Re: [PATCH 1/5] batman-adv: Start new development cycle

From: Leon Romanovsky <leon@kernel.org>
To: Sven Eckelmann <sven@narfation.org>
Cc: b.a.t.m.a.n@lists.open-mesh.org, Jiri Pirko <jiri@resnulli.us>,
	kuba@kernel.org, davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [PATCH 1/5] batman-adv: Start new development cycle
Date: Tue, 7 Feb 2023 12:41:53 +0200	[thread overview]
Message-ID: <Y+Iq8dv0QZGebBFU@unreal> (raw)
In-Reply-To: <4503106.V25eIC5XRa@ripper>

On Tue, Feb 07, 2023 at 10:50:08AM +0100, Sven Eckelmann wrote:
> On Tuesday, 7 February 2023 10:02:58 CET Leon Romanovsky wrote:
> > In cases where you can prove real userspace breakage, we simply stop to
> > update module versions.
> 
> That would be the worst option. Then the kernel shows bogus values and no one 
> is helped.

The thing is that you already show bogus values.

Most users don't compile their kernel, but use distro-based one. The
latter is a mix of base kernel, fixes and sometimes backports.

For example, on my system:
➜  kernel git:(wip/leon-for-next) modinfo batman_adv
filename:       /lib/modules/6.1.9-200.fc37.x86_64/kernel/net/batman-adv/batman-adv.ko.xz
....
version:        2022.3
description:    B.A.T.M.A.N. advanced
...
name:           batman_adv
vermagic:       6.1.9-200.fc37.x86_64 SMP preempt mod_unload

As you can see both of us have 2022.3 in version string, but are we
running same code?

The answer is no as you run debian and I'm running latest Fedora with
different kernel version, which means different batman_adv feature set.

Once you stop to update version, you will push users to look on the real
version (kernel) which really matters.

Thanks

> 
> 
> And how should I prove it to you? Is that enough?
> 
>     $ lsmod|grep '^batman_adv'
>     batman_adv            266240  0
>     $ sudo batctl -v
>     batctl debian-2022.3-2 [batman-adv: module not loaded]
>     $ sudo batctl if add enp70s0
>     Error - batman-adv module has not been loaded
>     $ sudo ip link show dev bat0       
>     8: bat0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
>         link/ether 7a:8b:21:b7:13:b8 brd ff:ff:ff:ff:ff:ff
>     $ sudo ip link set master bat0 dev enp70s0
>     $ sudo ip link set up dev bat0
>     $ sudo batctl n                         
>     Missing attributes from kernel
>     $ sudo batctl o
>     Missing attributes from kernel
> 
> 
> Expected was following output:
> 
>     $ sudo batctl -v
>     batctl debian-2022.3-2 [batman-adv: 2022.3]
>     $ sudo batctl if add enp70s0
>     $ sudo ip link show dev bat0
>     $ sudo ip link set up dev bat0
>     $ sudo batctl n
>     [B.A.T.M.A.N. adv 2022.3, MainIF/MAC: enp70s0/2c:f0:5d:04:70:39 (bat0/7a:8b:21:b7:13:b8 BATMAN_IV)]
>     IF             Neighbor              last-seen
>           enp70s0     50:7b:9d:ce:26:83    0.708s
>     $ sudo batctl o
>     [B.A.T.M.A.N. adv 2022.3, MainIF/MAC: enp70s0/2c:f0:5d:04:70:39 (bat0/7a:8b:21:b7:13:b8 BATMAN_IV)]
>        Originator        last-seen (#/255) Nexthop           [outgoingIF]
>      * 50:7b:9d:ce:26:83    0.684s   (255) 50:7b:9d:ce:26:83 [   enp70s0]
> 
> Kind regards,
> 	Sven