Merge pull request #8134 from keszybz/unit-load-paths

Various fixes to unit load paths, and systemd-analyze load-paths verb to list them

19 files changed, 452 insertions, 273 deletions

diff --git a/man/systemd-analyze.xml b/man/systemd-analyze.xml
index 5caaa09aa4..97a9b2cca7 100644
--- a/man/systemd-analyze.xml
+++ b/man/systemd-analyze.xml
@@ -94,6 +94,11 @@
     <cmdsynopsis>
       <command>systemd-analyze</command>
       <arg choice="opt" rep="repeat">OPTIONS</arg>
+      <arg choice="plain">unit-paths</arg>
+    </cmdsynopsis>
+    <cmdsynopsis>
+      <command>systemd-analyze</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
       <arg choice="plain">log-level</arg>
       <arg choice="opt"><replaceable>LEVEL</replaceable></arg>
     </cmdsynopsis>
@@ -188,6 +193,18 @@
     state. Its format is subject to change without notice and should
     not be parsed by applications.</para>
 
+    <para><command>systemd-analyze unit-paths</command> outputs a list of all
+    directories from which unit files, <filename>.d</filename> overrides, and
+    <filename>.wants</filename>, <filename>.requires</filename> symlinks may be
+    loaded. Combine with <option>--user</option> to retrieve the list for the user
+    manager instance, and <option>--global</option> for the global configuration of
+    user manager instances. Note that this verb prints the list that is compiled into
+    <command>systemd-analyze</command> itself, and does not comunicate with the
+    running manager. Use
+    <programlisting>systemctl [--user] [--global] show -p UnitPath --value</programlisting>
+    to retrieve the actual list that the manager uses, with any empty directories
+    omitted.</para>
+
     <para><command>systemd-analyze log-level</command>
     prints the current log level of the <command>systemd</command> daemon.
     If an optional argument <replaceable>LEVEL</replaceable> is provided, then the command changes the current log
@@ -243,6 +260,13 @@
 
     <variablelist>
       <varlistentry>
+        <term><option>--system</option></term>
+
+        <listitem><para>Operates on the system systemd instance. This
+        is the implied default.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
         <term><option>--user</option></term>
 
         <listitem><para>Operates on the user systemd
@@ -250,10 +274,10 @@
       </varlistentry>
 
       <varlistentry>
-        <term><option>--system</option></term>
+        <term><option>--global</option></term>
 
-        <listitem><para>Operates on the system systemd instance. This
-        is the implied default.</para></listitem>
+        <listitem><para>Operates on the system-wide configuration for
+        user systemd instance.</para></listitem>
       </varlistentry>
 
       <varlistentry>
diff --git a/man/systemd.generator.xml b/man/systemd.generator.xml
index 7ed6a2dc82..60ca0cecad 100644
--- a/man/systemd.generator.xml
+++ b/man/systemd.generator.xml
@@ -76,14 +76,33 @@
 
   <refsect1>
     <title>Description</title>
-    <para>Generators are small executables that live in <filename>&systemgeneratordir;/</filename> and other
-    directories listed above.
-    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> will execute those
-    binaries very early at bootup and at configuration reload time — before unit files are loaded.  Generators may
-    dynamically generate unit files (regular ones, instances as well as templates) and unit file
-    <filename>.d/</filename> drop-ins, or create symbolic links to unit files to add additional dependencies or
-    instantiate existing templates, thus extending or overriding existing definitions. Their main purpose is to convert
-    configuration files that are not native unit files dynamically into native unit files.</para>
+    <para>Generators are small executables that live in
+    <filename>&systemgeneratordir;/</filename> and other directories listed above.
+    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    will execute those binaries very early at bootup and at configuration reload time
+    — before unit files are loaded. Their main purpose is to convert configuration
+    that is not native into dynamically generated unit files.</para>
+
+    <para>Each generator is called with three directory paths that are to be used for
+    generator output. In these three directories, generators may dynamically generate
+    unit files (regular ones, instances, as well as templates), unit file
+    <filename>.d/</filename> drop-ins, and create symbolic links to unit files to add
+    additional dependencies, create aliases, or instantiate existing templates. Those
+    directories are included in the unit load path of
+    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+    allowing generated configuration to extend or override existing
+    definitions.</para>
+
+    <para>Directory paths for generator output differ by priority:
+    <filename>…/generator.early</filename> has priority higher than the admin
+    configuration in <filename>/etc</filename>, while
+    <filename>…/generator</filename> has lower priority than
+    <filename>/etc</filename> but higher than vendor configuration in
+    <filename>/usr</filename>, and <filename>…/generator.late</filename> has priority
+    lower than all other configuration. See the next section and the discussion of
+    unit load paths and unit overriding in
+    <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+    </para>
 
     <para>Generators are loaded from a set of paths determined during
     compilation, as listed above. System and user generators are loaded
@@ -110,171 +129,153 @@
   </refsect1>
 
   <refsect1>
-    <title>Writing generators</title>
+    <title>Output directories</title>
 
-    <para>Generators are invoked with three arguments: paths to
-    runtime directories where generators can place their generated
-    unit files or symlinks.</para>
+    <para>Generators are invoked with three arguments: paths to directories where
+    generators can place their generated unit files or symlinks. By default those
+    paths are runtime directories that are included in the search path of
+    <command>systemd</command>, but a generator may be called with different paths
+    for debugging purposes.</para>
 
     <orderedlist>
       <listitem>
         <para><parameter>normal-dir</parameter></para>
-        <para>argv[1] may be used to override unit files in
-        <filename>/usr</filename>, but not those in
-        <filename>/run</filename> or in <filename>/etc</filename>.
-        This means that unit files placed
-        in this directory take precedence over vendor unit
-        configuration but not over native user/administrator unit
-        configuration.</para>
+        <para>In normal use this is <filename>/run/systemd/generator</filename> in
+        case of the system generators and
+        <filename>$XDG_RUNTIME_DIR/generator</filename> in case of the user
+        generators. Unit files placed in this directory take precedence over vendor
+        unit configuration but not over native user/administrator unit configuration.
+        </para>
       </listitem>
 
       <listitem>
         <para><parameter>early-dir</parameter></para>
-        <para>argv[2] may be used to override unit files in
-        <filename>/usr</filename>, in <filename>/run</filename> and in
-        <filename>/etc</filename>. This means that unit files placed
-        in this directory take precedence over all configuration,
-        both vendor and user/administrator.</para>
+        <para>In normal use this is <filename>/run/systemd/generator.early</filename>
+        in case of the system generators and
+        <filename>$XDG_RUNTIME_DIR/generator.early</filename> in case of the user
+        generators. Unit files placed in this directory override unit files in
+        <filename>/usr</filename>, <filename>/run</filename> and
+        <filename>/etc</filename>. This means that unit files placed in this
+        directory take precedence over all normal configuration, both vendor and
+        user/administrator.</para>
       </listitem>
 
