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
  20 struct socket *afs_socket; /* my RxRPC socket */
  21 static struct workqueue_struct *afs_async_calls;
  22 static struct afs_call *afs_spare_incoming_call;
  23 atomic_t afs_outstanding_calls;
  24
  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 void afs_process_async_call(struct work_struct *);
  29 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  30 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  31 static int afs_deliver_cm_op_id(struct afs_call *);
  32
  33 /* asynchronous incoming call initial processing */
  34 static const struct afs_call_type afs_RXCMxxxx = {
  35         .name           = "CB.xxxx",
  36         .deliver        = afs_deliver_cm_op_id,
  37         .abort_to_error = afs_abort_to_error,
  38 };
  39
  40 static void afs_charge_preallocation(struct work_struct *);
  41
  42 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
  43
  44 /*
  45  * open an RxRPC socket and bind it to be a server for callback notifications
  46  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  47  */
  48 int afs_open_socket(void)
  49 {
  50         struct sockaddr_rxrpc srx;
  51         struct socket *socket;
  52         int ret;
  53
  54         _enter("");
  55
  56         ret = -ENOMEM;
  57         afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
  58         if (!afs_async_calls)
  59                 goto error_0;
  60
  61         ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
  62         if (ret < 0)
  63                 goto error_1;
  64
  65         socket->sk->sk_allocation = GFP_NOFS;
  66
  67         /* bind the callback manager's address to make this a server socket */
  68         srx.srx_family                  = AF_RXRPC;
  69         srx.srx_service                 = CM_SERVICE;
  70         srx.transport_type              = SOCK_DGRAM;
  71         srx.transport_len               = sizeof(srx.transport.sin);
  72         srx.transport.sin.sin_family    = AF_INET;
  73         srx.transport.sin.sin_port      = htons(AFS_CM_PORT);
  74         memset(&srx.transport.sin.sin_addr, 0,
  75                sizeof(srx.transport.sin.sin_addr));
  76
  77         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  78         if (ret < 0)
  79                 goto error_2;
  80
  81         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  82                                            afs_rx_discard_new_call);
  83
  84         ret = kernel_listen(socket, INT_MAX);
  85         if (ret < 0)
  86                 goto error_2;
  87
  88         afs_socket = socket;
  89         afs_charge_preallocation(NULL);
  90         _leave(" = 0");
  91         return 0;
  92
  93 error_2:
  94         sock_release(socket);
  95 error_1:
  96         destroy_workqueue(afs_async_calls);
  97 error_0:
  98         _leave(" = %d", ret);
  99         return ret;
 100 }
 101
 102 /*
 103  * close the RxRPC socket AFS was using
 104  */
 105 void afs_close_socket(void)
 106 {
 107         _enter("");
 108
 109         kernel_listen(afs_socket, 0);
 110         flush_workqueue(afs_async_calls);
 111
 112         if (afs_spare_incoming_call) {
 113                 afs_put_call(afs_spare_incoming_call);
 114                 afs_spare_incoming_call = NULL;
 115         }
 116
 117         _debug("outstanding %u", atomic_read(&afs_outstanding_calls));
 118         wait_on_atomic_t(&afs_outstanding_calls, atomic_t_wait,
 119                          TASK_UNINTERRUPTIBLE);
 120         _debug("no outstanding calls");
 121
 122         kernel_sock_shutdown(afs_socket, SHUT_RDWR);
 123         flush_workqueue(afs_async_calls);
 124         sock_release(afs_socket);
 125
 126         _debug("dework");
 127         destroy_workqueue(afs_async_calls);
 128         _leave("");
 129 }
 130
 131 /*
 132  * Allocate a call.
