Re: [PATCH v3 5/6] RDMA/rxe: Lookup kernel AH from ah index in UD WQEs

[Jason Gunthorpe <jgg@nvidia.com>]

On Thu, Jul 22, 2021 at 04:22:44PM -0500, Bob Pearson wrote:
> Add code to rxe_get_av in rxe_av.c to use the AH index in UD send WQEs
> to lookup the kernel AH. For old user providers continue to use the AV
> passed in WQEs. Move setting pkt->rxe to before the call to rxe_get_av()
> to get access to the AH pool.
> 
> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
>  drivers/infiniband/sw/rxe/rxe_av.c  | 20 +++++++++++++++++++-
>  drivers/infiniband/sw/rxe/rxe_req.c |  8 +++++---
>  2 files changed, 24 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_av.c b/drivers/infiniband/sw/rxe/rxe_av.c
> index 85580ea5eed0..38c7b6fb39d7 100644
> +++ b/drivers/infiniband/sw/rxe/rxe_av.c
> @@ -101,11 +101,29 @@ void rxe_av_fill_ip_info(struct rxe_av *av, struct rdma_ah_attr *attr)
>  
>  struct rxe_av *rxe_get_av(struct rxe_pkt_info *pkt)
>  {
> +	struct rxe_ah *ah;
> +	u32 ah_num;
> +
>  	if (!pkt || !pkt->qp)
>  		return NULL;
>  
>  	if (qp_type(pkt->qp) == IB_QPT_RC || qp_type(pkt->qp) == IB_QPT_UC)
>  		return &pkt->qp->pri_av;
>  
> -	return (pkt->wqe) ? &pkt->wqe->wr.wr.ud.av : NULL;
> +	if (!pkt->wqe)
> +		return NULL;
> +
> +	ah_num = pkt->wqe->wr.wr.ud.ah_num;
> +	if (ah_num) {
> +		/* only new user provider or kernel client */
> +		ah = rxe_pool_get_index(&pkt->rxe->ah_pool, ah_num);

rxe_pool_get_index() incr's a kref, but I don't see any put of that
kref in this code?

Jason