Multiple dracut module install script cleanups

- Replaced intances of `dracut_install` with `inst_simple`
- Removed calls to `test -x mark_hostonly` because the function is an
inbuilt dracut function
- Removed redundant installation of `systemd-ask-password` and
`systemd-tty-ask-password-agent` because they are already installed by
the systemd module. There is no need to install them again
- Removed multiple calls to the `mark_hostonly` function because the
`inst_simple` has a command-line switch for it
- Cleaned up the installation of the `zpool.cache`, `vdev_id.conf` and
`hostid` files to make the logic easier to follow
- Cleaned up and simplified the systemd service installation logic by
invoking systemctl instead of creating symlinks manually
- Replaced various hard-coded paths with dracut equivalents to better
conform with expected dracut behaviour
- Removed redundant call to `mkdir` (`inst_simple` creates the parent
directory if it does not exist on the destination initrd)

Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Reviewed-by: Andrew J. Hesford <ajh@sideband.org>
Signed-off-by: Savyasachee Jha <hi@savyasacheejha.com>
Closes #13010

contrib/dracut/90zfs/module-setup.sh.in

@@ -6,8 +6,8 @@ check() {
 	[ "${1}" = "-d" ] && return 0
 
 	# Verify the zfs tool chain
-	for tool in "@sbindir@/zgenhostid" "@sbindir@/zpool" "@sbindir@/zfs" "@mounthelperdir@/mount.zfs" ; do
+	for tool in "zgenhostid" "zpool" "zfs" "mount.zfs"; do
-		test -x "$tool" || return 1
+		command -v "${tool}" >/dev/null || return 1
 	done
 
 	return 0
@@ -38,90 +38,67 @@ install() {
 		head ||
 		{ dfatal "Failed to install essential binaries"; exit 1; }
 
-	# Lines 71-90 adapted from
+	# Adapted from https://github.com/zbm-dev/zfsbootmenu
-	# https://github.com/zbm-dev/zfsbootmenu/blob/9a03eab2b75647170bdc383903735a694ecd0ed6/dracut/module-setup.sh#L71
-	
 	if ! ldd "$(command -v zpool)" | grep -qF 'libgcc_s.so'; then
 		# On systems with gcc-config (Gentoo, Funtoo, etc.), use it to find libgcc_s
-		if command -v gcc-config >/dev/null 2>&1; then
+		if command -v gcc-config >/dev/null; then
-			dracut_install "/usr/lib/gcc/$(s=$(gcc-config -c); echo "${s%-*}/${s##*-}")/libgcc_s.so.1" ||
+			inst_simple "/usr/lib/gcc/$(s=$(gcc-config -c); echo "${s%-*}/${s##*-}")/libgcc_s.so.1" ||
 				{ dfatal "Unable to install libgcc_s.so"; exit 1; }
 			# Otherwise, use dracut's library installation function to find the right one
 		elif ! inst_libdir_file "libgcc_s.so*"; then
 			# If all else fails, just try looking for some gcc arch directory
-			dracut_install /usr/lib/gcc/*/*/libgcc_s.so* ||
+			inst_simple /usr/lib/gcc/*/*/libgcc_s.so* ||
 				{ dfatal "Unable to install libgcc_s.so"; exit 1; }
 		fi
 	fi
 
 	inst_hook cmdline 95 "${moddir}/parse-zfs.sh"
-	if [ -n "$systemdutildir" ] ; then
+	if [ -n "${systemdutildir}" ]; then
-		inst_script "${moddir}/zfs-generator.sh" "$systemdutildir"/system-generators/dracut-zfs-generator
+		inst_script "${moddir}/zfs-generator.sh" "${systemdutildir}/system-generators/dracut-zfs-generator"
 	fi
 	inst_hook pre-mount 90 "${moddir}/zfs-load-key.sh"
 	inst_hook mount 98 "${moddir}/mount-zfs.sh"
 	inst_hook cleanup 99 "${moddir}/zfs-needshutdown.sh"
 	inst_hook shutdown 20 "${moddir}/export-zfs.sh"
 
-	inst_simple "${moddir}/zfs-lib.sh" "/lib/dracut-zfs-lib.sh"
+	inst_script "${moddir}/zfs-lib.sh" "/lib/dracut-zfs-lib.sh"
-	if [ -e @sysconfdir@/zfs/zpool.cache ]; then
-		inst @sysconfdir@/zfs/zpool.cache
-		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @sysconfdir@/zfs/zpool.cache
-	fi
 
-	if [ -e @sysconfdir@/zfs/vdev_id.conf ]; then
+	# -H ensures they are marked host-only
-		inst @sysconfdir@/zfs/vdev_id.conf
+	# -o ensures there is no error upon absence of these files
-		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @sysconfdir@/zfs/vdev_id.conf
+	inst_multiple -o -H \
-	fi
+		"@sysconfdir@/zfs/zpool.cache" \
+		"@sysconfdir@/zfs/vdev_id.conf"
 
