1 files changed, 128 insertions, 45 deletions

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index c9f34b0a11df..6401cdf7a624 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -23,7 +23,6 @@ const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
 	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
 	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
 	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
-	[RXRPC_CALL_SERVER_ACCEPTING]		= "SvAccept",
 	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
 	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
 	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
@@ -41,6 +40,11 @@ const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
 
 struct kmem_cache *rxrpc_call_jar;
 
+static struct semaphore rxrpc_call_limiter =
+	__SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000);
+static struct semaphore rxrpc_kernel_call_limiter =
+	__SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000);
+
 static void rxrpc_call_timer_expired(struct timer_list *t)
 {
 	struct rxrpc_call *call = from_timer(call, t, timer);
@@ -49,10 +53,30 @@ static void rxrpc_call_timer_expired(struct timer_list *t)
 
 	if (call->state < RXRPC_CALL_COMPLETE) {
 		trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies);
-		rxrpc_queue_call(call);
+		__rxrpc_queue_call(call);
+	} else {
+		rxrpc_put_call(call, rxrpc_call_put);
+	}
+}
+
+void rxrpc_reduce_call_timer(struct rxrpc_call *call,
+			     unsigned long expire_at,
+			     unsigned long now,
+			     enum rxrpc_timer_trace why)
+{
+	if (rxrpc_try_get_call(call, rxrpc_call_got_timer)) {
+		trace_rxrpc_timer(call, why, now);
+		if (timer_reduce(&call->timer, expire_at))
+			rxrpc_put_call(call, rxrpc_call_put_notimer);
 	}
 }
 
+void rxrpc_delete_call_timer(struct rxrpc_call *call)
+{
+	if (del_timer_sync(&call->timer))
+		rxrpc_put_call(call, rxrpc_call_put_timer);
+}
+
 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
 
 /*
@@ -88,7 +112,7 @@ struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
 found_extant_call:
 	rxrpc_get_call(call, rxrpc_call_got);
 	read_unlock(&rx->call_lock);
-	_leave(" = %p [%d]", call, atomic_read(&call->usage));
+	_leave(" = %p [%d]", call, refcount_read(&call->ref));
 	return call;
 }
 
@@ -136,7 +160,7 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 	spin_lock_init(&call->notify_lock);
 	spin_lock_init(&call->input_lock);
 	rwlock_init(&call->state_lock);
-	atomic_set(&call->usage, 1);
+	refcount_set(&call->ref, 1);
 	call->debug_id = debug_id;
 	call->tx_total_len = -1;
 	call->next_rx_timo = 20 * HZ;
@@ -153,6 +177,7 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 	call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
 
 	call->rxnet = rxnet;
+	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
 	atomic_inc(&rxnet->nr_calls);
 	return call;
 
@@ -209,6 +234,34 @@ static void rxrpc_start_call_timer(struct rxrpc_call *call)
 }
 
 /*
+ * Wait for a call slot to become available.
+ */
+static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
+{
+	struct semaphore *limiter = &rxrpc_call_limiter;
+
+	if (p->kernel)
+		limiter = &rxrpc_kernel_call_limiter;
+	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
+		down(limiter);
+		return limiter;
+	}
+	return down_interruptible(limiter) < 0 ? NULL : limiter;
+}
+
+/*
+ * Release a call slot.
+ */
+static void rxrpc_put_call_slot(struct rxrpc_call *call)
+{
+	struct semaphore *limiter = &rxrpc_call_limiter;
+
+	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
+		limiter = &rxrpc_kernel_call_limiter;
+	up(limiter);
+}
+
+/*
  * Set up a call for the given parameters.
  * - Called with the socket lock held, which it must release.
  * - If it returns a call, the call's lock will need releasing by the caller.
@@ -224,25 +277,34 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 {
 	struct rxrpc_call *call, *xcall;
 	struct rxrpc_net *rxnet;
+	struct semaphore *limiter;
 	struct rb_node *parent, **pp;
 	const void *here = __builtin_return_address(0);
 	int ret;
 
 	_enter("%p,%lx", rx, p->user_call_ID);
 
+	limiter = rxrpc_get_call_slot(p, gfp);
+	if (!limiter) {
+		release_sock(&rx->sk);
+		return ERR_PTR(-ERESTARTSYS);
+	}
+
 	call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
 	if (IS_ERR(call)) {
 		release_sock(&rx->sk);
+		up(limiter);
 		_leave(" = %ld", PTR_ERR(call));
 		return call;
 	}
 
