2 files changed, 68 insertions, 0 deletions
diff --git a/modules.d/98dracut-systemd/dracut-shutdown.service b/modules.d/98dracut-systemd/dracut-shutdown.service
new file mode 100644
index 0000000..b2b704a
--- /dev/null
+++ b/modules.d/98dracut-systemd/dracut-shutdown.service
@@ -0,0 +1,15 @@
+#  This file is part of dracut.
+
+[Unit]
+Description=Restore /run/initramfs on shutdown
+Documentation=man:dracut-shutdown.service(8)
+After=local-fs.target boot.mount boot.automount
+Wants=local-fs.target
+ConditionPathExists=!/run/initramfs/bin/sh
+OnFailure=dracut-shutdown-onfailure.service
+
+[Service]
+RemainAfterExit=yes
+Type=oneshot
+ExecStart=/bin/true
+ExecStop=/usr/lib/dracut/dracut-initramfs-restore
diff --git a/modules.d/98dracut-systemd/dracut-shutdown.service.8.asc b/modules.d/98dracut-systemd/dracut-shutdown.service.8.asc
new file mode 100644
index 0000000..21ec88c
--- /dev/null
+++ b/modules.d/98dracut-systemd/dracut-shutdown.service.8.asc
@@ -0,0 +1,53 @@
+DRACUT-SHUTDOWN.SERVICE(8)
+===========================
+:doctype: manpage
+:man source:   dracut
+:man manual:   dracut
+
+NAME
+----
+dracut-shutdown.service - unpack the initramfs to /run/initramfs
+
+SYNOPSIS
+--------
+dracut-shutdown.service
+
+DESCRIPTION
+-----------
+This service unpacks the initramfs image to /run/initramfs.
+systemd pivots into /run/initramfs at shutdown, so the root filesystem
+can be safely unmounted.
+
+The following steps are executed during a shutdown:
+
+* systemd switches to the shutdown.target
+* systemd starts /lib/systemd/system/shutdown.target.wants/dracut-shutdown.service
+* dracut-shutdown.service executes /usr/lib/dracut/dracut-initramfs-restore which unpacks the initramfs to /run/initramfs
+* systemd finishes shutdown.target
+* systemd kills all processes
+* systemd tries to unmount everything and mounts the remaining read-only
+* systemd checks, if there is a /run/initramfs/shutdown executable
+* if yes, it does a pivot_root to /run/initramfs and executes ./shutdown. The old root is then mounted on /oldroot. /usr/lib/dracut/modules.d/99shutdown/shutdown.sh is the shutdown executable.
+* shutdown will try to umount every /oldroot mount and calls the various shutdown hooks from the dracut modules 
+
+This ensures, that all devices are disassembled and unmounted cleanly.
+
+To debug the shutdown process, you can get a shell in the shutdown procedure
+by injecting "rd.break=pre-shutdown rd.shell" or "rd.break=shutdown rd.shell".
+----
+# mkdir -p /run/initramfs/etc/cmdline.d
+# echo "rd.break=pre-shutdown rd.shell" > /run/initramfs/etc/cmdline.d/debug.conf
+# touch /run/initramfs/.need_shutdown
+----
+
+In case the unpack of the initramfs fails, dracut-shutdown-onfailure.service
+executes to make sure switch root doesn't happen, since it would result in
+switching to an incomplete initramfs.
+
+AUTHORS
+-------
+Harald Hoyer
+
+SEE ALSO
+--------
+*dracut*(8)