From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26082 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752775Ab2HGSwI (ORCPT ); Tue, 7 Aug 2012 14:52:08 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q77Iq8ia017146 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 7 Aug 2012 14:52:08 -0400 Message-ID: <5021652A.7020304@redhat.com> Date: Tue, 07 Aug 2012 20:57:46 +0200 From: Hans de Goede MIME-Version: 1.0 To: David Teigland CC: linux-watchdog@vger.kernel.org Subject: Re: [PATCH v2] watchdog: new option to skip ping in close References: <20120807182730.GE29229@redhat.com> In-Reply-To: <20120807182730.GE29229@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org Hi, Code wise this version gets an ACK from me, API wise I'm not sure, so lets see what Wim Van Sebroeck (the watchdog subsys maintainer) has to say on this patch. Regards, Hans On 08/07/2012 08:27 PM, David Teigland wrote: > If a daemon has /dev/watchdog open, and exits (say by crashing or > sigkill), watchdog_release() generates a new watchdog_ping(), extending > the life of the machine. However, the daemon may require control over > whether or not the watchdog is pinged, and the ping generated by close > compromises this control. > > Signed-off-by: David Teigland > --- > drivers/watchdog/watchdog_dev.c | 7 ++++++- > include/linux/watchdog.h | 2 ++ > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c > index ef8edec..47ae7fe 100644 > --- a/drivers/watchdog/watchdog_dev.c > +++ b/drivers/watchdog/watchdog_dev.c > @@ -394,6 +394,9 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, > if (err) > return err; > return put_user(val, p); > + case WDIOC_NOCLOSEPING: > + set_bit(WDOG_NO_CLOSE_PING, &wdd->status); > + return 0; > default: > return -ENOTTY; > } > @@ -480,7 +483,9 @@ static int watchdog_release(struct inode *inode, struct file *file) > if (!test_bit(WDOG_UNREGISTERED, &wdd->status)) > dev_crit(wdd->dev, "watchdog did not stop!\n"); > mutex_unlock(&wdd->lock); > - watchdog_ping(wdd); > + > + if (!test_bit(WDOG_NO_CLOSE_PING, &wdd->status)) > + watchdog_ping(wdd); > } > > /* Allow the owner module to be unloaded again */ > diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h > index da70f0f..4fa10ff 100644 > --- a/include/linux/watchdog.h > +++ b/include/linux/watchdog.h > @@ -31,6 +31,7 @@ struct watchdog_info { > #define WDIOC_SETPRETIMEOUT _IOWR(WATCHDOG_IOCTL_BASE, 8, int) > #define WDIOC_GETPRETIMEOUT _IOR(WATCHDOG_IOCTL_BASE, 9, int) > #define WDIOC_GETTIMELEFT _IOR(WATCHDOG_IOCTL_BASE, 10, int) > +#define WDIOC_NOCLOSEPING _IOR(WATCHDOG_IOCTL_BASE, 11, int) > > #define WDIOF_UNKNOWN -1 /* Unknown flag error */ > #define WDIOS_UNKNOWN -1 /* Unknown status error */ > @@ -140,6 +141,7 @@ struct watchdog_device { > #define WDOG_ALLOW_RELEASE 2 /* Did we receive the magic char ? */ > #define WDOG_NO_WAY_OUT 3 /* Is 'nowayout' feature set ? */ > #define WDOG_UNREGISTERED 4 /* Has the device been unregistered */ > +#define WDOG_NO_CLOSE_PING 5 /* Do not ping in watchdog_release() */ > }; > > #ifdef CONFIG_WATCHDOG_NOWAYOUT >