fs/afs/rxrpc.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Maintain an RxRPC server socket to do AFS communications through
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #include <linux/slab.h>
   9 #include <linux/sched/signal.h>
  10
  11 #include <net/sock.h>
  12 #include <net/af_rxrpc.h>
  13 #include "internal.h"
  14 #include "afs_cm.h"
  15 #include "protocol_yfs.h"
  16 #define RXRPC_TRACE_ONLY_DEFINE_ENUMS
  17 #include <trace/events/rxrpc.h>
  18
  19 struct workqueue_struct *afs_async_calls;
  20
  21 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  22 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  23 static void afs_process_async_call(struct work_struct *);
  24 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  25 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  26 static int afs_deliver_cm_op_id(struct afs_call *);
  27
  28 /* asynchronous incoming call initial processing */
  29 static const struct afs_call_type afs_RXCMxxxx = {
  30         .name           = "CB.xxxx",
  31         .deliver        = afs_deliver_cm_op_id,
  32 };
  33
  34 /*
  35  * open an RxRPC socket and bind it to be a server for callback notifications
  36  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  37  */
  38 int afs_open_socket(struct afs_net *net)
  39 {
  40         struct sockaddr_rxrpc srx;
  41         struct socket *socket;
  42         int ret;
  43
  44         _enter("");
  45
  46         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
  47         if (ret < 0)
  48                 goto error_1;
  49
  50         socket->sk->sk_allocation = GFP_NOFS;
  51
  52         /* bind the callback manager's address to make this a server socket */
  53         memset(&srx, 0, sizeof(srx));
  54         srx.srx_family                  = AF_RXRPC;
  55         srx.srx_service                 = CM_SERVICE;
  56         srx.transport_type              = SOCK_DGRAM;
  57         srx.transport_len               = sizeof(srx.transport.sin6);
  58         srx.transport.sin6.sin6_family  = AF_INET6;
  59         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
  60
  61         ret = rxrpc_sock_set_min_security_level(socket->sk,
  62                                                 RXRPC_SECURITY_ENCRYPT);
  63         if (ret < 0)
  64                 goto error_2;
  65
  66         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  67         if (ret == -EADDRINUSE) {
  68                 srx.transport.sin6.sin6_port = 0;
  69                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  70         }
  71         if (ret < 0)
  72                 goto error_2;
  73
  74         srx.srx_service = YFS_CM_SERVICE;
  75         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  76         if (ret < 0)
  77                 goto error_2;
  78
  79         /* Ideally, we'd turn on service upgrade here, but we can't because
  80          * OpenAFS is buggy and leaks the userStatus field from packet to
  81          * packet and between FS packets and CB packets - so if we try to do an
  82          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
  83          * it sends back to us.
  84          */
  85
  86         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  87                                            afs_rx_discard_new_call);
  88
  89         ret = kernel_listen(socket, INT_MAX);
  90         if (ret < 0)
  91                 goto error_2;
  92
  93         net->socket = socket;
  94         afs_charge_preallocation(&net->charge_preallocation_work);
  95         _leave(" = 0");
  96         return 0;
  97
  98 error_2:
  99         sock_release(socket);
 100 error_1:
 101         _leave(" = %d", ret);
 102         return ret;
 103 }
 104
 105 /*
 106  * close the RxRPC socket AFS was using
 107  */
 108 void afs_close_socket(struct afs_net *net)
 109 {
 110         _enter("");
 111
 112         kernel_listen(net->socket, 0);
 113         flush_workqueue(afs_async_calls);
 114
 115         if (net->spare_incoming_call) {
 116                 afs_put_call(net->spare_incoming_call);
 117                 net->spare_incoming_call = NULL;
 118         }
 119
 120         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
 121         wait_var_event(&net->nr_outstanding_calls,
 122                        !atomic_read(&net->nr_outstanding_calls));
 123         _debug("no outstanding calls");
 124
 125         kernel_sock_shutdown(net->socket, SHUT_RDWR);
 126         flush_workqueue(afs_async_calls);
 127         sock_release(net->socket);
 128
 129         _debug("dework");
 130         _leave("");
 131 }
 132
 133 /*
 134  * Allocate a call.
