+ /*
+ * If anything changed, wait for it to sync. This ensures that,
+ * from the system administrator's perspective, zpool(1M) commands
+ * are synchronous. This is important for things like zpool offline:
+ * when the command completes, you expect no further I/O from ZFS.
+ */
+ if (vd != NULL)
+ txg_wait_synced(spa->spa_dsl_pool, 0);
+