Description of Problem:

In fs/super.c:get_anon_super(), if the compare() function ever returns success,
the new super block is destroyed, but the newly allocated unnamed device doesn't
get released.

Version-Release number of selected component (if applicable):

2.4.18-0.4, 2.4.18-0.12

Steps to reproduce:

mkdir /tmp/pts
while true; do
  mount -t devpts devpts /tmp/pts
  umount /tmp/pts
done

Soon gives "Mount table full" errors

This seems to be fixed in 2.5.x by a reorganisation of the super-block
allocation code.