From: Saeed Mahameed <saeedm@mellanox.com>
Date: Wed, 4 Dec 2013 11:14:50 +0000 (+0200)
Subject: rdma_cm: garbage-collection thread for rdma_destroy_id()
X-Git-Tag: v4.1.12-92~293^2~1^2~58
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4c12b497beb5f38679860206cc171d6ec7277d8a;p=users%2Fjedix%2Flinux-maple.git

rdma_cm: garbage-collection thread for rdma_destroy_id()

garbage-collection thread for rdma_destroy_id,
so as not to paralyze ib_cm thread with wait_for_completion.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Extracted from following commit in Mellanox OFED-2.4
812c3972cf93e0d04f568ba353e87a1de7c9e006
(rdma_cm: race condition bug fixes)

Signed-off-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
(Ported from Mellanox OFED 2.4)

Signed-off-by: Mukesh Kacker <mukesh.kacker@oracle.com>
---

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 031b377a1557a..b728f80d60b05 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -84,6 +84,7 @@ static LIST_HEAD(dev_list);
 static LIST_HEAD(listen_any_list);
 static DEFINE_MUTEX(lock);
 static struct workqueue_struct *cma_wq;
+static struct workqueue_struct *cma_free_wq;
 static DEFINE_IDR(tcp_ps);
 static DEFINE_IDR(udp_ps);
 static DEFINE_IDR(ipoib_ps);
@@ -131,6 +132,7 @@ struct rdma_id_private {
 	struct completion	comp;
 	atomic_t		refcount;
 	struct mutex		handler_mutex;
+	struct work_struct	work;  /* garbage coll */
 
 	int			backlog;
 	int			timeout_ms;
@@ -1040,6 +1042,19 @@ static void cma_leave_mc_groups(struct rdma_id_private *id_priv)
 		}
 	}
 }
+static void __rdma_free(struct work_struct *work)
+{
+	struct rdma_id_private *id_priv;
+	id_priv = container_of(work, struct rdma_id_private, work);
+
+	wait_for_completion(&id_priv->comp);
+
+	if (id_priv->internal_id)
+		cma_deref_id(id_priv->id.context);
+
+	kfree(id_priv->id.route.path_rec);
+	kfree(id_priv);
+}
 
 void rdma_destroy_id(struct rdma_cm_id *id)
 {
@@ -1076,13 +1091,8 @@ void rdma_destroy_id(struct rdma_cm_id *id)
 
 	cma_release_port(id_priv);
 	cma_deref_id(id_priv);
-	wait_for_completion(&id_priv->comp);
-
-	if (id_priv->internal_id)
-		cma_deref_id(id_priv->id.context);
-
-	kfree(id_priv->id.route.path_rec);
-	kfree(id_priv);
+	INIT_WORK(&id_priv->work, __rdma_free);
+	queue_work(cma_free_wq, &id_priv->work);
 }
 EXPORT_SYMBOL(rdma_destroy_id);
 
@@ -3682,12 +3692,16 @@ static const struct ibnl_client_cbs cma_cb_table[] = {
 
 static int __init cma_init(void)
 {
-	int ret;
+	int ret = -ENOMEM;
 
 	cma_wq = create_singlethread_workqueue("rdma_cm");
 	if (!cma_wq)
 		return -ENOMEM;
 
+	cma_free_wq = create_singlethread_workqueue("rdma_cm_fr");
+	if (!cma_free_wq)
+		goto err1;
+
 	ib_sa_register_client(&sa_client);
 	rdma_addr_register_client(&addr_client);
 	register_netdevice_notifier(&cma_nb);
@@ -3705,6 +3719,9 @@ err:
 	unregister_netdevice_notifier(&cma_nb);
 	rdma_addr_unregister_client(&addr_client);
 	ib_sa_unregister_client(&sa_client);
+
+	destroy_workqueue(cma_free_wq);
+err1:
 	destroy_workqueue(cma_wq);
 	return ret;
 }
@@ -3716,6 +3733,8 @@ static void __exit cma_cleanup(void)
 	unregister_netdevice_notifier(&cma_nb);
 	rdma_addr_unregister_client(&addr_client);
 	ib_sa_unregister_client(&sa_client);
+	flush_workqueue(cma_free_wq);
+	destroy_workqueue(cma_free_wq);
 	destroy_workqueue(cma_wq);
 	idr_destroy(&tcp_ps);
 	idr_destroy(&udp_ps);