Use /lib/dracut/no-emergency-shell to control action on fail

Currently when action_on_fail is enabled, the emergency_shell won't be called
either. In kdump even though user specify the default action as emergency_shell,
dracut still skip it. Now change the implementation of action_on_fail to depend
on a file which is created by kdump when making kdump initrd, then remove it
at the beginning of kdump. This can solve the explicit emergency_shell problem.

Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: WANG Chao <chaowang@redhat.com>

dracut-kdump.sh

@@ -3,6 +3,10 @@
 exec &> /dev/console
 . /lib/dracut-lib.sh
 
+if [ -f "$initdir/lib/dracut/no-emergency-shell" ]; then
+    rm -f -- $initdir/lib/dracut/no-emergency-shell
+fi
+
 set -o pipefail
 KDUMP_PATH="/var/crash"
 CORE_COLLECTOR=""

dracut-module-setup.sh

@@ -400,6 +400,8 @@ kdump_check_iscsi_targets () {
 
 install() {
     kdump_install_conf
+    >"$initdir/lib/dracut/no-emergency-shell"
+
     if is_ssh_dump_target; then
         dracut_install /var/lib/random-seed || exit $?
     fi