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 ([email protected])
   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 sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 300         struct rxrpc_call *rxcall;
 301         struct msghdr msg;
 302         struct kvec iov[1];
 303         size_t len;
 304         s64 tx_total_len;
 305         int ret;
 306
 307         _enter(",{%pISp},", &srx->transport);
 308
 309         ASSERT(call->type != NULL);
 310         ASSERT(call->type->name != NULL);
 311
 312         _debug("____MAKE %p{%s,%x} [%d]____",
 313                call, call->type->name, key_serial(call->key),
 314                atomic_read(&call->net->nr_outstanding_calls));
 315
 316         call->addr_ix = ac->index;
 317         call->alist = afs_get_addrlist(ac->alist);
 318
 319         /* Work out the length we're going to transmit.  This is awkward for
 320          * calls such as FS.StoreData where there's an extra injection of data
 321          * after the initial fixed part.
 322          */
 323         tx_total_len = call->request_size;
 324         if (call->write_iter)
 325                 tx_total_len += iov_iter_count(call->write_iter);
 326
 327         /* If the call is going to be asynchronous, we need an extra ref for
 328          * the call to hold itself so the caller need not hang on to its ref.
 329          */
 330         if (call->async) {
 331                 afs_get_call(call, afs_call_trace_get);
 332                 call->drop_ref = true;
 333         }
 334
 335         /* create a call */
 336         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 337                                          (unsigned long)call,
 338                                          tx_total_len,
 339                                          call->max_lifespan,
 340                                          gfp,
 341                                          (call->async ?
 342                                           afs_wake_up_async_call :
 343                                           afs_wake_up_call_waiter),
 344                                          call->upgrade,
 345                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 346                                           RXRPC_UNINTERRUPTIBLE),
 347                                          call->debug_id);
 348         if (IS_ERR(rxcall)) {
 349                 ret = PTR_ERR(rxcall);
 350                 call->error = ret;
 351                 goto error_kill_call;
 352         }
 353
 354         call->rxcall = rxcall;
 355         call->issue_time = ktime_get_real();
 356
 357         /* send the request */
 358         iov[0].iov_base = call->request;
 359         iov[0].iov_len  = call->request_size;
 360
 361         msg.msg_name            = NULL;
 362         msg.msg_namelen         = 0;
 363         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);
 364         msg.msg_control         = NULL;
 365         msg.msg_controllen      = 0;
 366         msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 367
 368         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 369                                      &msg, call->request_size,
 370                                      afs_notify_end_request_tx);
 371         if (ret < 0)
 372                 goto error_do_abort;
 373
 374         if (call->write_iter) {
 375                 msg.msg_iter = *call->write_iter;
 376                 msg.msg_flags &= ~MSG_MORE;
 377                 trace_afs_send_data(call, &msg);
 378
 379                 ret = rxrpc_kernel_send_data(call->net->socket,
 380                                              call->rxcall, &msg,
 381                                              iov_iter_count(&msg.msg_iter),
 382                                              afs_notify_end_request_tx);
 383                 *call->write_iter = msg.msg_iter;
 384
 385                 trace_afs_sent_data(call, &msg, ret);
 386                 if (ret < 0)
 387                         goto error_do_abort;
 388         }
 389
 390         /* Note that at this point, we may have received the reply or an abort
 391          * - and an asynchronous call may already have completed.
 392          *
 393          * afs_wait_for_call_to_complete(call, ac)
 394          * must be called to synchronously clean up.
 395          */
 396         return;
 397
 398 error_do_abort:
 399         if (ret != -ECONNABORTED) {
 400                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 401                                         RX_USER_ABORT, ret,
 402                                         afs_abort_send_data_error);
 403         } else {
 404                 len = 0;
 405                 iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);
 406                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 407                                        &msg.msg_iter, &len, false,
 408                                        &call->abort_code, &call->service_id);
 409                 ac->abort_code = call->abort_code;
 410                 ac->responded = true;
 411         }
 412         call->error = ret;
 413         trace_afs_call_done(call);
 414 error_kill_call:
 415         if (call->type->done)
 416                 call->type->done(call);
 417
 418         /* We need to dispose of the extra ref we grabbed for an async call.
