net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/kallsyms.h>
  29 #include <linux/mm.h>
  30 #include <linux/slab.h>
  31 #include <linux/utsname.h>
  32 #include <linux/workqueue.h>
  33 #include <linux/in6.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/rpc_pipe_fs.h>
  37 #include <linux/sunrpc/metrics.h>
  38 #include <linux/sunrpc/bc_xprt.h>
  39
  40 #include "sunrpc.h"
  41
  42 #ifdef RPC_DEBUG
  43 # define RPCDBG_FACILITY        RPCDBG_CALL
  44 #endif
  45
  46 #define dprint_status(t)                                        \
  47         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  48                         __func__, t->tk_status)
  49
  50 /*
  51  * All RPC clients are linked into this list
  52  */
  53 static LIST_HEAD(all_clients);
  54 static DEFINE_SPINLOCK(rpc_client_lock);
  55
  56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  57
  58
  59 static void     call_start(struct rpc_task *task);
  60 static void     call_reserve(struct rpc_task *task);
  61 static void     call_reserveresult(struct rpc_task *task);
  62 static void     call_allocate(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 #if defined(CONFIG_NFS_V4_1)
  68 static void     call_bc_transmit(struct rpc_task *task);
  69 #endif /* CONFIG_NFS_V4_1 */
  70 static void     call_status(struct rpc_task *task);
  71 static void     call_transmit_status(struct rpc_task *task);
  72 static void     call_refresh(struct rpc_task *task);
  73 static void     call_refreshresult(struct rpc_task *task);
  74 static void     call_timeout(struct rpc_task *task);
  75 static void     call_connect(struct rpc_task *task);
  76 static void     call_connect_status(struct rpc_task *task);
  77
  78 static __be32   *rpc_encode_header(struct rpc_task *task);
  79 static __be32   *rpc_verify_header(struct rpc_task *task);
  80 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         spin_lock(&rpc_client_lock);
  85         list_add(&clnt->cl_clients, &all_clients);
  86         spin_unlock(&rpc_client_lock);
  87 }
  88
  89 static void rpc_unregister_client(struct rpc_clnt *clnt)
  90 {
  91         spin_lock(&rpc_client_lock);
  92         list_del(&clnt->cl_clients);
  93         spin_unlock(&rpc_client_lock);
  94 }
  95
  96 static int
  97 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  98 {
  99         static uint32_t clntid;
 100         int error;
 101
 102         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
 103         clnt->cl_dentry = ERR_PTR(-ENOENT);
 104         if (dir_name == NULL)
 105                 return 0;
 106
 107         clnt->cl_vfsmnt = rpc_get_mount();
 108         if (IS_ERR(clnt->cl_vfsmnt))
 109                 return PTR_ERR(clnt->cl_vfsmnt);
 110
 111         for (;;) {
 112                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 113                                 "%s/clnt%x", dir_name,
 114                                 (unsigned int)clntid++);
 115                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 116                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 117                 if (!IS_ERR(clnt->cl_dentry))
 118                         return 0;
 119                 error = PTR_ERR(clnt->cl_dentry);
 120                 if (error != -EEXIST) {
 121                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 122                                         clnt->cl_pathname, error);
 123                         rpc_put_mount();
 124                         return error;
 125                 }
 126         }
 127 }
 128
 129 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 130 {
 131         struct rpc_program      *program = args->program;
 132         struct rpc_version      *version;
 133         struct rpc_clnt         *clnt = NULL;
 134         struct rpc_auth         *auth;
 135         int err;
 136         size_t len;
 137
 138         /* sanity check the name before trying to print it */
 139         err = -EINVAL;
 140         len = strlen(args->servername);
 141         if (len > RPC_MAXNETNAMELEN)
 142                 goto out_no_rpciod;
 143         len++;
 144
 145         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 146                         program->name, args->servername, xprt);
