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-rw-r--r--lib/klist.c235
1 files changed, 116 insertions, 119 deletions
diff --git a/lib/klist.c b/lib/klist.c
index 120bd175aa7..cca37f96faa 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -1,38 +1,37 @@
/*
- * klist.c - Routines for manipulating klists.
+ * klist.c - Routines for manipulating klists.
*
+ * Copyright (C) 2005 Patrick Mochel
*
- * This klist interface provides a couple of structures that wrap around
- * struct list_head to provide explicit list "head" (struct klist) and
- * list "node" (struct klist_node) objects. For struct klist, a spinlock
- * is included that protects access to the actual list itself. struct
- * klist_node provides a pointer to the klist that owns it and a kref
- * reference count that indicates the number of current users of that node
- * in the list.
+ * This file is released under the GPL v2.
*
- * The entire point is to provide an interface for iterating over a list
- * that is safe and allows for modification of the list during the
- * iteration (e.g. insertion and removal), including modification of the
- * current node on the list.
+ * This klist interface provides a couple of structures that wrap around
+ * struct list_head to provide explicit list "head" (struct klist) and list
+ * "node" (struct klist_node) objects. For struct klist, a spinlock is
+ * included that protects access to the actual list itself. struct
+ * klist_node provides a pointer to the klist that owns it and a kref
+ * reference count that indicates the number of current users of that node
+ * in the list.
*
- * It works using a 3rd object type - struct klist_iter - that is declared
- * and initialized before an iteration. klist_next() is used to acquire the
- * next element in the list. It returns NULL if there are no more items.
- * Internally, that routine takes the klist's lock, decrements the reference
- * count of the previous klist_node and increments the count of the next
- * klist_node. It then drops the lock and returns.
+ * The entire point is to provide an interface for iterating over a list
+ * that is safe and allows for modification of the list during the
+ * iteration (e.g. insertion and removal), including modification of the
+ * current node on the list.
*
- * There are primitives for adding and removing nodes to/from a klist.
- * When deleting, klist_del() will simply decrement the reference count.
- * Only when the count goes to 0 is the node removed from the list.
- * klist_remove() will try to delete the node from the list and block
- * until it is actually removed. This is useful for objects (like devices)
- * that have been removed from the system and must be freed (but must wait
- * until all accessors have finished).
+ * It works using a 3rd object type - struct klist_iter - that is declared
+ * and initialized before an iteration. klist_next() is used to acquire the
+ * next element in the list. It returns NULL if there are no more items.
+ * Internally, that routine takes the klist's lock, decrements the
+ * reference count of the previous klist_node and increments the count of
+ * the next klist_node. It then drops the lock and returns.
*
- * Copyright (C) 2005 Patrick Mochel
- *
- * This file is released under the GPL v2.
+ * There are primitives for adding and removing nodes to/from a klist.
+ * When deleting, klist_del() will simply decrement the reference count.
+ * Only when the count goes to 0 is the node removed from the list.
+ * klist_remove() will try to delete the node from the list and block until
+ * it is actually removed. This is useful for objects (like devices) that
+ * have been removed from the system and must be freed (but must wait until
+ * all accessors have finished).
*/
#include <linux/klist.h>
@@ -40,10 +39,10 @@
/**
- * 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)
+ * 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
@@ -51,8 +50,7 @@
* functions that take and release references on the embedding
* objects.
*/
-
-void klist_init(struct klist * k, void (*get)(struct klist_node *),
+void klist_init(struct klist *k, void (*get)(struct klist_node *),
void (*put)(struct klist_node *))
{
INIT_LIST_HEAD(&k->k_list);
@@ -60,26 +58,23 @@ void klist_init(struct klist * k, void (*get)(struct klist_node *),
k->get = get;
k->put = put;
}
-
EXPORT_SYMBOL_GPL(klist_init);
-
-static void add_head(struct klist * k, struct klist_node * n)
+static void add_head(struct klist *k, struct klist_node *n)
{
spin_lock(&k->k_lock);
list_add(&n->n_node, &k->k_list);
spin_unlock(&k->k_lock);
}
-static void add_tail(struct klist * k, struct klist_node * n)
+static void add_tail(struct klist *k, struct klist_node *n)
{
spin_lock(&k->k_lock);
list_add_tail(&n->n_node, &k->k_list);
spin_unlock(&k->k_lock);
}
-
-static void klist_node_init(struct klist * k, struct klist_node * n)
+static void klist_node_init(struct klist *k, struct klist_node *n)
{
INIT_LIST_HEAD(&n->n_node);
init_completion(&n->n_removed);
@@ -89,60 +84,83 @@ static void klist_node_init(struct klist * k, struct klist_node * n)
k->get(n);
}
-
/**
- * klist_add_head - Initialize a klist_node and add it to front.
- * @n: node we're adding.
- * @k: klist it's going on.
+ * klist_add_head - Initialize a klist_node and add it to front.
+ * @n: node we're adding.
+ * @k: klist it's going on.
*/
-
-void klist_add_head(struct klist_node * n, struct klist * k)
+void klist_add_head(struct klist_node *n, struct klist *k)
{
klist_node_init(k, n);
add_head(k, n);
}
-
EXPORT_SYMBOL_GPL(klist_add_head);
-
/**
- * klist_add_tail - Initialize a klist_node and add it to back.
