typedef void vdev_hold_func_t(vdev_t *vd);
typedef void vdev_rele_func_t(vdev_t *vd);
-typedef struct vdev_ops {
+typedef const struct vdev_ops {
vdev_open_func_t *vdev_op_open;
vdev_close_func_t *vdev_op_close;
vdev_asize_func_t *vdev_op_asize;
avl_tree_t vq_read_tree;
avl_tree_t vq_write_tree;
avl_tree_t vq_pending_tree;
+ uint64_t vq_io_complete_ts;
+ uint64_t vq_io_delta_ts;
list_t vq_io_list;
kmutex_t vq_lock;
};