From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: Re: [RFC PATCH net-next 01/12] vhost_net: introduce helper to initialize tx iov iter Date: Tue, 22 May 2018 20:26:37 +0800 Message-ID: <2d54d4e2-c5fc-167b-9a8d-762aed2d1ba5@redhat.com> References: <1526893473-20128-1-git-send-email-jasowang@redhat.com> <1526893473-20128-2-git-send-email-jasowang@redhat.com> <20180521092400.00004c68@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Cc: mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org To: Jesse Brandeburg Return-path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60604 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751340AbeEVM0q (ORCPT ); Tue, 22 May 2018 08:26:46 -0400 In-Reply-To: <20180521092400.00004c68@intel.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 2018年05月22日 00:24, Jesse Brandeburg wrote: > Hi Jason, a few nits. > > On Mon, 21 May 2018 17:04:22 +0800 Jason wrote: >> Signed-off-by: Jason Wang >> --- >> drivers/vhost/net.c | 34 +++++++++++++++++++++++----------- >> 1 file changed, 23 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c >> index c4b49fc..15d191a 100644 >> --- a/drivers/vhost/net.c >> +++ b/drivers/vhost/net.c >> @@ -459,6 +459,26 @@ static bool vhost_exceeds_maxpend(struct vhost_net *net) >> min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2); >> } >> >> +static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter, >> + size_t hdr_size, int out) >> +{ >> + /* Skip header. TODO: support TSO. */ >> + size_t len = iov_length(vq->iov, out); >> + >> + iov_iter_init(iter, WRITE, vq->iov, out, len); >> + iov_iter_advance(iter, hdr_size); >> + /* Sanity check */ >> + if (!iov_iter_count(iter)) { >> + vq_err(vq, "Unexpected header len for TX: " >> + "%zd expected %zd\n", >> + len, hdr_size); > ok, it was like this before, but please unwrap the string in " ", there > should be no line breaks in string declarations and they are allowed to > go over 80 characters. Ok. > >> + return -EFAULT; >> + } >> + len = iov_iter_count(iter); >> + >> + return len; >> +} >> + >> /* Expects to be always run from workqueue - which acts as >> * read-size critical section for our kind of RCU. */ >> static void handle_tx(struct vhost_net *net) >> @@ -521,18 +541,10 @@ static void handle_tx(struct vhost_net *net) >> "out %d, int %d\n", out, in); >> break; >> } >> - /* Skip header. TODO: support TSO. */ >> - len = iov_length(vq->iov, out); >> - iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len); >> - iov_iter_advance(&msg.msg_iter, hdr_size); >> - /* Sanity check */ >> - if (!msg_data_left(&msg)) { >> - vq_err(vq, "Unexpected header len for TX: " >> - "%zd expected %zd\n", >> - len, hdr_size); >> + >> + len = init_iov_iter(vq, &msg.msg_iter, hdr_size, out); >> + if (len < 0) > len is declared as size_t, which is unsigned, and can never be > negative. I'm pretty sure this is a bug. Yes, let me fix it in next version. Thanks > > >> break; >> - } >> - len = msg_data_left(&msg); >> >> zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN >> && !vhost_exceeds_maxpend(net)