Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[karo-tx-linux.git] / include / linux / llist.h

diff --git a/include/linux/llist.h b/include/linux/llist.h
index 171baa90f6f69c6b55b15772d395f6a168bec4c7..d11738110a7aeff53b1349f994e3e435d2f0e76b 100644 (file)
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -109,6 +109,25 @@ static inline void init_llist_head(struct llist_head *list)
 #define llist_for_each(pos, node)                      \
        for ((pos) = (node); pos; (pos) = (pos)->next)
 
+/**
+ * llist_for_each_safe - iterate over some deleted entries of a lock-less list
+ *                      safe against removal of list entry
+ * @pos:       the &struct llist_node to use as a loop cursor
+ * @n:         another &struct llist_node to use as temporary storage
+ * @node:      the first entry of deleted list entries
+ *
+ * In general, some entries of the lock-less list can be traversed
+ * safely only after being deleted from list, so start with an entry
+ * instead of list head.
+ *
+ * If being used on entries deleted from lock-less list directly, the
+ * traverse order is from the newest to the oldest added entry.  If
+ * you want to traverse from the oldest to the newest, you must
+ * reverse the order by yourself before traversing.
+ */
+#define llist_for_each_safe(pos, n, node)                      \
+       for ((pos) = (node); (pos) && ((n) = (pos)->next, true); (pos) = (n))
+
 /**
  * llist_for_each_entry - iterate over some deleted entries of lock-less list of given type
  * @pos:       the type * to use as a loop cursor.