Initial import

1 files changed, 1356 insertions, 0 deletions

diff --git a/net/rxrpc/ar-ack.c b/net/rxrpc/ar-ack.c
new file mode 100644
index 000000000..e0547f521
--- /dev/null
+++ b/net/rxrpc/ar-ack.c
@@ -0,0 +1,1356 @@
+/* Management of Tx window, Tx resend, ACKs and out-of-sequence reception
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/circ_buf.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/udp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+/*
+ * How long to wait before scheduling ACK generation after seeing a
+ * packet with RXRPC_REQUEST_ACK set (in jiffies).
+ */
+unsigned rxrpc_requested_ack_delay = 1;
+
+/*
+ * How long to wait before scheduling an ACK with subtype DELAY (in jiffies).
+ *
+ * We use this when we've received new data packets.  If those packets aren't
+ * all consumed within this time we will send a DELAY ACK if an ACK was not
+ * requested to let the sender know it doesn't need to resend.
+ */
+unsigned rxrpc_soft_ack_delay = 1 * HZ;
+
+/*
+ * How long to wait before scheduling an ACK with subtype IDLE (in jiffies).
+ *
+ * We use this when we've consumed some previously soft-ACK'd packets when
+ * further packets aren't immediately received to decide when to send an IDLE
+ * ACK let the other end know that it can free up its Tx buffer space.
+ */
+unsigned rxrpc_idle_ack_delay = 0.5 * HZ;
+
+/*
+ * Receive window size in packets.  This indicates the maximum number of
+ * unconsumed received packets we're willing to retain in memory.  Once this
+ * limit is hit, we should generate an EXCEEDS_WINDOW ACK and discard further
+ * packets.
+ */
+unsigned rxrpc_rx_window_size = 32;
+
+/*
+ * Maximum Rx MTU size.  This indicates to the sender the size of jumbo packet
+ * made by gluing normal packets together that we're willing to handle.
+ */
+unsigned rxrpc_rx_mtu = 5692;
+
+/*
+ * The maximum number of fragments in a received jumbo packet that we tell the
+ * sender that we're willing to handle.
+ */
+unsigned rxrpc_rx_jumbo_max = 4;
+
+static const char *rxrpc_acks(u8 reason)
+{
+	static const char *const str[] = {
+		"---", "REQ", "DUP", "OOS", "WIN", "MEM", "PNG", "PNR", "DLY",
+		"IDL", "-?-"
+	};
+
+	if (reason >= ARRAY_SIZE(str))
+		reason = ARRAY_SIZE(str) - 1;
+	return str[reason];
+}
+
+static const s8 rxrpc_ack_priority[] = {
+	[0]				= 0,
+	[RXRPC_ACK_DELAY]		= 1,
+	[RXRPC_ACK_REQUESTED]		= 2,
+	[RXRPC_ACK_IDLE]		= 3,
+	[RXRPC_ACK_PING_RESPONSE]	= 4,
+	[RXRPC_ACK_DUPLICATE]		= 5,
+	[RXRPC_ACK_OUT_OF_SEQUENCE]	= 6,
+	[RXRPC_ACK_EXCEEDS_WINDOW]	= 7,
+	[RXRPC_ACK_NOSPACE]		= 8,
+};
+
+/*
+ * propose an ACK be sent
+ */
+void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
+			 __be32 serial, bool immediate)
+{
+	unsigned long expiry;
+	s8 prior = rxrpc_ack_priority[ack_reason];
+
+	ASSERTCMP(prior, >, 0);
+
+	_enter("{%d},%s,%%%x,%u",
+	       call->debug_id, rxrpc_acks(ack_reason), ntohl(serial),
+	       immediate);
+
+	if (prior < rxrpc_ack_priority[call->ackr_reason]) {
+		if (immediate)
+			goto cancel_timer;
+		return;
+	}
+
+	/* update DELAY, IDLE, REQUESTED and PING_RESPONSE ACK serial
+	 * numbers */
+	if (prior == rxrpc_ack_priority[call->ackr_reason]) {
+		if (prior <= 4)
+			call->ackr_serial = serial;
+		if (immediate)
+			goto cancel_timer;
+		return;
+	}
+
+	call->ackr_reason = ack_reason;
+	call->ackr_serial = serial;
+
+	switch (ack_reason) {
+	case RXRPC_ACK_DELAY:
+		_debug("run delay timer");
+		expiry = rxrpc_soft_ack_delay;
+		goto run_timer;
+
+	case RXRPC_ACK_IDLE:
+		if (!immediate) {
+			_debug("run defer timer");
+			expiry = rxrpc_idle_ack_delay;
+			goto run_timer;
+		}
+		goto cancel_timer;
+
+	case RXRPC_ACK_REQUESTED:
+		expiry = rxrpc_requested_ack_delay;
+		if (!expiry)
+			goto cancel_timer;
+		if (!immediate || serial == cpu_to_be32(1)) {
+			_debug("run defer timer");
+			goto run_timer;
+		}
+
+	default:
+		_debug("immediate ACK");
+		goto cancel_timer;
+	}
+
+run_timer:
+	expiry += jiffies;
+	if (!timer_pending(&call->ack_timer) ||
+	    time_after(call->ack_timer.expires, expiry))
+		mod_timer(&call->ack_timer, expiry);
+	return;
+
+cancel_timer:
+	_debug("cancel timer %%%u", ntohl(serial));
+	try_to_del_timer_sync(&call->ack_timer);
+	read_lock_bh(&call->state_lock);
+	if (call->state <= RXRPC_CALL_COMPLETE &&
+	    !test_and_set_bit(RXRPC_CALL_ACK, &call->events))
+		rxrpc_queue_call(call);
+	read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * propose an ACK be sent, locking the call structure
+ */
+void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
