10592 misc. metaslab and vdev related ZoL bug fixes
Portions contributed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed by: George Melikov <mail@gmelikov.ru>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Tony Hutter <hutter2@llnl.gov>
Reviewed by: Kody Kantor <kody.kantor@joyent.com>
Approved by: Dan McDonald <danmcd@joyent.com>

@@ -678,11 +678,10 @@
                 ASSERT(list_is_empty(&sci->sci_new_mapping_entries[i]));
         }
 
         VERIFY0(space_map_open(&prev_obsolete_sm, spa->spa_meta_objset,
             scip->scip_prev_obsolete_sm_object, 0, vd->vdev_asize, 0));
-        space_map_update(prev_obsolete_sm);
         counts = vdev_indirect_mapping_load_obsolete_counts(old_mapping);
         if (prev_obsolete_sm != NULL) {
                 vdev_indirect_mapping_load_obsolete_spacemap(old_mapping,
                     counts, prev_obsolete_sm);
         }

@@ -831,20 +830,18 @@
 
                 spa_feature_incr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx);
                 VERIFY0(space_map_open(&vd->vdev_obsolete_sm,
                     spa->spa_meta_objset, obsolete_sm_object,
                     0, vd->vdev_asize, 0));
-                space_map_update(vd->vdev_obsolete_sm);
         }
 
         ASSERT(vd->vdev_obsolete_sm != NULL);
         ASSERT3U(vdev_obsolete_sm_object(vd), ==,
             space_map_object(vd->vdev_obsolete_sm));
 
         space_map_write(vd->vdev_obsolete_sm,
             vd->vdev_obsolete_segments, SM_ALLOC, SM_NO_VDEVID, tx);
-        space_map_update(vd->vdev_obsolete_sm);
         range_tree_vacate(vd->vdev_obsolete_segments, NULL, NULL);
 }
 
 int
 spa_condense_init(spa_t *spa)