       <listitem>
         <para><parameter>late-dir</parameter></para>
-        <para>argv[3] may be used to extend the unit file tree without
-        overriding any other unit files. Any native configuration
-        files supplied by the vendor or user/administrator take
-        precedence over the generated ones placed in this directory.
-        </para>
+        <para>In normal use this is <filename>/run/systemd/generator.late</filename>
+        in case of the system generators and
+        <filename>$XDG_RUNTIME_DIR/generator.late</filename> in case of the user
+        generators. This directory may be used to extend the unit file tree without
+        overriding any other unit files. Any native configuration files supplied by
+        the vendor or user/administrator take precedence.</para>
       </listitem>
     </orderedlist>
+  </refsect1>
+
+  <refsect1>
+    <title>Notes about writing generators</title>
+
+    <itemizedlist>
+      <listitem>
+        <para>All generators are executed in parallel. That means all executables are
+        started at the very same time and need to be able to cope with this
+        parallelism.
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>Generators are run very early at boot and cannot rely on any external
+        services. They may not talk to any other process. That includes simple things
+        such as logging to
+        <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+        or <command>systemd</command> itself (this means: no
+        <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>)!
+        Non-essential file systems like <filename>/var</filename> and
+        <filename>/home</filename> are mounted after generators have run. Generators
+        can however rely on the most basic kernel functionality to be available,
+        including a mounted <filename>/sys</filename>, <filename>/proc</filename>,
+        <filename>/dev</filename>, <filename>/usr</filename>.
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>Units written by generators are removed when the configuration is
+        reloaded. That means the lifetime of the generated units is closely bound to
+        the reload cycles of <command>systemd</command> itself.</para>
+      </listitem>
+
+      <listitem>
+        <para>Generators should only be used to generate unit files and symlinks to
+        them, not any other kind of configuration. Due to the lifecycle logic
+        mentioned above, generators are not a good fit to generate dynamic
+        configuration for other services. If you need to generate dynamic
+        configuration for other services, do so in normal services you order before
+        the service in question.</para>
+      </listitem>
+
+      <listitem>
+        <para>Since
+        <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+
+        is not available (see above), log messages have to be written to
+        <filename>/dev/kmsg</filename> instead.</para>
+      </listitem>
+
+      <listitem>
+        <para>It is a good idea to use the <varname>SourcePath=</varname> directive
+        in generated unit files to specify the source configuration file you are
+        generating the unit from. This makes things more easily understood by the
+        user and also has the benefit that systemd can warn the user about
+        configuration files that changed on disk but have not been read yet by
+        systemd.</para>
+      </listitem>
 
-    <refsect2>
-      <title>Notes</title>
-
-      <itemizedlist>
-        <listitem>
-          <para>
-            All generators are executed in parallel. That means all
-            executables are started at the very same time and need to
-            be able to cope with this parallelism.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            Generators are run very early at boot and cannot rely on
-            any external services. They may not talk to any other
-            process. That includes simple things such as logging to
-            <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
-            or <command>systemd</command> itself (this means: no
-            <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>)!
-            Non-essential file systems like
-            <filename>/var</filename> and <filename>/home</filename>
-            are mounted after generators have run. Generators
-            can however rely on the most basic kernel functionality to be
-            available, including a mounted <filename>/sys</filename>,
-            <filename>/proc</filename>, <filename>/dev</filename>,
-            <filename>/usr</filename>.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            Units written by generators are removed when the configuration
-            is reloaded. That means the lifetime of the generated
-            units is closely bound to the reload cycles of
-            <command>systemd</command> itself.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            Generators should only be used to generate unit files and symlinks to them, not any other kind of
-            configuration. Due to the lifecycle logic mentioned above, generators are not a good fit to generate
-            dynamic configuration for other services. If you need to generate dynamic configuration for other services,
-            do so in normal services you order before the service in question.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            Since
-            <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
-            is not available (see above), log messages have to be
-            written to <filename>/dev/kmsg</filename> instead.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            It is a good idea to use the
-            <varname>SourcePath=</varname> directive in generated unit
-            files to specify the source configuration file you are
-            generating the unit from. This makes things more easily
-            understood by the user and also has the benefit that
-            systemd can warn the user about configuration files that
-            changed on disk but have not been read yet by systemd.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            Generators may write out dynamic unit files or just hook
-            unit files into other units with the usual
-            <filename>.wants/</filename> or
-            <filename>.requires/</filename> symlinks. Often, it is
-            nicer to simply instantiate a template unit file from
-            <filename>/usr</filename> with a generator instead of
-            writing out entirely dynamic unit files. Of course, this
-            works only if a single parameter is to be used.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>
-            If you are careful, you can implement generators in shell
-            scripts. We do recommend C code however, since generators
-            are executed synchronously and hence delay the
-            entire boot if they are slow.
-          </para>
-        </listitem>
-
-        <listitem>
-          <para>Regarding overriding semantics: there are two rules we
-          try to follow when thinking about the overriding semantics:
-          </para>
-
-          <orderedlist numeration="lowerroman">
-            <listitem>
-              <para>User configuration should override vendor
-              configuration. This (mostly) means that stuff from
-              <filename>/etc</filename> should override stuff from
-              <filename>/usr</filename>.</para>
-            </listitem>
-
-            <listitem>
-              <para>Native configuration should override non-native
-              configuration. This (mostly) means that stuff you
-              generate should never override native unit files for the
-              same purpose.</para>
-            </listitem>
-          </orderedlist>
-
-          <para>Of these two rules the first rule is probably the more
-          important one and breaks the second one sometimes. Hence,
-          when deciding whether to use argv[1], argv[2], or argv[3],
-          your default choice should probably be argv[1].</para>
-        </listitem>
-
-        <listitem>
-          <para>
-            Instead of heading off now and writing all kind of
-            generators for legacy configuration file formats, please
-            think twice! It is often a better idea to just deprecate
-            old stuff instead of keeping it artificially alive.
-          </para>
-        </listitem>
-      </itemizedlist>
-    </refsect2>
+      <listitem>
+        <para>Generators may write out dynamic unit files or just hook unit files
+        into other units with the usual <filename>.wants/</filename> or
+        <filename>.requires/</filename> symlinks. Often, it is nicer to simply
+        instantiate a template unit file from <filename>/usr</filename> with a
+        generator instead of writing out entirely dynamic unit files. Of course, this
+        works only if a single parameter is to be used.</para>
+      </listitem>
+
+      <listitem>
+        <para>If you are careful, you can implement generators in shell scripts. We
+        do recommend C code however, since generators are executed synchronously and
+        hence delay the entire boot if they are slow.</para>
+      </listitem>
+
+      <listitem>
+        <para>Regarding overriding semantics: there are two rules we try to follow
+        when thinking about the overriding semantics:</para>
+
+        <orderedlist numeration="lowerroman">
+          <listitem>
+            <para>User configuration should override vendor configuration. This
+            (mostly) means that stuff from <filename>/etc</filename> should override
+            stuff from <filename>/usr</filename>.</para>
+          </listitem>
+
+          <listitem>
+            <para>Native configuration should override non-native configuration. This
+            (mostly) means that stuff you generate should never override native unit
+            files for the same purpose.</para>
+          </listitem>
+        </orderedlist>
+
+        <para>Of these two rules the first rule is probably the more important one
+        and breaks the second one sometimes. Hence, when deciding whether to use
+        argv[1], argv[2], or argv[3], your default choice should probably be
+        argv[1].</para>
+      </listitem>
+
+      <listitem>
+        <para>Instead of heading off now and writing all kind of generators for
+        legacy configuration file formats, please think twice! It is often a better
+        idea to just deprecate old stuff instead of keeping it artificially alive.
+        </para>
+      </listitem>
+    </itemizedlist>
   </refsect1>
 
