Loading...
1/* SPDX-License-Identifier: GPL-2.0-only */
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 header contains various key-related definitions and helper function.
13 * UBIFS allows several key schemes, so we access key fields only via these
14 * helpers. At the moment only one key scheme is supported.
15 *
16 * Simple key scheme
17 * ~~~~~~~~~~~~~~~~~
18 *
19 * Keys are 64-bits long. First 32-bits are inode number (parent inode number
20 * in case of direntry key). Next 3 bits are node type. The last 29 bits are
21 * 4KiB offset in case of inode node, and direntry hash in case of a direntry
22 * node. We use "r5" hash borrowed from reiserfs.
23 */
24
25/*
26 * Lot's of the key helpers require a struct ubifs_info *c as the first parameter.
27 * But we are not using it at all currently. That's designed for future extensions of
28 * different c->key_format. But right now, there is only one key type, UBIFS_SIMPLE_KEY_FMT.
29 */
30
31#ifndef __UBIFS_KEY_H__
32#define __UBIFS_KEY_H__
33
34/**
35 * key_mask_hash - mask a valid hash value.
36 * @val: value to be masked
37 *
38 * We use hash values as offset in directories, so values %0 and %1 are
39 * reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
40 * function makes sure the reserved values are not used.
41 */
42static inline uint32_t key_mask_hash(uint32_t hash)
43{
44 hash &= UBIFS_S_KEY_HASH_MASK;
45 if (unlikely(hash <= 2))
46 hash += 3;
47 return hash;
48}
49
50/**
51 * key_r5_hash - R5 hash function (borrowed from reiserfs).
52 * @s: direntry name
53 * @len: name length
54 */
55static inline uint32_t key_r5_hash(const char *s, int len)
56{
57 uint32_t a = 0;
58 const signed char *str = (const signed char *)s;
59
60 while (len--) {
61 a += *str << 4;
62 a += *str >> 4;
63 a *= 11;
64 str++;
65 }
66
67 return key_mask_hash(a);
68}
69
70/**
71 * key_test_hash - testing hash function.
72 * @str: direntry name
73 * @len: name length
74 */
75static inline uint32_t key_test_hash(const char *str, int len)
76{
77 uint32_t a = 0;
78
79 len = min_t(uint32_t, len, 4);
80 memcpy(&a, str, len);
81 return key_mask_hash(a);
82}
83
84/**
85 * ino_key_init - initialize inode key.
86 * @c: UBIFS file-system description object
87 * @key: key to initialize
88 * @inum: inode number
89 */
90static inline void ino_key_init(const struct ubifs_info *c,
91 union ubifs_key *key, ino_t inum)
92{
93 key->u32[0] = inum;
94 key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
95}
96
97/**
98 * ino_key_init_flash - initialize on-flash inode key.
99 * @c: UBIFS file-system description object
100 * @k: key to initialize
101 * @inum: inode number
102 */
103static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
104 ino_t inum)
105{
106 union ubifs_key *key = k;
107
108 key->j32[0] = cpu_to_le32(inum);
109 key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
110 memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
111}
112
113/**
114 * lowest_ino_key - get the lowest possible inode key.
115 * @c: UBIFS file-system description object
116 * @key: key to initialize
117 * @inum: inode number
118 */
119static inline void lowest_ino_key(const struct ubifs_info *c,
120 union ubifs_key *key, ino_t inum)
121{
122 key->u32[0] = inum;
123 key->u32[1] = 0;
124}
125
126/**
127 * highest_ino_key - get the highest possible inode key.
128 * @c: UBIFS file-system description object
129 * @key: key to initialize
130 * @inum: inode number
131 */
132static inline void highest_ino_key(const struct ubifs_info *c,
133 union ubifs_key *key, ino_t inum)
134{
135 key->u32[0] = inum;
136 key->u32[1] = 0xffffffff;
137}
138
139/**
140 * dent_key_init - initialize directory entry key.
141 * @c: UBIFS file-system description object
142 * @key: key to initialize
143 * @inum: parent inode number
144 * @nm: direntry name and length. Not a string when encrypted!
145 */
146static inline void dent_key_init(const struct ubifs_info *c,
147 union ubifs_key *key, ino_t inum,
148 const struct fscrypt_name *nm)
149{
150 uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
151
152 ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
153 ubifs_assert(c, !nm->hash && !nm->minor_hash);
154 key->u32[0] = inum;
155 key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
156}
157
158/**
159 * dent_key_init_hash - initialize directory entry key without re-calculating
160 * hash function.
