From 1c39f5dbbfd2b44602d46936fe55361205196257 Mon Sep 17 00:00:00 2001 From: Michal Luczaj Date: Thu, 22 May 2025 01:18:21 +0200 Subject: [PATCH] vsock/virtio: Linger on unsent data Currently vsock's lingering effectively boils down to waiting (or timing out) until packets are consumed or dropped by the peer; be it by receiving the data, closing or shutting down the connection. To align with the semantics described in the SO_LINGER section of man socket(7) and to mimic AF_INET's behaviour more closely, change the logic of a lingering close(): instead of waiting for all data to be handled, block until data is considered sent from the vsock's transport point of view. That is until worker picks the packets for processing and decrements virtio_vsock_sock::bytes_unsent down to 0. Note that (some interpretation of) lingering was always limited to transports that called virtio_transport_wait_close() on transport release. This does not change, i.e. under Hyper-V and VMCI no lingering would be observed. The implementation does not adhere strictly to man page's interpretation of SO_LINGER: shutdown() will not trigger the lingering. This follows AF_INET. Reviewed-by: Stefano Garzarella Signed-off-by: Michal Luczaj Link: https://patch.msgid.link/20250522-vsock-linger-v6-1-2ad00b0e447e@rbox.co Signed-off-by: Paolo Abeni --- net/vmw_vsock/virtio_transport_common.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 6e7b727c781c..f2f1b166731b 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1195,12 +1195,14 @@ static void virtio_transport_wait_close(struct sock *sk, long timeout) { if (timeout) { DEFINE_WAIT_FUNC(wait, woken_wake_function); + struct vsock_sock *vsk = vsock_sk(sk); add_wait_queue(sk_sleep(sk), &wait); do { if (sk_wait_event(sk, &timeout, - sock_flag(sk, SOCK_DONE), &wait)) + virtio_transport_unsent_bytes(vsk) == 0, + &wait)) break; } while (!signal_pending(current) && timeout); -- 2.50.1