On 11/8/23 17:27, Chengming Zhou wrote:
CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled in the kernel config, so null_queue_rq() will return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE for some requests, which have been marked as IN_FLIGHT status. Then null_queue_rqs() put these requests in the rqlist and return back, blk-mq will try to queue them individually once again, caused the warning "WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE)" in blk_mq_start_request(). So handling of return value of null_queue_rq() in null_queue_rqs() is wrong, maybe we should __blk_mq_requeue_request() for these requests, before adding them in the rqlist?
Please follow the example of virtio_queue_rqs() and send any requests that need to be requeued back to the block layer core instead of handling these directly in null_queue_rqs(). Thanks, Bart.
