IB/cma: Fix ports memory leak in cma_configfs

The allocated ports structure in never freed. The free function should be
called by release_cma_ports_group, but the group is never released since
we don't remove its default group.

Remove default groups when device group is deleted.

Fixes: 045959db ("IB/cma: Add configfs for rdma_cm")
Link: https://lore.kernel.org/r/20200521072650.567908-1-leon@kernel.orgSigned-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/cma_configfs.c

@@ -322,8 +322,21 @@ static struct config_group *make_cma_dev(struct config_group *group,
 	return ERR_PTR(err);
 }
 
+static void drop_cma_dev(struct config_group *cgroup, struct config_item *item)
+{
+	struct config_group *group =
+		container_of(item, struct config_group, cg_item);
+	struct cma_dev_group *cma_dev_group =
+		container_of(group, struct cma_dev_group, device_group);
+
+	configfs_remove_default_groups(&cma_dev_group->ports_group);
+	configfs_remove_default_groups(&cma_dev_group->device_group);
+	config_item_put(item);
+}
+
 static struct configfs_group_operations cma_subsys_group_ops = {
 	.make_group	= make_cma_dev,
+	.drop_item	= drop_cma_dev,
 };
 
 static const struct config_item_type cma_subsys_type = {