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 F060DC43219 for ; Wed, 19 Oct 2022 15:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232621AbiJSPvS (ORCPT ); Wed, 19 Oct 2022 11:51:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232336AbiJSPup (ORCPT ); Wed, 19 Oct 2022 11:50:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 97980153E24; Wed, 19 Oct 2022 08:46:30 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2B60561846; Wed, 19 Oct 2022 15:45:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B874C433C1; Wed, 19 Oct 2022 15:45:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666194328; bh=Xth0BtK1NQ1Hk2Nxe9JXu1D9E0ErD3wODQtzBi2ym5s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=X7NCLo3rLbHHL28m3K6awBgXXuVSRkVx/W/iNG72TgwHP/QGzlwE5aXWsyqVDL8a1 wEVxfc5KbVlEy75SJuZbRbwsJMOnhIXDkwx1son+cOITqQlDQ0QvLnM/3vpOUpWxDb HbLPdNtqJWl5O8o1UbYh7zlAgnkN32FTKdxPKV6wyhB1WYcOsSnpdoj0ZTRn99gZMr iPhGYAE8dvgo6TX0YdBSx5q+k+NEbWsJ6hLnHxKQFgp4pZ3B6IICxoSEwrXnHdKp2B ZpdJhpUPWZk7qd6TWC3l1w3pOqDI5/xWccZqWU7R9AWYAYZ+3zLVIvBcRFWN20aSYA oDW8DAuiVCriw== Date: Wed, 19 Oct 2022 08:45:28 -0700 From: "Darrick J. Wong" To: Jeff Layton Cc: Christian Brauner , tytso@mit.edu, adilger.kernel@dilger.ca, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, fweimer@redhat.com, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH v7 0/9] fs: clean up handling of i_version counter Message-ID: References: <20221017105709.10830-1-jlayton@kernel.org> <20221019111315.hpilifogyvf3bixh@wittgenstein> <2b167dd9bda17f1324e9c526d868cc0d995dc660.camel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2b167dd9bda17f1324e9c526d868cc0d995dc660.camel@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, Oct 19, 2022 at 08:18:15AM -0400, Jeff Layton wrote: > On Wed, 2022-10-19 at 13:13 +0200, Christian Brauner wrote: > > On Mon, Oct 17, 2022 at 06:57:00AM -0400, Jeff Layton wrote: > > > This patchset is intended to clean up the handling of the i_version > > > counter by nfsd. Most of the changes are to internal interfaces. > > > > > > This set is not intended to address crash resilience, or the fact that > > > the counter is bumped before a change and not after. I intend to tackle > > > those in follow-on patchsets. > > > > > > My intention is to get this series included into linux-next soon, with > > > an eye toward merging most of it during the v6.2 merge window. The last > > > patch in the series is probably not suitable for merge as-is, at least > > > until we sort out the semantics we want to present to userland for it. > > > > Over the course of the series I struggled a bit - and sorry for losing > > focus - with what i_version is supposed to represent for userspace. So I > > would support not exposing it to userspace before that. But that > > shouldn't affect your other changes iiuc. > > Thanks Christian, > > It has been a real struggle to nail this down, and yeah I too am not > planning to expose this to userland until we have this much better > defined. Patch #9 is just to give you an idea of what this would > ultimately look like. I intend to re-post the first 8 patches with an > eye toward merge in v6.2, once we've settled on the naming. On that > note... > > I believe you had mentioned that you didn't like STATX_CHANGE_ATTR for > the name, and suggested STATX_I_VERSION (or something similar), which I > later shortened to STATX_VERSION. > > Dave C. objected to STATX_VERSION, as "version" fields in a struct > usually refer to the version of the struct itself rather than the > version of the thing it describes. It also sort of implies a monotonic > counter, and I'm not ready to require that just yet. > > What about STATX_CHANGE for the name (with corresponding names for the > field and other flags)? That drops the redundant "_ATTR" postfix, while > being sufficiently vague to allow for alternative implementations in the > future. > > Do you (or anyone else) have other suggestions for a name? Welllll it's really a u32 whose value doesn't have any intrinsic meaning other than "if (value_now != value_before) flush_cache();" right? I think it really only tracks changes to file data, right? STATX_CHANGE_COOKIE (wait, does this cookie augment i_ctime?) STATX_MOD_COOKIE (...or just file modifications/i_mtime?) STATX_MONITOR_COOKIE (...what are we monitoring??) STATX_MON_COOKIE STATX_COOKIE_MON STATX_COOKIE_MONSTER There we go. ;) In seriousness, I'd probably go with one of the first two. I wouldn't be opposed to the last one, either, but others may disagree. ;) --D > -- > Jeff Layton