From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E61B3C43613 for ; Wed, 19 Jun 2019 20:43:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B246D21721 for ; Wed, 19 Jun 2019 20:43:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726246AbfFSUnC (ORCPT ); Wed, 19 Jun 2019 16:43:02 -0400 Received: from fieldses.org ([173.255.197.46]:42490 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726230AbfFSUnC (ORCPT ); Wed, 19 Jun 2019 16:43:02 -0400 Received: by fieldses.org (Postfix, from userid 2815) id 93E818BF; Wed, 19 Jun 2019 16:43:01 -0400 (EDT) Date: Wed, 19 Jun 2019 16:43:01 -0400 From: Bruce Fields To: Chuck Lever Cc: linux-rdma@vger.kernel.org, Linux NFS Mailing List Subject: Re: [PATCH v2] svcrdma: Ignore source port when computing DRC hash Message-ID: <20190619204301.GA3044@fieldses.org> References: <20190611150116.4209.63309.stgit@klimt.1015granger.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Wed, Jun 19, 2019 at 04:25:57PM -0400, Chuck Lever wrote: > > > On Jun 11, 2019, at 11:01 AM, Chuck Lever wrote: > > > > The DRC appears to be effectively empty after an RPC/RDMA transport > > reconnect. The problem is that each connection uses a different > > source port, which defeats the DRC hash. > > > > Clients always have to disconnect before they send retransmissions > > to reset the connection's credit accounting, thus every retransmit > > on NFS/RDMA will miss the DRC. > > > > An NFS/RDMA client's IP source port is meaningless for RDMA > > transports. The transport layer typically sets the source port value > > on the connection to a random ephemeral port. The server already > > ignores it for the "secure port" check. See commit 16e4d93f6de7 > > ("NFSD: Ignore client's source port on RDMA transports"). > > > > The Linux NFS server's DRC resolves XID collisions from the same > > source IP address by using the checksum of the first 200 bytes of > > the RPC call header. > > > > Signed-off-by: Chuck Lever > > Cc: stable@vger.kernel.org # v4.14+ > > --- > > net/sunrpc/xprtrdma/svc_rdma_transport.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c > > index 027a3b0..0004535 100644 > > --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c > > +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c > > @@ -211,9 +211,14 @@ static void handle_connect_req(struct rdma_cm_id *new_cma_id, > > /* Save client advertised inbound read limit for use later in accept. */ > > newxprt->sc_ord = param->initiator_depth; > > > > - /* Set the local and remote addresses in the transport */ > > sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr; > > svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa)); > > + /* The remote port is arbitrary and not under the control of the > > + * client ULP. Set it to a fixed value so that the DRC continues > > + * to be effective after a reconnect. > > + */ > > + rpc_set_port((struct sockaddr *)&newxprt->sc_xprt.xpt_remote, 0); > > + > > sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr; > > svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa)); > > Hi Bruce, what's the disposition of this patch? I've queued it up locally for 5.2 and stable. Apologies, it got a little buried in my inbox, thanks for the reminder. --b.