systemctl: rework daemon_reload() functions

Let's split out the inner parts of verb_daemon_reload() as a function
daemon_reload() and then stop using the former outside of the verbs
logic, and instead call the latter whenever we need to reload the daemon
as auxiliary opeation.

This should make our logic more systematic as we don't have to provide
fake or misleading argc/argv to verb_daemon_reload() anymore.

9 files changed, 67 insertions, 32 deletions

diff --git a/src/systemctl/systemctl-add-dependency.c b/src/systemctl/systemctl-add-dependency.c
index 9276ed3e2b..120798b33f 100644
--- a/src/systemctl/systemctl-add-dependency.c
+++ b/src/systemctl/systemctl-add-dependency.c
@@ -78,7 +78,9 @@ int verb_add_dependency(int argc, char *argv[], void *userdata) {
                         goto finish;
                 }
 
-                r = verb_daemon_reload(argc, argv, userdata);
+                r = daemon_reload(ACTION_RELOAD, /* graceful= */ false);
+                if (r > 0)
+                        r = 0;
         }
 
 finish:
diff --git a/src/systemctl/systemctl-compat-telinit.c b/src/systemctl/systemctl-compat-telinit.c
index 1e771ef4a6..20325e5e1c 100644
--- a/src/systemctl/systemctl-compat-telinit.c
+++ b/src/systemctl/systemctl-compat-telinit.c
@@ -142,13 +142,14 @@ int start_with_fallback(void) {
 }
 
 int reload_with_fallback(void) {
-        /* First, try systemd via D-Bus. */
-        if (verb_daemon_reload(0, NULL, NULL) >= 0)
-                return 0;
 
-        /* Nothing else worked, so let's try signals */
         assert(IN_SET(arg_action, ACTION_RELOAD, ACTION_REEXEC));
 
+        /* First, try systemd via D-Bus */
+        if (daemon_reload(arg_action, /* graceful= */ true) > 0)
+                return 0;
+
+        /* That didn't work, so let's try signals */
         if (kill(1, arg_action == ACTION_RELOAD ? SIGHUP : SIGTERM) < 0)
                 return log_error_errno(errno, "kill() failed: %m");
 
@@ -157,7 +158,7 @@ int reload_with_fallback(void) {
 
 int exec_telinit(char *argv[]) {
         (void) rlimit_nofile_safe();
-        execv(TELINIT, argv);
+        (void) execv(TELINIT, argv);
 
         return log_error_errno(SYNTHETIC_ERRNO(EIO),
                                "Couldn't find an alternative telinit implementation to spawn.");
diff --git a/src/systemctl/systemctl-daemon-reload.c b/src/systemctl/systemctl-daemon-reload.c
index 35a10e84cc..33de7d161e 100644
--- a/src/systemctl/systemctl-daemon-reload.c
+++ b/src/systemctl/systemctl-daemon-reload.c
@@ -6,7 +6,7 @@
 #include "systemctl-util.h"
 #include "systemctl.h"
 
-int verb_daemon_reload(int argc, char *argv[], void *userdata) {
+int daemon_reload(enum action action, bool graceful) {
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
         const char *method;
@@ -19,7 +19,7 @@ int verb_daemon_reload(int argc, char *argv[], void *userdata) {
 
         polkit_agent_open_maybe();
 
-        switch (arg_action) {
+        switch (action) {
 
         case ACTION_RELOAD:
                 method = "Reload";
@@ -29,13 +29,8 @@ int verb_daemon_reload(int argc, char *argv[], void *userdata) {
                 method = "Reexecute";
                 break;
 
-        case ACTION_SYSTEMCTL:
-                method = streq(argv[0], "daemon-reexec") ? "Reexecute" :
-                                     /* "daemon-reload" */ "Reload";
-                break;
-
         default:
-                assert_not_reached();
+                return -EINVAL;
         }
 
         r = bus_message_new_method_call(bus, &m, bus_systemd_mgr, method);
@@ -50,14 +45,36 @@ int verb_daemon_reload(int argc, char *argv[], void *userdata) {
         r = sd_bus_call(bus, m, DEFAULT_TIMEOUT_USEC * 2, &error, NULL);
 
         /* On reexecution, we expect a disconnect, not a reply */
-        if (IN_SET(r, -ETIMEDOUT, -ECONNRESET) && streq(method, "Reexecute"))
-                r = 0;
+        if (IN_SET(r, -ETIMEDOUT, -ECONNRESET) && action == ACTION_REEXEC)
+                return 1;
+        if (r < 0) {
+                if (graceful) { /* If graceful mode is selected, debug log, but don't fail */
+                        log_debug_errno(r, "Failed to reload daemon via the bus, ignoring: %s", bus_error_message(&error, r));
+                        return 0;
+                }
 
-        if (r < 0 && arg_action == ACTION_SYSTEMCTL)
                 return log_error_errno(r, "Failed to reload daemon: %s", bus_error_message(&error, r));
+        }
+
+        return 1;
+}
 
-        /* Note that for the legacy commands (i.e. those with action != ACTION_SYSTEMCTL) we support
-         * fallbacks to the old ways of doing things, hence don't log any error in that case here. */
+int verb_daemon_reload(int argc, char *argv[], void *userdata) {
+        enum action a;
+        int r;
+
+        assert(argc >= 1);
+
+        if (streq(argv[0], "daemon-reexec"))
+                a = ACTION_REEXEC;
+        else if (streq(argv[0], "daemon-reload"))
+                a = ACTION_RELOAD;
+        else
+                assert_not_reached();
+
+        r = daemon_reload(a, /* graceful= */ false);
+        if (r < 0)
+                return r;
 
