core: Filter by unit name behind the D-Bus, instead on the client side (#3142)

This commit improves systemd performance on the systems which have
thousands of units.

src/core/dbus-manager.c

@@ -889,7 +889,7 @@ static int method_reset_failed(sd_bus_message *message, void *userdata, sd_bus_e
         return sd_bus_reply_method_return(message, NULL);
 }
 
-static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_error *error, char **states) {
+static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_error *error, char **states, char **patterns) {
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         Manager *m = userdata;
         const char *k;
@@ -929,6 +929,10 @@ static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_e
                     !strv_contains(states, unit_sub_state_to_string(u)))
                         continue;
 
+                if (!strv_isempty(patterns) &&
+                    !strv_fnmatch_or_empty(patterns, u->id, FNM_NOESCAPE))
+                        continue;
+
                 unit_path = unit_dbus_path(u);
                 if (!unit_path)
                         return -ENOMEM;
@@ -963,7 +967,7 @@ static int list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_e
 }
 
 static int method_list_units(sd_bus_message *message, void *userdata, sd_bus_error *error) {
-        return list_units_filtered(message, userdata, error, NULL);
+        return list_units_filtered(message, userdata, error, NULL, NULL);
 }
 
 static int method_list_units_filtered(sd_bus_message *message, void *userdata, sd_bus_error *error) {
@@ -974,7 +978,23 @@ static int method_list_units_filtered(sd_bus_message *message, void *userdata, s
         if (r < 0)
                 return r;
 
-        return list_units_filtered(message, userdata, error, states);
+        return list_units_filtered(message, userdata, error, states, NULL);
+}
+
+static int method_list_units_by_patterns(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        _cleanup_strv_free_ char **states = NULL;
+        _cleanup_strv_free_ char **patterns = NULL;
+        int r;
+
+        r = sd_bus_message_read_strv(message, &states);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read_strv(message, &patterns);
+        if (r < 0)
+                return r;
+
+        return list_units_filtered(message, userdata, error, states, patterns);
 }
 
 static int method_list_jobs(sd_bus_message *message, void *userdata, sd_bus_error *error) {
@@ -1465,7 +1485,7 @@ static int method_set_exit_code(sd_bus_message *message, void *userdata, sd_bus_
         return sd_bus_reply_method_return(message, NULL);
 }
 
-static int method_list_unit_files(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+static int list_unit_files_by_patterns(sd_bus_message *message, void *userdata, sd_bus_error *error, char **states, char **patterns) {
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         Manager *m = userdata;
         UnitFileList *item;
@@ -1490,7 +1510,7 @@ static int method_list_unit_files(sd_bus_message *message, void *userdata, sd_bu
         if (!h)
                 return -ENOMEM;
 
-        r = unit_file_get_list(m->unit_file_scope, NULL, h);
+        r = unit_file_get_list(m->unit_file_scope, NULL, h, states, patterns);
         if (r < 0)
                 goto fail;
 
