Re: [PATCH v2 07/14] fuse: use named constants for io-uring iovec indices

[Bernd Schubert <bernd@bsbernd.com>]

On 4/2/26 18:28, Joanne Koong wrote:
> Replace magic indices 0 and 1 for the iovec array with named constants
> FUSE_URING_IOV_HEADERS and FUSE_URING_IOV_PAYLOAD. This makes the usages
> self-documenting and prepares for buffer ring support which will also
> reference these iovec slots by index.
> 
> Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
> ---
>  fs/fuse/dev_uring.c | 24 +++++++++++++-----------
>  1 file changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
> index 045394a7ae41..a85acd9c2b71 100644
> --- a/fs/fuse/dev_uring.c
> +++ b/fs/fuse/dev_uring.c
> @@ -18,7 +18,8 @@ MODULE_PARM_DESC(enable_uring,
>  		 "Enable userspace communication through io-uring");
>  
>  #define FUSE_URING_IOV_SEGS 2 /* header and payload */
> -
> +#define FUSE_URING_IOV_HEADERS 0
> +#define FUSE_URING_IOV_PAYLOAD 1
>  
>  bool fuse_uring_enabled(void)
>  {
> @@ -1063,8 +1064,8 @@ static void fuse_uring_do_register(struct fuse_ring_ent *ent,
>  }
>  
>  /*
> - * sqe->addr is a ptr to an iovec array, iov[0] has the headers, iov[1]
> - * the payload
> + * sqe->addr is a ptr to an iovec array, iov[FUSE_URING_IOV_HEADERS] has the
> + * headers, iov[FUSE_URING_IOV_PAYLOAD] the payload
>   */
>  static int fuse_uring_get_iovec_from_sqe(const struct io_uring_sqe *sqe,
>  					 struct iovec iov[FUSE_URING_IOV_SEGS])
> @@ -1094,8 +1095,8 @@ fuse_uring_create_ring_ent(struct io_uring_cmd *cmd,
>  {
>  	struct fuse_ring *ring = queue->ring;
>  	struct fuse_ring_ent *ent;
> -	size_t payload_size;
>  	struct iovec iov[FUSE_URING_IOV_SEGS];
> +	struct iovec *headers, *payload;
>  	int err;
>  
>  	err = fuse_uring_get_iovec_from_sqe(cmd->sqe, iov);
> @@ -1106,15 +1107,16 @@ fuse_uring_create_ring_ent(struct io_uring_cmd *cmd,
>  	}
>  
>  	err = -EINVAL;
> -	if (iov[0].iov_len < sizeof(struct fuse_uring_req_header)) {
> -		pr_info_ratelimited("Invalid header len %zu\n", iov[0].iov_len);
> +	headers = &iov[FUSE_URING_IOV_HEADERS];
> +	if (headers->iov_len < sizeof(struct fuse_uring_req_header)) {
> +		pr_info_ratelimited("Invalid header len %zu\n", headers->iov_len);
>  		return ERR_PTR(err);
>  	}
>  
> -	payload_size = iov[1].iov_len;
> -	if (payload_size < ring->max_payload_sz) {
> +	payload = &iov[FUSE_URING_IOV_PAYLOAD];
> +	if (payload->iov_len < ring->max_payload_sz) {
>  		pr_info_ratelimited("Invalid req payload len %zu\n",
> -				    payload_size);
> +				    payload->iov_len);
>  		return ERR_PTR(err);
>  	}
>  
> @@ -1126,8 +1128,8 @@ fuse_uring_create_ring_ent(struct io_uring_cmd *cmd,
>  	INIT_LIST_HEAD(&ent->list);
>  
>  	ent->queue = queue;
> -	ent->headers = iov[0].iov_base;
> -	ent->payload = iov[1].iov_base;
> +	ent->headers = headers->iov_base;
> +	ent->payload = payload->iov_base;
>  
>  	atomic_inc(&ring->queue_refs);
>  	return ent;

LGTM, thanks, I should have done that from the beginning.

Reviewed-by: Bernd Schubert <bernd@bsbernd.com>