15 files changed, 37 insertions, 39 deletions

diff --git a/Documentation/power/freezing-of-tasks.txt b/Documentation/power/freezing-of-tasks.txt
index 587e0828053f..3ab9fbd2800a 100644
--- a/Documentation/power/freezing-of-tasks.txt
+++ b/Documentation/power/freezing-of-tasks.txt
@@ -21,7 +21,7 @@ freeze_processes() (defined in kernel/power/process.c) is called.  It executes
 try_to_freeze_tasks() that sets TIF_FREEZE for all of the freezable tasks and
 either wakes them up, if they are kernel threads, or sends fake signals to them,
 if they are user space processes.  A task that has TIF_FREEZE set, should react
-to it by calling the function called refrigerator() (defined in
+to it by calling the function called __refrigerator() (defined in
 kernel/freezer.c), which sets the task's PF_FROZEN flag, changes its state
 to TASK_UNINTERRUPTIBLE and makes it loop until PF_FROZEN is cleared for it.
 Then, we say that the task is 'frozen' and therefore the set of functions
@@ -29,10 +29,10 @@ handling this mechanism is referred to as 'the freezer' (these functions are
 defined in kernel/power/process.c, kernel/freezer.c & include/linux/freezer.h).
 User space processes are generally frozen before kernel threads.
 
-It is not recommended to call refrigerator() directly.  Instead, it is
-recommended to use the try_to_freeze() function (defined in
-include/linux/freezer.h), that checks the task's TIF_FREEZE flag and makes the
-task enter refrigerator() if the flag is set.
+__refrigerator() must not be called directly.  Instead, use the
+try_to_freeze() function (defined in include/linux/freezer.h), that checks
+the task's TIF_FREEZE flag and makes the task enter __refrigerator() if the
+flag is set.
 
 For user space processes try_to_freeze() is called automatically from the
 signal-handling code, but the freezable kernel threads need to call it
@@ -61,7 +61,7 @@ wait_event_freezable() and wait_event_freezable_timeout() macros.
 After the system memory state has been restored from a hibernation image and
 devices have been reinitialized, the function thaw_processes() is called in
 order to clear the PF_FROZEN flag for each frozen task.  Then, the tasks that
-have been frozen leave refrigerator() and continue running.
+have been frozen leave __refrigerator() and continue running.
 
 III. Which kernel threads are freezable?
 
diff --git a/drivers/net/irda/stir4200.c b/drivers/net/irda/stir4200.c
index 41c96b3d8152..e880c79d7bd8 100644
--- a/drivers/net/irda/stir4200.c
+++ b/drivers/net/irda/stir4200.c
@@ -750,7 +750,7 @@ static int stir_transmit_thread(void *arg)
 
                         write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
 
-                        refrigerator();
+                        try_to_freeze();
 
                         if (change_speed(stir, stir->speed))
                                 break;
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c
index 7ec14097fef1..98ab240072e5 100644
--- a/fs/btrfs/async-thread.c
+++ b/fs/btrfs/async-thread.c
@@ -340,7 +340,7 @@ again:
                 if (freezing(current)) {
                         worker->working = 0;
                         spin_unlock_irq(&worker->lock);
-                        refrigerator();
+                        try_to_freeze();
                 } else {
                         spin_unlock_irq(&worker->lock);
                         if (!kthread_should_stop()) {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 62afe5c5694e..622654fe051f 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1579,9 +1579,7 @@ static int cleaner_kthread(void *arg)
                         btrfs_run_defrag_inodes(root->fs_info);
                 }
 
-                if (freezing(current)) {
-                        refrigerator();
-                } else {
+                if (!try_to_freeze()) {
                         set_current_state(TASK_INTERRUPTIBLE);
                         if (!kthread_should_stop())
                                 schedule();
@@ -1635,9 +1633,7 @@ sleep:
                 wake_up_process(root->fs_info->cleaner_kthread);
                 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
 
-                if (freezing(current)) {
-                        refrigerator();
-                } else {
+                if (!try_to_freeze()) {
                         set_current_state(TASK_INTERRUPTIBLE);
                         if (!kthread_should_stop() &&
                             !btrfs_transaction_blocked(root->fs_info))
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9953d80145ad..877350ef0253 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2882,8 +2882,7 @@ cont_thread:
                 }
                 mutex_unlock(&eli->li_list_mtx);
 
-                if (freezing(current))
-                        refrigerator();
+                try_to_freeze();
 
                 cur = jiffies;
                 if ((time_after_eq(cur, next_wakeup)) ||
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 598646434362..8154d42e4647 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -951,8 +951,8 @@ int gfs2_logd(void *data)
                         wake_up(&sdp->sd_log_waitq);
 