 133  */
 134 static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
 135                                        gfp_t gfp)
 136 {
 137         struct afs_call *call;
 138         int o;
 139
 140         call = kzalloc(sizeof(*call), gfp);
 141         if (!call)
 142                 return NULL;
 143
 144         call->type = type;
 145         atomic_set(&call->usage, 1);
 146         INIT_WORK(&call->async_work, afs_process_async_call);
 147         init_waitqueue_head(&call->waitq);
 148
 149         o = atomic_inc_return(&afs_outstanding_calls);
 150         trace_afs_call(call, afs_call_trace_alloc, 1, o,
 151                        __builtin_return_address(0));
 152         return call;
 153 }
 154
 155 /*
 156  * Dispose of a reference on a call.
 157  */
 158 void afs_put_call(struct afs_call *call)
 159 {
 160         int n = atomic_dec_return(&call->usage);
 161         int o = atomic_read(&afs_outstanding_calls);
 162
 163         trace_afs_call(call, afs_call_trace_put, n + 1, o,
 164                        __builtin_return_address(0));
 165
 166         ASSERTCMP(n, >=, 0);
 167         if (n == 0) {
 168                 ASSERT(!work_pending(&call->async_work));
 169                 ASSERT(call->type->name != NULL);
 170
 171                 if (call->rxcall) {
 172                         rxrpc_kernel_end_call(afs_socket, call->rxcall);
 173                         call->rxcall = NULL;
 174                 }
 175                 if (call->type->destructor)
 176                         call->type->destructor(call);
 177
 178                 kfree(call->request);
 179                 kfree(call);
 180
 181                 o = atomic_dec_return(&afs_outstanding_calls);
 182                 trace_afs_call(call, afs_call_trace_free, 0, o,
 183                                __builtin_return_address(0));
 184                 if (o == 0)
 185                         wake_up_atomic_t(&afs_outstanding_calls);
 186         }
 187 }
 188
 189 /*
 190  * Queue the call for actual work.  Returns 0 unconditionally for convenience.
 191  */
 192 int afs_queue_call_work(struct afs_call *call)
 193 {
 194         int u = atomic_inc_return(&call->usage);
 195
 196         trace_afs_call(call, afs_call_trace_work, u,
 197                        atomic_read(&afs_outstanding_calls),
 198                        __builtin_return_address(0));
 199
 200         INIT_WORK(&call->work, call->type->work);
 201
 202         if (!queue_work(afs_wq, &call->work))
 203                 afs_put_call(call);
 204         return 0;
 205 }
 206
 207 /*
 208  * allocate a call with flat request and reply buffers
 209  */
 210 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
 211                                      size_t request_size, size_t reply_max)
 212 {
 213         struct afs_call *call;
 214
 215         call = afs_alloc_call(type, GFP_NOFS);
 216         if (!call)
 217                 goto nomem_call;
 218
 219         if (request_size) {
 220                 call->request_size = request_size;
 221                 call->request = kmalloc(request_size, GFP_NOFS);
 222                 if (!call->request)
 223                         goto nomem_free;
 224         }
 225
 226         if (reply_max) {
 227                 call->reply_max = reply_max;
 228                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 229                 if (!call->buffer)
 230                         goto nomem_free;
 231         }
 232
 233         init_waitqueue_head(&call->waitq);
 234         return call;
 235
 236 nomem_free:
 237         afs_put_call(call);
 238 nomem_call:
 239         return NULL;
 240 }
 241
 242 /*
 243  * clean up a call with flat buffer
 244  */
 245 void afs_flat_call_destructor(struct afs_call *call)
 246 {
 247         _enter("");
 248
 249         kfree(call->request);
 250         call->request = NULL;
 251         kfree(call->buffer);
 252         call->buffer = NULL;
 253 }
 254
 255 #define AFS_BVEC_MAX 8
 256
 257 /*
 258  * Load the given bvec with the next few pages.
