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 <jasow...@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
