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.

-v3: oom_kill grew a use of thaw_process() while this patch was
     pending.  Convert it to use __thaw_task() for now.  In the longer
     term, this should be handled by allowing tasks to die if killed
     even if it's frozen.

-v2: minor style update as suggested by Matt.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul Menage <menage@google.com>
Cc: Matt Helsley <matthltc@us.ibm.com>

1 files changed, 12 insertions, 19 deletions

diff --git a/kernel/freezer.c b/kernel/freezer.c
index b83c30e9483a..c851d588e29f 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 +154,18 @@ 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;
-        }
+        was_frozen = frozen(p);
+        if (was_frozen)
+                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);