RC_G_LOCKED
if ((rp->rc_gflags & RC_G_LOCKED) != 0) {
rp->rc_gflags |= RC_G_LOCKED;
KASSERT((rp->rc_gflags & RC_G_LOCKED) != 0);
rp->rc_gflags &= ~RC_G_LOCKED;
rp->rc_gflags = RC_G_LOCKED;
while ((rp->rc_gflags & RC_G_LOCKED) != 0) {
rp->rc_gflags |= RC_G_LOCKED;
KASSERT((rp->rc_gflags & RC_G_LOCKED) == 0);