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2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation.
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.
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
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
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
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.
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.
37 #ifndef __UBIFS_KEY_H__
38 #define __UBIFS_KEY_H__
41 * key_r5_hash - R5 hash function (borrowed from reiserfs).
45 static inline uint32_t key_r5_hash(const char *s
, int len
)
48 const signed char *str
= (const signed char *)s
;
57 a
&= UBIFS_S_KEY_HASH_MASK
;
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"
64 if (unlikely(a
>= 0 && a
<= 2))
70 * key_test_hash - testing hash function.
74 static inline uint32_t key_test_hash(const char *str
, int len
)
78 len
= min_t(uint32_t, len
, 4);
80 a
&= UBIFS_S_KEY_HASH_MASK
;
81 if (unlikely(a
>= 0 && a
<= 2))
87 * ino_key_init - initialize inode key.
88 * @c: UBIFS file-system description object
89 * @key: key to initialize
92 static inline void ino_key_init(const struct ubifs_info
*c
,
93 union ubifs_key
*key
, ino_t inum
)
96 key
->u32
[1] = UBIFS_INO_KEY
<< UBIFS_S_KEY_BLOCK_BITS
;
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
105 static inline void ino_key_init_flash(const struct ubifs_info
*c
, void *k
,
108 union ubifs_key
*key
= k
;
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);
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
121 static inline void lowest_ino_key(const struct ubifs_info
*c
,
122 union ubifs_key
*key
, ino_t inum
)
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
134 static inline void highest_ino_key(const struct ubifs_info
*c
,
135 union ubifs_key
*key
, ino_t inum
)
138 key
->u32
[1] = 0xffffffff;
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
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
)
152 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
154 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
156 key
->u32
[1] = hash
| (UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
160 * dent_key_init_hash - initialize directory entry key without re-calculating
162 * @c: UBIFS file-system description object
163 * @key: key to initialize
164 * @inum: parent inode number
165 * @hash: direntry name hash
167 static inline void dent_key_init_hash(const struct ubifs_info
*c
,
168 union ubifs_key
*key
, ino_t inum
,
171 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
173 key
->u32
[1] = hash
| (UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
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
183 static inline void dent_key_init_flash(const struct ubifs_info
*c
, void *k
,
184 ino_t inum
, const struct qstr
*nm
)
186 union ubifs_key
*key
= k
;
187 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
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);
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
202 static inline void lowest_dent_key(const struct ubifs_info
*c
,
203 union ubifs_key
*key
, ino_t inum
)
206 key
->u32
[1] = UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
;
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
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
)
220 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
222 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
224 key
->u32
[1] = hash
| (UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
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
235 static inline void xent_key_init_hash(const struct ubifs_info
*c
,
236 union ubifs_key
*key
, ino_t inum
,
239 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
241 key
->u32
[1] = hash
| (UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
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
251 static inline void xent_key_init_flash(const struct ubifs_info
*c
, void *k
,
252 ino_t inum
, const struct qstr
*nm
)
254 union ubifs_key
*key
= k
;
255 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
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);
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
270 static inline void lowest_xent_key(const struct ubifs_info
*c
,
271 union ubifs_key
*key
, ino_t inum
)
274 key
->u32
[1] = UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
;
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
284 static inline void data_key_init(const struct ubifs_info
*c
,
285 union ubifs_key
*key
, ino_t inum
,
288 ubifs_assert(!(block
& ~UBIFS_S_KEY_BLOCK_MASK
));
290 key
->u32
[1] = block
| (UBIFS_DATA_KEY
<< UBIFS_S_KEY_BLOCK_BITS
);
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
300 static inline void data_key_init_flash(const struct ubifs_info
*c
, void *k
,
301 ino_t inum
, unsigned int block
)
303 union ubifs_key
*key
= k
;
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);
313 * trun_key_init - initialize truncation node key.
314 * @c: UBIFS file-system description object
315 * @key: key to initialize
316 * @inum: inode number
318 * Note, UBIFS does not have truncation keys on the media and this function is
319 * only used for purposes of replay.
321 static inline void trun_key_init(const struct ubifs_info
*c
,
322 union ubifs_key
*key
, ino_t inum
)
325 key
->u32
[1] = UBIFS_TRUN_KEY
<< UBIFS_S_KEY_BLOCK_BITS
;
329 * key_type - get key type.
