3 files changed, 31 insertions, 6 deletions

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 0c4defe6d3b8..21724eee5206 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -231,8 +231,28 @@ extern int pm_test_level;
 #ifdef CONFIG_SUSPEND_FREEZER
 static inline int suspend_freeze_processes(void)
 {
-        int error = freeze_processes();
-        return error ? : freeze_kernel_threads();
+        int error;
+
+        error = freeze_processes();
+
+        /*
+         * freeze_processes() automatically thaws every task if freezing
+         * fails. So we need not do anything extra upon error.
+         */
+        if (error)
+                goto Finish;
+
+        error = freeze_kernel_threads();
+
+        /*
+         * freeze_kernel_threads() thaws only kernel threads upon freezing
+         * failure. So we have to thaw the userspace tasks ourselves.
+         */
+        if (error)
+                thaw_processes();
+
+ Finish:
+        return error;
 }
 
 static inline void suspend_thaw_processes(void)
diff --git a/kernel/power/process.c b/kernel/power/process.c
index eeca00311f39..7e426459e60a 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -143,7 +143,10 @@ int freeze_processes(void)
 /**
  * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
  *
- * On success, returns 0.  On failure, -errno and system is fully thawed.
+ * On success, returns 0.  On failure, -errno and only the kernel threads are
+ * thawed, so as to give a chance to the caller to do additional cleanups
+ * (if any) before thawing the userspace tasks. So, it is the responsibility
+ * of the caller to thaw the userspace tasks, when the time is right.
  */
 int freeze_kernel_threads(void)
 {
@@ -159,7 +162,7 @@ int freeze_kernel_threads(void)
         BUG_ON(in_atomic());
 
         if (error)
-                thaw_processes();
+                thaw_kernel_threads();
         return error;
 }
 
diff --git a/kernel/power/user.c b/kernel/power/user.c
index e5a21a857302..3e100075b13c 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -249,13 +249,15 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                 }
                 pm_restore_gfp_mask();
                 error = hibernation_snapshot(data->platform_support);
-                if (!error) {
+                if (error) {
+                        thaw_kernel_threads();
+                } else {
                         error = put_user(in_suspend, (int __user *)arg);
                         if (!error && !freezer_test_done)
                                 data->ready = 1;
                         if (freezer_test_done) {
                                 freezer_test_done = false;
-                                thaw_processes();
+                                thaw_kernel_threads();
                         }
                 }
                 break;