__CTR_FLAG_DELTA_DISKS
#define CTR_FLAG_DELTA_DISKS (1 << __CTR_FLAG_DELTA_DISKS)
if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))