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 /* UBIFS on-flash format version */
  40 #define UBIFS_FORMAT_VERSION 4
  41
  42 /* Minimum logical eraseblock size in bytes */
  43 #define UBIFS_MIN_LEB_SZ (15*1024)
  44
  45 /* Initial CRC32 value used when calculating CRC checksums */
  46 #define UBIFS_CRC32_INIT 0xFFFFFFFFU
  47
  48 /*
  49  * UBIFS does not try to compress data if its length is less than the below
  50  * constant.
  51  */
  52 #define UBIFS_MIN_COMPR_LEN 128
  53
  54 /* Root inode number */
  55 #define UBIFS_ROOT_INO 1
  56
  57 /* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
  58 #define UBIFS_FIRST_INO 64
  59
  60 /*
  61  * Maximum file name and extended attribute length (must be a multiple of 8,
  62  * minus 1).
  63  */
  64 #define UBIFS_MAX_NLEN 255
  65
  66 /* Maximum number of data journal heads */
  67 #define UBIFS_MAX_JHEADS 1
  68
  69 /*
  70  * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
  71  * which means that it does not treat the underlying media as consisting of
  72  * blocks like in case of hard drives. Do not be confused. UBIFS block is just
  73  * the maximum amount of data which one data node can have or which can be
  74  * attached to an inode node.
  75  */
  76 #define UBIFS_BLOCK_SIZE  4096
  77 #define UBIFS_BLOCK_SHIFT 12
  78 #define UBIFS_BLOCK_MASK  0x00000FFF
  79
  80 /* UBIFS padding byte pattern (must not be first or last byte of node magic) */
  81 #define UBIFS_PADDING_BYTE 0xCE
  82
  83 /* Maximum possible key length */
  84 #define UBIFS_MAX_KEY_LEN 16
  85
  86 /* Key length ("simple" format) */
  87 #define UBIFS_SK_LEN 8
  88
  89 /* Minimum index tree fanout */
  90 #define UBIFS_MIN_FANOUT 2
  91
  92 /* Maximum number of levels in UBIFS indexing B-tree */
  93 #define UBIFS_MAX_LEVELS 512
  94
  95 /* Maximum amount of data attached to an inode in bytes */
  96 #define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
  97
  98 /* LEB Properties Tree fanout (must be power of 2) and fanout shift */
  99 #define UBIFS_LPT_FANOUT 4
 100 #define UBIFS_LPT_FANOUT_SHIFT 2
 101
 102 /* LEB Properties Tree bit field sizes */
 103 #define UBIFS_LPT_CRC_BITS 16
 104 #define UBIFS_LPT_CRC_BYTES 2
 105 #define UBIFS_LPT_TYPE_BITS 4
 106
 107 /* The key is always at the same position in all keyed nodes */
 108 #define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
 109
 110 /*
 111  * LEB Properties Tree node types.
 112  *
 113  * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
 114  * UBIFS_LPT_NNODE: LPT internal node
 115  * UBIFS_LPT_LTAB: LPT's own lprops table
 116  * UBIFS_LPT_LSAVE: LPT's save table (big model only)
 117  * UBIFS_LPT_NODE_CNT: count of LPT node types
 118  * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
 119  */
 120 enum {
 121         UBIFS_LPT_PNODE,
 122         UBIFS_LPT_NNODE,
 123         UBIFS_LPT_LTAB,
 124         UBIFS_LPT_LSAVE,
 125         UBIFS_LPT_NODE_CNT,
 126         UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
 127 };
 128
 129 /*
 130  * UBIFS inode types.
 131  *
 132  * UBIFS_ITYPE_REG: regular file
 133  * UBIFS_ITYPE_DIR: directory
 134  * UBIFS_ITYPE_LNK: soft link
 135  * UBIFS_ITYPE_BLK: block device node
 136  * UBIFS_ITYPE_CHR: character device node
 137  * UBIFS_ITYPE_FIFO: fifo
 138  * UBIFS_ITYPE_SOCK: socket
 139  * UBIFS_ITYPES_CNT: count of supported file types
 140  */
 141 enum {
 142         UBIFS_ITYPE_REG,
 143         UBIFS_ITYPE_DIR,
 144         UBIFS_ITYPE_LNK,
 145         UBIFS_ITYPE_BLK,
 146         UBIFS_ITYPE_CHR,
 147         UBIFS_ITYPE_FIFO,
 148         UBIFS_ITYPE_SOCK,
 149         UBIFS_ITYPES_CNT,
 150 };
 151
 152 /*
 153  * Supported key hash functions.
