fs/ubifs/ubifs-media.h

   1 /*
   2  * This file is part of UBIFS.
   3  *
   4  * Copyright (C) 2006-2008 Nokia Corporation.
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  *
   8  * Authors: Artem Bityutskiy (Битюцкий Артём)
   9  *          Adrian Hunter
  10  */
  11
  12 /*
  13  * This file describes UBIFS on-flash format and contains definitions of all the
  14  * relevant data structures and constants.
  15  *
  16  * All UBIFS on-flash objects are stored in the form of nodes. All nodes start
  17  * with the UBIFS node magic number and have the same common header. Nodes
  18  * always sit at 8-byte aligned positions on the media and node header sizes are
  19  * also 8-byte aligned (except for the indexing node and the padding node).
  20  */
  21
  22 #ifndef __UBIFS_MEDIA_H__
  23 #define __UBIFS_MEDIA_H__
  24
  25 /* UBIFS node magic number (must not have the padding byte first or last) */
  26 #define UBIFS_NODE_MAGIC  0x06101831
  27
  28 /*
  29  * UBIFS on-flash format version. This version is increased when the on-flash
  30  * format is changing. If this happens, UBIFS is will support older versions as
  31  * well. But older UBIFS code will not support newer formats. Format changes
  32  * will be rare and only when absolutely necessary, e.g. to fix a bug or to add
  33  * a new feature.
  34  *
  35  * UBIFS went into mainline kernel with format version 4. The older formats
  36  * were development formats.
  37  */
  38 #define UBIFS_FORMAT_VERSION 4
  39
  40 /*
  41  * Read-only compatibility version. If the UBIFS format is changed, older UBIFS
  42  * implementations will not be able to mount newer formats in read-write mode.
  43  * However, depending on the change, it may be possible to mount newer formats
  44  * in R/O mode. This is indicated by the R/O compatibility version which is
  45  * stored in the super-block.
  46  *
  47  * This is needed to support boot-loaders which only need R/O mounting. With
  48  * this flag it is possible to do UBIFS format changes without a need to update
  49  * boot-loaders.
  50  */
  51 #define UBIFS_RO_COMPAT_VERSION 0
  52
  53 /* Minimum logical eraseblock size in bytes */
  54 #define UBIFS_MIN_LEB_SZ (15*1024)
  55
  56 /* Initial CRC32 value used when calculating CRC checksums */
  57 #define UBIFS_CRC32_INIT 0xFFFFFFFFU
  58
  59 /*
  60  * UBIFS does not try to compress data if its length is less than the below
  61  * constant.
  62  */
  63 #define UBIFS_MIN_COMPR_LEN 128
  64
  65 /*
  66  * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
  67  * shorter than uncompressed data length, UBIFS prefers to leave this data
  68  * node uncompress, because it'll be read faster.
  69  */
  70 #define UBIFS_MIN_COMPRESS_DIFF 64
  71
  72 /* Root inode number */
  73 #define UBIFS_ROOT_INO 1
  74
  75 /* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
  76 #define UBIFS_FIRST_INO 64
  77
  78 /*
  79  * Maximum file name and extended attribute length (must be a multiple of 8,
  80  * minus 1).
  81  */
  82 #define UBIFS_MAX_NLEN 255
  83
  84 /* Maximum number of data journal heads */
  85 #define UBIFS_MAX_JHEADS 1
  86
  87 /*
  88  * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
  89  * which means that it does not treat the underlying media as consisting of
  90  * blocks like in case of hard drives. Do not be confused. UBIFS block is just
  91  * the maximum amount of data which one data node can have or which can be
  92  * attached to an inode node.
