xref: /openbmc/u-boot/fs/ubifs/ubifs-media.h (revision dd1033e4)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation.
6  *
7  * Authors: Artem Bityutskiy (Битюцкий Артём)
8  *          Adrian Hunter
9  */
10 
11 /*
12  * This file describes UBIFS on-flash format and contains definitions of all the
13  * relevant data structures and constants.
14  *
15  * All UBIFS on-flash objects are stored in the form of nodes. All nodes start
16  * with the UBIFS node magic number and have the same common header. Nodes
17  * always sit at 8-byte aligned positions on the media and node header sizes are
18  * also 8-byte aligned (except for the indexing node and the padding node).
19  */
20 
21 #ifndef __UBIFS_MEDIA_H__
22 #define __UBIFS_MEDIA_H__
23 
24 /* UBIFS node magic number (must not have the padding byte first or last) */
25 #define UBIFS_NODE_MAGIC  0x06101831
26 
27 /*
28  * UBIFS on-flash format version. This version is increased when the on-flash
29  * format is changing. If this happens, UBIFS is will support older versions as
30  * well. But older UBIFS code will not support newer formats. Format changes
31  * will be rare and only when absolutely necessary, e.g. to fix a bug or to add
32  * a new feature.
33  *
34  * UBIFS went into mainline kernel with format version 4. The older formats
35  * were development formats.
36  */
37 #define UBIFS_FORMAT_VERSION 4
38 
39 /*
40  * Read-only compatibility version. If the UBIFS format is changed, older UBIFS
41  * implementations will not be able to mount newer formats in read-write mode.
42  * However, depending on the change, it may be possible to mount newer formats
43  * in R/O mode. This is indicated by the R/O compatibility version which is
44  * stored in the super-block.
45  *
46  * This is needed to support boot-loaders which only need R/O mounting. With
47  * this flag it is possible to do UBIFS format changes without a need to update
48  * boot-loaders.
49  */
50 #define UBIFS_RO_COMPAT_VERSION 0
51 
52 /* Minimum logical eraseblock size in bytes */
53 #define UBIFS_MIN_LEB_SZ (15*1024)
54 
55 /* Initial CRC32 value used when calculating CRC checksums */
56 #define UBIFS_CRC32_INIT 0xFFFFFFFFU
57 
58 /*
59  * UBIFS does not try to compress data if its length is less than the below
60  * constant.
61  */
62 #define UBIFS_MIN_COMPR_LEN 128
63 
64 /*
65  * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
66  * shorter than uncompressed data length, UBIFS prefers to leave this data
67  * node uncompress, because it'll be read faster.
68  */
69 #define UBIFS_MIN_COMPRESS_DIFF 64
70 
71 /* Root inode number */
72 #define UBIFS_ROOT_INO 1
73 
74 /* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
75 #define UBIFS_FIRST_INO 64
76 
77 /*
78  * Maximum file name and extended attribute length (must be a multiple of 8,
79  * minus 1).
80  */
81 #define UBIFS_MAX_NLEN 255
82 
83 /* Maximum number of data journal heads */
84 #define UBIFS_MAX_JHEADS 1
85 
86 /*
87  * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
88  * which means that it does not treat the underlying media as consisting of
89  * blocks like in case of hard drives. Do not be confused. UBIFS block is just
90  * the maximum amount of data which one data node can have or which can be
91  * attached to an inode node.
