Re: [RFC PATCH v4 10/17] virtio/vsock: fetch length for SEQPACKET record
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2021-02-11 14:18:32
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lkml, netdev, virtualization
On Sun, Feb 07, 2021 at 06:17:08PM +0300, Arseny Krasnov wrote:
quoted hunk ↗ jump to hunk
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 | 40 +++++++++++++++++++++++++ 2 files changed, 41 insertions(+)diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 4d0de3dee9a4..a5e8681bfc6a 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h@@ -85,6 +85,7 @@ 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 4572d01c8ea5..7ac552bfd90b 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c@@ -420,6 +420,46 @@ static size_t virtio_transport_drop_until_seq_begin(struct virtio_vsock_sock *vvreturn bytes_dropped; } +size_t virtio_transport_seqpacket_seq_get_len(struct vsock_sock *vsk) +{ + struct virtio_vsock_seq_hdr *seq_hdr; + struct virtio_vsock_sock *vvs; + struct virtio_vsock_pkt *pkt; + size_t bytes_dropped; + + vvs = vsk->trans; + + spin_lock_bh(&vvs->rx_lock); + + /* Fetch all orphaned 'RW', packets, and + * send credit update.
Single line?
+ */ + 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; + + seq_hdr = (struct virtio_vsock_seq_hdr *)pkt->buf; + vvs->user_read_seq_len = le32_to_cpu(seq_hdr->msg_len); + vvs->curr_rx_msg_cnt = le32_to_cpu(seq_hdr->msg_cnt); + virtio_transport_dec_rx_pkt(vvs, pkt); + virtio_transport_remove_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 int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, struct msghdr *msg, bool *msg_ready) -- 2.25.1