Re: [PATCH net] vhost_net: don't continue to call the recvmsg when meet errors
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2016-11-30 13:41:15
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On Wed, Nov 30, 2016 at 08:10:57PM +0800, Yunjian Wang wrote:
When we meet an error(err=-EBADFD) recvmsg,
How do you get EBADFD? Won't vhost_net_rx_peek_head_len return 0 in this case, breaking the loop?
quoted hunk ↗ jump to hunk
the error handling in vhost handle_rx() will continue. This will cause a soft CPU lockup in vhost thread. Signed-off-by: Yunjian Wang <redacted> --- drivers/vhost/net.c | 3 +++ 1 file changed, 3 insertions(+)diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 5dc128a..edc470b 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c@@ -717,6 +717,9 @@ static void handle_rx(struct vhost_net *net) pr_debug("Discarded rx packet: " " len %d, expected %zd\n", err, sock_len); vhost_discard_vq_desc(vq, headcount); + /* Don't continue to do, when meet errors. */ + if (err < 0) + goto out;
You might get e.g. EAGAIN and I think you need to retry in this case.
continue; } /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ -- 1.9.5.msysgit.1