From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753380AbcEWIZq (ORCPT ); Mon, 23 May 2016 04:25:46 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:54301 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753029AbcEWIZo (ORCPT ); Mon, 23 May 2016 04:25:44 -0400 Date: Mon, 23 May 2016 01:25:42 -0700 From: Christoph Hellwig To: Viacheslav Dubeyko Cc: Christoph Hellwig , Jaegeuk Kim , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, Vyacheslav.Dubeyko@hgst.com, Cyril.Guyot@hgst.com, Adam.Manzanares@hgst.com, Damien.LeMoal@hgst.com Subject: Re: [PATCH] f2fs: introduce on-disk layout version checking functionality Message-ID: <20160523082542.GA27833@infradead.org> References: <1463679966.3573.4.camel@slavad-ubuntu-14.04> <20160520075849.GA8067@infradead.org> <1463769043.2835.30.camel@slavad-ubuntu-14.04> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1463769043.2835.30.camel@slavad-ubuntu-14.04> User-Agent: Mutt/1.5.24 (2015-08-30) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 20, 2016 at 11:30:43AM -0700, Viacheslav Dubeyko wrote: > I am not sure that I follow to your point. The F2FS has "feature" field > (__le32 feature) into on-disk superblock (struct f2fs_super_block). The > suggested patch introduces the new F2FS_FEATURE_16TB_SUPPORT flag. And > it looks like as your comment. It does, but at the same time you also introduce a major version superblock field. > So, necessary changes in on-disk layout for 16+TB volumes support will > be incompatible with current available version of F2FS driver. It means > that, anyway, we need to increase version of on-disk layout (major_ver > of struct f2fs_super_block). The presence of superblock's version and > F2FS_FEATURE_16TB_SUPPORT flag will be very useful for consistency > checking by fsck tool. Why is the feature not enough for that?