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);
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
;
105 timer
= list_entry(kafstimod_list
.next
,
106 struct afs_timer
, link
);
107 timeout
= timer
->timo_jif
;
110 if (time_before_eq((unsigned long) timeout
, jif
))
114 timeout
= (long) timeout
- (long) jiffies
;
117 spin_unlock(&kafstimod_lock
);
119 schedule_timeout(timeout
);
121 set_current_state(TASK_INTERRUPTIBLE
);
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
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");
144 } /* end kafstimod() */
146 /*****************************************************************************/
150 void afs_kafstimod_add_timer(struct afs_timer
*timer
, unsigned long timeout
)
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
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
))
171 list_add_tail(&timer
->link
, _p
); /* insert before stopping point */
173 spin_unlock(&kafstimod_lock
);
175 wake_up(&kafstimod_sleepq
);
178 } /* end afs_kafstimod_add_timer() */
180 /*****************************************************************************/
183 * - returns 0 if the timer was deleted or -ENOENT if it wasn't queued
185 int afs_kafstimod_del_timer(struct afs_timer
*timer
)
191 spin_lock(&kafstimod_lock
);
193 if (list_empty(&timer
->link
))
196 list_del_init(&timer
->link
);
198 spin_unlock(&kafstimod_lock
);
200 wake_up(&kafstimod_sleepq
);
202 _leave(" = %d", ret
);
204 } /* end afs_kafstimod_del_timer() */