[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/afs/rxrpc.c b/src/kernel/linux/v4.14/fs/afs/rxrpc.c
new file mode 100644
index 0000000..7dc9c78
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/afs/rxrpc.c
@@ -0,0 +1,895 @@
+/* Maintain an RxRPC server socket to do AFS communications through
+ *
+ * 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/slab.h>
+#include <linux/sched/signal.h>
+
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "internal.h"
+#include "afs_cm.h"
+
+struct socket *afs_socket; /* my RxRPC socket */
+static struct workqueue_struct *afs_async_calls;
+static struct afs_call *afs_spare_incoming_call;
+atomic_t afs_outstanding_calls;
+
+static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
+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 void afs_process_async_call(struct work_struct *);
+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 *);
+
+/* asynchronous incoming call initial processing */
+static const struct afs_call_type afs_RXCMxxxx = {
+	.name		= "CB.xxxx",
+	.deliver	= afs_deliver_cm_op_id,
+	.abort_to_error	= afs_abort_to_error,
+};
+
+static void afs_charge_preallocation(struct work_struct *);
+
+static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
+
+static int afs_wait_atomic_t(atomic_t *p)
+{
+	schedule();
+	return 0;
+}
+
+/*
+ * open an RxRPC socket and bind it to be a server for callback notifications
+ * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
+ */
+int afs_open_socket(void)
+{
+	struct sockaddr_rxrpc srx;
+	struct socket *socket;
+	unsigned int min_level;
+	int ret;
+
+	_enter("");
+
+	ret = -ENOMEM;
+	afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
+	if (!afs_async_calls)
+		goto error_0;
+
+	ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
+	if (ret < 0)
+		goto error_1;
+
+	socket->sk->sk_allocation = GFP_NOFS;
+
+	/* bind the callback manager's address to make this a server socket */
+	srx.srx_family			= AF_RXRPC;
+	srx.srx_service			= CM_SERVICE;
+	srx.transport_type		= SOCK_DGRAM;
+	srx.transport_len		= sizeof(srx.transport.sin);
+	srx.transport.sin.sin_family	= AF_INET;
+	srx.transport.sin.sin_port	= htons(AFS_CM_PORT);
+	memset(&srx.transport.sin.sin_addr, 0,
+	       sizeof(srx.transport.sin.sin_addr));
+
+	min_level = RXRPC_SECURITY_ENCRYPT;
+	ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
+				(void *)&min_level, sizeof(min_level));
+	if (ret < 0)
+		goto error_2;
+
+	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
+	if (ret < 0)
+		goto error_2;
+
+	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;
+
+error_2:
+	sock_release(socket);
+error_1:
+	destroy_workqueue(afs_async_calls);
+error_0:
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * close the RxRPC socket AFS was using
+ */
+void afs_close_socket(void)
+{
+	_enter("");
+
+	kernel_listen(afs_socket, 0);
+	flush_workqueue(afs_async_calls);
+
+	if (afs_spare_incoming_call) {
+		afs_put_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);
+	_debug("no outstanding calls");
+
+	kernel_sock_shutdown(afs_socket, SHUT_RDWR);
+	flush_workqueue(afs_async_calls);
+	sock_release(afs_socket);
+
+	_debug("dework");
+	destroy_workqueue(afs_async_calls);
+	_leave("");
+}
+
+/*
+ * Allocate a call.
+ */
+static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
+				       gfp_t gfp)
+{
+	struct afs_call *call;
+	int o;
+
+	call = kzalloc(sizeof(*call), gfp);
+	if (!call)
+		return NULL;
+
+	call->type = type;
+	atomic_set(&call->usage, 1);
+	INIT_WORK(&call->async_work, afs_process_async_call);
+	init_waitqueue_head(&call->waitq);
+
+	o = atomic_inc_return(&afs_outstanding_calls);
+	trace_afs_call(call, afs_call_trace_alloc, 1, o,
+		       __builtin_return_address(0));
+	return call;
+}
+
+/*
+ * Dispose of a reference on a call.
