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
  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         atomic_set(&call->usage, 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, 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         int n = atomic_dec_return(&call->usage);
 167         int o = atomic_read(&net->nr_outstanding_calls);
 168
 169         trace_afs_call(call, afs_call_trace_put, n, o,
 170                        __builtin_return_address(0));
 171
 172         ASSERTCMP(n, >=, 0);
 173         if (n == 0) {
 174                 ASSERT(!work_pending(&call->async_work));
 175                 ASSERT(call->type->name != NULL);
 176
 177                 if (call->rxcall) {
 178                         rxrpc_kernel_end_call(net->socket, call->rxcall);
 179                         call->rxcall = NULL;
 180                 }
 181                 if (call->type->destructor)
 182                         call->type->destructor(call);
 183
 184                 afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
 185                 afs_put_addrlist(call->alist);
 186                 kfree(call->request);
 187
 188                 trace_afs_call(call, afs_call_trace_free, 0, o,
 189                                __builtin_return_address(0));
 190                 kfree(call);
 191
 192                 o = atomic_dec_return(&net->nr_outstanding_calls);
 193                 if (o == 0)
 194                         wake_up_var(&net->nr_outstanding_calls);
 195         }
 196 }
 197
 198 static struct afs_call *afs_get_call(struct afs_call *call,
 199                                      enum afs_call_trace why)
 200 {
 201         int u = atomic_inc_return(&call->usage);
 202
 203         trace_afs_call(call, why, u,
 204                        atomic_read(&call->net->nr_outstanding_calls),
 205                        __builtin_return_address(0));
 206         return call;
 207 }
 208
 209 /*
 210  * Queue the call for actual work.
 211  */
 212 static void afs_queue_call_work(struct afs_call *call)
 213 {
 214         if (call->type->work) {
 215                 INIT_WORK(&call->work, call->type->work);
 216
 217                 afs_get_call(call, afs_call_trace_work);
 218                 if (!queue_work(afs_wq, &call->work))
 219                         afs_put_call(call);
 220         }
 221 }
 222
 223 /*
 224  * allocate a call with flat request and reply buffers
 225  */
 226 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 227                                      const struct afs_call_type *type,
 228                                      size_t request_size, size_t reply_max)
 229 {
 230         struct afs_call *call;
 231
 232         call = afs_alloc_call(net, type, GFP_NOFS);
 233         if (!call)
 234                 goto nomem_call;
 235
 236         if (request_size) {
 237                 call->request_size = request_size;
 238                 call->request = kmalloc(request_size, GFP_NOFS);
 239                 if (!call->request)
 240                         goto nomem_free;
 241         }
 242
 243         if (reply_max) {
 244                 call->reply_max = reply_max;
 245                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 246                 if (!call->buffer)
 247                         goto nomem_free;
 248         }
 249
 250         afs_extract_to_buf(call, call->reply_max);
 251         call->operation_ID = type->op;
 252         init_waitqueue_head(&call->waitq);
 253         return call;
 254
 255 nomem_free:
 256         afs_put_call(call);
 257 nomem_call:
 258         return NULL;
 259 }
 260
 261 /*
 262  * clean up a call with flat buffer
 263  */
 264 void afs_flat_call_destructor(struct afs_call *call)
 265 {
 266         _enter("");
 267
 268         kfree(call->request);
 269         call->request = NULL;
 270         kfree(call->buffer);
 271         call->buffer = NULL;
 272 }
 273
 274 /*
 275  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 276  */
 277 static void afs_notify_end_request_tx(struct sock *sock,
 278                                       struct rxrpc_call *rxcall,
 279                                       unsigned long call_user_ID)
 280 {
 281         struct afs_call *call = (struct afs_call *)call_user_ID;
 282
 283         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 284 }
 285
 286 /*
 287  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 288  * error is stored into the call struct, which the caller must check for.
