*
* (C) 2004 William Irwin, Oracle
*/
+#include <linux/config.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/hash.h>
-void init_waitqueue_head(wait_queue_head_t *q)
-{
- spin_lock_init(&q->lock);
- INIT_LIST_HEAD(&q->task_list);
-}
-
-EXPORT_SYMBOL(init_waitqueue_head);
-
void fastcall add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
{
unsigned long flags;
}
EXPORT_SYMBOL(add_wait_queue_exclusive);
-void fastcall remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
+int fastcall remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
{
unsigned long flags;
+ struct list_head *list;
+ int seen, retval;
spin_lock_irqsave(&q->lock, flags);
- __remove_wait_queue(q, wait);
+ list = &q->task_list;
+ seen = 0;
+ retval = -1;
+
+ do {
+ struct list_head *next;
+ if (list == &wait->task_list)
+ seen++;
+ next = list->next;
+ if (next->prev != list) {
+ seen += 2;
+ break;
+ }
+ list = next;
+ } while (list != &q->task_list);
+
+ if (seen == 1) {
+ __remove_wait_queue(q, wait);
+ retval = 0;
+ }
spin_unlock_irqrestore(&q->lock, flags);
+ return retval;
}
EXPORT_SYMBOL(remove_wait_queue);