bio_add_page — attempt to add page to bio
int bio_add_page
(struct bio * bio, struct page * page, unsigned int len, unsigned int offset);
destination bio
page to add
vec entry length
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 bio's smaller than PAGE_SIZE, so it is always possible to add a single page to an empty bio.