linux/fs/afs/rxrpc.c
David Howells 34fa47612b afs: Fix race in async call refcounting
There's a race between afs_make_call() and afs_wake_up_async_call() in the
case that an error is returned from rxrpc_kernel_send_data() after it has
queued the final packet.

afs_make_call() will try and clean up the mess, but the call state may have
been moved on thereby causing afs_process_async_call() to also try and to
delete the call.

Fix this by:

 (1) Getting an extra ref for an asynchronous call for the call itself to
     hold.  This makes sure the call doesn't evaporate on us accidentally
     and will allow the call to be retained by the caller in a future
     patch.  The ref is released on leaving afs_make_call() or
     afs_wait_for_call_to_complete().

 (2) In the event of an error from rxrpc_kernel_send_data():

     (a) Don't set the call state to AFS_CALL_COMPLETE until *after* the
     	 call has been aborted and ended.  This prevents
     	 afs_deliver_to_call() from doing anything with any notifications
     	 it gets.

     (b) Explicitly end the call immediately to prevent further callbacks.

     (c) Cancel any queued async_work and wait for the work if it's
     	 executing.  This allows us to be sure the race won't recur when we
     	 change the state.  We put the work queue's ref on the call if we
     	 managed to cancel it.

     (d) Put the call's ref that we got in (1).  This belongs to us as long
     	 as the call is in state AFS_CALL_CL_REQUESTING.

Fixes: 341f741f04 ("afs: Refcount the afs_call struct")
Signed-off-by: David Howells <dhowells@redhat.com>
2019-01-17 15:17:28 +00:00

