base/SOURCES/0296-install-follow-unit-file-symlinks-in-usr-but-not-etc.patch

From 272378080241106862a9cca2e4e84857fe1aaf5c Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 8 Oct 2015 22:31:56 +0200
Subject: [PATCH] install: follow unit file symlinks in /usr, but not /etc when
 looking for [Install] data

Some distributions use alias unit files via symlinks in /usr to cover
for legacy service names. With this change we'll allow "systemctl
enable" on such aliases.

Previously, our rule was that symlinks are user configuration that
"systemctl enable" + "systemctl disable" creates and removes, while unit
files is where the instructions to do so are store. As a result of the
rule we'd never read install information through symlinks, since that
would mix enablement state with installation instructions.

Now, the new rule is that only symlinks inside of /etc are
configuration. Unit files, and symlinks in /usr are now valid for
installation instructions.

This patch is quite a rework of the whole install logic, and makes the
following addional changes:

- Adds a complete test "test-instal-root" that tests the install logic
  pretty comprehensively.

- Never uses canonicalize_file_name(), because that's incompatible with
  operation relative to a specific root directory.

- unit_file_get_state() is reworked to return a proper error, and
  returns the state in a call-by-ref parameter. This cleans up confusion
  between the enum type and errno-like errors.

- The new logic puts a limit on how long to follow unit file symlinks:
  it will do so only for 64 steps at max.

- The InstallContext object's fields are renamed to will_process and
  has_processed (will_install and has_installed) since they are also
  used for deinstallation and all kinds of other operations.

- The root directory is always verified before use.

- install.c is reordered to place the exported functions together.

- Stricter rules are followed when traversing symlinks: the unit suffix
  must say identical, and it's not allowed to link between regular units
  and templated units.

- Various modernizations

- The "invalid" unit file state has been renamed to "bad", in order to
  avoid confusion between UNIT_FILE_INVALID and
  _UNIT_FILE_STATE_INVALID. Given that the state should normally not be
  seen and is not documented this should not be a problematic change.
  The new name is now documented however.

Fixes #1375, #1718, #1706

Cherry-picked from: 79413b673b45adc98dfeaec882bbdda2343cb2f9
Resolves: #1159308
---
 Makefile.am                           |   12 +-
 man/systemctl.xml                     |   14 +-
 src/core/dbus-manager.c               |    6 +-
 src/core/dbus-unit.c                  |    4 +-
 src/core/load-fragment.c              |    2 +-
 src/core/manager.c                    |    2 +-
 src/core/snapshot.c                   |    2 +-
 src/core/unit.c                       |   19 +-
 src/dbus1-generator/dbus1-generator.c |    2 +-
 src/firstboot/firstboot.c             |   18 +-
 src/shared/cgroup-util.c              |    6 +-
 src/shared/install.c                  | 1909 +++++++++++++++++++--------------
 src/shared/install.h                  |   46 +-
 src/shared/path-util.c                |   34 +
 src/shared/path-util.h                |   27 +
 src/shared/unit-name.c                |   32 +-
 src/shared/unit-name.h                |   14 +-
 src/shared/util.c                     |   21 +
 src/shared/util.h                     |    1 +
 src/systemctl/systemctl.c             |    6 +-
 src/sysv-generator/sysv-generator.c   |   10 +-
 src/test/test-install-root.c          |  663 ++++++++++++
 src/test/test-install.c               |   71 +-
 23 files changed, 1998 insertions(+), 923 deletions(-)
 create mode 100644 src/test/test-install-root.c

diff --git a/Makefile.am b/Makefile.am
index 3af720bda..3a09e0a62 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1427,7 +1427,8 @@ tests += \
 	test-copy \
 	test-cap-list \
 	test-sigbus \
-	test-verbs
+	test-verbs \
+	test-install-root
 
 EXTRA_DIST += \
 	test/a.service \
@@ -1721,6 +1722,15 @@ test_verbs_SOURCES = \
 test_verbs_LDADD = \
 	libsystemd-shared.la
 
+test_install_root_SOURCES = \
+	src/test/test-install-root.c
+
+test_install_root_LDADD = \
+	libsystemd-units.la \
+	libsystemd-label.la \
+	libsystemd-internal.la \
+	libsystemd-shared.la
+
 test_namespace_LDADD = \
 	libsystemd-core.la
 
diff --git a/man/systemctl.xml b/man/systemctl.xml
index c6f584278..2d0678d18 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -905,10 +905,11 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
           <term><command>list-unit-files <optional><replaceable>PATTERN...</replaceable></optional></command></term>
 
           <listitem>
-            <para>List installed unit files. If one or more
-            <replaceable>PATTERN</replaceable>s are specified, only
-            units whose filename (just the last component of the path)
-            matches one of them are shown.</para>
+            <para>List installed unit files and their enablement state
+            (as reported by <command>is-enabled</command>). If one or
+            more <replaceable>PATTERN</replaceable>s are specified,
+            only units whose filename (just the last component of the
+            path) matches one of them are shown.</para>
           </listitem>
         </varlistentry>
 
@@ -1108,6 +1109,11 @@ kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
                     <entry>Unit file is not enabled.</entry>
                     <entry>1</entry>
                   </row>
+                  <row>
+                    <entry><literal>bad</literal></entry>
+                    <entry>Unit file is invalid or another error occured. Note that <command>is-enabled</command> wil not actually return this state, but print an error message instead. However the unit file listing printed by <command>list-unit-files</command> might show it.</entry>
+                    <entry>&gt; 0</entry>
+                  </row>
                 </tbody>
               </tgroup>
             </table>
diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 1ec350e03..faa124d92 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -1530,9 +1530,9 @@ static int method_get_unit_file_state(sd_bus *bus, sd_bus_message *message, void
 
         scope = m->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER;
 
-        state = unit_file_get_state(scope, NULL, name);
-        if (state < 0)
-                return state;
+        r = unit_file_get_state(scope, NULL, name, &state);
+        if (r < 0)
+                return r;
 
         return sd_bus_reply_method_return(message, "s", unit_file_state_to_string(state));
 }
diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 625d21ab8..227915efc 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -919,7 +919,7 @@ static int bus_unit_set_transient_property(
                 if (r < 0)
                         return r;
 
-                if (!unit_name_is_valid(s, TEMPLATE_INVALID) || !endswith(s, ".slice"))
+                if (!unit_name_is_valid(s, UNIT_NAME_PLAIN) || !endswith(s, ".slice"))
                         return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid slice name %s", s);
 
                 if (isempty(s)) {
@@ -967,7 +967,7 @@ static int bus_unit_set_transient_property(
                         return r;
 
                 while ((r = sd_bus_message_read(message, "s", &other)) > 0) {
-                        if (!unit_name_is_valid(other, TEMPLATE_INVALID))
+                        if (!unit_name_is_valid(other, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
                                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid unit name %s", other);
 
                         if (mode != UNIT_CHECK) {
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index ec4cf4eef..70c09188a 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -3409,7 +3409,7 @@ static int open_follow(char **filename, FILE **_f, Set *names, char **_final) {
                  * unit name. */
                 name = basename(*filename);
 
-                if (unit_name_is_valid(name, TEMPLATE_VALID)) {
+                if (unit_name_is_valid(name, UNIT_NAME_ANY)) {
 
                         id = set_get(names, name);
                         if (!id) {
diff --git a/src/core/manager.c b/src/core/manager.c
index 7483a96ec..bde17ce0b 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1328,7 +1328,7 @@ int manager_load_unit_prepare(
 
         t = unit_name_to_type(name);
 
-        if (t == _UNIT_TYPE_INVALID || !unit_name_is_valid(name, TEMPLATE_INVALID))
+        if (t == _UNIT_TYPE_INVALID || !unit_name_is_valid(name, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
                 return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Unit name %s is not valid.", name);
 
         ret = manager_get_unit(m, name);
diff --git a/src/core/snapshot.c b/src/core/snapshot.c
index b1d844877..f222ec232 100644
--- a/src/core/snapshot.c
+++ b/src/core/snapshot.c
@@ -201,7 +201,7 @@ int snapshot_create(Manager *m, const char *name, bool cleanup, sd_bus_error *e,
         assert(_s);
 
         if (name) {
-                if (!unit_name_is_valid(name, TEMPLATE_INVALID))
+                if (!unit_name_is_valid(name, UNIT_NAME_PLAIN))
                         return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Unit name %s is not valid.", name);
 
                 if (unit_name_to_type(name) != UNIT_SNAPSHOT)
diff --git a/src/core/unit.c b/src/core/unit.c
index 4fb2fd300..db5aa987e 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -158,7 +158,7 @@ int unit_add_name(Unit *u, const char *text) {
         if (!s)
                 return -ENOMEM;
 
-        if (!unit_name_is_valid(s, TEMPLATE_INVALID))
+        if (!unit_name_is_valid(s, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
                 return -EINVAL;
 
         assert_se((t = unit_name_to_type(s)) >= 0);
@@ -3119,12 +3119,18 @@ int unit_following_set(Unit *u, Set **s) {
 }
 
 UnitFileState unit_get_unit_file_state(Unit *u) {
+        int r;
+
         assert(u);
 
-        if (u->unit_file_state < 0 && u->fragment_path)
-                u->unit_file_state = unit_file_get_state(
-                                u->manager->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER,
-                                NULL, basename(u->fragment_path));
+        if (u->unit_file_state < 0 && u->fragment_path) {
+                r = unit_file_get_state(u->manager->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER,
+                                        NULL,
+                                        basename(u->fragment_path),
+                                        &u->unit_file_state);
+                if (r < 0)
+                        u->unit_file_state = UNIT_FILE_BAD;
+        }
 
         return u->unit_file_state;
 }
@@ -3135,7 +3141,8 @@ int unit_get_unit_file_preset(Unit *u) {
         if (u->unit_file_preset < 0 && u->fragment_path)
                 u->unit_file_preset = unit_file_query_preset(
                                 u->manager->running_as == SYSTEMD_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER,
-                                NULL, basename(u->fragment_path));
+                                NULL,
+                                basename(u->fragment_path));
 
         return u->unit_file_preset;
 }
diff --git a/src/dbus1-generator/dbus1-generator.c b/src/dbus1-generator/dbus1-generator.c
index 2e08af2df..c909a4b1d 100644
--- a/src/dbus1-generator/dbus1-generator.c
+++ b/src/dbus1-generator/dbus1-generator.c
@@ -188,7 +188,7 @@ static int add_dbus(const char *path, const char *fname, const char *type) {
         }
 
         if (service) {
-                if (!unit_name_is_valid(service, TEMPLATE_INVALID)) {
+                if (!unit_name_is_valid(service, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE)) {
                         log_warning("Unit name %s is not valid, ignoring.", service);
                         return 0;
                 }
diff --git a/src/firstboot/firstboot.c b/src/firstboot/firstboot.c
index a37ca170f..b77c1d887 100644
--- a/src/firstboot/firstboot.c
+++ b/src/firstboot/firstboot.c
@@ -50,8 +50,6 @@ static bool arg_copy_locale = false;
 static bool arg_copy_timezone = false;
 static bool arg_copy_root_password = false;
 
-#define prefix_roota(p) (arg_root ? (const char*) strjoina(arg_root, p) : (const char*) p)
-
 static void clear_string(char *x) {
 
         if (!x)
@@ -85,13 +83,13 @@ static void print_welcome(void) {
         if (done)
                 return;
 
-        os_release = prefix_roota("/etc/os-release");
+        os_release = prefix_roota(arg_root, "/etc/os-release");
         r = parse_env_file(os_release, NEWLINE,
                            "PRETTY_NAME", &pretty_name,
                            NULL);
         if (r == -ENOENT) {
 
-                os_release = prefix_roota("/usr/lib/os-release");
+                os_release = prefix_roota(arg_root, "/usr/lib/os-release");
                 r = parse_env_file(os_release, NEWLINE,
                                    "PRETTY_NAME", &pretty_name,
                                    NULL);
@@ -249,7 +247,7 @@ static int process_locale(void) {
         unsigned i = 0;
         int r;
 
-        etc_localeconf = prefix_roota("/etc/locale.conf");
+        etc_localeconf = prefix_roota(arg_root, "/etc/locale.conf");
         if (faccessat(AT_FDCWD, etc_localeconf, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
                 return 0;
 
@@ -323,7 +321,7 @@ static int process_timezone(void) {
         const char *etc_localtime, *e;
         int r;
 
-        etc_localtime = prefix_roota("/etc/localtime");
+        etc_localtime = prefix_roota(arg_root, "/etc/localtime");
         if (faccessat(AT_FDCWD, etc_localtime, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
                 return 0;
 
@@ -402,7 +400,7 @@ static int process_hostname(void) {
         const char *etc_hostname;
         int r;
 
-        etc_hostname = prefix_roota("/etc/hostname");
+        etc_hostname = prefix_roota(arg_root, "/etc/hostname");
         if (faccessat(AT_FDCWD, etc_hostname, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
                 return 0;
 
@@ -427,7 +425,7 @@ static int process_machine_id(void) {
         char id[SD_ID128_STRING_MAX];
         int r;
 
-        etc_machine_id = prefix_roota("/etc/machine-id");
+        etc_machine_id = prefix_roota(arg_root, "/etc/machine-id");
         if (faccessat(AT_FDCWD, etc_machine_id, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
                 return 0;
 
@@ -453,7 +451,7 @@ static int prompt_root_password(void) {
         if (!arg_prompt_root_password)
                 return 0;
 
-        etc_shadow = prefix_roota("/etc/shadow");
+        etc_shadow = prefix_roota(arg_root, "/etc/shadow");
         if (faccessat(AT_FDCWD, etc_shadow, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
                 return 0;
 
@@ -542,7 +540,7 @@ static int process_root_password(void) {
         const char *etc_shadow;
         int r;
 
-        etc_shadow = prefix_roota("/etc/shadow");
+        etc_shadow = prefix_roota(arg_root, "/etc/shadow");
         if (faccessat(AT_FDCWD, etc_shadow, F_OK, AT_SYMLINK_NOFOLLOW) >= 0)
                 return 0;
 
diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index dfd8689b7..cf757d2b2 100644
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -1147,7 +1147,7 @@ int cg_path_decode_unit(const char *cgroup, char **unit){
         c = strndupa(cgroup, e - cgroup);
         c = cg_unescape(c);
 
-        if (!unit_name_is_valid(c, TEMPLATE_INVALID))
+        if (!unit_name_is_valid(c, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
                 return -EINVAL;
 
         s = strdup(c);
@@ -1536,7 +1536,7 @@ int cg_slice_to_path(const char *unit, char **ret) {
         assert(unit);
         assert(ret);
 
-        if (!unit_name_is_valid(unit, TEMPLATE_INVALID))
+        if (!unit_name_is_valid(unit, UNIT_NAME_PLAIN))
                 return -EINVAL;
 
         if (!endswith(unit, ".slice"))
@@ -1553,7 +1553,7 @@ int cg_slice_to_path(const char *unit, char **ret) {
 
                 strcpy(stpncpy(n, p, dash - p), ".slice");
 
-                if (!unit_name_is_valid(n, TEMPLATE_INVALID))
+                if (!unit_name_is_valid(n, UNIT_NAME_PLAIN))
                         return -EINVAL;
 
                 escaped = cg_escape(n);
diff --git a/src/shared/install.c b/src/shared/install.c
index aa197e91b..5288bb450 100644
--- a/src/shared/install.c
+++ b/src/shared/install.c
@@ -39,15 +39,24 @@
 #include "specifier.h"
 #include "install-printf.h"
 #include "special.h"
+#include "fileio.h"
+
+#define UNIT_FILE_FOLLOW_SYMLINK_MAX 64
+
+typedef enum SearchFlags {
+        SEARCH_LOAD = 1,
+        SEARCH_FOLLOW_CONFIG_SYMLINKS = 2,
+} SearchFlags;
 
 typedef struct {
-        OrderedHashmap *will_install;
-        OrderedHashmap *have_installed;
+        OrderedHashmap *will_process;
+        OrderedHashmap *have_processed;
 } InstallContext;
 
 static int in_search_path(const char *path, char **search) {
         _cleanup_free_ char *parent = NULL;
         int r;
+        char **i;
 
         assert(path);
 
