On Mon, Apr 22, 2019 at 9:46 PM Sasha Levin sashal@kernel.org wrote:
From: Ilya Dryomov idryomov@gmail.com
[ Upstream commit 187df76325af5d9e12ae9daec1510307797e54f0 ]
A bvec can now consist of multiple physically contiguous pages. This means that bvec_iter_advance() can move to a different page while staying in the same bvec (i.e. ->bi_bvec_done != 0).
The messenger works in terms of segments which can now be defined as the smaller of a bvec and a page. The "more bytes to process in this segment" condition holds only if bvec_iter_advance() leaves us in the same bvec _and_ in the same page. On next bvec (possibly in the same page) and on next page (possibly in the same bvec) we may need to set ->last_piece.
Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Sasha Levin (Microsoft) sashal@kernel.org
net/ceph/messenger.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index f7d7f32ac673..ef5216206bdf 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -870,6 +870,7 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor, size_t bytes) { struct ceph_bio_iter *it = &cursor->bio_iter;
struct page *page = bio_iter_page(it->bio, it->iter); BUG_ON(bytes > cursor->resid); BUG_ON(bytes > bio_iter_len(it->bio, it->iter));@@ -881,7 +882,8 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor, return false; /* no more data */ }
if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done))
if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done &&page == bio_iter_page(it->bio, it->iter))) return false; /* more bytes to process in this segment */ if (!it->iter.bi_size) {@@ -929,6 +931,7 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor, size_t bytes) { struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter); BUG_ON(bytes > cursor->resid); BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));@@ -940,7 +943,8 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor, return false; /* no more data */ }
if (!bytes || cursor->bvec_iter.bi_bvec_done)
if (!bytes || (cursor->bvec_iter.bi_bvec_done &&page == bvec_iter_page(bvecs, cursor->bvec_iter))) return false; /* more bytes to process in this segment */ BUG_ON(cursor->last_piece);
Hi Sasha,
This shouldn't be needed. Multipage bvecs code is new in 5.1 (commit 07173c3ec276 ("block: enable multipage bvecs")), this commit just fixed the fall out.
Thanks,
Ilya