rxrpc: Support network namespacing

Support network namespacing in AF_RXRPC with the following changes:

 (1) All the local endpoint, peer and call lists, locks, counters, etc. are
     moved into the per-namespace record.

 (2) All the connection tracking is moved into the per-namespace record
     with the exception of the client connection ID tree, which is kept
     global so that connection IDs are kept unique per-machine.

 (3) Each namespace gets its own epoch.  This allows each network namespace
     to pretend to be a separate client machine.

 (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and
     the contents reflect the namespace.

fs/afs/ should be okay with this patch as it explicitly requires the current
net namespace to be init_net to permit a mount to proceed at the moment.  It
will, however, need updating so that cells, IP addresses and DNS records are
per-namespace also.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 75 insertions, 78 deletions

diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index e8dea0d49e7f..c86f3202f967 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -31,7 +31,7 @@
  *      may freely grant available channels to new calls and calls may be
  *      waiting on it for channels to become available.
  *
- *	The connection is on the rxrpc_active_client_conns list which is kept
+ *	The connection is on the rxnet->active_client_conns list which is kept
  *	in activation order for culling purposes.
  *
  *	rxrpc_nr_active_client_conns is held incremented also.
@@ -46,7 +46,7 @@
  *      expires, the EXPOSED flag is cleared and the connection transitions to
  *      the INACTIVE state.
  *
- *	The connection is on the rxrpc_idle_client_conns list which is kept in
+ *	The connection is on the rxnet->idle_client_conns list which is kept in
  *	order of how soon they'll expire.
  *
  * There are flags of relevance to the cache:
@@ -85,27 +85,13 @@ __read_mostly unsigned int rxrpc_reap_client_connections = 900;
 __read_mostly unsigned int rxrpc_conn_idle_client_expiry = 2 * 60 * HZ;
 __read_mostly unsigned int rxrpc_conn_idle_client_fast_expiry = 2 * HZ;
 
-static unsigned int rxrpc_nr_client_conns;
-static unsigned int rxrpc_nr_active_client_conns;
-static __read_mostly bool rxrpc_kill_all_client_conns;
-
-static DEFINE_SPINLOCK(rxrpc_client_conn_cache_lock);
-static DEFINE_SPINLOCK(rxrpc_client_conn_discard_mutex);
-static LIST_HEAD(rxrpc_waiting_client_conns);
-static LIST_HEAD(rxrpc_active_client_conns);
-static LIST_HEAD(rxrpc_idle_client_conns);
-
 /*
  * We use machine-unique IDs for our client connections.
  */
 DEFINE_IDR(rxrpc_client_conn_ids);
 static DEFINE_SPINLOCK(rxrpc_conn_id_lock);
 
-static void rxrpc_cull_active_client_conns(void);
-static void rxrpc_discard_expired_client_conns(struct work_struct *);
-
-static DECLARE_DELAYED_WORK(rxrpc_client_conn_reap,
-			    rxrpc_discard_expired_client_conns);
+static void rxrpc_cull_active_client_conns(struct rxrpc_net *);
 
 /*
  * Get a connection ID and epoch for a client connection from the global pool.
@@ -116,6 +102,7 @@ static DECLARE_DELAYED_WORK(rxrpc_client_conn_reap,
 static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn,
 					  gfp_t gfp)
 {
+	struct rxrpc_net *rxnet = conn->params.local->rxnet;
 	int id;
 
 	_enter("");
@@ -131,7 +118,7 @@ static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn,
 	spin_unlock(&rxrpc_conn_id_lock);
 	idr_preload_end();
 
-	conn->proto.epoch = rxrpc_epoch;
+	conn->proto.epoch = rxnet->epoch;
 	conn->proto.cid = id << RXRPC_CIDSHIFT;
 	set_bit(RXRPC_CONN_HAS_IDR, &conn->flags);
 	_leave(" [CID %x]", conn->proto.cid);
@@ -183,6 +170,7 @@ static struct rxrpc_connection *
 rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp)
 {
 	struct rxrpc_connection *conn;
+	struct rxrpc_net *rxnet = cp->local->rxnet;
 	int ret;
 
