base/dracut-lib.sh: for systemd start emergency.service

do not spawn the shell, start the emergency.service for systemd

modules.d/99base/dracut-lib.sh

@@ -825,11 +825,21 @@ emergency_shell()
         _rdshell_name=$2; action="Shutdown"; hook="shutdown-emergency"
         shift 2
     fi
+
     echo ; echo
     warn $@
     source_hook "$hook"
     echo
+
     if getargbool 1 rd.shell -y rdshell || getarg rd.break rdbreak; then
+        if [ -x /lib/systemd/systemd ]; then
+            > /.console_lock
+            echo "PS1=\"$_rdshell_name:\${PWD}# \"" >/etc/profile
+            systemctl start emergency.service
+            debug_off
+            while [ -e /.console_lock ]; do sleep 1; done
+            debug_on
+        else
             echo "Dropping to debug shell."
             echo
             export PS1="$_rdshell_name:\${PWD}# "
@@ -849,6 +859,7 @@ emergency_shell()
         # stop watchdog
             echo 'V' > /dev/watchdog
             setsid $CTTY /bin/sh -i -l 0<$_ctty 1>$_ctty 2>&1
+        fi
     else
         warn "$action has failed. To debug this issue add \"rd.shell\" to the kernel command line."
         # cause a kernel panic