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 #define AFS_BVEC_MAX 8
 275
 276 /*
 277  * Load the given bvec with the next few pages.
 278  */
 279 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 280                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
 281                           unsigned offset)
 282 {
 283         struct afs_operation *op = call->op;
 284         struct page *pages[AFS_BVEC_MAX];
 285         unsigned int nr, n, i, to, bytes = 0;
 286
 287         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
 288         n = find_get_pages_contig(op->store.mapping, first, nr, pages);
 289         ASSERTCMP(n, ==, nr);
 290
 291         msg->msg_flags |= MSG_MORE;
 292         for (i = 0; i < nr; i++) {
 293                 to = PAGE_SIZE;
 294                 if (first + i >= last) {
 295                         to = op->store.last_to;
 296                         msg->msg_flags &= ~MSG_MORE;
 297                 }
 298                 bv[i].bv_page = pages[i];
 299                 bv[i].bv_len = to - offset;
 300                 bv[i].bv_offset = offset;
 301                 bytes += to - offset;
 302                 offset = 0;
 303         }
 304
 305         iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
 306 }
 307
 308 /*
 309  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 310  */
 311 static void afs_notify_end_request_tx(struct sock *sock,
 312                                       struct rxrpc_call *rxcall,
 313                                       unsigned long call_user_ID)
 314 {
 315         struct afs_call *call = (struct afs_call *)call_user_ID;
 316
 317         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 318 }
 319
 320 /*
 321  * attach the data from a bunch of pages on an inode to a call
 322  */
 323 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
 324 {
 325         struct afs_operation *op = call->op;
 326         struct bio_vec bv[AFS_BVEC_MAX];
 327         unsigned int bytes, nr, loop, offset;
 328         pgoff_t first = op->store.first, last = op->store.last;
 329         int ret;
 330
 331         offset = op->store.first_offset;
 332         op->store.first_offset = 0;
 333
 334         do {
 335                 afs_load_bvec(call, msg, bv, first, last, offset);
 336                 trace_afs_send_pages(call, msg, first, last, offset);
 337
 338                 offset = 0;
 339                 bytes = msg->msg_iter.count;
 340                 nr = msg->msg_iter.nr_segs;
 341
 342                 ret = rxrpc_kernel_send_data(op->net->socket, call->rxcall, msg,
 343                                              bytes, afs_notify_end_request_tx);
 344                 for (loop = 0; loop < nr; loop++)
 345                         put_page(bv[loop].bv_page);
 346                 if (ret < 0)
 347                         break;
 348
 349                 first += nr;
 350         } while (first <= last);
 351
 352         trace_afs_sent_pages(call, op->store.first, last, first, ret);
 353         return ret;
 354 }
 355
 356 /*
 357  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 358  * error is stored into the call struct, which the caller must check for.
 359  */
 360 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 361 {
 362         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 363         struct rxrpc_call *rxcall;
 364         struct msghdr msg;
 365         struct kvec iov[1];
 366         s64 tx_total_len;
 367         int ret;
 368
 369         _enter(",{%pISp},", &srx->transport);
 370
 371         ASSERT(call->type != NULL);
 372         ASSERT(call->type->name != NULL);
 373
 374         _debug("____MAKE %p{%s,%x} [%d]____",
 375                call, call->type->name, key_serial(call->key),
 376                atomic_read(&call->net->nr_outstanding_calls));
 377
 378         call->addr_ix = ac->index;
 379         call->alist = afs_get_addrlist(ac->alist);
 380
 381         /* Work out the length we're going to transmit.  This is awkward for
 382          * calls such as FS.StoreData where there's an extra injection of data
 383          * after the initial fixed part.
 384          */
 385         tx_total_len = call->request_size;
 386         if (call->send_pages) {
 387                 struct afs_operation *op = call->op;
 388
 389                 if (op->store.last == op->store.first) {
 390                         tx_total_len += op->store.last_to - op->store.first_offset;
 391                 } else {
 392                         /* It looks mathematically like you should be able to
 393                          * combine the following lines with the ones above, but
 394                          * unsigned arithmetic is fun when it wraps...
 395                          */
 396                         tx_total_len += PAGE_SIZE - op->store.first_offset;
 397                         tx_total_len += op->store.last_to;
 398                         tx_total_len += (op->store.last - op->store.first - 1) * PAGE_SIZE;
 399                 }
 400         }
 401
 402         /* If the call is going to be asynchronous, we need an extra ref for
 403          * the call to hold itself so the caller need not hang on to its ref.