 289  */
 290 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 291 {
 292         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 293         struct rxrpc_call *rxcall;
 294         struct msghdr msg;
 295         struct kvec iov[1];
 296         size_t len;
 297         s64 tx_total_len;
 298         int ret;
 299
 300         _enter(",{%pISp},", &srx->transport);
 301
 302         ASSERT(call->type != NULL);
 303         ASSERT(call->type->name != NULL);
 304
 305         _debug("____MAKE %p{%s,%x} [%d]____",
 306                call, call->type->name, key_serial(call->key),
 307                atomic_read(&call->net->nr_outstanding_calls));
 308
 309         call->addr_ix = ac->index;
 310         call->alist = afs_get_addrlist(ac->alist);
 311
 312         /* Work out the length we're going to transmit.  This is awkward for
 313          * calls such as FS.StoreData where there's an extra injection of data
 314          * after the initial fixed part.
 315          */
 316         tx_total_len = call->request_size;
 317         if (call->write_iter)
 318                 tx_total_len += iov_iter_count(call->write_iter);
 319
 320         /* If the call is going to be asynchronous, we need an extra ref for
 321          * the call to hold itself so the caller need not hang on to its ref.
 322          */
 323         if (call->async) {
 324                 afs_get_call(call, afs_call_trace_get);
 325                 call->drop_ref = true;
 326         }
 327
 328         /* create a call */
 329         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 330                                          (unsigned long)call,
 331                                          tx_total_len, gfp,
 332                                          (call->async ?
 333                                           afs_wake_up_async_call :
 334                                           afs_wake_up_call_waiter),
 335                                          call->upgrade,
 336                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 337                                           RXRPC_UNINTERRUPTIBLE),
 338                                          call->debug_id);
 339         if (IS_ERR(rxcall)) {
 340                 ret = PTR_ERR(rxcall);
 341                 call->error = ret;
 342                 goto error_kill_call;
 343         }
 344
 345         call->rxcall = rxcall;
 346
 347         if (call->max_lifespan)
 348                 rxrpc_kernel_set_max_life(call->net->socket, rxcall,
 349                                           call->max_lifespan);
 350
 351         /* send the request */
 352         iov[0].iov_base = call->request;
 353         iov[0].iov_len  = call->request_size;
 354
 355         msg.msg_name            = NULL;
 356         msg.msg_namelen         = 0;
 357         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 358         msg.msg_control         = NULL;
 359         msg.msg_controllen      = 0;
 360         msg.msg_flags           = MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
 361
 362         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 363                                      &msg, call->request_size,
 364                                      afs_notify_end_request_tx);
 365         if (ret < 0)
 366                 goto error_do_abort;
 367
 368         if (call->write_iter) {
 369                 msg.msg_iter = *call->write_iter;
 370                 msg.msg_flags &= ~MSG_MORE;
 371                 trace_afs_send_data(call, &msg);
 372
 373                 ret = rxrpc_kernel_send_data(call->net->socket,
 374                                              call->rxcall, &msg,
 375                                              iov_iter_count(&msg.msg_iter),
 376                                              afs_notify_end_request_tx);
 377                 *call->write_iter = msg.msg_iter;
 378
 379                 trace_afs_sent_data(call, &msg, ret);
 380                 if (ret < 0)
 381                         goto error_do_abort;
 382         }
 383
 384         /* Note that at this point, we may have received the reply or an abort
 385          * - and an asynchronous call may already have completed.
 386          *
 387          * afs_wait_for_call_to_complete(call, ac)
 388          * must be called to synchronously clean up.
 389          */
 390         return;
 391
 392 error_do_abort:
 393         if (ret != -ECONNABORTED) {
 394                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 395                                         RX_USER_ABORT, ret, "KSD");
 396         } else {
 397                 len = 0;
 398                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 399                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 400                                        &msg.msg_iter, &len, false,
 401                                        &call->abort_code, &call->service_id);
 402                 ac->abort_code = call->abort_code;
 403                 ac->responded = true;
 404         }
 405         call->error = ret;
 406         trace_afs_call_done(call);
 407 error_kill_call:
 408         if (call->type->done)
 409                 call->type->done(call);
 410
 411         /* We need to dispose of the extra ref we grabbed for an async call.
