iser-target: Fix possible deadlock in RDMA_CM connection error

Before we reach to connection established we may get an
error event. In this case the core won't teardown this
connection (never established it), so we take care of freeing
it ourselves.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
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 4b8d518826b9d3340640602d05e66af7b8462571..147029adb8851f670ed10eaa5d7e43b8d1b04cbd 100644 (file)
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -222,7 +222,7 @@ fail:
 static void
 isert_free_rx_descriptors(struct isert_conn *isert_conn)
 {
-       struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+       struct ib_device *ib_dev = isert_conn->conn_device->ib_device;
        struct iser_rx_desc *rx_desc;
        int i;
 
@@ -719,8 +719,8 @@ out:
 static void
 isert_connect_release(struct isert_conn *isert_conn)
 {
-       struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
        struct isert_device *device = isert_conn->conn_device;
+       struct ib_device *ib_dev = device->ib_device;
 
        isert_dbg("conn %p\n", isert_conn);
 
@@ -728,7 +728,8 @@ isert_connect_release(struct isert_conn *isert_conn)
                isert_conn_free_fastreg_pool(isert_conn);
 
        isert_free_rx_descriptors(isert_conn);
-       rdma_destroy_id(isert_conn->conn_cm_id);
+       if (isert_conn->conn_cm_id)
+               rdma_destroy_id(isert_conn->conn_cm_id);
 
        if (isert_conn->conn_qp) {
                struct isert_comp *comp = isert_conn->conn_qp->recv_cq->cq_context;
@@ -878,12 +879,15 @@ isert_disconnected_handler(struct rdma_cm_id *cma_id,
        return 0;
 }
 
-static void
+static int
 isert_connect_error(struct rdma_cm_id *cma_id)
 {
        struct isert_conn *isert_conn = cma_id->qp->qp_context;
 
+       isert_conn->conn_cm_id = NULL;
        isert_put_conn(isert_conn);
+
+       return -1;
 }
 
 static int
@@ -912,7 +916,7 @@ isert_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
        case RDMA_CM_EVENT_REJECTED:       /* FALLTHRU */
        case RDMA_CM_EVENT_UNREACHABLE:    /* FALLTHRU */
        case RDMA_CM_EVENT_CONNECT_ERROR:
-               isert_connect_error(cma_id);
+               ret = isert_connect_error(cma_id);
                break;
        default:
                isert_err("Unhandled RDMA CMA event: %d\n", event->event);