[PATCH v3 net-next 0/2] RDS-TCP: Network namespace support

[PATCH v3 net-next 0/2] RDS-TCP: Network namespace support

[Sowmini Varadhan]

This patch series contains the set of changes to correctly set up 
the infra for PF_RDS sockets that use TCP as the transport in multiple
network namespaces.

Patch 1 in the series is the minimal set of changes to allow
a single instance of RDS-TCP to run in any (i.e init_net or other) net
namespace.  The changes in this patch set ensure that the execution of 
'modprobe [-r] rds_tcp' sets up the kernel TCP sockets 
relative to the current netns, so that RDS applications can send/recv
packets from that netns, and the netns can later be deleted cleanly.

Patch 2 of the series further allows multiple RDS-TCP instances,
one per network namespace. The changes in this patch allows dynamic
creation/tear-down of RDS-TCP client and server sockets  across all
current and future namespaces. 

v2 changes from RFC sent out earlier:
    David Ahern comments in patch 1, net_device notifier in patch 2, 
    patch 3 broken off and submitted separately.
v3: Cong Wang review comments.

Sowmini Varadhan (2):
  Make RDS-TCP work correctly when it is set up in a netns other than
    init_net
  Support multiple RDS-TCP listen endpoints, one per netns.

 net/rds/bind.c        |    3 +-
 net/rds/connection.c  |   16 +++--
 net/rds/ib.c          |    2 +-
 net/rds/ib_cm.c       |    5 +-
 net/rds/iw.c          |    2 +-
 net/rds/iw_cm.c       |    5 +-
 net/rds/rds.h         |   23 ++++++-
 net/rds/send.c        |    3 +-
 net/rds/tcp.c         |  165 +++++++++++++++++++++++++++++++++++++++++++-----
 net/rds/tcp.h         |    7 ++-
 net/rds/tcp_connect.c |    9 ++-
 net/rds/tcp_listen.c  |   40 ++++--------
 net/rds/transport.c   |    4 +-
 13 files changed, 214 insertions(+), 70 deletions(-)

[PATCH v3 net-next 1/2] RDS-TCP: Make RDS-TCP work correctly when it is set up in a netns other than init_net

[Sowmini Varadhan]

Open the sockets calling sock_create_kern() with the correct struct net
pointer, and use that struct net pointer when verifying the
address passed to rds_bind().

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
---
v2: David Ahern comments.

 net/rds/bind.c        |    3 ++-
 net/rds/connection.c  |   16 ++++++++++------
 net/rds/ib.c          |    2 +-
 net/rds/ib_cm.c       |    5 +++--
 net/rds/iw.c          |    2 +-
 net/rds/iw_cm.c       |    5 +++--
 net/rds/rds.h         |   23 +++++++++++++++++++----
 net/rds/send.c        |    3 ++-
 net/rds/tcp.c         |    4 ++--
 net/rds/tcp_connect.c |    3 ++-
 net/rds/tcp_listen.c  |   16 ++++++++++++----
 net/rds/transport.c   |    4 ++--
 12 files changed, 59 insertions(+), 27 deletions(-)

diff --git a/net/rds/bind.c b/net/rds/bind.c
index 4ebd29c..dd666fb 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.c
@@ -185,7 +185,8 @@ int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		ret = 0;
 		goto out;
 	}
-	trans = rds_trans_get_preferred(sin->sin_addr.s_addr);
+	trans = rds_trans_get_preferred(sock_net(sock->sk),
+					sin->sin_addr.s_addr);
 	if (!trans) {
 		ret = -EADDRNOTAVAIL;
 		rds_remove_bound(rs);
diff --git a/net/rds/connection.c b/net/rds/connection.c
index da6da57..d4fecb2 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -117,7 +117,8 @@ static void rds_conn_reset(struct rds_connection *conn)
  * For now they are not garbage collected once they're created.  They
  * are torn down as the module is removed, if ever.
  */
-static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
+static struct rds_connection *__rds_conn_create(struct net *net,
+						__be32 laddr, __be32 faddr,
 				       struct rds_transport *trans, gfp_t gfp,
 				       int is_outgoing)
 {
@@ -157,6 +158,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 	conn->c_faddr = faddr;
 	spin_lock_init(&conn->c_lock);
 	conn->c_next_tx_seq = 1;
+	rds_conn_net_set(conn, net);
 