+		       __be32 serial, bool immediate)
+{
+	s8 prior = rxrpc_ack_priority[ack_reason];
+
+	if (prior > rxrpc_ack_priority[call->ackr_reason]) {
+		spin_lock_bh(&call->lock);
+		__rxrpc_propose_ACK(call, ack_reason, serial, immediate);
+		spin_unlock_bh(&call->lock);
+	}
+}
+
+/*
+ * set the resend timer
+ */
+static void rxrpc_set_resend(struct rxrpc_call *call, u8 resend,
+			     unsigned long resend_at)
+{
+	read_lock_bh(&call->state_lock);
+	if (call->state >= RXRPC_CALL_COMPLETE)
+		resend = 0;
+
+	if (resend & 1) {
+		_debug("SET RESEND");
+		set_bit(RXRPC_CALL_RESEND, &call->events);
+	}
+
+	if (resend & 2) {
+		_debug("MODIFY RESEND TIMER");
+		set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+		mod_timer(&call->resend_timer, resend_at);
+	} else {
+		_debug("KILL RESEND TIMER");
+		del_timer_sync(&call->resend_timer);
+		clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+	}
+	read_unlock_bh(&call->state_lock);
+}
+
+/*
+ * resend packets
+ */
+static void rxrpc_resend(struct rxrpc_call *call)
+{
+	struct rxrpc_skb_priv *sp;
+	struct rxrpc_header *hdr;
+	struct sk_buff *txb;
+	unsigned long *p_txb, resend_at;
+	bool stop;
+	int loop;
+	u8 resend;
+
+	_enter("{%d,%d,%d,%d},",
+	       call->acks_hard, call->acks_unacked,
+	       atomic_read(&call->sequence),
+	       CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
+
+	stop = false;
+	resend = 0;
+	resend_at = 0;
+
+	for (loop = call->acks_tail;
+	     loop != call->acks_head || stop;
+	     loop = (loop + 1) &  (call->acks_winsz - 1)
+	     ) {
+		p_txb = call->acks_window + loop;
+		smp_read_barrier_depends();
+		if (*p_txb & 1)
+			continue;
+
+		txb = (struct sk_buff *) *p_txb;
+		sp = rxrpc_skb(txb);
+
+		if (sp->need_resend) {
+			sp->need_resend = false;
+
+			/* each Tx packet has a new serial number */
+			sp->hdr.serial =
+				htonl(atomic_inc_return(&call->conn->serial));
+
+			hdr = (struct rxrpc_header *) txb->head;
+			hdr->serial = sp->hdr.serial;
+
+			_proto("Tx DATA %%%u { #%d }",
+			       ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
+			if (rxrpc_send_packet(call->conn->trans, txb) < 0) {
+				stop = true;
+				sp->resend_at = jiffies + 3;
+			} else {
+				sp->resend_at =
+					jiffies + rxrpc_resend_timeout;
+			}
+		}
+
+		if (time_after_eq(jiffies + 1, sp->resend_at)) {
+			sp->need_resend = true;
+			resend |= 1;
+		} else if (resend & 2) {
+			if (time_before(sp->resend_at, resend_at))
+				resend_at = sp->resend_at;
+		} else {
+			resend_at = sp->resend_at;
+			resend |= 2;
+		}
+	}
+
+	rxrpc_set_resend(call, resend, resend_at);
+	_leave("");
+}
+
+/*
+ * handle resend timer expiry
+ */
+static void rxrpc_resend_timer(struct rxrpc_call *call)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *txb;
+	unsigned long *p_txb, resend_at;
+	int loop;
+	u8 resend;
+
+	_enter("%d,%d,%d",
+	       call->acks_tail, call->acks_unacked, call->acks_head);
+
+	if (call->state >= RXRPC_CALL_COMPLETE)
+		return;
+
+	resend = 0;
+	resend_at = 0;
+
+	for (loop = call->acks_unacked;
+	     loop != call->acks_head;
+	     loop = (loop + 1) &  (call->acks_winsz - 1)
+	     ) {
+		p_txb = call->acks_window + loop;
+		smp_read_barrier_depends();
+		txb = (struct sk_buff *) (*p_txb & ~1);
+		sp = rxrpc_skb(txb);
+
+		ASSERT(!(*p_txb & 1));
+
+		if (sp->need_resend) {
+			;
+		} else if (time_after_eq(jiffies + 1, sp->resend_at)) {
+			sp->need_resend = true;
+			resend |= 1;
+		} else if (resend & 2) {
+			if (time_before(sp->resend_at, resend_at))
+				resend_at = sp->resend_at;
+		} else {
+			resend_at = sp->resend_at;
+			resend |= 2;
+		}
+	}
+
+	rxrpc_set_resend(call, resend, resend_at);
+	_leave("");
+}
+
+/*
+ * process soft ACKs of our transmitted packets
+ * - these indicate packets the peer has or has not received, but hasn't yet
+ *   given to the consumer, and so can still be discarded and re-requested
+ */
+static int rxrpc_process_soft_ACKs(struct rxrpc_call *call,
+				   struct rxrpc_ackpacket *ack,
+				   struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *txb;
+	unsigned long *p_txb, resend_at;
+	int loop;
+	u8 sacks[RXRPC_MAXACKS], resend;
+
+	_enter("{%d,%d},{%d},",
+	       call->acks_hard,
+	       CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz),
+	       ack->nAcks);
+
+	if (skb_copy_bits(skb, 0, sacks, ack->nAcks) < 0)
+		goto protocol_error;
+
+	resend = 0;
+	resend_at = 0;
+	for (loop = 0; loop < ack->nAcks; loop++) {
+		p_txb = call->acks_window;
+		p_txb += (call->acks_tail + loop) & (call->acks_winsz - 1);
