Commit 7a54f46b authored by Joel Stanley's avatar Joel Stanley Committed by Linus Torvalds

kernel/reboot.c: add orderly_reboot for graceful reboot

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: default avatarJoel Stanley <joel@jms.id.au>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7975a9b7
......@@ -70,7 +70,8 @@ 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.
......
......@@ -387,8 +387,9 @@ 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[] = {
......@@ -397,8 +398,7 @@ 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);
......@@ -406,8 +406,33 @@ 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
......@@ -436,15 +461,33 @@ 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 (;;) {
......
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