Mount and ext3 issues with Busybox 1.2.2.1

[Rob Landley]

On Thursday 23 November 2006 5:40 pm, Denis Vlasenko wrote:
> On Thursday 23 November 2006 07:56, Jim Gifford wrote:
> > Rob Landley wrote:
> > > On Tuesday 21 November 2006 1:50 am, Jim Gifford wrote:
> > >   
> > >> Ok Guys figured out my issue ended up being something really stupid, 
> > >> some reason my boot script was failing to create /etc/mtab symlink to 
> > >> /proc/mounts. Don't know why but I'm investigating that right now.
> > >>     
> > >
> > > Why do you have "CONFIG_FEATURE_MTAB_SUPPORT" switched on?
> > >
> > > Rob
> >
> > I was just using make defconfig, which had that enabled.
> 
> Yes, it was, but it is off now in svn.
> Probably my fault...

No, it was on because make defconfig enables all functionality that sane 
people might actually want to use.

There are people out there who remove /proc from their kernels for the space 
savings (which is actually fairly noticeable in terms of embedded boards 
trying to get away with 4 megs of ram), and thus they haven't 
got /proc/mounts.  (Yeah, it's often the same people who like nommu because 
you don't need to waste RAM on page tables.)  If you symlink /etc/mtab 
to /proc/mounts any attempt to write to mtab (which is all the new code 
actually does) is a NOP, so the behavior's the same if the system's set up 
right.

Stuff that's off in defconfig essentially never gets tested, because 
allyesconfig enables things like SELINUX that nobody anywhere has a build 
environment set up for.  It doesn't even get compile tested.  That's why it 
was on by default, so it doesn't bit-rot.

This is a case of "configure what you actually need, understand what you're 
actually doing" that shows the project needs more "how to configure the 
sucker" documentation somewhere...

Rob
-- 
"Perfection is reached, not when there is no longer anything to add, but
when there is no longer anything to take away." - Antoine de Saint-Exupery