 	init_waitqueue_head(&conn->c_waitq);
 	INIT_LIST_HEAD(&conn->c_send_queue);
@@ -174,7 +176,7 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 	 * can bind to the destination address then we'd rather the messages
 	 * flow through loopback rather than either transport.
 	 */
-	loop_trans = rds_trans_get_preferred(faddr);
+	loop_trans = rds_trans_get_preferred(net, faddr);
 	if (loop_trans) {
 		rds_trans_put(loop_trans);
 		conn->c_loopback = 1;
@@ -260,17 +262,19 @@ static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
 	return conn;
 }
 
-struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
+struct rds_connection *rds_conn_create(struct net *net,
+				       __be32 laddr, __be32 faddr,
 				       struct rds_transport *trans, gfp_t gfp)
 {
-	return __rds_conn_create(laddr, faddr, trans, gfp, 0);
+	return __rds_conn_create(net, laddr, faddr, trans, gfp, 0);
 }
 EXPORT_SYMBOL_GPL(rds_conn_create);
 
-struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
+struct rds_connection *rds_conn_create_outgoing(struct net *net,
+						__be32 laddr, __be32 faddr,
 				       struct rds_transport *trans, gfp_t gfp)
 {
-	return __rds_conn_create(laddr, faddr, trans, gfp, 1);
+	return __rds_conn_create(net, laddr, faddr, trans, gfp, 1);
 }
 EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
 
diff --git a/net/rds/ib.c b/net/rds/ib.c
index ba2dffe..1381422 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -317,7 +317,7 @@ static void rds_ib_ic_info(struct socket *sock, unsigned int len,
  * allowed to influence which paths have priority.  We could call userspace
  * asserting this policy "routing".
  */
-static int rds_ib_laddr_check(__be32 addr)
+static int rds_ib_laddr_check(struct net *net, __be32 addr)
 {
 	int ret;
 	struct rdma_cm_id *cm_id;
diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c
index 0da2a45..f40d8f5 100644
--- a/net/rds/ib_cm.c
+++ b/net/rds/ib_cm.c
@@ -448,8 +448,9 @@ int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 		 (unsigned long long)be64_to_cpu(lguid),
 		 (unsigned long long)be64_to_cpu(fguid));
 
-	conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
-			       GFP_KERNEL);
+	/* RDS/IB is not currently netns aware, thus init_net */
+	conn = rds_conn_create(&init_net, dp->dp_daddr, dp->dp_saddr,
+			       &rds_ib_transport, GFP_KERNEL);
 	if (IS_ERR(conn)) {
 		rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 		conn = NULL;
diff --git a/net/rds/iw.c b/net/rds/iw.c
index 5899356..5d5a9d2 100644
--- a/net/rds/iw.c
+++ b/net/rds/iw.c
@@ -218,7 +218,7 @@ static void rds_iw_ic_info(struct socket *sock, unsigned int len,
  * allowed to influence which paths have priority.  We could call userspace
  * asserting this policy "routing".
  */
-static int rds_iw_laddr_check(__be32 addr)
+static int rds_iw_laddr_check(struct net *net, __be32 addr)
 {
 	int ret;
 	struct rdma_cm_id *cm_id;
diff --git a/net/rds/iw_cm.c b/net/rds/iw_cm.c
index 8f486fa..a6553a6 100644
--- a/net/rds/iw_cm.c
+++ b/net/rds/iw_cm.c
@@ -398,8 +398,9 @@ int rds_iw_cm_handle_connect(struct rdma_cm_id *cm_id,
 		 &dp->dp_saddr, &dp->dp_daddr,
 		 RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version));
 
-	conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_iw_transport,
-			       GFP_KERNEL);
+	/* RDS/IW is not currently netns aware, thus init_net */
+	conn = rds_conn_create(&init_net, dp->dp_daddr, dp->dp_saddr,
+			       &rds_iw_transport, GFP_KERNEL);
 	if (IS_ERR(conn)) {
 		rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
 		conn = NULL;
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 2260c1e..9005fb0 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -128,8 +128,21 @@ struct rds_connection {
 
