[PATCH] add klist_node_attached() to determine if a node is on a list or not.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff -Nru a/include/linux/klist.h b/include/linux/klist.h

2 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/klist.h b/include/linux/klist.h
index fb52f9d9d611..eebf5e5696ec 100644
--- a/include/linux/klist.h
+++ b/include/linux/klist.h
@@ -37,6 +37,8 @@ extern void klist_add_head(struct klist * k, struct klist_node * n);
 extern void klist_del(struct klist_node * n);
 extern void klist_remove(struct klist_node * n);
 
+extern int klist_node_attached(struct klist_node * n);
+
 
 struct klist_iter {
         struct klist            * i_klist;
diff --git a/lib/klist.c b/lib/klist.c
index 6f760424648b..02177d72dc89 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -112,6 +112,7 @@ 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;
 }
 
 static int klist_dec_and_del(struct klist_node * n)
@@ -154,6 +155,19 @@ EXPORT_SYMBOL_GPL(klist_remove);
 
 
 /**
+ *      klist_node_attached - Say whether a node is bound to a list or not.
+ *      @n:     Node that we're testing.
+ */
+
+int klist_node_attached(struct klist_node * n)
+{
+        return (n->n_klist != NULL);
+}
+
+EXPORT_SYMBOL_GPL(klist_node_attached);
+
+
+/**
  *      klist_iter_init_node - Initialize a klist_iter structure.
  *      @k:     klist we're iterating.
  *      @i:     klist_iter we're filling.
@@ -246,3 +260,5 @@ struct klist_node * klist_next(struct klist_iter * i)
 }
 
 EXPORT_SYMBOL_GPL(klist_next);
+
+