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authorPingfan Liu <kernelfans@gmail.com>2018-07-31 16:51:32 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-08-06 12:35:20 +0200
commit55f2503c3b69328735e88031ff8d6ba291bd952b (patch)
treec89f476f4866d1e3ee11aa8b8601c68a23e3b025 /kernel/power
parent82837ad5bda79cd13d64b9abad92e7872a06bc65 (diff)
downloadlinux-55f2503c3b69328735e88031ff8d6ba291bd952b.tar.bz2
PM / reboot: Eliminate race between reboot and suspend
At present, "systemctl suspend" and "shutdown" can run in parrallel. A system can suspend after devices_shutdown(), and resume. Then the shutdown task goes on to power off. This causes many devices are not really shut off. Hence replacing reboot_mutex with system_transition_mutex (renamed from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as system_transition_mutex can be better to reflect the purpose of the mutex. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/hibernate.c15
-rw-r--r--kernel/power/main.c12
-rw-r--r--kernel/power/suspend.c4
-rw-r--r--kernel/power/user.c4
4 files changed, 18 insertions, 17 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 38f3f96b4b12..abef759de7c8 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -338,7 +338,7 @@ static int create_image(int platform_mode)
* hibernation_snapshot - Quiesce devices and create a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
- * This routine must be called with pm_mutex held.
+ * This routine must be called with system_transition_mutex held.
*/
int hibernation_snapshot(int platform_mode)
{
@@ -500,8 +500,9 @@ static int resume_target_kernel(bool platform_mode)
* hibernation_restore - Quiesce devices and restore from a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
- * This routine must be called with pm_mutex held. If it is successful, control
- * reappears in the restored target kernel in hibernation_snapshot().
+ * This routine must be called with system_transition_mutex held. If it is
+ * successful, control reappears in the restored target kernel in
+ * hibernation_snapshot().
*/
int hibernation_restore(int platform_mode)
{
@@ -806,13 +807,13 @@ static int software_resume(void)
* name_to_dev_t() below takes a sysfs buffer mutex when sysfs
* is configured into the kernel. Since the regular hibernate
* trigger path is via sysfs which takes a buffer mutex before
- * calling hibernate functions (which take pm_mutex) this can
- * cause lockdep to complain about a possible ABBA deadlock
+ * calling hibernate functions (which take system_transition_mutex)
+ * this can cause lockdep to complain about a possible ABBA deadlock
* which cannot happen since we're in the boot code here and
* sysfs can't be invoked yet. Therefore, we use a subclass
* here to avoid lockdep complaining.
*/
- mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
if (swsusp_resume_device)
goto Check_image;
@@ -900,7 +901,7 @@ static int software_resume(void)
atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
Unlock:
- mutex_unlock(&pm_mutex);
+ mutex_unlock(&system_transition_mutex);
pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
return error;
Close_Finish:
diff --git a/kernel/power/main.c b/kernel/power/main.c
index d9706da10930..35b50823d83b 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -15,17 +15,16 @@
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/suspend.h>
#include "power.h"
-DEFINE_MUTEX(pm_mutex);
-
#ifdef CONFIG_PM_SLEEP
void lock_system_sleep(void)
{
current->flags |= PF_FREEZER_SKIP;
- mutex_lock(&pm_mutex);
+ mutex_lock(&system_transition_mutex);
}
EXPORT_SYMBOL_GPL(lock_system_sleep);
@@ -37,8 +36,9 @@ void unlock_system_sleep(void)
*
* Reason:
* Fundamentally, we just don't need it, because freezing condition
- * doesn't come into effect until we release the pm_mutex lock,
- * since the freezer always works with pm_mutex held.
+ * doesn't come into effect until we release the
+ * system_transition_mutex lock, since the freezer always works with
+ * system_transition_mutex held.
*
* More importantly, in the case of hibernation,
* unlock_system_sleep() gets called in snapshot_read() and
@@ -47,7 +47,7 @@ void unlock_system_sleep(void)
* enter the refrigerator, thus causing hibernation to lockup.
*/
current->flags &= ~PF_FREEZER_SKIP;
- mutex_unlock(&pm_mutex);
+ mutex_unlock(&system_transition_mutex);
}
EXPORT_SYMBOL_GPL(unlock_system_sleep);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 87331565e505..9e13afe65a14 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -556,7 +556,7 @@ static int enter_state(suspend_state_t state)
} else if (!valid_state(state)) {
return -EINVAL;
}
- if (!mutex_trylock(&pm_mutex))
+ if (!mutex_trylock(&system_transition_mutex))
return -EBUSY;
if (state == PM_SUSPEND_TO_IDLE)
@@ -590,7 +590,7 @@ static int enter_state(suspend_state_t state)
pm_pr_dbg("Finishing wakeup.\n");
suspend_finish();
Unlock:
- mutex_unlock(&pm_mutex);
+ mutex_unlock(&system_transition_mutex);
return error;
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index abd225550271..2d8b60a3c86b 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -216,7 +216,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!mutex_trylock(&pm_mutex))
+ if (!mutex_trylock(&system_transition_mutex))
return -EBUSY;
lock_device_hotplug();
@@ -394,7 +394,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
}
unlock_device_hotplug();
- mutex_unlock(&pm_mutex);
+ mutex_unlock(&system_transition_mutex);
return error;
}