 	/* Protocol version */
 	unsigned int		c_version;
+	possible_net_t		c_net;
 };
 
+static inline
+struct net *rds_conn_net(struct rds_connection *conn)
+{
+	return read_pnet(&conn->c_net);
+}
+
+static inline
+void rds_conn_net_set(struct rds_connection *conn, struct net *net)
+{
+	write_pnet(&conn->c_net, net);
+}
+
 #define RDS_FLAG_CONG_BITMAP	0x01
 #define RDS_FLAG_ACK_REQUIRED	0x02
 #define RDS_FLAG_RETRANSMITTED	0x04
@@ -417,7 +430,7 @@ struct rds_transport {
 	unsigned int		t_prefer_loopback:1;
 	unsigned int		t_type;
 
-	int (*laddr_check)(__be32 addr);
+	int (*laddr_check)(struct net *net, __be32 addr);
 	int (*conn_alloc)(struct rds_connection *conn, gfp_t gfp);
 	void (*conn_free)(void *data);
 	int (*conn_connect)(struct rds_connection *conn);
@@ -608,9 +621,11 @@ struct rds_message *rds_cong_update_alloc(struct rds_connection *conn);
 /* conn.c */
 int rds_conn_init(void);
 void rds_conn_exit(void);
-struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
+struct rds_connection *rds_conn_create(struct net *net,
+				       __be32 laddr, __be32 faddr,
 				       struct rds_transport *trans, gfp_t gfp);
-struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
+struct rds_connection *rds_conn_create_outgoing(struct net *net,
+						__be32 laddr, __be32 faddr,
 			       struct rds_transport *trans, gfp_t gfp);
 void rds_conn_shutdown(struct rds_connection *conn);
 void rds_conn_destroy(struct rds_connection *conn);
@@ -795,7 +810,7 @@ void rds_connect_complete(struct rds_connection *conn);
 /* transport.c */
 int rds_trans_register(struct rds_transport *trans);
 void rds_trans_unregister(struct rds_transport *trans);
-struct rds_transport *rds_trans_get_preferred(__be32 addr);
+struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr);
 void rds_trans_put(struct rds_transport *trans);
 unsigned int rds_trans_stats_info_copy(struct rds_info_iterator *iter,
 				       unsigned int avail);
diff --git a/net/rds/send.c b/net/rds/send.c
index e9430f5..2581b8e 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -1023,7 +1023,8 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len)
 	if (rs->rs_conn && rs->rs_conn->c_faddr == daddr)
 		conn = rs->rs_conn;
 	else {
-		conn = rds_conn_create_outgoing(rs->rs_bound_addr, daddr,
+		conn = rds_conn_create_outgoing(sock_net(sock->sk),
+						rs->rs_bound_addr, daddr,
 					rs->rs_transport,
 					sock->sk->sk_allocation);
 		if (IS_ERR(conn)) {
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index edac9ef..98f5de3 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -189,9 +189,9 @@ static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
 	spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 }
 
-static int rds_tcp_laddr_check(__be32 addr)
+static int rds_tcp_laddr_check(struct net *net, __be32 addr)
 {
-	if (inet_addr_type(&init_net, addr) == RTN_LOCAL)
+	if (inet_addr_type(net, addr) == RTN_LOCAL)
 		return 0;
 	return -EADDRNOTAVAIL;
 }
diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c
index 973109c..6473b7b 100644
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -79,7 +79,8 @@ int rds_tcp_conn_connect(struct rds_connection *conn)
 	struct sockaddr_in src, dest;
 	int ret;
 
-	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+	ret = sock_create_kern(rds_conn_net(conn), PF_INET,
+			       SOCK_STREAM, IPPROTO_TCP, &sock);
 	if (ret < 0)
 		goto out;
 
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 0da49e3..398ffe5 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -85,8 +85,9 @@ static int rds_tcp_accept_one(struct socket *sock)
 	struct inet_sock *inet;
 	struct rds_tcp_connection *rs_tcp;
 
-	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
-			       sock->sk->sk_protocol, &new_sock);
+	ret = sock_create_kern(sock_net(sock->sk), sock->sk->sk_family,
+			       sock->sk->sk_type, sock->sk->sk_protocol,
+			       &new_sock);
 	if (ret)
 		goto out;
 