 	# Synchronize initramfs and system hostid
-	if [ -f @sysconfdir@/hostid ]; then
+	if ! inst_simple -H @sysconfdir@/hostid; then
-		inst @sysconfdir@/hostid
+		if HOSTID="$(hostid 2>/dev/null)" && [ "${HOSTID}" != "00000000" ]; then
-		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @sysconfdir@/hostid
-	elif HOSTID="$(hostid 2>/dev/null)" && [ "${HOSTID}" != "00000000" ]; then
 			zgenhostid -o "${initdir}@sysconfdir@/hostid" "${HOSTID}"
-		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @sysconfdir@/hostid
+			mark_hostonly @sysconfdir@/hostid
+		fi
 	fi
 
 	if dracut_module_included "systemd"; then
+		inst_simple "${systemdsystemunitdir}/zfs-import.target"
+		systemctl -q --root "${initdir}" add-wants initrd.target zfs-import.target
 
-		dracut_install \
+		inst_simple "${moddir}/zfs-env-bootfs.service" "${systemdsystemunitdir}/zfs-env-bootfs.service"
-			systemd-ask-password \
+		systemctl -q --root "${initdir}" add-wants zfs-import.target zfs-env-bootfs.service
-			systemd-tty-ask-password-agent ||
-			{ dfatal "Failed to install essential systemd binaries"; exit 1; }
 
-		mkdir -p "${initdir}/$systemdsystemunitdir/zfs-import.target.wants"
+		for _service in \
-		for _service in "zfs-import-scan.service" "zfs-import-cache.service" ; do
+			"zfs-import-scan.service" \
-			dracut_install "@systemdunitdir@/$_service"
+			"zfs-import-cache.service" \
-			if ! [ -L "${initdir}/$systemdsystemunitdir/zfs-import.target.wants/$_service" ]; then
+			"zfs-load-module.service"; do
-				ln -sf ../$_service "${initdir}/$systemdsystemunitdir/zfs-import.target.wants/$_service"
+			inst_simple "${systemdsystemunitdir}/${_service}"
-				type mark_hostonly >/dev/null 2>&1 && mark_hostonly "@systemdunitdir@/$_service"
+			systemctl -q --root "${initdir}" add-wants zfs-import.target "${_service}"
-			fi
 		done
 
-		inst "${moddir}"/zfs-env-bootfs.service "${systemdsystemunitdir}"/zfs-env-bootfs.service
+		for _service in \
-		ln -s ../zfs-env-bootfs.service "${initdir}/${systemdsystemunitdir}/zfs-import.target.wants"/zfs-env-bootfs.service
+			"zfs-snapshot-bootfs.service" \
-		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @systemdunitdir@/zfs-env-bootfs.service
+			"zfs-rollback-bootfs.service"; do
-
+			inst_simple "${moddir}/${_service}" "${systemdsystemunitdir}/${_service}"
-		mkdir -p "${initdir}/$systemdsystemunitdir/initrd.target.wants"
+			systemctl -q --root "${initdir}" add-wants initrd.target "${_service}"
-		dracut_install @systemdunitdir@/zfs-import.target
-		if ! [ -L "${initdir}/$systemdsystemunitdir/initrd.target.wants"/zfs-import.target ]; then
-			ln -s ../zfs-import.target "${initdir}/$systemdsystemunitdir/initrd.target.wants"/zfs-import.target
-			type mark_hostonly >/dev/null 2>&1 && mark_hostonly @systemdunitdir@/zfs-import.target
-		fi
-
-		for _service in zfs-snapshot-bootfs.service zfs-rollback-bootfs.service ; do
-			inst "${moddir}/$_service" "${systemdsystemunitdir}/$_service"
-			if ! [ -L "${initdir}/$systemdsystemunitdir/initrd.target.wants/$_service" ]; then
-				ln -s "../$_service" "${initdir}/$systemdsystemunitdir/initrd.target.wants/$_service"
-			fi
 		done
 
-		# There isn't a pkg-config variable for this,
+		inst_simple "${moddir}/import-opts-generator.sh" "${systemdutildir}/system-environment-generators/zfs-import-opts.sh"
-		# and dracut doesn't automatically resolve anything this'd be next to
-		local systemdsystemenvironmentgeneratordir
-		systemdsystemenvironmentgeneratordir="$(pkg-config --variable=prefix systemd || echo "/usr")/lib/systemd/system-environment-generators"
-		mkdir -p "${initdir}/${systemdsystemenvironmentgeneratordir}"
-		inst "${moddir}"/import-opts-generator.sh "${systemdsystemenvironmentgeneratordir}"/zfs-import-opts.sh
 	fi
 }