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 1610CC6FA8A for ; Fri, 9 Sep 2022 14:43:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232113AbiIIOnj (ORCPT ); Fri, 9 Sep 2022 10:43:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232093AbiIIOng (ORCPT ); Fri, 9 Sep 2022 10:43:36 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3FEB11778F; Fri, 9 Sep 2022 07:43:35 -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 363A462007; Fri, 9 Sep 2022 14:43:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 632D3C433D6; Fri, 9 Sep 2022 14:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662734614; bh=jXc+YOCMq9/xoEX+tOTlV/SGQTrctfHXTzVY7GoW6yk=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=pKuSQ0WXtewALbm9bIXUwgShYUzZZMekwIFtT4+gNj6B05+lcXkzpq14+Z9vS8bVb orpamrV1hkAfBdiskqjjn6BFBh2cRJ9yo7gYVwIRXk1prXydRTGRhDVTMaZ0lN7LSW 6ecPmO7JBma7FXKXz1rA0nIPZy3kcE0311QzuB/Qxk3gL7srP6cZF/hA0pPsdrVjak 8pH4mu2zIEqtK8pTAEYqV6BLqmYnpHxyufyORlaTGoYHDoRpahAv52GnEzcgHBT+mP UQ+qf8rkZVNGDzMU2INyxkvrI1DefJ0Xzr+tul0HsZ22/cMdXrgI/lftE8ogTLllp2 RCqqdZPlrSPfA== Message-ID: <8b556c2dadb717a25ab47f02f70cfaaa6c6074c7.camel@kernel.org> Subject: Re: [man-pages RFC PATCH v4] statx, inode: document the new STATX_INO_VERSION field From: Jeff Layton To: Theodore Ts'o Cc: "J. Bruce Fields" , Jan Kara , NeilBrown , adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, brauner@kernel.org, fweimer@redhat.com, linux-man@vger.kernel.org, linux-api@vger.kernel.org, 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 Date: Fri, 09 Sep 2022 10:43:30 -0400 In-Reply-To: References: <771650a814ab1ff4dc5473d679936b747d9b6cf5.camel@kernel.org> <20220907135153.qvgibskeuz427abw@quack3> <166259786233.30452.5417306132987966849@noble.neil.brown.name> <20220908083326.3xsanzk7hy3ff4qs@quack3> <02928a8c5718590bea5739b13d6b6ebe66cac577.camel@kernel.org> <20220908155605.GD8951@fieldses.org> <9e06c506fd6b3e3118da0ec24276e85ea3ee45a1.camel@kernel.org> <6173b33e43ac8b0e4377b5d65fec7231608f71f7.camel@kernel.org> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4 (3.44.4-1.fc36) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, 2022-09-09 at 09:48 -0400, Theodore Ts'o wrote: > On Fri, Sep 09, 2022 at 08:47:17AM -0400, Jeff Layton wrote: > >=20 > > i_version only changes now if someone has queried it since it was last > > changed. That makes a huge difference in performance. We can try to > > optimize it further, but it probably wouldn't move the needle much unde= r > > real workloads. >=20 > Good point. And to be clear, from NFS's perspective, you only need to > have i_version bumped if there is a user-visible change to the > file. --- with an explicit exception here of the FIEMAP system call, > since in the case of a delayed allocation, FIEMAP might change from > reporting: >=20 > ext: logical_offset: physical_offset: length: expected: fla= gs: > 0: 0.. 0: 0.. 0: 0: las= t,unknown_loc,delalloc,eof >=20 > to this: >=20 > ext: logical_offset: physical_offset: length: expected: fla= gs: > 0: 0.. 0: 190087172.. 190087172: 1: las= t,eof >=20 > after a sync(2) or fsync(2) call, or after time passes. >=20 In general, we want to bump i_version if the ctime changes. I'm guessing that we don't change ctime on a delalloc? If it's not visible to NFS, then NFS won't care about it. We can't project FIEMAP info across the wire at this time, so we'd probably like to avoid seeing an i_version bump in due to delalloc. > > Great! That's what I was hoping for with ext4. Would you be willing to > > pick up these two patches for v6.1? > >=20 > > https://lore.kernel.org/linux-ext4/20220908172448.208585-3-jlayton@kern= el.org/T/#u > > https://lore.kernel.org/linux-ext4/20220908172448.208585-4-jlayton@kern= el.org/T/#u >=20 > I think you mean: >=20 > https://lore.kernel.org/linux-ext4/20220908172448.208585-2-jlayton@kernel= .org/T/#u > https://lore.kernel.org/linux-ext4/20220908172448.208585-3-jlayton@kernel= .org/T/#u >=20 > Right? >=20 > BTW, sorry for not responding to these patches earlier; between > preparing for the various Linux conferences in Dublin next week, and > being in Zurich and meeting with colleagues at $WORK all of this week, > I'm a bit behind on my patch reviews. >=20 No worries. As long as they're on your radar, that's fine. Thanks! --=20 Jeff Layton