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
  17 struct workqueue_struct *afs_async_calls;
  18
  19 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  20 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  21 static void afs_process_async_call(struct work_struct *);
  22 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  23 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  24 static int afs_deliver_cm_op_id(struct afs_call *);
  25
  26 /* asynchronous incoming call initial processing */
  27 static const struct afs_call_type afs_RXCMxxxx = {
  28         .name           = "CB.xxxx",
  29         .deliver        = afs_deliver_cm_op_id,
  30 };
  31
  32 /*
  33  * open an RxRPC socket and bind it to be a server for callback notifications
  34  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  35  */
  36 int afs_open_socket(struct afs_net *net)
  37 {
  38         struct sockaddr_rxrpc srx;
  39         struct socket *socket;
  40         int ret;
  41
  42         _enter("");
  43
  44         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
  45         if (ret < 0)
  46                 goto error_1;
  47
  48         socket->sk->sk_allocation = GFP_NOFS;
  49
  50         /* bind the callback manager's address to make this a server socket */
  51         memset(&srx, 0, sizeof(srx));
  52         srx.srx_family                  = AF_RXRPC;
  53         srx.srx_service                 = CM_SERVICE;
  54         srx.transport_type              = SOCK_DGRAM;
  55         srx.transport_len               = sizeof(srx.transport.sin6);
  56         srx.transport.sin6.sin6_family  = AF_INET6;
  57         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
  58
  59         ret = rxrpc_sock_set_min_security_level(socket->sk,
  60                                                 RXRPC_SECURITY_ENCRYPT);
  61         if (ret < 0)
  62                 goto error_2;
  63
  64         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  65         if (ret == -EADDRINUSE) {
  66                 srx.transport.sin6.sin6_port = 0;
  67                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  68         }
  69         if (ret < 0)
  70                 goto error_2;
  71
  72         srx.srx_service = YFS_CM_SERVICE;
  73         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  74         if (ret < 0)
  75                 goto error_2;
  76
  77         /* Ideally, we'd turn on service upgrade here, but we can't because
  78          * OpenAFS is buggy and leaks the userStatus field from packet to
  79          * packet and between FS packets and CB packets - so if we try to do an
  80          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
  81          * it sends back to us.
  82          */
  83
  84         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  85                                            afs_rx_discard_new_call);
  86
  87         ret = kernel_listen(socket, INT_MAX);
  88         if (ret < 0)
  89                 goto error_2;
  90
  91         net->socket = socket;
  92         afs_charge_preallocation(&net->charge_preallocation_work);
  93         _leave(" = 0");
  94         return 0;
  95
  96 error_2:
  97         sock_release(socket);
  98 error_1:
  99         _leave(" = %d", ret);
 100         return ret;
 101 }
 102
 103 /*
 104  * close the RxRPC socket AFS was using
 105  */
 106 void afs_close_socket(struct afs_net *net)
 107 {
 108         _enter("");
 109
 110         kernel_listen(net->socket, 0);
 111         flush_workqueue(afs_async_calls);
 112
 113         if (net->spare_incoming_call) {
 114                 afs_put_call(net->spare_incoming_call);
 115                 net->spare_incoming_call = NULL;
 116         }
 117
 118         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
 119         wait_var_event(&net->nr_outstanding_calls,
 120                        !atomic_read(&net->nr_outstanding_calls));
 121         _debug("no outstanding calls");
 122
 123         kernel_sock_shutdown(net->socket, SHUT_RDWR);
 124         flush_workqueue(afs_async_calls);
 125         sock_release(net->socket);
 126
 127         _debug("dework");
 128         _leave("");
 129 }
 130
 131 /*
 132  * Allocate a call.
 133  */
 134 static struct afs_call *afs_alloc_call(struct afs_net *net,
 135                                        const struct afs_call_type *type,
 136                                        gfp_t gfp)
 137 {
 138         struct afs_call *call;
 139         int o;
 140
 141         call = kzalloc(sizeof(*call), gfp);
 142         if (!call)
 143                 return NULL;
 144
 145         call->type = type;
 146         call->net = net;
 147         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 148         refcount_set(&call->ref, 1);
 149         INIT_WORK(&call->async_work, afs_process_async_call);
 150         init_waitqueue_head(&call->waitq);
 151         spin_lock_init(&call->state_lock);
 152         call->iter = &call->def_iter;
 153
 154         o = atomic_inc_return(&net->nr_outstanding_calls);
 155         trace_afs_call(call->debug_id, afs_call_trace_alloc, 1, o,
 156                        __builtin_return_address(0));
 157         return call;
 158 }
 159
 160 /*
 161  * Dispose of a reference on a call.
