2 files changed, 50 insertions, 21 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 5f3523e18e46..0ee1df0a0bd6 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -52,6 +52,7 @@ enum {
 #ifdef CONFIG_SUSPEND
         HIBERNATION_SUSPEND,
 #endif
+        HIBERNATION_TEST_RESUME,
         /* keep last */
         __HIBERNATION_AFTER_LAST
 };
@@ -647,12 +648,39 @@ static void power_down(void)
                 cpu_relax();
 }
 
+static int load_image_and_restore(void)
+{
+        int error;
+        unsigned int flags;
+
+        pr_debug("PM: Loading hibernation image.\n");
+
+        lock_device_hotplug();
+        error = create_basic_memory_bitmaps();
+        if (error)
+                goto Unlock;
+
+        error = swsusp_read(&flags);
+        swsusp_close(FMODE_READ);
+        if (!error)
+                hibernation_restore(flags & SF_PLATFORM_MODE);
+
+        printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
+        swsusp_free();
+        free_basic_memory_bitmaps();
+ Unlock:
+        unlock_device_hotplug();
+
+        return error;
+}
+
 /**
  * hibernate - Carry out system hibernation, including saving the image.
  */
 int hibernate(void)
 {
         int error, nr_calls = 0;
+        bool snapshot_test = false;
 
         if (!hibernation_available()) {
                 pr_debug("PM: Hibernation not available.\n");
@@ -704,8 +732,12 @@ int hibernate(void)
                 pr_debug("PM: writing image.\n");
                 error = swsusp_write(flags);
                 swsusp_free();
-                if (!error)
-                        power_down();
+                if (!error) {
+                        if (hibernation_mode == HIBERNATION_TEST_RESUME)
+                                snapshot_test = true;
+                        else
+                                power_down();
+                }
                 in_suspend = 0;
                 pm_restore_gfp_mask();
         } else {
@@ -716,6 +748,12 @@ int hibernate(void)
         free_basic_memory_bitmaps();
  Thaw:
         unlock_device_hotplug();
+        if (snapshot_test) {
+                pr_debug("PM: Checking hibernation image\n");
+                error = swsusp_check();
+                if (!error)
+                        error = load_image_and_restore();
+        }
         thaw_processes();
 
         /* Don't bother checking whether freezer_test_done is true */
@@ -748,7 +786,6 @@ int hibernate(void)
 static int software_resume(void)
 {
         int error, nr_calls = 0;
-        unsigned int flags;
 
         /*
          * If the user said "noresume".. bail out early.
@@ -844,24 +881,7 @@ static int software_resume(void)
         error = freeze_processes();
         if (error)
                 goto Close_Finish;
-
-        pr_debug("PM: Loading hibernation image.\n");
-
-        lock_device_hotplug();
-        error = create_basic_memory_bitmaps();
-        if (error)
-                goto Thaw;
-
-        error = swsusp_read(&flags);
-        swsusp_close(FMODE_READ);
-        if (!error)
-                hibernation_restore(flags & SF_PLATFORM_MODE);
-
-        printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
-        swsusp_free();
-        free_basic_memory_bitmaps();
- Thaw:
-        unlock_device_hotplug();
+        error = load_image_and_restore();
         thaw_processes();
  Finish:
         __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
@@ -887,6 +907,7 @@ static const char * const hibernation_modes[] = {
 #ifdef CONFIG_SUSPEND
         [HIBERNATION_SUSPEND]   = "suspend",
 #endif
+        [HIBERNATION_TEST_RESUME]       = "test_resume",
 };
 
 /*
@@ -933,6 +954,7 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 #ifdef CONFIG_SUSPEND
                 case HIBERNATION_SUSPEND:
 #endif
+                case HIBERNATION_TEST_RESUME:
                         break;
                 case HIBERNATION_PLATFORM:
                         if (hibernation_ops)
@@ -979,6 +1001,7 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 #ifdef CONFIG_SUSPEND
                 case HIBERNATION_SUSPEND:
 #endif
+                case HIBERNATION_TEST_RESUME:
                         hibernation_mode = mode;
                         break;
                 case HIBERNATION_PLATFORM:
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 160e1006640d..51cef8432154 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -348,6 +348,12 @@ static int swsusp_swap_check(void)
         if (res < 0)
                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 
+        /*
+         * Update the resume device to the one actually used,
+         * so the test_resume mode can use it in case it is
+         * invoked from hibernate() to test the snapshot.
+         */
+        swsusp_resume_device = hib_resume_bdev->bd_dev;
         return res;
 }