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 workqueue_struct *afs_async_calls;
  21
  22 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
  23 static long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
  24 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
  25 static void afs_process_async_call(struct work_struct *);
  26 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
  27 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
  28 static int afs_deliver_cm_op_id(struct afs_call *);
  29
  30 /* asynchronous incoming call initial processing */
  31 static const struct afs_call_type afs_RXCMxxxx = {
  32         .name           = "CB.xxxx",
  33         .deliver        = afs_deliver_cm_op_id,
  34 };
  35
  36 /*
  37  * open an RxRPC socket and bind it to be a server for callback notifications
  38  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
  39  */
  40 int afs_open_socket(struct afs_net *net)
  41 {
  42         struct sockaddr_rxrpc srx;
  43         struct socket *socket;
  44         int ret;
  45
  46         _enter("");
  47
  48         ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
  49         if (ret < 0)
  50                 goto error_1;
  51
  52         socket->sk->sk_allocation = GFP_NOFS;
  53
  54         /* bind the callback manager's address to make this a server socket */
  55         memset(&srx, 0, sizeof(srx));
  56         srx.srx_family                  = AF_RXRPC;
  57         srx.srx_service                 = CM_SERVICE;
  58         srx.transport_type              = SOCK_DGRAM;
  59         srx.transport_len               = sizeof(srx.transport.sin6);
  60         srx.transport.sin6.sin6_family  = AF_INET6;
  61         srx.transport.sin6.sin6_port    = htons(AFS_CM_PORT);
  62
  63         ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  64         if (ret == -EADDRINUSE) {
  65                 srx.transport.sin6.sin6_port = 0;
  66                 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
  67         }
  68         if (ret < 0)
  69                 goto error_2;
  70
  71         rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
  72                                            afs_rx_discard_new_call);
  73
  74         ret = kernel_listen(socket, INT_MAX);
  75         if (ret < 0)
  76                 goto error_2;
  77
  78         net->socket = socket;
  79         afs_charge_preallocation(&net->charge_preallocation_work);
  80         _leave(" = 0");
  81         return 0;
  82
  83 error_2:
  84         sock_release(socket);
  85 error_1:
  86         _leave(" = %d", ret);
  87         return ret;
  88 }
  89
  90 /*
  91  * close the RxRPC socket AFS was using
  92  */
  93 void afs_close_socket(struct afs_net *net)
  94 {
  95         _enter("");
  96
  97         kernel_listen(net->socket, 0);
  98         flush_workqueue(afs_async_calls);
  99
 100         if (net->spare_incoming_call) {
 101                 afs_put_call(net->spare_incoming_call);
 102                 net->spare_incoming_call = NULL;
 103         }
 104
 105         _debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
 106         wait_on_atomic_t(&net->nr_outstanding_calls, atomic_t_wait,
 107                          TASK_UNINTERRUPTIBLE);
 108         _debug("no outstanding calls");
 109
 110         kernel_sock_shutdown(net->socket, SHUT_RDWR);
 111         flush_workqueue(afs_async_calls);
 112         sock_release(net->socket);
 113
 114         _debug("dework");
 115         _leave("");
 116 }
 117
 118 /*
 119  * Allocate a call.
 120  */
 121 static struct afs_call *afs_alloc_call(struct afs_net *net,
 122                                        const struct afs_call_type *type,
 123                                        gfp_t gfp)
 124 {
 125         struct afs_call *call;
 126         int o;
 127
 128         call = kzalloc(sizeof(*call), gfp);
 129         if (!call)
 130                 return NULL;
 131
 132         call->type = type;
 133         call->net = net;
 134         atomic_set(&call->usage, 1);
 135         INIT_WORK(&call->async_work, afs_process_async_call);
 136         init_waitqueue_head(&call->waitq);
 137         spin_lock_init(&call->state_lock);
 138
 139         o = atomic_inc_return(&net->nr_outstanding_calls);
 140         trace_afs_call(call, afs_call_trace_alloc, 1, o,
 141                        __builtin_return_address(0));
 142         return call;
 143 }
 144
 145 /*
 146  * Dispose of a reference on a call.