 404          */
 405         if (call->async) {
 406                 afs_get_call(call, afs_call_trace_get);
 407                 call->drop_ref = true;
 408         }
 409
 410         /* create a call */
 411         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 412                                          (unsigned long)call,
 413                                          tx_total_len, gfp,
 414                                          (call->async ?
 415                                           afs_wake_up_async_call :
 416                                           afs_wake_up_call_waiter),
 417                                          call->upgrade,
 418                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 419                                           RXRPC_UNINTERRUPTIBLE),
 420                                          call->debug_id);
 421         if (IS_ERR(rxcall)) {
 422                 ret = PTR_ERR(rxcall);
 423                 call->error = ret;
 424                 goto error_kill_call;
 425         }
 426
 427         call->rxcall = rxcall;
 428
 429         if (call->max_lifespan)
 430                 rxrpc_kernel_set_max_life(call->net->socket, rxcall,
 431                                           call->max_lifespan);
 432
 433         /* send the request */
 434         iov[0].iov_base = call->request;
 435         iov[0].iov_len  = call->request_size;
 436
 437         msg.msg_name            = NULL;
 438         msg.msg_namelen         = 0;
 439         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 440         msg.msg_control         = NULL;
 441         msg.msg_controllen      = 0;
 442         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
 443
 444         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 445                                      &msg, call->request_size,
 446                                      afs_notify_end_request_tx);
 447         if (ret < 0)
 448                 goto error_do_abort;
 449
 450         if (call->send_pages) {
 451                 ret = afs_send_pages(call, &msg);
 452                 if (ret < 0)
 453                         goto error_do_abort;
 454         }
 455
 456         /* Note that at this point, we may have received the reply or an abort
 457          * - and an asynchronous call may already have completed.
 458          *
 459          * afs_wait_for_call_to_complete(call, ac)
 460          * must be called to synchronously clean up.
 461          */
 462         return;
 463
 464 error_do_abort:
 465         if (ret != -ECONNABORTED) {
 466                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 467                                         RX_USER_ABORT, ret, "KSD");
 468         } else {
 469                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 470                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 471                                        &msg.msg_iter, false,
 472                                        &call->abort_code, &call->service_id);
 473                 ac->abort_code = call->abort_code;
 474                 ac->responded = true;
 475         }
 476         call->error = ret;
 477         trace_afs_call_done(call);
 478 error_kill_call:
 479         if (call->type->done)
 480                 call->type->done(call);
 481
 482         /* We need to dispose of the extra ref we grabbed for an async call.
 483          * The call, however, might be queued on afs_async_calls and we need to
 484          * make sure we don't get any more notifications that might requeue it.
 485          */
 486         if (call->rxcall) {
 487                 rxrpc_kernel_end_call(call->net->socket, call->rxcall);
 488                 call->rxcall = NULL;
 489         }
 490         if (call->async) {
 491                 if (cancel_work_sync(&call->async_work))
 492                         afs_put_call(call);
 493                 afs_put_call(call);
 494         }
 495
 496         ac->error = ret;
 497         call->state = AFS_CALL_COMPLETE;
 498         _leave(" = %d", ret);
 499 }
 500
 501 /*
 502  * deliver messages to a call
 503  */
 504 static void afs_deliver_to_call(struct afs_call *call)
 505 {
 506         enum afs_call_state state;
 507         u32 abort_code, remote_abort = 0;
 508         int ret;
 509
 510         _enter("%s", call->type->name);
 511
 512         while (state = READ_ONCE(call->state),
 513                state == AFS_CALL_CL_AWAIT_REPLY ||
 514                state == AFS_CALL_SV_AWAIT_OP_ID ||
 515                state == AFS_CALL_SV_AWAIT_REQUEST ||
 516                state == AFS_CALL_SV_AWAIT_ACK
 517                ) {
 518                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 519                         iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
 520                         ret = rxrpc_kernel_recv_data(call->net->socket,
 521                                                      call->rxcall, &call->def_iter,
 522                                                      false, &remote_abort,
 523                                                      &call->service_id);
 524                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 525
