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>

3 files changed, 47 insertions, 5 deletions

diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index 6538a5cc27b6..62caae818173 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -157,6 +157,11 @@ struct rdma_cm_id {
 	u8			 port_num;
 };
 
+struct rdma_cm_id *__rdma_create_id(struct net *net,
+				  rdma_cm_event_handler event_handler,
+				  void *context, enum rdma_port_space ps,
+				  enum ib_qp_type qp_type, const char *caller);
+
 /**
  * rdma_create_id - Create an RDMA identifier.
  *
@@ -169,10 +174,9 @@ struct rdma_cm_id {
  *
  * The id holds a reference on the network namespace until it is destroyed.
  */
-struct rdma_cm_id *rdma_create_id(struct net *net,
-				  rdma_cm_event_handler event_handler,
-				  void *context, enum rdma_port_space ps,
-				  enum ib_qp_type qp_type);
+#define rdma_create_id(net, event_handler, context, ps, qp_type) \
+	__rdma_create_id((net), (event_handler), (context), (ps), (qp_type), \
+			 KBUILD_MODNAME)
 
 /**
   * rdma_destroy_id - Destroys an RDMA identifier.
@@ -284,6 +288,9 @@ int rdma_connect(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
  */
 int rdma_listen(struct rdma_cm_id *id, int backlog);
 
+int __rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param,
+		  const char *caller);
+
 /**
  * rdma_accept - Called to accept a connection request or response.
  * @id: Connection identifier associated with the request.
@@ -299,7 +306,8 @@ int rdma_listen(struct rdma_cm_id *id, int backlog);
  * state of the qp associated with the id is modified to error, such that any
  * previously posted receive buffers would be flushed.
  */
-int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
+#define rdma_accept(id, conn_param) \
+	__rdma_accept((id), (conn_param),  KBUILD_MODNAME)
 
 /**
  * rdma_notify - Notifies the RDMA CM of an asynchronous event that has
diff --git a/include/rdma/restrack.h b/include/rdma/restrack.h
index 2cdf8dcf4bdc..af886670af85 100644
--- a/include/rdma/restrack.h
+++ b/include/rdma/restrack.h
@@ -11,6 +11,7 @@
 #include <linux/sched.h>
 #include <linux/kref.h>
 #include <linux/completion.h>
+#include <linux/sched/task.h>
 
 /**
  * enum rdma_restrack_type - HW objects to track
@@ -29,6 +30,10 @@ enum rdma_restrack_type {
 	 */
 	RDMA_RESTRACK_QP,
 	/**
+	 * @RDMA_RESTRACK_CM_ID: Connection Manager ID (CM_ID)
+	 */
+	RDMA_RESTRACK_CM_ID,
+	/**
 	 * @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
 	 */
 	RDMA_RESTRACK_MAX
@@ -150,4 +155,19 @@ int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
  * @res:  resource entry
  */
 int rdma_restrack_put(struct rdma_restrack_entry *res);
+
+/**
+ * rdma_restrack_set_task() - set the task for this resource
+ * @res:  resource entry
+ * @task: task struct
+ */
+static inline void rdma_restrack_set_task(struct rdma_restrack_entry *res,
+					  struct task_struct *task)
+{
+	if (res->task)
+		put_task_struct(res->task);
+	get_task_struct(task);
+	res->task = task;
+}
+
 #endif /* _RDMA_RESTRACK_H_ */
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index 4c77e2a7b07e..0399aed06548 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -238,6 +238,8 @@ enum rdma_nldev_command {
 
 	RDMA_NLDEV_CMD_RES_QP_GET, /* can dump */
 
+	RDMA_NLDEV_CMD_RES_CM_ID_GET, /* can dump */
+
 	RDMA_NLDEV_NUM_OPS
 };
 
@@ -350,6 +352,18 @@ enum rdma_nldev_attr {
 	 */
 	RDMA_NLDEV_ATTR_RES_KERN_NAME,		/* string */
 
+	RDMA_NLDEV_ATTR_RES_CM_ID,		/* nested table */
+	RDMA_NLDEV_ATTR_RES_CM_ID_ENTRY,	/* nested table */
+	/*
+	 * rdma_cm_id port space.
+	 */
+	RDMA_NLDEV_ATTR_RES_PS,			/* u32 */
+	/*
+	 * Source and destination socket addresses
+	 */
+	RDMA_NLDEV_ATTR_RES_SRC_ADDR,		/* __kernel_sockaddr_storage */
+	RDMA_NLDEV_ATTR_RES_DST_ADDR,		/* __kernel_sockaddr_storage */
+
 	RDMA_NLDEV_ATTR_MAX
 };
 #endif /* _UAPI_RDMA_NETLINK_H */