#!/bin/sh
# root, one-time: install a FULL-DUPLEX journal whose target is a plain
# file -> journal rthread reads EOF and exits instantly (xindex frozen)
mkdir -p /tmp/jstress && chmod 777 /tmp/jstress
mountctl -a -2 -w /root/j2.bin -o memfifo=64k /tmp:wedge
mountctl -l /tmp
ps -axo pid,comm | grep journal     # only "journal w:wedge" remains
# trigger: any process writing to the mount; the observer watches for
# the D-state jwrite wedge and tries SIGKILL (stock kernel: unkillable)
./df2748 /tmp/jstress
