Backup and restore /run/initramfs via systemd services

This saves the space /run/initramfs is taking for the shutdown

Makefile

@@ -40,6 +40,7 @@ install: doc
 	mkdir -p $(DESTDIR)$(sysconfdir)/dracut.conf.d
 	install -m 0755 dracut-functions $(DESTDIR)$(pkglibdir)/dracut-functions
 	install -m 0755 dracut-logger $(DESTDIR)$(pkglibdir)/dracut-logger
+	install -m 0755 dracut-initramfs-backup.sh $(DESTDIR)$(pkglibdir)/dracut-initramfs-backup
 	cp -arx modules.d $(DESTDIR)$(pkglibdir)
 	install -m 0644 dracut.8 $(DESTDIR)$(mandir)/man8/dracut.8
 	install -m 0644 dracut-catimages.8 $(DESTDIR)$(mandir)/man8/dracut-catimages.8
@@ -47,6 +48,15 @@ install: doc
 	install -m 0644 dracut.conf.5 $(DESTDIR)$(mandir)/man5/dracut.conf.5
 	install -m 0644 dracut.cmdline.7 $(DESTDIR)$(mandir)/man7/dracut.cmdline.7
 	ln -s dracut.cmdline.7 $(DESTDIR)$(mandir)/man7/dracut.kernel.7
+	if [ -n "$(systemdsystemunitdir)" ]; then \
+		mkdir -p $(DESTDIR)$(systemdsystemunitdir); \
+		install -m 0644 dracut-backup.service $(DESTDIR)$(systemdsystemunitdir); \
+		install -m 0644 dracut-restore.service $(DESTDIR)$(systemdsystemunitdir); \
+		mkdir -p $(DESTDIR)$(systemdsystemunitdir)/sysinit.target.wants; \
+		mkdir -p $(DESTDIR)$(systemdsystemunitdir)/reboot.target.wants; \
+		ln -s ../dracut-backup.service $(DESTDIR)$(systemdsystemunitdir)/sysinit.target.wants/dracut-backup.service; \
+		ln -s ../dracut-restore.service $(DESTDIR)$(systemdsystemunitdir)/reboot.target.wants/dracut-restore.service; \
+	fi
 
 clean:
 	$(RM) *~
@@ -77,12 +87,14 @@ rpm: dracut-$(VERSION).tar.bz2
 	( mv "$$rpmbuild"/noarch/*.rpm .; mv "$$rpmbuild"/*.src.rpm .;rm -fr "$$rpmbuild"; ls *.rpm )
 
 syncheck:
-	@ret=0;for i in dracut-logger modules.d/99base/init modules.d/*/*.sh; do \
+	@ret=0;for i in dracut-initramfs-backup.sh dracut-logger \
+                        modules.d/99base/init modules.d/*/*.sh; do \
                 [ "$${i##*/}" = "module-setup.sh" ] && continue; \
                 [ "$${i##*/}" = "caps.sh" ] && continue; \
 		dash -n "$$i" ; ret=$$(($$ret+$$?)); \
 	done;exit $$ret
-	@ret=0;for i in dracut modules.d/02caps/caps.sh modules.d/*/module-setup.sh; do \
+	@ret=0;for i in mkinitrd-dracut.sh dracut modules.d/02caps/caps.sh \
+	                modules.d/*/module-setup.sh; do \
 		bash -n "$$i" ; ret=$$(($$ret+$$?)); \
 	done;exit $$ret
 

dracut-backup.service

@@ -0,0 +1,15 @@
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=Save /run/initramfs
+ConditionPathExists=/run/initramfs
+
+[Service]
+ExecStart=/usr/lib/dracut/dracut-initramfs-backup backup
+Type=oneshot
+RemainAfterExit=yes