161 * @c: UBIFS file-system description object
162 * @key: key to initialize
163 * @inum: parent inode number
164 * @hash: direntry name hash
165 */
166static inline void dent_key_init_hash(const struct ubifs_info *c,
167 union ubifs_key *key, ino_t inum,
168 uint32_t hash)
169{
170 ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
171 key->u32[0] = inum;
172 key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
173}
174
175/**
176 * dent_key_init_flash - initialize on-flash directory entry key.
177 * @c: UBIFS file-system description object
178 * @k: key to initialize
179 * @inum: parent inode number
180 * @nm: direntry name and length
181 */
182static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
183 ino_t inum,
184 const struct fscrypt_name *nm)
185{
186 union ubifs_key *key = k;
187 uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
188
189 ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
190 key->j32[0] = cpu_to_le32(inum);
191 key->j32[1] = cpu_to_le32(hash |
192 (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
193 memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
194}
195
196/**
197 * lowest_dent_key - get the lowest possible directory entry key.
198 * @c: UBIFS file-system description object
199 * @key: where to store the lowest key
200 * @inum: parent inode number
201 */
202static inline void lowest_dent_key(const struct ubifs_info *c,
203 union ubifs_key *key, ino_t inum)
204{
205 key->u32[0] = inum;
206 key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
207}
208
209/**
210 * xent_key_init - initialize extended attribute entry key.
211 * @c: UBIFS file-system description object
212 * @key: key to initialize
213 * @inum: host inode number
214 * @nm: extended attribute entry name and length
215 */
216static inline void xent_key_init(const struct ubifs_info *c,
217 union ubifs_key *key, ino_t inum,
218 const struct fscrypt_name *nm)
219{
220 uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
221
222 ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
223 key->u32[0] = inum;
224 key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
225}
226
227/**
228 * xent_key_init_flash - initialize on-flash extended attribute entry key.
229 * @c: UBIFS file-system description object
230 * @k: key to initialize
231 * @inum: host inode number
232 * @nm: extended attribute entry name and length
233 */
234static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
235 ino_t inum, const struct fscrypt_name *nm)
236{
237 union ubifs_key *key = k;
238 uint32_t hash = c->key_hash(fname_name(nm), fname_len(nm));
239
240 ubifs_assert(c, !(hash & ~UBIFS_S_KEY_HASH_MASK));
241 key->j32[0] = cpu_to_le32(inum);
242 key->j32[1] = cpu_to_le32(hash |
243 (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
244 memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
245}
246
247/**
248 * lowest_xent_key - get the lowest possible extended attribute entry key.
249 * @c: UBIFS file-system description object
250 * @key: where to store the lowest key
251 * @inum: host inode number
252 */
253static inline void lowest_xent_key(const struct ubifs_info *c,
254 union ubifs_key *key, ino_t inum)
255{
256 key->u32[0] = inum;
257 key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
258}
259
260/**
261 * data_key_init - initialize data key.
262 * @c: UBIFS file-system description object
263 * @key: key to initialize
264 * @inum: inode number
265 * @block: block number
266 */
267static inline void data_key_init(const struct ubifs_info *c,
268 union ubifs_key *key, ino_t inum,
269 unsigned int block)
270{
271 ubifs_assert(c, !(block & ~UBIFS_S_KEY_BLOCK_MASK));
272 key->u32[0] = inum;
273 key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
274}
275
276/**
277 * highest_data_key - get the highest possible data key for an inode.
278 * @c: UBIFS file-system description object
279 * @key: key to initialize
280 * @inum: inode number
281 */
282static inline void highest_data_key(const struct ubifs_info *c,
283 union ubifs_key *key, ino_t inum)
284{
285 data_key_init(c, key, inum, UBIFS_S_KEY_BLOCK_MASK);
286}
287
288/**
289 * trun_key_init - initialize truncation node key.
290 * @c: UBIFS file-system description object
291 * @key: key to initialize
292 * @inum: inode number
293 *
294 * Note, UBIFS does not have truncation keys on the media and this function is
295 * only used for purposes of replay.
296 */
297static inline void trun_key_init(const struct ubifs_info *c,
298 union ubifs_key *key, ino_t inum)
299{
300 key->u32[0] = inum;
301 key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
302}
303
304/**
305 * invalid_key_init - initialize invalid node key.
