QUEUE_FLAG_FAIL_IO
int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags);
blk_queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
blk_queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))