+ */
+void afs_put_call(struct afs_call *call)
+{
+	int n = atomic_dec_return(&call->usage);
+	int o = atomic_read(&afs_outstanding_calls);
+
+	trace_afs_call(call, afs_call_trace_put, n, o,
+		       __builtin_return_address(0));
+
+	ASSERTCMP(n, >=, 0);
+	if (n == 0) {
+		ASSERT(!work_pending(&call->async_work));
+		ASSERT(call->type->name != NULL);
+
+		if (call->rxcall) {
+			rxrpc_kernel_end_call(afs_socket, call->rxcall);
+			call->rxcall = NULL;
+		}
+		if (call->type->destructor)
+			call->type->destructor(call);
+
+		kfree(call->request);
+		kfree(call);
+
+		o = atomic_dec_return(&afs_outstanding_calls);
+		trace_afs_call(call, afs_call_trace_free, 0, o,
+			       __builtin_return_address(0));
+		if (o == 0)
+			wake_up_atomic_t(&afs_outstanding_calls);
+	}
+}
+
+/*
+ * Queue the call for actual work.  Returns 0 unconditionally for convenience.
+ */
+int afs_queue_call_work(struct afs_call *call)
+{
+	int u = atomic_inc_return(&call->usage);
+
+	trace_afs_call(call, afs_call_trace_work, u,
+		       atomic_read(&afs_outstanding_calls),
+		       __builtin_return_address(0));
+
+	INIT_WORK(&call->work, call->type->work);
+
+	if (!queue_work(afs_wq, &call->work))
+		afs_put_call(call);
+	return 0;
+}
+
+/*
+ * allocate a call with flat request and reply buffers
+ */
+struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
+				     size_t request_size, size_t reply_max)
+{
+	struct afs_call *call;
+
+	call = afs_alloc_call(type, GFP_NOFS);
+	if (!call)
+		goto nomem_call;
+
+	if (request_size) {
+		call->request_size = request_size;
+		call->request = kmalloc(request_size, GFP_NOFS);
+		if (!call->request)
+			goto nomem_free;
+	}
+
+	if (reply_max) {
+		call->reply_max = reply_max;
+		call->buffer = kmalloc(reply_max, GFP_NOFS);
+		if (!call->buffer)
+			goto nomem_free;
+	}
+
+	init_waitqueue_head(&call->waitq);
+	return call;
+
+nomem_free:
+	afs_put_call(call);
+nomem_call:
+	return NULL;
+}
+
+/*
+ * clean up a call with flat buffer
+ */
+void afs_flat_call_destructor(struct afs_call *call)
+{
+	_enter("");
+
+	kfree(call->request);
+	call->request = NULL;
+	kfree(call->buffer);
+	call->buffer = NULL;
+}
+
+#define AFS_BVEC_MAX 8
+
+/*
+ * Load the given bvec with the next few pages.
+ */
+static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
+			  struct bio_vec *bv, pgoff_t first, pgoff_t last,
+			  unsigned offset)
+{
+	struct page *pages[AFS_BVEC_MAX];
+	unsigned int nr, n, i, to, bytes = 0;
+
+	nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
+	n = find_get_pages_contig(call->mapping, first, nr, pages);
+	ASSERTCMP(n, ==, nr);
+
+	msg->msg_flags |= MSG_MORE;
+	for (i = 0; i < nr; i++) {
+		to = PAGE_SIZE;
+		if (first + i >= last) {
+			to = call->last_to;
+			msg->msg_flags &= ~MSG_MORE;
+		}
+		bv[i].bv_page = pages[i];
+		bv[i].bv_len = to - offset;
+		bv[i].bv_offset = offset;
+		bytes += to - offset;
+		offset = 0;
+	}
+
+	iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
+}
+
+/*
+ * Advance the AFS call state when the RxRPC call ends the transmit phase.