 412          * The call, however, might be queued on afs_async_calls and we need to
 413          * make sure we don't get any more notifications that might requeue it.
 414          */
 415         if (call->rxcall) {
 416                 rxrpc_kernel_end_call(call->net->socket, call->rxcall);
 417                 call->rxcall = NULL;
 418         }
 419         if (call->async) {
 420                 if (cancel_work_sync(&call->async_work))
 421                         afs_put_call(call);
 422                 afs_put_call(call);
 423         }
 424
 425         ac->error = ret;
 426         call->state = AFS_CALL_COMPLETE;
 427         _leave(" = %d", ret);
 428 }
 429
 430 /*
 431  * Log remote abort codes that indicate that we have a protocol disagreement
 432  * with the server.
 433  */
 434 static void afs_log_error(struct afs_call *call, s32 remote_abort)
 435 {
 436         static int max = 0;
 437         const char *msg;
 438         int m;
 439
 440         switch (remote_abort) {
 441         case RX_EOF:             msg = "unexpected EOF";        break;
 442         case RXGEN_CC_MARSHAL:   msg = "client marshalling";    break;
 443         case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";  break;
 444         case RXGEN_SS_MARSHAL:   msg = "server marshalling";    break;
 445         case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";  break;
 446         case RXGEN_DECODE:       msg = "opcode decode";         break;
 447         case RXGEN_SS_XDRFREE:   msg = "server XDR cleanup";    break;
 448         case RXGEN_CC_XDRFREE:   msg = "client XDR cleanup";    break;
 449         case -32:                msg = "insufficient data";     break;
 450         default:
 451                 return;
 452         }
 453
 454         m = max;
 455         if (m < 3) {
 456                 max = m + 1;
 457                 pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
 458                           msg, call->type->name,
 459                           &call->alist->addrs[call->addr_ix].transport);
 460         }
 461 }
 462
 463 /*
 464  * deliver messages to a call
 465  */
 466 static void afs_deliver_to_call(struct afs_call *call)
 467 {
 468         enum afs_call_state state;
 469         size_t len;
 470         u32 abort_code, remote_abort = 0;
 471         int ret;
 472
 473         _enter("%s", call->type->name);
 474
 475         while (state = READ_ONCE(call->state),
 476                state == AFS_CALL_CL_AWAIT_REPLY ||
 477                state == AFS_CALL_SV_AWAIT_OP_ID ||
 478                state == AFS_CALL_SV_AWAIT_REQUEST ||
 479                state == AFS_CALL_SV_AWAIT_ACK
 480                ) {
 481                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 482                         len = 0;
 483                         iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
 484                         ret = rxrpc_kernel_recv_data(call->net->socket,
 485                                                      call->rxcall, &call->def_iter,
 486                                                      &len, false, &remote_abort,
 487                                                      &call->service_id);
 488                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 489
 490                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 491                                 return;
 492                         if (ret < 0 || ret == 1) {
 493                                 if (ret == 1)
 494                                         ret = 0;
 495                                 goto call_complete;
 496                         }
 497                         return;
 498                 }
 499
 500                 if (!call->have_reply_time &&
 501                     rxrpc_kernel_get_reply_time(call->net->socket,
 502                                                 call->rxcall,
 503                                                 &call->reply_time))
 504                         call->have_reply_time = true;
 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                         afs_queue_call_work(call);
 513                         if (state == AFS_CALL_CL_PROC_REPLY) {
 514                                 if (call->op)
 515                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 516                                                 &call->op->server->flags);
 517                                 goto call_complete;
 518                         }
 519                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 520                         goto done;
 521                 case -EINPROGRESS:
 522                 case -EAGAIN:
 523                         goto out;
 524                 case -ECONNABORTED:
 525                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 526                         afs_log_error(call, call->abort_code);
 527                         goto done;
 528                 case -ENOTSUPP:
 529                         abort_code = RXGEN_OPCODE;
 530                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 531                                                 abort_code, ret, "KIV");
 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, "KUM");
 547                         goto local_abort;
 548                 default:
 549                         abort_code = RX_CALL_DEAD;
 550                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 551                                                 abort_code, ret, "KER");
 552                         goto local_abort;
 553                 }
 554         }
 555
 556 done:
 557         if (call->type->done)
 558                 call->type->done(call);
 559 out:
 560         _leave("");
 561         return;
 562
 563 local_abort:
 564         abort_code = 0;
 565 call_complete:
 566         afs_set_call_complete(call, ret, remote_abort);
 567         state = AFS_CALL_COMPLETE;
 568         goto done;
 569 }
 570
 571 /*
 572  * Wait synchronously for a call to complete and clean up the call struct.
