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14a958e6 FDBM |
1 | /* |
2 | * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | */ | |
13 | ||
14 | #include <crypto/hash.h> | |
15 | #include <linux/err.h> | |
16 | #include "hash.h" | |
17 | ||
18 | static struct crypto_shash *tfm; | |
19 | ||
20 | int __init btrfs_hash_init(void) | |
21 | { | |
22 | tfm = crypto_alloc_shash("crc32c", 0, 0); | |
23 | if (IS_ERR(tfm)) | |
24 | return PTR_ERR(tfm); | |
25 | ||
26 | return 0; | |
27 | } | |
28 | ||
29 | void btrfs_hash_exit(void) | |
30 | { | |
31 | crypto_free_shash(tfm); | |
32 | } | |
33 | ||
34 | u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length) | |
35 | { | |
36 | struct { | |
37 | struct shash_desc shash; | |
38 | char ctx[crypto_shash_descsize(tfm)]; | |
39 | } desc; | |
40 | int err; | |
41 | ||
42 | desc.shash.tfm = tfm; | |
43 | desc.shash.flags = 0; | |
44 | *(u32 *)desc.ctx = crc; | |
45 | ||
46 | err = crypto_shash_update(&desc.shash, address, length); | |
47 | BUG_ON(err); | |
48 | ||
49 | return *(u32 *)desc.ctx; | |
50 | } |