 154  *
 155  * UBIFS_KEY_HASH_R5: R5 hash
 156  * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
 157  */
 158 enum {
 159         UBIFS_KEY_HASH_R5,
 160         UBIFS_KEY_HASH_TEST,
 161 };
 162
 163 /*
 164  * Supported key formats.
 165  *
 166  * UBIFS_SIMPLE_KEY_FMT: simple key format
 167  */
 168 enum {
 169         UBIFS_SIMPLE_KEY_FMT,
 170 };
 171
 172 /*
 173  * The simple key format uses 29 bits for storing UBIFS block number and hash
 174  * value.
 175  */
 176 #define UBIFS_S_KEY_BLOCK_BITS 29
 177 #define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
 178 #define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
 179 #define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
 180
 181 /*
 182  * Key types.
 183  *
 184  * UBIFS_INO_KEY: inode node key
 185  * UBIFS_DATA_KEY: data node key
 186  * UBIFS_DENT_KEY: directory entry node key
 187  * UBIFS_XENT_KEY: extended attribute entry key
 188  * UBIFS_KEY_TYPES_CNT: number of supported key types
 189  */
 190 enum {
 191         UBIFS_INO_KEY,
 192         UBIFS_DATA_KEY,
 193         UBIFS_DENT_KEY,
 194         UBIFS_XENT_KEY,
 195         UBIFS_KEY_TYPES_CNT,
 196 };
 197
 198 /* Count of LEBs reserved for the superblock area */
 199 #define UBIFS_SB_LEBS 1
 200 /* Count of LEBs reserved for the master area */
 201 #define UBIFS_MST_LEBS 2
 202
 203 /* First LEB of the superblock area */
 204 #define UBIFS_SB_LNUM 0
 205 /* First LEB of the master area */
 206 #define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
 207 /* First LEB of the log area */
 208 #define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
 209
 210 /*
 211  * The below constants define the absolute minimum values for various UBIFS
 212  * media areas. Many of them actually depend of flash geometry and the FS
 213  * configuration (number of journal heads, orphan LEBs, etc). This means that
 214  * the smallest volume size which can be used for UBIFS cannot be pre-defined
 215  * by these constants. The file-system that meets the below limitation will not
 216  * necessarily mount. UBIFS does run-time calculations and validates the FS
 217  * size.
 218  */
 219
 220 /* Minimum number of logical eraseblocks in the log */
 221 #define UBIFS_MIN_LOG_LEBS 2
 222 /* Minimum number of bud logical eraseblocks (one for each head) */
 223 #define UBIFS_MIN_BUD_LEBS 3
 224 /* Minimum number of journal logical eraseblocks */
 225 #define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
 226 /* Minimum number of LPT area logical eraseblocks */
 227 #define UBIFS_MIN_LPT_LEBS 2
 228 /* Minimum number of orphan area logical eraseblocks */
 229 #define UBIFS_MIN_ORPH_LEBS 1
 230 /*
 231  * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
 232  * for GC, 1 for deletions, and at least 1 for committed data).
 233  */
 234 #define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
 235
 236 /* Minimum number of logical eraseblocks */
 237 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
 238                            UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
 239                            UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
 240
 241 /* Node sizes (N.B. these are guaranteed to be multiples of 8) */
 242 #define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
 243 #define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
 244 #define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
 245 #define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
 246 #define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
 247 #define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
 248 #define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
 249 #define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
 250 #define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
 251 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
 252 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
 253 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
 254 /* Extended attribute entry nodes are identical to directory entry nodes */
 255 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
 256 /* Only this does not have to be multiple of 8 bytes */
 257 #define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
 258
 259 /* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
 260 #define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
 261 #define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
 262 #define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
 263 #define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
 264
 265 /* The largest UBIFS node */
 266 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
 267
 268 /*
 269  * On-flash inode flags.
 270  *
 271  * UBIFS_COMPR_FL: use compression for this inode
 272  * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
 273  * UBIFS_IMMUTABLE_FL: inode is immutable
 274  * UBIFS_APPEND_FL: writes to the inode may only append data
 275  * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
 276  * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
 277  *
 278  * Note, these are on-flash flags which correspond to ioctl flags
 279  * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
 280  * have to be the same.
