shmem_add_to_page_cache
int shmem_add_to_page_cache(struct folio *folio,
err = shmem_add_to_page_cache(folio, mapping, index, NULL,
error = shmem_add_to_page_cache(folio, mapping, index,
error = shmem_add_to_page_cache(folio, mapping, index, NULL, gfp);
error = shmem_add_to_page_cache(folio, mapping, index,
ret = shmem_add_to_page_cache(folio, mapping, pgoff, NULL, gfp);