On 9/6/22 00:22, Christoph Hellwig wrote: > On Tue, Sep 06, 2022 at 12:10:54AM -0700, John Hubbard wrote: >> I would be delighted if that were somehow possible. Every time I think >> it's possible, it has fallen apart. The fact that bio_release_pages() >> will need to switch over from put_page() to unpin_user_page(), combined >> with the fact that there are a lot of callers that submit bios, has >> led me to the current approach. > > We can (temporarily) pass the gup flag to bio_release_pages or even > better add a new bio_unpin_pages helper that undoes the pin side. > That is: don't try to reuse the old APIs, but ad new ones, just like > we do on the lower layers. OK...so, to confirm: the idea is to convert these callsites (below) to call a new bio_unpin_pages() routine that does unpin_user_page(). $ git grep -nw bio_release_pages block/bio.c:1474: bio_release_pages(bio, true); block/bio.c:1490: bio_release_pages(bio, false); block/blk-map.c:308: bio_release_pages(bio, false); block/blk-map.c:610: bio_release_pages(bio, bio_data_dir(bio) == READ); block/fops.c:99: bio_release_pages(&bio, should_dirty); block/fops.c:165: bio_release_pages(bio, false); block/fops.c:289: bio_release_pages(bio, false); fs/direct-io.c:510: bio_release_pages(bio, should_dirty); fs/iomap/direct-io.c:185: bio_release_pages(bio, false); fs/zonefs/super.c:793: bio_release_pages(bio, false); And these can probably be done in groups, not as one big patch--your other email also asked to break them up into block, iomap, and legacy. That would be nice, I really hate the ugly dio_w*() wrappers, thanks for this help. :) thanks, -- John Hubbard NVIDIA
