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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 C4B4CC433E7 for ; Thu, 8 Oct 2020 22:28:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80AFC22241 for ; Thu, 8 Oct 2020 22:28:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730359AbgJHW2O (ORCPT ); Thu, 8 Oct 2020 18:28:14 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:53841 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725941AbgJHW2O (ORCPT ); Thu, 8 Oct 2020 18:28:14 -0400 Received: from localhost (unknown [67.5.25.97]) (Authenticated sender: josh@joshtriplett.org) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 755C5100006; Thu, 8 Oct 2020 22:28:07 +0000 (UTC) Date: Thu, 8 Oct 2020 15:28:05 -0700 From: Josh Triplett To: Andreas Dilger Cc: "Theodore Y. Ts'o" , "Darrick J. Wong" , Jan Kara , Linux Kernel Mailing List , Ext4 Developers List Subject: Re: ext4 regression in v5.9-rc2 from e7bfb5c9bb3d on ro fs with overlapped bitmaps Message-ID: <20201008222805.GB45658@localhost> References: <20201006025110.GJ49559@magnolia> <20201006031834.GA5797@mit.edu> <20201006050306.GA8098@localhost> <20201006133533.GC5797@mit.edu> <20201007080304.GB1112@localhost> <20201007143211.GA235506@mit.edu> <20201007201424.GB15049@localhost> <20201008191231.GA44285@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Thu, Oct 08, 2020 at 01:25:57PM -0600, Andreas Dilger wrote: > On Oct 8, 2020, at 1:12 PM, Josh Triplett wrote: > > On Wed, Oct 07, 2020 at 08:57:12PM -0600, Andreas Dilger wrote: > >> I *do* think that inline_data is an under-appreciated feature that I > >> would be happy to see some improvements with. I don't think that small > >> files are a niche use case, and if we can clean up the inline_data code > >> to work with 128-byte inodes I'm not against that, even though I'm not > >> going to use that combination of features myself. > > > > I'd love to see that happen. At the time, it seemed like too large of a > > change to block on, which is why I ended up deciding to switch to > > 256-byte inodes. > > Does that mean you are using inline_data with 256-byte inodes? I am, yes, and it mostly works great. I've hit zero issues with it in the filesystems I'm generating. > That would also be good to know, since there haven't been any > well-known users of this feature so far (AFAIK). Since you are using > this in a read-only manner, you won't hit the one know issue when an > inline_data inode is extended to use an external block that may > temporarily leave the inode in an inconsistent state. I've run into a few other issues with it in other tools, as well. mke2fs with inline_data generates invalid files given xattrs: https://lore.kernel.org/linux-ext4/20200926102512.GA11386@localhost/T/#u And extlinux doesn't like inline_data at all: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=971002 I'll report any other issues I run into using inline_data. I agree that it's deeply underappreciated. - Josh