8115 parallel zfs mount

*** 20,30 ****
   */
  
  /*
   * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2016 Toomas Soome <tsoome@me.com>
!  * Copyright (c) 2016 by Delphix. All rights reserved.
   * Copyright 2016 Nexenta Systems, Inc.
   */
  
  /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  /*        All Rights Reserved   */
--- 20,30 ----
   */
  
  /*
   * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2016 Toomas Soome <tsoome@me.com>
!  * Copyright (c) 2016, 2017 by Delphix. All rights reserved.
   * Copyright 2016 Nexenta Systems, Inc.
   */
  
  /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  /*        All Rights Reserved   */
*** 414,423 ****
--- 414,424 ----
  #define VSW_VOLATILEDEV 0x10    /* vfs_dev can change each time fs is mounted */
  #define VSW_STATS       0x20    /* file system can collect stats */
  #define VSW_XID         0x40    /* file system supports extended ids */
  #define VSW_CANLOFI     0x80    /* file system supports lofi mounts */
  #define VSW_ZMOUNT      0x100   /* file system always allowed in a zone */
+ #define VSW_MOUNTDEV    0x200   /* file system is mounted via device path */
  
  #define VSW_INSTALLED   0x8000  /* this vsw is associated with a file system */
  
  /*
   * A flag for vfs_setpath().