[PATCH] Cleanup patch for process freezing

1. Establish a simple API for process freezing defined in linux/include/sched.h:

   frozen(process)		Check for frozen process
   freezing(process)		Check if a process is being frozen
   freeze(process)		Tell a process to freeze (go to refrigerator)
   thaw_process(process)	Restart process
   frozen_process(process)	Process is frozen now

2. Remove all references to PF_FREEZE and PF_FROZEN from all
   kernel sources except sched.h

3. Fix numerous locations where try_to_freeze is manually done by a driver

4. Remove the argument that is no longer necessary from two function calls.

5. Some whitespace cleanup

6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
   cleared before setting PF_FROZEN, recalc_sigpending does not check
   PF_FROZEN).

This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!

Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

47 files changed, 126 insertions, 113 deletions

diff --git a/Documentation/power/kernel_threads.txt b/Documentation/power/kernel_threads.txt
index 60b548105edf..fb57784986b1 100644
--- a/Documentation/power/kernel_threads.txt
+++ b/Documentation/power/kernel_threads.txt
@@ -12,8 +12,7 @@ refrigerator. Code to do this looks like this:
         do {
                 hub_events();
                 wait_event_interruptible(khubd_wait, !list_empty(&hub_event_list));
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+                try_to_freeze();
         } while (!signal_pending(current));
 
 from drivers/usb/core/hub.c::hub_thread()
diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
index c7c3459fde43..4e1627cc5b51 100644
--- a/Documentation/power/swsusp.txt
+++ b/Documentation/power/swsusp.txt
@@ -164,8 +164,7 @@ place where the thread is safe to be frozen (no kernel semaphores
 should be held at that point and it must be safe to sleep there), and
 add:
 
-            if (current->flags & PF_FREEZE)
-                    refrigerator(PF_FREEZE);
+            try_to_freeze();
 
 If the thread is needed for writing the image to storage, you should
 instead set the PF_NOFREEZE process flag when creating the thread.
diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c
index d8d8f3d4304d..36a2dffc8ebd 100644
--- a/arch/frv/kernel/signal.c
+++ b/arch/frv/kernel/signal.c
@@ -536,10 +536,8 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
         if (!user_mode(regs))
                 return 1;
 
-        if (current->flags & PF_FREEZE) {
-                refrigerator(0);
+        if (try_to_freeze())
                 goto no_signal;
-        }
 
         if (!oldset)
                 oldset = &current->blocked;
diff --git a/arch/h8300/kernel/signal.c b/arch/h8300/kernel/signal.c
index a4799d633ef4..5aab87eae1f9 100644
--- a/arch/h8300/kernel/signal.c
+++ b/arch/h8300/kernel/signal.c
@@ -517,10 +517,8 @@ asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset)
         if ((regs->ccr & 0x10))
                 return 1;
 
-        if (current->flags & PF_FREEZE) {
-                refrigerator(0);
+        if (try_to_freeze())
                 goto no_signal;
-        }
 
         current->thread.esp0 = (unsigned long) regs;
 
diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 08540bc4ba3e..2451a3a99440 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -573,7 +573,7 @@ static int balanced_irq(void *unused)
         for ( ; ; ) {
                 set_current_state(TASK_INTERRUPTIBLE);
                 time_remaining = schedule_timeout(time_remaining);
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
                 if (time_after(jiffies,
                                 prev_balance_time+balanced_irq_interval)) {
                         do_irq_balance();
diff --git a/arch/i386/kernel/signal.c b/arch/i386/kernel/signal.c
index b9b8f4e20fad..ac5b1e975c5c 100644
--- a/arch/i386/kernel/signal.c
+++ b/arch/i386/kernel/signal.c
@@ -608,10 +608,8 @@ int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
         if (!user_mode(regs))
                 return 1;
 
-        if (current->flags & PF_FREEZE) {
-                refrigerator(0);
+        if (try_to_freeze)
                 goto no_signal;
-        }
 
         if (!oldset)
                 oldset = &current->blocked;
diff --git a/arch/m32r/kernel/signal.c b/arch/m32r/kernel/signal.c
index 50311eb07a24..5aef7e406ef5 100644
--- a/arch/m32r/kernel/signal.c
+++ b/arch/m32r/kernel/signal.c
@@ -371,10 +371,8 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
         if (!user_mode(regs))
                 return 1;
 