 419          * The call, however, might be queued on afs_async_calls and we need to
 420          * make sure we don't get any more notifications that might requeue it.
 421          */
 422         if (call->rxcall)
 423                 rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);
 424         if (call->async) {
 425                 if (cancel_work_sync(&call->async_work))
 426                         afs_put_call(call);
 427                 afs_put_call(call);
 428         }
 429
 430         ac->error = ret;
 431         call->state = AFS_CALL_COMPLETE;
 432         _leave(" = %d", ret);
 433 }
 434
 435 /*
 436  * Log remote abort codes that indicate that we have a protocol disagreement
 437  * with the server.
 438  */
 439 static void afs_log_error(struct afs_call *call, s32 remote_abort)
 440 {
 441         static int max = 0;
 442         const char *msg;
 443         int m;
 444
 445         switch (remote_abort) {
 446         case RX_EOF:             msg = "unexpected EOF";        break;
 447         case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 448         case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 449         case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 450         case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 451         case RXGEN_DECODE:       msg = "opcode decode";         break;
 452         case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 453         case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 454         case -32:                msg = "insufficient data";     break;
 455         default:
 456                 return;
 457         }
 458
 459         m = max;
 460         if (m < 3) {
 461                 max = m + 1;
 462                 pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 463                           msg, call->type->name,
 464                           &call->alist->addrs[call->addr_ix].transport);
 465         }
 466 }
 467
 468 /*
 469  * deliver messages to a call
 470  */
 471 static void afs_deliver_to_call(struct afs_call *call)
 472 {
 473         enum afs_call_state state;
 474         size_t len;
 475         u32 abort_code, remote_abort = 0;
 476         int ret;
 477
 478         _enter("%s", call->type->name);
 479
 480         while (state = READ_ONCE(call->state),
 481                state == AFS_CALL_CL_AWAIT_REPLY ||
 482                state == AFS_CALL_SV_AWAIT_OP_ID ||
 483                state == AFS_CALL_SV_AWAIT_REQUEST ||
 484                state == AFS_CALL_SV_AWAIT_ACK
 485                ) {
 486                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 487                         len = 0;
 488                         iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);
 489                         ret = rxrpc_kernel_recv_data(call->net->socket,
 490                                                      call->rxcall, &call->def_iter,
 491                                                      &len, false, &remote_abort,
 492                                                      &call->service_id);
 493                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 494
 495                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 496                                 return;
 497                         if (ret < 0 || ret == 1) {
 498                                 if (ret == 1)
 499                                         ret = 0;
 500                                 goto call_complete;
 501                         }
 502                         return;
 503                 }
 504
 505                 ret = call->type->deliver(call);
 506                 state = READ_ONCE(call->state);
 507                 if (ret == 0 && call->unmarshalling_error)
 508                         ret = -EBADMSG;
 509                 switch (ret) {
 510                 case 0:
 511                         afs_queue_call_work(call);
 512                         if (state == AFS_CALL_CL_PROC_REPLY) {
 513                                 if (call->op)
 514                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 515                                                 &call->op->server->flags);
 516                                 goto call_complete;
 517                         }
 518                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 519                         goto done;
 520                 case -EINPROGRESS:
 521                 case -EAGAIN:
 522                         goto out;
 523                 case -ECONNABORTED:
 524                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 525                         afs_log_error(call, call->abort_code);
 526                         goto done;
 527                 case -ENOTSUPP:
 528                         abort_code = RXGEN_OPCODE;
 529                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 530                                                 abort_code, ret,
 531                                                 afs_abort_op_not_supported);
 532                         goto local_abort;
 533                 case -EIO:
 534                         pr_err("kAFS: Call %u in bad state %u\n",
 535                                call->debug_id, state);
 536                         fallthrough;
 537                 case -ENODATA:
 538                 case -EBADMSG:
 539                 case -EMSGSIZE:
 540                 case -ENOMEM:
 541                 case -EFAULT:
 542                         abort_code = RXGEN_CC_UNMARSHAL;
 543                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 544                                 abort_code = RXGEN_SS_UNMARSHAL;
 545                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 546                                                 abort_code, ret,
 547                                                 afs_abort_unmarshal_error);
 548                         goto local_abort;
 549                 default:
 550                         abort_code = RX_CALL_DEAD;
 551                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 552                                                 abort_code, ret,
 553                                                 afs_abort_general_error);
 554                         goto local_abort;
 555                 }
 556         }
 557
 558 done:
 559         if (call->type->done)
 560                 call->type->done(call);
 561 out:
 562         _leave("");
 563         return;
 564
 565 local_abort:
 566         abort_code = 0;
 567 call_complete:
 568         afs_set_call_complete(call, ret, remote_abort);
 569         state = AFS_CALL_COMPLETE;
 570         goto done;
 571 }
 572
 573 /*
 574  * Wait synchronously for a call to complete and clean up the call struct.
 575  */
 576 long afs_wait_for_call_to_complete(struct afs_call *call,
 577                                    struct afs_addr_cursor *ac)
 578 {
 579         long ret;
 580         bool rxrpc_complete = false;
 581
 582         DECLARE_WAITQUEUE(myself, current);
 583
 584         _enter("");
 585
 586         ret = call->error;
 587         if (ret < 0)
 588                 goto out;
 589
 590         add_wait_queue(&call->waitq, &myself);
 591         for (;;) {
 592                 set_current_state(TASK_UNINTERRUPTIBLE);
 593
 594                 /* deliver any messages that are in the queue */
 595                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 596                     call->need_attention) {
 597                         call->need_attention = false;
 598                         __set_current_state(TASK_RUNNING);
 599                         afs_deliver_to_call(call);
 600                         continue;
 601                 }
 602
 603                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 604                         break;
 605
 606                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 607                         /* rxrpc terminated the call. */
 608                         rxrpc_complete = true;
 609                         break;
 610                 }
 611
 612                 schedule();
 613         }
 614
 615         remove_wait_queue(&call->waitq, &myself);
 616         __set_current_state(TASK_RUNNING);
 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         spin_lock_bh(&call->state_lock);
 632         ac->abort_code = call->abort_code;
 633         ac->error = call->error;
 634         spin_unlock_bh(&call->state_lock);
 635
 636         ret = ac->error;
 637         switch (ret) {
 638         case 0:
 639                 ret = call->ret0;
 640                 call->ret0 = 0;
 641
 642                 fallthrough;
 643         case -ECONNABORTED:
 644                 ac->responded = true;
 645                 break;
 646         }
 647
 648 out:
 649         _debug("call complete");
 650         afs_put_call(call);
 651         _leave(" = %p", (void *)ret);
 652         return ret;
 653 }
 654
 655 /*
 656  * wake up a waiting call
 657  */
 658 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 659                                     unsigned long call_user_ID)
 660 {
 661         struct afs_call *call = (struct afs_call *)call_user_ID;
 662
 663         call->need_attention = true;
 664         wake_up(&call->waitq);
 665 }
 666
 667 /*
 668  * wake up an asynchronous call
 669  */
 670 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 671                                    unsigned long call_user_ID)
 672 {
 673         struct afs_call *call = (struct afs_call *)call_user_ID;
 674         int r;
 675
 676         trace_afs_notify_call(rxcall, call);
 677         call->need_attention = true;
 678
 679         if (__refcount_inc_not_zero(&call->ref, &r)) {
 680                 trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
 681                                atomic_read(&call->net->nr_outstanding_calls),
 682                                __builtin_return_address(0));
 683
 684                 if (!queue_work(afs_async_calls, &call->async_work))
 685                         afs_put_call(call);
 686         }
 687 }
 688
 689 /*
 690  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 691  * to the call struct that we either need to release or to pass on.