306 * @c: UBIFS file-system description object
307 * @key: key to initialize
308 *
309 * This is a helper function which marks a @key object as invalid.
310 */
311static inline void invalid_key_init(const struct ubifs_info *c,
312 union ubifs_key *key)
313{
314 key->u32[0] = 0xDEADBEAF;
315 key->u32[1] = UBIFS_INVALID_KEY;
316}
317
318/**
319 * key_type - get key type.
320 * @c: UBIFS file-system description object
321 * @key: key to get type of
322 */
323static inline int key_type(const struct ubifs_info *c,
324 const union ubifs_key *key)
325{
326 return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
327}
328
329/**
330 * key_type_flash - get type of a on-flash formatted key.
331 * @c: UBIFS file-system description object
332 * @k: key to get type of
333 */
334static inline int key_type_flash(const struct ubifs_info *c, const void *k)
335{
336 const union ubifs_key *key = k;
337
338 return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
339}
340
341/**
342 * key_inum - fetch inode number from key.
343 * @c: UBIFS file-system description object
344 * @k: key to fetch inode number from
345 */
346static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
347{
348 const union ubifs_key *key = k;
349
350 return key->u32[0];
351}
352
353/**
354 * key_inum_flash - fetch inode number from an on-flash formatted key.
355 * @c: UBIFS file-system description object
356 * @k: key to fetch inode number from
357 */
358static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
359{
360 const union ubifs_key *key = k;
361
362 return le32_to_cpu(key->j32[0]);
363}
364
365/**
366 * key_hash - get directory entry hash.
367 * @c: UBIFS file-system description object
368 * @key: the key to get hash from
369 */
370static inline uint32_t key_hash(const struct ubifs_info *c,
371 const union ubifs_key *key)
372{
373 return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
374}
375
376/**
377 * key_hash_flash - get directory entry hash from an on-flash formatted key.
378 * @c: UBIFS file-system description object
379 * @k: the key to get hash from
380 */
381static inline uint32_t key_hash_flash(const struct ubifs_info *c, const void *k)
382{
383 const union ubifs_key *key = k;
384
385 return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
386}
387
388/**
389 * key_block - get data block number.
390 * @c: UBIFS file-system description object
391 * @key: the key to get the block number from
392 */
393static inline unsigned int key_block(const struct ubifs_info *c,
394 const union ubifs_key *key)
395{
396 return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
397}
398
399/**
400 * key_block_flash - get data block number from an on-flash formatted key.
401 * @c: UBIFS file-system description object
402 * @k: the key to get the block number from
403 */
404static inline unsigned int key_block_flash(const struct ubifs_info *c,
405 const void *k)
406{
407 const union ubifs_key *key = k;
408
409 return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK;
410}
411
412/**
413 * key_read - transform a key to in-memory format.
414 * @c: UBIFS file-system description object
415 * @from: the key to transform
416 * @to: the key to store the result
417 */
418static inline void key_read(const struct ubifs_info *c, const void *from,
419 union ubifs_key *to)
420{
421 const union ubifs_key *f = from;
422
423 to->u32[0] = le32_to_cpu(f->j32[0]);
424 to->u32[1] = le32_to_cpu(f->j32[1]);
425}
426
427/**
428 * key_write - transform a key from in-memory format.
429 * @c: UBIFS file-system description object
430 * @from: the key to transform
431 * @to: the key to store the result
432 */
433static inline void key_write(const struct ubifs_info *c,
434 const union ubifs_key *from, void *to)
435{
436 union ubifs_key *t = to;
437
438 t->j32[0] = cpu_to_le32(from->u32[0]);
439 t->j32[1] = cpu_to_le32(from->u32[1]);
440 memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
441}
442
443/**
444 * key_write_idx - transform a key from in-memory format for the index.
445 * @c: UBIFS file-system description object
446 * @from: the key to transform
447 * @to: the key to store the result
448 */
449static inline void key_write_idx(const struct ubifs_info *c,
450 const union ubifs_key *from, void *to)
451{
452 union ubifs_key *t = to;
453
454 t->j32[0] = cpu_to_le32(from->u32[0]);
455 t->j32[1] = cpu_to_le32(from->u32[1]);
456}
457
458/**
459 * key_copy - copy a key.
