SF_ATTACHPENDING
if (sd->s_flags & SF_ATTACHPENDING) {
if (!usl_sync_check_sig(sd, sd->s_acqsig, SF_ATTACHPENDING))
if (!(sd->s_flags & SF_ATTACHPENDING)) {
sd->s_flags &= ~SF_ATTACHPENDING;
if (!(sd->s_flags & SF_ATTACHPENDING)) {
sd->s_flags &= ~SF_ATTACHPENDING;