Re: [PATCH 5/6] iser-target: Ignore completions for FRWRs in isert_cq_tx_work

[Sagi Grimberg <sagig@dev.mellanox.co.il>]

On 3/4/2014 2:01 AM, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
>
> This patch changes IB_WR_FAST_REG_MR + IB_WR_LOCAL_INV related
> work requests to include a ISER_FRWR_LI_WRID value in order to
> signal isert_cq_tx_work() that these requests should be ignored.
>
> This is necessary because even though IB_SEND_SIGNALED is not
> set for either work request, during a QP failure event the work
> requests will be returned with exception status from the TX
> completion queue.
>
> Cc: Sagi Grimberg <sagig@mellanox.com>
> Cc: Or Gerlitz <ogerlitz@mellanox.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>   drivers/infiniband/ulp/isert/ib_isert.c |    8 ++++++--
>   drivers/infiniband/ulp/isert/ib_isert.h |    1 +
>   2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
> index c9d488f..003b5d0 100644
> --- a/drivers/infiniband/ulp/isert/ib_isert.c
> +++ b/drivers/infiniband/ulp/isert/ib_isert.c
> @@ -1738,8 +1738,10 @@ isert_cq_tx_work(struct work_struct *work)
>   			pr_debug("TX wc.status: 0x%08x\n", wc.status);
>   			pr_debug("TX wc.vendor_err: 0x%08x\n", wc.vendor_err);
>   
> -			atomic_dec(&isert_conn->post_send_buf_count);
> -			isert_cq_tx_comp_err(tx_desc, isert_conn);
> +			if (wc.wr_id != ISER_FRWR_LI_WRID) {

Better to use ISER_FASTREG_LI_WRID - I changed it in the initiator.

> +				atomic_dec(&isert_conn->post_send_buf_count);
> +				isert_cq_tx_comp_err(tx_desc, isert_conn);
> +			}
>   		}
>   	}
>   
> @@ -2202,6 +2204,7 @@ isert_fast_reg_mr(struct fast_reg_descriptor *fr_desc,
>   
>   	if (!fr_desc->valid) {
>   		memset(&inv_wr, 0, sizeof(inv_wr));
> +		inv_wr.wr_id = ISER_FRWR_LI_WRID;
>   		inv_wr.opcode = IB_WR_LOCAL_INV;
>   		inv_wr.ex.invalidate_rkey = fr_desc->data_mr->rkey;
>   		wr = &inv_wr;
> @@ -2212,6 +2215,7 @@ isert_fast_reg_mr(struct fast_reg_descriptor *fr_desc,
>   
>   	/* Prepare FASTREG WR */
>   	memset(&fr_wr, 0, sizeof(fr_wr));
> +	fr_wr.wr_id = ISER_FRWR_LI_WRID;
>   	fr_wr.opcode = IB_WR_FAST_REG_MR;
>   	fr_wr.wr.fast_reg.iova_start =
>   		fr_desc->data_frpl->page_list[0] + page_off;
> diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
> index 41e799f..599b4e2 100644
> --- a/drivers/infiniband/ulp/isert/ib_isert.h
> +++ b/drivers/infiniband/ulp/isert/ib_isert.h
> @@ -6,6 +6,7 @@
>   
>   #define ISERT_RDMA_LISTEN_BACKLOG	10
>   #define ISCSI_ISER_SG_TABLESIZE		256
> +#define ISER_FRWR_LI_WRID		0xffffffffffffffffULL
>   
>   enum isert_desc_type {
>   	ISCSI_TX_CONTROL,