@@ -55,7 +64,11 @@ static int in_search_path(const char *path, char **search) {
         if (r < 0)
                 return r;
 
-        return strv_contains(search, parent);
+        STRV_FOREACH(i, search)
+                if (path_equal(parent, *i))
+                        return true;
+
+        return false;
 }
 
 static int get_config_path(UnitFileScope scope, bool runtime, const char *root_dir, char **ret) {
@@ -66,6 +79,9 @@ static int get_config_path(UnitFileScope scope, bool runtime, const char *root_d
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(ret);
 
+        /* This determines where we shall create or remove our
+         * installation ("configuration") symlinks */
+
         switch (scope) {
 
         case UNIT_FILE_SYSTEM:
@@ -113,6 +129,186 @@ static int get_config_path(UnitFileScope scope, bool runtime, const char *root_d
         return 0;
 }
 
+static bool is_config_path(UnitFileScope scope, const char *path) {
+        int r;
+
+        assert(scope >= 0);
+        assert(scope < _UNIT_FILE_SCOPE_MAX);
+        assert(path);
+
+        /* Checks whether the specified path is intended for
+         * configuration or is outside of it */
+
+        switch (scope) {
+
+        case UNIT_FILE_SYSTEM:
+        case UNIT_FILE_GLOBAL:
+                return path_startswith(path, "/etc") ||
+                        path_startswith(path, SYSTEM_CONFIG_UNIT_PATH) ||
+                        path_startswith(path, "/run");
+
+
+        case UNIT_FILE_USER: {
+                _cleanup_free_ char *p = NULL;
+
+                r = user_config_home(&p);
+                if (r < 0)
+                        return r;
+                if (r > 0 && path_startswith(path, p))
+                        return true;
+
+                free(p);
+                p = NULL;
+
+                r = user_runtime_dir(&p);
+                if (r < 0)
+                        return r;
+                if (r > 0 && path_startswith(path, p))
+                        return true;
+
+                return false;
+        }
+
+        default:
+                assert_not_reached("Bad scope");
+        }
+}
+
+
+static int verify_root_dir(UnitFileScope scope, const char **root_dir) {
+        int r;
+
+        assert(root_dir);
+
+        /* Verifies that the specified root directory to operate on
+         * makes sense. Reset it to NULL if it is the root directory
+         * or set to empty */
+
+        if (isempty(*root_dir) || path_equal(*root_dir, "/")) {
+                *root_dir = NULL;
+                return 0;
+        }
+
+        if (scope != UNIT_FILE_SYSTEM)
+                return -EINVAL;
+
+        r = is_dir(*root_dir, true);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return -ENOTDIR;
+
+        return 0;
+}
+
+int unit_file_changes_add(
+                UnitFileChange **changes,
+                unsigned *n_changes,
+                UnitFileChangeType type,
+                const char *path,
+                const char *source) {
+
+        UnitFileChange *c;
+        unsigned i;
+
+        assert(path);
+        assert(!changes == !n_changes);
+
+        if (!changes)
+                return 0;
+
+        c = realloc(*changes, (*n_changes + 1) * sizeof(UnitFileChange));
+        if (!c)
+                return -ENOMEM;
+
+        *changes = c;
+        i = *n_changes;
+
+        c[i].type = type;
+        c[i].path = strdup(path);
+        if (!c[i].path)
+                return -ENOMEM;
+
+        path_kill_slashes(c[i].path);
+
+        if (source) {
+                c[i].source = strdup(source);
+                if (!c[i].source) {
+                        free(c[i].path);
+                        return -ENOMEM;
+                }
+
+                path_kill_slashes(c[i].path);
+        } else
+                c[i].source = NULL;
+
+        *n_changes = i+1;
+        return 0;
+}
+
+void unit_file_changes_free(UnitFileChange *changes, unsigned n_changes) {
+        unsigned i;
+
+        assert(changes || n_changes == 0);
+
+        if (!changes)
+                return;
+
+        for (i = 0; i < n_changes; i++) {
+                free(changes[i].path);
+                free(changes[i].source);
+        }
+
+        free(changes);
+}
+
+static int create_symlink(
+                const char *old_path,
+                const char *new_path,
+                bool force,
+                UnitFileChange **changes,
+                unsigned *n_changes) {
+
+        _cleanup_free_ char *dest = NULL;
+        int r;
+
+        assert(old_path);
+        assert(new_path);
+
+        /* Actually create a symlink, and remember that we did. Is
+         * smart enough to check if there's already a valid symlink in
+         * place. */
+
+        mkdir_parents_label(new_path, 0755);
+
+        if (symlink(old_path, new_path) >= 0) {
+                unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, new_path, old_path);
+                return 0;
+        }
+
+        if (errno != EEXIST)
+                return -errno;
+
+        r = readlink_malloc(new_path, &dest);
+        if (r < 0)
+                return r;
+
+        if (path_equal(dest, old_path))
+                return 0;
+
+        if (!force)
+                return -EEXIST;
+
+        r = symlink_atomic(old_path, new_path);
+        if (r < 0)
+                return r;
+
+        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, new_path, NULL);
+        unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, new_path, old_path);
+
+        return 0;
+}
+
 static int mark_symlink_for_removal(
                 Set **remove_symlinks_to,
                 const char *p) {
@@ -136,7 +332,7 @@ static int mark_symlink_for_removal(
         if (r < 0)
                 return r == -EEXIST ? 0 : r;
 
-        return 0;
+        return 1;
 }
 
 static int remove_marked_symlinks_fd(
@@ -144,10 +340,9 @@ static int remove_marked_symlinks_fd(
                 int fd,
                 const char *path,
                 const char *config_path,
-                bool *deleted,
+                bool *restart,
                 UnitFileChange **changes,
-                unsigned *n_changes,
-                char** instance_whitelist) {
+                unsigned *n_changes) {
 
         _cleanup_closedir_ DIR *d = NULL;
         int r = 0;
@@ -156,7 +351,7 @@ static int remove_marked_symlinks_fd(
         assert(fd >= 0);
         assert(path);
         assert(config_path);
-        assert(deleted);
+        assert(restart);
 
         d = fdopendir(fd);
         if (!d) {
@@ -205,42 +400,23 @@ static int remove_marked_symlinks_fd(
                         }
 
                         /* This will close nfd, regardless whether it succeeds or not */
-                        q = remove_marked_symlinks_fd(remove_symlinks_to, nfd, p, config_path, deleted, changes, n_changes, instance_whitelist);
+                        q = remove_marked_symlinks_fd(remove_symlinks_to, nfd, p, config_path, restart, changes, n_changes);
                         if (q < 0 && r == 0)
                                 r = q;
 
                 } else if (de->d_type == DT_LNK) {
                         _cleanup_free_ char *p = NULL, *dest = NULL;
-                        int q;
                         bool found;
+                        int q;
 
-                        if (!unit_name_is_valid(de->d_name, TEMPLATE_VALID))
+                        if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
                                 continue;
 
-                        if (unit_name_is_instance(de->d_name) &&
-                            instance_whitelist &&
-                            !strv_contains(instance_whitelist, de->d_name)) {
-
-                                _cleanup_free_ char *w;
-
-                                /* OK, the file is not listed directly
-                                 * in the whitelist, so let's check if
-                                 * the template of it might be
-                                 * listed. */
-
-                                w = unit_name_template(de->d_name);
-                                if (!w)
-                                        return -ENOMEM;
-
-                                if (!strv_contains(instance_whitelist, w))
-                                        continue;
-                        }
-
                         p = path_make_absolute(de->d_name, path);
                         if (!p)
                                 return -ENOMEM;
 
-                        q = readlink_and_canonicalize(p, &dest);
+                        q = readlink_malloc(p, &dest);
                         if (q < 0) {
                                 if (q == -ENOENT)
                                         continue;
@@ -250,9 +426,15 @@ static int remove_marked_symlinks_fd(
                                 continue;
                         }
 
+                        /* We remove all links pointing to a file or
+                         * path that is marked, as well as all files
+                         * sharing the same name as a file that is
+                         * marked. */
+
                         found =
-                                set_get(remove_symlinks_to, dest) ||
-                                set_get(remove_symlinks_to, basename(dest));
+                                set_contains(remove_symlinks_to, dest) ||
+                                set_contains(remove_symlinks_to, basename(dest)) ||
+                                set_contains(remove_symlinks_to, de->d_name);
 
                         if (!found)
                                 continue;
@@ -264,18 +446,15 @@ static int remove_marked_symlinks_fd(
                         }
 
                         path_kill_slashes(p);
-                        rmdir_parents(p, config_path);
-                        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, p, NULL);
+                        (void) rmdir_parents(p, config_path);
 
-                        if (!set_get(remove_symlinks_to, p)) {
+                        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, p, NULL);
 
-                                q = mark_symlink_for_removal(&remove_symlinks_to, p);
-                                if (q < 0) {
-                                        if (r == 0)
-                                                r = q;
-                                } else
-                                        *deleted = true;
-                        }
+                        q = mark_symlink_for_removal(&remove_symlinks_to, p);
+                        if (q < 0)
+                                return q;
+                        if (q > 0)
+                                *restart = true;
                 }
         }
 
@@ -286,12 +465,11 @@ static int remove_marked_symlinks(
                 Set *remove_symlinks_to,
                 const char *config_path,
                 UnitFileChange **changes,
-                unsigned *n_changes,
-                char** instance_whitelist) {
+                unsigned *n_changes) {
 
         _cleanup_close_ int fd = -1;
         int r = 0;
-        bool deleted;
+        bool restart;
 
         assert(config_path);
 
@@ -304,7 +482,7 @@ static int remove_marked_symlinks(
 
         do {
                 int q, cfd;
-                deleted = false;
+                restart = false;
 
                 cfd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
                 if (cfd < 0) {
@@ -313,15 +491,16 @@ static int remove_marked_symlinks(
                 }
 
                 /* This takes possession of cfd and closes it */
-                q = remove_marked_symlinks_fd(remove_symlinks_to, cfd, config_path, config_path, &deleted, changes, n_changes, instance_whitelist);
+                q = remove_marked_symlinks_fd(remove_symlinks_to, cfd, config_path, config_path, &restart, changes, n_changes);
                 if (r == 0)
                         r = q;
-        } while (deleted);
+        } while (restart);
 
         return r;
 }
 
 static int find_symlinks_fd(
+                const char *root_dir,
                 const char *name,
                 int fd,
                 const char *path,
@@ -380,7 +559,7 @@ static int find_symlinks_fd(
                         }
 
                         /* This will close nfd, regardless whether it succeeds or not */
-                        q = find_symlinks_fd(name, nfd, p, config_path, same_name_link);
+                        q = find_symlinks_fd(root_dir, name, nfd, p, config_path, same_name_link);
                         if (q > 0)
                                 return 1;
                         if (r == 0)
@@ -397,7 +576,7 @@ static int find_symlinks_fd(
                                 return -ENOMEM;
 
                         /* Acquire symlink destination */
-                        q = readlink_and_canonicalize(p, &dest);
+                        q = readlink_malloc(p, &dest);
                         if (q < 0) {
                                 if (q == -ENOENT)
                                         continue;
@@ -407,6 +586,18 @@ static int find_symlinks_fd(
                                 continue;
                         }
 
+                        /* Make absolute */
+                        if (!path_is_absolute(dest)) {
+                                char *x;
+
+                                x = prefix_root(root_dir, dest);
+                                if (!x)
+                                        return -ENOMEM;
+
+                                free(dest);
+                                dest = x;
+                        }
+
                         /* Check if the symlink itself matches what we
                          * are looking for */
                         if (path_is_absolute(name))
@@ -442,6 +633,7 @@ static int find_symlinks_fd(
 }
 
 static int find_symlinks(
+                const char *root_dir,
                 const char *name,
                 const char *config_path,
                 bool *same_name_link) {
@@ -460,7 +652,7 @@ static int find_symlinks(
         }
 
         /* This takes possession of fd and closes it */
-        return find_symlinks_fd(name, fd, config_path, config_path, same_name_link);
+        return find_symlinks_fd(root_dir, name, fd, config_path, config_path, same_name_link);
 }
 
 static int find_symlinks_in_scope(
@@ -469,385 +661,104 @@ static int find_symlinks_in_scope(
                 const char *name,
                 UnitFileState *state) {
 
-        int r;
         _cleanup_free_ char *normal_path = NULL, *runtime_path = NULL;
         bool same_name_link_runtime = false, same_name_link = false;
+        int r;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(name);
 
-        /* First look in runtime config path */
-        r = get_config_path(scope, true, root_dir, &normal_path);
+        /* First look in the normal config path */
+        r = get_config_path(scope, false, root_dir, &normal_path);
         if (r < 0)
                 return r;
 
-        r = find_symlinks(name, normal_path, &same_name_link_runtime);
+        r = find_symlinks(root_dir, name, normal_path, &same_name_link);
         if (r < 0)
                 return r;
-        else if (r > 0) {
-                *state = UNIT_FILE_ENABLED_RUNTIME;
+        if (r > 0) {
+                *state = UNIT_FILE_ENABLED;
                 return r;
         }
 
-        /* Then look in the normal config path */
-        r = get_config_path(scope, false, root_dir, &runtime_path);
+        /* Then look in runtime config path */
+        r = get_config_path(scope, true, root_dir, &runtime_path);
         if (r < 0)
                 return r;
 
-        r = find_symlinks(name, runtime_path, &same_name_link);
+        r = find_symlinks(root_dir, name, runtime_path, &same_name_link_runtime);
         if (r < 0)
                 return r;
-        else if (r > 0) {
-                *state = UNIT_FILE_ENABLED;
+        if (r > 0) {
+                *state = UNIT_FILE_ENABLED_RUNTIME;
                 return r;
         }
 
         /* Hmm, we didn't find it, but maybe we found the same name
          * link? */
+        if (same_name_link) {
+                *state = UNIT_FILE_LINKED;
+                return 1;
+        }
         if (same_name_link_runtime) {
                 *state = UNIT_FILE_LINKED_RUNTIME;
                 return 1;
-        } else if (same_name_link) {
-                *state = UNIT_FILE_LINKED;
-                return 1;
         }
 
         return 0;
 }
 
-int unit_file_mask(
-                UnitFileScope scope,
-                bool runtime,
-                const char *root_dir,
-                char **files,
-                bool force,
-                UnitFileChange **changes,
-                unsigned *n_changes) {
-
-        char **i;
-        _cleanup_free_ char *prefix = NULL;
-        int r;
+static void install_info_free(InstallInfo *i) {
 
-        assert(scope >= 0);
-        assert(scope < _UNIT_FILE_SCOPE_MAX);
+        if (!i)
+                return;
 
-        r = get_config_path(scope, runtime, root_dir, &prefix);
-        if (r < 0)
-                return r;
+        free(i->name);
+        free(i->path);
+        strv_free(i->aliases);
+        strv_free(i->wanted_by);
+        strv_free(i->required_by);
+        strv_free(i->also);
+        free(i->default_instance);
+        free(i->symlink_target);
+        free(i);
+}
 
-        STRV_FOREACH(i, files) {
-                _cleanup_free_ char *path = NULL;
+static OrderedHashmap* install_info_hashmap_free(OrderedHashmap *m) {
+        InstallInfo *i;
 
-                if (!unit_name_is_valid(*i, TEMPLATE_VALID)) {
-                        if (r == 0)
-                                r = -EINVAL;
-                        continue;
-                }
+        while ((i = ordered_hashmap_steal_first(m)))
+                install_info_free(i);
 
-                path = path_make_absolute(*i, prefix);
-                if (!path) {
-                        r = -ENOMEM;
-                        break;
-                }
+        ordered_hashmap_free(m);
 
