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linux-stable/fs/afs/rxrpc.c
David Howells 248f219cb8 rxrpc: Rewrite the data and ack handling code 
Rewrite the data and ack handling code such that:

 (1) Parsing of received ACK and ABORT packets and the distribution and the
     filing of DATA packets happens entirely within the data_ready context
     called from the UDP socket.  This allows us to process and discard ACK
     and ABORT packets much more quickly (they're no longer stashed on a
     queue for a background thread to process).

 (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim().  We instead
     keep track of the offset and length of the content of each packet in
     the sk_buff metadata.  This means we don't do any allocation in the
     receive path.

 (3) Jumbo DATA packet parsing is now done in data_ready context.  Rather
     than cloning the packet once for each subpacket and pulling/trimming
     it, we file the packet multiple times with an annotation for each
     indicating which subpacket is there.  From that we can directly
     calculate the offset and length.

 (4) A call's receive queue can be accessed without taking locks (memory
     barriers do have to be used, though).

 (5) Incoming calls are set up from preallocated resources and immediately
     made live.  They can than have packets queued upon them and ACKs
     generated.  If insufficient resources exist, DATA packet #1 is given a
     BUSY reply and other DATA packets are discarded).

 (6) sk_buffs no longer take a ref on their parent call.

To make this work, the following changes are made:

 (1) Each call's receive buffer is now a circular buffer of sk_buff
     pointers (rxtx_buffer) rather than a number of sk_buff_heads spread
     between the call and the socket.  This permits each sk_buff to be in
     the buffer multiple times.  The receive buffer is reused for the
     transmit buffer.

 (2) A circular buffer of annotations (rxtx_annotations) is kept parallel
     to the data buffer.  Transmission phase annotations indicate whether a
     buffered packet has been ACK'd or not and whether it needs
     retransmission.

     Receive phase annotations indicate whether a slot holds a whole packet
     or a jumbo subpacket and, if the latter, which subpacket.  They also
     note whether the packet has been decrypted in place.

 (3) DATA packet window tracking is much simplified.  Each phase has just
     two numbers representing the window (rx_hard_ack/rx_top and
     tx_hard_ack/tx_top).

     The hard_ack number is the sequence number before base of the window,
     representing the last packet the other side says it has consumed.
     hard_ack starts from 0 and the first packet is sequence number 1.

     The top number is the sequence number of the highest-numbered packet
     residing in the buffer.  Packets between hard_ack+1 and top are
     soft-ACK'd to indicate they've been received, but not yet consumed.

     Four macros, before(), before_eq(), after() and after_eq() are added
     to compare sequence numbers within the window.  This allows for the
     top of the window to wrap when the hard-ack sequence number gets close
     to the limit.

     Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also
     to indicate when rx_top and tx_top point at the packets with the
     LAST_PACKET bit set, indicating the end of the phase.

 (4) Calls are queued on the socket 'receive queue' rather than packets.
     This means that we don't need have to invent dummy packets to queue to
     indicate abnormal/terminal states and we don't have to keep metadata
     packets (such as ABORTs) around

 (5) The offset and length of a (sub)packet's content are now passed to
     the verify_packet security op.  This is currently expected to decrypt
     the packet in place and validate it.

     However, there's now nowhere to store the revised offset and length of
     the actual data within the decrypted blob (there may be a header and
     padding to skip) because an sk_buff may represent multiple packets, so
     a locate_data security op is added to retrieve these details from the
     sk_buff content when needed.

 (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is
     individually secured and needs to be individually decrypted.  The code
     to do this is broken out into rxrpc_recvmsg_data() and shared with the
     kernel API.  It now iterates over the call's receive buffer rather
     than walking the socket receive queue.

Additional changes:

 (1) The timers are condensed to a single timer that is set for the soonest
     of three timeouts (delayed ACK generation, DATA retransmission and
     call lifespan).

 (2) Transmission of ACK and ABORT packets is effected immediately from
     process-context socket ops/kernel API calls that cause them instead of
     them being punted off to a background work item.  The data_ready
     handler still has to defer to the background, though.

