udev_enumerate_add_match_sysattr 209 src/core/umount.c r = udev_enumerate_add_match_sysattr(e, "loop/backing_file", NULL); udev_enumerate_add_match_sysattr 160 src/udev/udevadm-trigger.c udev_enumerate_add_match_sysattr(udev_enumerate, key, val);