fix booting via dracut generated initramfs

Dracut and Systemd updated how they integrate with each other, because
of this our current integrations stopped working (around the time
4.1.13 came out).  This patch addresses that issue and gets us booting
again.

Thanks to @Rudd-O for doing the work to get dracut working again and
letting me submit this on his behalf.

Signed-off-by: Manuel Amador (Rudd-O) <rudd-o@rudd-o.com>
Signed-off-by: Matthew Thode <mthode@mthode.org>
Closes #3605
Closes #4478

configure.ac

@@ -114,6 +114,7 @@ AC_CONFIG_FILES([
 	contrib/Makefile
 	contrib/bash_completion.d/Makefile
 	contrib/dracut/Makefile
+	contrib/dracut/02zfsexpandknowledge/Makefile
 	contrib/dracut/90zfs/Makefile
 	contrib/initramfs/Makefile
 	module/Makefile

contrib/dracut/02zfsexpandknowledge/Makefile.am

@@ -0,0 +1,22 @@
+pkgdracutdir = $(dracutdir)/modules.d/02zfsexpandknowledge
+pkgdracut_SCRIPTS = \
+	module-setup.sh
+
+EXTRA_DIST = \
+	$(top_srcdir)/contrib/dracut/02zfsexpandknowledge/module-setup.sh.in
+
+$(pkgdracut_SCRIPTS):
+	-$(SED) -e 's,@bindir\@,$(bindir),g' \
+		-e 's,@sbindir\@,$(sbindir),g' \
+		-e 's,@datadir\@,$(datadir),g' \
+		-e 's,@dracutdir\@,$(dracutdir),g' \
+		-e 's,@udevdir\@,$(udevdir),g' \
+		-e 's,@udevruledir\@,$(udevruledir),g' \
+		-e 's,@sysconfdir\@,$(sysconfdir),g' \
+		"$(top_srcdir)/contrib/dracut/02zfsexpandknowledge/$@.in" >'$@'
+
+clean-local::
+	-$(RM) $(pkgdracut_SCRIPTS)
+
+distclean-local::
+	-$(RM) $(pkgdracut_SCRIPTS)

