[BusyBox] followup on mount oddity from my previous email

[Rob Landley]

On Friday 12 December 2003 05:38, Robert P. J. Day wrote:
> On Fri, 12 Dec 2003, Erik Andersen wrote:
> > On Fri Dec 12, 2003 at 05:12:43AM -0500, Robert P. J. Day wrote:
> > >   mount -n -t proc /proc /proc
> > >   echo "Remounting the root filesystem read-write."
> > >   mount -n -o remount,rw /dev/root /        <-- that's failing
> >
> > Could you apply this patch to busybox and try again?
> > http://busybox.net/cgi-bin/cvsweb/busybox/util-linux/mount.c?r1=1.114&r2=
> >1.115&diff_format=u
>
> that didn't appear to make any difference.
>
> rday

You might want to look at this oddity.  It's from Vladamir.  I've tried asking 
him what he was thinking, but he doesn't speak english.

http://www.busybox.net/cgi-bin/cvsweb/busybox/shell/ash.c?r1=1.65&r2=1.66

As far as I can tell, wheter or not "APPLETS_ALWAYS_WIN" is compiled it, the 
behavior will trigger anyway as long as there's no "/" in the name.  And 
instead of forking and calling run_applet_by_name (which is what it used to 
do, and the logical choice), it will instead call "/bin/busybox".

Now stop and think: we're running a perfectly good version of busybox already, 
loaded into memory.  The main reason to call the built-in behavior rather 
than execing another file is we might be in a chroot environment or something 
and not have access to even our own executable anymore.  In additon, assuming 
that it lives at /bin/busybox when it could be /usr/bin/busybox or in the 
root directory or might in fact be named /bin/sh (as a standalone shell) and 
there not BE a /bin/busybox...  Shelling out to that is STUPID, and the 
behavior before this patch was correct.

This patch broke ash.  Badly.  I don't know what it was trying to accomplish, 
the comment calls it a "small bugfix" when it's a major (bad) behavior 
change.  I asked earlier, and Vladamir never replied.  The patch looks really 
bad to me.  I _think_ that the built-in mount is being called for you, even 
if you have an external mount executable, because of this patch.

Comments?

Rob