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 E9511C77B73 for ; Tue, 25 Apr 2023 17:45:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234840AbjDYRpZ (ORCPT ); Tue, 25 Apr 2023 13:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbjDYRpY (ORCPT ); Tue, 25 Apr 2023 13:45:24 -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 6D9239022; Tue, 25 Apr 2023 10:45:23 -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 08B4D616EA; Tue, 25 Apr 2023 17:45:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 086B6C433EF; Tue, 25 Apr 2023 17:45:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1682444722; bh=UetGMwdP/tJrV8Yar8w3RMh5cMJTojk25/r7z2kcvRU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=HvLIP+2XBMjvYn4QXFyN8ilV9wqrHd8tSi2COur0+kfILmSIGtIutF9kne4MM5yjY G5hUsYOpqizVtkL9O9FT3G8B1OGIe8ep4V3SfdGBLLEkEmgYUSedAc81RFyFbryW3c f5z+iilG2EcmnGH6LaChNt21Wm8OlGjUw8J1P5JcowZAZjVi8wF1czTA8JxvXsoDSM XZt+K3PB/fgOG7oktH+1iCZrVeOazyhiekMbfQkA7NWiovV4ugbexbSHZ88n7acfWl KC4Y5PvwicwYLcAbql/jy0qtE34PWuU9tiyDRD/OWzCEjHIJTz2DFzg+Axj3tkl0fv V7nFvWGdknCSQ== Message-ID: Subject: Re: [PATCH v2 1/3] fs: add infrastructure for multigrain inode i_m/ctime From: Jeff Layton To: NeilBrown Cc: Alexander Viro , Christian Brauner , "Darrick J. Wong" , Hugh Dickins , Andrew Morton , Dave Chinner , Chuck Lever , Jan Kara , Amir Goldstein , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org Date: Tue, 25 Apr 2023 13:45:19 -0400 In-Reply-To: <168237601955.24821.11999779095797667429@noble.neil.brown.name> References: <20230424151104.175456-1-jlayton@kernel.org> , <20230424151104.175456-2-jlayton@kernel.org> , <168237287734.24821.11016713590413362200@noble.neil.brown.name> , <404a9a8066b0735c9f355214d4eadf0d975b3188.camel@kernel.org> <168237601955.24821.11999779095797667429@noble.neil.brown.name> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.48.0 (3.48.0-1.fc38) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, 2023-04-25 at 08:40 +1000, NeilBrown wrote: > On Tue, 25 Apr 2023, Jeff Layton wrote: > > On Tue, 2023-04-25 at 07:47 +1000, NeilBrown wrote: > > > On Tue, 25 Apr 2023, Jeff Layton wrote: > > > > + /* > > > > + * Warn if someone sets SB_MULTIGRAIN_TS, but doesn't turn down t= he ts > > > > + * granularity. > > > > + */ > > > > + return (sb->s_flags & SB_MULTIGRAIN_TS) && > > > > + !WARN_ON_ONCE(sb->s_time_gran =3D=3D 1); > > >=20 > > > Maybe=20 > > > !WARN_ON_ONCE(sb->s_time_gran & SB_MULTIGRAIN_TS); > > > ?? > > >=20 > >=20 > > I'm not sure I understand what you mean here. >=20 > That's fair, as what I wrote didn't make any sense. > I meant to write: >=20 > !WARN_ON_ONCE(sb->s_time_gran & I_CTIME_QUERIED); >=20 > to make it explicit that s_time_gran must leave space for > I_CTIME_QUERIED to be set (as you write below). Specifically that > s_time_gran mustn't be odd.=20 > =20 Erm...it may be an unpopular opinion, but I find that more confusing than just ensuring that the s_time_gran > 1. I keep wondering if we might want to carve out other low-order bits too for some later purpose, at which point trying to check this using flags wouldn't work right. I think I might just stick with what I have here, at least for now. --=20 Jeff Layton