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 <net/sock.h>
  14 #include <net/af_rxrpc.h>
  15 #include <rxrpc/packet.h>
  16 #include "internal.h"
  17 #include "afs_cm.h"
  18
  19 struct socket *afs_socket; /* my RxRPC socket */
  20 static struct workqueue_struct *afs_async_calls;
  21 static struct afs_call *afs_spare_incoming_call;
  22 static atomic_t afs_outstanding_calls;
  23
  24 static void afs_free_call(struct afs_call *);
  25 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  26 static int afs_wait_for_call_to_complete(struct afs_call *);
  27 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  28 static int afs_dont_wait_for_call_to_complete(struct afs_call *);
  29 static void afs_process_async_call(struct work_struct *);
  30 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  31 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  32 static int afs_deliver_cm_op_id(struct afs_call *);
  33
  34 /* synchronous call management */
  35 const struct afs_wait_mode afs_sync_call = {
  36         .notify_rx      = afs_wake_up_call_waiter,
  37         .wait           = afs_wait_for_call_to_complete,
  38 };
  39
  40 /* asynchronous call management */
  41 const struct afs_wait_mode afs_async_call = {
  42         .notify_rx      = afs_wake_up_async_call,
  43         .wait           = afs_dont_wait_for_call_to_complete,
  44 };
  45
  46 /* asynchronous incoming call management */
  47 static const struct afs_wait_mode afs_async_incoming_call = {
  48         .notify_rx      = afs_wake_up_async_call,
  49 };
  50
  51 /* asynchronous incoming call initial processing */
  52 static const struct afs_call_type afs_RXCMxxxx = {
  53         .name           = "CB.xxxx",
  54         .deliver        = afs_deliver_cm_op_id,
  55         .abort_to_error = afs_abort_to_error,
  56 };
  57
  58 static void afs_charge_preallocation(struct work_struct *);
  59
  60 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
  61
  62 static int afs_wait_atomic_t(atomic_t *p)
  63 {
  64         schedule();
  65         return 0;
  66 }
  67
  68 /*
  69  * open an RxRPC socket and bind it to be a server for callback notifications
  70  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  71  */
  72 int afs_open_socket(void)
  73 {
  74         struct sockaddr_rxrpc srx;
  75         struct socket *socket;
  76         int ret;
  77
  78         _enter("");
  79
  80         ret = -ENOMEM;
  81         afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
  82         if (!afs_async_calls)
  83                 goto error_0;
  84
  85         ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
  86         if (ret < 0)
  87                 goto error_1;
  88
  89         socket->sk->sk_allocation = GFP_NOFS;
  90
  91         /* bind the callback manager's address to make this a server socket */
  92         srx.srx_family                  = AF_RXRPC;
  93         srx.srx_service                 = CM_SERVICE;
  94         srx.transport_type              = SOCK_DGRAM;
  95         srx.transport_len               = sizeof(srx.transport.sin);
  96         srx.transport.sin.sin_family    = AF_INET;
  97         srx.transport.sin.sin_port      = htons(AFS_CM_PORT);
  98         memset(&srx.transport.sin.sin_addr, 0,
  99                sizeof(srx.transport.sin.sin_addr));
 100
 101         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 102         if (ret < 0)
 103                 goto error_2;
 104
 105         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
 106                                            afs_rx_discard_new_call);
 107
 108         ret = kernel_listen(socket, INT_MAX);
 109         if (ret < 0)
 110                 goto error_2;
 111
 112         afs_socket = socket;
 113         afs_charge_preallocation(NULL);
 114         _leave(" = 0");
 115         return 0;
 116
 117 error_2:
 118         sock_release(socket);
 119 error_1:
 120         destroy_workqueue(afs_async_calls);
 121 error_0:
 122         _leave(" = %d", ret);
 123         return ret;
 124 }
 125
 126 /*
 127  * close the RxRPC socket AFS was using
 128  */
 129 void afs_close_socket(void)
 130 {
 131         _enter("");
 132
 133         if (afs_spare_incoming_call) {
 134                 atomic_inc(&afs_outstanding_calls);
 135                 afs_free_call(afs_spare_incoming_call);
 136                 afs_spare_incoming_call = NULL;
 137         }
 138
 139         _debug("outstanding %u", atomic_read(&afs_outstanding_calls));
 140         wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
 141                          TASK_UNINTERRUPTIBLE);
 142         _debug("no outstanding calls");
 143
