Commit | Line | Data |
---|---|---|
1e51764a AB |
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 | #ifndef __UBIFS_KEY_H__ | |
38 | #define __UBIFS_KEY_H__ | |
39 | ||
40 | /** | |
41 | * key_r5_hash - R5 hash function (borrowed from reiserfs). | |
42 | * @s: direntry name | |
43 | * @len: name length | |
44 | */ | |
45 | static inline uint32_t key_r5_hash(const char *s, int len) | |
46 | { | |
47 | uint32_t a = 0; | |
48 | const signed char *str = (const signed char *)s; | |
49 | ||
50 | while (*str) { | |
51 | a += *str << 4; | |
52 | a += *str >> 4; | |
53 | a *= 11; | |
54 | str++; | |
55 | } | |
56 | ||
57 | a &= UBIFS_S_KEY_HASH_MASK; | |
58 | ||
59 | /* | |
60 | * We use hash values as offset in directories, so values %0 and %1 are | |
61 | * reserved for "." and "..". %2 is reserved for "end of readdir" | |
62 | * marker. | |
63 | */ | |
64 | if (unlikely(a >= 0 && a <= 2)) | |
65 | a += 3; | |
66 | return a; | |
67 | } | |
68 | ||
69 | /** | |
70 | * key_test_hash - testing hash function. | |
71 | * @str: direntry name | |
72 | * @len: name length | |
73 | */ | |
74 | static inline uint32_t key_test_hash(const char *str, int len) | |
75 | { | |
76 | uint32_t a = 0; | |
77 | ||
78 | len = min_t(uint32_t, len, 4); | |
79 | memcpy(&a, str, len); | |
80 | a &= UBIFS_S_KEY_HASH_MASK; | |
81 | if (unlikely(a >= 0 && a <= 2)) | |
82 | a += 3; | |
83 | return a; | |
84 | } | |
85 | ||
86 | /** | |
87 | * ino_key_init - initialize inode key. | |
88 | * @c: UBIFS file-system description object | |
89 | * @key: key to initialize | |
90 | * @inum: inode number | |
91 | */ | |
92 | static inline void ino_key_init(const struct ubifs_info *c, | |
93 | union ubifs_key *key, ino_t inum) | |
94 | { | |
95 | key->u32[0] = inum; | |
96 | key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS; | |
97 | } | |
98 | ||
99 | /** | |
100 | * ino_key_init_flash - initialize on-flash inode key. | |
101 | * @c: UBIFS file-system description object | |
102 | * @k: key to initialize | |
103 | * @inum: inode number | |
104 | */ | |
105 | static inline void ino_key_init_flash(const struct ubifs_info *c, void *k, | |
106 | ino_t inum) | |
107 | { | |
108 | union ubifs_key *key = k; | |
109 | ||
110 | key->j32[0] = cpu_to_le32(inum); | |
111 | key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS); | |
112 | memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8); | |
113 | } | |
114 | ||
115 | /** | |
116 | * lowest_ino_key - get the lowest possible inode key. | |
117 | * @c: UBIFS file-system description object | |
118 | * @key: key to initialize | |
119 | * @inum: inode number | |
120 | */ | |
121 | static inline void lowest_ino_key(const struct ubifs_info *c, | |
122 | union ubifs_key *key, ino_t inum) | |
123 | { | |
124 | key->u32[0] = inum; | |
125 | key->u32[1] = 0; | |
126 | } | |
127 | ||
128 | /** | |
129 | * highest_ino_key - get the highest possible inode key. | |
130 | * @c: UBIFS file-system description object | |
131 | * @key: key to initialize | |
132 | * @inum: inode number | |
133 | */ | |
134 | static inline void highest_ino_key(const struct ubifs_info *c, | |
135 | union ubifs_key *key, ino_t inum) | |
136 | { | |
137 | key->u32[0] = inum; | |
138 | key->u32[1] = 0xffffffff; | |
139 | } | |
140 | ||
141 | /** | |
142 | * dent_key_init - initialize directory entry key. | |
143 | * @c: UBIFS file-system description object | |
144 | * @key: key to initialize | |
145 | * @inum: parent inode number | |
146 | * @nm: direntry name and length | |
147 | */ | |
148 | static inline void dent_key_init(const struct ubifs_info *c, | |
149 | union ubifs_key *key, ino_t inum, | |
150 | const struct qstr *nm) | |
151 | { | |
152 | uint32_t hash = c->key_hash(nm->name, nm->len); | |
153 | ||
154 | ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK)); | |
155 | key->u32[0] = inum; | |
156 | key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS); | |
157 | } | |
158 | ||
159 | /** | |
160 | * dent_key_init_hash - initialize directory entry key without re-calculating | |
161 | * hash function. | |
162 | * @c: UBIFS file-system description object | |
163 | * @key: key to initialize | |
164 | * @inum: parent inode number | |
165 | * @hash: direntry name hash | |
166 | */ | |
167 | static inline void dent_key_init_hash(const struct ubifs_info *c, | |
168 | union ubifs_key *key, ino_t inum, | |
169 | uint32_t hash) | |
170 | { | |
171 | ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK)); | |
172 | key->u32[0] = inum; | |
173 | key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS); | |
174 | } | |
175 | ||
176 | /** | |
177 | * dent_key_init_flash - initialize on-flash directory entry key. | |
178 | * @c: UBIFS file-system description object | |
179 | * @k: key to initialize | |
180 | * @inum: parent inode number | |
181 | * @nm: direntry name and length | |
182 | */ | |
183 | static inline void dent_key_init_flash(const struct ubifs_info *c, void *k, | |
184 | ino_t inum, const struct qstr *nm) | |
185 | { | |
186 | union ubifs_key *key = k; | |
187 | uint32_t hash = c->key_hash(nm->name, nm->len); | |
188 | ||
189 | ubifs_assert(!(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 | */ | |
202 | static 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 | */ | |
216 | static inline void xent_key_init(const struct ubifs_info *c, | |
217 | union ubifs_key *key, ino_t inum, | |
218 | const struct qstr *nm) | |
219 | { | |
220 | uint32_t hash = c->key_hash(nm->name, nm->len); | |
221 | ||
222 | ubifs_assert(!(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_hash - initialize extended attribute entry key without | |
229 | * re-calculating hash function. | |
230 | * @c: UBIFS file-system description object | |
231 | * @key: key to initialize | |
232 | * @inum: host inode number | |
