diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 53750dece80e..720ef05a24fe 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -18,6 +18,7 @@
 
 struct socket *afs_socket; /* my RxRPC socket */
 static struct workqueue_struct *afs_async_calls;
+static struct afs_call *afs_spare_incoming_call;
 static atomic_t afs_outstanding_calls;
 
 static void afs_free_call(struct afs_call *);
@@ -26,7 +27,8 @@ static int afs_wait_for_call_to_complete(struct afs_call *);
 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
 static int afs_dont_wait_for_call_to_complete(struct afs_call *);
 static void afs_process_async_call(struct work_struct *);
-static void afs_rx_new_call(struct sock *);
+static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
+static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
 static int afs_deliver_cm_op_id(struct afs_call *);
 
 /* synchronous call management */
@@ -54,8 +56,10 @@ static const struct afs_call_type afs_RXCMxxxx = {
 };
 
 static void afs_collect_incoming_call(struct work_struct *);
+static void afs_charge_preallocation(struct work_struct *);
 
 static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
+static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
 
 static int afs_wait_atomic_t(atomic_t *p)
 {
@@ -100,13 +104,15 @@ int afs_open_socket(void)
 	if (ret < 0)
 		goto error_2;
 
-	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call);
+	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
+					   afs_rx_discard_new_call);
 
 	ret = kernel_listen(socket, INT_MAX);
 	if (ret < 0)
 		goto error_2;
 
 	afs_socket = socket;
+	afs_charge_preallocation(NULL);
 	_leave(" = 0");
 	return 0;
 
@@ -126,6 +132,12 @@ void afs_close_socket(void)
 {
 	_enter("");
 
+	if (afs_spare_incoming_call) {
+		atomic_inc(&afs_outstanding_calls);
+		afs_free_call(afs_spare_incoming_call);
+		afs_spare_incoming_call = NULL;
+	}
+
 	_debug("outstanding %u", atomic_read(&afs_outstanding_calls));
 	wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
 			 TASK_UNINTERRUPTIBLE);
@@ -635,12 +647,65 @@ static void afs_collect_incoming_call(struct work_struct *work)
 		afs_free_call(call);
 }
 
+static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
+{
+	struct afs_call *call = (struct afs_call *)user_call_ID;
+
+	call->rxcall = rxcall;
+}
+
+/*
+ * Charge the incoming call preallocation.
+ */
+static void afs_charge_preallocation(struct work_struct *work)
+{
+	struct afs_call *call = afs_spare_incoming_call;
+
+	for (;;) {
+		if (!call) {
+			call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
+			if (!call)
+				break;
+
+			INIT_WORK(&call->async_work, afs_process_async_call);
+			call->wait_mode = &afs_async_incoming_call;
+			call->type = &afs_RXCMxxxx;
+			init_waitqueue_head(&call->waitq);
+			call->state = AFS_CALL_AWAIT_OP_ID;
+		}
+
+		if (rxrpc_kernel_charge_accept(afs_socket,
+					       afs_wake_up_async_call,
+					       afs_rx_attach,
+					       (unsigned long)call,
+					       GFP_KERNEL) < 0)
+			break;
+		call = NULL;
+	}
+	afs_spare_incoming_call = call;
+}
+
+/*
+ * Discard a preallocated call when a socket is shut down.
+ */
+static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
+				    unsigned long user_call_ID)
+{
+	struct afs_call *call = (struct afs_call *)user_call_ID;
+
+	atomic_inc(&afs_outstanding_calls);
+	call->rxcall = NULL;
+	afs_free_call(call);
+}
+
 /*
  * Notification of an incoming call.
  */
-static void afs_rx_new_call(struct sock *sk)
+static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
+			    unsigned long user_call_ID)
 {
 	queue_work(afs_wq, &afs_collect_incoming_call_work);
+	queue_work(afs_wq, &afs_charge_preallocation_work);
 }
 
