[SPDK] Some questions about SPDK bdev module

I have read the source code of SPDK and implemented my own bdev module by referencing official bdev modules like null, malloc and aio. But I still have some questions and hope someone can explain.

1.When a bdev is deleted, the 'destruct' function pointer of spdk_bdev_fn_table is called and the block device is closed. I find that ongoing spdk_bdev_io is not explicitly completed by calling spdk_bdev_io_complete(). Are these spdk_bdev_io cleaned automatically by SPDK framework?

2.How to write the json config that corresponds to the rpc call of 'log_set_flag'? I have tried many ways but still can not work and I have to implement my own version of rpc call in my own bdev module to enable json config.

Thanks!