Man page 9 : list_cut_position

list_cut_position - cut a list into two

void list_cut_position(struct list_head *  list , struct list_head *  head , struct list_head *  entry );

list
    a new list to add all removed entries

head
    a list with entries

entry
    an entry within head, could be the head itself and if so we wonAqt cut the list

This helper moves the initial part of head, up to and including entry, from head to list. You should pass on entry an element you know is on head. list should be an empty list or a list you do not care about losing its data.