SUNRPC: Update svcxdr_init_decode() to call xdr_set_scratch_folio()

The only snag here is that __folio_alloc_node() doesn't handle
NUMA_NO_NODE, so I also need to update svc_pool_map_get_node() to return
numa_mem_id() instead. I arrived at this approach by looking at what
other users of __folio_alloc_node() do for this case.

Signed-off-by: Anna Schumaker <[e-mail]>

include/linux/sunrpc/svc.h

···
 	struct xdr_buf		rq_arg;
 	struct xdr_stream	rq_arg_stream;
 	struct xdr_stream	rq_res_stream;
-	struct page		*rq_scratch_page;
+	struct folio		*rq_scratch_folio;
 	struct xdr_buf		rq_res;
 	unsigned long		rq_maxpages;	/* num of entries in rq_pages */
 	struct page *		*rq_pages;
···
 	buf->len = buf->head->iov_len + buf->page_len + buf->tail->iov_len;
 
 	xdr_init_decode(xdr, buf, argv->iov_base, NULL);
-	xdr_set_scratch_page(xdr, rqstp->rq_scratch_page);
+	xdr_set_scratch_folio(xdr, rqstp->rq_scratch_folio);
 }
 
 /**

net/sunrpc/svc.c

···
 		if (m->mode == SVC_POOL_PERNODE)
 			return m->pool_to[pidx];
 	}
-	return NUMA_NO_NODE;
+	return numa_mem_id();
 }
 /*
  * Set the given thread's cpus_allowed mask so that it
···
 	folio_batch_release(&rqstp->rq_fbatch);
 	kfree(rqstp->rq_bvec);
 	svc_release_buffer(rqstp);
-	if (rqstp->rq_scratch_page)
-		put_page(rqstp->rq_scratch_page);
+	if (rqstp->rq_scratch_folio)
+		folio_put(rqstp->rq_scratch_folio);
 	kfree(rqstp->rq_resp);
 	kfree(rqstp->rq_argp);
 	kfree(rqstp->rq_auth_data);
···
 	rqstp->rq_server = serv;
 	rqstp->rq_pool = pool;
 
-	rqstp->rq_scratch_page = alloc_pages_node(node, GFP_KERNEL, 0);
-	if (!rqstp->rq_scratch_page)
+	rqstp->rq_scratch_folio = __folio_alloc_node(GFP_KERNEL, 0, node);
+	if (!rqstp->rq_scratch_folio)
 		goto out_enomem;
 
 	rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);