From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754656Ab2IFNja (ORCPT ); Thu, 6 Sep 2012 09:39:30 -0400 Received: from mail-vb0-f46.google.com ([209.85.212.46]:34053 "EHLO mail-vb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752742Ab2IFNj2 (ORCPT ); Thu, 6 Sep 2012 09:39:28 -0400 MIME-Version: 1.0 In-Reply-To: <87y5knz6l5.fsf@devron.myhome.or.jp> References: <1346774264-8031-1-git-send-email-linkinjeon@gmail.com> <20120904161747.GJ23464@ZenIV.linux.org.uk> <87harc34d9.fsf@devron.myhome.or.jp> <87y5knz6l5.fsf@devron.myhome.or.jp> Date: Thu, 6 Sep 2012 22:39:27 +0900 Message-ID: Subject: Re: [PATCH v2 1/5] fat: allocate persistent inode numbers From: Namjae Jeon To: OGAWA Hirofumi Cc: Al Viro , akpm@linux-foundation.org, bfields@fieldses.org, linux-kernel@vger.kernel.org, Namjae Jeon , Ravishankar N , Amit Sahrawat Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2012/9/6 OGAWA Hirofumi : > Namjae Jeon writes: > >>>> In this long discusstion about the FAT acceptance over NFS, our belief >>>> is still that the objective should be to reduce errors as much as >>>> possible and then if there are certain scenarios - at least that could >>>> be highlighted as a limitation in Documentation instead of completely >>>> discarding the usage of FAT over NFS. So how about puttting rename >>>> scenario as a limitation ? In ideal scenario how many times this is >>>> going to happen ? >>> >>> My understanding of your patches is to introduce the silent corruption >>> bug by getting wrong location via ino on some cases, instead of >>> ESTALE. And make surprise to userland by change ino. >>> >>> Why is it safe to change ino? If you are saying to remove the changing >>> ino on rename, how handle the case of collision? >> Yes, agreed this would lead to collision. So, If we are choosing >> 'i_pos' as inode >> number, We need to have a mechanism to avoid this 'i_pos' being reused. >> >> We can have one thing over here. As a part of avoidance for such scenarios - >> We can return EBUSY for this rename operation. i.e., If the inode is being >> referenced then in such cases it makes sense to return EBUSY over NFS and >> forcus on the large part of the solution which is making FAT stable. >> >> Let me know your opinion. > > It sounds like sane to provide the limited but stable behavior, with the > option. But at first, I'd like to see the read-only export but clean > solution, and make it stable. (I'm not thinking about the implementation > detail. It may be the stable ino solution, or may not be.) Hi. OGAWA. I Agree. Once, I will check whether it is possible to implement read-only export or not. And If I face some problem or have some concern, I will discuss about it with you. > > After that, we can make it writable incrementally. Okay. Thanks a lot. > -- > OGAWA Hirofumi