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Date: Fri, 15 Dec 2023 15:17:12 +0100
From: Florian Westphal <fw@strlen.de>
To: "D. Wythe" <alibuda@linux.alibaba.com>
Cc: pablo@netfilter.org, kadlec@netfilter.org, fw@strlen.de,
	bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, coreteam@netfilter.org,
	netfilter-devel@vger.kernel.org, davem@davemloft.net,
	edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
	ast@kernel.org
Subject: Re: [RFC nf-next v1 1/2] netfilter: bpf: support prog update
Message-ID: <20231215141712.GA17065@breakpoint.cc>
References: <1702609653-45835-1-git-send-email-alibuda@linux.alibaba.com>
 <1702609653-45835-2-git-send-email-alibuda@linux.alibaba.com>
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D. Wythe <alibuda@linux.alibaba.com> wrote:
>  	const struct nf_defrag_hook *defrag_hook;
> +	const struct bpf_prog __rcu *nf_prog;

Hmm, why do we need this pointer?
Can't you just re-use bpf_nf_link->link.prog?

> +	rcu_assign_pointer(nf_link->nf_prog, new_prog);
> +	old_prog = xchg(&link->prog, new_prog);

This looks redundant, I think you can remove the nf_prog
pointer again.

Rest LGTM.