 135  */
 136 static struct afs_call *afs_alloc_call(struct afs_net *net,
 137                                        const struct afs_call_type *type,
 138                                        gfp_t gfp)
 139 {
 140         struct afs_call *call;
 141         int o;
 142
 143         call = kzalloc(sizeof(*call), gfp);
 144         if (!call)
 145                 return NULL;
 146
 147         call->type = type;
 148         call->net = net;
 149         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 150         refcount_set(&call->ref, 1);
 151         INIT_WORK(&call->async_work, afs_process_async_call);
 152         init_waitqueue_head(&call->waitq);
 153         spin_lock_init(&call->state_lock);
 154         call->iter = &call->def_iter;
 155
 156         o = atomic_inc_return(&net->nr_outstanding_calls);
 157         trace_afs_call(call->debug_id, afs_call_trace_alloc, 1, o,
 158                        __builtin_return_address(0));
 159         return call;
 160 }
 161
 162 /*
 163  * Dispose of a reference on a call.
 164  */
 165 void afs_put_call(struct afs_call *call)
 166 {
 167         struct afs_net *net = call->net;
 168         unsigned int debug_id = call->debug_id;
 169         bool zero;
 170         int r, o;
 171
 172         zero = __refcount_dec_and_test(&call->ref, &r);
 173         o = atomic_read(&net->nr_outstanding_calls);
 174         trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
 175                        __builtin_return_address(0));
 176
 177         if (zero) {
 178                 ASSERT(!work_pending(&call->async_work));
 179                 ASSERT(call->type->name != NULL);
 180
 181                 if (call->rxcall) {
 182                         rxrpc_kernel_shutdown_call(net->socket, call->rxcall);
 183                         rxrpc_kernel_put_call(net->socket, call->rxcall);
 184                         call->rxcall = NULL;
 185                 }
 186                 if (call->type->destructor)
 187                         call->type->destructor(call);
 188
 189                 afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
 190                 afs_put_addrlist(call->alist);
 191                 kfree(call->request);
 192
 193                 trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,
 194                                __builtin_return_address(0));
 195                 kfree(call);
 196
 197                 o = atomic_dec_return(&net->nr_outstanding_calls);
 198                 if (o == 0)
 199                         wake_up_var(&net->nr_outstanding_calls);
 200         }
 201 }
 202
 203 static struct afs_call *afs_get_call(struct afs_call *call,
 204                                      enum afs_call_trace why)
 205 {
 206         int r;
 207
 208         __refcount_inc(&call->ref, &r);
 209
 210         trace_afs_call(call->debug_id, why, r + 1,
 211                        atomic_read(&call->net->nr_outstanding_calls),
 212                        __builtin_return_address(0));
 213         return call;
 214 }
 215
 216 /*
 217  * Queue the call for actual work.
 218  */
 219 static void afs_queue_call_work(struct afs_call *call)
 220 {
 221         if (call->type->work) {
 222                 INIT_WORK(&call->work, call->type->work);
 223
 224                 afs_get_call(call, afs_call_trace_work);
 225                 if (!queue_work(afs_wq, &call->work))
 226                         afs_put_call(call);
 227         }
 228 }
 229
 230 /*
 231  * allocate a call with flat request and reply buffers
 232  */
 233 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 234                                      const struct afs_call_type *type,
 235                                      size_t request_size, size_t reply_max)
 236 {
 237         struct afs_call *call;
 238
 239         call = afs_alloc_call(net, type, GFP_NOFS);
 240         if (!call)
 241                 goto nomem_call;
 242
 243         if (request_size) {
 244                 call->request_size = request_size;
 245                 call->request = kmalloc(request_size, GFP_NOFS);
 246                 if (!call->request)
 247                         goto nomem_free;
 248         }
 249
 250         if (reply_max) {
 251                 call->reply_max = reply_max;
 252                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 253                 if (!call->buffer)
 254                         goto nomem_free;
 255         }
 256
 257         afs_extract_to_buf(call, call->reply_max);
 258         call->operation_ID = type->op;
 259         init_waitqueue_head(&call->waitq);
 260         return call;
 261
 262 nomem_free:
 263         afs_put_call(call);
 264 nomem_call:
 265         return NULL;
 266 }
 267
 268 /*
 269  * clean up a call with flat buffer
 270  */
 271 void afs_flat_call_destructor(struct afs_call *call)
 272 {
 273         _enter("");
 274
 275         kfree(call->request);
 276         call->request = NULL;
 277         kfree(call->buffer);
 278         call->buffer = NULL;
 279 }
 280
 281 /*
 282  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 283  */
 284 static void afs_notify_end_request_tx(struct sock *sock,
 285                                       struct rxrpc_call *rxcall,
 286                                       unsigned long call_user_ID)
 287 {
 288         struct afs_call *call = (struct afs_call *)call_user_ID;
 289
 290         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 291 }
 292
 293 /*
 294  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 295  * error is stored into the call struct, which the caller must check for.