460 * @c: UBIFS file-system description object
461 * @from: the key to copy from
462 * @to: the key to copy to
463 */
464static inline void key_copy(const struct ubifs_info *c,
465 const union ubifs_key *from, union ubifs_key *to)
466{
467 to->u64[0] = from->u64[0];
468}
469
470/**
471 * keys_cmp - compare keys.
472 * @c: UBIFS file-system description object
473 * @key1: the first key to compare
474 * @key2: the second key to compare
475 *
476 * This function compares 2 keys and returns %-1 if @key1 is less than
477 * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
478 */
479static inline int keys_cmp(const struct ubifs_info *c,
480 const union ubifs_key *key1,
481 const union ubifs_key *key2)
482{
483 if (key1->u32[0] < key2->u32[0])
484 return -1;
485 if (key1->u32[0] > key2->u32[0])
486 return 1;
487 if (key1->u32[1] < key2->u32[1])
488 return -1;
489 if (key1->u32[1] > key2->u32[1])
490 return 1;
491
492 return 0;
493}
494
495/**
496 * keys_eq - determine if keys are equivalent.
497 * @c: UBIFS file-system description object
498 * @key1: the first key to compare
499 * @key2: the second key to compare
500 *
501 * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
502 * %0 if not.
503 */
504static inline int keys_eq(const struct ubifs_info *c,
505 const union ubifs_key *key1,
506 const union ubifs_key *key2)
507{
508 if (key1->u32[0] != key2->u32[0])
509 return 0;
510 if (key1->u32[1] != key2->u32[1])
511 return 0;
512 return 1;
513}
514
515/**
516 * is_hash_key - is a key vulnerable to hash collisions.
517 * @c: UBIFS file-system description object
518 * @key: key
519 *
520 * This function returns %1 if @key is a hashed key or %0 otherwise.
521 */
522static inline int is_hash_key(const struct ubifs_info *c,
523 const union ubifs_key *key)
524{
525 int type = key_type(c, key);
526
527 return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
528}
529
530/**
531 * key_max_inode_size - get maximum file size allowed by current key format.
532 * @c: UBIFS file-system description object
533 */
534static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
535{
536 switch (c->key_fmt) {
537 case UBIFS_SIMPLE_KEY_FMT:
538 return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
539 default:
540 return 0;
541 }
542}
543
544#endif /* !__UBIFS_KEY_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 header contains various key-related definitions and helper function.
25 * UBIFS allows several key schemes, so we access key fields only via these
26 * helpers. At the moment only one key scheme is supported.
27 *
28 * Simple key scheme
29 * ~~~~~~~~~~~~~~~~~
30 *
31 * Keys are 64-bits long. First 32-bits are inode number (parent inode number
32 * in case of direntry key). Next 3 bits are node type. The last 29 bits are
33 * 4KiB offset in case of inode node, and direntry hash in case of a direntry
34 * node. We use "r5" hash borrowed from reiserfs.
35 */
36
37/*
38 * Lot's of the key helpers require a struct ubifs_info *c as the first parameter.
39 * But we are not using it at all currently. That's designed for future extensions of
40 * different c->key_format. But right now, there is only one key type, UBIFS_SIMPLE_KEY_FMT.
41 */
42
43#ifndef __UBIFS_KEY_H__
44#define __UBIFS_KEY_H__
45
46/**
47 * key_mask_hash - mask a valid hash value.
48 * @val: value to be masked
49 *
50 * We use hash values as offset in directories, so values %0 and %1 are
51 * reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
52 * function makes sure the reserved values are not used.
53 */
54static inline uint32_t key_mask_hash(uint32_t hash)
55{
56 hash &= UBIFS_S_KEY_HASH_MASK;
57 if (unlikely(hash <= 2))
58 hash += 3;
59 return hash;
60}
61
62/**
63 * key_r5_hash - R5 hash function (borrowed from reiserfs).
64 * @s: direntry name
65 * @len: name length
66 */
67static inline uint32_t key_r5_hash(const char *s, int len)
68{
69 uint32_t a = 0;
70 const signed char *str = (const signed char *)s;
71
72 while (*str) {
73 a += *str << 4;
74 a += *str >> 4;
75 a *= 11;
76 str++;
77 }
78
79 return key_mask_hash(a);
80}
81
82/**
83 * key_test_hash - testing hash function.
