4185 New hash algorithm support

*** 21,30 ****
--- 21,31 ----
  
  /*
   * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2013 by Delphix. All rights reserved.
   * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  * Copyright 2013 Saso Kiselkov. All rights reserved.
   */
  
  /*
   * SPA: Storage Pool Allocator
   *
*** 2408,2417 ****
--- 2409,2437 ----
                  spa_activate(spa, orig_mode);
  
                  return (spa_load(spa, state, SPA_IMPORT_EXISTING, B_TRUE));
          }
  
+         /* Grab the secret checksum salt from the MOS. */
+         if (spa_dir_prop(spa, DMU_POOL_CHECKSUM_SALT,
+             &spa->spa_cksum_salt_obj) == 0) {
+                 if (zap_lookup(spa->spa_meta_objset, spa->spa_cksum_salt_obj,
+                     DMU_POOL_CHECKSUM_SALT, 1,
+                     sizeof (spa->spa_cksum_salt.zcs_bytes),
+                     spa->spa_cksum_salt.zcs_bytes) != 0) {
+                         /*
+                          * MOS format is broken, the salt object is there but
+                          * is missing the actual salt value.
+                          */
+                         return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
+                 }
+         } else {
+                 /* Generate a new salt for subsequent use */
+                 (void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
+                     sizeof (spa->spa_cksum_salt.zcs_bytes));
+         }
+ 
          if (spa_dir_prop(spa, DMU_POOL_SYNC_BPOBJ, &obj) != 0)
                  return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
          error = bpobj_open(&spa->spa_deferred_bpobj, spa->spa_meta_objset, obj);
          if (error != 0)
                  return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
*** 3554,3563 ****
--- 3574,3592 ----
           */
          if (version >= SPA_VERSION_ZPOOL_HISTORY)
                  spa_history_create_obj(spa, tx);
  
          /*
+          * Generate some random noise for salted checksums to operate on. As
+          * soon as a salted checksum is used for the first time we will
+          * generate the persistent MOS object to hold the salt (see
+          * spa_activate_salted_cksum).
+          */
+         (void) random_get_pseudo_bytes(spa->spa_cksum_salt.zcs_bytes,
+             sizeof (spa->spa_cksum_salt.zcs_bytes));
+ 
+         /*
           * Set pool properties.
           */
          spa->spa_bootfs = zpool_prop_default_numeric(ZPOOL_PROP_BOOTFS);
          spa->spa_delegation = zpool_prop_default_numeric(ZPOOL_PROP_DELEGATION);
          spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);