namespace-util: port namespace_get_leader() to PidRef

src/basic/namespace-util.c

@@ -351,31 +351,46 @@ int pidref_in_same_namespace(PidRef *pid1, PidRef *pid2, NamespaceType type) {
         return fd_inode_same(ns1, ns2);
 }
 
-int namespace_get_leader(pid_t pid, NamespaceType type, pid_t *ret) {
+int namespace_get_leader(PidRef *pidref, NamespaceType type, PidRef *ret) {
         int r;
 
-        assert(pid >= 0);
+        /* Note: we don't bother with pidref_is_set()/pidref_is_remote() here, as the first call we do,
+         * pidref_get_ppid_as_pidref() calls those anyway */
+
         assert(type >= 0 && type < _NAMESPACE_TYPE_MAX);
         assert(ret);
 
-        for (;;) {
-                pid_t ppid;
+        _cleanup_(pidref_done) PidRef current = PIDREF_NULL;
+        PidRef *c = pidref;
 
-                r = pid_get_ppid(pid, &ppid);
+        for (;;) {
+                _cleanup_(pidref_done) PidRef parent = PIDREF_NULL;
+
+                r = pidref_get_ppid_as_pidref(c, &parent);
                 if (r < 0)
                         return r;
 
-                r = in_same_namespace(pid, ppid, type);
+                r = pidref_in_same_namespace(c, &parent, type);
                 if (r < 0)
                         return r;
                 if (r == 0) {
                         /* If the parent and the child are not in the same namespace, then the child is
                          * the leader we are looking for. */
-                        *ret = pid;
+
+                        if (pidref_is_set(&current))
+                                *ret = TAKE_PIDREF(current);
+                        else {
+                                r = pidref_copy(c, ret);
+                                if (r < 0)
+                                        return r;
+                        }
+
                         return 0;
                 }
 
-                pid = ppid;
+                pidref_done(&current);
+                current = TAKE_PIDREF(parent);
+                c = &current;
         }
 }
 

src/basic/namespace-util.h

@@ -62,7 +62,7 @@ static inline int in_same_namespace(pid_t pid1, pid_t pid2, NamespaceType type)
                                         type);
 }
 
-int namespace_get_leader(pid_t pid, NamespaceType type, pid_t *ret);
+int namespace_get_leader(PidRef *pidref, NamespaceType type, PidRef *ret);
 
 int detach_mount_namespace(void);
 int detach_mount_namespace_harder(uid_t target_uid, gid_t target_gid);