- * @n: node we're adding.
- * @k: klist it's going on.
+ * klist_add_tail - Initialize a klist_node and add it to back.
+ * @n: node we're adding.
+ * @k: klist it's going on.
*/
-
-void klist_add_tail(struct klist_node * n, struct klist * k)
+void klist_add_tail(struct klist_node *n, struct klist *k)
{
klist_node_init(k, n);
add_tail(k, n);
}
-
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)
+static void klist_release(struct kref *kref)
{
- struct klist_node * n = container_of(kref, struct klist_node, n_ref);
+ 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)
+static int klist_dec_and_del(struct klist_node *n)
{
return kref_put(&n->n_ref, klist_release);
}
-
/**
- * klist_del - Decrement the reference count of node and try to remove.
- * @n: node we're deleting.
+ * klist_del - Decrement the reference count of node and try to remove.
+ * @n: node we're deleting.
*/
-
-void klist_del(struct klist_node * n)
+void klist_del(struct klist_node *n)
{
- struct klist * k = n->n_klist;
+ struct klist *k = n->n_klist;
void (*put)(struct klist_node *) = k->put;
spin_lock(&k->k_lock);
@@ -152,48 +170,40 @@ void klist_del(struct klist_node * n)
if (put)
put(n);
}
-
EXPORT_SYMBOL_GPL(klist_del);
-
/**
- * klist_remove - Decrement the refcount of node and wait for it to go away.
- * @n: node we're removing.
+ * klist_remove - Decrement the refcount of node and wait for it to go away.
+ * @n: node we're removing.
*/
-
-void klist_remove(struct klist_node * n)
+void klist_remove(struct klist_node *n)
{
klist_del(n);
wait_for_completion(&n->n_removed);
}
-
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.
+ * 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)
+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.
- * @n: node to start with.
+ * klist_iter_init_node - Initialize a klist_iter structure.
+ * @k: klist we're iterating.
+ * @i: klist_iter we're filling.
+ * @n: node to start with.
*
- * Similar to klist_iter_init(), but starts the action off with @n,
- * instead of with the list head.
+ * Similar to klist_iter_init(), but starts the action off with @n,
+ * instead of with the list head.
*/
-
-void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_node * n)
+void klist_iter_init_node(struct klist *k, struct klist_iter *i,
+ struct klist_node *n)
{
i->i_klist = k;
i->i_head = &k->k_list;
@@ -201,66 +211,56 @@ void klist_iter_init_node(struct klist * k, struct klist_iter * i, struct klist_
if (n)
kref_get(&n->n_ref);
}
-
EXPORT_SYMBOL_GPL(klist_iter_init_node);
-
/**
- * klist_iter_init - Iniitalize a klist_iter structure.
- * @k: klist we're iterating.
- * @i: klist_iter structure we're filling.
+ * klist_iter_init - Iniitalize a klist_iter structure.
+ * @k: klist we're iterating.
+ * @i: klist_iter structure we're filling.
*
- * Similar to klist_iter_init_node(), but start with the list head.
+ * Similar to klist_iter_init_node(), but start with the list head.
*/
-
-void klist_iter_init(struct klist * k, struct klist_iter * i)
+void klist_iter_init(struct klist *k, struct klist_iter *i)
{
klist_iter_init_node(k, i, NULL);
}
-
EXPORT_SYMBOL_GPL(klist_iter_init);
-
/**
- * klist_iter_exit - Finish a list iteration.
- * @i: Iterator structure.
+ * klist_iter_exit - Finish a list iteration.
+ * @i: Iterator structure.
*
- * Must be called when done iterating over list, as it decrements the
- * refcount of the current node. Necessary in case iteration exited before
- * the end of the list was reached, and always good form.
+ * Must be called when done iterating over list, as it decrements the
+ * refcount of the current node. Necessary in case iteration exited before
+ * the end of the list was reached, and always good form.
*/
-
-void klist_iter_exit(struct klist_iter * i)
+void klist_iter_exit(struct klist_iter *i)
{
if (i->i_cur) {
klist_del(i->i_cur);
i->i_cur = NULL;
}
}
-
EXPORT_SYMBOL_GPL(klist_iter_exit);
-
-static struct klist_node * to_klist_node(struct list_head * n)
+static struct klist_node *to_klist_node(struct list_head *n)
{
return container_of(n, struct klist_node, n_node);
}
-
/**
- * klist_next - Ante up next node in list.
- * @i: Iterator structure.
+ * klist_next - Ante up next node in list.
+ * @i: Iterator structure.
*
- * First grab list lock. Decrement the reference count of the previous
- * node, if there was one. Grab the next node, increment its reference
- * count, drop the lock, and return that next node.
+ * First grab list lock. Decrement the reference count of the previous
+ * node, if there was one. Grab the next node, increment its reference
+ * count, drop the lock, and return that next node.
*/
-
-struct klist_node * klist_next(struct klist_iter * i)
+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;
+ 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);
@@ -281,7 +281,4 @@ struct klist_node * klist_next(struct klist_iter * i)
put(lnode);
return knode;
}
-
EXPORT_SYMBOL_GPL(klist_next);
-
-