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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 498A8C43381 for ; Fri, 22 Feb 2019 12:13:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 191A62075A for ; Fri, 22 Feb 2019 12:13:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726043AbfBVMNA (ORCPT ); Fri, 22 Feb 2019 07:13:00 -0500 Received: from mail-qt1-f193.google.com ([209.85.160.193]:44006 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725926AbfBVMNA (ORCPT ); Fri, 22 Feb 2019 07:13:00 -0500 Received: by mail-qt1-f193.google.com with SMTP id y4so2129524qtc.10 for ; Fri, 22 Feb 2019 04:12:59 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=ruGOZYW4RZGWSAWSA11jr0aFZHZV+AWmN1lC0pTdvvU=; b=PQN+9FBa0WvbjbIU4yncL4JPwjzwRB+Wwwd2KiDt9IkdG6yAs8PnQVczRooWPrIIYa RsoqKDJk5QEfuuDWgbOpp0kienotd1y9aFFJwVnWGC9hkre0wErIf+IyI6U+ptYi3JhG KlkRtNJL6RnOr0R1jLuPaHGSQQbvRSD9D/rPVDz/ktCA6G+fk/KjggMUQNVmXgiEEuSt QPRGbQurp2ApC4YiOxZEkvVJQx0o4ti2Er/B5snLud1676h72Rn25jXCAQN579eEjw2z eTRhH1k9lIBpHwdd/z7+luRPkrMQG66CJGKYaGaiVR8UgygT+IvIiM+5tm9AHGXzPxUs l2LQ== X-Gm-Message-State: AHQUAuZZJRlbg4MN3wQktxGIbIp/FbZ7fIVUMumT8aT1VZrM6Ginrj/P H5uyCYonRJgF5n6+NOm+L1EBOg== X-Google-Smtp-Source: AHgI3IYOtY6w37XyPKCX1LoroyeXAEFCacS9BvAMuLhT7EYO8hXIrNxzrHyEaNMUzCzjCmyj0GAFUA== X-Received: by 2002:ac8:37d5:: with SMTP id e21mr2779696qtc.214.1550837578838; Fri, 22 Feb 2019 04:12:58 -0800 (PST) Received: from dwysocha.rdu.csb (75-26-10-140.lightspeed.rlghnc.sbcglobal.net. [75.26.10.140]) by smtp.gmail.com with ESMTPSA id j66sm1146533qkj.27.2019.02.22.04.12.57 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Feb 2019 04:12:58 -0800 (PST) Message-ID: <1550837576.6456.3.camel@redhat.com> Subject: Re: [PATCH 1/1] SUNRPC: fix handling of half-closed connection From: Dave Wysochanski To: Olga Kornievskaia , trond.myklebust@hammerspace.com, anna.schumaker@netapp.com Cc: linux-nfs@vger.kernel.org Date: Fri, 22 Feb 2019 07:12:56 -0500 In-Reply-To: <20190220145650.21566-1-olga.kornievskaia@gmail.com> References: <20190220145650.21566-1-olga.kornievskaia@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-14.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Hi Olga, Do you have a reproducer for this? A number of months ago I did a significant amount of testing with half-closed connections, after we had reports of connections stuck in FIN_WAIT2 in some older kernels. What I found was with kernels that had the tcp keepalives (commit 7f260e8575bf53b93b77978c1e39f8e67612759c), I could only reproduce a hang of a few minutes, after which time the tcp keepalive code would reset the connection. That said it was a while ago and something subtle may have changed. Also I'm not not sure if your header implies an indefinite hang or just a few minutes. Thanks. On Wed, 2019-02-20 at 09:56 -0500, Olga Kornievskaia wrote: > From: Olga Kornievskaia > > When server replies with an ACK to client's FIN/ACK, client ends > up stuck in a TCP_FIN_WAIT2 state and client's mount hangs. > Instead, make sure to close and reset client's socket and transport > when transitioned into that state. > > Signed-off-by: Olga Kornievskaia > --- >  net/sunrpc/xprtsock.c | 2 ++ >  1 file changed, 2 insertions(+) > > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c > index 618e9c2..812e5e3 100644 > --- a/net/sunrpc/xprtsock.c > +++ b/net/sunrpc/xprtsock.c > @@ -1502,6 +1502,7 @@ static void xs_tcp_state_change(struct sock > *sk) >   clear_bit(XPRT_CLOSE_WAIT, &xprt->state); >   smp_mb__after_atomic(); >   break; > + case TCP_FIN_WAIT2: >   case TCP_CLOSE_WAIT: >   /* The server initiated a shutdown of the socket */ >   xprt->connect_cookie++; > @@ -2152,6 +2153,7 @@ static void xs_tcp_shutdown(struct rpc_xprt > *xprt) >   kernel_sock_shutdown(sock, SHUT_RDWR); >   trace_rpc_socket_shutdown(xprt, sock); >   break; > + case TCP_FIN_WAIT2: >   case TCP_CLOSE: >   case TCP_TIME_WAIT: >   xs_reset_transport(transport);