 /*
diff --git a/include/net/af_rxrpc.h b/include/net/af_rxrpc.h
index 08ed8729126c..9cf551be916b 100644
--- a/include/net/af_rxrpc.h
+++ b/include/net/af_rxrpc.h
@@ -21,10 +21,14 @@ struct rxrpc_call;
 
 typedef void (*rxrpc_notify_rx_t)(struct sock *, struct rxrpc_call *,
 				  unsigned long);
-typedef void (*rxrpc_notify_new_call_t)(struct sock *);
+typedef void (*rxrpc_notify_new_call_t)(struct sock *, struct rxrpc_call *,
+					unsigned long);
+typedef void (*rxrpc_discard_new_call_t)(struct rxrpc_call *, unsigned long);
+typedef void (*rxrpc_user_attach_call_t)(struct rxrpc_call *, unsigned long);
 
 void rxrpc_kernel_new_call_notification(struct socket *,
-					rxrpc_notify_new_call_t);
+					rxrpc_notify_new_call_t,
+					rxrpc_discard_new_call_t);
 struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *,
 					   struct sockaddr_rxrpc *,
 					   struct key *,
@@ -43,5 +47,7 @@ struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *, unsigned long,
 int rxrpc_kernel_reject_call(struct socket *);
 void rxrpc_kernel_get_peer(struct socket *, struct rxrpc_call *,
 			   struct sockaddr_rxrpc *);
+int rxrpc_kernel_charge_accept(struct socket *, rxrpc_notify_rx_t,
+			       rxrpc_user_attach_call_t, unsigned long, gfp_t);
 
 #endif /* _NET_RXRPC_H */
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index f13cca1e973e..1e8cf3ded81f 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -193,7 +193,7 @@ static int rxrpc_listen(struct socket *sock, int backlog)
 {
 	struct sock *sk = sock->sk;
 	struct rxrpc_sock *rx = rxrpc_sk(sk);
-	unsigned int max;
+	unsigned int max, old;
 	int ret;
 
 	_enter("%p,%d", rx, backlog);
@@ -212,9 +212,13 @@ static int rxrpc_listen(struct socket *sock, int backlog)
 			backlog = max;
 		else if (backlog < 0 || backlog > max)
 			break;
+		old = sk->sk_max_ack_backlog;
 		sk->sk_max_ack_backlog = backlog;
-		rx->sk.sk_state = RXRPC_SERVER_LISTENING;
-		ret = 0;
+		ret = rxrpc_service_prealloc(rx, GFP_KERNEL);
+		if (ret == 0)
+			rx->sk.sk_state = RXRPC_SERVER_LISTENING;
+		else
+			sk->sk_max_ack_backlog = old;
 		break;
 	default:
 		ret = -EBUSY;
@@ -303,16 +307,19 @@ EXPORT_SYMBOL(rxrpc_kernel_end_call);
  * rxrpc_kernel_new_call_notification - Get notifications of new calls
  * @sock: The socket to intercept received messages on
  * @notify_new_call: Function to be called when new calls appear
+ * @discard_new_call: Function to discard preallocated calls
  *
  * Allow a kernel service to be given notifications about new calls.
  */
 void rxrpc_kernel_new_call_notification(
 	struct socket *sock,
-	rxrpc_notify_new_call_t notify_new_call)
+	rxrpc_notify_new_call_t notify_new_call,
+	rxrpc_discard_new_call_t discard_new_call)
 {
 	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
 
 	rx->notify_new_call = notify_new_call;
+	rx->discard_new_call = discard_new_call;
 }
 EXPORT_SYMBOL(rxrpc_kernel_new_call_notification);
 
@@ -622,6 +629,7 @@ static int rxrpc_release_sock(struct sock *sk)
 	}
 
 	/* try to flush out this socket */
+	rxrpc_discard_prealloc(rx);
 	rxrpc_release_calls_on_socket(rx);
 	flush_workqueue(rxrpc_workqueue);
 	rxrpc_purge_queue(&sk->sk_receive_queue);
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 027791261768..45e1c269f90e 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -64,19 +64,42 @@ enum {
 };
 