 147  */
 148 void afs_put_call(struct afs_call *call)
 149 {
 150         struct afs_net *net = call->net;
 151         int n = atomic_dec_return(&call->usage);
 152         int o = atomic_read(&net->nr_outstanding_calls);
 153
 154         trace_afs_call(call, afs_call_trace_put, n + 1, o,
 155                        __builtin_return_address(0));
 156
 157         ASSERTCMP(n, >=, 0);
 158         if (n == 0) {
 159                 ASSERT(!work_pending(&call->async_work));
 160                 ASSERT(call->type->name != NULL);
 161
 162                 if (call->rxcall) {
 163                         rxrpc_kernel_end_call(net->socket, call->rxcall);
 164                         call->rxcall = NULL;
 165                 }
 166                 if (call->type->destructor)
 167                         call->type->destructor(call);
 168
 169                 afs_put_server(call->net, call->cm_server);
 170                 afs_put_cb_interest(call->net, call->cbi);
 171                 kfree(call->request);
 172                 kfree(call);
 173
 174                 o = atomic_dec_return(&net->nr_outstanding_calls);
 175                 trace_afs_call(call, afs_call_trace_free, 0, o,
 176                                __builtin_return_address(0));
 177                 if (o == 0)
 178                         wake_up_atomic_t(&net->nr_outstanding_calls);
 179         }
 180 }
 181
 182 /*
 183  * Queue the call for actual work.  Returns 0 unconditionally for convenience.
 184  */
 185 int afs_queue_call_work(struct afs_call *call)
 186 {
 187         int u = atomic_inc_return(&call->usage);
 188
 189         trace_afs_call(call, afs_call_trace_work, u,
 190                        atomic_read(&call->net->nr_outstanding_calls),
 191                        __builtin_return_address(0));
 192
 193         INIT_WORK(&call->work, call->type->work);
 194
 195         if (!queue_work(afs_wq, &call->work))
 196                 afs_put_call(call);
 197         return 0;
 198 }
 199
 200 /*
 201  * allocate a call with flat request and reply buffers
 202  */
 203 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
 204                                      const struct afs_call_type *type,
 205                                      size_t request_size, size_t reply_max)
 206 {
 207         struct afs_call *call;
 208
 209         call = afs_alloc_call(net, type, GFP_NOFS);
 210         if (!call)
 211                 goto nomem_call;
 212
 213         if (request_size) {
 214                 call->request_size = request_size;
 215                 call->request = kmalloc(request_size, GFP_NOFS);
 216                 if (!call->request)
 217                         goto nomem_free;
 218         }
 219
 220         if (reply_max) {
 221                 call->reply_max = reply_max;
 222                 call->buffer = kmalloc(reply_max, GFP_NOFS);
 223                 if (!call->buffer)
 224                         goto nomem_free;
 225         }
 226
 227         call->operation_ID = type->op;
 228         init_waitqueue_head(&call->waitq);
 229         return call;
 230
 231 nomem_free:
 232         afs_put_call(call);
 233 nomem_call:
 234         return NULL;
 235 }
 236
 237 /*
 238  * clean up a call with flat buffer
 239  */
 240 void afs_flat_call_destructor(struct afs_call *call)
 241 {
 242         _enter("");
 243
 244         kfree(call->request);
 245         call->request = NULL;
 246         kfree(call->buffer);
 247         call->buffer = NULL;
 248 }
 249
 250 #define AFS_BVEC_MAX 8
 251
 252 /*
 253  * Load the given bvec with the next few pages.
 254  */
 255 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
 256                           struct bio_vec *bv, pgoff_t first, pgoff_t last,
 257                           unsigned offset)
 258 {
 259         struct page *pages[AFS_BVEC_MAX];
 260         unsigned int nr, n, i, to, bytes = 0;
 261
 262         nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
 263         n = find_get_pages_contig(call->mapping, first, nr, pages);
 264         ASSERTCMP(n, ==, nr);
 265
 266         msg->msg_flags |= MSG_MORE;
 267         for (i = 0; i < nr; i++) {
 268                 to = PAGE_SIZE;
 269                 if (first + i >= last) {
 270                         to = call->last_to;
 271                         msg->msg_flags &= ~MSG_MORE;
 272                 }
 273                 bv[i].bv_page = pages[i];
 274                 bv[i].bv_len = to - offset;
 275                 bv[i].bv_offset = offset;
 276                 bytes += to - offset;
 277                 offset = 0;
 278         }
 279
 280         iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
 281 }
 282
 283 /*
 284  * Advance the AFS call state when the RxRPC call ends the transmit phase.