 162  */
 163 void afs_put_call(struct afs_call *call)
 164 {
 165         struct afs_net *net = call->net;
 166         unsigned int debug_id = call->debug_id;
 167         bool zero;
 168         int r, o;
 169
 170         zero = __refcount_dec_and_test(&call->ref, &r);
 171         o = atomic_read(&net->nr_outstanding_calls);
 172         trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
 173                        __builtin_return_address(0));
 174
 175         if (zero) {
 176                 ASSERT(!work_pending(&call->async_work));
 177                 ASSERT(call->type->name != NULL);
 178
 179                 if (call->rxcall) {
 180                         rxrpc_kernel_end_call(net->socket, call->rxcall);
 181                         call->rxcall = NULL;
 182                 }
 183                 if (call->type->destructor)
 184                         call->type->destructor(call);
 185
 186                 afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
 187                 afs_put_addrlist(call->alist);
 188                 kfree(call->request);
 189
 190                 trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,
 191                                __builtin_return_address(0));
 192                 kfree(call);
 193
 194                 o = atomic_dec_return(&net->nr_outstanding_calls);
 195                 if (o == 0)
 196                         wake_up_var(&net->nr_outstanding_calls);
 197         }
 198 }
 199
 200 static struct afs_call *afs_get_call(struct afs_call *call,
 201                                      enum afs_call_trace why)
 202 {
 203         int r;
 204
 205         __refcount_inc(&call->ref, &r);
 206
 207         trace_afs_call(call->debug_id, why, r + 1,
 208                        atomic_read(&call->net->nr_outstanding_calls),
 209                        __builtin_return_address(0));
 210         return call;
 211 }
 212
 213 /*
 214  * Queue the call for actual work.
 215  */
 216 static void afs_queue_call_work(struct afs_call *call)
 217 {
 218         if (call->type->work) {
 219                 INIT_WORK(&call->work, call->type->work);
 220
 221                 afs_get_call(call, afs_call_trace_work);
 222                 if (!queue_work(afs_wq, &call->work))
 223                         afs_put_call(call);
 224         }
 225 }
 226
 227 /*
 228  * allocate a call with flat request and reply buffers
 229  */
 230 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 231                                      const struct afs_call_type *type,
 232                                      size_t request_size, size_t reply_max)
 233 {
 234         struct afs_call *call;
 235
 236         call = afs_alloc_call(net, type, GFP_NOFS);
 237         if (!call)
 238                 goto nomem_call;
 239
 240         if (request_size) {
 241                 call->request_size = request_size;
 242                 call->request = kmalloc(request_size, GFP_NOFS);
 243                 if (!call->request)
 244                         goto nomem_free;
 245         }
 246
 247         if (reply_max) {
 248                 call->reply_max = reply_max;
 249                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 250                 if (!call->buffer)
 251                         goto nomem_free;
 252         }
 253
 254         afs_extract_to_buf(call, call->reply_max);
 255         call->operation_ID = type->op;
 256         init_waitqueue_head(&call->waitq);
 257         return call;
 258
 259 nomem_free:
 260         afs_put_call(call);
 261 nomem_call:
 262         return NULL;
 263 }
 264
 265 /*
 266  * clean up a call with flat buffer
 267  */
 268 void afs_flat_call_destructor(struct afs_call *call)
 269 {
 270         _enter("");
 271
 272         kfree(call->request);
 273         call->request = NULL;
 274         kfree(call->buffer);
 275         call->buffer = NULL;
 276 }
 277
 278 /*
 279  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 280  */
 281 static void afs_notify_end_request_tx(struct sock *sock,
 282                                       struct rxrpc_call *rxcall,
 283                                       unsigned long call_user_ID)
 284 {
 285         struct afs_call *call = (struct afs_call *)call_user_ID;
 286
 287         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 288 }
 289
 290 /*
 291  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 292  * error is stored into the call struct, which the caller must check for.
