Fix dracut. Document it.

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

@@ -9,13 +9,10 @@ check() {
 	for tool in "zgenhostid" "zpool" "zfs" "mount.zfs"; do
 		command -v "${tool}" >/dev/null || return 1
 	done
-
-	return 0
 }
 
 depends() {
 	echo udev-rules
-	return 0
 }
 
 installkernel() {
@@ -39,7 +36,6 @@ install() {
 		{ dfatal "Failed to install essential binaries"; exit 1; }
 
 	# Adapted from https://github.com/zbm-dev/zfsbootmenu
-
 	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; then
@@ -79,7 +75,6 @@ install() {
 	fi
 
 	if dracut_module_included "systemd"; then
-
 		inst_simple "${systemdsystemunitdir}/zfs-import.target"
 		systemctl -q --root "${initdir}" add-wants initrd.target zfs-import.target
 

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

@@ -3,46 +3,71 @@
 
 . /lib/dracut-zfs-lib.sh
 
-ZFS_DATASET=""
-ZFS_POOL=""
-
-case "${root}" in
-	zfs:*) ;;
-	*) return ;;
-esac
+decode_root_args || return 0
 
 GENERATOR_FILE=/run/systemd/generator/sysroot.mount
 GENERATOR_EXTENSION=/run/systemd/generator/sysroot.mount.d/zfs-enhancement.conf
 
-if [ -e "$GENERATOR_FILE" ] && [ -e "$GENERATOR_EXTENSION" ] ; then
-	# If the ZFS sysroot.mount flag exists, the initial RAM disk configured
-	# it to mount ZFS on root.  In that case, we bail early.  This flag
-	# file gets created by the zfs-generator program upon successful run.
-	info "ZFS: There is a sysroot.mount and zfs-generator has extended it."
-	info "ZFS: Delegating root mount to sysroot.mount."
-	# Let us tell the initrd to run on shutdown.
-	# We have a shutdown hook to run
-	# because we imported the pool.
+if [ -e "$GENERATOR_FILE" ] && [ -e "$GENERATOR_EXTENSION" ]; then
+	# We're under systemd and dracut-zfs-generator ran to completion.
+	info "ZFS: Delegating root mount to sysroot.mount at al."
+
 	# We now prevent Dracut from running this thing again.
-	for zfsmounthook in "$hookdir"/mount/*zfs* ; do
-		if [ -f "$zfsmounthook" ] ; then
-			rm -f "$zfsmounthook"
-		fi
-	done
+	rm -f "$hookdir"/mount/*zfs*
 	return
 fi
+
 info "ZFS: No sysroot.mount exists or zfs-generator did not extend it."
 info "ZFS: Mounting root with the traditional mount-zfs.sh instead."
 
+# ask_for_password tries prompt cmd
+#
+# Wraps around plymouth ask-for-password and adds fallback to tty password ask
+# if plymouth is not present.
+ask_for_password() {
+    tries="$1"
+    prompt="$2"
+    cmd="$3"
+
+    {
+        flock -s 9
+
+        # Prompt for password with plymouth, if installed and running.
+        if plymouth --ping 2>/dev/null; then
+            plymouth ask-for-password \
+                --prompt "$prompt" --number-of-tries="$tries" | \
+                eval "$cmd"
+            ret=$?
+        else
+            i=1
+            while [ "$i" -le "$tries" ]; do
+                printf "%s [%i/%i]:" "$prompt" "$i" "$tries" >&2
+                eval "$cmd" && ret=0 && break
+                ret=$?
+                i=$((i+1))
+                printf '\n' >&2
+            done
+            unset i
+        fi
+    } 9>/.console_lock
+
+    [ "$ret" -ne 0 ] && echo "Wrong password" >&2
+    return "$ret"
+}
+
+
 # Delay until all required block devices are present.
 modprobe zfs 2>/dev/null
 udevadm settle
 
+ZFS_DATASET=
+ZFS_POOL=
+
 if [ "${root}" = "zfs:AUTO" ] ; then
-	if ! ZFS_DATASET="$(find_bootfs)" ; then
+	if ! ZFS_DATASET="$(zpool get -Ho value bootfs | grep -m1 -vFx -)"; then
 		# shellcheck disable=SC2086
 		zpool import -N -a ${ZPOOL_IMPORT_OPTS}
-		if ! ZFS_DATASET="$(find_bootfs)" ; then
+		if ! ZFS_DATASET="$(zpool get -Ho value bootfs | grep -m1 -vFx -)"; then
 			warn "ZFS: No bootfs attribute found in importable pools."
 			zpool export -aF
 
@@ -53,34 +78,43 @@ if [ "${root}" = "zfs:AUTO" ] ; then
 	info "ZFS: Using ${ZFS_DATASET} as root."
 fi
 