+		smp_read_barrier_depends();
+		txb = (struct sk_buff *) (*p_txb & ~1);
+		sp = rxrpc_skb(txb);
+
+		switch (sacks[loop]) {
+		case RXRPC_ACK_TYPE_ACK:
+			sp->need_resend = false;
+			*p_txb |= 1;
+			break;
+		case RXRPC_ACK_TYPE_NACK:
+			sp->need_resend = true;
+			*p_txb &= ~1;
+			resend = 1;
+			break;
+		default:
+			_debug("Unsupported ACK type %d", sacks[loop]);
+			goto protocol_error;
+		}
+	}
+
+	smp_mb();
+	call->acks_unacked = (call->acks_tail + loop) & (call->acks_winsz - 1);
+
+	/* anything not explicitly ACK'd is implicitly NACK'd, but may just not
+	 * have been received or processed yet by the far end */
+	for (loop = call->acks_unacked;
+	     loop != call->acks_head;
+	     loop = (loop + 1) &  (call->acks_winsz - 1)
+	     ) {
+		p_txb = call->acks_window + loop;
+		smp_read_barrier_depends();
+		txb = (struct sk_buff *) (*p_txb & ~1);
+		sp = rxrpc_skb(txb);
+
+		if (*p_txb & 1) {
+			/* packet must have been discarded */
+			sp->need_resend = true;
+			*p_txb &= ~1;
+			resend |= 1;
+		} else if (sp->need_resend) {
+			;
+		} else if (time_after_eq(jiffies + 1, sp->resend_at)) {
+			sp->need_resend = true;
+			resend |= 1;
+		} else if (resend & 2) {
+			if (time_before(sp->resend_at, resend_at))
+				resend_at = sp->resend_at;
+		} else {
+			resend_at = sp->resend_at;
+			resend |= 2;
+		}
+	}
+
+	rxrpc_set_resend(call, resend, resend_at);
+	_leave(" = 0");
+	return 0;
+
+protocol_error:
+	_leave(" = -EPROTO");
+	return -EPROTO;
+}
+
+/*
+ * discard hard-ACK'd packets from the Tx window
+ */
+static void rxrpc_rotate_tx_window(struct rxrpc_call *call, u32 hard)
+{
+	unsigned long _skb;
+	int tail = call->acks_tail, old_tail;
+	int win = CIRC_CNT(call->acks_head, tail, call->acks_winsz);
+
+	_enter("{%u,%u},%u", call->acks_hard, win, hard);
+
+	ASSERTCMP(hard - call->acks_hard, <=, win);
+
+	while (call->acks_hard < hard) {
+		smp_read_barrier_depends();
+		_skb = call->acks_window[tail] & ~1;
+		rxrpc_free_skb((struct sk_buff *) _skb);
+		old_tail = tail;
+		tail = (tail + 1) & (call->acks_winsz - 1);
+		call->acks_tail = tail;
+		if (call->acks_unacked == old_tail)
+			call->acks_unacked = tail;
+		call->acks_hard++;
+	}
+
+	wake_up(&call->tx_waitq);
+}
+
+/*
+ * clear the Tx window in the event of a failure
+ */
+static void rxrpc_clear_tx_window(struct rxrpc_call *call)
+{
+	rxrpc_rotate_tx_window(call, atomic_read(&call->sequence));
+}
+
+/*
+ * drain the out of sequence received packet queue into the packet Rx queue
+ */
+static int rxrpc_drain_rx_oos_queue(struct rxrpc_call *call)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	bool terminal;
+	int ret;
+
+	_enter("{%d,%d}", call->rx_data_post, call->rx_first_oos);
+
+	spin_lock_bh(&call->lock);
+
+	ret = -ECONNRESET;
+	if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
+		goto socket_unavailable;
+
+	skb = skb_dequeue(&call->rx_oos_queue);
+	if (skb) {
+		sp = rxrpc_skb(skb);
+
+		_debug("drain OOS packet %d [%d]",
+		       ntohl(sp->hdr.seq), call->rx_first_oos);
+
+		if (ntohl(sp->hdr.seq) != call->rx_first_oos) {
+			skb_queue_head(&call->rx_oos_queue, skb);
+			call->rx_first_oos = ntohl(rxrpc_skb(skb)->hdr.seq);
+			_debug("requeue %p {%u}", skb, call->rx_first_oos);
+		} else {
+			skb->mark = RXRPC_SKB_MARK_DATA;
+			terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
+				!(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
+			ret = rxrpc_queue_rcv_skb(call, skb, true, terminal);
+			BUG_ON(ret < 0);
+			_debug("drain #%u", call->rx_data_post);
+			call->rx_data_post++;
+
+			/* find out what the next packet is */
+			skb = skb_peek(&call->rx_oos_queue);
+			if (skb)
+				call->rx_first_oos =
+					ntohl(rxrpc_skb(skb)->hdr.seq);
+			else
+				call->rx_first_oos = 0;
+			_debug("peek %p {%u}", skb, call->rx_first_oos);
+		}
+	}
+
+	ret = 0;
+socket_unavailable:
+	spin_unlock_bh(&call->lock);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * insert an out of sequence packet into the buffer
+ */
+static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
+				    struct sk_buff *skb)
+{
+	struct rxrpc_skb_priv *sp, *psp;
+	struct sk_buff *p;
+	u32 seq;
+
+	sp = rxrpc_skb(skb);
+	seq = ntohl(sp->hdr.seq);
+	_enter(",,{%u}", seq);
+
+	skb->destructor = rxrpc_packet_destructor;
+	ASSERTCMP(sp->call, ==, NULL);
+	sp->call = call;
+	rxrpc_get_call(call);
+
+	/* insert into the buffer in sequence order */
+	spin_lock_bh(&call->lock);
+
+	skb_queue_walk(&call->rx_oos_queue, p) {
+		psp = rxrpc_skb(p);
