linux/fs/btrfs/hash.c

55 lines
1.2 KiB
C

/*
* Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 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.
*/
#include <crypto/hash.h>
#include <linux/err.h>
#include "hash.h"
static struct crypto_shash *tfm;
int __init btrfs_hash_init(void)
{
tfm = crypto_alloc_shash("crc32c", 0, 0);
return PTR_ERR_OR_ZERO(tfm);
}
const char* btrfs_crc32c_impl(void)
{
return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
}
void btrfs_hash_exit(void)
{
crypto_free_shash(tfm);
}
u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
{
SHASH_DESC_ON_STACK(shash, tfm);
u32 *ctx = (u32 *)shash_desc_ctx(shash);
u32 retval;
int err;
shash->tfm = tfm;
shash->flags = 0;
*ctx = crc;
err = crypto_shash_update(shash, address, length);
BUG_ON(err);
retval = *ctx;
barrier_data(ctx);
return retval;
}