  93  */
  94 #define UBIFS_BLOCK_SIZE  4096
  95 #define UBIFS_BLOCK_SHIFT 12
  96
  97 /* UBIFS padding byte pattern (must not be first or last byte of node magic) */
  98 #define UBIFS_PADDING_BYTE 0xCE
  99
 100 /* Maximum possible key length */
 101 #define UBIFS_MAX_KEY_LEN 16
 102
 103 /* Key length ("simple" format) */
 104 #define UBIFS_SK_LEN 8
 105
 106 /* Minimum index tree fanout */
 107 #define UBIFS_MIN_FANOUT 3
 108
 109 /* Maximum number of levels in UBIFS indexing B-tree */
 110 #define UBIFS_MAX_LEVELS 512
 111
 112 /* Maximum amount of data attached to an inode in bytes */
 113 #define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
 114
 115 /* LEB Properties Tree fanout (must be power of 2) and fanout shift */
 116 #define UBIFS_LPT_FANOUT 4
 117 #define UBIFS_LPT_FANOUT_SHIFT 2
 118
 119 /* LEB Properties Tree bit field sizes */
 120 #define UBIFS_LPT_CRC_BITS 16
 121 #define UBIFS_LPT_CRC_BYTES 2
 122 #define UBIFS_LPT_TYPE_BITS 4
 123
 124 /* The key is always at the same position in all keyed nodes */
 125 #define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
 126
 127 /* Garbage collector journal head number */
 128 #define UBIFS_GC_HEAD   0
 129 /* Base journal head number */
 130 #define UBIFS_BASE_HEAD 1
 131 /* Data journal head number */
 132 #define UBIFS_DATA_HEAD 2
 133
 134 /*
 135  * LEB Properties Tree node types.
 136  *
 137  * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
 138  * UBIFS_LPT_NNODE: LPT internal node
 139  * UBIFS_LPT_LTAB: LPT's own lprops table
 140  * UBIFS_LPT_LSAVE: LPT's save table (big model only)
 141  * UBIFS_LPT_NODE_CNT: count of LPT node types
 142  * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
 143  */
 144 enum {
 145         UBIFS_LPT_PNODE,
 146         UBIFS_LPT_NNODE,
 147         UBIFS_LPT_LTAB,
 148         UBIFS_LPT_LSAVE,
 149         UBIFS_LPT_NODE_CNT,
 150         UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
 151 };
 152
 153 /*
 154  * UBIFS inode types.
 155  *
 156  * UBIFS_ITYPE_REG: regular file
 157  * UBIFS_ITYPE_DIR: directory
 158  * UBIFS_ITYPE_LNK: soft link
 159  * UBIFS_ITYPE_BLK: block device node
 160  * UBIFS_ITYPE_CHR: character device node
 161  * UBIFS_ITYPE_FIFO: fifo
 162  * UBIFS_ITYPE_SOCK: socket
 163  * UBIFS_ITYPES_CNT: count of supported file types
 164  */
 165 enum {
 166         UBIFS_ITYPE_REG,
 167         UBIFS_ITYPE_DIR,
 168         UBIFS_ITYPE_LNK,
 169         UBIFS_ITYPE_BLK,
 170         UBIFS_ITYPE_CHR,
 171         UBIFS_ITYPE_FIFO,
 172         UBIFS_ITYPE_SOCK,
 173         UBIFS_ITYPES_CNT,
 174 };
 175
 176 /*
 177  * Supported key hash functions.
 178  *
 179  * UBIFS_KEY_HASH_R5: R5 hash
 180  * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
 181  */
 182 enum {
 183         UBIFS_KEY_HASH_R5,
 184         UBIFS_KEY_HASH_TEST,
 185 };
 186
 187 /*
 188  * Supported key formats.
 189  *
 190  * UBIFS_SIMPLE_KEY_FMT: simple key format
 191  */
 192 enum {
 193         UBIFS_SIMPLE_KEY_FMT,
 194 };
 195
 196 /*
 197  * The simple key format uses 29 bits for storing UBIFS block number and hash
 198  * value.
 199  */
 200 #define UBIFS_S_KEY_BLOCK_BITS 29
 201 #define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
 202 #define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
 203 #define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
 204
 205 /*
 206  * Key types.