 147
 148         err = rpciod_up();
 149         if (err)
 150                 goto out_no_rpciod;
 151         err = -EINVAL;
 152         if (!xprt)
 153                 goto out_no_xprt;
 154
 155         if (args->version >= program->nrvers)
 156                 goto out_err;
 157         version = program->version[args->version];
 158         if (version == NULL)
 159                 goto out_err;
 160
 161         err = -ENOMEM;
 162         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 163         if (!clnt)
 164                 goto out_err;
 165         clnt->cl_parent = clnt;
 166
 167         clnt->cl_server = clnt->cl_inline_name;
 168         if (len > sizeof(clnt->cl_inline_name)) {
 169                 char *buf = kmalloc(len, GFP_KERNEL);
 170                 if (buf != NULL)
 171                         clnt->cl_server = buf;
 172                 else
 173                         len = sizeof(clnt->cl_inline_name);
 174         }
 175         strlcpy(clnt->cl_server, args->servername, len);
 176
 177         clnt->cl_xprt     = xprt;
 178         clnt->cl_procinfo = version->procs;
 179         clnt->cl_maxproc  = version->nrprocs;
 180         clnt->cl_protname = program->name;
 181         clnt->cl_prog     = args->prognumber ? : program->number;
 182         clnt->cl_vers     = version->number;
 183         clnt->cl_stats    = program->stats;
 184         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 185         err = -ENOMEM;
 186         if (clnt->cl_metrics == NULL)
 187                 goto out_no_stats;
 188         clnt->cl_program  = program;
 189         INIT_LIST_HEAD(&clnt->cl_tasks);
 190         spin_lock_init(&clnt->cl_lock);
 191
 192         if (!xprt_bound(clnt->cl_xprt))
 193                 clnt->cl_autobind = 1;
 194
 195         clnt->cl_timeout = xprt->timeout;
 196         if (args->timeout != NULL) {
 197                 memcpy(&clnt->cl_timeout_default, args->timeout,
 198                                 sizeof(clnt->cl_timeout_default));
 199                 clnt->cl_timeout = &clnt->cl_timeout_default;
 200         }
 201
 202         clnt->cl_rtt = &clnt->cl_rtt_default;
 203         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 204         clnt->cl_principal = NULL;
 205         if (args->client_name) {
 206                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 207                 if (!clnt->cl_principal)
 208                         goto out_no_principal;
 209         }
 210
 211         kref_init(&clnt->cl_kref);
 212
 213         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 214         if (err < 0)
 215                 goto out_no_path;
 216
 217         auth = rpcauth_create(args->authflavor, clnt);
 218         if (IS_ERR(auth)) {
 219                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 220                                 args->authflavor);
 221                 err = PTR_ERR(auth);
 222                 goto out_no_auth;
 223         }
 224
 225         /* save the nodename */
 226         clnt->cl_nodelen = strlen(init_utsname()->nodename);
 227         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 228                 clnt->cl_nodelen = UNX_MAXNODENAME;
 229         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
 230         rpc_register_client(clnt);
 231         return clnt;
 232
 233 out_no_auth:
 234         if (!IS_ERR(clnt->cl_dentry)) {
 235                 rpc_rmdir(clnt->cl_dentry);
 236                 rpc_put_mount();
 237         }
 238 out_no_path:
 239         kfree(clnt->cl_principal);
 240 out_no_principal:
 241         rpc_free_iostats(clnt->cl_metrics);
 242 out_no_stats:
 243         if (clnt->cl_server != clnt->cl_inline_name)
 244                 kfree(clnt->cl_server);
 245         kfree(clnt);
 246 out_err:
 247         xprt_put(xprt);
 248 out_no_xprt:
 249         rpciod_down();
 250 out_no_rpciod:
 251         return ERR_PTR(err);
 252 }
 253
 254 /*
 255  * rpc_create - create an RPC client and transport with one call
 256  * @args: rpc_clnt create argument structure
 257  *
 258  * Creates and initializes an RPC transport and an RPC client.