 259  */
 260 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 261                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
 262                           unsigned offset)
 263 {
 264         struct page *pages[AFS_BVEC_MAX];
 265         unsigned int nr, n, i, to, bytes = 0;
 266
 267         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
 268         n = find_get_pages_contig(call->mapping, first, nr, pages);
 269         ASSERTCMP(n, ==, nr);
 270
 271         msg->msg_flags |= MSG_MORE;
 272         for (i = 0; i < nr; i++) {
 273                 to = PAGE_SIZE;
 274                 if (first + i >= last) {
 275                         to = call->last_to;
 276                         msg->msg_flags &= ~MSG_MORE;
 277                 }
 278                 bv[i].bv_page = pages[i];
 279                 bv[i].bv_len = to - offset;
 280                 bv[i].bv_offset = offset;
 281                 bytes += to - offset;
 282                 offset = 0;
 283         }
 284
 285         iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
 286 }
 287
 288 /*
 289  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 290  */
 291 static void afs_notify_end_request_tx(struct sock *sock,
 292                                       struct rxrpc_call *rxcall,
 293                                       unsigned long call_user_ID)
 294 {
 295         struct afs_call *call = (struct afs_call *)call_user_ID;
 296
 297         if (call->state == AFS_CALL_REQUESTING)
 298                 call->state = AFS_CALL_AWAIT_REPLY;
 299 }
 300
 301 /*
 302  * attach the data from a bunch of pages on an inode to a call
 303  */
 304 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
 305 {
 306         struct bio_vec bv[AFS_BVEC_MAX];
 307         unsigned int bytes, nr, loop, offset;
 308         pgoff_t first = call->first, last = call->last;
 309         int ret;
 310
 311         offset = call->first_offset;
 312         call->first_offset = 0;
 313
 314         do {
 315                 afs_load_bvec(call, msg, bv, first, last, offset);
 316                 offset = 0;
 317                 bytes = msg->msg_iter.count;
 318                 nr = msg->msg_iter.nr_segs;
 319
 320                 ret = rxrpc_kernel_send_data(afs_socket, call->rxcall, msg,
 321                                              bytes, afs_notify_end_request_tx);
 322                 for (loop = 0; loop < nr; loop++)
 323                         put_page(bv[loop].bv_page);
 324                 if (ret < 0)
 325                         break;
 326
 327                 first += nr;
 328         } while (first <= last);
 329
 330         return ret;
 331 }
 332
 333 /*
 334  * initiate a call
 335  */
 336 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
 337                   bool async)
 338 {
 339         struct sockaddr_rxrpc srx;
 340         struct rxrpc_call *rxcall;
 341         struct msghdr msg;
 342         struct kvec iov[1];
 343         size_t offset;
 344         s64 tx_total_len;
 345         u32 abort_code;
 346         int ret;
 347
 348         _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
 349
 350         ASSERT(call->type != NULL);
 351         ASSERT(call->type->name != NULL);
 352
 353         _debug("____MAKE %p{%s,%x} [%d]____",
 354                call, call->type->name, key_serial(call->key),
 355                atomic_read(&afs_outstanding_calls));
 356
 357         call->async = async;
 358
 359         memset(&srx, 0, sizeof(srx));
 360         srx.srx_family = AF_RXRPC;
 361         srx.srx_service = call->service_id;
 362         srx.transport_type = SOCK_DGRAM;
 363         srx.transport_len = sizeof(srx.transport.sin);
 364         srx.transport.sin.sin_family = AF_INET;
 365         srx.transport.sin.sin_port = call->port;
 366         memcpy(&srx.transport.sin.sin_addr, addr, 4);
 367
 368         /* Work out the length we're going to transmit.  This is awkward for
 369          * calls such as FS.StoreData where there's an extra injection of data
 370          * after the initial fixed part.
 371          */
 372         tx_total_len = call->request_size;
 373         if (call->send_pages) {
 374                 tx_total_len += call->last_to - call->first_offset;
 375                 tx_total_len += (call->last - call->first) * PAGE_SIZE;
 376         }
 377
 378         /* create a call */
 379         rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
 380                                          (unsigned long)call,
 381                                          tx_total_len, gfp,
 382                                          (async ?
