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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_mask_hash - mask a valid hash value.
42 * @val: value to be masked
44 * We use hash values as offset in directories, so values %0 and %1 are
45 * reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
46 * function makes sure the reserved values are not used.
48 static inline uint32_t key_mask_hash(uint32_t hash
)
50 hash
&= UBIFS_S_KEY_HASH_MASK
;
51 if (unlikely(hash
<= 2))
57 * key_r5_hash - R5 hash function (borrowed from reiserfs).
61 static inline uint32_t key_r5_hash(const char *s
, int len
)
64 const signed char *str
= (const signed char *)s
;
73 return key_mask_hash(a
);
77 * key_test_hash - testing hash function.
81 static inline uint32_t key_test_hash(const char *str
, int len
)
85 len
= min_t(uint32_t, len
, 4);
87 return key_mask_hash(a
);
91 * ino_key_init - initialize inode key.
92 * @c: UBIFS file-system description object
93 * @key: key to initialize
96 static inline void ino_key_init(const struct ubifs_info
*c
,
97 union ubifs_key
*key
, ino_t inum
)
100 key
->u32
[1] = UBIFS_INO_KEY
<< UBIFS_S_KEY_BLOCK_BITS
;
104 * ino_key_init_flash - initialize on-flash inode key.
105 * @c: UBIFS file-system description object
106 * @k: key to initialize
107 * @inum: inode number
109 static inline void ino_key_init_flash(const struct ubifs_info
*c
, void *k
,
112 union ubifs_key
*key
= k
;
114 key
->j32
[0] = cpu_to_le32(inum
);
115 key
->j32
[1] = cpu_to_le32(UBIFS_INO_KEY
<< UBIFS_S_KEY_BLOCK_BITS
);
116 memset(k
+ 8, 0, UBIFS_MAX_KEY_LEN
- 8);
120 * lowest_ino_key - get the lowest possible inode key.
121 * @c: UBIFS file-system description object
122 * @key: key to initialize
123 * @inum: inode number
125 static inline void lowest_ino_key(const struct ubifs_info
*c
,
126 union ubifs_key
*key
, ino_t inum
)
133 * highest_ino_key - get the highest possible inode key.
134 * @c: UBIFS file-system description object
135 * @key: key to initialize
136 * @inum: inode number
138 static inline void highest_ino_key(const struct ubifs_info
*c
,
139 union ubifs_key
*key
, ino_t inum
)
142 key
->u32
[1] = 0xffffffff;
146 * dent_key_init - initialize directory entry key.
147 * @c: UBIFS file-system description object
148 * @key: key to initialize
149 * @inum: parent inode number
150 * @nm: direntry name and length
152 static inline void dent_key_init(const struct ubifs_info
*c
,
153 union ubifs_key
*key
, ino_t inum
,
154 const struct qstr
*nm
)
156 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
158 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
160 key
->u32
[1] = hash
| (UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
164 * dent_key_init_hash - initialize directory entry key without re-calculating
166 * @c: UBIFS file-system description object
167 * @key: key to initialize
168 * @inum: parent inode number
169 * @hash: direntry name hash
171 static inline void dent_key_init_hash(const struct ubifs_info
*c
,
172 union ubifs_key
*key
, ino_t inum
,
175 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
177 key
->u32
[1] = hash
| (UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
181 * dent_key_init_flash - initialize on-flash directory entry key.
182 * @c: UBIFS file-system description object
183 * @k: key to initialize
184 * @inum: parent inode number
185 * @nm: direntry name and length
187 static inline void dent_key_init_flash(const struct ubifs_info
*c
, void *k
,
188 ino_t inum
, const struct qstr
*nm
)
190 union ubifs_key
*key
= k
;
191 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
193 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
194 key
->j32
[0] = cpu_to_le32(inum
);
195 key
->j32
[1] = cpu_to_le32(hash
|
196 (UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
));
197 memset(k
+ 8, 0, UBIFS_MAX_KEY_LEN
- 8);
201 * lowest_dent_key - get the lowest possible directory entry key.
202 * @c: UBIFS file-system description object
203 * @key: where to store the lowest key
204 * @inum: parent inode number
206 static inline void lowest_dent_key(const struct ubifs_info
*c
,
207 union ubifs_key
*key
, ino_t inum
)
210 key
->u32
[1] = UBIFS_DENT_KEY
<< UBIFS_S_KEY_HASH_BITS
;
214 * xent_key_init - initialize extended attribute entry key.
215 * @c: UBIFS file-system description object
216 * @key: key to initialize
217 * @inum: host inode number
218 * @nm: extended attribute entry name and length
220 static inline void xent_key_init(const struct ubifs_info
*c
,
221 union ubifs_key
*key
, ino_t inum
,
222 const struct qstr
*nm
)
224 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
226 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
228 key
->u32
[1] = hash
| (UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
232 * xent_key_init_hash - initialize extended attribute entry key without
233 * re-calculating hash function.
