On Mon, Apr 07, 2025 at 08:41:43PM +0200, Michal Luczaj wrote:
Change the behaviour of a lingering close(): instead of waiting for all
data to be consumed, block until data is considered sent, i.e. until worker
picks the packets and decrements virtio_vsock_sock::bytes_unsent down to 0.
Do linger on shutdown() just as well.
I think this should go in a separate patch.
Signed-off-by: Michal Luczaj <m...@rbox.co>
---
include/net/af_vsock.h | 1 +
net/vmw_vsock/af_vsock.c | 25 +++++++++++++++++++++++++
net/vmw_vsock/virtio_transport_common.c | 25 +++----------------------
3 files changed, 29 insertions(+), 22 deletions(-)
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index
9e85424c834353d016a527070dd62e15ff3bfce1..bd8b88d70423051dd05fc445fe37971af631ba03
100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -221,6 +221,7 @@ void vsock_for_each_connected_socket(struct vsock_transport
*transport,
void (*fn)(struct sock *sk));
int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
bool vsock_find_cid(unsigned int cid);
+void vsock_linger(struct sock *sk, long timeout);
/**** TAP ****/
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index
fc6afbc8d6806a4d98c66abc3af4bd139c583b08..383c6644d047589035c0439c47d1440273e67ea9
100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1013,6 +1013,29 @@ static int vsock_getname(struct socket *sock,
return err;
}
+void vsock_linger(struct sock *sk, long timeout)
+{
+ if (timeout) {
I would prefer to avoid a whole nested block and return immediately
in such a case. (It's pre-existing, but since we are moving this code
I'd fix it).
if (!timeout)
return;
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+ ssize_t (*unsent)(struct vsock_sock *vsk);
+ struct vsock_sock *vsk = vsock_sk(sk);
+
transport->unsent_bytes can be NULL, this will panic with hyperv or
vmci transport, especially because we now call this function in
vsock_shutdown().
I'd skip that call if transports don't implement it, but please add
a comment on top of this function about that.
+ unsent = vsk->transport->unsent_bytes;
+ if (!unsent)
+ return;
+
+ add_wait_queue(sk_sleep(sk), &wait);
+
+ do {
+ if (sk_wait_event(sk, &timeout, unsent(vsk) == 0,
&wait))
+ break;
+ } while (!signal_pending(current) && timeout);
+
+ remove_wait_queue(sk_sleep(sk), &wait);
+ }
+}
+EXPORT_SYMBOL_GPL(vsock_linger);
+
static int vsock_shutdown(struct socket *sock, int mode)
{
int err;
@@ -1056,6 +1079,8 @@ static int vsock_shutdown(struct socket *sock, int mode)
if (sock_type_connectible(sk->sk_type)) {
sock_reset_flag(sk, SOCK_DONE);
vsock_send_shutdown(sk, mode);
+ if (sock_flag(sk, SOCK_LINGER))
+ vsock_linger(sk, sk->sk_lingertime);
}
}
diff --git a/net/vmw_vsock/virtio_transport_common.c
b/net/vmw_vsock/virtio_transport_common.c
index
7f7de6d8809655fe522749fbbc9025df71f071bd..66ff2e694e474ad16f70248cc1dc235f4e1ebaa1
100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1192,23 +1192,6 @@ static void virtio_transport_remove_sock(struct
vsock_sock *vsk)
vsock_remove_sock(vsk);
}
-static void virtio_transport_wait_close(struct sock *sk, long timeout)
-{
- if (timeout) {
- DEFINE_WAIT_FUNC(wait, woken_wake_function);
-
- add_wait_queue(sk_sleep(sk), &wait);
-
- do {
- if (sk_wait_event(sk, &timeout,
- sock_flag(sk, SOCK_DONE), &wait))
- break;
- } while (!signal_pending(current) && timeout);
-
- remove_wait_queue(sk_sleep(sk), &wait);
- }
-}
Anyway in this patch we are doing 3 things:
1. check unsent_bytes during wait_close()
2. move wait_close in af_vsock.c adding vsock_linger()
3. call vsock_linger() also during vsock_shutdown()
I think this is a clear signal that we need to split it into at least
3 patches.
-
static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,
bool cancel_timeout)
{
@@ -1279,15 +1262,13 @@ static bool virtio_transport_close(struct vsock_sock
*vsk)
(void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
- virtio_transport_wait_close(sk, sk->sk_lingertime);
+ vsock_linger(sk, sk->sk_lingertime);
Might it make sense, as you did for vsock_shutdown(), to move this
to af_vsock.c (in another patch) so that we support it for all
transports?
- if (sock_flag(sk, SOCK_DONE)) {
+ if (sock_flag(sk, SOCK_DONE))
return true;
- }
Please avoid this unrelated changes, if you really want to fix them,
add another patch in the series where to fix them.
sock_hold(sk);
- INIT_DELAYED_WORK(&vsk->close_work,
- virtio_transport_close_timeout);
+ INIT_DELAYED_WORK(&vsk->close_work, virtio_transport_close_timeout);
Ditto.
These 2 could go together in a single `cleanup` patch, although I
usually avoid it so that `git blame` makes sense. But if we want to
make checkpatch happy, that's fine.
Thanks,
Stefano
vsk->close_work_scheduled = true;
schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
return false;
--
2.49.0
