Function vdev_dtl_sync

freebsd/contrib/openzfs/module/zfs/vdev.c:3083–3156

}

static void
vdev_dtl_sync(vdev_t *vd, uint64_t txg)
{
	spa_t *spa = vd->vdev_spa;
	range_tree_t *rt = vd->vdev_dtl[DTL_MISSING];
	objset_t *mos = spa->spa_meta_objset;
	range_tree_t *rtsync;
	dmu_tx_t *tx;
	uint64_t object = space_map_object(vd->vdev_dtl_sm);

	ASSERT(vdev_is_concrete(vd));
	ASSERT(vd->vdev_ops->vdev_op_leaf);

	tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);

	if (vd->vdev_detached || vd->vdev_top->vdev_removing) {
		mutex_enter(&vd->vdev_dtl_lock);
		space_map_free(vd->vdev_dtl_sm, tx);
		space_map_close(vd->vdev_dtl_sm);
		vd->vdev_dtl_sm = NULL;
		mutex_exit(&vd->vdev_dtl_lock);

		/*
		 * We only destroy the leaf ZAP for detached leaves or for
		 * removed log devices. Removed data devices handle leaf ZAP
		 * cleanup later, once cancellation is no longer possible.
		 */
		if (vd->vdev_leaf_zap != 0 && (vd->vdev_detached ||
		    vd->vdev_top->vdev_islog)) {
			vdev_destroy_unlink_zap(vd, vd->vdev_leaf_zap, tx);
			vd->vdev_leaf_zap = 0;
		}

		dmu_tx_commit(tx);
		return;
	}

	if (vd->vdev_dtl_sm == NULL) {
		uint64_t new_object;

		new_object = space_map_alloc(mos, zfs_vdev_dtl_sm_blksz, tx);
		VERIFY3U(new_object, !=, 0);

		VERIFY0(space_map_open(&vd->vdev_dtl_sm, mos, new_object,
		    0, -1ULL, 0));
		ASSERT(vd->vdev_dtl_sm != NULL);
	}

	rtsync = range_tree_create(NULL, RANGE_SEG64, NULL, 0, 0);

	mutex_enter(&vd->vdev_dtl_lock);
	range_tree_walk(rt, range_tree_add, rtsync);
	mutex_exit(&vd->vdev_dtl_lock);

	space_map_truncate(vd->vdev_dtl_sm, zfs_vdev_dtl_sm_blksz, tx);
	space_map_write(vd->vdev_dtl_sm, rtsync, SM_ALLOC, SM_NO_VDEVID, tx);
	range_tree_vacate(rtsync, NULL, NULL);