From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9539F47A48 for ; Sat, 1 Jun 2024 23:48:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717285696; cv=none; b=cVsRVvJjpYlBwqw4ndMtvRxhzOtdxehYHg9+HCq3qupQsfPjowU3TuJhXD/qI1vgbJcETg/xGvaKButrWn6c/FHPrfFoXMs3d19OS4Av/pPhOo1LdA/j71/NouzT2WGn2JSK8LkUjFNpT50p+LTcL3PIuOdsNbJWZY+4B8y6KV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717285696; c=relaxed/simple; bh=XiBW7GKqJSQGCNWjnrWKwhkS5Pq7XANlIVYUKrSecgg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LJlUURQGopNzd6j0i7RBCKtnm9uvND7ObjtQkOqi1e618zSvyF2y87JjD5h6nMoBjcfCqsonuRd6iU9V229OXSUSUdXJIJUgcLcYuzNPW8adyXEUp1+Yli2IPQ4vEZ2KtxpdTOQEGtTsbNAaNKhGLM7FeE0yN3Qrb375CB51VlQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oLKp5Z51; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oLKp5Z51" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5010C116B1; Sat, 1 Jun 2024 23:48:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717285696; bh=XiBW7GKqJSQGCNWjnrWKwhkS5Pq7XANlIVYUKrSecgg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=oLKp5Z51qmWQ30srqs/TGZ+83tjyLt9S2r6ckNoE8SjaPBHqFzxL2TFzNZvOQi0su 8LrK4RV1gL/Z70JzV6a24EIp00sEZ5rj8bzAo87zCk5LCgi+hTbAbdlLiP5tVTePIP p4IXUCPHPy15nIazM0wD0Yq6LKhvadqg1Pd+N2nOqPx5Qbx9tpj7nmPmyPZFOml7pK FhQH+P5JDEcOCaNfDU2qLIZwNe6gZyrA65du7jd+9eLpw3DIydrYV5myZpcZPKwv/L cmnG4f1Zxa78zOPDVc0lcmWmBP0kQEAdAdsOwupMxn/kuiO8TNuSA7C5VjVMAeQk87 k6Vtsjp2mvysA== Date: Sat, 1 Jun 2024 16:48:14 -0700 From: Jakub Kicinski To: Stephen Hemminger Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, Jaroslav Pulchart , dsahern@kernel.org Subject: Re: [PATCH net] inet: bring NLM_DONE out to a separate recv() in inet_dump_ifaddr() Message-ID: <20240601164814.3c34c807@kernel.org> In-Reply-To: <20240601161013.10d5e52c@hermes.local> References: <20240601212517.644844-1-kuba@kernel.org> <20240601161013.10d5e52c@hermes.local> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 1 Jun 2024 16:10:13 -0700 Stephen Hemminger wrote: > Sorry, I disagree. > > You can't just fix the problem areas. The split was an ABI change, and there could > be a problem in any dump. This the ABI version of the old argument > If a tree falls in a forest and no one is around to hear it, does it make a sound? > > All dumps must behave the same. You are stuck with the legacy behavior. The dump partitioning is up to the family. Multiple families coalesce NLM_DONE from day 1. "All dumps must behave the same" is saying we should convert all families to be poorly behaved. Admittedly changing the most heavily used parts of rtnetlink is very risky. And there's couple more corner cases which I'm afraid someone will hit. I'm adding this helper to clearly annotate "legacy" callbacks, so we don't regress again. At the same time nobody should use this in new code or "just to be safe" (read: because they don't understand netlink).