[PATCH v4 3/5] vsock/virtio: fix locking in virtio_transport_inc_tx_pkt()

From: Stefano Garzarella
Date: Wed Jul 17 2019 - 07:30:53 EST


fwd_cnt and last_fwd_cnt are protected by rx_lock, so we should use
the same spinlock also if we are in the TX path.

Move also buf_alloc under the same lock.

Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
include/linux/virtio_vsock.h | 2 +-
net/vmw_vsock/virtio_transport_common.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 49fc9d20bc43..4c7781f4b29b 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -35,7 +35,6 @@ struct virtio_vsock_sock {

/* Protected by tx_lock */
u32 tx_cnt;
- u32 buf_alloc;
u32 peer_fwd_cnt;
u32 peer_buf_alloc;

@@ -43,6 +42,7 @@ struct virtio_vsock_sock {
u32 fwd_cnt;
u32 last_fwd_cnt;
u32 rx_bytes;
+ u32 buf_alloc;
struct list_head rx_queue;
};

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index a85559d4d974..34a2b42313b7 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -210,11 +210,11 @@ static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,

void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
{
- spin_lock_bh(&vvs->tx_lock);
+ spin_lock_bh(&vvs->rx_lock);
vvs->last_fwd_cnt = vvs->fwd_cnt;
pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
- spin_unlock_bh(&vvs->tx_lock);
+ spin_unlock_bh(&vvs->rx_lock);
}
EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);

--
2.20.1