On Mon, Nov 26, 2018 at 10:46 AM Kirill Tkhai <[email protected]> wrote: > > It looks like we can optimize old_req page replacement > and avoid copying by simple updating the request's page. > > Signed-off-by: Kirill Tkhai <[email protected]> > --- > fs/fuse/file.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > index c6650c68b31a..83b54b082c86 100644 > --- a/fs/fuse/file.c > +++ b/fs/fuse/file.c > @@ -1778,7 +1778,7 @@ static bool fuse_writepage_in_flight(struct fuse_req > *new_req, > if (old_req->num_pages == 1 && old_req != first_req) { > struct backing_dev_info *bdi = > inode_to_bdi(page->mapping->host); > > - copy_highpage(old_req->pages[0], page); > + swap(old_req->pages[0], page);
This would mess up refcounting for all pages involved. need to swap with the temp page in new_req. Fixed version in #for-next. Thanks, Miklos