                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
-                if (freezing(current))
-                        refrigerator();
+
+                try_to_freeze();
 
                 do {
                         prepare_to_wait(&sdp->sd_logd_waitq, &wait,
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 7e528dc14f85..d49669e92652 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -1427,8 +1427,8 @@ int gfs2_quotad(void *data)
                 /* Check for & recover partially truncated inodes */
                 quotad_check_trunc_list(sdp);
 
-                if (freezing(current))
-                        refrigerator();
+                try_to_freeze();
+
                 t = min(quotad_timeo, statfs_timeo);
 
                 prepare_to_wait(&sdp->sd_quota_wait, &wait, TASK_INTERRUPTIBLE);
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index fea8dd661d2b..a96cff0c5f1d 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -166,7 +166,7 @@ loop:
                  */
                 jbd_debug(1, "Now suspending kjournald\n");
                 spin_unlock(&journal->j_state_lock);
-                refrigerator();
+                try_to_freeze();
                 spin_lock(&journal->j_state_lock);
         } else {
                 /*
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 0fa0123151d3..c0a5f9f1b127 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -173,7 +173,7 @@ loop:
                  */
                 jbd_debug(1, "Now suspending kjournald2\n");
                 write_unlock(&journal->j_state_lock);
-                refrigerator();
+                try_to_freeze();
                 write_lock(&journal->j_state_lock);
         } else {
                 /*
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index cc5f811ed383..2eb952c41a69 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2349,7 +2349,7 @@ int jfsIOWait(void *arg)
 
                 if (freezing(current)) {
                         spin_unlock_irq(&log_redrive_lock);
-                        refrigerator();
+                        try_to_freeze();
                 } else {
                         set_current_state(TASK_INTERRUPTIBLE);
                         spin_unlock_irq(&log_redrive_lock);
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index af9606057dde..bb8b661bcc50 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -2800,7 +2800,7 @@ int jfs_lazycommit(void *arg)
 
                 if (freezing(current)) {
                         LAZY_UNLOCK(flags);
-                        refrigerator();
+                        try_to_freeze();
                 } else {
                         DECLARE_WAITQUEUE(wq, current);
 
@@ -2994,7 +2994,7 @@ int jfs_sync(void *arg)
 
                 if (freezing(current)) {
                         TXN_UNLOCK();
-                        refrigerator();
+                        try_to_freeze();
                 } else {
                         set_current_state(TASK_INTERRUPTIBLE);
                         TXN_UNLOCK();
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index bb24ab6c282f..0e72ad6f22aa 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -2470,7 +2470,7 @@ static int nilfs_segctor_thread(void *arg)
 
         if (freezing(current)) {
                 spin_unlock(&sci->sc_state_lock);
-                refrigerator();
+                try_to_freeze();
                 spin_lock(&sci->sc_state_lock);
         } else {
                 DEFINE_WAIT(wait);
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index cf0ac056815f..018829936d6d 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1703,7 +1703,7 @@ xfsbufd(
 
                 if (unlikely(freezing(current))) {
                         set_bit(XBT_FORCE_SLEEP, &target->bt_flags);
-                        refrigerator();
+                        try_to_freeze();
                 } else {
                         clear_bit(XBT_FORCE_SLEEP, &target->bt_flags);
                 }
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index a5386e3ee756..7a9427e9fe47 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -47,18 +47,17 @@ 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 refrigerator(void);
+extern bool __refrigerator(void);
 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();
 }
 
 extern bool freeze_task(struct task_struct *p, bool sig_only);
@@ -181,12 +180,12 @@ 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 bool __refrigerator(void) { 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) {}
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 3f460104a9d6..732f14f5944f 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -23,10 +23,11 @@ static inline void frozen_process(void)
 }
 
 /* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(void)
+bool __refrigerator(void)
 {
         /* Hmm, should we be allowed to suspend when there are realtime
            processes around? */
+        bool was_frozen = false;
         long save;
 
         task_lock(current);
@@ -35,7 +36,7 @@ void refrigerator(void)
                 task_unlock(current);
         } else {
                 task_unlock(current);
-                return;
+                return was_frozen;
         }
         save = current->state;
         pr_debug("%s entered refrigerator\n", current->comm);
@@ -51,6 +52,7 @@ void refrigerator(void)
                 set_current_state(TASK_UNINTERRUPTIBLE);
                 if (!frozen(current))
                         break;
+                was_frozen = true;
                 schedule();
         }
 
@@ -65,8 +67,10 @@ void refrigerator(void)
          * synchronization which depends on ordered task state change.
          */
         set_current_state(save);
+
+        return was_frozen;
 }
-EXPORT_SYMBOL(refrigerator);
+EXPORT_SYMBOL(__refrigerator);
 
 static void fake_signal_wake_up(struct task_struct *p)
 {