LOCAL: listen for ldi notifications of disk offline/degrade

*** 19,29 ****
   * CDDL HEADER END
   */
  /*
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
!  * Copyright 2011 Joyent, Inc. All rights reserved.
   */
  
  #ifndef _SYS_VDEV_DISK_H
  #define _SYS_VDEV_DISK_H
  
--- 19,30 ----
   * CDDL HEADER END
   */
  /*
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
!  * Copyright (c) 2012 Joyent, Inc. All rights reserved.
!  * Copyright 2012 Nexenta Systems, Inc.  All rights reserved.
   */
  
  #ifndef _SYS_VDEV_DISK_H
  #define _SYS_VDEV_DISK_H
  
*** 42,51 ****
--- 43,54 ----
  #ifdef _KERNEL
  typedef struct vdev_disk {
          ddi_devid_t     vd_devid;
          char            *vd_minor;
          ldi_handle_t    vd_lh;
+         list_t          vd_ldi_cbs;
+         boolean_t       vd_ldi_offline;
  } vdev_disk_t;
  #endif
  
  extern int vdev_disk_physio(vdev_t *, caddr_t, size_t, uint64_t, int);