431struct ubifs_ch {
 432        __le32 magic;
 433        __le32 crc;
 434        __le64 sqnum;
 435        __le32 len;
 436        __u8 node_type;
 437        __u8 group_type;
 438        __u8 padding[2];
 439} __packed;
 440
 441/**
 442 * union ubifs_dev_desc - device node descriptor.
 443 * @new: new type device descriptor
 444 * @huge: huge type device descriptor
 445 *
 446 * This data structure describes major/minor numbers of a device node. In an
 447 * inode is a device node then its data contains an object of this type. UBIFS
 448 * uses standard Linux "new" and "huge" device node encodings.
 449 */
 450union ubifs_dev_desc {
 451        __le32 new;
 452        __le64 huge;
 453} __packed;
 454
 455/**
 456 * struct ubifs_ino_node - inode node.
 457 * @ch: common header
 458 * @key: node key
 459 * @creat_sqnum: sequence number at time of creation
 460 * @size: inode size in bytes (amount of uncompressed data)
 461 * @atime_sec: access time seconds
 462 * @ctime_sec: creation time seconds
 463 * @mtime_sec: modification time seconds
 464 * @atime_nsec: access time nanoseconds
 465 * @ctime_nsec: creation time nanoseconds
 466 * @mtime_nsec: modification time nanoseconds
 467 * @nlink: number of hard links
 468 * @uid: owner ID
 469 * @gid: group ID
 470 * @mode: access flags
 471 * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
 472 * @data_len: inode data length
 473 * @xattr_cnt: count of extended attributes this inode has
 474 * @xattr_size: summarized size of all extended attributes in bytes
 475 * @padding1: reserved for future, zeroes
 476 * @xattr_names: sum of lengths of all extended attribute names belonging to
 477 *               this inode
 478 * @compr_type: compression type used for this inode
 479 * @padding2: reserved for future, zeroes
 480 * @data: data attached to the inode
 481 *
 482 * Note, even though inode compression type is defined by @compr_type, some
 483 * nodes of this inode may be compressed with different compressor - this
 484 * happens if compression type is changed while the inode already has data
 485 * nodes. But @compr_type will be use for further writes to the inode.
 486 *
 487 * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
 488 * the padding fields.
 489 */
 490struct ubifs_ino_node {
 491        struct ubifs_ch ch;
 492        __u8 key[UBIFS_MAX_KEY_LEN];
 493        __le64 creat_sqnum;
 494        __le64 size;
 495        __le64 atime_sec;
 496        __le64 ctime_sec;
 497        __le64 mtime_sec;
 498        __le32 atime_nsec;
 499        __le32 ctime_nsec;
 500        __le32 mtime_nsec;
 501        __le32 nlink;
 502        __le32 uid;
 503        __le32 gid;
 504        __le32 mode;
 505        __le32 flags;
 506        __le32 data_len;
 507        __le32 xattr_cnt;
 508        __le32 xattr_size;
 509        __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
 510        __le32 xattr_names;
 511        __le16 compr_type;
 512        __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
 513        __u8 data[];
 514} __packed;
 515
 516/**
 517 * struct ubifs_dent_node - directory entry node.
 518 * @ch: common header
 519 * @key: node key
 520 * @inum: target inode number
 521 * @padding1: reserved for future, zeroes
 522 * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
 523 * @nlen: name length
 524 * @padding2: reserved for future, zeroes
 525 * @name: zero-terminated name
 526 *
 527 * Note, do not forget to amend 'zero_dent_node_unused()' function when
 528 * changing the padding fields.
 529 */
 530struct ubifs_dent_node {
 531        struct ubifs_ch ch;
 532        __u8 key[UBIFS_MAX_KEY_LEN];
 533        __le64 inum;
 534        __u8 padding1;
 535        __u8 type;
 536        __le16 nlen;
 537        __u8 padding2[4]; /* Watch 'zero_dent_node_unused()' if changing! */
 538        __u8 name[];
 539} __packed;
 540
 541/**
 542 * struct ubifs_data_node - data node.
 543 * @ch: common header
 544 * @key: node key
 545 * @size: uncompressed data size in bytes
 546 * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
 547 * @padding: reserved for future, zeroes
 548 * @data: data
 549 *
 550 * Note, do not forget to amend 'zero_data_node_unused()' function when
 551 * changing the padding fields.
