From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 410921A73B; Thu, 9 Nov 2023 15:24:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3921F30DC; Thu, 9 Nov 2023 07:24:18 -0800 (PST) Received: by verein.lst.de (Postfix, from userid 2407) id 40FE467373; Thu, 9 Nov 2023 16:24:13 +0100 (CET) Date: Thu, 9 Nov 2023 16:24:12 +0100 From: Christoph Hellwig To: John Garry Cc: axboe@kernel.dk, kbusch@kernel.org, hch@lst.de, sagi@grimberg.me, jejb@linux.ibm.com, martin.petersen@oracle.com, djwong@kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, chandan.babu@oracle.com, dchinner@redhat.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, jbongio@google.com, linux-api@vger.kernel.org Subject: Re: [PATCH 12/21] fs: xfs: Introduce FORCEALIGN inode flag Message-ID: <20231109152412.GA1521@lst.de> References: <20230929102726.2985188-1-john.g.garry@oracle.com> <20230929102726.2985188-13-john.g.garry@oracle.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230929102726.2985188-13-john.g.garry@oracle.com> User-Agent: Mutt/1.5.17 (2007-11-01) On Fri, Sep 29, 2023 at 10:27:17AM +0000, John Garry wrote: > From: "Darrick J. Wong" > > Add a new inode flag to require that all file data extent mappings must > be aligned (both the file offset range and the allocated space itself) > to the extent size hint. Having a separate COW extent size hint is no > longer allowed. > > The goal here is to enable sysadmins and users to mandate that all space > mappings in a file must have a startoff/blockcount that are aligned to > (say) a 2MB alignment and that the startblock/blockcount will follow the > same alignment. This needs a good explanation of why someone would want this.