 	_enter("");
@@ -213,9 +201,9 @@ rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp)
 	if (ret < 0)
 		goto error_2;
 
-	write_lock(&rxrpc_connection_lock);
-	list_add_tail(&conn->proc_link, &rxrpc_connection_proc_list);
-	write_unlock(&rxrpc_connection_lock);
+	write_lock(&rxnet->conn_lock);
+	list_add_tail(&conn->proc_link, &rxnet->conn_proc_list);
+	write_unlock(&rxnet->conn_lock);
 
 	/* We steal the caller's peer ref. */
 	cp->peer = NULL;
@@ -243,12 +231,13 @@ error_0:
  */
 static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn)
 {
+	struct rxrpc_net *rxnet = conn->params.local->rxnet;
 	int id_cursor, id, distance, limit;
 
 	if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags))
 		goto dont_reuse;
 
-	if (conn->proto.epoch != rxrpc_epoch)
+	if (conn->proto.epoch != rxnet->epoch)
 		goto mark_dont_reuse;
 
 	/* The IDR tree gets very expensive on memory if the connection IDs are
@@ -440,12 +429,13 @@ error:
 /*
  * Activate a connection.
  */
-static void rxrpc_activate_conn(struct rxrpc_connection *conn)
+static void rxrpc_activate_conn(struct rxrpc_net *rxnet,
+				struct rxrpc_connection *conn)
 {
 	trace_rxrpc_client(conn, -1, rxrpc_client_to_active);
 	conn->cache_state = RXRPC_CONN_CLIENT_ACTIVE;
-	rxrpc_nr_active_client_conns++;
-	list_move_tail(&conn->cache_link, &rxrpc_active_client_conns);
+	rxnet->nr_active_client_conns++;
+	list_move_tail(&conn->cache_link, &rxnet->active_client_conns);
 }
 
 /*
@@ -460,7 +450,8 @@ static void rxrpc_activate_conn(struct rxrpc_connection *conn)
  * channels if it has been culled to make space and then re-requested by a new
  * call.
  */
-static void rxrpc_animate_client_conn(struct rxrpc_connection *conn)
+static void rxrpc_animate_client_conn(struct rxrpc_net *rxnet,
+				      struct rxrpc_connection *conn)
 {
 	unsigned int nr_conns;
 
@@ -469,12 +460,12 @@ static void rxrpc_animate_client_conn(struct rxrpc_connection *conn)
 	if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE)
 		goto out;
 
-	spin_lock(&rxrpc_client_conn_cache_lock);
+	spin_lock(&rxnet->client_conn_cache_lock);
 
-	nr_conns = rxrpc_nr_client_conns;
+	nr_conns = rxnet->nr_client_conns;
 	if (!test_and_set_bit(RXRPC_CONN_COUNTED, &conn->flags)) {
 		trace_rxrpc_client(conn, -1, rxrpc_client_count);
-		rxrpc_nr_client_conns = nr_conns + 1;
+		rxnet->nr_client_conns = nr_conns + 1;
 	}
 
 	switch (conn->cache_state) {
@@ -494,21 +485,21 @@ static void rxrpc_animate_client_conn(struct rxrpc_connection *conn)
 	}
 
 out_unlock:
-	spin_unlock(&rxrpc_client_conn_cache_lock);
+	spin_unlock(&rxnet->client_conn_cache_lock);
 out:
 	_leave(" [%d]", conn->cache_state);
 	return;
 
 activate_conn:
 	_debug("activate");
-	rxrpc_activate_conn(conn);
+	rxrpc_activate_conn(rxnet, conn);
 	goto out_unlock;
 
 wait_for_capacity:
 	_debug("wait");
 	trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting);
 	conn->cache_state = RXRPC_CONN_CLIENT_WAITING;
-	list_move_tail(&conn->cache_link, &rxrpc_waiting_client_conns);
+	list_move_tail(&conn->cache_link, &rxnet->waiting_client_conns);
 	goto out_unlock;
 }
 
@@ -660,18 +651,19 @@ int rxrpc_connect_call(struct rxrpc_call *call,
 		       struct sockaddr_rxrpc *srx,
 		       gfp_t gfp)
 {
+	struct rxrpc_net *rxnet = cp->local->rxnet;
 	int ret;
 
