[RFC PATCH v2 09/13] virtio/vsock: implement fetch of record length
From: Arseny Krasnov <hidden>
Date: 2021-01-15 05:45:12
Also in:
kvm, lkml
Subsystem:
networking [general], the rest, virtio and vhost vsock driver, virtio core, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefan Hajnoczi, Stefano Garzarella, "Michael S. Tsirkin", Jason Wang
This adds transport callback which tries to fetch record begin marker from socket's rx queue. It is called from af_vsock.c before reading data packets of record. Signed-off-by: Arseny Krasnov <redacted> --- include/linux/virtio_vsock.h | 1 + net/vmw_vsock/virtio_transport_common.c | 33 +++++++++++++++++++++++++ 2 files changed, 34 insertions(+)
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 7f0ef5204e33..af8705ea8b95 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h@@ -84,6 +84,7 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, size_t len, int flags); +size_t virtio_transport_seqpacket_seq_get_len(struct vsock_sock *vsk); s64 virtio_transport_stream_has_data(struct vsock_sock *vsk); s64 virtio_transport_stream_has_space(struct vsock_sock *vsk);
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 4328f653a477..fe1272e74517 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c@@ -420,6 +420,39 @@ static size_t virtio_transport_drop_until_seq_begin(struct virtio_vsock_sock *vv return bytes_dropped; } +size_t virtio_transport_seqpacket_seq_get_len(struct vsock_sock *vsk) +{ + struct virtio_vsock_sock *vvs = vsk->trans; + struct virtio_vsock_pkt *pkt; + size_t bytes_dropped; + + spin_lock_bh(&vvs->rx_lock); + + /* Fetch all orphaned 'RW', packets, and + * send credit update. + */ + bytes_dropped = virtio_transport_drop_until_seq_begin(vvs); + + if (list_empty(&vvs->rx_queue)) + goto out; + + pkt = list_first_entry(&vvs->rx_queue, struct virtio_vsock_pkt, list); + + vvs->user_read_copied = 0; + vvs->user_read_seq_len = le32_to_cpu(pkt->hdr.flags); + virtio_transport_del_n_free_pkt(pkt); +out: + spin_unlock_bh(&vvs->rx_lock); + + if (bytes_dropped) + virtio_transport_send_credit_update(vsk, + VIRTIO_VSOCK_TYPE_SEQPACKET, + NULL); + + return vvs->user_read_seq_len; +} +EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_seq_get_len); + static ssize_t virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, struct msghdr *msg, size_t user_buf_len)
--
2.25.1