From 7a54f46b301cfab8a0d7365aa186545f8b98f22e Mon Sep 17 00:00:00 2001 From: Joel Stanley Date: Wed, 15 Apr 2015 16:16:53 -0700 Subject: [PATCH] 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: Joel Stanley Cc: Fabian Frederick Cc: Benjamin Herrenschmidt Cc: Michael Ellerman Cc: Rusty Russell Cc: Jeremy Kerr Cc: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 67fc8fc..a7ff409 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -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. diff --git a/kernel/reboot.c b/kernel/reboot.c index 5925f5a..d20c85d 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -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 (;;) { -- 2.7.4