+ */
+static void afs_notify_end_request_tx(struct sock *sock,
+				      struct rxrpc_call *rxcall,
+				      unsigned long call_user_ID)
+{
+	struct afs_call *call = (struct afs_call *)call_user_ID;
+
+	if (call->state == AFS_CALL_REQUESTING)
+		call->state = AFS_CALL_AWAIT_REPLY;
+}
+
+/*
+ * attach the data from a bunch of pages on an inode to a call
+ */
+static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
+{
+	struct bio_vec bv[AFS_BVEC_MAX];
+	unsigned int bytes, nr, loop, offset;
+	pgoff_t first = call->first, last = call->last;
+	int ret;
+
+	offset = call->first_offset;
+	call->first_offset = 0;
+
+	do {
+		afs_load_bvec(call, msg, bv, first, last, offset);
+		offset = 0;
+		bytes = msg->msg_iter.count;
+		nr = msg->msg_iter.nr_segs;
+
+		ret = rxrpc_kernel_send_data(afs_socket, call->rxcall, msg,
+					     bytes, afs_notify_end_request_tx);
+		for (loop = 0; loop < nr; loop++)
+			put_page(bv[loop].bv_page);
+		if (ret < 0)
+			break;
+
+		first += nr;
+	} while (first <= last);
+
+	return ret;
+}
+
+/*
+ * initiate a call
+ */
+int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
+		  bool async)
+{
+	struct sockaddr_rxrpc srx;
+	struct rxrpc_call *rxcall;
+	struct msghdr msg;
+	struct kvec iov[1];
+	size_t offset;
+	s64 tx_total_len;
+	u32 abort_code;
+	int ret;
+
+	_enter("%x,{%d},", addr->s_addr, ntohs(call->port));
+
+	ASSERT(call->type != NULL);
+	ASSERT(call->type->name != NULL);
+
+	_debug("____MAKE %p{%s,%x} [%d]____",
+	       call, call->type->name, key_serial(call->key),
+	       atomic_read(&afs_outstanding_calls));
+
+	call->async = async;
+
+	memset(&srx, 0, sizeof(srx));
+	srx.srx_family = AF_RXRPC;
+	srx.srx_service = call->service_id;
+	srx.transport_type = SOCK_DGRAM;
+	srx.transport_len = sizeof(srx.transport.sin);
+	srx.transport.sin.sin_family = AF_INET;
+	srx.transport.sin.sin_port = call->port;
+	memcpy(&srx.transport.sin.sin_addr, addr, 4);
+
+	/* Work out the length we're going to transmit.  This is awkward for
+	 * calls such as FS.StoreData where there's an extra injection of data
+	 * after the initial fixed part.
+	 */
+	tx_total_len = call->request_size;
+	if (call->send_pages) {
+		if (call->last == call->first) {
+			tx_total_len += call->last_to - call->first_offset;
+		} else {
+			/* It looks mathematically like you should be able to
+			 * combine the following lines with the ones above, but
+			 * unsigned arithmetic is fun when it wraps...
+			 */
+			tx_total_len += PAGE_SIZE - call->first_offset;
+			tx_total_len += call->last_to;
+			tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
+		}
+	}
+
+	/* create a call */
+	rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
+					 (unsigned long)call,
+					 tx_total_len, gfp,
+					 (async ?
+					  afs_wake_up_async_call :
+					  afs_wake_up_call_waiter));
+	call->key = NULL;
+	if (IS_ERR(rxcall)) {
+		ret = PTR_ERR(rxcall);
+		goto error_kill_call;
+	}
+
+	call->rxcall = rxcall;
+
+	/* send the request */
+	iov[0].iov_base	= call->request;
+	iov[0].iov_len	= call->request_size;
+
+	msg.msg_name		= NULL;
+	msg.msg_namelen		= 0;
+	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
+		      call->request_size);
+	msg.msg_control		= NULL;
+	msg.msg_controllen	= 0;
+	msg.msg_flags		= (call->send_pages ? MSG_MORE : 0);
+
+	/* We have to change the state *before* sending the last packet as
+	 * rxrpc might give us the reply before it returns from sending the
+	 * request.  Further, if the send fails, we may already have been given
+	 * a notification and may have collected it.
