Remove the kdump error handler isolation wrapper

The wrapper is introduced in commit 002337c, according to the commit
message, the only usage of the wrapper is when dracut-initqueue calls
"systemctl start emergency" directly. In that case, emergency
is started, but not in a isolation mode, which means dracut-initqueue
is still running. On the other hand, emergency will call
"systemctl start dracut-initqueue" again when default action is dump_to_rootfs.

systemd would block on the last dracut-initqueue, waiting for the first
instance to exit, which leaves us hang.

In previous commit we added initqueue status detect in dump_to_rootfs,
so now even without the wrapper, it will not hang.

And actually, previously, with the wrapper, emergency might still hang
for like 30s. When dracut called emergency service because initqueue
timed out, dump_to_rootfs will try start initqueue again and timeout
again. Now with the wrapper removed, we can avoid these two kinds of
hangs, bacause without the isolation we can detect initqueue service
status correctly in such case.

Also remove the invalid header comments in service file, the service
is not part of systemd code. And sync the service spec with dracut.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Coiby Xu <coxu@redhat.com>

dracut-kdump-emergency.service

@@ -1,27 +1,26 @@
-#  This file is part of systemd.
-#
-#  systemd is free software; you can redistribute it and/or modify it
-#  under the terms of the GNU Lesser General Public License as published by
-#  the Free Software Foundation; either version 2.1 of the License, or
-#  (at your option) any later version.
-
-# This service will be placed in kdump initramfs and replace both the systemd
-# emergency service and dracut emergency shell. IOW, any emergency will be
-# kick this service and in turn isolating to kdump error handler.
+# This service will run the real kdump error handler code. Executing the
+# failure action configured in kdump.conf
 
 [Unit]
-Description=Kdump Emergency
+Description=Kdump Error Handler
 DefaultDependencies=no
-IgnoreOnIsolate=yes
+After=systemd-vconsole-setup.service
+Wants=systemd-vconsole-setup.service
 
 [Service]
-ExecStart=/usr/bin/systemctl --no-block isolate kdump-error-handler.service
+Environment=HOME=/
+Environment=DRACUT_SYSTEMD=1
+Environment=NEWROOT=/sysroot
+WorkingDirectory=/
+ExecStart=/bin/kdump-error-handler.sh
+ExecStopPost=-/bin/rm -f -- /.console_lock
 Type=oneshot
 StandardInput=tty-force
 StandardOutput=inherit
 StandardError=inherit
 KillMode=process
 IgnoreSIGPIPE=no
+TasksMax=infinity
 
 # Bash ignores SIGTERM, so we send SIGHUP instead, to ensure that bash
 # terminates cleanly.

dracut-kdump-error-handler.service

@@ -1,33 +0,0 @@
-#  This file is part of systemd.
-#
-#  systemd is free software; you can redistribute it and/or modify it
-#  under the terms of the GNU Lesser General Public License as published by
-#  the Free Software Foundation; either version 2.1 of the License, or
-#  (at your option) any later version.
-
-# This service will run the real kdump error handler code. Executing the
-# failure action configured in kdump.conf
-
-[Unit]
-Description=Kdump Error Handler
-DefaultDependencies=no
-After=systemd-vconsole-setup.service
-Wants=systemd-vconsole-setup.service
-AllowIsolate=yes
-
-[Service]
-Environment=HOME=/
-Environment=DRACUT_SYSTEMD=1
-Environment=NEWROOT=/sysroot
-WorkingDirectory=/
-ExecStart=/bin/kdump-error-handler.sh
-Type=oneshot
-StandardInput=tty-force
-StandardOutput=inherit
-StandardError=inherit
-KillMode=process
-IgnoreSIGPIPE=no
-
-# Bash ignores SIGTERM, so we send SIGHUP instead, to ensure that bash
-# terminates cleanly.
-KillSignal=SIGHUP

dracut-module-setup.sh

@@ -1026,7 +1026,6 @@ install() {
     inst "$moddir/kdump-capture.service" "$systemdsystemunitdir/kdump-capture.service"
     systemctl -q --root "$initdir" add-wants initrd.target kdump-capture.service
     inst "$moddir/kdump-error-handler.sh" "/usr/bin/kdump-error-handler.sh"
-    inst "$moddir/kdump-error-handler.service" "$systemdsystemunitdir/kdump-error-handler.service"
     # Replace existing emergency service and emergency target
     cp "$moddir/kdump-emergency.service" "$initdir/$systemdsystemunitdir/emergency.service"
     cp "$moddir/kdump-emergency.target" "$initdir/$systemdsystemunitdir/emergency.target"

kexec-tools.spec

@@ -49,7 +49,6 @@ Source101: dracut-module-setup.sh
 Source102: dracut-monitor_dd_progress
 Source103: dracut-kdump-error-handler.sh
 Source104: dracut-kdump-emergency.service
-Source105: dracut-kdump-error-handler.service
 Source106: dracut-kdump-capture.service
 Source107: dracut-kdump-emergency.target
 Source108: dracut-early-kdump.sh
@@ -220,7 +219,6 @@ cp %{SOURCE101} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpb
 cp %{SOURCE102} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE102}}
 cp %{SOURCE103} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE103}}
 cp %{SOURCE104} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE104}}
-cp %{SOURCE105} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE105}}
 cp %{SOURCE106} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE106}}
 cp %{SOURCE107} $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE107}}
 chmod 755 $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/99kdumpbase/%{remove_dracut_prefix %{SOURCE100}}