1007 lines
24 KiB
C

/* 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"
#include "protocol_yfs.h"
struct workqueue_struct *afs_async_calls;
static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
static void afs_delete_async_call(struct work_struct *);
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,
};
/*
* 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(struct afs_net *net)
{
struct sockaddr_rxrpc srx;
struct socket *socket;
unsigned int min_level;
int ret;
_enter("");
ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &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 */
memset(&srx, 0, sizeof(srx));
srx.srx_family = AF_RXRPC;
srx.srx_service = CM_SERVICE;
srx.transport_type = SOCK_DGRAM;
srx.transport_len = sizeof(srx.transport.sin6);
srx.transport.sin6.sin6_family = AF_INET6;
srx.transport.sin6.sin6_port = htons(AFS_CM_PORT);
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 == -EADDRINUSE) {
srx.transport.sin6.sin6_port = 0;
ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
}
if (ret < 0)
goto error_2;
srx.srx_service = YFS_CM_SERVICE;
ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
if (ret < 0)
goto error_2;
/* Ideally, we'd turn on service upgrade here, but we can't because
* OpenAFS is buggy and leaks the userStatus field from packet to
* packet and between FS packets and CB packets - so if we try to do an
* upgrade on an FS packet, OpenAFS will leak that into the CB packet
* it sends back to us.
*/
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;
net->socket = socket;
afs_charge_preallocation(&net->charge_preallocation_work);
_leave(" = 0");
return 0;
error_2:
sock_release(socket);
error_1:
_leave(" = %d", ret);
return ret;
}
/*
* close the RxRPC socket AFS was using
*/
void afs_close_socket(struct afs_net *net)
{
_enter("");
kernel_listen(net->socket, 0);
flush_workqueue(afs_async_calls);
if (net->spare_incoming_call) {
afs_put_call(net->spare_incoming_call);
net->spare_incoming_call = NULL;
}
_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
wait_var_event(&net->nr_outstanding_calls,
!atomic_read(&net->nr_outstanding_calls));
_debug("no outstanding calls");
kernel_sock_shutdown(net->socket, SHUT_RDWR);
flush_workqueue(afs_async_calls);
sock_release(net->socket);
_debug("dework");
_leave("");
}
/*
* Allocate a call.
*/
static struct afs_call *afs_alloc_call(struct afs_net *net,
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;
call->net = net;
call->debug_id = atomic_inc_return(&rxrpc_debug_id);
atomic_set(&call->usage, 1);
INIT_WORK(&call->async_work, afs_process_async_call);
init_waitqueue_head(&call->waitq);
spin_lock_init(&call->state_lock);
call->_iter = &call->iter;
o = atomic_inc_return(&net->nr_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)
{
struct afs_net *net = call->net;
int n = atomic_dec_return(&call->usage);
int o = atomic_read(&net->nr_outstanding_calls);
trace_afs_call(call, afs_call_trace_put, n + 1, 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(net->socket, call->rxcall);
call->rxcall = NULL;
}
if (call->type->destructor)
call->type->destructor(call);
afs_put_server(call->net, call->cm_server);
afs_put_cb_interest(call->net, call->cbi);
afs_put_addrlist(call->alist);
kfree(call->request);
trace_afs_call(call, afs_call_trace_free, 0, o,
__builtin_return_address(0));
kfree(call);
o = atomic_dec_return(&net->nr_outstanding_calls);
if (o == 0)
wake_up_var(&net->nr_outstanding_calls);
}
}
static struct afs_call *afs_get_call(struct afs_call *call,
enum afs_call_trace why)
{
int u = atomic_inc_return(&call->usage);
trace_afs_call(call, why, u,
atomic_read(&call->net->nr_outstanding_calls),
__builtin_return_address(0));
return call;
}
/*
* Queue the call for actual work.
*/
static void afs_queue_call_work(struct afs_call *call)
{
if (call->type->work) {
INIT_WORK(&call->work, call->type->work);
afs_get_call(call, afs_call_trace_work);
if (!queue_work(afs_wq, &call->work))
afs_put_call(call);
}
}
/*
* allocate a call with flat request and reply buffers
*/
struct afs_call *afs_alloc_flat_call(struct afs_net *net,
const struct afs_call_type *type,
size_t request_size, size_t reply_max)
{
struct afs_call *call;
call = afs_alloc_call(net, 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;
}
afs_extract_to_buf(call, call->reply_max);
call->operation_ID = type->op;
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, 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;
afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_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);
trace_afs_send_pages(call, msg, first, last, offset);
offset = 0;
bytes = msg->msg_iter.count;
nr = msg->msg_iter.nr_segs;
ret = rxrpc_kernel_send_data(call->net->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);
trace_afs_sent_pages(call, call->first, last, first, ret);
return ret;
}
/*
* initiate a call
*/