 293  */
 294 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 295 {
 296         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 297         struct rxrpc_call *rxcall;
 298         struct msghdr msg;
 299         struct kvec iov[1];
 300         size_t len;
 301         s64 tx_total_len;
 302         int ret;
 303
 304         _enter(",{%pISp},", &srx->transport);
 305
 306         ASSERT(call->type != NULL);
 307         ASSERT(call->type->name != NULL);
 308
 309         _debug("____MAKE %p{%s,%x} [%d]____",
 310                call, call->type->name, key_serial(call->key),
 311                atomic_read(&call->net->nr_outstanding_calls));
 312
 313         call->addr_ix = ac->index;
 314         call->alist = afs_get_addrlist(ac->alist);
 315
 316         /* Work out the length we're going to transmit.  This is awkward for
 317          * calls such as FS.StoreData where there's an extra injection of data
 318          * after the initial fixed part.
 319          */
 320         tx_total_len = call->request_size;
 321         if (call->write_iter)
 322                 tx_total_len += iov_iter_count(call->write_iter);
 323
 324         /* If the call is going to be asynchronous, we need an extra ref for
 325          * the call to hold itself so the caller need not hang on to its ref.
 326          */
 327         if (call->async) {
 328                 afs_get_call(call, afs_call_trace_get);
 329                 call->drop_ref = true;
 330         }
 331
 332         /* create a call */
 333         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 334                                          (unsigned long)call,
 335                                          tx_total_len, gfp,
 336                                          (call->async ?
 337                                           afs_wake_up_async_call :
 338                                           afs_wake_up_call_waiter),
 339                                          call->upgrade,
 340                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 341                                           RXRPC_UNINTERRUPTIBLE),
 342                                          call->debug_id);
 343         if (IS_ERR(rxcall)) {
 344                 ret = PTR_ERR(rxcall);
 345                 call->error = ret;
 346                 goto error_kill_call;
 347         }
 348
 349         call->rxcall = rxcall;
 350
 351         if (call->max_lifespan)
 352                 rxrpc_kernel_set_max_life(call->net->socket, rxcall,
 353                                           call->max_lifespan);
 354
 355         /* send the request */
 356         iov[0].iov_base = call->request;
 357         iov[0].iov_len  = call->request_size;
 358
 359         msg.msg_name            = NULL;
 360         msg.msg_namelen         = 0;
 361         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 362         msg.msg_control         = NULL;
 363         msg.msg_controllen      = 0;
 364         msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 365
 366         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 367                                      &msg, call->request_size,
 368                                      afs_notify_end_request_tx);
 369         if (ret < 0)
 370                 goto error_do_abort;
 371
 372         if (call->write_iter) {
 373                 msg.msg_iter = *call->write_iter;
 374                 msg.msg_flags &= ~MSG_MORE;
 375                 trace_afs_send_data(call, &msg);
 376
 377                 ret = rxrpc_kernel_send_data(call->net->socket,
 378                                              call->rxcall, &msg,
 379                                              iov_iter_count(&msg.msg_iter),
 380                                              afs_notify_end_request_tx);
 381                 *call->write_iter = msg.msg_iter;
 382
 383                 trace_afs_sent_data(call, &msg, ret);
 384                 if (ret < 0)
 385                         goto error_do_abort;
 386         }
 387
 388         /* Note that at this point, we may have received the reply or an abort
 389          * - and an asynchronous call may already have completed.
 390          *
 391          * afs_wait_for_call_to_complete(call, ac)
 392          * must be called to synchronously clean up.
 393          */
 394         return;
 395
 396 error_do_abort:
 397         if (ret != -ECONNABORTED) {
 398                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 399                                         RX_USER_ABORT, ret, "KSD");
 400         } else {
 401                 len = 0;
 402                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 403                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 404                                        &msg.msg_iter, &len, false,
 405                                        &call->abort_code, &call->service_id);
 406                 ac->abort_code = call->abort_code;
 407                 ac->responded = true;
 408         }
 409         call->error = ret;
 410         trace_afs_call_done(call);
 411 error_kill_call:
 412         if (call->type->done)
 413                 call->type->done(call);
 414
 415         /* We need to dispose of the extra ref we grabbed for an async call.
 416          * The call, however, might be queued on afs_async_calls and we need to
 417          * make sure we don't get any more notifications that might requeue it.
 418          */
 419         if (call->rxcall) {
 420                 rxrpc_kernel_end_call(call->net->socket, call->rxcall);
 421                 call->rxcall = NULL;
 422         }
 423         if (call->async) {
 424                 if (cancel_work_sync(&call->async_work))
 425                         afs_put_call(call);
 426                 afs_put_call(call);
 427         }
 428
 429         ac->error = ret;
 430         call->state = AFS_CALL_COMPLETE;
 431         _leave(" = %d", ret);
 432 }
 433
 434 /*
 435  * Log remote abort codes that indicate that we have a protocol disagreement
 436  * with the server.