 259  *
 260  * It can ping the server in order to determine if it is up, and to see if
 261  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 262  * this behavior so asynchronous tasks can also use rpc_create.
 263  */
 264 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 265 {
 266         struct rpc_xprt *xprt;
 267         struct rpc_clnt *clnt;
 268         struct xprt_create xprtargs = {
 269                 .ident = args->protocol,
 270                 .srcaddr = args->saddress,
 271                 .dstaddr = args->address,
 272                 .addrlen = args->addrsize,
 273         };
 274         char servername[48];
 275
 276         /*
 277          * If the caller chooses not to specify a hostname, whip
 278          * up a string representation of the passed-in address.
 279          */
 280         if (args->servername == NULL) {
 281                 servername[0] = '\0';
 282                 switch (args->address->sa_family) {
 283                 case AF_INET: {
 284                         struct sockaddr_in *sin =
 285                                         (struct sockaddr_in *)args->address;
 286                         snprintf(servername, sizeof(servername), "%pI4",
 287                                  &sin->sin_addr.s_addr);
 288                         break;
 289                 }
 290                 case AF_INET6: {
 291                         struct sockaddr_in6 *sin =
 292                                         (struct sockaddr_in6 *)args->address;
 293                         snprintf(servername, sizeof(servername), "%pI6",
 294                                  &sin->sin6_addr);
 295                         break;
 296                 }
 297                 default:
 298                         /* caller wants default server name, but
 299                          * address family isn't recognized. */
 300                         return ERR_PTR(-EINVAL);
 301                 }
 302                 args->servername = servername;
 303         }
 304
 305         xprt = xprt_create_transport(&xprtargs);
 306         if (IS_ERR(xprt))
 307                 return (struct rpc_clnt *)xprt;
 308
 309         /*
 310          * By default, kernel RPC client connects from a reserved port.
 311          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 312          * but it is always enabled for rpciod, which handles the connect
 313          * operation.
 314          */
 315         xprt->resvport = 1;
 316         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 317                 xprt->resvport = 0;
 318
 319         clnt = rpc_new_client(args, xprt);
 320         if (IS_ERR(clnt))
 321                 return clnt;
 322
 323         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 324                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
 325                 if (err != 0) {
 326                         rpc_shutdown_client(clnt);
 327                         return ERR_PTR(err);
 328                 }
 329         }
 330
 331         clnt->cl_softrtry = 1;
 332         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 333                 clnt->cl_softrtry = 0;
 334
 335         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 336                 clnt->cl_autobind = 1;
 337         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 338                 clnt->cl_discrtry = 1;
 339         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 340                 clnt->cl_chatty = 1;
 341
 342         return clnt;
 343 }
 344 EXPORT_SYMBOL_GPL(rpc_create);
 345
 346 /*
 347  * This function clones the RPC client structure. It allows us to share the
 348  * same transport while varying parameters such as the authentication
 349  * flavour.
 350  */
 351 struct rpc_clnt *
 352 rpc_clone_client(struct rpc_clnt *clnt)
 353 {
 354         struct rpc_clnt *new;
 355         int err = -ENOMEM;
 356
 357         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 358         if (!new)
 359                 goto out_no_clnt;
 360         new->cl_parent = clnt;
 361         /* Turn off autobind on clones */
 362         new->cl_autobind = 0;
 363         INIT_LIST_HEAD(&new->cl_tasks);
 364         spin_lock_init(&new->cl_lock);
 365         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 366         new->cl_metrics = rpc_alloc_iostats(clnt);
 367         if (new->cl_metrics == NULL)
 368                 goto out_no_stats;
 369         if (clnt->cl_principal) {
 370                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
 371                 if (new->cl_principal == NULL)
 372                         goto out_no_principal;
 373         }
 374         kref_init(&new->cl_kref);
 375         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 376         if (err != 0)
 377                 goto out_no_path;
 378         if (new->cl_auth)
 379                 atomic_inc(&new->cl_auth->au_count);
 380         xprt_get(clnt->cl_xprt);
 381         kref_get(&clnt->cl_kref);
 382         rpc_register_client(new);
 383         rpciod_up();
 384         return new;
 385 out_no_path:
 386         kfree(new->cl_principal);
 387 out_no_principal:
 388         rpc_free_iostats(new->cl_metrics);
 389 out_no_stats:
 390         kfree(new);
 391 out_no_clnt:
 392         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 393         return ERR_PTR(err);
 394 }
 395 EXPORT_SYMBOL_GPL(rpc_clone_client);
 396
 397 /*
 398  * Properly shut down an RPC client, terminating all outstanding
 399  * requests.
