[PATCH 3/8] Hibernation: Add PM_RESTORE_PREPARE and PM_POST_RESTORE notifiers (rev. 2)

Rafael J. Wysocki
2007-11-19T22:40:35Z

From: Alan Stern <stern@rowland.harvard.edu>

Add PM_RESTORE_PREPARE and PM_POST_RESTORE notifiers to the PM core, to be used
in analogy with the existing PM_HIBERNATION_PREPARE and PM_POST_HIBERNATION
notifiers.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: "Rafael J. Wysocki" <rjw@sisk.pl>
---
Documentation/power/notifiers.txt | 8 ++++++++
include/linux/notifier.h | 2 ++
kernel/power/disk.c | 5 +++++
kernel/power/user.c | 31 +++++++++++++++++++------------
4 files changed, 34 insertions(+), 12 deletions(-)

Index: linux-2.6/Documentation/power/notifiers.txt
===================================================================
--- linux-2.6.orig/Documentation/power/notifiers.txt
+++ linux-2.6/Documentation/power/notifiers.txt
@@ -28,6 +28,14 @@ PM_POST_HIBERNATION The system memory st
hibernation. Device drivers' .resume() callbacks have
been executed and tasks have been thawed.

+PM_RESTORE_PREPARE The system is going to restore a hibernation image.
+ If all goes well the restored kernel will issue a
+ PM_POST_HIBERNATION notification.
+
+PM_POST_RESTORE An error occurred during the hibernation restore.
+ Device drivers' .resume() callbacks have been executed
+ and tasks have been thawed.
+
PM_SUSPEND_PREPARE The system is preparing for a suspend.

PM_POST_SUSPEND The system has just resumed or an error occured during
Index: linux-2.6/include/linux/notifier.h
===================================================================
--- linux-2.6.orig/include/linux/notifier.h
+++ linux-2.6/include/linux/notifier.h
@@ -230,6 +230,8 @@ static inline int notifier_to_errno(int
#define PM_POST_HIBERNATION 0x0002 /* Hibernation finished */
#define PM_SUSPEND_PREPARE 0x0003 /* Going to suspend the system */
#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 */

/* Console keyboard events.
* Note: KBD_KEYCODE is always sent before KBD_UNBOUND_KEYCODE, KBD_UNICODE and
Index: linux-2.6/kernel/power/disk.c
===================================================================
--- linux-2.6.orig/kernel/power/disk.c
+++ linux-2.6/kernel/power/disk.c
@@ -499,6 +499,10 @@ static int software_resume(void)
goto Unlock;
}

+ error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
+ if (error)
+ goto Finish;
+
error = create_basic_memory_bitmaps();
if (error)
goto Finish;
@@ -522,6 +526,7 @@ static int software_resume(void)
Done:
free_basic_memory_bitmaps();
Finish:
+ pm_notifier_call_chain(PM_POST_RESTORE);
atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
Unlock:
Index: linux-2.6/kernel/power/user.c
===================================================================
--- linux-2.6.orig/kernel/power/user.c
+++ linux-2.6/kernel/power/user.c
@@ -67,6 +67,7 @@ atomic_t snapshot_device_available = ATO
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
+ int error;

if (!atomic_add_unless(&snapshot_device_available, -1, 0))
return -EBUSY;
@@ -87,9 +88,19 @@ static int snapshot_open(struct inode *i
data->swap = swsusp_resume_device ?
swap_type_of(swsusp_resume_device, 0, NULL) : -1;
data->mode = O_RDONLY;
+ error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
+ if (error)
+ pm_notifier_call_chain(PM_POST_RESTORE);
} else {
data->swap = -1;
data->mode = O_WRONLY;
+ error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
+ if (error)
+ pm_notifier_call_chain(PM_POST_HIBERNATION);
+ }
+ if (error) {
+ atomic_inc(&snapshot_device_available);
+ return error;
}
data->frozen = 0;
data->ready = 0;
@@ -111,6 +122,8 @@ static int snapshot_release(struct inode
thaw_processes();
mutex_unlock(&pm_mutex);
}
+ pm_notifier_call_chain(data->mode == O_WRONLY ?
+ PM_POST_HIBERNATION : PM_POST_RESTORE);
atomic_inc(&snapshot_device_available);
return 0;
}
@@ -174,18 +187,13 @@ static int snapshot_ioctl(struct inode *
if (data->frozen)
break;
mutex_lock(&pm_mutex);
- error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
- if (!error) {
- printk("Syncing filesystems ... ");
- sys_sync();
- printk("done.\n");
-
- error = freeze_processes();
- if (error)
- thaw_processes();
- }
+ printk("Syncing filesystems ... ");
+ sys_sync();
+ printk("done.\n");
+
+ error = freeze_processes();
if (error)
- pm_notifier_call_chain(PM_POST_HIBERNATION);
+ thaw_processes();
mutex_unlock(&pm_mutex);
if (!error)
data->frozen = 1;
@@ -196,7 +204,6 @@ static int snapshot_ioctl(struct inode *
break;
mutex_lock(&pm_mutex);
thaw_processes();
- pm_notifier_call_chain(PM_POST_HIBERNATION);
mutex_unlock(&pm_mutex);
data->frozen = 0;
break;