 281  */
 282 enum {
 283         UBIFS_COMPR_FL     = 0x01,
 284         UBIFS_SYNC_FL      = 0x02,
 285         UBIFS_IMMUTABLE_FL = 0x04,
 286         UBIFS_APPEND_FL    = 0x08,
 287         UBIFS_DIRSYNC_FL   = 0x10,
 288         UBIFS_XATTR_FL     = 0x20,
 289 };
 290
 291 /* Inode flag bits used by UBIFS */
 292 #define UBIFS_FL_MASK 0x0000001F
 293
 294 /*
 295  * UBIFS compression algorithms.
 296  *
 297  * UBIFS_COMPR_NONE: no compression
 298  * UBIFS_COMPR_LZO: LZO compression
 299  * UBIFS_COMPR_ZLIB: ZLIB compression
 300  * UBIFS_COMPR_TYPES_CNT: count of supported compression types
 301  */
 302 enum {
 303         UBIFS_COMPR_NONE,
 304         UBIFS_COMPR_LZO,
 305         UBIFS_COMPR_ZLIB,
 306         UBIFS_COMPR_TYPES_CNT,
 307 };
 308
 309 /*
 310  * UBIFS node types.
 311  *
 312  * UBIFS_INO_NODE: inode node
 313  * UBIFS_DATA_NODE: data node
 314  * UBIFS_DENT_NODE: directory entry node
 315  * UBIFS_XENT_NODE: extended attribute node
 316  * UBIFS_TRUN_NODE: truncation node
 317  * UBIFS_PAD_NODE: padding node
 318  * UBIFS_SB_NODE: superblock node
 319  * UBIFS_MST_NODE: master node
 320  * UBIFS_REF_NODE: LEB reference node
 321  * UBIFS_IDX_NODE: index node
 322  * UBIFS_CS_NODE: commit start node
 323  * UBIFS_ORPH_NODE: orphan node
 324  * UBIFS_NODE_TYPES_CNT: count of supported node types
 325  *
 326  * Note, we index arrays by these numbers, so keep them low and contiguous.
 327  * Node type constants for inodes, direntries and so on have to be the same as
 328  * corresponding key type constants.
 329  */
 330 enum {
 331         UBIFS_INO_NODE,
 332         UBIFS_DATA_NODE,
 333         UBIFS_DENT_NODE,
 334         UBIFS_XENT_NODE,
 335         UBIFS_TRUN_NODE,
 336         UBIFS_PAD_NODE,
 337         UBIFS_SB_NODE,
 338         UBIFS_MST_NODE,
 339         UBIFS_REF_NODE,
 340         UBIFS_IDX_NODE,
 341         UBIFS_CS_NODE,
 342         UBIFS_ORPH_NODE,
 343         UBIFS_NODE_TYPES_CNT,
 344 };
 345
 346 /*
 347  * Master node flags.
 348  *
 349  * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
 350  * UBIFS_MST_NO_ORPHS: no orphan inodes present
 351  * UBIFS_MST_RCVRY: written by recovery
 352  */
 353 enum {
 354         UBIFS_MST_DIRTY = 1,
 355         UBIFS_MST_NO_ORPHS = 2,
 356         UBIFS_MST_RCVRY = 4,
 357 };
 358
 359 /*
 360  * Node group type (used by recovery to recover whole group or none).
 361  *
 362  * UBIFS_NO_NODE_GROUP: this node is not part of a group
 363  * UBIFS_IN_NODE_GROUP: this node is a part of a group
 364  * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
 365  */
 366 enum {
 367         UBIFS_NO_NODE_GROUP = 0,
 368         UBIFS_IN_NODE_GROUP,
 369         UBIFS_LAST_OF_NODE_GROUP,
 370 };
 371
 372 /*
 373  * Superblock flags.
 374  *
 375  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
 376  */
 377 enum {
 378         UBIFS_FLG_BIGLPT = 0x02,
 379 };
 380
 381 /**
 382  * struct ubifs_ch - common header node.
 383  * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
 384  * @crc: CRC-32 checksum of the node header
 385  * @sqnum: sequence number
 386  * @len: full node length
 387  * @node_type: node type
 388  * @group_type: node group type
 389  * @padding: reserved for future, zeroes
 390  *
 391  * Every UBIFS node starts with this common part. If the node has a key, the
 392  * key always goes next.