 /*
+ * Service backlog preallocation.
+ *
+ * This contains circular buffers of preallocated peers, connections and calls
+ * for incoming service calls and their head and tail pointers.  This allows
+ * calls to be set up in the data_ready handler, thereby avoiding the need to
+ * shuffle packets around so much.
+ */
+struct rxrpc_backlog {
+	unsigned short		peer_backlog_head;
+	unsigned short		peer_backlog_tail;
+	unsigned short		conn_backlog_head;
+	unsigned short		conn_backlog_tail;
+	unsigned short		call_backlog_head;
+	unsigned short		call_backlog_tail;
+#define RXRPC_BACKLOG_MAX	32
+	struct rxrpc_peer	*peer_backlog[RXRPC_BACKLOG_MAX];
+	struct rxrpc_connection	*conn_backlog[RXRPC_BACKLOG_MAX];
+	struct rxrpc_call	*call_backlog[RXRPC_BACKLOG_MAX];
+};
+
+/*
  * RxRPC socket definition
  */
 struct rxrpc_sock {
 	/* WARNING: sk has to be the first member */
 	struct sock		sk;
 	rxrpc_notify_new_call_t	notify_new_call; /* Func to notify of new call */
+	rxrpc_discard_new_call_t discard_new_call; /* Func to discard a new call */
 	struct rxrpc_local	*local;		/* local endpoint */
 	struct hlist_node	listen_link;	/* link in the local endpoint's listen list */
 	struct list_head	secureq;	/* calls awaiting connection security clearance */
 	struct list_head	acceptq;	/* calls awaiting acceptance */
+	struct rxrpc_backlog	*backlog;	/* Preallocation for services */
 	struct key		*key;		/* security for this socket */
 	struct key		*securities;	/* list of server security descriptors */
-	struct rb_root		calls;		/* outstanding calls on this socket */
+	struct rb_root		calls;		/* User ID -> call mapping */
 	unsigned long		flags;
 #define RXRPC_SOCK_CONNECTED		0	/* connect_srx is set */
 	rwlock_t		call_lock;	/* lock for calls */
@@ -290,6 +313,7 @@ enum rxrpc_conn_cache_state {
 enum rxrpc_conn_proto_state {
 	RXRPC_CONN_UNUSED,		/* Connection not yet attempted */
 	RXRPC_CONN_CLIENT,		/* Client connection */
+	RXRPC_CONN_SERVICE_PREALLOC,	/* Service connection preallocation */
 	RXRPC_CONN_SERVICE_UNSECURED,	/* Service unsecured connection */
 	RXRPC_CONN_SERVICE_CHALLENGING,	/* Service challenging for security */
 	RXRPC_CONN_SERVICE,		/* Service secured connection */
@@ -408,6 +432,7 @@ enum rxrpc_call_state {
 	RXRPC_CALL_CLIENT_AWAIT_REPLY,	/* - client awaiting reply */
 	RXRPC_CALL_CLIENT_RECV_REPLY,	/* - client receiving reply phase */
 	RXRPC_CALL_CLIENT_FINAL_ACK,	/* - client sending final ACK phase */
+	RXRPC_CALL_SERVER_PREALLOC,	/* - service preallocation */
 	RXRPC_CALL_SERVER_SECURING,	/* - server securing request connection */
 	RXRPC_CALL_SERVER_ACCEPTING,	/* - server accepting request */
 	RXRPC_CALL_SERVER_RECV_REQUEST,	/* - server receiving request */
@@ -534,6 +559,8 @@ extern struct workqueue_struct *rxrpc_workqueue;
 /*
  * call_accept.c
  */
+int rxrpc_service_prealloc(struct rxrpc_sock *, gfp_t);
+void rxrpc_discard_prealloc(struct rxrpc_sock *);
 void rxrpc_accept_incoming_calls(struct rxrpc_local *);
 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *, unsigned long,
 				     rxrpc_notify_rx_t);
@@ -557,6 +584,7 @@ extern struct list_head rxrpc_calls;
 extern rwlock_t rxrpc_call_lock;
 
