Symbol: VQ_UNMOUNT
sys/kern/vfs_mount.c
2420
vfs_event_signal(NULL, VQ_UNMOUNT, 0);
usr.sbin/autofs/autounmountd.c
328
EV_SET(&event, 0, EVFILT_FS, EV_ADD | EV_CLEAR, VQ_MOUNT | VQ_UNMOUNT, 0, NULL);