[v4,3/3] io_uring: Remove unnecessary BUILD_BUG_ON
Commit Message
In the io_uring_cmd_prep_async() there is an unnecessary compilation time
check to check if cmd is correctly placed at field 48 of the SQE.
This is unnecessary, since this check is already in place at
io_uring_init():
BUILD_BUG_SQE_ELEM(48, __u64, addr3);
Remove it and the uring_cmd_pdu_size() function, which is not used
anymore.
Keith started a discussion about this topic in the following thread:
Link: https://lore.kernel.org/lkml/ZDBmQOhbyU0iLhMw@kbusch-mbp.dhcp.thefacebook.com/
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
io_uring/uring_cmd.c | 3 ---
io_uring/uring_cmd.h | 8 --------
2 files changed, 11 deletions(-)
Comments
On Thu, May 04, 2023 at 05:18:56AM -0700, Breno Leitao wrote:
> In the io_uring_cmd_prep_async() there is an unnecessary compilation time
> check to check if cmd is correctly placed at field 48 of the SQE.
>
> This is unnecessary, since this check is already in place at
> io_uring_init():
>
> BUILD_BUG_SQE_ELEM(48, __u64, addr3);
>
> Remove it and the uring_cmd_pdu_size() function, which is not used
> anymore.
>
> Keith started a discussion about this topic in the following thread:
> Link: https://lore.kernel.org/lkml/ZDBmQOhbyU0iLhMw@kbusch-mbp.dhcp.thefacebook.com/
>
> Signed-off-by: Breno Leitao <leitao@debian.org>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Thanks,
Ming
@@ -70,9 +70,6 @@ int io_uring_cmd_prep_async(struct io_kiocb *req)
{
struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
- BUILD_BUG_ON(uring_cmd_pdu_size(0) != 16);
- BUILD_BUG_ON(uring_cmd_pdu_size(1) != 80);
-
memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
ioucmd->sqe = req->async_data;
return 0;
@@ -3,11 +3,3 @@
int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags);
int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_uring_cmd_prep_async(struct io_kiocb *req);
-
-/*
- * The URING_CMD payload starts at 'cmd' in the first sqe, and continues into
- * the following sqe if SQE128 is used.
- */
-#define uring_cmd_pdu_size(is_sqe128) \
- ((1 + !!(is_sqe128)) * sizeof(struct io_uring_sqe) - \
- offsetof(struct io_uring_sqe, cmd))