dracut-initramfs-backup.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
+# ex: ts=8 sw=4 sts=4 et filetype=sh
+
+set -e
+cd /run/initramfs
+
+if [ "x$1" = "xbackup" ]; then
+    compress="gzip"
+    command -v pigz > /dev/null 2>&1 && compress="pigz"
+    find . |cpio -H newc -o --quiet \
+        | pigz > /var/lib/initramfs/_run_initramfs-backup.cpio.gz
+    mv -f /var/lib/initramfs/_run_initramfs-backup.cpio.gz \
+        /var/lib/initramfs/run_initramfs-backup.cpio.gz
+    rm -fr etc bin lib lib64 sbin shutdown tmp usr var
+    > .backuped
+elif [ "x$1" = "xrestore" ]; then
+    [ -f .backuped -a -f /var/lib/initramfs/run_initramfs-backup.cpio.gz ] || exit 1
+    zcat /var/lib/initramfs/run_initramfs-backup.cpio.gz  | cpio -id >/dev/null 2>&1
+    rm .backuped
+    rm -f /var/lib/initramfs/run_initramfs-backup.cpio.gz
+fi

dracut-restore.service

@@ -0,0 +1,18 @@
+#  This file is part of systemd.
+#
+#  systemd is free software; you can redistribute it and/or modify it
+#  under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+
+[Unit]
+Description=Restore /run/initramfs
+After=getty@tty1.service prefdm.service
+Before=reboot.service
+DefaultDependencies=no
+ConditionPathExists=/run/initramfs/.backuped
+
+[Service]
+ExecStart=/usr/lib/dracut/dracut-initramfs-backup restore
+Type=oneshot
+RemainAfterExit=yes

dracut.spec

@@ -27,6 +27,7 @@ Source0: http://www.kernel.org/pub/linux/utils/boot/dracut/dracut-%{version}.tar
 
 BuildArch: noarch
 BuildRequires: dash bash git
+
 %if 0%{?fedora} || 0%{?rhel} > 6
 BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 %endif
@@ -51,6 +52,10 @@ Obsoletes: nash <= 6.0.93
 Obsoletes: libbdevid-python <= 6.0.93
 %endif
 
+%if 0%{?fedora} > 16 || 0%{?rhel} > 6
+BuildRequires: systemd-units
+%endif
+
 %if 0%{?suse_version} > 9999
 Obsoletes: mkinitrd < 2.6.1
 Provides: mkinitrd = 2.6.1
@@ -161,7 +166,8 @@ rm -rf $RPM_BUILD_ROOT
 make install DESTDIR=$RPM_BUILD_ROOT \
      libdir=%{_prefix}/lib \
      bindir=%{_bindir} \
-     sysconfdir=/etc mandir=%{_mandir}
+     sysconfdir=/etc mandir=%{_mandir} \
+     systemdsystemunitdir=%{_unitdir}
 
 echo %{name}-%{version}-%{release} > $RPM_BUILD_ROOT/%{dracutlibdir}/modules.d/10rpmversion/dracut-version
 
@@ -217,6 +223,7 @@ rm -rf $RPM_BUILD_ROOT
 %dir %{dracutlibdir}/modules.d
 %{dracutlibdir}/dracut-functions
 %{dracutlibdir}/dracut-logger
+%{dracutlibdir}/dracut-initramfs-backup
 %config(noreplace) /etc/dracut.conf
 %if 0%{?fedora} || 0%{?suse_version} || 0%{?rhel} > 6
 %config /etc/dracut.conf.d/01-dist.conf
@@ -266,6 +273,10 @@ rm -rf $RPM_BUILD_ROOT
 %config(noreplace) /etc/logrotate.d/dracut_log
 %attr(0644,root,root) %ghost %config(missingok,noreplace) %{_localstatedir}/log/dracut.log
 %dir %{_sharedstatedir}/initramfs
+%if 0%{?fedora} > 16 || 0%{?rhel} > 6
+%{_unitdir}/*.service
+%{_unitdir}/*/*.service
+%endif
 
 %files network
 %defattr(-,root,root,0755)