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 <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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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 <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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joel Stanley · Linus Torvalds
1 parent 7975a9b732
Showing 2 changed files with 50 additions and 6 deletions Side-by-side Diff
include/linux/reboot.h
kernel/reboot.c
@@ -70,7 +70,8 @@
 #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 @@
 }
  
 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 @@
 		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 @@
 		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
  
  
@@ -436,14 +461,32 @@
  * 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)
 {
...	...	@@ -70,7 +70,8 @@
70	70	#define POWEROFF_CMD_PATH_LEN 256
71	71	extern char poweroff_cmd[POWEROFF_CMD_PATH_LEN];
72	72
73		-extern int orderly_poweroff(bool force);
	73	+extern void orderly_poweroff(bool force);
	74	+extern void orderly_reboot(void);
74	75
75	76	/*
76	77	* Emergency restart, callable from an interrupt handler.
...	...	@@ -387,8 +387,9 @@
387	387	}
388	388
389	389	char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
	390	+static const char reboot_cmd[] = "/sbin/reboot";
390	391
391		-static int __orderly_poweroff(bool force)
	392	+static int run_cmd(const char *cmd)
392	393	{
393	394	char **argv;
394	395	static char *envp[] = {
...	...	@@ -397,8 +398,7 @@
397	398	NULL
398	399	};
399	400	int ret;
400		-
401		- argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL);
	401	+ argv = argv_split(GFP_KERNEL, cmd, NULL);
402	402	if (argv) {
403	403	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
404	404	argv_free(argv);
405	405
...	...	@@ -406,8 +406,33 @@
406	406	ret = -ENOMEM;
407	407	}
408	408
	409	+ return ret;
	410	+}
	411	+
	412	+static int __orderly_reboot(void)
	413	+{
	414	+ int ret;
	415	+
	416	+ ret = run_cmd(reboot_cmd);
	417	+
	418	+ if (ret) {
	419	+ pr_warn("Failed to start orderly reboot: forcing the issue\n");
	420	+ emergency_sync();
	421	+ kernel_restart(NULL);
	422	+ }
	423	+
	424	+ return ret;
	425	+}
	426	+
	427	+static int __orderly_poweroff(bool force)
	428	+{
	429	+ int ret;
	430	+
	431	+ ret = run_cmd(poweroff_cmd);
	432	+
409	433	if (ret && force) {
410	434	pr_warn("Failed to start orderly shutdown: forcing the issue\n");
	435	+
411	436	/*
412	437	* I guess this should try to kick off some daemon to sync and
413	438	* poweroff asap. Or not even bother syncing if we're doing an
414	439
415	440
...	...	@@ -436,14 +461,32 @@
436	461	* This may be called from any context to trigger a system shutdown.
437	462	* If the orderly shutdown fails, it will force an immediate shutdown.
438	463	*/
439		-int orderly_poweroff(bool force)
	464	+void orderly_poweroff(bool force)
440	465	{
441	466	if (force) /* do not override the pending "true" */
442	467	poweroff_force = true;
443	468	schedule_work(&poweroff_work);
444		- return 0;
445	469	}
446	470	EXPORT_SYMBOL_GPL(orderly_poweroff);
	471	+
	472	+static void reboot_work_func(struct work_struct *work)
	473	+{
	474	+ __orderly_reboot();
	475	+}
	476	+
	477	+static DECLARE_WORK(reboot_work, reboot_work_func);
	478	+
	479	+/**
	480	+ * orderly_reboot - Trigger an orderly system reboot
	481	+ *
	482	+ * This may be called from any context to trigger a system reboot.
	483	+ * If the orderly reboot fails, it will force an immediate reboot.
	484	+ */
	485	+void orderly_reboot(void)
	486	+{
	487	+ schedule_work(&reboot_work);
	488	+}
	489	+EXPORT_SYMBOL_GPL(orderly_reboot);
447	490
448	491	static int __init reboot_setup(char *str)
449	492	{