fs/afs/rxrpc.c

   1 /* Maintain an RxRPC server socket to do AFS communications through
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/sched/signal.h>
  14
  15 #include <net/sock.h>
  16 #include <net/af_rxrpc.h>
  17 #include "internal.h"
  18 #include "afs_cm.h"
  19 #include "protocol_yfs.h"
  20
  21 struct workqueue_struct *afs_async_calls;
  22
  23 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  24 static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
  25 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  26 static void afs_process_async_call(struct work_struct *);
  27 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  28 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  29 static int afs_deliver_cm_op_id(struct afs_call *);
  30
  31 /* asynchronous incoming call initial processing */
  32 static const struct afs_call_type afs_RXCMxxxx = {
  33         .name           = "CB.xxxx",
  34         .deliver        = afs_deliver_cm_op_id,
  35 };
  36
  37 /*
  38  * open an RxRPC socket and bind it to be a server for callback notifications
  39  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  40  */
  41 int afs_open_socket(struct afs_net *net)
  42 {
  43         struct sockaddr_rxrpc srx;
  44         struct socket *socket;
  45         unsigned int min_level;
  46         int ret;
  47
  48         _enter("");
  49
  50         ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
  51         if (ret < 0)
  52                 goto error_1;
  53
  54         socket->sk->sk_allocation = GFP_NOFS;
  55
  56         /* bind the callback manager's address to make this a server socket */
  57         memset(&srx, 0, sizeof(srx));
  58         srx.srx_family                  = AF_RXRPC;
  59         srx.srx_service                 = CM_SERVICE;
  60         srx.transport_type              = SOCK_DGRAM;
  61         srx.transport_len               = sizeof(srx.transport.sin6);
  62         srx.transport.sin6.sin6_family  = AF_INET6;
  63         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
  64
  65         min_level = RXRPC_SECURITY_ENCRYPT;
  66         ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
  67                                 (void *)&min_level, sizeof(min_level));
  68         if (ret < 0)
  69                 goto error_2;
  70
  71         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  72         if (ret == -EADDRINUSE) {
  73                 srx.transport.sin6.sin6_port = 0;
  74                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  75         }
  76         if (ret < 0)
  77                 goto error_2;
  78
  79         srx.srx_service = YFS_CM_SERVICE;
  80         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  81         if (ret < 0)
  82                 goto error_2;
  83
  84         /* Ideally, we'd turn on service upgrade here, but we can't because
  85          * OpenAFS is buggy and leaks the userStatus field from packet to
  86          * packet and between FS packets and CB packets - so if we try to do an
  87          * upgrade on an FS packet, OpenAFS will leak that into the CB packet
  88          * it sends back to us.
  89          */
  90
  91         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  92                                            afs_rx_discard_new_call);
  93
  94         ret = kernel_listen(socket, INT_MAX);
  95         if (ret < 0)
  96                 goto error_2;
  97
  98         net->socket = socket;
  99         afs_charge_preallocation(&net->charge_preallocation_work);
 100         _leave(" = 0");
 101         return 0;
 102
 103 error_2:
 104         sock_release(socket);
 105 error_1:
 106         _leave(" = %d", ret);
 107         return ret;
 108 }
 109
 110 /*
 111  * close the RxRPC socket AFS was using
 112  */
 113 void afs_close_socket(struct afs_net *net)
 114 {
 115         _enter("");
 116
 117         kernel_listen(net->socket, 0);
 118         flush_workqueue(afs_async_calls);
 119
 120         if (net->spare_incoming_call) {
 121                 afs_put_call(net->spare_incoming_call);
 122                 net->spare_incoming_call = NULL;
 123         }
 124
 125         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
 126         wait_var_event(&net->nr_outstanding_calls,
 127                        !atomic_read(&net->nr_outstanding_calls));
 128         _debug("no outstanding calls");
 129
 130         kernel_sock_shutdown(net->socket, SHUT_RDWR);
 131         flush_workqueue(afs_async_calls);
 132         sock_release(net->socket);
 133
 134         _debug("dework");
 135         _leave("");
 136 }
 137
 138 /*
 139  * Allocate a call.
