Add common orderly_poweroff()

Various pieces of code around the kernel want to be able to trigger an
orderly poweroff.  This pulls them together into a single
implementation.

By default the poweroff command is /sbin/poweroff, but it can be set
via sysctl: kernel/poweroff_cmd.  This is split at whitespace, so it
can include command-line arguments.

This patch replaces four other instances of invoking either "poweroff"
or "shutdown -h now": two sbus drivers, and acpi thermal
management.

sparc64 has its own "powerd"; still need to determine whether it should
be replaced by orderly_poweroff().

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David S. Miller <davem@davemloft.net>

diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 88a6fc7..58f1338 100644 (file)
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -40,6 +40,7 @@
 #include <linux/jiffies.h>
 #include <linux/kmod.h>
 #include <linux/seq_file.h>
+#include <linux/reboot.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_bus.h>
@@ -59,7 +60,6 @@
 #define ACPI_THERMAL_NOTIFY_CRITICAL   0xF0
 #define ACPI_THERMAL_NOTIFY_HOT                0xF1
 #define ACPI_THERMAL_MODE_ACTIVE       0x00
-#define ACPI_THERMAL_PATH_POWEROFF     "/sbin/poweroff"
 
 #define ACPI_THERMAL_MAX_ACTIVE        10
 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
@@ -419,26 +419,6 @@ static int acpi_thermal_get_devices(struct acpi_thermal *tz)
        return 0;
 }
 
-static int acpi_thermal_call_usermode(char *path)
-{
-       char *argv[2] = { NULL, NULL };
-       char *envp[3] = { NULL, NULL, NULL };
-
-
-       if (!path)
-               return -EINVAL;
-
-       argv[0] = path;
-
-       /* minimal command environment */
-       envp[0] = "HOME=/";
-       envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
-
-       call_usermodehelper(argv[0], argv, envp, 0);
-
-       return 0;
-}
-
 static int acpi_thermal_critical(struct acpi_thermal *tz)
 {
        if (!tz || !tz->trips.critical.flags.valid)
@@ -456,7 +436,7 @@ static int acpi_thermal_critical(struct acpi_thermal *tz)
        acpi_bus_generate_event(tz->device, ACPI_THERMAL_NOTIFY_CRITICAL,
                                tz->trips.critical.flags.enabled);
 
-       acpi_thermal_call_usermode(ACPI_THERMAL_PATH_POWEROFF);
+       orderly_poweroff(true);
 
        return 0;
 }

diff --git a/drivers/sbus/char/bbc_envctrl.c b/drivers/sbus/char/bbc_envctrl.c
index a54e414..e821a15 100644 (file)
--- a/drivers/sbus/char/bbc_envctrl.c
+++ b/drivers/sbus/char/bbc_envctrl.c
@@ -7,6 +7,7 @@
 #include <linux/kthread.h>
 #include <linux/delay.h>
 #include <linux/kmod.h>
+#include <linux/reboot.h>
 #include <asm/oplib.h>
 #include <asm/ebus.h>
 
@@ -170,8 +171,6 @@ static void get_current_temps(struct bbc_cpu_temperature *tp)
 static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
 {
        static int shutting_down = 0;
-       static char *envp[] = { "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
-       char *argv[] = { "/sbin/shutdown", "-h", "now", NULL };
        char *type = "???";
        s8 val = -1;
 
@@ -195,7 +194,7 @@ static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
        printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
 
        shutting_down = 1;
-       if (call_usermodehelper("/sbin/shutdown", argv, envp, 0) < 0)
+       if (orderly_poweroff(true) < 0)
                printk(KERN_CRIT "envctrl: shutdown execution failed\n");
 }
 

diff --git a/drivers/sbus/char/envctrl.c b/drivers/sbus/char/envctrl.c
index 8328aca..dadabef 100644 (file)
--- a/drivers/sbus/char/envctrl.c
+++ b/drivers/sbus/char/envctrl.c
@@ -26,6 +26,7 @@
 #include <linux/ioport.h>
 #include <linux/miscdevice.h>
 #include <linux/kmod.h>
+#include <linux/reboot.h>
 
 #include <asm/ebus.h>
 #include <asm/uaccess.h>
@@ -966,10 +967,6 @@ static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
 static void envctrl_do_shutdown(void)
 {
        static int inprog = 0;
-       static char *envp[] = { 
-               "HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
-       char *argv[] = { 
-               "/sbin/shutdown", "-h", "now", NULL };  
        int ret;
 
        if (inprog != 0)
@@ -977,7 +974,7 @@ static void envctrl_do_shutdown(void)
 
        inprog = 1;
        printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
-       ret = call_usermodehelper("/sbin/shutdown", argv, envp, 0);
+       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 */

diff --git a/include/linux/reboot.h b/include/linux/reboot.h
index 1dd1c70..85ea63f 100644 (file)
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -67,6 +67,11 @@ extern void kernel_power_off(void);
 
 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);
+
 /*
  * Emergency restart, callable from an interrupt handler.
  */

diff --git a/kernel/sys.c b/kernel/sys.c
index 4d141ae..aeded9a 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -2286,3 +2286,61 @@ asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
        }
        return err ? -EFAULT : 0;
 }
+
+char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
+
+static void argv_cleanup(char **argv, char **envp)
+{
+       argv_free(argv);
+}
+
+/**
+ * orderly_poweroff - Trigger an orderly system poweroff
+ * @force: force poweroff if command execution fails
+ *
+ * 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)
+{
+       int argc;
+       char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
+       static char *envp[] = {
+               "HOME=/",
+               "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
+               NULL
+       };
+       int ret = -ENOMEM;
+       struct subprocess_info *info;
+
+       if (argv == NULL) {
+               printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
+                      __func__, poweroff_cmd);
+               goto out;
+       }
+
+       info = call_usermodehelper_setup(argv[0], argv, envp);
+       if (info == NULL) {
+               argv_free(argv);
+               goto out;
+       }
+
+       call_usermodehelper_setcleanup(info, argv_cleanup);
+
+       ret = call_usermodehelper_exec(info, -1);
+
+  out:
+       if (ret && force) {
+               printk(KERN_WARNING "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 emergency shutdown? */
+               emergency_sync();
+               kernel_power_off();
+       }
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(orderly_poweroff);

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7063ebc..44a1d69 100644 (file)
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -46,6 +46,7 @@
 #include <linux/syscalls.h>
 #include <linux/nfs_fs.h>
 #include <linux/acpi.h>
+#include <linux/reboot.h>
 
 #include <asm/uaccess.h>
 #include <asm/processor.h>
@@ -705,6 +706,15 @@ static ctl_table kern_table[] = {
                .proc_handler   = &proc_dointvec,
        },
 #endif
+       {
+               .ctl_name       = CTL_UNNUMBERED,
+               .procname       = "poweroff_cmd",
+               .data           = &poweroff_cmd,
+               .maxlen         = POWEROFF_CMD_PATH_LEN,
+               .mode           = 0644,
+               .proc_handler   = &proc_dostring,
+               .strategy       = &sysctl_string,
+       },
 
        { .ctl_name = 0 }
 };