 (3) A shutdown op is added to the AF_RXRPC socket so that the AFS
     filesystem can shut down the socket and flush its own work items
     before closing the socket to deal with any in-progress service calls.

Future additional changes that will need to be considered:

 (1) Make sure that a call doesn't hog the front of the queue by receiving
     data from the network as fast as userspace is consuming it to the
     exclusion of other calls.

 (2) Transmit delayed ACKs from within recvmsg() when we've consumed
     sufficiently more packets to avoid the background work item needing to
     run.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:12 +01:00

805 lines
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/* 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 <net/sock.h>
#include <net/af_rxrpc.h>
#include <rxrpc/packet.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;
static atomic_t afs_outstanding_calls;
static void afs_free_call(struct afs_call *);
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 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 *, 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 */
const struct afs_wait_mode afs_sync_call = {
.notify_rx = afs_wake_up_call_waiter,
.wait = afs_wait_for_call_to_complete,
};
/* asynchronous call management */
const struct afs_wait_mode afs_async_call = {
.notify_rx = afs_wake_up_async_call,
.wait = afs_dont_wait_for_call_to_complete,
};
/* asynchronous incoming call management */
static const struct afs_wait_mode afs_async_incoming_call = {
.notify_rx = afs_wake_up_async_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;
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));
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("");
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);
_debug("no outstanding calls");
flush_workqueue(afs_async_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("");
}
/*
* free a call
*/
static void afs_free_call(struct afs_call *call)
{
_debug("DONE %p{%s} [%d]",
call, call->type->name, atomic_read(&afs_outstanding_calls));
ASSERTCMP(call->rxcall, ==, NULL);
ASSERT(!work_pending(&call->async_work));
ASSERT(call->type->name != NULL);
kfree(call->request);
kfree(call);
if (atomic_dec_and_test(&afs_outstanding_calls))
wake_up_atomic_t(&afs_outstanding_calls);
}
/*
* End a call but do not free it
*/
static void afs_end_call_nofree(struct afs_call *call)
{
if (call->rxcall) {
rxrpc_kernel_end_call(afs_socket, call->rxcall);
call->rxcall = NULL;
}
if (call->type->destructor)
call->type->destructor(call);
}
/*
* End a call and free it
*/
static void afs_end_call(struct afs_call *call)
{
afs_end_call_nofree(call);
afs_free_call(call);
}
/*
* 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 = kzalloc(sizeof(*call), GFP_NOFS);
if (!call)
goto nomem_call;
_debug("CALL %p{%s} [%d]",
call, type->name, atomic_read(&afs_outstanding_calls));
atomic_inc(&afs_outstanding_calls);
call->type = type;
call->request_size = request_size;
call->reply_max = reply_max;
if (request_size) {
call->request = kmalloc(request_size, GFP_NOFS);
if (!call->request)
goto nomem_free;
}
if (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_free_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;
}
/*
* 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 kvec *iov)
{
struct page *pages[8];
unsigned count, n, loop, offset, to;
pgoff_t first = call->first, last = call->last;
int ret;
_enter("");
offset = call->first_offset;
call->first_offset = 0;
do {
_debug("attach %lx-%lx", first, last);
count = last - first + 1;
if (count > ARRAY_SIZE(pages))
count = ARRAY_SIZE(pages);
n = find_get_pages_contig(call->mapping, first, count, pages);
ASSERTCMP(n, ==, count);
loop = 0;
do {
msg->msg_flags = 0;
to = PAGE_SIZE;
if (first + loop >= last)
to = call->last_to;
else
msg->msg_flags = MSG_MORE;
iov->iov_base = kmap(pages[loop]) + offset;
iov->iov_len = to - offset;
offset = 0;
_debug("- range %u-%u%s",
offset, to, msg->msg_flags ? " [more]" : "");
iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
iov, 1, to - offset);
/* have to change the state *before* sending the last
* packet as RxRPC might give us the reply before it
* returns from sending the request */
if (first + loop >= last)
call->state = AFS_CALL_AWAIT_REPLY;
ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
msg, to - offset);
kunmap(pages[loop]);
if (ret < 0)
break;
} while (++loop < count);
first += count;
for (loop = 0; loop < count; loop++)
put_page(pages[loop]);
if (ret < 0)
break;
} while (first <= last);
_leave(" = %d", ret);
return ret;
}
/*
* initiate a call
*/