234 * @c: UBIFS file-system description object
235 * @key: key to initialize
236 * @inum: host inode number
237 * @hash: extended attribute entry name hash
239 static inline void xent_key_init_hash(const struct ubifs_info
*c
,
240 union ubifs_key
*key
, ino_t inum
,
243 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
245 key
->u32
[1] = hash
| (UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
);
249 * xent_key_init_flash - initialize on-flash extended attribute entry key.
250 * @c: UBIFS file-system description object
251 * @k: key to initialize
252 * @inum: host inode number
253 * @nm: extended attribute entry name and length
255 static inline void xent_key_init_flash(const struct ubifs_info
*c
, void *k
,
256 ino_t inum
, const struct qstr
*nm
)
258 union ubifs_key
*key
= k
;
259 uint32_t hash
= c
->key_hash(nm
->name
, nm
->len
);
261 ubifs_assert(!(hash
& ~UBIFS_S_KEY_HASH_MASK
));
262 key
->j32
[0] = cpu_to_le32(inum
);
263 key
->j32
[1] = cpu_to_le32(hash
|
264 (UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
));
265 memset(k
+ 8, 0, UBIFS_MAX_KEY_LEN
- 8);
269 * lowest_xent_key - get the lowest possible extended attribute entry key.
270 * @c: UBIFS file-system description object
271 * @key: where to store the lowest key
272 * @inum: host inode number
274 static inline void lowest_xent_key(const struct ubifs_info
*c
,
275 union ubifs_key
*key
, ino_t inum
)
278 key
->u32
[1] = UBIFS_XENT_KEY
<< UBIFS_S_KEY_HASH_BITS
;
282 * data_key_init - initialize data key.
283 * @c: UBIFS file-system description object
284 * @key: key to initialize
285 * @inum: inode number
286 * @block: block number
288 static inline void data_key_init(const struct ubifs_info
*c
,
289 union ubifs_key
*key
, ino_t inum
,
292 ubifs_assert(!(block
& ~UBIFS_S_KEY_BLOCK_MASK
));
294 key
->u32
[1] = block
| (UBIFS_DATA_KEY
<< UBIFS_S_KEY_BLOCK_BITS
);
298 * data_key_init_flash - initialize on-flash data key.
299 * @c: UBIFS file-system description object
300 * @k: key to initialize
301 * @inum: inode number
302 * @block: block number
304 static inline void data_key_init_flash(const struct ubifs_info
*c
, void *k
,
305 ino_t inum
, unsigned int block
)
307 union ubifs_key
*key
= k
;
309 ubifs_assert(!(block
& ~UBIFS_S_KEY_BLOCK_MASK
));
310 key
->j32
[0] = cpu_to_le32(inum
);
311 key
->j32
[1] = cpu_to_le32(block
|
312 (UBIFS_DATA_KEY
<< UBIFS_S_KEY_BLOCK_BITS
));
313 memset(k
+ 8, 0, UBIFS_MAX_KEY_LEN
- 8);
317 * trun_key_init - initialize truncation node key.
318 * @c: UBIFS file-system description object
319 * @key: key to initialize
320 * @inum: inode number
322 * Note, UBIFS does not have truncation keys on the media and this function is
323 * only used for purposes of replay.
325 static inline void trun_key_init(const struct ubifs_info
*c
,
326 union ubifs_key
*key
, ino_t inum
)
329 key
->u32
[1] = UBIFS_TRUN_KEY
<< UBIFS_S_KEY_BLOCK_BITS
;
333 * key_type - get key type.
334 * @c: UBIFS file-system description object
335 * @key: key to get type of
337 static inline int key_type(const struct ubifs_info
*c
,
338 const union ubifs_key
*key
)
340 return key
->u32
[1] >> UBIFS_S_KEY_BLOCK_BITS
;
344 * key_type_flash - get type of a on-flash formatted key.
345 * @c: UBIFS file-system description object
346 * @k: key to get type of
348 static inline int key_type_flash(const struct ubifs_info
*c
, const void *k
)
350 const union ubifs_key
*key
= k
;
352 return le32_to_cpu(key
->j32
[1]) >> UBIFS_S_KEY_BLOCK_BITS
;
356 * key_inum - fetch inode number from key.
357 * @c: UBIFS file-system description object
358 * @k: key to fetch inode number from
360 static inline ino_t
key_inum(const struct ubifs_info
*c
, const void *k
)
362 const union ubifs_key
*key
= k
;
368 * key_inum_flash - fetch inode number from an on-flash formatted key.
369 * @c: UBIFS file-system description object
370 * @k: key to fetch inode number from
372 static inline ino_t
key_inum_flash(const struct ubifs_info
*c
, const void *k
)
374 const union ubifs_key
*key
= k
;
376 return le32_to_cpu(key
->j32
[0]);
380 * key_hash - get directory entry hash.
381 * @c: UBIFS file-system description object
382 * @key: the key to get hash from
384 static inline int key_hash(const struct ubifs_info
*c
,
385 const union ubifs_key
*key
)
387 return key
->u32
[1] & UBIFS_S_KEY_HASH_MASK
;
391 * key_hash_flash - get directory entry hash from an on-flash formatted key.