92  */
93 #define UBIFS_BLOCK_SIZE  4096
94 #define UBIFS_BLOCK_SHIFT 12
95 
96 /* UBIFS padding byte pattern (must not be first or last byte of node magic) */
97 #define UBIFS_PADDING_BYTE 0xCE
98 
99 /* Maximum possible key length */
100 #define UBIFS_MAX_KEY_LEN 16
101 
102 /* Key length ("simple" format) */
103 #define UBIFS_SK_LEN 8
104 
105 /* Minimum index tree fanout */
106 #define UBIFS_MIN_FANOUT 3
107 
108 /* Maximum number of levels in UBIFS indexing B-tree */
109 #define UBIFS_MAX_LEVELS 512
110 
111 /* Maximum amount of data attached to an inode in bytes */
112 #define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
113 
114 /* LEB Properties Tree fanout (must be power of 2) and fanout shift */
115 #define UBIFS_LPT_FANOUT 4
116 #define UBIFS_LPT_FANOUT_SHIFT 2
117 
118 /* LEB Properties Tree bit field sizes */
119 #define UBIFS_LPT_CRC_BITS 16
120 #define UBIFS_LPT_CRC_BYTES 2
121 #define UBIFS_LPT_TYPE_BITS 4
122 
123 /* The key is always at the same position in all keyed nodes */
124 #define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
125 
126 /* Garbage collector journal head number */
127 #define UBIFS_GC_HEAD   0
128 /* Base journal head number */
129 #define UBIFS_BASE_HEAD 1
130 /* Data journal head number */
131 #define UBIFS_DATA_HEAD 2
132 
133 /*
134  * LEB Properties Tree node types.
135  *
136  * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
137  * UBIFS_LPT_NNODE: LPT internal node
138  * UBIFS_LPT_LTAB: LPT's own lprops table
139  * UBIFS_LPT_LSAVE: LPT's save table (big model only)
140  * UBIFS_LPT_NODE_CNT: count of LPT node types
141  * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
142  */
143 enum {
144 	UBIFS_LPT_PNODE,
145 	UBIFS_LPT_NNODE,
146 	UBIFS_LPT_LTAB,
147 	UBIFS_LPT_LSAVE,
148 	UBIFS_LPT_NODE_CNT,
149 	UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
150 };
151 
152 /*
153  * UBIFS inode types.
154  *
155  * UBIFS_ITYPE_REG: regular file
156  * UBIFS_ITYPE_DIR: directory
157  * UBIFS_ITYPE_LNK: soft link
158  * UBIFS_ITYPE_BLK: block device node
159  * UBIFS_ITYPE_CHR: character device node
160  * UBIFS_ITYPE_FIFO: fifo
161  * UBIFS_ITYPE_SOCK: socket
162  * UBIFS_ITYPES_CNT: count of supported file types
163  */
164 enum {
165 	UBIFS_ITYPE_REG,
166 	UBIFS_ITYPE_DIR,
167 	UBIFS_ITYPE_LNK,
168 	UBIFS_ITYPE_BLK,
169 	UBIFS_ITYPE_CHR,
170 	UBIFS_ITYPE_FIFO,
171 	UBIFS_ITYPE_SOCK,
172 	UBIFS_ITYPES_CNT,
173 };
174 
175 /*
176  * Supported key hash functions.
177  *
178  * UBIFS_KEY_HASH_R5: R5 hash
179  * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
180  */
181 enum {
182 	UBIFS_KEY_HASH_R5,
183 	UBIFS_KEY_HASH_TEST,
184 };
185 
186 /*
187  * Supported key formats.
188  *
189  * UBIFS_SIMPLE_KEY_FMT: simple key format
190  */
191 enum {
192 	UBIFS_SIMPLE_KEY_FMT,
193 };
194 
195 /*
196  * The simple key format uses 29 bits for storing UBIFS block number and hash
197  * value.
198  */
199 #define UBIFS_S_KEY_BLOCK_BITS 29
200 #define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
201 #define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
202 #define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
203 
204 /*
205  * Key types.
