xref: /openbmc/u-boot/fs/ubifs/ubifs-media.h (revision 607232e4)
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__ */
776