From patchwork Thu May 25 07:00:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 9747845 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1E34760246 for ; Thu, 25 May 2017 07:00:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 08F0427CAF for ; Thu, 25 May 2017 07:00:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F1A9427EE2; Thu, 25 May 2017 07:00:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6014027CAF for ; Thu, 25 May 2017 07:00:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755912AbdEYHAn (ORCPT ); Thu, 25 May 2017 03:00:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:35395 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755860AbdEYHAm (ORCPT ); Thu, 25 May 2017 03:00:42 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7BE19AB5D; Thu, 25 May 2017 07:00:41 +0000 (UTC) From: NeilBrown To: Trond Myklebust , Anna Schumaker Date: Thu, 25 May 2017 17:00:32 +1000 Cc: linux-nfs@vger.kernel.org Subject: [PATCH] SUNRPC: ensure correct error is reported by xs_tcp_setup_socket() Message-ID: <871srdifov.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If you attempt a TCP mount from an host that is unreachable in a way that triggers an immediate error from kernel_connect(), that error does not propagate up, instead EAGAIN is reported. This results in call_connect_status receiving the wrong error. A case that it easy to demonstrate is to attempt to mount from an address that results in ENETUNREACH, but first deleting any default route. Without this patch, the mount.nfs process is persistently runnable and is hard to kill. With this patch it exits as it should. The problem is caused by the fact that xs_tcp_force_close() eventually calls xprt_wake_pending_tasks(xprt, -EAGAIN); which causes an error return of -EAGAIN. so when xs_tcp_setup_sock() calls xprt_wake_pending_tasks(xprt, status); the status is ignored. Fixes: 4efdd92c9211 ("SUNRPC: Remove TCP client connection reset hack") Signed-off-by: NeilBrown --- net/sunrpc/xprtsock.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 16aff8ddc16f..d5b54c020dec 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2432,7 +2432,12 @@ static void xs_tcp_setup_socket(struct work_struct *work) case -ENETUNREACH: case -EADDRINUSE: case -ENOBUFS: - /* retry with existing socket, after a delay */ + /* + * xs_tcp_force_close() wakes tasks with -EIO. + * We need to wake them first to ensure the + * correct error code. + */ + xprt_wake_pending_tasks(xprt, status); xs_tcp_force_close(xprt); goto out; }