 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *, unsigned long);
+struct rxrpc_call *rxrpc_alloc_call(gfp_t);
 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *,
 					 struct rxrpc_conn_parameters *,
 					 struct sockaddr_rxrpc *,
@@ -573,6 +601,7 @@ void rxrpc_get_call(struct rxrpc_call *, enum rxrpc_call_trace);
 void rxrpc_put_call(struct rxrpc_call *, enum rxrpc_call_trace);
 void rxrpc_get_call_for_skb(struct rxrpc_call *, struct sk_buff *);
 void rxrpc_put_call_for_skb(struct rxrpc_call *, struct sk_buff *);
+void rxrpc_cleanup_call(struct rxrpc_call *);
 void __exit rxrpc_destroy_all_calls(void);
 
 static inline bool rxrpc_is_service_call(const struct rxrpc_call *call)
@@ -757,6 +786,7 @@ struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *,
 struct rxrpc_connection *rxrpc_incoming_connection(struct rxrpc_local *,
 						   struct sockaddr_rxrpc *,
 						   struct sk_buff *);
+struct rxrpc_connection *rxrpc_prealloc_service_connection(gfp_t);
 void rxrpc_unpublish_service_conn(struct rxrpc_connection *);
 
 /*
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 4c71efcf82ed..cc7194e05a15 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -20,12 +20,210 @@
 #include <linux/in6.h>
 #include <linux/icmp.h>
 #include <linux/gfp.h>
+#include <linux/circ_buf.h>
 #include <net/sock.h>
 #include <net/af_rxrpc.h>
 #include <net/ip.h>
 #include "ar-internal.h"
 