@@ -108,7 +109,8 @@ static int rds_tcp_accept_one(struct socket *sock)
 		 &inet->inet_saddr, ntohs(inet->inet_sport),
 		 &inet->inet_daddr, ntohs(inet->inet_dport));
 
-	conn = rds_conn_create(inet->inet_saddr, inet->inet_daddr,
+	conn = rds_conn_create(sock_net(sock->sk),
+			       inet->inet_saddr, inet->inet_daddr,
 			       &rds_tcp_transport, GFP_KERNEL);
 	if (IS_ERR(conn)) {
 		ret = PTR_ERR(conn);
@@ -187,7 +189,13 @@ int rds_tcp_listen_init(void)
 	struct socket *sock = NULL;
 	int ret;
 
-	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+	/* MUST call sock_create_kern directly so that we avoid get_net()
+	 * in sk_alloc(). Doing a get_net() will result in cleanup_net()
+	 * never getting invoked, which will leave sock and other things
+	 * in limbo.
+	 */
+	ret = sock_create_kern(current->nsproxy->net_ns, PF_INET,
+			       SOCK_STREAM, IPPROTO_TCP, &sock);
 	if (ret < 0)
 		goto out;
 
diff --git a/net/rds/transport.c b/net/rds/transport.c
index 83498e1..f3afd1d 100644
--- a/net/rds/transport.c
+++ b/net/rds/transport.c
@@ -77,7 +77,7 @@ void rds_trans_put(struct rds_transport *trans)
 		module_put(trans->t_owner);
 }
 
-struct rds_transport *rds_trans_get_preferred(__be32 addr)
+struct rds_transport *rds_trans_get_preferred(struct net *net, __be32 addr)
 {
 	struct rds_transport *ret = NULL;
 	struct rds_transport *trans;
@@ -90,7 +90,7 @@ struct rds_transport *rds_trans_get_preferred(__be32 addr)
 	for (i = 0; i < RDS_TRANS_COUNT; i++) {
 		trans = transports[i];
 
-		if (trans && (trans->laddr_check(addr) == 0) &&
+		if (trans && (trans->laddr_check(net, addr) == 0) &&
 		    (!trans->t_owner || try_module_get(trans->t_owner))) {
 			ret = trans;
 			break;
-- 
1.7.1

[PATCH v3 net-next 2/2] RDS-TCP: Support multiple RDS-TCP listen endpoints, one per netns.

[Sowmini Varadhan]

Register pernet subsys init/stop functions that will set up
and tear down per-net RDS-TCP listen endpoints. Unregister
pernet subusys functions on 'modprobe -r' to clean up these
end points.

Enable keepalive on both accept and connect socket endpoints.
The keepalive timer expiration will ensure that client socket
endpoints will be removed as appropriate from the netns when
an interface is removed from a namespace.

Register a device notifier callback that will clean up all
sockets (and thus avoid the need to wait for keepalive timeout)
when the loopback device is unregistered from the netns indicating
that the netns is getting deleted.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
---
v2: net_device notifier for synchronous cleanup of sockets.
v3: Cong Wang comments

 net/rds/tcp.c         |  161 ++++++++++++++++++++++++++++++++++++++++++++-----
 net/rds/tcp.h         |    7 ++-
 net/rds/tcp_connect.c |    6 +-
 net/rds/tcp_listen.c  |   38 +++---------
 4 files changed, 162 insertions(+), 50 deletions(-)

diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 98f5de3..c42b60b 100644
--- a/net/rds/tcp.c
+++ b/net/rds/tcp.c
@@ -35,6 +35,9 @@
 #include <linux/in.h>
 #include <linux/module.h>
 #include <net/tcp.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/tcp.h>
 
 #include "rds.h"
 #include "tcp.h"
@@ -250,16 +253,7 @@ static void rds_tcp_destroy_conns(void)
 	}
 }
 