+	 */
+	if (!call->send_pages)
+		call->state = AFS_CALL_AWAIT_REPLY;
+	ret = rxrpc_kernel_send_data(afs_socket, rxcall,
+				     &msg, call->request_size,
+				     afs_notify_end_request_tx);
+	if (ret < 0)
+		goto error_do_abort;
+
+	if (call->send_pages) {
+		ret = afs_send_pages(call, &msg);
+		if (ret < 0)
+			goto error_do_abort;
+	}
+
+	/* at this point, an async call may no longer exist as it may have
+	 * already completed */
+	if (call->async)
+		return -EINPROGRESS;
+
+	return afs_wait_for_call_to_complete(call);
+
+error_do_abort:
+	call->state = AFS_CALL_COMPLETE;
+	if (ret != -ECONNABORTED) {
+		rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT,
+					ret, "KSD");
+	} else {
+		abort_code = 0;
+		offset = 0;
+		rxrpc_kernel_recv_data(afs_socket, rxcall, NULL, 0, &offset,
+				       false, &abort_code);
+		ret = call->type->abort_to_error(abort_code);
+	}
+error_kill_call:
+	afs_put_call(call);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * deliver messages to a call
+ */
+static void afs_deliver_to_call(struct afs_call *call)
+{
+	u32 abort_code;
+	int ret;
+
+	_enter("%s", call->type->name);
+
+	while (call->state == AFS_CALL_AWAIT_REPLY ||
+	       call->state == AFS_CALL_AWAIT_OP_ID ||
+	       call->state == AFS_CALL_AWAIT_REQUEST ||
+	       call->state == AFS_CALL_AWAIT_ACK
+	       ) {
+		if (call->state == AFS_CALL_AWAIT_ACK) {
+			size_t offset = 0;
+			ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
+						     NULL, 0, &offset, false,
+						     &call->abort_code);
+			trace_afs_recv_data(call, 0, offset, false, ret);
+
+			if (ret == -EINPROGRESS || ret == -EAGAIN)
+				return;
+			if (ret == 1 || ret < 0) {
+				call->state = AFS_CALL_COMPLETE;
+				goto done;
+			}
+			return;
+		}
+
+		ret = call->type->deliver(call);
+		switch (ret) {
+		case 0:
+			if (call->state == AFS_CALL_AWAIT_REPLY)
+				call->state = AFS_CALL_COMPLETE;
+			goto done;
+		case -EINPROGRESS:
+		case -EAGAIN:
+			goto out;
+		case -ECONNABORTED:
+			goto call_complete;
+		case -ENOTCONN:
+			abort_code = RX_CALL_DEAD;
+			rxrpc_kernel_abort_call(afs_socket, call->rxcall,
+						abort_code, ret, "KNC");
+			goto save_error;
+		case -ENOTSUPP:
+			abort_code = RXGEN_OPCODE;
+			rxrpc_kernel_abort_call(afs_socket, call->rxcall,
+						abort_code, ret, "KIV");
+			goto save_error;
+		case -ENODATA:
+		case -EBADMSG:
+		case -EMSGSIZE:
+		default:
+			abort_code = RXGEN_CC_UNMARSHAL;
+			if (call->state != AFS_CALL_AWAIT_REPLY)
+				abort_code = RXGEN_SS_UNMARSHAL;
+			rxrpc_kernel_abort_call(afs_socket, call->rxcall,
+						abort_code, -EBADMSG, "KUM");
+			goto save_error;
+		}
+	}
+
+done:
+	if (call->state == AFS_CALL_COMPLETE && call->incoming)
+		afs_put_call(call);
+out:
+	_leave("");
+	return;
+
+save_error:
+	call->error = ret;
+call_complete:
+	call->state = AFS_CALL_COMPLETE;
+	goto done;
+}
+
+/*
+ * wait synchronously for a call to complete
+ */
+static int afs_wait_for_call_to_complete(struct afs_call *call)
+{
+	int ret;
+
+	DECLARE_WAITQUEUE(myself, current);
+
+	_enter("");
+
+	add_wait_queue(&call->waitq, &myself);
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		/* deliver any messages that are in the queue */
+		if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
+			call->need_attention = false;
+			__set_current_state(TASK_RUNNING);
