LOCKFS_BUSY
#define LOCKFS_IS_BUSY(LF) ((LF)->lf_flags & LOCKFS_BUSY)
#define LOCKFS_CLR_BUSY(LF) ((LF)->lf_flags &= ~LOCKFS_BUSY)
#define LOCKFS_SET_BUSY(LF) ((LF)->lf_flags |= LOCKFS_BUSY)