| Message ID | 1480483072-14201-2-git-send-email-jasowang@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, Nov 30, 2016 at 01:17:52PM +0800, Jason Wang wrote: > We trigger uarg->callback() immediately after we decide do datacopy > even if caller want to do zerocopy. This will cause the callback > (vhost_net_zerocopy_callback) decrease the refcount. But when we meet > an error afterwards, the error handling in vhost handle_tx() will try > to decrease it again. This is wrong and fix this by delay the > uarg->callback() until we're sure there's no errors. > > Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> > --- > The patch is needed for -stable. > --- > drivers/net/macvtap.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c > index bceca28..7869b06 100644 > --- a/drivers/net/macvtap.c > +++ b/drivers/net/macvtap.c > @@ -742,13 +742,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, > > if (zerocopy) > err = zerocopy_sg_from_iter(skb, from); > - else { > + else > err = skb_copy_datagram_from_iter(skb, 0, from, len); > - if (!err && m && m->msg_control) { > - struct ubuf_info *uarg = m->msg_control; > - uarg->callback(uarg, false); > - } > - } > > if (err) > goto err_kfree; > @@ -779,7 +774,11 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, > skb_shinfo(skb)->destructor_arg = m->msg_control; > skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; > skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; > + } else if (m && m->msg_control) { > + struct ubuf_info *uarg = m->msg_control; > + uarg->callback(uarg, false); > } > + > if (vlan) { > skb->dev = vlan->dev; > dev_queue_xmit(skb); > -- > 2.7.4
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index bceca28..7869b06 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -742,13 +742,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, if (zerocopy) err = zerocopy_sg_from_iter(skb, from); - else { + else err = skb_copy_datagram_from_iter(skb, 0, from, len); - if (!err && m && m->msg_control) { - struct ubuf_info *uarg = m->msg_control; - uarg->callback(uarg, false); - } - } if (err) goto err_kfree; @@ -779,7 +774,11 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m, skb_shinfo(skb)->destructor_arg = m->msg_control; skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; + } else if (m && m->msg_control) { + struct ubuf_info *uarg = m->msg_control; + uarg->callback(uarg, false); } + if (vlan) { skb->dev = vlan->dev; dev_queue_xmit(skb);
We trigger uarg->callback() immediately after we decide do datacopy even if caller want to do zerocopy. This will cause the callback (vhost_net_zerocopy_callback) decrease the refcount. But when we meet an error afterwards, the error handling in vhost handle_tx() will try to decrease it again. This is wrong and fix this by delay the uarg->callback() until we're sure there's no errors. Signed-off-by: Jason Wang <jasowang@redhat.com> --- The patch is needed for -stable. --- drivers/net/macvtap.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)