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_put_server(call->net, call->server, afs_server_trace_put_call);
 185                 afs_put_cb_interest(call->net, call->cbi);
 186                 afs_put_addrlist(call->alist);
 187                 kfree(call->request);
 188
 189                 trace_afs_call(call, afs_call_trace_free, 0, o,
 190                                __builtin_return_address(0));
 191                 kfree(call);
 192
 193                 o = atomic_dec_return(&net->nr_outstanding_calls);
 194                 if (o == 0)
 195                         wake_up_var(&net->nr_outstanding_calls);
 196         }
 197 }
 198
 199 static struct afs_call *afs_get_call(struct afs_call *call,
 200                                      enum afs_call_trace why)
 201 {
 202         int u = atomic_inc_return(&call->usage);
 203
 204         trace_afs_call(call, why, u,
 205                        atomic_read(&call->net->nr_outstanding_calls),
 206                        __builtin_return_address(0));
 207         return call;
 208 }
 209
 210 /*
 211  * Queue the call for actual work.
 212  */
 213 static void afs_queue_call_work(struct afs_call *call)
 214 {
 215         if (call->type->work) {
 216                 INIT_WORK(&call->work, call->type->work);
 217
 218                 afs_get_call(call, afs_call_trace_work);
 219                 if (!queue_work(afs_wq, &call->work))
 220                         afs_put_call(call);
 221         }
 222 }
 223
 224 /*
 225  * allocate a call with flat request and reply buffers
 226  */
 227 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 228                                      const struct afs_call_type *type,
 229                                      size_t request_size, size_t reply_max)
 230 {
 231         struct afs_call *call;
 232
 233         call = afs_alloc_call(net, type, GFP_NOFS);
 234         if (!call)
 235                 goto nomem_call;
 236
 237         if (request_size) {
 238                 call->request_size = request_size;
 239                 call->request = kmalloc(request_size, GFP_NOFS);
 240                 if (!call->request)
 241                         goto nomem_free;
 242         }
 243
 244         if (reply_max) {
 245                 call->reply_max = reply_max;
 246                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 247                 if (!call->buffer)
 248                         goto nomem_free;
 249         }
 250
 251         afs_extract_to_buf(call, call->reply_max);
 252         call->operation_ID = type->op;
 253         init_waitqueue_head(&call->waitq);
 254         return call;
 255
 256 nomem_free:
 257         afs_put_call(call);
 258 nomem_call:
 259         return NULL;
 260 }
 261
 262 /*
 263  * clean up a call with flat buffer
 264  */
 265 void afs_flat_call_destructor(struct afs_call *call)
 266 {
 267         _enter("");
 268
 269         kfree(call->request);
 270         call->request = NULL;
 271         kfree(call->buffer);
 272         call->buffer = NULL;
 273 }
 274
 275 #define AFS_BVEC_MAX 8
 276
 277 /*
 278  * Load the given bvec with the next few pages.
 279  */
 280 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 281                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
 282                           unsigned offset)
 283 {
 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(call->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 = call->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 bio_vec bv[AFS_BVEC_MAX];
 326         unsigned int bytes, nr, loop, offset;
 327         pgoff_t first = call->first, last = call->last;
 328         int ret;
 329
 330         offset = call->first_offset;
 331         call->first_offset = 0;
 332
 333         do {
 334                 afs_load_bvec(call, msg, bv, first, last, offset);
 335                 trace_afs_send_pages(call, msg, first, last, offset);
 336
 337                 offset = 0;
 338                 bytes = msg->msg_iter.count;
 339                 nr = msg->msg_iter.nr_segs;
 340
 341                 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
 342                                              bytes, afs_notify_end_request_tx);
 343                 for (loop = 0; loop < nr; loop++)
 344                         put_page(bv[loop].bv_page);
 345                 if (ret < 0)
 346                         break;
 347
 348                 first += nr;
 349         } while (first <= last);
 350
 351         trace_afs_sent_pages(call, call->first, last, first, ret);
 352         return ret;
 353 }
 354
 355 /*
 356  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
 357  * error is stored into the call struct, which the caller must check for.
 358  */
 359 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 360 {
 361         struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
 362         struct rxrpc_call *rxcall;
 363         struct msghdr msg;
 364         struct kvec iov[1];
 365         s64 tx_total_len;
 366         int ret;
 367
 368         _enter(",{%pISp},", &srx->transport);
 369
 370         ASSERT(call->type != NULL);
 371         ASSERT(call->type->name != NULL);
 372
 373         _debug("____MAKE %p{%s,%x} [%d]____",
 374                call, call->type->name, key_serial(call->key),
 375                atomic_read(&call->net->nr_outstanding_calls));
 376
 377         call->addr_ix = ac->index;
 378         call->alist = afs_get_addrlist(ac->alist);
 379
 380         /* Work out the length we're going to transmit.  This is awkward for
 381          * calls such as FS.StoreData where there's an extra injection of data
 382          * after the initial fixed part.