-ZFS_DATASET="${ZFS_DATASET:-${root#zfs:}}"
+ZFS_DATASET="${ZFS_DATASET:-${root}}"
 ZFS_POOL="${ZFS_DATASET%%/*}"
 
-if import_pool "${ZFS_POOL}" ; then
-	# Load keys if we can or if we need to
-	if [ "$(zpool list -H -o feature@encryption "${ZFS_POOL}")" = 'active' ]; then
-		# if the root dataset has encryption enabled
-		ENCRYPTIONROOT="$(zfs get -H -o value encryptionroot "${ZFS_DATASET}")"
-		if ! [ "${ENCRYPTIONROOT}" = "-" ]; then
-			KEYSTATUS="$(zfs get -H -o value keystatus "${ENCRYPTIONROOT}")"
-			# if the key needs to be loaded
-			if [ "$KEYSTATUS" = "unavailable" ]; then
-				# decrypt them
-				ask_for_password \
-					--tries 5 \
-					--prompt "Encrypted ZFS password for ${ENCRYPTIONROOT}: " \
-					--cmd "zfs load-key '${ENCRYPTIONROOT}'"
-			fi
+
+if ! zpool get -Ho name "${ZFS_POOL}" > /dev/null 2>&1; then
+    info "ZFS: Importing pool ${ZFS_POOL}..."
+    # shellcheck disable=SC2086
+    if ! zpool import -N ${ZPOOL_IMPORT_OPTS} "${ZFS_POOL}"; then
+        warn "ZFS: Unable to import pool ${ZFS_POOL}"
+        rootok=0
+        return 1
+    fi
+fi
+
+# Load keys if we can or if we need to
+# TODO: for_relevant_root_children like in zfs-load-key.sh.in
+if [ "$(zpool get -Ho value feature@encryption "${ZFS_POOL}")" = 'active' ]; then
+	# if the root dataset has encryption enabled
+	ENCRYPTIONROOT="$(zfs get -Ho value encryptionroot "${ZFS_DATASET}")"
+	if ! [ "${ENCRYPTIONROOT}" = "-" ]; then
+		KEYSTATUS="$(zfs get -Ho value keystatus "${ENCRYPTIONROOT}")"
+		# if the key needs to be loaded
+		if [ "$KEYSTATUS" = "unavailable" ]; then
+			# decrypt them
+			ask_for_password \
+				5 \
+				"Encrypted ZFS password for ${ENCRYPTIONROOT}: " \
+				"zfs load-key '${ENCRYPTIONROOT}'"
 		fi
 	fi
-	# Let us tell the initrd to run on shutdown.
-	# We have a shutdown hook to run
-	# because we imported the pool.
-	info "ZFS: Mounting dataset ${ZFS_DATASET}..."
-	if mount_dataset "${ZFS_DATASET}" ; then
-		ROOTFS_MOUNTED=yes
-		return 0
-	fi
 fi
 
-rootok=0
+# Let us tell the initrd to run on shutdown.
+# We have a shutdown hook to run
+# because we imported the pool.
+info "ZFS: Mounting dataset ${ZFS_DATASET}..."
+if ! mount_dataset "${ZFS_DATASET}"; then
+  rootok=0
+  return 1
+fi

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

@@ -1,7 +1,8 @@
 #!/bin/sh
 # shellcheck disable=SC2034,SC2154
 
-. /lib/dracut-lib.sh
+# shellcheck source=zfs-lib.sh.in
+. /lib/dracut-zfs-lib.sh
 
 # Let the command line override our host id.
 spl_hostid=$(getarg spl_hostid=)
@@ -15,52 +16,20 @@ else
 	warn "ZFS: Pools may not import correctly."
 fi
 
