From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7F9D217C9E; Mon, 8 Jul 2024 18:47:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720464460; cv=none; b=Uq1BzwHNUnaSdAKp+cMNtEuY15aq9gkhCbwRxiPXwjsGCHwFY3aNBwIfhi24Btf/jG+dVzy5GgXoEF3yHo8sQJeTcFvsvauCBfQhuGDx/cwPgTODfGtnl3LdOVk4c7OYwkVF4bPTp32UTCOcrUZ6R1fDXIY5bg4QqHs0gc+pt0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720464460; c=relaxed/simple; bh=v31gl1I9OIcRmv77OmqWlCzEeZq6WOtR9ckY+p4HFoM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=M4kSiqDr7FGEaiHWtwehsyRVqumNAcIQJFxt7LFR8y9Y2oQZYSpDQyHzyIERrCbZfp5yhfhXbrvwYCPcdkH5WcEmlNGqIivefAIKDMaTkwG7pRr51o0MGvX0CmjJhsvASzRV+nEuYPHbgVa5opM9/yazMFeupJPyHYWlUNu0NyI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JVrSYqr+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JVrSYqr+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19259C116B1; Mon, 8 Jul 2024 18:47:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720464460; bh=v31gl1I9OIcRmv77OmqWlCzEeZq6WOtR9ckY+p4HFoM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JVrSYqr+1qSVnArfid1TPu00dGCFcKaSnisHbXvjsY9S6ELI7mwnhSKVTbSd2oQpI mRMITfr0ATkLE8+3WFFLhRaOsjMh2U3HT1wc7kdVE5G+1r9YXbqUCkzoTGU6vdco14 m9iGJSXziOeQ8FbKTrhds3sZ9Kbgjd8zwExhR8BIwDJGbCvtcamUor/gq5w0cTu2nc 6Vjkj4JpcUvaYO/BLLD/MwxH+tESDtfmSUkViWJASao1Z9NnIijNm0UwV12PCDc3jx CT/vD0y+ltf0G366leHHF0oi9NKV3tK9D3C3B1DMzxoyd8gFJuKjgOn7HIyM6ymeoi ebz1/5YzFOetA== Date: Mon, 8 Jul 2024 11:47:39 -0700 From: "Darrick J. Wong" To: Jeff Layton Cc: Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Chandan Babu R , Theodore Ts'o , Andreas Dilger , Chris Mason , Josef Bacik , David Sterba , Hugh Dickins , Andrew Morton , Jonathan Corbet , Dave Chinner , Andi Kleen , Christoph Hellwig , Uros Bizjak , Kent Overstreet , kernel-team@fb.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v4 6/9] xfs: switch to multigrain timestamps Message-ID: <20240708184739.GP612460@frogsfrogsfrogs> References: <20240708-mgtime-v4-0-a0f3c6fb57f3@kernel.org> <20240708-mgtime-v4-6-a0f3c6fb57f3@kernel.org> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240708-mgtime-v4-6-a0f3c6fb57f3@kernel.org> On Mon, Jul 08, 2024 at 11:53:39AM -0400, Jeff Layton wrote: > Enable multigrain timestamps, which should ensure that there is an > apparent change to the timestamp whenever it has been written after > being actively observed via getattr. > > Also, anytime the mtime changes, the ctime must also change, and those > are now the only two options for xfs_trans_ichgtime. Have that function > unconditionally bump the ctime, and ASSERT that XFS_ICHGTIME_CHG is > always set. > > Finally, stop setting STATX_CHANGE_COOKIE in getattr, since the ctime > should give us better semantics now. > > Signed-off-by: Jeff Layton > --- > fs/xfs/libxfs/xfs_trans_inode.c | 6 +++--- > fs/xfs/xfs_iops.c | 10 +++------- > fs/xfs/xfs_super.c | 2 +- > 3 files changed, 7 insertions(+), 11 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_trans_inode.c b/fs/xfs/libxfs/xfs_trans_inode.c > index 69fc5b981352..1f3639bbf5f0 100644 > --- a/fs/xfs/libxfs/xfs_trans_inode.c > +++ b/fs/xfs/libxfs/xfs_trans_inode.c > @@ -62,12 +62,12 @@ xfs_trans_ichgtime( > ASSERT(tp); > xfs_assert_ilocked(ip, XFS_ILOCK_EXCL); > > - tv = current_time(inode); > + /* If the mtime changes, then ctime must also change */ > + ASSERT(flags & XFS_ICHGTIME_CHG); > > + tv = inode_set_ctime_current(inode); > if (flags & XFS_ICHGTIME_MOD) > inode_set_mtime_to_ts(inode, tv); > - if (flags & XFS_ICHGTIME_CHG) > - inode_set_ctime_to_ts(inode, tv); > if (flags & XFS_ICHGTIME_CREATE) > ip->i_crtime = tv; > } > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c > index a00dcbc77e12..d25872f818fa 100644 > --- a/fs/xfs/xfs_iops.c > +++ b/fs/xfs/xfs_iops.c > @@ -592,8 +592,9 @@ xfs_vn_getattr( > stat->gid = vfsgid_into_kgid(vfsgid); > stat->ino = ip->i_ino; > stat->atime = inode_get_atime(inode); > - stat->mtime = inode_get_mtime(inode); > - stat->ctime = inode_get_ctime(inode); > + > + fill_mg_cmtime(stat, request_mask, inode); Sooo... for setting up a commit-range operation[1], XFS_IOC_START_COMMIT could populate its freshness data by calling: struct kstat dummy; fill_mg_ctime(&dummy, STATX_CTIME | STATX_MTIME, inode); and then using dummy.[cm]time to populate the freshness data that it gives to userspace, right? Having set QUERIED, a write to the file immediately afterwards will cause a (tiny) increase in ctime_nsec which will cause the XFS_IOC_COMMIT_RANGE to reject the commit[2]. Right? --D [1] https://lore.kernel.org/linux-xfs/20240227174649.GL6184@frogsfrogsfrogs/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/commit/?h=atomic-file-commits&id=0520d89c2698874c1f56ddf52ec4b8a3595baa14 > + > stat->blocks = XFS_FSB_TO_BB(mp, ip->i_nblocks + ip->i_delayed_blks); > > if (xfs_has_v3inodes(mp)) { > @@ -603,11 +604,6 @@ xfs_vn_getattr( > } > } > > - if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) { > - stat->change_cookie = inode_query_iversion(inode); > - stat->result_mask |= STATX_CHANGE_COOKIE; > - } > - > /* > * Note: If you add another clause to set an attribute flag, please > * update attributes_mask below. > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c > index 27e9f749c4c7..210481b03fdb 100644 > --- a/fs/xfs/xfs_super.c > +++ b/fs/xfs/xfs_super.c > @@ -2052,7 +2052,7 @@ static struct file_system_type xfs_fs_type = { > .init_fs_context = xfs_init_fs_context, > .parameters = xfs_fs_parameters, > .kill_sb = xfs_kill_sb, > - .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, > + .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME, > }; > MODULE_ALIAS_FS("xfs"); > > > -- > 2.45.2 > >