IB/cma: Add support for network namespaces

Add support for network namespaces in the ib_cma module. This is
accomplished by:

1. Adding network namespace parameter for rdma_create_id. This parameter is
   used to populate the network namespace field in rdma_id_private.
   rdma_create_id keeps a reference on the network namespace.
2. Using the network namespace from the rdma_id instead of init_net inside
   of ib_cma, when listening on an ID and when looking for an ID for an
   incoming request.
3. Decrementing the reference count for the appropriate network namespace
   when calling rdma_destroy_id.

In order to preserve the current behavior init_net is passed when calling
from other modules.

Signed-off-by: Guy Shapiro <guysh@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Yotam Kenneth <yotamke@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index ac03c32..7e93eb1 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -600,7 +600,8 @@
 	return 0;
 }
 
-struct rdma_cm_id *rdma_create_id(rdma_cm_event_handler event_handler,
+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)
 {
@@ -624,7 +625,7 @@
 	INIT_LIST_HEAD(&id_priv->listen_list);
 	INIT_LIST_HEAD(&id_priv->mc_list);
 	get_random_bytes(&id_priv->seq_num, sizeof id_priv->seq_num);
-	id_priv->id.route.addr.dev_addr.net = &init_net;
+	id_priv->id.route.addr.dev_addr.net = get_net(net);
 
 	return &id_priv->id;
 }
@@ -1278,7 +1279,7 @@
 		       cma_protocol_roce(&id_priv->id);
 
 	return !addr->dev_addr.bound_dev_if ||
-	       (net_eq(dev_net(net_dev), &init_net) &&
+	       (net_eq(dev_net(net_dev), addr->dev_addr.net) &&
 		addr->dev_addr.bound_dev_if == net_dev->ifindex);
 }
 
@@ -1339,7 +1340,7 @@
 		}
 	}
 
-	bind_list = cma_ps_find(&init_net,
+	bind_list = cma_ps_find(*net_dev ? dev_net(*net_dev) : &init_net,
 				rdma_ps_from_service_id(req.service_id),
 				cma_port_from_service_id(req.service_id));
 	id_priv = cma_find_listener(bind_list, cm_id, ib_event, &req, *net_dev);
@@ -1411,6 +1412,7 @@
 static void cma_release_port(struct rdma_id_private *id_priv)
 {
 	struct rdma_bind_list *bind_list = id_priv->bind_list;
+	struct net *net = id_priv->id.route.addr.dev_addr.net;
 
 	if (!bind_list)
 		return;
@@ -1418,7 +1420,7 @@
 	mutex_lock(&lock);
 	hlist_del(&id_priv->node);
 	if (hlist_empty(&bind_list->owners)) {
-		cma_ps_remove(&init_net, bind_list->ps, bind_list->port);
+		cma_ps_remove(net, bind_list->ps, bind_list->port);
 		kfree(bind_list);
 	}
 	mutex_unlock(&lock);
@@ -1477,6 +1479,7 @@
 		cma_deref_id(id_priv->id.context);
 
 	kfree(id_priv->id.route.path_rec);
+	put_net(id_priv->id.route.addr.dev_addr.net);
 	kfree(id_priv);
 }
 EXPORT_SYMBOL(rdma_destroy_id);
@@ -1607,7 +1610,8 @@
 		      ib_event->param.req_rcvd.primary_path->service_id;
 	int ret;
 
-	id = rdma_create_id(listen_id->event_handler, listen_id->context,
+	id = rdma_create_id(listen_id->route.addr.dev_addr.net,
+			    listen_id->event_handler, listen_id->context,
 			    listen_id->ps, ib_event->param.req_rcvd.qp_type);
 	if (IS_ERR(id))
 		return NULL;
@@ -1662,9 +1666,10 @@
 	struct rdma_id_private *id_priv;
 	struct rdma_cm_id *id;
 	const sa_family_t ss_family = listen_id->route.addr.src_addr.ss_family;
+	struct net *net = listen_id->route.addr.dev_addr.net;
 	int ret;
 
-	id = rdma_create_id(listen_id->event_handler, listen_id->context,
+	id = rdma_create_id(net, listen_id->event_handler, listen_id->context,
 			    listen_id->ps, IB_QPT_UD);
 	if (IS_ERR(id))
 		return NULL;
@@ -1901,7 +1906,8 @@
 		return -ECONNABORTED;
 
