diff options
Diffstat (limited to 'mkfs.ubifs/key.h')
| -rw-r--r-- | mkfs.ubifs/key.h | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/mkfs.ubifs/key.h b/mkfs.ubifs/key.h deleted file mode 100644 index d3a02d4..0000000 --- a/mkfs.ubifs/key.h +++ /dev/null @@ -1,189 +0,0 @@ -/* - * 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; - - len = len; - 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(union ubifs_key *key, ino_t inum) -{ - key->u32[0] = inum; - key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS; -} - -/** - * 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); -} - -/** - * 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(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); -} - -/** - * 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 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 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]); -} - -/** - * 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 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; -} - -#endif /* !__UBIFS_KEY_H__ */ |