[Yaffs] how to tracerse a directory object?

hello,every one。
The first statement in my native language is not English, so I expression might not be so good！

In the yaffs,i get a directory's yaffs_obj struct,i want to find all files in this directory. I konw that every directory obj has a member children(struct list_head type),the children files of this directory is in this children list.
but i find strcut list_head just have two members,next and prev pointer! How can i get the children files's yaffs_obj by this list(struct list_head children)?