contrib/dracut/02zfsexpandknowledge/module-setup.sh.in

@@ -0,0 +1,132 @@
+#!/bin/sh
+
+get_devtype() {
+  local typ
+  typ=$(udevadm info --query=property --name="$1" | grep "^ID_FS_TYPE=" | sed 's|^ID_FS_TYPE=||')
+  if [ "$typ" = "" ] ; then
+     typ=$(blkid -c /dev/null "$1" -o value -s TYPE)
+  fi
+  echo "$typ"
+}
+
+get_pool_devices() {
+  # also present in 99zfssystemd
+  local poolconfigtemp
+  local poolconfigoutput
+  local pooldev
+  local prefix
+  poolconfigtemp=`mktemp`
+  @sbindir@/zpool list -v -H "$1" > "$poolconfigtemp" 2>&1
+  if [ "$?" != "0" ] ; then
+    poolconfigoutput=$(cat "$poolconfigtemp")
+    dinfo "zfsexpandknowledge: pool $1 cannot be listed: $poolconfigoutput"
+  else
+    while read pooldev ; do
+      for prefix in /dev/disk/* /dev/mapper ; do
+        if [ -e "$prefix"/"$pooldev" ] ; then
+          dinfo "zfsexpandknowledge: pool $1 has device $prefix/$pooldev"
+          echo `readlink -f "$prefix"/"$pooldev"`
+          break
+        fi
+      done
+    done < <(cat "$poolconfigtemp" | awk -F '\t' 'NR>1 { print $2 }')
+  fi
+  rm -f "$poolconfigtemp"
+}
+
+find_zfs_block_devices() {
+    local dev
+    local blockdev
+    local mp
+    local fstype
+    local pool
+    local key
+    local n
+    local poolconfigoutput
+    numfields=`head -1 /proc/self/mountinfo | awk '{print NF}'`
+    if [ "$numfields" == "10" ] ; then
+        fields="n n n n mp n n fstype dev n"
+    else
+        fields="n n n n mp n n n fstype dev n"
+    fi
+    while read $fields ; do
+       if [ "$fstype" != "zfs" ]; then continue ; fi
+       if [ "$mp" == "$1" ]; then
+           pool=$(echo "$dev" | cut -d / -f 1)
+           get_pool_devices "$pool"
+       fi
+    done < /proc/self/mountinfo
+}
+
+array_contains () {
+  local e
+  for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
+  return 1
+}
+
+check() {
+    local mp
+    local dev
+    local blockdevs
+    local fstype
+    local majmin
+    local _slavedev
+    local _slavedevname
+    local _slavedevtype
+    local _slavemajmin
+    local _dev
+
+if [[ $hostonly ]]; then
+
+    for mp in \
+        "/" \
+        "/etc" \
+        "/bin" \
+        "/sbin" \
+        "/lib" \
+        "/lib64" \
+        "/usr" \
+        "/usr/bin" \
+        "/usr/sbin" \
+        "/usr/lib" \
+        "/usr/lib64" \
+        "/boot";
+    do
+        mp=$(readlink -f "$mp")
+        mountpoint "$mp" >/dev/null 2>&1 || continue
+        blockdevs=$(find_zfs_block_devices "$mp")
+        if [ -z "$blockdevs" ] ; then continue ; fi
+        dinfo "zfsexpandknowledge: block devices backing ZFS dataset $mp: $blockdevs"
+        for dev in $blockdevs
+        do
+            array_contains "$dev" "${host_devs[@]}" || host_devs+=("$dev")
+            fstype=$(get_devtype "$dev")
+            host_fs_types["$dev"]="$fstype"
+            majmin=$(get_maj_min "$dev")
+            if [[ -d /sys/dev/block/$majmin/slaves ]] ; then
+                for _slavedev in /sys/dev/block/$majmin/slaves/*; do
+                    [[ -f $_slavedev/dev ]] || continue
+                    _slavedev=/dev/$(basename "$_slavedev")
+                    _slavedevname=$(udevadm info --query=property --name="$_slavedev" | grep "^DEVNAME=" | sed 's|^DEVNAME=||')
+                    _slavedevtype=$(get_devtype "$_slavedevname")
+                    _slavemajmin=$(get_maj_min "$_slavedevname")
+                    dinfo "zfsexpandknowledge: slave block device backing ZFS dataset $mp: $_slavedevname"
+                    array_contains "$_slavedevname" "${host_devs[@]}" || host_devs+=("$_slavedevname")
+                    host_fs_types["$_slavedevname"]="$_slavedevtype"
+                done
+            fi
+        done
+    done
+    for a in "${host_devs[@]}"
+        do
+        dinfo "zfsexpandknowledge: host device $a"
+    done
+    for a in "${!host_fs_types[@]}"
+        do
+        dinfo "zfsexpandknowledge: device $a of type ${host_fs_types[$a]}"
+    done
+
+fi
+
+return 1
+}

contrib/dracut/90zfs/Makefile.am

@@ -4,6 +4,7 @@ pkgdracut_SCRIPTS = \
 	module-setup.sh \
 	mount-zfs.sh \
 	parse-zfs.sh \
+	zfs-generator.sh \
 	zfs-lib.sh
 
 EXTRA_DIST = \
@@ -11,6 +12,7 @@ EXTRA_DIST = \
 	$(top_srcdir)/contrib/dracut/90zfs/module-setup.sh.in \
 	$(top_srcdir)/contrib/dracut/90zfs/mount-zfs.sh.in \
 	$(top_srcdir)/contrib/dracut/90zfs/parse-zfs.sh.in \
+	$(top_srcdir)/contrib/dracut/90zfs/zfs-generator.sh.in \
 	$(top_srcdir)/contrib/dracut/90zfs/zfs-lib.sh.in
 
 $(pkgdracut_SCRIPTS):
@@ -19,6 +21,7 @@ $(pkgdracut_SCRIPTS):
 		-e 's,@udevdir\@,$(udevdir),g' \
 		-e 's,@udevruledir\@,$(udevruledir),g' \
 		-e 's,@sysconfdir\@,$(sysconfdir),g' \
+		-e 's,@systemdunitdir\@,$(systemdunitdir),g' \
 		"$(top_srcdir)/contrib/dracut/90zfs/$@.in" >'$@'
 
 distclean-local::