 383          */
 384         tx_total_len = call->request_size;
 385         if (call->send_pages) {
 386                 if (call->last == call->first) {
 387                         tx_total_len += call->last_to - call->first_offset;
 388                 } else {
 389                         /* It looks mathematically like you should be able to
 390                          * combine the following lines with the ones above, but
 391                          * unsigned arithmetic is fun when it wraps...
 392                          */
 393                         tx_total_len += PAGE_SIZE - call->first_offset;
 394                         tx_total_len += call->last_to;
 395                         tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
 396                 }
 397         }
 398
 399         /* If the call is going to be asynchronous, we need an extra ref for
 400          * the call to hold itself so the caller need not hang on to its ref.
 401          */
 402         if (call->async) {
 403                 afs_get_call(call, afs_call_trace_get);
 404                 call->drop_ref = true;
 405         }
 406
 407         /* create a call */
 408         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 409                                          (unsigned long)call,
 410                                          tx_total_len, gfp,
 411                                          (call->async ?
 412                                           afs_wake_up_async_call :
 413                                           afs_wake_up_call_waiter),
 414                                          call->upgrade,
 415                                          (call->intr ? RXRPC_PREINTERRUPTIBLE :
 416                                           RXRPC_UNINTERRUPTIBLE),
 417                                          call->debug_id);
 418         if (IS_ERR(rxcall)) {
 419                 ret = PTR_ERR(rxcall);
 420                 call->error = ret;
 421                 goto error_kill_call;
 422         }
 423
 424         call->rxcall = rxcall;
 425
 426         if (call->max_lifespan)
 427                 rxrpc_kernel_set_max_life(call->net->socket, rxcall,
 428                                           call->max_lifespan);
 429
 430         /* send the request */
 431         iov[0].iov_base = call->request;
 432         iov[0].iov_len  = call->request_size;
 433
 434         msg.msg_name            = NULL;
 435         msg.msg_namelen         = 0;
 436         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 437         msg.msg_control         = NULL;
 438         msg.msg_controllen      = 0;
 439         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
 440
 441         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 442                                      &msg, call->request_size,
 443                                      afs_notify_end_request_tx);
 444         if (ret < 0)
 445                 goto error_do_abort;
 446
 447         if (call->send_pages) {
 448                 ret = afs_send_pages(call, &msg);
 449                 if (ret < 0)
 450                         goto error_do_abort;
 451         }
 452
 453         /* Note that at this point, we may have received the reply or an abort
 454          * - and an asynchronous call may already have completed.
 455          *
 456          * afs_wait_for_call_to_complete(call, ac)
 457          * must be called to synchronously clean up.
 458          */
 459         return;
 460
 461 error_do_abort:
 462         if (ret != -ECONNABORTED) {
 463                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 464                                         RX_USER_ABORT, ret, "KSD");
 465         } else {
 466                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 467                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 468                                        &msg.msg_iter, false,
 469                                        &call->abort_code, &call->service_id);
 470                 ac->abort_code = call->abort_code;
 471                 ac->responded = true;
 472         }
 473         call->error = ret;
 474         trace_afs_call_done(call);
 475 error_kill_call:
 476         if (call->type->done)
 477                 call->type->done(call);
 478
 479         /* We need to dispose of the extra ref we grabbed for an async call.
 480          * The call, however, might be queued on afs_async_calls and we need to
 481          * make sure we don't get any more notifications that might requeue it.