-                if (symlink("/dev/null", path) >= 0) {
-                        unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, path, "/dev/null");
-                        continue;
-                }
+        return NULL;
+}
 
-                if (errno == EEXIST) {
+static void install_context_done(InstallContext *c) {
+        assert(c);
 
-                        if (null_or_empty_path(path) > 0)
-                                continue;
+        c->will_process = install_info_hashmap_free(c->will_process);
+        c->have_processed = install_info_hashmap_free(c->have_processed);
+}
 
-                        if (force) {
-                                if (symlink_atomic("/dev/null", path) >= 0) {
-                                        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, path, NULL);
-                                        unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, path, "/dev/null");
-                                        continue;
-                                }
-                        }
+static InstallInfo *install_info_find(InstallContext *c, const char *name) {
+        InstallInfo *i;
 
-                        if (r == 0)
-                                r = -EEXIST;
-                } else {
-                        if (r == 0)
-                                r = -errno;
-                }
-        }
+        i = ordered_hashmap_get(c->have_processed, name);
+        if (i)
+                return i;
 
-        return r;
-}
-
-int unit_file_unmask(
-                UnitFileScope scope,
-                bool runtime,
-                const char *root_dir,
-                char **files,
-                UnitFileChange **changes,
-                unsigned *n_changes) {
-
-        char **i, *config_path = NULL;
-        int r, q;
-        Set *remove_symlinks_to = NULL;
-
-        assert(scope >= 0);
-        assert(scope < _UNIT_FILE_SCOPE_MAX);
-
-        r = get_config_path(scope, runtime, root_dir, &config_path);
-        if (r < 0)
-                goto finish;
-
-        STRV_FOREACH(i, files) {
-                _cleanup_free_ char *path = NULL;
-
-                if (!unit_name_is_valid(*i, TEMPLATE_VALID)) {
-                        if (r == 0)
-                                r = -EINVAL;
-                        continue;
-                }
-
-                path = path_make_absolute(*i, config_path);
-                if (!path) {
-                        r = -ENOMEM;
-                        break;
-                }
-
-                q = null_or_empty_path(path);
-                if (q > 0) {
-                        if (unlink(path) < 0)
-                                q = -errno;
-                        else {
-                                q = mark_symlink_for_removal(&remove_symlinks_to, path);
-                                unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, path, NULL);
-                        }
-                }
-
-                if (q != -ENOENT && r == 0)
-                        r = q;
-        }
-
-
-finish:
-        q = remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes, files);
-        if (r == 0)
-                r = q;
-
-        set_free_free(remove_symlinks_to);
-        free(config_path);
-
-        return r;
-}
-
-int unit_file_link(
-                UnitFileScope scope,
-                bool runtime,
-                const char *root_dir,
-                char **files,
-                bool force,
-                UnitFileChange **changes,
-                unsigned *n_changes) {
-
-        _cleanup_lookup_paths_free_ LookupPaths paths = {};
-        char **i;
-        _cleanup_free_ char *config_path = NULL;
-        int r, q;
-
-        assert(scope >= 0);
-        assert(scope < _UNIT_FILE_SCOPE_MAX);
-
-        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
-        if (r < 0)
-                return r;
-
-        r = get_config_path(scope, runtime, root_dir, &config_path);
-        if (r < 0)
-                return r;
-
-        STRV_FOREACH(i, files) {
-                _cleanup_free_ char *path = NULL;
-                char *fn;
-                struct stat st;
-
-                fn = basename(*i);
-
-                if (!path_is_absolute(*i) ||
-                    !unit_name_is_valid(fn, TEMPLATE_VALID)) {
-                        if (r == 0)
-                                r = -EINVAL;
-                        continue;
-                }
-
-                if (lstat(*i, &st) < 0) {
-                        if (r == 0)
-                                r = -errno;
-                        continue;
-                }
-
-                if (!S_ISREG(st.st_mode)) {
-                        r = -ENOENT;
-                        continue;
-                }
-
-                q = in_search_path(*i, paths.unit_path);
-                if (q < 0)
-                        return q;
-
-                if (q > 0)
-                        continue;
-
-                path = path_make_absolute(fn, config_path);
-                if (!path)
-                        return -ENOMEM;
-
-                if (symlink(*i, path) >= 0) {
-                        unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, path, *i);
-                        continue;
-                }
-
-                if (errno == EEXIST) {
-                        _cleanup_free_ char *dest = NULL;
-
-                        q = readlink_and_make_absolute(path, &dest);
-                        if (q < 0 && errno != ENOENT) {
-                                if (r == 0)
-                                        r = q;
-                                continue;
-                        }
-
-                        if (q >= 0 && path_equal(dest, *i))
-                                continue;
-
-                        if (force) {
-                                if (symlink_atomic(*i, path) >= 0) {
-                                        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, path, NULL);
-                                        unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, path, *i);
-                                        continue;
-                                }
-                        }
-
-                        if (r == 0)
-                                r = -EEXIST;
-                } else {
-                        if (r == 0)
-                                r = -errno;
-                }
-        }
-
-        return r;
-}
-
-void unit_file_list_free(Hashmap *h) {
-        UnitFileList *i;
-
-        while ((i = hashmap_steal_first(h))) {
-                free(i->path);
-                free(i);
-        }
-
-        hashmap_free(h);
-}
-
-int unit_file_changes_add(
-                UnitFileChange **changes,
-                unsigned *n_changes,
-                UnitFileChangeType type,
-                const char *path,
-                const char *source) {
-
-        UnitFileChange *c;
-        unsigned i;
-
-        assert(path);
-        assert(!changes == !n_changes);
-
-        if (!changes)
-                return 0;
-
-        c = realloc(*changes, (*n_changes + 1) * sizeof(UnitFileChange));
-        if (!c)
-                return -ENOMEM;
-
-        *changes = c;
-        i = *n_changes;
-
-        c[i].type = type;
-        c[i].path = strdup(path);
-        if (!c[i].path)
-                return -ENOMEM;
-
-        path_kill_slashes(c[i].path);
-
-        if (source) {
-                c[i].source = strdup(source);
-                if (!c[i].source) {
-                        free(c[i].path);
-                        return -ENOMEM;
-                }
-
-                path_kill_slashes(c[i].path);
-        } else
-                c[i].source = NULL;
-
-        *n_changes = i+1;
-        return 0;
-}
-
-void unit_file_changes_free(UnitFileChange *changes, unsigned n_changes) {
-        unsigned i;
-
-        assert(changes || n_changes == 0);
-
-        if (!changes)
-                return;
-
-        for (i = 0; i < n_changes; i++) {
-                free(changes[i].path);
-                free(changes[i].source);
-        }
-
-        free(changes);
-}
-
-static void install_info_free(InstallInfo *i) {
-        assert(i);
-
-        free(i->name);
-        free(i->path);
-        strv_free(i->aliases);
-        strv_free(i->wanted_by);
-        strv_free(i->required_by);
-        strv_free(i->also);
-        free(i->default_instance);
-        free(i);
-}
-
-static void install_info_hashmap_free(OrderedHashmap *m) {
-        InstallInfo *i;
-
-        if (!m)
-                return;
-
-        while ((i = ordered_hashmap_steal_first(m)))
-                install_info_free(i);
-
-        ordered_hashmap_free(m);
-}
-
-static void install_context_done(InstallContext *c) {
-        assert(c);
-
-        install_info_hashmap_free(c->will_install);
-        install_info_hashmap_free(c->have_installed);
-
-        c->will_install = c->have_installed = NULL;
+        return ordered_hashmap_get(c->will_process, name);
 }
 
 static int install_info_add(
                 InstallContext *c,
                 const char *name,
-                const char *path) {
+                const char *path,
+                InstallInfo **ret) {
+
         InstallInfo *i = NULL;
         int r;
 
@@ -857,20 +768,24 @@ static int install_info_add(
         if (!name)
                 name = basename(path);
 
-        if (!unit_name_is_valid(name, TEMPLATE_VALID))
+        if (!unit_name_is_valid(name, UNIT_NAME_ANY))
                 return -EINVAL;
 
-        if (ordered_hashmap_get(c->have_installed, name) ||
-            ordered_hashmap_get(c->will_install, name))
+        i = install_info_find(c, name);
+        if (i) {
+                if (ret)
+                        *ret = i;
                 return 0;
+        }
 
-        r = ordered_hashmap_ensure_allocated(&c->will_install, &string_hash_ops);
+        r = ordered_hashmap_ensure_allocated(&c->will_process, &string_hash_ops);
         if (r < 0)
                 return r;
 
         i = new0(InstallInfo, 1);
         if (!i)
                 return -ENOMEM;
+        i->type = _UNIT_FILE_TYPE_INVALID;
 
         i->name = strdup(name);
         if (!i->name) {
@@ -886,10 +801,13 @@ static int install_info_add(
                 }
         }
 
-        r = ordered_hashmap_put(c->will_install, i->name, i);
+        r = ordered_hashmap_put(c->will_process, i->name, i);
         if (r < 0)
                 goto fail;
 
+        if (ret)
+                *ret = i;
+
         return 0;
 
 fail:
@@ -901,15 +819,16 @@ fail:
 
 static int install_info_add_auto(
                 InstallContext *c,
-                const char *name_or_path) {
+                const char *name_or_path,
+                InstallInfo **ret) {
 
         assert(c);
         assert(name_or_path);
 
         if (path_is_absolute(name_or_path))
-                return install_info_add(c, NULL, name_or_path);
+                return install_info_add(c, NULL, name_or_path, ret);
         else
-                return install_info_add(c, name_or_path, NULL);
+                return install_info_add(c, name_or_path, NULL, ret);
 }
 
 static int config_parse_also(
@@ -928,6 +847,7 @@ static int config_parse_also(
         const char *word, *state;
         InstallContext *c = data;
         InstallInfo *i = userdata;
+        int r;
 
         assert(filename);
         assert(lvalue);
@@ -935,19 +855,20 @@ static int config_parse_also(
 
         FOREACH_WORD_QUOTED(word, l, rvalue, state) {
                 _cleanup_free_ char *n;
-                int r;
 
                 n = strndup(word, l);
                 if (!n)
                         return -ENOMEM;
 
-                r = install_info_add(c, n, NULL);
+                r = install_info_add(c, n, NULL, NULL);
                 if (r < 0)
                         return r;
 
-                r = strv_extend(&i->also, n);
+                r = strv_push(&i->also, n);
                 if (r < 0)
                         return r;
+
+                n = NULL;
         }
         if (!isempty(state))
                 log_syntax(unit, LOG_ERR, filename, line, EINVAL,
@@ -1026,9 +947,7 @@ static int unit_file_load(
                 InstallInfo *info,
                 const char *path,
                 const char *root_dir,
-                bool allow_symlink,
-                bool load,
-                bool *also) {
+                SearchFlags flags) {
 
         const ConfigTableItem items[] = {
                 { "Install", "Alias",           config_parse_strv,             0, &info->aliases           },
@@ -1041,7 +960,9 @@ static int unit_file_load(
         };
 
         _cleanup_fclose_ FILE *f = NULL;
-        int fd, r;
+        _cleanup_close_ int fd = -1;
+        struct stat st;
+        int r;
 
         assert(c);
         assert(info);
@@ -1050,20 +971,43 @@ static int unit_file_load(
         if (!isempty(root_dir))
                 path = strjoina(root_dir, "/", path);
 
-        if (!load) {
-                r = access(path, F_OK) ? -errno : 0;
-                return r;
+        if (!(flags & SEARCH_LOAD)) {
+                r = lstat(path, &st);
+                if (r < 0)
+                        return -errno;
+
+                if (null_or_empty(&st))
+                        info->type = UNIT_FILE_TYPE_MASKED;
+                else if (S_ISREG(st.st_mode))
+                        info->type = UNIT_FILE_TYPE_REGULAR;
+                else if (S_ISLNK(st.st_mode))
+                        return -ELOOP;
+                else if (S_ISDIR(st.st_mode))
+                        return -EISDIR;
+                else
+                        return -ENOTTY;
+
+                return 0;
         }
 
-        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|(allow_symlink ? 0 : O_NOFOLLOW));
+        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
         if (fd < 0)
                 return -errno;
+        if (fstat(fd, &st) < 0)
+                return -errno;
+        if (null_or_empty(&st)) {
+               info->type = UNIT_FILE_MASKED;
+                return 0;
+        }
+        if (S_ISDIR(st.st_mode))
+                return -EISDIR;
+        if (!S_ISREG(st.st_mode))
+                return -ENOTTY;
 
         f = fdopen(fd, "re");
-        if (!f) {
-                safe_close(fd);
-                return -ENOMEM;
-        }
+        if (!f)
+                return -errno;
+        fd = -1;
 
         r = config_parse(NULL, path, f,
                          NULL,
@@ -1072,8 +1016,7 @@ static int unit_file_load(
         if (r < 0)
                 return r;
 
-        if (also)
-                *also = !strv_isempty(info->also);
+        info->type = UNIT_FILE_TYPE_REGULAR;
 
         return
                 (int) strv_length(info->aliases) +
@@ -1081,14 +1024,73 @@ static int unit_file_load(
                 (int) strv_length(info->required_by);
 }
 
+static int unit_file_load_or_readlink(
+                InstallContext *c,
+                InstallInfo *info,
+                const char *path,
+                const char *root_dir,
+                SearchFlags flags) {
+
+        _cleanup_free_ char *np = NULL;
+        int r;
+
+        r = unit_file_load(c, info, path, root_dir, flags);
+        if (r != -ELOOP)
+                return r;
+
+        /* This is a symlink, let's read it. */
+
+        r = readlink_and_make_absolute_root(root_dir, path, &np);
+        if (r < 0)
+                return r;
+
+        if (path_equal(np, "/dev/null"))
+                info->type = UNIT_FILE_TYPE_MASKED;
+        else {
+                const char *bn;
+                UnitType a, b;
+
+                bn = basename(np);
+
+                if (unit_name_is_valid(info->name, UNIT_NAME_PLAIN)) {
+
+                        if (!unit_name_is_valid(bn, UNIT_NAME_PLAIN))
+                                return -EINVAL;
+
+                } else if (unit_name_is_valid(info->name, UNIT_NAME_INSTANCE)) {
+
+                        if (!unit_name_is_valid(bn, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
+                                return -EINVAL;
+
+                } else if (unit_name_is_valid(info->name, UNIT_NAME_TEMPLATE)) {
+
+                        if (!unit_name_is_valid(bn, UNIT_NAME_TEMPLATE))
+                                return -EINVAL;
+                } else
+                        return -EINVAL;
+
+                /* Enforce that the symlink destination does not
+                 * change the unit file type. */
+
+                a = unit_name_to_type(info->name);
+                b = unit_name_to_type(bn);
+                if (a < 0 || b < 0 || a != b)
+                        return -EINVAL;
+
+                info->type = UNIT_FILE_TYPE_SYMLINK;
+                info->symlink_target = np;
+                np = NULL;
+        }
+
+        return 0;
+}
+
 static int unit_file_search(
                 InstallContext *c,
                 InstallInfo *info,
                 const LookupPaths *paths,
                 const char *root_dir,
-                bool allow_symlink,
-                bool load,
-                bool *also) {
+                SearchFlags flags) {
 
         char **p;
         int r;
@@ -1097,8 +1099,12 @@ static int unit_file_search(
         assert(info);
         assert(paths);
 
+        /* Was this unit already loaded? */
+        if (info->type != _UNIT_FILE_TYPE_INVALID)
+                return 0;
+
         if (info->path)
-                return unit_file_load(c, info, info->path, root_dir, allow_symlink, load, also);
+                return unit_file_load_or_readlink(c, info, info->path, root_dir, flags);
 
         assert(info->name);
 
@@ -1109,14 +1115,15 @@ static int unit_file_search(
                 if (!path)
                         return -ENOMEM;
 
