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vhost_net: fix wrong iter offset when setting number of buffers

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In commit ba7438aed9 ("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 6e03f896b5 ("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 6e03f896b5
("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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2015-02-15 16:35:17 +08:00 committed by David S. Miller
parent ca9f1fd263
commit 0960b6417e
1 changed files with 6 additions and 5 deletions
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11
drivers/vhost/net.c
View file

@ -528,9 +528,9 @@ static void handle_rx(struct vhost_net *net)
.msg_controllen = 0, .msg_controllen = 0,
.msg_flags = MSG_DONTWAIT, .msg_flags = MSG_DONTWAIT,
}; };
struct virtio_net_hdr_mrg_rxbuf hdr = { struct virtio_net_hdr hdr = {
.hdr.flags = 0, .flags = 0,
.hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE .gso_type = VIRTIO_NET_HDR_GSO_NONE
}; };
size_t total_len = 0; size_t total_len = 0;
int err, mergeable; int err, mergeable;
@ -539,6 +539,7 @@ static void handle_rx(struct vhost_net *net)
size_t vhost_len, sock_len; size_t vhost_len, sock_len;
struct socket *sock; struct socket *sock;
struct iov_iter fixup; struct iov_iter fixup;
__virtio16 num_buffers;
mutex_lock(&vq->mutex); mutex_lock(&vq->mutex);
sock = vq->private_data; sock = vq->private_data;
@ -616,9 +617,9 @@ static void handle_rx(struct vhost_net *net)
} }
/* TODO: Should check and handle checksum. */ /* TODO: Should check and handle checksum. */
hdr.num_buffers = cpu_to_vhost16(vq, headcount); num_buffers = cpu_to_vhost16(vq, headcount);
if (likely(mergeable) && 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"); vq_err(vq, "Failed num_buffers write");
vhost_discard_vq_desc(vq, headcount); vhost_discard_vq_desc(vq, headcount);
break; break;