From: Dave Chinner <david@fromorbit.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Jiri Kosina <jikos@kernel.org>,
Alan Stern <stern@rowland.harvard.edu>,
Pavel Machek <pavel@ucw.cz>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@lst.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>, Tejun Heo <tj@kernel.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-pm@vger.kernel.org
Subject: Re: [PATCH 0/3] PM, vfs: use filesystem freezing instead of kthread freezer
Date: Tue, 3 Nov 2015 11:10:53 +1100 [thread overview]
Message-ID: <20151103001053.GL10656@dastard> (raw)
In-Reply-To: <2258525.D9qdTJBeTN@vostro.rjw.lan>
On Mon, Nov 02, 2015 at 03:43:07AM +0100, Rafael J. Wysocki wrote:
> I guess it may also helps to address the case when a device is removed from a
> suspended system, written to on another system in the meantime and inserted
> back into the (still suspended) original system which then is resumed. Today
> this is an almost guaranteed data corruption scenario, but if the filesystem in
> question is properly frozen during suspend, the driver should be able to detect
> superblock changes during unfreeze.
Never going to work. There is no guarantee that a write to a
filesystem by a third party device is going to change the superblock
(or any metadata in the rest of the filesystem) in any detectable
way. Hence freezing filesystems will not prevent Bad Things
Happening if you do this while your system is suspended.
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2015-11-03 0:10 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-30 13:47 [PATCH 0/3] PM, vfs: use filesystem freezing instead of kthread freezer Jiri Kosina
2015-10-30 13:47 ` [PATCH 1/3] power, vfs: move away from PF_KTHREAD freezing in favor of fs freezing Jiri Kosina
2015-10-30 14:04 ` kbuild test robot
2015-10-31 8:55 ` Oliver Neukum
2015-11-02 3:01 ` Neil Brown
2015-11-02 7:54 ` yalin wang
2015-11-02 11:05 ` Jiri Kosina
2015-10-30 13:47 ` [PATCH 2/3] freezer: get rid of the kthread freezer Jiri Kosina
2015-10-30 14:08 ` kbuild test robot
2015-10-30 14:12 ` kbuild test robot
2015-10-30 13:48 ` [PATCH 3/3] freezer: warn if anyone is trying to use freezer on kthreads Jiri Kosina
2015-10-30 15:29 ` [PATCH 0/3] PM, vfs: use filesystem freezing instead of kthread freezer Alan Stern
2015-10-30 17:44 ` Pavel Machek
2015-10-30 19:40 ` Jiri Kosina
2015-10-30 20:41 ` Alan Stern
2015-10-30 21:17 ` Jiri Kosina
2015-10-31 3:15 ` Rafael J. Wysocki
2015-10-31 8:19 ` Jiri Kosina
2015-11-02 2:43 ` Rafael J. Wysocki
2015-11-02 10:45 ` Jiri Kosina
2015-11-02 11:00 ` Oliver Neukum
2015-11-02 15:18 ` Alan Stern
2015-11-03 0:10 ` Dave Chinner [this message]
2015-11-03 4:06 ` Rafael J. Wysocki
2015-11-03 9:31 ` Jan Kara
2015-11-03 21:33 ` Rafael J. Wysocki
2015-10-31 16:01 ` Alan Stern
2015-10-31 15:56 ` Alan Stern
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