6 files changed, 23 insertions, 46 deletions

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index ba4f512d2938..93f411a52872 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -61,7 +61,6 @@ static inline bool try_to_freeze(void)
 }
 
 extern bool freeze_task(struct task_struct *p, bool sig_only);
-extern void cancel_freezing(struct task_struct *p);
 
 #ifdef CONFIG_CGROUP_FREEZER
 extern int cgroup_freezing_or_frozen(struct task_struct *task);
diff --git a/kernel/freezer.c b/kernel/freezer.c
index b8b562124ba9..11e32d419dec 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -129,21 +129,6 @@ out_unlock:
         return ret;
 }
 
-void cancel_freezing(struct task_struct *p)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&freezer_lock, flags);
-        if (freezing(p)) {
-                pr_debug("  clean up: %s\n", p->comm);
-                clear_freeze_flag(p);
-                spin_lock(&p->sighand->siglock);
-                recalc_sigpending_and_wake(p);
-                spin_unlock(&p->sighand->siglock);
-        }
-        spin_unlock_irqrestore(&freezer_lock, flags);
-}
-
 void __thaw_task(struct task_struct *p)
 {
         unsigned long flags;
@@ -153,10 +138,18 @@ void __thaw_task(struct task_struct *p)
          * be visible to @p as waking up implies wmb.  Waking up inside
          * freezer_lock also prevents wakeups from leaking outside
          * refrigerator.
+         *
+         * If !FROZEN, @p hasn't reached refrigerator, recalc sigpending to
+         * avoid leaving dangling TIF_SIGPENDING behind.
          */
         spin_lock_irqsave(&freezer_lock, flags);
         clear_freeze_flag(p);
-        if (frozen(p))
+        if (frozen(p)) {
                 wake_up_process(p);
+        } else {
+                spin_lock(&p->sighand->siglock);
+                recalc_sigpending_and_wake(p);
+                spin_unlock(&p->sighand->siglock);
+        }
         spin_unlock_irqrestore(&freezer_lock, flags);
 }
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 196c01268ebd..ba2319ffc860 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -607,17 +607,6 @@ static void power_down(void)
         while(1);
 }
 
-static int prepare_processes(void)
-{
-        int error = 0;
-
-        if (freeze_processes()) {
-                error = -EBUSY;
-                thaw_processes();
-        }
-        return error;
-}
-
 /**
  * hibernate - Carry out system hibernation, including saving the image.
  */
@@ -650,7 +639,7 @@ int hibernate(void)
         sys_sync();
         printk("done.\n");
 
-        error = prepare_processes();
+        error = freeze_processes();
         if (error)
                 goto Finish;
 
@@ -811,7 +800,7 @@ static int software_resume(void)
                 goto close_finish;
 
         pr_debug("PM: Preparing processes for restore.\n");
-        error = prepare_processes();
+        error = freeze_processes();
         if (error) {
                 swsusp_close(FMODE_READ);
                 goto Done;
diff --git a/kernel/power/process.c b/kernel/power/process.c
index e59676f5811d..ce643838a00c 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -91,11 +91,6 @@ static int try_to_freeze_tasks(bool sig_only)
         elapsed_csecs = elapsed_csecs64;
 
         if (todo) {
-                /* This does not unfreeze processes that are already frozen
-                 * (we have slightly ugly calling convention in that respect,
-                 * and caller must call thaw_processes() if something fails),
-                 * but it cleans up leftover PF_FREEZE requests.
-                 */
                 printk("\n");
                 printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds "
                        "(%d tasks refusing to freeze, wq_busy=%d):\n",
@@ -103,14 +98,11 @@ static int try_to_freeze_tasks(bool sig_only)
                        elapsed_csecs / 100, elapsed_csecs % 100,
                        todo - wq_busy, wq_busy);
 
-                thaw_workqueues();
-
                 read_lock(&tasklist_lock);
                 do_each_thread(g, p) {
                         if (!wakeup && !freezer_should_skip(p) &&
                             freezing(p) && !frozen(p))
                                 sched_show_task(p);
-                        cancel_freezing(p);
                 } while_each_thread(g, p);
                 read_unlock(&tasklist_lock);
         } else {
@@ -123,6 +115,8 @@ static int try_to_freeze_tasks(bool sig_only)
 
 /**
  * freeze_processes - Signal user space processes to enter the refrigerator.
+ *
+ * On success, returns 0.  On failure, -errno and system is fully thawed.
  */
 int freeze_processes(void)
 {
@@ -137,11 +131,15 @@ int freeze_processes(void)
         printk("\n");
         BUG_ON(in_atomic());
 
+        if (error)
+                thaw_processes();
         return error;
 }
 
 /**
  * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
+ *
+ * On success, returns 0.  On failure, -errno and system is fully thawed.
  */
 int freeze_kernel_threads(void)
 {
@@ -155,6 +153,8 @@ int freeze_kernel_threads(void)
         printk("\n");
         BUG_ON(in_atomic());
 
+        if (error)
+                thaw_processes();
         return error;
 }
 
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4953dc054c53..d336b27d1104 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -106,13 +106,11 @@ static int suspend_prepare(void)
                 goto Finish;
 
         error = suspend_freeze_processes();
-        if (error) {
-                suspend_stats.failed_freeze++;
-                dpm_save_failed_step(SUSPEND_FREEZE);
-        } else
+        if (!error)
                 return 0;
 
-        suspend_thaw_processes();
+        suspend_stats.failed_freeze++;
+        dpm_save_failed_step(SUSPEND_FREEZE);
         usermodehelper_enable();
  Finish:
         pm_notifier_call_chain(PM_POST_SUSPEND);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 6d8f535c2b88..7cc3f5bc5c24 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -257,10 +257,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
                         break;
 
                 error = freeze_processes();
-                if (error) {
-                        thaw_processes();
+                if (error)
                         usermodehelper_enable();
-                }
                 if (!error)
                         data->frozen = 1;
                 break;