535 lines
14 KiB
C
535 lines
14 KiB
C
/*
|
|
* This file is part of UBIFS.
|
|
*
|
|
* Copyright (C) 2006-2008 Nokia Corporation.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published by
|
|
* the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with
|
|
* this program; if not, write to the Free Software Foundation, Inc., 51
|
|
* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*
|
|
* Authors: Artem Bityutskiy (Битюцкий Артём)
|
|
* Adrian Hunter
|
|
*/
|
|
|
|
/*
|
|
* This header contains various key-related definitions and helper function.
|
|
* UBIFS allows several key schemes, so we access key fields only via these
|
|
* helpers. At the moment only one key scheme is supported.
|
|
*
|
|
* Simple key scheme
|
|
* ~~~~~~~~~~~~~~~~~
|
|
*
|
|
* Keys are 64-bits long. First 32-bits are inode number (parent inode number
|
|
* in case of direntry key). Next 3 bits are node type. The last 29 bits are
|
|
* 4KiB offset in case of inode node, and direntry hash in case of a direntry
|
|
* node. We use "r5" hash borrowed from reiserfs.
|
|
*/
|
|
|
|
#ifndef __UBIFS_KEY_H__
|
|
#define __UBIFS_KEY_H__
|
|
|
|
/**
|
|
* key_mask_hash - mask a valid hash value.
|
|
* @val: value to be masked
|
|
*
|
|
* We use hash values as offset in directories, so values %0 and %1 are
|
|
* reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
|
|
* function makes sure the reserved values are not used.
|
|
*/
|
|
static inline uint32_t key_mask_hash(uint32_t hash)
|
|
{
|
|
hash &= UBIFS_S_KEY_HASH_MASK;
|
|
if (unlikely(hash <= 2))
|
|
hash += 3;
|
|
return hash;
|
|
}
|
|
|
|
/**
|
|
* key_r5_hash - R5 hash function (borrowed from reiserfs).
|
|
* @s: direntry name
|
|
* @len: name length
|
|
*/
|
|
static inline uint32_t key_r5_hash(const char *s, int len)
|
|
{
|
|
uint32_t a = 0;
|
|
const signed char *str = (const signed char *)s;
|
|
|
|
while (*str) {
|
|
a += *str << 4;
|
|
a += *str >> 4;
|
|
a *= 11;
|
|
str++;
|
|
}
|
|
|
|
return key_mask_hash(a);
|
|
}
|
|
|
|
/**
|
|
* key_test_hash - testing hash function.
|
|
* @str: direntry name
|
|
* @len: name length
|
|
*/
|
|
static inline uint32_t key_test_hash(const char *str, int len)
|
|
{
|
|
uint32_t a = 0;
|
|
|
|
len = min_t(uint32_t, len, 4);
|
|
memcpy(&a, str, len);
|
|
return key_mask_hash(a);
|
|
}
|
|
|
|
/**
|
|
* ino_key_init - initialize inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void ino_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* ino_key_init_flash - initialize on-flash inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
|
|
ino_t inum)
|
|
{
|
|
union ubifs_key *key = k;
|
|
|
|
key->j32[0] = cpu_to_le32(inum);
|
|
key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
|
|
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* lowest_ino_key - get the lowest possible inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void lowest_ino_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = 0;
|
|
}
|
|
|
|
/**
|
|
* highest_ino_key - get the highest possible inode key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void highest_ino_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = 0xffffffff;
|
|
}
|
|
|
|
/**
|
|
* dent_key_init - initialize directory entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: parent inode number
|
|
* @nm: direntry name and length
|
|
*/
|
|
static inline void dent_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
const struct qstr *nm)
|
|
{
|
|
uint32_t hash = c->key_hash(nm->name, nm->len);
|
|
|
|
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
|
|
}
|
|
|
|
/**
|
|
* dent_key_init_hash - initialize directory entry key without re-calculating
|
|
* hash function.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: parent inode number
|
|
* @hash: direntry name hash
|
|
*/
|
|
static inline void dent_key_init_hash(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
uint32_t hash)
|
|
{
|
|
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
|
|
}
|
|
|
|
/**
|
|
* dent_key_init_flash - initialize on-flash directory entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to initialize
|
|
* @inum: parent inode number
|
|
* @nm: direntry name and length
|
|
*/
|
|
static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
|
|
ino_t inum, const struct qstr *nm)
|
|
{
|
|
union ubifs_key *key = k;
|
|
uint32_t hash = c->key_hash(nm->name, nm->len);
|
|
|
|
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->j32[0] = cpu_to_le32(inum);
|
|
key->j32[1] = cpu_to_le32(hash |
|
|
(UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
