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Date: Tue, 29 Nov 2011 13:18:11 +0000
From: Alasdair G Kergon <agk@redhat.com>
To: Jan Kara <jack@suse.cz>
Cc: Mikulas Patocka <mpatocka@redhat.com>, esandeen@redhat.com,
        Surbhi Palande <csurbhi@gmail.com>, linux-kernel@vger.kernel.org,
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        Christopher Chaltain <christopher.chaltain@canonical.com>,
        Valerie Aurora <val@vaaconsulting.com>
Subject: Re: [dm-devel] [PATCH] deadlock with suspend and quotas
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On Tue, Nov 29, 2011 at 02:09:13PM +0100, Jan Kara wrote:
>   Hmm, then why do these operations suspend the filesystem if they
> apparently don't need it? Sorry for my ignorance, I never seriously worked
> with LVM code...

They don't suspend it if they don't need to.

dm-ioctl.h:
/*
 * Set this to avoid attempting to freeze any filesystem when suspending.
 */
#define DM_SKIP_LOCKFS_FLAG     (1 << 10) /* In */

Alasdair