 393  */
 394 struct ubifs_ch {
 395         __le32 magic;
 396         __le32 crc;
 397         __le64 sqnum;
 398         __le32 len;
 399         __u8 node_type;
 400         __u8 group_type;
 401         __u8 padding[2];
 402 } __attribute__ ((packed));
 403
 404 /**
 405  * union ubifs_dev_desc - device node descriptor.
 406  * @new: new type device descriptor
 407  * @huge: huge type device descriptor
 408  *
 409  * This data structure describes major/minor numbers of a device node. In an
 410  * inode is a device node then its data contains an object of this type. UBIFS
 411  * uses standard Linux "new" and "huge" device node encodings.
 412  */
 413 union ubifs_dev_desc {
 414         __le32 new;
 415         __le64 huge;
 416 } __attribute__ ((packed));
 417
 418 /**
 419  * struct ubifs_ino_node - inode node.
 420  * @ch: common header
 421  * @key: node key
 422  * @creat_sqnum: sequence number at time of creation
 423  * @size: inode size in bytes (amount of uncompressed data)
 424  * @atime_sec: access time seconds
 425  * @ctime_sec: creation time seconds
 426  * @mtime_sec: modification time seconds
 427  * @atime_nsec: access time nanoseconds
 428  * @ctime_nsec: creation time nanoseconds
 429  * @mtime_nsec: modification time nanoseconds
 430  * @nlink: number of hard links
 431  * @uid: owner ID
 432  * @gid: group ID
 433  * @mode: access flags
 434  * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
 435  * @data_len: inode data length
 436  * @xattr_cnt: count of extended attributes this inode has
 437  * @xattr_size: summarized size of all extended attributes in bytes
 438  * @padding1: reserved for future, zeroes
 439  * @xattr_names: sum of lengths of all extended attribute names belonging to
 440  *               this inode
 441  * @compr_type: compression type used for this inode
 442  * @padding2: reserved for future, zeroes
 443  * @data: data attached to the inode
 444  *
 445  * Note, even though inode compression type is defined by @compr_type, some
 446  * nodes of this inode may be compressed with different compressor - this
 447  * happens if compression type is changed while the inode already has data
 448  * nodes. But @compr_type will be use for further writes to the inode.
 449  *
 450  * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
 451  * the padding fields.
 452  */
 453 struct ubifs_ino_node {
 454         struct ubifs_ch ch;
 455         __u8 key[UBIFS_MAX_KEY_LEN];
 456         __le64 creat_sqnum;
 457         __le64 size;
 458         __le64 atime_sec;
 459         __le64 ctime_sec;
 460         __le64 mtime_sec;
 461         __le32 atime_nsec;
 462         __le32 ctime_nsec;
 463         __le32 mtime_nsec;
 464         __le32 nlink;
 465         __le32 uid;
 466         __le32 gid;
 467         __le32 mode;
 468         __le32 flags;
 469         __le32 data_len;
 470         __le32 xattr_cnt;
 471         __le32 xattr_size;
 472         __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
 473         __le32 xattr_names;
 474         __le16 compr_type;
 475         __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
 476         __u8 data[];
 477 } __attribute__ ((packed));
 478
 479 /**
 480  * struct ubifs_dent_node - directory entry node.
 481  * @ch: common header
 482  * @key: node key
 483  * @inum: target inode number
 484  * @padding1: reserved for future, zeroes
 485  * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
 486  * @nlen: name length
 487  * @padding2: reserved for future, zeroes
 488  * @name: zero-terminated name
 489  *
 490  * Note, do not forget to amend 'zero_dent_node_unused()' function when
 491  * changing the padding fields.
 492  */
 493 struct ubifs_dent_node {
 494         struct ubifs_ch ch;
 495         __u8 key[UBIFS_MAX_KEY_LEN];
 496         __le64 inum;
 497         __u8 padding1;
 498         __u8 type;
 499         __le16 nlen;
 500         __u8 padding2[4]; /* Watch 'zero_dent_node_unused()' if changing! */
 501         __u8 name[];
 502 } __attribute__ ((packed));
 503
 504 /**
 505  * struct ubifs_data_node - data node.
 506  * @ch: common header
 507  * @key: node key
 508  * @size: uncompressed data size in bytes
 509  * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
 510  * @padding: reserved for future, zeroes
 511  * @data: data
 512  *
 513  * Note, do not forget to amend 'zero_data_node_unused()' function when
 514  * changing the padding fields.