   <refsect1>
@@ -283,22 +284,18 @@
       <title>systemd-fstab-generator</title>
 
       <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
-      converts <filename>/etc/fstab</filename> into native mount
-      units. It uses argv[1] as location to place the generated unit
-      files in order to allow the user to override
-      <filename>/etc/fstab</filename> with her own native unit files,
-      but also to ensure that <filename>/etc/fstab</filename>
-      overrides any vendor default from <filename>/usr</filename>.
-      </para>
-
-      <para>After editing <filename>/etc/fstab</filename>, the user
-      should invoke <command>systemctl daemon-reload</command>. This
-      will re-run all generators and cause <command>systemd</command>
-      to reload units from disk. To actually mount new directories
-      added to <filename>fstab</filename>, <command>systemctl start
-      <replaceable>/path/to/mountpoint</replaceable></command> or
-      <command>systemctl start local-fs.target</command> may be used.
-      </para>
+      converts <filename>/etc/fstab</filename> into native mount units. It uses
+      argv[1] as location to place the generated unit files in order to allow the
+      user to override <filename>/etc/fstab</filename> with her own native unit
+      files, but also to ensure that <filename>/etc/fstab</filename> overrides any
+      vendor default from <filename>/usr</filename>.</para>
+
+      <para>After editing <filename>/etc/fstab</filename>, the user should invoke
+      <command>systemctl daemon-reload</command>. This will re-run all generators and
+      cause <command>systemd</command> to reload units from disk. To actually mount
+      new directories added to <filename>fstab</filename>, <command>systemctl start
+      <replaceable>/path/to/mountpoint</replaceable></command> or <command>systemctl
+      start local-fs.target</command> may be used.</para>
     </example>
 
     <example>
@@ -307,9 +304,9 @@
       <para><citerefentry><refentrytitle>systemd-system-update-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
       temporarily redirects <filename>default.target</filename> to
       <filename>system-update.target</filename>, if a system update is
-      scheduled. Since this needs to override the default user
-      configuration for <filename>default.target</filename>, it uses
-      argv[2]. For details about this logic, see
+      scheduled. Since this needs to override the default user configuration for
+      <filename>default.target</filename>, it uses argv[2]. For details about this
+      logic, see
       <citerefentry><refentrytitle>systemd.offline-updates</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
       </para>
     </example>
diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index 90ca378e84..0e27c5dd8e 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -65,19 +65,31 @@
     <filename><replaceable>slice</replaceable>.slice</filename>,
     <filename><replaceable>scope</replaceable>.scope</filename></para>
 
-    <para><literallayout><filename>/etc/systemd/system/*</filename>
+    <para><literallayout><filename>/etc/systemd/system.control/*</filename>
+<filename>/run/systemd/system.control/*</filename>
+<filename>/run/systemd/transient/*</filename>
+<filename>/run/systemd/generator.early/*</filename>
+<filename>/etc/systemd/system/*</filename>
 <filename>/run/systemd/system/*</filename>
-<filename>/usr/lib/systemd/system/*</filename>
+<filename>/run/systemd/generator/*</filename>
 <filename>…</filename>
+<filename>/usr/lib/systemd/system/*</filename>
+<filename>/run/systemd/generator.late/*</filename>
     </literallayout></para>
 
-    <para><literallayout><filename>~/.config/systemd/user/*</filename>
+    <para><literallayout><filename>~/.config/systemd/user.control/*</filename>
+<filename>$XDG_RUNTIME_DIR/systemd/user.control/*</filename>
+<filename>$XDG_RUNTIME_DIR/systemd/transient/*</filename>
+<filename>$XDG_RUNTIME_DIR/systemd/generator.early/*</filename>
+<filename>~/.config/systemd/user/*</filename>
 <filename>/etc/systemd/user/*</filename>
 <filename>$XDG_RUNTIME_DIR/systemd/user/*</filename>
 <filename>/run/systemd/user/*</filename>
+<filename>$XDG_RUNTIME_DIR/systemd/generator/*</filename>
 <filename>~/.local/share/systemd/user/*</filename>
-<filename>/usr/lib/systemd/user/*</filename>
 <filename>…</filename>
+<filename>/usr/lib/systemd/user/*</filename>
+<filename>$XDG_RUNTIME_DIR/systemd/generator.late/*</filename>
     </literallayout></para>
   </refsynopsisdiv>
 
@@ -343,6 +355,22 @@
         </thead>
         <tbody>
           <row>
+            <entry><filename>/etc/systemd/system.control</filename></entry>
+            <entry morerows="1">Persistent and transient configuration created using the dbus API</entry>
+          </row>
+          <row>
+            <entry><filename>/run/systemd/system.control</filename></entry>
+          </row>
+          <row>
+            <entry><filename>/run/systemd/transient</filename></entry>
+            <entry>Dynamic configuration for transient units</entry>
+          </row>
+          <row>
+            <entry><filename>/run/systemd/generator.early</filename></entry>
+            <entry>Generated units with high priority (see <replaceable>early-dir</replaceable> in <citerefentry
+            ><refentrytitle>system.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry>
+          </row>
+          <row>
             <entry><filename>/etc/systemd/system</filename></entry>
             <entry>Local configuration</entry>
           </row>
@@ -351,8 +379,21 @@
             <entry>Runtime units</entry>
           </row>
           <row>
+            <entry><filename>/run/systemd/generator</filename></entry>
+            <entry>Generated units with medium priority (see <replaceable>normal-dir</replaceable> in <citerefentry
+            ><refentrytitle>system.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry>
+          </row>
+          <row>
+            <entry><filename>/usr/local/lib/systemd/system</filename></entry>
+            <entry morerows="1">Units of installed packages</entry>
+          </row>
+          <row>
             <entry><filename>/usr/lib/systemd/system</filename></entry>
-            <entry>Units of installed packages</entry>
+          </row>
+          <row>
+            <entry><filename>/run/systemd/generator.late</filename></entry>
+            <entry>Generated units with low priority (see <replaceable>late-dir</replaceable> in <citerefentry
+            ><refentrytitle>system.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry>
           </row>
         </tbody>
       </tgroup>
@@ -374,12 +415,25 @@
         </thead>
         <tbody>
           <row>
-            <entry><filename>$XDG_CONFIG_HOME/systemd/user</filename></entry>
-            <entry>User configuration (only used when $XDG_CONFIG_HOME is set)</entry>
+            <entry><filename>$XDG_CONFIG_HOME/systemd/user.control</filename> or <filename
+            >~/.config/systemd/user.control</filename></entry>
+            <entry morerows="1">Persistent and transient configuration created using the dbus API (<varname>$XDG_CONFIG_HOME</varname> is used if set, <filename>~/.config</filename> otherwise)</entry>
+          </row>
+          <row>
+            <entry><filename>$XDG_RUNTIME_DIR/systemd/user.control</filename></entry>
+          </row>
+          <row>
+            <entry><filename>/run/systemd/transient</filename></entry>
+            <entry>Dynamic configuration for transient units</entry>
+          </row>
+          <row>
+            <entry><filename>/run/systemd/generator.early</filename></entry>
+            <entry>Generated units with high priority (see <replaceable>early-dir</replaceable> in <citerefentry
+            ><refentrytitle>system.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry>
           </row>
           <row>
-            <entry><filename>$HOME/.config/systemd/user</filename></entry>
-            <entry>User configuration (only used when $XDG_CONFIG_HOME is not set)</entry>
+            <entry><filename>$XDG_CONFIG_HOME/systemd/user</filename> or <filename>$HOME/.config/systemd/user</filename></entry>
+            <entry>User configuration (<varname>$XDG_CONFIG_HOME</varname> is used if set, <filename>~/.config</filename> otherwise)</entry>
           </row>
           <row>
             <entry><filename>/etc/systemd/user</filename></entry>
@@ -394,27 +448,50 @@
             <entry>Runtime units</entry>
           </row>
           <row>
-            <entry><filename>$XDG_DATA_HOME/systemd/user</filename></entry>
-            <entry>Units of packages that have been installed in the home directory (only used when $XDG_DATA_HOME is set)</entry>
+            <entry><filename>$XDG_RUNTIME_DIR/systemd/generator</filename></entry>
+            <entry>Generated units with medium priority (see <replaceable>normal-dir</replaceable> in <citerefentry
+            ><refentrytitle>system.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry>
           </row>
           <row>
-            <entry><filename>$HOME/.local/share/systemd/user</filename></entry>
-            <entry>Units of packages that have been installed in the home directory (only used when $XDG_DATA_HOME is not set)</entry>
+            <entry><filename>$XDG_DATA_HOME/systemd/user</filename> or <filename>$HOME/.local/share/systemd/user</filename></entry>
+            <entry>Units of packages that have been installed in the home directory (<varname>$XDG_DATA_HOME</varname> is used if set, <filename>~/.local/share</filename> otherwise)</entry>
+          </row>
+          <row>
+            <entry><filename>$dir/systemd/user</filename> for each <varname noindex='true'>$dir</varname> in <varname>$XDG_DATA_DIRS</varname></entry>
+            <entry>Additional locations for installed user units, one for each entry in <varname>$XDG_DATA_DIRS</varname></entry>
+          </row>
+          <row>
+            <entry><filename>/usr/local/lib/systemd/user</filename></entry>
+            <entry morerows="1">Units of packages that have been installed system-wide</entry>
           </row>
           <row>
             <entry><filename>/usr/lib/systemd/user</filename></entry>
-            <entry>Units of packages that have been installed system-wide</entry>
+          </row>
+          <row>
+            <entry><filename>$XDG_RUNTIME_DIR/systemd/generator.late</filename></entry>
+            <entry>Generated units with low priority (see <replaceable>late-dir</replaceable> in <citerefentry
+            ><refentrytitle>system.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>)</entry>
           </row>
         </tbody>
       </tgroup>
     </table>
 
