51 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			51 lines
		
	
	
	
		
			1.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
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								/*
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								 * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com>
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								 *
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								 * This program is free software; you can redistribute it and/or
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								 * modify it under the terms of the GNU General Public
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								 * License v2 as published by the Free Software Foundation.
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								 *
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								 * This program is distributed in the hope that it will be useful,
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								 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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								 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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								 * General Public License for more details.
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								 */
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								#include <crypto/hash.h>
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								#include <linux/err.h>
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								#include "hash.h"
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								static struct crypto_shash *tfm;
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								int __init btrfs_hash_init(void)
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								{
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									tfm = crypto_alloc_shash("crc32c", 0, 0);
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									if (IS_ERR(tfm))
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										return PTR_ERR(tfm);
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									return 0;
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								}
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								void btrfs_hash_exit(void)
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								{
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									crypto_free_shash(tfm);
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								}
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								u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
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								{
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									struct {
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										struct shash_desc shash;
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										char ctx[crypto_shash_descsize(tfm)];
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									} desc;
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									int err;
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									desc.shash.tfm = tfm;
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									desc.shash.flags = 0;
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									*(u32 *)desc.ctx = crc;
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									err = crypto_shash_update(&desc.shash, address, length);
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									BUG_ON(err);
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									return *(u32 *)desc.ctx;
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								}
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