systemctl: clean up start_unit_one() error handling

Let's split exit code handling in two: "r" is only used for errno-style
errors, and "ret" is used for exit() codes. Then, let's use EXIT_SUCCESS
for checking whether the latter is already used.

This way it should always be clear what kind of error we are processing,
and when we propaate one into the other.

Moreover this allows us to drop "q" form all inner loops, avoiding
confusion when to use "q" and when "r" to store received errors.

Fixes: #9704
(cherry picked from commit 0e8d9c0c4d7e71487c486f626c59853cfb031d16)

Related: #846319

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 1929692480b176d4b305043218c223a669a9dad9..4af9deb98dbb2f09d25064b060ad72f3c73ca5e8 100644 (file)
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -3004,12 +3004,12 @@ static enum action verb_to_action(const char *verb) {
 
 static int start_unit(int argc, char *argv[], void *userdata) {
         _cleanup_(bus_wait_for_jobs_freep) BusWaitForJobs *w = NULL;
+        _cleanup_(wait_context_free) WaitContext wait_context = {};
         const char *method, *mode, *one_name, *suffix = NULL;
         _cleanup_strv_free_ char **names = NULL;
+        int r, ret = EXIT_SUCCESS;
         sd_bus *bus;
-        _cleanup_(wait_context_free) WaitContext wait_context = {};
         char **name;
-        int r = 0;
 
         if (arg_wait && !STR_IN_SET(argv[0], "start", "restart")) {
                 log_error("--wait may only be used with the 'start' or 'restart' commands.");
@@ -3096,16 +3096,15 @@ static int start_unit(int argc, char *argv[], void *userdata) {
 
         STRV_FOREACH(name, names) {
                 _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
-                int q;
 
-                q = start_unit_one(bus, method, *name, mode, &error, w, arg_wait ? &wait_context : NULL);
-                if (r >= 0 && q < 0)
-                        r = translate_bus_error_to_exit_status(q, &error);
+                r = start_unit_one(bus, method, *name, mode, &error, w, arg_wait ? &wait_context : NULL);
+                if (ret == EXIT_SUCCESS && r < 0)
+                        ret = translate_bus_error_to_exit_status(r, &error);
         }
 
         if (!arg_no_block) {
-                int q, arg_count = 0;
                 const char* extra_args[4] = {};
+                int arg_count = 0;
 
                 if (arg_scope != UNIT_FILE_SYSTEM)
                         extra_args[arg_count++] = "--user";
@@ -3119,9 +3118,9 @@ static int start_unit(int argc, char *argv[], void *userdata) {
                         extra_args[arg_count++] = arg_host;
                 }
 
-                q = bus_wait_for_jobs(w, arg_quiet, extra_args);
-                if (q < 0)
-                        return q;
+                r = bus_wait_for_jobs(w, arg_quiet, extra_args);
+                if (r < 0)
+                        return r;
 
                 /* When stopping units, warn if they can still be triggered by
                  * another active unit (socket, path, timer) */
@@ -3130,16 +3129,15 @@ static int start_unit(int argc, char *argv[], void *userdata) {
                                 check_triggering_units(bus, *name);
         }
 
-        if (r >= 0 && arg_wait && !set_isempty(wait_context.unit_paths)) {
-                int q;
-                q = sd_event_loop(wait_context.event);
-                if (q < 0)
-                        return log_error_errno(q, "Failed to run event loop: %m");
+        if (ret == EXIT_SUCCESS && arg_wait && !set_isempty(wait_context.unit_paths)) {
+                r = sd_event_loop(wait_context.event);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to run event loop: %m");
                 if (wait_context.any_failed)
-                        r = EXIT_FAILURE;
+                        ret = EXIT_FAILURE;
         }
 
-        return r;
+        return ret;
 }
 
 #if ENABLE_LOGIND