|
|
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* lowest_dent_key - get the lowest possible directory entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: where to store the lowest key
|
|
* @inum: parent inode number
|
|
*/
|
|
static inline void lowest_dent_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
|
|
}
|
|
|
|
/**
|
|
* xent_key_init - initialize extended attribute entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: host inode number
|
|
* @nm: extended attribute entry name and length
|
|
*/
|
|
static inline void xent_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
const struct qstr *nm)
|
|
{
|
|
uint32_t hash = c->key_hash(nm->name, nm->len);
|
|
|
|
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
|
|
}
|
|
|
|
/**
|
|
* xent_key_init_flash - initialize on-flash extended attribute entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to initialize
|
|
* @inum: host inode number
|
|
* @nm: extended attribute entry name and length
|
|
*/
|
|
static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
|
|
ino_t inum, const struct qstr *nm)
|
|
{
|
|
union ubifs_key *key = k;
|
|
uint32_t hash = c->key_hash(nm->name, nm->len);
|
|
|
|
ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
|
|
key->j32[0] = cpu_to_le32(inum);
|
|
key->j32[1] = cpu_to_le32(hash |
|
|
(UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
|
|
memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* lowest_xent_key - get the lowest possible extended attribute entry key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: where to store the lowest key
|
|
* @inum: host inode number
|
|
*/
|
|
static inline void lowest_xent_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
|
|
}
|
|
|
|
/**
|
|
* data_key_init - initialize data key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
* @block: block number
|
|
*/
|
|
static inline void data_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum,
|
|
unsigned int block)
|
|
{
|
|
ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
|
|
key->u32[0] = inum;
|
|
key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
|
|
}
|
|
|
|
/**
|
|
* highest_data_key - get the highest possible data key for an inode.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*/
|
|
static inline void highest_data_key(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
data_key_init(c, key, inum, UBIFS_S_KEY_BLOCK_MASK);
|
|
}
|
|
|
|
/**
|
|
* trun_key_init - initialize truncation node key.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to initialize
|
|
* @inum: inode number
|
|
*
|
|
* Note, UBIFS does not have truncation keys on the media and this function is
|
|
* only used for purposes of replay.
|
|
*/
|
|
static inline void trun_key_init(const struct ubifs_info *c,
|
|
union ubifs_key *key, ino_t inum)
|
|
{
|
|
key->u32[0] = inum;
|
|
key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* key_type - get key type.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key to get type of
|
|
*/
|
|
static inline int key_type(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* key_type_flash - get type of a on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to get type of
|
|
*/
|
|
static inline int key_type_flash(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
|
|
}
|
|
|
|
/**
|
|
* key_inum - fetch inode number from key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to fetch inode number from
|
|
*/
|
|
static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return key->u32[0];
|
|
}
|
|
|
|
/**
|
|
* key_inum_flash - fetch inode number from an on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: key to fetch inode number from
|
|
*/
|
|
static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[0]);
|
|
}
|
|
|
|
/**
|
|
* key_hash - get directory entry hash.
|
|
* @c: UBIFS file-system description object
|
|
* @key: the key to get hash from
|
|
*/
|
|
static inline uint32_t key_hash(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_hash_flash - get directory entry hash from an on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: the key to get hash from
|
|
*/
|
|
static inline uint32_t key_hash_flash(const struct ubifs_info *c, const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_block - get data block number.
|
|
* @c: UBIFS file-system description object
|
|
* @key: the key to get the block number from
|
|
*/
|
|
static inline unsigned int key_block(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_block_flash - get data block number from an on-flash formatted key.