 526                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 527                                 return;
 528                         if (ret < 0 || ret == 1) {
 529                                 if (ret == 1)
 530                                         ret = 0;
 531                                 goto call_complete;
 532                         }
 533                         return;
 534                 }
 535
 536                 if (!call->have_reply_time &&
 537                     rxrpc_kernel_get_reply_time(call->net->socket,
 538                                                 call->rxcall,
 539                                                 &call->reply_time))
 540                         call->have_reply_time = true;
 541
 542                 ret = call->type->deliver(call);
 543                 state = READ_ONCE(call->state);
 544                 if (ret == 0 && call->unmarshalling_error)
 545                         ret = -EBADMSG;
 546                 switch (ret) {
 547                 case 0:
 548                         afs_queue_call_work(call);
 549                         if (state == AFS_CALL_CL_PROC_REPLY) {
 550                                 if (call->op)
 551                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 552                                                 &call->op->server->flags);
 553                                 goto call_complete;
 554                         }
 555                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 556                         goto done;
 557                 case -EINPROGRESS:
 558                 case -EAGAIN:
 559                         goto out;
 560                 case -ECONNABORTED:
 561                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 562                         goto done;
 563                 case -ENOTSUPP:
 564                         abort_code = RXGEN_OPCODE;
 565                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 566                                                 abort_code, ret, "KIV");
 567                         goto local_abort;
 568                 case -EIO:
 569                         pr_err("kAFS: Call %u in bad state %u\n",
 570                                call->debug_id, state);
 571                         fallthrough;
 572                 case -ENODATA:
 573                 case -EBADMSG:
 574                 case -EMSGSIZE:
 575                         abort_code = RXGEN_CC_UNMARSHAL;
 576                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 577                                 abort_code = RXGEN_SS_UNMARSHAL;
 578                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 579                                                 abort_code, ret, "KUM");
 580                         goto local_abort;
 581                 default:
 582                         abort_code = RX_USER_ABORT;
 583                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 584                                                 abort_code, ret, "KER");
 585                         goto local_abort;
 586                 }
 587         }
 588
 589 done:
 590         if (call->type->done)
 591                 call->type->done(call);
 592 out:
 593         _leave("");
 594         return;
 595
 596 local_abort:
 597         abort_code = 0;
 598 call_complete:
 599         afs_set_call_complete(call, ret, remote_abort);
 600         state = AFS_CALL_COMPLETE;
 601         goto done;
 602 }
 603
 604 /*
 605  * Wait synchronously for a call to complete and clean up the call struct.
 606  */
 607 long afs_wait_for_call_to_complete(struct afs_call *call,
 608                                    struct afs_addr_cursor *ac)
 609 {
 610         long ret;
 611         bool rxrpc_complete = false;
 612
 613         DECLARE_WAITQUEUE(myself, current);
 614
 615         _enter("");
 616
 617         ret = call->error;
 618         if (ret < 0)
 619                 goto out;
 620
 621         add_wait_queue(&call->waitq, &myself);
 622         for (;;) {
 623                 set_current_state(TASK_UNINTERRUPTIBLE);
 624
 625                 /* deliver any messages that are in the queue */
 626                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 627                     call->need_attention) {
 628                         call->need_attention = false;
 629                         __set_current_state(TASK_RUNNING);
 630                         afs_deliver_to_call(call);
 631                         continue;
 632                 }
 633
 634                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 635                         break;
 636
 637                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 638                         /* rxrpc terminated the call. */
 639                         rxrpc_complete = true;
 640                         break;
 641                 }
 642
 643                 schedule();
 644         }
 645
 646         remove_wait_queue(&call->waitq, &myself);
 647         __set_current_state(TASK_RUNNING);
 648
 649         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 650                 if (rxrpc_complete) {
 651                         afs_set_call_complete(call, call->error, call->abort_code);
 652                 } else {