 515  */
 516 struct ubifs_data_node {
 517         struct ubifs_ch ch;
 518         __u8 key[UBIFS_MAX_KEY_LEN];
 519         __le32 size;
 520         __le16 compr_type;
 521         __u8 padding[2]; /* Watch 'zero_data_node_unused()' if changing! */
 522         __u8 data[];
 523 } __attribute__ ((packed));
 524
 525 /**
 526  * struct ubifs_trun_node - truncation node.
 527  * @ch: common header
 528  * @inum: truncated inode number
 529  * @padding: reserved for future, zeroes
 530  * @old_size: size before truncation
 531  * @new_size: size after truncation
 532  *
 533  * This node exists only in the journal and never goes to the main area. Note,
 534  * do not forget to amend 'zero_trun_node_unused()' function when changing the
 535  * padding fields.
 536  */
 537 struct ubifs_trun_node {
 538         struct ubifs_ch ch;
 539         __le32 inum;
 540         __u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
 541         __le64 old_size;
 542         __le64 new_size;
 543 } __attribute__ ((packed));
 544
 545 /**
 546  * struct ubifs_pad_node - padding node.
 547  * @ch: common header
 548  * @pad_len: how many bytes after this node are unused (because padded)
 549  * @padding: reserved for future, zeroes
 550  */
 551 struct ubifs_pad_node {
 552         struct ubifs_ch ch;
 553         __le32 pad_len;
 554 } __attribute__ ((packed));
 555
 556 /**
 557  * struct ubifs_sb_node - superblock node.
 558  * @ch: common header
 559  * @padding: reserved for future, zeroes
 560  * @key_hash: type of hash function used in keys
 561  * @key_fmt: format of the key
 562  * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
 563  * @min_io_size: minimal input/output unit size
 564  * @leb_size: logical eraseblock size in bytes
 565  * @leb_cnt: count of LEBs used by file-system
 566  * @max_leb_cnt: maximum count of LEBs used by file-system
 567  * @max_bud_bytes: maximum amount of data stored in buds
 568  * @log_lebs: log size in logical eraseblocks
 569  * @lpt_lebs: number of LEBs used for lprops table
 570  * @orph_lebs: number of LEBs used for recording orphans
 571  * @jhead_cnt: count of journal heads
 572  * @fanout: tree fanout (max. number of links per indexing node)
 573  * @lsave_cnt: number of LEB numbers in LPT's save table
 574  * @fmt_version: UBIFS on-flash format version
 575  * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
 576  * @padding1: reserved for future, zeroes
 577  * @rp_uid: reserve pool UID
 578  * @rp_gid: reserve pool GID
 579  * @rp_size: size of the reserved pool in bytes
 580  * @padding2: reserved for future, zeroes
 581  * @time_gran: time granularity in nanoseconds
 582  * @uuid: UUID generated when the file system image was created
 583  */
 584 struct ubifs_sb_node {
 585         struct ubifs_ch ch;
 586         __u8 padding[2];
 587         __u8 key_hash;
 588         __u8 key_fmt;
 589         __le32 flags;
 590         __le32 min_io_size;
 591         __le32 leb_size;
 592         __le32 leb_cnt;
 593         __le32 max_leb_cnt;
 594         __le64 max_bud_bytes;
 595         __le32 log_lebs;
 596         __le32 lpt_lebs;
 597         __le32 orph_lebs;
 598         __le32 jhead_cnt;
 599         __le32 fanout;
 600         __le32 lsave_cnt;
 601         __le32 fmt_version;
 602         __le16 default_compr;
 603         __u8 padding1[2];
 604         __le32 rp_uid;
 605         __le32 rp_gid;
 606         __le64 rp_size;
 607         __le32 time_gran;
 608         __u8 uuid[16];
 609         __u8 padding2[3972];
 610 } __attribute__ ((packed));
 611
 612 /**
 613  * struct ubifs_mst_node - master node.