 482          */
 483         if (call->rxcall) {
 484                 rxrpc_kernel_end_call(call->net->socket, call->rxcall);
 485                 call->rxcall = NULL;
 486         }
 487         if (call->async) {
 488                 if (cancel_work_sync(&call->async_work))
 489                         afs_put_call(call);
 490                 afs_put_call(call);
 491         }
 492
 493         ac->error = ret;
 494         call->state = AFS_CALL_COMPLETE;
 495         _leave(" = %d", ret);
 496 }
 497
 498 /*
 499  * deliver messages to a call
 500  */
 501 static void afs_deliver_to_call(struct afs_call *call)
 502 {
 503         enum afs_call_state state;
 504         u32 abort_code, remote_abort = 0;
 505         int ret;
 506
 507         _enter("%s", call->type->name);
 508
 509         while (state = READ_ONCE(call->state),
 510                state == AFS_CALL_CL_AWAIT_REPLY ||
 511                state == AFS_CALL_SV_AWAIT_OP_ID ||
 512                state == AFS_CALL_SV_AWAIT_REQUEST ||
 513                state == AFS_CALL_SV_AWAIT_ACK
 514                ) {
 515                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 516                         iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
 517                         ret = rxrpc_kernel_recv_data(call->net->socket,
 518                                                      call->rxcall, &call->def_iter,
 519                                                      false, &remote_abort,
 520                                                      &call->service_id);
 521                         trace_afs_receive_data(call, &call->def_iter, false, ret);
 522
 523                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 524                                 return;
 525                         if (ret < 0 || ret == 1) {
 526                                 if (ret == 1)
 527                                         ret = 0;
 528                                 goto call_complete;
 529                         }
 530                         return;
 531                 }
 532
 533                 if (!call->have_reply_time &&
 534                     rxrpc_kernel_get_reply_time(call->net->socket,
 535                                                 call->rxcall,
 536                                                 &call->reply_time))
 537                         call->have_reply_time = true;
 538
 539                 ret = call->type->deliver(call);
 540                 state = READ_ONCE(call->state);
 541                 switch (ret) {
 542                 case 0:
 543                         afs_queue_call_work(call);
 544                         if (state == AFS_CALL_CL_PROC_REPLY) {
 545                                 if (call->cbi)
 546                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 547                                                 &call->cbi->server->flags);
 548                                 goto call_complete;
 549                         }
 550                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 551                         goto done;
 552                 case -EINPROGRESS:
 553                 case -EAGAIN:
 554                         goto out;
 555                 case -ECONNABORTED:
 556                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 557                         goto done;
 558                 case -ENOTSUPP:
 559                         abort_code = RXGEN_OPCODE;
 560                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 561                                                 abort_code, ret, "KIV");
 562                         goto local_abort;
 563                 case -EIO:
 564                         pr_err("kAFS: Call %u in bad state %u\n",
 565                                call->debug_id, state);
 566                         /* Fall through */
 567                 case -ENODATA:
 568                 case -EBADMSG:
 569                 case -EMSGSIZE:
 570                         abort_code = RXGEN_CC_UNMARSHAL;
 571                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 572                                 abort_code = RXGEN_SS_UNMARSHAL;
 573                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 574                                                 abort_code, ret, "KUM");
 575                         goto local_abort;
 576                 default:
 577                         abort_code = RX_USER_ABORT;
 578                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 579                                                 abort_code, ret, "KER");
 580                         goto local_abort;
 581                 }
 582         }
 583
 584 done:
 585         if (call->type->done)
 586                 call->type->done(call);
 587 out:
 588         _leave("");
 589         return;
 590
 591 local_abort:
 592         abort_code = 0;
 593 call_complete:
 594         afs_set_call_complete(call, ret, remote_abort);
 595         state = AFS_CALL_COMPLETE;
 596         goto done;
 597 }
 598
 599 /*
 600  * Wait synchronously for a call to complete and clean up the call struct.
