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authorTejun Heo <htejun@gmail.com>2008-04-22 18:58:46 +0900
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-30 16:52:47 -0700
commit93dd40013f4f7f4b18d19d0d77855f025bcc57c3 (patch)
tree81f61934013cbfbfec720e0798d13189571364b5
parent1da43e4a9ee942c9c967dbe8839476571df0c3ed (diff)
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klist: implement klist_add_{after|before}()
Add klist_add_after() and klist_add_before() which puts a new node after and before an existing node, respectively. This is useful for callers which need to keep klist ordered. Note that synchronizing between simultaneous additions for ordering is the caller's responsibility. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--include/linux/klist.h2
-rw-r--r--lib/klist.c33
2 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/klist.h b/include/linux/klist.h
index a119c0da8977..b49385f13419 100644
--- a/include/linux/klist.h
+++ b/include/linux/klist.h
@@ -46,6 +46,8 @@ struct klist_node {
extern void klist_add_tail(struct klist_node * n, struct klist * k);
extern void klist_add_head(struct klist_node * n, struct klist * k);
+extern void klist_add_after(struct klist_node *n, struct klist_node *pos);
+extern void klist_add_before(struct klist_node *n, struct klist_node *pos);
extern void klist_del(struct klist_node * n);
extern void klist_remove(struct klist_node * n);
diff --git a/lib/klist.c b/lib/klist.c
index 120bd175aa78..ebba9488046e 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -120,6 +120,39 @@ void klist_add_tail(struct klist_node * n, struct klist * k)
EXPORT_SYMBOL_GPL(klist_add_tail);
+/**
+ * klist_add_after - Init a klist_node and add it after an existing node
+ * @n: node we're adding.
+ * @pos: node to put @n after
+ */
+void klist_add_after(struct klist_node *n, struct klist_node *pos)
+{
+ struct klist *k = pos->n_klist;
+
+ klist_node_init(k, n);
+ spin_lock(&k->k_lock);
+ list_add(&n->n_node, &pos->n_node);
+ spin_unlock(&k->k_lock);
+}
+EXPORT_SYMBOL_GPL(klist_add_after);
+
+/**
+ * klist_add_before - Init a klist_node and add it before an existing node
+ * @n: node we're adding.
+ * @pos: node to put @n after
+ */
+void klist_add_before(struct klist_node *n, struct klist_node *pos)
+{
+ struct klist *k = pos->n_klist;
+
+ klist_node_init(k, n);
+ spin_lock(&k->k_lock);
+ list_add_tail(&n->n_node, &pos->n_node);
+ spin_unlock(&k->k_lock);
+}
+EXPORT_SYMBOL_GPL(klist_add_before);
+
+
static void klist_release(struct kref * kref)
{
struct klist_node * n = container_of(kref, struct klist_node, n_ref);