 /*
+ * Preallocate a single service call, connection and peer and, if possible,
+ * give them a user ID and attach the user's side of the ID to them.
+ */
+static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
+				      struct rxrpc_backlog *b,
+				      rxrpc_notify_rx_t notify_rx,
+				      rxrpc_user_attach_call_t user_attach_call,
+				      unsigned long user_call_ID, gfp_t gfp)
+{
+	const void *here = __builtin_return_address(0);
+	struct rxrpc_call *call;
+	int max, tmp;
+	unsigned int size = RXRPC_BACKLOG_MAX;
+	unsigned int head, tail, call_head, call_tail;
+
+	max = rx->sk.sk_max_ack_backlog;
+	tmp = rx->sk.sk_ack_backlog;
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [full %u]", max);
+		return -ENOBUFS;
+	}
+	max -= tmp;
+
+	/* We don't need more conns and peers than we have calls, but on the
+	 * other hand, we shouldn't ever use more peers than conns or conns
+	 * than calls.
+	 */
+	call_head = b->call_backlog_head;
+	call_tail = READ_ONCE(b->call_backlog_tail);
+	tmp = CIRC_CNT(call_head, call_tail, size);
+	if (tmp >= max) {
+		_leave(" = -ENOBUFS [enough %u]", tmp);
+		return -ENOBUFS;
+	}
+	max = tmp + 1;
+
+	head = b->peer_backlog_head;
+	tail = READ_ONCE(b->peer_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
+		if (!peer)
+			return -ENOMEM;
+		b->peer_backlog[head] = peer;
+		smp_store_release(&b->peer_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	head = b->conn_backlog_head;
+	tail = READ_ONCE(b->conn_backlog_tail);
+	if (CIRC_CNT(head, tail, size) < max) {
+		struct rxrpc_connection *conn;
+
+		conn = rxrpc_prealloc_service_connection(gfp);
+		if (!conn)
+			return -ENOMEM;
+		b->conn_backlog[head] = conn;
+		smp_store_release(&b->conn_backlog_head,
+				  (head + 1) & (size - 1));
+	}
+
+	/* Now it gets complicated, because calls get registered with the
+	 * socket here, particularly if a user ID is preassigned by the user.
+	 */
+	call = rxrpc_alloc_call(gfp);
+	if (!call)
+		return -ENOMEM;
+	call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
+	call->state = RXRPC_CALL_SERVER_PREALLOC;
+
+	trace_rxrpc_call(call, rxrpc_call_new_service,
+			 atomic_read(&call->usage),
+			 here, (const void *)user_call_ID);
+
+	write_lock(&rx->call_lock);
+	if (user_attach_call) {
+		struct rxrpc_call *xcall;
+		struct rb_node *parent, **pp;
+
+		/* Check the user ID isn't already in use */
+		pp = &rx->calls.rb_node;
+		parent = NULL;
+		while (*pp) {
+			parent = *pp;
+			xcall = rb_entry(parent, struct rxrpc_call, sock_node);
+			if (user_call_ID < call->user_call_ID)
+				pp = &(*pp)->rb_left;
+			else if (user_call_ID > call->user_call_ID)
+				pp = &(*pp)->rb_right;
+			else
+				goto id_in_use;
+		}
+
+		call->user_call_ID = user_call_ID;
+		call->notify_rx = notify_rx;
+		rxrpc_get_call(call, rxrpc_call_got);
+		user_attach_call(call, user_call_ID);
+		rxrpc_get_call(call, rxrpc_call_got_userid);
+		rb_link_node(&call->sock_node, parent, pp);
+		rb_insert_color(&call->sock_node, &rx->calls);
+		set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
+	}
+
+	write_unlock(&rx->call_lock);
+
+	write_lock(&rxrpc_call_lock);
+	list_add_tail(&call->link, &rxrpc_calls);
+	write_unlock(&rxrpc_call_lock);
+
+	b->call_backlog[call_head] = call;
+	smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
+	_leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
+	return 0;
+
+id_in_use:
+	write_unlock(&rx->call_lock);
+	rxrpc_cleanup_call(call);
+	_leave(" = -EBADSLT");
+	return -EBADSLT;
+}
+
+/*
+ * Preallocate sufficient service connections, calls and peers to cover the
+ * entire backlog of a socket.  When a new call comes in, if we don't have
+ * sufficient of each available, the call gets rejected as busy or ignored.
+ *
+ * The backlog is replenished when a connection is accepted or rejected.
+ */