 383                                           afs_wake_up_async_call :
 384                                           afs_wake_up_call_waiter),
 385                                          call->upgrade);
 386         call->key = NULL;
 387         if (IS_ERR(rxcall)) {
 388                 ret = PTR_ERR(rxcall);
 389                 goto error_kill_call;
 390         }
 391
 392         call->rxcall = rxcall;
 393
 394         /* send the request */
 395         iov[0].iov_base = call->request;
 396         iov[0].iov_len  = call->request_size;
 397
 398         msg.msg_name            = NULL;
 399         msg.msg_namelen         = 0;
 400         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
 401                       call->request_size);
 402         msg.msg_control         = NULL;
 403         msg.msg_controllen      = 0;
 404         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
 405
 406         /* We have to change the state *before* sending the last packet as
 407          * rxrpc might give us the reply before it returns from sending the
 408          * request.  Further, if the send fails, we may already have been given
 409          * a notification and may have collected it.
 410          */
 411         if (!call->send_pages)
 412                 call->state = AFS_CALL_AWAIT_REPLY;
 413         ret = rxrpc_kernel_send_data(afs_socket, rxcall,
 414                                      &msg, call->request_size,
 415                                      afs_notify_end_request_tx);
 416         if (ret < 0)
 417                 goto error_do_abort;
 418
 419         if (call->send_pages) {
 420                 ret = afs_send_pages(call, &msg);
 421                 if (ret < 0)
 422                         goto error_do_abort;
 423         }
 424
 425         /* at this point, an async call may no longer exist as it may have
 426          * already completed */
 427         if (call->async)
 428                 return -EINPROGRESS;
 429
 430         return afs_wait_for_call_to_complete(call);
 431
 432 error_do_abort:
 433         call->state = AFS_CALL_COMPLETE;
 434         if (ret != -ECONNABORTED) {
 435                 rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT,
 436                                         ret, "KSD");
 437         } else {
 438                 abort_code = 0;
 439                 offset = 0;
 440                 rxrpc_kernel_recv_data(afs_socket, rxcall, NULL, 0, &offset,
 441                                        false, &abort_code, &call->service_id);
 442                 ret = call->type->abort_to_error(abort_code);
 443         }
 444 error_kill_call:
 445         afs_put_call(call);
 446         _leave(" = %d", ret);
 447         return ret;
 448 }
 449
 450 /*
 451  * deliver messages to a call
 452  */
 453 static void afs_deliver_to_call(struct afs_call *call)
 454 {
 455         u32 abort_code;
 456         int ret;
 457
 458         _enter("%s", call->type->name);
 459
 460         while (call->state == AFS_CALL_AWAIT_REPLY ||
 461                call->state == AFS_CALL_AWAIT_OP_ID ||
 462                call->state == AFS_CALL_AWAIT_REQUEST ||
 463                call->state == AFS_CALL_AWAIT_ACK
 464                ) {
 465                 if (call->state == AFS_CALL_AWAIT_ACK) {
 466                         size_t offset = 0;
 467                         ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 468                                                      NULL, 0, &offset, false,
 469                                                      &call->abort_code,
 470                                                      &call->service_id);
 471                         trace_afs_recv_data(call, 0, offset, false, ret);
 472
 473                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 474                                 return;
 475                         if (ret == 1 || ret < 0) {
 476                                 call->state = AFS_CALL_COMPLETE;
 477                                 goto done;
 478                         }
 479                         return;
 480                 }
 481
 482                 ret = call->type->deliver(call);
 483                 switch (ret) {
 484                 case 0:
 485                         if (call->state == AFS_CALL_AWAIT_REPLY)
 486                                 call->state = AFS_CALL_COMPLETE;
 487                         goto done;
 488                 case -EINPROGRESS:
 489                 case -EAGAIN:
 490                         goto out;
 491                 case -ECONNABORTED:
 492                         goto call_complete;
 493                 case -ENOTCONN:
 494                         abort_code = RX_CALL_DEAD;
 495                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 496                                                 abort_code, ret, "KNC");