 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
 
-	rxrpc_discard_expired_client_conns(NULL);
-	rxrpc_cull_active_client_conns();
+	rxrpc_discard_expired_client_conns(&rxnet->client_conn_reaper.work);
+	rxrpc_cull_active_client_conns(rxnet);
 
 	ret = rxrpc_get_client_conn(call, cp, srx, gfp);
 	if (ret < 0)
 		return ret;
 
-	rxrpc_animate_client_conn(call->conn);
+	rxrpc_animate_client_conn(rxnet, call->conn);
 	rxrpc_activate_channels(call->conn);
 
 	ret = rxrpc_wait_for_channel(call, gfp);
@@ -729,6 +721,7 @@ void rxrpc_disconnect_client_call(struct rxrpc_call *call)
 	unsigned int channel = call->cid & RXRPC_CHANNELMASK;
 	struct rxrpc_connection *conn = call->conn;
 	struct rxrpc_channel *chan = &conn->channels[channel];
+	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&call->socket->sk));
 
 	trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect);
 	call->conn = NULL;
@@ -750,7 +743,7 @@ void rxrpc_disconnect_client_call(struct rxrpc_call *call)
 		/* We must deactivate or idle the connection if it's now
 		 * waiting for nothing.
 		 */
-		spin_lock(&rxrpc_client_conn_cache_lock);
+		spin_lock(&rxnet->client_conn_cache_lock);
 		if (conn->cache_state == RXRPC_CONN_CLIENT_WAITING &&
 		    list_empty(&conn->waiting_calls) &&
 		    !conn->active_chans)
@@ -787,14 +780,14 @@ void rxrpc_disconnect_client_call(struct rxrpc_call *call)
 	 * list.  It might even get moved back to the active list whilst we're
 	 * waiting for the lock.
 	 */
-	spin_lock(&rxrpc_client_conn_cache_lock);
+	spin_lock(&rxnet->client_conn_cache_lock);
 
 	switch (conn->cache_state) {
 	case RXRPC_CONN_CLIENT_ACTIVE:
 		if (list_empty(&conn->waiting_calls)) {
 			rxrpc_deactivate_one_channel(conn, channel);
 			if (!conn->active_chans) {
-				rxrpc_nr_active_client_conns--;
+				rxnet->nr_active_client_conns--;
 				goto idle_connection;
 			}
 			goto out;
@@ -820,7 +813,7 @@ void rxrpc_disconnect_client_call(struct rxrpc_call *call)
 	}
 
 out:
-	spin_unlock(&rxrpc_client_conn_cache_lock);
+	spin_unlock(&rxnet->client_conn_cache_lock);
 out_2:
 	spin_unlock(&conn->channel_lock);
 	rxrpc_put_connection(conn);
@@ -835,11 +828,11 @@ idle_connection:
 		trace_rxrpc_client(conn, channel, rxrpc_client_to_idle);
 		conn->idle_timestamp = jiffies;
 		conn->cache_state = RXRPC_CONN_CLIENT_IDLE;
-		list_move_tail(&conn->cache_link, &rxrpc_idle_client_conns);
-		if (rxrpc_idle_client_conns.next == &conn->cache_link &&
-		    !rxrpc_kill_all_client_conns)
+		list_move_tail(&conn->cache_link, &rxnet->idle_client_conns);
+		if (rxnet->idle_client_conns.next == &conn->cache_link &&
+		    !rxnet->kill_all_client_conns)
 			queue_delayed_work(rxrpc_workqueue,
-					   &rxrpc_client_conn_reap,
+					   &rxnet->client_conn_reaper,
 					   rxrpc_conn_idle_client_expiry);
 	} else {
 		trace_rxrpc_client(conn, channel, rxrpc_client_to_inactive);
@@ -857,6 +850,7 @@ rxrpc_put_one_client_conn(struct rxrpc_connection *conn)
 {
 	struct rxrpc_connection *next = NULL;
 	struct rxrpc_local *local = conn->params.local;
+	struct rxrpc_net *rxnet = local->rxnet;
 	unsigned int nr_conns;
 