330 * @c: UBIFS file-system description object
331 * @key: key to get type of
333 static inline int key_type(const struct ubifs_info
*c
,
334 const union ubifs_key
*key
)
336 return key
->u32
[1] >> UBIFS_S_KEY_BLOCK_BITS
;
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
344 static inline int key_type_flash(const struct ubifs_info
*c
, const void *k
)
346 const union ubifs_key
*key
= k
;
348 return le32_to_cpu(key
->j32
[1]) >> UBIFS_S_KEY_BLOCK_BITS
;
352 * key_inum - fetch inode number from key.
353 * @c: UBIFS file-system description object
354 * @k: key to fetch inode number from
356 static inline ino_t
key_inum(const struct ubifs_info
*c
, const void *k
)
358 const union ubifs_key
*key
= k
;
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
368 static inline ino_t
key_inum_flash(const struct ubifs_info
*c
, const void *k
)
370 const union ubifs_key
*key
= k
;
372 return le32_to_cpu(key
->j32
[0]);
376 * key_hash - get directory entry hash.
377 * @c: UBIFS file-system description object
378 * @key: the key to get hash from
380 static inline int key_hash(const struct ubifs_info
*c
,
381 const union ubifs_key
*key
)
383 return key
->u32
[1] & UBIFS_S_KEY_HASH_MASK
;
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
391 static inline int key_hash_flash(const struct ubifs_info
*c
, const void *k
)
393 const union ubifs_key
*key
= k
;
395 return le32_to_cpu(key
->j32
[1]) & UBIFS_S_KEY_HASH_MASK
;
399 * key_block - get data block number.
400 * @c: UBIFS file-system description object
401 * @key: the key to get the block number from
403 static inline unsigned int key_block(const struct ubifs_info
*c
,
404 const union ubifs_key
*key
)
406 return key
->u32
[1] & UBIFS_S_KEY_BLOCK_MASK
;
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
414 static inline unsigned int key_block_flash(const struct ubifs_info
*c
,
417 const union ubifs_key
*key
= k
;
419 return le32_to_cpu(key
->j32
[1]) & UBIFS_S_KEY_BLOCK_MASK
;
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
428 static inline void key_read(const struct ubifs_info
*c
, const void *from
,
431 const union ubifs_key
*f
= from
;
433 to
->u32
[0] = le32_to_cpu(f
->j32
[0]);
434 to
->u32
[1] = le32_to_cpu(f
->j32
[1]);
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
443 static inline void key_write(const struct ubifs_info
*c
,
444 const union ubifs_key
*from
, void *to
)
446 union ubifs_key
*t
= to
;
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);
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
459 static inline void key_write_idx(const struct ubifs_info
*c
,
460 const union ubifs_key
*from
, void *to
)
462 union ubifs_key
*t
= to
;
464 t
->j32
[0] = cpu_to_le32(from
->u32
[0]);
465 t
->j32
[1] = cpu_to_le32(from
->u32
[1]);
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
474 static inline void key_copy(const struct ubifs_info
*c
,
475 const union ubifs_key
*from
, union ubifs_key
*to
)
477 to
->u64
[0] = from
->u64
[0];
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
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.
489 static inline int keys_cmp(const struct ubifs_info
*c
,
490 const union ubifs_key
*key1
,
491 const union ubifs_key
*key2
)
493 if (key1
->u32
[0] < key2
->u32
[0])
495 if (key1
->u32
[0] > key2
->u32
[0])
497 if (key1
->u32
[1] < key2
->u32
[1])
499 if (key1
->u32
[1] > key2
->u32
[1])
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
511 * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
514 static inline int keys_eq(const struct ubifs_info
*c
,
515 const union ubifs_key
*key1
,
516 const union ubifs_key
*key2
)
518 if (key1
->u32
[0] != key2
->u32
[0])
520 if (key1
->u32
[1] != key2
->u32
[1])
526 * is_hash_key - is a key vulnerable to hash collisions.
527 * @c: UBIFS file-system description object
530 * This function returns %1 if @key is a hashed key or %0 otherwise.
532 static inline int is_hash_key(const struct ubifs_info
*c
,
533 const union ubifs_key
*key
)
535 int type
= key_type(c
, key
);
537 return type
== UBIFS_DENT_KEY
|| type
== UBIFS_XENT_KEY
;
541 * key_max_inode_size - get maximum file size allowed by current key format.
542 * @c: UBIFS file-system description object
544 static inline unsigned long long key_max_inode_size(const struct ubifs_info
*c
)
546 switch (c
->key_fmt
) {
547 case UBIFS_SIMPLE_KEY_FMT
:
548 return (1ULL << UBIFS_S_KEY_BLOCK_BITS
) * UBIFS_BLOCK_SIZE
;
553 #endif /* !__UBIFS_KEY_H__ */