Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC0A1C282C4 for ; Mon, 4 Feb 2019 20:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4B5220821 for ; Mon, 4 Feb 2019 20:11:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727740AbfBDULq (ORCPT ); Mon, 4 Feb 2019 15:11:46 -0500 Received: from fieldses.org ([173.255.197.46]:51814 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727692AbfBDULp (ORCPT ); Mon, 4 Feb 2019 15:11:45 -0500 Received: by fieldses.org (Postfix, from userid 2815) id 7DE2B1E3A; Mon, 4 Feb 2019 15:11:45 -0500 (EST) Date: Mon, 4 Feb 2019 15:11:45 -0500 From: Bruce Fields To: Chuck Lever Cc: Linux NFS Mailing List , simo@redhat.com Subject: Re: [PATCH RFC 09/10] SUNRPC: Remove xdr_buf_trim() Message-ID: <20190204201145.GF1816@fieldses.org> References: <20190201195538.11389.96106.stgit@manet.1015granger.net> <20190201195814.11389.4023.stgit@manet.1015granger.net> <20190204194615.GC1816@fieldses.org> <014F38E7-993C-4FD6-A8C6-9FE113A54A03@oracle.com> <20190204200044.GD1816@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Mon, Feb 04, 2019 at 03:07:26PM -0500, Chuck Lever wrote: > > > > On Feb 4, 2019, at 3:00 PM, Bruce Fields wrote: > > > > On Mon, Feb 04, 2019 at 02:49:11PM -0500, Chuck Lever wrote: > >> > >> > >>> On Feb 4, 2019, at 2:46 PM, bfields@fieldses.org wrote: > >>> > >>> On Fri, Feb 01, 2019 at 02:58:14PM -0500, Chuck Lever wrote: > >>>> The key action of xdr_buf_trim() is that it shortens buf->len, the > >>>> length of the xdr_buf' content. The other actions -- shortening the > >>>> head, pages, and tail components -- are actually not necessary. In > >>>> some cases, changing the size of those components corrupts the RPC > >>>> message contained in the buffer. > >>> > >>> That's really burying the lede.... Is there an actual user-visible bug > >>> here? > >> > >> I don't think so. This is more of the form: > >> > >> a) the function does fundamentally the wrong thing, so > >> > >> b) certain changes to this code path result is unexpected and incorrect > >> behavior > >> > >> Thus typically only developers hacking on this code run into a problem. > > > > OK, got it. It'd help just to make it clear in the changelog that that > > this is an accident waiting to happen rather than a current bug (as far > > as we know). > > With said improvement to the changelog, can I add your Acked-by > when I submit this through Anna's tree? Sure, thanks. --b.