 400  */
 401 void rpc_shutdown_client(struct rpc_clnt *clnt)
 402 {
 403         dprintk("RPC:       shutting down %s client for %s\n",
 404                         clnt->cl_protname, clnt->cl_server);
 405
 406         while (!list_empty(&clnt->cl_tasks)) {
 407                 rpc_killall_tasks(clnt);
 408                 wait_event_timeout(destroy_wait,
 409                         list_empty(&clnt->cl_tasks), 1*HZ);
 410         }
 411
 412         rpc_release_client(clnt);
 413 }
 414 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 415
 416 /*
 417  * Free an RPC client
 418  */
 419 static void
 420 rpc_free_client(struct kref *kref)
 421 {
 422         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 423
 424         dprintk("RPC:       destroying %s client for %s\n",
 425                         clnt->cl_protname, clnt->cl_server);
 426         if (!IS_ERR(clnt->cl_dentry)) {
 427                 rpc_rmdir(clnt->cl_dentry);
 428                 rpc_put_mount();
 429         }
 430         if (clnt->cl_parent != clnt) {
 431                 rpc_release_client(clnt->cl_parent);
 432                 goto out_free;
 433         }
 434         if (clnt->cl_server != clnt->cl_inline_name)
 435                 kfree(clnt->cl_server);
 436 out_free:
 437         rpc_unregister_client(clnt);
 438         rpc_free_iostats(clnt->cl_metrics);
 439         kfree(clnt->cl_principal);
 440         clnt->cl_metrics = NULL;
 441         xprt_put(clnt->cl_xprt);
 442         rpciod_down();
 443         kfree(clnt);
 444 }
 445
 446 /*
 447  * Free an RPC client
 448  */
 449 static void
 450 rpc_free_auth(struct kref *kref)
 451 {
 452         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 453
 454         if (clnt->cl_auth == NULL) {
 455                 rpc_free_client(kref);
 456                 return;
 457         }
 458
 459         /*
 460          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 461          *       release remaining GSS contexts. This mechanism ensures
 462          *       that it can do so safely.
 463          */
 464         kref_init(kref);
 465         rpcauth_release(clnt->cl_auth);
 466         clnt->cl_auth = NULL;
 467         kref_put(kref, rpc_free_client);
 468 }
 469
 470 /*
 471  * Release reference to the RPC client
 472  */
 473 void
 474 rpc_release_client(struct rpc_clnt *clnt)
 475 {
 476         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 477
 478         if (list_empty(&clnt->cl_tasks))
 479                 wake_up(&destroy_wait);
 480         kref_put(&clnt->cl_kref, rpc_free_auth);
 481 }
 482
 483 /**
 484  * rpc_bind_new_program - bind a new RPC program to an existing client
 485  * @old: old rpc_client
 486  * @program: rpc program to set
 487  * @vers: rpc program version
 488  *
 489  * Clones the rpc client and sets up a new RPC program. This is mainly
 490  * of use for enabling different RPC programs to share the same transport.
 491  * The Sun NFSv2/v3 ACL protocol can do this.