-static void rds_tcp_exit(void)
-{
-	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
-	rds_tcp_listen_stop();
-	rds_tcp_destroy_conns();
-	rds_trans_unregister(&rds_tcp_transport);
-	rds_tcp_recv_exit();
-	kmem_cache_destroy(rds_tcp_conn_slab);
-}
-module_exit(rds_tcp_exit);
+static void rds_tcp_exit(void);
 
 struct rds_transport rds_tcp_transport = {
 	.laddr_check		= rds_tcp_laddr_check,
@@ -281,6 +275,136 @@ struct rds_transport rds_tcp_transport = {
 	.t_prefer_loopback	= 1,
 };
 
+static int rds_tcp_netid;
+
+/* per-network namespace private data for this module */
+struct rds_tcp_net {
+	struct socket *rds_tcp_listen_sock;
+	struct work_struct rds_tcp_accept_w;
+};
+
+static void rds_tcp_accept_worker(struct work_struct *work)
+{
+	struct rds_tcp_net *rtn = container_of(work,
+					       struct rds_tcp_net,
+					       rds_tcp_accept_w);
+
+	while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0)
+		cond_resched();
+}
+
+void rds_tcp_accept_work(struct sock *sk)
+{
+	struct net *net = sock_net(sk);
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+
+	queue_work(rds_wq, &rtn->rds_tcp_accept_w);
+}
+
+static __net_init int rds_tcp_init_net(struct net *net)
+{
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+
+	rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net);
+	if (!rtn->rds_tcp_listen_sock) {
+		pr_warn("could not set up listen sock\n");
+		return -EAFNOSUPPORT;
+	}
+	INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
+	return 0;
+}
+
+static void __net_exit rds_tcp_exit_net(struct net *net)
+{
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+
+	/* If rds_tcp_exit_net() is called as a result of netns deletion,
+	 * the rds_tcp_kill_sock() device notifier would already have cleaned
+	 * up the listen socket, thus there is no work to do in this function.
+	 *
+	 * If rds_tcp_exit_net() is called as a result of module unload,
+	 * i.e., due to rds_tcp_exit() -> unregister_pernet_subsys(), then
+	 * we do need to clean up the listen socket here.
+	 */
+	if (rtn->rds_tcp_listen_sock) {
+		rds_tcp_listen_stop(rtn->rds_tcp_listen_sock);
+		rtn->rds_tcp_listen_sock = NULL;
+		flush_work(&rtn->rds_tcp_accept_w);
+	}
+}
+
+static struct pernet_operations rds_tcp_net_ops = {
+	.init = rds_tcp_init_net,
+	.exit = rds_tcp_exit_net,
+	.id = &rds_tcp_netid,
+	.size = sizeof(struct rds_tcp_net),
+};
+
+static void rds_tcp_kill_sock(struct net *net)
+{
+	struct rds_tcp_connection *tc, *_tc;
+	struct sock *sk;
+	LIST_HEAD(tmp_list);
+	struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
+
+	rds_tcp_listen_stop(rtn->rds_tcp_listen_sock);
+	rtn->rds_tcp_listen_sock = NULL;
+	flush_work(&rtn->rds_tcp_accept_w);
+	spin_lock_irq(&rds_tcp_conn_lock);
+	list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
+		struct net *c_net = read_pnet(&tc->conn->c_net);
+
+		if (net != c_net || !tc->t_sock)
+			continue;
+		list_move_tail(&tc->t_tcp_node, &tmp_list);
+	}
+	spin_unlock_irq(&rds_tcp_conn_lock);
+	list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
+		sk = tc->t_sock->sk;
+		sk->sk_prot->disconnect(sk, 0);
+		tcp_done(sk);
+		if (tc->conn->c_passive)
+			rds_conn_destroy(tc->conn->c_passive);
+		rds_conn_destroy(tc->conn);
+	}
+}
+
+static int rds_tcp_dev_event(struct notifier_block *this,
+			     unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	/* rds-tcp registers as a pernet subys, so the ->exit will only
+	 * get invoked after network acitivity has quiesced. We need to
+	 * clean up all sockets  to quiesce network activity, and use
+	 * the unregistration of the per-net loopback device as a trigger
+	 * to start that cleanup.
+	 */
+	if (event == NETDEV_UNREGISTER_FINAL &&
+	    dev->ifindex == LOOPBACK_IFINDEX)
+		rds_tcp_kill_sock(dev_net(dev));
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block rds_tcp_dev_notifier = {
+	.notifier_call        = rds_tcp_dev_event,
+	.priority = -10, /* must be called after other network notifiers */
+};
+
+static void rds_tcp_exit(void)
+{
+	rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
+	unregister_pernet_subsys(&rds_tcp_net_ops);
+	if (unregister_netdevice_notifier(&rds_tcp_dev_notifier))
+		pr_warn("could not unregister rds_tcp_dev_notifier\n");
+	rds_tcp_destroy_conns();
+	rds_trans_unregister(&rds_tcp_transport);
+	rds_tcp_recv_exit();
+	kmem_cache_destroy(rds_tcp_conn_slab);
+}
+module_exit(rds_tcp_exit);
+
 static int rds_tcp_init(void)
 {
 	int ret;
@@ -293,6 +417,16 @@ static int rds_tcp_init(void)
 		goto out;
 	}
 
