[PATCH v2 1/3] envctrl: Ignore orderly_poweroff return value

[PATCH v2 1/3] envctrl: Ignore orderly_poweroff return value

[Joel Stanley]

orderly_poweroff() unconditionally returns 0, so remove the dead code
that checks the return value.

A future patch will change the return type to void.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 drivers/sbus/char/bbc_envctrl.c | 3 +--
 drivers/sbus/char/envctrl.c     | 7 +------
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/sbus/char/bbc_envctrl.c b/drivers/sbus/char/bbc_envctrl.c
index 0787b97..228c782 100644
--- a/drivers/sbus/char/bbc_envctrl.c
+++ b/drivers/sbus/char/bbc_envctrl.c
@@ -160,8 +160,7 @@ static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
 	printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
 
 	shutting_down = 1;
-	if (orderly_poweroff(true) < 0)
-		printk(KERN_CRIT "envctrl: shutdown execution failed\n");
+	orderly_poweroff(true);
 }
 
 #define WARN_INTERVAL	(30 * HZ)
diff --git a/drivers/sbus/char/envctrl.c b/drivers/sbus/char/envctrl.c
index af15a2f..7946852 100644
--- a/drivers/sbus/char/envctrl.c
+++ b/drivers/sbus/char/envctrl.c
@@ -970,18 +970,13 @@ static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
 static void envctrl_do_shutdown(void)
 {
 	static int inprog = 0;
-	int ret;
 
 	if (inprog != 0)
 		return;
 
 	inprog = 1;
 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
-	ret = orderly_poweroff(true);
-	if (ret < 0) {
-		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n"); 
-		inprog = 0;  /* unlikely to succeed, but we could try again */
-	}
+	orderly_poweroff(true);
 }
 
 static struct task_struct *kenvctrld_task;
-- 
2.1.4

[PATCH v2 2/3] kernel/reboot.c: Add orderly_reboot for graceful reboot

[Joel Stanley]

The kernel has orderly_poweroff which allows the kernel to initiate a
graceful shutdown of userspace, by running /sbin/poweroff. This adds
orderly_reboot that will cause userspace to shut itself down by calling
/sbin/reboot.

This will be used for shutdown initiated by a system controller on
platforms that do not use ACPI.

orderly_reboot() should be used when the system wants to allow userspace
to gracefully shut itself down. For cases where the system may
imminently catch on fire, the existing emergency_restart() provides an
immediate reboot without involving userspace.

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
V2:
 - remove unused return value from orderly_*
 - use correct command in orderly_poweroff
 - the reboot command will not have a proc knob to control it, so
   it can be made const and static

 include/linux/reboot.h |  3 ++-
 kernel/reboot.c        | 53 +++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 50 insertions(+), 6 deletions(-)

diff --git a/include/linux/reboot.h b/include/linux/reboot.h
index 48bf152..dc5e3bd 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -67,7 +67,8 @@ void ctrl_alt_del(void);
 #define POWEROFF_CMD_PATH_LEN	256
 extern char poweroff_cmd[POWEROFF_CMD_PATH_LEN];
 
-extern int orderly_poweroff(bool force);
+extern void orderly_poweroff(bool force);
+extern void orderly_reboot(void);
 
 /*
  * Emergency restart, callable from an interrupt handler.
diff --git a/kernel/reboot.c b/kernel/reboot.c
index a3a9e24..0ace9f6 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -306,8 +306,9 @@ void ctrl_alt_del(void)
 }
 
 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
+static const char reboot_cmd[] = "/sbin/reboot";
 
-static int __orderly_poweroff(bool force)
+static int run_cmd(const char *cmd)
 {
 	char **argv;
 	static char *envp[] = {
@@ -316,8 +317,7 @@ static int __orderly_poweroff(bool force)
 		NULL
 	};
 	int ret;
-
-	argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL);
+	argv = argv_split(GFP_KERNEL, cmd, NULL);
 	if (argv) {
 		ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
 		argv_free(argv);
@@ -325,8 +325,33 @@ static int __orderly_poweroff(bool force)
 		ret = -ENOMEM;
 	}
 
+	return ret;
+}
+
+static int __orderly_reboot(void)
+{
+	int ret;
+
+	ret = run_cmd(reboot_cmd);
+
+	if (ret) {
+		pr_warn("Failed to start orderly reboot: forcing the issue\n");
+		emergency_sync();
+		kernel_restart(NULL);
+	}
+
+	return ret;
+}
+
+static int __orderly_poweroff(bool force)
+{
+	int ret;
+
+	ret = run_cmd(poweroff_cmd);
+
 	if (ret && force) {
 		pr_warn("Failed to start orderly shutdown: forcing the issue\n");
+
 		/*
 		 * I guess this should try to kick off some daemon to sync and
 		 * poweroff asap.  Or not even bother syncing if we're doing an
@@ -355,15 +380,33 @@ static DECLARE_WORK(poweroff_work, poweroff_work_func);
  * This may be called from any context to trigger a system shutdown.
  * If the orderly shutdown fails, it will force an immediate shutdown.
  */
-int orderly_poweroff(bool force)
+void orderly_poweroff(bool force)
 {
 	if (force) /* do not override the pending "true" */
 		poweroff_force = true;
 	schedule_work(&poweroff_work);
-	return 0;
 }
 EXPORT_SYMBOL_GPL(orderly_poweroff);
 