 144         flush_workqueue(afs_async_calls);
 145         kernel_sock_shutdown(afs_socket, SHUT_RDWR);
 146         flush_workqueue(afs_async_calls);
 147         sock_release(afs_socket);
 148
 149         _debug("dework");
 150         destroy_workqueue(afs_async_calls);
 151         _leave("");
 152 }
 153
 154 /*
 155  * free a call
 156  */
 157 static void afs_free_call(struct afs_call *call)
 158 {
 159         _debug("DONE %p{%s} [%d]",
 160                call, call->type->name, atomic_read(&afs_outstanding_calls));
 161
 162         ASSERTCMP(call->rxcall, ==, NULL);
 163         ASSERT(!work_pending(&call->async_work));
 164         ASSERT(call->type->name != NULL);
 165
 166         kfree(call->request);
 167         kfree(call);
 168
 169         if (atomic_dec_and_test(&afs_outstanding_calls))
 170                 wake_up_atomic_t(&afs_outstanding_calls);
 171 }
 172
 173 /*
 174  * End a call but do not free it
 175  */
 176 static void afs_end_call_nofree(struct afs_call *call)
 177 {
 178         if (call->rxcall) {
 179                 rxrpc_kernel_end_call(afs_socket, call->rxcall);
 180                 call->rxcall = NULL;
 181         }
 182         if (call->type->destructor)
 183                 call->type->destructor(call);
 184 }
 185
 186 /*
 187  * End a call and free it
 188  */
 189 static void afs_end_call(struct afs_call *call)
 190 {
 191         afs_end_call_nofree(call);
 192         afs_free_call(call);
 193 }
 194
 195 /*
 196  * allocate a call with flat request and reply buffers
 197  */
 198 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
 199                                      size_t request_size, size_t reply_max)
 200 {
 201         struct afs_call *call;
 202
 203         call = kzalloc(sizeof(*call), GFP_NOFS);
 204         if (!call)
 205                 goto nomem_call;
 206
 207         _debug("CALL %p{%s} [%d]",
 208                call, type->name, atomic_read(&afs_outstanding_calls));
 209         atomic_inc(&afs_outstanding_calls);
 210
 211         call->type = type;
 212         call->request_size = request_size;
 213         call->reply_max = reply_max;
 214
 215         if (request_size) {
 216                 call->request = kmalloc(request_size, GFP_NOFS);
 217                 if (!call->request)
 218                         goto nomem_free;
 219         }
 220
 221         if (reply_max) {
 222                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 223                 if (!call->buffer)
 224                         goto nomem_free;
 225         }
 226
 227         init_waitqueue_head(&call->waitq);
 228         return call;
 229
 230 nomem_free:
 231         afs_free_call(call);
 232 nomem_call:
 233         return NULL;
 234 }
 235
 236 /*
 237  * clean up a call with flat buffer
 238  */
 239 void afs_flat_call_destructor(struct afs_call *call)
 240 {
 241         _enter("");
 242
 243         kfree(call->request);
 244         call->request = NULL;
 245         kfree(call->buffer);
 246         call->buffer = NULL;
 247 }
 248
 249 /*
 250  * attach the data from a bunch of pages on an inode to a call
 251  */
 252 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
 253                           struct kvec *iov)
 254 {
 255         struct page *pages[8];
 256         unsigned count, n, loop, offset, to;
 257         pgoff_t first = call->first, last = call->last;
 258         int ret;
 259
 260         _enter("");
 261
 262         offset = call->first_offset;
 263         call->first_offset = 0;
 264
 265         do {
 266                 _debug("attach %lx-%lx", first, last);
 267
 268                 count = last - first + 1;
 269                 if (count > ARRAY_SIZE(pages))
 270                         count = ARRAY_SIZE(pages);
 271                 n = find_get_pages_contig(call->mapping, first, count, pages);
 272                 ASSERTCMP(n, ==, count);
 273
 274                 loop = 0;
 275                 do {
 276                         msg->msg_flags = 0;
 277                         to = PAGE_SIZE;
 278                         if (first + loop >= last)
 279                                 to = call->last_to;
 280                         else
 281                                 msg->msg_flags = MSG_MORE;
 282                         iov->iov_base = kmap(pages[loop]) + offset;
 283                         iov->iov_len = to - offset;
 284                         offset = 0;
 285
 286                         _debug("- range %u-%u%s",
 287                                offset, to, msg->msg_flags ? " [more]" : "");
 288                         iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
