From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [dm-devel] [PATCH] deadlock with suspend and quotas Date: Tue, 29 Nov 2011 14:32:39 +0100 Message-ID: <20111129133239.GA9926@quack.suse.cz> References: <20111129101901.GA5635@quack.suse.cz> <20111129102156.GA7463@quack.suse.cz> <20111129111136.GC5635@quack.suse.cz> <20111129130913.GE5635@quack.suse.cz> <20111129131811.GS7595@agk-dp.fab.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20111129131811.GS7595@agk-dp.fab.redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org To: Alasdair G Kergon Cc: Jan Kara , Mikulas Patocka , esandeen@redhat.com, Surbhi Palande , linux-kernel@vger.kernel.org, dm-devel@redhat.com, linux-fsdevel@vger.kernel.org, Christopher Chaltain , Valerie Aurora List-Id: dm-devel.ids On Tue 29-11-11 13:18:11, Alasdair G Kergon wrote: > 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 */ Thanks. I was now checking in detail and indeed FIFREEZE fails if ->freeze_fs is not set. And only xfs, ext3, ext4, reiserfs, jfs, nilfs2, and gfs2 provide this function. So I was correct in assuming that when filesystem supports FIFREEZE it must make sure no modifications happen to the filesystem. So I believe that my original plan for sync to skip frozen filesystem is correct. Honza -- Jan Kara SUSE Labs, CR