-        if (current->flags & PF_FREEZE) {
-                refrigerator(0);
+        if (try_to_freeze()) 
                 goto no_signal;
-        }
 
         if (!oldset)
                 oldset = &current->blocked;
diff --git a/arch/ppc/kernel/signal.c b/arch/ppc/kernel/signal.c
index 7c8437da09d5..8aaeb6f4e750 100644
--- a/arch/ppc/kernel/signal.c
+++ b/arch/ppc/kernel/signal.c
@@ -705,8 +705,7 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
         unsigned long frame, newsp;
         int signr, ret;
 
-        if (current->flags & PF_FREEZE) {
-                refrigerator(PF_FREEZE);
+        if (try_to_freeze()) {
                 signr = 0;
                 if (!signal_pending(current))
                         goto no_signal;
diff --git a/arch/x86_64/kernel/signal.c b/arch/x86_64/kernel/signal.c
index 98b7ba95d581..98590a989f3d 100644
--- a/arch/x86_64/kernel/signal.c
+++ b/arch/x86_64/kernel/signal.c
@@ -425,7 +425,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
         if (!user_mode(regs))
                 return 1;
 
-        if (try_to_freeze(0))
+        if (try_to_freeze())
                 goto no_signal;
 
         if (!oldset)
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 7f3d78de265c..7b838342f0a3 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1251,8 +1251,7 @@ static int kcdrwd(void *foobar)
                         VPRINTK("kcdrwd: wake up\n");
 
                         /* make swsusp happy with our thread */
-                        if (current->flags & PF_FREEZE)
-                                refrigerator(PF_FREEZE);
+                        try_to_freeze();
 
                         list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
                                 if (!pkt->sleep_time)
diff --git a/drivers/ieee1394/ieee1394_core.c b/drivers/ieee1394/ieee1394_core.c
index 2d9a9b74e687..629070b83a33 100644
--- a/drivers/ieee1394/ieee1394_core.c
+++ b/drivers/ieee1394/ieee1394_core.c
@@ -1041,10 +1041,8 @@ static int hpsbpkt_thread(void *__hi)
 
         while (1) {
                 if (down_interruptible(&khpsbpkt_sig)) {
-                        if (current->flags & PF_FREEZE) {
-                                refrigerator(0);
+                        if (try_to_freeze())
                                 continue;
-                        }
                         printk("khpsbpkt: received unexpected signal?!\n" );
                         break;
                 }
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c
index 32abb6dda888..9a46c3b44bf8 100644
--- a/drivers/ieee1394/nodemgr.c
+++ b/drivers/ieee1394/nodemgr.c
@@ -1510,7 +1510,7 @@ static int nodemgr_host_thread(void *__hi)
 
                 if (down_interruptible(&hi->reset_sem) ||
                     down_interruptible(&nodemgr_serialize)) {
-                        if (try_to_freeze(PF_FREEZE))
+                        if (try_to_freeze())
                                 continue;
                         printk("NodeMgr: received unexpected signal?!\n" );
                         break;
diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index e152d0fa0cdd..c77a82e46055 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -439,7 +439,7 @@ static int gameport_thread(void *nothing)
         do {
                 gameport_handle_events();
                 wait_event_interruptible(gameport_wait, !list_empty(&gameport_event_list));
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
         } while (!signal_pending(current));
 
         printk(KERN_DEBUG "gameport: kgameportd exiting\n");
diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index feab4970406e..341824c48529 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -344,7 +344,7 @@ static int serio_thread(void *nothing)
         do {
                 serio_handle_events();
                 wait_event_interruptible(serio_wait, !list_empty(&serio_event_list));
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
         } while (!signal_pending(current));
 
         printk(KERN_DEBUG "serio: kseriod exiting\n");
diff --git a/drivers/macintosh/therm_adt746x.c b/drivers/macintosh/therm_adt746x.c
index 5ba190ce14a0..c9ca1118e449 100644
--- a/drivers/macintosh/therm_adt746x.c
+++ b/drivers/macintosh/therm_adt746x.c
@@ -328,9 +328,7 @@ static int monitor_task(void *arg)
         struct thermostat* th = arg;
 
         while(!kthread_should_stop()) {
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
-
+                try_to_freeze();
                 msleep_interruptible(2000);
 
