core: rework generator dir logic, move the dirs into LookupPaths structure

A long time ago – when generators where first introduced – the directories for
them were randomly created via mkdtemp(). This was changed later so that they
use fixed name directories now. Let's make use of this, and add the genrator
dirs to the LookupPaths structure and into the unit file search path maintained
in it. This has the benefit that the generator dirs are now normal part of the
search path for all tools, and thus are shown in "systemctl list-unit-files"
too.

6 files changed, 30 insertions, 124 deletions

diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 00372b92b4..739bd14b9e 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -1924,7 +1924,7 @@ const sd_bus_vtable bus_manager_vtable[] = {
         SD_BUS_PROPERTY("Environment", "as", NULL, offsetof(Manager, environment), 0),
         SD_BUS_PROPERTY("ConfirmSpawn", "b", bus_property_get_bool, offsetof(Manager, confirm_spawn), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("ShowStatus", "b", bus_property_get_bool, offsetof(Manager, show_status), SD_BUS_VTABLE_PROPERTY_CONST),
-        SD_BUS_PROPERTY("UnitPath", "as", NULL, offsetof(Manager, lookup_paths.unit_path), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("UnitPath", "as", NULL, offsetof(Manager, lookup_paths.search_path), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("DefaultStandardOutput", "s", bus_property_get_exec_output, offsetof(Manager, default_std_output), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("DefaultStandardError", "s", bus_property_get_exec_output, offsetof(Manager, default_std_output), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_WRITABLE_PROPERTY("RuntimeWatchdogUSec", "t", bus_property_get_usec, property_set_runtime_watchdog, offsetof(Manager, runtime_watchdog), 0),
diff --git a/src/core/load-dropin.c b/src/core/load-dropin.c
index 22b71b6f5e..1c65055a3f 100644
--- a/src/core/load-dropin.c
+++ b/src/core/load-dropin.c
@@ -55,7 +55,7 @@ int unit_load_dropin(Unit *u) {
         SET_FOREACH(t, u->names, i) {
                 char **p;
 
-                STRV_FOREACH(p, u->manager->lookup_paths.unit_path) {
+                STRV_FOREACH(p, u->manager->lookup_paths.search_path) {
                         unit_file_process_dir(u->manager->unit_path_cache, *p, t, ".wants", UNIT_WANTS,
                                               add_dependency_consumer, u, NULL);
                         unit_file_process_dir(u->manager->unit_path_cache, *p, t, ".requires", UNIT_REQUIRES,
diff --git a/src/core/load-dropin.h b/src/core/load-dropin.h
index d8a4aefbb3..942d26724e 100644
--- a/src/core/load-dropin.h
+++ b/src/core/load-dropin.h
@@ -25,7 +25,7 @@
 /* Read service data supplementary drop-in directories */
 
 static inline int unit_find_dropin_paths(Unit *u, char ***paths) {
-        return unit_file_find_dropin_paths(u->manager->lookup_paths.unit_path,
+        return unit_file_find_dropin_paths(u->manager->lookup_paths.search_path,
                                            u->manager->unit_path_cache,
                                            u->names,
                                            paths);
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index f1a874cfdf..3a77ceb551 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -3574,7 +3574,7 @@ static int load_from_path(Unit *u, const char *path) {
         } else  {
                 char **p;
 
-                STRV_FOREACH(p, u->manager->lookup_paths.unit_path) {
+                STRV_FOREACH(p, u->manager->lookup_paths.search_path) {
 
                         /* Instead of opening the path right away, we manually
                          * follow all symlinks and add their name to our unit
diff --git a/src/core/manager.c b/src/core/manager.c
index e739795e70..79dc77d50e 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1053,7 +1053,7 @@ static void manager_build_unit_path_cache(Manager *m) {
         /* This simply builds a list of files we know exist, so that
          * we don't always have to go to disk */
 