-	if (p->intr)
-		__set_bit(RXRPC_CALL_IS_INTR, &call->flags);
+	call->interruptibility = p->interruptibility;
 	call->tx_total_len = p->tx_total_len;
 	trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
-			 atomic_read(&call->usage),
+			 refcount_read(&call->ref),
 			 here, (const void *)p->user_call_ID);
+	if (p->kernel)
+		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
 
 	/* We need to protect a partially set up call against the user as we
 	 * will be acting outside the socket lock.
@@ -277,9 +339,9 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 	write_unlock(&rx->call_lock);
 
 	rxnet = call->rxnet;
-	write_lock(&rxnet->call_lock);
-	list_add_tail(&call->link, &rxnet->calls);
-	write_unlock(&rxnet->call_lock);
+	spin_lock_bh(&rxnet->call_lock);
+	list_add_tail_rcu(&call->link, &rxnet->calls);
+	spin_unlock_bh(&rxnet->call_lock);
 
 	/* From this point on, the call is protected by its own lock. */
 	release_sock(&rx->sk);
@@ -289,10 +351,10 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 	 */
 	ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
 	if (ret < 0)
-		goto error;
+		goto error_attached_to_socket;
 
 	trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
-			 atomic_read(&call->usage), here, NULL);
+			 refcount_read(&call->ref), here, NULL);
 
 	rxrpc_start_call_timer(call);
 
@@ -309,18 +371,29 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 error_dup_user_ID:
 	write_unlock(&rx->call_lock);
 	release_sock(&rx->sk);
-	ret = -EEXIST;
-
-error:
 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
-				    RX_CALL_DEAD, ret);
+				    RX_CALL_DEAD, -EEXIST);
 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
-			 atomic_read(&call->usage), here, ERR_PTR(ret));
+			 refcount_read(&call->ref), here, ERR_PTR(-EEXIST));
 	rxrpc_release_call(rx, call);
 	mutex_unlock(&call->user_mutex);
 	rxrpc_put_call(call, rxrpc_call_put);
-	_leave(" = %d", ret);
-	return ERR_PTR(ret);
+	_leave(" = -EEXIST");
+	return ERR_PTR(-EEXIST);
+
+	/* We got an error, but the call is attached to the socket and is in
+	 * need of release.  However, we might now race with recvmsg() when
+	 * completing the call queues it.  Return 0 from sys_sendmsg() and
+	 * leave the error to recvmsg() to deal with.
+	 */
+error_attached_to_socket:
+	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
+			 refcount_read(&call->ref), here, ERR_PTR(ret));
+	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
+	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
+				    RX_CALL_DEAD, ret);
+	_leave(" = c=%08x [err]", call->debug_id);
+	return call;
 }
 
 /*
@@ -341,9 +414,7 @@ void rxrpc_incoming_call(struct rxrpc_sock *rx,
 	call->call_id		= sp->hdr.callNumber;
 	call->service_id	= sp->hdr.serviceId;
 	call->cid		= sp->hdr.cid;
-	call->state		= RXRPC_CALL_SERVER_ACCEPTING;
-	if (sp->hdr.securityIndex > 0)
-		call->state	= RXRPC_CALL_SERVER_SECURING;
+	call->state		= RXRPC_CALL_SERVER_SECURING;
 	call->cong_tstamp	= skb->tstamp;
 
 	/* Set the channel for this call.  We don't get channel_lock as we're
@@ -373,8 +444,9 @@ void rxrpc_incoming_call(struct rxrpc_sock *rx,
 bool rxrpc_queue_call(struct rxrpc_call *call)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_fetch_add_unless(&call->usage, 1, 0);
-	if (n == 0)
+	int n;
+
+	if (!__refcount_inc_not_zero(&call->ref, &n))
 		return false;
 	if (rxrpc_queue_work(&call->processor))
 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
@@ -390,7 +462,7 @@ bool rxrpc_queue_call(struct rxrpc_call *call)
 bool __rxrpc_queue_call(struct rxrpc_call *call)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_read(&call->usage);
+	int n = refcount_read(&call->ref);
 	ASSERTCMP(n, >=, 1);
 	if (rxrpc_queue_work(&call->processor))
 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
@@ -407,22 +479,34 @@ void rxrpc_see_call(struct rxrpc_call *call)
 {
 	const void *here = __builtin_return_address(0);
 	if (call) {
-		int n = atomic_read(&call->usage);
+		int n = refcount_read(&call->ref);
 
 		trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
 				 here, NULL);
 	}
 }
 
+bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
+{
+	const void *here = __builtin_return_address(0);
+	int n;
+
+	if (!__refcount_inc_not_zero(&call->ref, &n))
+		return false;
+	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
+	return true;
+}
+
 /*
  * Note the addition of a ref on a call.
  */
 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_inc_return(&call->usage);
+	int n;
 
-	trace_rxrpc_call(call->debug_id, op, n, here, NULL);
+	__refcount_inc(&call->ref, &n);
+	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
 }
 
 /*
@@ -447,10 +531,10 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 	struct rxrpc_connection *conn = call->conn;
 	bool put = false;
 
-	_enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
+	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
 
 	trace_rxrpc_call(call->debug_id, rxrpc_call_release,
-			 atomic_read(&call->usage),
+			 refcount_read(&call->ref),
 			 here, (const void *)call->flags);
 
 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
@@ -460,7 +544,8 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 		BUG();
 	spin_unlock_bh(&call->lock);
 
-	del_timer_sync(&call->timer);
+	rxrpc_put_call_slot(call);
+	rxrpc_delete_call_timer(call);
 
 	/* Make sure we don't get any more notifications */
 	write_lock_bh(&rx->recvmsg_lock);
@@ -497,8 +582,6 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 		rxrpc_disconnect_call(call);
 	if (call->security)
 		call->security->free_call_crypto(call);
-
-	rxrpc_cleanup_ring(call);
 	_leave("");
 }
 
@@ -540,21 +623,21 @@ void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 	struct rxrpc_net *rxnet = call->rxnet;
 	const void *here = __builtin_return_address(0);
 	unsigned int debug_id = call->debug_id;
+	bool dead;
 	int n;
 
 	ASSERT(call != NULL);
 
-	n = atomic_dec_return(&call->usage);
+	dead = __refcount_dec_and_test(&call->ref, &n);
 	trace_rxrpc_call(debug_id, op, n, here, NULL);
-	ASSERTCMP(n, >=, 0);
-	if (n == 0) {
+	if (dead) {
 		_debug("call %d dead", call->debug_id);
 		ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 
 		if (!list_empty(&call->link)) {
-			write_lock(&rxnet->call_lock);
+			spin_lock_bh(&rxnet->call_lock);
 			list_del_init(&call->link);
-			write_unlock(&rxnet->call_lock);
+			spin_unlock_bh(&rxnet->call_lock);
 		}
 
 		rxrpc_cleanup_call(call);
@@ -569,6 +652,8 @@ static void rxrpc_destroy_call(struct work_struct *work)
 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
 	struct rxrpc_net *rxnet = call->rxnet;
 
+	rxrpc_delete_call_timer(call);
+
 	rxrpc_put_connection(call->conn);
 	rxrpc_put_peer(call->peer);
 	kfree(call->rxtx_buffer);
@@ -603,8 +688,6 @@ void rxrpc_cleanup_call(struct rxrpc_call *call)
 
 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 
-	del_timer_sync(&call->timer);
-
 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 
@@ -626,7 +709,7 @@ void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 	_enter("");
 
 	if (!list_empty(&rxnet->calls)) {
-		write_lock(&rxnet->call_lock);
+		spin_lock_bh(&rxnet->call_lock);
 
 		while (!list_empty(&rxnet->calls)) {
 			call = list_entry(rxnet->calls.next,
@@ -637,16 +720,16 @@ void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 			list_del_init(&call->link);
 
 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
-			       call, atomic_read(&call->usage),
+			       call, refcount_read(&call->ref),
 			       rxrpc_call_states[call->state],
 			       call->flags, call->events);
 
-			write_unlock(&rxnet->call_lock);
+			spin_unlock_bh(&rxnet->call_lock);
 			cond_resched();
-			write_lock(&rxnet->call_lock);
+			spin_lock_bh(&rxnet->call_lock);
 		}
 
-		write_unlock(&rxnet->call_lock);
+		spin_unlock_bh(&rxnet->call_lock);
 	}
 
 	atomic_dec(&rxnet->nr_calls);