Merge pull request #22375 from michaelolbrich/watchdog

fix watchdog handling during reboot

src/shared/watchdog.c

@@ -133,6 +133,10 @@ static int open_watchdog(void) {
         fn = !watchdog_device || path_equal(watchdog_device, "/dev/watchdog") ?
                 "/dev/watchdog0" : watchdog_device;
 
+        r = free_and_strdup(&watchdog_device, fn);
+        if (r < 0)
+                return log_oom_debug();
+
         watchdog_fd = open(fn, O_WRONLY|O_CLOEXEC);
         if (watchdog_fd < 0)
                 return log_debug_errno(errno, "Failed to open watchdog device %s, ignoring: %m", fn);

src/shutdown/shutdown.c

@@ -531,8 +531,9 @@ int main(int argc, char *argv[]) {
                           need_md_detach ? " MD devices," : "");
         }
 
-        /* We're done with the watchdog. */
-        watchdog_close(true);
+        /* We're done with the watchdog. Note that the watchdog is explicitly not
+         * stopped here. It remains active to guard against any issues during the
+         * rest of the shutdown sequence. */
         watchdog_free_device();
 
         arguments[0] = NULL;