-        STRV_FOREACH(i, m->lookup_paths.unit_path) {
+        STRV_FOREACH(i, m->lookup_paths.search_path) {
                 struct dirent *de;
 
                 d = opendir(*i);
@@ -1116,18 +1116,13 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 
         assert(m);
 
-        dual_timestamp_get(&m->generators_start_timestamp);
-        r = manager_run_generators(m);
-        dual_timestamp_get(&m->generators_finish_timestamp);
+        r = lookup_paths_init(&m->lookup_paths, m->running_as, true, NULL);
         if (r < 0)
                 return r;
 
-        r = lookup_paths_init(
-                        &m->lookup_paths, m->running_as, true,
-                        NULL,
-                        m->generator_unit_path,
-                        m->generator_unit_path_early,
-                        m->generator_unit_path_late);
+        dual_timestamp_get(&m->generators_start_timestamp);
+        r = manager_run_generators(m);
+        dual_timestamp_get(&m->generators_finish_timestamp);
         if (r < 0)
                 return r;
 
@@ -2542,17 +2537,12 @@ int manager_reload(Manager *m) {
         manager_undo_generators(m);
         lookup_paths_free(&m->lookup_paths);
 
-        /* Find new unit paths */
-        q = manager_run_generators(m);
+        q = lookup_paths_init(&m->lookup_paths, m->running_as, true, NULL);
         if (q < 0 && r >= 0)
                 r = q;
 
-        q = lookup_paths_init(
-                        &m->lookup_paths, m->running_as, true,
-                        NULL,
-                        m->generator_unit_path,
-                        m->generator_unit_path_early,
-                        m->generator_unit_path_late);
+        /* Find new unit paths */
+        q = manager_run_generators(m);
         if (q < 0 && r >= 0)
                 r = q;
 
@@ -2732,77 +2722,6 @@ void manager_check_finished(Manager *m) {
         manager_invalidate_startup_units(m);
 }
 
-static int create_generator_dir(Manager *m, char **generator, const char *name) {
-        char *p;
-        int r;
-
-        assert(m);
-        assert(generator);
-        assert(name);
-
-        if (*generator)
-                return 0;
-
-        if (m->running_as == MANAGER_SYSTEM && getpid() == 1) {
-                /* systemd --system, not running --test */
-
-                p = strappend("/run/systemd/", name);
-                if (!p)
-                        return log_oom();
-
-                r = mkdir_p_label(p, 0755);
-                if (r < 0) {
-                        log_error_errno(r, "Failed to create generator directory %s: %m", p);
-                        free(p);
-                        return r;
-                }
-        } else if (m->running_as == MANAGER_USER) {
-                const char *s = NULL;
-
-                s = getenv("XDG_RUNTIME_DIR");
-                if (!s)
-                        return -EINVAL;
-                p = strjoin(s, "/systemd/", name, NULL);
-                if (!p)
-                        return log_oom();
-
-                r = mkdir_p_label(p, 0755);
-                if (r < 0) {
-                        log_error_errno(r, "Failed to create generator directory %s: %m", p);
-                        free(p);
-                        return r;
-                }
-        } else {
-                /* systemd --system --test */
-
-                p = strjoin("/tmp/systemd-", name, ".XXXXXX", NULL);
-                if (!p)
-                        return log_oom();
-
-                if (!mkdtemp(p)) {
-                        log_error_errno(errno, "Failed to create generator directory %s: %m", p);
-                        free(p);
-                        return -errno;
-                }
-        }
-
-        *generator = p;
-        return 0;
-}
-
-static void trim_generator_dir(Manager *m, char **generator) {
-        assert(m);
-        assert(generator);
-
-        if (!*generator)
-                return;
-
-        if (rmdir(*generator) >= 0)
-                *generator = mfree(*generator);
-
-        return;
-}
-
 static int manager_run_generators(Manager *m) {
         _cleanup_strv_free_ char **paths = NULL;
         const char *argv[5];
@@ -2821,62 +2740,53 @@ static int manager_run_generators(Manager *m) {
         /* Optimize by skipping the whole process by not creating output directories
          * if no generators are found. */
         STRV_FOREACH(path, paths) {
-                r = access(*path, F_OK);
-                if (r == 0)
+                if (access(*path, F_OK) >= 0)
                         goto found;
                 if (errno != ENOENT)
                         log_warning_errno(errno, "Failed to open generator directory %s: %m", *path);
         }
+
         return 0;
 