 601  */
 602 long afs_wait_for_call_to_complete(struct afs_call *call,
 603                                    struct afs_addr_cursor *ac)
 604 {
 605         long ret;
 606         bool rxrpc_complete = false;
 607
 608         DECLARE_WAITQUEUE(myself, current);
 609
 610         _enter("");
 611
 612         ret = call->error;
 613         if (ret < 0)
 614                 goto out;
 615
 616         add_wait_queue(&call->waitq, &myself);
 617         for (;;) {
 618                 set_current_state(TASK_UNINTERRUPTIBLE);
 619
 620                 /* deliver any messages that are in the queue */
 621                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 622                     call->need_attention) {
 623                         call->need_attention = false;
 624                         __set_current_state(TASK_RUNNING);
 625                         afs_deliver_to_call(call);
 626                         continue;
 627                 }
 628
 629                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 630                         break;
 631
 632                 if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
 633                         /* rxrpc terminated the call. */
 634                         rxrpc_complete = true;
 635                         break;
 636                 }
 637
 638                 schedule();
 639         }
 640
 641         remove_wait_queue(&call->waitq, &myself);
 642         __set_current_state(TASK_RUNNING);
 643
 644         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 645                 if (rxrpc_complete) {
 646                         afs_set_call_complete(call, call->error, call->abort_code);
 647                 } else {
 648                         /* Kill off the call if it's still live. */
 649                         _debug("call interrupted");
 650                         if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 651                                                     RX_USER_ABORT, -EINTR, "KWI"))
 652                                 afs_set_call_complete(call, -EINTR, 0);
 653                 }
 654         }
 655
 656         spin_lock_bh(&call->state_lock);
 657         ac->abort_code = call->abort_code;
 658         ac->error = call->error;
 659         spin_unlock_bh(&call->state_lock);
 660
 661         ret = ac->error;
 662         switch (ret) {
 663         case 0:
 664                 ret = call->ret0;
 665                 call->ret0 = 0;
 666
 667                 /* Fall through */
 668         case -ECONNABORTED:
 669                 ac->responded = true;
 670                 break;
 671         }
 672
 673 out:
 674         _debug("call complete");
 675         afs_put_call(call);
 676         _leave(" = %p", (void *)ret);
 677         return ret;
 678 }
 679
 680 /*
 681  * wake up a waiting call
 682  */
 683 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 684                                     unsigned long call_user_ID)
 685 {
 686         struct afs_call *call = (struct afs_call *)call_user_ID;
 687
 688         call->need_attention = true;
 689         wake_up(&call->waitq);
 690 }
 691
 692 /*
 693  * wake up an asynchronous call
 694  */
 695 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 696                                    unsigned long call_user_ID)
 697 {
 698         struct afs_call *call = (struct afs_call *)call_user_ID;
 699         int u;
 700
 701         trace_afs_notify_call(rxcall, call);
 702         call->need_attention = true;
 703
 704         u = atomic_fetch_add_unless(&call->usage, 1, 0);
 705         if (u != 0) {
 706                 trace_afs_call(call, afs_call_trace_wake, u + 1,
 707                                atomic_read(&call->net->nr_outstanding_calls),
 708                                __builtin_return_address(0));
 709
 710                 if (!queue_work(afs_async_calls, &call->async_work))
 711                         afs_put_call(call);
 712         }
 713 }
 714
 715 /*
 716  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 717  * to the call struct that we either need to release or to pass on.
 718  */
 719 static void afs_process_async_call(struct work_struct *work)
 720 {
 721         struct afs_call *call = container_of(work, struct afs_call, async_work);
 722
 723         _enter("");
 724
 725         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 726                 call->need_attention = false;
 727                 afs_deliver_to_call(call);
 728         }
 729
 730         afs_put_call(call);
 731         _leave("");
 732 }
 733
 734 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 735 {
 736         struct afs_call *call = (struct afs_call *)user_call_ID;
 737
 738         call->rxcall = rxcall;
 739 }
 740
 741 /*
 742  * Charge the incoming call preallocation.
 743  */
 744 void afs_charge_preallocation(struct work_struct *work)
 745 {
 746         struct afs_net *net =
 747                 container_of(work, struct afs_net, charge_preallocation_work);
 748         struct afs_call *call = net->spare_incoming_call;
 749
 750         for (;;) {
 751                 if (!call) {
 752                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 753                         if (!call)
 754                                 break;
 755
 756                         call->drop_ref = true;
 757                         call->async = true;
 758                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 759                         init_waitqueue_head(&call->waitq);
 760                         afs_extract_to_tmp(call);
 761                 }
 762
 763                 if (rxrpc_kernel_charge_accept(net->socket,
 764                                                afs_wake_up_async_call,
 765                                                afs_rx_attach,
 766                                                (unsigned long)call,
 767                                                GFP_KERNEL,
 768                                                call->debug_id) < 0)
 769                         break;
 770                 call = NULL;
 771         }
 772         net->spare_incoming_call = call;
 773 }
 774
 775 /*
 776  * Discard a preallocated call when a socket is shut down.
 777  */
 778 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 779                                     unsigned long user_call_ID)
 780 {
 781         struct afs_call *call = (struct afs_call *)user_call_ID;
 782
 783         call->rxcall = NULL;
 784         afs_put_call(call);
 785 }
 786
 787 /*
 788  * Notification of an incoming call.
 789  */
 790 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 791                             unsigned long user_call_ID)
 792 {
 793         struct afs_net *net = afs_sock2net(sk);
 794
 795         queue_work(afs_wq, &net->charge_preallocation_work);
 796 }
 797
 798 /*
 799  * Grab the operation ID from an incoming cache manager call.  The socket
 800  * buffer is discarded on error or if we don't yet have sufficient data.