 140  */
 141 static struct afs_call *afs_alloc_call(struct afs_net *net,
 142                                        const struct afs_call_type *type,
 143                                        gfp_t gfp)
 144 {
 145         struct afs_call *call;
 146         int o;
 147
 148         call = kzalloc(sizeof(*call), gfp);
 149         if (!call)
 150                 return NULL;
 151
 152         call->type = type;
 153         call->net = net;
 154         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 155         atomic_set(&call->usage, 1);
 156         INIT_WORK(&call->async_work, afs_process_async_call);
 157         init_waitqueue_head(&call->waitq);
 158         spin_lock_init(&call->state_lock);
 159         call->_iter = &call->iter;
 160
 161         o = atomic_inc_return(&net->nr_outstanding_calls);
 162         trace_afs_call(call, afs_call_trace_alloc, 1, o,
 163                        __builtin_return_address(0));
 164         return call;
 165 }
 166
 167 /*
 168  * Dispose of a reference on a call.
 169  */
 170 void afs_put_call(struct afs_call *call)
 171 {
 172         struct afs_net *net = call->net;
 173         int n = atomic_dec_return(&call->usage);
 174         int o = atomic_read(&net->nr_outstanding_calls);
 175
 176         trace_afs_call(call, afs_call_trace_put, n + 1, o,
 177                        __builtin_return_address(0));
 178
 179         ASSERTCMP(n, >=, 0);
 180         if (n == 0) {
 181                 ASSERT(!work_pending(&call->async_work));
 182                 ASSERT(call->type->name != NULL);
 183
 184                 if (call->rxcall) {
 185                         rxrpc_kernel_end_call(net->socket, call->rxcall);
 186                         call->rxcall = NULL;
 187                 }
 188                 if (call->type->destructor)
 189                         call->type->destructor(call);
 190
 191                 afs_put_server(call->net, call->cm_server);
 192                 afs_put_cb_interest(call->net, call->cbi);
 193                 afs_put_addrlist(call->alist);
 194                 kfree(call->request);
 195
 196                 trace_afs_call(call, afs_call_trace_free, 0, o,
 197                                __builtin_return_address(0));
 198                 kfree(call);
 199
 200                 o = atomic_dec_return(&net->nr_outstanding_calls);
 201                 if (o == 0)
 202                         wake_up_var(&net->nr_outstanding_calls);
 203         }
 204 }
 205
 206 /*
 207  * Queue the call for actual work.
 208  */
 209 static void afs_queue_call_work(struct afs_call *call)
 210 {
 211         if (call->type->work) {
 212                 int u = atomic_inc_return(&call->usage);
 213
 214                 trace_afs_call(call, afs_call_trace_work, u,
 215                                atomic_read(&call->net->nr_outstanding_calls),
 216                                __builtin_return_address(0));
 217
 218                 INIT_WORK(&call->work, call->type->work);
 219
 220                 if (!queue_work(afs_wq, &call->work))
 221                         afs_put_call(call);
 222         }
 223 }
 224
 225 /*
 226  * allocate a call with flat request and reply buffers
 227  */
 228 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 229                                      const struct afs_call_type *type,
 230                                      size_t request_size, size_t reply_max)
 231 {
 232         struct afs_call *call;
 233
 234         call = afs_alloc_call(net, type, GFP_NOFS);
 235         if (!call)
 236                 goto nomem_call;
 237
 238         if (request_size) {
 239                 call->request_size = request_size;
 240                 call->request = kmalloc(request_size, GFP_NOFS);
 241                 if (!call->request)
 242                         goto nomem_free;
 243         }
 244
 245         if (reply_max) {
 246                 call->reply_max = reply_max;
 247                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 248                 if (!call->buffer)
 249                         goto nomem_free;
 250         }
 251
 252         afs_extract_to_buf(call, call->reply_max);
 253         call->operation_ID = type->op;
 254         init_waitqueue_head(&call->waitq);
 255         return call;
 256
 257 nomem_free:
 258         afs_put_call(call);
 259 nomem_call:
 260         return NULL;
 261 }
 262
 263 /*
 264  * clean up a call with flat buffer
 265  */
 266 void afs_flat_call_destructor(struct afs_call *call)
 267 {
 268         _enter("");
 269
 270         kfree(call->request);
 271         call->request = NULL;
 272         kfree(call->buffer);
 273         call->buffer = NULL;
 274 }
 275
 276 #define AFS_BVEC_MAX 8
 277
 278 /*
 279  * Load the given bvec with the next few pages.
