Re: [PATCH RFC net-next v4 09/12] vsock/loopback: add netns support

[Bobby Eshleman <bobbyeshleman@gmail.com>]

On Wed, Aug 06, 2025 at 08:12:39PM +0100, Simon Horman wrote:
> On Tue, Aug 05, 2025 at 02:49:17PM -0700, Bobby Eshleman wrote:
> > From: Bobby Eshleman <bobbyeshleman@meta.com>
> > 

...

> 
> This change needs to be squashed into
> PATCH 3/12 vsock: add netns to af_vsock core
> 
> To avoid build breakage.
> 
> Likewise with the other change to vsock_loopback_seqpacket_allow below.
> And I think also for a number of other changes made by PATCH 3/12.
> 
> Please make sure that patches don't introduce transient build failures.
> It breaks bisection.

Will do, thanks!

> 
> 
> On the topic of vsock_loopback_seqpacket_allow, also:
> 
> * Please line wrap this so that the code is 80 columns wide or less,
>   as is still preferred for Networking code.
> 
>   Flagged by checkpatch.pl --max-line-length=80
> 
> * Can we move the definition of vsock_loopback_seqpacket_allow() here?
>   The function itself is is trivial. And doing so would avoid a forward
>   declaration.
> 
> >  static bool vsock_loopback_msgzerocopy_allow(void)
> >  {
> >  	return true;
> 
> ...
> 
> > +int vsock_loopback_init_net(struct net *net)
> > +{
> > +	net->vsock.loopback = kmalloc(GFP_KERNEL, sizeof(struct vsock_loopback));
> > +	if (!net->vsock.loopback)
> > +		return -ENOMEM;
> > +
> > +	return vsock_loopback_init_vsock(net->vsock.loopback);
> > +}
> > +
> > +void vsock_loopback_exit_net(struct net *net)
> > +{
> > +	vsock_loopback_deinit_vsock(net->vsock.loopback);
> > +	kfree(net->vsock.loopback);
> > +}
> 
> I think EXPORT_SYMBOL_GPL is needed for both vsock_loopback_exit_net and
> vsock_loopback_init_net for the case where CONFIG_VSOCKETS=m
> 
> Also, in Kconfig VSOCKETS_LOOPBACK depends on VSOCKETS. But this code adds
> a reverse dependency. As it stands it's possible to configure VSOCKETS
> without VSOCKETS_LOOPBACK, which will not compile.
> 
> Perhaps stub implementations of vsock_loopback_init_net and
> vsock_loopback_exit_net should be implemented in af_vsock.h if
> VSOCKETS_LOOPBACK is not enabled?
> 

Roger that, makes sense. Thanks for the review!

Best,
Bobby