 289                                       iov, 1, to - offset);
 290
 291                         /* have to change the state *before* sending the last
 292                          * packet as RxRPC might give us the reply before it
 293                          * returns from sending the request */
 294                         if (first + loop >= last)
 295                                 call->state = AFS_CALL_AWAIT_REPLY;
 296                         ret = rxrpc_kernel_send_data(afs_socket, call->rxcall,
 297                                                      msg, to - offset);
 298                         kunmap(pages[loop]);
 299                         if (ret < 0)
 300                                 break;
 301                 } while (++loop < count);
 302                 first += count;
 303
 304                 for (loop = 0; loop < count; loop++)
 305                         put_page(pages[loop]);
 306                 if (ret < 0)
 307                         break;
 308         } while (first <= last);
 309
 310         _leave(" = %d", ret);
 311         return ret;
 312 }
 313
 314 /*
 315  * initiate a call
 316  */
 317 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 318                   const struct afs_wait_mode *wait_mode)
 319 {
 320         struct sockaddr_rxrpc srx;
 321         struct rxrpc_call *rxcall;
 322         struct msghdr msg;
 323         struct kvec iov[1];
 324         int ret;
 325
 326         _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
 327
 328         ASSERT(call->type != NULL);
 329         ASSERT(call->type->name != NULL);
 330
 331         _debug("____MAKE %p{%s,%x} [%d]____",
 332                call, call->type->name, key_serial(call->key),
 333                atomic_read(&afs_outstanding_calls));
 334
 335         call->wait_mode = wait_mode;
 336         INIT_WORK(&call->async_work, afs_process_async_call);
 337
 338         memset(&srx, 0, sizeof(srx));
 339         srx.srx_family = AF_RXRPC;
 340         srx.srx_service = call->service_id;
 341         srx.transport_type = SOCK_DGRAM;
 342         srx.transport_len = sizeof(srx.transport.sin);
 343         srx.transport.sin.sin_family = AF_INET;
 344         srx.transport.sin.sin_port = call->port;
 345         memcpy(&srx.transport.sin.sin_addr, addr, 4);
 346
 347         /* create a call */
 348         rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
 349                                          (unsigned long) call, gfp,
 350                                          wait_mode->notify_rx);
 351         call->key = NULL;
 352         if (IS_ERR(rxcall)) {
 353                 ret = PTR_ERR(rxcall);
 354                 goto error_kill_call;
 355         }
 356
 357         call->rxcall = rxcall;
 358
 359         /* send the request */
 360         iov[0].iov_base = call->request;
 361         iov[0].iov_len  = call->request_size;
 362
 363         msg.msg_name            = NULL;
 364         msg.msg_namelen         = 0;
 365         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
 366                       call->request_size);
 367         msg.msg_control         = NULL;
 368         msg.msg_controllen      = 0;
 369         msg.msg_flags           = (call->send_pages ? MSG_MORE : 0);
 370
 371         /* have to change the state *before* sending the last packet as RxRPC
 372          * might give us the reply before it returns from sending the
 373          * request */
 374         if (!call->send_pages)
 375                 call->state = AFS_CALL_AWAIT_REPLY;
 376         ret = rxrpc_kernel_send_data(afs_socket, rxcall,
 377                                      &msg, call->request_size);
 378         if (ret < 0)
 379                 goto error_do_abort;
 380
 381         if (call->send_pages) {
 382                 ret = afs_send_pages(call, &msg, iov);
 383                 if (ret < 0)
 384                         goto error_do_abort;
 385         }
 386
 387         /* at this point, an async call may no longer exist as it may have
 388          * already completed */
 389         return wait_mode->wait(call);
 390
 391 error_do_abort:
 392         rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT, -ret, "KSD");
 393 error_kill_call:
 394         afs_end_call(call);
 395         _leave(" = %d", ret);
 396         return ret;
 397 }
 398
 399 /*
 400  * deliver messages to a call
 401  */
 402 static void afs_deliver_to_call(struct afs_call *call)
 403 {
 404         u32 abort_code;
 405         int ret;
 406
 407         _enter("%s", call->type->name);
 408
 409         while (call->state == AFS_CALL_AWAIT_REPLY ||
 410                call->state == AFS_CALL_AWAIT_OP_ID ||
 411                call->state == AFS_CALL_AWAIT_REQUEST ||