-wait_for_zfs=0
-case "${root}" in
-	""|zfs|zfs:)
-		# We'll take root unset, root=zfs, or root=zfs:
-		# No root set, so we want to read the bootfs attribute.  We
-		# can't do that until udev settles so we'll set dummy values
-		# and hope for the best later on.
-		root="zfs:AUTO"
-		rootok=1
-		wait_for_zfs=1
-
-		info "ZFS: Enabling autodetection of bootfs after udev settles."
-		;;
-
-	ZFS=*|zfs:*|FILESYSTEM=*)
-		# root is explicit ZFS root.  Parse it now.  We can handle
-		# a root=... param in any of the following formats:
-		# root=ZFS=rpool/ROOT
-		# root=zfs:rpool/ROOT
-		# root=zfs:FILESYSTEM=rpool/ROOT
-		# root=FILESYSTEM=rpool/ROOT
-		# root=ZFS=pool+with+space/ROOT+WITH+SPACE (translates to root=ZFS=pool with space/ROOT WITH SPACE)
-
-		# Strip down to just the pool/fs
-		root="${root#zfs:}"
-		root="${root#FILESYSTEM=}"
-		root="zfs:${root#ZFS=}"
-		# switch + with spaces because kernel cmdline does not allow us to quote parameters
-		root=$(echo "$root" | tr '+' ' ')
-		rootok=1
-		wait_for_zfs=1
-
-		info "ZFS: Set ${root} as bootfs."
-		;;
-
-	*)
-		info "ZFS: no ZFS-on-root"
-esac
-
-# Make sure Dracut is happy that we have a root and will wait for ZFS
-# modules to settle before mounting.
-if [ "${wait_for_zfs}" -eq 1 ]; then
-	ln -s /dev/null /dev/root 2>/dev/null
-	initqueuedir="${hookdir}/initqueue/finished"
-	test -d "${initqueuedir}" || {
-		initqueuedir="${hookdir}/initqueue-finished"
-	}
-	echo '[ -e /dev/zfs ]' > "${initqueuedir}/zfs.sh"
+if decode_root_args; then
+	if [ "$root" = "zfs:AUTO" ]; then
+		info "ZFS: Boot dataset autodetected from bootfs=."
+	else
+		info "ZFS: Boot dataset is ${root}."
+	fi
+
+	rootok=1
+	# Make sure Dracut is happy that we have a root and will wait for ZFS
+	# modules to settle before mounting.
+	if [ -n "${wait_for_zfs}" ]; then
+		ln -s null /dev/root
+		echo '[ -e /dev/zfs ]' > "${hookdir}/initqueue/finished/zfs.sh"
+	fi
+else
+	info "ZFS: no ZFS-on-root."
 fi

contrib/dracut/90zfs/zfs-env-bootfs.service.in

@@ -8,7 +8,7 @@ Before=zfs-import.target
 
 [Service]
 Type=oneshot
-ExecStart=/bin/sh -c "exec systemctl set-environment BOOTFS=$(@sbindir@/zpool list -H -o bootfs | grep -m1 -v '^-$')"
+ExecStart=/bin/sh -c "exec systemctl set-environment BOOTFS=$(@sbindir@/zpool list -H -o bootfs | grep -m1 -vFx -)"
 
 [Install]
 WantedBy=zfs-import.target

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

@@ -1,5 +1,5 @@
 #!/bin/sh
-# shellcheck disable=SC2016,SC1004
+# shellcheck disable=SC2016,SC1004,SC2154
 
 grep -wq debug /proc/cmdline && debug=1
 [ -n "$debug" ] && echo "zfs-generator: starting" >> /dev/kmsg
@@ -10,37 +10,17 @@ GENERATOR_DIR="$1"
     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
-command -v getarg >/dev/null 2>&1 || {
-    [ -n "$debug" ] && echo "zfs-generator: loading Dracut library from $dracutlib" >> /dev/kmsg
-    . "$dracutlib"
-}
-
+# shellcheck source=zfs-lib.sh.in
 . /lib/dracut-zfs-lib.sh
+decode_root_args || exit 0
 
-[ -z "$root" ]       && root=$(getarg root=)
-[ -z "$rootfstype" ] && rootfstype=$(getarg rootfstype=)
-[ -z "$rootflags" ]  && rootflags=$(getarg rootflags=)
-
-# If root is not ZFS= or zfs: or rootfstype is not zfs
-# then we are not supposed to handle it.
-[ "${root##zfs:}" = "${root}" ] &&
-	[ "${root##ZFS=}" = "${root}" ] &&
-	[ "$rootfstype" != "zfs" ] &&
-	exit 0
-
+[ -z "${rootflags}" ] && rootflags=$(getarg rootflags=)
 case ",${rootflags}," in
 	*,zfsutil,*) ;;
 	,,)	rootflags=zfsutil ;;
 	*)	rootflags="zfsutil,${rootflags}" ;;
 esac
 
-if [ "${root}" != "zfs:AUTO" ]; then
-  root="${root##zfs:}"
-  root="${root##ZFS=}"
-fi
-
 [ -n "$debug" ] && echo "zfs-generator: writing extension for sysroot.mount to $GENERATOR_DIR/sysroot.mount.d/zfs-enhancement.conf" >> /dev/kmsg
 
 
@@ -89,7 +69,7 @@ else
   _zfs_generator_cb() {
       dset="${1}"
       mpnt="${2}"
-      unit="sysroot$(echo "$mpnt" | tr '/' '-').mount"
+      unit="$(systemd-escape --suffix=mount -p "/sysroot${mpnt}")"
 
       {
           echo "[Unit]"