RDMA/iwcm: Release resources if iw_cm module initialization fails

The failure during iw_cm module initialization partially left the system
with unreleased memory and other resources. Rewrite the module init/exit
routines in such way that netlink commands will be opened only after
successful initialization.

Fixes: b493d91d ("iwcm: common code for port mapper")
Link: https://lore.kernel.org/r/b01239f99cb1a3e6d2b0694c242d89e6410bcd93.1627048781.git.leonro@nvidia.comSigned-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/iwcm.c

@@ -1186,29 +1186,34 @@ static int __init iw_cm_init(void)
 
 	ret = iwpm_init(RDMA_NL_IWCM);
 	if (ret)
-		pr_err("iw_cm: couldn't init iwpm\n");
-	else
-		rdma_nl_register(RDMA_NL_IWCM, iwcm_nl_cb_table);
+		return ret;
+
 	iwcm_wq = alloc_ordered_workqueue("iw_cm_wq", 0);
 	if (!iwcm_wq)
-		return -ENOMEM;
+		goto err_alloc;
 
 	iwcm_ctl_table_hdr = register_net_sysctl(&init_net, "net/iw_cm",
 						 iwcm_ctl_table);
 	if (!iwcm_ctl_table_hdr) {
 		pr_err("iw_cm: couldn't register sysctl paths\n");
-		destroy_workqueue(iwcm_wq);
-		return -ENOMEM;
+		goto err_sysctl;
 	}
 
+	rdma_nl_register(RDMA_NL_IWCM, iwcm_nl_cb_table);
 	return 0;
+
+err_sysctl:
+	destroy_workqueue(iwcm_wq);
+err_alloc:
+	iwpm_exit(RDMA_NL_IWCM);
+	return -ENOMEM;
 }
 
 static void __exit iw_cm_cleanup(void)
 {
+	rdma_nl_unregister(RDMA_NL_IWCM);
 	unregister_net_sysctl_table(iwcm_ctl_table_hdr);
 	destroy_workqueue(iwcm_wq);
-	rdma_nl_unregister(RDMA_NL_IWCM);
 	iwpm_exit(RDMA_NL_IWCM);
 }