 573  */
 574 long afs_wait_for_call_to_complete(struct afs_call *call,
 575                                    struct afs_addr_cursor *ac)
 576 {
 577         long ret;
 578         bool rxrpc_complete = false;
 579
 580         DECLARE_WAITQUEUE(myself, current);
 581
 582         _enter("");
 583
 584         ret = call->error;
 585         if (ret < 0)
 586                 goto out;
 587
 588         add_wait_queue(&call->waitq, &myself);
 589         for (;;) {
 590                 set_current_state(TASK_UNINTERRUPTIBLE);
 591
 592                 /* deliver any messages that are in the queue */
 593                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 594                     call->need_attention) {
 595                         call->need_attention = false;
 596                         __set_current_state(TASK_RUNNING);
 597                         afs_deliver_to_call(call);
 598                         continue;
 599                 }
 600
 601                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 602                         break;
 603
 604                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 605                         /* rxrpc terminated the call. */
 606                         rxrpc_complete = true;
 607                         break;
 608                 }
 609
 610                 schedule();
 611         }
 612
 613         remove_wait_queue(&call->waitq, &myself);
 614         __set_current_state(TASK_RUNNING);
 615
 616         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 617                 if (rxrpc_complete) {
 618                         afs_set_call_complete(call, call->error, call->abort_code);
 619                 } else {
 620                         /* Kill off the call if it's still live. */
 621                         _debug("call interrupted");
 622                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 623                                                     RX_USER_ABORT, -EINTR, "KWI"))
 624                                 afs_set_call_complete(call, -EINTR, 0);
 625                 }
 626         }
 627
 628         spin_lock_bh(&call->state_lock);
 629         ac->abort_code = call->abort_code;
 630         ac->error = call->error;
 631         spin_unlock_bh(&call->state_lock);
 632
 633         ret = ac->error;
 634         switch (ret) {
 635         case 0:
 636                 ret = call->ret0;
 637                 call->ret0 = 0;
 638
 639                 fallthrough;
 640         case -ECONNABORTED:
 641                 ac->responded = true;
 642                 break;
 643         }
 644
 645 out:
 646         _debug("call complete");
 647         afs_put_call(call);
 648         _leave(" = %p", (void *)ret);
 649         return ret;
 650 }
 651
 652 /*
 653  * wake up a waiting call
 654  */
 655 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 656                                     unsigned long call_user_ID)
 657 {
 658         struct afs_call *call = (struct afs_call *)call_user_ID;
 659
 660         call->need_attention = true;
 661         wake_up(&call->waitq);
 662 }
 663
 664 /*
 665  * wake up an asynchronous call
 666  */
 667 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 668                                    unsigned long call_user_ID)
 669 {
 670         struct afs_call *call = (struct afs_call *)call_user_ID;
 671         int u;
 672
 673         trace_afs_notify_call(rxcall, call);
 674         call->need_attention = true;
 675
 676         u = atomic_fetch_add_unless(&call->usage, 1, 0);
 677         if (u != 0) {
 678                 trace_afs_call(call, afs_call_trace_wake, u + 1,
 679                                atomic_read(&call->net->nr_outstanding_calls),
 680                                __builtin_return_address(0));
 681
 682                 if (!queue_work(afs_async_calls, &call->async_work))
 683                         afs_put_call(call);
 684         }
 685 }
 686
 687 /*
 688  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 689  * to the call struct that we either need to release or to pass on.
