On Wed, May 25, 2022 at 07:37:45AM -0600, Keith Busch wrote: > On Wed, May 25, 2022 at 09:49:41AM +0200, Pankaj Raghav wrote: > > On Tue, May 24, 2022 at 09:38:32AM -0600, Keith Busch wrote: > > > On Tue, May 24, 2022 at 04:17:54PM +0200, Pankaj Raghav wrote: > > > > On Mon, May 23, 2022 at 02:01:14PM -0700, Keith Busch wrote: > > > > > - if (WARN_ON_ONCE(!max_append_sectors)) > > > > > - return 0; > > > > I don't see this check in the append path. Should it be added in > > > > bio_iov_add_zone_append_page() function? > > > > > > I'm not sure this check makes a lot of sense. If it just returns 0 here, then > > > won't that get bio_iov_iter_get_pages() stuck in an infinite loop? The bio > > > isn't filling, the iov isn't advancing, and 0 indicates keep-going. > > Yeah but if max_append_sectors is zero, then bio_add_hw_page() also > > returns 0 as follows: > > .... > > if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors) > > return 0; > > .... > > With WARN_ON_ONCE, we at least get a warning message if it gets stuck in an > > infinite loop because of max_append_sectors being zero right? > > The return for this function is the added length, not an indicator of success. > And we already handle '0' as an error from bio_iov_add_zone_append_page(): > > if (bio_add_hw_page(q, bio, page, len, offset, > queue_max_zone_append_sectors(q), &same_page) != len) Ah. I didn't see the `!=len` part. Sorry for the noise and ignore this comment. > return -EINVAL; -- Pankaj Raghav