-                r = unit_file_load(c, info, path, root_dir, allow_symlink, load, also);
-                if (r >= 0) {
+                r = unit_file_load_or_readlink(c, info, path, root_dir, flags);
+                if (r < 0) {
+                        if (r != -ENOENT)
+                                return r;
+                } else {
                         info->path = path;
                         path = NULL;
                         return r;
                 }
-                if (r != -ENOENT && r != -ELOOP)
-                        return r;
         }
 
         if (unit_name_is_instance(info->name)) {
@@ -1138,92 +1145,149 @@ static int unit_file_search(
                         if (!path)
                                 return -ENOMEM;
 
-                        r = unit_file_load(c, info, path, root_dir, allow_symlink, load, also);
-                        if (r >= 0) {
+                        r = unit_file_load_or_readlink(c, info, path, root_dir, flags);
+                        if (r < 0) {
+                                if (r != -ENOENT)
+                                        return r;
+                        } else {
                                 info->path = path;
                                 path = NULL;
                                 return r;
                         }
-                        if (r != -ENOENT && r != -ELOOP)
-                                return r;
                 }
         }
 
         return -ENOENT;
 }
 
-static int unit_file_can_install(
-                const LookupPaths *paths,
+static int install_info_follow(
+                InstallContext *c,
+                InstallInfo *i,
                 const char *root_dir,
-                const char *name,
-                bool allow_symlink,
-                bool *also) {
+                SearchFlags flags) {
+
+        assert(c);
+        assert(i);
+
+        if (i->type != UNIT_FILE_TYPE_SYMLINK)
+                return -EINVAL;
+        if (!i->symlink_target)
+                return -EINVAL;
+
+        /* If the basename doesn't match, the caller should add a
+         * complete new entry for this. */
+
+        if (!streq(basename(i->symlink_target), i->name))
+                return -EXDEV;
+
+        free(i->path);
+        i->path = i->symlink_target;
+        i->symlink_target = NULL;
+        i->type = _UNIT_FILE_TYPE_INVALID;
+
+        return unit_file_load_or_readlink(c, i, i->path, root_dir, flags);
+}
+
+static int install_info_traverse(
+                UnitFileScope scope,
+                InstallContext *c,
+                const char *root_dir,
+                const LookupPaths *paths,
+                InstallInfo *start,
+                SearchFlags flags,
+                InstallInfo **ret) {
 
-        _cleanup_(install_context_done) InstallContext c = {};
         InstallInfo *i;
+        unsigned k = 0;
         int r;
 
         assert(paths);
-        assert(name);
+        assert(start);
+        assert(c);
 
-        r = install_info_add_auto(&c, name);
+        r = unit_file_search(c, start, paths, root_dir, flags);
         if (r < 0)
                 return r;
 
-        assert_se(i = ordered_hashmap_first(c.will_install));
+        i = start;
+        while (i->type == UNIT_FILE_TYPE_SYMLINK) {
+                /* Follow the symlink */
 
-        r = unit_file_search(&c, i, paths, root_dir, allow_symlink, true, also);
+                if (++k > UNIT_FILE_FOLLOW_SYMLINK_MAX)
+                        return -ELOOP;
 
-        if (r >= 0)
-                r =
-                        (int) strv_length(i->aliases) +
-                        (int) strv_length(i->wanted_by) +
-                        (int) strv_length(i->required_by);
+                if (!(flags & SEARCH_FOLLOW_CONFIG_SYMLINKS) && is_config_path(scope, i->path))
+                        return -ELOOP;
 
-        return r;
-}
+                r = install_info_follow(c, i, root_dir, flags);
+                if (r < 0) {
+                        _cleanup_free_ char *buffer = NULL;
+                        const char *bn;
 
-static int create_symlink(
-                const char *old_path,
-                const char *new_path,
-                bool force,
-                UnitFileChange **changes,
-                unsigned *n_changes) {
+                        if (r != -EXDEV)
+                                return r;
 
-        _cleanup_free_ char *dest = NULL;
-        int r;
+                        /* Target has a different name, create a new
+                         * install info object for that, and continue
+                         * with that. */
 
-        assert(old_path);
-        assert(new_path);
+                        bn = basename(i->symlink_target);
 
-        mkdir_parents_label(new_path, 0755);
+                        if (unit_name_is_valid(i->name, UNIT_NAME_INSTANCE) &&
+                            unit_name_is_valid(bn, UNIT_NAME_TEMPLATE)) {
 
-        if (symlink(old_path, new_path) >= 0) {
-                unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, new_path, old_path);
-                return 0;
+                                _cleanup_free_ char *instance = NULL;
+
+                                r = unit_name_to_instance(i->name, &instance);
+                                if (r < 0)
+                                        return r;
+
+                                buffer = unit_name_replace_instance(bn, instance);
+                                if (!buffer)
+                                        return -ENOMEM;
+
+                                bn = buffer;
+                        }
+
+                        r = install_info_add(c, bn, NULL, &i);
+                        if (r < 0)
+                                return r;
+
+                        r = unit_file_search(c, i, paths, root_dir, flags);
+                        if (r < 0)
+                                return r;
+                }
+
+                /* Try again, with the new target we found. */
         }
 
-        if (errno != EEXIST)
-                return -errno;
+        if (ret)
+                *ret = i;
 
-        r = readlink_and_make_absolute(new_path, &dest);
-        if (r < 0)
-                return r;
+        return 0;
+}
+
+static int install_info_discover(
+                UnitFileScope scope,
+                InstallContext *c,
+                const char *root_dir,
+                const LookupPaths *paths,
+                const char *name,
+                SearchFlags flags,
+                InstallInfo **ret) {
 
-        if (path_equal(dest, old_path))
-                return 0;
+        InstallInfo *i;
+        int r;
 
-        if (!force)
-                return -EEXIST;
+        assert(c);
+        assert(paths);
+        assert(name);
 
-        r = symlink_atomic(old_path, new_path);
+        r = install_info_add_auto(c, name, &i);
         if (r < 0)
                 return r;
 
-        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, new_path, NULL);
-        unit_file_changes_add(changes, n_changes, UNIT_FILE_SYMLINK, new_path, old_path);
-
-        return 0;
+        return install_info_traverse(scope, c, root_dir, paths, i, flags, ret);
 }
 
 static int install_info_symlink_alias(
@@ -1298,7 +1362,7 @@ static int install_info_symlink_wants(
                 if (q < 0)
                         return q;
 
-                if (!unit_name_is_valid(dst, TEMPLATE_VALID)) {
+                if (!unit_name_is_valid(dst, UNIT_NAME_ANY)) {
                         r = -EINVAL;
                         continue;
                 }
@@ -1358,6 +1422,9 @@ static int install_info_apply(
         assert(paths);
         assert(config_path);
 
+        if (i->type != UNIT_FILE_TYPE_REGULAR)
+                return 0;
+
         r = install_info_symlink_alias(i, config_path, force, changes, n_changes);
 
         q = install_info_symlink_wants(i, config_path, i->wanted_by, ".wants/", force, changes, n_changes);
@@ -1376,53 +1443,59 @@ static int install_info_apply(
 }
 
 static int install_context_apply(
+                UnitFileScope scope,
                 InstallContext *c,
                 const LookupPaths *paths,
                 const char *config_path,
                 const char *root_dir,
                 bool force,
+                SearchFlags flags,
                 UnitFileChange **changes,
                 unsigned *n_changes) {
 
         InstallInfo *i;
-        int r, q;
+        int r;
 
         assert(c);
         assert(paths);
         assert(config_path);
 
-        if (!ordered_hashmap_isempty(c->will_install)) {
-                r = ordered_hashmap_ensure_allocated(&c->have_installed, &string_hash_ops);
-                if (r < 0)
-                        return r;
+        if (ordered_hashmap_isempty(c->will_process))
+                return 0;
 
-                r = ordered_hashmap_reserve(c->have_installed, ordered_hashmap_size(c->will_install));
-                if (r < 0)
-                        return r;
-        }
+        r = ordered_hashmap_ensure_allocated(&c->have_processed, &string_hash_ops);
+        if (r < 0)
+                return r;
 
         r = 0;
-        while ((i = ordered_hashmap_first(c->will_install))) {
-                assert_se(ordered_hashmap_move_one(c->have_installed, c->will_install, i->name) == 0);
+        while ((i = ordered_hashmap_first(c->will_process))) {
+                int q;
 
-                q = unit_file_search(c, i, paths, root_dir, false, true, NULL);
-                if (q < 0) {
-                        if (r >= 0)
-                                r = q;
+                q = ordered_hashmap_move_one(c->have_processed, c->will_process, i->name);
+                if (q < 0)
+                        return q;
 
+                r = install_info_traverse(scope, c, root_dir, paths, i, flags, NULL);
+                if (r < 0)
                         return r;
-                } else if (r >= 0)
-                        r += q;
+
+                if (i->type != UNIT_FILE_TYPE_REGULAR)
+                        continue;
 
                 q = install_info_apply(i, paths, config_path, root_dir, force, changes, n_changes);
-                if (r >= 0 && q < 0)
-                        r = q;
+                if (r >= 0) {
+                        if (q < 0)
+                                r = q;
+                        else
+                                r+= q;
+                }
         }
 
         return r;
 }
 
 static int install_context_mark_for_removal(
+                UnitFileScope scope,
                 InstallContext *c,
                 const LookupPaths *paths,
                 Set **remove_symlinks_to,
@@ -1430,96 +1503,109 @@ static int install_context_mark_for_removal(
                 const char *root_dir) {
 
         InstallInfo *i;
-        int r, q;
+        int r;
 
         assert(c);
         assert(paths);
         assert(config_path);
 
         /* Marks all items for removal */
-
-        if (!ordered_hashmap_isempty(c->will_install)) {
-                r = ordered_hashmap_ensure_allocated(&c->have_installed, &string_hash_ops);
+        if (!ordered_hashmap_isempty(c->will_process)) {
+                r = ordered_hashmap_ensure_allocated(&c->have_processed, &string_hash_ops);
                 if (r < 0)
                         return r;
 
-                r = ordered_hashmap_reserve(c->have_installed, ordered_hashmap_size(c->will_install));
+                r = ordered_hashmap_reserve(c->have_processed, ordered_hashmap_size(c->will_process));
                 if (r < 0)
                         return r;
         }
 
         r = 0;
-        while ((i = ordered_hashmap_first(c->will_install))) {
-                assert_se(ordered_hashmap_move_one(c->have_installed, c->will_install, i->name) == 0);
-
-                q = unit_file_search(c, i, paths, root_dir, false, true, NULL);
-                if (q == -ENOENT) {
-                        /* do nothing */
-                } else if (q < 0) {
-                        if (r >= 0)
-                                r = q;
+        while ((i = ordered_hashmap_first(c->will_process))) {
+
+                r = ordered_hashmap_move_one(c->have_processed, c->will_process, i->name);
+                if (r < 0)
+                        return r;
 
+                r = install_info_traverse(scope, c, root_dir, paths, i, SEARCH_LOAD|SEARCH_FOLLOW_CONFIG_SYMLINKS, NULL);
+                if (r < 0)
                         return r;
-                } else if (r >= 0)
-                        r += q;
-
-                if (unit_name_is_instance(i->name)) {
-                        char *unit_file;
-
-                        if (i->path) {
-                                unit_file = basename(i->path);
-
-                                if (unit_name_is_instance(unit_file))
-                                        /* unit file named as instance exists, thus all symlinks
-                                         * pointing to it will be removed */
-                                        q = mark_symlink_for_removal(remove_symlinks_to, i->name);
-                                else
-                                        /* does not exist, thus we will mark for removal symlinks
-                                         * to template unit file */
-                                        q = mark_symlink_for_removal(remove_symlinks_to, unit_file);
-                        } else {
-                                /* If i->path is not set, it means that we didn't actually find
-                                 * the unit file. But we can still remove symlinks to the
-                                 * nonexistent template. */
-                                unit_file = unit_name_template(i->name);
-                                if (!unit_file)
-                                        return log_oom();
-
-                                q = mark_symlink_for_removal(remove_symlinks_to, unit_file);
-                                free(unit_file);
-                        }
-                } else
-                        q = mark_symlink_for_removal(remove_symlinks_to, i->name);
 
-                if (r >= 0 && q < 0)
+                if (i->type != UNIT_FILE_TYPE_REGULAR)
+                        continue;
+
+                r = mark_symlink_for_removal(remove_symlinks_to, i->name);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int unit_file_mask(
+                UnitFileScope scope,
+                bool runtime,
+                const char *root_dir,
+                char **files,
+                bool force,
+                UnitFileChange **changes,
+                unsigned *n_changes) {
+
+        _cleanup_free_ char *prefix = NULL;
+        char **i;
+        int r;
+
+        assert(scope >= 0);
+        assert(scope < _UNIT_FILE_SCOPE_MAX);
+
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
+        r = get_config_path(scope, runtime, root_dir, &prefix);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(i, files) {
+                _cleanup_free_ char *path = NULL;
+                int q;
+                if (!unit_name_is_valid(*i, UNIT_NAME_ANY)) {
+                        if (r == 0)
+                                r = -EINVAL;
+                        continue;
+                }
+
+                path = path_make_absolute(*i, prefix);
+                if (!path)
+                        return -ENOMEM;
+
+                q = create_symlink("/dev/null", path, force, changes, n_changes);
+                if (q < 0 && r >= 0)
                         r = q;
         }
 
         return r;
 }
 
-int unit_file_add_dependency(
+int unit_file_unmask(
                 UnitFileScope scope,
                 bool runtime,
                 const char *root_dir,
                 char **files,
-                char *target,
-                UnitDependency dep,
-                bool force,
                 UnitFileChange **changes,
                 unsigned *n_changes) {
 
-        _cleanup_lookup_paths_free_ LookupPaths paths = {};
-        _cleanup_(install_context_done) InstallContext c = {};
+        _cleanup_set_free_free_ Set *remove_symlinks_to = NULL;
         _cleanup_free_ char *config_path = NULL;
+        _cleanup_free_ char **todo = NULL;
+        size_t n_todo = 0, n_allocated = 0;
         char **i;
-        int r;
-        InstallInfo *info;
+        int r, q;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
 
-        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        r = verify_root_dir(scope, &root_dir);
         if (r < 0)
                 return r;
 
@@ -1528,57 +1614,222 @@ int unit_file_add_dependency(
                 return r;
 
         STRV_FOREACH(i, files) {
-                UnitFileState state;
+                _cleanup_free_ char *path = NULL;
 
-                state = unit_file_get_state(scope, root_dir, *i);
-                if (state < 0)
-                        return log_error_errno(state, "Failed to get unit file state for %s: %m", *i);
+                if (!unit_name_is_valid(*i, UNIT_NAME_ANY))
+                        return -EINVAL;
 
-                if (state == UNIT_FILE_MASKED || state == UNIT_FILE_MASKED_RUNTIME) {
-                        log_error("Failed to enable unit: Unit %s is masked", *i);
-                        return -ENOTSUP;
-                }
+                path = path_make_absolute(*i, config_path);
+                if (!path)
+                        return -ENOMEM;
 
-                r = install_info_add_auto(&c, *i);
+                r = null_or_empty_path(path);
+                if (r == -ENOENT)
+                        continue;
                 if (r < 0)
                         return r;
+                if (r == 0)
+                        continue;
+
+                if (!GREEDY_REALLOC0(todo, n_allocated, n_todo + 2))
+                        return -ENOMEM;
+
+                todo[n_todo++] = *i;
         }
 
-        if (!ordered_hashmap_isempty(c.will_install)) {
-                r = ordered_hashmap_ensure_allocated(&c.have_installed, &string_hash_ops);
-                if (r < 0)
-                        return r;
+        strv_uniq(todo);
 
