[PATCH v2] PM / sleep: make pm notifier called symmetrically

From: Lianwei Wang
Date: Mon Jun 20 2016 - 02:52:58 EST


This makes pm notifier PREPARE/POST symmetrical: if PREPARE
fails, we will only undo what ever happened on PREPARE.

It fixes the unbalanced cpu hotplug enable in cpu pm notifier.

Signed-off-by: Lianwei Wang <lianwei.wang@xxxxxxxxx>
---
kernel/power/hibernate.c | 20 ++++++++++++--------
kernel/power/main.c | 11 +++++++++--
kernel/power/power.h | 2 ++
kernel/power/suspend.c | 10 ++++++----
kernel/power/user.c | 14 ++++++++------
5 files changed, 37 insertions(+), 20 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index fca9254280ee..126e24caa82e 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -647,7 +647,7 @@ static void power_down(void)
*/
int hibernate(void)
{
- int error;
+ int error, nr_calls = 0;

if (!hibernation_available()) {
pr_debug("PM: Hibernation not available.\n");
@@ -662,9 +662,11 @@ int hibernate(void)
}

pm_prepare_console();
- error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
- if (error)
+ error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
+ if (error) {
+ nr_calls--;
goto Exit;
+ }

printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
@@ -714,7 +716,7 @@ int hibernate(void)
/* Don't bother checking whether freezer_test_done is true */
freezer_test_done = false;
Exit:
- pm_notifier_call_chain(PM_POST_HIBERNATION);
+ __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
pm_restore_console();
atomic_inc(&snapshot_device_available);
Unlock:
@@ -740,7 +742,7 @@ int hibernate(void)
*/
static int software_resume(void)
{
- int error;
+ int error, nr_calls = 0;
unsigned int flags;

/*
@@ -827,9 +829,11 @@ static int software_resume(void)
}

pm_prepare_console();
- error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
- if (error)
+ error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
+ if (error) {
+ nr_calls--;
goto Close_Finish;
+ }

pr_debug("PM: Preparing processes for restore.\n");
error = freeze_processes();
@@ -855,7 +859,7 @@ static int software_resume(void)
unlock_device_hotplug();
thaw_processes();
Finish:
- pm_notifier_call_chain(PM_POST_RESTORE);
+ __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
pm_restore_console();
atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 27946975eff0..5ea50b1b7595 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -38,12 +38,19 @@ int unregister_pm_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL_GPL(unregister_pm_notifier);

-int pm_notifier_call_chain(unsigned long val)
+int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
{
- int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
+ int ret;
+
+ ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
+ nr_to_call, nr_calls);

return notifier_to_errno(ret);
}
+int pm_notifier_call_chain(unsigned long val)
+{
+ return __pm_notifier_call_chain(val, -1, NULL);
+}

/* If set, devices may be suspended and resumed asynchronously. */
int pm_async_enabled = 1;
diff --git a/kernel/power/power.h b/kernel/power/power.h
index efe1b3b17c88..51f02ecaf125 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -200,6 +200,8 @@ static inline void suspend_test_finish(const char *label) {}

#ifdef CONFIG_PM_SLEEP
/* kernel/power/main.c */
+extern int __pm_notifier_call_chain(unsigned long val, int nr_to_call,
+ int *nr_calls);
extern int pm_notifier_call_chain(unsigned long val);
#endif

diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 5b70d64b871e..0acab9d7f96f 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -266,16 +266,18 @@ static int suspend_test(int level)
*/
static int suspend_prepare(suspend_state_t state)
{
- int error;
+ int error, nr_calls = 0;

if (!sleep_state_supported(state))
return -EPERM;

pm_prepare_console();

- error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
- if (error)
+ error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
+ if (error) {
+ nr_calls--;
goto Finish;
+ }

trace_suspend_resume(TPS("freeze_processes"), 0, true);
error = suspend_freeze_processes();
@@ -286,7 +288,7 @@ static int suspend_prepare(suspend_state_t state)
suspend_stats.failed_freeze++;
dpm_save_failed_step(SUSPEND_FREEZE);
Finish:
- pm_notifier_call_chain(PM_POST_SUSPEND);
+ __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
pm_restore_console();
return error;
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 526e8911460a..35310b627388 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -47,7 +47,7 @@ atomic_t snapshot_device_available = ATOMIC_INIT(1);
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
- int error;
+ int error, nr_calls = 0;

if (!hibernation_available())
return -EPERM;
@@ -74,9 +74,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)
swap_type_of(swsusp_resume_device, 0, NULL) : -1;
data->mode = O_RDONLY;
data->free_bitmaps = false;
- error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
+ error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
if (error)
- pm_notifier_call_chain(PM_POST_HIBERNATION);
+ __pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
} else {
/*
* Resuming. We may need to wait for the image device to
@@ -86,13 +86,15 @@ static int snapshot_open(struct inode *inode, struct file *filp)

data->swap = -1;
data->mode = O_WRONLY;
- error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
+ error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
if (!error) {
error = create_basic_memory_bitmaps();
data->free_bitmaps = !error;
- }
+ } else
+ nr_calls--;
+
if (error)
- pm_notifier_call_chain(PM_POST_RESTORE);
+ __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
}
if (error)
atomic_inc(&snapshot_device_available);
--
1.9.1