Re: [PATCH mptcp-next v2 22/36] mptcp: change is_backup interfaces as get_flags

[Geliang Tang <geliang@kernel.org>]

On Mon, 2024-11-04 at 19:55 +0100, Matthieu Baerts wrote:
> Hi Geliang,
> 
> On 22/10/2024 11:14, Geliang Tang wrote:
> > From: Geliang Tang <tanggeliang@kylinos.cn>
> > 
> > The is_backup() interface of path manager is not very common. A
> > more
> > common approach is to add a get_flags() interface to obtain the
> > flags
> > value of a given address. Then is_backup() can be implemented
> > through
> > get_flags() by test whether backup flag is set in the flags value.
> 
> Out of curiosity, is this going to simplify something later on?
> Because
> with this description, it is hard to see the value of this patch.
> 
> The backup flag is special: that's the only one that is linked to a
> bit
> that will appear in the packets, the only one that needs to be known
> by
> the other peer. In this case, I think it makes sense to have
> dedicated
> helpers to retrieve this info, and not the rest.
> 
> Except if you think we will need to extract the other flags later?

Yes, I am preparing for the use of other flags in the future. In that
case, we don't need to add another function pointer interface in struct
mptcp_pm_ops.

This patch is resent in "BPF path manager, part 3".

Thanks,
-Geliang

> 
> Cheers,
> Matt