linux-ext4 - Re: Something wrong with extent-based journal creation

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]

Message-ID: <20090617153126.GA25451@mit.edu>
Date:	Wed, 17 Jun 2009 11:31:26 -0400
From:	Theodore Tso <tytso@....edu>
To:	Andreas Dilger <adilger@....com>
Cc:	Eric Sandeen <sandeen@...hat.com>,
	ext4 development <linux-ext4@...r.kernel.org>
Subject: Re: Something wrong with extent-based journal creation

On Wed, Jun 17, 2009 at 02:04:32AM -0600, Andreas Dilger wrote:
> On Jun 16, 2009  17:38 -0500, Eric Sandeen wrote:
> > I've narrowed it down to the commit (961306d3) which creates the journal
> > with extent format; if that's commented out, it works fine.
> 
> Hmm, this seems like it might be a troublesome feature...  Are we sure
> that there is proper kernel/tool compatibility for an extent-mapped
> journal?  At least none of the Lustre code has any support for this,
> though they can handle the INCOMPAT_EXTENTS feature, and I don't think
> this was present in older kernels either.
> 
> I haven't looked at the code for this yet, so it may be that it will
> "just work", but if this is a new feature I would urge caution w.r.t.
> compatibility before this is merged upstream (in either e2fsprogs or
> the kernel).

Extent-based journals "just works", at least in the kernel; I didn't
need to make any changes to the kernel before I added support to using
an extent-mapped journal; if the kernel supports extents, it should
expert extent-mapped journals without any difficults.  The patch to
add this was merged in before e2fsprogs 1.41.1 was released, so mke2fs
has been creating extent-based journals for a while.

    	 	  	       		      - Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html