 207  *
 208  * UBIFS_INO_KEY: inode node key
 209  * UBIFS_DATA_KEY: data node key
 210  * UBIFS_DENT_KEY: directory entry node key
 211  * UBIFS_XENT_KEY: extended attribute entry key
 212  * UBIFS_KEY_TYPES_CNT: number of supported key types
 213  */
 214 enum {
 215         UBIFS_INO_KEY,
 216         UBIFS_DATA_KEY,
 217         UBIFS_DENT_KEY,
 218         UBIFS_XENT_KEY,
 219         UBIFS_KEY_TYPES_CNT,
 220 };
 221
 222 /* Count of LEBs reserved for the superblock area */
 223 #define UBIFS_SB_LEBS 1
 224 /* Count of LEBs reserved for the master area */
 225 #define UBIFS_MST_LEBS 2
 226
 227 /* First LEB of the superblock area */
 228 #define UBIFS_SB_LNUM 0
 229 /* First LEB of the master area */
 230 #define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
 231 /* First LEB of the log area */
 232 #define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
 233
 234 /*
 235  * The below constants define the absolute minimum values for various UBIFS
 236  * media areas. Many of them actually depend of flash geometry and the FS
 237  * configuration (number of journal heads, orphan LEBs, etc). This means that
 238  * the smallest volume size which can be used for UBIFS cannot be pre-defined
 239  * by these constants. The file-system that meets the below limitation will not
 240  * necessarily mount. UBIFS does run-time calculations and validates the FS
 241  * size.
 242  */
 243
 244 /* Minimum number of logical eraseblocks in the log */
 245 #define UBIFS_MIN_LOG_LEBS 2
 246 /* Minimum number of bud logical eraseblocks (one for each head) */
 247 #define UBIFS_MIN_BUD_LEBS 3
 248 /* Minimum number of journal logical eraseblocks */
 249 #define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
 250 /* Minimum number of LPT area logical eraseblocks */
 251 #define UBIFS_MIN_LPT_LEBS 2
 252 /* Minimum number of orphan area logical eraseblocks */
 253 #define UBIFS_MIN_ORPH_LEBS 1
 254 /*
 255  * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
 256  * for GC, 1 for deletions, and at least 1 for committed data).
 257  */
 258 #define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
 259
 260 /* Minimum number of logical eraseblocks */
 261 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
 262                            UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
 263                            UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
 264
 265 /* Node sizes (N.B. these are guaranteed to be multiples of 8) */
 266 #define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
 267 #define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
 268 #define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
 269 #define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
 270 #define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
 271 #define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
 272 #define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
 273 #define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
 274 #define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
 275 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
 276 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
 277 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
 278 /* Extended attribute entry nodes are identical to directory entry nodes */
 279 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
 280 /* Only this does not have to be multiple of 8 bytes */
 281 #define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
 282
 283 /* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
 284 #define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
 285 #define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
 286 #define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
 287 #define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
 288
 289 /* The largest UBIFS node */
 290 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
 291
 292 /*
 293  * On-flash inode flags.
 294  *
 295  * UBIFS_COMPR_FL: use compression for this inode
 296  * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
 297  * UBIFS_IMMUTABLE_FL: inode is immutable
 298  * UBIFS_APPEND_FL: writes to the inode may only append data
 299  * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
 300  * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
 301  *
 302  * Note, these are on-flash flags which correspond to ioctl flags
 303  * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
 304  * have to be the same.
 305  */
 306 enum {
 307         UBIFS_COMPR_FL     = 0x01,
 308         UBIFS_SYNC_FL      = 0x02,
 309         UBIFS_IMMUTABLE_FL = 0x04,
 310         UBIFS_APPEND_FL    = 0x08,
 311         UBIFS_DIRSYNC_FL   = 0x10,
 312         UBIFS_XATTR_FL     = 0x20,
 313 };
 314
 315 /* Inode flag bits used by UBIFS */
 316 #define UBIFS_FL_MASK 0x0000001F
 317
 318 /*
 319  * UBIFS compression algorithms.
 320  *
 321  * UBIFS_COMPR_NONE: no compression
 322  * UBIFS_COMPR_LZO: LZO compression
 323  * UBIFS_COMPR_ZLIB: ZLIB compression
 324  * UBIFS_COMPR_TYPES_CNT: count of supported compression types
 325  */
 326 enum {
 327         UBIFS_COMPR_NONE,
 328         UBIFS_COMPR_LZO,
 329         UBIFS_COMPR_ZLIB,
 330         UBIFS_COMPR_TYPES_CNT,
 331 };
 332
 333 /*
 334  * UBIFS node types.