 #ifndef DEBUG
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0c6b5b6baff6..3802f7a17f16 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2976,8 +2976,7 @@ static int md_thread(void * arg)
                 wait_event_interruptible_timeout(thread->wqueue,
                                                  test_bit(THREAD_WAKEUP, &thread->flags),
                                                  thread->timeout);
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+                try_to_freeze();
 
                 clear_bit(THREAD_WAKEUP, &thread->flags);
 
diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index d6b7a9de471e..f11daae91cd4 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -391,8 +391,7 @@ static int dvb_frontend_thread(void *data)
                         break;
                 }
 
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+                try_to_freeze();
 
                 if (down_interruptible(&fepriv->sem))
                         break;
diff --git a/drivers/media/video/msp3400.c b/drivers/media/video/msp3400.c
index 1b7d38e96f14..b4ee9dfe6d42 100644
--- a/drivers/media/video/msp3400.c
+++ b/drivers/media/video/msp3400.c
@@ -750,8 +750,7 @@ static int msp34xx_sleep(struct msp3400c *msp, int timeout)
 #endif
                 }
         }
-        if (current->flags & PF_FREEZE)
-                refrigerator(PF_FREEZE);
+        try_to_freeze();
         remove_wait_queue(&msp->wq, &wait);
         return msp->restart;
 }
diff --git a/drivers/media/video/video-buf-dvb.c b/drivers/media/video/video-buf-dvb.c
index 5f870075b55e..15f5bb486963 100644
--- a/drivers/media/video/video-buf-dvb.c
+++ b/drivers/media/video/video-buf-dvb.c
@@ -62,8 +62,7 @@ static int videobuf_dvb_thread(void *data)
                         break;
                 if (kthread_should_stop())
                         break;
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+                try_to_freeze();
 
                 /* feed buffer data to demux */
                 if (buf->state == STATE_DONE)
diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c
index 047202c4d9a8..5a4a08a7c951 100644
--- a/drivers/net/8139too.c
+++ b/drivers/net/8139too.c
@@ -1606,7 +1606,7 @@ static int rtl8139_thread (void *data)
                 do {
                         timeout = interruptible_sleep_on_timeout (&tp->thr_wait, timeout);
                         /* make swsusp happy with our thread */
-                        try_to_freeze(PF_FREEZE);
+                        try_to_freeze();
                 } while (!signal_pending (current) && (timeout > 0));
 
                 if (signal_pending (current)) {
diff --git a/drivers/net/irda/sir_kthread.c b/drivers/net/irda/sir_kthread.c
index 18cea1099530..c65054364bca 100644
--- a/drivers/net/irda/sir_kthread.c
+++ b/drivers/net/irda/sir_kthread.c
@@ -135,8 +135,7 @@ static int irda_thread(void *startup)
                 remove_wait_queue(&irda_rq_queue.kick, &wait);
 
                 /* make swsusp happy with our thread */
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+                try_to_freeze();
 
                 run_irda_queue();
         }
diff --git a/drivers/net/irda/stir4200.c b/drivers/net/irda/stir4200.c
index 66f488c13717..15f207323d97 100644
--- a/drivers/net/irda/stir4200.c
+++ b/drivers/net/irda/stir4200.c
@@ -763,7 +763,7 @@ static int stir_transmit_thread(void *arg)
         {
 #ifdef CONFIG_PM
                 /* if suspending, then power off and wait */
-                if (unlikely(current->flags & PF_FREEZE)) {
+                if (unlikely(freezing(current))) {
                         if (stir->receiving)
                                 receive_stop(stir);
                         else
@@ -771,7 +771,7 @@ static int stir_transmit_thread(void *arg)
 
                         write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
 
-                        refrigerator(PF_FREEZE);
+                        refrigerator();
 
                         if (change_speed(stir, stir->speed))
                                 break;
diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
index fb10a2db63ad..d72e0385e4f2 100644
--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -2918,7 +2918,7 @@ static int airo_thread(void *data) {
                         flush_signals(current);
 
