Add systemd unit files for ZFS startup

This adds systemd unit files replacing the functionality offered by
the SysV init script found in etc/init.d.

It has been developed and tested on Fedora 19, Fedora 20
and openSuSE 13.1.

Four unit files and one target are offered.

zfs-import-cache.service:
    Import pools from /etc/zfs/zpool.cache. This unit will wait for
    udev to settle.
zfs-import-scan.service:
    Import pools by scanning /dev/disk/by-id for zvols. This unit will
    only run if /etc/zfs/zpool.cache is not present. This unit will wait
    for udev to settle
zfs-mount.service:
    Mount ZFS native filesystems. It contains a dependency to be loaded
    before local-fs.target.
zfs-share.service:
    Share NFS/SMB filesystems. This unit contains a dependency that
    will cause it to be restarted whenever the smb or nfs-server unit
    is restarted, restoring the shares added.
zfs.target:
    This target pulls in the other units in order to start ZFS. It's
    the only unit that can be enabled/disabled, all other services
    are static and pulled in by dependencies. It will honour zfs=off
    and zfs=no options on the kernel command line.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes openzfs#2108

config/user-systemd.m4

@@ -0,0 +1,29 @@
+AC_DEFUN([ZFS_AC_CONFIG_USER_SYSTEMD], [
+	AC_ARG_ENABLE(systemd,
+		AC_HELP_STRING([--enable-systemd],
+		[install systemd unit/preset files [[default: yes]]]),
+		[],enable_systemd=yes)
+
+	AC_ARG_WITH(systemdunitdir,
+		AC_HELP_STRING([--with-systemdunitdir=DIR],
+		[install systemd unit files in dir [[/usr/lib/systemd/system]]]),
+		systemdunitdir=$withval,systemdunitdir=/usr/lib/systemd/system)
+
+	AC_ARG_WITH(systemdpresetdir,
+		AC_HELP_STRING([--with-systemdpresetdir=DIR],
+		[install systemd preset files in dir [[/usr/lib/systemd/system-preset]]]),
+		systemdpresetdir=$withval,systemdpresetdir=/usr/lib/systemd/system-preset)
+
+	AS_IF([test "x$enable_systemd" = xyes],
+		[
+		ZFS_INIT_SYSTEMD=systemd
+		ZFS_MODULE_LOAD=modules-load.d
+		modulesloaddir=/usr/lib/modules-load.d
+		])
+
+	AC_SUBST(ZFS_INIT_SYSTEMD)
+	AC_SUBST(ZFS_MODULE_LOAD)
+	AC_SUBST(systemdunitdir)
+	AC_SUBST(systemdpresetdir)
+	AC_SUBST(modulesloaddir)
+])

config/user-sysvinit.m4

@@ -0,0 +1,11 @@
+AC_DEFUN([ZFS_AC_CONFIG_USER_SYSVINIT], [
+	AC_ARG_ENABLE(sysvinit,
+		AC_HELP_STRING([--enable-sysvinit],
+		[install SysV init scripts [default: yes]]),
+		[],enable_sysvinit=yes)
+
+	AS_IF([test "x$enable_sysvinit" = xyes],
+		[ZFS_INIT_SYSV=init.d])
+
+	AC_SUBST(ZFS_INIT_SYSV)
+])

config/user.m4

@@ -3,6 +3,8 @@ dnl # Default ZFS user configuration
 dnl #
 AC_DEFUN([ZFS_AC_CONFIG_USER], [
 	ZFS_AC_CONFIG_USER_UDEV
+	ZFS_AC_CONFIG_USER_SYSTEMD
+	ZFS_AC_CONFIG_USER_SYSVINIT
 	ZFS_AC_CONFIG_USER_DRACUT
 	ZFS_AC_CONFIG_USER_ARCH
 	ZFS_AC_CONFIG_USER_IOCTL

configure.ac

@@ -64,6 +64,9 @@ AC_CONFIG_FILES([
 	etc/Makefile
 	etc/init.d/Makefile
 	etc/zfs/Makefile
+	etc/systemd/Makefile
+	etc/systemd/system/Makefile
+	etc/modules-load.d/Makefile
 	man/Makefile
 	man/man1/Makefile
 	man/man5/Makefile

