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| author | Yunjian Wang <wangyunjian@huawei.com> | 2020-12-29 10:01:48 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-01-04 13:18:52 -0800 |
| commit | 01e31bea7e622f1890c274f4aaaaf8bccd296aa5 (patch) | |
| tree | 2921fb5f2a2e41f54389133e5dbf0b26593422a5 /drivers/vhost | |
| parent | 10ad3e998fa0c25315f27cf3002ff8b02dc31c38 (diff) | |
| download | lwn-01e31bea7e622f1890c274f4aaaaf8bccd296aa5.tar.gz lwn-01e31bea7e622f1890c274f4aaaaf8bccd296aa5.zip | |
vhost_net: fix ubuf refcount incorrectly when sendmsg fails
Currently the vhost_zerocopy_callback() maybe be called to decrease
the refcount when sendmsg fails in tun. The error handling in vhost
handle_tx_zerocopy() will try to decrease the same refcount again.
This is wrong. To fix this issue, we only call vhost_net_ubuf_put()
when vq->heads[nvq->desc].len == VHOST_DMA_IN_PROGRESS.
Fixes: bab632d69ee4 ("vhost: vhost TX zero-copy support")
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/1609207308-20544-1-git-send-email-wangyunjian@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/net.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 531a00d703cd..c8784dfafdd7 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -863,6 +863,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) size_t len, total_len = 0; int err; struct vhost_net_ubuf_ref *ubufs; + struct ubuf_info *ubuf; bool zcopy_used; int sent_pkts = 0; @@ -895,9 +896,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) /* use msg_control to pass vhost zerocopy ubuf info to skb */ if (zcopy_used) { - struct ubuf_info *ubuf; ubuf = nvq->ubuf_info + nvq->upend_idx; - vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head); vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS; ubuf->callback = vhost_zerocopy_callback; @@ -927,7 +926,8 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock) err = sock->ops->sendmsg(sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { - vhost_net_ubuf_put(ubufs); + if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS) + vhost_net_ubuf_put(ubufs); nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; } |