@@ -1518,6 +1538,26 @@ fail:
         return r;
 }
 
+static int method_list_unit_files(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return list_unit_files_by_patterns(message, userdata, error, NULL, NULL);
+}
+
+static int method_list_unit_files_by_patterns(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        _cleanup_strv_free_ char **states = NULL;
+        _cleanup_strv_free_ char **patterns = NULL;
+        int r;
+
+        r = sd_bus_message_read_strv(message, &states);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read_strv(message, &patterns);
+        if (r < 0)
+                return r;
+
+        return list_unit_files_by_patterns(message, userdata, error, states, patterns);
+}
+
 static int method_get_unit_file_state(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         Manager *m = userdata;
         const char *name;
@@ -2073,6 +2113,7 @@ const sd_bus_vtable bus_manager_vtable[] = {
         SD_BUS_METHOD("ResetFailed", NULL, NULL, method_reset_failed, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ListUnits", NULL, "a(ssssssouso)", method_list_units, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ListUnitsFiltered", "as", "a(ssssssouso)", method_list_units_filtered, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("ListUnitsByPatterns", "asas", "a(ssssssouso)", method_list_units_by_patterns, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ListJobs", NULL, "a(usssoo)", method_list_jobs, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("Subscribe", NULL, NULL, method_subscribe, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("Unsubscribe", NULL, NULL, method_unsubscribe, SD_BUS_VTABLE_UNPRIVILEGED),
@@ -2091,6 +2132,7 @@ const sd_bus_vtable bus_manager_vtable[] = {
         SD_BUS_METHOD("UnsetEnvironment", "as", NULL, method_unset_environment, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("UnsetAndSetEnvironment", "asas", NULL, method_unset_and_set_environment, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ListUnitFiles", NULL, "a(ss)", method_list_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("ListUnitFilesByPatterns", "asas", "a(ss)", method_list_unit_files_by_patterns, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("GetUnitFileState", "s", "s", method_get_unit_file_state, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("EnableUnitFiles", "asbb", "ba(sss)", method_enable_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("DisableUnitFiles", "asb", "a(sss)", method_disable_unit_files, SD_BUS_VTABLE_UNPRIVILEGED),

src/core/org.freedesktop.systemd1.conf

@@ -68,10 +68,18 @@
                        send_interface="org.freedesktop.systemd1.Manager"
                        send_member="ListUnitsFiltered"/>
 
+                <allow send_destination="org.freedesktop.systemd1"
+                       send_interface="org.freedesktop.systemd1.Manager"
+                       send_member="ListUnitsByPatterns"/>
+
                 <allow send_destination="org.freedesktop.systemd1"
                        send_interface="org.freedesktop.systemd1.Manager"
                        send_member="ListUnitFiles"/>
 
+                <allow send_destination="org.freedesktop.systemd1"
+                       send_interface="org.freedesktop.systemd1.Manager"
+                       send_member="ListUnitFilesByPatterns"/>
+
                 <allow send_destination="org.freedesktop.systemd1"
                        send_interface="org.freedesktop.systemd1.Manager"
                        send_member="GetUnitFileState"/>

src/shared/install.c

@@ -2653,7 +2653,9 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(UnitFileList*, unit_file_list_free_one);
 int unit_file_get_list(
                 UnitFileScope scope,
                 const char *root_dir,
-                Hashmap *h) {
+                Hashmap *h,
+                char **states,
+                char **patterns) {
 
         _cleanup_lookup_paths_free_ LookupPaths paths = {};
         char **i;
@@ -2685,6 +2687,9 @@ int unit_file_get_list(
                         if (!unit_name_is_valid(de->d_name, UNIT_NAME_ANY))
                                 continue;
 
+                        if (!strv_fnmatch_or_empty(patterns, de->d_name, FNM_NOESCAPE))
+                                continue;
+
                         if (hashmap_get(h, de->d_name))
                                 continue;
 
@@ -2705,6 +2710,10 @@ int unit_file_get_list(
                         if (r < 0)
                                 f->state = UNIT_FILE_BAD;
 
+                        if (!strv_isempty(states) &&
+                            !strv_contains(states, unit_file_state_to_string(f->state)))
+                                continue;
+
                         r = hashmap_put(h, basename(f->path), f);
                         if (r < 0)
                                 return r;

src/shared/install.h

@@ -232,7 +232,7 @@ int unit_file_add_dependency(
 int unit_file_get_state(UnitFileScope scope, const char *root_dir, const char *filename, UnitFileState *ret);
 int unit_file_exists(UnitFileScope scope, const LookupPaths *paths, const char *name);
 
-int unit_file_get_list(UnitFileScope scope, const char *root_dir, Hashmap *h);
+int unit_file_get_list(UnitFileScope scope, const char *root_dir, Hashmap *h, char **states, char **patterns);
 Hashmap* unit_file_list_free(Hashmap *h);
 
 int unit_file_changes_add(UnitFileChange **changes, unsigned *n_changes, UnitFileChangeType type, const char *path, const char *source);

src/systemctl/systemctl.c

@@ -541,6 +541,7 @@ static int get_unit_list(
         size_t size = c;
         int r;
         UnitInfo u;
+        bool fallback = false;
 
         assert(bus);
         assert(unit_infos);
@@ -552,8 +553,7 @@ static int get_unit_list(
                         "org.freedesktop.systemd1",
                         "/org/freedesktop/systemd1",
                         "org.freedesktop.systemd1.Manager",
-                        "ListUnitsFiltered");
+                        "ListUnitsByPatterns");
-
         if (r < 0)
                 return bus_log_create_error(r);
 
