On Mon, May 19, 2025 at 03:06:48PM +0800, Xuewei Niu wrote:
The virtio_vsock_sock has a new field called bytes_unread as the return
value of the SIOCINQ ioctl.
Though the rx_bytes exists, we introduce a bytes_unread field to the
virtio_vsock_sock struct. The reason is that it will not be updated
until the skbuff is fully consumed, which causes inconsistency.
The byte_unread is increased by the length of the skbuff when skbuff is
enqueued, and it is decreased when dequeued.
Signed-off-by: Xuewei Niu <niuxuewei.nxw@xxxxxxxxxxxx>
---
drivers/vhost/vsock.c | 1 +
include/linux/virtio_vsock.h | 2 ++
net/vmw_vsock/virtio_transport.c | 1 +
net/vmw_vsock/virtio_transport_common.c | 17 +++++++++++++++++
net/vmw_vsock/vsock_loopback.c | 1 +
5 files changed, 22 insertions(+)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 802153e23073..0f20af6e5036 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -452,6 +452,7 @@ static struct virtio_transport vhost_transport = {
.notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat,
.unsent_bytes = virtio_transport_unsent_bytes,
+ .unread_bytes = virtio_transport_unread_bytes,
.read_skb = virtio_transport_read_skb,
},
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 0387d64e2c66..0a7bd240113a 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -142,6 +142,7 @@ struct virtio_vsock_sock {
u32 buf_alloc;
struct sk_buff_head rx_queue;
u32 msg_count;
+ size_t bytes_unread;
Can we just use `rx_bytes` field we already have?
Thanks,
Stefano
};
struct virtio_vsock_pkt_info {
@@ -195,6 +196,7 @@ s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk);
ssize_t virtio_transport_unsent_bytes(struct vsock_sock *vsk);
+ssize_t virtio_transport_unread_bytes(struct vsock_sock *vsk);
void virtio_transport_consume_skb_sent(struct sk_buff *skb,
bool consume);
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index f0e48e6911fc..917881537b63 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -585,6 +585,7 @@ static struct virtio_transport virtio_transport = {
.notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat,
.unsent_bytes = virtio_transport_unsent_bytes,
+ .unread_bytes = virtio_transport_unread_bytes,
.read_skb = virtio_transport_read_skb,
},
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 7f7de6d88096..11eae88c60fc 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -632,6 +632,7 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
free_space = vvs->buf_alloc - fwd_cnt_delta;
low_rx_bytes = (vvs->rx_bytes <
sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX));
+ vvs->bytes_unread -= total;
spin_unlock_bh(&vvs->rx_lock);
@@ -782,6 +783,7 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
}
virtio_transport_dec_rx_pkt(vvs, pkt_len);
+ vvs->bytes_unread -= pkt_len;
kfree_skb(skb);
}
@@ -1132,6 +1134,19 @@ ssize_t virtio_transport_unsent_bytes(struct vsock_sock *vsk)
}
EXPORT_SYMBOL_GPL(virtio_transport_unsent_bytes);
+ssize_t virtio_transport_unread_bytes(struct vsock_sock *vsk)
+{
+ struct virtio_vsock_sock *vvs = vsk->trans;
+ size_t ret;
+
+ spin_lock_bh(&vvs->rx_lock);
+ ret = vvs->bytes_unread;
+ spin_unlock_bh(&vvs->rx_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtio_transport_unread_bytes);
+
static int virtio_transport_reset(struct vsock_sock *vsk,
struct sk_buff *skb)
{
@@ -1365,6 +1380,8 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
goto out;
}
+ vvs->bytes_unread += len;
+
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)
vvs->msg_count++;
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index 6e78927a598e..13a77db2a76f 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -99,6 +99,7 @@ static struct virtio_transport loopback_transport = {
.notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat,
.unsent_bytes = virtio_transport_unsent_bytes,
+ .unread_bytes = virtio_transport_unread_bytes,
.read_skb = virtio_transport_read_skb,
},
--
2.34.1
