mount_ext2fs returning ENODEV on 6.1

[Perry Hutchison]

> >> > # ll /dev/ad0s7
> >> > crw-r-----  1 root  operator    0,  93 Sep  4 02:30 /dev/ad0s7
> >> > # file -s /dev/ad0s7
> >> > /dev/ad0s7: Linux rev 1.0 ext2 filesystem data
> >> > # grep -w ad0s7 /etc/fstab
> >> > /dev/ad0s7      /linux          ext2fs  ro              0       0
> >> > # ll -d /linux
> >> > drwxr-xr-x  2 root  wheel  512 Aug 24 12:09 /linux
> >> > # mount /linux
> >> > mount_ext2fs: /dev/ad0s7: Operation not supported by device
> >> 
> >> No ext2fs support in your kernel?
> >
> > I had not thought that was the problem, since according to
> > something in the docs or manpages -- which I now cannot locate
> > -- missing kernel support should have resulted in a different
> > message.  How would I check, to be sure?  I am using the kernel
> > from the installation CD, not one I have built:
> >
> > # uname -a
> > FreeBSD fbsd61 6.1-RELEASE FreeBSD 6.1-RELEASE #0: Sun May  7 04:32:43 UTC 2006     root at opus.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
> 
> The standard kernel doesn't have ext2fs support now; I doubt the 6.1
> release was different.  Try loading it as a module; "kldload ext2fs".

It seems not to be that easy :(

  # kldload ext2fs
  kldload: can't load ext2fs: No such file or directory

Where is ext2fs.ko supposed to have come from?  A search for ext2fs
in the Handbook found nothing applicable, and I have already built
and installed /usr/ports/sysutils/e2fsprogs.