4185 New hash algorithm support

*** 20,29 ****
--- 20,30 ----
   */
  /*
   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2012 by Delphix. All rights reserved.
   * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+  * Copyright 2013 Saso Kiselkov. All rights reserved.
   */
  
  #ifndef _SYS_SPA_H
  #define _SYS_SPA_H
  
*** 51,60 ****
--- 52,62 ----
  typedef struct spa_aux_vdev spa_aux_vdev_t;
  typedef struct ddt ddt_t;
  typedef struct ddt_entry ddt_entry_t;
  struct dsl_pool;
  struct dsl_dataset;
+ struct zfeature_info;
  
  /*
   * General-purpose 32-bit and 64-bit bitfield encodings.
   */
  #define BF32_DECODE(x, low, len)        P2PHASE((x) >> (low), 1U << (len))
*** 122,131 ****
--- 124,141 ----
  typedef struct zio_cksum {
          uint64_t        zc_word[4];
  } zio_cksum_t;
  
  /*
+  * Some checksums/hashes need a 256-bit initialization salt. This salt is kept
+  * secret and is suitable for use in MAC algorithms as the key.
+  */
+ typedef struct zio_cksum_salt {
+         uint8_t         zcs_bytes[32];
+ } zio_cksum_salt_t;
+ 
+ /*
   * Each block is described by its DVAs, time of birth, checksum, etc.
   * The word-by-word, bit-by-bit layout of the blkptr is as follows:
   *
   *      64      56      48      40      32      24      16      8       0
   *      +-------+-------+-------+-------+-------+-------+-------+-------+
*** 621,630 ****
--- 631,643 ----
  extern uint64_t bp_get_dsize(spa_t *spa, const blkptr_t *bp);
  extern boolean_t spa_has_slogs(spa_t *spa);
  extern boolean_t spa_is_root(spa_t *spa);
  extern boolean_t spa_writeable(spa_t *spa);
  
+ /* Salted checksum handling */
+ extern int spa_activate_salted_cksum(spa_t *spa, struct zfeature_info *feature);
+ 
  extern int spa_mode(spa_t *spa);
  extern uint64_t strtonum(const char *str, char **nptr);
  
  extern char *spa_his_ievent_table[];