 335  *
 336  * UBIFS_INO_NODE: inode node
 337  * UBIFS_DATA_NODE: data node
 338  * UBIFS_DENT_NODE: directory entry node
 339  * UBIFS_XENT_NODE: extended attribute node
 340  * UBIFS_TRUN_NODE: truncation node
 341  * UBIFS_PAD_NODE: padding node
 342  * UBIFS_SB_NODE: superblock node
 343  * UBIFS_MST_NODE: master node
 344  * UBIFS_REF_NODE: LEB reference node
 345  * UBIFS_IDX_NODE: index node
 346  * UBIFS_CS_NODE: commit start node
 347  * UBIFS_ORPH_NODE: orphan node
 348  * UBIFS_NODE_TYPES_CNT: count of supported node types
 349  *
 350  * Note, we index arrays by these numbers, so keep them low and contiguous.
 351  * Node type constants for inodes, direntries and so on have to be the same as
 352  * corresponding key type constants.
 353  */
 354 enum {
 355         UBIFS_INO_NODE,
 356         UBIFS_DATA_NODE,
 357         UBIFS_DENT_NODE,
 358         UBIFS_XENT_NODE,
 359         UBIFS_TRUN_NODE,
 360         UBIFS_PAD_NODE,
 361         UBIFS_SB_NODE,
 362         UBIFS_MST_NODE,
 363         UBIFS_REF_NODE,
 364         UBIFS_IDX_NODE,
 365         UBIFS_CS_NODE,
 366         UBIFS_ORPH_NODE,
 367         UBIFS_NODE_TYPES_CNT,
 368 };
 369
 370 /*
 371  * Master node flags.
 372  *
 373  * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
 374  * UBIFS_MST_NO_ORPHS: no orphan inodes present
 375  * UBIFS_MST_RCVRY: written by recovery
 376  */
 377 enum {
 378         UBIFS_MST_DIRTY = 1,
 379         UBIFS_MST_NO_ORPHS = 2,
 380         UBIFS_MST_RCVRY = 4,
 381 };
 382
 383 /*
 384  * Node group type (used by recovery to recover whole group or none).
 385  *
 386  * UBIFS_NO_NODE_GROUP: this node is not part of a group
 387  * UBIFS_IN_NODE_GROUP: this node is a part of a group
 388  * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
 389  */
 390 enum {
 391         UBIFS_NO_NODE_GROUP = 0,
 392         UBIFS_IN_NODE_GROUP,
 393         UBIFS_LAST_OF_NODE_GROUP,
 394 };
 395
 396 /*
 397  * Superblock flags.
 398  *
 399  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
 400  * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
 401  */
 402 enum {
 403         UBIFS_FLG_BIGLPT = 0x02,
 404         UBIFS_FLG_SPACE_FIXUP = 0x04,
 405 };
 406
 407 /**
 408  * struct ubifs_ch - common header node.
 409  * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
 410  * @crc: CRC-32 checksum of the node header
 411  * @sqnum: sequence number
 412  * @len: full node length
 413  * @node_type: node type
 414  * @group_type: node group type
 415  * @padding: reserved for future, zeroes
 416  *
 417  * Every UBIFS node starts with this common part. If the node has a key, the
 418  * key always goes next.
 419  */
 420 struct ubifs_ch {
 421         __le32 magic;
 422         __le32 crc;
 423         __le64 sqnum;
 424         __le32 len;
 425         __u8 node_type;
 426         __u8 group_type;
 427         __u8 padding[2];
 428 } __packed;
 429
 430 /**
 431  * union ubifs_dev_desc - device node descriptor.
 432  * @new: new type device descriptor
 433  * @huge: huge type device descriptor
 434  *
 435  * This data structure describes major/minor numbers of a device node. In an
 436  * inode is a device node then its data contains an object of this type. UBIFS
 437  * uses standard Linux "new" and "huge" device node encodings.
 438  */
 439 union ubifs_dev_desc {
 440         __le32 new;
 441         __le64 huge;
 442 } __packed;
 443
 444 /**
 445  * struct ubifs_ino_node - inode node.
