xref: /openbmc/linux/fs/ubifs/ubifs-media.h (revision 545e4006)
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, 2 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 + 5)
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__ */
746