shmem_alloc_folio
folio = shmem_alloc_folio(gfp, order, info, aligned_index);
folio = shmem_alloc_folio(gfp, 0, info, index);
new = shmem_alloc_folio(alloc_gfp, order, info, index);
new = shmem_alloc_folio(gfp, folio_order(old), info, index);
folio = shmem_alloc_folio(gfp, 0, info, pgoff);