+		if (ntohl(psp->hdr.seq) > seq) {
+			_debug("insert oos #%u before #%u",
+			       seq, ntohl(psp->hdr.seq));
+			skb_insert(p, skb, &call->rx_oos_queue);
+			goto inserted;
+		}
+	}
+
+	_debug("append oos #%u", seq);
+	skb_queue_tail(&call->rx_oos_queue, skb);
+inserted:
+
+	/* we might now have a new front to the queue */
+	if (call->rx_first_oos == 0 || seq < call->rx_first_oos)
+		call->rx_first_oos = seq;
+
+	read_lock(&call->state_lock);
+	if (call->state < RXRPC_CALL_COMPLETE &&
+	    call->rx_data_post == call->rx_first_oos) {
+		_debug("drain rx oos now");
+		set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
+	}
+	read_unlock(&call->state_lock);
+
+	spin_unlock_bh(&call->lock);
+	_leave(" [stored #%u]", call->rx_first_oos);
+}
+
+/*
+ * clear the Tx window on final ACK reception
+ */
+static void rxrpc_zap_tx_window(struct rxrpc_call *call)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	unsigned long _skb, *acks_window;
+	u8 winsz = call->acks_winsz;
+	int tail;
+
+	acks_window = call->acks_window;
+	call->acks_window = NULL;
+
+	while (CIRC_CNT(call->acks_head, call->acks_tail, winsz) > 0) {
+		tail = call->acks_tail;
+		smp_read_barrier_depends();
+		_skb = acks_window[tail] & ~1;
+		smp_mb();
+		call->acks_tail = (call->acks_tail + 1) & (winsz - 1);
+
+		skb = (struct sk_buff *) _skb;
+		sp = rxrpc_skb(skb);
+		_debug("+++ clear Tx %u", ntohl(sp->hdr.seq));
+		rxrpc_free_skb(skb);
+	}
+
+	kfree(acks_window);
+}
+
+/*
+ * process the extra information that may be appended to an ACK packet
+ */
+static void rxrpc_extract_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
+				  unsigned int latest, int nAcks)
+{
+	struct rxrpc_ackinfo ackinfo;
+	struct rxrpc_peer *peer;
+	unsigned int mtu;
+
+	if (skb_copy_bits(skb, nAcks + 3, &ackinfo, sizeof(ackinfo)) < 0) {
+		_leave(" [no ackinfo]");
+		return;
+	}
+
+	_proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
+	       latest,
+	       ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU),
+	       ntohl(ackinfo.rwind), ntohl(ackinfo.jumbo_max));
+
+	mtu = min(ntohl(ackinfo.rxMTU), ntohl(ackinfo.maxMTU));
+
+	peer = call->conn->trans->peer;
+	if (mtu < peer->maxdata) {
+		spin_lock_bh(&peer->lock);
+		peer->maxdata = mtu;
+		peer->mtu = mtu + peer->hdrsize;
+		spin_unlock_bh(&peer->lock);
+		_net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
+	}
+}
+
+/*
+ * process packets in the reception queue
+ */
+static int rxrpc_process_rx_queue(struct rxrpc_call *call,
+				  u32 *_abort_code)
+{
+	struct rxrpc_ackpacket ack;
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	bool post_ACK;
+	int latest;
+	u32 hard, tx;
+
+	_enter("");
+
+process_further:
+	skb = skb_dequeue(&call->rx_queue);
+	if (!skb)
+		return -EAGAIN;
+
+	_net("deferred skb %p", skb);
+
+	sp = rxrpc_skb(skb);
+
+	_debug("process %s [st %d]", rxrpc_pkts[sp->hdr.type], call->state);
+
+	post_ACK = false;
+
+	switch (sp->hdr.type) {
+		/* data packets that wind up here have been received out of
+		 * order, need security processing or are jumbo packets */
+	case RXRPC_PACKET_TYPE_DATA:
+		_proto("OOSQ DATA %%%u { #%u }",
+		       ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
+
+		/* secured packets must be verified and possibly decrypted */
+		if (rxrpc_verify_packet(call, skb, _abort_code) < 0)
+			goto protocol_error;
+
+		rxrpc_insert_oos_packet(call, skb);
+		goto process_further;
+
+		/* partial ACK to process */
+	case RXRPC_PACKET_TYPE_ACK:
+		if (skb_copy_bits(skb, 0, &ack, sizeof(ack)) < 0) {
+			_debug("extraction failure");
+			goto protocol_error;
+		}
+		if (!skb_pull(skb, sizeof(ack)))
+			BUG();
+
+		latest = ntohl(sp->hdr.serial);
+		hard = ntohl(ack.firstPacket);
+		tx = atomic_read(&call->sequence);
+
+		_proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
+		       latest,
+		       ntohs(ack.maxSkew),
+		       hard,
+		       ntohl(ack.previousPacket),
+		       ntohl(ack.serial),
+		       rxrpc_acks(ack.reason),
+		       ack.nAcks);
+
+		rxrpc_extract_ackinfo(call, skb, latest, ack.nAcks);
+
+		if (ack.reason == RXRPC_ACK_PING) {
+			_proto("Rx ACK %%%u PING Request", latest);
+			rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
+					  sp->hdr.serial, true);
+		}
+
+		/* discard any out-of-order or duplicate ACKs */
+		if (latest - call->acks_latest <= 0) {
+			_debug("discard ACK %d <= %d",
+			       latest, call->acks_latest);
+			goto discard;
+		}
+		call->acks_latest = latest;
+
+		if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+		    call->state != RXRPC_CALL_CLIENT_AWAIT_REPLY &&
