4101 metaslab_debug should allow for fine-grained control
4102 space_maps should store more information about themselves
4103 space map object blocksize should be increased
4104 ::spa_space no longer works
4105 removing a mirrored log device results in a leaked object
4106 asynchronously load metaslab
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <seb@delphix.com>

*** 455,464 ****
--- 455,472 ----
  void
  spa_deadman(void *arg)
  {
          spa_t *spa = arg;
  
+         /*
+          * Disable the deadman timer if the pool is suspended.
+          */
+         if (spa_suspended(spa)) {
+                 VERIFY(cyclic_reprogram(spa->spa_deadman_cycid, CY_INFINITY));
+                 return;
+         }
+ 
          zfs_dbgmsg("slow spa_sync: started %llu seconds ago, calls %llu",
              (gethrtime() - spa->spa_sync_starttime) / NANOSEC,
              ++spa->spa_deadman_calls);
          if (zfs_deadman_enabled)
                  vdev_deadman(spa->spa_root_vdev);
*** 1023,1033 ****
           */
          if (error == 0)
                  txg_wait_synced(spa->spa_dsl_pool, txg);
  
          if (vd != NULL) {
!                 ASSERT(!vd->vdev_detached || vd->vdev_dtl_smo.smo_object == 0);
                  spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
                  vdev_free(vd);
                  spa_config_exit(spa, SCL_ALL, spa);
          }
  
--- 1031,1041 ----
           */
          if (error == 0)
                  txg_wait_synced(spa->spa_dsl_pool, txg);
  
          if (vd != NULL) {
!                 ASSERT(!vd->vdev_detached || vd->vdev_dtl_sm == NULL);
                  spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
                  vdev_free(vd);
                  spa_config_exit(spa, SCL_ALL, spa);
          }
  
*** 1700,1710 ****
          }
  #endif
  
          refcount_init();
          unique_init();
!         space_map_init();
          zio_init();
          dmu_init();
          zil_init();
          vdev_cache_stat_init();
          zfs_prop_init();
--- 1708,1718 ----
          }
  #endif
  
          refcount_init();
          unique_init();
!         range_tree_init();
          zio_init();
          dmu_init();
          zil_init();
          vdev_cache_stat_init();
          zfs_prop_init();
*** 1723,1733 ****
  
          vdev_cache_stat_fini();
          zil_fini();
          dmu_fini();
          zio_fini();
!         space_map_fini();
          unique_fini();
          refcount_fini();
  
          avl_destroy(&spa_namespace_avl);
          avl_destroy(&spa_spare_avl);
--- 1731,1741 ----
  
          vdev_cache_stat_fini();
          zil_fini();
          dmu_fini();
          zio_fini();
!         range_tree_fini();
          unique_fini();
          refcount_fini();
  
          avl_destroy(&spa_namespace_avl);
          avl_destroy(&spa_spare_avl);