Re: DISKLABEL_EI option for system with MBR

[David Holland <dholland-tech%netbsd.org@localhost>]

On Tue, Feb 14, 2017 at 04:10:11PM -0500, Mouse wrote:
 > > [B]ased on things I saw when hacking lfs last year (all of which got
 > > fixed), I wouldn't rely on FFS_EI until someone gives it a good
 > > thorough audit, preferably with some kind of automated checking tool.
 > 
 > What sort of things?  (If you care to say, of course.)  I've been using
 > FFS_EI semi-routinely (as in, I build ~all my kernels with it, and,
 > while I don't want it all the time, when I do I haven't hesitated) and
 > have never seen any issues I can ascribe to it.

I found places in ufs/ where the byte swaps were missing. This will in
general fail silently unless you happen to read through such a path
and notice you got the wrong thing... or write through such a path and
notice that the volume has been corrupted.

I totally forget what they were, but probably it can be dug out of the
source-changes archive.

In any event because of the large number of code sites that touch
things that need to be swapped, without some kind of automated
crosscheck it's practically a given that some of them are wrong.

 > I haven't been trying to stress it, though.  Also, depending on what
 > vintage you're talking about, it may have got broken - or broken worse
 > - in between the versions I use and the versions you looked at.

Indeed.

-- 
David A. Holland
dholland%netbsd.org@localhost