IB/core: Simplify rdma cgroup registration

RDMA cgroup registration routine always returns success, so simplify
function to be void and run clang formatter over whole CONFIG_CGROUP_RDMA
art of core_priv.h.

This reduces unwinding error path for regular registration and future net
namespace change functionality for rdma device.
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/cgroup.c

@@ -21,12 +21,11 @@
  * Register with the rdma cgroup. Should be called before
  * exposing rdma device to user space applications to avoid
  * resource accounting leak.
- * Returns 0 on success or otherwise failure code.
  */
-int ib_device_register_rdmacg(struct ib_device *device)
+void ib_device_register_rdmacg(struct ib_device *device)
 {
 	device->cg_device.name = device->name;
-	return rdmacg_register_device(&device->cg_device);
+	rdmacg_register_device(&device->cg_device);
 }
 
 /**

drivers/infiniband/core/core_priv.h

@@ -115,7 +115,7 @@ void ib_cache_cleanup_one(struct ib_device *device);
 void ib_cache_release_one(struct ib_device *device);
 
 #ifdef CONFIG_CGROUP_RDMA
-int ib_device_register_rdmacg(struct ib_device *device);
+void ib_device_register_rdmacg(struct ib_device *device);
 void ib_device_unregister_rdmacg(struct ib_device *device);
 
 int ib_rdmacg_try_charge(struct ib_rdmacg_object *cg_obj,
@@ -126,21 +126,26 @@ void ib_rdmacg_uncharge(struct ib_rdmacg_object *cg_obj,
 			struct ib_device *device,
 			enum rdmacg_resource_type resource_index);
 #else
-static inline int ib_device_register_rdmacg(struct ib_device *device)
-{ return 0; }
+static inline void ib_device_register_rdmacg(struct ib_device *device)
+{
+}
 
 static inline void ib_device_unregister_rdmacg(struct ib_device *device)
-{ }
+{
+}
 
 static inline int ib_rdmacg_try_charge(struct ib_rdmacg_object *cg_obj,
 				       struct ib_device *device,
 				       enum rdmacg_resource_type resource_index)
-{ return 0; }
+{
+	return 0;
+}
 
 static inline void ib_rdmacg_uncharge(struct ib_rdmacg_object *cg_obj,
 				      struct ib_device *device,
 				      enum rdmacg_resource_type resource_index)
-{ }
+{
+}
 #endif
 
 static inline bool rdma_is_upper_dev_rcu(struct net_device *dev,

drivers/infiniband/core/device.c

@@ -599,12 +599,7 @@ int ib_register_device(struct ib_device *device, const char *name)
 
 	device->index = __dev_new_index();
 
-	ret = ib_device_register_rdmacg(device);
-	if (ret) {
-		dev_warn(&device->dev,
-			 "Couldn't register device with rdma cgroup\n");
-		goto dev_cleanup;
-	}
+	ib_device_register_rdmacg(device);
 
 	ret = ib_device_register_sysfs(device);
 	if (ret) {
@@ -627,7 +622,6 @@ int ib_register_device(struct ib_device *device, const char *name)
 
 cg_cleanup:
 	ib_device_unregister_rdmacg(device);
-dev_cleanup:
 	cleanup_device(device);
 out:
 	mutex_unlock(&device_mutex);

include/linux/cgroup_rdma.h

@@ -39,7 +39,7 @@ struct rdmacg_device {
  * APIs for RDMA/IB stack to publish when a device wants to
  * participate in resource accounting
  */
-int rdmacg_register_device(struct rdmacg_device *device);
+void rdmacg_register_device(struct rdmacg_device *device);
 void rdmacg_unregister_device(struct rdmacg_device *device);
 
 /* APIs for RDMA/IB stack to charge/uncharge pool specific resources */

kernel/cgroup/rdma.c

@@ -313,10 +313,8 @@ EXPORT_SYMBOL(rdmacg_try_charge);
  * If IB stack wish a device to participate in rdma cgroup resource
  * tracking, it must invoke this API to register with rdma cgroup before
  * any user space application can start using the RDMA resources.
- * Returns 0 on success or EINVAL when table length given is beyond
- * supported size.
  */
-int rdmacg_register_device(struct rdmacg_device *device)
+void rdmacg_register_device(struct rdmacg_device *device)
 {
 	INIT_LIST_HEAD(&device->dev_node);
 	INIT_LIST_HEAD(&device->rpools);
@@ -324,7 +322,6 @@ int rdmacg_register_device(struct rdmacg_device *device)
 	mutex_lock(&rdmacg_mutex);
 	list_add_tail(&device->dev_node, &rdmacg_devices);
 	mutex_unlock(&rdmacg_mutex);
-	return 0;
 }
 EXPORT_SYMBOL(rdmacg_register_device);