@@ -561,7 +561,34 @@ static int get_unit_list(
         if (r < 0)
                 return bus_log_create_error(r);
 
+        r = sd_bus_message_append_strv(m, patterns);
+        if (r < 0)
+                return bus_log_create_error(r);
+
         r = sd_bus_call(bus, m, 0, &error, &reply);
+        if (r < 0 && sd_bus_error_has_name(&error, SD_BUS_ERROR_UNKNOWN_METHOD)) {
+                /* Fallback to legacy ListUnitsFiltered method */
+                fallback = true;
+                log_debug_errno(r, "Failed to list units: %s Falling back to ListUnitsFiltered method.", bus_error_message(&error, r));
+                m = sd_bus_message_unref(m);
+                sd_bus_error_free(&error);
+
+                r = sd_bus_message_new_method_call(
+                                bus,
+                                &m,
+                                "org.freedesktop.systemd1",
+                                "/org/freedesktop/systemd1",
+                                "org.freedesktop.systemd1.Manager",
+                                "ListUnitsFiltered");
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_append_strv(m, arg_states);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_call(bus, m, 0, &error, &reply);
+        }
         if (r < 0)
                 return log_error_errno(r, "Failed to list units: %s", bus_error_message(&error, r));
 
@@ -572,7 +599,7 @@ static int get_unit_list(
         while ((r = bus_parse_unit_info(reply, &u)) > 0) {
                 u.machine = machine;
 
-                if (!output_show_unit(&u, patterns))
+                if (!output_show_unit(&u, fallback ? patterns : NULL))
                         continue;
 
                 if (!GREEDY_REALLOC(*unit_infos, size, c+1))
@@ -1282,7 +1309,7 @@ static int compare_unit_file_list(const void *a, const void *b) {
         return strcasecmp(basename(u->path), basename(v->path));
 }
 
-static bool output_show_unit_file(const UnitFileList *u, char **patterns) {
+static bool output_show_unit_file(const UnitFileList *u, char **states, char **patterns) {
         assert(u);
 
         if (!strv_fnmatch_or_empty(patterns, basename(u->path), FNM_NOESCAPE))
@@ -1299,8 +1326,8 @@ static bool output_show_unit_file(const UnitFileList *u, char **patterns) {
                         return false;
         }
 
-        if (!strv_isempty(arg_states) &&
+        if (!strv_isempty(states) &&
-            !strv_find(arg_states, unit_file_state_to_string(u->state)))
+            !strv_find(states, unit_file_state_to_string(u->state)))
                 return false;
 
         return true;
@@ -1373,6 +1400,7 @@ static int list_unit_files(int argc, char *argv[], void *userdata) {
         const char *state;
         char *path;
         int r;
+        bool fallback = false;
 
         pager_open(arg_no_pager, false);
 
@@ -1386,7 +1414,7 @@ static int list_unit_files(int argc, char *argv[], void *userdata) {
                 if (!h)
                         return log_oom();
 
-                r = unit_file_get_list(arg_scope, arg_root, h);
+                r = unit_file_get_list(arg_scope, arg_root, h, arg_states, strv_skip(argv, 1));
                 if (r < 0) {
                         unit_file_list_free(h);
                         return log_error_errno(r, "Failed to get unit file list: %m");
@@ -1401,7 +1429,7 @@ static int list_unit_files(int argc, char *argv[], void *userdata) {
                 }
 
                 HASHMAP_FOREACH(u, h, i) {
-                        if (!output_show_unit_file(u, strv_skip(argv, 1)))
+                        if (!output_show_unit_file(u, NULL, NULL))
                                 continue;
 