206  *
207  * UBIFS_INO_KEY: inode node key
208  * UBIFS_DATA_KEY: data node key
209  * UBIFS_DENT_KEY: directory entry node key
210  * UBIFS_XENT_KEY: extended attribute entry key
211  * UBIFS_KEY_TYPES_CNT: number of supported key types
212  */
213 enum {
214 	UBIFS_INO_KEY,
215 	UBIFS_DATA_KEY,
216 	UBIFS_DENT_KEY,
217 	UBIFS_XENT_KEY,
218 	UBIFS_KEY_TYPES_CNT,
219 };
220 
221 /* Count of LEBs reserved for the superblock area */
222 #define UBIFS_SB_LEBS 1
223 /* Count of LEBs reserved for the master area */
224 #define UBIFS_MST_LEBS 2
225 
226 /* First LEB of the superblock area */
227 #define UBIFS_SB_LNUM 0
228 /* First LEB of the master area */
229 #define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
230 /* First LEB of the log area */
231 #define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
232 
233 /*
234  * The below constants define the absolute minimum values for various UBIFS
235  * media areas. Many of them actually depend of flash geometry and the FS
236  * configuration (number of journal heads, orphan LEBs, etc). This means that
237  * the smallest volume size which can be used for UBIFS cannot be pre-defined
238  * by these constants. The file-system that meets the below limitation will not
239  * necessarily mount. UBIFS does run-time calculations and validates the FS
240  * size.
241  */
242 
243 /* Minimum number of logical eraseblocks in the log */
244 #define UBIFS_MIN_LOG_LEBS 2
245 /* Minimum number of bud logical eraseblocks (one for each head) */
246 #define UBIFS_MIN_BUD_LEBS 3
247 /* Minimum number of journal logical eraseblocks */
248 #define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
249 /* Minimum number of LPT area logical eraseblocks */
250 #define UBIFS_MIN_LPT_LEBS 2
251 /* Minimum number of orphan area logical eraseblocks */
252 #define UBIFS_MIN_ORPH_LEBS 1
253 /*
254  * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
255  * for GC, 1 for deletions, and at least 1 for committed data).
256  */
257 #define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
258 
259 /* Minimum number of logical eraseblocks */
260 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
261 			   UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
262 			   UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
263 
264 /* Node sizes (N.B. these are guaranteed to be multiples of 8) */
265 #define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
266 #define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
267 #define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
268 #define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
269 #define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
270 #define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
271 #define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
272 #define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
273 #define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
274 #define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
275 #define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
276 #define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
277 /* Extended attribute entry nodes are identical to directory entry nodes */
278 #define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
279 /* Only this does not have to be multiple of 8 bytes */
280 #define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
281 
282 /* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
283 #define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
284 #define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
285 #define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
286 #define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
287 
288 /* The largest UBIFS node */
289 #define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
290 
291 /*
292  * On-flash inode flags.
293  *
294  * UBIFS_COMPR_FL: use compression for this inode
295  * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
296  * UBIFS_IMMUTABLE_FL: inode is immutable
297  * UBIFS_APPEND_FL: writes to the inode may only append data
298  * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
299  * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
300  *
301  * Note, these are on-flash flags which correspond to ioctl flags
302  * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
303  * have to be the same.
304  */
305 enum {
306 	UBIFS_COMPR_FL     = 0x01,
307 	UBIFS_SYNC_FL      = 0x02,
308 	UBIFS_IMMUTABLE_FL = 0x04,
309 	UBIFS_APPEND_FL    = 0x08,
310 	UBIFS_DIRSYNC_FL   = 0x10,
311 	UBIFS_XATTR_FL     = 0x20,
312 };
313 
314 /* Inode flag bits used by UBIFS */
315 #define UBIFS_FL_MASK 0x0000001F
316 
317 /*
318  * UBIFS compression algorithms.
319  *
320  * UBIFS_COMPR_NONE: no compression
321  * UBIFS_COMPR_LZO: LZO compression
322  * UBIFS_COMPR_ZLIB: ZLIB compression
323  * UBIFS_COMPR_TYPES_CNT: count of supported compression types
324  */
325 enum {
326 	UBIFS_COMPR_NONE,
327 	UBIFS_COMPR_LZO,
328 	UBIFS_COMPR_ZLIB,
329 	UBIFS_COMPR_TYPES_CNT,
330 };
331 
332 /*
333  * UBIFS node types.