 280  */
 281 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 282                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
 283                           unsigned offset)
 284 {
 285         struct page *pages[AFS_BVEC_MAX];
 286         unsigned int nr, n, i, to, bytes = 0;
 287
 288         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
 289         n = find_get_pages_contig(call->mapping, first, nr, pages);
 290         ASSERTCMP(n, ==, nr);
 291
 292         msg->msg_flags |= MSG_MORE;
 293         for (i = 0; i < nr; i++) {
 294                 to = PAGE_SIZE;
 295                 if (first + i >= last) {
 296                         to = call->last_to;
 297                         msg->msg_flags &= ~MSG_MORE;
 298                 }
 299                 bv[i].bv_page = pages[i];
 300                 bv[i].bv_len = to - offset;
 301                 bv[i].bv_offset = offset;
 302                 bytes += to - offset;
 303                 offset = 0;
 304         }
 305
 306         iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
 307 }
 308
 309 /*
 310  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 311  */
 312 static void afs_notify_end_request_tx(struct sock *sock,
 313                                       struct rxrpc_call *rxcall,
 314                                       unsigned long call_user_ID)
 315 {
 316         struct afs_call *call = (struct afs_call *)call_user_ID;
 317
 318         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 319 }
 320
 321 /*
 322  * attach the data from a bunch of pages on an inode to a call
 323  */
 324 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
 325 {
 326         struct bio_vec bv[AFS_BVEC_MAX];
 327         unsigned int bytes, nr, loop, offset;
 328         pgoff_t first = call->first, last = call->last;
 329         int ret;
 330
 331         offset = call->first_offset;
 332         call->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(call->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, call->first, last, first, ret);
 353         return ret;
 354 }
 355
 356 /*
 357  * initiate a call
 358  */
 359 long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 360                    gfp_t gfp, bool async)
 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->async = async;
 379         call->addr_ix = ac->index;
 380         call->alist = afs_get_addrlist(ac->alist);
 381
 382         /* Work out the length we're going to transmit.  This is awkward for
 383          * calls such as FS.StoreData where there's an extra injection of data
 384          * after the initial fixed part.
 385          */
 386         tx_total_len = call->request_size;
 387         if (call->send_pages) {
 388                 if (call->last == call->first) {
 389                         tx_total_len += call->last_to - call->first_offset;
 390                 } else {
 391                         /* It looks mathematically like you should be able to
 392                          * combine the following lines with the ones above, but
 393                          * unsigned arithmetic is fun when it wraps...
 394                          */
 395                         tx_total_len += PAGE_SIZE - call->first_offset;
 396                         tx_total_len += call->last_to;
 397                         tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
 398                 }
 399         }
 400
 401         /* create a call */
 402         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 403                                          (unsigned long)call,
 404                                          tx_total_len, gfp,
 405                                          (async ?