 296  */
 297 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 298 {
 299         struct afs_address *addr = &ac->alist->addrs[ac->index];
 300         struct rxrpc_peer *peer = addr->peer;
 301         struct rxrpc_call *rxcall;
 302         struct msghdr msg;
 303         struct kvec iov[1];
 304         size_t len;
 305         s64 tx_total_len;
 306         int ret;
 307
 308         _enter(",{%pISp},", rxrpc_kernel_remote_addr(addr->peer));
 309
 310         ASSERT(call->type != NULL);
 311         ASSERT(call->type->name != NULL);
 312
 313         _debug("____MAKE %p{%s,%x} [%d]____",
 314                call, call->type->name, key_serial(call->key),
 315                atomic_read(&call->net->nr_outstanding_calls));
 316
 317         call->addr_ix = ac->index;
 318         call->alist = afs_get_addrlist(ac->alist);
 319
 320         /* Work out the length we're going to transmit.  This is awkward for
 321          * calls such as FS.StoreData where there's an extra injection of data
 322          * after the initial fixed part.
 323          */
 324         tx_total_len = call->request_size;
 325         if (call->write_iter)
 326                 tx_total_len += iov_iter_count(call->write_iter);
 327
 328         /* If the call is going to be asynchronous, we need an extra ref for
 329          * the call to hold itself so the caller need not hang on to its ref.
 330          */
 331         if (call->async) {
 332                 afs_get_call(call, afs_call_trace_get);
 333                 call->drop_ref = true;
 334         }
 335
 336         /* create a call */
 337         rxcall = rxrpc_kernel_begin_call(call->net->socket, peer, call->key,
 338                                          (unsigned long)call,
 339                                          tx_total_len,
 340                                          call->max_lifespan,
 341                                          gfp,
 342                                          (call->async ?
 343                                           afs_wake_up_async_call :
 344                                           afs_wake_up_call_waiter),
 345                                          addr->service_id,
 346                                          call->upgrade,
 347                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 348                                           RXRPC_UNINTERRUPTIBLE),
 349                                          call->debug_id);
 350         if (IS_ERR(rxcall)) {
 351                 ret = PTR_ERR(rxcall);
 352                 call->error = ret;
 353                 goto error_kill_call;
 354         }
 355
 356         call->rxcall = rxcall;
 357         call->issue_time = ktime_get_real();
 358
 359         /* send the request */
 360         iov[0].iov_base = call->request;
 361         iov[0].iov_len  = call->request_size;
 362
 363         msg.msg_name            = NULL;
 364         msg.msg_namelen         = 0;
 365         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);
 366         msg.msg_control         = NULL;
 367         msg.msg_controllen      = 0;
 368         msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 369
 370         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 371                                      &msg, call->request_size,
 372                                      afs_notify_end_request_tx);
 373         if (ret < 0)
 374                 goto error_do_abort;
 375
 376         if (call->write_iter) {
 377                 msg.msg_iter = *call->write_iter;
 378                 msg.msg_flags &= ~MSG_MORE;
 379                 trace_afs_send_data(call, &msg);
 380
 381                 ret = rxrpc_kernel_send_data(call->net->socket,
 382                                              call->rxcall, &msg,
 383                                              iov_iter_count(&msg.msg_iter),
 384                                              afs_notify_end_request_tx);
 385                 *call->write_iter = msg.msg_iter;
 386
 387                 trace_afs_sent_data(call, &msg, ret);
 388                 if (ret < 0)
 389                         goto error_do_abort;
 390         }
 391
 392         /* Note that at this point, we may have received the reply or an abort
 393          * - and an asynchronous call may already have completed.
