Re: [PATCH net-next v18 20/25] ovpn: implement peer add/get/dump/delete via netlink

On 17/01/2025 12:48, Sabrina Dubroca wrote:
[...]

With the delayed socket release (which is similar to what was in v11,
but now with refcounting on the netdevice which should make
rtnl_link_unregister in ovpn_cleanup wait [*]), we may return to
userspace as if the peer was gone, but the socket hasn't been detached
yet.

A userspace application that tries to remove the peer and immediately
re-create it with the same socket could get EBUSY if the workqueue
hasn't done its job yet. That would be quite confusing to the
application.

So I would add a completion to wait here until the socket has been
fully detached. Something like below.

[*] I don't think the current refcounting fully protects against that,
I'll comment on 05/25

Sabrina, after the other changes I acknowledged, do you still have 
comments for 5/25?

Thanks a lot!

Regards,

-- 
Antonio Quartulli
OpenVPN Inc.