X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=lib%2Fklist.c;h=120bd175aa7855044fdb5a440b6fc189b21344b3;hp=a70c836c5c4c2617f6929407034a8706b57c4886;hb=4d0eb0049ce94101f7f169f89216ba58475219e2;hpb=1e231efe50ffe4d291be24d2fe393188de9c4b08

diff --git a/lib/klist.c b/lib/klist.c
index a70c836c5c4c..120bd175aa78 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -42,12 +42,23 @@
 /**
  *	klist_init - Initialize a klist structure. 
  *	@k:	The klist we're initializing.
+ *	@get:	The get function for the embedding object (NULL if none)
+ *	@put:	The put function for the embedding object (NULL if none)
+ *
+ * Initialises the klist structure.  If the klist_node structures are
+ * going to be embedded in refcounted objects (necessary for safe
+ * deletion) then the get/put arguments are used to initialise
+ * functions that take and release references on the embedding
+ * objects.
  */
 
-void klist_init(struct klist * k)
+void klist_init(struct klist * k, void (*get)(struct klist_node *),
+		void (*put)(struct klist_node *))
 {
 	INIT_LIST_HEAD(&k->k_list);
 	spin_lock_init(&k->k_lock);
+	k->get = get;
+	k->put = put;
 }
 
 EXPORT_SYMBOL_GPL(klist_init);
@@ -74,6 +85,8 @@ static void klist_node_init(struct klist * k, struct klist_node * n)
 	init_completion(&n->n_removed);
 	kref_init(&n->n_ref);
 	n->n_klist = k;
+	if (k->get)
+		k->get(n);
 }
 
 
@@ -110,6 +123,7 @@ EXPORT_SYMBOL_GPL(klist_add_tail);
 static void klist_release(struct kref * kref)
 {
 	struct klist_node * n = container_of(kref, struct klist_node, n_ref);
+
 	list_del(&n->n_node);
 	complete(&n->n_removed);
 	n->n_klist = NULL;
@@ -129,10 +143,14 @@ static int klist_dec_and_del(struct klist_node * n)
 void klist_del(struct klist_node * n)
 {
 	struct klist * k = n->n_klist;
+	void (*put)(struct klist_node *) = k->put;
 
 	spin_lock(&k->k_lock);
-	klist_dec_and_del(n);
+	if (!klist_dec_and_del(n))
+		put = NULL;
 	spin_unlock(&k->k_lock);
+	if (put)
+		put(n);
 }
 
 EXPORT_SYMBOL_GPL(klist_del);
@@ -145,10 +163,7 @@ EXPORT_SYMBOL_GPL(klist_del);
 
 void klist_remove(struct klist_node * n)
 {
-	struct klist * k = n->n_klist;
-	spin_lock(&k->k_lock);
-	klist_dec_and_del(n);
-	spin_unlock(&k->k_lock);
+	klist_del(n);
 	wait_for_completion(&n->n_removed);
 }
 
@@ -183,6 +198,8 @@ void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_
 	i->i_klist = k;
 	i->i_head = &k->k_list;
 	i->i_cur = n;
+	if (n)
+		kref_get(&n->n_ref);
 }
 
 EXPORT_SYMBOL_GPL(klist_iter_init_node);
@@ -242,12 +259,15 @@ static struct klist_node * to_klist_node(struct list_head * n)
 struct klist_node * klist_next(struct klist_iter * i)
 {
 	struct list_head * next;
+	struct klist_node * lnode = i->i_cur;
 	struct klist_node * knode = NULL;
+	void (*put)(struct klist_node *) = i->i_klist->put;
 
 	spin_lock(&i->i_klist->k_lock);
-	if (i->i_cur) {
-		next = i->i_cur->n_node.next;
-		klist_dec_and_del(i->i_cur);
+	if (lnode) {
+		next = lnode->n_node.next;
+		if (!klist_dec_and_del(lnode))
+			put = NULL;
 	} else
 		next = i->i_head->next;
 
@@ -257,6 +277,8 @@ struct klist_node * klist_next(struct klist_iter * i)
 	}
 	i->i_cur = knode;
 	spin_unlock(&i->i_klist->k_lock);
+	if (put && lnode)
+		put(lnode);
 	return knode;
 }