 412                call->state == AFS_CALL_AWAIT_ACK
 413                ) {
 414                 if (call->state == AFS_CALL_AWAIT_ACK) {
 415                         size_t offset = 0;
 416                         ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 417                                                      NULL, 0, &offset, false,
 418                                                      &call->abort_code);
 419                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 420                                 return;
 421                         if (ret == 1) {
 422                                 call->state = AFS_CALL_COMPLETE;
 423                                 goto done;
 424                         }
 425                         return;
 426                 }
 427
 428                 ret = call->type->deliver(call);
 429                 switch (ret) {
 430                 case 0:
 431                         if (call->state == AFS_CALL_AWAIT_REPLY)
 432                                 call->state = AFS_CALL_COMPLETE;
 433                         goto done;
 434                 case -EINPROGRESS:
 435                 case -EAGAIN:
 436                         goto out;
 437                 case -ENOTCONN:
 438                         abort_code = RX_CALL_DEAD;
 439                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 440                                                 abort_code, -ret, "KNC");
 441                         goto do_abort;
 442                 case -ENOTSUPP:
 443                         abort_code = RX_INVALID_OPERATION;
 444                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 445                                                 abort_code, -ret, "KIV");
 446                         goto do_abort;
 447                 case -ENODATA:
 448                 case -EBADMSG:
 449                 case -EMSGSIZE:
 450                 default:
 451                         abort_code = RXGEN_CC_UNMARSHAL;
 452                         if (call->state != AFS_CALL_AWAIT_REPLY)
 453                                 abort_code = RXGEN_SS_UNMARSHAL;
 454                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 455                                                 abort_code, EBADMSG, "KUM");
 456                         goto do_abort;
 457                 }
 458         }
 459
 460 done:
 461         if (call->state == AFS_CALL_COMPLETE && call->incoming)
 462                 afs_end_call(call);
 463 out:
 464         _leave("");
 465         return;
 466
 467 do_abort:
 468         call->error = ret;
 469         call->state = AFS_CALL_COMPLETE;
 470         goto done;
 471 }
 472
 473 /*
 474  * wait synchronously for a call to complete
 475  */
 476 static int afs_wait_for_call_to_complete(struct afs_call *call)
 477 {
 478         const char *abort_why;
 479         int ret;
 480
 481         DECLARE_WAITQUEUE(myself, current);
 482
 483         _enter("");
 484
 485         add_wait_queue(&call->waitq, &myself);
 486         for (;;) {
 487                 set_current_state(TASK_INTERRUPTIBLE);
 488
 489                 /* deliver any messages that are in the queue */
 490                 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 491                         call->need_attention = false;
 492                         __set_current_state(TASK_RUNNING);
 493                         afs_deliver_to_call(call);
 494                         continue;
 495                 }
 496
 497                 abort_why = "KWC";
 498                 ret = call->error;
 499                 if (call->state == AFS_CALL_COMPLETE)
 500                         break;
 501                 abort_why = "KWI";
 502                 ret = -EINTR;
 503                 if (signal_pending(current))
 504                         break;
 505                 schedule();
 506         }
 507
 508         remove_wait_queue(&call->waitq, &myself);
 509         __set_current_state(TASK_RUNNING);
 510
 511         /* kill the call */
 512         if (call->state < AFS_CALL_COMPLETE) {
 513                 _debug("call incomplete");
 514                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 515                                         RX_CALL_DEAD, -ret, abort_why);
 516         }
 517
 518         _debug("call complete");
 519         afs_end_call(call);
 520         _leave(" = %d", ret);
 521         return ret;
 522 }
 523
 524 /*
 525  * wake up a waiting call
 526  */
 527 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 528                                     unsigned long call_user_ID)
 529 {