 394          *
 395          * afs_wait_for_call_to_complete(call, ac)
 396          * must be called to synchronously clean up.
 397          */
 398         return;
 399
 400 error_do_abort:
 401         if (ret != -ECONNABORTED) {
 402                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 403                                         RX_USER_ABORT, ret,
 404                                         afs_abort_send_data_error);
 405         } else {
 406                 len = 0;
 407                 iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);
 408                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 409                                        &msg.msg_iter, &len, false,
 410                                        &call->abort_code, &call->service_id);
 411                 call->responded = true;
 412         }
 413         call->error = ret;
 414         trace_afs_call_done(call);
 415 error_kill_call:
 416         if (call->type->done)
 417                 call->type->done(call);
 418
 419         /* We need to dispose of the extra ref we grabbed for an async call.
 420          * The call, however, might be queued on afs_async_calls and we need to
 421          * make sure we don't get any more notifications that might requeue it.
 422          */
 423         if (call->rxcall)
 424                 rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);
 425         if (call->async) {
 426                 if (cancel_work_sync(&call->async_work))
 427                         afs_put_call(call);
 428                 afs_set_call_complete(call, ret, 0);
 429         }
 430
 431         call->error = ret;
 432         call->state = AFS_CALL_COMPLETE;
 433         _leave(" = %d", ret);
 434 }
 435
 436 /*
 437  * Log remote abort codes that indicate that we have a protocol disagreement
 438  * with the server.
 439  */
 440 static void afs_log_error(struct afs_call *call, s32 remote_abort)
 441 {
 442         static int max = 0;
 443         const char *msg;
 444         int m;
 445
 446         switch (remote_abort) {
 447         case RX_EOF:             msg = "unexpected EOF";        break;
 448         case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 449         case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 450         case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 451         case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 452         case RXGEN_DECODE:       msg = "opcode decode";         break;
 453         case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 454         case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 455         case -32:                msg = "insufficient data";     break;
 456         default:
 457                 return;
 458         }
 459
 460         m = max;
 461         if (m < 3) {
 462                 max = m + 1;
 463                 pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 464                           msg, call->type->name,
 465                           rxrpc_kernel_remote_addr(call->alist->addrs[call->addr_ix].peer));
 466         }
 467 }
 468
 469 /*
 470  * deliver messages to a call
 471  */
 472 static void afs_deliver_to_call(struct afs_call *call)
 473 {
 474         enum afs_call_state state;
 475         size_t len;
 476         u32 abort_code, remote_abort = 0;
 477         int ret;
 478
 479         _enter("%s", call->type->name);
 480
 481         while (state = READ_ONCE(call->state),
 482                state == AFS_CALL_CL_AWAIT_REPLY ||
 483                state == AFS_CALL_SV_AWAIT_OP_ID ||
 484                state == AFS_CALL_SV_AWAIT_REQUEST ||
 485                state == AFS_CALL_SV_AWAIT_ACK
 486                ) {
 487                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 488                         len = 0;
 489                         iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);
 490                         ret = rxrpc_kernel_recv_data(call->net->socket,
 491                                                      call->rxcall, &call->def_iter,
 492                                                      &len, false, &remote_abort,
 493                                                      &call->service_id);
 494                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 495
 496                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 497                                 return;
 498                         if (ret < 0 || ret == 1) {
 499                                 if (ret == 1)
 500                                         ret = 0;
 501                                 goto call_complete;
 502                         }
 503                         return;
 504                 }
 505
 506                 ret = call->type->deliver(call);
 507                 state = READ_ONCE(call->state);
 508                 if (ret == 0 && call->unmarshalling_error)
 509                         ret = -EBADMSG;
 510                 switch (ret) {
 511                 case 0:
 512                         call->responded = true;
 513                         afs_queue_call_work(call);
 514                         if (state == AFS_CALL_CL_PROC_REPLY) {
 515                                 if (call->op)
 516                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 517                                                 &call->op->server->flags);
 518                                 goto call_complete;
 519                         }
 520                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 521                         goto done;
 522                 case -EINPROGRESS:
 523                 case -EAGAIN:
 524                         goto out;
 525                 case -ECONNABORTED:
 526                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 527                         call->responded = true;
