Function vdev_draid_spare_create

freebsd/contrib/openzfs/module/zfs/vdev_draid.c:1866–1955

* Add virtual dRAID spares to the list of valid spares. In order to accomplish * this the existing array must be freed and reallocated with the additional * entries. */

 * entries.
 */
int
vdev_draid_spare_create(nvlist_t *nvroot, vdev_t *vd, uint64_t *ndraidp,
    uint64_t next_vdev_id)
{
	uint64_t draid_nspares = 0;
	uint64_t ndraid = 0;
	int error;

	for (uint64_t i = 0; i < vd->vdev_children; i++) {
		vdev_t *cvd = vd->vdev_child[i];

		if (cvd->vdev_ops == &vdev_draid_ops) {
			vdev_draid_config_t *vdc = cvd->vdev_tsd;
			draid_nspares += vdc->vdc_nspares;
			ndraid++;
		}
	}

	if (draid_nspares == 0) {
		*ndraidp = ndraid;
		return (0);
	}

	nvlist_t **old_spares, **new_spares;
	uint_t old_nspares;
	error = nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES,
	    &old_spares, &old_nspares);
	if (error)
		old_nspares = 0;

	/* Allocate memory and copy of the existing spares. */
	new_spares = kmem_alloc(sizeof (nvlist_t *) *
	    (draid_nspares + old_nspares), KM_SLEEP);
	for (uint_t i = 0; i < old_nspares; i++)
		new_spares[i] = fnvlist_dup(old_spares[i]);

	/* Add new distributed spares to ZPOOL_CONFIG_SPARES. */
	uint64_t n = old_nspares;
	for (uint64_t vdev_id = 0; vdev_id < vd->vdev_children; vdev_id++) {
		vdev_t *cvd = vd->vdev_child[vdev_id];
		char path[64];

		if (cvd->vdev_ops != &vdev_draid_ops)
			continue;

		vdev_draid_config_t *vdc = cvd->vdev_tsd;
		uint64_t nspares = vdc->vdc_nspares;
		uint64_t nparity = vdc->vdc_nparity;

		for (uint64_t spare_id = 0; spare_id < nspares; spare_id++) {
			bzero(path, sizeof (path));
			(void) snprintf(path, sizeof (path) - 1,
			    "%s%llu-%llu-%llu", VDEV_TYPE_DRAID,
			    (u_longlong_t)nparity,
			    (u_longlong_t)next_vdev_id + vdev_id,
			    (u_longlong_t)spare_id);

			nvlist_t *spare = fnvlist_alloc();