ia64/linux-2.6.18-xen.hg

view fs/afs/kafstimod.c @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /* kafstimod.c: AFS timeout daemon
2 *
3 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
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.
10 */
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/sched.h>
15 #include <linux/completion.h>
16 #include "cell.h"
17 #include "volume.h"
18 #include "kafstimod.h"
19 #include <asm/errno.h>
20 #include "internal.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 /*****************************************************************************/
33 /*
34 * start the timeout daemon
35 */
36 int afs_kafstimod_start(void)
37 {
38 int ret;
40 ret = kernel_thread(kafstimod, NULL, 0);
41 if (ret < 0)
42 return ret;
44 wait_for_completion(&kafstimod_alive);
46 return ret;
47 } /* end afs_kafstimod_start() */
49 /*****************************************************************************/
50 /*
51 * stop the timeout daemon
52 */
53 void afs_kafstimod_stop(void)
54 {
55 /* get rid of my daemon */
56 kafstimod_die = 1;
57 wake_up(&kafstimod_sleepq);
58 wait_for_completion(&kafstimod_dead);
60 } /* end afs_kafstimod_stop() */
62 /*****************************************************************************/
63 /*
64 * timeout processing daemon
65 */
66 static int kafstimod(void *arg)
67 {
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 */
79 loop:
80 set_current_state(TASK_INTERRUPTIBLE);
81 add_wait_queue(&kafstimod_sleepq, &myself);
83 for (;;) {
84 unsigned long jif;
85 signed long timeout;
87 /* deal with the server being asked to die */
88 if (kafstimod_die) {
89 remove_wait_queue(&kafstimod_sleepq, &myself);
90 _leave("");
91 complete_and_exit(&kafstimod_dead, 0);
92 }
94 try_to_freeze();
96 /* discard pending signals */
97 afs_discard_my_signals();
99 /* work out the time to elapse before the next event */
100 spin_lock(&kafstimod_lock);
101 if (list_empty(&kafstimod_list)) {
102 timeout = MAX_SCHEDULE_TIMEOUT;
103 }
104 else {
105 timer = list_entry(kafstimod_list.next,
106 struct afs_timer, link);
107 timeout = timer->timo_jif;
108 jif = jiffies;
110 if (time_before_eq((unsigned long) timeout, jif))
111 goto immediate;
113 else {
114 timeout = (long) timeout - (long) jiffies;
115 }
116 }
117 spin_unlock(&kafstimod_lock);
119 schedule_timeout(timeout);
121 set_current_state(TASK_INTERRUPTIBLE);
122 }
124 /* the thing on the front of the queue needs processing
125 * - we come here with the lock held and timer pointing to the expired
126 * entry
127 */
128 immediate:
129 remove_wait_queue(&kafstimod_sleepq, &myself);
130 set_current_state(TASK_RUNNING);
132 _debug("@@@ Begin Timeout of %p", timer);
134 /* dequeue the timer */
135 list_del_init(&timer->link);
136 spin_unlock(&kafstimod_lock);
138 /* call the timeout function */
139 timer->ops->timed_out(timer);
141 _debug("@@@ End Timeout");
142 goto loop;
144 } /* end kafstimod() */
146 /*****************************************************************************/
147 /*
148 * (re-)queue a timer
149 */
150 void afs_kafstimod_add_timer(struct afs_timer *timer, unsigned long timeout)
151 {
152 struct afs_timer *ptimer;
153 struct list_head *_p;
155 _enter("%p,%lu", timer, timeout);
157 spin_lock(&kafstimod_lock);
159 list_del(&timer->link);
161 /* the timer was deferred or reset - put it back in the queue at the
162 * right place */
163 timer->timo_jif = jiffies + timeout;
165 list_for_each(_p, &kafstimod_list) {
166 ptimer = list_entry(_p, struct afs_timer, link);
167 if (time_before(timer->timo_jif, ptimer->timo_jif))
168 break;
169 }
171 list_add_tail(&timer->link, _p); /* insert before stopping point */
173 spin_unlock(&kafstimod_lock);
175 wake_up(&kafstimod_sleepq);
177 _leave("");
178 } /* end afs_kafstimod_add_timer() */
180 /*****************************************************************************/
181 /*
182 * dequeue a timer
183 * - returns 0 if the timer was deleted or -ENOENT if it wasn't queued
184 */
185 int afs_kafstimod_del_timer(struct afs_timer *timer)
186 {
187 int ret = 0;
189 _enter("%p", timer);
191 spin_lock(&kafstimod_lock);
193 if (list_empty(&timer->link))
194 ret = -ENOENT;
195 else
196 list_del_init(&timer->link);
198 spin_unlock(&kafstimod_lock);
200 wake_up(&kafstimod_sleepq);
202 _leave(" = %d", ret);
203 return ret;
204 } /* end afs_kafstimod_del_timer() */