-                r = ordered_hashmap_reserve(c.have_installed, ordered_hashmap_size(c.will_install));
-                if (r < 0)
-                        return r;
+        r = 0;
+        STRV_FOREACH(i, todo) {
+                _cleanup_free_ char *path = NULL;
+
+                path = path_make_absolute(*i, config_path);
+                if (!path)
+                        return -ENOMEM;
+
+                if (unlink(path) < 0) {
+                        if (errno != -ENOENT && r >= 0)
+                                r = -errno;
+                } else {
+                        q = mark_symlink_for_removal(&remove_symlinks_to, path);
+                        if (q < 0)
+                                return q;
+
+                        unit_file_changes_add(changes, n_changes, UNIT_FILE_UNLINK, path, NULL);
+                }
         }
 
-        while ((info = ordered_hashmap_first(c.will_install))) {
-                assert_se(ordered_hashmap_move_one(c.have_installed, c.will_install, info->name) == 0);
+        q = remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes);
+        if (r >= 0)
+                r = q;
 
-                r = unit_file_search(&c, info, &paths, root_dir, false, false, NULL);
-                if (r < 0)
-                        return r;
+        return r;
+}
 
-                if (dep == UNIT_WANTS)
-                        r = strv_extend(&info->wanted_by, target);
-                else if (dep == UNIT_REQUIRES)
-                        r = strv_extend(&info->required_by, target);
-                else
-                        r = -EINVAL;
+int unit_file_link(
+                UnitFileScope scope,
+                bool runtime,
+                const char *root_dir,
+                char **files,
+                bool force,
+                UnitFileChange **changes,
+                unsigned *n_changes) {
 
-                if (r < 0)
-                        return r;
+        _cleanup_lookup_paths_free_ LookupPaths paths = {};
+        _cleanup_free_ char *config_path = NULL;
+        _cleanup_free_ char **todo = NULL;
+        size_t n_todo = 0, n_allocated = 0;
+        char **i;
+        int r,q;
 
-                r = install_info_apply(info, &paths, config_path, root_dir, force, changes, n_changes);
-                if (r < 0)
-                        return r;
+        assert(scope >= 0);
+        assert(scope < _UNIT_FILE_SCOPE_MAX);
+
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
+        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        if (r < 0)
+                return r;
+
+        r = get_config_path(scope, runtime, root_dir, &config_path);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(i, files) {
+                _cleanup_free_ char *full = NULL;
+                struct stat st;
+                char *fn;
+
+                if (!path_is_absolute(*i))
+                        return -EINVAL;
+
+                fn = basename(*i);
+                if (!unit_name_is_valid(fn, UNIT_NAME_ANY))
+                        return -EINVAL;
+
+                full = prefix_root(root_dir, *i);
+                if (!full)
+                        return -ENOMEM;
+
+                if (lstat(full, &st) < 0)
+                        return -errno;
+                if (S_ISLNK(st.st_mode))
+                        return -ELOOP;
+                if (S_ISDIR(st.st_mode))
+                        return -EISDIR;
+                if (!S_ISREG(st.st_mode))
+                        return -ENOTTY;
+
+                q = in_search_path(*i, paths.unit_path);
+                if (q < 0)
+                        return q;
+                if (q > 0)
+                        continue;
+
+                if (!GREEDY_REALLOC0(todo, n_allocated, n_todo + 2))
+                        return -ENOMEM;
+
+                todo[n_todo++] = *i;
         }
 
-        return 0;
+        strv_uniq(todo);
+
+        r = 0;
+        STRV_FOREACH(i, todo) {
+                _cleanup_free_ char *path = NULL;
+
+                path = path_make_absolute(basename(*i), config_path);
+                if (!path)
+                        return -ENOMEM;
+
+                q = create_symlink(*i, path, force, changes, n_changes);
+                if (q < 0 && r >= 0)
+                        r = q;
+        }
+
+        return r;
+}
+
+int unit_file_add_dependency(
+                UnitFileScope scope,
+                bool runtime,
+                const char *root_dir,
+                char **files,
+                const char *target,
+                UnitDependency dep,
+                bool force,
+                UnitFileChange **changes,
+                unsigned *n_changes) {
+
+        _cleanup_lookup_paths_free_ LookupPaths paths = {};
+        _cleanup_(install_context_done) InstallContext c = {};
+        _cleanup_free_ char *config_path = NULL;
+        InstallInfo *i, *target_info;
+        char **f;
+        int r;
+
+        assert(scope >= 0);
+        assert(scope < _UNIT_FILE_SCOPE_MAX);
+        assert(target);
+
+        if (!IN_SET(dep, UNIT_WANTS, UNIT_REQUIRES))
+                return -EINVAL;
+
+        if (!unit_name_is_valid(target, UNIT_NAME_ANY))
+                return -EINVAL;
+
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
+        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        if (r < 0)
+                return r;
+
+        r = get_config_path(scope, runtime, root_dir, &config_path);
+        if (r < 0)
+                return r;
+
+        r = install_info_discover(scope, &c, root_dir, &paths, target, SEARCH_FOLLOW_CONFIG_SYMLINKS, &target_info);
+        if (r < 0)
+                return r;
+        if (target_info->type == UNIT_FILE_TYPE_MASKED)
+                return -ESHUTDOWN;
+
+        assert(target_info->type == UNIT_FILE_TYPE_REGULAR);
+
+        STRV_FOREACH(f, files) {
+                char ***l;
+
+                r = install_info_discover(scope, &c, root_dir, &paths, *f, SEARCH_FOLLOW_CONFIG_SYMLINKS, &i);
+                 if (r < 0)
+                         return r;
+                if (i->type == UNIT_FILE_TYPE_MASKED)
+                        return -ESHUTDOWN;
+
+                assert(i->type == UNIT_FILE_TYPE_REGULAR);
+
+                /* We didn't actually load anything from the unit
+                 * file, but instead just add in our new symlink to
+                 * create. */
+
+                 if (dep == UNIT_WANTS)
+                        l = &i->wanted_by;
+                 else
+                        l = &i->required_by;
+
+                strv_free(*l);
+                *l = strv_new(target_info->name, NULL);
+                if (!*l)
+                        return -ENOMEM;
+         }
+
+        return install_context_apply(scope, &c, &paths, config_path, root_dir, force, SEARCH_FOLLOW_CONFIG_SYMLINKS, changes, n_changes);
 }
 
+
 int unit_file_enable(
                 UnitFileScope scope,
                 bool runtime,
@@ -1590,13 +1841,18 @@ int unit_file_enable(
 
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         _cleanup_(install_context_done) InstallContext c = {};
-        char **i;
         _cleanup_free_ char *config_path = NULL;
+        InstallInfo *i;
+        char **f;
         int r;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
 
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
         r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
                 return r;
@@ -1605,21 +1861,14 @@ int unit_file_enable(
         if (r < 0)
                 return r;
 
-        STRV_FOREACH(i, files) {
-                UnitFileState state;
-
-                /* We only want to know if this unit is masked, so we ignore
-                 * errors from unit_file_get_state, deferring other checks.
-                 * This allows templated units to be enabled on the fly. */
-                state = unit_file_get_state(scope, root_dir, *i);
-                if (state == UNIT_FILE_MASKED || state == UNIT_FILE_MASKED_RUNTIME) {
-                        log_error("Failed to enable unit: Unit %s is masked", *i);
-                        return -ENOTSUP;
-                }
-
-                r = install_info_add_auto(&c, *i);
+        STRV_FOREACH(f, files) {
+                r = install_info_discover(scope, &c, root_dir, &paths, *f, SEARCH_LOAD, &i);
                 if (r < 0)
                         return r;
+                if (i->type == UNIT_FILE_TYPE_MASKED)
+                        return -ESHUTDOWN;
+
+                assert(i->type == UNIT_FILE_TYPE_REGULAR);
         }
 
         /* This will return the number of symlink rules that were
@@ -1627,7 +1876,7 @@ int unit_file_enable(
         useful to determine whether the passed files had any
         installation data at all. */
 
-        return install_context_apply(&c, &paths, config_path, root_dir, force, changes, n_changes);
+        return install_context_apply(scope, &c, &paths, config_path, root_dir, force, SEARCH_LOAD, changes, n_changes);
 }
 
 int unit_file_disable(
@@ -1640,14 +1889,18 @@ int unit_file_disable(
 
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         _cleanup_(install_context_done) InstallContext c = {};
-        char **i;
         _cleanup_free_ char *config_path = NULL;
         _cleanup_set_free_free_ Set *remove_symlinks_to = NULL;
-        int r, q;
+        char **i;
+        int r;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
 
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
         r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
                 return r;
@@ -1657,18 +1910,19 @@ int unit_file_disable(
                 return r;
 
         STRV_FOREACH(i, files) {
-                r = install_info_add_auto(&c, *i);
+                if (!unit_name_is_valid(*i, UNIT_NAME_ANY))
+                        return -EINVAL;
+
+                r = install_info_add(&c, *i, NULL, NULL);
                 if (r < 0)
                         return r;
         }
 
-        r = install_context_mark_for_removal(&c, &paths, &remove_symlinks_to, config_path, root_dir);
-
-        q = remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes, files);
-        if (r >= 0)
-                r = q;
+        r = install_context_mark_for_removal(scope, &c, &paths, &remove_symlinks_to, config_path, root_dir);
+        if (r < 0)
+                return r;
 
-        return r;
+        return remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes);
 }
 
 int unit_file_reenable(
@@ -1679,21 +1933,30 @@ int unit_file_reenable(
                 bool force,
                 UnitFileChange **changes,
                 unsigned *n_changes) {
+
+        char **n;
         int r;
+        size_t l, i;
+
+        /* First, we invoke the disable command with only the basename... */
+        l = strv_length(files);
+        n = newa(char*, l+1);
+        for (i = 0; i < l; i++)
+                n[i] = basename(files[i]);
+        n[i] = NULL;
 
-        r = unit_file_disable(scope, runtime, root_dir, files,
-                              changes, n_changes);
+        r = unit_file_disable(scope, runtime, root_dir, n, changes, n_changes);
         if (r < 0)
                 return r;
 
-        return unit_file_enable(scope, runtime, root_dir, files, force,
-                                changes, n_changes);
+        /* But the enable command with the full name */
+        return unit_file_enable(scope, runtime, root_dir, files, force, changes, n_changes);
 }
 
 int unit_file_set_default(
                 UnitFileScope scope,
                 const char *root_dir,
-                const char *file,
+                const char *name,
                 bool force,
                 UnitFileChange **changes,
                 unsigned *n_changes) {
@@ -1701,42 +1964,40 @@ int unit_file_set_default(
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         _cleanup_(install_context_done) InstallContext c = {};
         _cleanup_free_ char *config_path = NULL;
-        char *path;
+        InstallInfo *i;
+        const char *path;
         int r;
-        InstallInfo *i = NULL;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
-        assert(file);
+        assert(name);
 
-        if (unit_name_to_type(file) != UNIT_TARGET)
+        if (unit_name_to_type(name) != UNIT_TARGET)
+                return -EINVAL;
+        if (streq(name, SPECIAL_DEFAULT_TARGET))
                 return -EINVAL;
 
-        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        r = verify_root_dir(scope, &root_dir);
         if (r < 0)
                 return r;
 
-        r = get_config_path(scope, false, root_dir, &config_path);
+        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
                 return r;
 
-        r = install_info_add_auto(&c, file);
+        r = get_config_path(scope, false, root_dir, &config_path);
         if (r < 0)
                 return r;
 
-        assert_se(i = ordered_hashmap_first(c.will_install));
-
-        r = unit_file_search(&c, i, &paths, root_dir, false, true, NULL);
+        r = install_info_discover(scope, &c, root_dir, &paths, name, 0, &i);
         if (r < 0)
                 return r;
+        if (i->type == UNIT_FILE_TYPE_MASKED)
+                return -ESHUTDOWN;
 
         path = strjoina(config_path, "/" SPECIAL_DEFAULT_TARGET);
 
-        r = create_symlink(i->path, path, force, changes, n_changes);
-        if (r < 0)
-                return r;
-
-        return 0;
+        return create_symlink(i->path, path, force, changes, n_changes);
 }
 
 int unit_file_get_default(
@@ -1745,127 +2006,100 @@ int unit_file_get_default(
                 char **name) {
 
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
-        char **p;
+        _cleanup_(install_context_done) InstallContext c = {};
+        InstallInfo *i;
+        char *n;
         int r;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(name);
 
-        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        r = verify_root_dir(scope, &root_dir);
         if (r < 0)
                 return r;
 
-        STRV_FOREACH(p, paths.unit_path) {
-                _cleanup_free_ char *path = NULL, *tmp = NULL;
-                char *n;
-
-                path = path_join(root_dir, *p, SPECIAL_DEFAULT_TARGET);
-                if (!path)
-                        return -ENOMEM;
-
-                r = readlink_malloc(path, &tmp);
-                if (r == -ENOENT)
-                        continue;
-                else if (r == -EINVAL)
-                        /* not a symlink */
-                        n = strdup(SPECIAL_DEFAULT_TARGET);
-                else if (r < 0)
-                        return r;
-                else
-                        n = strdup(basename(tmp));
+        r = lookup_paths_init_from_scope(&paths, scope, root_dir);
+        if (r < 0)
+                return r;
 
-                if (!n)
-                        return -ENOMEM;
+        r = install_info_discover(scope, &c, root_dir, &paths, SPECIAL_DEFAULT_TARGET, SEARCH_FOLLOW_CONFIG_SYMLINKS, &i);
+        if (r < 0)
+                return r;
+        if (i->type == UNIT_FILE_TYPE_MASKED)
+                return -ESHUTDOWN;
 
-                *name = n;
-                return 0;
-        }
+        n = strdup(i->name);
+        if (!n)
+                return -ENOMEM;
 
-        return -ENOENT;
+        *name = n;
+        return 0;
 }
 
 UnitFileState unit_file_lookup_state(
                 UnitFileScope scope,
                 const char *root_dir,
                 const LookupPaths *paths,
-                const char *name) {
-
-        UnitFileState state = _UNIT_FILE_STATE_INVALID;
-        char **i;
-        _cleanup_free_ char *path = NULL;
+                const char *name,
+                UnitFileState *ret) {
+        _cleanup_(install_context_done) InstallContext c = {};
+        InstallInfo *i;
+        UnitFileState state;
         int r;
 
         assert(paths);
+        assert(name);
 
-        if (!unit_name_is_valid(name, TEMPLATE_VALID))
+        if (!unit_name_is_valid(name, UNIT_NAME_ANY))
                 return -EINVAL;
 
-        STRV_FOREACH(i, paths->unit_path) {
-                struct stat st;
-                char *partial;
-                bool also = false;
-
-                free(path);
-                path = path_join(root_dir, *i, name);
-                if (!path)
-                        return -ENOMEM;
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
 
-                if (root_dir)
-                        partial = path + strlen(root_dir);
-                else
-                        partial = path;
+        r = install_info_discover(scope, &c, root_dir, paths, name, SEARCH_LOAD|SEARCH_FOLLOW_CONFIG_SYMLINKS, &i);
+        if (r < 0)
+                return r;
 
-                /*
-                 * Search for a unit file in our default paths, to
-                 * be sure, that there are no broken symlinks.
-                 */
-                if (lstat(path, &st) < 0) {
-                        r = -errno;
-                        if (errno != ENOENT)
-                                return r;
+        /* Shortcut things, if the caller just wants to know if this unit exists. */
+        if (!ret)
+                return 0;
 
-                        if (!unit_name_is_instance(name))
-                                continue;
-                } else {
-                        if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode))
-                                return -ENOENT;
+        switch (i->type) {
 
-                        r = null_or_empty_path(path);
-                        if (r < 0 && r != -ENOENT)
-                                return r;
-                        else if (r > 0) {
-                                state = path_startswith(*i, "/run") ?
-                                        UNIT_FILE_MASKED_RUNTIME : UNIT_FILE_MASKED;
-                                return state;
-                        }
-                }
+        case UNIT_FILE_TYPE_MASKED:
+                state = path_startswith(i->path, "/run") ? UNIT_FILE_MASKED_RUNTIME : UNIT_FILE_MASKED;
+                break;
 