+		    call->state != RXRPC_CALL_SERVER_SEND_REPLY &&
+		    call->state != RXRPC_CALL_SERVER_AWAIT_ACK)
+			goto discard;
+
+		_debug("Tx=%d H=%u S=%d", tx, call->acks_hard, call->state);
+
+		if (hard > 0) {
+			if (hard - 1 > tx) {
+				_debug("hard-ACK'd packet %d not transmitted"
+				       " (%d top)",
+				       hard - 1, tx);
+				goto protocol_error;
+			}
+
+			if ((call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY ||
+			     call->state == RXRPC_CALL_SERVER_AWAIT_ACK) &&
+			    hard > tx)
+				goto all_acked;
+
+			smp_rmb();
+			rxrpc_rotate_tx_window(call, hard - 1);
+		}
+
+		if (ack.nAcks > 0) {
+			if (hard - 1 + ack.nAcks > tx) {
+				_debug("soft-ACK'd packet %d+%d not"
+				       " transmitted (%d top)",
+				       hard - 1, ack.nAcks, tx);
+				goto protocol_error;
+			}
+
+			if (rxrpc_process_soft_ACKs(call, &ack, skb) < 0)
+				goto protocol_error;
+		}
+		goto discard;
+
+		/* complete ACK to process */
+	case RXRPC_PACKET_TYPE_ACKALL:
+		goto all_acked;
+
+		/* abort and busy are handled elsewhere */
+	case RXRPC_PACKET_TYPE_BUSY:
+	case RXRPC_PACKET_TYPE_ABORT:
+		BUG();
+
+		/* connection level events - also handled elsewhere */
+	case RXRPC_PACKET_TYPE_CHALLENGE:
+	case RXRPC_PACKET_TYPE_RESPONSE:
+	case RXRPC_PACKET_TYPE_DEBUG:
+		BUG();
+	}
+
+	/* if we've had a hard ACK that covers all the packets we've sent, then
+	 * that ends that phase of the operation */
+all_acked:
+	write_lock_bh(&call->state_lock);
+	_debug("ack all %d", call->state);
+
+	switch (call->state) {
+	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+		break;
+	case RXRPC_CALL_SERVER_AWAIT_ACK:
+		_debug("srv complete");
+		call->state = RXRPC_CALL_COMPLETE;
+		post_ACK = true;
+		break;
+	case RXRPC_CALL_CLIENT_SEND_REQUEST:
+	case RXRPC_CALL_SERVER_RECV_REQUEST:
+		goto protocol_error_unlock; /* can't occur yet */
+	default:
+		write_unlock_bh(&call->state_lock);
+		goto discard; /* assume packet left over from earlier phase */
+	}
+
+	write_unlock_bh(&call->state_lock);
+
+	/* if all the packets we sent are hard-ACK'd, then we can discard
+	 * whatever we've got left */
+	_debug("clear Tx %d",
+	       CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz));
+
+	del_timer_sync(&call->resend_timer);
+	clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+	clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+
+	if (call->acks_window)
+		rxrpc_zap_tx_window(call);
+
+	if (post_ACK) {
+		/* post the final ACK message for userspace to pick up */
+		_debug("post ACK");
+		skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
+		sp->call = call;
+		rxrpc_get_call(call);
+		spin_lock_bh(&call->lock);
+		if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
+			BUG();
+		spin_unlock_bh(&call->lock);
+		goto process_further;
+	}
+
+discard:
+	rxrpc_free_skb(skb);
+	goto process_further;
+
+protocol_error_unlock:
+	write_unlock_bh(&call->state_lock);
+protocol_error:
+	rxrpc_free_skb(skb);
+	_leave(" = -EPROTO");
+	return -EPROTO;
+}
+
+/*
+ * post a message to the socket Rx queue for recvmsg() to pick up
+ */
+static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
+			      bool fatal)
+{
+	struct rxrpc_skb_priv *sp;
+	struct sk_buff *skb;
+	int ret;
+
+	_enter("{%d,%lx},%u,%u,%d",
+	       call->debug_id, call->flags, mark, error, fatal);
+
+	/* remove timers and things for fatal messages */
+	if (fatal) {
+		del_timer_sync(&call->resend_timer);
+		del_timer_sync(&call->ack_timer);
+		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+	}
+
+	if (mark != RXRPC_SKB_MARK_NEW_CALL &&
+	    !test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
+		_leave("[no userid]");
+		return 0;
+	}
+
+	if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
+		skb = alloc_skb(0, GFP_NOFS);
+		if (!skb)
+			return -ENOMEM;
+
+		rxrpc_new_skb(skb);
+
+		skb->mark = mark;
+
+		sp = rxrpc_skb(skb);
+		memset(sp, 0, sizeof(*sp));
+		sp->error = error;
+		sp->call = call;
+		rxrpc_get_call(call);
+
+		spin_lock_bh(&call->lock);
+		ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
+		spin_unlock_bh(&call->lock);
+		BUG_ON(ret < 0);
+	}
+
+	return 0;
+}
+
+/*
+ * handle background processing of incoming call packets and ACK / abort
+ * generation
+ */
+void rxrpc_process_call(struct work_struct *work)
+{
+	struct rxrpc_call *call =
+		container_of(work, struct rxrpc_call, processor);
+	struct rxrpc_ackpacket ack;
+	struct rxrpc_ackinfo ackinfo;
+	struct rxrpc_header hdr;
+	struct msghdr msg;