int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
const struct afs_wait_mode *wait_mode)
{
struct sockaddr_rxrpc srx;
struct rxrpc_call *rxcall;
struct msghdr msg;
struct kvec iov[1];
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->wait_mode = wait_mode;
INIT_WORK(&call->async_work, afs_process_async_call);
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);
/* create a call */
rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
(unsigned long) call, gfp,
wait_mode->notify_rx);
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);
/* have to change the state *before* sending the last packet as RxRPC
* might give us the reply before it returns from sending the
* request */
if (!call->send_pages)
call->state = AFS_CALL_AWAIT_REPLY;
ret = rxrpc_kernel_send_data(afs_socket, rxcall,
&msg, call->request_size);
if (ret < 0)
goto error_do_abort;
if (call->send_pages) {
ret = afs_send_pages(call, &msg, iov);
if (ret < 0)
goto error_do_abort;
}
/* at this point, an async call may no longer exist as it may have
* already completed */
return wait_mode->wait(call);
error_do_abort:
rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
error_kill_call:
afs_end_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);
if (ret == -EINPROGRESS || ret == -EAGAIN)
return;
if (ret == 1) {
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 -ENOTCONN:
abort_code = RX_CALL_DEAD;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code, -ret, "KNC");
goto do_abort;
case -ENOTSUPP:
abort_code = RX_INVALID_OPERATION;
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
abort_code, -ret, "KIV");
goto do_abort;
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 do_abort;
}
}
done:
if (call->state == AFS_CALL_COMPLETE && call->incoming)
afs_end_call(call);
out:
_leave("");
return;
do_abort:
call->error = ret;
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)
{
const char *abort_why;
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;
}
abort_why = "KWC";
ret = call->error;
if (call->state == AFS_CALL_COMPLETE)
break;
abort_why = "KWI";
ret = -EINTR;
if (signal_pending(current))
break;
schedule();
}
remove_wait_queue(&call->waitq, &myself);
__set_current_state(TASK_RUNNING);
/* kill the call */
if (call->state < AFS_CALL_COMPLETE) {
_debug("call incomplete");
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
RX_CALL_DEAD, -ret, abort_why);
}
_debug("call complete");
afs_end_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;
call->need_attention = true;
queue_work(afs_async_calls, &call->async_work);
}
/*
* put a call into asynchronous mode
* - mustn't touch the call descriptor as the call my have completed by the
* time we get here
*/
static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
{
_enter("");
return -EINPROGRESS;
}
/*
* delete an asynchronous call
*/
static void afs_delete_async_call(struct work_struct *work)
{
struct afs_call *call = container_of(work, struct afs_call, async_work);
_enter("");
afs_free_call(call);
_leave("");
}
/*
* perform processing on an asynchronous call
*/
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->wait_mode) {
if (call->wait_mode->async_complete)
call->wait_mode->async_complete(call->reply,
call->error);
call->reply = NULL;
/* kill the call */
afs_end_call_nofree(call);
/* we can't just delete the call because the work item may be
* queued */
call->async_work.func = afs_delete_async_call;
queue_work(afs_async_calls, &call->async_work);
}
_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 = 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, struct rxrpc_call *rxcall,
unsigned long user_call_ID)
{
atomic_inc(&afs_outstanding_calls);
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->operation_ID, 4, true);
if (ret < 0)
return ret;
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;
/* pass responsibility for the remainer of this message off to the
* cache manager op */
return call->type->deliver(call);
}
/*
* send an empty reply
*/
void afs_send_empty_reply(struct afs_call *call)
{
struct msghdr msg;
_enter("");
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)) {
case 0:
_leave(" [replied]");
return;
case -ENOMEM:
_debug("oom");
rxrpc_kernel_abort_call(afs_socket, call->rxcall,
RX_USER_ABORT, ENOMEM, "KOO");
default:
afs_end_call(call);
_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("");
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);
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");
}
afs_end_call(call);
_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);
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;
}
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