Function vdev_compact_children

freebsd/contrib/openzfs/module/zfs/vdev.c:502–534

* Remove any holes in the child array. */

 * Remove any holes in the child array.
 */
void
vdev_compact_children(vdev_t *pvd)
{
	vdev_t **newchild, *cvd;
	int oldc = pvd->vdev_children;
	int newc;

	ASSERT(spa_config_held(pvd->vdev_spa, SCL_ALL, RW_WRITER) == SCL_ALL);

	if (oldc == 0)
		return;

	for (int c = newc = 0; c < oldc; c++)
		if (pvd->vdev_child[c])
			newc++;

	if (newc > 0) {
		newchild = kmem_zalloc(newc * sizeof (vdev_t *), KM_SLEEP);

		for (int c = newc = 0; c < oldc; c++) {
			if ((cvd = pvd->vdev_child[c]) != NULL) {
				newchild[newc] = cvd;
				cvd->vdev_id = newc++;
			}
		}
	} else {
		newchild = NULL;
	}

	kmem_free(pvd->vdev_child, oldc * sizeof (vdev_t *));
	pvd->vdev_child = newchild;
	pvd->vdev_children = newc;
}

/*
 * Allocate and minimally initialize a vdev_t.