-    <para>Additional units might be loaded into systemd ("linked")
-    from directories not on the unit load path. See the
-    <command>link</command> command for
+    <para>The set of load paths for the user manager instance may be augmented or
+    changed using various environment variables. And environment variables may in
+    turn be set using environment generators, see
+    <citerefentry><refentrytitle>system.environment-generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
+    In particular, <varname>$XDG_DATA_HOME</varname> and
+    <varname>$XDG_DATA_DIRS</varname> may be easily set using
+    <citerefentry><refentrytitle>systemd-environment-d-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+    Thus, directories listed here are just the defaults. To see the actual list that
+    would be used based on compilation options and current environment use
+    <programlisting>systemd-analyze --user unit-paths</programlisting>
+    </para>
+
+    <para>Moreover, additional units might be loaded into systemd ("linked") from
+    directories not on the unit load path. See the <command>link</command> command
+    for
     <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
-    Also, some units are dynamically created via a
-    <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
     </para>
   </refsect1>
 
diff --git a/shell-completion/bash/systemd-analyze b/shell-completion/bash/systemd-analyze
index fb30487613..a66ddccb02 100644
--- a/shell-completion/bash/systemd-analyze
+++ b/shell-completion/bash/systemd-analyze
@@ -36,13 +36,13 @@ _systemd_analyze() {
         local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD-1]}
 
         local -A OPTS=(
-               [STANDALONE]='-h --help --version --system --user --order --require --no-pager
+               [STANDALONE]='-h --help --version --system --user --global --order --require --no-pager
                              --man=no --generators=yes'
                       [ARG]='-H --host -M --machine --fuzz --from-pattern --to-pattern'
         )
 
         local -A VERBS=(
-                [STANDALONE]='time blame plot dump calendar'
+                [STANDALONE]='time blame plot dump unit-paths calendar'
                 [CRITICAL_CHAIN]='critical-chain'
                 [DOT]='dot'
                 [LOG_LEVEL]='log-level'
@@ -85,7 +85,7 @@ _systemd_analyze() {
 
         elif __contains_word "$verb" ${VERBS[STANDALONE]}; then
                 if [[ $cur = -* ]]; then
-                        comps='--help --version --system --user'
+                        comps='--help --version --system --user --global'
                 fi
 
         elif __contains_word "$verb" ${VERBS[CRITICAL_CHAIN]}; then
@@ -95,7 +95,7 @@ _systemd_analyze() {
 
         elif __contains_word "$verb" ${VERBS[DOT]}; then
                 if [[ $cur = -* ]]; then
-                        comps='--help --version --system --user --from-pattern --to-pattern --order --require'
+                        comps='--help --version --system --user --global --from-pattern --to-pattern --order --require'
                 fi
 
         elif __contains_word "$verb" ${VERBS[LOG_LEVEL]}; then
@@ -119,7 +119,7 @@ _systemd_analyze() {
 
         elif __contains_word "$verb" ${VERBS[VERIFY]}; then
                 if [[ $cur = -* ]]; then
-                        comps='--help --version --system --user --man=no --generators=yes'
+                        comps='--help --version --system --user --global --man=no --generators=yes'
                 else
                         comps=$( compgen -A file -- "$cur" )
                         compopt -o filenames
diff --git a/shell-completion/zsh/_systemd-analyze b/shell-completion/zsh/_systemd-analyze
index ae13f4bbde..bccdb951f1 100644
--- a/shell-completion/zsh/_systemd-analyze
+++ b/shell-completion/zsh/_systemd-analyze
@@ -33,6 +33,7 @@ _systemd_analyze_command(){
         'plot:Output SVG graphic showing service initialization'
         'dot:Dump dependency graph (in dot(1) format)'
         'dump:Dump server status'
+        'unit-paths':List unit load paths'
         'log-level:Get/set systemd log threshold'
         'log-target:Get/set systemd log target'
         'service-watchdogs:Get/set service watchdog status'
@@ -62,6 +63,7 @@ _arguments \
     '--version[Show package version]' \
     '--system[Operate on system systemd instance]' \
     '--user[Operate on user systemd instance]' \
+    '--global[Show global user instance config]' \
     '--no-pager[Do not pipe output into a pager]' \
     '--man=[Do (not) check for existence of man pages]:boolean:(1 0)' \
     '--order[When generating graph for dot, show only order]' \
diff --git a/src/analyze/analyze.c b/src/analyze/analyze.c
index aab61e4de3..2d65fdbdb8 100644
--- a/src/analyze/analyze.c
+++ b/src/analyze/analyze.c
@@ -80,7 +80,7 @@ static usec_t arg_fuzz = 0;
 static bool arg_no_pager = false;
 static BusTransport arg_transport = BUS_TRANSPORT_LOCAL;
 static const char *arg_host = NULL;
-static bool arg_user = false;
+static UnitFileScope arg_scope = UNIT_FILE_SYSTEM;
 static bool arg_man = true;
 static bool arg_generators = false;
 
