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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DB2F4C04A6A for ; Wed, 9 Aug 2023 14:44:43 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RLXrp40PTz30Py for ; Thu, 10 Aug 2023 00:44:42 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=parknet.co.jp (client-ip=210.171.160.6; helo=mail.parknet.co.jp; envelope-from=hirofumi@parknet.co.jp; receiver=lists.ozlabs.org) Received: from mail.parknet.co.jp (mail.parknet.co.jp [210.171.160.6]) by lists.ozlabs.org (Postfix) with ESMTP id 4RLXrg2xfxz2xgp for ; Thu, 10 Aug 2023 00:44:34 +1000 (AEST) Received: from ibmpc.myhome.or.jp (server.parknet.ne.jp [210.171.168.39]) by mail.parknet.co.jp (Postfix) with ESMTPSA id 593222055FA0; Wed, 9 Aug 2023 23:44:33 +0900 (JST) Received: from devron.myhome.or.jp (foobar@devron.myhome.or.jp [192.168.0.3]) by ibmpc.myhome.or.jp (8.17.2/8.17.2/Debian-1) with ESMTPS id 379EiWdd218003 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 9 Aug 2023 23:44:33 +0900 Received: from devron.myhome.or.jp (foobar@localhost [127.0.0.1]) by devron.myhome.or.jp (8.17.2/8.17.2/Debian-1) with ESMTPS id 379EiV6k197737 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Wed, 9 Aug 2023 23:44:31 +0900 Received: (from hirofumi@localhost) by devron.myhome.or.jp (8.17.2/8.17.2/Submit) id 379EiQ5o197730; Wed, 9 Aug 2023 23:44:26 +0900 From: OGAWA Hirofumi To: Jeff Layton Subject: Re: [PATCH v7 05/13] fat: make fat_update_time get its own timestamp In-Reply-To: <7edc9239f73022b9c2a1d3f4f946153f85f94739.camel@kernel.org> (Jeff Layton's message of "Wed, 09 Aug 2023 10:22:54 -0400") References: <20230807-mgctime-v7-0-d1dec143a704@kernel.org> <20230807-mgctime-v7-5-d1dec143a704@kernel.org> <87msz08vc7.fsf@mail.parknet.co.jp> <52bead1d6a33fec89944b96e2ec20d1ea8747a9a.camel@kernel.org> <878rak8hia.fsf@mail.parknet.co.jp> <7edc9239f73022b9c2a1d3f4f946153f85f94739.camel@kernel.org> Date: Wed, 09 Aug 2023 23:44:26 +0900 Message-ID: <874jl88ed1.fsf@mail.parknet.co.jp> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Latchesar Ionkov , Martin Brandenburg , Konstantin Komarov , "Darrick J. Wong" , Dominique Martinet , Christian Schoenebeck , ecryptfs@vger.kernel.org, Yue Hu , David Howells , Chris Mason , Andreas Dilger , Hans de Goede , Marc Dionne , linux-xfs@vger.kernel.org, linux-afs@lists.infradead.org, linux-mtd@lists.infradead.org, Mike Marshall , Paulo Alcantara , linux-cifs@vger.kernel.org, Eric Van Hensbergen , Andreas Gruenbacher , Miklos Szeredi , Richard Weinberger , Mark Fasheh , linux-unionfs@vger.kernel.org, Hugh Dickins , Benjamin Coddington , Tyler Hicks , cluster-devel@redhat.com, coda@cs.cmu.edu, linux-mm@kvack.org, Ilya Dryomov , Iurii Zaikin , Namjae Jeon , Trond Myklebust , codalist@telemann.coda.cs.cmu.edu, Shyam Prasad N , Amir Goldstein , Kees Cook , ocfs2-devel@lists.linux.dev, Josef Bacik , Tom Talpey , Tejun Heo , Alexander Viro , Ronnie Sahlberg , David Sterba , Jaegeuk Kim , ceph-devel@vger.kernel.org, Xiubo Li , Jan Harkes , Christian Brauner , linux-ext4@vger.kernel.org, Theodore Ts'o , Joseph Qi , Greg Kroah-Hartman , v9fs@lists.linux.d ev, ntfs3@lists.linux.dev, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, Steve French , Sergey Senozhatsky , Luis Chamberlain , devel@lists.orangefs.org, Anna Schumaker , Jan Kara , Bob Peterson , linux-fsdevel@vger.kernel.org, Andrew Morton , Sungjong Seo , linux-erofs@lists.ozlabs.org, linux-nfs@vger.kernel.org, linux-btrfs@vger.kernel.org, Joel Becker Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" Jeff Layton writes: > I'm a little confused too. Why do you believe this will break > -o relatime handling? This patch changes two things: > > 1/ it has fat_update_time fetch its own timestamp (and ignore the "now" > parameter). This is in line with the changes in patch #3 of this series, > which explains the rationale for this in more detail. > > 2/ it changes fat_update_time to also update the i_version if any of > S_CTIME|S_MTIME|S_VERSION are set. relatime is all about the S_ATIME, > and it is specifically excluded from that set. > > The rationale for the second change is is also in patch #3, but > basically, we can't guarantee that current_time hasn't changed since we > last checked for inode_needs_update_time, so if any of > S_CTIME/S_MTIME/S_VERSION have changed, then we need to assume that any > of them may need to be changed and attempt to update all 3. > > That said, I think the logic in fat_update_time isn't quite right. I > think want something like this on top of this patch to ensure that the > S_CTIME and S_MTIME get updated, even if the flags only have S_VERSION > set. > > Thoughts? I'm not talking about "relatime" at all, I'm always talking about "lazytime". I_DIRTY_TIME delays to update on disk inode only if changed timestamp. But you changed it to I_DIRTY_SYNC, i.e. always update on disk inode by timestamp. Thanks. > ---------------------8<----------------------- > > diff --git a/fs/fat/misc.c b/fs/fat/misc.c > index 080a5035483f..313eef02f45c 100644 > --- a/fs/fat/misc.c > +++ b/fs/fat/misc.c > @@ -346,15 +346,21 @@ int fat_update_time(struct inode *inode, int flags) > if (inode->i_ino == MSDOS_ROOT_INO) > return 0; > > - if (flags & (S_ATIME | S_CTIME | S_MTIME)) { > - fat_truncate_time(inode, NULL, flags); > - if (inode->i_sb->s_flags & SB_LAZYTIME) > - dirty_flags |= I_DIRTY_TIME; > - else > - dirty_flags |= I_DIRTY_SYNC; > - } > + /* > + * If any of the flags indicate an expicit change to the file, then we > + * need to ensure that we attempt to update all of 3. We do not do > + * this in the case of an S_ATIME-only update. > + */ > + if (flags & (S_CTIME | S_MTIME | S_VERSION)) > + flags |= S_CTIME | S_MTIME | S_VERSION; > + > + fat_truncate_time(inode, NULL, flags); > + if (inode->i_sb->s_flags & SB_LAZYTIME) > + dirty_flags |= I_DIRTY_TIME; > + else > + dirty_flags |= I_DIRTY_SYNC; > > - if ((flags & (S_VERSION|S_CTIME|S_MTIME)) && inode_maybe_inc_iversion(inode, false)) > + if ((flags & S_VERSION) && inode_maybe_inc_iversion(inode, false)) > dirty_flags |= I_DIRTY_SYNC; > -- OGAWA Hirofumi