RE: [PATCH] io_uring: Change res2 parameter type in io_uring_cmd_done

[lizetao <lizetao1@huawei.com>]

Hi,

> -----Original Message-----
> From: Bernd Schubert <bschubert@ddn.com>
> Sent: Monday, December 2, 2024 10:22 PM
> To: Jens Axboe <axboe@kernel.dk>; Pavel Begunkov
> <asml.silence@gmail.com>; Kanchan Joshi <joshi.k@samsung.com>
> Cc: io-uring@vger.kernel.org; Bernd Schubert <bschubert@ddn.com>;
> stable@vger.kernel.org
> Subject: [PATCH] io_uring: Change res2 parameter type in
> io_uring_cmd_done
> 
> Change the type of the res2 parameter in io_uring_cmd_done from ssize_t to
> u64. This aligns the parameter type with io_req_set_cqe32_extra, which
> expects u64 arguments.
> The change eliminates potential issues on 32-bit architectures where ssize_t
> might be 32-bit.
> 
> Only user of passing res2 is drivers/nvme/host/ioctl.c and it actually passes
> u64.
> 
> Fixes: ee692a21e9bf ("fs,io_uring: add infrastructure for uring-cmd")
> Signed-off-by: Bernd Schubert <bschubert@ddn.com>
> Cc: stable@vger.kernel.org
> ---
>  include/linux/io_uring/cmd.h | 2 +-
>  io_uring/uring_cmd.c         | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
> index
> 578a3fdf5c719cf45fd4b6f9c894204d6b4f946c..75691ca2043acdf687709bb2f2
> 7829a1bc7a1103 100644
> --- a/include/linux/io_uring/cmd.h
> +++ b/include/linux/io_uring/cmd.h
> @@ -43,7 +43,7 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned
> long len, int rw,
>   * Note: the caller should never hard code @issue_flags and is only allowed
>   * to pass the mask provided by the core io_uring code.
>   */
> -void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
> +void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, u64 res2,
>  			unsigned issue_flags);
> 
>  void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd, diff --git
> a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c index
> d9fb2143f56ff5d13483687fa949c293f9b8dbef..af842e9b4eb975ba56aaeaaa0
> c2e207a7732beba 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -151,7 +151,7 @@ static inline void io_req_set_cqe32_extra(struct
> io_kiocb *req,
>   * Called by consumers of io_uring_cmd, if they originally returned
>   * -EIOCBQUEUED upon receiving the command.
>   */
> -void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t
> res2,
> +void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, u64
> +res2,
>  		       unsigned issue_flags)
>  {
>  	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
> 
> ---
> base-commit: 7af08b57bcb9ebf78675c50069c54125c0a8b795
> change-id: 20241202-io_uring_cmd_done-res2-as-u64-217a4e47b93f
> 
> Best regards,
> --
> Bernd Schubert <bschubert@ddn.com>
> 

I have applied this patch to the linux-block/for-next branch and tested compilation
using the CONFIG_IO_URING=y and CONFIG_IO_URING=n options respectively.
A small suggestion is that when CONFIG_IO_URING=n, the ret2 parameter type of io_uring_cmd_done can
also be changed to u64.

Tested-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Li Zetao <lizetao1@huawei.com>

--
Li Zetao