+	struct kvec iov[5];
+	unsigned long bits;
+	__be32 data, pad;
+	size_t len;
+	int genbit, loop, nbit, ioc, ret, mtu;
+	u32 abort_code = RX_PROTOCOL_ERROR;
+	u8 *acks = NULL;
+
+	//printk("\n--------------------\n");
+	_enter("{%d,%s,%lx} [%lu]",
+	       call->debug_id, rxrpc_call_states[call->state], call->events,
+	       (jiffies - call->creation_jif) / (HZ / 10));
+
+	if (test_and_set_bit(RXRPC_CALL_PROC_BUSY, &call->flags)) {
+		_debug("XXXXXXXXXXXXX RUNNING ON MULTIPLE CPUS XXXXXXXXXXXXX");
+		return;
+	}
+
+	/* there's a good chance we're going to have to send a message, so set
+	 * one up in advance */
+	msg.msg_name	= &call->conn->trans->peer->srx.transport.sin;
+	msg.msg_namelen	= sizeof(call->conn->trans->peer->srx.transport.sin);
+	msg.msg_control	= NULL;
+	msg.msg_controllen = 0;
+	msg.msg_flags	= 0;
+
+	hdr.epoch	= call->conn->epoch;
+	hdr.cid		= call->cid;
+	hdr.callNumber	= call->call_id;
+	hdr.seq		= 0;
+	hdr.type	= RXRPC_PACKET_TYPE_ACK;
+	hdr.flags	= call->conn->out_clientflag;
+	hdr.userStatus	= 0;
+	hdr.securityIndex = call->conn->security_ix;
+	hdr._rsvd	= 0;
+	hdr.serviceId	= call->conn->service_id;
+
+	memset(iov, 0, sizeof(iov));
+	iov[0].iov_base	= &hdr;
+	iov[0].iov_len	= sizeof(hdr);
+
+	/* deal with events of a final nature */
+	if (test_bit(RXRPC_CALL_RELEASE, &call->events)) {
+		rxrpc_release_call(call);
+		clear_bit(RXRPC_CALL_RELEASE, &call->events);
+	}
+
+	if (test_bit(RXRPC_CALL_RCVD_ERROR, &call->events)) {
+		int error;
+
+		clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
+		clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
+		clear_bit(RXRPC_CALL_ABORT, &call->events);
+
+		error = call->conn->trans->peer->net_error;
+		_debug("post net error %d", error);
+
+		if (rxrpc_post_message(call, RXRPC_SKB_MARK_NET_ERROR,
+				       error, true) < 0)
+			goto no_mem;
+		clear_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
+		goto kill_ACKs;
+	}
+
+	if (test_bit(RXRPC_CALL_CONN_ABORT, &call->events)) {
+		ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
+
+		clear_bit(RXRPC_CALL_REJECT_BUSY, &call->events);
+		clear_bit(RXRPC_CALL_ABORT, &call->events);
+
+		_debug("post conn abort");
+
+		if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
+				       call->conn->error, true) < 0)
+			goto no_mem;
+		clear_bit(RXRPC_CALL_CONN_ABORT, &call->events);
+		goto kill_ACKs;
+	}
+
+	if (test_bit(RXRPC_CALL_REJECT_BUSY, &call->events)) {
+		hdr.type = RXRPC_PACKET_TYPE_BUSY;
+		genbit = RXRPC_CALL_REJECT_BUSY;
+		goto send_message;
+	}
+
+	if (test_bit(RXRPC_CALL_ABORT, &call->events)) {
+		ASSERTCMP(call->state, >, RXRPC_CALL_COMPLETE);
+
+		if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
+				       ECONNABORTED, true) < 0)
+			goto no_mem;
+		hdr.type = RXRPC_PACKET_TYPE_ABORT;
+		data = htonl(call->abort_code);
+		iov[1].iov_base = &data;
+		iov[1].iov_len = sizeof(data);
+		genbit = RXRPC_CALL_ABORT;
+		goto send_message;
+	}
+
+	if (test_bit(RXRPC_CALL_ACK_FINAL, &call->events)) {
+		genbit = RXRPC_CALL_ACK_FINAL;
+
+		ack.bufferSpace	= htons(8);
+		ack.maxSkew	= 0;
+		ack.serial	= 0;
+		ack.reason	= RXRPC_ACK_IDLE;
+		ack.nAcks	= 0;
+		call->ackr_reason = 0;
+
+		spin_lock_bh(&call->lock);
+		ack.serial = call->ackr_serial;
+		ack.previousPacket = call->ackr_prev_seq;
+		ack.firstPacket = htonl(call->rx_data_eaten + 1);
+		spin_unlock_bh(&call->lock);
+
+		pad = 0;
+
+		iov[1].iov_base = &ack;
+		iov[1].iov_len	= sizeof(ack);
+		iov[2].iov_base = &pad;
+		iov[2].iov_len	= 3;
+		iov[3].iov_base = &ackinfo;
+		iov[3].iov_len	= sizeof(ackinfo);
+		goto send_ACK;
+	}
+
+	if (call->events & ((1 << RXRPC_CALL_RCVD_BUSY) |
+			    (1 << RXRPC_CALL_RCVD_ABORT))
+	    ) {
+		u32 mark;
+
+		if (test_bit(RXRPC_CALL_RCVD_ABORT, &call->events))
+			mark = RXRPC_SKB_MARK_REMOTE_ABORT;
+		else
+			mark = RXRPC_SKB_MARK_BUSY;
+
+		_debug("post abort/busy");
+		rxrpc_clear_tx_window(call);
+		if (rxrpc_post_message(call, mark, ECONNABORTED, true) < 0)
+			goto no_mem;
+
+		clear_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
+		clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
+		goto kill_ACKs;
+	}
+
+	if (test_and_clear_bit(RXRPC_CALL_RCVD_ACKALL, &call->events)) {
+		_debug("do implicit ackall");
+		rxrpc_clear_tx_window(call);
+	}
+
+	if (test_bit(RXRPC_CALL_LIFE_TIMER, &call->events)) {
+		write_lock_bh(&call->state_lock);
+		if (call->state <= RXRPC_CALL_COMPLETE) {
+			call->state = RXRPC_CALL_LOCALLY_ABORTED;
+			call->abort_code = RX_CALL_TIMEOUT;