233 | * @hash: extended attribute entry name hash | |
234 | */ | |
235 | static inline void xent_key_init_hash(const struct ubifs_info *c, | |
236 | union ubifs_key *key, ino_t inum, | |
237 | uint32_t hash) | |
238 | { | |
239 | ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK)); | |
240 | key->u32[0] = inum; | |
241 | key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS); | |
242 | } | |
243 | ||
244 | /** | |
245 | * xent_key_init_flash - initialize on-flash extended attribute entry key. | |
246 | * @c: UBIFS file-system description object | |
247 | * @k: key to initialize | |
248 | * @inum: host inode number | |
249 | * @nm: extended attribute entry name and length | |
250 | */ | |
251 | static inline void xent_key_init_flash(const struct ubifs_info *c, void *k, | |
252 | ino_t inum, const struct qstr *nm) | |
253 | { | |
254 | union ubifs_key *key = k; | |
255 | uint32_t hash = c->key_hash(nm->name, nm->len); | |
256 | ||
257 | ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK)); | |
258 | key->j32[0] = cpu_to_le32(inum); | |
259 | key->j32[1] = cpu_to_le32(hash | | |
260 | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS)); | |
261 | memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8); | |
262 | } | |
263 | ||
264 | /** | |
265 | * lowest_xent_key - get the lowest possible extended attribute entry key. | |
266 | * @c: UBIFS file-system description object | |
267 | * @key: where to store the lowest key | |
268 | * @inum: host inode number | |
269 | */ | |
270 | static inline void lowest_xent_key(const struct ubifs_info *c, | |
271 | union ubifs_key *key, ino_t inum) | |
272 | { | |
273 | key->u32[0] = inum; | |
274 | key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS; | |
275 | } | |
276 | ||
277 | /** | |
278 | * data_key_init - initialize data key. | |
279 | * @c: UBIFS file-system description object | |
280 | * @key: key to initialize | |
281 | * @inum: inode number | |
282 | * @block: block number | |
283 | */ | |
284 | static inline void data_key_init(const struct ubifs_info *c, | |
285 | union ubifs_key *key, ino_t inum, | |
286 | unsigned int block) | |
287 | { | |
288 | ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK)); | |
289 | key->u32[0] = inum; | |
290 | key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS); | |
291 | } | |
292 | ||
293 | /** | |
294 | * data_key_init_flash - initialize on-flash data key. | |
295 | * @c: UBIFS file-system description object | |
296 | * @k: key to initialize | |
297 | * @inum: inode number | |
298 | * @block: block number | |
299 | */ | |
300 | static inline void data_key_init_flash(const struct ubifs_info *c, void *k, | |
301 | ino_t inum, unsigned int block) | |
302 | { | |
303 | union ubifs_key *key = k; | |
304 | ||
305 | ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK)); | |
306 | key->j32[0] = cpu_to_le32(inum); | |
307 | key->j32[1] = cpu_to_le32(block | | |
308 | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS)); | |
309 | memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8); | |
310 | } | |
311 | ||
312 | /** | |
313 | * trun_key_init - initialize truncation node key. | |
314 | * @c: UBIFS file-system description object | |
315 | * @key: key to initialize | |
316 | * @inum: inode number | |
317 | * | |
318 | * Note, UBIFS does not have truncation keys on the media and this function is | |
319 | * only used for purposes of replay. | |
320 | */ | |
321 | static inline void trun_key_init(const struct ubifs_info *c, | |
322 | union ubifs_key *key, ino_t inum) | |
323 | { | |
324 | key->u32[0] = inum; | |
325 | key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS; | |
326 | } | |
327 | ||
328 | /** | |
329 | * key_type - get key type. | |
330 | * @c: UBIFS file-system description object | |
331 | * @key: key to get type of | |
332 | */ | |
333 | static 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 | */ | |
344 | static inline int key_type_flash(const struct ubifs_info *c, const void *k) | |
345 | { | |
346 | const union ubifs_key *key = k; | |
347 | ||
0ecb9529 | 348 | return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS; |
1e51764a AB |
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 | */ | |
356 | static 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 | */ | |
368 | static 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 | */ | |
380 | static inline int 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 | */ | |
391 | static inline int 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 | */ | |
403 | static 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 | */ | |
414 | static inline unsigned int key_block_flash(const struct ubifs_info *c, | |
415 | const void *k) | |
416 | { | |
417 | const union ubifs_key *key = k; | |
418 | ||
0ecb9529 | 419 | return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK; |
1e51764a AB |
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 | */ | |
428 | static 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 | */ | |
443 | static 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 | */ | |
459 | static 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 | */ | |
474 | static 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 | |
4793e7c5 | 487 | * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2. |
1e51764a AB |
488 | */ |
489 | static 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 | ||
4793e7c5 AH |
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 | */ | |
514 | static 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 | ||
1e51764a AB |
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 | */ | |
532 | static 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 | */ | |
544 | static 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 | #endif /* !__UBIFS_KEY_H__ */ |