-                r = find_symlinks_in_scope(scope, root_dir, name, &state);
+        case UNIT_FILE_TYPE_REGULAR:
+                r = find_symlinks_in_scope(scope, root_dir, i->name, &state);
                 if (r < 0)
                         return r;
-                else if (r > 0)
-                        return state;
-
-                r = unit_file_can_install(paths, root_dir, partial, true, &also);
-                if (r < 0 && errno != ENOENT)
-                        return r;
-                else if (r > 0)
-                        return UNIT_FILE_DISABLED;
-                else if (r == 0) {
-                        if (also)
-                                return UNIT_FILE_INDIRECT;
-                        return UNIT_FILE_STATIC;
+                if (r == 0) {
+                        if (UNIT_FILE_INSTALL_INFO_HAS_RULES(i))
+                                state = UNIT_FILE_DISABLED;
+                        else if (UNIT_FILE_INSTALL_INFO_HAS_ALSO(i))
+                                state = UNIT_FILE_INDIRECT;
+                        else
+                                state = UNIT_FILE_STATIC;
                 }
+
+                break;
+
+        default:
+                assert_not_reached("Unexpect unit file type.");
         }
 
-        return r < 0 ? r : state;
+        *ret = state;
+        return 0;
 }
 
-UnitFileState unit_file_get_state(
+int unit_file_get_state(
                 UnitFileScope scope,
                 const char *root_dir,
-                const char *name) {
+                const char *name,
+                UnitFileState *ret) {
 
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         int r;
@@ -1874,14 +2108,15 @@ UnitFileState unit_file_get_state(
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(name);
 
-        if (root_dir && scope != UNIT_FILE_SYSTEM)
-                return -EINVAL;
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
 
         r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
                 return r;
 
-        return unit_file_lookup_state(scope, root_dir, &paths, name);
+        return unit_file_lookup_state(scope, root_dir, &paths, name, ret);
 }
 
 int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char *name) {
@@ -1893,6 +2128,13 @@ int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(name);
 
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
+        if (!unit_name_is_valid(name, UNIT_NAME_ANY))
+                return -EINVAL;
+
         if (scope == UNIT_FILE_SYSTEM)
                 r = conf_files_list(&files, ".preset", root_dir,
                                     "/etc/systemd/system-preset",
@@ -1909,13 +2151,14 @@ int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char
                                     "/usr/lib/systemd/user-preset",
                                     NULL);
         else
-                return 1;
+                return 1; /* Default is "enable" */
 
         if (r < 0)
                 return r;
 
         STRV_FOREACH(p, files) {
                 _cleanup_fclose_ FILE *f;
+                char line[LINE_MAX];
 
                 f = fopen(*p, "re");
                 if (!f) {
@@ -1925,39 +2168,38 @@ int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char
                         return -errno;
                 }
 
-                for (;;) {
-                        char line[LINE_MAX], *l;
-
-                        if (!fgets(line, sizeof(line), f))
-                                break;
+                FOREACH_LINE(line, f, return -errno) {
+                        const char *parameter;
+                        char *l;
 
                         l = strstrip(line);
-                        if (!*l)
-                                continue;
 
-                        if (strchr(COMMENTS "\n", *l))
+                        if (isempty(l))
+                                continue;
+                        if (strchr(COMMENTS, *l))
                                 continue;
 
-                        if (first_word(l, "enable")) {
-                                l += 6;
-                                l += strspn(l, WHITESPACE);
-
-                                if (fnmatch(l, name, FNM_NOESCAPE) == 0) {
+                        parameter = first_word(l, "enable");
+                        if (parameter) {
+                                if (fnmatch(parameter, name, FNM_NOESCAPE) == 0) {
                                         log_debug("Preset file says enable %s.", name);
                                         return 1;
                                 }
 
-                        } else if (first_word(l, "disable")) {
-                                l += 7;
-                                l += strspn(l, WHITESPACE);
+                                continue;
+                        }
 
-                                if (fnmatch(l, name, FNM_NOESCAPE) == 0) {
+                        parameter = first_word(l, "disable");
+                        if (parameter) {
+                                if (fnmatch(parameter, name, FNM_NOESCAPE) == 0) {
                                         log_debug("Preset file says disable %s.", name);
                                         return 0;
                                 }
 
-                        } else
-                                log_debug("Couldn't parse line '%s'", l);
+                                continue;
+                        }
+
+                        log_debug("Couldn't parse line '%s'", l);
                 }
         }
 
@@ -1966,6 +2208,86 @@ int unit_file_query_preset(UnitFileScope scope, const char *root_dir, const char
         return 1;
 }
 
+static int execute_preset(
+                UnitFileScope scope,
+                InstallContext *plus,
+                InstallContext *minus,
+                const LookupPaths *paths,
+                const char *config_path,
+                const char *root_dir,
+                char **files,
+                UnitFilePresetMode mode,
+                bool force,
+                UnitFileChange **changes,
+                unsigned *n_changes) {
+
+        int r;
+
+        assert(plus);
+        assert(minus);
+        assert(paths);
+        assert(config_path);
+
+        if (mode != UNIT_FILE_PRESET_ENABLE_ONLY) {
+                _cleanup_set_free_free_ Set *remove_symlinks_to = NULL;
+
+                r = install_context_mark_for_removal(scope, minus, paths, &remove_symlinks_to, config_path, root_dir);
+                if (r < 0)
+                        return r;
+
+                r = remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes);
+        } else
+                r = 0;
+
+        if (mode != UNIT_FILE_PRESET_DISABLE_ONLY) {
+                int q;
+
+                /* Returns number of symlinks that where supposed to be installed. */
+                q = install_context_apply(scope, plus, paths, config_path, root_dir, force, SEARCH_LOAD, changes, n_changes);
+                if (r >= 0) {
+                        if (q < 0)
+                                r = q;
+                        else
+                                r+= q;
+                }
+        }
+
+        return r;
+}
+
+static int preset_prepare_one(
+                UnitFileScope scope,
+                InstallContext *plus,
+                InstallContext *minus,
+                LookupPaths *paths,
+                const char *root_dir,
+                UnitFilePresetMode mode,
+                const char *name) {
+
+        InstallInfo *i;
+        int r;
+
+        if (install_info_find(plus, name) ||
+            install_info_find(minus, name))
+                return 0;
+
+        r = unit_file_query_preset(scope, root_dir, name);
+        if (r < 0)
+                return r;
+
+        if (r > 0) {
+                r = install_info_discover(scope, plus, root_dir, paths, name, SEARCH_LOAD|SEARCH_FOLLOW_CONFIG_SYMLINKS, &i);
+                if (r < 0)
+                        return r;
+
+                if (i->type == UNIT_FILE_TYPE_MASKED)
+                        return -ESHUTDOWN;
+        } else
+                r = install_info_discover(scope, minus, root_dir, paths, name, SEARCH_FOLLOW_CONFIG_SYMLINKS, &i);
+
+        return r;
+}
+
 int unit_file_preset(
                 UnitFileScope scope,
                 bool runtime,
@@ -1980,12 +2302,16 @@ int unit_file_preset(
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         _cleanup_free_ char *config_path = NULL;
         char **i;
-        int r, q;
+        int r;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(mode < _UNIT_FILE_PRESET_MAX);
 
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
         r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
                 return r;
@@ -1995,44 +2321,15 @@ int unit_file_preset(
                 return r;
 
         STRV_FOREACH(i, files) {
-
-                if (!unit_name_is_valid(*i, TEMPLATE_VALID))
+                if (!unit_name_is_valid(*i, UNIT_NAME_ANY))
                         return -EINVAL;
 
-                r = unit_file_query_preset(scope, root_dir, *i);
-                if (r < 0)
-                        return r;
-
-                if (r && mode != UNIT_FILE_PRESET_DISABLE_ONLY)
-                        r = install_info_add_auto(&plus, *i);
-                else if (!r && mode != UNIT_FILE_PRESET_ENABLE_ONLY)
-                        r = install_info_add_auto(&minus, *i);
-                else
-                        r = 0;
+                r = preset_prepare_one(scope, &plus, &minus, &paths, root_dir, mode, *i);
                 if (r < 0)
                         return r;
         }
 
-        r = 0;
-
-        if (mode != UNIT_FILE_PRESET_ENABLE_ONLY) {
-                _cleanup_set_free_free_ Set *remove_symlinks_to = NULL;
-
-                r = install_context_mark_for_removal(&minus, &paths, &remove_symlinks_to, config_path, root_dir);
-
-                q = remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes, files);
-                if (r == 0)
-                        r = q;
-        }
-
-        if (mode != UNIT_FILE_PRESET_DISABLE_ONLY) {
-                /* Returns number of symlinks that where supposed to be installed. */
-                q = install_context_apply(&plus, &paths, config_path, root_dir, force, changes, n_changes);
-                if (r == 0)
-                        r = q;
-        }
-
-        return r;
+        return execute_preset(scope, &plus, &minus, &paths, config_path, root_dir, files, mode, force, changes, n_changes);
 }
 
 int unit_file_preset_all(
@@ -2048,12 +2345,16 @@ int unit_file_preset_all(
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         _cleanup_free_ char *config_path = NULL;
         char **i;
-        int r, q;
+        int r;
 
         assert(scope >= 0);
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(mode < _UNIT_FILE_PRESET_MAX);
 
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
+
         r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
                 return r;
@@ -2092,48 +2393,21 @@ int unit_file_preset_all(
                         if (hidden_file(de->d_name))
                                 continue;
 
-                        if (!unit_name_is_valid(de->d_name, TEMPLATE_VALID))
+                        if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
                                 continue;
 
                         dirent_ensure_type(d, de);
 
-                        if (de->d_type != DT_REG)
+                        if (!IN_SET(de->d_type, DT_LNK, DT_REG))
                                 continue;
 
-                        r = unit_file_query_preset(scope, root_dir, de->d_name);
-                        if (r < 0)
-                                return r;
-
-                        if (r && mode != UNIT_FILE_PRESET_DISABLE_ONLY)
-                                r = install_info_add_auto(&plus, de->d_name);
-                        else if (!r && mode != UNIT_FILE_PRESET_ENABLE_ONLY)
-                                r = install_info_add_auto(&minus, de->d_name);
-                        else
-                                r = 0;
+                        r = preset_prepare_one(scope, &plus, &minus, &paths, root_dir, mode, de->d_name);
                         if (r < 0)
                                 return r;
                 }
         }
 
-        r = 0;
-
-        if (mode != UNIT_FILE_PRESET_ENABLE_ONLY) {
-                _cleanup_set_free_free_ Set *remove_symlinks_to = NULL;
-
-                r = install_context_mark_for_removal(&minus, &paths, &remove_symlinks_to, config_path, root_dir);
-
-                q = remove_marked_symlinks(remove_symlinks_to, config_path, changes, n_changes, NULL);
-                if (r == 0)
-                        r = q;
-        }
-
-        if (mode != UNIT_FILE_PRESET_DISABLE_ONLY) {
-                q = install_context_apply(&plus, &paths, config_path, root_dir, force, changes, n_changes);
-                if (r == 0)
-                        r = q;
-        }
-
-        return r;
+        return execute_preset(scope, &plus, &minus, &paths, config_path, root_dir, NULL, mode, force, changes, n_changes);
 }
 
 static void unit_file_list_free_one(UnitFileList *f) {
@@ -2144,6 +2418,17 @@ static void unit_file_list_free_one(UnitFileList *f) {
         free(f);
 }
 
+Hashmap* unit_file_list_free(Hashmap *h) {
+        UnitFileList *i;
+
+        while ((i = hashmap_steal_first(h)))
+                unit_file_list_free_one(i);
+
+        hashmap_free(h);
+
+        return NULL;
+}
+
 DEFINE_TRIVIAL_CLEANUP_FUNC(UnitFileList*, unit_file_list_free_one);
 
 int unit_file_get_list(
@@ -2159,14 +2444,9 @@ int unit_file_get_list(
         assert(scope < _UNIT_FILE_SCOPE_MAX);
         assert(h);
 
-        if (root_dir && scope != UNIT_FILE_SYSTEM)
-                return -EINVAL;
-
-        if (root_dir) {
-                r = access(root_dir, F_OK);
-                if (r < 0)
-                        return -errno;
-        }
+        r = verify_root_dir(scope, &root_dir);
+        if (r < 0)
+                return r;
 
         r = lookup_paths_init_from_scope(&paths, scope, root_dir);
         if (r < 0)
@@ -2191,7 +2471,6 @@ int unit_file_get_list(
                 for (;;) {
                         _cleanup_(unit_file_list_free_onep) UnitFileList *f = NULL;
                         struct dirent *de;
-                        _cleanup_free_ char *path = NULL;
 
                         errno = 0;
                         de = readdir(d);
@@ -2204,7 +2483,7 @@ int unit_file_get_list(
                         if (hidden_file(de->d_name))
                                 continue;
 
-                        if (!unit_name_is_valid(de->d_name, TEMPLATE_VALID))
+                        if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
                                 continue;
 
                         if (hashmap_get(h, de->d_name))
@@ -2223,44 +2502,14 @@ int unit_file_get_list(
                         if (!f->path)
                                 return -ENOMEM;
 
-                        r = null_or_empty_path(f->path);
-                        if (r < 0 && r != -ENOENT)
-                                return r;
-                        else if (r > 0) {
-                                f->state =
-                                        path_startswith(*i, "/run") ?
-                                        UNIT_FILE_MASKED_RUNTIME : UNIT_FILE_MASKED;
-                                goto found;
-                        }
-
-                        r = find_symlinks_in_scope(scope, root_dir, de->d_name, &f->state);
+                        r = unit_file_lookup_state(scope, root_dir, &paths, basename(f->path), &f->state);
                         if (r < 0)
-                                return r;
-                        else if (r > 0) {
-                                f->state = UNIT_FILE_ENABLED;
-                                goto found;
-                        }
-
-                        path = path_make_absolute(de->d_name, *i);
-                        if (!path)
-                                return -ENOMEM;
+                                f->state = UNIT_FILE_BAD;
 
-                        r = unit_file_can_install(&paths, root_dir, path, true, NULL);
-                        if (r == -EINVAL ||  /* Invalid setting? */
-                            r == -EBADMSG || /* Invalid format? */
-                            r == -ENOENT     /* Included file not found? */)
-                                f->state = UNIT_FILE_INVALID;
-                        else if (r < 0)
-                                return r;
-                        else if (r > 0)
-                                f->state = UNIT_FILE_DISABLED;
-                        else
-                                f->state = UNIT_FILE_STATIC;
-
-                found:
                         r = hashmap_put(h, basename(f->path), f);
                         if (r < 0)
                                 return r;
+
                         f = NULL; /* prevent cleanup */
                 }
         }
@@ -2278,7 +2527,7 @@ static const char* const unit_file_state_table[_UNIT_FILE_STATE_MAX] = {
         [UNIT_FILE_STATIC] = "static",
         [UNIT_FILE_DISABLED] = "disabled",
         [UNIT_FILE_INDIRECT] = "indirect",
-        [UNIT_FILE_INVALID] = "invalid",
+        [UNIT_FILE_BAD] = "bad",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(unit_file_state, UnitFileState);
diff --git a/src/shared/install.h b/src/shared/install.h
index d729e6ed1..87a40b67c 100644
--- a/src/shared/install.h
+++ b/src/shared/install.h
@@ -24,6 +24,7 @@
 #include "hashmap.h"
 #include "unit-name.h"
 #include "path-lookup.h"
+#include "strv.h"
 
 typedef enum UnitFileScope {
         UNIT_FILE_SYSTEM,
@@ -43,7 +44,7 @@ typedef enum UnitFileState {
         UNIT_FILE_STATIC,
         UNIT_FILE_DISABLED,
         UNIT_FILE_INDIRECT,
-        UNIT_FILE_INVALID,
+        UNIT_FILE_BAD,
         _UNIT_FILE_STATE_MAX,
         _UNIT_FILE_STATE_INVALID = -1
 } UnitFileState;
@@ -74,6 +75,14 @@ typedef struct UnitFileList {
         UnitFileState state;
 } UnitFileList;
 