                 /* make swsusp happy with our thread */
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 if (test_bit(JOB_DIE, &ai->flags))
                         break;
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index d136b3c8fac9..48e4f04530d8 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -718,7 +718,7 @@ static int pccardd(void *__skt)
                 }
 
                 schedule();
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 if (!skt->thread)
                         break;
diff --git a/drivers/pnp/pnpbios/core.c b/drivers/pnp/pnpbios/core.c
index e939c93a931c..778a324028f4 100644
--- a/drivers/pnp/pnpbios/core.c
+++ b/drivers/pnp/pnpbios/core.c
@@ -182,7 +182,7 @@ static int pnp_dock_thread(void * unused)
                 msleep_interruptible(2000);
 
                 if(signal_pending(current)) {
-                        if (try_to_freeze(PF_FREEZE))
+                        if (try_to_freeze())
                                 continue;
                         break;
                 }
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d2d648ee8640..a8d879a85d04 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2808,7 +2808,7 @@ static int hub_thread(void *__unused)
         do {
                 hub_events();
                 wait_event_interruptible(khubd_wait, !list_empty(&hub_event_list)); 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
         } while (!signal_pending(current));
 
         pr_debug ("%s: khubd exiting\n", usbcore_name);
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 037a7f163822..a9be85103d23 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -1554,8 +1554,7 @@ static int sleep_thread(struct fsg_dev *fsg)
         rc = wait_event_interruptible(fsg->thread_wqh,
                         fsg->thread_wakeup_needed);
         fsg->thread_wakeup_needed = 0;
-        if (current->flags & PF_FREEZE)
-                refrigerator(PF_FREEZE);
+        try_to_freeze();
         return (rc ? -EINTR : 0);
 }
 
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 35c1ca6b5a8e..77e7fc258aa2 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -847,10 +847,8 @@ retry:
                 wait_event_interruptible_timeout(us->delay_wait,
                                 test_bit(US_FLIDX_DISCONNECTING, &us->flags),
                                 delay_use * HZ);
-                if (current->flags & PF_FREEZE) {
-                        refrigerator(PF_FREEZE);
+                if (try_to_freeze())
                         goto retry;
-                }
         }
 
         /* If the device is still connected, perform the scanning */
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index b460927ec32a..312cf3220f12 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -646,7 +646,7 @@ static int w1_control(void *data)
         while (!control_needs_exit || have_to_wait) {
                 have_to_wait = 0;
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
                 msleep_interruptible(w1_timeout * 1000);
 
                 if (signal_pending(current))
@@ -725,7 +725,7 @@ int w1_process(void *data)
         allow_signal(SIGTERM);
 
         while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
                 msleep_interruptible(w1_timeout * 1000);
 
                 if (signal_pending(current))
diff --git a/fs/afs/kafsasyncd.c b/fs/afs/kafsasyncd.c
index 6fc88ae8ad94..7ac07d0d47b9 100644
--- a/fs/afs/kafsasyncd.c
+++ b/fs/afs/kafsasyncd.c
@@ -116,7 +116,7 @@ static int kafsasyncd(void *arg)
                 remove_wait_queue(&kafsasyncd_sleepq, &myself);
                 set_current_state(TASK_RUNNING);
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 afs_discard_my_signals();
diff --git a/fs/afs/kafstimod.c b/fs/afs/kafstimod.c
index 86e710dd057e..65bc05ab8182 100644
--- a/fs/afs/kafstimod.c
+++ b/fs/afs/kafstimod.c
@@ -91,7 +91,7 @@ static int kafstimod(void *arg)
                         complete_and_exit(&kafstimod_dead, 0);
                 }
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 afs_discard_my_signals();
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index 1e6f2e2ad4a3..5e7b43949517 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -167,7 +167,7 @@ loop:
         }
 