 492  */
 493 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 494                                       struct rpc_program *program,
 495                                       u32 vers)
 496 {
 497         struct rpc_clnt *clnt;
 498         struct rpc_version *version;
 499         int err;
 500
 501         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 502         version = program->version[vers];
 503         clnt = rpc_clone_client(old);
 504         if (IS_ERR(clnt))
 505                 goto out;
 506         clnt->cl_procinfo = version->procs;
 507         clnt->cl_maxproc  = version->nrprocs;
 508         clnt->cl_protname = program->name;
 509         clnt->cl_prog     = program->number;
 510         clnt->cl_vers     = version->number;
 511         clnt->cl_stats    = program->stats;
 512         err = rpc_ping(clnt, RPC_TASK_SOFT);
 513         if (err != 0) {
 514                 rpc_shutdown_client(clnt);
 515                 clnt = ERR_PTR(err);
 516         }
 517 out:
 518         return clnt;
 519 }
 520 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 521
 522 /*
 523  * Default callback for async RPC calls
 524  */
 525 static void
 526 rpc_default_callback(struct rpc_task *task, void *data)
 527 {
 528 }
 529
 530 static const struct rpc_call_ops rpc_default_ops = {
 531         .rpc_call_done = rpc_default_callback,
 532 };
 533
 534 /**
 535  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 536  * @task_setup_data: pointer to task initialisation data
 537  */
 538 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 539 {
 540         struct rpc_task *task, *ret;
 541
 542         task = rpc_new_task(task_setup_data);
 543         if (task == NULL) {
 544                 rpc_release_calldata(task_setup_data->callback_ops,
 545                                 task_setup_data->callback_data);
 546                 ret = ERR_PTR(-ENOMEM);
 547                 goto out;
 548         }
 549
 550         if (task->tk_status != 0) {
 551                 ret = ERR_PTR(task->tk_status);
 552                 rpc_put_task(task);
 553                 goto out;
 554         }
 555         atomic_inc(&task->tk_count);
 556         rpc_execute(task);
 557         ret = task;
 558 out:
 559         return ret;
 560 }
 561 EXPORT_SYMBOL_GPL(rpc_run_task);
 562
 563 /**
 564  * rpc_call_sync - Perform a synchronous RPC call
 565  * @clnt: pointer to RPC client
 566  * @msg: RPC call parameters
 567  * @flags: RPC call flags
 568  */
 569 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 570 {
 571         struct rpc_task *task;
 572         struct rpc_task_setup task_setup_data = {
 573                 .rpc_client = clnt,
 574                 .rpc_message = msg,
 575                 .callback_ops = &rpc_default_ops,
 576                 .flags = flags,
 577         };
 578         int status;
 579
 580         BUG_ON(flags & RPC_TASK_ASYNC);
 581
 582         task = rpc_run_task(&task_setup_data);
 583         if (IS_ERR(task))
 584                 return PTR_ERR(task);
 585         status = task->tk_status;
 586         rpc_put_task(task);
 587         return status;
 588 }
 589 EXPORT_SYMBOL_GPL(rpc_call_sync);
 590
 591 /**
 592  * rpc_call_async - Perform an asynchronous RPC call
 593  * @clnt: pointer to RPC client
 594  * @msg: RPC call parameters
 595  * @flags: RPC call flags
 596  * @tk_ops: RPC call ops
 597  * @data: user call data
 598  */
 599 int
 600 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 601                const struct rpc_call_ops *tk_ops, void *data)
 602 {
 603         struct rpc_task *task;
 604         struct rpc_task_setup task_setup_data = {
 605                 .rpc_client = clnt,
 606                 .rpc_message = msg,
 607                 .callback_ops = tk_ops,
 608                 .callback_data = data,
 609                 .flags = flags|RPC_TASK_ASYNC,
 610         };
 611
 612         task = rpc_run_task(&task_setup_data);
 613         if (IS_ERR(task))
 614                 return PTR_ERR(task);
 615         rpc_put_task(task);
 616         return 0;
 617 }
 618 EXPORT_SYMBOL_GPL(rpc_call_async);
 619
 620 #if defined(CONFIG_NFS_V4_1)
 621 /**
 622  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 623  * rpc_execute against it
 624  * @ops: RPC call ops
 625  */
 626 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 627                                         const struct rpc_call_ops *tk_ops)
 628 {
 629         struct rpc_task *task;
 630         struct xdr_buf *xbufp = &req->rq_snd_buf;
 631         struct rpc_task_setup task_setup_data = {
 632                 .callback_ops = tk_ops,
 633         };
 634
 635         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 636         /*
 637          * Create an rpc_task to send the data
 638          */
 639         task = rpc_new_task(&task_setup_data);
 640         if (!task) {
 641                 xprt_free_bc_request(req);
 642                 goto out;
 643         }
 644         task->tk_rqstp = req;
 645
 646         /*
 647          * Set up the xdr_buf length.