 690  */
 691 static void afs_process_async_call(struct work_struct *work)
 692 {
 693         struct afs_call *call = container_of(work, struct afs_call, async_work);
 694
 695         _enter("");
 696
 697         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 698                 call->need_attention = false;
 699                 afs_deliver_to_call(call);
 700         }
 701
 702         afs_put_call(call);
 703         _leave("");
 704 }
 705
 706 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 707 {
 708         struct afs_call *call = (struct afs_call *)user_call_ID;
 709
 710         call->rxcall = rxcall;
 711 }
 712
 713 /*
 714  * Charge the incoming call preallocation.
 715  */
 716 void afs_charge_preallocation(struct work_struct *work)
 717 {
 718         struct afs_net *net =
 719                 container_of(work, struct afs_net, charge_preallocation_work);
 720         struct afs_call *call = net->spare_incoming_call;
 721
 722         for (;;) {
 723                 if (!call) {
 724                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 725                         if (!call)
 726                                 break;
 727
 728                         call->drop_ref = true;
 729                         call->async = true;
 730                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 731                         init_waitqueue_head(&call->waitq);
 732                         afs_extract_to_tmp(call);
 733                 }
 734
 735                 if (rxrpc_kernel_charge_accept(net->socket,
 736                                                afs_wake_up_async_call,
 737                                                afs_rx_attach,
 738                                                (unsigned long)call,
 739                                                GFP_KERNEL,
 740                                                call->debug_id) < 0)
 741                         break;
 742                 call = NULL;
 743         }
 744         net->spare_incoming_call = call;
 745 }
 746
 747 /*
 748  * Discard a preallocated call when a socket is shut down.
 749  */
 750 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 751                                     unsigned long user_call_ID)
 752 {
 753         struct afs_call *call = (struct afs_call *)user_call_ID;
 754
 755         call->rxcall = NULL;
 756         afs_put_call(call);
 757 }
 758
 759 /*
 760  * Notification of an incoming call.
 761  */
 762 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 763                             unsigned long user_call_ID)
 764 {
 765         struct afs_net *net = afs_sock2net(sk);
 766
 767         queue_work(afs_wq, &net->charge_preallocation_work);
 768 }
 769
 770 /*
 771  * Grab the operation ID from an incoming cache manager call.  The socket
 772  * buffer is discarded on error or if we don't yet have sufficient data.
 773  */
 774 static int afs_deliver_cm_op_id(struct afs_call *call)
 775 {
 776         int ret;
 777
 778         _enter("{%zu}", iov_iter_count(call->iter));
 779
 780         /* the operation ID forms the first four bytes of the request data */
 781         ret = afs_extract_data(call, true);
 782         if (ret < 0)
 783                 return ret;
 784
 785         call->operation_ID = ntohl(call->tmp);
 786         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 787
 788         /* ask the cache manager to route the call (it'll change the call type
 789          * if successful) */
 790         if (!afs_cm_incoming_call(call))
 791                 return -ENOTSUPP;
 792
 793         trace_afs_cb_call(call);
 794
 795         /* pass responsibility for the remainer of this message off to the
 796          * cache manager op */
 797         return call->type->deliver(call);
 798 }
 799
 800 /*
 801  * Advance the AFS call state when an RxRPC service call ends the transmit
 802  * phase.
