From: Jason Wang <jasowang@redhat.com>
To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: mst@redhat.com, wangyunjian@huawei.com, Jason Wang <jasowang@redhat.com>
Subject: [PATCH net 2/2] macvtap: handle ubuf refcount correctly when meet erros
Date: Wed, 30 Nov 2016 13:17:52 +0800 [thread overview]
Message-ID: <1480483072-14201-2-git-send-email-jasowang@redhat.com> (raw)
In-Reply-To: <1480483072-14201-1-git-send-email-jasowang@redhat.com>
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(-)
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
next prev parent reply other threads:[~2016-11-30 5:18 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-30 5:17 [PATCH net 1/2] tun: handle ubuf refcount correctly when meet erros Jason Wang
2016-11-30 5:17 ` Jason Wang [this message]
2016-11-30 13:58 ` [PATCH net 2/2] macvtap: " Michael S. Tsirkin
2016-11-30 13:57 ` [PATCH net 1/2] tun: " Michael S. Tsirkin
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