[Devel] [PATCH RH7 2/9] Port: diff-fence-watchdog-add-support-of-crash

[Pavel Tikhomirov]

Author: Dmitry Guryanov
Email: dguryanov at parallels.com
Subject: watchdog: add support of crash
Date: Thu, 10 Jan 2013 15:25:07 +0400

* [fence-watchdog] The ability to choose, which action to perform
	in case	of timeout: crash, reboot or poweroff.
	The configuration is done via sysfs files:
		/sys/kernel/watchdog_available_actions
		/sys/kernel/watchdog_action. (PSBM-13631)

Add ability to choose, which action to perform in case
of timeout and add support of crash: crash, reboot or poweroff.

Two sysfs files added:
/sys/kernel/watchdog_available_actions and /sys/kernel/watchdog_action.

https://jira.sw.ru/browse/PSBM-13631

Signed-off-by: Dmitry Guryanov <dguryanov at parallels.com>
Acked-by: Pavel Emelyanov <xemul at parallels.com>

Changes in v4:
	* add poweroff action

Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
---
 kernel/fence-watchdog.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 82 insertions(+), 3 deletions(-)

diff --git a/kernel/fence-watchdog.c b/kernel/fence-watchdog.c
index e25140f..ca07da5 100644
--- a/kernel/fence-watchdog.c
+++ b/kernel/fence-watchdog.c
@@ -14,17 +14,49 @@
 #include <linux/jiffies.h>
 #include <linux/reboot.h>
 #include <linux/fence-watchdog.h>
+#include <linux/device.h>
+#include <linux/kmsg_dump.h>
 
 #define MAX_U64			(~(u64)0)
 #define MAX_JIFFIES_DELTA	(10 * 365UL * 24UL * 3600UL * HZ)
+#define ACTION_NAME_LEN		16
+
+enum {
+	FENCE_WDOG_CRASH = 0,
+	FENCE_WDOG_REBOOT = 1,
+	FENCE_WDOG_POWEROFF = 2,
+};
+
+const char *action_names[] = {"crash", "reboot", "poweroff", NULL};
+
 
 DEFINE_VVAR(volatile unsigned long, fence_wdog_jiffies64) = MAX_U64;
+static int fence_wdog_action = FENCE_WDOG_CRASH;
 
 void fence_wdog_do_fence(void)
 {
-	lockdep_off();
-	local_irq_enable();
-	emergency_restart();
+	char *killer = NULL;
+
+	switch (fence_wdog_action) {
+	case FENCE_WDOG_CRASH:
+		panic_on_oops = 1;
+		wmb();
+		*killer = 1;
+		break;
+	case FENCE_WDOG_REBOOT:
+		lockdep_off();
+		local_irq_enable();
+		emergency_restart();
+		break;
+	case FENCE_WDOG_POWEROFF:
+		lockdep_off();
+		local_irq_enable();
+		sysdev_shutdown();
+		printk(KERN_EMERG "System halted.\n");
+		kmsg_dump(KMSG_DUMP_HALT);
+		machine_halt();
+		break;
+	}
 }
 
 inline void fence_wdog_check_timer(void)
@@ -77,12 +109,59 @@ static ssize_t fence_wdog_timer_store(struct kobject *kobj,
 	return count;
 }
 
+static ssize_t fence_wdog_action_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%s\n", action_names[fence_wdog_action]);
+}
+
+static ssize_t fence_wdog_action_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	char str_action[ACTION_NAME_LEN];
+	int i = 0;
+
+	if (sscanf(buf, "%15s", str_action) != 1)
+		return -EINVAL;
+
+	for (i = 0; action_names[i]; i++) {
+		if ((!strnicmp(str_action, action_names[i], ACTION_NAME_LEN))) {
+			fence_wdog_action = i;
+			return count;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t fence_wdog_available_actions_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	int i, ret = 0;
+
+	for (i = 0; action_names[i] != NULL; i++)
+		ret += sprintf(&buf[ret], "%s ", action_names[i]);
+
+	ret += sprintf(&buf[ret], "\n");
+	return ret;
+}
+
 static struct kobj_attribute fence_wdog_timer_attr =
 	__ATTR(watchdog_timer, 0644,
 		fence_wdog_timer_show, fence_wdog_timer_store);
 
+static struct kobj_attribute fence_wdog_action_attr =
+	__ATTR(watchdog_action, 0644,
+		fence_wdog_action_show, fence_wdog_action_store);
+
+static struct kobj_attribute fence_wdog_available_actions_attr =
+	__ATTR(watchdog_available_actions, 0644,
+		fence_wdog_available_actions_show, NULL);
+
 static struct attribute *fence_wdog_attrs[] = {
 	&fence_wdog_timer_attr.attr,
+	&fence_wdog_action_attr.attr,
+	&fence_wdog_available_actions_attr.attr,
 	NULL,
 };
 
-- 
1.9.3