+typedef enum UnitFileType {
+        UNIT_FILE_TYPE_REGULAR,
+        UNIT_FILE_TYPE_SYMLINK,
+        UNIT_FILE_TYPE_MASKED,
+       _UNIT_FILE_TYPE_MAX,
+        _UNIT_FILE_TYPE_INVALID = -1,
+} UnitFileType;
+
 typedef struct {
         char *name;
         char *path;
@@ -85,8 +94,26 @@ typedef struct {
         char **also;
 
         char *default_instance;
+
+        UnitFileType type;
+
+        char *symlink_target;
 } InstallInfo;
 
+static inline bool UNIT_FILE_INSTALL_INFO_HAS_RULES(InstallInfo *i) {
+        assert(i);
+
+        return !strv_isempty(i->aliases) ||
+               !strv_isempty(i->wanted_by) ||
+               !strv_isempty(i->required_by);
+}
+
+static inline bool UNIT_FILE_INSTALL_INFO_HAS_ALSO(InstallInfo *i) {
+        assert(i);
+
+        return !strv_isempty(i->also);
+}
+
 int unit_file_enable(UnitFileScope scope, bool runtime, const char *root_dir, char **files, bool force, UnitFileChange **changes, unsigned *n_changes);
 int unit_file_disable(UnitFileScope scope, bool runtime, const char *root_dir, char **files, UnitFileChange **changes, unsigned *n_changes);
 int unit_file_reenable(UnitFileScope scope, bool runtime, const char *root_dir, char **files, bool force, UnitFileChange **changes, unsigned *n_changes);
@@ -97,21 +124,14 @@ int unit_file_mask(UnitFileScope scope, bool runtime, const char *root_dir, char
 int unit_file_unmask(UnitFileScope scope, bool runtime, const char *root_dir, char **files, UnitFileChange **changes, unsigned *n_changes);
 int unit_file_set_default(UnitFileScope scope, const char *root_dir, const char *file, bool force, UnitFileChange **changes, unsigned *n_changes);
 int unit_file_get_default(UnitFileScope scope, const char *root_dir, char **name);
-int unit_file_add_dependency(UnitFileScope scope, bool runtime, const char *root_dir, char **files, char *target, UnitDependency dep, bool force, UnitFileChange **changes, unsigned *n_changes);
-
-UnitFileState unit_file_lookup_state(
-                UnitFileScope scope,
-                const char *root_dir,
-                const LookupPaths *paths,
-                const char *name);
-UnitFileState unit_file_get_state(
-                UnitFileScope scope,
-                const char *root_dir,
-                const char *filename);
+int unit_file_add_dependency(UnitFileScope scope, bool runtime, const char *root_dir, char **files, const char *target, UnitDependency dep, bool force, UnitFileChange **changes, unsigned *n_changes);
+
+int unit_file_lookup_state(UnitFileScope scope, const char *root_dir,const LookupPaths *paths, const char *name, UnitFileState *ret);
+int unit_file_get_state(UnitFileScope scope, const char *root_dir, const char *filename, UnitFileState *ret);
 
 int unit_file_get_list(UnitFileScope scope, const char *root_dir, Hashmap *h);
+Hashmap* unit_file_list_free(Hashmap *h);
 
-void unit_file_list_free(Hashmap *h);
 int unit_file_changes_add(UnitFileChange **changes, unsigned *n_changes, UnitFileChangeType type, const char *path, const char *source);
 void unit_file_changes_free(UnitFileChange *changes, unsigned n_changes);
 
diff --git a/src/shared/path-util.c b/src/shared/path-util.c
index d5510bf56..1181ffb9d 100644
--- a/src/shared/path-util.c
+++ b/src/shared/path-util.c
@@ -704,3 +704,37 @@ int fsck_exists(const char *fstype) {
 
         return 0;
 }
+
+char *prefix_root(const char *root, const char *path) {
+        char *n, *p;
+        size_t l;
+
+        /* If root is passed, prefixes path with it. Otherwise returns
+         * it as is. */
+
+        assert(path);
+
+        /* First, drop duplicate prefixing slashes from the path */
+        while (path[0] == '/' && path[1] == '/')
+                path++;
+
+        if (isempty(root) || path_equal(root, "/"))
+                return strdup(path);
+
+        l = strlen(root) + 1 + strlen(path) + 1;
+
+        n = new(char, l);
+        if (!n)
+                return NULL;
+
+        p = stpcpy(n, root);
+
+        while (p > n && p[-1] == '/')
+                p--;
+
+        if (path[0] != '/')
+                *(p++) = '/';
+
+        strcpy(p, path);
+        return n;
+}
diff --git a/src/shared/path-util.h b/src/shared/path-util.h
index ca81b49cb..71bb740e9 100644
--- a/src/shared/path-util.h
+++ b/src/shared/path-util.h
@@ -63,6 +63,33 @@ bool paths_check_timestamp(const char* const* paths, usec_t *paths_ts_usec, bool
 
 int fsck_exists(const char *fstype);
 
+char *prefix_root(const char *root, const char *path);
+
+/* Similar to prefix_root(), but returns an alloca() buffer, or
+ * possibly a const pointer into the path parameter */
+#define prefix_roota(root, path)                                        \
+        ({                                                              \
+                const char* _path = (path), *_root = (root), *_ret;     \
+                char *_p, *_n;                                          \
+                size_t _l;                                              \
+                while (_path[0] == '/' && _path[1] == '/')              \
+                        _path ++;                                       \
+                if (isempty(_root) || path_equal(_root, "/"))           \
+                        _ret = _path;                                   \
+                else {                                                  \
+                        _l = strlen(_root) + 1 + strlen(_path) + 1;     \
+                        _n = alloca(_l);                                \
+                        _p = stpcpy(_n, _root);                         \
+                        while (_p > _n && _p[-1] == '/')                \
+                                _p--;                                   \
+                        if (_path[0] != '/')                            \
+                                *(_p++) = '/';                          \
+                        strcpy(_p, _path);                              \
+                        _ret = _n;                                      \
+                }                                                       \
+                _ret;                                                   \
+        })
+
 /* Iterates through the path prefixes of the specified path, going up
  * the tree, to root. Also returns "" (and not "/"!) for the root
  * directory. Excludes the specified directory itself */
diff --git a/src/shared/unit-name.c b/src/shared/unit-name.c
index f728af4a8..b7827d14b 100644
--- a/src/shared/unit-name.c
+++ b/src/shared/unit-name.c
@@ -63,16 +63,13 @@ static const char* const unit_load_state_table[_UNIT_LOAD_STATE_MAX] = {
 
 DEFINE_STRING_TABLE_LOOKUP(unit_load_state, UnitLoadState);
 
-bool unit_name_is_valid(const char *n, enum template_valid template_ok) {
+bool unit_name_is_valid(const char *n, UnitNameFlags flags) {
         const char *e, *i, *at;
 
-        /* Valid formats:
-         *
-         *         string@instance.suffix
-         *         string.suffix
-         */
+        assert((flags & ~(UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE)) == 0);
 
-        assert(IN_SET(template_ok, TEMPLATE_VALID, TEMPLATE_INVALID));
+        if (_unlikely_(flags == 0))
+                return false;
 
         if (isempty(n))
                 return false;
@@ -96,15 +93,22 @@ bool unit_name_is_valid(const char *n, enum template_valid template_ok) {
                         return false;
         }
 
-        if (at) {
-                if (at == n)
-                        return false;
+        if (at == n)
+                return false;
 
-                if (template_ok != TEMPLATE_VALID && at+1 == e)
-                        return false;
-        }
+        if (flags & UNIT_NAME_PLAIN)
+                if (!at)
+                        return true;
+
+        if (flags & UNIT_NAME_INSTANCE)
+                if (at && e > at + 1)
+                        return true;
+
+        if (flags & UNIT_NAME_TEMPLATE)
+                if (at && e == at + 1)
+                        return true;
 
-        return true;
+        return false;
 }
 
 bool unit_instance_is_valid(const char *i) {
diff --git a/src/shared/unit-name.h b/src/shared/unit-name.h
index 6f139cc4c..436486062 100644
--- a/src/shared/unit-name.h
+++ b/src/shared/unit-name.h
@@ -107,6 +107,13 @@ enum UnitDependency {
         _UNIT_DEPENDENCY_INVALID = -1
 };
 
+typedef enum UnitNameFlags {
+        UNIT_NAME_PLAIN = 1,      /* Allow foo.service */
+        UNIT_NAME_INSTANCE = 2,   /* Allow foo@bar.service */
+        UNIT_NAME_TEMPLATE = 4,   /* Allow foo@.service */
+        UNIT_NAME_ANY = UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE,
+} UnitNameFlags;
+
 const char *unit_type_to_string(UnitType i) _const_;
 UnitType unit_type_from_string(const char *s) _pure_;
 
@@ -117,12 +124,7 @@ int unit_name_to_instance(const char *n, char **instance);
 char* unit_name_to_prefix(const char *n);
 char* unit_name_to_prefix_and_instance(const char *n);
 
-enum template_valid {
-        TEMPLATE_INVALID,
-        TEMPLATE_VALID,
-};
-
-bool unit_name_is_valid(const char *n, enum template_valid template_ok) _pure_;
+bool unit_name_is_valid(const char *n, UnitNameFlags flags) _pure_;
 bool unit_prefix_is_valid(const char *p) _pure_;
 bool unit_instance_is_valid(const char *i) _pure_;
 
diff --git a/src/shared/util.c b/src/shared/util.c
index a24aa7f93..036677eb4 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -1094,6 +1094,27 @@ int readlink_and_canonicalize(const char *p, char **r) {
         return 0;
 }
 
+
+int readlink_and_make_absolute_root(const char *root, const char *path, char **ret) {
+        _cleanup_free_ char *target = NULL, *t = NULL;
+        const char *full;
+        int r;
+
+        full = prefix_roota(root, path);
+        r = readlink_malloc(full, &target);
+        if (r < 0)
+                return r;
+
+        t = file_in_same_dir(path, target);
+        if (!t)
+                return -ENOMEM;
+
+        *ret = t;
+        t = NULL;
+
+        return 0;
+}
+
 int reset_all_signal_handlers(void) {
         int sig, r = 0;
 
diff --git a/src/shared/util.h b/src/shared/util.h
index b4a4a491f..a441e44ff 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -281,6 +281,7 @@ int readlink_malloc(const char *p, char **r);
 int readlink_value(const char *p, char **ret);
 int readlink_and_make_absolute(const char *p, char **r);
 int readlink_and_canonicalize(const char *p, char **r);
+int readlink_and_make_absolute_root(const char *root, const char *path, char **ret);
 
 int reset_all_signal_handlers(void);
 int reset_signal_mask(void);
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index bf5bb398b..95ddf3be7 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -1304,7 +1304,7 @@ static void output_unit_file_list(const UnitFileList *units, unsigned c) {
                 if (u->state == UNIT_FILE_MASKED ||
                     u->state == UNIT_FILE_MASKED_RUNTIME ||
                     u->state == UNIT_FILE_DISABLED ||
-                    u->state == UNIT_FILE_INVALID) {
+                    u->state == UNIT_FILE_BAD) {
                         on  = ansi_highlight_red();
                         off = ansi_highlight_off();
                 } else if (u->state == UNIT_FILE_ENABLED) {
@@ -5637,8 +5637,8 @@ static int unit_is_enabled(sd_bus *bus, char **args) {
                 STRV_FOREACH(name, names) {
                         UnitFileState state;
 
-                        state = unit_file_get_state(arg_scope, arg_root, *name);
-                        if (state < 0)
+                        r = unit_file_get_state(arg_scope, arg_root, *name, &state);
+                        if (r < 0)
                                 return log_error_errno(state, "Failed to get unit file state for %s: %m", *name);
 
                         if (state == UNIT_FILE_ENABLED ||
diff --git a/src/sysv-generator/sysv-generator.c b/src/sysv-generator/sysv-generator.c
index d60e75a06..7e0e7fc28 100644
--- a/src/sysv-generator/sysv-generator.c
+++ b/src/sysv-generator/sysv-generator.c
@@ -712,6 +712,7 @@ static int fix_order(SysvStub *s, Hashmap *all_services) {
 
 static int enumerate_sysv(const LookupPaths *lp, Hashmap *all_services) {
         char **path;
+        int r;
 
         STRV_FOREACH(path, lp->sysvinit_path) {
                 _cleanup_closedir_ DIR *d = NULL;
@@ -728,7 +729,6 @@ static int enumerate_sysv(const LookupPaths *lp, Hashmap *all_services) {
                         _cleanup_free_ char *fpath = NULL, *name = NULL;
                         _cleanup_free_ SysvStub *service = NULL;
                         struct stat st;
-                        int r;
 
                         if (hidden_file(de->d_name))
                                 continue;
@@ -755,8 +755,12 @@ static int enumerate_sysv(const LookupPaths *lp, Hashmap *all_services) {
                         if (!fpath)
                                 return log_oom();
 
-                        if (unit_file_lookup_state(UNIT_FILE_SYSTEM, NULL, lp, name) >= 0) {
-                                log_debug("Native unit for %s already exists, skipping", name);
+                        r = unit_file_lookup_state(UNIT_FILE_SYSTEM, NULL, lp, name, NULL);
+                        if (r < 0 && r != -ENOENT) {
+                                log_debug_errno(r, "Failed to detect whether %s exists, skipping: %m", name);
+                                continue;
+                        } else if (r >= 0) {
+                                log_debug("Native unit for %s already exists, skipping.", name);
                                 continue;
                         }
 
