STRIPE_BATCH_READY
clear_bit(STRIPE_BATCH_READY, &sh->state);
if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state))
clear_bit(STRIPE_BATCH_READY, &tmp->state);
(1 << STRIPE_BATCH_READY) |
set_bit(STRIPE_BATCH_READY, &sh->state);
return test_bit(STRIPE_BATCH_READY, &sh->state) &&