334  *
335  * UBIFS_INO_NODE: inode node
336  * UBIFS_DATA_NODE: data node
337  * UBIFS_DENT_NODE: directory entry node
338  * UBIFS_XENT_NODE: extended attribute node
339  * UBIFS_TRUN_NODE: truncation node
340  * UBIFS_PAD_NODE: padding node
341  * UBIFS_SB_NODE: superblock node
342  * UBIFS_MST_NODE: master node
343  * UBIFS_REF_NODE: LEB reference node
344  * UBIFS_IDX_NODE: index node
345  * UBIFS_CS_NODE: commit start node
346  * UBIFS_ORPH_NODE: orphan node
347  * UBIFS_NODE_TYPES_CNT: count of supported node types
348  *
349  * Note, we index arrays by these numbers, so keep them low and contiguous.
350  * Node type constants for inodes, direntries and so on have to be the same as
351  * corresponding key type constants.
352  */
353 enum {
354 	UBIFS_INO_NODE,
355 	UBIFS_DATA_NODE,
356 	UBIFS_DENT_NODE,
357 	UBIFS_XENT_NODE,
358 	UBIFS_TRUN_NODE,
359 	UBIFS_PAD_NODE,
360 	UBIFS_SB_NODE,
361 	UBIFS_MST_NODE,
362 	UBIFS_REF_NODE,
363 	UBIFS_IDX_NODE,
364 	UBIFS_CS_NODE,
365 	UBIFS_ORPH_NODE,
366 	UBIFS_NODE_TYPES_CNT,
367 };
368 
369 /*
370  * Master node flags.
371  *
372  * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
373  * UBIFS_MST_NO_ORPHS: no orphan inodes present
374  * UBIFS_MST_RCVRY: written by recovery
375  */
376 enum {
377 	UBIFS_MST_DIRTY = 1,
378 	UBIFS_MST_NO_ORPHS = 2,
379 	UBIFS_MST_RCVRY = 4,
380 };
381 
382 /*
383  * Node group type (used by recovery to recover whole group or none).
384  *
385  * UBIFS_NO_NODE_GROUP: this node is not part of a group
386  * UBIFS_IN_NODE_GROUP: this node is a part of a group
387  * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
388  */
389 enum {
390 	UBIFS_NO_NODE_GROUP = 0,
391 	UBIFS_IN_NODE_GROUP,
392 	UBIFS_LAST_OF_NODE_GROUP,
393 };
394 
395 /*
396  * Superblock flags.
397  *
398  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
399  * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
400  */
401 enum {
402 	UBIFS_FLG_BIGLPT = 0x02,
403 	UBIFS_FLG_SPACE_FIXUP = 0x04,
404 };
405 
406 /**
407  * struct ubifs_ch - common header node.
408  * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
409  * @crc: CRC-32 checksum of the node header
410  * @sqnum: sequence number
411  * @len: full node length
412  * @node_type: node type
413  * @group_type: node group type
414  * @padding: reserved for future, zeroes
415  *
416  * Every UBIFS node starts with this common part. If the node has a key, the
417  * key always goes next.
418  */
419 struct ubifs_ch {
420 	__le32 magic;
421 	__le32 crc;
422 	__le64 sqnum;
423 	__le32 len;
424 	__u8 node_type;
425 	__u8 group_type;
426 	__u8 padding[2];
427 } __packed;
428 
429 /**
430  * union ubifs_dev_desc - device node descriptor.
431  * @new: new type device descriptor
432  * @huge: huge type device descriptor
433  *
434  * This data structure describes major/minor numbers of a device node. In an
435  * inode is a device node then its data contains an object of this type. UBIFS
436  * uses standard Linux "new" and "huge" device node encodings.
437  */
438 union ubifs_dev_desc {
439 	__le32 new;
440 	__le64 huge;
441 } __packed;
442 
443 /**
444  * struct ubifs_ino_node - inode node.
