HAMMER_PFSD_SLAVE
pfsd->mirror_flags |= HAMMER_PFSD_SLAVE;
(((pfsd)->mirror_flags & HAMMER_PFSD_SLAVE) != 0)
pfsm->pfsd.mirror_flags &= ~HAMMER_PFSD_SLAVE;
pfsm->pfsd.mirror_flags |= HAMMER_PFSD_SLAVE;