 406                                           afs_wake_up_async_call :
 407                                           afs_wake_up_call_waiter),
 408                                          call->upgrade,
 409                                          call->debug_id);
 410         if (IS_ERR(rxcall)) {
 411                 ret = PTR_ERR(rxcall);
 412                 call->error = ret;
 413                 goto error_kill_call;
 414         }
 415
 416         call->rxcall = rxcall;
 417
 418         /* send the request */
 419         iov[0].iov_base = call->request;
 420         iov[0].iov_len  = call->request_size;
 421
 422         msg.msg_name            = NULL;
 423         msg.msg_namelen         = 0;
 424         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
 425         msg.msg_control         = NULL;
 426         msg.msg_controllen      = 0;
 427         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
 428
 429         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 430                                      &msg, call->request_size,
 431                                      afs_notify_end_request_tx);
 432         if (ret < 0)
 433                 goto error_do_abort;
 434
 435         if (call->send_pages) {
 436                 ret = afs_send_pages(call, &msg);
 437                 if (ret < 0)
 438                         goto error_do_abort;
 439         }
 440
 441         /* at this point, an async call may no longer exist as it may have
 442          * already completed */
 443         if (call->async)
 444                 return -EINPROGRESS;
 445
 446         return afs_wait_for_call_to_complete(call, ac);
 447
 448 error_do_abort:
 449         call->state = AFS_CALL_COMPLETE;
 450         if (ret != -ECONNABORTED) {
 451                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 452                                         RX_USER_ABORT, ret, "KSD");
 453         } else {
 454                 iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
 455                 rxrpc_kernel_recv_data(call->net->socket, rxcall,
 456                                        &msg.msg_iter, false,
 457                                        &call->abort_code, &call->service_id);
 458                 ac->abort_code = call->abort_code;
 459                 ac->responded = true;
 460         }
 461         call->error = ret;
 462         trace_afs_call_done(call);
 463 error_kill_call:
 464         if (call->type->done)
 465                 call->type->done(call);
 466         afs_put_call(call);
 467         ac->error = ret;
 468         _leave(" = %d", ret);
 469         return ret;
 470 }
 471
 472 /*
 473  * deliver messages to a call
 474  */
 475 static void afs_deliver_to_call(struct afs_call *call)
 476 {
 477         enum afs_call_state state;
 478         u32 abort_code, remote_abort = 0;
 479         int ret;
 480
 481         _enter("%s", call->type->name);
 482
 483         while (state = READ_ONCE(call->state),
 484                state == AFS_CALL_CL_AWAIT_REPLY ||
 485                state == AFS_CALL_SV_AWAIT_OP_ID ||
 486                state == AFS_CALL_SV_AWAIT_REQUEST ||
 487                state == AFS_CALL_SV_AWAIT_ACK
 488                ) {
 489                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 490                         iov_iter_kvec(&call->iter, READ, NULL, 0, 0);
 491                         ret = rxrpc_kernel_recv_data(call->net->socket,
 492                                                      call->rxcall, &call->iter,
 493                                                      false, &remote_abort,
 494                                                      &call->service_id);
 495                         trace_afs_receive_data(call, &call->iter, false, ret);
 496
 497                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 498                                 return;
 499                         if (ret < 0 || ret == 1) {
 500                                 if (ret == 1)
 501                                         ret = 0;
 502                                 goto call_complete;
 503                         }
 504                         return;
 505                 }
 506
 507                 if (call->want_reply_time &&
 508                     rxrpc_kernel_get_reply_time(call->net->socket,
 509                                                 call->rxcall,
 510                                                 &call->reply_time))
 511                         call->want_reply_time = false;
 512
 513                 ret = call->type->deliver(call);
 514                 state = READ_ONCE(call->state);
 515                 switch (ret) {
 516                 case 0:
 517                         afs_queue_call_work(call);
 518                         if (state == AFS_CALL_CL_PROC_REPLY) {
 519                                 if (call->cbi)
 520                                         set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
 521                                                 &call->cbi->server->flags);
 522                                 goto call_complete;
 523                         }
 524                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 525                         goto done;
 526                 case -EINPROGRESS:
 527                 case -EAGAIN:
 528                         goto out;
 529                 case -ECONNABORTED:
 530                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 531                         goto done;
 532                 case -ENOTSUPP:
 533                         abort_code = RXGEN_OPCODE;
