PM / sleep: make PM notifiers called symmetrically

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@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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);