From 45a267dbb40f5cf15efa23ce815c4fe0b4674aa2 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 22 Jan 2018 15:20:15 +0100 Subject: libceph: handle zero-length data items rbd needs this for null copyups -- if copyup data is all zeroes, we want to save some I/O and network bandwidth. See rbd_obj_issue_copyup() in the next commit. Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder --- net/ceph/messenger.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index 91a57857cf11..cee4b3d307de 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1605,13 +1605,18 @@ static int write_partial_message_data(struct ceph_connection *con) * been revoked, so use the zero page. */ crc = do_datacrc ? le32_to_cpu(msg->footer.data_crc) : 0; - while (cursor->resid) { + while (cursor->total_resid) { struct page *page; size_t page_offset; size_t length; bool last_piece; int ret; + if (!cursor->resid) { + ceph_msg_data_advance(cursor, 0); + continue; + } + page = ceph_msg_data_next(cursor, &page_offset, &length, &last_piece); ret = ceph_tcp_sendpage(con->sock, page, page_offset, @@ -2327,7 +2332,12 @@ static int read_partial_msg_data(struct ceph_connection *con) if (do_datacrc) crc = con->in_data_crc; - while (cursor->resid) { + while (cursor->total_resid) { + if (!cursor->resid) { + ceph_msg_data_advance(cursor, 0); + continue; + } + page = ceph_msg_data_next(cursor, &page_offset, &length, NULL); ret = ceph_tcp_recvpage(con->sock, page, page_offset, length); if (ret <= 0) { -- cgit v1.2.3