Re: [PATCH net-next v3 08/24] ovpn: introduce the ovpn_socket object

2024-05-08, 22:38:58 +0200, Antonio Quartulli wrote:

On 08/05/2024 19:10, Sabrina Dubroca wrote:

quoted

2024-05-06, 03:16:21 +0200, Antonio Quartulli wrote:

quoted

diff --git a/drivers/net/ovpn/socket.c b/drivers/net/ovpn/socket.c
new file mode 100644
index 000000000000..a4a4d69162f0
--- /dev/null
+++ b/drivers/net/ovpn/socket.c

[...]

quoted

+
+/* Finalize release of socket, called after RCU grace period */

kref_put seems to call ovpn_socket_release_kref without waiting, and
then that calls ovpn_socket_detach immediately as well. Am I missing
something?

hmm what do we need to wait for exactly? (Maybe I am missing something)
The ovpn_socket will survive a bit longer thanks to kfree_rcu.

The way I read this comment, it says that ovpn_socket_detach will be
called after one RCU grace period, but I don't see where that grace
period would come from.

    ovpn_socket_put -> kref_put(release=ovpn_socket_release_kref) ->
      ovpn_socket_release_kref -> ovpn_socket_detach

No grace period here.

Or am I misinterpreting the comment? There will be a grace period
caused by kfree_rcu before the ovpn_socket is actually freed, is that
what the comment means?

quoted

quoted

+static void ovpn_socket_detach(struct socket *sock)
+{
+	if (!sock)
+		return;
+
+	sockfd_put(sock);
+}

-- 
Sabrina