From: Oleg Nesterov Date: Fri, 23 Jun 2006 09:05:54 +0000 (-0700) Subject: [PATCH] list: introduce list_replace() helper X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=54e73770357142e297c916c7865f5fca7499f69c;p=openwrt%2Fstaging%2Fblogic.git [PATCH] list: introduce list_replace() helper list_replace() is similar to list_replace_rcu(), but unlike list_replace_rcu() it could be used when list_empty(old) == 1 doesn't use barriers Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/list.h b/include/linux/list.h index 76f05718342c..a02642e4710a 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -197,12 +197,35 @@ static inline void list_del_rcu(struct list_head *entry) entry->prev = LIST_POISON2; } +/** + * list_replace - replace old entry by new one + * @old : the element to be replaced + * @new : the new element to insert + * Note: if 'old' was empty, it will be overwritten. + */ +static inline void list_replace(struct list_head *old, + struct list_head *new) +{ + new->next = old->next; + new->next->prev = new; + new->prev = old->prev; + new->prev->next = new; +} + +static inline void list_replace_init(struct list_head *old, + struct list_head *new) +{ + list_replace(old, new); + INIT_LIST_HEAD(old); +} + /* * list_replace_rcu - replace old entry by new one * @old : the element to be replaced * @new : the new element to insert * * The old entry will be replaced with the new entry atomically. + * Note: 'old' should not be empty. */ static inline void list_replace_rcu(struct list_head *old, struct list_head *new)