 285  */
 286 static void afs_notify_end_request_tx(struct sock *sock,
 287                                       struct rxrpc_call *rxcall,
 288                                       unsigned long call_user_ID)
 289 {
 290         struct afs_call *call = (struct afs_call *)call_user_ID;
 291
 292         afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
 293 }
 294
 295 /*
 296  * attach the data from a bunch of pages on an inode to a call
 297  */
 298 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
 299 {
 300         struct bio_vec bv[AFS_BVEC_MAX];
 301         unsigned int bytes, nr, loop, offset;
 302         pgoff_t first = call->first, last = call->last;
 303         int ret;
 304
 305         offset = call->first_offset;
 306         call->first_offset = 0;
 307
 308         do {
 309                 afs_load_bvec(call, msg, bv, first, last, offset);
 310                 trace_afs_send_pages(call, msg, first, last, offset);
 311
 312                 offset = 0;
 313                 bytes = msg->msg_iter.count;
 314                 nr = msg->msg_iter.nr_segs;
 315
 316                 ret = rxrpc_kernel_send_data(call->net->socket, call->rxcall, msg,
 317                                              bytes, afs_notify_end_request_tx);
 318                 for (loop = 0; loop < nr; loop++)
 319                         put_page(bv[loop].bv_page);
 320                 if (ret < 0)
 321                         break;
 322
 323                 first += nr;
 324         } while (first <= last);
 325
 326         trace_afs_sent_pages(call, call->first, last, first, ret);
 327         return ret;
 328 }
 329
 330 /*
 331  * initiate a call
 332  */
 333 long afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call,
 334                    gfp_t gfp, bool async)
 335 {
 336         struct sockaddr_rxrpc *srx = ac->addr;
 337         struct rxrpc_call *rxcall;
 338         struct msghdr msg;
 339         struct kvec iov[1];
 340         size_t offset;
 341         s64 tx_total_len;
 342         int ret;
 343
 344         _enter(",{%pISp},", &srx->transport);
 345
 346         ASSERT(call->type != NULL);
 347         ASSERT(call->type->name != NULL);
 348
 349         _debug("____MAKE %p{%s,%x} [%d]____",
 350                call, call->type->name, key_serial(call->key),
 351                atomic_read(&call->net->nr_outstanding_calls));
 352
 353         call->async = async;
 354
 355         /* Work out the length we're going to transmit.  This is awkward for
 356          * calls such as FS.StoreData where there's an extra injection of data
 357          * after the initial fixed part.
 358          */
 359         tx_total_len = call->request_size;
 360         if (call->send_pages) {
 361                 if (call->last == call->first) {
 362                         tx_total_len += call->last_to - call->first_offset;
 363                 } else {
 364                         /* It looks mathematically like you should be able to
 365                          * combine the following lines with the ones above, but
 366                          * unsigned arithmetic is fun when it wraps...
 367                          */
 368                         tx_total_len += PAGE_SIZE - call->first_offset;
 369                         tx_total_len += call->last_to;
 370                         tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
 371                 }
 372         }
 373
 374         /* create a call */
 375         rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
 376                                          (unsigned long)call,
 377                                          tx_total_len, gfp,
 378                                          (async ?
