Re: [PATCH v4 2/6] io_uring/zcrx: return error from io_zcrx_map_area_*

[David Wei <dw@davidwei.uk>]

On 2025-07-02 07:29, Pavel Begunkov wrote:
> io_zcrx_map_area_*() helpers return the number of processed niovs, which
> we use to unroll some of the mappings for user memory areas. It's
> unhandy, and dmabuf doesn't care about it. Return an error code instead
> and move failure partial unmapping into io_zcrx_map_area_umem().
> 
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
>   io_uring/zcrx.c | 27 ++++++++++++++-------------
>   1 file changed, 14 insertions(+), 13 deletions(-)
> 
> diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
> index 99a253c1c6c5..2cde88988260 100644
> --- a/io_uring/zcrx.c
> +++ b/io_uring/zcrx.c

...

> @@ -254,29 +254,30 @@ static int io_zcrx_map_area_umem(struct io_zcrx_ifq *ifq, struct io_zcrx_area *a
>   			break;
>   		}
>   	}
> -	return i;
> +
> +	if (i != area->nia.num_niovs) {
> +		__io_zcrx_unmap_area(ifq, area, i);
> +		return -EINVAL;
> +	}
> +	return 0;
>   }

Does io_release_dmabuf() still need to be called in
io_zcrx_map_area_dmabuf() in case of failure, if say
net_mp_niov_set_dma_addr() fails in the loop?