long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
gfp_t gfp, bool async)
{
struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
struct rxrpc_call *rxcall;
struct msghdr msg;
struct kvec iov[1];
s64 tx_total_len;
int ret;
_enter(",{%pISp},", &srx->transport);
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(&call->net->nr_outstanding_calls));
call->async = async;
call->addr_ix = ac->index;
call->alist = afs_get_addrlist(ac->alist);
/* 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;
}
}
/* If the call is going to be asynchronous, we need an extra ref for
* the call to hold itself so the caller need not hang on to its ref.
*/
if (call->async)
afs_get_call(call, afs_call_trace_get);
/* create a call */
rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
(unsigned long)call,
tx_total_len, gfp,
(async ?
afs_wake_up_async_call :
afs_wake_up_call_waiter),
call->upgrade,
call->debug_id);
if (IS_ERR(rxcall)) {
ret = PTR_ERR(rxcall);
call->error = ret;
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, iov, 1, call->request_size);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
ret = rxrpc_kernel_send_data(call->net->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;
}
/* Note that at this point, we may have received the reply or an abort
* - and an asynchronous call may already have completed.
*/
if (call->async) {
afs_put_call(call);
return -EINPROGRESS;
}
return afs_wait_for_call_to_complete(call, ac);
error_do_abort:
if (ret != -ECONNABORTED) {
rxrpc_kernel_abort_call(call->net->socket, rxcall,
RX_USER_ABORT, ret, "KSD");
} else {
iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
rxrpc_kernel_recv_data(call->net->socket, rxcall,
&msg.msg_iter, false,
&call->abort_code, &call->service_id);
ac->abort_code = call->abort_code;
ac->responded = true;
}
call->error = ret;
trace_afs_call_done(call);
error_kill_call:
if (call->type->done)
call->type->done(call);
/* We need to dispose of the extra ref we grabbed for an async call.
* The call, however, might be queued on afs_async_calls and we need to
* make sure we don't get any more notifications that might requeue it.
*/
if (call->rxcall) {
rxrpc_kernel_end_call(call->net->socket, call->rxcall);
call->rxcall = NULL;
}
if (call->async) {
if (cancel_work_sync(&call->async_work))
afs_put_call(call);
afs_put_call(call);
}
ac->error = ret;
call->state = AFS_CALL_COMPLETE;
afs_put_call(call);
_leave(" = %d", ret);
return ret;
}
/*
* deliver messages to a call
*/
static void afs_deliver_to_call(struct afs_call *call)
{
enum afs_call_state state;
u32 abort_code, remote_abort = 0;
int ret;
_enter("%s", call->type->name);
while (state = READ_ONCE(call->state),
state == AFS_CALL_CL_AWAIT_REPLY ||
state == AFS_CALL_SV_AWAIT_OP_ID ||
state == AFS_CALL_SV_AWAIT_REQUEST ||
state == AFS_CALL_SV_AWAIT_ACK
) {
if (state == AFS_CALL_SV_AWAIT_ACK) {
iov_iter_kvec(&call->iter, READ, NULL, 0, 0);
ret = rxrpc_kernel_recv_data(call->net->socket,
call->rxcall, &call->iter,
false, &remote_abort,
&call->service_id);
trace_afs_receive_data(call, &call->iter, false, ret);
if (ret == -EINPROGRESS || ret == -EAGAIN)
return;
if (ret < 0 || ret == 1) {
if (ret == 1)
ret = 0;
goto call_complete;
}
return;
}
if (call->want_reply_time &&
rxrpc_kernel_get_reply_time(call->net->socket,
call->rxcall,
&call->reply_time))
call->want_reply_time = false;
ret = call->type->deliver(call);
state = READ_ONCE(call->state);
switch (ret) {
case 0:
afs_queue_call_work(call);
if (state == AFS_CALL_CL_PROC_REPLY) {
if (call->cbi)
set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
&call->cbi->server->flags);
goto call_complete;
}
ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
goto done;
case -EINPROGRESS:
case -EAGAIN:
goto out;
case -ECONNABORTED:
ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
goto done;
case -ENOTSUPP:
abort_code = RXGEN_OPCODE;
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
abort_code, ret, "KIV");
goto local_abort;
case -EIO:
pr_err("kAFS: Call %u in bad state %u\n",
call->debug_id, state);
/* Fall through */
case -ENODATA:
case -EBADMSG:
case -EMSGSIZE:
default:
abort_code = RXGEN_CC_UNMARSHAL;
if (state != AFS_CALL_CL_AWAIT_REPLY)
abort_code = RXGEN_SS_UNMARSHAL;
rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
abort_code, ret, "KUM");
goto local_abort;
}
}
done:
if (call->type->done)
call->type->done(call);
if (state == AFS_CALL_COMPLETE && call->incoming)
afs_put_call(call);
out:
_leave("");
return;
local_abort:
abort_code = 0;
call_complete:
afs_set_call_complete(call, ret, remote_abort);
state = AFS_CALL_COMPLETE;
goto done;
}
/*
* wait synchronously for a call to complete
*/
static long afs_wait_for_call_to_complete(struct afs_call *call,
struct afs_addr_cursor *ac)
{
signed long rtt2, timeout;
long ret;
bool stalled = false;
u64 rtt;
u32 life, last_life;
DECLARE_WAITQUEUE(myself, current);
_enter("");
rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