445  * @ch: common header
446  * @key: node key
447  * @creat_sqnum: sequence number at time of creation
448  * @size: inode size in bytes (amount of uncompressed data)
449  * @atime_sec: access time seconds
450  * @ctime_sec: creation time seconds
451  * @mtime_sec: modification time seconds
452  * @atime_nsec: access time nanoseconds
453  * @ctime_nsec: creation time nanoseconds
454  * @mtime_nsec: modification time nanoseconds
455  * @nlink: number of hard links
456  * @uid: owner ID
457  * @gid: group ID
458  * @mode: access flags
459  * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
460  * @data_len: inode data length
461  * @xattr_cnt: count of extended attributes this inode has
462  * @xattr_size: summarized size of all extended attributes in bytes
463  * @padding1: reserved for future, zeroes
464  * @xattr_names: sum of lengths of all extended attribute names belonging to
465  *               this inode
466  * @compr_type: compression type used for this inode
467  * @padding2: reserved for future, zeroes
468  * @data: data attached to the inode
469  *
470  * Note, even though inode compression type is defined by @compr_type, some
471  * nodes of this inode may be compressed with different compressor - this
472  * happens if compression type is changed while the inode already has data
473  * nodes. But @compr_type will be use for further writes to the inode.
474  *
475  * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
476  * the padding fields.
477  */
478 struct ubifs_ino_node {
479 	struct ubifs_ch ch;
480 	__u8 key[UBIFS_MAX_KEY_LEN];
481 	__le64 creat_sqnum;
482 	__le64 size;
483 	__le64 atime_sec;
484 	__le64 ctime_sec;
485 	__le64 mtime_sec;
486 	__le32 atime_nsec;
487 	__le32 ctime_nsec;
488 	__le32 mtime_nsec;
489 	__le32 nlink;
490 	__le32 uid;
491 	__le32 gid;
492 	__le32 mode;
493 	__le32 flags;
494 	__le32 data_len;
495 	__le32 xattr_cnt;
496 	__le32 xattr_size;
497 	__u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
498 	__le32 xattr_names;
499 	__le16 compr_type;
500 	__u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
501 	__u8 data[];
502 } __packed;
503 
504 /**
505  * struct ubifs_dent_node - directory entry node.
506  * @ch: common header
507  * @key: node key
508  * @inum: target inode number
509  * @padding1: reserved for future, zeroes
510  * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
511  * @nlen: name length
512  * @padding2: reserved for future, zeroes
513  * @name: zero-terminated name
514  *
515  * Note, do not forget to amend 'zero_dent_node_unused()' function when
516  * changing the padding fields.
517  */
518 struct ubifs_dent_node {
519 	struct ubifs_ch ch;
520 	__u8 key[UBIFS_MAX_KEY_LEN];
521 	__le64 inum;
522 	__u8 padding1;
523 	__u8 type;
524 	__le16 nlen;
525 	__u8 padding2[4]; /* Watch 'zero_dent_node_unused()' if changing! */
526 #ifndef __UBOOT__
527 	__u8 name[];
528 #else
529 	char name[];
530 #endif
531 } __packed;
532 
533 /**
534  * struct ubifs_data_node - data node.
535  * @ch: common header
536  * @key: node key
537  * @size: uncompressed data size in bytes
538  * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
539  * @padding: reserved for future, zeroes
540  * @data: data
541  *
542  * Note, do not forget to amend 'zero_data_node_unused()' function when
543  * changing the padding fields.
544  */
545 struct ubifs_data_node {
546 	struct ubifs_ch ch;
547 	__u8 key[UBIFS_MAX_KEY_LEN];
548 	__le32 size;
549 	__le16 compr_type;
550 	__u8 padding[2]; /* Watch 'zero_data_node_unused()' if changing! */
551 	__u8 data[];
552 } __packed;
553 
554 /**
555  * struct ubifs_trun_node - truncation node.
556  * @ch: common header
557  * @inum: truncated inode number
558  * @padding: reserved for future, zeroes
559  * @old_size: size before truncation
560  * @new_size: size after truncation
561  *
562  * This node exists only in the journal and never goes to the main area. Note,
563  * do not forget to amend 'zero_trun_node_unused()' function when changing the
564  * padding fields.