 437  */
 438 static void afs_log_error(struct afs_call *call, s32 remote_abort)
 439 {
 440         static int max = 0;
 441         const char *msg;
 442         int m;
 443
 444         switch (remote_abort) {
 445         case RX_EOF:             msg = "unexpected EOF";        break;
 446         case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 447         case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 448         case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 449         case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 450         case RXGEN_DECODE:       msg = "opcode decode";         break;
 451         case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 452         case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 453         case -32:                msg = "insufficient data";     break;
 454         default:
 455                 return;
 456         }
 457
 458         m = max;
 459         if (m < 3) {
 460                 max = m + 1;
 461                 pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 462                           msg, call->type->name,
 463                           &call->alist->addrs[call->addr_ix].transport);
 464         }
 465 }
 466
 467 /*
 468  * deliver messages to a call
 469  */
 470 static void afs_deliver_to_call(struct afs_call *call)
 471 {
 472         enum afs_call_state state;
 473         size_t len;
 474         u32 abort_code, remote_abort = 0;
 475         int ret;
 476
 477         _enter("%s", call->type->name);
 478
 479         while (state = READ_ONCE(call->state),
 480                state == AFS_CALL_CL_AWAIT_REPLY ||
 481                state == AFS_CALL_SV_AWAIT_OP_ID ||
 482                state == AFS_CALL_SV_AWAIT_REQUEST ||
 483                state == AFS_CALL_SV_AWAIT_ACK
 484                ) {
 485                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 486                         len = 0;
 487                         iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
 488                         ret = rxrpc_kernel_recv_data(call->net->socket,
 489                                                      call->rxcall, &call->def_iter,
 490                                                      &len, false, &remote_abort,
 491                                                      &call->service_id);
 492                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 493
 494                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 495                                 return;
 496                         if (ret < 0 || ret == 1) {
 497                                 if (ret == 1)
 498                                         ret = 0;
 499                                 goto call_complete;
 500                         }
 501                         return;
 502                 }
 503
 504                 if (!call->have_reply_time &&
 505                     rxrpc_kernel_get_reply_time(call->net->socket,
 506                                                 call->rxcall,
 507                                                 &call->reply_time))
 508                         call->have_reply_time = true;
 509
 510                 ret = call->type->deliver(call);
 511                 state = READ_ONCE(call->state);
 512                 if (ret == 0 && call->unmarshalling_error)
 513                         ret = -EBADMSG;
 514                 switch (ret) {
 515                 case 0:
 516                         afs_queue_call_work(call);
 517                         if (state == AFS_CALL_CL_PROC_REPLY) {
 518                                 if (call->op)
 519                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 520                                                 &call->op->server->flags);
 521                                 goto call_complete;
 522                         }
 523                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 524                         goto done;
 525                 case -EINPROGRESS:
 526                 case -EAGAIN:
 527                         goto out;
 528                 case -ECONNABORTED:
 529                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 530                         afs_log_error(call, call->abort_code);
 531                         goto done;
 532                 case -ENOTSUPP:
 533                         abort_code = RXGEN_OPCODE;
 534                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 535                                                 abort_code, ret, "KIV");
 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, "KUM");
 551                         goto local_abort;
 552                 default:
 553                         abort_code = RX_CALL_DEAD;
 554                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 555                                                 abort_code, ret, "KER");
 556                         goto local_abort;
 557                 }
 558         }
 559
 560 done:
 561         if (call->type->done)
 562                 call->type->done(call);
 563 out:
 564         _leave("");
 565         return;
 566
 567 local_abort:
 568         abort_code = 0;
 569 call_complete:
 570         afs_set_call_complete(call, ret, remote_abort);
 571         state = AFS_CALL_COMPLETE;
 572         goto done;
 573 }
 574
 575 /*
 576  * Wait synchronously for a call to complete and clean up the call struct.
