[PATCH] fix klist semantics for lists which have elements removed on traversal

[pandora-kernel.git] / lib / klist.c

diff --git a/lib/klist.c b/lib/klist.c
index a70c836..bb2f355 100644 (file)
--- 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);
 }
 
 
@@ -110,9 +123,12 @@ 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);
+       void (*put)(struct klist_node *) = n->n_klist->put;
        list_del(&n->n_node);
        complete(&n->n_removed);
        n->n_klist = NULL;
+       if (put)
+               put(n);
 }
 
 static int klist_dec_and_del(struct klist_node * n)