 552 */
 553struct ubifs_data_node {
 554        struct ubifs_ch ch;
 555        __u8 key[UBIFS_MAX_KEY_LEN];
 556        __le32 size;
 557        __le16 compr_type;
 558        __u8 padding[2]; /* Watch 'zero_data_node_unused()' if changing! */
 559        __u8 data[];
 560} __packed;
 561
 562/**
 563 * struct ubifs_trun_node - truncation node.
 564 * @ch: common header
 565 * @inum: truncated inode number
 566 * @padding: reserved for future, zeroes
 567 * @old_size: size before truncation
 568 * @new_size: size after truncation
 569 *
 570 * This node exists only in the journal and never goes to the main area. Note,
 571 * do not forget to amend 'zero_trun_node_unused()' function when changing the
 572 * padding fields.
 573 */
 574struct ubifs_trun_node {
 575        struct ubifs_ch ch;
 576        __le32 inum;
 577        __u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
 578        __le64 old_size;
 579        __le64 new_size;
 580} __packed;
 581
 582/**
 583 * struct ubifs_pad_node - padding node.
 584 * @ch: common header
 585 * @pad_len: how many bytes after this node are unused (because padded)
 586 * @padding: reserved for future, zeroes
 587 */
 588struct ubifs_pad_node {
 589        struct ubifs_ch ch;
 590        __le32 pad_len;
 591} __packed;
 592
 593/**
 594 * struct ubifs_sb_node - superblock node.
 595 * @ch: common header
 596 * @padding: reserved for future, zeroes
 597 * @key_hash: type of hash function used in keys
 598 * @key_fmt: format of the key
 599 * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
 600 * @min_io_size: minimal input/output unit size
 601 * @leb_size: logical eraseblock size in bytes
 602 * @leb_cnt: count of LEBs used by file-system
 603 * @max_leb_cnt: maximum count of LEBs used by file-system
 604 * @max_bud_bytes: maximum amount of data stored in buds
 605 * @log_lebs: log size in logical eraseblocks
 606 * @lpt_lebs: number of LEBs used for lprops table
 607 * @orph_lebs: number of LEBs used for recording orphans
 608 * @jhead_cnt: count of journal heads
 609 * @fanout: tree fanout (max. number of links per indexing node)
 610 * @lsave_cnt: number of LEB numbers in LPT's save table
 611 * @fmt_version: UBIFS on-flash format version
 612 * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
 613 * @padding1: reserved for future, zeroes
 614 * @rp_uid: reserve pool UID
 615 * @rp_gid: reserve pool GID
 616 * @rp_size: size of the reserved pool in bytes
 617 * @padding2: reserved for future, zeroes
 618 * @time_gran: time granularity in nanoseconds
 619 * @uuid: UUID generated when the file system image was created
 620 * @ro_compat_version: UBIFS R/O compatibility version
 621 */
 622struct ubifs_sb_node {
 623        struct ubifs_ch ch;
 624        __u8 padding[2];
 625        __u8 key_hash;
 626        __u8 key_fmt;
 627        __le32 flags;
 628        __le32 min_io_size;
 629        __le32 leb_size;
 630        __le32 leb_cnt;
 631        __le32 max_leb_cnt;
 632        __le64 max_bud_bytes;
 633        __le32 log_lebs;
 634        __le32 lpt_lebs;
 635        __le32 orph_lebs;
 636        __le32 jhead_cnt;
 637        __le32 fanout;
 638        __le32 lsave_cnt;
 639        __le32 fmt_version;
 640        __le16 default_compr;
 641        __u8 padding1[2];
 642        __le32 rp_uid;
 643        __le32 rp_gid;
 644        __le64 rp_size;
 645        __le32 time_gran;
 646        __u8 uuid[16];
 647        __le32 ro_compat_version;
 648        __u8 padding2[3968];
 649} __packed;
 650
 651/**
 652 * struct ubifs_mst_node - master node.
