> On 29 Jul 2021, at 20:26, mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx wrote:
>
> From: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx>
>
> The net/sunrpc/xprtrdma module creates its QP using rdma_create_qp() and
> immediately post receives, implicitly assuming the QP is in the INIT
> state and thus valid for ib_post_recv().
>
> The patch noted in Fixes: removed the RESET->INIT modifiy from
> rdma_create_qp(), breaking NFS rdma for verbs providers that fail the
> ib_post_recv() for a bad state.
>
> This situation was proven using kprobes in rvt_post_recv() and
> rvt_modify_qp(). The traces showed that the rvt_post_recv() failed before
> ANY modify QP and that the current state was RESET.
>
> Fix by reverting the patch below.
>
> Fixes: dc70f7c3ed34 ("RDMA/cma: Remove unnecessary INIT->INIT transition")
> Cc: Haakon Bugge <haakon.bugge@xxxxxxxxxx>
> Cc: Chuck Lever III <chuck.lever@xxxxxxxxxx>
> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
Thxs, Håkon
> ---
> drivers/infiniband/core/cma.c | 17 ++++++++++++++++-
> 1 file changed, 16 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index 515a7e9..5d3b8b8 100644
> --- a/drivers/infiniband/core/cma.c
> +++ b/drivers/infiniband/core/cma.c
> @@ -926,12 +926,25 @@ static int cma_init_ud_qp(struct rdma_id_private *id_priv, struct ib_qp *qp)
> return ret;
> }
>
> +static int cma_init_conn_qp(struct rdma_id_private *id_priv, struct ib_qp *qp)
> +{
> + struct ib_qp_attr qp_attr;
> + int qp_attr_mask, ret;
> +
> + qp_attr.qp_state = IB_QPS_INIT;
> + ret = rdma_init_qp_attr(&id_priv->id, &qp_attr, &qp_attr_mask);
> + if (ret)
> + return ret;
> +
> + return ib_modify_qp(qp, &qp_attr, qp_attr_mask);
> +}
> +
> int rdma_create_qp(struct rdma_cm_id *id, struct ib_pd *pd,
> struct ib_qp_init_attr *qp_init_attr)
> {
> struct rdma_id_private *id_priv;
> struct ib_qp *qp;
> - int ret = 0;
> + int ret;
>
> id_priv = container_of(id, struct rdma_id_private, id);
> if (id->device != pd->device) {
> @@ -948,6 +961,8 @@ int rdma_create_qp(struct rdma_cm_id *id, struct ib_pd *pd,
>
> if (id->qp_type == IB_QPT_UD)
> ret = cma_init_ud_qp(id_priv, qp);
> + else
> + ret = cma_init_conn_qp(id_priv, qp);
> if (ret)
> goto out_destroy;
>
> --
> 1.8.3.1
>
