how to loopback mount a JFFS2 filesystem on my linux box?

[Robert P. J. Day]

  i swear i once knew how to do this, but it's lost in the mists of
time.  i used "mkfs.jffs2" to create a simple JFFS2 image, and now i
just want to mount it on my fedora core 3 system using a loopback
mount.

  i have the jffs2 and mtdcore modules currently loaded, and normally,
what i would try is:

  # mkdir m
  # mount -o loop -t jffs2 <jffs2.img file> m

but what i get is:

# mount -o loop -t jffs2 hello.img m
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
       or too many mounted file systems
       (could this be the IDE device where you in fact use
       ide-scsi so that sr0 or sda or so is needed?)

  i *vaguely* recall needing to do a bit more work, like loading
another module or two.  any pointers to a URL for this?  thanks.

rday