Re: [PATCH for-next v3 1/2] RDMA/rxe: Remove unnecessary mr testing

Bob Pearson
2022-10-24T16:26:01Z

On 10/23/22 22:31, Li Zhijian wrote:
> Before the testing, we already passed it to rxe_mr_copy() where mr could
> be dereferenced. so this checking is not needed.
>
> The only way that mr is NULL is when it reaches below line 780 with
> 'qp->resp.mr = NULL', which is not possible in Bob's explanation[1].
>
> 778 if (res->state == rdatm_res_state_new) {
> 779 if (!res->replay) {
> 780 mr = qp->resp.mr;
> 781 qp->resp.mr = NULL;
> 782 } else {
>
> [1] https://lore.kernel.org/lkml/30ff25c4-ce66-eac4-eaa2-64c0db203a19@gmail.com/
>
> CC: Bob Pearson <rpearsonhpe@gmail.com>
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> ---
> V3: remove WARN_ON # Yanjun and Bob
> ---
> drivers/infiniband/sw/rxe/rxe_resp.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> index ed5a09e86417..b02639cf8cba 100644
> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> @@ -811,8 +811,7 @@ static enum resp_states read_reply(struct rxe_qp *qp,
>
> rxe_mr_copy(mr, res->read.va, payload_addr(&ack_pkt),
> payload, RXE_FROM_MR_OBJ);
> - if (mr)
> - rxe_put(mr);
> + rxe_put(mr);
>
> if (bth_pad(&ack_pkt)) {
> u8 *pad = payload_addr(&ack_pkt) + payload;

Reviewed-by: Bob Pearson <rpearsonhpe@gmail.com>