re #13613 rb4516 Tunables needs volatile keyword

*** 20,29 ****
--- 20,32 ----
   */
  /*
   *      Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   *      Use is subject to license terms.
   */
+ /*
+  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  */
  
  /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  /*        All Rights Reserved   */
  
  #ifndef _NFS_RNODE4_H
*** 385,395 ****
          nfs4_open_stream_t      **re_osp; /* held reference */
  } nfs4_opinst_t;
  
  #ifdef _KERNEL
  
! extern long nrnode;
  
  /* Used for r_delay_interval */
  #define NFS4_INITIAL_DELAY_INTERVAL      1
  #define NFS4_MAX_DELAY_INTERVAL         20
  
--- 388,398 ----
          nfs4_open_stream_t      **re_osp; /* held reference */
  } nfs4_opinst_t;
  
  #ifdef _KERNEL
  
! extern volatile long nrnode;
  
  /* Used for r_delay_interval */
  #define NFS4_INITIAL_DELAY_INTERVAL      1
  #define NFS4_MAX_DELAY_INTERVAL         20