 379                                           afs_wake_up_async_call :
 380                                           afs_wake_up_call_waiter),
 381                                          call->upgrade);
 382         if (IS_ERR(rxcall)) {
 383                 ret = PTR_ERR(rxcall);
 384                 goto error_kill_call;
 385         }
 386
 387         call->rxcall = rxcall;
 388
 389         /* send the request */
 390         iov[0].iov_base = call->request;
 391         iov[0].iov_len  = call->request_size;
 392
 393         msg.msg_name            = NULL;
 394         msg.msg_namelen         = 0;
 395         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
 396                       call->request_size);
 397         msg.msg_control         = NULL;
 398         msg.msg_controllen      = 0;
 399         msg.msg_flags           = MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
 400
 401         ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
 402                                      &msg, call->request_size,
 403                                      afs_notify_end_request_tx);
 404         if (ret < 0)
 405                 goto error_do_abort;
 406
 407         if (call->send_pages) {
 408                 ret = afs_send_pages(call, &msg);
 409                 if (ret < 0)
 410                         goto error_do_abort;
 411         }
 412
 413         /* at this point, an async call may no longer exist as it may have
 414          * already completed */
 415         if (call->async)
 416                 return -EINPROGRESS;
 417
 418         return afs_wait_for_call_to_complete(call, ac);
 419
 420 error_do_abort:
 421         call->state = AFS_CALL_COMPLETE;
 422         if (ret != -ECONNABORTED) {
 423                 rxrpc_kernel_abort_call(call->net->socket, rxcall,
 424                                         RX_USER_ABORT, ret, "KSD");
 425         } else {
 426                 offset = 0;
 427                 rxrpc_kernel_recv_data(call->net->socket, rxcall, NULL,
 428                                        0, &offset, false, &call->abort_code,
 429                                        &call->service_id);
 430                 ac->abort_code = call->abort_code;
 431                 ac->responded = true;
 432         }
 433         call->error = ret;
 434         trace_afs_call_done(call);
 435 error_kill_call:
 436         afs_put_call(call);
 437         ac->error = ret;
 438         _leave(" = %d", ret);
 439         return ret;
 440 }
 441
 442 /*
 443  * deliver messages to a call
 444  */
 445 static void afs_deliver_to_call(struct afs_call *call)
 446 {
 447         enum afs_call_state state;
 448         u32 abort_code, remote_abort = 0;
 449         int ret;
 450
 451         _enter("%s", call->type->name);
 452
 453         while (state = READ_ONCE(call->state),
 454                state == AFS_CALL_CL_AWAIT_REPLY ||
 455                state == AFS_CALL_SV_AWAIT_OP_ID ||
 456                state == AFS_CALL_SV_AWAIT_REQUEST ||
 457                state == AFS_CALL_SV_AWAIT_ACK
 458                ) {
 459                 if (state == AFS_CALL_SV_AWAIT_ACK) {
 460                         size_t offset = 0;
 461                         ret = rxrpc_kernel_recv_data(call->net->socket,
 462                                                      call->rxcall,
 463                                                      NULL, 0, &offset, false,
 464                                                      &remote_abort,
 465                                                      &call->service_id);
 466                         trace_afs_recv_data(call, 0, offset, false, ret);
 467
 468                         if (ret == -EINPROGRESS || ret == -EAGAIN)
 469                                 return;
 470                         if (ret < 0 || ret == 1) {
 471                                 if (ret == 1)
 472                                         ret = 0;
 473                                 goto call_complete;
 474                         }
 475                         return;
 476                 }
 477
 478                 ret = call->type->deliver(call);
 479                 state = READ_ONCE(call->state);
 480                 switch (ret) {
 481                 case 0:
 482                         if (state == AFS_CALL_CL_PROC_REPLY)
 483                                 goto call_complete;
 484                         ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
 485                         goto done;
 486                 case -EINPROGRESS:
 487                 case -EAGAIN:
 488                         goto out;
 489                 case -EIO:
 490                 case -ECONNABORTED:
 491                         ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
 492                         goto done;
 493                 case -ENOTCONN:
 494                         abort_code = RX_CALL_DEAD;
 495                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 496                                                 abort_code, ret, "KNC");
 497                         goto local_abort;
 498                 case -ENOTSUPP:
 499                         abort_code = RXGEN_OPCODE;
 500                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 501                                                 abort_code, ret, "KIV");
 502                         goto local_abort;
 503                 case -ENODATA:
