Interrupting fsck during startup

[Michael ODonnell]

In certain time-critical situations it is desirable that we be able to
interrupt fsck as it tries to preen certain huge filesystems.  Yes, we
know that interrupting fsck is not good sysadmin hygiene and we generally
discourage such behavior, but when a machine is being (re)booted in a
crisis situation where seconds matter it's at least an option we'd like
to have available to us.  In some older distributions of Linux it was
possible to interrupt fsck via Ctl-C even if it was launched from one
of the init scripts, but this "feature" seems not to be available with
some more recent distributions we're working with, including CentOS5.2.
Does anybody know how to enable this or what was changed or why?

This is apparently quite a thorny issue as it involves trying to make
sense of the esoterica associated with job-control, signal handling,
ttys and /dev/console, any one of which is challenging by itself and
nearly impenetrable in combination...  >-/