int metaslab_load(metaslab_t *);
void metaslab_unload(metaslab_t *);
+uint64_t metaslab_allocated_space(metaslab_t *);
+
void metaslab_sync(metaslab_t *, uint64_t);
void metaslab_sync_done(metaslab_t *, uint64_t);
void metaslab_sync_reassess(metaslab_group_t *);