 692  */
 693 static void afs_process_async_call(struct work_struct *work)
 694 {
 695         struct afs_call *call = container_of(work, struct afs_call, async_work);
 696
 697         _enter("");
 698
 699         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 700                 call->need_attention = false;
 701                 afs_deliver_to_call(call);
 702         }
 703
 704         afs_put_call(call);
 705         _leave("");
 706 }
 707
 708 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 709 {
 710         struct afs_call *call = (struct afs_call *)user_call_ID;
 711
 712         call->rxcall = rxcall;
 713 }
 714
 715 /*
 716  * Charge the incoming call preallocation.
 717  */
 718 void afs_charge_preallocation(struct work_struct *work)
 719 {
 720         struct afs_net *net =
 721                 container_of(work, struct afs_net, charge_preallocation_work);
 722         struct afs_call *call = net->spare_incoming_call;
 723
 724         for (;;) {
 725                 if (!call) {
 726                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 727                         if (!call)
 728                                 break;
 729
 730                         call->drop_ref = true;
 731                         call->async = true;
 732                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 733                         init_waitqueue_head(&call->waitq);
 734                         afs_extract_to_tmp(call);
 735                 }
 736
 737                 if (rxrpc_kernel_charge_accept(net->socket,
 738                                                afs_wake_up_async_call,
 739                                                afs_rx_attach,
 740                                                (unsigned long)call,
 741                                                GFP_KERNEL,
 742                                                call->debug_id) < 0)
 743                         break;
 744                 call = NULL;
 745         }
 746         net->spare_incoming_call = call;
 747 }
 748
 749 /*
 750  * Discard a preallocated call when a socket is shut down.
 751  */
 752 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 753                                     unsigned long user_call_ID)
 754 {
 755         struct afs_call *call = (struct afs_call *)user_call_ID;
 756
 757         call->rxcall = NULL;
 758         afs_put_call(call);
 759 }
 760
 761 /*
 762  * Notification of an incoming call.
 763  */
 764 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 765                             unsigned long user_call_ID)
 766 {
 767         struct afs_net *net = afs_sock2net(sk);
 768
 769         queue_work(afs_wq, &net->charge_preallocation_work);
 770 }
 771
 772 /*
 773  * Grab the operation ID from an incoming cache manager call.  The socket
 774  * buffer is discarded on error or if we don't yet have sufficient data.
 775  */
 776 static int afs_deliver_cm_op_id(struct afs_call *call)
 777 {
 778         int ret;
 779
 780         _enter("{%zu}", iov_iter_count(call->iter));
 781
 782         /* the operation ID forms the first four bytes of the request data */
 783         ret = afs_extract_data(call, true);
 784         if (ret < 0)
 785                 return ret;
 786
 787         call->operation_ID = ntohl(call->tmp);
 788         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 789
 790         /* ask the cache manager to route the call (it'll change the call type
 791          * if successful) */
 792         if (!afs_cm_incoming_call(call))
 793                 return -ENOTSUPP;
 794
 795         trace_afs_cb_call(call);
 796
 797         /* pass responsibility for the remainer of this message off to the
 798          * cache manager op */
 799         return call->type->deliver(call);
 800 }
 801
 802 /*
 803  * Advance the AFS call state when an RxRPC service call ends the transmit
 804  * phase.