84 * @str: direntry name
85 * @len: name length
86 */
87static inline uint32_t key_test_hash(const char *str, int len)
88{
89 uint32_t a = 0;
90
91 len = min_t(uint32_t, len, 4);
92 memcpy(&a, str, len);
93 return key_mask_hash(a);
94}
95
96/**
97 * ino_key_init - initialize inode key.
98 * @c: UBIFS file-system description object
99 * @key: key to initialize
100 * @inum: inode number
101 */
102static inline void ino_key_init(const struct ubifs_info *c,
103 union ubifs_key *key, ino_t inum)
104{
105 key->u32[0] = inum;
106 key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
107}
108
109/**
110 * ino_key_init_flash - initialize on-flash inode key.
111 * @c: UBIFS file-system description object
112 * @k: key to initialize
113 * @inum: inode number
114 */
115static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
116 ino_t inum)
117{
118 union ubifs_key *key = k;
119
120 key->j32[0] = cpu_to_le32(inum);
121 key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
122 memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
123}
124
125/**
126 * lowest_ino_key - get the lowest possible inode key.
127 * @c: UBIFS file-system description object
128 * @key: key to initialize
129 * @inum: inode number
130 */
131static inline void lowest_ino_key(const struct ubifs_info *c,
132 union ubifs_key *key, ino_t inum)
133{
134 key->u32[0] = inum;
135 key->u32[1] = 0;
136}
137
138/**
139 * highest_ino_key - get the highest possible inode key.
140 * @c: UBIFS file-system description object
141 * @key: key to initialize
142 * @inum: inode number
143 */
144static inline void highest_ino_key(const struct ubifs_info *c,
145 union ubifs_key *key, ino_t inum)
146{
147 key->u32[0] = inum;
148 key->u32[1] = 0xffffffff;
149}
150
151/**
152 * dent_key_init - initialize directory entry key.
153 * @c: UBIFS file-system description object
154 * @key: key to initialize
155 * @inum: parent inode number
156 * @nm: direntry name and length
157 */
158static inline void dent_key_init(const struct ubifs_info *c,
159 union ubifs_key *key, ino_t inum,
160 const struct qstr *nm)
161{
162 uint32_t hash = c->key_hash(nm->name, nm->len);
163
164 ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
165 key->u32[0] = inum;
166 key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
167}
168
169/**
170 * dent_key_init_hash - initialize directory entry key without re-calculating
171 * hash function.
172 * @c: UBIFS file-system description object
173 * @key: key to initialize
174 * @inum: parent inode number
175 * @hash: direntry name hash
176 */
177static inline void dent_key_init_hash(const struct ubifs_info *c,
178 union ubifs_key *key, ino_t inum,
179 uint32_t hash)
180{
181 ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
182 key->u32[0] = inum;
183 key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
184}
185
186/**
187 * dent_key_init_flash - initialize on-flash directory entry key.
188 * @c: UBIFS file-system description object
189 * @k: key to initialize
190 * @inum: parent inode number
191 * @nm: direntry name and length
192 */
193static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
194 ino_t inum, const struct qstr *nm)
195{
196 union ubifs_key *key = k;
197 uint32_t hash = c->key_hash(nm->name, nm->len);
198
199 ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
200 key->j32[0] = cpu_to_le32(inum);
201 key->j32[1] = cpu_to_le32(hash |
202 (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
203 memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
204}
205
206/**
207 * lowest_dent_key - get the lowest possible directory entry key.
208 * @c: UBIFS file-system description object
209 * @key: where to store the lowest key
210 * @inum: parent inode number
211 */
212static inline void lowest_dent_key(const struct ubifs_info *c,
213 union ubifs_key *key, ino_t inum)
214{
215 key->u32[0] = inum;
216 key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
217}
218
219/**
220 * xent_key_init - initialize extended attribute entry key.
221 * @c: UBIFS file-system description object
222 * @key: key to initialize
223 * @inum: host inode number
224 * @nm: extended attribute entry name and length
225 */
226static inline void xent_key_init(const struct ubifs_info *c,
227 union ubifs_key *key, ino_t inum,
228 const struct qstr *nm)
229{
230 uint32_t hash = c->key_hash(nm->name, nm->len);
231
232 ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
233 key->u32[0] = inum;
234 key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
235}
236
237/**
238 * xent_key_init_flash - initialize on-flash extended attribute entry key.