etc/Makefile.am

@@ -1 +1,2 @@
-SUBDIRS = init.d zfs
+SUBDIRS = zfs $(ZFS_INIT_SYSTEMD) $(ZFS_INIT_SYSV) $(ZFS_MODULE_LOAD)
+DIST_SUBDIRS = init.d zfs systemd modules-load.d

etc/modules-load.d/.gitignore

@@ -0,0 +1 @@
+*.conf

etc/modules-load.d/Makefile.am

@@ -0,0 +1,13 @@
+modulesload_DATA = \
+	$(top_srcdir)/etc/modules-load.d/zfs.conf
+
+EXTRA_DIST = \
+	$(top_srcdir)/etc/modules-load.d/zfs.conf.in
+
+$(modulesload_DATA):
+	-$(SED) \
+		-e '' \
+		'$@.in' >'$@'
+
+distclean-local::
+	-$(RM) $(modulesload_DATA)

etc/modules-load.d/zfs.conf.in

@@ -0,0 +1 @@
+zfs

etc/systemd/Makefile.am

@@ -0,0 +1 @@
+SUBDIRS = system

etc/systemd/system/.gitignore

@@ -0,0 +1,3 @@
+*.service
+*.target
+*.preset

etc/systemd/system/50-zfs.preset.in

@@ -0,0 +1,2 @@
+# ZFS is enabled by default
+enable zfs.*

etc/systemd/system/Makefile.am

@@ -0,0 +1,31 @@
+systemdpreset_DATA = \
+	$(top_srcdir)/etc/systemd/system/50-zfs.preset
+systemdunit_DATA = \
+	$(top_srcdir)/etc/systemd/system/zfs-import-scan.service \
+	$(top_srcdir)/etc/systemd/system/zfs-import-cache.service \
+	$(top_srcdir)/etc/systemd/system/zfs-mount.service \
+	$(top_srcdir)/etc/systemd/system/zfs-share.service \
+	$(top_srcdir)/etc/systemd/system/zfs.target
+
+EXTRA_DIST = \
+	$(top_srcdir)/etc/systemd/system/zfs-import-scan.service.in \
+	$(top_srcdir)/etc/systemd/system/zfs-import-cache.service.in \
+	$(top_srcdir)/etc/systemd/system/zfs-mount.service.in \
+	$(top_srcdir)/etc/systemd/system/zfs-share.service.in \
+	$(top_srcdir)/etc/systemd/system/zfs.target.in \
+	$(top_srcdir)/etc/systemd/system/50-zfs.preset.in
+
+$(systemdunit_DATA):
+	-$(SED) -e 's,@bindir\@,$(bindir),g' \
+		-e 's,@sbindir\@,$(sbindir),g' \
+		-e 's,@sysconfdir\@,$(sysconfdir),g' \
+		'$@.in' >'$@'
+
+$(systemdpreset_DATA):
+	-$(SED) -e 's,@bindir\@,$(bindir),g' \
+		-e 's,@sbindir\@,$(sbindir),g' \
+		-e 's,@sysconfdir\@,$(sysconfdir),g' \
+		'$@.in' >'$@'
+
+distclean-local::
+	-$(RM) $(systemdunit_DATA) $(systemdpreset_DATA)

etc/systemd/system/zfs-import-cache.service.in

@@ -0,0 +1,11 @@
+[Unit]
+Description=Import ZFS pools by cache file
+DefaultDependencies=no
+Requires=systemd-udev-settle.service
+After=systemd-udev-settle.service
+ConditionPathExists=@sysconfdir@/zfs/zpool.cache
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=@sbindir@/zpool import -c @sysconfdir@/zfs/zpool.cache -aN

etc/systemd/system/zfs-import-scan.service.in

@@ -0,0 +1,11 @@
+[Unit]
+Description=Import ZFS pools by device scanning
+DefaultDependencies=no
+Requires=systemd-udev-settle.service
+After=systemd-udev-settle.service
+ConditionPathExists=!@sysconfdir@/zfs/zpool.cache
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=@sbindir@/zpool import -d /dev/disk/by-id -aN

