expandable RAID-Z

*** 62,81 ****
  typedef void    vdev_close_func_t(vdev_t *vd);
  typedef int     vdev_probe_func_t(vdev_t *vd);
  typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
  typedef int     vdev_io_start_func_t(zio_t *zio);
  typedef int     vdev_io_done_func_t(zio_t *zio);
! typedef void    vdev_state_change_func_t(vdev_t *vd, int, int);
  
  typedef struct vdev_ops {
          vdev_open_func_t                *vdev_op_open;
          vdev_close_func_t               *vdev_op_close;
          vdev_probe_func_t               *vdev_op_probe;
          vdev_asize_func_t               *vdev_op_asize;
          vdev_io_start_func_t            *vdev_op_io_start;
          vdev_io_done_func_t             *vdev_op_io_done;
          vdev_state_change_func_t        *vdev_op_state_change;
          char                            vdev_op_type[16];
          boolean_t                       vdev_op_leaf;
  } vdev_ops_t;
  
  /*
--- 62,83 ----
  typedef void    vdev_close_func_t(vdev_t *vd);
  typedef int     vdev_probe_func_t(vdev_t *vd);
  typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
  typedef int     vdev_io_start_func_t(zio_t *zio);
  typedef int     vdev_io_done_func_t(zio_t *zio);
! typedef void    vdev_state_change_func_t(vdev_t *vd, int fauled, int degraded);
! typedef uint8_t vdev_grid_func_t(vdev_t *vd);
  
  typedef struct vdev_ops {
          vdev_open_func_t                *vdev_op_open;
          vdev_close_func_t               *vdev_op_close;
          vdev_probe_func_t               *vdev_op_probe;
          vdev_asize_func_t               *vdev_op_asize;
          vdev_io_start_func_t            *vdev_op_io_start;
          vdev_io_done_func_t             *vdev_op_io_done;
          vdev_state_change_func_t        *vdev_op_state_change;
+         vdev_grid_func_t                *vdev_op_grid;
          char                            vdev_op_type[16];
          boolean_t                       vdev_op_leaf;
  } vdev_ops_t;
  
  /*