From: Christoph Hellwig <hch@infradead.org>
To: Theodore Tso <tytso@mit.edu>,
Nigel Cunningham <nigel@nigel.suspend2.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
Xavier Bestel <xavier.bestel@free.fr>,
Pekka Enberg <penberg@cs.helsinki.fi>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Back to the future.
Date: Fri, 27 Apr 2007 11:10:12 +0100 [thread overview]
Message-ID: <20070427101012.GA1714@infradead.org> (raw)
In-Reply-To: <20070426213806.GE24852@thunk.org>
On Thu, Apr 26, 2007 at 05:38:07PM -0400, Theodore Tso wrote:
> On Fri, Apr 27, 2007 at 06:08:01AM +1000, Nigel Cunningham wrote:
> > We tried that. It would need some work. IIRC remounting filesystems
> > read-only makes files become marked read-only. Perfectly sensible,
> > except that if you then remount the filesystem rw at resume time, all
> > those files are still marked ro and userspace crashes and burns. Not
> > unfixable, I'll agree, but there is more work to do there.
>
> There are other solutions, though. One is that we could export a
> system call interface which freezes a filesystem and prevents any
> further I/O. We mostly have something like that right now (via the
> the write_super_lockfs function in the superblock operations
> structure), but we haven't exported it to userspace.
It is exported on XFS ;-)
> We would also need a similar interface to freeze any block device I/O,
> in case you have a database running and doing direct I/O to a block
> device. (Or again, we could simply not support that case; how many
> people will be running running a database accessing a block deivce on
> their laptop?)
block device I/O uses generic_file*whateveriscurrenthere*_write, which
checks for the freeze flag, so the infrastructure for that is there
aswell.
next prev parent reply other threads:[~2007-04-27 10:10 UTC|newest]
Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-26 6:04 Back to the future Nigel Cunningham
2007-04-26 7:28 ` Pekka Enberg
[not found] ` <1177573348.50 25.224.camel@nigel.suspend2.net>
2007-04-26 7:42 ` Nigel Cunningham
2007-04-26 8:17 ` Pekka Enberg
2007-04-26 9:28 ` Nigel Cunningham
2007-04-26 17:29 ` Luca Tettamanti
2007-04-26 16:56 ` Linus Torvalds
2007-04-26 17:03 ` Xavier Bestel
2007-04-26 17:34 ` Linus Torvalds
2007-04-26 20:08 ` Nigel Cunningham
2007-04-26 20:45 ` Linus Torvalds
2007-04-26 20:50 ` Nigel Cunningham
2007-04-27 0:10 ` Olivier Galibert
2007-04-27 10:21 ` Daniel Pittman
2007-04-27 23:19 ` Nigel Cunningham
2007-04-26 21:38 ` Theodore Tso
2007-04-27 10:10 ` Christoph Hellwig [this message]
2007-04-26 22:08 ` Rafael J. Wysocki
2007-04-26 22:20 ` Nigel Cunningham
2007-04-26 23:15 ` Linus Torvalds
2007-04-27 7:51 ` Pekka Enberg
2007-04-26 17:07 ` Linus Torvalds
2007-04-26 18:22 ` Chase Venters
2007-04-26 18:50 ` David Lang
2007-04-26 19:56 ` Nigel Cunningham
2007-04-27 4:52 ` Pekka J Enberg
2007-04-27 6:08 ` Nigel Cunningham
2007-04-27 6:18 ` Pekka J Enberg
2007-04-27 6:29 ` Pekka J Enberg
2007-04-27 6:34 ` Nigel Cunningham
2007-04-27 6:50 ` Pekka J Enberg
2007-04-27 7:03 ` Nigel Cunningham
2007-04-27 7:24 ` Pekka J Enberg
2007-04-27 9:50 ` Oliver Neukum
2007-04-27 10:12 ` Pekka J Enberg
2007-04-27 19:07 ` Oliver Neukum
2007-04-28 9:22 ` Pekka Enberg
2007-04-28 13:37 ` Oliver Neukum
2007-05-03 12:06 ` Pavel Machek
2007-05-04 21:52 ` Indan Zupancic
2007-05-05 9:16 ` Pavel Machek
2007-05-05 12:02 ` Indan Zupancic
2007-04-28 10:35 ` Rafael J. Wysocki
2007-04-28 18:43 ` David Lang