-        return r < 0 ? r : 0;
+        return 0;
 }
diff --git a/src/systemctl/systemctl-daemon-reload.h b/src/systemctl/systemctl-daemon-reload.h
index d4215cc37c..ced34ce44e 100644
--- a/src/systemctl/systemctl-daemon-reload.h
+++ b/src/systemctl/systemctl-daemon-reload.h
@@ -1,4 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
+#include "systemctl.h"
+
+int daemon_reload(enum action, bool graceful);
+
 int verb_daemon_reload(int argc, char *argv[], void *userdata);
diff --git a/src/systemctl/systemctl-edit.c b/src/systemctl/systemctl-edit.c
index 4b19bf7015..f5123e80c1 100644
--- a/src/systemctl/systemctl-edit.c
+++ b/src/systemctl/systemctl-edit.c
@@ -569,8 +569,11 @@ int verb_edit(int argc, char *argv[], void *userdata) {
 
         r = 0;
 
-        if (!arg_no_reload && !install_client_side())
-                r = verb_daemon_reload(argc, argv, userdata);
+        if (!arg_no_reload && !install_client_side()) {
+                r = daemon_reload(ACTION_RELOAD, /* graceful= */ false);
+                if (r > 0)
+                        r = 0;
+        }
 
 end:
         STRV_FOREACH_PAIR(original, tmp, paths) {
diff --git a/src/systemctl/systemctl-enable.c b/src/systemctl/systemctl-enable.c
index f258d9643b..3da2cd928a 100644
--- a/src/systemctl/systemctl-enable.c
+++ b/src/systemctl/systemctl-enable.c
@@ -86,7 +86,9 @@ int verb_enable(int argc, char *argv[], void *userdata) {
         if (strv_isempty(names)) {
                 if (arg_no_reload || install_client_side())
                         return 0;
-                return verb_daemon_reload(argc, argv, userdata);
+
+                r = daemon_reload(ACTION_RELOAD, /* graceful= */ false);
+                return r > 0 ? 0 : r;
         }
 
         if (streq(verb, "disable")) {
@@ -234,9 +236,11 @@ int verb_enable(int argc, char *argv[], void *userdata) {
                         goto finish;
 
                 /* Try to reload if enabled */
-                if (!arg_no_reload)
-                        r = verb_daemon_reload(argc, argv, userdata);
-                else
+                if (!arg_no_reload) {
+                        r = daemon_reload(ACTION_RELOAD, /* graceful= */ false);
+                        if (r > 0)
+                                r = 0;
+                } else
                         r = 0;
         }
 
diff --git a/src/systemctl/systemctl-preset-all.c b/src/systemctl/systemctl-preset-all.c
index fa98a9bf80..8e36ddc0c0 100644
--- a/src/systemctl/systemctl-preset-all.c
+++ b/src/systemctl/systemctl-preset-all.c
@@ -51,7 +51,9 @@ int verb_preset_all(int argc, char *argv[], void *userdata) {
                         goto finish;
                 }
 
-                r = verb_daemon_reload(argc, argv, userdata);
+                r = daemon_reload(ACTION_RELOAD, /* graceful= */ false);
+                if (r > 0)
+                        r = 0;
         }
 
 finish:
diff --git a/src/systemctl/systemctl-set-default.c b/src/systemctl/systemctl-set-default.c
index db149e78cf..5f9186aa38 100644
--- a/src/systemctl/systemctl-set-default.c
+++ b/src/systemctl/systemctl-set-default.c
@@ -132,9 +132,11 @@ int verb_set_default(int argc, char *argv[], void *userdata) {
                         goto finish;
 
                 /* Try to reload if enabled */
-                if (!arg_no_reload)
-                        r = verb_daemon_reload(argc, argv, userdata);
-                else
+                if (!arg_no_reload) {
+                        r = daemon_reload(ACTION_RELOAD, /* graceful= */ false);
+                        if (r > 0)
+                                r = 0;
+                } else
                         r = 0;
         }
 
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index ec29e12e39..e81703ebe8 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -1051,8 +1051,8 @@ static int systemctl_main(int argc, char *argv[]) {
                 { "cat",                   2,        VERB_ANY, VERB_ONLINE_ONLY, verb_cat                     },
                 { "status",                VERB_ANY, VERB_ANY, VERB_ONLINE_ONLY, verb_show                    },
                 { "help",                  VERB_ANY, VERB_ANY, VERB_ONLINE_ONLY, verb_show                    },
-                { "daemon-reload",         VERB_ANY, 1,        VERB_ONLINE_ONLY, verb_daemon_reload           },
-                { "daemon-reexec",         VERB_ANY, 1,        VERB_ONLINE_ONLY, verb_daemon_reload           },
+                { "daemon-reload",         1,        1,        VERB_ONLINE_ONLY, verb_daemon_reload           },
+                { "daemon-reexec",         1,        1,        VERB_ONLINE_ONLY, verb_daemon_reload           },
                 { "log-level",             VERB_ANY, 2,        VERB_ONLINE_ONLY, verb_log_setting             },
                 { "log-target",            VERB_ANY, 2,        VERB_ONLINE_ONLY, verb_log_setting             },
                 { "service-log-level",     2,        3,        VERB_ONLINE_ONLY, verb_service_log_setting     },