From: Mike Snitzer <snitzer@redhat.com>
To: Spelic <spelic@shiftmail.org>
Cc: "Lukáš Czerner" <lczerner@redhat.com>,
"device-mapper development" <dm-devel@redhat.com>,
linux-ext4@vger.kernel.org, "Dave Chinner" <david@fromorbit.com>,
xfs@oss.sgi.com
Subject: Re: Ext4 and xfs problems in dm-thin on allocation and discard
Date: Tue, 19 Jun 2012 09:34:42 -0400 [thread overview]
Message-ID: <20120619133441.GA7001@redhat.com> (raw)
In-Reply-To: <4FE062B3.7080702@shiftmail.org>
On Tue, Jun 19 2012 at 7:29am -0400,
Spelic <spelic@shiftmail.org> wrote:
> On 06/19/12 08:32, Lukáš Czerner wrote:
> >
> >So do I understand correctly that even though the discard came
> >through and thinp took advantage of it it still returns EOPNOTSUPP ?
> >This seems rather suboptimal. IIRC there was a discussion to add an
> >option to enable/disable sending discard in thinp target down
> >to the device.
>
> I'll ask this too...
> do I understand correctly that dm-thin returns EOPNOTSUPP to the
> filesystem layer even though it is using the discard to unmap
> blocks, and at that point XFS stops sending discards down there
> (while ext4 keeps sending them)?
Are you actually seeing that? Or are you just seizing on Lukas'
misunderstanding?
> This looks like a bug of dm-thin to me. Discards are "supported" in
> such a scenario.
>
> Do you have a patch for dm-thin so to prevent it sending EOPTNOTSUPP ?
thinp should _not_ be sending -EOPNOTSUPP unless 'ignore_discard' is
provided as a feature when loading thin-pool's DM table.
--
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next prev parent reply other threads:[~2012-06-19 13:34 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-18 21:33 Ext4 and xfs problems in dm-thin on allocation and discard Spelic
2012-06-19 1:57 ` Dave Chinner
2012-06-19 3:12 ` Mike Snitzer
2012-06-19 6:32 ` Lukáš Czerner
2012-06-19 11:29 ` Spelic
2012-06-19 12:20 ` Lukáš Czerner
2012-06-19 13:34 ` Mike Snitzer [this message]
2012-06-19 13:16 ` Mike Snitzer
2012-06-19 13:25 ` Lukáš Czerner
2012-06-19 13:30 ` Mike Snitzer
2012-06-19 13:52 ` Spelic
2012-06-19 14:05 ` Eric Sandeen
2012-06-19 14:44 ` Mike Snitzer
2012-06-19 18:48 ` Mike Snitzer
2012-06-19 20:06 ` Dave Chinner
2012-06-19 20:21 ` Ted Ts'o
2012-06-19 20:39 ` Dave Chinner
2012-06-20 9:01 ` Christoph Hellwig
2012-06-19 21:37 ` Spelic
2012-06-19 23:12 ` Dave Chinner
2012-06-20 12:11 ` Spelic
2012-06-20 22:53 ` Dave Chinner
2012-06-21 17:47 ` Mike Snitzer
2012-06-21 23:29 ` Dave Chinner
2012-07-01 14:53 ` Paolo Bonzini
2012-07-02 13:00 ` Mike Snitzer
2012-07-02 13:15 ` Paolo Bonzini
2012-06-19 14:09 ` Lukáš Czerner
2012-06-19 14:19 ` Ted Ts'o
2012-06-19 14:23 ` Eric Sandeen
2012-06-19 14:37 ` Lukáš Czerner
2012-06-19 14:43 ` [dm-devel] " Alasdair G Kergon
2012-06-19 15:28 ` Mike Snitzer
2012-06-19 16:03 ` [dm-devel] " Alasdair G Kergon
2012-06-19 19:58 ` Ted Ts'o
2012-06-19 20:44 ` Mike Snitzer
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