 801  */
 802 static int afs_deliver_cm_op_id(struct afs_call *call)
 803 {
 804         int ret;
 805
 806         _enter("{%zu}", iov_iter_count(call->iter));
 807
 808         /* the operation ID forms the first four bytes of the request data */
 809         ret = afs_extract_data(call, true);
 810         if (ret < 0)
 811                 return ret;
 812
 813         call->operation_ID = ntohl(call->tmp);
 814         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 815
 816         /* ask the cache manager to route the call (it'll change the call type
 817          * if successful) */
 818         if (!afs_cm_incoming_call(call))
 819                 return -ENOTSUPP;
 820
 821         trace_afs_cb_call(call);
 822
 823         /* pass responsibility for the remainer of this message off to the
 824          * cache manager op */
 825         return call->type->deliver(call);
 826 }
 827
 828 /*
 829  * Advance the AFS call state when an RxRPC service call ends the transmit
 830  * phase.
 831  */
 832 static void afs_notify_end_reply_tx(struct sock *sock,
 833                                     struct rxrpc_call *rxcall,
 834                                     unsigned long call_user_ID)
 835 {
 836         struct afs_call *call = (struct afs_call *)call_user_ID;
 837
 838         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 839 }
 840
 841 /*
 842  * send an empty reply
 843  */
 844 void afs_send_empty_reply(struct afs_call *call)
 845 {
 846         struct afs_net *net = call->net;
 847         struct msghdr msg;
 848
 849         _enter("");
 850
 851         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 852
 853         msg.msg_name            = NULL;
 854         msg.msg_namelen         = 0;
 855         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 856         msg.msg_control         = NULL;
 857         msg.msg_controllen      = 0;
 858         msg.msg_flags           = 0;
 859
 860         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 861                                        afs_notify_end_reply_tx)) {
 862         case 0:
 863                 _leave(" [replied]");
 864                 return;
 865
 866         case -ENOMEM:
 867                 _debug("oom");
 868                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 869                                         RX_USER_ABORT, -ENOMEM, "KOO");
 870                 /* Fall through */
 871         default:
 872                 _leave(" [error]");
 873                 return;
 874         }
 875 }
 876
 877 /*
 878  * send a simple reply
 879  */
 880 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 881 {
 882         struct afs_net *net = call->net;
 883         struct msghdr msg;
 884         struct kvec iov[1];
 885         int n;
 886
 887         _enter("");
 888
 889         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 890
 891         iov[0].iov_base         = (void *) buf;
 892         iov[0].iov_len          = len;
 893         msg.msg_name            = NULL;
 894         msg.msg_namelen         = 0;
 895         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 896         msg.msg_control         = NULL;
 897         msg.msg_controllen      = 0;
 898         msg.msg_flags           = 0;
 899
 900         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 901                                    afs_notify_end_reply_tx);
 902         if (n >= 0) {
 903                 /* Success */
 904                 _leave(" [replied]");
 905                 return;
 906         }
 907
 908         if (n == -ENOMEM) {
 909                 _debug("oom");
 910                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 911                                         RX_USER_ABORT, -ENOMEM, "KOO");
 912         }
 913         _leave(" [error]");
 914 }
 915
 916 /*
 917  * Extract a piece of data from the received data socket buffers.
 918  */
 919 int afs_extract_data(struct afs_call *call, bool want_more)
 920 {
 921         struct afs_net *net = call->net;
 922         struct iov_iter *iter = call->iter;
 923         enum afs_call_state state;
 924         u32 remote_abort = 0;
 925         int ret;
 926
 927         _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
 928
 929         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 930                                      want_more, &remote_abort,
 931                                      &call->service_id);
 932         if (ret == 0 || ret == -EAGAIN)
 933                 return ret;
 934
 935         state = READ_ONCE(call->state);
 936         if (ret == 1) {
 937                 switch (state) {
 938                 case AFS_CALL_CL_AWAIT_REPLY:
 939                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 940                         break;
 941                 case AFS_CALL_SV_AWAIT_REQUEST:
 942                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 943                         break;
 944                 case AFS_CALL_COMPLETE:
 945                         kdebug("prem complete %d", call->error);
 946                         return afs_io_error(call, afs_io_error_extract);
 947                 default:
 948                         break;
 949                 }
 950                 return 0;
 951         }
 952
 953         afs_set_call_complete(call, ret, remote_abort);
 954         return ret;
 955 }
 956
 957 /*
 958  * Log protocol error production.
 959  */
 960 noinline int afs_protocol_error(struct afs_call *call, int error,
 961                                 enum afs_eproto_cause cause)
 962 {
 963         trace_afs_protocol_error(call, error, cause);
 964         return error;
 965 }