+	ret = register_netdevice_notifier(&rds_tcp_dev_notifier);
+	if (ret) {
+		pr_warn("could not register rds_tcp_dev_notifier\n");
+		goto out;
+	}
+
+	ret = register_pernet_subsys(&rds_tcp_net_ops);
+	if (ret)
+		goto out_slab;
+
 	ret = rds_tcp_recv_init();
 	if (ret)
 		goto out_slab;
@@ -301,19 +435,14 @@ static int rds_tcp_init(void)
 	if (ret)
 		goto out_recv;
 
-	ret = rds_tcp_listen_init();
-	if (ret)
-		goto out_register;
-
 	rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 
 	goto out;
 
-out_register:
-	rds_trans_unregister(&rds_tcp_transport);
 out_recv:
 	rds_tcp_recv_exit();
 out_slab:
+	unregister_pernet_subsys(&rds_tcp_net_ops);
 	kmem_cache_destroy(rds_tcp_conn_slab);
 out:
 	return ret;
diff --git a/net/rds/tcp.h b/net/rds/tcp.h
index 0dbdd37..64f873c 100644
--- a/net/rds/tcp.h
+++ b/net/rds/tcp.h
@@ -52,6 +52,7 @@ u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc);
 u32 rds_tcp_snd_una(struct rds_tcp_connection *tc);
 u64 rds_tcp_map_seq(struct rds_tcp_connection *tc, u32 seq);
 extern struct rds_transport rds_tcp_transport;
+void rds_tcp_accept_work(struct sock *sk);
 
 /* tcp_connect.c */
 int rds_tcp_conn_connect(struct rds_connection *conn);
@@ -59,9 +60,11 @@ void rds_tcp_conn_shutdown(struct rds_connection *conn);
 void rds_tcp_state_change(struct sock *sk);
 
 /* tcp_listen.c */
-int rds_tcp_listen_init(void);
-void rds_tcp_listen_stop(void);
+struct socket *rds_tcp_listen_init(struct net *);
+void rds_tcp_listen_stop(struct socket *);
 void rds_tcp_listen_data_ready(struct sock *sk);
+int rds_tcp_accept_one(struct socket *sock);
+int rds_tcp_keepalive(struct socket *sock);
 
 /* tcp_recv.c */
 int rds_tcp_recv_init(void);
diff --git a/net/rds/tcp_connect.c b/net/rds/tcp_connect.c
index 6473b7b..5cb1687 100644
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -112,10 +112,12 @@ int rds_tcp_conn_connect(struct rds_connection *conn)
 	rdsdebug("connect to address %pI4 returned %d\n", &conn->c_faddr, ret);
 	if (ret == -EINPROGRESS)
 		ret = 0;
-	if (ret == 0)
+	if (ret == 0) {
+		rds_tcp_keepalive(sock);
 		sock = NULL;
-	else
+	} else {
 		rds_tcp_restore_callbacks(sock, conn->c_transport_data);
+	}
 
 out:
 	if (sock)
diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c
index 398ffe5..444d78d 100644
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -38,14 +38,7 @@
 #include "rds.h"
 #include "tcp.h"
 
