From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0C3EF11CBA; Mon, 3 Aug 2026 18:33:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785782014; cv=none; b=czai9TAt2w4Jy/qSbf5e2d3BpvqJbQcpp6EWOHO/Y3tBaJjFOLovaeL7nZZaejE8Z3J5hhgQPJjrDbPG3yYGGLivcrouP9oEiaRjqW8VRgrJpHYWGZfn2TN/LmCP4+bhRHezJ1zMpdI0QumhVzNBmKtrkbIiwg2LSgHXD/aHwuI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785782014; c=relaxed/simple; bh=KbaYKjPQbOZ3r8DYPKOBxpc/BOGdwUTPsHIuekTJQII=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=RJjUkSyQYjXZvy1J37v/b5hNH2IyTSkUcibPPECCopv81tqSp9bciJPH4HZe77qc2QD99boF3FIfATaQBKlBcfyaTSy18pSEvVSgw8pl+ITLRIR4JqTfwcOa/Xbml4TfWlZ1PhEfCTZ4KIn0SO6YhxNptJBva7V7mkkYJkkhjrI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UIe+WohI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UIe+WohI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65B641F00A3D; Mon, 3 Aug 2026 18:33:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785782012; bh=d3H8AeFjY8Fj/K6xTP6kBik4k1lsFrnOIh14q8FYCmA=; h=Date:From:To:Cc:In-Reply-To:References:Subject; b=UIe+WohI6JC/AzWFeap8OWqAkCw3on1h6Y8SUlSmCWIJwH6D2kD/TAeWqttwIEuqc GSSdmtDxkBo3OuwyuVu5Hy0hCqlg53UsqXUEHzi/FUiUmXGKIg9fPweJA/Swxbp4OI 8QwB1ic0G6IbCxeWwA4dPzJHEd+aa8tzK4qj+1Yw3eIBpYY1H8T5OnZ0CW5OQiLCa0 3kACU9GwZ5J+EvXMcoWlEhI34kpI86rgNCYRMe3XUpM8OCeVz1ImoJ17bWF6Yn8t+s bRew7KldsI9nwBaf9A/u7AyzKQoQlIybJpKR8K6uGMy8rFkgPp3IzrAbWhLSq16s5z wxZ9HjtB6XHvg== Received: from phl-compute-10.internal (phl-compute-10.internal [10.202.2.50]) by mailfauth.phl.internal (Postfix) with ESMTP id 63924F40067; Mon, 3 Aug 2026 14:33:31 -0400 (EDT) Received: from phl-imap-15 ([10.202.2.104]) by phl-compute-10.internal (MEProxy); Mon, 03 Aug 2026 14:33:31 -0400 X-ME-Sender: X-ME-Proxy-Cause: dmFkZTF5FTUneQDRbQR3tEhnTNN0JLSTrNn2pVmbtnXB3UkJcYWp/woaLefjUbRZQg7LPU wjUvTQva3YNiahlBORROC5bTronq35kiEjZOD4MXky15N1PWF/+XkJfq4dCuuvGI3F8tA3 T6Tx+iXlMI9l4kuQszT1fbeqJ1mp2T3iVcXh2QNxoNRn0+0qHeczVb4DDhwxtxqdAL7G3Z eLeCirGnZsBwfhx/d1tX8/xTrcknDD+ahwhjGKyeH9IyCIjHbLIfLd7SFgZk/X8QIiDlZf gfHH0fO3v8LdTCHRrd8EFkxI5VNe2PH78SzC4yMHTqDQ3wMNqp5lvlBEe2ItIrk/n8PSfB aLUIiQQcj0K3CvXhwnRA22XQ1aN98LQEX9gO6yWZ68wuFzWtl03zV9w+GQvHiB42VNJHDU nye5GYdPCN+Hx5dXWIC6XvKaHqh+htNVNVu8ZtNHRUTPHPOppzrs6P06r+v3+78dQ0Wdzn e965XO99tdlP0L+wCPD148+wFfYzw0yzpeBWTk89/J9QoDYIWfl0UgvwcFpAQeCNcpD9yD hUYYCYNj3tX01cT4TVV1Eoy0z30RAFod7TLCIdufSN6GHAzKRkzBVSuhEAPeo3eLDNL97M CN2fdZi0LMSxWV6lPD1yR/Z8NyTyywxRwyaPkht7nB/aWknNTeyhF/jKkOaA X-ME-Proxy: Feedback-ID: ifa6e4810:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 42F32780070; Mon, 3 Aug 2026 14:33:31 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: A0Y-jwfPBytZ Date: Mon, 03 Aug 2026 14:33:10 -0400 From: "Chuck Lever" To: "Jeff Layton" , NeilBrown , "Olga Kornievskaia" , "Dai Ngo" , "Tom Talpey" Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, "kernel test robot" Message-Id: <848f6735-7b63-43d9-aadb-eeb1f0290d57@app.fastmail.com> In-Reply-To: <43a111b0927e4291eb0dfae08def19be1e32e02d.camel@kernel.org> References: <20260803-dir-deleg-v1-0-51be76861821@kernel.org> <20260803-dir-deleg-v1-1-51be76861821@kernel.org> <54f8ab19-fb1b-4cd6-9600-e3d3d6971173@app.fastmail.com> <43a111b0927e4291eb0dfae08def19be1e32e02d.camel@kernel.org> Subject: Re: [PATCH 1/2] nfsd: fix type mismatch and explain host-endian xdr buffer usage Content-Type: text/plain Content-Transfer-Encoding: 7bit On Mon, Aug 3, 2026, at 12:23 PM, Jeff Layton wrote: > On Mon, 2026-08-03 at 12:04 -0400, Chuck Lever wrote: >> Number 3: Yes, we have a sordid history of grabbing a piece of >> the xdr_buf's tail iov for temporary storage. That doesn't make >> it wise to do, and assumes behavior about that buffer that is >> not guaranteed by sunrpc's API contracts. That makes life hard >> when future changes need to change that buffer to, say, a page >> rather than kmalloc'd memory. Or when I want to convert this >> code to use xdrgen instead of hand-rolled encoding. > > I had no idea this practice was suddenly forbidden. That has certainly > not been communicated to me in any of the previous review rounds over > the last couple of years. I've been removing instances of this anti-pattern for some time. I haven't seen new code (until now) that tries to do this. It simply hasn't come up recently and I typically don't look closely for it. >> So what you've done is fine for operational prototype code, but >> not something we can carry forward as production code. The sparse >> warning is a canary, it's not the actual structural problem. > > Does this mean you intend to drop dir delegation series again? No. It's deep in nfsd-next now, and this is a long-term issue, not an immediate on-the-wire behavioral problem or a vulnerability. -- Chuck Lever