[PATCH net-next v4 2/3] vsock: Move lingering logic to af_vsock core

[Michal Luczaj]

Lingering should be transport-independent in the long run. In preparation
for supporting other transports, as well the linger on shutdown(), move
code to core.

Generalize by querying vsock_transport::unsent_bytes(), guard against the
callback being unimplemented. Do not pass sk_lingertime explicitly. Pull
SOCK_LINGER check into vsock_linger().

Flatten the function. Remove the nested block by inverting the condition:
return early on !timeout.

Suggested-by: Stefano Garzarella <sgarz...@redhat.com>
Signed-off-by: Michal Luczaj <m...@rbox.co>
---
 include/net/af_vsock.h                  |  1 +
 net/vmw_vsock/af_vsock.c                | 30 ++++++++++++++++++++++++++++++
 net/vmw_vsock/virtio_transport_common.c | 23 ++---------------------
 3 files changed, 33 insertions(+), 21 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 
9e85424c834353d016a527070dd62e15ff3bfce1..d56e6e135158939087d060dfcf65d3fdaea53bf3
 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);
 
 /**** TAP ****/
 
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 
fc6afbc8d6806a4d98c66abc3af4bd139c583b08..a31ad6b141cd38d1806df4b5d417924bb8607e32
 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1013,6 +1013,36 @@ static int vsock_getname(struct socket *sock,
        return err;
 }
 
+void vsock_linger(struct sock *sk)
+{
+       DEFINE_WAIT_FUNC(wait, woken_wake_function);
+       ssize_t (*unsent)(struct vsock_sock *vsk);
+       struct vsock_sock *vsk = vsock_sk(sk);
+       long timeout;
+
+       if (!sock_flag(sk, SOCK_LINGER))
+               return;
+
+       timeout = sk->sk_lingertime;
+       if (!timeout)
+               return;
+
+       /* unsent_bytes() may be unimplemented. */
+       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;
diff --git a/net/vmw_vsock/virtio_transport_common.c 
b/net/vmw_vsock/virtio_transport_common.c
index 
045ac53f69735e1979162aea8c9ab5961407640c..aa308f285bf1bcf4c689407033de854c6f85a639
 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1192,25 +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);
-               struct vsock_sock *vsk = vsock_sk(sk);
-
-               add_wait_queue(sk_sleep(sk), &wait);
-
-               do {
-                       if (sk_wait_event(sk, &timeout,
-                                         virtio_transport_unsent_bytes(vsk) == 
0,
-                                         &wait))
-                               break;
-               } while (!signal_pending(current) && timeout);
-
-               remove_wait_queue(sk_sleep(sk), &wait);
-       }
-}
-
 static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,
                                               bool cancel_timeout)
 {
@@ -1280,8 +1261,8 @@ static bool virtio_transport_close(struct vsock_sock *vsk)
        if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
                (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);
+       if (!(current->flags & PF_EXITING))
+               vsock_linger(sk);
 
        if (sock_flag(sk, SOCK_DONE)) {
                return true;

-- 
2.49.0