 614  * @ch: common header
 615  * @highest_inum: highest inode number in the committed index
 616  * @cmt_no: commit number
 617  * @flags: various flags (%UBIFS_MST_DIRTY, etc)
 618  * @log_lnum: start of the log
 619  * @root_lnum: LEB number of the root indexing node
 620  * @root_offs: offset within @root_lnum
 621  * @root_len: root indexing node length
 622  * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
 623  * not reserved and should be reserved on mount)
 624  * @ihead_lnum: LEB number of index head
 625  * @ihead_offs: offset of index head
 626  * @index_size: size of index on flash
 627  * @total_free: total free space in bytes
 628  * @total_dirty: total dirty space in bytes
 629  * @total_used: total used space in bytes (includes only data LEBs)
 630  * @total_dead: total dead space in bytes (includes only data LEBs)
 631  * @total_dark: total dark space in bytes (includes only data LEBs)
 632  * @lpt_lnum: LEB number of LPT root nnode
 633  * @lpt_offs: offset of LPT root nnode
 634  * @nhead_lnum: LEB number of LPT head
 635  * @nhead_offs: offset of LPT head
 636  * @ltab_lnum: LEB number of LPT's own lprops table
 637  * @ltab_offs: offset of LPT's own lprops table
 638  * @lsave_lnum: LEB number of LPT's save table (big model only)
 639  * @lsave_offs: offset of LPT's save table (big model only)
 640  * @lscan_lnum: LEB number of last LPT scan
 641  * @empty_lebs: number of empty logical eraseblocks
 642  * @idx_lebs: number of indexing logical eraseblocks
 643  * @leb_cnt: count of LEBs used by file-system
 644  * @padding: reserved for future, zeroes
 645  */
 646 struct ubifs_mst_node {
 647         struct ubifs_ch ch;
 648         __le64 highest_inum;
 649         __le64 cmt_no;
 650         __le32 flags;
 651         __le32 log_lnum;
 652         __le32 root_lnum;
 653         __le32 root_offs;
 654         __le32 root_len;
 655         __le32 gc_lnum;
 656         __le32 ihead_lnum;
 657         __le32 ihead_offs;
 658         __le64 index_size;
 659         __le64 total_free;
 660         __le64 total_dirty;
 661         __le64 total_used;
 662         __le64 total_dead;
 663         __le64 total_dark;
 664         __le32 lpt_lnum;
 665         __le32 lpt_offs;
 666         __le32 nhead_lnum;
 667         __le32 nhead_offs;
 668         __le32 ltab_lnum;
 669         __le32 ltab_offs;
 670         __le32 lsave_lnum;
 671         __le32 lsave_offs;
 672         __le32 lscan_lnum;
 673         __le32 empty_lebs;
 674         __le32 idx_lebs;
 675         __le32 leb_cnt;
 676         __u8 padding[344];
 677 } __attribute__ ((packed));
 678
 679 /**
 680  * struct ubifs_ref_node - logical eraseblock reference node.
 681  * @ch: common header
 682  * @lnum: the referred logical eraseblock number
 683  * @offs: start offset in the referred LEB
 684  * @jhead: journal head number
 685  * @padding: reserved for future, zeroes
 686  */
 687 struct ubifs_ref_node {
 688         struct ubifs_ch ch;
 689         __le32 lnum;
 690         __le32 offs;
 691         __le32 jhead;
 692         __u8 padding[28];
 693 } __attribute__ ((packed));
 694
 695 /**
 696  * struct ubifs_branch - key/reference/length branch
 697  * @lnum: LEB number of the target node
 698  * @offs: offset within @lnum
 699  * @len: target node length
 700  * @key: key
 701  */
 702 struct ubifs_branch {
 703         __le32 lnum;
 704         __le32 offs;
 705         __le32 len;
 706         __u8 key[];
 707 } __attribute__ ((packed));
 708
 709 /**
 710  * struct ubifs_idx_node - indexing node.
 711  * @ch: common header
 712  * @child_cnt: number of child index nodes
 713  * @level: tree level
 714  * @branches: LEB number / offset / length / key branches
 715  */
 716 struct ubifs_idx_node {
 717         struct ubifs_ch ch;
 718         __le16 child_cnt;
 719         __le16 level;
 720         __u8 branches[];
 721 } __attribute__ ((packed));
 722
 723 /**
 724  * struct ubifs_cs_node - commit start node.
 725  * @ch: common header
 726  * @cmt_no: commit number
 727  */
 728 struct ubifs_cs_node {
 729         struct ubifs_ch ch;
 730         __le64 cmt_no;
 731 } __attribute__ ((packed));
 732
 733 /**
 734  * struct ubifs_orph_node - orphan node.
 735  * @ch: common header
 736  * @cmt_no: commit number (also top bit is set on the last node of the commit)
 737  * @inos: inode numbers of orphans
 738  */
 739 struct ubifs_orph_node {
 740         struct ubifs_ch ch;
 741         __le64 cmt_no;
 742         __le64 inos[];
 743 } __attribute__ ((packed));
 744
 745 #endif /* __UBIFS_MEDIA_H__ */