 446  * @ch: common header
 447  * @key: node key
 448  * @creat_sqnum: sequence number at time of creation
 449  * @size: inode size in bytes (amount of uncompressed data)
 450  * @atime_sec: access time seconds
 451  * @ctime_sec: creation time seconds
 452  * @mtime_sec: modification time seconds
 453  * @atime_nsec: access time nanoseconds
 454  * @ctime_nsec: creation time nanoseconds
 455  * @mtime_nsec: modification time nanoseconds
 456  * @nlink: number of hard links
 457  * @uid: owner ID
 458  * @gid: group ID
 459  * @mode: access flags
 460  * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
 461  * @data_len: inode data length
 462  * @xattr_cnt: count of extended attributes this inode has
 463  * @xattr_size: summarized size of all extended attributes in bytes
 464  * @padding1: reserved for future, zeroes
 465  * @xattr_names: sum of lengths of all extended attribute names belonging to
 466  *               this inode
 467  * @compr_type: compression type used for this inode
 468  * @padding2: reserved for future, zeroes
 469  * @data: data attached to the inode
 470  *
 471  * Note, even though inode compression type is defined by @compr_type, some
 472  * nodes of this inode may be compressed with different compressor - this
 473  * happens if compression type is changed while the inode already has data
 474  * nodes. But @compr_type will be use for further writes to the inode.
 475  *
 476  * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
 477  * the padding fields.
 478  */
 479 struct ubifs_ino_node {
 480         struct ubifs_ch ch;
 481         __u8 key[UBIFS_MAX_KEY_LEN];
 482         __le64 creat_sqnum;
 483         __le64 size;
 484         __le64 atime_sec;
 485         __le64 ctime_sec;
 486         __le64 mtime_sec;
 487         __le32 atime_nsec;
 488         __le32 ctime_nsec;
 489         __le32 mtime_nsec;
 490         __le32 nlink;
 491         __le32 uid;
 492         __le32 gid;
 493         __le32 mode;
 494         __le32 flags;
 495         __le32 data_len;
 496         __le32 xattr_cnt;
 497         __le32 xattr_size;
 498         __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
 499         __le32 xattr_names;
 500         __le16 compr_type;
 501         __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
 502         __u8 data[];
 503 } __packed;
 504
 505 /**
 506  * struct ubifs_dent_node - directory entry node.
 507  * @ch: common header
 508  * @key: node key
 509  * @inum: target inode number
 510  * @padding1: reserved for future, zeroes
 511  * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
 512  * @nlen: name length
 513  * @padding2: reserved for future, zeroes
 514  * @name: zero-terminated name
 515  *
 516  * Note, do not forget to amend 'zero_dent_node_unused()' function when
 517  * changing the padding fields.
 518  */
 519 struct ubifs_dent_node {
 520         struct ubifs_ch ch;
 521         __u8 key[UBIFS_MAX_KEY_LEN];
 522         __le64 inum;
 523         __u8 padding1;
 524         __u8 type;
 525         __le16 nlen;
 526         __u8 padding2[4]; /* Watch 'zero_dent_node_unused()' if changing! */
 527 #ifndef __UBOOT__
 528         __u8 name[];
 529 #else
 530         char name[];
 531 #endif
 532 } __packed;
 533
 534 /**
 535  * struct ubifs_data_node - data node.
 536  * @ch: common header
 537  * @key: node key
 538  * @size: uncompressed data size in bytes
 539  * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
 540  * @padding: reserved for future, zeroes
 541  * @data: data
 542  *
 543  * Note, do not forget to amend 'zero_data_node_unused()' function when
 544  * changing the padding fields.
 545  */
 546 struct ubifs_data_node {
 547         struct ubifs_ch ch;
 548         __u8 key[UBIFS_MAX_KEY_LEN];
 549         __le32 size;
 550         __le16 compr_type;
 551         __u8 padding[2]; /* Watch 'zero_data_node_unused()' if changing! */
 552         __u8 data[];
 553 } __packed;
 554
 555 /**
 556  * struct ubifs_trun_node - truncation node.
 557  * @ch: common header
 558  * @inum: truncated inode number
 559  * @padding: reserved for future, zeroes
 560  * @old_size: size before truncation
 561  * @new_size: size after truncation
 562  *
 563  * This node exists only in the journal and never goes to the main area. Note,
 564  * do not forget to amend 'zero_trun_node_unused()' function when changing the
 565  * padding fields.