 	/* Create a new RDMA id for the new IW CM ID */
-	new_cm_id = rdma_create_id(listen_id->id.event_handler,
+	new_cm_id = rdma_create_id(listen_id->id.route.addr.dev_addr.net,
+				   listen_id->id.event_handler,
 				   listen_id->id.context,
 				   RDMA_PS_TCP, IB_QPT_RC);
 	if (IS_ERR(new_cm_id)) {
@@ -2029,12 +2035,13 @@
 {
 	struct rdma_id_private *dev_id_priv;
 	struct rdma_cm_id *id;
+	struct net *net = id_priv->id.route.addr.dev_addr.net;
 	int ret;
 
 	if (cma_family(id_priv) == AF_IB && !rdma_cap_ib_cm(cma_dev->device, 1))
 		return;
 
-	id = rdma_create_id(cma_listen_handler, id_priv, id_priv->id.ps,
+	id = rdma_create_id(net, cma_listen_handler, id_priv, id_priv->id.ps,
 			    id_priv->id.qp_type);
 	if (IS_ERR(id))
 		return;
@@ -2708,7 +2715,8 @@
 	if (!bind_list)
 		return -ENOMEM;
 
-	ret = cma_ps_alloc(&init_net, ps, bind_list, snum);
+	ret = cma_ps_alloc(id_priv->id.route.addr.dev_addr.net, ps, bind_list,
+			   snum);
 	if (ret < 0)
 		goto err;
 
@@ -2727,13 +2735,14 @@
 	static unsigned int last_used_port;
 	int low, high, remaining;
 	unsigned int rover;
+	struct net *net = id_priv->id.route.addr.dev_addr.net;
 
-	inet_get_local_port_range(&init_net, &low, &high);
+	inet_get_local_port_range(net, &low, &high);
 	remaining = (high - low) + 1;
 	rover = prandom_u32() % remaining + low;
 retry:
 	if (last_used_port != rover &&
-	    !cma_ps_find(&init_net, ps, (unsigned short)rover)) {
+	    !cma_ps_find(net, ps, (unsigned short)rover)) {
 		int ret = cma_alloc_port(ps, id_priv, rover);
 		/*
 		 * Remember previously used port number in order to avoid
@@ -2799,7 +2808,7 @@
 	if (snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 		return -EACCES;
 
-	bind_list = cma_ps_find(&init_net, ps, snum);
+	bind_list = cma_ps_find(id_priv->id.route.addr.dev_addr.net, ps, snum);
 	if (!bind_list) {
 		ret = cma_alloc_port(ps, id_priv, snum);
 	} else {
@@ -2991,8 +3000,11 @@
 		if (addr->sa_family == AF_INET)
 			id_priv->afonly = 1;
 #if IS_ENABLED(CONFIG_IPV6)
-		else if (addr->sa_family == AF_INET6)
-			id_priv->afonly = init_net.ipv6.sysctl.bindv6only;
+		else if (addr->sa_family == AF_INET6) {
+			struct net *net = id_priv->id.route.addr.dev_addr.net;
+
+			id_priv->afonly = net->ipv6.sysctl.bindv6only;
+		}
 #endif
 	}
 	ret = cma_get_port(id_priv);
@@ -3797,6 +3809,7 @@
 	dev_addr = &id_priv->id.route.addr.dev_addr;
 
 	if ((dev_addr->bound_dev_if == ndev->ifindex) &&
+	    (net_eq(dev_net(ndev), dev_addr->net)) &&
 	    memcmp(dev_addr->src_dev_addr, ndev->dev_addr, ndev->addr_len)) {
 		printk(KERN_INFO "RDMA CM addr change for ndev %s used by id %p\n",
 		       ndev->name, &id_priv->id);
@@ -3822,9 +3835,6 @@
 	struct rdma_id_private *id_priv;
 	int ret = NOTIFY_DONE;
 
-	if (dev_net(ndev) != &init_net)
-		return NOTIFY_DONE;
-
 	if (event != NETDEV_BONDING_FAILOVER)
 		return NOTIFY_DONE;