 577  */
 578 long afs_wait_for_call_to_complete(struct afs_call *call,
 579                                    struct afs_addr_cursor *ac)
 580 {
 581         long ret;
 582         bool rxrpc_complete = false;
 583
 584         DECLARE_WAITQUEUE(myself, current);
 585
 586         _enter("");
 587
 588         ret = call->error;
 589         if (ret < 0)
 590                 goto out;
 591
 592         add_wait_queue(&call->waitq, &myself);
 593         for (;;) {
 594                 set_current_state(TASK_UNINTERRUPTIBLE);
 595
 596                 /* deliver any messages that are in the queue */
 597                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 598                     call->need_attention) {
 599                         call->need_attention = false;
 600                         __set_current_state(TASK_RUNNING);
 601                         afs_deliver_to_call(call);
 602                         continue;
 603                 }
 604
 605                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 606                         break;
 607
 608                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 609                         /* rxrpc terminated the call. */
 610                         rxrpc_complete = true;
 611                         break;
 612                 }
 613
 614                 schedule();
 615         }
 616
 617         remove_wait_queue(&call->waitq, &myself);
 618         __set_current_state(TASK_RUNNING);
 619
 620         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 621                 if (rxrpc_complete) {
 622                         afs_set_call_complete(call, call->error, call->abort_code);
 623                 } else {
 624                         /* Kill off the call if it's still live. */
 625                         _debug("call interrupted");
 626                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 627                                                     RX_USER_ABORT, -EINTR, "KWI"))
 628                                 afs_set_call_complete(call, -EINTR, 0);
 629                 }
 630         }
 631
 632         spin_lock_bh(&call->state_lock);
 633         ac->abort_code = call->abort_code;
 634         ac->error = call->error;
 635         spin_unlock_bh(&call->state_lock);
 636
 637         ret = ac->error;
 638         switch (ret) {
 639         case 0:
 640                 ret = call->ret0;
 641                 call->ret0 = 0;
 642
 643                 fallthrough;
 644         case -ECONNABORTED:
 645                 ac->responded = true;
 646                 break;
 647         }
 648
 649 out:
 650         _debug("call complete");
 651         afs_put_call(call);
 652         _leave(" = %p", (void *)ret);
 653         return ret;
 654 }
 655
 656 /*
 657  * wake up a waiting call
 658  */
 659 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 660                                     unsigned long call_user_ID)
 661 {
 662         struct afs_call *call = (struct afs_call *)call_user_ID;
 663
 664         call->need_attention = true;
 665         wake_up(&call->waitq);
 666 }
 667
 668 /*
 669  * wake up an asynchronous call
 670  */
 671 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 672                                    unsigned long call_user_ID)
 673 {
 674         struct afs_call *call = (struct afs_call *)call_user_ID;
 675         int r;
 676
 677         trace_afs_notify_call(rxcall, call);
 678         call->need_attention = true;
 679
 680         if (__refcount_inc_not_zero(&call->ref, &r)) {
 681                 trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
 682                                atomic_read(&call->net->nr_outstanding_calls),
 683                                __builtin_return_address(0));
 684
 685                 if (!queue_work(afs_async_calls, &call->async_work))
 686                         afs_put_call(call);
 687         }
 688 }
 689
 690 /*
 691  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 692  * to the call struct that we either need to release or to pass on.
 693  */
 694 static void afs_process_async_call(struct work_struct *work)
 695 {
 696         struct afs_call *call = container_of(work, struct afs_call, async_work);
 697
 698         _enter("");
 699
 700         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 701                 call->need_attention = false;
 702                 afs_deliver_to_call(call);
 703         }
 704
 705         afs_put_call(call);
 706         _leave("");
 707 }
 708
 709 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 710 {
 711         struct afs_call *call = (struct afs_call *)user_call_ID;
 712
 713         call->rxcall = rxcall;
 714 }
 715
 716 /*
 717  * Charge the incoming call preallocation.
 718  */
 719 void afs_charge_preallocation(struct work_struct *work)
 720 {
 721         struct afs_net *net =
 722                 container_of(work, struct afs_net, charge_preallocation_work);
 723         struct afs_call *call = net->spare_incoming_call;
 724
 725         for (;;) {
 726                 if (!call) {
 727                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 728                         if (!call)
 729                                 break;
 730
 731                         call->drop_ref = true;
 732                         call->async = true;
 733                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 734                         init_waitqueue_head(&call->waitq);
 735                         afs_extract_to_tmp(call);
 736                 }
 737
 738                 if (rxrpc_kernel_charge_accept(net->socket,
 739                                                afs_wake_up_async_call,
 740                                                afs_rx_attach,
 741                                                (unsigned long)call,
 742                                                GFP_KERNEL,
 743                                                call->debug_id) < 0)
 744                         break;
 745                 call = NULL;
 746         }
 747         net->spare_incoming_call = call;
 748 }
 749
 750 /*
 751  * Discard a preallocated call when a socket is shut down.