@@ -132,10 +132,12 @@ struct host_info {
 };
 
 static int acquire_bus(bool need_full_bus, sd_bus **bus) {
+        bool user = arg_scope != UNIT_FILE_SYSTEM;
+
         if (need_full_bus)
-                return bus_connect_transport(arg_transport, arg_host, arg_user, bus);
+                return bus_connect_transport(arg_transport, arg_host, user, bus);
         else
-                return bus_connect_transport_systemd(arg_transport, arg_host, arg_user, bus);
+                return bus_connect_transport_systemd(arg_transport, arg_host, user, bus);
 }
 
 static int bus_get_uint64_property(sd_bus *bus, const char *path, const char *interface, const char *property, uint64_t *val) {
@@ -294,7 +296,12 @@ static int acquire_boot_times(sd_bus *bus, struct boot_times **bt) {
                 return -EINPROGRESS;
         }
 
-        if (arg_user) {
+        if (arg_scope == UNIT_FILE_SYSTEM) {
+                if (times.initrd_time > 0)
+                        times.kernel_done_time = times.initrd_time;
+                else
+                        times.kernel_done_time = times.userspace_time;
+        } else {
                 /*
                  * User-instance-specific timestamps processing
                  * (see comment to reverse_offset in struct boot_times).
@@ -312,11 +319,6 @@ static int acquire_boot_times(sd_bus *bus, struct boot_times **bt) {
 
                 subtract_timestamp(&times.unitsload_start_time, times.reverse_offset);
                 subtract_timestamp(&times.unitsload_finish_time, times.reverse_offset);
-        } else {
-                if (times.initrd_time)
-                        times.kernel_done_time = times.initrd_time;
-                else
-                        times.kernel_done_time = times.userspace_time;
         }
 
         cached = true;
@@ -439,8 +441,7 @@ static int acquire_time_data(sd_bus *bus, struct unit_times **out) {
         return c;
 
 fail:
-        if (unit_times)
-                free_unit_times(unit_times, (unsigned) c);
+        free_unit_times(unit_times, (unsigned) c);
         return r;
 }
 
@@ -537,11 +538,11 @@ static int pretty_boot_time(sd_bus *bus, char **_buf) {
         size = sizeof(buf);
 
         size = strpcpyf(&ptr, size, "Startup finished in ");
-        if (t->firmware_time)
+        if (t->firmware_time > 0)
                 size = strpcpyf(&ptr, size, "%s (firmware) + ", format_timespan(ts, sizeof(ts), t->firmware_time - t->loader_time, USEC_PER_MSEC));
-        if (t->loader_time)
+        if (t->loader_time > 0)
                 size = strpcpyf(&ptr, size, "%s (loader) + ", format_timespan(ts, sizeof(ts), t->loader_time, USEC_PER_MSEC));
-        if (t->kernel_time)
+        if (t->kernel_time > 0)
                 size = strpcpyf(&ptr, size, "%s (kernel) + ", format_timespan(ts, sizeof(ts), t->kernel_done_time, USEC_PER_MSEC));
         if (t->initrd_time > 0)
                 size = strpcpyf(&ptr, size, "%s (initrd) + ", format_timespan(ts, sizeof(ts), t->userspace_time - t->initrd_time, USEC_PER_MSEC));
@@ -550,7 +551,7 @@ static int pretty_boot_time(sd_bus *bus, char **_buf) {
         if (t->kernel_time > 0)
                 strpcpyf(&ptr, size, "= %s", format_timespan(ts, sizeof(ts), t->firmware_time + t->finish_time, USEC_PER_MSEC));
 
-        if (unit_id && (activated_time > 0 && activated_time != USEC_INFINITY))
+        if (unit_id && activated_time > 0 && activated_time != USEC_INFINITY)
                 size = strpcpyf(&ptr, size, "\n%s reached after %s in userspace", unit_id, format_timespan(ts, sizeof(ts), activated_time - t->userspace_time, USEC_PER_MSEC));
         else if (unit_id && activated_time == 0)
                 size = strpcpyf(&ptr, size, "\n%s was never reached", unit_id);
@@ -629,14 +630,14 @@ static int analyze_plot(int argc, char *argv[], void *userdata) {
 
         if (boot->firmware_time > boot->loader_time)
                 m++;
-        if (boot->loader_time) {
+        if (boot->loader_time > 0) {
                 m++;
                 if (width < 1000.0)
                         width = 1000.0;
         }
-        if (boot->initrd_time)
+        if (boot->initrd_time > 0)
                 m++;
-        if (boot->kernel_time)
+        if (boot->kernel_time > 0)
                 m++;
 
         for (u = times; u < times + n; u++) {
@@ -725,22 +726,22 @@ static int analyze_plot(int argc, char *argv[], void *userdata) {
         svg("<g transform=\"translate(%.3f,100)\">\n", 20.0 + (SCALE_X * boot->firmware_time));
         svg_graph_box(m, -(double) boot->firmware_time, boot->finish_time);
 
-        if (boot->firmware_time) {
+        if (boot->firmware_time > 0) {
                 svg_bar("firmware", -(double) boot->firmware_time, -(double) boot->loader_time, y);
                 svg_text(true, -(double) boot->firmware_time, y, "firmware");
                 y++;
         }
-        if (boot->loader_time) {
+        if (boot->loader_time > 0) {
                 svg_bar("loader", -(double) boot->loader_time, 0, y);
                 svg_text(true, -(double) boot->loader_time, y, "loader");
                 y++;
         }
-        if (boot->kernel_time) {
+        if (boot->kernel_time > 0) {
                 svg_bar("kernel", 0, boot->kernel_done_time, y);
                 svg_text(true, 0, y, "kernel");
                 y++;
         }
-        if (boot->initrd_time) {
+        if (boot->initrd_time > 0) {
                 svg_bar("initrd", boot->initrd_time, boot->userspace_time, y);
                 svg_text(true, boot->initrd_time, y, "initrd");
                 y++;
@@ -818,7 +819,7 @@ static int list_dependencies_print(const char *name, unsigned int level, unsigne
         printf("%s", special_glyph(last ? TREE_RIGHT : TREE_BRANCH));
 
         if (times) {
-                if (times->time)
+                if (times->time > 0)
                         printf("%s%s @%s +%s%s", ansi_highlight_red(), name,
                                format_timespan(ts, sizeof(ts), times->activating - boot->userspace_time, USEC_PER_MSEC),
                                format_timespan(ts2, sizeof(ts2), times->time, USEC_PER_MSEC), ansi_normal());
@@ -864,6 +865,11 @@ static int list_dependencies_compare(const void *_a, const void *_b) {
         return usb - usa;
 }
 
+static bool times_in_range(const struct unit_times *times, const struct boot_times *boot) {
+        return times &&
+                times->activated > 0 && times->activated <= boot->finish_time;
+}
+
 static int list_dependencies_one(sd_bus *bus, const char *name, unsigned int level, char ***units,
                                  unsigned int branches) {
         _cleanup_strv_free_ char **deps = NULL;
@@ -889,11 +895,9 @@ static int list_dependencies_one(sd_bus *bus, const char *name, unsigned int lev
 
         STRV_FOREACH(c, deps) {
                 times = hashmap_get(unit_times_hashmap, *c);
-                if (times
-                    && times->activated
-                    && times->activated <= boot->finish_time
-                    && (times->activated >= service_longest
-                        || service_longest == 0)) {
+                if (times_in_range(times, boot) &&
+                    (times->activated >= service_longest
+                     || service_longest == 0)) {
                         service_longest = times->activated;
                         break;
                 }
@@ -904,7 +908,8 @@ static int list_dependencies_one(sd_bus *bus, const char *name, unsigned int lev
 
