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authorJason Wang <jasowang@redhat.com>2016-11-30 13:17:51 +0800
committerDavid S. Miller <davem@davemloft.net>2016-11-30 15:06:01 -0500
commitaf1cc7a2b86ddb8668ac38097866bedd7b849a76 (patch)
tree2bf4382bcca7c8ce0e04e5395436c620cbcd0de2 /drivers
parent4ccfd6383a1a4838ed034120f00d02dbdc681d6f (diff)
downloadlinux-af1cc7a2b86ddb8668ac38097866bedd7b849a76.tar.bz2
tun: handle ubuf refcount correctly when meet errors
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. Reported-by: wangyunjian <wangyunjian@huawei.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/tun.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 8093e39ae263..db6acecabeaa 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1246,13 +1246,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
if (zerocopy)
err = zerocopy_sg_from_iter(skb, from);
- else {
+ else
err = skb_copy_datagram_from_iter(skb, 0, from, len);
- if (!err && msg_control) {
- struct ubuf_info *uarg = msg_control;
- uarg->callback(uarg, false);
- }
- }
if (err) {
this_cpu_inc(tun->pcpu_stats->rx_dropped);
@@ -1298,6 +1293,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
skb_shinfo(skb)->destructor_arg = msg_control;
skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+ } else if (msg_control) {
+ struct ubuf_info *uarg = msg_control;
+ uarg->callback(uarg, false);
}
skb_reset_network_header(skb);