+ * Change the GUID for the pool. This is done so that we can later
+ * re-import a pool built from a clone of our own vdevs. We will modify
+ * the root vdev's guid, our own pool guid, and then mark all of our
+ * vdevs dirty. Note that we must make sure that all our vdevs are
+ * online when we do this, or else any vdevs that weren't present
+ * would be orphaned from our pool. We are also going to issue a
+ * sysevent to update any watchers.
+ */
+int
+spa_change_guid(spa_t *spa)
+{
+ uint64_t oldguid, newguid;
+ uint64_t txg;
+
+ if (!(spa_mode_global & FWRITE))
+ return (EROFS);
+
+ txg = spa_vdev_enter(spa);
+
+ if (spa->spa_root_vdev->vdev_state != VDEV_STATE_HEALTHY)
+ return (spa_vdev_exit(spa, NULL, txg, ENXIO));
+
+ oldguid = spa_guid(spa);
+ newguid = spa_generate_guid(NULL);
+ ASSERT3U(oldguid, !=, newguid);
+
+ spa->spa_root_vdev->vdev_guid = newguid;
+ spa->spa_root_vdev->vdev_guid_sum += (newguid - oldguid);
+
+ vdev_config_dirty(spa->spa_root_vdev);
+
+ spa_event_notify(spa, NULL, FM_EREPORT_ZFS_POOL_REGUID);
+
+ return (spa_vdev_exit(spa, NULL, txg, 0));
+}
+
+/*