                         units[c++] = *u;
@@ -1411,6 +1439,7 @@ static int list_unit_files(int argc, char *argv[], void *userdata) {
                 assert(c <= n_units);
                 hashmap_free(h);
         } else {
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
                 sd_bus *bus;
 
@@ -1418,15 +1447,44 @@ static int list_unit_files(int argc, char *argv[], void *userdata) {
                 if (r < 0)
                         return r;
 
-                r = sd_bus_call_method(
+                r = sd_bus_message_new_method_call(
                                 bus,
+                                &m,
                                 "org.freedesktop.systemd1",
                                 "/org/freedesktop/systemd1",
                                 "org.freedesktop.systemd1.Manager",
-                                "ListUnitFiles",
+                                "ListUnitFilesByPatterns");
-                                &error,
+                if (r < 0)
-                                &reply,
+                        return bus_log_create_error(r);
-                                NULL);
+
+                r = sd_bus_message_append_strv(m, arg_states);
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_message_append_strv(m, strv_skip(argv, 1));
+                if (r < 0)
+                        return bus_log_create_error(r);
+
+                r = sd_bus_call(bus, m, 0, &error, &reply);
+                if (r < 0 && sd_bus_error_has_name(&error, SD_BUS_ERROR_UNKNOWN_METHOD)) {
+                        /* Fallback to legacy ListUnitFiles method */
+                        fallback = true;
+                        log_debug_errno(r, "Failed to list unit files: %s Falling back to ListUnitsFiles method.", bus_error_message(&error, r));
+                        m = sd_bus_message_unref(m);
+                        sd_bus_error_free(&error);
+
+                        r = sd_bus_message_new_method_call(
+                                        bus,
+                                        &m,
+                                        "org.freedesktop.systemd1",
+                                        "/org/freedesktop/systemd1",
+                                        "org.freedesktop.systemd1.Manager",
+                                        "ListUnitFiles");
+                        if (r < 0)
+                                return bus_log_create_error(r);
+
+                        r = sd_bus_call(bus, m, 0, &error, &reply);
+                }
                 if (r < 0)
                         return log_error_errno(r, "Failed to list unit files: %s", bus_error_message(&error, r));
 
@@ -1444,7 +1502,9 @@ static int list_unit_files(int argc, char *argv[], void *userdata) {
                                 unit_file_state_from_string(state)
                         };
 
-                        if (output_show_unit_file(&units[c], strv_skip(argv, 1)))
+                        if (output_show_unit_file(&units[c],
+                            fallback ? arg_states : NULL,
+                            fallback ? strv_skip(argv, 1) : NULL))
                                 c++;
 
                 }

src/test/test-install-root.c

@@ -606,7 +606,7 @@ static void test_preset_and_list(const char *root) {
         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);
+        assert_se(unit_file_get_list(UNIT_FILE_SYSTEM, root, h, NULL, NULL) >= 0);
 
         p = strjoina(root, "/usr/lib/systemd/system/preset-yes.service");
         q = strjoina(root, "/usr/lib/systemd/system/preset-no.service");

src/test/test-install.c

@@ -50,7 +50,7 @@ int main(int argc, char* argv[]) {
         log_parse_environment();
 
         h = hashmap_new(&string_hash_ops);
-        r = unit_file_get_list(UNIT_FILE_SYSTEM, NULL, h);
+        r = unit_file_get_list(UNIT_FILE_SYSTEM, NULL, h, NULL, NULL);
         assert_se(r == 0);
 
         HASHMAP_FOREACH(p, h, i) {

src/test/test-unit-file.c

@@ -53,7 +53,7 @@ static int test_unit_file_get_set(void) {
         h = hashmap_new(&string_hash_ops);
         assert_se(h);
 
-        r = unit_file_get_list(UNIT_FILE_SYSTEM, NULL, h);
+        r = unit_file_get_list(UNIT_FILE_SYSTEM, NULL, h, NULL, NULL);
 
         if (r == -EPERM || r == -EACCES) {
                 printf("Skipping test: unit_file_get_list: %s", strerror(-r));