 497                         goto save_error;
 498                 case -ENOTSUPP:
 499                         abort_code = RXGEN_OPCODE;
 500                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 501                                                 abort_code, ret, "KIV");
 502                         goto save_error;
 503                 case -ENODATA:
 504                 case -EBADMSG:
 505                 case -EMSGSIZE:
 506                 default:
 507                         abort_code = RXGEN_CC_UNMARSHAL;
 508                         if (call->state != AFS_CALL_AWAIT_REPLY)
 509                                 abort_code = RXGEN_SS_UNMARSHAL;
 510                         rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 511                                                 abort_code, -EBADMSG, "KUM");
 512                         goto save_error;
 513                 }
 514         }
 515
 516 done:
 517         if (call->state == AFS_CALL_COMPLETE && call->incoming)
 518                 afs_put_call(call);
 519 out:
 520         _leave("");
 521         return;
 522
 523 save_error:
 524         call->error = ret;
 525 call_complete:
 526         call->state = AFS_CALL_COMPLETE;
 527         goto done;
 528 }
 529
 530 /*
 531  * wait synchronously for a call to complete
 532  */
 533 static int afs_wait_for_call_to_complete(struct afs_call *call)
 534 {
 535         signed long rtt2, timeout;
 536         int ret;
 537         u64 rtt;
 538         u32 life, last_life;
 539
 540         DECLARE_WAITQUEUE(myself, current);
 541
 542         _enter("");
 543
 544         rtt = rxrpc_kernel_get_rtt(afs_socket, call->rxcall);
 545         rtt2 = nsecs_to_jiffies64(rtt) * 2;
 546         if (rtt2 < 2)
 547                 rtt2 = 2;
 548
 549         timeout = rtt2;
 550         last_life = rxrpc_kernel_check_life(afs_socket, call->rxcall);
 551
 552         add_wait_queue(&call->waitq, &myself);
 553         for (;;) {
 554                 set_current_state(TASK_UNINTERRUPTIBLE);
 555
 556                 /* deliver any messages that are in the queue */
 557                 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 558                         call->need_attention = false;
 559                         __set_current_state(TASK_RUNNING);
 560                         afs_deliver_to_call(call);
 561                         continue;
 562                 }
 563
 564                 if (call->state == AFS_CALL_COMPLETE)
 565                         break;
 566
 567                 life = rxrpc_kernel_check_life(afs_socket, call->rxcall);
 568                 if (timeout == 0 &&
 569                     life == last_life && signal_pending(current))
 570                                 break;
 571
 572                 if (life != last_life) {
 573                         timeout = rtt2;
 574                         last_life = life;
 575                 }
 576
 577                 timeout = schedule_timeout(timeout);
 578         }
 579
 580         remove_wait_queue(&call->waitq, &myself);
 581         __set_current_state(TASK_RUNNING);
 582
 583         /* Kill off the call if it's still live. */
 584         if (call->state < AFS_CALL_COMPLETE) {
 585                 _debug("call interrupted");
 586                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 587                                         RX_USER_ABORT, -EINTR, "KWI");
 588         }
 589
 590         ret = call->error;
 591         _debug("call complete");
 592         afs_put_call(call);
 593         _leave(" = %d", ret);
 594         return ret;
 595 }
 596
 597 /*
 598  * wake up a waiting call
 599  */
 600 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 601                                     unsigned long call_user_ID)
 602 {
 603         struct afs_call *call = (struct afs_call *)call_user_ID;
 604
 605         call->need_attention = true;
 606         wake_up(&call->waitq);
 607 }
 608
 609 /*
 610  * wake up an asynchronous call
 611  */
 612 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 613                                    unsigned long call_user_ID)
 614 {
 615         struct afs_call *call = (struct afs_call *)call_user_ID;
 616         int u;
 617
 618         trace_afs_notify_call(rxcall, call);
 619         call->need_attention = true;
 620
 621         u = __atomic_add_unless(&call->usage, 1, 0);
 622         if (u != 0) {
 623                 trace_afs_call(call, afs_call_trace_wake, u,
 624                                atomic_read(&afs_outstanding_calls),
 625                                __builtin_return_address(0));
 626
 627                 if (!queue_work(afs_async_calls, &call->async_work))
 628                         afs_put_call(call);
 629         }
 630 }
 631
 632 /*
 633  * Delete an asynchronous call.  The work item carries a ref to the call struct
 634  * that we need to release.
