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Linux kernel mirror (for testing)
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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
18static struct crypto_shash *tfm;
19
20int __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
29void btrfs_hash_exit(void)
30{
31 crypto_free_shash(tfm);
32}
33
34u32 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}