 	trace_rxrpc_client(conn, -1, rxrpc_client_cleanup);
@@ -875,18 +869,18 @@ rxrpc_put_one_client_conn(struct rxrpc_connection *conn)
 
 	if (test_bit(RXRPC_CONN_COUNTED, &conn->flags)) {
 		trace_rxrpc_client(conn, -1, rxrpc_client_uncount);
-		spin_lock(&rxrpc_client_conn_cache_lock);
-		nr_conns = --rxrpc_nr_client_conns;
+		spin_lock(&rxnet->client_conn_cache_lock);
+		nr_conns = --rxnet->nr_client_conns;
 
 		if (nr_conns < rxrpc_max_client_connections &&
-		    !list_empty(&rxrpc_waiting_client_conns)) {
-			next = list_entry(rxrpc_waiting_client_conns.next,
+		    !list_empty(&rxnet->waiting_client_conns)) {
+			next = list_entry(rxnet->waiting_client_conns.next,
 					  struct rxrpc_connection, cache_link);
 			rxrpc_get_connection(next);
-			rxrpc_activate_conn(next);
+			rxrpc_activate_conn(rxnet, next);
 		}
 
-		spin_unlock(&rxrpc_client_conn_cache_lock);
+		spin_unlock(&rxnet->client_conn_cache_lock);
 	}
 
 	rxrpc_kill_connection(conn);
@@ -921,10 +915,10 @@ void rxrpc_put_client_conn(struct rxrpc_connection *conn)
 /*
  * Kill the longest-active client connections to make room for new ones.
  */
-static void rxrpc_cull_active_client_conns(void)
+static void rxrpc_cull_active_client_conns(struct rxrpc_net *rxnet)
 {
 	struct rxrpc_connection *conn;
-	unsigned int nr_conns = rxrpc_nr_client_conns;
+	unsigned int nr_conns = rxnet->nr_client_conns;
 	unsigned int nr_active, limit;
 
 	_enter("");
@@ -936,12 +930,12 @@ static void rxrpc_cull_active_client_conns(void)
 	}
 	limit = rxrpc_reap_client_connections;
 
-	spin_lock(&rxrpc_client_conn_cache_lock);
-	nr_active = rxrpc_nr_active_client_conns;
+	spin_lock(&rxnet->client_conn_cache_lock);
+	nr_active = rxnet->nr_active_client_conns;
 
 	while (nr_active > limit) {
-		ASSERT(!list_empty(&rxrpc_active_client_conns));
-		conn = list_entry(rxrpc_active_client_conns.next,
+		ASSERT(!list_empty(&rxnet->active_client_conns));
+		conn = list_entry(rxnet->active_client_conns.next,
 				  struct rxrpc_connection, cache_link);
 		ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_ACTIVE);
 
@@ -953,14 +947,14 @@ static void rxrpc_cull_active_client_conns(void)
 			trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting);
 			conn->cache_state = RXRPC_CONN_CLIENT_WAITING;
 			list_move_tail(&conn->cache_link,
-				       &rxrpc_waiting_client_conns);
+				       &rxnet->waiting_client_conns);
 		}
 
 		nr_active--;
 	}
 
-	rxrpc_nr_active_client_conns = nr_active;
-	spin_unlock(&rxrpc_client_conn_cache_lock);
+	rxnet->nr_active_client_conns = nr_active;
+	spin_unlock(&rxnet->client_conn_cache_lock);
 	ASSERTCMP(nr_active, >=, 0);
 	_leave(" [culled]");
 }
@@ -972,22 +966,25 @@ static void rxrpc_cull_active_client_conns(void)
  * This may be called from conn setup or from a work item so cannot be
  * considered non-reentrant.
  */
-static void rxrpc_discard_expired_client_conns(struct work_struct *work)
+void rxrpc_discard_expired_client_conns(struct work_struct *work)
 {
 	struct rxrpc_connection *conn;
+	struct rxrpc_net *rxnet =
+		container_of(to_delayed_work(work),
+			     struct rxrpc_net, client_conn_reaper);
 	unsigned long expiry, conn_expires_at, now;
 	unsigned int nr_conns;
 	bool did_discard = false;
 
