[RFC PATCH v3 3/3] nvme: wire up support for async passthrough

[Keith Busch]

On Tue, Mar 16, 2021 at 07:31:26PM +0530, Kanchan Joshi wrote:
> @@ -1179,6 +1278,20 @@ static int nvme_submit_user_cmd(struct request_queue *q,
>  			req->cmd_flags |= REQ_INTEGRITY;
>  		}
>  	}
> +	if (ioucmd) { /* async handling */
> +		u32 effects;
> +
> +		effects = nvme_command_effects(ns->ctrl, ns, cmd->common.opcode);
> +		/* filter commands with non-zero effects, keep it simple for now*/

You shouldn't need to be concerned with this. You've wired up the ioucmd
only to the NVME_IOCTL_IO_CMD, and nvme_command_effects() can only
return 0 for that.

It would be worth adding support for NVME_IOCTL_IO_CMD64 too, though,
and that doesn't change the effects handling either.

> +		if (effects) {
> +			ret = -EOPNOTSUPP;
> +			goto out_unmap;
> +		}
> +		nvme_setup_uring_cmd_data(req, ioucmd, meta, write);
> +		blk_execute_rq_nowait(ns ? ns->disk : NULL, req, 0,
> +					nvme_end_async_pt);
> +		return 0;
> +	}