cgls: make function to query cgroup root public

No functional change.

3 files changed, 61 insertions, 46 deletions

diff --git a/src/cgls/cgls.c b/src/cgls/cgls.c
index b55aa86a40..e6ec9640a8 100644
--- a/src/cgls/cgls.c
+++ b/src/cgls/cgls.c
@@ -120,50 +120,6 @@ static int parse_argv(int argc, char *argv[]) {
         return 1;
 }
 
-static int get_cgroup_root(char **ret) {
-        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
-        _cleanup_free_ char *unit = NULL, *path = NULL;
-        const char *m;
-        int r;
-
-        if (!arg_machine) {
-                r = cg_get_root_path(ret);
-                if (r == -ENOMEDIUM)
-                        return log_error_errno(r, "Failed to get root control group path: No cgroup filesystem mounted on /sys/fs/cgroup");
-                else if (r < 0)
-                        return log_error_errno(r, "Failed to get root control group path: %m");
-
-                return 0;
-        }
-
-        m = strjoina("/run/systemd/machines/", arg_machine);
-        r = parse_env_file(m, NEWLINE, "SCOPE", &unit, NULL);
-        if (r < 0)
-                return log_error_errno(r, "Failed to load machine data: %m");
-
-        path = unit_dbus_path_from_name(unit);
-        if (!path)
-                return log_oom();
-
-        r = bus_connect_transport_systemd(BUS_TRANSPORT_LOCAL, NULL, false, &bus);
-        if (r < 0)
-                return log_error_errno(r, "Failed to create bus connection: %m");
-
-        r = sd_bus_get_property_string(
-                        bus,
-                        "org.freedesktop.systemd1",
-                        path,
-                        unit_dbus_interface_from_name(unit),
-                        "ControlGroup",
-                        &error,
-                        ret);
-        if (r < 0)
-                return log_error_errno(r, "Failed to query unit control group path: %s", bus_error_message(&error, r));
-
-        return 0;
-}
-
 static void show_cg_info(const char *controller, const char *path) {
 
         if (cg_all_unified() <= 0 && controller && !streq(controller, SYSTEMD_CGROUP_CONTROLLER))
@@ -198,7 +154,7 @@ int main(int argc, char *argv[]) {
                 _cleanup_free_ char *root = NULL;
                 int i;
 
-                r = get_cgroup_root(&root);
+                r = show_cgroup_get_root_and_warn(arg_machine, &root);
                 if (r < 0)
                         goto finish;
 
@@ -267,7 +223,7 @@ int main(int argc, char *argv[]) {
                 if (!done) {
                         _cleanup_free_ char *root = NULL;
 
-                        r = get_cgroup_root(&root);
+                        r = show_cgroup_get_root_and_warn(arg_machine, &root);
                         if (r < 0)
                                 goto finish;
 
diff --git a/src/shared/cgroup-show.c b/src/shared/cgroup-show.c
index f5bb0603c3..105710436e 100644
--- a/src/shared/cgroup-show.c
+++ b/src/shared/cgroup-show.c
@@ -24,10 +24,15 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include <systemd/sd-bus.h>
+
 #include "alloc-util.h"
+#include "bus-error.h"
+#include "bus-util.h"
 #include "cgroup-show.h"
 #include "cgroup-util.h"
 #include "fd-util.h"
+#include "fileio.h"
 #include "format-util.h"
 #include "locale-util.h"
 #include "macro.h"
@@ -36,6 +41,7 @@
 #include "process-util.h"
 #include "string-util.h"
 #include "terminal-util.h"
+#include "unit-name.h"
 
 static void show_pid_array(
                 pid_t pids[],
@@ -310,3 +316,52 @@ int show_cgroup_and_extra_by_spec(
 
         return show_cgroup_and_extra(controller, path, prefix, n_columns, extra_pids, n_extra_pids, flags);
 }
+
+int show_cgroup_get_root_and_warn(
+                const char *machine,
+                char **ret) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        _cleanup_free_ char *unit = NULL, *path = NULL;
+        const char *m;
+        int r;
+
+        if (!machine) {
+                r = cg_get_root_path(ret);
+                if (r == -ENOMEDIUM)
+                        return log_error_errno(r, "Failed to get root control group path.\n"
+                                                  "No cgroup filesystem mounted on /sys/fs/cgroup");
+                else if (r < 0)
+                        return log_error_errno(r, "Failed to get root control group path: %m");
+
+                return 0;
+        }
+
+        m = strjoina("/run/systemd/machines/", machine);
+        r = parse_env_file(m, NEWLINE, "SCOPE", &unit, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to load machine data: %m");
+
+        path = unit_dbus_path_from_name(unit);
+        if (!path)
+                return log_oom();
+
+        r = bus_connect_transport_systemd(BUS_TRANSPORT_LOCAL, NULL, false, &bus);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create bus connection: %m");
+
+        r = sd_bus_get_property_string(
+                        bus,
+                        "org.freedesktop.systemd1",
+                        path,
+                        unit_dbus_interface_from_name(unit),
+                        "ControlGroup",
+                        &error,
+                        ret);
+        if (r < 0)
+                return log_error_errno(r, "Failed to query unit control group path: %s",
+                                       bus_error_message(&error, r));
+
+        return 0;
+}
diff --git a/src/shared/cgroup-show.h b/src/shared/cgroup-show.h
index 5c1d6e6d98..0574f40552 100644
--- a/src/shared/cgroup-show.h
+++ b/src/shared/cgroup-show.h
@@ -30,3 +30,7 @@ int show_cgroup(const char *controller, const char *path, const char *prefix, un
 
 int show_cgroup_and_extra_by_spec(const char *spec, const char *prefix, unsigned n_columns, const pid_t extra_pids[], unsigned n_extra_pids, OutputFlags flags);
 int show_cgroup_and_extra(const char *controller, const char *path, const char *prefix, unsigned n_columns, const pid_t extra_pids[], unsigned n_extra_pids, OutputFlags flags);
+
+int show_cgroup_get_root_and_warn(
+                const char *machine,
+                char **ret);