[PATCH v2 1/3] PM suspend/hibernate: Call notifier after freezing processes

From: Pali RohÃr
Date: Sun Jun 21 2015 - 07:22:12 EST


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 RohÃr <pali.rohar@xxxxxxxxx>
---
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 8d7a1ef..ba2a945 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -277,8 +277,10 @@ 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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
Please read the FAQ at http://www.tux.org/lkml/