 534                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 535                                                 abort_code, ret, "KIV");
 536                         goto local_abort;
 537                 case -EIO:
 538                         pr_err("kAFS: Call %u in bad state %u\n",
 539                                call->debug_id, state);
 540                         /* Fall through */
 541                 case -ENODATA:
 542                 case -EBADMSG:
 543                 case -EMSGSIZE:
 544                 default:
 545                         abort_code = RXGEN_CC_UNMARSHAL;
 546                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 547                                 abort_code = RXGEN_SS_UNMARSHAL;
 548                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 549                                                 abort_code, ret, "KUM");
 550                         goto local_abort;
 551                 }
 552         }
 553
 554 done:
 555         if (call->type->done)
 556                 call->type->done(call);
 557         if (state == AFS_CALL_COMPLETE && call->incoming)
 558                 afs_put_call(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
 573  */
 574 static long afs_wait_for_call_to_complete(struct afs_call *call,
 575                                           struct afs_addr_cursor *ac)
 576 {
 577         signed long rtt2, timeout;
 578         long ret;
 579         u64 rtt;
 580         u32 life, last_life;
 581
 582         DECLARE_WAITQUEUE(myself, current);
 583
 584         _enter("");
 585
 586         rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
 587         rtt2 = nsecs_to_jiffies64(rtt) * 2;
 588         if (rtt2 < 2)
 589                 rtt2 = 2;
 590
 591         timeout = rtt2;
 592         last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
 593
 594         add_wait_queue(&call->waitq, &myself);
 595         for (;;) {
 596                 set_current_state(TASK_UNINTERRUPTIBLE);
 597
 598                 /* deliver any messages that are in the queue */
 599                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 600                     call->need_attention) {
 601                         call->need_attention = false;
 602                         __set_current_state(TASK_RUNNING);
 603                         afs_deliver_to_call(call);
 604                         continue;
 605                 }
 606
 607                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 608                         break;
 609
 610                 life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
 611                 if (timeout == 0 &&
 612                     life == last_life && signal_pending(current))
 613                                 break;
 614
 615                 if (life != last_life) {
 616                         timeout = rtt2;
 617                         last_life = life;
 618                 }
 619
 620                 timeout = schedule_timeout(timeout);
 621         }
 622
 623         remove_wait_queue(&call->waitq, &myself);
 624         __set_current_state(TASK_RUNNING);
 625
 626         /* Kill off the call if it's still live. */
 627         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 628                 _debug("call interrupted");
 629                 if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 630                                             RX_USER_ABORT, -EINTR, "KWI"))
 631                         afs_set_call_complete(call, -EINTR, 0);
 632         }
 633
 634         spin_lock_bh(&call->state_lock);
 635         ac->abort_code = call->abort_code;
 636         ac->error = call->error;
 637         spin_unlock_bh(&call->state_lock);
 638
 639         ret = ac->error;
 640         switch (ret) {
 641         case 0:
 642                 if (call->ret_reply0) {
 643                         ret = (long)call->reply[0];
 644                         call->reply[0] = NULL;
 645                 }
 646                 /* Fall through */
 647         case -ECONNABORTED:
 648                 ac->responded = true;
 649                 break;
 650         }
 651
 652         _debug("call complete");
 653         afs_put_call(call);
 654         _leave(" = %p", (void *)ret);
 655         return ret;
 656 }
 657
 658 /*
 659  * wake up a waiting call
 660  */
 661 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 662                                     unsigned long call_user_ID)
 663 {
 664         struct afs_call *call = (struct afs_call *)call_user_ID;
 665
 666         call->need_attention = true;
 667         wake_up(&call->waitq);
 668 }
 669
 670 /*
 671  * wake up an asynchronous call
 672  */
 673 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 674                                    unsigned long call_user_ID)
 675 {
 676         struct afs_call *call = (struct afs_call *)call_user_ID;
 677         int u;
 678
 679         trace_afs_notify_call(rxcall, call);
 680         call->need_attention = true;
 681
 682         u = atomic_fetch_add_unless(&call->usage, 1, 0);
 683         if (u != 0) {
 684                 trace_afs_call(call, afs_call_trace_wake, u,
 685                                atomic_read(&call->net->nr_outstanding_calls),
 686                                __builtin_return_address(0));
 687
 688                 if (!queue_work(afs_async_calls, &call->async_work))
 689                         afs_put_call(call);
 690         }
 691 }
 692
 693 /*
 694  * Delete an asynchronous call.  The work item carries a ref to the call struct
 695  * that we need to release.
