Man page 9 : find_get_pages_tag

find_get_pages_tag - find and return pages that match tag

unsigned find_get_pages_tag(struct address_space *  mapping , pgoff_t *  index , int  tag , unsigned int  nr_pages , struct page **  pages );

mapping
    the address_space to search

index
    the starting page index

tag
    the tag index

nr_pages
    the maximum number of pages

pages
    where the resulting pages are placed

Like find_get_pages, except we only return pages which are tagged with tag. We update index to index the next page for the traversal.