From mboxrd@z Thu Jan 1 00:00:00 1970 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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 53219C433DF for ; Fri, 3 Jul 2020 08:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 379FD20826 for ; Fri, 3 Jul 2020 08:58:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726477AbgGCI6y (ORCPT ); Fri, 3 Jul 2020 04:58:54 -0400 Received: from nautica.notk.org ([91.121.71.147]:51096 "EHLO nautica.notk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgGCI6y (ORCPT ); Fri, 3 Jul 2020 04:58:54 -0400 Received: by nautica.notk.org (Postfix, from userid 1001) id C3C1DC01E; Fri, 3 Jul 2020 10:58:52 +0200 (CEST) Date: Fri, 3 Jul 2020 10:58:37 +0200 From: Dominique Martinet To: Jianyong Wu Cc: ericvh@gmail.com, lucho@ionkov.net, v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, Steve.Capper@arm.com, Kaly.Xin@arm.com, justin.he@arm.com, wei.chen@arm.com Subject: Re: [PATCH v3] 9p: retrieve fid from file when file instance exist. Message-ID: <20200703085837.GA3857@nautica> References: <20200703082018.8160-1-jianyong.wu@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200703082018.8160-1-jianyong.wu@arm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jianyong Wu wrote on Fri, Jul 03, 2020: > In the current setattr implementation in 9p, fid is always retrieved > from dentry no matter file instance exists or not. Thus, there may be > some info related to opened file instance dropped. So it's better > to retrieve fid from file instance when it has passed to setattr. > > for example: > fd=open("tmp", O_RDWR); > ftruncate(fd, 10); > > The file context related with the fd will be lost as fid is > retrieved from dentry, then the backend can't get the info of > file context. It is against the original intention of user and > may lead to bug. > > Signed-off-by: Jianyong Wu ACK. I've picked this up for tests, will push to linux-next when I finally manage to find time for these... -- Dominique