 696  */
 697 static void afs_delete_async_call(struct work_struct *work)
 698 {
 699         struct afs_call *call = container_of(work, struct afs_call, async_work);
 700
 701         _enter("");
 702
 703         afs_put_call(call);
 704
 705         _leave("");
 706 }
 707
 708 /*
 709  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 710  * to the call struct that we either need to release or to pass on.
 711  */
 712 static void afs_process_async_call(struct work_struct *work)
 713 {
 714         struct afs_call *call = container_of(work, struct afs_call, async_work);
 715
 716         _enter("");
 717
 718         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 719                 call->need_attention = false;
 720                 afs_deliver_to_call(call);
 721         }
 722
 723         if (call->state == AFS_CALL_COMPLETE) {
 724                 /* We have two refs to release - one from the alloc and one
 725                  * queued with the work item - and we can't just deallocate the
 726                  * call because the work item may be queued again.
 727                  */
 728                 call->async_work.func = afs_delete_async_call;
 729                 if (!queue_work(afs_async_calls, &call->async_work))
 730                         afs_put_call(call);
 731         }
 732
 733         afs_put_call(call);
 734         _leave("");
 735 }
 736
 737 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 738 {
 739         struct afs_call *call = (struct afs_call *)user_call_ID;
 740
 741         call->rxcall = rxcall;
 742 }
 743
 744 /*
 745  * Charge the incoming call preallocation.
 746  */
 747 void afs_charge_preallocation(struct work_struct *work)
 748 {
 749         struct afs_net *net =
 750                 container_of(work, struct afs_net, charge_preallocation_work);
 751         struct afs_call *call = net->spare_incoming_call;
 752
 753         for (;;) {
 754                 if (!call) {
 755                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 756                         if (!call)
 757                                 break;
 758
 759                         call->async = true;
 760                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 761                         init_waitqueue_head(&call->waitq);
 762                         afs_extract_to_tmp(call);
 763                 }
 764
 765                 if (rxrpc_kernel_charge_accept(net->socket,
 766                                                afs_wake_up_async_call,
 767                                                afs_rx_attach,
 768                                                (unsigned long)call,
 769                                                GFP_KERNEL,
 770                                                call->debug_id) < 0)
 771                         break;
 772                 call = NULL;
 773         }
 774         net->spare_incoming_call = call;
 775 }
 776
 777 /*
 778  * Discard a preallocated call when a socket is shut down.
 779  */
 780 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 781                                     unsigned long user_call_ID)
 782 {
 783         struct afs_call *call = (struct afs_call *)user_call_ID;
 784
 785         call->rxcall = NULL;
 786         afs_put_call(call);
 787 }
 788
 789 /*
 790  * Notification of an incoming call.
 791  */
 792 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 793                             unsigned long user_call_ID)
 794 {
 795         struct afs_net *net = afs_sock2net(sk);
 796
 797         queue_work(afs_wq, &net->charge_preallocation_work);
 798 }
 799
 800 /*
 801  * Grab the operation ID from an incoming cache manager call.  The socket
 802  * buffer is discarded on error or if we don't yet have sufficient data.
 803  */
 804 static int afs_deliver_cm_op_id(struct afs_call *call)
 805 {
 806         int ret;
 807
 808         _enter("{%zu}", iov_iter_count(call->_iter));
 809
 810         /* the operation ID forms the first four bytes of the request data */
 811         ret = afs_extract_data(call, true);
 812         if (ret < 0)
 813                 return ret;
 814
 815         call->operation_ID = ntohl(call->tmp);
 816         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 817
 818         /* ask the cache manager to route the call (it'll change the call type
 819          * if successful) */
 820         if (!afs_cm_incoming_call(call))
 821                 return -ENOTSUPP;
 822
 823         trace_afs_cb_call(call);
 824
 825         /* pass responsibility for the remainer of this message off to the
 826          * cache manager op */
 827         return call->type->deliver(call);
 828 }
 829
 830 /*
 831  * Advance the AFS call state when an RxRPC service call ends the transmit
 832  * phase.
