RCOMMIT
while (rp->r_flags & RCOMMIT) {
rp->r_flags |= RCOMMIT;
rp->r_flags &= ~RCOMMIT;
ASSERT(rp->r_flags & RCOMMIT);
ASSERT(rp->r_flags & RCOMMIT);
while (rp->r_flags & RCOMMIT) {
rp->r_flags |= RCOMMIT;
rp->r_flags &= ~RCOMMIT;