From: Ken Helias <kenhel...@firemail.de>
Many places in the code uses list_add_tail/list_add to insert an entry
before/after another entry. This confuses the reader because these are usually
used to add an item to a list_head and not an entry. hlist already have
functions to do the same which makes the code a lot more readable. It would be
a lot easier to understand when all places use a self explaining function name
instead of misusing other functions.
Signed-off-by: Ken Helias <kenhel...@firemail.de>
Cc: Dipankar Sarma <dipan...@in.ibm.com>
Cc: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
Cc: Oleg Nesterov <o...@redhat.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Ken Helias <kenhel...@firemail.de>
Cc: Dave Jones <da...@redhat.com>
---
include/linux/list.h | 22 ++++++++++++++++++++++
include/linux/rculist.h | 38 ++++++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/include/linux/list.h b/include/linux/list.h
index ab43d01..5ea0eca 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -76,6 +76,28 @@ static inline void list_add_tail(struct list_head *new,
struct list_head *head)
__list_add(new, head->prev, head);
}
+/**
+ * list_add_after
+ * @n: new entry to be added
+ * @prev: the existing element to add the new element after.
+ *
+ * Description:
+ * Adds the specified element to the specified list
+ * after the specified node.
+ */
+#define list_add_after(n, prev) list_add(n, prev)
+
+/**
+ * list_add_before
+ * @n: new entry to be added
+ * @next: the existing element to add the new element before.
+ *
+ * Description:
+ * Adds the specified element to the specified list
+ * before the specified node.
+ */
+#define list_add_before(n, next) list_add_tail(n, next)
+
/*
* Delete a list entry by making the prev/next entries
* point to each other.
diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 648773f..eec274d 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -103,6 +103,44 @@ static inline void list_add_tail_rcu(struct list_head *new,
}
/**
+ * list_add_after_rcu
+ * @n: new entry to be added
+ * @prev: the existing element to add the new element after.
+ *
+ * Description:
+ * Adds the specified element to the specified list
+ * after the specified node while permitting racing traversals.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+#define list_add_after_rcu(n, next) list_add_rcu(n, next)
+
+/**
+ * list_add_before_rcu
+ * @n: new entry to be added
+ * @next: the existing element to add the new element before.
+ *
+ * Description:
+ * Adds the specified element to the specified list
+ * before the specified node while permitting racing traversals.
+ *
+ * The caller must take whatever precautions are necessary
+ * (such as holding appropriate locks) to avoid racing
+ * with another list-mutation primitive, such as list_add_tail_rcu()
+ * or list_del_rcu(), running on this same list.
+ * However, it is perfectly legal to run concurrently with
+ * the _rcu list-traversal primitives, such as
+ * list_for_each_entry_rcu().
+ */
+#define list_add_before_rcu(n, next) list_add_tail_rcu(n, next)
+
+/**
* list_del_rcu - deletes entry from list without re-initialization
* @entry: the element to delete from the list.
*
--
2.0.0
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