 504                 case -EBADMSG:
 505                 case -EMSGSIZE:
 506                 default:
 507                         abort_code = RXGEN_CC_UNMARSHAL;
 508                         if (state != AFS_CALL_CL_AWAIT_REPLY)
 509                                 abort_code = RXGEN_SS_UNMARSHAL;
 510                         rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 511                                                 abort_code, -EBADMSG, "KUM");
 512                         goto local_abort;
 513                 }
 514         }
 515
 516 done:
 517         if (state == AFS_CALL_COMPLETE && call->incoming)
 518                 afs_put_call(call);
 519 out:
 520         _leave("");
 521         return;
 522
 523 local_abort:
 524         abort_code = 0;
 525 call_complete:
 526         afs_set_call_complete(call, ret, remote_abort);
 527         state = AFS_CALL_COMPLETE;
 528         goto done;
 529 }
 530
 531 /*
 532  * wait synchronously for a call to complete
 533  */
 534 static long afs_wait_for_call_to_complete(struct afs_call *call,
 535                                           struct afs_addr_cursor *ac)
 536 {
 537         signed long rtt2, timeout;
 538         long ret;
 539         u64 rtt;
 540         u32 life, last_life;
 541
 542         DECLARE_WAITQUEUE(myself, current);
 543
 544         _enter("");
 545
 546         rtt = rxrpc_kernel_get_rtt(call->net->socket, call->rxcall);
 547         rtt2 = nsecs_to_jiffies64(rtt) * 2;
 548         if (rtt2 < 2)
 549                 rtt2 = 2;
 550
 551         timeout = rtt2;
 552         last_life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
 553
 554         add_wait_queue(&call->waitq, &myself);
 555         for (;;) {
 556                 set_current_state(TASK_UNINTERRUPTIBLE);
 557
 558                 /* deliver any messages that are in the queue */
 559                 if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
 560                     call->need_attention) {
 561                         call->need_attention = false;
 562                         __set_current_state(TASK_RUNNING);
 563                         afs_deliver_to_call(call);
 564                         continue;
 565                 }
 566
 567                 if (afs_check_call_state(call, AFS_CALL_COMPLETE))
 568                         break;
 569
 570                 life = rxrpc_kernel_check_life(call->net->socket, call->rxcall);
 571                 if (timeout == 0 &&
 572                     life == last_life && signal_pending(current))
 573                                 break;
 574
 575                 if (life != last_life) {
 576                         timeout = rtt2;
 577                         last_life = life;
 578                 }
 579
 580                 timeout = schedule_timeout(timeout);
 581         }
 582
 583         remove_wait_queue(&call->waitq, &myself);
 584         __set_current_state(TASK_RUNNING);
 585
 586         /* Kill off the call if it's still live. */
 587         if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
 588                 _debug("call interrupted");
 589                 if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
 590                                             RX_USER_ABORT, -EINTR, "KWI"))
 591                         afs_set_call_complete(call, -EINTR, 0);
 592         }
 593
 594         spin_lock_bh(&call->state_lock);
 595         ac->abort_code = call->abort_code;
 596         ac->error = call->error;
 597         spin_unlock_bh(&call->state_lock);
 598
 599         ret = ac->error;
 600         switch (ret) {
 601         case 0:
 602                 if (call->ret_reply0) {
 603                         ret = (long)call->reply[0];
 604                         call->reply[0] = NULL;
 605                 }
 606                 /* Fall through */
 607         case -ECONNABORTED:
 608                 ac->responded = true;
 609                 break;
 610         }
 611
 612         _debug("call complete");
 613         afs_put_call(call);
 614         _leave(" = %p", (void *)ret);
 615         return ret;
 616 }
 617
 618 /*
 619  * wake up a waiting call
 620  */
 621 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
 622                                     unsigned long call_user_ID)
 623 {
 624         struct afs_call *call = (struct afs_call *)call_user_ID;
 625
 626         call->need_attention = true;
 627         wake_up(&call->waitq);
 628 }
 629
 630 /*
 631  * wake up an asynchronous call
 632  */
 633 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
 634                                    unsigned long call_user_ID)
 635 {
 636         struct afs_call *call = (struct afs_call *)call_user_ID;
 637         int u;
 638
 639         trace_afs_notify_call(rxcall, call);
 640         call->need_attention = true;
 641
 642         u = __atomic_add_unless(&call->usage, 1, 0);
 643         if (u != 0) {
 644                 trace_afs_call(call, afs_call_trace_wake, u,
 645                                atomic_read(&call->net->nr_outstanding_calls),
 646                                __builtin_return_address(0));
 647
 648                 if (!queue_work(afs_async_calls, &call->async_work))
 649                         afs_put_call(call);
 650         }
 651 }
 652
 653 /*
 654  * Delete an asynchronous call.  The work item carries a ref to the call struct
 655  * that we need to release.
