From: Fabian Vogt <fvogt@suse.com>
Subject: Use /etc/fstab for /sysroot instead of custom sysroot.mount

systemd-fstab-generator is capable of mounting /sysroot itself,
looking at /proc/cmdline if root= is set.

Index: dracut-043/modules.d/00systemd/module-setup.sh
===================================================================
--- dracut-043.orig/modules.d/00systemd/module-setup.sh
+++ dracut-043/modules.d/00systemd/module-setup.sh
@@ -14,7 +14,7 @@ check() {
 
 # called by dracut
 depends() {
-    return 0
+    echo fs-lib
 }
 
 installkernel() {
@@ -22,6 +22,23 @@ installkernel() {
     instmods -s efivarfs
 }
 
+fstab_sysroot() {
+    local _dev=/dev/block/$(find_root_block_device)
+    local _fstype _flags _subvol
+    if [ -e $_dev ]; then
+        _dev=$(shorten_persistent_dev "$(get_persistent_dev "$_dev")")
+        _fstype="$(find_mp_fstype /)"
+        _flags="$(find_mp_fsopts /)"
+
+        if [[ $use_fstab != yes ]] && [[ $_fstype = btrfs ]]; then
+            _subvol=$(findmnt -e -v -n -o FSROOT --target /) \
+		&& _subvol=${_subvol#/}
+            _flags="$_flags,${_subvol:+subvol=$_subvol}"
+        fi
+        printf "%s /sysroot %s %s 1 1\n" "$_dev" "$_fstype" "${_flags#,}"
+    fi
+}
+
 # called by dracut
 install() {
     local _mods
@@ -216,5 +233,8 @@ install() {
     } >> "$initdir/etc/systemd/journald.conf"
 
     ln_r "${systemdsystemunitdir}/multi-user.target" "${systemdsystemunitdir}/default.target"
+
+    # Add entry for /sysroot to /etc/fstab
+    fstab_sysroot >> "$initdir/etc/fstab"
 }
 
Index: dracut-043/modules.d/95rootfs-block/module-setup.sh
===================================================================
--- dracut-043.orig/modules.d/95rootfs-block/module-setup.sh
+++ dracut-043/modules.d/95rootfs-block/module-setup.sh
@@ -48,22 +48,25 @@ cmdline_rootfs() {
 
 # called by dracut
 cmdline() {
-    cmdline_rootfs
-    cmdline_journal
+    # When using systemd, we're storing the root device in /etc/fstab instead.
+    if ! dracut_module_included "systemd"; then
+        cmdline_rootfs
+        cmdline_journal
+    fi
 }
 
 # called by dracut
 install() {
-    if [[ $hostonly_cmdline == "yes" ]]; then
-        local _journaldev=$(cmdline_journal)
-        [[ $_journaldev ]] && printf "%s\n" "$_journaldev" >> "${initdir}/etc/cmdline.d/95root-journaldev.conf"
-        local _rootdev=$(cmdline_rootfs)
-        [[ $_rootdev ]] && printf "%s\n" "$_rootdev" >> "${initdir}/etc/cmdline.d/95root-dev.conf"
-    fi
-
     inst_multiple umount
     inst_multiple tr
     if ! dracut_module_included "systemd"; then
+        if [[ $hostonly_cmdline == "yes" ]]; then
+            local _journaldev=$(cmdline_journal)
+            [[ $_journaldev ]] && printf "%s\n" "$_journaldev" >> "${initdir}/etc/cmdline.d/95root-journaldev.conf"
+            local _rootdev=$(cmdline_rootfs)
+            [[ $_rootdev ]] && printf "%s\n" "$_rootdev" >> "${initdir}/etc/cmdline.d/95root-dev.conf"
+        fi
+
         inst_hook cmdline 95 "$moddir/parse-block.sh"
         inst_hook pre-udev 30 "$moddir/block-genrules.sh"
         inst_hook mount 99 "$moddir/mount-root.sh"
Index: dracut-043/modules.d/98dracut-systemd/dracut-cmdline.sh
===================================================================
--- dracut-043.orig/modules.d/98dracut-systemd/dracut-cmdline.sh
+++ dracut-043/modules.d/98dracut-systemd/dracut-cmdline.sh
@@ -68,8 +68,12 @@ case "$root" in
         rootok=1 ;;
 esac
 