 805  */
 806 static void afs_notify_end_reply_tx(struct sock *sock,
 807                                     struct rxrpc_call *rxcall,
 808                                     unsigned long call_user_ID)
 809 {
 810         struct afs_call *call = (struct afs_call *)call_user_ID;
 811
 812         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 813 }
 814
 815 /*
 816  * send an empty reply
 817  */
 818 void afs_send_empty_reply(struct afs_call *call)
 819 {
 820         struct afs_net *net = call->net;
 821         struct msghdr msg;
 822
 823         _enter("");
 824
 825         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 826
 827         msg.msg_name            = NULL;
 828         msg.msg_namelen         = 0;
 829         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, NULL, 0, 0);
 830         msg.msg_control         = NULL;
 831         msg.msg_controllen      = 0;
 832         msg.msg_flags           = 0;
 833
 834         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 835                                        afs_notify_end_reply_tx)) {
 836         case 0:
 837                 _leave(" [replied]");
 838                 return;
 839
 840         case -ENOMEM:
 841                 _debug("oom");
 842                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 843                                         RXGEN_SS_MARSHAL, -ENOMEM,
 844                                         afs_abort_oom);
 845                 fallthrough;
 846         default:
 847                 _leave(" [error]");
 848                 return;
 849         }
 850 }
 851
 852 /*
 853  * send a simple reply
 854  */
 855 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 856 {
 857         struct afs_net *net = call->net;
 858         struct msghdr msg;
 859         struct kvec iov[1];
 860         int n;
 861
 862         _enter("");
 863
 864         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 865
 866         iov[0].iov_base         = (void *) buf;
 867         iov[0].iov_len          = len;
 868         msg.msg_name            = NULL;
 869         msg.msg_namelen         = 0;
 870         iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);
 871         msg.msg_control         = NULL;
 872         msg.msg_controllen      = 0;
 873         msg.msg_flags           = 0;
 874
 875         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 876                                    afs_notify_end_reply_tx);
 877         if (n >= 0) {
 878                 /* Success */
 879                 _leave(" [replied]");
 880                 return;
 881         }
 882
 883         if (n == -ENOMEM) {
 884                 _debug("oom");
 885                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 886                                         RXGEN_SS_MARSHAL, -ENOMEM,
 887                                         afs_abort_oom);
 888         }
 889         _leave(" [error]");
 890 }
 891
 892 /*
 893  * Extract a piece of data from the received data socket buffers.
 894  */
 895 int afs_extract_data(struct afs_call *call, bool want_more)
 896 {
 897         struct afs_net *net = call->net;
 898         struct iov_iter *iter = call->iter;
 899         enum afs_call_state state;
 900         u32 remote_abort = 0;
 901         int ret;
 902
 903         _enter("{%s,%zu,%zu},%d",
 904                call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 905
 906         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 907                                      &call->iov_len, want_more, &remote_abort,
 908                                      &call->service_id);
 909         trace_afs_receive_data(call, call->iter, want_more, ret);
 910         if (ret == 0 || ret == -EAGAIN)
 911                 return ret;
 912
 913         state = READ_ONCE(call->state);
 914         if (ret == 1) {
 915                 switch (state) {
 916                 case AFS_CALL_CL_AWAIT_REPLY:
 917                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 918                         break;
 919                 case AFS_CALL_SV_AWAIT_REQUEST:
 920                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 921                         break;
 922                 case AFS_CALL_COMPLETE:
 923                         kdebug("prem complete %d", call->error);
 924                         return afs_io_error(call, afs_io_error_extract);
 925                 default:
 926                         break;
 927                 }
 928                 return 0;
 929         }
 930
 931         afs_set_call_complete(call, ret, remote_abort);
 932         return ret;
 933 }
 934
 935 /*
 936  * Log protocol error production.
 937  */
 938 noinline int afs_protocol_error(struct afs_call *call,
 939                                 enum afs_eproto_cause cause)
 940 {
 941         trace_afs_protocol_error(call, cause);
 942         if (call)
 943                 call->unmarshalling_error = true;
 944         return -EBADMSG;
 945 }