Received: by 2002:a25:c205:0:0:0:0:0 with SMTP id s5csp3828082ybf; Tue, 3 Mar 2020 13:40:33 -0800 (PST) X-Google-Smtp-Source: ADFU+vsNzwBWAQh0zw6RvTX9Ir2oJjnNEvib/4R2tTCgkYU16orJgXshHd0WGgongcL+Eqm0LxkQ X-Received: by 2002:aca:5303:: with SMTP id h3mr428660oib.74.1583271631846; Tue, 03 Mar 2020 13:40:31 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1583271631; cv=none; d=google.com; s=arc-20160816; b=O0MNQS1k78UifWbphakqoREX8QjyqQO57Ts9wMUE75zT4GRFoojoghXEfAPD9C90Ua cC2G7gXvuGPHPyjCBb85nW+cXETmZc9p/mDpbuicQ+y2G69AyZr8yHkcDqMlxkM8BqBr kQp50nsLRMx9rQKO1NPfI0nLtaywyQ+bvSkRiOoI/jZ0GeM/ZFMaITdejkD1SJo7ezry Bjk9d2Fw59cMDyE0KeKla7XirD9GzWSSafhCxXU8LnhC9JvcdJQ8oNEAEI4JVtF8vmtG k5QUc6B7wVTHo56cN0ifah5XUkG0F02ZJ+1C1fpWgUkvjS2MHSsQRta/pYf5cCX5t/ce lbeg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=3sx1vwQWdvQ5Z2ZWTgaCbJGjCVKxUP31T5G8RYrSA9g=; b=g4+Oz03SQLx5K2j+AusesxgtiHwmrYyp07+f5ecGdUk4AEECHtUvZdeb9Ip0/kwLU8 vPcfAwj/QcPoF8o/Vax3dyR8dY4qlKOu8jmQrAIKjWuwqdJHZ9JKNzbmJAs9v5tt3PkD 0qqRUvfDtBP6IzfeUcLv8f292aIzfFF5VzEvD0sd3qWLIEI4bVjAN80QRRmlhqm/OWO9 3LidqfWJvxRrRc/VRoaZBt7+X4t6PqYs9e7bV6QZAxxM6MhKjjok3FsX/OIUcYr6lg49 SbOd4p3im0uEob9jT8Y512EkV97h4J9OrhX3oSqgJwUVTJ4H5tak+oC1hImi6VbE3yok 49aw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2020-01-29 header.b=zaZ8UEh5; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id s64si27404oig.147.2020.03.03.13.40.19; Tue, 03 Mar 2020 13:40:31 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2020-01-29 header.b=zaZ8UEh5; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730536AbgCCS5P (ORCPT + 99 others); Tue, 3 Mar 2020 13:57:15 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:34482 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730344AbgCCS5O (ORCPT ); Tue, 3 Mar 2020 13:57:14 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 023Is7td050119; Tue, 3 Mar 2020 18:57:09 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2020-01-29; bh=3sx1vwQWdvQ5Z2ZWTgaCbJGjCVKxUP31T5G8RYrSA9g=; b=zaZ8UEh5QMzNbdzHE6voY1AIV/S2dUkTMkHhtDcPX1Qrlza/3uIFLPIZIgQBuafC5O5Q V8zUGRUjb0mABFgZNtk2YjjYf1uYU3yFqOsnfY8aWV++UxS2HsVpXxYezjG1bEgC7IoZ BEp6TsrxrgmgL88szeAZmvztKnlj4VqzZf373eE9o2g6LSJkoIBYKwSL5Yw0753MrIrs cKb4ffWwMby8vkCzRHOM0C0MLZT+50sYBAymZ0wPK38jd3dnoxNmkKPMpm4V6qvqJQRg D4z/5Sf7emOWDgFmc8wr9dMSBZUafyiduKlATGRiWyPpbu6wosuN9CwlL0e4UTc439Aw sQ== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2yffwqs991-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 03 Mar 2020 18:57:09 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 023IqTvw072605; Tue, 3 Mar 2020 18:57:08 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2yg1p555qm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 03 Mar 2020 18:57:08 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 023Iv6it011726; Tue, 3 Mar 2020 18:57:07 GMT Received: from localhost.localdomain (/10.211.9.80) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 03 Mar 2020 10:57:06 -0800 From: Dongli Zhang To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: julien@xen.org, boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org, joe.jin@oracle.com Subject: [PATCH v2 2/2] xenbus: req->err should be updated before req->state Date: Tue, 3 Mar 2020 10:47:52 -0800 Message-Id: <20200303184752.20821-2-dongli.zhang@oracle.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200303184752.20821-1-dongli.zhang@oracle.com> References: <20200303184752.20821-1-dongli.zhang@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9549 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0 mlxlogscore=980 mlxscore=0 spamscore=0 adultscore=0 bulkscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003030124 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9549 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 spamscore=0 impostorscore=0 malwarescore=0 mlxlogscore=999 mlxscore=0 suspectscore=0 phishscore=0 clxscore=1015 bulkscore=0 adultscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003030124 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds the barrier to guarantee that req->err is always updated before req->state. Otherwise, read_reply() would not return ERR_PTR(req->err) but req->body, when process_writes()->xb_write() is failed. Signed-off-by: Dongli Zhang --- drivers/xen/xenbus/xenbus_comms.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c index 852ed161fc2a..eb5151fc8efa 100644 --- a/drivers/xen/xenbus/xenbus_comms.c +++ b/drivers/xen/xenbus/xenbus_comms.c @@ -397,6 +397,8 @@ static int process_writes(void) if (state.req->state == xb_req_state_aborted) kfree(state.req); else { + /* write err, then update state */ + virt_wmb(); state.req->state = xb_req_state_got_reply; wake_up(&state.req->wq); } -- 2.17.1