-[ -z "$root" ] && die "No or empty root= argument"
-[ -z "$rootok" ] && die "Don't know how to handle 'root=$root'"
+if [ -z "$root" ]; then
+    root=$(findmnt --fstab -n --output source --target /sysroot)
+    [ -z "$root" ] && die "No or empty root= argument and not in fstab"
+elif [ -z "$rootok" ]; then
+    die "Don't know how to handle 'root=$root'"
+fi
 
 export root rflags fstype netroot NEWROOT
 
Index: dracut-043/modules.d/98dracut-systemd/rootfs-generator.sh
===================================================================
--- dracut-043.orig/modules.d/98dracut-systemd/rootfs-generator.sh
+++ dracut-043/modules.d/98dracut-systemd/rootfs-generator.sh
@@ -36,35 +36,6 @@ generator_wait_for_dev()
     fi
 }
 
-generator_mount_rootfs()
-{
-    local _type=$2
-    local _flags=$3
-    local _name
-
-    [ -z "$1" ] && return 0
-
-    _name=$(dev_unit_name "$1")
-    [ -d "$GENERATOR_DIR" ] || mkdir -p "$GENERATOR_DIR"
-    if ! [ -f "$GENERATOR_DIR"/sysroot.mount ]; then
-        {
-            echo "[Unit]"
-            echo "Before=initrd-root-fs.target"
-            echo "RequiresOverridable=systemd-fsck@${_name}.service"
-            echo "After=systemd-fsck@${_name}.service"
-            echo "[Mount]"
-            echo "Where=/sysroot"
-            echo "What=$1"
-            echo "Options=${_flags}"
-            echo "Type=${_type}"
-        } > "$GENERATOR_DIR"/sysroot.mount
-    fi
-    if ! [ -L "$GENERATOR_DIR"/initrd-root-fs.target.requires/sysroot.mount ]; then
-        [ -d "$GENERATOR_DIR"/initrd-root-fs.target.requires ] || mkdir -p "$GENERATOR_DIR"/initrd-root-fs.target.requires
-        ln -s ../sysroot.mount "$GENERATOR_DIR"/initrd-root-fs.target.requires/sysroot.mount
-    fi
-}
-
 generator_fsck_after_pre_mount()
 {
     local _name
@@ -111,9 +82,12 @@ esac
 GENERATOR_DIR="$1"
 
 if [ "${root%%:*}" = "block" ]; then
-   generator_wait_for_dev "${root#block:}" "$RDRETRY"
-   generator_fsck_after_pre_mount "${root#block:}"
-   strstr "$(cat /proc/cmdline)" 'root=' || generator_mount_rootfs "${root#block:}" "$(getarg rootfstype=)" "$(getarg rootflags=)"
+    generator_wait_for_dev "${root#block:}" "$RDRETRY"
+    generator_fsck_after_pre_mount "${root#block:}"
+    if ! [ -L "$GENERATOR_DIR"/initrd-root-fs.target.requires/sysroot.mount ]; then
+        [ -d "$GENERATOR_DIR"/initrd-root-fs.target.requires ] || mkdir -p "$GENERATOR_DIR"/initrd-root-fs.target.requires
+        ln -s ../sysroot.mount "$GENERATOR_DIR"/initrd-root-fs.target.requires/sysroot.mount
+    fi
 fi
 
 exit 0
Index: dracut-043/modules.d/99base/init.sh
===================================================================
--- dracut-043.orig/modules.d/99base/init.sh
+++ dracut-043/modules.d/99base/init.sh
@@ -128,8 +128,12 @@ make_trace_mem "hook cmdline" '1+:mem' '
 getarg 'rd.break=cmdline' -d 'rdbreak=cmdline' && emergency_shell -n cmdline "Break before cmdline"
 source_hook cmdline
 
-[ -z "$root" ] && die "No or empty root= argument"
-[ -z "$rootok" ] && die "Don't know how to handle 'root=$root'"
+if [ -z "$root" ]; then
+    root=$(findmnt --fstab -n --output source --target /sysroot)
+    [ -z "$root" ] && die "No or empty root= argument and not in fstab"
+elif [ -z "$rootok" ]; then
+    die "Don't know how to handle 'root=$root'"
+fi
 
 export root rflags fstype netroot NEWROOT