 530         struct afs_call *call = (struct afs_call *)call_user_ID;
 531
 532         call->need_attention = true;
 533         wake_up(&call->waitq);
 534 }
 535
 536 /*
 537  * wake up an asynchronous call
 538  */
 539 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 540                                    unsigned long call_user_ID)
 541 {
 542         struct afs_call *call = (struct afs_call *)call_user_ID;
 543
 544         call->need_attention = true;
 545         queue_work(afs_async_calls, &call->async_work);
 546 }
 547
 548 /*
 549  * put a call into asynchronous mode
 550  * - mustn't touch the call descriptor as the call my have completed by the
 551  *   time we get here
 552  */
 553 static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
 554 {
 555         _enter("");
 556         return -EINPROGRESS;
 557 }
 558
 559 /*
 560  * delete an asynchronous call
 561  */
 562 static void afs_delete_async_call(struct work_struct *work)
 563 {
 564         struct afs_call *call = container_of(work, struct afs_call, async_work);
 565
 566         _enter("");
 567
 568         afs_free_call(call);
 569
 570         _leave("");
 571 }
 572
 573 /*
 574  * perform processing on an asynchronous call
 575  */
 576 static void afs_process_async_call(struct work_struct *work)
 577 {
 578         struct afs_call *call = container_of(work, struct afs_call, async_work);
 579
 580         _enter("");
 581
 582         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 583                 call->need_attention = false;
 584                 afs_deliver_to_call(call);
 585         }
 586
 587         if (call->state == AFS_CALL_COMPLETE && call->wait_mode) {
 588                 if (call->wait_mode->async_complete)
 589                         call->wait_mode->async_complete(call->reply,
 590                                                         call->error);
 591                 call->reply = NULL;
 592
 593                 /* kill the call */
 594                 afs_end_call_nofree(call);
 595
 596                 /* we can't just delete the call because the work item may be
 597                  * queued */
 598                 call->async_work.func = afs_delete_async_call;
 599                 queue_work(afs_async_calls, &call->async_work);
 600         }
 601
 602         _leave("");
 603 }
 604
 605 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 606 {
 607         struct afs_call *call = (struct afs_call *)user_call_ID;
 608
 609         call->rxcall = rxcall;
 610 }
 611
 612 /*
 613  * Charge the incoming call preallocation.
 614  */
 615 static void afs_charge_preallocation(struct work_struct *work)
 616 {
 617         struct afs_call *call = afs_spare_incoming_call;
 618
 619         for (;;) {
 620                 if (!call) {
 621                         call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
 622                         if (!call)
 623                                 break;
 624
 625                         INIT_WORK(&call->async_work, afs_process_async_call);
 626                         call->wait_mode = &afs_async_incoming_call;
 627                         call->type = &afs_RXCMxxxx;
 628                         init_waitqueue_head(&call->waitq);
 629                         call->state = AFS_CALL_AWAIT_OP_ID;
 630                 }
 631
 632                 if (rxrpc_kernel_charge_accept(afs_socket,
 633                                                afs_wake_up_async_call,
 634                                                afs_rx_attach,
 635                                                (unsigned long)call,
 636                                                GFP_KERNEL) < 0)
 637                         break;
 638                 call = NULL;
 639         }
 640         afs_spare_incoming_call = call;
 641 }
 642
 643 /*
 644  * Discard a preallocated call when a socket is shut down.
 645  */
 646 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 647                                     unsigned long user_call_ID)
 648 {
 649         struct afs_call *call = (struct afs_call *)user_call_ID;
 650
 651         atomic_inc(&afs_outstanding_calls);
 652         call->rxcall = NULL;
 653         afs_free_call(call);
 654 }
 655
 656 /*
 657  * Notification of an incoming call.
 658  */
 659 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 660                             unsigned long user_call_ID)
 661 {
 662         atomic_inc(&afs_outstanding_calls);
 663         queue_work(afs_wq, &afs_charge_preallocation_work);
 664 }
 665
 666 /*
 667  * Grab the operation ID from an incoming cache manager call.  The socket
 668  * buffer is discarded on error or if we don't yet have sufficient data.