         STRV_FOREACH(c, deps) {
                 times = hashmap_get(unit_times_hashmap, *c);
-                if (times && times->activated && times->activated <= boot->finish_time && (service_longest - times->activated) <= arg_fuzz)
+                if (times_in_range(times, boot) &&
+                    service_longest - times->activated <= arg_fuzz)
                         to_print++;
         }
 
@@ -913,10 +918,8 @@ static int list_dependencies_one(sd_bus *bus, const char *name, unsigned int lev
 
         STRV_FOREACH(c, deps) {
                 times = hashmap_get(unit_times_hashmap, *c);
-                if (!times
-                    || !times->activated
-                    || times->activated > boot->finish_time
-                    || service_longest - times->activated > arg_fuzz)
+                if (!times_in_range(times, boot) ||
+                    service_longest - times->activated > arg_fuzz)
                         continue;
 
                 to_print--;
@@ -938,7 +941,7 @@ static int list_dependencies_one(sd_bus *bus, const char *name, unsigned int lev
                 if (r < 0)
                         return r;
 
-                if (!to_print)
+                if (to_print == 0)
                         break;
         }
         return 0;
@@ -1414,6 +1417,21 @@ static int get_or_set_log_target(int argc, char *argv[], void *userdata) {
         return (argc == 1) ? get_log_target(argc, argv, userdata) : set_log_target(argc, argv, userdata);
 }
 
+static int dump_unit_paths(int argc, char *argv[], void *userdata) {
+        _cleanup_lookup_paths_free_ LookupPaths paths = {};
+        int r;
+        char **p;
+
+        r = lookup_paths_init(&paths, arg_scope, 0, NULL);
+        if (r < 0)
+                return log_error_errno(r, "lookup_paths_init() failed: %m");
+
+        STRV_FOREACH(p, paths.search_path)
+                puts(*p);
+
+        return 0;
+}
+
 #if HAVE_SECCOMP
 static void dump_syscall_filter(const SyscallFilterSet *set) {
         const char *syscall;
@@ -1584,10 +1602,7 @@ static int service_watchdogs(int argc, char *argv[], void *userdata) {
 }
 
 static int do_verify(int argc, char *argv[], void *userdata) {
-        return verify_units(strv_skip(argv, 1),
-                            arg_user ? UNIT_FILE_USER : UNIT_FILE_SYSTEM,
-                            arg_man,
-                            arg_generators);
+        return verify_units(strv_skip(argv, 1), arg_scope, arg_man, arg_generators);
 }
 
 static int help(int argc, char *argv[], void *userdata) {
@@ -1601,6 +1616,7 @@ static int help(int argc, char *argv[], void *userdata) {
                "     --no-pager            Do not pipe output into a pager\n"
                "     --system              Operate on system systemd instance\n"
                "     --user                Operate on user systemd instance\n"
+               "     --global              Operate on global user configuration\n"
                "  -H --host=[USER@]HOST    Operate on remote host\n"
                "  -M --machine=CONTAINER   Operate on local container\n"
                "     --order               Show only order in the graph\n"
@@ -1620,6 +1636,7 @@ static int help(int argc, char *argv[], void *userdata) {
                "  log-level [LEVEL]        Get/set logging threshold for manager\n"
                "  log-target [TARGET]      Get/set logging target for manager\n"
                "  dump                     Output state serialization of service manager\n"
+               "  unit-paths               List load directories for units\n"
                "  syscall-filter [NAME...] Print list of syscalls in seccomp filter\n"
                "  verify FILE...           Check unit files for correctness\n"
                "  calendar SPEC...         Validate repetitive calendar time events\n"
@@ -1638,8 +1655,9 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_VERSION = 0x100,
                 ARG_ORDER,
                 ARG_REQUIRE,
-                ARG_USER,
                 ARG_SYSTEM,
+                ARG_USER,
+                ARG_GLOBAL,
                 ARG_DOT_FROM_PATTERN,
                 ARG_DOT_TO_PATTERN,
                 ARG_FUZZ,
@@ -1653,8 +1671,9 @@ static int parse_argv(int argc, char *argv[]) {
                 { "version",      no_argument,       NULL, ARG_VERSION          },
                 { "order",        no_argument,       NULL, ARG_ORDER            },
                 { "require",      no_argument,       NULL, ARG_REQUIRE          },
-                { "user",         no_argument,       NULL, ARG_USER             },
                 { "system",       no_argument,       NULL, ARG_SYSTEM           },
+                { "user",         no_argument,       NULL, ARG_USER             },
+                { "global",       no_argument,       NULL, ARG_GLOBAL           },
                 { "from-pattern", required_argument, NULL, ARG_DOT_FROM_PATTERN },
                 { "to-pattern",   required_argument, NULL, ARG_DOT_TO_PATTERN   },
                 { "fuzz",         required_argument, NULL, ARG_FUZZ             },
@@ -1680,12 +1699,16 @@ static int parse_argv(int argc, char *argv[]) {
                 case ARG_VERSION:
                         return version();
 
+                case ARG_SYSTEM:
+                        arg_scope = UNIT_FILE_SYSTEM;
+                        break;
+
                 case ARG_USER:
-                        arg_user = true;
+                        arg_scope = UNIT_FILE_USER;
                         break;
 
-                case ARG_SYSTEM:
-                        arg_user = false;
+                case ARG_GLOBAL:
+                        arg_scope = UNIT_FILE_GLOBAL;
                         break;
 
                 case ARG_ORDER:
@@ -1763,6 +1786,12 @@ static int parse_argv(int argc, char *argv[]) {
                         assert_not_reached("Unhandled option code.");
                 }
 
+        if (arg_scope == UNIT_FILE_GLOBAL &&
+            !STR_IN_SET(argv[optind] ?: "time", "dot", "unit-paths", "verify")) {
+                log_error("Option --global only makes sense with verbs dot, unit-paths, verify.");
+                return -EINVAL;
+        }
+
         return 1; /* work to do */
 }
 