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

@@ -40,16 +40,22 @@ install() {
 	dracut_install awk
 	dracut_install head
 	inst_hook cmdline 95 "${moddir}/parse-zfs.sh"
-	inst_hook mount 98 "${moddir}/mount-zfs.sh"
+	if [ -n "$systemdutildir" ] ; then
+		inst_script "${moddir}/zfs-generator.sh" "$systemdutildir"/system-generators/dracut-zfs-generator
+	else
+		inst_hook mount 98 "${moddir}/mount-zfs.sh"
+	fi
 	inst_hook shutdown 30 "${moddir}/export-zfs.sh"
 
 	inst_simple "${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
 		inst @sysconfdir@/zfs/vdev_id.conf
+		type mark_hostonly >/dev/null 2>&1 && mark_hostonly @sysconfdir@/zfs/vdev_id.conf
 	fi
 
 	# Synchronize initramfs and system hostid
@@ -58,4 +64,15 @@ install() {
 	CC=`hostid | cut -b 5,6`
 	DD=`hostid | cut -b 7,8`
 	printf "\x${DD}\x${CC}\x${BB}\x${AA}" > "${initdir}/etc/hostid"
+
+	if dracut_module_included "systemd"; then
+		mkdir -p "${initdir}/$systemdsystemunitdir/initrd.target.wants"
+		for _item in scan cache ; do
+			dracut_install @systemdunitdir@/zfs-import-$_item.service
+			if ! [ -L "${initdir}/$systemdsystemunitdir/initrd.target.wants"/zfs-import-$_item.service ]; then
+				ln -s ../zfs-import-$_item.service "${initdir}/$systemdsystemunitdir/initrd.target.wants"/zfs-import-$_item.service
+				type mark_hostonly >/dev/null 2>&1 && mark_hostonly @systemdunitdir@/zfs-import-$_item.service
+			fi
+		done
+	fi
 }

contrib/dracut/90zfs/zfs-generator.sh.in

@@ -0,0 +1,39 @@
+#!/bin/bash
+
+GENERATOR_DIR="$1"
+[ -z "$GENERATOR_DIR" ] && exit 1
+
+[ -f /lib/dracut-lib.sh ] && dracutlib=/lib/dracut-lib.sh
+[ -f /usr/lib/dracut/modules.d/99base/dracut-lib.sh ] && dracutlib=/usr/lib/dracut/modules.d/99base/dracut-lib.sh
+
+type getarg >/dev/null 2>&1 || . "$dracutlib"
+
+[ -z "$root" ]       && root=$(getarg root=)
+[ -z "$rootfstype" ] && rootfstype=$(getarg rootfstype=)
+[ -z "$rootflags" ]  && rootflags=$(getarg rootflags=)
+
+[ "${root##zfs:}" = "${root}" -a "${root##ZFS=}" = "${root}" -a "$rootfstype" != "zfs" ] && exit 0
+
+rootfstype=zfs
+if echo "${rootflags}" | grep -q zfsutil ; then
+    true
+else
+    rootflags=zfsutil
+fi
+
+root="${root##zfs:}"
+root="${root##ZFS=}"
+
+[ -d "$GENERATOR_DIR" ] || mkdir "$GENERATOR_DIR"
+[ -d "$GENERATOR_DIR/sysroot.mount.d" ] || mkdir "$GENERATOR_DIR/sysroot.mount.d"
+
+{
+    echo "[Unit]"
+    echo "After=zfs-import-scan.service"
+    echo "After=zfs-import-cache.service"
+    echo ""
+    echo "[Mount]"
+    echo "What=${root}"
+    echo "Type=${rootfstype}"
+    echo "Options=${rootflags}"
+} > "$GENERATOR_DIR/sysroot.mount.d/zfs-enhancement.conf"

contrib/dracut/Makefile.am

@@ -1,3 +1,3 @@
-SUBDIRS = 90zfs
+SUBDIRS = 02zfsexpandknowledge 90zfs
 
 EXTRA_DIST = README.dracut.markdown