rtt2 = nsecs_to_jiffies64(rtt) * 2;
if (rtt2 < 2)
rtt2 = 2;
timeout = rtt2;
last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
add_wait_queue(&call->waitq, &myself);
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
/* deliver any messages that are in the queue */
if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
call->need_attention) {
call->need_attention = false;
__set_current_state(TASK_RUNNING);
afs_deliver_to_call(call);
continue;
}
if (afs_check_call_state(call, AFS_CALL_COMPLETE))
break;
life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
if (timeout == 0 &&
life == last_life && signal_pending(current)) {
if (stalled)
break;
__set_current_state(TASK_RUNNING);
rxrpc_kernel_probe_life(call->net->socket, call->rxcall);
timeout = rtt2;
stalled = true;
continue;
}
if (life != last_life) {
timeout = rtt2;
last_life = life;
stalled = false;
}
timeout = schedule_timeout(timeout);
}
remove_wait_queue(&call->waitq, &myself);
__set_current_state(TASK_RUNNING);
/* Kill off the call if it's still live. */
if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
_debug("call interrupted");
if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
RX_USER_ABORT, -EINTR, "KWI"))
afs_set_call_complete(call, -EINTR, 0);
}
spin_lock_bh(&call->state_lock);
ac->abort_code = call->abort_code;
ac->error = call->error;
spin_unlock_bh(&call->state_lock);
ret = ac->error;
switch (ret) {
case 0:
if (call->ret_reply0) {
ret = (long)call->reply[0];
call->reply[0] = NULL;
}
/* Fall through */
case -ECONNABORTED:
ac->responded = true;
break;
}
_debug("call complete");
afs_put_call(call);
_leave(" = %p", (void *)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_fetch_add_unless(&call->usage, 1, 0);
if (u != 0) {
trace_afs_call(call, afs_call_trace_wake, u,
atomic_read(&call->net->nr_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) {
/* 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.
*/
void afs_charge_preallocation(struct work_struct *work)
{
struct afs_net *net =
container_of(work, struct afs_net, charge_preallocation_work);
struct afs_call *call = net->spare_incoming_call;
for (;;) {
if (!call) {
call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
if (!call)
break;
call->async = true;
call->state = AFS_CALL_SV_AWAIT_OP_ID;
init_waitqueue_head(&call->waitq);
afs_extract_to_tmp(call);
}
if (rxrpc_kernel_charge_accept(net->socket,
afs_wake_up_async_call,
afs_rx_attach,
(unsigned long)call,
GFP_KERNEL,
call->debug_id) < 0)
break;
call = NULL;
}
net->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)
{
struct afs_net *net = afs_sock2net(sk);
queue_work(afs_wq, &net->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}", iov_iter_count(call->_iter));
/* the operation ID forms the first four bytes of the request data */
ret = afs_extract_data(call, true);
if (ret < 0)
return ret;
call->operation_ID = ntohl(call->tmp);
afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
/* 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;
afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
}
/*
* send an empty reply
*/
void afs_send_empty_reply(struct afs_call *call)
{
struct afs_net *net = call->net;
struct msghdr msg;
_enter("");
rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
msg.msg_name = NULL;
msg.msg_namelen = 0;
iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
afs_notify_end_reply_tx)) {
case 0:
_leave(" [replied]");
return;
case -ENOMEM:
_debug("oom");
rxrpc_kernel_abort_call(net->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 afs_net *net = call->net;
struct msghdr msg;
struct kvec iov[1];
int n;
_enter("");
rxrpc_kernel_set_tx_length(net->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, iov, 1, len);
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
n = rxrpc_kernel_send_data(net->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(net->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, bool want_more)
{
struct afs_net *net = call->net;
struct iov_iter *iter = call->_iter;
enum afs_call_state state;
u32 remote_abort = 0;
int ret;
_enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
want_more, &remote_abort,
&call->service_id);
if (ret == 0 || ret == -EAGAIN)
return ret;
state = READ_ONCE(call->state);
if (ret == 1) {
switch (state) {
case AFS_CALL_CL_AWAIT_REPLY:
afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
break;
case AFS_CALL_SV_AWAIT_REQUEST:
afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
break;
case AFS_CALL_COMPLETE:
kdebug("prem complete %d", call->error);
return afs_io_error(call, afs_io_error_extract);
default:
break;
}
return 0;
}
afs_set_call_complete(call, ret, remote_abort);
return ret;
}
/*
* Log protocol error production.
*/
noinline int afs_protocol_error(struct afs_call *call, int error,
enum afs_eproto_cause cause)
{
trace_afs_protocol_error(call, error, cause);
return error;
}