diff --git a/src/test/test-install-root.c b/src/test/test-install-root.c
new file mode 100644
index 000000000..89d91d3d6
--- /dev/null
+++ b/src/test/test-install-root.c
@@ -0,0 +1,663 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "fileio.h"
+#include "install.h"
+#include "mkdir.h"
+#include "util.h"
+
+static void test_basic_mask_and_enable(const char *root) {
+        const char *p;
+        UnitFileState state;
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", NULL) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", NULL) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", NULL) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", NULL) == -ENOENT);
+
+        p = strjoina(root, "/usr/lib/systemd/system/a.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", NULL) >= 0);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        p = strjoina(root, "/usr/lib/systemd/system/b.service");
+        assert_se(symlink("a.service", p) >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", NULL) >= 0);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        p = strjoina(root, "/usr/lib/systemd/system/c.service");
+        assert_se(symlink("/usr/lib/systemd/system/a.service", p) >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", NULL) >= 0);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        p = strjoina(root, "/usr/lib/systemd/system/d.service");
+        assert_se(symlink("c.service", p) >= 0);
+
+        /* This one is interesting, as d follows a relative, then an absolute symlink */
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", NULL) >= 0);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_mask(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/dev/null"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/a.service");
+        assert_se(streq(changes[0].path, p));
+
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", &state) >= 0 && state == UNIT_FILE_MASKED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", &state) >= 0 && state == UNIT_FILE_MASKED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", &state) >= 0 && state == UNIT_FILE_MASKED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", &state) >= 0 && state == UNIT_FILE_MASKED);
+
+        /* Enabling a masked unit should fail! */
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), false, &changes, &n_changes) == -ESHUTDOWN);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_unmask(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/a.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), false, &changes, &n_changes) == 1);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/a.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/a.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+
+        /* Enabling it again should succeed but be a NOP */
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), false, &changes, &n_changes) == 1);
+        assert_se(n_changes == 0);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/a.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        /* Disabling a disabled unit must suceed but be a NOP */
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("a.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 0);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        /* Let's enable this indirectly via a symlink */
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("d.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/a.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/a.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+
+        /* Let's try to reenable */
+
+        assert_se(unit_file_reenable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("b.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 2);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/a.service");
+        assert_se(streq(changes[0].path, p));
+        assert_se(changes[1].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[1].source, "/usr/lib/systemd/system/a.service"));
+        assert_se(streq(changes[1].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "a.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "b.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "c.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "d.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+}
+
+static void test_linked_units(const char *root) {
+        const char *p, *q;
+        UnitFileState state;
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0, i;
+
+        /*
+         * We'll test three cases here:
+         *
+         * a) a unit file in /opt, that we use "systemctl link" and
+         * "systemctl enable" on to make it available to the system
+         *
+         * b) a unit file in /opt, that is statically linked into
+         * /usr/lib/systemd/system, that "enable" should work on
+         * correctly.
+         *
+         * c) a unit file in /opt, that is linked into
+         * /etc/systemd/system, and where "enable" should result in
+         * -ELOOP, since using information from /etc to generate
+         * information in /etc should not be allowed.
+         */
+
+        p = strjoina(root, "/opt/linked.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        p = strjoina(root, "/opt/linked2.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        p = strjoina(root, "/opt/linked3.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked.service", NULL) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked2.service", NULL) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked3.service", NULL) == -ENOENT);
+
+        p = strjoina(root, "/usr/lib/systemd/system/linked2.service");
+        assert_se(symlink("/opt/linked2.service", p) >= 0);
+
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/linked3.service");
+        assert_se(symlink("/opt/linked3.service", p) >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked2.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked3.service", &state) >= 0 && state == UNIT_FILE_LINKED);
+
+        /* First, let's link the unit into the search path */
+        assert_se(unit_file_link(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("/opt/linked.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/opt/linked.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/linked.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked.service", &state) >= 0 && state == UNIT_FILE_LINKED);
+
+        /* Let's unlink it from the search path again */
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("linked.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/linked.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked.service", NULL) == -ENOENT);
+
+        /* Now, let's not just link it, but also enable it */
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("/opt/linked.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 2);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/linked.service");
+        q = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/linked.service");
+        for (i = 0 ; i < n_changes; i++) {
+                assert_se(changes[i].type == UNIT_FILE_SYMLINK);
+                assert_se(streq(changes[i].source, "/opt/linked.service"));
+
+                if (p && streq(changes[i].path, p))
+                        p = NULL;
+                else if (q && streq(changes[i].path, q))
+                        q = NULL;
+                else
+                        assert_not_reached("wut?");
+        }
+        assert(!p && !q);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+
+        /* And let's unlink it again */
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("linked.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 2);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/linked.service");
+        q = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/linked.service");
+        for (i = 0; i < n_changes; i++) {
+                assert_se(changes[i].type == UNIT_FILE_UNLINK);
+
+                if (p && streq(changes[i].path, p))
+                        p = NULL;
+                else if (q && streq(changes[i].path, q))
+                        q = NULL;
+                else
+                        assert_not_reached("wut?");
+        }
+        assert(!p && !q);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "linked.service", NULL) == -ENOENT);
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("linked2.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 2);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/linked2.service");
+        q = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/linked2.service");
+        for (i = 0 ; i < n_changes; i++) {
+                assert_se(changes[i].type == UNIT_FILE_SYMLINK);
+                assert_se(streq(changes[i].source, "/opt/linked2.service"));
+
+                if (p && streq(changes[i].path, p))
+                        p = NULL;
+                else if (q && streq(changes[i].path, q))
+                        q = NULL;
+                else
+                        assert_not_reached("wut?");
+        }
+        assert(!p && !q);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("linked3.service"), false, &changes, &n_changes) == -ELOOP);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+}
+
+static void test_default(const char *root) {
+        _cleanup_free_ char *def = NULL;
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0;
+        const char *p;
+
+        p = strjoina(root, "/usr/lib/systemd/system/test-default-real.target");
+        assert_se(write_string_file(p, "# pretty much empty") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/test-default.target");
+        assert_se(symlink("test-default-real.target", p) >= 0);
+
+        assert_se(unit_file_get_default(UNIT_FILE_SYSTEM, root, &def) == -ENOENT);
+
+        assert_se(unit_file_set_default(UNIT_FILE_SYSTEM, root, "idontexist.target", false, &changes, &n_changes) == -ENOENT);
+        assert_se(n_changes == 0);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_default(UNIT_FILE_SYSTEM, root, &def) == -ENOENT);
+
+        assert_se(unit_file_set_default(UNIT_FILE_SYSTEM, root, "test-default.target", false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/test-default-real.target"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/default.target");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_default(UNIT_FILE_SYSTEM, root, &def) >= 0);
+        assert_se(streq_ptr(def, "test-default-real.target"));
+}
+
+static void test_add_dependency(const char *root) {
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0;
+        const char *p;
+
+        p = strjoina(root, "/usr/lib/systemd/system/real-add-dependency-test-target.target");
+        assert_se(write_string_file(p, "# pretty much empty") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/add-dependency-test-target.target");
+        assert_se(symlink("real-add-dependency-test-target.target", p) >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/real-add-dependency-test-service.service");
+        assert_se(write_string_file(p, "# pretty much empty") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/add-dependency-test-service.service");
+        assert_se(symlink("real-add-dependency-test-service.service", p) >= 0);
+
+        assert_se(unit_file_add_dependency(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("add-dependency-test-service.service"), "add-dependency-test-target.target", UNIT_WANTS, false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/real-add-dependency-test-service.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/real-add-dependency-test-target.target.wants/real-add-dependency-test-service.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+}
+
+static void test_template_enable(const char *root) {
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0;
+        UnitFileState state;
+        const char *p;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) == -ENOENT);
+
+        p = strjoina(root, "/usr/lib/systemd/system/template@.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "DefaultInstance=def\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/template-symlink@.service");
+        assert_se(symlink("template@.service", p) >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("template@.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/template@.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/template@def.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@def.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("template@.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("template@foo.service"), false, &changes, &n_changes) >= 0);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/template@.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/template@foo.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("template@foo.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@quux.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@quux.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("template-symlink@quux.service"), false, &changes, &n_changes) >= 0);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/template@.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/template@quux.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template@quux.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@def.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@foo.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "template-symlink@quux.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+}
+
+static void test_indirect(const char *root) {
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0;
+        UnitFileState state;
+        const char *p;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirecta.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirectb.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirectc.service", &state) == -ENOENT);
+
+        p = strjoina(root, "/usr/lib/systemd/system/indirecta.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "Also=indirectb.service\n") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/indirectb.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/indirectc.service");
+        assert_se(symlink("indirecta.service", p) >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirecta.service", &state) >= 0 && state == UNIT_FILE_INDIRECT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirectb.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirectc.service", &state) >= 0 && state == UNIT_FILE_INDIRECT);
+
+        assert_se(unit_file_enable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("indirectc.service"), false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/indirectb.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/indirectb.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirecta.service", &state) >= 0 && state == UNIT_FILE_INDIRECT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirectb.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "indirectc.service", &state) >= 0 && state == UNIT_FILE_INDIRECT);
+
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("indirectc.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/indirectb.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+}
+
+static void test_preset_and_list(const char *root) {
+        UnitFileChange *changes = NULL;
+        unsigned n_changes = 0, i;
+        const char *p, *q;
+        UnitFileState state;
+        bool got_yes = false, got_no = false;
+        Iterator j;
+        UnitFileList *fl;
+        Hashmap *h;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-yes.service", &state) == -ENOENT);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-no.service", &state) == -ENOENT);
+
+        p = strjoina(root, "/usr/lib/systemd/system/preset-yes.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/preset-no.service");
+        assert_se(write_string_file(p,
+                                    "[Install]\n"
+                                    "WantedBy=multi-user.target\n") >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system-preset/test.preset");
+        assert_se(write_string_file(p,
+                                    "enable *-yes.*\n"
+                                    "disable *\n") >= 0);
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-yes.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-no.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_preset(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("preset-yes.service"), UNIT_FILE_PRESET_FULL, false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_SYMLINK);
+        assert_se(streq(changes[0].source, "/usr/lib/systemd/system/preset-yes.service"));
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/preset-yes.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-yes.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-no.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_disable(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("preset-yes.service"), &changes, &n_changes) >= 0);
+        assert_se(n_changes == 1);
+        assert_se(changes[0].type == UNIT_FILE_UNLINK);
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/preset-yes.service");
+        assert_se(streq(changes[0].path, p));
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-yes.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-no.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_preset(UNIT_FILE_SYSTEM, false, root, STRV_MAKE("preset-no.service"), UNIT_FILE_PRESET_FULL, false, &changes, &n_changes) >= 0);
+        assert_se(n_changes == 0);
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-yes.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-no.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(unit_file_preset_all(UNIT_FILE_SYSTEM, false, root, UNIT_FILE_PRESET_FULL, false, &changes, &n_changes) >= 0);
+
+        assert_se(n_changes > 0);
+
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/multi-user.target.wants/preset-yes.service");
+
+        for (i = 0; i < n_changes; i++) {
+
+                if (changes[i].type == UNIT_FILE_SYMLINK) {
+                        assert_se(streq(changes[i].source, "/usr/lib/systemd/system/preset-yes.service"));
+                        assert_se(streq(changes[i].path, p));
+                } else
+                        assert_se(changes[i].type == UNIT_FILE_UNLINK);
+        }
+
+        unit_file_changes_free(changes, n_changes);
+        changes = NULL; n_changes = 0;
+
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-yes.service", &state) >= 0 && state == UNIT_FILE_ENABLED);
+        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, "preset-no.service", &state) >= 0 && state == UNIT_FILE_DISABLED);
+
+        assert_se(h = hashmap_new(&string_hash_ops));
+        assert_se(unit_file_get_list(UNIT_FILE_SYSTEM, root, h) >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system/preset-yes.service");
+        q = strjoina(root, "/usr/lib/systemd/system/preset-no.service");
+
+        HASHMAP_FOREACH(fl, h, j) {
+                assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, root, basename(fl->path), &state) >= 0);
+                assert_se(fl->state == state);
+
+                if (streq(fl->path, p)) {
+                        got_yes = true;
+                        assert_se(fl->state == UNIT_FILE_ENABLED);
+                } else if (streq(fl->path, q)) {
+                        got_no = true;
+                        assert_se(fl->state == UNIT_FILE_DISABLED);
+                } else
+                        assert_se(IN_SET(fl->state, UNIT_FILE_DISABLED, UNIT_FILE_STATIC, UNIT_FILE_INDIRECT));
+        }
+
+        unit_file_list_free(h);
+
+        assert_se(got_yes && got_no);
+}
+
+int main(int argc, char *argv[]) {
+        char root[] = "/tmp/rootXXXXXX";
+        const char *p;
+
+        assert_se(mkdtemp(root));
+
+        p = strjoina(root, "/usr/lib/systemd/system/");
+        assert_se(mkdir_p(p, 0755) >= 0);
+
+        p = strjoina(root, SYSTEM_CONFIG_UNIT_PATH"/");
+        assert_se(mkdir_p(p, 0755) >= 0);
+
+        p = strjoina(root, "/run/systemd/system/");
+        assert_se(mkdir_p(p, 0755) >= 0);
+
+        p = strjoina(root, "/opt/");
+        assert_se(mkdir_p(p, 0755) >= 0);
+
+        p = strjoina(root, "/usr/lib/systemd/system-preset/");
+        assert_se(mkdir_p(p, 0755) >= 0);
+
+        test_basic_mask_and_enable(root);
+        test_linked_units(root);
+        test_default(root);
+        test_add_dependency(root);
+        test_template_enable(root);
+        test_indirect(root);
+        test_preset_and_list(root);
+
+        assert_se(rm_rf_dangerous(root, false, true, false));
+
+        return 0;
+}
diff --git a/src/test/test-install.c b/src/test/test-install.c
index 467970b00..08a1faf2c 100644
--- a/src/test/test-install.c
+++ b/src/test/test-install.c
@@ -50,17 +50,19 @@ int main(int argc, char* argv[]) {
         const char *const files2[] = { "/home/lennart/test.service", NULL };
         UnitFileChange *changes = NULL;
         unsigned n_changes = 0;
+        UnitFileState state = 0;
 
         h = hashmap_new(&string_hash_ops);
         r = unit_file_get_list(UNIT_FILE_SYSTEM, NULL, h);
         assert_se(r == 0);
 
         HASHMAP_FOREACH(p, h, i) {
-                UnitFileState s;
+                UnitFileState s = _UNIT_FILE_STATE_INVALID;
 
-                s = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(p->path));
+                r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(p->path), &s);
 
-                assert_se(p->state == s);
+                assert_se((r < 0 && p->state == UNIT_FILE_BAD) ||
+                          (p->state == s));
 
                 fprintf(stderr, "%s (%s)\n",
                         p->path,
@@ -82,7 +84,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_ENABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_ENABLED);
 
         log_error("disable");
 
@@ -95,7 +99,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_DISABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_DISABLED);
 
         log_error("mask");
         changes = NULL;
@@ -110,7 +116,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_MASKED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_MASKED);
 
         log_error("unmask");
         changes = NULL;
@@ -125,7 +133,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_DISABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_DISABLED);
 
         log_error("mask");
         changes = NULL;
@@ -137,7 +147,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_MASKED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_MASKED);
 
         log_error("disable");
         changes = NULL;
@@ -152,7 +164,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_MASKED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_MASKED);
 
         log_error("umask");
         changes = NULL;
@@ -164,7 +178,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0]) == UNIT_FILE_DISABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, files[0], &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_DISABLED);
 
         log_error("enable files2");
         changes = NULL;
@@ -176,19 +192,22 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == UNIT_FILE_ENABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_ENABLED);
 
         log_error("disable files2");
         changes = NULL;
         n_changes = 0;
 
-        r = unit_file_disable(UNIT_FILE_SYSTEM, false, NULL, (char**) files2, &changes, &n_changes);
+        r = unit_file_disable(UNIT_FILE_SYSTEM, false, NULL, STRV_MAKE(basename(files2[0])), &changes, &n_changes);
         assert_se(r >= 0);
 
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == _UNIT_FILE_STATE_INVALID);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r < 0);
 
         log_error("link files2");
         changes = NULL;
@@ -200,19 +219,22 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == UNIT_FILE_LINKED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_LINKED);
 
         log_error("disable files2");
         changes = NULL;
         n_changes = 0;
 
-        r = unit_file_disable(UNIT_FILE_SYSTEM, false, NULL, (char**) files2, &changes, &n_changes);
+        r = unit_file_disable(UNIT_FILE_SYSTEM, false, NULL, STRV_MAKE(basename(files2[0])), &changes, &n_changes);
         assert_se(r >= 0);
 
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == _UNIT_FILE_STATE_INVALID);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r < 0);
 
         log_error("link files2");
         changes = NULL;
@@ -224,7 +246,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == UNIT_FILE_LINKED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_LINKED);
 
         log_error("reenable files2");
         changes = NULL;
@@ -236,19 +260,22 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == UNIT_FILE_ENABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_ENABLED);
 
         log_error("disable files2");
         changes = NULL;
         n_changes = 0;
 
-        r = unit_file_disable(UNIT_FILE_SYSTEM, false, NULL, (char**) files2, &changes, &n_changes);
+        r = unit_file_disable(UNIT_FILE_SYSTEM, false, NULL, STRV_MAKE(basename(files2[0])), &changes, &n_changes);
         assert_se(r >= 0);
 
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0])) == _UNIT_FILE_STATE_INVALID);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files2[0]), &state);
+        assert_se(r < 0);
         log_error("preset files");
         changes = NULL;
         n_changes = 0;
@@ -259,7 +286,9 @@ int main(int argc, char* argv[]) {
         dump_changes(changes, n_changes);
         unit_file_changes_free(changes, n_changes);
 
-        assert_se(unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files[0])) == UNIT_FILE_ENABLED);
+        r = unit_file_get_state(UNIT_FILE_SYSTEM, NULL, basename(files[0]), &state);
+        assert_se(r >= 0);
+        assert_se(state == UNIT_FILE_ENABLED);
 
         return 0;
 }