+static void reboot_work_func(struct work_struct *work)
+{
+	__orderly_reboot();
+}
+
+static DECLARE_WORK(reboot_work, reboot_work_func);
+
+/**
+ * orderly_reboot - Trigger an orderly system reboot
+ *
+ * This may be called from any context to trigger a system reboot.
+ * If the orderly reboot fails, it will force an immediate reboot.
+ */
+void orderly_reboot(void)
+{
+	schedule_work(&reboot_work);
+}
+EXPORT_SYMBOL_GPL(orderly_reboot);
+
 static int __init reboot_setup(char *str)
 {
 	for (;;) {
-- 
2.1.4

[PATCH v2 3/3] powerpc/powernv: Reboot when requested by firmware

[Joel Stanley]

Use orderly_reboot so userspace will to shut itself down via the reboot
path. This is required for graceful reboot initiated by the BMC, such
as when a user uses ipmitool to issue a 'chassis power cycle' command.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/platforms/powernv/opal-power.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/opal-power.c b/arch/powerpc/platforms/powernv/opal-power.c
index 48bf5b0..ac46c2c 100644
--- a/arch/powerpc/platforms/powernv/opal-power.c
+++ b/arch/powerpc/platforms/powernv/opal-power.c
@@ -29,8 +29,9 @@ static int opal_power_control_event(struct notifier_block *nb,
 
 	switch (type) {
 	case SOFT_REBOOT:
-		/* Fall through. The service processor is responsible for
-		 * bringing the machine back up */
+		pr_info("OPAL: reboot requested\n");
+		orderly_reboot();
+		break;
 	case SOFT_OFF:
 		pr_info("OPAL: poweroff requested\n");
 		orderly_poweroff(true);
-- 
2.1.4

Re: [PATCH v2 1/3] envctrl: Ignore orderly_poweroff return value

[David Miller]

From: Joel Stanley <joel@jms.id.au>
Date: Wed,  1 Apr 2015 17:34:46 +1030

> orderly_poweroff() unconditionally returns 0, so remove the dead code
> that checks the return value.
> 
> A future patch will change the return type to void.
> 
> Signed-off-by: Joel Stanley <joel@jms.id.au>

Acked-by: David S. Miller <davem@davemloft.net>

Re: [PATCH v2 2/3] kernel/reboot.c: Add orderly_reboot for graceful reboot

[Julian Calaby]

Hi Joel,

On Wed, Apr 1, 2015 at 6:04 PM, Joel Stanley <joel@jms.id.au> wrote:
> The kernel has orderly_poweroff which allows the kernel to initiate a
> graceful shutdown of userspace, by running /sbin/poweroff. This adds
> orderly_reboot that will cause userspace to shut itself down by calling
> /sbin/reboot.
>
> This will be used for shutdown initiated by a system controller on
> platforms that do not use ACPI.
>
> orderly_reboot() should be used when the system wants to allow userspace
> to gracefully shut itself down. For cases where the system may
> imminently catch on fire, the existing emergency_restart() provides an
> immediate reboot without involving userspace.
>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
> V2:
>  - remove unused return value from orderly_*
>  - use correct command in orderly_poweroff
>  - the reboot command will not have a proc knob to control it, so
>    it can be made const and static
>
>  include/linux/reboot.h |  3 ++-
>  kernel/reboot.c        | 53 +++++++++++++++++++++++++++++++++++++++++++++-----
>  2 files changed, 50 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/reboot.h b/include/linux/reboot.h
> index 48bf152..dc5e3bd 100644
> --- a/include/linux/reboot.h
> +++ b/include/linux/reboot.h
> @@ -67,7 +67,8 @@ void ctrl_alt_del(void);
>  #define POWEROFF_CMD_PATH_LEN  256
>  extern char poweroff_cmd[POWEROFF_CMD_PATH_LEN];
>
> -extern int orderly_poweroff(bool force);
> +extern void orderly_poweroff(bool force);

Should making orderly_poweroff() void be in a separate patch?

Thanks,

-- 
Julian Calaby

Email: julian.calaby@gmail.com
Profile: http://www.google.com/profiles/julian.calaby/