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=-22.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 8AFFFC433E0 for ; Wed, 24 Feb 2021 20:05:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5664C64E24 for ; Wed, 24 Feb 2021 20:05:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235052AbhBXUFD (ORCPT ); Wed, 24 Feb 2021 15:05:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233743AbhBXUDO (ORCPT ); Wed, 24 Feb 2021 15:03:14 -0500 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66873C061574 for ; Wed, 24 Feb 2021 12:02:33 -0800 (PST) Received: by fieldses.org (Postfix, from userid 2815) id 683B82501; Wed, 24 Feb 2021 15:02:31 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 683B82501 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1614196951; bh=IxdrWW0QbqIEm1tKN2LHx+3jR61wgBt62ovT8qDge2w=; h=Date:To:Cc:Subject:References:In-Reply-To:From:From; b=iXn9ZzIwdhMLFHRjcEauCCP56pfPJesYU/5e9C/Rz8snzlPHhPzKBykk3AhxxAJ2h ab0iMkzdgZPnN8czV8dFZ51bISQ1C1OiJM8E5tt44DumxBQrKTN7PP3a50MAfN+5Lx uY/D0roO1zYzVcIfpRibWOzGZU8KOJv0/Zv9CoTg= Date: Wed, 24 Feb 2021 15:02:31 -0500 To: Chuck Lever Cc: Timo Rothenpieler , Linux NFS Mailing List , Olga Kornievskaia , Dai Ngo Subject: Re: [PATCH] svcrdma: disable timeouts on rdma backchannel Message-ID: <20210224200231.GD11591@fieldses.org> References: <20210222233619.21568-1-timo@rothenpieler.org> 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) From: bfields@fieldses.org (J. Bruce Fields) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Wed, Feb 24, 2021 at 02:18:18PM +0000, Chuck Lever wrote: > > > > On Feb 22, 2021, at 6:36 PM, Timo Rothenpieler wrote: > > > > This brings it in line with the regular tcp backchannel, which also has > > all those timeouts disabled. > > > > Prevents the backchannel from timing out, getting some async operations > > like server side copying getting stuck indefinitely on the client side. > > > > Signed-off-by: Timo Rothenpieler > > Thanks for your patch! I've included it in the for-rc branch at > > git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git So, I'm sure this patch makes sense. But I'm also curious why it's not recovering. What I think should happen: - clp->cl_cb_state should be set to NFSD4_CB_DOWN. - This should cause the next SEQUENCE reply to have SEQ4_STATUS_CB_PATH_DOWN set. - That should poke the client to recover. (Maybe by sending a BIND_CONN_TO_SESSION call?) I'd be curious whether any of that's actually happening. --b. > > > > --- > > Did the same testing with this applied than before, and could not > > observe it getting stuck, same as with the previous patch, which I > > removed before testing this one. > > > > This obviously still does not fix the issue of it being seemingly unable > > to reestablish the disconnected backchannel. > > An event that disconnects the backchannel but leaves the main connection > > intact seems a pretty rare occurance though, outside of this issue. > > > > net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c > > index 63f8be974df2..8186ab6f99f1 100644 > > --- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c > > +++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c > > @@ -252,9 +252,9 @@ xprt_setup_rdma_bc(struct xprt_create *args) > > xprt->timeout = &xprt_rdma_bc_timeout; > > xprt_set_bound(xprt); > > xprt_set_connected(xprt); > > - xprt->bind_timeout = RPCRDMA_BIND_TO; > > - xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO; > > - xprt->idle_timeout = RPCRDMA_IDLE_DISC_TO; > > + xprt->bind_timeout = 0; > > + xprt->reestablish_timeout = 0; > > + xprt->idle_timeout = 0; > > > > xprt->prot = XPRT_TRANSPORT_BC_RDMA; > > xprt->ops = &xprt_rdma_bc_procs; > > -- > > 2.25.1 > > > > -- > Chuck Lever > >