SDF_DIRTY
if (((sd->flags & SDF_DIRTY) != 0 || *(int *)addr != 0)) {
sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
if ((sd->flags & SDF_DIRTY) != 0) {
sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
if ((sd->flags & SDF_DIRTY) != 0) {
sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);
sd->flags |= SDF_DIRTY;
sd->flags &= ~(SDF_FLUSHING|SDF_DIRTY);