 752  */
 753 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 754                                     unsigned long user_call_ID)
 755 {
 756         struct afs_call *call = (struct afs_call *)user_call_ID;
 757
 758         call->rxcall = NULL;
 759         afs_put_call(call);
 760 }
 761
 762 /*
 763  * Notification of an incoming call.
 764  */
 765 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 766                             unsigned long user_call_ID)
 767 {
 768         struct afs_net *net = afs_sock2net(sk);
 769
 770         queue_work(afs_wq, &net->charge_preallocation_work);
 771 }
 772
 773 /*
 774  * Grab the operation ID from an incoming cache manager call.  The socket
 775  * buffer is discarded on error or if we don't yet have sufficient data.
 776  */
 777 static int afs_deliver_cm_op_id(struct afs_call *call)
 778 {
 779         int ret;
 780
 781         _enter("{%zu}", iov_iter_count(call->iter));
 782
 783         /* the operation ID forms the first four bytes of the request data */
 784         ret = afs_extract_data(call, true);
 785         if (ret < 0)
 786                 return ret;
 787
 788         call->operation_ID = ntohl(call->tmp);
 789         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 790
 791         /* ask the cache manager to route the call (it'll change the call type
 792          * if successful) */
 793         if (!afs_cm_incoming_call(call))
 794                 return -ENOTSUPP;
 795
 796         trace_afs_cb_call(call);
 797
 798         /* pass responsibility for the remainer of this message off to the
 799          * cache manager op */
 800         return call->type->deliver(call);
 801 }
 802
 803 /*
 804  * Advance the AFS call state when an RxRPC service call ends the transmit
 805  * phase.
 806  */
 807 static void afs_notify_end_reply_tx(struct sock *sock,
 808                                     struct rxrpc_call *rxcall,
 809                                     unsigned long call_user_ID)
 810 {
 811         struct afs_call *call = (struct afs_call *)call_user_ID;
 812
 813         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 814 }
 815
 816 /*
 817  * send an empty reply
 818  */
 819 void afs_send_empty_reply(struct afs_call *call)
 820 {
 821         struct afs_net *net = call->net;
 822         struct msghdr msg;
 823
 824         _enter("");
 825
 826         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 827
 828         msg.msg_name            = NULL;
 829         msg.msg_namelen         = 0;
 830         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 831         msg.msg_control         = NULL;
 832         msg.msg_controllen      = 0;
 833         msg.msg_flags           = 0;
 834
 835         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 836                                        afs_notify_end_reply_tx)) {
 837         case 0:
 838                 _leave(" [replied]");
 839                 return;
 840
 841         case -ENOMEM:
 842                 _debug("oom");
 843                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 844                                         RXGEN_SS_MARSHAL, -ENOMEM, "KOO");
 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, WRITE, 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, "KOO");
 887         }
 888         _leave(" [error]");
 889 }
 890
 891 /*
 892  * Extract a piece of data from the received data socket buffers.
 893  */
 894 int afs_extract_data(struct afs_call *call, bool want_more)
 895 {
 896         struct afs_net *net = call->net;
 897         struct iov_iter *iter = call->iter;
 898         enum afs_call_state state;
 899         u32 remote_abort = 0;
 900         int ret;
 901
 902         _enter("{%s,%zu,%zu},%d",
 903                call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 904
 905         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 906                                      &call->iov_len, want_more, &remote_abort,
 907                                      &call->service_id);
 908         if (ret == 0 || ret == -EAGAIN)
 909                 return ret;
 910
 911         state = READ_ONCE(call->state);
 912         if (ret == 1) {
 913                 switch (state) {
 914                 case AFS_CALL_CL_AWAIT_REPLY:
 915                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 916                         break;
 917                 case AFS_CALL_SV_AWAIT_REQUEST:
 918                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 919                         break;
 920                 case AFS_CALL_COMPLETE:
 921                         kdebug("prem complete %d", call->error);
 922                         return afs_io_error(call, afs_io_error_extract);
 923                 default:
 924                         break;
 925                 }
 926                 return 0;
 927         }
 928
 929         afs_set_call_complete(call, ret, remote_abort);
 930         return ret;
 931 }
 932
 933 /*
 934  * Log protocol error production.
 935  */
 936 noinline int afs_protocol_error(struct afs_call *call,
 937                                 enum afs_eproto_cause cause)
 938 {
 939         trace_afs_protocol_error(call, cause);
 940         if (call)
 941                 call->unmarshalling_error = true;
 942         return -EBADMSG;
 943 }