Merge branch 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into pm-freezer

* 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits)
  freezer: fix wait_event_freezable/__thaw_task races
  freezer: kill unused set_freezable_with_signal()
  dmatest: don't use set_freezable_with_signal()
  usb_storage: don't use set_freezable_with_signal()
  freezer: remove unused @sig_only from freeze_task()
  freezer: use lock_task_sighand() in fake_signal_wake_up()
  freezer: restructure __refrigerator()
  freezer: fix set_freezable[_with_signal]() race
  freezer: remove should_send_signal() and update frozen()
  freezer: remove now unused TIF_FREEZE
  freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE
  cgroup_freezer: prepare for removal of TIF_FREEZE
  freezer: clean up freeze_processes() failure path
  freezer: kill PF_FREEZING
  freezer: test freezable conditions while holding freezer_lock
  freezer: make freezing indicate freeze condition in effect
  freezer: use dedicated lock instead of task_lock() + memory barrier
  freezer: don't distinguish nosig tasks on thaw
  freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks
  freezer: rename thaw_process() to __thaw_task() and simplify the implementation
  ...

1 files changed, 38 insertions, 70 deletions

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index a5386e3ee75..09570ac22be 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -5,71 +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)
-{
-	clear_tsk_thread_flag(p, TIF_FREEZE);
-}
-
-static inline bool should_send_signal(struct task_struct *p)
+static inline bool freezing(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 */
 
@@ -118,23 +105,6 @@ static inline int freezer_should_skip(struct task_struct *p)
 }
 
 /*
- * Tell the freezer that the current task should be frozen by it
- */
-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);
-}
-
-/*
  * Freezer-friendly wrappers around wait_event_interruptible(),
  * wait_event_killable() and wait_event_interruptible_timeout(), originally
  * defined in <linux/wait.h>
@@ -152,47 +122,45 @@ static inline void set_freezable_with_signal(void)
 #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 bool frozen(struct task_struct *p) { return false; }
+static inline bool freezing(struct task_struct *p) { return false; }
 
-static inline void refrigerator(void) {}
+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 wait_event_freezable(wq, condition)				\
 		wait_event_interruptible(wq, condition)