+			afs_deliver_to_call(call);
+			continue;
+		}
+
+		if (call->state == AFS_CALL_COMPLETE ||
+		    signal_pending(current))
+			break;
+		schedule();
+	}
+
+	remove_wait_queue(&call->waitq, &myself);
+	__set_current_state(TASK_RUNNING);
+
+	/* Kill off the call if it's still live. */
+	if (call->state < AFS_CALL_COMPLETE) {
+		_debug("call interrupted");
+		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
+					RX_USER_ABORT, -EINTR, "KWI");
+	}
+
+	ret = call->error;
+	_debug("call complete");
+	afs_put_call(call);
+	_leave(" = %d", ret);
+	return ret;
+}
+
+/*
+ * wake up a waiting call
+ */
+static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
+				    unsigned long call_user_ID)
+{
+	struct afs_call *call = (struct afs_call *)call_user_ID;
+
+	call->need_attention = true;
+	wake_up(&call->waitq);
+}
+
+/*
+ * wake up an asynchronous call
+ */
+static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
+				   unsigned long call_user_ID)
+{
+	struct afs_call *call = (struct afs_call *)call_user_ID;
+	int u;
+
+	trace_afs_notify_call(rxcall, call);
+	call->need_attention = true;
+
+	u = __atomic_add_unless(&call->usage, 1, 0);
+	if (u != 0) {
+		trace_afs_call(call, afs_call_trace_wake, u + 1,
+			       atomic_read(&afs_outstanding_calls),
+			       __builtin_return_address(0));
+
+		if (!queue_work(afs_async_calls, &call->async_work))
+			afs_put_call(call);
+	}
+}
+
+/*
+ * Delete an asynchronous call.  The work item carries a ref to the call struct
+ * that we need to release.
+ */
+static void afs_delete_async_call(struct work_struct *work)
+{
+	struct afs_call *call = container_of(work, struct afs_call, async_work);
+
+	_enter("");
+
+	afs_put_call(call);
+
+	_leave("");
+}
+
+/*
+ * Perform I/O processing on an asynchronous call.  The work item carries a ref
+ * to the call struct that we either need to release or to pass on.
+ */
+static void afs_process_async_call(struct work_struct *work)
+{
+	struct afs_call *call = container_of(work, struct afs_call, async_work);
+
+	_enter("");
+
+	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
+		call->need_attention = false;
+		afs_deliver_to_call(call);
+	}
+
+	if (call->state == AFS_CALL_COMPLETE) {
+		call->reply = NULL;
+
+		/* We have two refs to release - one from the alloc and one
+		 * queued with the work item - and we can't just deallocate the
+		 * call because the work item may be queued again.
+		 */
+		call->async_work.func = afs_delete_async_call;
+		if (!queue_work(afs_async_calls, &call->async_work))
+			afs_put_call(call);
+	}
+
+	afs_put_call(call);
+	_leave("");
+}
+
+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 = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
+			if (!call)
+				break;
+
+			call->async = true;
+			call->state = AFS_CALL_AWAIT_OP_ID;
+			init_waitqueue_head(&call->waitq);
+		}
+
+		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;
+
+	call->rxcall = NULL;
+	afs_put_call(call);
+}
+
+/*
+ * Notification of an incoming call.
+ */
+static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
+			    unsigned long user_call_ID)
+{
+	queue_work(afs_wq, &afs_charge_preallocation_work);
+}
+
+/*
+ * Grab the operation ID from an incoming cache manager call.  The socket
+ * buffer is discarded on error or if we don't yet have sufficient data.