-	_enter("%c", work ? 'w' : 'n');
+	_enter("");
 
-	if (list_empty(&rxrpc_idle_client_conns)) {
+	if (list_empty(&rxnet->idle_client_conns)) {
 		_leave(" [empty]");
 		return;
 	}
 
 	/* Don't double up on the discarding */
-	if (!spin_trylock(&rxrpc_client_conn_discard_mutex)) {
+	if (!spin_trylock(&rxnet->client_conn_discard_lock)) {
 		_leave(" [already]");
 		return;
 	}
@@ -995,19 +992,19 @@ static void rxrpc_discard_expired_client_conns(struct work_struct *work)
 	/* We keep an estimate of what the number of conns ought to be after
 	 * we've discarded some so that we don't overdo the discarding.
 	 */
-	nr_conns = rxrpc_nr_client_conns;
+	nr_conns = rxnet->nr_client_conns;
 
 next:
-	spin_lock(&rxrpc_client_conn_cache_lock);
+	spin_lock(&rxnet->client_conn_cache_lock);
 
-	if (list_empty(&rxrpc_idle_client_conns))
+	if (list_empty(&rxnet->idle_client_conns))
 		goto out;
 
-	conn = list_entry(rxrpc_idle_client_conns.next,
+	conn = list_entry(rxnet->idle_client_conns.next,
 			  struct rxrpc_connection, cache_link);
 	ASSERT(test_bit(RXRPC_CONN_EXPOSED, &conn->flags));
 
-	if (!rxrpc_kill_all_client_conns) {
+	if (!rxnet->kill_all_client_conns) {
 		/* If the number of connections is over the reap limit, we
 		 * expedite discard by reducing the expiry timeout.  We must,
 		 * however, have at least a short grace period to be able to do
@@ -1030,7 +1027,7 @@ next:
 	conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE;
 	list_del_init(&conn->cache_link);
 
-	spin_unlock(&rxrpc_client_conn_cache_lock);
+	spin_unlock(&rxnet->client_conn_cache_lock);
 
 	/* When we cleared the EXPOSED flag, we took on responsibility for the
 	 * reference that that had on the usage count.  We deal with that here.
@@ -1050,14 +1047,14 @@ not_yet_expired:
 	 * then things get messier.
 	 */
 	_debug("not yet");
-	if (!rxrpc_kill_all_client_conns)
+	if (!rxnet->kill_all_client_conns)
 		queue_delayed_work(rxrpc_workqueue,
-				   &rxrpc_client_conn_reap,
+				   &rxnet->client_conn_reaper,
 				   conn_expires_at - now);
 
 out:
-	spin_unlock(&rxrpc_client_conn_cache_lock);
-	spin_unlock(&rxrpc_client_conn_discard_mutex);
+	spin_unlock(&rxnet->client_conn_cache_lock);
+	spin_unlock(&rxnet->client_conn_discard_lock);
 	_leave("");
 }
 
@@ -1065,17 +1062,17 @@ out:
  * Preemptively destroy all the client connection records rather than waiting
  * for them to time out
  */
-void __exit rxrpc_destroy_all_client_connections(void)
+void rxrpc_destroy_all_client_connections(struct rxrpc_net *rxnet)
 {
 	_enter("");
 
-	spin_lock(&rxrpc_client_conn_cache_lock);
-	rxrpc_kill_all_client_conns = true;
-	spin_unlock(&rxrpc_client_conn_cache_lock);
+	spin_lock(&rxnet->client_conn_cache_lock);
+	rxnet->kill_all_client_conns = true;
+	spin_unlock(&rxnet->client_conn_cache_lock);
 
-	cancel_delayed_work(&rxrpc_client_conn_reap);
+	cancel_delayed_work(&rxnet->client_conn_reaper);
 
-	if (!queue_delayed_work(rxrpc_workqueue, &rxrpc_client_conn_reap, 0))
+	if (!queue_delayed_work(rxrpc_workqueue, &rxnet->client_conn_reaper, 0))
 		_debug("destroy: queue failed");
 
 	_leave("");