 669  */
 670 static int afs_deliver_cm_op_id(struct afs_call *call)
 671 {
 672         int ret;
 673
 674         _enter("{%zu}", call->offset);
 675
 676         ASSERTCMP(call->offset, <, 4);
 677
 678         /* the operation ID forms the first four bytes of the request data */
 679         ret = afs_extract_data(call, &call->operation_ID, 4, true);
 680         if (ret < 0)
 681                 return ret;
 682
 683         call->state = AFS_CALL_AWAIT_REQUEST;
 684         call->offset = 0;
 685
 686         /* ask the cache manager to route the call (it'll change the call type
 687          * if successful) */
 688         if (!afs_cm_incoming_call(call))
 689                 return -ENOTSUPP;
 690
 691         /* pass responsibility for the remainer of this message off to the
 692          * cache manager op */
 693         return call->type->deliver(call);
 694 }
 695
 696 /*
 697  * send an empty reply
 698  */
 699 void afs_send_empty_reply(struct afs_call *call)
 700 {
 701         struct msghdr msg;
 702
 703         _enter("");
 704
 705         msg.msg_name            = NULL;
 706         msg.msg_namelen         = 0;
 707         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
 708         msg.msg_control         = NULL;
 709         msg.msg_controllen      = 0;
 710         msg.msg_flags           = 0;
 711
 712         call->state = AFS_CALL_AWAIT_ACK;
 713         switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0)) {
 714         case 0:
 715                 _leave(" [replied]");
 716                 return;
 717
 718         case -ENOMEM:
 719                 _debug("oom");
 720                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 721                                         RX_USER_ABORT, ENOMEM, "KOO");
 722         default:
 723                 afs_end_call(call);
 724                 _leave(" [error]");
 725                 return;
 726         }
 727 }
 728
 729 /*
 730  * send a simple reply
 731  */
 732 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 733 {
 734         struct msghdr msg;
 735         struct kvec iov[1];
 736         int n;
 737
 738         _enter("");
 739
 740         iov[0].iov_base         = (void *) buf;
 741         iov[0].iov_len          = len;
 742         msg.msg_name            = NULL;
 743         msg.msg_namelen         = 0;
 744         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
 745         msg.msg_control         = NULL;
 746         msg.msg_controllen      = 0;
 747         msg.msg_flags           = 0;
 748
 749         call->state = AFS_CALL_AWAIT_ACK;
 750         n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len);
 751         if (n >= 0) {
 752                 /* Success */
 753                 _leave(" [replied]");
 754                 return;
 755         }
 756
 757         if (n == -ENOMEM) {
 758                 _debug("oom");
 759                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 760                                         RX_USER_ABORT, ENOMEM, "KOO");
 761         }
 762         afs_end_call(call);
 763         _leave(" [error]");
 764 }
 765
 766 /*
 767  * Extract a piece of data from the received data socket buffers.
 768  */
 769 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 770                      bool want_more)
 771 {
 772         int ret;
 773
 774         _enter("{%s,%zu},,%zu,%d",
 775                call->type->name, call->offset, count, want_more);
 776
 777         ASSERTCMP(call->offset, <=, count);
 778
 779         ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 780                                      buf, count, &call->offset,
 781                                      want_more, &call->abort_code);
 782         if (ret == 0 || ret == -EAGAIN)
 783                 return ret;
 784
 785         if (ret == 1) {
 786                 switch (call->state) {
 787                 case AFS_CALL_AWAIT_REPLY:
 788                         call->state = AFS_CALL_COMPLETE;
 789                         break;
 790                 case AFS_CALL_AWAIT_REQUEST:
 791                         call->state = AFS_CALL_REPLYING;
 792                         break;
 793                 default:
 794                         break;
 795                 }
 796                 return 0;
 797         }
 798
 799         if (ret == -ECONNABORTED)
 800                 call->error = call->type->abort_to_error(call->abort_code);
 801         else
 802                 call->error = ret;
 803         call->state = AFS_CALL_COMPLETE;
 804         return ret;
 805 }