 653                         /* Kill off the call if it's still live. */
 654                         _debug("call interrupted");
 655                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 656                                                     RX_USER_ABORT, -EINTR, "KWI"))
 657                                 afs_set_call_complete(call, -EINTR, 0);
 658                 }
 659         }
 660
 661         spin_lock_bh(&call->state_lock);
 662         ac->abort_code = call->abort_code;
 663         ac->error = call->error;
 664         spin_unlock_bh(&call->state_lock);
 665
 666         ret = ac->error;
 667         switch (ret) {
 668         case 0:
 669                 ret = call->ret0;
 670                 call->ret0 = 0;
 671
 672                 fallthrough;
 673         case -ECONNABORTED:
 674                 ac->responded = true;
 675                 break;
 676         }
 677
 678 out:
 679         _debug("call complete");
 680         afs_put_call(call);
 681         _leave(" = %p", (void *)ret);
 682         return ret;
 683 }
 684
 685 /*
 686  * wake up a waiting call
 687  */
 688 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 689                                     unsigned long call_user_ID)
 690 {
 691         struct afs_call *call = (struct afs_call *)call_user_ID;
 692
 693         call->need_attention = true;
 694         wake_up(&call->waitq);
 695 }
 696
 697 /*
 698  * wake up an asynchronous call
 699  */
 700 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 701                                    unsigned long call_user_ID)
 702 {
 703         struct afs_call *call = (struct afs_call *)call_user_ID;
 704         int u;
 705
 706         trace_afs_notify_call(rxcall, call);
 707         call->need_attention = true;
 708
 709         u = atomic_fetch_add_unless(&call->usage, 1, 0);
 710         if (u != 0) {
 711                 trace_afs_call(call, afs_call_trace_wake, u + 1,
 712                                atomic_read(&call->net->nr_outstanding_calls),
 713                                __builtin_return_address(0));
 714
 715                 if (!queue_work(afs_async_calls, &call->async_work))
 716                         afs_put_call(call);
 717         }
 718 }
 719
 720 /*
 721  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 722  * to the call struct that we either need to release or to pass on.
 723  */
 724 static void afs_process_async_call(struct work_struct *work)
 725 {
 726         struct afs_call *call = container_of(work, struct afs_call, async_work);
 727
 728         _enter("");
 729
 730         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 731                 call->need_attention = false;
 732                 afs_deliver_to_call(call);
 733         }
 734
 735         afs_put_call(call);
 736         _leave("");
 737 }
 738
 739 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 740 {
 741         struct afs_call *call = (struct afs_call *)user_call_ID;
 742
 743         call->rxcall = rxcall;
 744 }
 745
 746 /*
 747  * Charge the incoming call preallocation.
 748  */
 749 void afs_charge_preallocation(struct work_struct *work)
 750 {
 751         struct afs_net *net =
 752                 container_of(work, struct afs_net, charge_preallocation_work);
 753         struct afs_call *call = net->spare_incoming_call;
 754
 755         for (;;) {
 756                 if (!call) {
 757                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 758                         if (!call)
 759                                 break;
 760
 761                         call->drop_ref = true;
 762                         call->async = true;
 763                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 764                         init_waitqueue_head(&call->waitq);
 765                         afs_extract_to_tmp(call);
 766                 }
 767
 768                 if (rxrpc_kernel_charge_accept(net->socket,
 769                                                afs_wake_up_async_call,
 770                                                afs_rx_attach,
 771                                                (unsigned long)call,
 772                                                GFP_KERNEL,
 773                                                call->debug_id) < 0)
 774                         break;
 775                 call = NULL;
 776         }
 777         net->spare_incoming_call = call;
 778 }
 779
 780 /*
 781  * Discard a preallocated call when a socket is shut down.
 782  */
 783 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 784                                     unsigned long user_call_ID)
 785 {
 786         struct afs_call *call = (struct afs_call *)user_call_ID;
 787
 788         call->rxcall = NULL;
 789         afs_put_call(call);
 790 }
 791
 792 /*
 793  * Notification of an incoming call.
 794  */
 795 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 796                             unsigned long user_call_ID)
 797 {
 798         struct afs_net *net = afs_sock2net(sk);
 799
 800         queue_work(afs_wq, &net->charge_preallocation_work);
 801 }
 802
 803 /*
 804  * Grab the operation ID from an incoming cache manager call.  The socket
 805  * buffer is discarded on error or if we don't yet have sufficient data.