@@ -1783,6 +1812,7 @@ int main(int argc, char *argv[]) {
                 { "set-log-target",    2,        2,        0,            set_log_target         },
                 { "get-log-target",    VERB_ANY, 1,        0,            get_log_target         },
                 { "dump",              VERB_ANY, 1,        0,            dump                   },
+                { "unit-paths",        1,        1,        0,            dump_unit_paths        },
                 { "syscall-filter",    VERB_ANY, VERB_ANY, 0,            dump_syscall_filters   },
                 { "verify",            2,        VERB_ANY, 0,            do_verify              },
                 { "calendar",          2,        VERB_ANY, 0,            test_calendar          },
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index 228af69d88..33f3469f07 100644
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -1260,9 +1260,9 @@ static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer, size_
         if (!lease->have_subnet_mask) {
                 r = dhcp_lease_set_default_subnet_mask(lease);
                 if (r < 0) {
-                        log_dhcp_client(client, "received lease lacks subnet "
-                                        "mask, and a fallback one can not be "
-                                        "generated, ignoring");
+                        log_dhcp_client(client,
+                                        "received lease lacks subnet mask, "
+                                        "and a fallback one cannot be generated, ignoring");
                         return -ENOMSG;
                 }
         }
@@ -1331,9 +1331,9 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, size_t le
         if (lease->subnet_mask == INADDR_ANY) {
                 r = dhcp_lease_set_default_subnet_mask(lease);
                 if (r < 0) {
-                        log_dhcp_client(client, "received lease lacks subnet "
-                                        "mask, and a fallback one can not be "
-                                        "generated, ignoring");
+                        log_dhcp_client(client,
+                                        "received lease lacks subnet mask, "
+                                        "and a fallback one cannot be generated, ignoring");
                         return -ENOMSG;
                 }
         }
diff --git a/src/libudev/libudev-device.c b/src/libudev/libudev-device.c
index 82df426491..8e65cfd40a 100644
--- a/src/libudev/libudev-device.c
+++ b/src/libudev/libudev-device.c
@@ -143,7 +143,7 @@ _public_ const char *udev_device_get_driver(struct udev_device *udev_device)
  *
  * Retrieve the devtype string of the udev device.
  *
- * Returns: the devtype name of the udev device, or #NULL if it can not be determined
+ * Returns: the devtype name of the udev device, or #NULL if it cannot be determined
  **/
 _public_ const char *udev_device_get_devtype(struct udev_device *udev_device)
 {
@@ -168,7 +168,7 @@ _public_ const char *udev_device_get_devtype(struct udev_device *udev_device)
  * Retrieve the subsystem string of the udev device. The string does not
  * contain any "/".
  *
- * Returns: the subsystem name of the udev device, or #NULL if it can not be determined
+ * Returns: the subsystem name of the udev device, or #NULL if it cannot be determined
  **/
 _public_ const char *udev_device_get_subsystem(struct udev_device *udev_device)
 {
diff --git a/src/network/netdev/vxlan.c b/src/network/netdev/vxlan.c
index ad050efeca..c9fd931718 100644
--- a/src/network/netdev/vxlan.c
+++ b/src/network/netdev/vxlan.c
@@ -200,14 +200,14 @@ int config_parse_vxlan_address(const char *unit,
 
         if (streq(lvalue, "Group")) {
                 if (r <= 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "vxlan invalid multicast '%s' address, ignoring assignment: %s", lvalue, rvalue);
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "vxlan %s invalid multicast address, ignoring assignment: %s", lvalue, rvalue);
                         return 0;
                 }
 
                 v->remote_family = f;
         } else {
                 if (r > 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "vxlan %s can not be multicast address, ignoring assignment: %s", lvalue, rvalue);
+                        log_syntax(unit, LOG_ERR, filename, line, 0, "vxlan %s cannot be a multicast address, ignoring assignment: %s", lvalue, rvalue);
                         return 0;
                 }
 
diff --git a/src/network/networkd-address.c b/src/network/networkd-address.c
index ca5b54bdbf..7e722b1a2e 100644
--- a/src/network/networkd-address.c
+++ b/src/network/networkd-address.c
@@ -776,7 +776,7 @@ int config_parse_address(const char *unit,
         if (!e && f == AF_INET) {
                 r = in4_addr_default_prefixlen(&buffer.in, &n->prefixlen);
                 if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Prefix length not specified, and a default one can not be deduced for '%s', ignoring assignment", address);
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Prefix length not specified, and a default one cannot be deduced for '%s', ignoring assignment", address);
                         return 0;
                 }
         }
diff --git a/src/network/networkd-ipv6-proxy-ndp.c b/src/network/networkd-ipv6-proxy-ndp.c
index 31b7c6b0f4..1a357ac8e6 100644
--- a/src/network/networkd-ipv6-proxy-ndp.c
+++ b/src/network/networkd-ipv6-proxy-ndp.c
@@ -142,7 +142,7 @@ int config_parse_ipv6_proxy_ndp_address(
         r = in_addr_is_null(AF_INET6, &buffer);
         if (r != 0) {
                 log_syntax(unit, LOG_ERR, filename, line, r,
-                           "IPv6 proxy NDP address can not be the ANY address, ignoring: %s", rvalue);
+                           "IPv6 proxy NDP address cannot be the ANY address, ignoring: %s", rvalue);
                 return 0;
         }
 
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 2dc3de3f6a..48da83c497 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -635,13 +635,13 @@ int config_parse_netdev(const char *unit,
         case NETDEV_KIND_VCAN:
                 r = hashmap_put(network->stacked_netdevs, netdev->ifname, netdev);
                 if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Can not add NetDev '%s' to network: %m", rvalue);
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Cannot add NetDev '%s' to network: %m", rvalue);
                         return 0;
                 }
 
                 break;
         default:
-                assert_not_reached("Can not parse NetDev");
+                assert_not_reached("Cannot parse NetDev");
         }
 
         netdev_ref(netdev);
@@ -894,12 +894,12 @@ int config_parse_ipv6token(
 
         r = in_addr_is_null(AF_INET6, &buffer);
         if (r != 0) {
-                log_syntax(unit, LOG_ERR, filename, line, r, "IPv6 token can not be the ANY address, ignoring: %s", rvalue);
+                log_syntax(unit, LOG_ERR, filename, line, r, "IPv6 token cannot be the ANY address, ignoring: %s", rvalue);
                 return 0;
         }
 
         if ((buffer.in6.s6_addr32[0] | buffer.in6.s6_addr32[1]) != 0) {
-                log_syntax(unit, LOG_ERR, filename, line, 0, "IPv6 token can not be longer than 64 bits, ignoring: %s", rvalue);
+                log_syntax(unit, LOG_ERR, filename, line, 0, "IPv6 token cannot be longer than 64 bits, ignoring: %s", rvalue);
                 return 0;
         }
 
diff --git a/src/shared/path-lookup.c b/src/shared/path-lookup.c
index d57c78a8b1..5f31831c99 100644
--- a/src/shared/path-lookup.c
+++ b/src/shared/path-lookup.c
@@ -169,6 +169,8 @@ int xdg_user_dirs(char ***ret_config_dirs, char ***ret_data_dirs) {
 static char** user_dirs(
                 const char *persistent_config,
                 const char *runtime_config,
+                const char *global_persistent_config,
+                const char *global_runtime_config,
                 const char *generator,
                 const char *generator_early,
                 const char *generator_late,
@@ -209,12 +211,19 @@ static char** user_dirs(
         if (strv_extend(&res, persistent_config) < 0)
                 return NULL;
 
+        /* global config has lower priority than the user config of the same type */
+        if (strv_extend(&res, global_persistent_config) < 0)
+                return NULL;
+
         if (strv_extend_strv(&res, (char**) user_config_unit_paths, false) < 0)
                 return NULL;
 
         if (strv_extend(&res, runtime_config) < 0)
                 return NULL;
 
+        if (strv_extend(&res, global_runtime_config) < 0)
+                return NULL;
+
         if (strv_extend(&res, generator) < 0)
                 return NULL;
 
@@ -411,11 +420,11 @@ static int acquire_control_dirs(UnitFileScope scope, char **persistent, char **r
         }
 
         case UNIT_FILE_USER:
-                r = xdg_user_config_dir(&a, "/systemd/system.control");
+                r = xdg_user_config_dir(&a, "/systemd/user.control");
                 if (r < 0 && r != -ENXIO)
                         return r;
 