etc/systemd/system/zfs-mount.service.in

@@ -0,0 +1,15 @@
+[Unit]
+Description=Mount ZFS filesystems
+DefaultDependencies=no
+Wants=zfs-import-cache.service
+Wants=zfs-import-scan.service
+Requires=systemd-udev-settle.service
+After=systemd-udev-settle.service
+After=zfs-import-cache.service
+After=zfs-import-scan.service
+Before=local-fs.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=@sbindir@/zfs mount -a

etc/systemd/system/zfs-share.service.in

@@ -0,0 +1,11 @@
+[Unit]
+Description=ZFS file system shares
+After=nfs-server.service
+After=smb.service
+PartOf=nfs-server.service
+PartOf=smb.service
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=@sbindir@/zfs share -a

etc/systemd/system/zfs.target.in

@@ -0,0 +1,7 @@
+[Unit]
+Description=ZFS startup target
+Requires=zfs-mount.service
+Requires=zfs-share.service
+
+[Install]
+WantedBy=multi-user.target

rpm/generic/zfs.spec.in

@@ -10,7 +10,24 @@
 
 %bcond_with    debug
 %bcond_with    blkid
+%bcond_with    systemd
 
+# Generic enable switch for systemd
+%if %{with systemd}
+%define _systemd 1
+%endif
+
+# Fedora >= 15 comes with systemd, but only >= 18 has
+# the proper macros
+%if 0%{?fedora} >= 18
+%define _systemd 1
+%endif
+
+# opensuse >= 12.1 comes with systemd, but only >= 13.1
+# has the proper macros
+%if 0%{?suse_version} >= 1310
+%define _systemd 1
+%endif
 
 Name:           @PACKAGE@
 Version:        @VERSION@
@@ -38,6 +55,12 @@ BuildRequires:  libuuid-devel
 BuildRequires:  libblkid-devel
 %endif
 %endif
+%if 0%{?_systemd}
+Requires(post): systemd
+Requires(preun): systemd
+Requires(postun): systemd
+BuildRequires: systemd
+%endif
 
 %description
 This package contains the ZFS command line utilities and libraries.
@@ -85,6 +108,11 @@ image which is ZFS aware.
 %else
     %define blkid --without-blkid
 %endif
+%if 0%{?_systemd}
+    %define systemd --enable-systemd --with-systemdunitdir=%{_unitdir} --with-systemdpresetdir=%{_presetdir} --disable-sysvinit
+%else
+    %define systemd --enable-sysvinit --disable-systemd
+%endif
 
 %setup -q
 
@@ -95,7 +123,8 @@ image which is ZFS aware.
     --with-dracutdir=%{_dracutdir} \
     --disable-static \
     %{debug} \
-    %{blkid}
+    %{blkid} \
+    %{systemd}
 make %{?_smp_mflags}
 
 %install
@@ -105,16 +134,28 @@ find %{?buildroot}%{_libdir} -name '*.la' -exec rm -f {} \;
 
 %post
 /sbin/ldconfig
+%if 0%{?_systemd}
+%systemd_post zfs.target
+%else
 [ -x /sbin/chkconfig ] && /sbin/chkconfig --add zfs
+%endif
 exit 0
 
 %preun
+%if 0%{?_systemd}
+%systemd_preun zfs.target
+%else
 if [ $1 -eq 0 ] ; then
     [ -x /sbin/chkconfig ] && /sbin/chkconfig --del zfs
 fi
+%endif
 exit 0
 
-%postun -p /sbin/ldconfig
+%postun
+/sbin/ldconfig
+%if 0%{?_systemd}
+%systemd_postun zfs.target
+%endif
 
 %files
 %doc AUTHORS COPYRIGHT DISCLAIMER
@@ -129,7 +170,13 @@ exit 0
 %{_udevdir}/zvol_id
 %{_udevdir}/rules.d/*
 %config(noreplace) %{_sysconfdir}/%{name}
+%if 0%{?_systemd}
+/usr/lib/modules-load.d/*
+%{_unitdir}/*
+%{_presetdir}/*
+%else
 %{_sysconfdir}/init.d/*
+%endif
 
 %files devel
 %{_libdir}/*.so