Stefano Garzarella
2021-May-13 12:18 UTC
[RFC PATCH v9 11/19] virtio/vsock: dequeue callback for SOCK_SEQPACKET
On Sat, May 08, 2021 at 07:35:20PM +0300, Arseny Krasnov wrote:>This adds transport callback and it's logic for SEQPACKET dequeue. >Callback fetches RW packets from rx queue of socket until whole record >is copied(if user's buffer is full, user is not woken up). This is done >to not stall sender, because if we wake up user and it leaves syscall, >nobody will send credit update for rest of record, and sender will wait >for next enter of read syscall at receiver's side. So if user buffer is >full, we just send credit update and drop data. > >Signed-off-by: Arseny Krasnov <arseny.krasnov at kaspersky.com> >--- > v8 -> v9: > 1) Check for RW packet type is removed from loop(all packet now > considered RW). > 2) Locking in loop is fixed. > 3) cpu_to_le32()/le32_to_cpu() now used. > 4) MSG_TRUNC handling removed from transport. > > include/linux/virtio_vsock.h | 5 ++ > net/vmw_vsock/virtio_transport_common.c | 64 +++++++++++++++++++++++++ > 2 files changed, 69 insertions(+) > >diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h >index dc636b727179..02acf6e9ae04 100644 >--- a/include/linux/virtio_vsock.h >+++ b/include/linux/virtio_vsock.h >@@ -80,6 +80,11 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk, > struct msghdr *msg, > size_t len, int flags); > >+ssize_t >+virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, >+ struct msghdr *msg, >+ int flags, >+ bool *msg_ready); > 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 ad0d34d41444..f649a21dd23b 100644 >--- a/net/vmw_vsock/virtio_transport_common.c >+++ b/net/vmw_vsock/virtio_transport_common.c >@@ -393,6 +393,58 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk, > return err; > } > >+static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk, >+ struct msghdr *msg, >+ int flags, >+ bool *msg_ready) >+{ >+ struct virtio_vsock_sock *vvs = vsk->trans; >+ struct virtio_vsock_pkt *pkt; >+ int err = 0; >+ size_t user_buf_len = msg->msg_iter.count;Forgot to mention that also here is better to use `msg_data_left(msg)` Thanks, Stefano