[PATCH 1/3] PM suspend/hibernate: Call notifier after freezing processes
From: Pali Rohár <hidden>
Date: 2015-04-05 17:21:17
Also in:
dm-devel, linux-pm, lkml
Subsystem:
hibernation (aka software suspend, aka swsusp), suspend to ram, the rest · Maintainers:
"Rafael J. Wysocki", Linus Torvalds
To prevent race conditions on userspace processes with I/O some taks must be called after processes are freezed. This patch adds new events which are delivered by pm_notifier_call_chain() after freezing processes when doing suspend or hibernate action. Signed-off-by: Pali Rohár <redacted> --- include/linux/suspend.h | 2 ++ kernel/power/hibernate.c | 2 ++ kernel/power/suspend.c | 4 +++- 3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 5efe743..bc743c8 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h@@ -368,6 +368,8 @@ static inline bool hibernation_available(void) { return false; } #define PM_POST_SUSPEND 0x0004 /* Suspend finished */ #define PM_RESTORE_PREPARE 0x0005 /* Going to restore a saved image */ #define PM_POST_RESTORE 0x0006 /* Restore failed */ +#define PM_HIBERNATION_AFTER_FREEZE 0x0007 /* After hibernation freeze */ +#define PM_SUSPEND_AFTER_FREEZE 0x0008 /* After suspend freeze */ extern struct mutex pm_mutex;
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 2329daa..184f7ee 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c@@ -671,6 +671,8 @@ int hibernate(void) if (error) goto Exit; + pm_notifier_call_chain(PM_HIBERNATION_AFTER_FREEZE); + lock_device_hotplug(); /* Allocate memory management structures */ error = create_basic_memory_bitmaps();
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index b7d6b3a..1776938 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c@@ -268,8 +268,10 @@ static int suspend_prepare(suspend_state_t state) trace_suspend_resume(TPS("freeze_processes"), 0, true); error = suspend_freeze_processes(); trace_suspend_resume(TPS("freeze_processes"), 0, false); - if (!error) + if (!error) { + pm_notifier_call_chain(PM_SUSPEND_AFTER_FREEZE); return 0; + } suspend_stats.failed_freeze++; dpm_save_failed_step(SUSPEND_FREEZE);
--
1.7.9.5