+ */
+static int afs_deliver_cm_op_id(struct afs_call *call)
+{
+	int ret;
+
+	_enter("{%zu}", call->offset);
+
+	ASSERTCMP(call->offset, <, 4);
+
+	/* the operation ID forms the first four bytes of the request data */
+	ret = afs_extract_data(call, &call->tmp, 4, true);
+	if (ret < 0)
+		return ret;
+
+	call->operation_ID = ntohl(call->tmp);
+	call->state = AFS_CALL_AWAIT_REQUEST;
+	call->offset = 0;
+
+	/* ask the cache manager to route the call (it'll change the call type
+	 * if successful) */
+	if (!afs_cm_incoming_call(call))
+		return -ENOTSUPP;
+
+	trace_afs_cb_call(call);
+
+	/* pass responsibility for the remainer of this message off to the
+	 * cache manager op */
+	return call->type->deliver(call);
+}
+
+/*
+ * Advance the AFS call state when an RxRPC service call ends the transmit
+ * phase.
+ */
+static void afs_notify_end_reply_tx(struct sock *sock,
+				    struct rxrpc_call *rxcall,
+				    unsigned long call_user_ID)
+{
+	struct afs_call *call = (struct afs_call *)call_user_ID;
+
+	if (call->state == AFS_CALL_REPLYING)
+		call->state = AFS_CALL_AWAIT_ACK;
+}
+
+/*
+ * send an empty reply
+ */
+void afs_send_empty_reply(struct afs_call *call)
+{
+	struct msghdr msg;
+
+	_enter("");
+
+	rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, 0);
+
+	msg.msg_name		= NULL;
+	msg.msg_namelen		= 0;
+	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
+	msg.msg_control		= NULL;
+	msg.msg_controllen	= 0;
+	msg.msg_flags		= 0;
+
+	call->state = AFS_CALL_AWAIT_ACK;
+	switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0,
+				       afs_notify_end_reply_tx)) {
+	case 0:
+		_leave(" [replied]");
+		return;
+
+	case -ENOMEM:
+		_debug("oom");
+		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
+					RX_USER_ABORT, -ENOMEM, "KOO");
+	default:
+		_leave(" [error]");
+		return;
+	}
+}
+
+/*
+ * send a simple reply
+ */
+void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
+{
+	struct msghdr msg;
+	struct kvec iov[1];
+	int n;
+
+	_enter("");
+
+	rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, len);
+
+	iov[0].iov_base		= (void *) buf;
+	iov[0].iov_len		= len;
+	msg.msg_name		= NULL;
+	msg.msg_namelen		= 0;
+	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
+	msg.msg_control		= NULL;
+	msg.msg_controllen	= 0;
+	msg.msg_flags		= 0;
+
+	call->state = AFS_CALL_AWAIT_ACK;
+	n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len,
+				   afs_notify_end_reply_tx);
+	if (n >= 0) {
+		/* Success */
+		_leave(" [replied]");
+		return;
+	}
+
+	if (n == -ENOMEM) {
+		_debug("oom");
+		rxrpc_kernel_abort_call(afs_socket, call->rxcall,
+					RX_USER_ABORT, -ENOMEM, "KOO");
+	}
+	_leave(" [error]");
+}
+
+/*
+ * Extract a piece of data from the received data socket buffers.
+ */
+int afs_extract_data(struct afs_call *call, void *buf, size_t count,
+		     bool want_more)
+{
+	int ret;
+
+	_enter("{%s,%zu},,%zu,%d",
+	       call->type->name, call->offset, count, want_more);
+
+	ASSERTCMP(call->offset, <=, count);
+
+	ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
+				     buf, count, &call->offset,
+				     want_more, &call->abort_code);
+	trace_afs_recv_data(call, count, call->offset, want_more, ret);
+	if (ret == 0 || ret == -EAGAIN)
+		return ret;
+
+	if (ret == 1) {
+		switch (call->state) {
+		case AFS_CALL_AWAIT_REPLY:
+			call->state = AFS_CALL_COMPLETE;
+			break;
+		case AFS_CALL_AWAIT_REQUEST:
+			call->state = AFS_CALL_REPLYING;
+			break;
+		default:
+			break;
+		}
+		return 0;
+	}
+
+	if (ret == -ECONNABORTED)
+		call->error = call->type->abort_to_error(call->abort_code);
+	else
+		call->error = ret;
+	call->state = AFS_CALL_COMPLETE;
+	return ret;
+}