 656  */
 657 static void afs_delete_async_call(struct work_struct *work)
 658 {
 659         struct afs_call *call = container_of(work, struct afs_call, async_work);
 660
 661         _enter("");
 662
 663         afs_put_call(call);
 664
 665         _leave("");
 666 }
 667
 668 /*
 669  * Perform I/O processing on an asynchronous call.  The work item carries a ref
 670  * to the call struct that we either need to release or to pass on.
 671  */
 672 static void afs_process_async_call(struct work_struct *work)
 673 {
 674         struct afs_call *call = container_of(work, struct afs_call, async_work);
 675
 676         _enter("");
 677
 678         if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
 679                 call->need_attention = false;
 680                 afs_deliver_to_call(call);
 681         }
 682
 683         if (call->state == AFS_CALL_COMPLETE) {
 684                 call->reply[0] = NULL;
 685
 686                 /* We have two refs to release - one from the alloc and one
 687                  * queued with the work item - and we can't just deallocate the
 688                  * call because the work item may be queued again.
 689                  */
 690                 call->async_work.func = afs_delete_async_call;
 691                 if (!queue_work(afs_async_calls, &call->async_work))
 692                         afs_put_call(call);
 693         }
 694
 695         afs_put_call(call);
 696         _leave("");
 697 }
 698
 699 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
 700 {
 701         struct afs_call *call = (struct afs_call *)user_call_ID;
 702
 703         call->rxcall = rxcall;
 704 }
 705
 706 /*
 707  * Charge the incoming call preallocation.
 708  */
 709 void afs_charge_preallocation(struct work_struct *work)
 710 {
 711         struct afs_net *net =
 712                 container_of(work, struct afs_net, charge_preallocation_work);
 713         struct afs_call *call = net->spare_incoming_call;
 714
 715         for (;;) {
 716                 if (!call) {
 717                         call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
 718                         if (!call)
 719                                 break;
 720
 721                         call->async = true;
 722                         call->state = AFS_CALL_SV_AWAIT_OP_ID;
 723                         init_waitqueue_head(&call->waitq);
 724                 }
 725
 726                 if (rxrpc_kernel_charge_accept(net->socket,
 727                                                afs_wake_up_async_call,
 728                                                afs_rx_attach,
 729                                                (unsigned long)call,
 730                                                GFP_KERNEL) < 0)
 731                         break;
 732                 call = NULL;
 733         }
 734         net->spare_incoming_call = call;
 735 }
 736
 737 /*
 738  * Discard a preallocated call when a socket is shut down.
 739  */
 740 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
 741                                     unsigned long user_call_ID)
 742 {
 743         struct afs_call *call = (struct afs_call *)user_call_ID;
 744
 745         call->rxcall = NULL;
 746         afs_put_call(call);
 747 }
 748
 749 /*
 750  * Notification of an incoming call.
 751  */
 752 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
 753                             unsigned long user_call_ID)
 754 {
 755         struct afs_net *net = afs_sock2net(sk);
 756
 757         queue_work(afs_wq, &net->charge_preallocation_work);
 758 }
 759
 760 /*
 761  * Grab the operation ID from an incoming cache manager call.  The socket
 762  * buffer is discarded on error or if we don't yet have sufficient data.
 763  */
 764 static int afs_deliver_cm_op_id(struct afs_call *call)
 765 {
 766         int ret;
 767
 768         _enter("{%zu}", call->offset);
 769
 770         ASSERTCMP(call->offset, <, 4);
 771
 772         /* the operation ID forms the first four bytes of the request data */
 773         ret = afs_extract_data(call, &call->tmp, 4, true);
 774         if (ret < 0)
 775                 return ret;
 776
 777         call->operation_ID = ntohl(call->tmp);
 778         afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
 779         call->offset = 0;
 780
 781         /* ask the cache manager to route the call (it'll change the call type
 782          * if successful) */
 783         if (!afs_cm_incoming_call(call))
 784                 return -ENOTSUPP;
 785
 786         trace_afs_cb_call(call);
 787
 788         /* pass responsibility for the remainer of this message off to the
 789          * cache manager op */
 790         return call->type->deliver(call);
 791 }
 792
 793 /*
 794  * Advance the AFS call state when an RxRPC service call ends the transmit
 795  * phase.
