Man page 9 : bio_add_pc_page

bio_add_pc_page - attempt to add page to bio

int bio_add_pc_page(struct request_queue *  q , struct bio *  bio , struct page *  page , unsigned int  len , unsigned int  offset );

q
    the target queue

bio
    destination bio

page
    page to add

len
    vec entry length

offset
    vec entry offset

Attempt to add a page to the bio_vec maplist. This can fail for a number of reasons, such as the bio being full or target block device limitations. The target block device must allow bioAqs up to PAGE_SIZE, so it is always possible to add a single page to an empty bio.

This should only be used by REQ_PC bios.