Move dracut specifics to dracut module

Dracut depends on the environment variable BOOTFS to be set after pool
import. This dracut specific systemd ExecStartPost command should not be
called for any non-dracut systems, so let's move it to a static systemd
unit that.

Reviewed-by: Manuel Amador (Rudd-O) <[email protected]>
Reviewed-by: Matthew Thode <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Michael Niewöhner <[email protected]>
Closes #8510 

4 files changed, 25 insertions, 3 deletions

diff --git a/contrib/dracut/90zfs/.gitignore b/contrib/dracut/90zfs/.gitignore
index eb41fce4f..85c23f75e 100644
--- a/contrib/dracut/90zfs/.gitignore
+++ b/contrib/dracut/90zfs/.gitignore
@@ -6,3 +6,4 @@ zfs-generator.sh
 zfs-lib.sh
 zfs-load-key.sh
 zfs-needshutdown.sh
+zfs-env-bootfs.service
diff --git a/contrib/dracut/90zfs/Makefile.am b/contrib/dracut/90zfs/Makefile.am
index afcd51022..0a557f57f 100644
--- a/contrib/dracut/90zfs/Makefile.am
+++ b/contrib/dracut/90zfs/Makefile.am
@@ -9,6 +9,9 @@ pkgdracut_SCRIPTS = \
 	zfs-needshutdown.sh \
 	zfs-lib.sh
 
+pkgdracut_DATA = \
+	zfs-env-bootfs.service
+
 EXTRA_DIST = \
 	$(top_srcdir)/contrib/dracut/90zfs/export-zfs.sh.in \
 	$(top_srcdir)/contrib/dracut/90zfs/module-setup.sh.in \
@@ -17,9 +20,10 @@ EXTRA_DIST = \
 	$(top_srcdir)/contrib/dracut/90zfs/zfs-generator.sh.in \
 	$(top_srcdir)/contrib/dracut/90zfs/zfs-load-key.sh.in \
 	$(top_srcdir)/contrib/dracut/90zfs/zfs-needshutdown.sh.in \
-	$(top_srcdir)/contrib/dracut/90zfs/zfs-lib.sh.in
+	$(top_srcdir)/contrib/dracut/90zfs/zfs-lib.sh.in \
+	$(top_srcdir)/contrib/dracut/90zfs/zfs-env-bootfs.service.in
 
-$(pkgdracut_SCRIPTS):%:%.in
+$(pkgdracut_SCRIPTS) $(pkgdracut_DATA) :%:%.in
 	-$(SED) -e 's,@bindir\@,$(bindir),g' \
 		-e 's,@sbindir\@,$(sbindir),g' \
 		-e 's,@udevdir\@,$(udevdir),g' \
@@ -30,4 +34,4 @@ $(pkgdracut_SCRIPTS):%:%.in
 		$< >'$@'
 
 distclean-local::
-	-$(RM) $(pkgdracut_SCRIPTS)
+	-$(RM) $(pkgdracut_SCRIPTS) $(pkgdracut_DATA)
diff --git a/contrib/dracut/90zfs/module-setup.sh.in b/contrib/dracut/90zfs/module-setup.sh.in
index f595a369c..4efc4b018 100755
--- a/contrib/dracut/90zfs/module-setup.sh.in
+++ b/contrib/dracut/90zfs/module-setup.sh.in
@@ -98,6 +98,9 @@ install() {
 				type mark_hostonly >/dev/null 2>&1 && mark_hostonly @systemdunitdir@/zfs-import-$_item.service
 			fi
 		done
+		inst "${moddir}"/zfs-env-bootfs.service "${systemdsystemunitdir}"/zfs-env-bootfs.service
+		ln -s ../zfs-env-bootfs.service "${initdir}/${systemdsystemunitdir}/zfs-import.target.wants"/zfs-env-bootfs.service
+		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @systemdunitdir@/zfs-env-bootfs.service
 		dracut_install systemd-ask-password
 		dracut_install systemd-tty-ask-password-agent
 		mkdir -p "${initdir}/$systemdsystemunitdir/initrd.target.wants"
diff --git a/contrib/dracut/90zfs/zfs-env-bootfs.service.in b/contrib/dracut/90zfs/zfs-env-bootfs.service.in
new file mode 100644
index 000000000..3cdf69100
--- /dev/null
+++ b/contrib/dracut/90zfs/zfs-env-bootfs.service.in
@@ -0,0 +1,14 @@
+[Unit]
+Description=Set BOOTFS environment for dracut
+Documentation=man:zpool(8)
+DefaultDependencies=no
+After=zfs-import-cache.service
+After=zfs-import-scan.service
+Before=zfs-import.target
+
+[Service]
+Type=oneshot
+ExecStart=/bin/sh -c "/bin/systemctl set-environment BOOTFS=$(@sbindir@/zpool list -H -o bootfs | grep -m1 -v '^-$')"
+
+[Install]
+WantedBy=zfs-import.target