 806  */
 807 static int afs_deliver_cm_op_id(struct afs_call *call)
 808 {
 809         int ret;
 810
 811         _enter("{%zu}", iov_iter_count(call->iter));
 812
 813         /* the operation ID forms the first four bytes of the request data */
 814         ret = afs_extract_data(call, true);
 815         if (ret < 0)
 816                 return ret;
 817
 818         call->operation_ID = ntohl(call->tmp);
 819         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 820
 821         /* ask the cache manager to route the call (it'll change the call type
 822          * if successful) */
 823         if (!afs_cm_incoming_call(call))
 824                 return -ENOTSUPP;
 825
 826         trace_afs_cb_call(call);
 827
 828         /* pass responsibility for the remainer of this message off to the
 829          * cache manager op */
 830         return call->type->deliver(call);
 831 }
 832
 833 /*
 834  * Advance the AFS call state when an RxRPC service call ends the transmit
 835  * phase.
 836  */
 837 static void afs_notify_end_reply_tx(struct sock *sock,
 838                                     struct rxrpc_call *rxcall,
 839                                     unsigned long call_user_ID)
 840 {
 841         struct afs_call *call = (struct afs_call *)call_user_ID;
 842
 843         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 844 }
 845
 846 /*
 847  * send an empty reply
 848  */
 849 void afs_send_empty_reply(struct afs_call *call)
 850 {
 851         struct afs_net *net = call->net;
 852         struct msghdr msg;
 853
 854         _enter("");
 855
 856         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 857
 858         msg.msg_name            = NULL;
 859         msg.msg_namelen         = 0;
 860         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 861         msg.msg_control         = NULL;
 862         msg.msg_controllen      = 0;
 863         msg.msg_flags           = 0;
 864
 865         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 866                                        afs_notify_end_reply_tx)) {
 867         case 0:
 868                 _leave(" [replied]");
 869                 return;
 870
 871         case -ENOMEM:
 872                 _debug("oom");
 873                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 874                                         RX_USER_ABORT, -ENOMEM, "KOO");
 875                 fallthrough;
 876         default:
 877                 _leave(" [error]");
 878                 return;
 879         }
 880 }
 881
 882 /*
 883  * send a simple reply
 884  */
 885 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 886 {
 887         struct afs_net *net = call->net;
 888         struct msghdr msg;
 889         struct kvec iov[1];
 890         int n;
 891
 892         _enter("");
 893
 894         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 895
 896         iov[0].iov_base         = (void *) buf;
 897         iov[0].iov_len          = len;
 898         msg.msg_name            = NULL;
 899         msg.msg_namelen         = 0;
 900         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 901         msg.msg_control         = NULL;
 902         msg.msg_controllen      = 0;
 903         msg.msg_flags           = 0;
 904
 905         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 906                                    afs_notify_end_reply_tx);
 907         if (n >= 0) {
 908                 /* Success */
 909                 _leave(" [replied]");
 910                 return;
 911         }
 912
 913         if (n == -ENOMEM) {
 914                 _debug("oom");
 915                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 916                                         RX_USER_ABORT, -ENOMEM, "KOO");
 917         }
 918         _leave(" [error]");
 919 }
 920
 921 /*
 922  * Extract a piece of data from the received data socket buffers.
 923  */
 924 int afs_extract_data(struct afs_call *call, bool want_more)
 925 {
 926         struct afs_net *net = call->net;
 927         struct iov_iter *iter = call->iter;
 928         enum afs_call_state state;
 929         u32 remote_abort = 0;
 930         int ret;
 931
 932         _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
 933
 934         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 935                                      want_more, &remote_abort,
 936                                      &call->service_id);
 937         if (ret == 0 || ret == -EAGAIN)
 938                 return ret;
 939
 940         state = READ_ONCE(call->state);
 941         if (ret == 1) {
 942                 switch (state) {
 943                 case AFS_CALL_CL_AWAIT_REPLY:
 944                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 945                         break;
 946                 case AFS_CALL_SV_AWAIT_REQUEST:
 947                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 948                         break;
 949                 case AFS_CALL_COMPLETE:
 950                         kdebug("prem complete %d", call->error);
 951                         return afs_io_error(call, afs_io_error_extract);
 952                 default:
 953                         break;
 954                 }
 955                 return 0;
 956         }
 957
 958         afs_set_call_complete(call, ret, remote_abort);
 959         return ret;
 960 }
 961
 962 /*
 963  * Log protocol error production.
 964  */
 965 noinline int afs_protocol_error(struct afs_call *call,
 966                                 enum afs_eproto_cause cause)
 967 {
 968         trace_afs_protocol_error(call, cause);
 969         if (call)
 970                 call->unmarshalling_error = true;
 971         return -EBADMSG;
 972 }