-/*
- * cheesy, but simple..
- */
-static void rds_tcp_accept_worker(struct work_struct *work);
-static DECLARE_WORK(rds_tcp_listen_work, rds_tcp_accept_worker);
-static struct socket *rds_tcp_listen_sock;
-
-static int rds_tcp_keepalive(struct socket *sock)
+int rds_tcp_keepalive(struct socket *sock)
 {
 	/* values below based on xs_udp_default_timeout */
 	int keepidle = 5; /* send a probe 'keepidle' secs after last data */
@@ -77,7 +70,7 @@ static int rds_tcp_keepalive(struct socket *sock)
 	return ret;
 }
 
-static int rds_tcp_accept_one(struct socket *sock)
+int rds_tcp_accept_one(struct socket *sock)
 {
 	struct socket *new_sock = NULL;
 	struct rds_connection *conn;
@@ -150,12 +143,6 @@ static int rds_tcp_accept_one(struct socket *sock)
 	return ret;
 }
 
-static void rds_tcp_accept_worker(struct work_struct *work)
-{
-	while (rds_tcp_accept_one(rds_tcp_listen_sock) == 0)
-		cond_resched();
-}
-
 void rds_tcp_listen_data_ready(struct sock *sk)
 {
 	void (*ready)(struct sock *sk);
@@ -176,26 +163,20 @@ void rds_tcp_listen_data_ready(struct sock *sk)
 	 * socket
 	 */
 	if (sk->sk_state == TCP_LISTEN)
-		queue_work(rds_wq, &rds_tcp_listen_work);
+		rds_tcp_accept_work(sk);
 
 out:
 	read_unlock(&sk->sk_callback_lock);
 	ready(sk);
 }
 
-int rds_tcp_listen_init(void)
+struct socket *rds_tcp_listen_init(struct net *net)
 {
 	struct sockaddr_in sin;
 	struct socket *sock = NULL;
 	int ret;
 
-	/* MUST call sock_create_kern directly so that we avoid get_net()
-	 * in sk_alloc(). Doing a get_net() will result in cleanup_net()
-	 * never getting invoked, which will leave sock and other things
-	 * in limbo.
-	 */
-	ret = sock_create_kern(current->nsproxy->net_ns, PF_INET,
-			       SOCK_STREAM, IPPROTO_TCP, &sock);
+	ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
 	if (ret < 0)
 		goto out;
 
@@ -219,17 +200,15 @@ int rds_tcp_listen_init(void)
 	if (ret < 0)
 		goto out;
 
-	rds_tcp_listen_sock = sock;
-	sock = NULL;
+	return sock;
 out:
 	if (sock)
 		sock_release(sock);
-	return ret;
+	return NULL;
 }
 
-void rds_tcp_listen_stop(void)
+void rds_tcp_listen_stop(struct socket *sock)
 {
-	struct socket *sock = rds_tcp_listen_sock;
 	struct sock *sk;
 
 	if (!sock)
@@ -250,5 +229,4 @@ void rds_tcp_listen_stop(void)
 	/* wait for accepts to stop and close the socket */
 	flush_workqueue(rds_wq);
 	sock_release(sock);
-	rds_tcp_listen_sock = NULL;
 }
-- 
1.7.1

Re: [PATCH v3 net-next 0/2] RDS-TCP: Network namespace support

[David Miller]

From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Date: Wed,  5 Aug 2015 01:43:24 -0400

> This patch series contains the set of changes to correctly set up 
> the infra for PF_RDS sockets that use TCP as the transport in multiple
> network namespaces.
> 
> Patch 1 in the series is the minimal set of changes to allow
> a single instance of RDS-TCP to run in any (i.e init_net or other) net
> namespace.  The changes in this patch set ensure that the execution of 
> 'modprobe [-r] rds_tcp' sets up the kernel TCP sockets 
> relative to the current netns, so that RDS applications can send/recv
> packets from that netns, and the netns can later be deleted cleanly.
> 
> Patch 2 of the series further allows multiple RDS-TCP instances,
> one per network namespace. The changes in this patch allows dynamic
> creation/tear-down of RDS-TCP client and server sockets  across all
> current and future namespaces. 
> 
> v2 changes from RFC sent out earlier:
>     David Ahern comments in patch 1, net_device notifier in patch 2, 
>     patch 3 broken off and submitted separately.
> v3: Cong Wang review comments.

Series applied, thanks.