+extern int zfs_prop_get_written_int(zfs_handle_t *zhp, const char *propname,
+ uint64_t *propvalue);
+extern int zfs_prop_get_written(zfs_handle_t *zhp, const char *propname,
+ char *propbuf, int proplen, boolean_t literal);
+extern int zfs_get_snapused_int(zfs_handle_t *firstsnap, zfs_handle_t *lastsnap,
+ uint64_t *usedp);
+extern uint64_t getprop_uint64(zfs_handle_t *, zfs_prop_t, char **);