core: split up manager_get_unit_by_pid()

Let's move the actual cgroup part of it into a new separate function
manager_get_unit_by_pid_cgroup(), and then make
manager_get_unit_by_pid() just a wrapper that also checks the two pid
hashmaps.

Then, let's make sure the various calls that want to deliver events to
the owners of a PID check both hashmaps and the cgroup and deliver the
event to *each* of them. OTOH make sure bus calls like GetUnitByPID()
continue to check the PID hashmaps first and the cgroup only as
fallback.

1 files changed, 17 insertions, 7 deletions

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 9f06b28f26..0a5a08aeba 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -1378,9 +1378,8 @@ Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) {
         }
 }
 
-Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
+Unit *manager_get_unit_by_pid_cgroup(Manager *m, pid_t pid) {
         _cleanup_free_ char *cgroup = NULL;
-        Unit *u;
         int r;
 
         assert(m);
@@ -1388,6 +1387,21 @@ Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
         if (pid <= 0)
                 return NULL;
 
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
+        if (r < 0)
+                return NULL;
+
+        return manager_get_unit_by_cgroup(m, cgroup);
+}
+
+Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
+        Unit *u;
+
+        assert(m);
+
+        if (pid <= 0)
+                return NULL;
+
         if (pid == 1)
                 return hashmap_get(m->units, SPECIAL_INIT_SCOPE);
 
@@ -1399,11 +1413,7 @@ Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) {
         if (u)
                 return u;
 
-        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
-        if (r < 0)
-                return NULL;
-
-        return manager_get_unit_by_cgroup(m, cgroup);
+        return manager_get_unit_by_pid_cgroup(m, pid);
 }
 
 int manager_notify_cgroup_empty(Manager *m, const char *cgroup) {