 635  */
 636 static void afs_delete_async_call(struct work_struct *work)
 637 {
 638         struct afs_call *call = container_of(work, struct afs_call, async_work);
 639
 640         _enter("");
 641
 642         afs_put_call(call);
 643
 644         _leave("");
 645 }
 646
 647 /*
 648  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 649  * to the call struct that we either need to release or to pass on.
 650  */
 651 static void afs_process_async_call(struct work_struct *work)
 652 {
 653         struct afs_call *call = container_of(work, struct afs_call, async_work);
 654
 655         _enter("");
 656
 657         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 658                 call->need_attention = false;
 659                 afs_deliver_to_call(call);
 660         }
 661
 662         if (call->state == AFS_CALL_COMPLETE) {
 663                 call->reply = NULL;
 664
 665                 /* We have two refs to release - one from the alloc and one
 666                  * queued with the work item - and we can't just deallocate the
 667                  * call because the work item may be queued again.
 668                  */
 669                 call->async_work.func = afs_delete_async_call;
 670                 if (!queue_work(afs_async_calls, &call->async_work))
 671                         afs_put_call(call);
 672         }
 673
 674         afs_put_call(call);
 675         _leave("");
 676 }
 677
 678 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 679 {
 680         struct afs_call *call = (struct afs_call *)user_call_ID;
 681
 682         call->rxcall = rxcall;
 683 }
 684
 685 /*
 686  * Charge the incoming call preallocation.
 687  */
 688 static void afs_charge_preallocation(struct work_struct *work)
 689 {
 690         struct afs_call *call = afs_spare_incoming_call;
 691
 692         for (;;) {
 693                 if (!call) {
 694                         call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
 695                         if (!call)
 696                                 break;
 697
 698                         call->async = true;
 699                         call->state = AFS_CALL_AWAIT_OP_ID;
 700                         init_waitqueue_head(&call->waitq);
 701                 }
 702
 703                 if (rxrpc_kernel_charge_accept(afs_socket,
 704                                                afs_wake_up_async_call,
 705                                                afs_rx_attach,
 706                                                (unsigned long)call,
 707                                                GFP_KERNEL) < 0)
 708                         break;
 709                 call = NULL;
 710         }
 711         afs_spare_incoming_call = call;
 712 }
 713
 714 /*
 715  * Discard a preallocated call when a socket is shut down.
 716  */
 717 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 718                                     unsigned long user_call_ID)
 719 {
 720         struct afs_call *call = (struct afs_call *)user_call_ID;
 721
 722         call->rxcall = NULL;
 723         afs_put_call(call);
 724 }
 725
 726 /*
 727  * Notification of an incoming call.
 728  */
 729 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 730                             unsigned long user_call_ID)
 731 {
 732         queue_work(afs_wq, &afs_charge_preallocation_work);
 733 }
 734
 735 /*
 736  * Grab the operation ID from an incoming cache manager call.  The socket
 737  * buffer is discarded on error or if we don't yet have sufficient data.
 738  */
 739 static int afs_deliver_cm_op_id(struct afs_call *call)
 740 {
 741         int ret;
 742
 743         _enter("{%zu}", call->offset);
 744
 745         ASSERTCMP(call->offset, <, 4);
 746
 747         /* the operation ID forms the first four bytes of the request data */
 748         ret = afs_extract_data(call, &call->tmp, 4, true);
 749         if (ret < 0)
 750                 return ret;
 751
 752         call->operation_ID = ntohl(call->tmp);
 753         call->state = AFS_CALL_AWAIT_REQUEST;
 754         call->offset = 0;
 755
 756         /* ask the cache manager to route the call (it'll change the call type
 757          * if successful) */
 758         if (!afs_cm_incoming_call(call))
 759                 return -ENOTSUPP;
 760
 761         trace_afs_cb_call(call);
 762
 763         /* pass responsibility for the remainer of this message off to the
 764          * cache manager op */
 765         return call->type->deliver(call);
 766 }
 767
 768 /*
 769  * Advance the AFS call state when an RxRPC service call ends the transmit
 770  * phase.