 796  */
 797 static void afs_notify_end_reply_tx(struct sock *sock,
 798                                     struct rxrpc_call *rxcall,
 799                                     unsigned long call_user_ID)
 800 {
 801         struct afs_call *call = (struct afs_call *)call_user_ID;
 802
 803         afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
 804 }
 805
 806 /*
 807  * send an empty reply
 808  */
 809 void afs_send_empty_reply(struct afs_call *call)
 810 {
 811         struct afs_net *net = call->net;
 812         struct msghdr msg;
 813
 814         _enter("");
 815
 816         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
 817
 818         msg.msg_name            = NULL;
 819         msg.msg_namelen         = 0;
 820         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
 821         msg.msg_control         = NULL;
 822         msg.msg_controllen      = 0;
 823         msg.msg_flags           = 0;
 824
 825         switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
 826                                        afs_notify_end_reply_tx)) {
 827         case 0:
 828                 _leave(" [replied]");
 829                 return;
 830
 831         case -ENOMEM:
 832                 _debug("oom");
 833                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 834                                         RX_USER_ABORT, -ENOMEM, "KOO");
 835         default:
 836                 _leave(" [error]");
 837                 return;
 838         }
 839 }
 840
 841 /*
 842  * send a simple reply
 843  */
 844 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
 845 {
 846         struct afs_net *net = call->net;
 847         struct msghdr msg;
 848         struct kvec iov[1];
 849         int n;
 850
 851         _enter("");
 852
 853         rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
 854
 855         iov[0].iov_base         = (void *) buf;
 856         iov[0].iov_len          = len;
 857         msg.msg_name            = NULL;
 858         msg.msg_namelen         = 0;
 859         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
 860         msg.msg_control         = NULL;
 861         msg.msg_controllen      = 0;
 862         msg.msg_flags           = 0;
 863
 864         n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
 865                                    afs_notify_end_reply_tx);
 866         if (n >= 0) {
 867                 /* Success */
 868                 _leave(" [replied]");
 869                 return;
 870         }
 871
 872         if (n == -ENOMEM) {
 873                 _debug("oom");
 874                 rxrpc_kernel_abort_call(net->socket, call->rxcall,
 875                                         RX_USER_ABORT, -ENOMEM, "KOO");
 876         }
 877         _leave(" [error]");
 878 }
 879
 880 /*
 881  * Extract a piece of data from the received data socket buffers.
 882  */
 883 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
 884                      bool want_more)
 885 {
 886         struct afs_net *net = call->net;
 887         enum afs_call_state state;
 888         u32 remote_abort;
 889         int ret;
 890
 891         _enter("{%s,%zu},,%zu,%d",
 892                call->type->name, call->offset, count, want_more);
 893
 894         ASSERTCMP(call->offset, <=, count);
 895
 896         ret = rxrpc_kernel_recv_data(net->socket, call->rxcall,
 897                                      buf, count, &call->offset,
 898                                      want_more, &remote_abort,
 899                                      &call->service_id);
 900         trace_afs_recv_data(call, count, call->offset, want_more, ret);
 901         if (ret == 0 || ret == -EAGAIN)
 902                 return ret;
 903
 904         state = READ_ONCE(call->state);
 905         if (ret == 1) {
 906                 switch (state) {
 907                 case AFS_CALL_CL_AWAIT_REPLY:
 908                         afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
 909                         break;
 910                 case AFS_CALL_SV_AWAIT_REQUEST:
 911                         afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
 912                         break;
 913                 case AFS_CALL_COMPLETE:
 914                         kdebug("prem complete %d", call->error);
 915                         return -EIO;
 916                 default:
 917                         break;
 918                 }
 919                 return 0;
 920         }
 921
 922         afs_set_call_complete(call, ret, remote_abort);
 923         return ret;
 924 }