 803  */
 804 static void afs_notify_end_reply_tx(struct sock *sock,
 805                                     struct rxrpc_call *rxcall,
 806                                     unsigned long call_user_ID)
 807 {
 808         struct afs_call *call = (struct afs_call *)call_user_ID;
 809
 810         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 811 }
 812
 813 /*
 814  * send an empty reply
 815  */
 816 void afs_send_empty_reply(struct afs_call *call)
 817 {
 818         struct afs_net *net = call->net;
 819         struct msghdr msg;
 820
 821         _enter("");
 822
 823         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 824
 825         msg.msg_name            = NULL;
 826         msg.msg_namelen         = 0;
 827         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 828         msg.msg_control         = NULL;
 829         msg.msg_controllen      = 0;
 830         msg.msg_flags           = 0;
 831
 832         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 833                                        afs_notify_end_reply_tx)) {
 834         case 0:
 835                 _leave(" [replied]");
 836                 return;
 837
 838         case -ENOMEM:
 839                 _debug("oom");
 840                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 841                                         RXGEN_SS_MARSHAL, -ENOMEM, "KOO");
 842                 fallthrough;
 843         default:
 844                 _leave(" [error]");
 845                 return;
 846         }
 847 }
 848
 849 /*
 850  * send a simple reply
 851  */
 852 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 853 {
 854         struct afs_net *net = call->net;
 855         struct msghdr msg;
 856         struct kvec iov[1];
 857         int n;
 858
 859         _enter("");
 860
 861         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 862
 863         iov[0].iov_base         = (void *) buf;
 864         iov[0].iov_len          = len;
 865         msg.msg_name            = NULL;
 866         msg.msg_namelen         = 0;
 867         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 868         msg.msg_control         = NULL;
 869         msg.msg_controllen      = 0;
 870         msg.msg_flags           = 0;
 871
 872         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 873                                    afs_notify_end_reply_tx);
 874         if (n >= 0) {
 875                 /* Success */
 876                 _leave(" [replied]");
 877                 return;
 878         }
 879
 880         if (n == -ENOMEM) {
 881                 _debug("oom");
 882                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 883                                         RXGEN_SS_MARSHAL, -ENOMEM, "KOO");
 884         }
 885         _leave(" [error]");
 886 }
 887
 888 /*
 889  * Extract a piece of data from the received data socket buffers.
 890  */
 891 int afs_extract_data(struct afs_call *call, bool want_more)
 892 {
 893         struct afs_net *net = call->net;
 894         struct iov_iter *iter = call->iter;
 895         enum afs_call_state state;
 896         u32 remote_abort = 0;
 897         int ret;
 898
 899         _enter("{%s,%zu,%zu},%d",
 900                call->type->name, call->iov_len, iov_iter_count(iter), want_more);
 901
 902         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 903                                      &call->iov_len, want_more, &remote_abort,
 904                                      &call->service_id);
 905         if (ret == 0 || ret == -EAGAIN)
 906                 return ret;
 907
 908         state = READ_ONCE(call->state);
 909         if (ret == 1) {
 910                 switch (state) {
 911                 case AFS_CALL_CL_AWAIT_REPLY:
 912                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 913                         break;
 914                 case AFS_CALL_SV_AWAIT_REQUEST:
 915                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 916                         break;
 917                 case AFS_CALL_COMPLETE:
 918                         kdebug("prem complete %d", call->error);
 919                         return afs_io_error(call, afs_io_error_extract);
 920                 default:
 921                         break;
 922                 }
 923                 return 0;
 924         }
 925
 926         afs_set_call_complete(call, ret, remote_abort);
 927         return ret;
 928 }
 929
 930 /*
 931  * Log protocol error production.
 932  */
 933 noinline int afs_protocol_error(struct afs_call *call,
 934                                 enum afs_eproto_cause cause)
 935 {
 936         trace_afs_protocol_error(call, cause);
 937         if (call)
 938                 call->unmarshalling_error = true;
 939         return -EBADMSG;
 940 }