 771  */
 772 static void afs_notify_end_reply_tx(struct sock *sock,
 773                                     struct rxrpc_call *rxcall,
 774                                     unsigned long call_user_ID)
 775 {
 776         struct afs_call *call = (struct afs_call *)call_user_ID;
 777
 778         if (call->state == AFS_CALL_REPLYING)
 779                 call->state = AFS_CALL_AWAIT_ACK;
 780 }
 781
 782 /*
 783  * send an empty reply
 784  */
 785 void afs_send_empty_reply(struct afs_call *call)
 786 {
 787         struct msghdr msg;
 788
 789         _enter("");
 790
 791         rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, 0);
 792
 793         msg.msg_name            = NULL;
 794         msg.msg_namelen         = 0;
 795         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
 796         msg.msg_control         = NULL;
 797         msg.msg_controllen      = 0;
 798         msg.msg_flags           = 0;
 799
 800         call->state = AFS_CALL_AWAIT_ACK;
 801         switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0,
 802                                        afs_notify_end_reply_tx)) {
 803         case 0:
 804                 _leave(" [replied]");
 805                 return;
 806
 807         case -ENOMEM:
 808                 _debug("oom");
 809                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 810                                         RX_USER_ABORT, -ENOMEM, "KOO");
 811         default:
 812                 _leave(" [error]");
 813                 return;
 814         }
 815 }
 816
 817 /*
 818  * send a simple reply
 819  */
 820 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 821 {
 822         struct msghdr msg;
 823         struct kvec iov[1];
 824         int n;
 825
 826         _enter("");
 827
 828         rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, len);
 829
 830         iov[0].iov_base         = (void *) buf;
 831         iov[0].iov_len          = len;
 832         msg.msg_name            = NULL;
 833         msg.msg_namelen         = 0;
 834         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
 835         msg.msg_control         = NULL;
 836         msg.msg_controllen      = 0;
 837         msg.msg_flags           = 0;
 838
 839         call->state = AFS_CALL_AWAIT_ACK;
 840         n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len,
 841                                    afs_notify_end_reply_tx);
 842         if (n >= 0) {
 843                 /* Success */
 844                 _leave(" [replied]");
 845                 return;
 846         }
 847
 848         if (n == -ENOMEM) {
 849                 _debug("oom");
 850                 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
 851                                         RX_USER_ABORT, -ENOMEM, "KOO");
 852         }
 853         _leave(" [error]");
 854 }
 855
 856 /*
 857  * Extract a piece of data from the received data socket buffers.
 858  */
 859 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 860                      bool want_more)
 861 {
 862         int ret;
 863
 864         _enter("{%s,%zu},,%zu,%d",
 865                call->type->name, call->offset, count, want_more);
 866
 867         ASSERTCMP(call->offset, <=, count);
 868
 869         ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
 870                                      buf, count, &call->offset,
 871                                      want_more, &call->abort_code,
 872                                      &call->service_id);
 873         trace_afs_recv_data(call, count, call->offset, want_more, ret);
 874         if (ret == 0 || ret == -EAGAIN)
 875                 return ret;
 876
 877         if (ret == 1) {
 878                 switch (call->state) {
 879                 case AFS_CALL_AWAIT_REPLY:
 880                         call->state = AFS_CALL_COMPLETE;
 881                         break;
 882                 case AFS_CALL_AWAIT_REQUEST:
 883                         call->state = AFS_CALL_REPLYING;
 884                         break;
 885                 default:
 886                         break;
 887                 }
 888                 return 0;
 889         }
 890
 891         if (ret == -ECONNABORTED)
 892                 call->error = call->type->abort_to_error(call->abort_code);
 893         else
 894                 call->error = ret;
 895         call->state = AFS_CALL_COMPLETE;
 896         return ret;
 897 }