1 /* kafstimod.c: AFS timeout daemon
3 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/sched.h>
15 #include <linux/completion.h>
18 #include "kafstimod.h"
19 #include <asm/errno.h>
22 static DECLARE_COMPLETION(kafstimod_alive);
23 static DECLARE_COMPLETION(kafstimod_dead);
24 static DECLARE_WAIT_QUEUE_HEAD(kafstimod_sleepq);
25 static int kafstimod_die;
27 static LIST_HEAD(kafstimod_list);
28 static DEFINE_SPINLOCK(kafstimod_lock);
30 static int kafstimod(void *arg);
32 /*****************************************************************************/
34 * start the timeout daemon
36 int afs_kafstimod_start(void)
40 ret = kernel_thread(kafstimod, NULL, 0);
44 wait_for_completion(&kafstimod_alive);
47 } /* end afs_kafstimod_start() */
49 /*****************************************************************************/
51 * stop the timeout daemon
53 void afs_kafstimod_stop(void)
55 /* get rid of my daemon */
57 wake_up(&kafstimod_sleepq);
58 wait_for_completion(&kafstimod_dead);
60 } /* end afs_kafstimod_stop() */
62 /*****************************************************************************/
64 * timeout processing daemon
66 static int kafstimod(void *arg)
68 struct afs_timer *timer;
70 DECLARE_WAITQUEUE(myself, current);
72 printk("kAFS: Started kafstimod %d\n", current->pid);
74 daemonize("kafstimod");
76 complete(&kafstimod_alive);
78 /* loop around looking for things to attend to */
80 set_current_state(TASK_INTERRUPTIBLE);
81 add_wait_queue(&kafstimod_sleepq, &myself);
87 /* deal with the server being asked to die */
89 remove_wait_queue(&kafstimod_sleepq, &myself);
91 complete_and_exit(&kafstimod_dead, 0);
94 /* discard pending signals */
95 afs_discard_my_signals();
97 /* work out the time to elapse before the next event */
98 spin_lock(&kafstimod_lock);
99 if (list_empty(&kafstimod_list)) {
100 timeout = MAX_SCHEDULE_TIMEOUT;
103 timer = list_entry(kafstimod_list.next,
104 struct afs_timer, link);
105 timeout = timer->timo_jif;
108 if (time_before_eq((unsigned long) timeout, jif))
112 timeout = (long) timeout - (long) jiffies;
115 spin_unlock(&kafstimod_lock);
117 schedule_timeout(timeout);
119 set_current_state(TASK_INTERRUPTIBLE);
122 /* the thing on the front of the queue needs processing
123 * - we come here with the lock held and timer pointing to the expired
127 remove_wait_queue(&kafstimod_sleepq, &myself);
128 set_current_state(TASK_RUNNING);
130 _debug("@@@ Begin Timeout of %p", timer);
132 /* dequeue the timer */
133 list_del_init(&timer->link);
134 spin_unlock(&kafstimod_lock);
136 /* call the timeout function */
137 timer->ops->timed_out(timer);
139 _debug("@@@ End Timeout");
142 } /* end kafstimod() */
144 /*****************************************************************************/
148 void afs_kafstimod_add_timer(struct afs_timer *timer, unsigned long timeout)
150 struct afs_timer *ptimer;
151 struct list_head *_p;
153 _enter("%p,%lu", timer, timeout);
155 spin_lock(&kafstimod_lock);
157 list_del(&timer->link);
159 /* the timer was deferred or reset - put it back in the queue at the
161 timer->timo_jif = jiffies + timeout;
163 list_for_each(_p, &kafstimod_list) {
164 ptimer = list_entry(_p, struct afs_timer, link);
165 if (time_before(timer->timo_jif, ptimer->timo_jif))
169 list_add_tail(&timer->link, _p); /* insert before stopping point */
171 spin_unlock(&kafstimod_lock);
173 wake_up(&kafstimod_sleepq);
176 } /* end afs_kafstimod_add_timer() */
178 /*****************************************************************************/
181 * - returns 0 if the timer was deleted or -ENOENT if it wasn't queued
183 int afs_kafstimod_del_timer(struct afs_timer *timer)
189 spin_lock(&kafstimod_lock);
191 if (list_empty(&timer->link))
194 list_del_init(&timer->link);
196 spin_unlock(&kafstimod_lock);
198 wake_up(&kafstimod_sleepq);
200 _leave(" = %d", ret);
202 } /* end afs_kafstimod_del_timer() */