1 files changed, 95 insertions, 87 deletions

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 1effc8b56b4..0ab54e16a91 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -5,70 +5,58 @@
 
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/atomic.h>
 
 #ifdef CONFIG_FREEZER
+extern atomic_t system_freezing_cnt;	/* nr of freezing conds in effect */
+extern bool pm_freezing;		/* PM freezing in effect */
+extern bool pm_nosig_freezing;		/* PM nosig freezing in effect */
+
 /*
  * Check if a process has been frozen
  */
-static inline int frozen(struct task_struct *p)
+static inline bool frozen(struct task_struct *p)
 {
 	return p->flags & PF_FROZEN;
 }
 
-/*
- * Check if there is a request to freeze a process
- */
-static inline int freezing(struct task_struct *p)
-{
-	return test_tsk_thread_flag(p, TIF_FREEZE);
-}
-
-/*
- * Request that a process be frozen
- */
-static inline void set_freeze_flag(struct task_struct *p)
-{
-	set_tsk_thread_flag(p, TIF_FREEZE);
-}
+extern bool freezing_slow_path(struct task_struct *p);
 
 /*
- * Sometimes we may need to cancel the previous 'freeze' request
+ * Check if there is a request to freeze a process
  */
-static inline void clear_freeze_flag(struct task_struct *p)
+static inline bool freezing(struct task_struct *p)
 {
-	clear_tsk_thread_flag(p, TIF_FREEZE);
-}
-
-static inline bool should_send_signal(struct task_struct *p)
-{
-	return !(p->flags & PF_FREEZER_NOSIG);
+	if (likely(!atomic_read(&system_freezing_cnt)))
+		return false;
+	return freezing_slow_path(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 void refrigerator(void);
+extern bool __refrigerator(bool check_kthr_stop);
 extern int freeze_processes(void);
+extern int freeze_kernel_threads(void);
 extern void thaw_processes(void);
 
-static inline int try_to_freeze(void)
+static inline bool try_to_freeze(void)
 {
-	if (freezing(current)) {
-		refrigerator();
-		return 1;
-	} else
-		return 0;
+	might_sleep();
+	if (likely(!freezing(current)))
+		return false;
+	return __refrigerator(false);
 }
 
-extern bool freeze_task(struct task_struct *p, bool sig_only);
-extern void cancel_freezing(struct task_struct *p);
+extern bool freeze_task(struct task_struct *p);
+extern bool set_freezable(void);
 
 #ifdef CONFIG_CGROUP_FREEZER
-extern int cgroup_freezing_or_frozen(struct task_struct *task);
+extern bool cgroup_freezing(struct task_struct *task);
 #else /* !CONFIG_CGROUP_FREEZER */
-static inline int cgroup_freezing_or_frozen(struct task_struct *task)
+static inline bool cgroup_freezing(struct task_struct *task)
 {
-	return 0;
+	return false;
 }
 #endif /* !CONFIG_CGROUP_FREEZER */
 
@@ -79,33 +67,27 @@ static inline int cgroup_freezing_or_frozen(struct task_struct *task)
  * appropriately in case the child has exited before the freezing of tasks is
  * complete.  However, we don't want kernel threads to be frozen in unexpected
  * places, so we allow them to block freeze_processes() instead or to set
- * PF_NOFREEZE if needed and PF_FREEZER_SKIP is only set for userland vfork
- * parents.  Fortunately, in the ____call_usermodehelper() case the parent won't
- * really block freeze_processes(), since ____call_usermodehelper() (the child)
- * does a little before exec/exit and it can't be frozen before waking up the
- * parent.
+ * PF_NOFREEZE if needed. Fortunately, in the ____call_usermodehelper() case the
+ * parent won't really block freeze_processes(), since ____call_usermodehelper()
+ * (the child) does a little before exec/exit and it can't be frozen before
+ * waking up the parent.
  */
 
-/*
- * If the current task is a user space one, tell the freezer not to count it as
- * freezable.
- */
+
+/* Tell the freezer not to count the current task as freezable. */
 static inline void freezer_do_not_count(void)
 {
-	if (current->mm)
-		current->flags |= PF_FREEZER_SKIP;
+	current->flags |= PF_FREEZER_SKIP;
 }
 
 /*
- * If the current task is a user space one, tell the freezer to count it as
- * freezable again and try to freeze it.
+ * Tell the freezer to count the current task as freezable again and try to
+ * freeze it.
  */
 static inline void freezer_count(void)
 {
-	if (current->mm) {
-		current->flags &= ~PF_FREEZER_SKIP;
-		try_to_freeze();
-	}
+	current->flags &= ~PF_FREEZER_SKIP;
+	try_to_freeze();
 }
 
