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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3FAF5C352A1 for ; Tue, 6 Dec 2022 21:04:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229841AbiLFVE6 (ORCPT ); Tue, 6 Dec 2022 16:04:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229840AbiLFVEw (ORCPT ); Tue, 6 Dec 2022 16:04:52 -0500 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B059747316; Tue, 6 Dec 2022 13:04:50 -0800 (PST) Received: from cwcc.thunk.org (pool-173-48-120-46.bstnma.fios.verizon.net [173.48.120.46]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 2B6L4hb3003623 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 6 Dec 2022 16:04:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1670360684; bh=fMwVX4UxKI+NUwzpQSTT4neoisRqyhXXltho6hFAv6s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=C3R9Naw1FOBHaZbZ/jPo0zymWFHZpNtg1gNlYf1+8WMXW1z1I9VUM5bYzvKGJ74w3 e/95Lxv0KRF9x+P3vAdIKe6wqV9Hfc5WkHH2AWRR5c3kxFlBZQPLmLviD0wzE3n+6k z4rFbs4hTwFKUrp1IJJgMqmId9BdCny0M1EuWKsgf71medCamOB40yLDQfHBO9ZNbE 6SBwIh3EeBXkDT2V1XwJNtCxC29u+pLyDE83GFvE26s99GnO6+EVWHEIgKPtQiNzmm q7dYRAB39d+zUAaQgDxYfbWpLqBOe+ZF7tu0B+GXjMHL6UKb7XukZ2U9e6zKI8wijO Aq654mE9DhOzA== Received: by cwcc.thunk.org (Postfix, from userid 15806) id 2798C15C3489; Tue, 6 Dec 2022 16:04:43 -0500 (EST) Date: Tue, 6 Dec 2022 16:04:43 -0500 From: "Theodore Ts'o" To: Eric Biggers Cc: linux-ext4@vger.kernel.org, linux-fscrypt@vger.kernel.org, Harshad Shirwadkar Subject: Re: [PATCH 0/7] ext4 fast-commit fixes Message-ID: References: <20221106224841.279231-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221106224841.279231-1-ebiggers@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Sun, Nov 06, 2022 at 02:48:34PM -0800, Eric Biggers wrote: > From: Eric Biggers > This series fixes several bugs in the fast-commit feature. > > Patch 6 may be the most controversial patch of this series, since it > would make old kernels unable to replay fast-commit journals created by > new kernels. I'd appreciate any thoughts on whether that's okay. I can > drop that patch if needed. Mumble. Normally, it's something we would avoid, since there aren't that many users using fast commit, since it's not enabled by default. And given that the off-by-one errors are bugs, an it's a question of old kernels requiring a pretty buggy layout, the question is whether it's worth it to do an explicit version / feature flag and support both for some period of time. I'm inclined to say no, and just let things slide, and instead make sure that e2fsck can handle both the old and the new format, and let that handle the fast commit replay if necessary. Harshad, what do you think? - Ted