2007-04-28 19:37 ` Rafael J. Wysocki
2007-04-27 21:24 ` Rafael J. Wysocki
2007-04-27 21:44 ` Linus Torvalds
2007-04-27 22:04 ` Rafael J. Wysocki
2007-04-27 22:08 ` Linus Torvalds
2007-04-27 22:41 ` Rafael J. Wysocki
2007-04-27 22:26 ` David Lang
2007-04-27 23:21 ` Rafael J. Wysocki
2007-04-27 23:01 ` David Lang
2007-04-28 0:02 ` Rafael J. Wysocki
2007-04-27 23:17 ` Linus Torvalds
2007-04-27 23:45 ` Rafael J. Wysocki
2007-04-27 23:57 ` Nigel Cunningham
2007-04-27 23:50 ` David Lang
2007-04-28 0:40 ` Linus Torvalds
2007-04-28 6:58 ` Oliver Neukum
2007-04-28 9:16 ` Pekka J Enberg
2007-04-28 18:28 ` David Lang
2007-05-03 17:18 ` Pavel Machek
2007-05-07 2:13 ` David Lang
2007-05-07 3:33 ` Kyle Moffett
2007-05-07 12:48 ` Pavel Machek
2007-05-07 12:52 ` Oliver Neukum
2007-05-07 14:37 ` david
2007-05-07 19:51 ` Pavel Machek
2007-05-07 19:55 ` david
2007-05-07 20:38 ` Pavel Machek
2007-05-08 17:36 ` Disconnect
2007-04-27 23:59 ` Linus Torvalds
2007-04-28 0:18 ` Linus Torvalds
2007-05-05 11:42 ` Pavel Machek
2007-04-28 0:50 ` Paul Mackerras
2007-04-28 1:00 ` Rafael J. Wysocki
2007-04-28 1:12 ` Linus Torvalds
2007-04-28 0:54 ` David Lang
2007-04-28 1:44 ` Rafael J. Wysocki
2007-04-28 2:51 ` Daniel Hazelton
2007-04-28 7:00 ` progress meter in s2disk (was Re: Back to the future.) Pavel Machek
2007-04-28 8:50 ` Back to the future Pavel Machek
2007-04-28 9:24 ` Rafael J. Wysocki
2007-04-28 16:28 ` Linus Torvalds
2007-04-28 17:50 ` Rafael J. Wysocki
2007-04-28 21:25 ` Linus Torvalds
2007-04-28 23:03 ` Rafael J. Wysocki
2007-04-28 23:45 ` Linus Torvalds
2007-04-29 0:01 ` Nigel Cunningham
2007-04-29 5:01 ` Bojan Smojver
2007-04-29 3:43 ` Kyle Moffett
2007-04-29 8:57 ` Rafael J. Wysocki
2007-04-29 8:59 ` Pavel Machek
2007-04-29 9:32 ` Rafael J. Wysocki
2007-04-29 8:23 ` Pavel Machek
2007-04-29 9:22 ` Rafael J. Wysocki
2007-04-28 18:32 ` David Lang
2007-04-28 19:14 ` Rafael J. Wysocki
2007-04-28 18:44 ` David Lang
2007-05-03 15:25 ` Pavel Machek
2007-04-27 22:07 ` Nigel Cunningham
2007-04-28 1:03 ` Kyle Moffett
2007-04-28 1:15 ` Rafael J. Wysocki
2007-04-28 0:51 ` David Lang
2007-04-28 1:25 ` Kyle Moffett
2007-05-03 15:10 ` Pavel Machek
2007-05-03 16:53 ` Kyle Moffett
2007-05-04 7:52 ` David Greaves
2007-05-04 13:27 ` Kyle Moffett
2007-04-28 0:18 ` Jeremy Fitzhardinge
2007-04-28 1:00 ` Matthew Garrett
2007-04-28 1:05 ` Jeremy Fitzhardinge
2007-05-03 15:14 ` Pavel Machek
2007-06-01 19:00 ` Eric W. Biederman
2007-04-28 1:08 ` Rafael J. Wysocki
2007-04-27 20:44 ` Rafael J. Wysocki
2007-04-28 19:09 ` Bill Davidsen
2007-04-26 22:40 ` Pavel Machek
2007-04-27 5:41 ` Pekka Enberg
2007-04-27 14:55 ` Pavel Machek
2007-04-27 21:39 ` Nigel Cunningham
2007-04-26 22:42 ` Pavel Machek
2007-04-26 22:24 ` David Lang
2007-04-26 23:12 ` Pavel Machek
2007-04-26 22:49 ` David Lang
2007-04-26 23:27 ` Pavel Machek
2007-04-26 22:56 ` David Lang
2007-04-27 0:23 ` Olivier Galibert
2007-04-27 12:49 ` Pavel Machek
2007-04-27 21:26 ` Rafael J. Wysocki
2007-04-27 22:12 ` David Lang
2007-04-26 8:38 ` Jan Engelhardt
2007-04-26 9:33 ` Nigel Cunningham
2007-04-28 0:28 ` Bojan Smojver
[not found] <8e5l8-7SD-21@gated-at.bofh.it>
[not found] ` <8e6Ka-1uR-3@gated-at.bofh.it>
[not found] ` <8e6TS-1Id-11@gated-at.bofh.it>
[not found] ` <8efu9-6mF-1@gated-at.bofh.it>
[not found] ` <8ekWV-6FF-33@gated-at.bofh.it>
[not found] ` <8el6y-6Sj-5@gated-at.bofh.it>
[not found] ` <8elpT-7wY-21@gated-at.bofh.it>
2007-04-28 11:04 ` Bodo Eggert
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