         wake_up(&journal->j_wait_done_commit);
-        if (current->flags & PF_FREEZE) {
+        if (freezing(current)) {
                 /*
                  * The simpler the better. Flushing journal isn't a
                  * good idea, because that depends on threads that may
@@ -175,7 +175,7 @@ loop:
                  */
                 jbd_debug(1, "Now suspending kjournald\n");
                 spin_unlock(&journal->j_state_lock);
-                refrigerator(PF_FREEZE);
+                refrigerator();
                 spin_lock(&journal->j_state_lock);
         } else {
                 /*
diff --git a/fs/jfs/jfs_logmgr.c b/fs/jfs/jfs_logmgr.c
index 7c8387ed4192..79d07624bfe1 100644
--- a/fs/jfs/jfs_logmgr.c
+++ b/fs/jfs/jfs_logmgr.c
@@ -2359,9 +2359,9 @@ int jfsIOWait(void *arg)
                         lbmStartIO(bp);
                         spin_lock_irq(&log_redrive_lock);
                 }
-                if (current->flags & PF_FREEZE) {
+                if (freezing(current)) {
                         spin_unlock_irq(&log_redrive_lock);
-                        refrigerator(PF_FREEZE);
+                        refrigerator();
                 } else {
                         add_wait_queue(&jfs_IO_thread_wait, &wq);
                         set_current_state(TASK_INTERRUPTIBLE);
diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index 8cbaaff1d5fa..121c981ff453 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/fs/jfs/jfs_txnmgr.c
@@ -2788,9 +2788,9 @@ int jfs_lazycommit(void *arg)
                 /* In case a wakeup came while all threads were active */
                 jfs_commit_thread_waking = 0;
 
-                if (current->flags & PF_FREEZE) {
+                if (freezing(current)) {
                         LAZY_UNLOCK(flags);
-                        refrigerator(PF_FREEZE);
+                        refrigerator();
                 } else {
                         DECLARE_WAITQUEUE(wq, current);
 
@@ -2987,9 +2987,9 @@ int jfs_sync(void *arg)
                 /* Add anon_list2 back to anon_list */
                 list_splice_init(&TxAnchor.anon_list2, &TxAnchor.anon_list);
 
-                if (current->flags & PF_FREEZE) {
+                if (freezing(current)) {
                         TXN_UNLOCK();
-                        refrigerator(PF_FREEZE);
+                        refrigerator();
                 } else {
                         DECLARE_WAITQUEUE(wq, current);
 
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index fd77ed1d710d..14b3ce87fa29 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -313,7 +313,7 @@ static int nlm_wait_on_grace(wait_queue_head_t *queue)
         prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
         if (!signalled ()) {
                 schedule_timeout(NLMCLNT_GRACE_WAIT);
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
                 if (!signalled ())
                         status = 0;
         }
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index c60e69431e11..df0cba239dd5 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -1771,9 +1771,9 @@ xfsbufd(
 
         INIT_LIST_HEAD(&tmp);
         do {
-                if (unlikely(current->flags & PF_FREEZE)) {
+                if (unlikely(freezing(current))) {
                         xfsbufd_force_sleep = 1;
-                        refrigerator(PF_FREEZE);
+                        refrigerator();
                 } else {
                         xfsbufd_force_sleep = 0;
                 }
diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c
index 5fe9af38aa20..f6dd7de25927 100644
--- a/fs/xfs/linux-2.6/xfs_super.c
+++ b/fs/xfs/linux-2.6/xfs_super.c
@@ -483,7 +483,7 @@ xfssyncd(
                 set_current_state(TASK_INTERRUPTIBLE);
                 timeleft = schedule_timeout(timeleft);
                 /* swsusp */
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
                 if (vfsp->vfs_flag & VFS_UMOUNT)
                         break;
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2c69682b0444..e7fd09b0557f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1245,33 +1245,78 @@ extern void normalize_rt_tasks(void);
 
 #endif
 
-/* try_to_freeze
- *
- * Checks whether we need to enter the refrigerator
- * and returns 1 if we did so.
- */
 #ifdef CONFIG_PM
-extern void refrigerator(unsigned long);
+/*
+ * Check if a process has been frozen
+ */
+static inline int 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 p->flags & PF_FREEZE;
+}
+
+/*
+ * Request that a process be frozen
+ * FIXME: SMP problem. We may not modify other process' flags!
+ */
+static inline void freeze(struct task_struct *p)
+{
+        p->flags |= PF_FREEZE;
+}
+
+/*
+ * Wake up a frozen process
+ */
+static inline int thaw_process(struct task_struct *p)
+{
+        if (frozen(p)) {
+                p->flags &= ~PF_FROZEN;
+                wake_up_process(p);
+                return 1;
+        }
+        return 0;
+}
+
+/*
+ * freezing is complete, mark process as frozen
+ */
+static inline void frozen_process(struct task_struct *p)
+{
+        p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
+}
+
+extern void refrigerator(void);
 extern int freeze_processes(void);
 extern void thaw_processes(void);
 