565  */
566 struct ubifs_trun_node {
567 	struct ubifs_ch ch;
568 	__le32 inum;
569 	__u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
570 	__le64 old_size;
571 	__le64 new_size;
572 } __packed;
573 
574 /**
575  * struct ubifs_pad_node - padding node.
576  * @ch: common header
577  * @pad_len: how many bytes after this node are unused (because padded)
578  * @padding: reserved for future, zeroes
579  */
580 struct ubifs_pad_node {
581 	struct ubifs_ch ch;
582 	__le32 pad_len;
583 } __packed;
584 
585 /**
586  * struct ubifs_sb_node - superblock node.
587  * @ch: common header
588  * @padding: reserved for future, zeroes
589  * @key_hash: type of hash function used in keys
590  * @key_fmt: format of the key
591  * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
592  * @min_io_size: minimal input/output unit size
593  * @leb_size: logical eraseblock size in bytes
594  * @leb_cnt: count of LEBs used by file-system
595  * @max_leb_cnt: maximum count of LEBs used by file-system
596  * @max_bud_bytes: maximum amount of data stored in buds
597  * @log_lebs: log size in logical eraseblocks
598  * @lpt_lebs: number of LEBs used for lprops table
599  * @orph_lebs: number of LEBs used for recording orphans
600  * @jhead_cnt: count of journal heads
601  * @fanout: tree fanout (max. number of links per indexing node)
602  * @lsave_cnt: number of LEB numbers in LPT's save table
603  * @fmt_version: UBIFS on-flash format version
604  * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
605  * @padding1: reserved for future, zeroes
606  * @rp_uid: reserve pool UID
607  * @rp_gid: reserve pool GID
608  * @rp_size: size of the reserved pool in bytes
609  * @padding2: reserved for future, zeroes
610  * @time_gran: time granularity in nanoseconds
611  * @uuid: UUID generated when the file system image was created
612  * @ro_compat_version: UBIFS R/O compatibility version
613  */
614 struct ubifs_sb_node {
615 	struct ubifs_ch ch;
616 	__u8 padding[2];
617 	__u8 key_hash;
618 	__u8 key_fmt;
619 	__le32 flags;
620 	__le32 min_io_size;
621 	__le32 leb_size;
622 	__le32 leb_cnt;
623 	__le32 max_leb_cnt;
624 	__le64 max_bud_bytes;
625 	__le32 log_lebs;
626 	__le32 lpt_lebs;
627 	__le32 orph_lebs;
628 	__le32 jhead_cnt;
629 	__le32 fanout;
630 	__le32 lsave_cnt;
631 	__le32 fmt_version;
632 	__le16 default_compr;
633 	__u8 padding1[2];
634 	__le32 rp_uid;
635 	__le32 rp_gid;
636 	__le64 rp_size;
637 	__le32 time_gran;
638 	__u8 uuid[16];
639 	__le32 ro_compat_version;
640 	__u8 padding2[3968];
641 } __packed;
642 
643 /**
644  * struct ubifs_mst_node - master node.
