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-rw-r--r--include/linux/klist.h2
-rw-r--r--lib/klist.c43
2 files changed, 40 insertions, 5 deletions
diff --git a/include/linux/klist.h b/include/linux/klist.h
index 8ea98db223e5..d5a27af9dba5 100644
--- a/include/linux/klist.h
+++ b/include/linux/klist.h
@@ -13,7 +13,6 @@
13#define _LINUX_KLIST_H 13#define _LINUX_KLIST_H
14 14
15#include <linux/spinlock.h> 15#include <linux/spinlock.h>
16#include <linux/completion.h>
17#include <linux/kref.h> 16#include <linux/kref.h>
18#include <linux/list.h> 17#include <linux/list.h>
19 18
@@ -41,7 +40,6 @@ struct klist_node {
41 void *n_klist; /* never access directly */ 40 void *n_klist; /* never access directly */
42 struct list_head n_node; 41 struct list_head n_node;
43 struct kref n_ref; 42 struct kref n_ref;
44 struct completion n_removed;
45}; 43};
46 44
47extern void klist_add_tail(struct klist_node *n, struct klist *k); 45extern void klist_add_tail(struct klist_node *n, struct klist *k);
diff --git a/lib/klist.c b/lib/klist.c
index bbdd3015c2c7..573d6068a42e 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -36,6 +36,7 @@
36 36
37#include <linux/klist.h> 37#include <linux/klist.h>
38#include <linux/module.h> 38#include <linux/module.h>
39#include <linux/sched.h>
39 40
40/* 41/*
41 * Use the lowest bit of n_klist to mark deleted nodes and exclude 42 * Use the lowest bit of n_klist to mark deleted nodes and exclude
@@ -108,7 +109,6 @@ static void add_tail(struct klist *k, struct klist_node *n)
108static void klist_node_init(struct klist *k, struct klist_node *n) 109static void klist_node_init(struct klist *k, struct klist_node *n)
109{ 110{
110 INIT_LIST_HEAD(&n->n_node); 111 INIT_LIST_HEAD(&n->n_node);
111 init_completion(&n->n_removed);
112 kref_init(&n->n_ref); 112 kref_init(&n->n_ref);
113 knode_set_klist(n, k); 113 knode_set_klist(n, k);
114 if (k->get) 114 if (k->get)
@@ -171,13 +171,34 @@ void klist_add_before(struct klist_node *n, struct klist_node *pos)
171} 171}
172EXPORT_SYMBOL_GPL(klist_add_before); 172EXPORT_SYMBOL_GPL(klist_add_before);
173 173
174struct klist_waiter {
175 struct list_head list;
176 struct klist_node *node;
177 struct task_struct *process;
178 int woken;
179};
180
181static DEFINE_SPINLOCK(klist_remove_lock);
182static LIST_HEAD(klist_remove_waiters);
183
174static void klist_release(struct kref *kref) 184static void klist_release(struct kref *kref)
175{ 185{
186 struct klist_waiter *waiter, *tmp;
176 struct klist_node *n = container_of(kref, struct klist_node, n_ref); 187 struct klist_node *n = container_of(kref, struct klist_node, n_ref);
177 188
178 WARN_ON(!knode_dead(n)); 189 WARN_ON(!knode_dead(n));
179 list_del(&n->n_node); 190 list_del(&n->n_node);
180 complete(&n->n_removed); 191 spin_lock(&klist_remove_lock);
192 list_for_each_entry_safe(waiter, tmp, &klist_remove_waiters, list) {
193 if (waiter->node != n)
194 continue;
195
196 waiter->woken = 1;
197 mb();
198 wake_up_process(waiter->process);
199 list_del(&waiter->list);
200 }
201 spin_unlock(&klist_remove_lock);
181 knode_set_klist(n, NULL); 202 knode_set_klist(n, NULL);
182} 203}
183 204
@@ -217,8 +238,24 @@ EXPORT_SYMBOL_GPL(klist_del);
217 */ 238 */
218void klist_remove(struct klist_node *n) 239void klist_remove(struct klist_node *n)
219{ 240{
241 struct klist_waiter waiter;
242
243 waiter.node = n;
244 waiter.process = current;
245 waiter.woken = 0;
246 spin_lock(&klist_remove_lock);
247 list_add(&waiter.list, &klist_remove_waiters);
248 spin_unlock(&klist_remove_lock);
249
220 klist_del(n); 250 klist_del(n);
221 wait_for_completion(&n->n_removed); 251
252 for (;;) {
253 set_current_state(TASK_UNINTERRUPTIBLE);
254 if (waiter.woken)
255 break;
256 schedule();
257 }
258 __set_current_state(TASK_RUNNING);
222} 259}
223EXPORT_SYMBOL_GPL(klist_remove); 260EXPORT_SYMBOL_GPL(klist_remove);
224 261