-static inline int try_to_freeze(unsigned long refrigerator_flags)
+static inline int try_to_freeze(void)
 {
-        if (unlikely(current->flags & PF_FREEZE)) {
-                refrigerator(refrigerator_flags);
+        if (freezing(current)) {
+                refrigerator();
                 return 1;
         } else
                 return 0;
 }
 #else
-static inline void refrigerator(unsigned long flag) {}
+static inline int frozen(struct task_struct *p) { return 0; }
+static inline int freezing(struct task_struct *p) { return 0; }
+static inline void freeze(struct task_struct *p) { BUG(); }
+static inline int thaw_process(struct task_struct *p) { return 1; }
+static inline void frozen_process(struct task_struct *p) { BUG(); }
+
+static inline void refrigerator(void) {}
 static inline int freeze_processes(void) { BUG(); return 0; }
 static inline void thaw_processes(void) {}
 
-static inline int try_to_freeze(unsigned long refrigerator_flags)
-{
-        return 0;
-}
+static inline int try_to_freeze(void) { return 0; }
+
 #endif /* CONFIG_PM */
 #endif /* __KERNEL__ */
 
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 78d92dc6a1ed..0a086640bcfc 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -32,7 +32,7 @@ static inline int freezeable(struct task_struct * p)
 }
 
 /* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(unsigned long flag)
+void refrigerator(void)
 {
         /* Hmm, should we be allowed to suspend when there are realtime
            processes around? */
@@ -41,14 +41,13 @@ void refrigerator(unsigned long flag)
         current->state = TASK_UNINTERRUPTIBLE;
         pr_debug("%s entered refrigerator\n", current->comm);
         printk("=");
-        current->flags &= ~PF_FREEZE;
 
+        frozen_process(current);
         spin_lock_irq(&current->sighand->siglock);
         recalc_sigpending(); /* We sent fake signal, clean it up */
         spin_unlock_irq(&current->sighand->siglock);
 
-        current->flags |= PF_FROZEN;
-        while (current->flags & PF_FROZEN)
+        while (frozen(current))
                 schedule();
         pr_debug("%s left refrigerator\n", current->comm);
         current->state = save;
@@ -57,10 +56,10 @@ void refrigerator(unsigned long flag)
 /* 0 = success, else # of processes that we failed to stop */
 int freeze_processes(void)
 {
-       int todo;
-       unsigned long start_time;
+        int todo;
+        unsigned long start_time;
         struct task_struct *g, *p;
-        
+
         printk( "Stopping tasks: " );
         start_time = jiffies;
         do {
@@ -70,14 +69,12 @@ int freeze_processes(void)
                         unsigned long flags;
                         if (!freezeable(p))
                                 continue;
-                        if ((p->flags & PF_FROZEN) ||
+                        if ((frozen(p)) ||
                             (p->state == TASK_TRACED) ||
                             (p->state == TASK_STOPPED))
                                 continue;
 
-                        /* FIXME: smp problem here: we may not access other process' flags
-                           without locking */
-                        p->flags |= PF_FREEZE;
+                        freeze(p);
                         spin_lock_irqsave(&p->sighand->siglock, flags);
                         signal_wake_up(p, 0);
                         spin_unlock_irqrestore(&p->sighand->siglock, flags);
@@ -91,7 +88,7 @@ int freeze_processes(void)
                         return todo;
                 }
         } while(todo);
-        
+
         printk( "|\n" );
         BUG_ON(in_atomic());
         return 0;
@@ -106,10 +103,7 @@ void thaw_processes(void)
         do_each_thread(g, p) {
                 if (!freezeable(p))
                         continue;
-                if (p->flags & PF_FROZEN) {
-                        p->flags &= ~PF_FROZEN;
-                        wake_up_process(p);
-                } else
+                if (!thaw_process(p))
                         printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
         } while_each_thread(g, p);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 76080d142e3d..6fa9ea4ae44c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4174,8 +4174,7 @@ static int migration_thread(void * data)
                 struct list_head *head;
                 migration_req_t *req;
 
