linux-kernel - Re: [dm-devel] [PATCH] deadlock with suspend and quotas

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 30 Nov 2011 13:05:14 +0000
From:	Alasdair G Kergon <agk@...hat.com>
To:	Mikulas Patocka <mpatocka@...hat.com>, Jan Kara <jack@...e.cz>,
	Alasdair G Kergon <agk@...hat.com>, esandeen@...hat.com,
	Surbhi Palande <csurbhi@...il.com>,
	linux-kernel@...r.kernel.org, dm-devel@...hat.com,
	linux-fsdevel@...r.kernel.org,
	Christopher Chaltain <christopher.chaltain@...onical.com>,
	Valerie Aurora <val@...consulting.com>
Subject: Re: [dm-devel] [PATCH] deadlock with suspend and quotas

On Wed, Nov 30, 2011 at 07:14:18AM -0500, Mikulas Patocka wrote:
> On Wed, 30 Nov 2011, Jan Kara wrote:
> > > So if you skip sync of frozen filesystems, you introduce a data
> > > corruption if someone takes a snapshot of ext2.
> >   Yes, because ext2 cannot really be frozen, it is (errorneously) marked
> > as such but it is not frozen...

This is just getting into semantics.  AFAIK (and it was before my involvement)
LVM used the term 'lockfs' for this operation when it was introduced to ext2.
It later got renamed in-kernel to 'frozen' to bring it into line with newer
filesystems.  But userspace and the interface still retain the original
'lockfs' name.

There is no further I/O sent to the filesystem during the 'lockfs' operation:
LVM uses dm to block that.

Alasdair

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/