[PATCH net] vhost_net: fix wrong iter offset when setting number of buffers
From: Jason Wang <jasowang@redhat.com>
Date: 2015-02-15 08:35:56
Also in:
kvm, lkml
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
In commit ba7438aed924 ("vhost: don't bother copying iovecs in
handle_rx(), kill memcpy_toiovecend()"), we advance iov iter fixup
sizeof(struct virtio_net_hdr) bytes and fill the number of buffers
after doing the socket recvmsg(). This work well but was broken after
commit 6e03f896b52c ("Merge
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net") which tries
to advance sizeof(struct virtio_net_hdr_mrg_rxbuf). It will fill the
number of buffers at the wrong place. This patch fixes this.
Fixes 6e03f896b52c
("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")
Cc: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/net.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 8dccca9..afa06d2 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c@@ -528,9 +528,9 @@ static void handle_rx(struct vhost_net *net) .msg_controllen = 0, .msg_flags = MSG_DONTWAIT, }; - struct virtio_net_hdr_mrg_rxbuf hdr = { - .hdr.flags = 0, - .hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE + struct virtio_net_hdr hdr = { + .flags = 0, + .gso_type = VIRTIO_NET_HDR_GSO_NONE }; size_t total_len = 0; int err, mergeable;
@@ -539,6 +539,7 @@ static void handle_rx(struct vhost_net *net) size_t vhost_len, sock_len; struct socket *sock; struct iov_iter fixup; + __virtio16 num_buffers; mutex_lock(&vq->mutex); sock = vq->private_data;
@@ -616,9 +617,9 @@ static void handle_rx(struct vhost_net *net) } /* TODO: Should check and handle checksum. */ - hdr.num_buffers = cpu_to_vhost16(vq, headcount); + num_buffers = cpu_to_vhost16(vq, headcount); if (likely(mergeable) && - copy_to_iter(&hdr.num_buffers, 2, &fixup) != 2) { + copy_to_iter(&num_buffers, 2, &fixup) != 2) { vq_err(vq, "Failed num_buffers write"); vhost_discard_vq_desc(vq, headcount); break;
--
1.9.1