 566  */
 567 struct ubifs_trun_node {
 568         struct ubifs_ch ch;
 569         __le32 inum;
 570         __u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
 571         __le64 old_size;
 572         __le64 new_size;
 573 } __packed;
 574
 575 /**
 576  * struct ubifs_pad_node - padding node.
 577  * @ch: common header
 578  * @pad_len: how many bytes after this node are unused (because padded)
 579  * @padding: reserved for future, zeroes
 580  */
 581 struct ubifs_pad_node {
 582         struct ubifs_ch ch;
 583         __le32 pad_len;
 584 } __packed;
 585
 586 /**
 587  * struct ubifs_sb_node - superblock node.
 588  * @ch: common header
 589  * @padding: reserved for future, zeroes
 590  * @key_hash: type of hash function used in keys
 591  * @key_fmt: format of the key
 592  * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
 593  * @min_io_size: minimal input/output unit size
 594  * @leb_size: logical eraseblock size in bytes
 595  * @leb_cnt: count of LEBs used by file-system
 596  * @max_leb_cnt: maximum count of LEBs used by file-system
 597  * @max_bud_bytes: maximum amount of data stored in buds
 598  * @log_lebs: log size in logical eraseblocks
 599  * @lpt_lebs: number of LEBs used for lprops table
 600  * @orph_lebs: number of LEBs used for recording orphans
 601  * @jhead_cnt: count of journal heads
 602  * @fanout: tree fanout (max. number of links per indexing node)
 603  * @lsave_cnt: number of LEB numbers in LPT's save table
 604  * @fmt_version: UBIFS on-flash format version
 605  * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
 606  * @padding1: reserved for future, zeroes
 607  * @rp_uid: reserve pool UID
 608  * @rp_gid: reserve pool GID
 609  * @rp_size: size of the reserved pool in bytes
 610  * @padding2: reserved for future, zeroes
 611  * @time_gran: time granularity in nanoseconds
 612  * @uuid: UUID generated when the file system image was created
 613  * @ro_compat_version: UBIFS R/O compatibility version
 614  */
 615 struct ubifs_sb_node {
 616         struct ubifs_ch ch;
 617         __u8 padding[2];
 618         __u8 key_hash;
 619         __u8 key_fmt;
 620         __le32 flags;
 621         __le32 min_io_size;
 622         __le32 leb_size;
 623         __le32 leb_cnt;
 624         __le32 max_leb_cnt;
 625         __le64 max_bud_bytes;
 626         __le32 log_lebs;
 627         __le32 lpt_lebs;
 628         __le32 orph_lebs;
 629         __le32 jhead_cnt;
 630         __le32 fanout;
 631         __le32 lsave_cnt;
 632         __le32 fmt_version;
 633         __le16 default_compr;
 634         __u8 padding1[2];
 635         __le32 rp_uid;
 636         __le32 rp_gid;
 637         __le64 rp_size;
 638         __le32 time_gran;
 639         __u8 uuid[16];
 640         __le32 ro_compat_version;
 641         __u8 padding2[3968];
 642 } __packed;
 643
 644 /**
 645  * struct ubifs_mst_node - master node.