+			set_bit(RXRPC_CALL_ABORT, &call->events);
+		}
+		write_unlock_bh(&call->state_lock);
+
+		_debug("post timeout");
+		if (rxrpc_post_message(call, RXRPC_SKB_MARK_LOCAL_ERROR,
+				       ETIME, true) < 0)
+			goto no_mem;
+
+		clear_bit(RXRPC_CALL_LIFE_TIMER, &call->events);
+		goto kill_ACKs;
+	}
+
+	/* deal with assorted inbound messages */
+	if (!skb_queue_empty(&call->rx_queue)) {
+		switch (rxrpc_process_rx_queue(call, &abort_code)) {
+		case 0:
+		case -EAGAIN:
+			break;
+		case -ENOMEM:
+			goto no_mem;
+		case -EKEYEXPIRED:
+		case -EKEYREJECTED:
+		case -EPROTO:
+			rxrpc_abort_call(call, abort_code);
+			goto kill_ACKs;
+		}
+	}
+
+	/* handle resending */
+	if (test_and_clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
+		rxrpc_resend_timer(call);
+	if (test_and_clear_bit(RXRPC_CALL_RESEND, &call->events))
+		rxrpc_resend(call);
+
+	/* consider sending an ordinary ACK */
+	if (test_bit(RXRPC_CALL_ACK, &call->events)) {
+		_debug("send ACK: window: %d - %d { %lx }",
+		       call->rx_data_eaten, call->ackr_win_top,
+		       call->ackr_window[0]);
+
+		if (call->state > RXRPC_CALL_SERVER_ACK_REQUEST &&
+		    call->ackr_reason != RXRPC_ACK_PING_RESPONSE) {
+			/* ACK by sending reply DATA packet in this state */
+			clear_bit(RXRPC_CALL_ACK, &call->events);
+			goto maybe_reschedule;
+		}
+
+		genbit = RXRPC_CALL_ACK;
+
+		acks = kzalloc(call->ackr_win_top - call->rx_data_eaten,
+			       GFP_NOFS);
+		if (!acks)
+			goto no_mem;
+
+		//hdr.flags	= RXRPC_SLOW_START_OK;
+		ack.bufferSpace	= htons(8);
+		ack.maxSkew	= 0;
+		ack.serial	= 0;
+		ack.reason	= 0;
+
+		spin_lock_bh(&call->lock);
+		ack.reason = call->ackr_reason;
+		ack.serial = call->ackr_serial;
+		ack.previousPacket = call->ackr_prev_seq;
+		ack.firstPacket = htonl(call->rx_data_eaten + 1);
+
+		ack.nAcks = 0;
+		for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) {
+			nbit = loop * BITS_PER_LONG;
+			for (bits = call->ackr_window[loop]; bits; bits >>= 1
+			     ) {
+				_debug("- l=%d n=%d b=%lx", loop, nbit, bits);
+				if (bits & 1) {
+					acks[nbit] = RXRPC_ACK_TYPE_ACK;
+					ack.nAcks = nbit + 1;
+				}
+				nbit++;
+			}
+		}
+		call->ackr_reason = 0;
+		spin_unlock_bh(&call->lock);
+
+		pad = 0;
+
+		iov[1].iov_base = &ack;
+		iov[1].iov_len	= sizeof(ack);
+		iov[2].iov_base = acks;
+		iov[2].iov_len	= ack.nAcks;
+		iov[3].iov_base = &pad;
+		iov[3].iov_len	= 3;
+		iov[4].iov_base = &ackinfo;
+		iov[4].iov_len	= sizeof(ackinfo);
+
+		switch (ack.reason) {
+		case RXRPC_ACK_REQUESTED:
+		case RXRPC_ACK_DUPLICATE:
+		case RXRPC_ACK_OUT_OF_SEQUENCE:
+		case RXRPC_ACK_EXCEEDS_WINDOW:
+		case RXRPC_ACK_NOSPACE:
+		case RXRPC_ACK_PING:
+		case RXRPC_ACK_PING_RESPONSE:
+			goto send_ACK_with_skew;
+		case RXRPC_ACK_DELAY:
+		case RXRPC_ACK_IDLE:
+			goto send_ACK;
+		}
+	}
+
+	/* handle completion of security negotiations on an incoming
+	 * connection */
+	if (test_and_clear_bit(RXRPC_CALL_SECURED, &call->events)) {
+		_debug("secured");
+		spin_lock_bh(&call->lock);
+
+		if (call->state == RXRPC_CALL_SERVER_SECURING) {
+			_debug("securing");
+			write_lock(&call->conn->lock);
+			if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+			    !test_bit(RXRPC_CALL_RELEASE, &call->events)) {
+				_debug("not released");
+				call->state = RXRPC_CALL_SERVER_ACCEPTING;
+				list_move_tail(&call->accept_link,
+					       &call->socket->acceptq);
+			}
+			write_unlock(&call->conn->lock);
+			read_lock(&call->state_lock);
+			if (call->state < RXRPC_CALL_COMPLETE)
+				set_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
+			read_unlock(&call->state_lock);
+		}
+
+		spin_unlock_bh(&call->lock);
+		if (!test_bit(RXRPC_CALL_POST_ACCEPT, &call->events))
+			goto maybe_reschedule;
+	}
+
+	/* post a notification of an acceptable connection to the app */
+	if (test_bit(RXRPC_CALL_POST_ACCEPT, &call->events)) {
+		_debug("post accept");
+		if (rxrpc_post_message(call, RXRPC_SKB_MARK_NEW_CALL,
+				       0, false) < 0)
+			goto no_mem;
+		clear_bit(RXRPC_CALL_POST_ACCEPT, &call->events);
+		goto maybe_reschedule;
+	}
+
+	/* handle incoming call acceptance */
+	if (test_and_clear_bit(RXRPC_CALL_ACCEPTED, &call->events)) {
+		_debug("accepted");
+		ASSERTCMP(call->rx_data_post, ==, 0);
+		call->rx_data_post = 1;
+		read_lock_bh(&call->state_lock);
+		if (call->state < RXRPC_CALL_COMPLETE)
+			set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events);
+		read_unlock_bh(&call->state_lock);
+	}
+
+	/* drain the out of sequence received packet queue into the packet Rx
