RDMA/nldev: provide detailed CM_ID information

Implement RDMA nldev netlink interface to get detailed CM_ID information.

Because cm_id's are attached to rdma devices in various work queue
contexts, the pid and task information at restrak_add() time is sometimes
not useful.  For example, an nvme/f host connection cm_id ends up being
bound to a device in a work queue context and the resulting pid at attach
time no longer exists after connection setup.  So instead we mark all
cm_id's created via the rdma_ucm as "user", and all others as "kernel".
This required tweaking the restrack code a little.  It also required
wrapping some rdma_cm functions to allow passing the module name string.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c
index 41a780085e6d..6da949e7a50b 100644
--- a/drivers/infiniband/core/restrack.c
+++ b/drivers/infiniband/core/restrack.c
@@ -3,12 +3,15 @@
  * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
  */
 
+#include <rdma/rdma_cm.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/restrack.h>
 #include <linux/mutex.h>
 #include <linux/sched/task.h>
 #include <linux/pid_namespace.h>
 
+#include "cma_priv.h"
+
 void rdma_restrack_init(struct rdma_restrack_root *res)
 {
 	init_rwsem(&res->rwsem);
@@ -44,7 +47,7 @@ static void set_kern_name(struct rdma_restrack_entry *res)
 	struct ib_qp *qp;
 
 	if (type != RDMA_RESTRACK_QP)
-		/* PD and CQ types already have this name embedded in */
+		/* Other types already have this name embedded in */
 		return;
 
 	qp = container_of(res, struct ib_qp, res);
@@ -67,6 +70,9 @@ static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
 		return container_of(res, struct ib_cq, res)->device;
 	case RDMA_RESTRACK_QP:
 		return container_of(res, struct ib_qp, res)->device;
+	case RDMA_RESTRACK_CM_ID:
+		return container_of(res, struct rdma_id_private,
+				    res)->id.device;
 	default:
 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
 		return NULL;
@@ -82,6 +88,8 @@ static bool res_is_user(struct rdma_restrack_entry *res)
 		return container_of(res, struct ib_cq, res)->uobject;
 	case RDMA_RESTRACK_QP:
 		return container_of(res, struct ib_qp, res)->uobject;
+	case RDMA_RESTRACK_CM_ID:
+		return !res->kern_name;
 	default:
 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
 		return false;
@@ -96,8 +104,8 @@ void rdma_restrack_add(struct rdma_restrack_entry *res)
 		return;
 
 	if (res_is_user(res)) {
-		get_task_struct(current);
-		res->task = current;
+		if (!res->task)
+			rdma_restrack_set_task(res, current);
 		res->kern_name = NULL;
 	} else {
 		set_kern_name(res);