239 * @c: UBIFS file-system description object
240 * @k: key to initialize
241 * @inum: host inode number
242 * @nm: extended attribute entry name and length
243 */
244static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
245 ino_t inum, const struct qstr *nm)
246{
247 union ubifs_key *key = k;
248 uint32_t hash = c->key_hash(nm->name, nm->len);
249
250 ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
251 key->j32[0] = cpu_to_le32(inum);
252 key->j32[1] = cpu_to_le32(hash |
253 (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
254 memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
255}
256
257/**
258 * lowest_xent_key - get the lowest possible extended attribute entry key.
259 * @c: UBIFS file-system description object
260 * @key: where to store the lowest key
261 * @inum: host inode number
262 */
263static inline void lowest_xent_key(const struct ubifs_info *c,
264 union ubifs_key *key, ino_t inum)
265{
266 key->u32[0] = inum;
267 key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
268}
269
270/**
271 * data_key_init - initialize data key.
272 * @c: UBIFS file-system description object
273 * @key: key to initialize
274 * @inum: inode number
275 * @block: block number
276 */
277static inline void data_key_init(const struct ubifs_info *c,
278 union ubifs_key *key, ino_t inum,
279 unsigned int block)
280{
281 ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
282 key->u32[0] = inum;
283 key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
284}
285
286/**
287 * highest_data_key - get the highest possible data key for an inode.
288 * @c: UBIFS file-system description object
289 * @key: key to initialize
290 * @inum: inode number
291 */
292static inline void highest_data_key(const struct ubifs_info *c,
293 union ubifs_key *key, ino_t inum)
294{
295 data_key_init(c, key, inum, UBIFS_S_KEY_BLOCK_MASK);
296}
297
298/**
299 * trun_key_init - initialize truncation node key.
300 * @c: UBIFS file-system description object
301 * @key: key to initialize
302 * @inum: inode number
303 *
304 * Note, UBIFS does not have truncation keys on the media and this function is
305 * only used for purposes of replay.
306 */
307static inline void trun_key_init(const struct ubifs_info *c,
308 union ubifs_key *key, ino_t inum)
309{
310 key->u32[0] = inum;
311 key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
312}
313
314/**
315 * invalid_key_init - initialize invalid node key.
316 * @c: UBIFS file-system description object
317 * @key: key to initialize
318 *
319 * This is a helper function which marks a @key object as invalid.
320 */
321static inline void invalid_key_init(const struct ubifs_info *c,
322 union ubifs_key *key)
323{
324 key->u32[0] = 0xDEADBEAF;
325 key->u32[1] = UBIFS_INVALID_KEY;
326}
327
328/**
329 * key_type - get key type.
330 * @c: UBIFS file-system description object
331 * @key: key to get type of
332 */
333static inline int key_type(const struct ubifs_info *c,
334 const union ubifs_key *key)
335{
336 return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
337}
338
339/**
340 * key_type_flash - get type of a on-flash formatted key.
341 * @c: UBIFS file-system description object
342 * @k: key to get type of
343 */
344static inline int key_type_flash(const struct ubifs_info *c, const void *k)
345{
346 const union ubifs_key *key = k;
347
348 return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
349}
350
351/**
352 * key_inum - fetch inode number from key.
353 * @c: UBIFS file-system description object
354 * @k: key to fetch inode number from
355 */
356static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
357{
358 const union ubifs_key *key = k;
359
360 return key->u32[0];
361}
362
363/**
364 * key_inum_flash - fetch inode number from an on-flash formatted key.
365 * @c: UBIFS file-system description object
366 * @k: key to fetch inode number from
367 */
368static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
369{
370 const union ubifs_key *key = k;
371
372 return le32_to_cpu(key->j32[0]);
373}
374
375/**
376 * key_hash - get directory entry hash.
377 * @c: UBIFS file-system description object
378 * @key: the key to get hash from
379 */
380static inline uint32_t key_hash(const struct ubifs_info *c,
381 const union ubifs_key *key)
382{
383 return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
384}
385
386/**
387 * key_hash_flash - get directory entry hash from an on-flash formatted key.
388 * @c: UBIFS file-system description object
389 * @k: the key to get hash from
390 */
391static inline uint32_t key_hash_flash(const struct ubifs_info *c, const void *k)
392{
393 const union ubifs_key *key = k;
394
395 return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
396}
397
398/**
399 * key_block - get data block number.
