Line data    Source code

       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           0 : int __init btrfs_hash_init(void)
      21             : {
      22           0 :         tfm = crypto_alloc_shash("crc32c", 0, 0);
      23           0 :         if (IS_ERR(tfm))
      24           0 :                 return PTR_ERR(tfm);
      25             : 
      26             :         return 0;
      27             : }
      28             : 
      29           0 : void btrfs_hash_exit(void)
      30             : {
      31           0 :         crypto_free_shash(tfm);
      32           0 : }
      33             : 
      34     5966186 : u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
      35             : {
      36             :         struct {
      37             :                 struct shash_desc shash;
      38     5966186 :                 char ctx[crypto_shash_descsize(tfm)];
      39     5966186 :         } desc;
      40             :         int err;
      41             : 
      42     5966186 :         desc.shash.tfm = tfm;
      43     5966186 :         desc.shash.flags = 0;
      44     5966186 :         *(u32 *)desc.ctx = crc;
      45             : 
      46     5966186 :         err = crypto_shash_update(&desc.shash, address, length);
      47     5970266 :         BUG_ON(err);
      48             : 
      49     5970266 :         return *(u32 *)desc.ctx;
      50             : }