curzone reality check and teardown changes to use the RIGHT zone

*** 479,489 ****
   */
  
  #define TREE_ROOT(t) \
          ((t)->tree_exi != NULL && \
          (((t)->tree_exi->exi_vp->v_flag & VROOT) || \
!         VN_IS_CURZONEROOT((t)->tree_exi->exi_vp)))
  
  #define TREE_EXPORTED(t) \
          ((t)->tree_exi && !PSEUDO((t)->tree_exi))
  
  #define EXPTABLESIZE   256
--- 479,489 ----
   */
  
  #define TREE_ROOT(t) \
          ((t)->tree_exi != NULL && \
          (((t)->tree_exi->exi_vp->v_flag & VROOT) || \
!         VN_CMP((t)->tree_exi->exi_zone->zone_rootvp, (t)->tree_exi->exi_vp)))
  
  #define TREE_EXPORTED(t) \
          ((t)->tree_exi && !PSEUDO((t)->tree_exi))
  
  #define EXPTABLESIZE   256
*** 531,547 ****
          struct charset_cache    *exi_charset;
          unsigned                exi_volatile_dev:1;
          unsigned                exi_moved:1;
          int                     exi_id;
          avl_node_t              exi_id_link;
!         zoneid_t                exi_zoneid;
  #ifdef VOLATILE_FH_TEST
          uint32_t                exi_volatile_id;
          struct ex_vol_rename    *exi_vol_rename;
          kmutex_t                exi_vol_rename_lock;
  #endif /* VOLATILE_FH_TEST */
  };
  
  typedef struct exportinfo exportinfo_t;
  typedef struct exportdata exportdata_t;
  typedef struct secinfo secinfo_t;
  
--- 531,561 ----
          struct charset_cache    *exi_charset;
          unsigned                exi_volatile_dev:1;
          unsigned                exi_moved:1;
          int                     exi_id;
          avl_node_t              exi_id_link;
!         /*
!          * Soft-reference/backpointer to the zone.  The ZSD callbacks we have
!          * invoke cleanup code that crosses into OTHER cleanup functions that
!          * may assume same-zone context and attempt to find their own ZSD,
!          * using "curzone" when in fact "curzone" is global when called from
!          * NFS's ZSD cleanup (see lm_unexport->nlm_unexport for an example).
!          *
!          * During ZSD shutdown or destroy callbacks, the zone structure
!          * does not have its mutex held, and it has just-enough references
!          * to not free from underneath us.  This field is not a proper
!          * referenced-held zone pointer, and only ZSD callbacks should use
!          * it.
!          */
!         struct zone             *exi_zone;
  #ifdef VOLATILE_FH_TEST
          uint32_t                exi_volatile_id;
          struct ex_vol_rename    *exi_vol_rename;
          kmutex_t                exi_vol_rename_lock;
  #endif /* VOLATILE_FH_TEST */
  };
+ #define exi_zoneid exi_zone->zone_id
  
  typedef struct exportinfo exportinfo_t;
  typedef struct exportdata exportdata_t;
  typedef struct secinfo secinfo_t;