3525 Persistent L2ARC

*** 1477,1490 ****
                          if (vdev_open(vd) != 0)
                                  continue;
  
                          (void) vdev_validate_aux(vd);
  
!                         if (!vdev_is_dead(vd))
!                                 l2arc_add_vdev(spa, vd);
                  }
          }
  
          /*
           * Purge vdevs that were dropped
           */
          for (i = 0; i < oldnvdevs; i++) {
--- 1477,1503 ----
                          if (vdev_open(vd) != 0)
                                  continue;
  
                          (void) vdev_validate_aux(vd);
  
!                         if (!vdev_is_dead(vd)) {
!                                 boolean_t persist = B_FALSE;
! 
!                                 if (spa->spa_load_state != SPA_LOAD_TRYIMPORT) {
!                                         /*
!                                          * Only allow to do the L2ARC rebuild
!                                          * when not doing a spa try-load.
!                                          */
!                                         (void) nvlist_lookup_boolean_value(
!                                             l2cache[i],
!                                             ZPOOL_CONFIG_L2CACHE_PERSISTENT,
!                                             &persist);
                                  }
+                                 l2arc_add_vdev(spa, vd, persist);
                          }
+                 }
+         }
  
          /*
           * Purge vdevs that were dropped
           */
          for (i = 0; i < oldnvdevs; i++) {
*** 3878,3892 ****
          if (spa->spa_spares.sav_config) {
                  nvlist_free(spa->spa_spares.sav_config);
                  spa->spa_spares.sav_config = NULL;
                  spa_load_spares(spa);
          }
-         if (spa->spa_l2cache.sav_config) {
-                 nvlist_free(spa->spa_l2cache.sav_config);
-                 spa->spa_l2cache.sav_config = NULL;
-                 spa_load_l2cache(spa);
-         }
  
          VERIFY(nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
              &nvroot) == 0);
          if (error == 0)
                  error = spa_validate_aux(spa, nvroot, -1ULL,
--- 3891,3900 ----