|
|
* @c: UBIFS file-system description object
|
|
* @k: the key to get the block number from
|
|
*/
|
|
static inline unsigned int key_block_flash(const struct ubifs_info *c,
|
|
const void *k)
|
|
{
|
|
const union ubifs_key *key = k;
|
|
|
|
return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK;
|
|
}
|
|
|
|
/**
|
|
* key_read - transform a key to in-memory format.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to transform
|
|
* @to: the key to store the result
|
|
*/
|
|
static inline void key_read(const struct ubifs_info *c, const void *from,
|
|
union ubifs_key *to)
|
|
{
|
|
const union ubifs_key *f = from;
|
|
|
|
to->u32[0] = le32_to_cpu(f->j32[0]);
|
|
to->u32[1] = le32_to_cpu(f->j32[1]);
|
|
}
|
|
|
|
/**
|
|
* key_write - transform a key from in-memory format.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to transform
|
|
* @to: the key to store the result
|
|
*/
|
|
static inline void key_write(const struct ubifs_info *c,
|
|
const union ubifs_key *from, void *to)
|
|
{
|
|
union ubifs_key *t = to;
|
|
|
|
t->j32[0] = cpu_to_le32(from->u32[0]);
|
|
t->j32[1] = cpu_to_le32(from->u32[1]);
|
|
memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
|
|
}
|
|
|
|
/**
|
|
* key_write_idx - transform a key from in-memory format for the index.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to transform
|
|
* @to: the key to store the result
|
|
*/
|
|
static inline void key_write_idx(const struct ubifs_info *c,
|
|
const union ubifs_key *from, void *to)
|
|
{
|
|
union ubifs_key *t = to;
|
|
|
|
t->j32[0] = cpu_to_le32(from->u32[0]);
|
|
t->j32[1] = cpu_to_le32(from->u32[1]);
|
|
}
|
|
|
|
/**
|
|
* key_copy - copy a key.
|
|
* @c: UBIFS file-system description object
|
|
* @from: the key to copy from
|
|
* @to: the key to copy to
|
|
*/
|
|
static inline void key_copy(const struct ubifs_info *c,
|
|
const union ubifs_key *from, union ubifs_key *to)
|
|
{
|
|
to->u64[0] = from->u64[0];
|
|
}
|
|
|
|
/**
|
|
* keys_cmp - compare keys.
|
|
* @c: UBIFS file-system description object
|
|
* @key1: the first key to compare
|
|
* @key2: the second key to compare
|
|
*
|
|
* This function compares 2 keys and returns %-1 if @key1 is less than
|
|
* @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
|
|
*/
|
|
static inline int keys_cmp(const struct ubifs_info *c,
|
|
const union ubifs_key *key1,
|
|
const union ubifs_key *key2)
|
|
{
|
|
if (key1->u32[0] < key2->u32[0])
|
|
return -1;
|
|
if (key1->u32[0] > key2->u32[0])
|
|
return 1;
|
|
if (key1->u32[1] < key2->u32[1])
|
|
return -1;
|
|
if (key1->u32[1] > key2->u32[1])
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* keys_eq - determine if keys are equivalent.
|
|
* @c: UBIFS file-system description object
|
|
* @key1: the first key to compare
|
|
* @key2: the second key to compare
|
|
*
|
|
* This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
|
|
* %0 if not.
|
|
*/
|
|
static inline int keys_eq(const struct ubifs_info *c,
|
|
const union ubifs_key *key1,
|
|
const union ubifs_key *key2)
|
|
{
|
|
if (key1->u32[0] != key2->u32[0])
|
|
return 0;
|
|
if (key1->u32[1] != key2->u32[1])
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* is_hash_key - is a key vulnerable to hash collisions.
|
|
* @c: UBIFS file-system description object
|
|
* @key: key
|
|
*
|
|
* This function returns %1 if @key is a hashed key or %0 otherwise.
|
|
*/
|
|
static inline int is_hash_key(const struct ubifs_info *c,
|
|
const union ubifs_key *key)
|
|
{
|
|
int type = key_type(c, key);
|
|
|
|
return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
|
|
}
|
|
|
|
/**
|
|
* key_max_inode_size - get maximum file size allowed by current key format.
|
|
* @c: UBIFS file-system description object
|
|
*/
|
|
static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
|
|
{
|
|
switch (c->key_fmt) {
|
|
case UBIFS_SIMPLE_KEY_FMT:
|
|
return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#endif /* !__UBIFS_KEY_H__ */
|