+extern boolean_t zfs_allocatable_devs(nvlist_t *);
+extern void zpool_get_rewind_policy(nvlist_t *, zpool_rewind_policy_t *);
+
+extern int zfs_zpl_version_map(int spa_version);
+extern int zfs_spa_version_map(int zpl_version);
+extern const char *zfs_history_event_names[LOG_END];