From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752725AbaINKwk (ORCPT ); Sun, 14 Sep 2014 06:52:40 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:43839 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752426AbaINKwj (ORCPT ); Sun, 14 Sep 2014 06:52:39 -0400 Message-ID: <5415737D.2030209@gmail.com> Date: Sun, 14 Sep 2014 18:52:45 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, David Vrabel , stefano.stabellini@eu.citrix.com, mukesh.rathor@oracle.com CC: xen-devel@lists.xenproject.org, "linux-kernel@vger.kernel.org" Subject: [PATCH 4/4] drivers/xen/xenbus/xenbus_client.c: Improve the failure processing for __xenbus_switch_state() References: <54157282.40402@gmail.com> In-Reply-To: <54157282.40402@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When failure occurs, need return failure code instead of 0, or the upper caller will misunderstand. Also when retry for EAGAIN reason, better to schedule out for a while, so can let others have chance to continue their tasks (especially, their tasks are related EAGAIN under UP kernel). Signed-off-by: Chen Gang --- drivers/xen/xenbus/xenbus_client.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index 620ffd2..fc8699b 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include @@ -196,7 +197,7 @@ again: err = xenbus_transaction_start(&xbt); if (err) { xenbus_switch_fatal(dev, depth, err, "starting transaction"); - return 0; + return err; } err = xenbus_scanf(xbt, dev->nodename, "state", "%d", ¤t_state); @@ -213,13 +214,15 @@ again: abort: err = xenbus_transaction_end(xbt, abort); if (err) { - if (err == -EAGAIN && !abort) + if (err == -EAGAIN && !abort) { + msleep(20); goto again; + } xenbus_switch_fatal(dev, depth, err, "ending transaction"); } else dev->state = state; - return 0; + return err; } /** -- 1.9.3