+int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (!b) {
+		b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
+		if (!b)
+			return -ENOMEM;
+		rx->backlog = b;
+	}
+
+	if (rx->discard_new_call)
+		return 0;
+
+	while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp) == 0)
+		;
+
+	return 0;
+}
+
+/*
+ * Discard the preallocation on a service.
+ */
+void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
+{
+	struct rxrpc_backlog *b = rx->backlog;
+	unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
+
+	if (!b)
+		return;
+	rx->backlog = NULL;
+
+	head = b->peer_backlog_head;
+	tail = b->peer_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_peer *peer = b->peer_backlog[tail];
+		kfree(peer);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->conn_backlog_head;
+	tail = b->conn_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_connection *conn = b->conn_backlog[tail];
+		write_lock(&rxrpc_connection_lock);
+		list_del(&conn->link);
+		list_del(&conn->proc_link);
+		write_unlock(&rxrpc_connection_lock);
+		kfree(conn);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	head = b->call_backlog_head;
+	tail = b->call_backlog_tail;
+	while (CIRC_CNT(head, tail, size) > 0) {
+		struct rxrpc_call *call = b->call_backlog[tail];
+		if (rx->discard_new_call) {
+			_debug("discard %lx", call->user_call_ID);
+			rx->discard_new_call(call, call->user_call_ID);
+		}
+		rxrpc_call_completed(call);
+		rxrpc_release_call(rx, call);
+		rxrpc_put_call(call, rxrpc_call_put);
+		tail = (tail + 1) & (size - 1);
+	}
+
+	kfree(b);
+}
+
+/*
  * generate a connection-level abort
  */
 static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx,
@@ -450,3 +648,34 @@ int rxrpc_kernel_reject_call(struct socket *sock)
 	return ret;
 }
 EXPORT_SYMBOL(rxrpc_kernel_reject_call);
+
+/*
+ * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
+ * @sock: The socket on which to preallocate
+ * @notify_rx: Event notification function for the call
+ * @user_attach_call: Func to attach call to user_call_ID
+ * @user_call_ID: The tag to attach to the preallocated call
+ * @gfp: The allocation conditions.
+ *
+ * Charge up the socket with preallocated calls, each with a user ID.  A
+ * function should be provided to effect the attachment from the user's side.
+ * The user is given a ref to hold on the call.
+ *
+ * Note that the call may be come connected before this function returns.
+ */
+int rxrpc_kernel_charge_accept(struct socket *sock,
+			       rxrpc_notify_rx_t notify_rx,
+			       rxrpc_user_attach_call_t user_attach_call,
+			       unsigned long user_call_ID, gfp_t gfp)
+{
+	struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
+	struct rxrpc_backlog *b = rx->backlog;
+
+	if (sock->sk->sk_state == RXRPC_CLOSE)
+		return -ESHUTDOWN;
+
+	return rxrpc_service_prealloc_one(rx, b, notify_rx,
+					  user_attach_call, user_call_ID,
+					  gfp);
+}
+EXPORT_SYMBOL(rxrpc_kernel_charge_accept);
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index f843397e03b6..d233adc9b5e5 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -31,6 +31,7 @@ const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
 	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
 	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
 	[RXRPC_CALL_CLIENT_FINAL_ACK]		= "ClFnlACK",
+	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
 	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
 	[RXRPC_CALL_SERVER_ACCEPTING]		= "SvAccept",
 	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
@@ -71,7 +72,6 @@ DEFINE_RWLOCK(rxrpc_call_lock);
 static void rxrpc_call_life_expired(unsigned long _call);
 static void rxrpc_ack_time_expired(unsigned long _call);
 static void rxrpc_resend_time_expired(unsigned long _call);
-static void rxrpc_cleanup_call(struct rxrpc_call *call);
 