 528                         afs_log_error(call, call->abort_code);
 529                         goto done;
 530                 case -ENOTSUPP:
 531                         call->responded = true;
 532                         abort_code = RXGEN_OPCODE;
 533                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 534                                                 abort_code, ret,
 535                                                 afs_abort_op_not_supported);
 536                         goto local_abort;
 537                 case -EIO:
 538                         pr_err("kAFS: Call %u in bad state %u\n",
 539                                call->debug_id, state);
 540                         fallthrough;
 541                 case -ENODATA:
 542                 case -EBADMSG:
 543                 case -EMSGSIZE:
 544                 case -ENOMEM:
 545                 case -EFAULT:
 546                         abort_code = RXGEN_CC_UNMARSHAL;
 547                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 548                                 abort_code = RXGEN_SS_UNMARSHAL;
 549                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 550                                                 abort_code, ret,
 551                                                 afs_abort_unmarshal_error);
 552                         goto local_abort;
 553                 default:
 554                         abort_code = RX_CALL_DEAD;
 555                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 556                                                 abort_code, ret,
 557                                                 afs_abort_general_error);
 558                         goto local_abort;
 559                 }
 560         }
 561
 562 done:
 563         if (call->type->done)
 564                 call->type->done(call);
 565 out:
 566         _leave("");
 567         return;
 568
 569 local_abort:
 570         abort_code = 0;
 571 call_complete:
 572         afs_set_call_complete(call, ret, remote_abort);
 573         state = AFS_CALL_COMPLETE;
 574         goto done;
 575 }
 576
 577 /*
 578  * Wait synchronously for a call to complete.
 579  */
 580 void afs_wait_for_call_to_complete(struct afs_call *call, struct afs_addr_cursor *ac)
 581 {
 582         bool rxrpc_complete = false;
 583
 584         _enter("");
 585
 586         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 587                 DECLARE_WAITQUEUE(myself, current);
 588
 589                 add_wait_queue(&call->waitq, &myself);
 590                 for (;;) {
 591                         set_current_state(TASK_UNINTERRUPTIBLE);
 592
 593                         /* deliver any messages that are in the queue */
 594                         if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 595                             call->need_attention) {
 596                                 call->need_attention = false;
 597                                 __set_current_state(TASK_RUNNING);
 598                                 afs_deliver_to_call(call);
 599                                 continue;
 600                         }
 601
 602                         if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 603                                 break;
 604
 605                         if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 606                                 /* rxrpc terminated the call. */
 607                                 rxrpc_complete = true;
 608                                 break;
 609                         }
 610
 611                         schedule();
 612                 }
 613
 614                 remove_wait_queue(&call->waitq, &myself);
 615                 __set_current_state(TASK_RUNNING);
 616         }
 617
 618         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 619                 if (rxrpc_complete) {
 620                         afs_set_call_complete(call, call->error, call->abort_code);
 621                 } else {
 622                         /* Kill off the call if it's still live. */
 623                         _debug("call interrupted");
 624                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 625                                                     RX_USER_ABORT, -EINTR,
 626                                                     afs_abort_interrupted))
 627                                 afs_set_call_complete(call, -EINTR, 0);
 628                 }
 629         }
 630
 631         if (call->error == 0 || call->error == -ECONNABORTED)
 632                 call->responded = true;
 633 }
 634
 635 /*
 636  * wake up a waiting call
 637  */
 638 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 639                                     unsigned long call_user_ID)
 640 {
 641         struct afs_call *call = (struct afs_call *)call_user_ID;
 642
 643         call->need_attention = true;
 644         wake_up(&call->waitq);
 645 }
 646
 647 /*
 648  * wake up an asynchronous call
 649  */
 650 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 651                                    unsigned long call_user_ID)
 652 {
 653         struct afs_call *call = (struct afs_call *)call_user_ID;
 654         int r;
 655
 656         trace_afs_notify_call(rxcall, call);
 657         call->need_attention = true;
 658
 659         if (__refcount_inc_not_zero(&call->ref, &r)) {
 660                 trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
 661                                atomic_read(&call->net->nr_outstanding_calls),
 662                                __builtin_return_address(0));
 663
 664                 if (!queue_work(afs_async_calls, &call->async_work))
 665                         afs_put_call(call);
 666         }
 667 }
 668
 669 /*
 670  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 671  * to the call struct that we either need to release or to pass on.