400 * @c: UBIFS file-system description object
401 * @key: the key to get the block number from
402 */
403static inline unsigned int key_block(const struct ubifs_info *c,
404 const union ubifs_key *key)
405{
406 return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
407}
408
409/**
410 * key_block_flash - get data block number from an on-flash formatted key.
411 * @c: UBIFS file-system description object
412 * @k: the key to get the block number from
413 */
414static inline unsigned int key_block_flash(const struct ubifs_info *c,
415 const void *k)
416{
417 const union ubifs_key *key = k;
418
419 return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK;
420}
421
422/**
423 * key_read - transform a key to in-memory format.
424 * @c: UBIFS file-system description object
425 * @from: the key to transform
426 * @to: the key to store the result
427 */
428static inline void key_read(const struct ubifs_info *c, const void *from,
429 union ubifs_key *to)
430{
431 const union ubifs_key *f = from;
432
433 to->u32[0] = le32_to_cpu(f->j32[0]);
434 to->u32[1] = le32_to_cpu(f->j32[1]);
435}
436
437/**
438 * key_write - transform a key from in-memory format.
439 * @c: UBIFS file-system description object
440 * @from: the key to transform
441 * @to: the key to store the result
442 */
443static inline void key_write(const struct ubifs_info *c,
444 const union ubifs_key *from, void *to)
445{
446 union ubifs_key *t = to;
447
448 t->j32[0] = cpu_to_le32(from->u32[0]);
449 t->j32[1] = cpu_to_le32(from->u32[1]);
450 memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
451}
452
453/**
454 * key_write_idx - transform a key from in-memory format for the index.
455 * @c: UBIFS file-system description object
456 * @from: the key to transform
457 * @to: the key to store the result
458 */
459static inline void key_write_idx(const struct ubifs_info *c,
460 const union ubifs_key *from, void *to)
461{
462 union ubifs_key *t = to;
463
464 t->j32[0] = cpu_to_le32(from->u32[0]);
465 t->j32[1] = cpu_to_le32(from->u32[1]);
466}
467
468/**
469 * key_copy - copy a key.
470 * @c: UBIFS file-system description object
471 * @from: the key to copy from
472 * @to: the key to copy to
473 */
474static inline void key_copy(const struct ubifs_info *c,
475 const union ubifs_key *from, union ubifs_key *to)
476{
477 to->u64[0] = from->u64[0];
478}
479
480/**
481 * keys_cmp - compare keys.
482 * @c: UBIFS file-system description object
483 * @key1: the first key to compare
484 * @key2: the second key to compare
485 *
486 * This function compares 2 keys and returns %-1 if @key1 is less than
487 * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
488 */
489static inline int keys_cmp(const struct ubifs_info *c,
490 const union ubifs_key *key1,
491 const union ubifs_key *key2)
492{
493 if (key1->u32[0] < key2->u32[0])
494 return -1;
495 if (key1->u32[0] > key2->u32[0])
496 return 1;
497 if (key1->u32[1] < key2->u32[1])
498 return -1;
499 if (key1->u32[1] > key2->u32[1])
500 return 1;
501
502 return 0;
503}
504
505/**
506 * keys_eq - determine if keys are equivalent.
507 * @c: UBIFS file-system description object
508 * @key1: the first key to compare
509 * @key2: the second key to compare
510 *
511 * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
512 * %0 if not.
513 */
514static inline int keys_eq(const struct ubifs_info *c,
515 const union ubifs_key *key1,
516 const union ubifs_key *key2)
517{
518 if (key1->u32[0] != key2->u32[0])
519 return 0;
520 if (key1->u32[1] != key2->u32[1])
521 return 0;
522 return 1;
523}
524
525/**
526 * is_hash_key - is a key vulnerable to hash collisions.
527 * @c: UBIFS file-system description object
528 * @key: key
529 *
530 * This function returns %1 if @key is a hashed key or %0 otherwise.
531 */
532static inline int is_hash_key(const struct ubifs_info *c,
533 const union ubifs_key *key)
534{
535 int type = key_type(c, key);
536
537 return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
538}
539
540/**
541 * key_max_inode_size - get maximum file size allowed by current key format.
542 * @c: UBIFS file-system description object
543 */
544static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
545{
546 switch (c->key_fmt) {
547 case UBIFS_SIMPLE_KEY_FMT:
548 return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
549 default:
550 return 0;
551 }
552}
553
554#endif /* !__UBIFS_KEY_H__ */