 /*
@@ -117,70 +99,93 @@ static inline int freezer_should_skip(struct task_struct *p)
 }
 
 /*
- * Tell the freezer that the current task should be frozen by it
+ * These macros are intended to be used whenever you want allow a task that's
+ * sleeping in TASK_UNINTERRUPTIBLE or TASK_KILLABLE state to be frozen. Note
+ * that neither return any clear indication of whether a freeze event happened
+ * while in this function.
  */
-static inline void set_freezable(void)
-{
-	current->flags &= ~PF_NOFREEZE;
-}
 
-/*
- * Tell the freezer that the current task should be frozen by it and that it
- * should send a fake signal to the task to freeze it.
- */
-static inline void set_freezable_with_signal(void)
-{
-	current->flags &= ~(PF_NOFREEZE | PF_FREEZER_NOSIG);
-}
+/* Like schedule(), but should not block the freezer. */
+#define freezable_schedule()						\
+({									\
+	freezer_do_not_count();						\
+	schedule();							\
+	freezer_count();						\
+})
+
+/* Like schedule_timeout_killable(), but should not block the freezer. */
+#define freezable_schedule_timeout_killable(timeout)			\
+({									\
+	long __retval;							\
+	freezer_do_not_count();						\
+	__retval = schedule_timeout_killable(timeout);			\
+	freezer_count();						\
+	__retval;							\
+})
 
 /*
- * Freezer-friendly wrappers around wait_event_interruptible() and
- * wait_event_interruptible_timeout(), originally defined in <linux/wait.h>
+ * Freezer-friendly wrappers around wait_event_interruptible(),
+ * wait_event_killable() and wait_event_interruptible_timeout(), originally
+ * defined in <linux/wait.h>
  */
 
+#define wait_event_freezekillable(wq, condition)			\
+({									\
+	int __retval;							\
+	freezer_do_not_count();						\
+	__retval = wait_event_killable(wq, (condition));		\
+	freezer_count();						\
+	__retval;							\
+})
+
 #define wait_event_freezable(wq, condition)				\
 ({									\
 	int __retval;							\
-	do {								\
+	for (;;) {							\
 		__retval = wait_event_interruptible(wq, 		\
 				(condition) || freezing(current));	\
-		if (__retval && !freezing(current))			\
+		if (__retval || (condition))				\
 			break;						\
-		else if (!(condition))					\
-			__retval = -ERESTARTSYS;			\
-	} while (try_to_freeze());					\
+		try_to_freeze();					\
+	}								\
 	__retval;							\
 })
 
-
 #define wait_event_freezable_timeout(wq, condition, timeout)		\
 ({									\
 	long __retval = timeout;					\
-	do {								\
+	for (;;) {							\
 		__retval = wait_event_interruptible_timeout(wq,		\
 				(condition) || freezing(current),	\
 				__retval); 				\
-	} while (try_to_freeze());					\
+		if (__retval <= 0 || (condition))			\
+			break;						\
+		try_to_freeze();					\
+	}								\
 	__retval;							\
 })
+
 #else /* !CONFIG_FREEZER */
-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 void refrigerator(void) {}
-static inline int freeze_processes(void) { BUG(); return 0; }
+static inline bool frozen(struct task_struct *p) { return false; }
+static inline bool freezing(struct task_struct *p) { return false; }
+static inline void __thaw_task(struct task_struct *t) {}
+
+static inline bool __refrigerator(bool check_kthr_stop) { return false; }
+static inline int freeze_processes(void) { return -ENOSYS; }
+static inline int freeze_kernel_threads(void) { return -ENOSYS; }
 static inline void thaw_processes(void) {}
 
-static inline int try_to_freeze(void) { return 0; }
+static inline bool try_to_freeze(void) { return false; }
 
 static inline void freezer_do_not_count(void) {}
 static inline void freezer_count(void) {}
 static inline int freezer_should_skip(struct task_struct *p) { return 0; }
 static inline void set_freezable(void) {}
-static inline void set_freezable_with_signal(void) {}
+
+#define freezable_schedule()  schedule()
+
+#define freezable_schedule_timeout_killable(timeout)			\
+	schedule_timeout_killable(timeout)
 
 #define wait_event_freezable(wq, condition)				\
 		wait_event_interruptible(wq, condition)
@@ -188,6 +193,9 @@ static inline void set_freezable_with_signal(void) {}
 #define wait_event_freezable_timeout(wq, condition, timeout)		\
 		wait_event_interruptible_timeout(wq, condition, timeout)
 
+#define wait_event_freezekillable(wq, condition)		\
+		wait_event_killable(wq, condition)
+
 #endif /* !CONFIG_FREEZER */
 
 #endif	/* FREEZER_H_INCLUDED */