From: Thomas Gleixner <tglx@linutronix.de>
To: Jeff Layton <jlayton@kernel.org>,
John Stultz <jstultz@google.com>, Stephen Boyd <sboyd@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Jonathan Corbet <corbet@lwn.net>,
Chandan Babu R <chandan.babu@oracle.com>,
"Darrick J. Wong" <djwong@kernel.org>,
Theodore Ts'o <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
Chris Mason <clm@fb.com>, Josef Bacik <josef@toxicpanda.com>,
David Sterba <dsterba@suse.com>, Hugh Dickins <hughd@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Chuck Lever <chuck.lever@oracle.com>,
Vadim Fedorenko <vadim.fedorenko@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org,
linux-btrfs@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [PATCH v8 01/11] timekeeping: move multigrain timestamp floor handling into timekeeper
Date: Mon, 30 Sep 2024 22:15:39 +0200 [thread overview]
Message-ID: <871q102904.ffs@tglx> (raw)
In-Reply-To: <753938ef8e46e9f3d9ea7d977537cd8f5a6533b2.camel@kernel.org>
On Mon, Sep 30 2024 at 15:27, Jeff Layton wrote:
> On Mon, 2024-09-30 at 21:13 +0200, Thomas Gleixner wrote:
>> So if that's the intended behaviour then the changelog is misleading at
>> best.
>
> That is the intended behavior and I'll plan to fix the changelog to
> clarify this point:
>
> If someone jumps the realtime clock backward by a large value, then the
> realtime timestamp _can_ appear to go backward. This is a problem today
> even without this patchset.
Correct.
> If two files get stamped and a realtime clock jump backward happens in
> between them, all bets are off as to which one will appear to have been
> modified first. I don't think that is something we can reasonably
> prevent, since we must stamp files according to the realtime clock.
True. I just was utterly confused about the changelog.
> The main thing I'm trying to prevent is the timestamps being misordered
> in the absence of such a clock jump. Without tracking the floor as I am
> here, that's a possibility.
Correct.
next prev parent reply other threads:[~2024-09-30 20:15 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-14 17:07 [PATCH v8 00/11] fs: multigrain timestamp redux Jeff Layton
2024-09-14 17:07 ` [PATCH v8 01/11] timekeeping: move multigrain timestamp floor handling into timekeeper Jeff Layton
2024-09-14 20:10 ` John Stultz
2024-09-14 23:14 ` Jeff Layton
2024-09-16 10:12 ` Thomas Gleixner
2024-09-16 10:32 ` Thomas Gleixner
2024-09-16 10:57 ` Jeff Layton
2024-09-30 19:16 ` Thomas Gleixner
2024-09-30 19:37 ` Jeff Layton
2024-09-30 20:19 ` Thomas Gleixner
2024-09-30 20:53 ` Jeff Layton
2024-09-30 21:35 ` Thomas Gleixner
2024-10-01 9:45 ` Jeff Layton
2024-10-01 12:45 ` Thomas Gleixner
2024-10-02 12:41 ` Jeff Layton
2024-09-19 16:50 ` Jeff Layton
2024-09-30 19:43 ` Thomas Gleixner
2024-09-30 20:12 ` Jeff Layton
2024-09-30 19:13 ` Thomas Gleixner
2024-09-30 19:27 ` Jeff Layton
2024-09-30 20:15 ` Thomas Gleixner [this message]
2024-09-14 17:07 ` [PATCH v8 02/11] fs: add infrastructure for multigrain timestamps Jeff Layton
2024-09-14 17:07 ` [PATCH v8 03/11] fs: have setattr_copy handle multigrain timestamps appropriately Jeff Layton
2024-09-14 17:07 ` [PATCH v8 04/11] fs: handle delegated timestamps in setattr_copy_mgtime Jeff Layton
2024-09-14 17:07 ` [PATCH v8 05/11] fs: tracepoints around multigrain timestamp events Jeff Layton
2024-09-15 8:21 ` Steven Rostedt
2024-09-14 17:07 ` [PATCH v8 06/11] fs: add percpu counters for significant " Jeff Layton
2024-09-16 10:20 ` Thomas Gleixner
2024-09-14 17:07 ` [PATCH v8 07/11] Documentation: add a new file documenting multigrain timestamps Jeff Layton
2024-09-16 1:01 ` Bagas Sanjaya
2024-09-19 16:53 ` Jeff Layton
2024-09-14 17:07 ` [PATCH v8 08/11] xfs: switch to " Jeff Layton
2024-09-14 17:07 ` [PATCH v8 09/11] ext4: " Jeff Layton
2024-09-14 17:07 ` [PATCH v8 10/11] btrfs: convert " Jeff Layton
2024-09-14 17:07 ` [PATCH v8 11/11] tmpfs: add support for " Jeff Layton
2024-09-26 16:59 ` [PATCH v8 00/11] fs: multigrain timestamp redux Randy Dunlap
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