[Ocfs2-tools-devel] [PATCH 3/3] mkfs.ocfs2: Add 64bit journal support.

[Joel Becker]

On Sun, Sep 07, 2008 at 02:42:41PM -0700, Mark Fasheh wrote:
> > 	Yup.  Any thoughts?  I was just thinking a INCOMPAT_JBD2.  The
> > kernel only needs to know about the bit (jbd and jbd2 handle the journal
> > superblock compat checks properly).  Our tools will start supporting
> > INCOMPAT_JBD2 when they start rejecting unknown journal superblock bits.
> > Sound good?
> 
> Hmm... Well actually, how about a compat bit instead? We're only worried
> about stopping fsck, and since it's more strict than the kernel about
> bits...

	So, old kernel sees it as compat, but JBD/JBD2 handle the
journal superblock bits if necessary.  Bonus, it's safe if we haven't
turned on any extended features.
	In userspace, old fsck is stringent and will fail.  Old tunefs
is also stringent.  Debugfs will print garbage for the journal
tag list.

Joel

-- 

"Behind every successful man there's a lot of unsuccessful years."
        - Bob Brown

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127