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>

*** 22,33 ****
  /*
   * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
- #pragma ident   "%Z%%M% %I%     %E% SMI"
- 
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <ctype.h>
--- 22,31 ----
*** 35,44 ****
--- 33,44 ----
  #include <signal.h>
  #include <errno.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <libproc.h>
+ #include <limits.h>
+ #include "ptools_common.h"
  
  #define NOREAP_TIME 60          /* wait 60 seconds before allow a reap */
  
  static volatile int interrupt;
  static int Fflag;
*** 51,65 ****
  }
  
  static int
  open_usage(pid_t pid, int *perr)
  {
!         char path[64];
          struct stat64 st;
          int fd;
  
!         (void) snprintf(path, sizeof (path), "/proc/%d/usage", (int)pid);
  
          /*
           * Attempt to open the usage file, and return the fd if we can
           * confirm this is a regular file provided by /proc.
           */
--- 51,65 ----
  }
  
  static int
  open_usage(pid_t pid, int *perr)
  {
!         char path[PATH_MAX];
          struct stat64 st;
          int fd;
  
!         (void) proc_snprintf(path, sizeof (path), "/proc/%d/usage", (int)pid);
  
          /*
           * Attempt to open the usage file, and return the fd if we can
           * confirm this is a regular file provided by /proc.
           */