Re: [PATCHv4 for-next 1/1] RDMA/rxe: Disable ipv6 features when ipv6.disable in cmdline

[Leon Romanovsky <leonro@nvidia.com>]

On Mon, Apr 12, 2021 at 03:44:07PM -0300, Jason Gunthorpe wrote:
> On Sun, Apr 11, 2021 at 09:56:41PM -0400, Zhu Yanjun wrote:
> > From: Zhu Yanjun <zyjzyj2000@gmail.com>
> > 
> > When ipv6.disable=1 is set in cmdline, ipv6 is actually disabled
> > in the stack. As such, the operations of ipv6 in RXE will fail.
> > So ipv6 features in RXE should also be disabled in RXE.
> > 
> > Link: https://lore.kernel.org/linux-rdma/880d7b59-4b17-a44f-1a91-88257bfc3aaa@redhat.com/T/#t
> > Fixes: 8700e3e7c4857 ("Soft RoCE driver")
> > Reported-by: Yi Zhang <yi.zhang@redhat.com>
> > Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
> > Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
> > Tested-by: Yi Zhang <yi.zhang@redhat.com>
> 
> Is this signature block accurate? I'm pretty sure Leon didn't look at
> this version of the patch.

Yes, I didn't look.

> 
> Did Yi test this version, or is this leftover from a prior version?
> 
> > ---
> > V3->V4: I do not know how to reproduce Jason's problem. So I just ignore
> >         the -EAFNOSUPPORT error. Hope this can fix Jason's problem.
> 
> Who is Jason?
> 
> > diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
> > index 01662727dca0..b12137257af7 100644
> > --- a/drivers/infiniband/sw/rxe/rxe_net.c
> > +++ b/drivers/infiniband/sw/rxe/rxe_net.c
> > @@ -620,6 +620,11 @@ static int rxe_net_ipv6_init(void)
> >  	recv_sockets.sk6 = rxe_setup_udp_tunnel(&init_net,
> >  						htons(ROCE_V2_UDP_DPORT), true);
> >  	if (IS_ERR(recv_sockets.sk6)) {
> > +		/* Though IPv6 is not supported, IPv4 still needs to continue
> > +		 */
> > +		if (PTR_ERR(recv_sockets.sk6) == -EAFNOSUPPORT)
> > +			return 0;
> 
> At least this looks OK to me and the original report certainly said
> the error was EAFNOSUPPORT

The failure can be received only if udp_sock_create() fails in the
rxe_setup_udp_tunnel(). It will print an error despite us not want this.

> 
> Please clarify what is going on with the signature block

And fix error print.

Thanks

> 
> Jason