two pidref tweaks (#35918)

src/basic/pidref.c

@@ -219,37 +219,32 @@ PidRef* pidref_free(PidRef *pidref) {
         return mfree(pidref);
 }
 
-int pidref_copy(const PidRef *pidref, PidRef *dest) {
-        _cleanup_close_ int dup_fd = -EBADF;
-        pid_t dup_pid = 0;
+int pidref_copy(const PidRef *pidref, PidRef *ret) {
+        _cleanup_(pidref_done) PidRef copy = PIDREF_NULL;
 
         /* If NULL is passed we'll generate a PidRef that refers to no process. This makes it easy to
          * copy pidref fields that might or might not reference a process yet. */
 
-        assert(dest);
+        assert(ret);
 
         if (pidref) {
                 if (pidref_is_remote(pidref)) /* Propagate remote flag */
-                        dup_fd = -EREMOTE;
+                        copy.fd = -EREMOTE;
                 else if (pidref->fd >= 0) {
-                        dup_fd = fcntl(pidref->fd, F_DUPFD_CLOEXEC, 3);
-                        if (dup_fd < 0) {
+                        copy.fd = fcntl(pidref->fd, F_DUPFD_CLOEXEC, 3);
+                        if (copy.fd < 0) {
                                 if (!ERRNO_IS_RESOURCE(errno))
                                         return -errno;
 
-                                dup_fd = -EBADF;
+                                copy.fd = -EBADF;
                         }
                 }
 
-                if (pidref->pid > 0)
-                        dup_pid = pidref->pid;
+                copy.pid = pidref->pid;
+                copy.fd_id = pidref->fd_id;
         }
 
-        *dest = (PidRef) {
-                .fd = TAKE_FD(dup_fd),
-                .pid = dup_pid,
-        };
-
+        *ret = TAKE_PIDREF(copy);
         return 0;
 }
 
@@ -406,22 +401,17 @@ int pidref_wait(const PidRef *pidref, siginfo_t *ret, int options) {
                 return -ECHILD;
 
         siginfo_t si = {};
-
-        if (pidref->fd >= 0) {
+        if (pidref->fd >= 0)
                 r = RET_NERRNO(waitid(P_PIDFD, pidref->fd, &si, options));
-                if (r >= 0) {
-                        if (ret)
-                                *ret = si;
-                        return r;
-                }
-                if (r != -EINVAL) /* P_PIDFD was added in kernel 5.4 only */
-                        return r;
-        }
+        else
+                r = RET_NERRNO(waitid(P_PID, pidref->pid, &si, options));
+        if (r < 0)
+                return r;
 
-        r = RET_NERRNO(waitid(P_PID, pidref->pid, &si, options));
-        if (r >= 0 && ret)
+        if (ret)
                 *ret = si;
-        return r;
+
+        return 0;
 }
 
 int pidref_wait_for_terminate(const PidRef *pidref, siginfo_t *ret) {

src/basic/pidref.h

@@ -83,7 +83,7 @@ void pidref_done(PidRef *pidref);
 PidRef* pidref_free(PidRef *pidref);
 DEFINE_TRIVIAL_CLEANUP_FUNC(PidRef*, pidref_free);
 
-int pidref_copy(const PidRef *pidref, PidRef *dest);
+int pidref_copy(const PidRef *pidref, PidRef *ret);
 int pidref_dup(const PidRef *pidref, PidRef **ret);
 
 int pidref_new_from_pid(pid_t pid, PidRef **ret);