Make better use of dracut functions when building initramfs

Setting up the module involves multiple redundant calls to a bunch of
dracut functions wheich can be combined into one. Additionally, the mass
of code required to load libgcc_s.so* can be replaced with one dracut
function. This has the additional effect of removing errors involving
the non-installation of libgcc_s.so* which are seen on debian bullseye
when using version 2.1.2-1~bpo11+1 from the backports repository.

The systemd binaries are separated out into their own `dracut_install`
function call so they do not get pulled in when dracut does not load the
systemd module.

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

@@ -20,59 +20,30 @@ depends() {
 
 installkernel() {
 	instmods zfs
-	instmods zcommon
-	instmods znvpair
-	instmods zavl
-	instmods zunicode
-	instmods zlua
-	instmods icp
-	instmods spl
-	instmods zlib_deflate
-	instmods zlib_inflate
 }
 
 install() {
-	inst_rules @udevruledir@/90-zfs.rules
-	inst_rules @udevruledir@/69-vdev.rules
-	inst_rules @udevruledir@/60-zvol.rules
-	dracut_install hostid
-	dracut_install grep
-	dracut_install @sbindir@/zgenhostid
-	dracut_install @sbindir@/zfs
-	dracut_install @sbindir@/zpool
-	# Workaround for https://github.com/openzfs/zfs/issues/4749 by
-	# ensuring libgcc_s.so(.1) is included
-	if ldd @sbindir@/zpool | grep -qF 'libgcc_s.so'; then
-		# Dracut will have already tracked and included it
-		:;
-	elif command -v gcc-config >/dev/null 2>&1; then
-		# On systems with gcc-config (Gentoo, Funtoo, etc.):
-		# Use the current profile to resolve the appropriate path
-		s="$(gcc-config -c)"
-		dracut_install "/usr/lib/gcc/${s%-*}/${s##*-}/libgcc_s.so"*
-	elif [ "$(echo /usr/lib/libgcc_s.so*)" != "/usr/lib/libgcc_s.so*" ]; then
-		# Try a simple path first
-		dracut_install /usr/lib/libgcc_s.so*
-	elif [ "$(echo /lib*/libgcc_s.so*)" != "/lib*/libgcc_s.so*" ]; then
-		# SUSE
-		dracut_install /lib*/libgcc_s.so*
-	else
-		# Fallback: Guess the path and include all matches
-		dracut_install /usr/lib*/gcc/**/libgcc_s.so*
-	fi
-	# shellcheck disable=SC2050
-	if [ @LIBFETCH_DYNAMIC@ -gt 0 ]; then
-		for d in $libdirs; do
-			[ -e "$d/@LIBFETCH_SONAME@" ] && dracut_install "$d/@LIBFETCH_SONAME@"
-		done
-	fi
-	dracut_install @mounthelperdir@/mount.zfs
-	dracut_install @udevdir@/vdev_id
-	dracut_install awk
-	dracut_install cut
-	dracut_install tr
-	dracut_install head
-	dracut_install @udevdir@/zvol_id
+	inst_rules \
+		@udevruledir@/90-zfs.rules \
+		@udevruledir@/69-vdev.rules \
+		@udevruledir@/60-zvol.rules
+	
+	dracut_install \
+		@sbindir@/zgenhostid \
+		@sbindir@/zfs \
+		@sbindir@/zpool \
+		@udevdir@/vdev_id \
+		@udevdir@/zvol_id \
+		@mounthelperdir@/mount.zfs \
+		hostid \
+		grep \
+		awk \
+		tr \
+		cut \
+		head
+		
+	inst_libdir_file "libgcc_s.so*"
+	
 	inst_hook cmdline 95 "${moddir}/parse-zfs.sh"
 	if [ -n "$systemdutildir" ] ; then
 		inst_script "${moddir}/zfs-generator.sh" "$systemdutildir"/system-generators/dracut-zfs-generator
@@ -103,6 +74,9 @@ install() {
 	fi
 
 	if dracut_module_included "systemd"; then
+
+		dracut_install systemd-ask-password systemd-tty-ask-password-agent
+
 		mkdir -p "${initdir}/$systemdsystemunitdir/zfs-import.target.wants"
 		for _service in "zfs-import-scan.service" "zfs-import-cache.service" ; do
 			dracut_install "@systemdunitdir@/$_service"
@@ -116,9 +90,6 @@ install() {
 		ln -s ../zfs-env-bootfs.service "${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"
 		dracut_install @systemdunitdir@/zfs-import.target
 		if ! [ -L "${initdir}/$systemdsystemunitdir/initrd.target.wants"/zfs-import.target ]; then