Function vdev_label_sync

freebsd/contrib/openzfs/module/zfs/vdev_label.c:1753–1806

* Write all even or odd labels to all leaves of the specified vdev. */

 * Write all even or odd labels to all leaves of the specified vdev.
 */
static void
vdev_label_sync(zio_t *zio, uint64_t *good_writes,
    vdev_t *vd, int l, uint64_t txg, int flags)
{
	nvlist_t *label;
	vdev_phys_t *vp;
	abd_t *vp_abd;
	char *buf;
	size_t buflen;

	for (int c = 0; c < vd->vdev_children; c++) {
		vdev_label_sync(zio, good_writes,
		    vd->vdev_child[c], l, txg, flags);
	}

	if (!vd->vdev_ops->vdev_op_leaf)
		return;

	if (!vdev_writeable(vd))
		return;

	/*
	 * The top-level config never needs to be written to a distributed
	 * spare.  When read vdev_dspare_label_read_config() will generate
	 * the config for the vdev_label_read_config().
	 */
	if (vd->vdev_ops == &vdev_draid_spare_ops)
		return;

	/*
	 * Generate a label describing the top-level config to which we belong.
	 */
	label = spa_config_generate(vd->vdev_spa, vd, txg, B_FALSE);

	vp_abd = abd_alloc_linear(sizeof (vdev_phys_t), B_TRUE);
	abd_zero(vp_abd, sizeof (vdev_phys_t));
	vp = abd_to_buf(vp_abd);

	buf = vp->vp_nvlist;
	buflen = sizeof (vp->vp_nvlist);

	if (!nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP)) {
		for (; l < VDEV_LABELS; l += 2) {
			vdev_label_write(zio, vd, l, vp_abd,
			    offsetof(vdev_label_t, vl_vdev_phys),
			    sizeof (vdev_phys_t),
			    vdev_label_sync_done, good_writes,
			    flags | ZIO_FLAG_DONT_PROPAGATE);
		}
	}

	abd_free(vp_abd);
	nvlist_free(label);
}

static int
vdev_label_sync_list(spa_t *spa, int l, uint64_t txg, int flags)