 646  * @ch: common header
 647  * @highest_inum: highest inode number in the committed index
 648  * @cmt_no: commit number
 649  * @flags: various flags (%UBIFS_MST_DIRTY, etc)
 650  * @log_lnum: start of the log
 651  * @root_lnum: LEB number of the root indexing node
 652  * @root_offs: offset within @root_lnum
 653  * @root_len: root indexing node length
 654  * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
 655  * not reserved and should be reserved on mount)
 656  * @ihead_lnum: LEB number of index head
 657  * @ihead_offs: offset of index head
 658  * @index_size: size of index on flash
 659  * @total_free: total free space in bytes
 660  * @total_dirty: total dirty space in bytes
 661  * @total_used: total used space in bytes (includes only data LEBs)
 662  * @total_dead: total dead space in bytes (includes only data LEBs)
 663  * @total_dark: total dark space in bytes (includes only data LEBs)
 664  * @lpt_lnum: LEB number of LPT root nnode
 665  * @lpt_offs: offset of LPT root nnode
 666  * @nhead_lnum: LEB number of LPT head
 667  * @nhead_offs: offset of LPT head
 668  * @ltab_lnum: LEB number of LPT's own lprops table
 669  * @ltab_offs: offset of LPT's own lprops table
 670  * @lsave_lnum: LEB number of LPT's save table (big model only)
 671  * @lsave_offs: offset of LPT's save table (big model only)
 672  * @lscan_lnum: LEB number of last LPT scan
 673  * @empty_lebs: number of empty logical eraseblocks
 674  * @idx_lebs: number of indexing logical eraseblocks
 675  * @leb_cnt: count of LEBs used by file-system
 676  * @padding: reserved for future, zeroes
 677  */
 678 struct ubifs_mst_node {
 679         struct ubifs_ch ch;
 680         __le64 highest_inum;
 681         __le64 cmt_no;
 682         __le32 flags;
 683         __le32 log_lnum;
 684         __le32 root_lnum;
 685         __le32 root_offs;
 686         __le32 root_len;
 687         __le32 gc_lnum;
 688         __le32 ihead_lnum;
 689         __le32 ihead_offs;
 690         __le64 index_size;
 691         __le64 total_free;
 692         __le64 total_dirty;
 693         __le64 total_used;
 694         __le64 total_dead;
 695         __le64 total_dark;
 696         __le32 lpt_lnum;
 697         __le32 lpt_offs;
 698         __le32 nhead_lnum;
 699         __le32 nhead_offs;
 700         __le32 ltab_lnum;
 701         __le32 ltab_offs;
 702         __le32 lsave_lnum;
 703         __le32 lsave_offs;
 704         __le32 lscan_lnum;
 705         __le32 empty_lebs;
 706         __le32 idx_lebs;
 707         __le32 leb_cnt;
 708         __u8 padding[344];
 709 } __packed;
 710
 711 /**
 712  * struct ubifs_ref_node - logical eraseblock reference node.
 713  * @ch: common header
 714  * @lnum: the referred logical eraseblock number
 715  * @offs: start offset in the referred LEB
 716  * @jhead: journal head number
 717  * @padding: reserved for future, zeroes
 718  */
 719 struct ubifs_ref_node {
 720         struct ubifs_ch ch;
 721         __le32 lnum;
 722         __le32 offs;
 723         __le32 jhead;
 724         __u8 padding[28];
 725 } __packed;
 726
 727 /**
 728  * struct ubifs_branch - key/reference/length branch
 729  * @lnum: LEB number of the target node
 730  * @offs: offset within @lnum
 731  * @len: target node length
 732  * @key: key
 733  */
 734 struct ubifs_branch {
 735         __le32 lnum;
 736         __le32 offs;
 737         __le32 len;
 738 #ifndef __UBOOT__
 739         __u8 key[];
 740 #else
 741         char key[];
 742 #endif
 743 } __packed;
 744
 745 /**
 746  * struct ubifs_idx_node - indexing node.
 747  * @ch: common header
 748  * @child_cnt: number of child index nodes
 749  * @level: tree level
 750  * @branches: LEB number / offset / length / key branches
 751  */
 752 struct ubifs_idx_node {
 753         struct ubifs_ch ch;
 754         __le16 child_cnt;
 755         __le16 level;
 756 #ifndef __UBOOT__
 757         __u8 branches[];
 758 #else
 759         char branches[];
 760 #endif
 761 } __packed;
 762
 763 /**
 764  * struct ubifs_cs_node - commit start node.
 765  * @ch: common header
 766  * @cmt_no: commit number
 767  */
 768 struct ubifs_cs_node {
 769         struct ubifs_ch ch;
 770         __le64 cmt_no;
 771 } __packed;
 772
 773 /**
 774  * struct ubifs_orph_node - orphan node.
 775  * @ch: common header
 776  * @cmt_no: commit number (also top bit is set on the last node of the commit)
 777  * @inos: inode numbers of orphans
 778  */
 779 struct ubifs_orph_node {
 780         struct ubifs_ch ch;
 781         __le64 cmt_no;
 782         __le64 inos[];
 783 } __packed;
 784
 785 #endif /* __UBIFS_MEDIA_H__ */