+	 * queue */
+	if (test_and_clear_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events)) {
+		while (call->rx_data_post == call->rx_first_oos)
+			if (rxrpc_drain_rx_oos_queue(call) < 0)
+				break;
+		goto maybe_reschedule;
+	}
+
+	/* other events may have been raised since we started checking */
+	goto maybe_reschedule;
+
+send_ACK_with_skew:
+	ack.maxSkew = htons(atomic_read(&call->conn->hi_serial) -
+			    ntohl(ack.serial));
+send_ACK:
+	mtu = call->conn->trans->peer->if_mtu;
+	mtu -= call->conn->trans->peer->hdrsize;
+	ackinfo.maxMTU	= htonl(mtu);
+	ackinfo.rwind	= htonl(rxrpc_rx_window_size);
+
+	/* permit the peer to send us jumbo packets if it wants to */
+	ackinfo.rxMTU	= htonl(rxrpc_rx_mtu);
+	ackinfo.jumbo_max = htonl(rxrpc_rx_jumbo_max);
+
+	hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
+	_proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
+	       ntohl(hdr.serial),
+	       ntohs(ack.maxSkew),
+	       ntohl(ack.firstPacket),
+	       ntohl(ack.previousPacket),
+	       ntohl(ack.serial),
+	       rxrpc_acks(ack.reason),
+	       ack.nAcks);
+
+	del_timer_sync(&call->ack_timer);
+	if (ack.nAcks > 0)
+		set_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags);
+	goto send_message_2;
+
+send_message:
+	_debug("send message");
+
+	hdr.serial = htonl(atomic_inc_return(&call->conn->serial));
+	_proto("Tx %s %%%u", rxrpc_pkts[hdr.type], ntohl(hdr.serial));
+send_message_2:
+
+	len = iov[0].iov_len;
+	ioc = 1;
+	if (iov[4].iov_len) {
+		ioc = 5;
+		len += iov[4].iov_len;
+		len += iov[3].iov_len;
+		len += iov[2].iov_len;
+		len += iov[1].iov_len;
+	} else if (iov[3].iov_len) {
+		ioc = 4;
+		len += iov[3].iov_len;
+		len += iov[2].iov_len;
+		len += iov[1].iov_len;
+	} else if (iov[2].iov_len) {
+		ioc = 3;
+		len += iov[2].iov_len;
+		len += iov[1].iov_len;
+	} else if (iov[1].iov_len) {
+		ioc = 2;
+		len += iov[1].iov_len;
+	}
+
+	ret = kernel_sendmsg(call->conn->trans->local->socket,
+			     &msg, iov, ioc, len);
+	if (ret < 0) {
+		_debug("sendmsg failed: %d", ret);
+		read_lock_bh(&call->state_lock);
+		if (call->state < RXRPC_CALL_DEAD)
+			rxrpc_queue_call(call);
+		read_unlock_bh(&call->state_lock);
+		goto error;
+	}
+
+	switch (genbit) {
+	case RXRPC_CALL_ABORT:
+		clear_bit(genbit, &call->events);
+		clear_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
+		goto kill_ACKs;
+
+	case RXRPC_CALL_ACK_FINAL:
+		write_lock_bh(&call->state_lock);
+		if (call->state == RXRPC_CALL_CLIENT_FINAL_ACK)
+			call->state = RXRPC_CALL_COMPLETE;
+		write_unlock_bh(&call->state_lock);
+		goto kill_ACKs;
+
+	default:
+		clear_bit(genbit, &call->events);
+		switch (call->state) {
+		case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+		case RXRPC_CALL_CLIENT_RECV_REPLY:
+		case RXRPC_CALL_SERVER_RECV_REQUEST:
+		case RXRPC_CALL_SERVER_ACK_REQUEST:
+			_debug("start ACK timer");
+			rxrpc_propose_ACK(call, RXRPC_ACK_DELAY,
+					  call->ackr_serial, false);
+		default:
+			break;
+		}
+		goto maybe_reschedule;
+	}
+
+kill_ACKs:
+	del_timer_sync(&call->ack_timer);
+	if (test_and_clear_bit(RXRPC_CALL_ACK_FINAL, &call->events))
+		rxrpc_put_call(call);
+	clear_bit(RXRPC_CALL_ACK, &call->events);
+
+maybe_reschedule:
+	if (call->events || !skb_queue_empty(&call->rx_queue)) {
+		read_lock_bh(&call->state_lock);
+		if (call->state < RXRPC_CALL_DEAD)
+			rxrpc_queue_call(call);
+		read_unlock_bh(&call->state_lock);
+	}
+
+	/* don't leave aborted connections on the accept queue */
+	if (call->state >= RXRPC_CALL_COMPLETE &&
+	    !list_empty(&call->accept_link)) {
+		_debug("X unlinking once-pending call %p { e=%lx f=%lx c=%x }",
+		       call, call->events, call->flags,
+		       ntohl(call->conn->cid));
+
+		read_lock_bh(&call->state_lock);
+		if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+		    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
+			rxrpc_queue_call(call);
+		read_unlock_bh(&call->state_lock);
+	}
+
+error:
+	clear_bit(RXRPC_CALL_PROC_BUSY, &call->flags);
+	kfree(acks);
+
+	/* because we don't want two CPUs both processing the work item for one
+	 * call at the same time, we use a flag to note when it's busy; however
+	 * this means there's a race between clearing the flag and setting the
+	 * work pending bit and the work item being processed again */
+	if (call->events && !work_pending(&call->processor)) {
+		_debug("jumpstart %x", ntohl(call->conn->cid));
+		rxrpc_queue_call(call);
+	}
+
+	_leave("");
+	return;
+
+no_mem:
+	_debug("out of memory");
+	goto maybe_reschedule;
+}