From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751471AbdE3N0u (ORCPT ); Tue, 30 May 2017 09:26:50 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:49578 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751082AbdE3N0s (ORCPT ); Tue, 30 May 2017 09:26:48 -0400 Subject: Re: [PATCH] xen: don't print error message in case of missing Xenstore entry To: Juergen Gross , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org References: <20170529091339.1449-1-jgross@suse.com> From: Boris Ostrovsky Message-ID: <69e13959-26a5-a794-2fa7-3933bc6f22f0@oracle.com> Date: Tue, 30 May 2017 09:25:33 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170529091339.1449-1-jgross@suse.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/29/2017 05:13 AM, Juergen Gross wrote: > When registering for the Xenstore watch of the node control/sysrq the > handler will be called at once. Don't issue an error message if the > Xenstore node isn't there, as it will be created only when an event > is being triggered. > > Signed-off-by: Juergen Gross > --- > drivers/xen/manage.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c > index c1ec8ee80924..7ddd0803da23 100644 > --- a/drivers/xen/manage.c > +++ b/drivers/xen/manage.c > @@ -277,8 +277,11 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path, > err = xenbus_transaction_start(&xbt); > if (err) > return; > - if (xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key) < 0) { > - pr_err("Unable to read sysrq code in control/sysrq\n"); > + err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key); > + if (err < 0) { > + if (err != -ENOENT) Can we distinguish initialization invocation from actual watch firing? E.g. '|| (system_state >= SYSTEM_RUNNING)'? -boris > + pr_err("Error %d reading sysrq code in control/sysrq\n", > + err); > xenbus_transaction_end(xbt, 1); > return; > }