Target/iser: Consider DIF and RDMA_READ completions when calculating post_send counter

If protection is involved, iSER target must wait for
completion of RDMA_READ before sending SCSI response.
So we must consider that when calculating post_send_buf_count
additions, also when processing good/error completions.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index e4ebb4c..faec224 100644 (file)
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -1705,6 +1705,7 @@ isert_completion_rdma_write(struct iser_tx_desc *tx_desc,
 
 fail_mr_status:
        device->unreg_rdma_mem(isert_cmd, isert_conn);
+       wr->send_wr_num = 0;
        if (ret)
                transport_send_check_condition_and_sense(se_cmd,
                                                         se_cmd->pi_err, 0);
@@ -1838,7 +1839,18 @@ isert_response_completion(struct iser_tx_desc *tx_desc,
                queue_work(isert_comp_wq, &isert_cmd->comp_work);
                return;
        }
-       atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+
+       /**
+        * If send_wr_num is 0 this means that we got
+        * RDMA completion and we cleared it and we should
+        * simply decrement the response post. else the
+        * response is incorporated in send_wr_num, just
+        * sub it.
+        **/
+       if (wr->send_wr_num)
+               atomic_sub(wr->send_wr_num, &isert_conn->post_send_buf_count);
+       else
+               atomic_dec(&isert_conn->post_send_buf_count);
 
        cmd->i_state = ISTATE_SENT_STATUS;
        isert_completion_put(tx_desc, isert_cmd, ib_dev);
@@ -1871,7 +1883,7 @@ __isert_send_completion(struct iser_tx_desc *tx_desc,
                break;
        case ISER_IB_RDMA_WRITE:
                pr_debug("isert_send_completion: Got ISER_IB_RDMA_WRITE\n");
-               atomic_dec(&isert_conn->post_send_buf_count);
+               atomic_sub(wr->send_wr_num, &isert_conn->post_send_buf_count);
                isert_completion_rdma_write(tx_desc, isert_cmd);
                break;
        case ISER_IB_RDMA_READ:
@@ -1922,7 +1934,18 @@ isert_cq_drain_comp_llist(struct isert_conn *isert_conn, struct ib_device *ib_de
                llnode = llist_next(llnode);
                wr = &t->isert_cmd->rdma_wr;
 
-               atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+               /**
+                * If send_wr_num is 0 this means that we got
+                * RDMA completion and we cleared it and we should
+                * simply decrement the response post. else the
+                * response is incorporated in send_wr_num, just
+                * sub it.
+                **/
+               if (wr->send_wr_num)
+                       atomic_sub(wr->send_wr_num,
+                                  &isert_conn->post_send_buf_count);
+               else
+                       atomic_dec(&isert_conn->post_send_buf_count);
                isert_completion_put(t, t->isert_cmd, ib_dev);
        }
 }
@@ -1941,7 +1964,18 @@ isert_cq_tx_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn
                llnode = llist_next(llnode);
                wr = &t->isert_cmd->rdma_wr;
 
-               atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+               /**
+                * If send_wr_num is 0 this means that we got
+                * RDMA completion and we cleared it and we should
+                * simply decrement the response post. else the
+                * response is incorporated in send_wr_num, just
+                * sub it.
+                **/
+               if (wr->send_wr_num)
+                       atomic_sub(wr->send_wr_num,
+                                  &isert_conn->post_send_buf_count);
+               else
+                       atomic_dec(&isert_conn->post_send_buf_count);
                isert_completion_put(t, t->isert_cmd, ib_dev);
        }
        tx_desc->comp_llnode_batch = NULL;
@@ -2795,14 +2829,15 @@ isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
                isert_init_send_wr(isert_conn, isert_cmd,
                                   &isert_cmd->tx_desc.send_wr, true);
                isert_cmd->rdma_wr.s_send_wr.next = &isert_cmd->tx_desc.send_wr;
+               wr->send_wr_num += 1;
        }
 
-       atomic_add(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+       atomic_add(wr->send_wr_num, &isert_conn->post_send_buf_count);
 
        rc = ib_post_send(isert_conn->conn_qp, wr->send_wr, &wr_failed);
        if (rc) {
                pr_warn("ib_post_send() failed for IB_WR_RDMA_WRITE\n");
-               atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+               atomic_sub(wr->send_wr_num, &isert_conn->post_send_buf_count);
        }
 
        if (se_cmd->prot_op == TARGET_PROT_NORMAL)