svcrdma: Adjust the number of entries in svc_rdma_send_ctxt::sc_pages

Allow allocation of more entries in the sc_pages[] array when the
maximum size of an RPC message is increased.

Reviewed-by: Jeff Layton <[e-mail]>
Reviewed-by: NeilBrown <[e-mail]>
Signed-off-by: Chuck Lever <[e-mail]>

include/linux/sunrpc/svc_rdma.h

···
 	void			*sc_xprt_buf;
 	int			sc_page_count;
 	int			sc_cur_sge_no;
-	struct page		*sc_pages[RPCSVC_MAXPAGES];
+	unsigned long		sc_maxpages;
+	struct page		**sc_pages;
 	struct ib_sge		sc_sges[];
 };
 

net/sunrpc/xprtrdma/svc_rdma_sendto.c

···
 {
 	int node = ibdev_to_node(rdma->sc_cm_id->device);
 	struct svc_rdma_send_ctxt *ctxt;
+	unsigned long pages;
 	dma_addr_t addr;
 	void *buffer;
 	int i;
···
 			    GFP_KERNEL, node);
 	if (!ctxt)
 		goto fail0;
+	pages = svc_serv_maxpages(rdma->sc_xprt.xpt_server);
+	ctxt->sc_pages = kcalloc_node(pages, sizeof(struct page *),
+				      GFP_KERNEL, node);
+	if (!ctxt->sc_pages)
+		goto fail1;
+	ctxt->sc_maxpages = pages;
 	buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node);
 	if (!buffer)
-		goto fail1;
+		goto fail2;
 	addr = ib_dma_map_single(rdma->sc_pd->device, buffer,
 				 rdma->sc_max_req_size, DMA_TO_DEVICE);
 	if (ib_dma_mapping_error(rdma->sc_pd->device, addr))
-		goto fail2;
+		goto fail3;
 
 	svc_rdma_send_cid_init(rdma, &ctxt->sc_cid);
 
···
 		ctxt->sc_sges[i].lkey = rdma->sc_pd->local_dma_lkey;
 	return ctxt;
 
-fail2:
+fail3:
 	kfree(buffer);
+fail2:
+	kfree(ctxt->sc_pages);
 fail1:
 	kfree(ctxt);
 fail0:
···
 				    rdma->sc_max_req_size,
 				    DMA_TO_DEVICE);
 		kfree(ctxt->sc_xprt_buf);
+		kfree(ctxt->sc_pages);
 		kfree(ctxt);
 	}
 }