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