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>
This commit is contained in:
Pingfan Liu
2018-07-31 16:51:32 +08:00
committed by Rafael J. Wysocki
parent 82837ad5bd
commit 55f2503c3b
10 changed files with 40 additions and 36 deletions

View File

@@ -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;
}