shmem_get_folio_gfp
return shmem_get_folio_gfp(inode, index, write_end, foliop, sgp,
err = shmem_get_folio_gfp(inode, vmf->pgoff, 0, &folio, SGP_CACHE,
error = shmem_get_folio_gfp(inode, index, i_size_read(inode),