-                r = xdg_user_runtime_dir(runtime, "/systemd/system.control");
+                r = xdg_user_runtime_dir(runtime, "/systemd/user.control");
                 if (r < 0) {
                         if (r != -ENXIO)
                                 return r;
@@ -484,6 +493,7 @@ int lookup_paths_init(
         _cleanup_free_ char
                 *root = NULL,
                 *persistent_config = NULL, *runtime_config = NULL,
+                *global_persistent_config = NULL, *global_runtime_config = NULL,
                 *generator = NULL, *generator_early = NULL, *generator_late = NULL,
                 *transient = NULL,
                 *persistent_control = NULL, *runtime_control = NULL;
@@ -522,6 +532,12 @@ int lookup_paths_init(
         if (r < 0)
                 return r;
 
+        if (scope == UNIT_FILE_USER) {
+                r = acquire_config_dirs(UNIT_FILE_GLOBAL, &global_persistent_config, &global_runtime_config);
+                if (r < 0)
+                        return r;
+        }
+
         if ((flags & LOOKUP_PATHS_EXCLUDE_GENERATED) == 0) {
                 /* Note: if XDG_RUNTIME_DIR is not set, this will fail completely with ENXIO */
                 r = acquire_generator_dirs(scope, tempdir,
@@ -610,20 +626,21 @@ int lookup_paths_init(
                                         runtime_config,
                                         "/run/systemd/user",
                                         STRV_IFNOTNULL(generator),
-                                        "/usr/local/lib/systemd/user",
                                         "/usr/local/share/systemd/user",
+                                        "/usr/share/systemd/user",
+                                        "/usr/local/lib/systemd/user",
                                         USER_DATA_UNIT_PATH,
                                         "/usr/lib/systemd/user",
-                                        "/usr/share/systemd/user",
                                         STRV_IFNOTNULL(generator_late),
                                         NULL);
                         break;
 
                 case UNIT_FILE_USER:
                         add = user_dirs(persistent_config, runtime_config,
+                                        global_persistent_config, global_runtime_config,
                                         generator, generator_early, generator_late,
                                         transient,
-                                        persistent_config, runtime_control);
+                                        persistent_control, runtime_control);
                         break;
 
                 default:
diff --git a/src/test/test-path-lookup.c b/src/test/test-path-lookup.c
index 834b061980..0541033d77 100644
--- a/src/test/test-path-lookup.c
+++ b/src/test/test-path-lookup.c
@@ -52,6 +52,36 @@ static void test_paths(UnitFileScope scope) {
         assert_se(rm_rf(template, REMOVE_ROOT|REMOVE_PHYSICAL) >= 0);
 }
 
+static void test_user_and_global_paths(void) {
+        _cleanup_lookup_paths_free_ LookupPaths lp_global = {}, lp_user = {};
+        char **u, **g, **p;
+        unsigned k = 0;
+
+        assert_se(unsetenv("SYSTEMD_UNIT_PATH") == 0);
+
+        assert_se(lookup_paths_init(&lp_global, UNIT_FILE_GLOBAL, 0, NULL) == 0);
+        assert_se(lookup_paths_init(&lp_user, UNIT_FILE_USER, 0, NULL) == 0);
+        g = lp_global.search_path;
+        u = lp_user.search_path;
+
+        /* Go over all entries in global search path, and verify
+         * that they also exist in the user search path. Skip any
+         * entries in user search path which don't exist in the global
+         * one, but not vice versa. */
+        log_info("/* %s */", __func__);
+        STRV_FOREACH(p, g) {
+                while (u[k] && !streq(*p, u[k])) {
+                        log_info("+ %s", u[k]);
+                        k++;
+                }
+                log_info("  %s", *p);
+                assert(u[k]); /* If NULL, we didn't find a matching entry */
+                k++;
+        }
+        STRV_FOREACH(p, u + k)
+                log_info("+ %s", *p);
+}
+
 static void print_generator_binary_paths(UnitFileScope scope) {
         _cleanup_strv_free_ char **paths;
         char **dir;
@@ -72,6 +102,8 @@ int main(int argc, char **argv) {
         test_paths(UNIT_FILE_USER);
         test_paths(UNIT_FILE_GLOBAL);
 
+        test_user_and_global_paths();
+
         print_generator_binary_paths(UNIT_FILE_SYSTEM);
         print_generator_binary_paths(UNIT_FILE_USER);
 
diff --git a/src/timedate/timedatectl.c b/src/timedate/timedatectl.c
index 19a382c1b2..d0a510468e 100644
--- a/src/timedate/timedatectl.c
+++ b/src/timedate/timedatectl.c
@@ -136,7 +136,7 @@ static void print_status_info(const StatusInfo *i) {
         if (i->rtc_local)
                 printf("\n%s"
                        "Warning: The system is configured to read the RTC time in the local time zone.\n"
-                       "         This mode can not be fully supported. It will create various problems\n"
+                       "         This mode cannot be fully supported. It will create various problems\n"
                        "         with time zone changes and daylight saving time adjustments. The RTC\n"
                        "         time is never updated, it relies on external facilities to maintain it.\n"
                        "         If at all possible, use RTC in UTC by calling\n"
diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c
index bea800171b..3d7cfd5be5 100644
--- a/src/timesync/timesyncd.c
+++ b/src/timesync/timesyncd.c
@@ -147,7 +147,7 @@ int main(int argc, char *argv[]) {
 
         if (clock_is_localtime(NULL) > 0) {
                 log_info("The system is configured to read the RTC time in the local time zone. "
-                         "This mode can not be fully supported. All system time to RTC updates are disabled.");
+                         "This mode cannot be fully supported. All system time to RTC updates are disabled.");
                 m->rtc_local_time = true;
         }
 
diff --git a/src/udev/cdrom_id/cdrom_id.c b/src/udev/cdrom_id/cdrom_id.c
index 9644861adc..5e7bebeb16 100644
--- a/src/udev/cdrom_id/cdrom_id.c
+++ b/src/udev/cdrom_id/cdrom_id.c
@@ -566,7 +566,7 @@ static int cd_profiles(struct udev *udev, int fd)
         log_debug("GET CONFIGURATION: size of features buffer 0x%04x", len);
 
         if (len > sizeof(features)) {
-                log_debug("can not get features in a single query, truncating");
+                log_debug("cannot get features in a single query, truncating");
                 len = sizeof(features);
         } else if (len <= 8)
                 len = sizeof(features);
@@ -588,7 +588,7 @@ static int cd_profiles(struct udev *udev, int fd)
         log_debug("GET CONFIGURATION: size of features buffer 0x%04x", len);
 
         if (len > sizeof(features)) {
-                log_debug("can not get features in a single query, truncating");
+                log_debug("cannot get features in a single query, truncating");
                 len = sizeof(features);
         }
 
diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c
index bb845889cc..6a3ee93ca2 100644
--- a/src/udev/udev-node.c
+++ b/src/udev/udev-node.c
@@ -265,7 +265,7 @@ static int node_permissions_apply(struct udev_device *dev, bool apply,
                 mode |= S_IFCHR;
 
         if (lstat(devnode, &stats) != 0) {
-                err = log_debug_errno(errno, "can not stat() node '%s' (%m)", devnode);
+                err = log_debug_errno(errno, "cannot stat() node '%s' (%m)", devnode);
                 goto out;
         }
 
diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 5c757d513f..615c4ed3e2 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -648,7 +648,7 @@ static bool is_devpath_busy(Manager *manager, struct event *event) {
 
         /* check if queue contains events we depend on */
         LIST_FOREACH(event, loop_event, manager->events) {
-                /* we already found a later event, earlier can not block us, no need to check again */
+                /* we already found a later event, earlier cannot block us, no need to check again */
                 if (loop_event->seqnum < event->delaying_seqnum)
                         continue;