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+                try_to_freeze();
 
                 spin_lock_irq(&rq->lock);
 
diff --git a/kernel/signal.c b/kernel/signal.c
index d1258729a5f9..ca1186eef938 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -213,7 +213,7 @@ static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked)
 fastcall void recalc_sigpending_tsk(struct task_struct *t)
 {
         if (t->signal->group_stop_count > 0 ||
-            (t->flags & PF_FREEZE) ||
+            (freezing(t)) ||
             PENDING(&t->pending, &t->blocked) ||
             PENDING(&t->signal->shared_pending, &t->blocked))
                 set_tsk_thread_flag(t, TIF_SIGPENDING);
@@ -2231,8 +2231,7 @@ sys_rt_sigtimedwait(const sigset_t __user *uthese,
                         current->state = TASK_INTERRUPTIBLE;
                         timeout = schedule_timeout(timeout);
 
-                        if (current->flags & PF_FREEZE)
-                                refrigerator(PF_FREEZE);
+                        try_to_freeze();
                         spin_lock_irq(&current->sighand->siglock);
                         sig = dequeue_signal(current, &these, &info);
                         current->blocked = current->real_blocked;
diff --git a/mm/pdflush.c b/mm/pdflush.c
index 38ce279cc8cd..d6781951267e 100644
--- a/mm/pdflush.c
+++ b/mm/pdflush.c
@@ -105,7 +105,7 @@ static int __pdflush(struct pdflush_work *my_work)
                 spin_unlock_irq(&pdflush_lock);
 
                 schedule();
-                if (try_to_freeze(PF_FREEZE)) {
+                if (try_to_freeze()) {
                         spin_lock_irq(&pdflush_lock);
                         continue;
                 }
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4b8e62a19370..1fa312a8db77 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1216,8 +1216,8 @@ static int kswapd(void *p)
         order = 0;
         for ( ; ; ) {
                 unsigned long new_order;
-                if (current->flags & PF_FREEZE)
-                        refrigerator(PF_FREEZE);
+
+                try_to_freeze();
 
                 prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
                 new_order = pgdat->kswapd_max_order;
diff --git a/net/rxrpc/krxiod.c b/net/rxrpc/krxiod.c
index 2b537f425a17..dada34a77b21 100644
--- a/net/rxrpc/krxiod.c
+++ b/net/rxrpc/krxiod.c
@@ -138,7 +138,7 @@ static int rxrpc_krxiod(void *arg)
 
                 _debug("### End Work");
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 rxrpc_discard_my_signals();
diff --git a/net/rxrpc/krxsecd.c b/net/rxrpc/krxsecd.c
index 6020c89d9228..1aadd026d354 100644
--- a/net/rxrpc/krxsecd.c
+++ b/net/rxrpc/krxsecd.c
@@ -107,7 +107,7 @@ static int rxrpc_krxsecd(void *arg)
 
                 _debug("### End Inbound Calls");
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 rxrpc_discard_my_signals();
diff --git a/net/rxrpc/krxtimod.c b/net/rxrpc/krxtimod.c
index 249c2b0290bb..3ac81cdd1211 100644
--- a/net/rxrpc/krxtimod.c
+++ b/net/rxrpc/krxtimod.c
@@ -90,7 +90,7 @@ static int krxtimod(void *arg)
                         complete_and_exit(&krxtimod_dead, 0);
                 }
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 /* discard pending signals */
                 rxrpc_discard_my_signals();
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 05907035bc96..56db8f13e6cb 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1185,8 +1185,8 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
         arg->page_len = (pages-2)*PAGE_SIZE;
         arg->len = (pages-1)*PAGE_SIZE;
         arg->tail[0].iov_len = 0;
-        
-        try_to_freeze(PF_FREEZE);
+
+        try_to_freeze();
         if (signalled())
                 return -EINTR;
 
@@ -1227,7 +1227,7 @@ svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
 
                 schedule_timeout(timeout);
 
-                try_to_freeze(PF_FREEZE);
+                try_to_freeze();
 
                 spin_lock_bh(&serv->sv_lock);
                 remove_wait_queue(&rqstp->rq_wait, &wait);