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-rw-r--r--fs/afs/kafstimod.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/fs/afs/kafstimod.c b/fs/afs/kafstimod.c
new file mode 100644
index 00000000000..86e710dd057
--- /dev/null
+++ b/fs/afs/kafstimod.c
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+/* kafstimod.c: AFS timeout daemon
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include "cell.h"
+#include "volume.h"
+#include "kafstimod.h"
+#include <asm/errno.h>
+#include "internal.h"
+
+static DECLARE_COMPLETION(kafstimod_alive);
+static DECLARE_COMPLETION(kafstimod_dead);
+static DECLARE_WAIT_QUEUE_HEAD(kafstimod_sleepq);
+static int kafstimod_die;
+
+static LIST_HEAD(kafstimod_list);
+static DEFINE_SPINLOCK(kafstimod_lock);
+
+static int kafstimod(void *arg);
+
+/*****************************************************************************/
+/*
+ * start the timeout daemon
+ */
+int afs_kafstimod_start(void)
+{
+ int ret;
+
+ ret = kernel_thread(kafstimod, NULL, 0);
+ if (ret < 0)
+ return ret;
+
+ wait_for_completion(&kafstimod_alive);
+
+ return ret;
+} /* end afs_kafstimod_start() */
+
+/*****************************************************************************/
+/*
+ * stop the timeout daemon
+ */
+void afs_kafstimod_stop(void)
+{
+ /* get rid of my daemon */
+ kafstimod_die = 1;
+ wake_up(&kafstimod_sleepq);
+ wait_for_completion(&kafstimod_dead);
+
+} /* end afs_kafstimod_stop() */
+
+/*****************************************************************************/
+/*
+ * timeout processing daemon
+ */
+static int kafstimod(void *arg)
+{
+ struct afs_timer *timer;
+
+ DECLARE_WAITQUEUE(myself, current);
+
+ printk("kAFS: Started kafstimod %d\n", current->pid);
+
+ daemonize("kafstimod");
+
+ complete(&kafstimod_alive);
+
+ /* loop around looking for things to attend to */
+ loop:
+ set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&kafstimod_sleepq, &myself);
+
+ for (;;) {
+ unsigned long jif;
+ signed long timeout;
+
+ /* deal with the server being asked to die */
+ if (kafstimod_die) {
+ remove_wait_queue(&kafstimod_sleepq, &myself);
+ _leave("");
+ complete_and_exit(&kafstimod_dead, 0);
+ }
+
+ try_to_freeze(PF_FREEZE);
+
+ /* discard pending signals */
+ afs_discard_my_signals();
+
+ /* work out the time to elapse before the next event */
+ spin_lock(&kafstimod_lock);
+ if (list_empty(&kafstimod_list)) {
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ }
+ else {
+ timer = list_entry(kafstimod_list.next,
+ struct afs_timer, link);
+ timeout = timer->timo_jif;
+ jif = jiffies;
+
+ if (time_before_eq((unsigned long) timeout, jif))
+ goto immediate;
+
+ else {
+ timeout = (long) timeout - (long) jiffies;
+ }
+ }
+ spin_unlock(&kafstimod_lock);
+
+ schedule_timeout(timeout);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+
+ /* the thing on the front of the queue needs processing
+ * - we come here with the lock held and timer pointing to the expired
+ * entry
+ */
+ immediate:
+ remove_wait_queue(&kafstimod_sleepq, &myself);
+ set_current_state(TASK_RUNNING);
+
+ _debug("@@@ Begin Timeout of %p", timer);
+
+ /* dequeue the timer */
+ list_del_init(&timer->link);
+ spin_unlock(&kafstimod_lock);
+
+ /* call the timeout function */
+ timer->ops->timed_out(timer);
+
+ _debug("@@@ End Timeout");
+ goto loop;
+
+} /* end kafstimod() */
+
+/*****************************************************************************/
+/*
+ * (re-)queue a timer
+ */
+void afs_kafstimod_add_timer(struct afs_timer *timer, unsigned long timeout)
+{
+ struct afs_timer *ptimer;
+ struct list_head *_p;
+
+ _enter("%p,%lu", timer, timeout);
+
+ spin_lock(&kafstimod_lock);
+
+ list_del(&timer->link);
+
+ /* the timer was deferred or reset - put it back in the queue at the
+ * right place */
+ timer->timo_jif = jiffies + timeout;
+
+ list_for_each(_p, &kafstimod_list) {
+ ptimer = list_entry(_p, struct afs_timer, link);
+ if (time_before(timer->timo_jif, ptimer->timo_jif))
+ break;
+ }
+
+ list_add_tail(&timer->link, _p); /* insert before stopping point */
+
+ spin_unlock(&kafstimod_lock);
+
+ wake_up(&kafstimod_sleepq);
+
+ _leave("");
+} /* end afs_kafstimod_add_timer() */
+
+/*****************************************************************************/
+/*
+ * dequeue a timer
+ * - returns 0 if the timer was deleted or -ENOENT if it wasn't queued
+ */
+int afs_kafstimod_del_timer(struct afs_timer *timer)
+{
+ int ret = 0;
+
+ _enter("%p", timer);
+
+ spin_lock(&kafstimod_lock);
+
+ if (list_empty(&timer->link))
+ ret = -ENOENT;
+ else
+ list_del_init(&timer->link);
+
+ spin_unlock(&kafstimod_lock);
+
+ wake_up(&kafstimod_sleepq);
+
+ _leave(" = %d", ret);
+ return ret;
+} /* end afs_kafstimod_del_timer() */