Re: [PATCH 1/2] io_uring: Pass whole sqe to commands

From: Christoph Hellwig
Date: Thu Apr 20 2023 - 00:57:22 EST


On Wed, Apr 19, 2023 at 03:29:29AM -0700, Breno Leitao wrote:
> struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
> - const struct nvme_uring_cmd *cmd = ioucmd->cmd;
> + const struct nvme_uring_cmd *cmd = (struct nvme_uring_cmd *)ioucmd->sqe->cmd;

Please don't add the pointless cast. And in general avoid the overly
long lines.

I suspect most other users should just also defined their structures
const instead of adding all theses casts thare are a sign of problems,
but that's a pre-existing issue.
> struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
> - size_t cmd_size;
> + size_t size = sizeof(struct io_uring_sqe);
>
> BUILD_BUG_ON(uring_cmd_pdu_size(0) != 16);
> BUILD_BUG_ON(uring_cmd_pdu_size(1) != 80);
>
> - cmd_size = uring_cmd_pdu_size(req->ctx->flags & IORING_SETUP_SQE128);
> + if (req->ctx->flags & IORING_SETUP_SQE128)
> + size <<= 1;


Why does this stop using uring_cmd_pdu_size()?