OS-3280 need a way to specify the root of a native system in the lx brand
OS-3279 lx brand should allow delegated datasets
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

*** 23,32 ****
--- 23,33 ----
   * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  #include "lint.h"
+ #include "thr_uberdata.h"
  #include <sys/types.h>
  #include <sys/syscall.h>
  #include <sys/zone.h>
  #include <sys/priv.h>
  #include <priv_private.h>
*** 238,243 ****
--- 239,251 ----
  
  int
  zone_list_datalink(zoneid_t zoneid, int *dlnump, datalink_id_t *linkids)
  {
          return (syscall(SYS_zone, ZONE_LIST_DATALINK, zoneid, dlnump, linkids));
+ }
+ 
+ const char *
+ zone_get_nroot()
+ {
+         uberdata_t *udp = curthread->ul_uberdata;
+         return (udp->ub_broot);
  }