392 * @c: UBIFS file-system description object
393 * @k: the key to get hash from
395 static inline int key_hash_flash(const struct ubifs_info
*c
, const void *k
)
397 const union ubifs_key
*key
= k
;
399 return le32_to_cpu(key
->j32
[1]) & UBIFS_S_KEY_HASH_MASK
;
403 * key_block - get data block number.
404 * @c: UBIFS file-system description object
405 * @key: the key to get the block number from
407 static inline unsigned int key_block(const struct ubifs_info
*c
,
408 const union ubifs_key
*key
)
410 return key
->u32
[1] & UBIFS_S_KEY_BLOCK_MASK
;
414 * key_block_flash - get data block number from an on-flash formatted key.
415 * @c: UBIFS file-system description object
416 * @k: the key to get the block number from
418 static inline unsigned int key_block_flash(const struct ubifs_info
*c
,
421 const union ubifs_key
*key
= k
;
423 return le32_to_cpu(key
->j32
[1]) & UBIFS_S_KEY_BLOCK_MASK
;
427 * key_read - transform a key to in-memory format.
428 * @c: UBIFS file-system description object
429 * @from: the key to transform
430 * @to: the key to store the result
432 static inline void key_read(const struct ubifs_info
*c
, const void *from
,
435 const union ubifs_key
*f
= from
;
437 to
->u32
[0] = le32_to_cpu(f
->j32
[0]);
438 to
->u32
[1] = le32_to_cpu(f
->j32
[1]);
442 * key_write - transform a key from in-memory format.
443 * @c: UBIFS file-system description object
444 * @from: the key to transform
445 * @to: the key to store the result
447 static inline void key_write(const struct ubifs_info
*c
,
448 const union ubifs_key
*from
, void *to
)
450 union ubifs_key
*t
= to
;
452 t
->j32
[0] = cpu_to_le32(from
->u32
[0]);
453 t
->j32
[1] = cpu_to_le32(from
->u32
[1]);
454 memset(to
+ 8, 0, UBIFS_MAX_KEY_LEN
- 8);
458 * key_write_idx - transform a key from in-memory format for the index.
459 * @c: UBIFS file-system description object
460 * @from: the key to transform
461 * @to: the key to store the result
463 static inline void key_write_idx(const struct ubifs_info
*c
,
464 const union ubifs_key
*from
, void *to
)
466 union ubifs_key
*t
= to
;
468 t
->j32
[0] = cpu_to_le32(from
->u32
[0]);
469 t
->j32
[1] = cpu_to_le32(from
->u32
[1]);
473 * key_copy - copy a key.
474 * @c: UBIFS file-system description object
475 * @from: the key to copy from
476 * @to: the key to copy to
478 static inline void key_copy(const struct ubifs_info
*c
,
479 const union ubifs_key
*from
, union ubifs_key
*to
)
481 to
->u64
[0] = from
->u64
[0];
485 * keys_cmp - compare keys.
486 * @c: UBIFS file-system description object
487 * @key1: the first key to compare
488 * @key2: the second key to compare
490 * This function compares 2 keys and returns %-1 if @key1 is less than
491 * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
493 static inline int keys_cmp(const struct ubifs_info
*c
,
494 const union ubifs_key
*key1
,
495 const union ubifs_key
*key2
)
497 if (key1
->u32
[0] < key2
->u32
[0])
499 if (key1
->u32
[0] > key2
->u32
[0])
501 if (key1
->u32
[1] < key2
->u32
[1])
503 if (key1
->u32
[1] > key2
->u32
[1])
510 * keys_eq - determine if keys are equivalent.
511 * @c: UBIFS file-system description object
512 * @key1: the first key to compare
513 * @key2: the second key to compare
515 * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
518 static inline int keys_eq(const struct ubifs_info
*c
,
519 const union ubifs_key
*key1
,
520 const union ubifs_key
*key2
)
522 if (key1
->u32
[0] != key2
->u32
[0])
524 if (key1
->u32
[1] != key2
->u32
[1])
530 * is_hash_key - is a key vulnerable to hash collisions.
531 * @c: UBIFS file-system description object
534 * This function returns %1 if @key is a hashed key or %0 otherwise.
536 static inline int is_hash_key(const struct ubifs_info
*c
,
537 const union ubifs_key
*key
)
539 int type
= key_type(c
, key
);
541 return type
== UBIFS_DENT_KEY
|| type
== UBIFS_XENT_KEY
;
545 * key_max_inode_size - get maximum file size allowed by current key format.
546 * @c: UBIFS file-system description object
548 static inline unsigned long long key_max_inode_size(const struct ubifs_info
*c
)
550 switch (c
->key_fmt
) {
551 case UBIFS_SIMPLE_KEY_FMT
:
552 return (1ULL << UBIFS_S_KEY_BLOCK_BITS
) * UBIFS_BLOCK_SIZE
;
557 #endif /* !__UBIFS_KEY_H__ */