 672  */
 673 static void afs_process_async_call(struct work_struct *work)
 674 {
 675         struct afs_call *call = container_of(work, struct afs_call, async_work);
 676
 677         _enter("");
 678
 679         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 680                 call->need_attention = false;
 681                 afs_deliver_to_call(call);
 682         }
 683
 684         afs_put_call(call);
 685         _leave("");
 686 }
 687
 688 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 689 {
 690         struct afs_call *call = (struct afs_call *)user_call_ID;
 691
 692         call->rxcall = rxcall;
 693 }
 694
 695 /*
 696  * Charge the incoming call preallocation.
 697  */
 698 void afs_charge_preallocation(struct work_struct *work)
 699 {
 700         struct afs_net *net =
 701                 container_of(work, struct afs_net, charge_preallocation_work);
 702         struct afs_call *call = net->spare_incoming_call;
 703
 704         for (;;) {
 705                 if (!call) {
 706                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 707                         if (!call)
 708                                 break;
 709
 710                         call->drop_ref = true;
 711                         call->async = true;
 712                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 713                         init_waitqueue_head(&call->waitq);
 714                         afs_extract_to_tmp(call);
 715                 }
 716
 717                 if (rxrpc_kernel_charge_accept(net->socket,
 718                                                afs_wake_up_async_call,
 719                                                afs_rx_attach,
 720                                                (unsigned long)call,
 721                                                GFP_KERNEL,
 722                                                call->debug_id) < 0)
 723                         break;
 724                 call = NULL;
 725         }
 726         net->spare_incoming_call = call;
 727 }
 728
 729 /*
 730  * Discard a preallocated call when a socket is shut down.
 731  */
 732 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 733                                     unsigned long user_call_ID)
 734 {
 735         struct afs_call *call = (struct afs_call *)user_call_ID;
 736
 737         call->rxcall = NULL;
 738         afs_put_call(call);
 739 }
 740
 741 /*
 742  * Notification of an incoming call.
 743  */
 744 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 745                             unsigned long user_call_ID)
 746 {
 747         struct afs_net *net = afs_sock2net(sk);
 748
 749         queue_work(afs_wq, &net->charge_preallocation_work);
 750 }
 751
 752 /*
 753  * Grab the operation ID from an incoming cache manager call.  The socket
 754  * buffer is discarded on error or if we don't yet have sufficient data.
 755  */
 756 static int afs_deliver_cm_op_id(struct afs_call *call)
 757 {
 758         int ret;
 759
 760         _enter("{%zu}", iov_iter_count(call->iter));
 761
 762         /* the operation ID forms the first four bytes of the request data */
 763         ret = afs_extract_data(call, true);
 764         if (ret < 0)
 765                 return ret;
 766
 767         call->operation_ID = ntohl(call->tmp);
 768         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 769
 770         /* ask the cache manager to route the call (it'll change the call type
 771          * if successful) */
 772         if (!afs_cm_incoming_call(call))
 773                 return -ENOTSUPP;
 774
 775         trace_afs_cb_call(call);
 776
 777         /* pass responsibility for the remainer of this message off to the
 778          * cache manager op */
 779         return call->type->deliver(call);
 780 }
 781
 782 /*
 783  * Advance the AFS call state when an RxRPC service call ends the transmit
 784  * phase.
