From: "Michael S. Tsirkin" <mst@redhat.com>
To: wangyunjian <wangyunjian@huawei.com>
Cc: willemdebruijn.kernel@gmail.com, netdev@vger.kernel.org,
jerry.lilijun@huawei.com,
virtualization@lists.linux-foundation.org, xudingke@huawei.com,
brian.huangbin@huawei.com, chenchanghu@huawei.com
Subject: Re: [PATCH net v2 1/2] vhost_net: fix ubuf refcount incorrectly when sendmsg fails
Date: Wed, 16 Dec 2020 15:56:45 -0500 [thread overview]
Message-ID: <20201216155633-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <62db7d3d2af50f379ec28452921b3261af33db0b.1608065644.git.wangyunjian@huawei.com>
On Wed, Dec 16, 2020 at 04:20:20PM +0800, wangyunjian wrote:
> From: Yunjian Wang <wangyunjian@huawei.com>
>
> 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: 0690899b4d45 ("tun: experimental zero copy tx support")
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> drivers/vhost/net.c | 6 +++---
> 1 file 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;
> }
> --
> 2.23.0
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WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: wangyunjian <wangyunjian@huawei.com>
Cc: netdev@vger.kernel.org, jasowang@redhat.com,
willemdebruijn.kernel@gmail.com,
virtualization@lists.linux-foundation.org,
jerry.lilijun@huawei.com, chenchanghu@huawei.com,
xudingke@huawei.com, brian.huangbin@huawei.com
Subject: Re: [PATCH net v2 1/2] vhost_net: fix ubuf refcount incorrectly when sendmsg fails
Date: Wed, 16 Dec 2020 15:56:45 -0500 [thread overview]
Message-ID: <20201216155633-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <62db7d3d2af50f379ec28452921b3261af33db0b.1608065644.git.wangyunjian@huawei.com>
On Wed, Dec 16, 2020 at 04:20:20PM +0800, wangyunjian wrote:
> From: Yunjian Wang <wangyunjian@huawei.com>
>
> 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: 0690899b4d45 ("tun: experimental zero copy tx support")
>
> Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> drivers/vhost/net.c | 6 +++---
> 1 file 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;
> }
> --
> 2.23.0
next prev parent reply other threads:[~2020-12-16 20:57 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 1:48 [PATCH net 0/2] fixes for vhost_net wangyunjian
2020-12-15 1:48 ` [PATCH net 1/2] vhost_net: fix ubuf refcount incorrectly when sendmsg fails wangyunjian
2020-12-15 2:45 ` Willem de Bruijn
2020-12-15 2:45 ` Willem de Bruijn
2020-12-15 7:51 ` wangyunjian
2020-12-15 1:48 ` [PATCH net 2/2] vhost_net: fix high cpu load " wangyunjian
2020-12-15 4:09 ` Jason Wang
2020-12-15 4:09 ` Jason Wang
2020-12-15 8:03 ` wangyunjian
2020-12-16 5:56 ` Jason Wang
2020-12-16 5:56 ` Jason Wang
2020-12-16 7:43 ` wangyunjian
2020-12-16 7:47 ` Jason Wang
2020-12-16 7:47 ` Jason Wang
2020-12-16 8:20 ` [PATCH net v2 0/2] fixes for vhost_net wangyunjian
2020-12-16 8:20 ` [PATCH net v2 1/2] vhost_net: fix ubuf refcount incorrectly when sendmsg fails wangyunjian
2020-12-16 14:17 ` Willem de Bruijn
2020-12-16 14:17 ` Willem de Bruijn
2020-12-16 20:56 ` Michael S. Tsirkin [this message]
2020-12-16 20:56 ` Michael S. Tsirkin
2020-12-16 8:20 ` [PATCH net v2 2/2] vhost_net: fix high cpu load " wangyunjian
2020-12-16 9:23 ` Michael S. Tsirkin
2020-12-16 9:23 ` Michael S. Tsirkin
2020-12-17 2:38 ` wangyunjian
2020-12-17 3:19 ` Jason Wang
2020-12-17 3:19 ` Jason Wang
2020-12-21 23:07 ` Willem de Bruijn
2020-12-21 23:07 ` Willem de Bruijn
2020-12-22 4:41 ` Jason Wang
2020-12-22 4:41 ` Jason Wang
2020-12-22 14:24 ` Willem de Bruijn
2020-12-22 14:24 ` Willem de Bruijn
2020-12-23 2:53 ` Jason Wang
2020-12-23 2:53 ` Jason Wang
2020-12-23 13:21 ` wangyunjian
2020-12-23 13:48 ` Willem de Bruijn
2020-12-23 13:48 ` Willem de Bruijn
2020-12-23 2:46 ` wangyunjian
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