645  * @ch: common header
646  * @highest_inum: highest inode number in the committed index
647  * @cmt_no: commit number
648  * @flags: various flags (%UBIFS_MST_DIRTY, etc)
649  * @log_lnum: start of the log
650  * @root_lnum: LEB number of the root indexing node
651  * @root_offs: offset within @root_lnum
652  * @root_len: root indexing node length
653  * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
654  * not reserved and should be reserved on mount)
655  * @ihead_lnum: LEB number of index head
656  * @ihead_offs: offset of index head
657  * @index_size: size of index on flash
658  * @total_free: total free space in bytes
659  * @total_dirty: total dirty space in bytes
660  * @total_used: total used space in bytes (includes only data LEBs)
661  * @total_dead: total dead space in bytes (includes only data LEBs)
662  * @total_dark: total dark space in bytes (includes only data LEBs)
663  * @lpt_lnum: LEB number of LPT root nnode
664  * @lpt_offs: offset of LPT root nnode
665  * @nhead_lnum: LEB number of LPT head
666  * @nhead_offs: offset of LPT head
667  * @ltab_lnum: LEB number of LPT's own lprops table
668  * @ltab_offs: offset of LPT's own lprops table
669  * @lsave_lnum: LEB number of LPT's save table (big model only)
670  * @lsave_offs: offset of LPT's save table (big model only)
671  * @lscan_lnum: LEB number of last LPT scan
672  * @empty_lebs: number of empty logical eraseblocks
673  * @idx_lebs: number of indexing logical eraseblocks
674  * @leb_cnt: count of LEBs used by file-system
675  * @padding: reserved for future, zeroes
676  */
677 struct ubifs_mst_node {
678 	struct ubifs_ch ch;
679 	__le64 highest_inum;
680 	__le64 cmt_no;
681 	__le32 flags;
682 	__le32 log_lnum;
683 	__le32 root_lnum;
684 	__le32 root_offs;
685 	__le32 root_len;
686 	__le32 gc_lnum;
687 	__le32 ihead_lnum;
688 	__le32 ihead_offs;
689 	__le64 index_size;
690 	__le64 total_free;
691 	__le64 total_dirty;
692 	__le64 total_used;
693 	__le64 total_dead;
694 	__le64 total_dark;
695 	__le32 lpt_lnum;
696 	__le32 lpt_offs;
697 	__le32 nhead_lnum;
698 	__le32 nhead_offs;
699 	__le32 ltab_lnum;
700 	__le32 ltab_offs;
701 	__le32 lsave_lnum;
702 	__le32 lsave_offs;
703 	__le32 lscan_lnum;
704 	__le32 empty_lebs;
705 	__le32 idx_lebs;
706 	__le32 leb_cnt;
707 	__u8 padding[344];
708 } __packed;
709 
710 /**
711  * struct ubifs_ref_node - logical eraseblock reference node.
712  * @ch: common header
713  * @lnum: the referred logical eraseblock number
714  * @offs: start offset in the referred LEB
715  * @jhead: journal head number
716  * @padding: reserved for future, zeroes
717  */
718 struct ubifs_ref_node {
719 	struct ubifs_ch ch;
720 	__le32 lnum;
721 	__le32 offs;
722 	__le32 jhead;
723 	__u8 padding[28];
724 } __packed;
725 
726 /**
727  * struct ubifs_branch - key/reference/length branch
728  * @lnum: LEB number of the target node
729  * @offs: offset within @lnum
730  * @len: target node length
731  * @key: key
732  */
733 struct ubifs_branch {
734 	__le32 lnum;
735 	__le32 offs;
736 	__le32 len;
737 #ifndef __UBOOT__
738 	__u8 key[];
739 #else
740 	char key[];
741 #endif
742 } __packed;
743 
744 /**
745  * struct ubifs_idx_node - indexing node.
746  * @ch: common header
747  * @child_cnt: number of child index nodes
748  * @level: tree level
749  * @branches: LEB number / offset / length / key branches
750  */
751 struct ubifs_idx_node {
752 	struct ubifs_ch ch;
753 	__le16 child_cnt;
754 	__le16 level;
755 #ifndef __UBOOT__
756 	__u8 branches[];
757 #else
758 	char branches[];
759 #endif
760 } __packed;
761 
762 /**
763  * struct ubifs_cs_node - commit start node.
764  * @ch: common header
765  * @cmt_no: commit number
766  */
767 struct ubifs_cs_node {
768 	struct ubifs_ch ch;
769 	__le64 cmt_no;
770 } __packed;
771 
772 /**
773  * struct ubifs_orph_node - orphan node.
774  * @ch: common header
775  * @cmt_no: commit number (also top bit is set on the last node of the commit)
776  * @inos: inode numbers of orphans
777  */
778 struct ubifs_orph_node {
779 	struct ubifs_ch ch;
780 	__le64 cmt_no;
781 	__le64 inos[];
782 } __packed;
783 
784 #endif /* __UBIFS_MEDIA_H__ */
785