Re: [PATCH net-next v2 4/4] rds: Fix endianness annotations for RDS extension headers

[Allison Henderson <allison.henderson@oracle.com>]

On Wed, 2025-08-20 at 23:25 +0530, Ujwal Kundur wrote:
> Per the RDS 3.1 spec [1], RDS extension headers EXTHDR_NPATHS and
> EXTHDR_GEN_NUM are be16 and be32 values respectively, exchanged during
> normal operations over-the-wire (RDS Ping/Pong). This contrasts their
> declarations as host endian unsigned ints.
> 
> Fix the annotations across occurrences. Flagged by Sparse.
> 
> [1] https://oss.oracle.com/projects/rds/dist/documentation/rds-3.1-spec.html 
> 
> Signed-off-by: Ujwal Kundur <ujwal.kundur@gmail.com>
This looks much better now.  Thank you!
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
> ---
>  net/rds/message.c | 4 ++--
>  net/rds/recv.c    | 4 ++--
>  net/rds/send.c    | 4 ++--
>  3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/net/rds/message.c b/net/rds/message.c
> index 7af59d2443e5..199a899a43e9 100644
> --- a/net/rds/message.c
> +++ b/net/rds/message.c
> @@ -44,8 +44,8 @@ static unsigned int	rds_exthdr_size[__RDS_EXTHDR_MAX] = {
>  [RDS_EXTHDR_VERSION]	= sizeof(struct rds_ext_header_version),
>  [RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
>  [RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
> -[RDS_EXTHDR_NPATHS]	= sizeof(u16),
> -[RDS_EXTHDR_GEN_NUM]	= sizeof(u32),
> +[RDS_EXTHDR_NPATHS]	= sizeof(__be16),
> +[RDS_EXTHDR_GEN_NUM]	= sizeof(__be32),
>  };
>  
>  void rds_message_addref(struct rds_message *rm)
> diff --git a/net/rds/recv.c b/net/rds/recv.c
> index 5627f80013f8..66205d6924bf 100644
> --- a/net/rds/recv.c
> +++ b/net/rds/recv.c
> @@ -202,8 +202,8 @@ static void rds_recv_hs_exthdrs(struct rds_header *hdr,
>  	unsigned int pos = 0, type, len;
>  	union {
>  		struct rds_ext_header_version version;
> -		u16 rds_npaths;
> -		u32 rds_gen_num;
> +		__be16 rds_npaths;
> +		__be32 rds_gen_num;
>  	} buffer;
>  	u32 new_peer_gen_num = 0;
>  
> diff --git a/net/rds/send.c b/net/rds/send.c
> index 42d991bc8543..0b3d0ef2f008 100644
> --- a/net/rds/send.c
> +++ b/net/rds/send.c
> @@ -1454,8 +1454,8 @@ rds_send_probe(struct rds_conn_path *cp, __be16 sport,
>  
>  	if (RDS_HS_PROBE(be16_to_cpu(sport), be16_to_cpu(dport)) &&
>  	    cp->cp_conn->c_trans->t_mp_capable) {
> -		u16 npaths = cpu_to_be16(RDS_MPATH_WORKERS);
> -		u32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num);
> +		__be16 npaths = cpu_to_be16(RDS_MPATH_WORKERS);
> +		__be32 my_gen_num = cpu_to_be32(cp->cp_conn->c_my_gen_num);
>  
>  		rds_message_add_extension(&rm->m_inc.i_hdr,
>  					  RDS_EXTHDR_NPATHS, &npaths,