 833  */
 834 static void afs_notify_end_reply_tx(struct sock *sock,
 835                                     struct rxrpc_call *rxcall,
 836                                     unsigned long call_user_ID)
 837 {
 838         struct afs_call *call = (struct afs_call *)call_user_ID;
 839
 840         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 841 }
 842
 843 /*
 844  * send an empty reply
 845  */
 846 void afs_send_empty_reply(struct afs_call *call)
 847 {
 848         struct afs_net *net = call->net;
 849         struct msghdr msg;
 850
 851         _enter("");
 852
 853         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 854
 855         msg.msg_name            = NULL;
 856         msg.msg_namelen         = 0;
 857         iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
 858         msg.msg_control         = NULL;
 859         msg.msg_controllen      = 0;
 860         msg.msg_flags           = 0;
 861
 862         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 863                                        afs_notify_end_reply_tx)) {
 864         case 0:
 865                 _leave(" [replied]");
 866                 return;
 867
 868         case -ENOMEM:
 869                 _debug("oom");
 870                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 871                                         RX_USER_ABORT, -ENOMEM, "KOO");
 872         default:
 873                 _leave(" [error]");
 874                 return;
 875         }
 876 }
 877
 878 /*
 879  * send a simple reply
 880  */
 881 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 882 {
 883         struct afs_net *net = call->net;
 884         struct msghdr msg;
 885         struct kvec iov[1];
 886         int n;
 887
 888         _enter("");
 889
 890         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 891
 892         iov[0].iov_base         = (void *) buf;
 893         iov[0].iov_len          = len;
 894         msg.msg_name            = NULL;
 895         msg.msg_namelen         = 0;
 896         iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
 897         msg.msg_control         = NULL;
 898         msg.msg_controllen      = 0;
 899         msg.msg_flags           = 0;
 900
 901         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 902                                    afs_notify_end_reply_tx);
 903         if (n >= 0) {
 904                 /* Success */
 905                 _leave(" [replied]");
 906                 return;
 907         }
 908
 909         if (n == -ENOMEM) {
 910                 _debug("oom");
 911                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 912                                         RX_USER_ABORT, -ENOMEM, "KOO");
 913         }
 914         _leave(" [error]");
 915 }
 916
 917 /*
 918  * Extract a piece of data from the received data socket buffers.
 919  */
 920 int afs_extract_data(struct afs_call *call, bool want_more)
 921 {
 922         struct afs_net *net = call->net;
 923         struct iov_iter *iter = call->_iter;
 924         enum afs_call_state state;
 925         u32 remote_abort = 0;
 926         int ret;
 927
 928         _enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
 929
 930         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
 931                                      want_more, &remote_abort,
 932                                      &call->service_id);
 933         if (ret == 0 || ret == -EAGAIN)
 934                 return ret;
 935
 936         state = READ_ONCE(call->state);
 937         if (ret == 1) {
 938                 switch (state) {
 939                 case AFS_CALL_CL_AWAIT_REPLY:
 940                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 941                         break;
 942                 case AFS_CALL_SV_AWAIT_REQUEST:
 943                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 944                         break;
 945                 case AFS_CALL_COMPLETE:
 946                         kdebug("prem complete %d", call->error);
 947                         return afs_io_error(call, afs_io_error_extract);
 948                 default:
 949                         break;
 950                 }
 951                 return 0;
 952         }
 953
 954         afs_set_call_complete(call, ret, remote_abort);
 955         return ret;
 956 }
 957
 958 /*
 959  * Log protocol error production.
 960  */
 961 noinline int afs_protocol_error(struct afs_call *call, int error,
 962                                 enum afs_eproto_cause cause)
 963 {
 964         trace_afs_protocol_error(call, error, cause);
 965         return error;
 966 }