 785  */
 786 static void afs_notify_end_reply_tx(struct sock *sock,
 787                                     struct rxrpc_call *rxcall,
 788                                     unsigned long call_user_ID)
 789 {
 790         struct afs_call *call = (struct afs_call *)call_user_ID;
 791
 792         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 793 }
 794
 795 /*
 796  * send an empty reply
 797  */
 798 void afs_send_empty_reply(struct afs_call *call)
 799 {
 800         struct afs_net *net = call->net;
 801         struct msghdr msg;
 802
 803         _enter("");
 804
 805         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 806
 807         msg.msg_name            = NULL;
 808         msg.msg_namelen         = 0;
 809         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, NULL, 0, 0);
 810         msg.msg_control         = NULL;
 811         msg.msg_controllen      = 0;
 812         msg.msg_flags           = 0;
 813
 814         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 815                                        afs_notify_end_reply_tx)) {
 816         case 0:
 817                 _leave(" [replied]");
 818                 return;
 819
 820         case -ENOMEM:
 821                 _debug("oom");
 822                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 823                                         RXGEN_SS_MARSHAL, -ENOMEM,
 824                                         afs_abort_oom);
 825                 fallthrough;
 826         default:
 827                 _leave(" [error]");
 828                 return;
 829         }
 830 }
 831
 832 /*
 833  * send a simple reply
 834  */
 835 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 836 {
 837         struct afs_net *net = call->net;
 838         struct msghdr msg;
 839         struct kvec iov[1];
 840         int n;
 841
 842         _enter("");
 843
 844         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 845
 846         iov[0].iov_base         = (void *) buf;
 847         iov[0].iov_len          = len;
 848         msg.msg_name            = NULL;
 849         msg.msg_namelen         = 0;
 850         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);
 851         msg.msg_control         = NULL;
 852         msg.msg_controllen      = 0;
 853         msg.msg_flags           = 0;
 854
 855         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 856                                    afs_notify_end_reply_tx);
 857         if (n >= 0) {
 858                 /* Success */
 859                 _leave(" [replied]");
 860                 return;
 861         }
 862
 863         if (n == -ENOMEM) {
 864                 _debug("oom");
 865                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 866                                         RXGEN_SS_MARSHAL, -ENOMEM,
 867                                         afs_abort_oom);
 868         }
 869         _leave(" [error]");
 870 }
 871
 872 /*
 873  * Extract a piece of data from the received data socket buffers.
 874  */
 875 int afs_extract_data(struct afs_call *call, bool want_more)
 876 {
 877         struct afs_net *net = call->net;
 878         struct iov_iter *iter = call->iter;
 879         enum afs_call_state state;
 880         u32 remote_abort = 0;
 881         int ret;
 882
 883         _enter("{%s,%zu,%zu},%d",
 884                call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 885
 886         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 887                                      &call->iov_len, want_more, &remote_abort,
 888                                      &call->service_id);
 889         trace_afs_receive_data(call, call->iter, want_more, ret);
 890         if (ret == 0 || ret == -EAGAIN)
 891                 return ret;
 892
 893         state = READ_ONCE(call->state);
 894         if (ret == 1) {
 895                 switch (state) {
 896                 case AFS_CALL_CL_AWAIT_REPLY:
 897                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 898                         break;
 899                 case AFS_CALL_SV_AWAIT_REQUEST:
 900                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 901                         break;
 902                 case AFS_CALL_COMPLETE:
 903                         kdebug("prem complete %d", call->error);
 904                         return afs_io_error(call, afs_io_error_extract);
 905                 default:
 906                         break;
 907                 }
 908                 return 0;
 909         }
 910
 911         afs_set_call_complete(call, ret, remote_abort);
 912         return ret;
 913 }
 914
 915 /*
 916  * Log protocol error production.
 917  */
 918 noinline int afs_protocol_error(struct afs_call *call,
 919                                 enum afs_eproto_cause cause)
 920 {
 921         trace_afs_protocol_error(call, cause);
 922         if (call)
 923                 call->unmarshalling_error = true;
 924         return -EBADMSG;
 925 }