nspawn: hook var-lib-machines.mount to machines.target and remote-fs.target

/var can be on a remote filesystem, thus hooking it to local-fs.target is not correct.

Also, only install the mount unit when machined is enabled, because
machined is the one managing the underlying device, and thus makes no
sense without machined.

Fixes #1175

Makefile.am

@@ -269,8 +269,10 @@ INSTALL_DIRS =
 
 SHUTDOWN_TARGET_WANTS =
 LOCAL_FS_TARGET_WANTS =
+REMOTE_FS_TARGET_WANTS =
 MULTI_USER_TARGET_WANTS =
 GRAPHICAL_TARGET_WANTS =
+MACHINES_TARGET_WANTS =
 RESCUE_TARGET_WANTS =
 SYSINIT_TARGET_WANTS =
 SOCKETS_TARGET_WANTS =
@@ -287,6 +289,8 @@ GENERAL_ALIASES =
 install-target-wants-hook:
 	what="$(SHUTDOWN_TARGET_WANTS)" && wants=shutdown.target && dir=$(systemunitdir) && $(add-wants)
 	what="$(LOCAL_FS_TARGET_WANTS)" && wants=local-fs.target && dir=$(systemunitdir) && $(add-wants)
+	what="$(REMOTE_FS_TARGET_WANTS)" && wants=remote-fs.target && dir=$(systemunitdir) && $(add-wants)
+	what="$(MACHINES_TARGET_WANTS)" && wants=machines.target && dir=$(systemunitdir) && $(add-wants)
 	what="$(MULTI_USER_TARGET_WANTS)" && wants=multi-user.target && dir=$(systemunitdir) && $(add-wants)
 	what="$(GRAPHICAL_TARGET_WANTS)" && wants=graphical.target && dir=$(systemunitdir) && $(add-wants)
 	what="$(RESCUE_TARGET_WANTS)" && wants=rescue.target && dir=$(systemunitdir) && $(add-wants)
@@ -539,7 +543,6 @@ dist_systemunit_DATA = \
 	units/sys-kernel-debug.mount \
 	units/sys-fs-fuse-connections.mount \
 	units/tmp.mount \
-	units/var-lib-machines.mount \
 	units/printer.target \
 	units/sound.target \
 	units/bluetooth.target \
@@ -5322,6 +5325,10 @@ endif
 
 # ------------------------------------------------------------------------------
 if ENABLE_MACHINED
+
+dist_systemunit_DATA += \
+	units/var-lib-machines.mount
+
 systemd_machined_SOURCES = \
 	src/machine/machined.c \
 	src/machine/machined.h
@@ -6568,7 +6575,9 @@ SYSINIT_TARGET_WANTS += \
 
 LOCAL_FS_TARGET_WANTS += \
 	systemd-remount-fs.service \
-	tmp.mount \
+	tmp.mount
+
+REMOTE_FS_TARGET_WANTS += \
 	var-lib-machines.mount
 
 MULTI_USER_TARGET_WANTS += \
@@ -6584,6 +6593,11 @@ SYSINIT_TARGET_WANTS += \
 	systemd-sysctl.service \
 	systemd-ask-password-console.path
 
+if ENABLE_MACHINED
+MACHINES_TARGET_WANTS += \
+	var-lib-machines.mount
+endif
+
 if HAVE_SYSV_COMPAT
 SYSTEM_UNIT_ALIASES += \
 	poweroff.target runlevel0.target \

units/meson.build

@@ -101,8 +101,8 @@ units = [
         ['timers.target',                       ''],
         ['umount.target',                       ''],
         ['user.slice',                          ''],
-        ['var-lib-machines.mount',              '',
-         'local-fs.target.wants/'],
+        ['var-lib-machines.mount',              'ENABLE_MACHINED',
+         'remote-fs.target.wants/ machines.target.wants/'],
 ]
 
 in_units = [