Re: [PATCH v3 6/9] io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT

[Breno Leitao <leitao@debian.org>]

Hello Gabriel,

On Thu, Aug 17, 2023 at 02:38:46PM -0400, Gabriel Krisman Bertazi wrote:
> Breno Leitao <leitao@debian.org> writes:
> 
> > +#if defined(CONFIG_NET)
> >  int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
> >  {
> >  	struct socket *sock = cmd->file->private_data;
> > @@ -189,8 +219,16 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
> >  		if (ret)
> >  			return ret;
> >  		return arg;
> > +	case SOCKET_URING_OP_GETSOCKOPT:
> > +		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
> >  	default:
> >  		return -EOPNOTSUPP;
> >  	}
> >  }
> > +#else
> > +int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
> > +{
> > +	return -EOPNOTSUPP;
> > +}
> > +#endif
> >  EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
> 
> The CONFIG_NET guards are unrelated and need to go in a separate commit.
> Specially because it is not only gating getsockopt, but also the already
> merged SOCKET_URING_OP_SIOCINQ/_OP_SIOCOUTQ.

Well, so far, if CONFIG_NET is disable, and you call
io_uring_cmd_getsockopt, the callbacks will be called and returned
-EOPNOTSUPP.

With this new patch, it will eventually call sk_getsockopt which does
not exist in the CONFIG_NET=n world. That is why I have this
protection now. I.e, this `#if defined(CONFIG_NET)` is only necessary now,
since it is the first time this function (io_uring_cmd_sock) will call a
function that does not exist if CONFIG_NET is disabled.

I can split it in a different patch, if you think it makes a difference.