From 6719138d368016bbdd706eb99831e589a152ee15 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Sat, 20 Aug 2011 11:31:39 +0200
Subject: [PATCH] freezer: rename thaw_process() to __thaw_task() and simplify
 the implementation

thaw_process() now has only internal users - system and cgroup
freezers.  Remove the unnecessary return value, rename, unexport and
collapse __thaw_process() into it.  This will help further updates to
the freezer code.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul Menage <menage@google.com>
---
 include/linux/freezer.h |  3 +--
 kernel/cgroup_freezer.c |  7 +++----
 kernel/freezer.c        | 30 +++++++++++-------------------
 kernel/power/process.c  |  2 +-
 4 files changed, 16 insertions(+), 26 deletions(-)

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 8ee31e5d810b..80a455d1dc72 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -45,7 +45,7 @@ static inline bool should_send_signal(struct task_struct *p)
 }
 
 /* Takes and releases task alloc lock using task_lock() */
-extern int thaw_process(struct task_struct *p);
+extern void __thaw_task(struct task_struct *t);
 
 extern bool __refrigerator(bool check_kthr_stop);
 extern int freeze_processes(void);
@@ -167,7 +167,6 @@ static inline int frozen(struct task_struct *p) { return 0; }
 static inline int freezing(struct task_struct *p) { return 0; }
 static inline void set_freeze_flag(struct task_struct *p) {}
 static inline void clear_freeze_flag(struct task_struct *p) {}
-static inline int thaw_process(struct task_struct *p) { return 1; }
 
 static inline bool __refrigerator(bool check_kthr_stop) { return false; }
 static inline int freeze_processes(void) { BUG(); return 0; }
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index e691818d7e45..e7fa0ec0690e 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -130,7 +130,7 @@ struct cgroup_subsys freezer_subsys;
  *   write_lock css_set_lock (cgroup iterator start)
  *    task->alloc_lock
  *   read_lock css_set_lock (cgroup iterator start)
- *    task->alloc_lock (inside thaw_process(), prevents race with refrigerator())
+ *    task->alloc_lock (inside __thaw_task(), prevents race with refrigerator())
  *     sighand->siglock
  */
 static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
@@ -300,9 +300,8 @@ static void unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
 	struct task_struct *task;
 
 	cgroup_iter_start(cgroup, &it);
-	while ((task = cgroup_iter_next(cgroup, &it))) {
-		thaw_process(task);
-	}
+	while ((task = cgroup_iter_next(cgroup, &it)))
+		__thaw_task(task);
 	cgroup_iter_end(cgroup, &it);
 
 	freezer->state = CGROUP_THAWED;
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 656492c7d79b..f5db7fd4ee52 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -145,18 +145,8 @@ void cancel_freezing(struct task_struct *p)
 	}
 }
 
-static int __thaw_process(struct task_struct *p)
-{
-	if (frozen(p)) {
-		p->flags &= ~PF_FROZEN;
-		return 1;
-	}
-	clear_freeze_flag(p);
-	return 0;
-}
-
 /*
- * Wake up a frozen process
+ * Wake up a frozen task
  *
  * task_lock() is needed to prevent the race with refrigerator() which may
  * occur if the freezing of tasks fails.  Namely, without the lock, if the
@@ -164,15 +154,17 @@ static int __thaw_process(struct task_struct *p)
  * refrigerator() could call frozen_process(), in which case the task would be
  * frozen and no one would thaw it.
  */
-int thaw_process(struct task_struct *p)
+void __thaw_task(struct task_struct *p)
 {
+	bool was_frozen;
+
 	task_lock(p);
-	if (__thaw_process(p) == 1) {
-		task_unlock(p);
-		wake_up_process(p);
-		return 1;
-	}
+	if ((was_frozen = frozen(p)))
+		p->flags &= ~PF_FROZEN;
+	else
+		clear_freeze_flag(p);
 	task_unlock(p);
-	return 0;
+
+	if (was_frozen)
+		wake_up_process(p);
 }
-EXPORT_SYMBOL(thaw_process);
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 0cf3a27a6c9d..bec09c392d81 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -176,7 +176,7 @@ static void thaw_tasks(bool nosig_only)
 		if (cgroup_freezing_or_frozen(p))
 			continue;
 
-		thaw_process(p);
+		__thaw_task(p);
 	} while_each_thread(g, p);
 	read_unlock(&tasklist_lock);
 }
-- 
2.39.5