[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>

diff --git a/Documentation/power/kernel_threads.txt b/Documentation/power/kernel_threads.txt
index 60b5481..fb57784 100644 (file)
--- 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 c7c3459..4e1627c 100644 (file)
--- 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 d8d8f3d..36a2dff 100644 (file)
--- 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 a4799d6..5aab87e 100644 (file)
--- 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 08540bc..2451a3a 100644 (file)
--- 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 b9b8f4e..ac5b1e9 100644 (file)
--- 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 50311eb..5aef7e4 100644 (file)
--- 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 7c8437d..8aaeb6f 100644 (file)
--- 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 98b7ba9..98590a9 100644 (file)
--- 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 7f3d78d..7b83834 100644 (file)
--- 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 2d9a9b7..629070b 100644 (file)
--- 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 32abb6d..9a46c3b 100644 (file)
--- 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 e152d0f..c77a82e 100644 (file)
--- 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 feab497..341824c 100644 (file)
--- 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 5ba190c..c9ca111 100644 (file)
--- 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 0c6b5b6..3802f7a 100644 (file)
--- 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 d6b7a9d..f11daae 100644 (file)
--- 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 1b7d38e..b4ee9df 100644 (file)
--- 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 5f87007..15f5bb4 100644 (file)
--- 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 047202c..5a4a08a 100644 (file)
--- 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 18cea10..c650543 100644 (file)
--- 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 66f488c..15f2073 100644 (file)
--- 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 fb10a2d..d72e038 100644 (file)
--- 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 d136b3c..48e4f04 100644 (file)
--- 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 e939c93..778a324 100644 (file)
--- 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 d2d648e..a8d879a 100644 (file)
--- 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 037a7f1..a9be851 100644 (file)
--- 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 35c1ca6..77e7fc2 100644 (file)
--- 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 b460927..312cf32 100644 (file)
--- 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 6fc88ae..7ac07d0 100644 (file)
--- 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 86e710d..65bc05a 100644 (file)
--- 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 1e6f2e2..5e7b439 100644 (file)
--- 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 7c8387e..79d0762 100644 (file)
--- 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 8cbaaff..121c981 100644 (file)
--- 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 fd77ed1..14b3ce8 100644 (file)
--- 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 c60e694..df0cba2 100644 (file)
--- 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 5fe9af3..f6dd7de 100644 (file)
--- 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 2c69682..e7fd09b 100644 (file)
--- 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 78d92dc..0a08664 100644 (file)
--- 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 76080d1..6fa9ea4 100644 (file)
--- 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 d125872..ca1186e 100644 (file)
--- 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 38ce279..d678195 100644 (file)
--- 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 4b8e62a..1fa312a 100644 (file)
--- 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 2b537f4..dada34a 100644 (file)
--- 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 6020c89..1aadd02 100644 (file)
--- 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 249c2b0..3ac81cd 100644 (file)
--- 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 0590703..56db8f1 100644 (file)
--- 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);