Message ID | 20220630204212.1265638-8-kbusch@fb.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | block: support for partial sector reads | expand |
On Thu, Jun 30, 2022 at 01:42:07PM -0700, Keith Busch wrote: > void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) > { > size_t size = iov_iter_count(iter); > > WARN_ON_ONCE(bio->bi_max_vecs); > > + if (bio->bi_max_vecs) { > + bio_copy_bvec(bio, iter); > + return; > + } Obviously the WARN_ON_ONCE needs to go away with this. And with the follow on users in this series, there's also a bug with putting page references on these at bio_endio, so don't try testing pre-registered buffers with this series. I'll send a fix in the v2 if we get that far.
diff --git a/block/bio.c b/block/bio.c index b0c85778257a..391cad726ff2 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1130,12 +1130,25 @@ void __bio_release_pages(struct bio *bio, bool mark_dirty) } EXPORT_SYMBOL_GPL(__bio_release_pages); +static void bio_copy_bvec(struct bio *bio, struct iov_iter *iter) +{ + memcpy(&bio->bi_io_vec[bio->bi_vcnt], iter->bvec, + iter->nr_segs * sizeof(struct bio_vec)); + bio->bi_vcnt += iter->nr_segs; + bio->bi_iter.bi_size += iov_iter_count(iter); +} + void bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter) { size_t size = iov_iter_count(iter); WARN_ON_ONCE(bio->bi_max_vecs); + if (bio->bi_max_vecs) { + bio_copy_bvec(bio, iter); + return; + } + if (bio_op(bio) == REQ_OP_ZONE_APPEND) { struct request_queue *q = bdev_get_queue(bio->bi_bdev); size_t max_sectors = queue_max_zone_append_sectors(q);