  found:
-        r = create_generator_dir(m, &m->generator_unit_path, "generator");
+        r = mkdir_p_label(m->lookup_paths.generator, 0755);
         if (r < 0)
                 goto finish;
 
-        r = create_generator_dir(m, &m->generator_unit_path_early, "generator.early");
+        r = mkdir_p_label(m->lookup_paths.generator_early, 0755);
         if (r < 0)
                 goto finish;
 
-        r = create_generator_dir(m, &m->generator_unit_path_late, "generator.late");
+        r = mkdir_p_label(m->lookup_paths.generator_late, 0755);
         if (r < 0)
                 goto finish;
 
         argv[0] = NULL; /* Leave this empty, execute_directory() will fill something in */
-        argv[1] = m->generator_unit_path;
-        argv[2] = m->generator_unit_path_early;
-        argv[3] = m->generator_unit_path_late;
+        argv[1] = m->lookup_paths.generator;
+        argv[2] = m->lookup_paths.generator_early;
+        argv[3] = m->lookup_paths.generator_late;
         argv[4] = NULL;
 
         RUN_WITH_UMASK(0022)
                 execute_directories((const char* const*) paths, DEFAULT_TIMEOUT_USEC, (char**) argv);
 
 finish:
-        trim_generator_dir(m, &m->generator_unit_path);
-        trim_generator_dir(m, &m->generator_unit_path_early);
-        trim_generator_dir(m, &m->generator_unit_path_late);
+        /* Trim empty dirs */
+        (void) rmdir(m->lookup_paths.generator);
+        (void) rmdir(m->lookup_paths.generator_early);
+        (void) rmdir(m->lookup_paths.generator_late);
         return r;
 }
 
-static void remove_generator_dir(Manager *m, char **generator) {
-        assert(m);
-        assert(generator);
-
-        if (!*generator)
-                return;
-
-        strv_remove(m->lookup_paths.unit_path, *generator);
-        (void) rm_rf(*generator, REMOVE_ROOT);
-
-        *generator = mfree(*generator);
-}
-
 static void manager_undo_generators(Manager *m) {
         assert(m);
 
-        remove_generator_dir(m, &m->generator_unit_path);
-        remove_generator_dir(m, &m->generator_unit_path_early);
-        remove_generator_dir(m, &m->generator_unit_path_late);
+        if (m->lookup_paths.generator)
+                (void) rm_rf(m->lookup_paths.generator, REMOVE_ROOT);
+        if (m->lookup_paths.generator_early)
+                (void) rm_rf(m->lookup_paths.generator_early, REMOVE_ROOT);
+        if (m->lookup_paths.generator_late)
+                (void) rm_rf(m->lookup_paths.generator_late, REMOVE_ROOT);
 }
 
 int manager_environment_add(Manager *m, char **minus, char **plus) {
diff --git a/src/core/manager.h b/src/core/manager.h
index 9803f73129..5471bd7a0d 100644
--- a/src/core/manager.h
+++ b/src/core/manager.h
@@ -162,10 +162,6 @@ struct Manager {
         dual_timestamp units_load_start_timestamp;
         dual_timestamp units_load_finish_timestamp;
 
-        char *generator_unit_path;
-        char *generator_unit_path_early;
-        char *generator_unit_path_late;
-
         struct udev* udev;
 
         /* Data specific to the device subsystem */