bootc-fstab-edit: improve service dependencies

Looking at the target definitions:
- multi-user.target Requires basic.target
- basic.target Requires sysinit.target
- sysinit.target Wants local-fs.target
- local-fs.target is After local-fs-pre.target

local-fs-pre.target is wanted by some services, but it's indirect,
so it's cleaner to be WantedBy local-fs.target and Wants local-fs-pre.target.

While at it add Conflicts=shutdown.target.

Signed-off-by: Etienne Champetier <[email protected]>

lib/src/generator.rs

@@ -72,16 +72,18 @@ fn generate_fstab_editor(unit_dir: &Dir) -> Result<()> {
         EDIT_UNIT,
         "[Unit]\n\
 DefaultDependencies=no\n\
+Conflicts=shutdown.target\n\
 After=systemd-fsck-root.service\n\
 Before=local-fs-pre.target local-fs.target shutdown.target systemd-remount-fs.service\n\
+Wants=local-fs-pre.target\n\
 \n\
 [Service]\n\
 Type=oneshot\n\
 RemainAfterExit=yes\n\
 ExecStart=bootc internals fixup-etc-fstab\n\
 ",
     )?;
-    let target = "local-fs-pre.target.wants";
+    let target = "local-fs.target.wants";
     unit_dir.create_dir_all(target)?;
     unit_dir.symlink(&format!("../{EDIT_UNIT}"), &format!("{target}/{EDIT_UNIT}"))?;
     Ok(())