xa_alloc
int xa_alloc(struct xarray *, uint32_t *, void *, struct xa_limit, gfp_t);
err = xa_alloc(&chains_xa(chains), &chain_s->xa_idx, chain_s,
err = xa_alloc(&prios_xa(chains), &prio_s->xa_idx, prio_s,
return xa_alloc(&uobj->ufile->idr, &uobj->id, NULL, xa_limit_32b,