 653 * @ch: common header
 654 * @highest_inum: highest inode number in the committed index
 655 * @cmt_no: commit number
 656 * @flags: various flags (%UBIFS_MST_DIRTY, etc)
 657 * @log_lnum: start of the log
 658 * @root_lnum: LEB number of the root indexing node
 659 * @root_offs: offset within @root_lnum
 660 * @root_len: root indexing node length
 661 * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
 662 * not reserved and should be reserved on mount)
 663 * @ihead_lnum: LEB number of index head
 664 * @ihead_offs: offset of index head
 665 * @index_size: size of index on flash
 666 * @total_free: total free space in bytes
 667 * @total_dirty: total dirty space in bytes
 668 * @total_used: total used space in bytes (includes only data LEBs)
 669 * @total_dead: total dead space in bytes (includes only data LEBs)
 670 * @total_dark: total dark space in bytes (includes only data LEBs)
 671 * @lpt_lnum: LEB number of LPT root nnode
 672 * @lpt_offs: offset of LPT root nnode
 673 * @nhead_lnum: LEB number of LPT head
 674 * @nhead_offs: offset of LPT head
 675 * @ltab_lnum: LEB number of LPT's own lprops table
 676 * @ltab_offs: offset of LPT's own lprops table
 677 * @lsave_lnum: LEB number of LPT's save table (big model only)
 678 * @lsave_offs: offset of LPT's save table (big model only)
 679 * @lscan_lnum: LEB number of last LPT scan
 680 * @empty_lebs: number of empty logical eraseblocks
 681 * @idx_lebs: number of indexing logical eraseblocks
 682 * @leb_cnt: count of LEBs used by file-system
 683 * @padding: reserved for future, zeroes
 684 */
 685struct ubifs_mst_node {
 686        struct ubifs_ch ch;
 687        __le64 highest_inum;
 688        __le64 cmt_no;
 689        __le32 flags;
 690        __le32 log_lnum;
 691        __le32 root_lnum;
 692        __le32 root_offs;
 693        __le32 root_len;
 694        __le32 gc_lnum;
 695        __le32 ihead_lnum;
 696        __le32 ihead_offs;
 697        __le64 index_size;
 698        __le64 total_free;
 699        __le64 total_dirty;
 700        __le64 total_used;
 701        __le64 total_dead;
 702        __le64 total_dark;
 703        __le32 lpt_lnum;
 704        __le32 lpt_offs;
 705        __le32 nhead_lnum;
 706        __le32 nhead_offs;
 707        __le32 ltab_lnum;
 708        __le32 ltab_offs;
 709        __le32 lsave_lnum;
 710        __le32 lsave_offs;
 711        __le32 lscan_lnum;
 712        __le32 empty_lebs;
 713        __le32 idx_lebs;
 714        __le32 leb_cnt;
 715        __u8 padding[344];
 716} __packed;
 717
 718/**
 719 * struct ubifs_ref_node - logical eraseblock reference node.
 720 * @ch: common header
 721 * @lnum: the referred logical eraseblock number
 722 * @offs: start offset in the referred LEB
 723 * @jhead: journal head number
 724 * @padding: reserved for future, zeroes
 725 */
 726struct ubifs_ref_node {
 727        struct ubifs_ch ch;
 728        __le32 lnum;
 729        __le32 offs;
 730        __le32 jhead;
 731        __u8 padding[28];
 732} __packed;
 733
 734/**
 735 * struct ubifs_branch - key/reference/length branch
 736 * @lnum: LEB number of the target node
 737 * @offs: offset within @lnum
 738 * @len: target node length
 739 * @key: key
 740 */
 741struct ubifs_branch {
 742        __le32 lnum;
 743        __le32 offs;
 744        __le32 len;
 745        __u8 key[];
 746} __packed;
 747
 748/**
 749 * struct ubifs_idx_node - indexing node.
 750 * @ch: common header
 751 * @child_cnt: number of child index nodes
 752 * @level: tree level
 753 * @branches: LEB number / offset / length / key branches
 754 */
 755struct ubifs_idx_node {
 756        struct ubifs_ch ch;
 757        __le16 child_cnt;
 758        __le16 level;
 759        __u8 branches[];
 760} __packed;
 761
 762/**
 763 * struct ubifs_cs_node - commit start node.
 764 * @ch: common header
 765 * @cmt_no: commit number
 766 */
 767struct ubifs_cs_node {
 768        struct ubifs_ch ch;
 769        __le64 cmt_no;
 770} __packed;
 771
 772/**
 773 * struct ubifs_orph_node - orphan node.
 774 * @ch: common header
 775 * @cmt_no: commit number (also top bit is set on the last node of the commit)
 776 * @inos: inode numbers of orphans
 777 */
 778struct ubifs_orph_node {
 779        struct ubifs_ch ch;
 780        __le64 cmt_no;
 781        __le64 inos[];
 782} __packed;
 783
 784#endif /* __UBIFS_MEDIA_H__ */
 785
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