 /*
  * find an extant server call
@@ -113,7 +113,7 @@ found_extant_call:
 /*
  * allocate a new call
  */
-static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
+struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
 {
 	struct rxrpc_call *call;
 
@@ -392,6 +392,9 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
 	if (call_id <= conn->channels[chan].call_counter)
 		goto old_call; /* TODO: Just drop packet */
 
+	/* Temporary: Mirror the backlog prealloc ref (TODO: use prealloc) */
+	rxrpc_get_call(candidate, rxrpc_call_got);
+
 	/* make the call available */
 	_debug("new call");
 	call = candidate;
@@ -596,6 +599,9 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 	del_timer_sync(&call->ack_timer);
 	del_timer_sync(&call->lifetimer);
 
+	/* We have to release the prealloc backlog ref */
+	if (rxrpc_is_service_call(call))
+		rxrpc_put_call(call, rxrpc_call_put);
 	_leave("");
 }
 
@@ -682,7 +688,7 @@ static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 /*
  * clean up a call
  */
-static void rxrpc_cleanup_call(struct rxrpc_call *call)
+void rxrpc_cleanup_call(struct rxrpc_call *call)
 {
 	_net("DESTROY CALL %d", call->debug_id);
 
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 9c6685b97e70..8da82e3aa00e 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -286,6 +286,8 @@ static void rxrpc_connection_reaper(struct work_struct *work)
 		ASSERTCMP(atomic_read(&conn->usage), >, 0);
 		if (likely(atomic_read(&conn->usage) > 1))
 			continue;
+		if (conn->state == RXRPC_CONN_SERVICE_PREALLOC)
+			continue;
 
 		idle_timestamp = READ_ONCE(conn->idle_timestamp);
 		_debug("reap CONN %d { u=%d,t=%ld }",
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c
index 316a92107fee..189338a60457 100644
--- a/net/rxrpc/conn_service.c
+++ b/net/rxrpc/conn_service.c
@@ -119,6 +119,30 @@ replace_old_connection:
 }
 
 /*
+ * Preallocate a service connection.  The connection is placed on the proc and
+ * reap lists so that we don't have to get the lock from BH context.
+ */
+struct rxrpc_connection *rxrpc_prealloc_service_connection(gfp_t gfp)
+{
+	struct rxrpc_connection *conn = rxrpc_alloc_connection(gfp);
+
+	if (conn) {
+		/* We maintain an extra ref on the connection whilst it is on
+		 * the rxrpc_connections list.
+		 */
+		conn->state = RXRPC_CONN_SERVICE_PREALLOC;
+		atomic_set(&conn->usage, 2);
+
+		write_lock(&rxrpc_connection_lock);
+		list_add_tail(&conn->link, &rxrpc_connections);
+		list_add_tail(&conn->proc_link, &rxrpc_connection_proc_list);
+		write_unlock(&rxrpc_connection_lock);
+	}
+
+	return conn;
+}
+
+/*
  * get a record of an incoming connection
  */
 struct rxrpc_connection *rxrpc_incoming_connection(struct rxrpc_local *local,
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 6c4b7df05e95..5906579060cd 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -102,7 +102,7 @@ int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
 		    rx->notify_new_call) {
 			spin_unlock_bh(&sk->sk_receive_queue.lock);
 			skb_queue_tail(&call->knlrecv_queue, skb);
-			rx->notify_new_call(&rx->sk);
+			rx->notify_new_call(&rx->sk, NULL, 0);
 		} else if (call->notify_rx) {
 			spin_unlock_bh(&sk->sk_receive_queue.lock);
 			skb_queue_tail(&call->knlrecv_queue, skb);
diff --git a/net/rxrpc/proc.c b/net/rxrpc/proc.c
index dfad23821a62..d529d1b4021c 100644
--- a/net/rxrpc/proc.c
+++ b/net/rxrpc/proc.c
@@ -17,6 +17,7 @@
 static const char *const rxrpc_conn_states[RXRPC_CONN__NR_STATES] = {
 	[RXRPC_CONN_UNUSED]			= "Unused  ",
 	[RXRPC_CONN_CLIENT]			= "Client  ",
+	[RXRPC_CONN_SERVICE_PREALLOC]		= "SvPrealc",
 	[RXRPC_CONN_SERVICE_UNSECURED]		= "SvUnsec ",
 	[RXRPC_CONN_SERVICE_CHALLENGING]	= "SvChall ",
 	[RXRPC_CONN_SERVICE]			= "SvSecure",
@@ -156,6 +157,11 @@ static int rxrpc_connection_seq_show(struct seq_file *seq, void *v)
 	}
 
 	conn = list_entry(v, struct rxrpc_connection, proc_link);
+	if (conn->state == RXRPC_CONN_SERVICE_PREALLOC) {
+		strcpy(lbuff, "no_local");
+		strcpy(rbuff, "no_connection");
+		goto print;
+	}
 
 	sprintf(lbuff, "%pI4:%u",
 		&conn->params.local->srx.transport.sin.sin_addr,
@@ -164,7 +170,7 @@ static int rxrpc_connection_seq_show(struct seq_file *seq, void *v)
 	sprintf(rbuff, "%pI4:%u",
 		&conn->params.peer->srx.transport.sin.sin_addr,
 		ntohs(conn->params.peer->srx.transport.sin.sin_port));
-
+print:
 	seq_printf(seq,
 		   "UDP   %-22.22s %-22.22s %4x %08x %s %3u"
 		   " %s %08x %08x %08x\n",