 648          * This also indicates that the buffer is XDR encoded already.
 649          */
 650         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 651                         xbufp->tail[0].iov_len;
 652
 653         task->tk_action = call_bc_transmit;
 654         atomic_inc(&task->tk_count);
 655         BUG_ON(atomic_read(&task->tk_count) != 2);
 656         rpc_execute(task);
 657
 658 out:
 659         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 660         return task;
 661 }
 662 #endif /* CONFIG_NFS_V4_1 */
 663
 664 void
 665 rpc_call_start(struct rpc_task *task)
 666 {
 667         task->tk_action = call_start;
 668 }
 669 EXPORT_SYMBOL_GPL(rpc_call_start);
 670
 671 /**
 672  * rpc_peeraddr - extract remote peer address from clnt's xprt
 673  * @clnt: RPC client structure
 674  * @buf: target buffer
 675  * @bufsize: length of target buffer
 676  *
 677  * Returns the number of bytes that are actually in the stored address.
 678  */
 679 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 680 {
 681         size_t bytes;
 682         struct rpc_xprt *xprt = clnt->cl_xprt;
 683
 684         bytes = sizeof(xprt->addr);
 685         if (bytes > bufsize)
 686                 bytes = bufsize;
 687         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 688         return xprt->addrlen;
 689 }
 690 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 691
 692 /**
 693  * rpc_peeraddr2str - return remote peer address in printable format
 694  * @clnt: RPC client structure
 695  * @format: address format
 696  *
 697  */
 698 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 699                              enum rpc_display_format_t format)
 700 {
 701         struct rpc_xprt *xprt = clnt->cl_xprt;
 702
 703         if (xprt->address_strings[format] != NULL)
 704                 return xprt->address_strings[format];
 705         else
 706                 return "unprintable";
 707 }
 708 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 709
 710 void
 711 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 712 {
 713         struct rpc_xprt *xprt = clnt->cl_xprt;
 714         if (xprt->ops->set_buffer_size)
 715                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 716 }
 717 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 718
 719 /*
 720  * Return size of largest payload RPC client can support, in bytes
 721  *
 722  * For stream transports, this is one RPC record fragment (see RFC
 723  * 1831), as we don't support multi-record requests yet.  For datagram
 724  * transports, this is the size of an IP packet minus the IP, UDP, and
 725  * RPC header sizes.
 726  */
 727 size_t rpc_max_payload(struct rpc_clnt *clnt)
 728 {
 729         return clnt->cl_xprt->max_payload;
 730 }
 731 EXPORT_SYMBOL_GPL(rpc_max_payload);
 732
 733 /**
 734  * rpc_force_rebind - force transport to check that remote port is unchanged
 735  * @clnt: client to rebind
 736  *
 737  */
 738 void rpc_force_rebind(struct rpc_clnt *clnt)
 739 {
 740         if (clnt->cl_autobind)
 741                 xprt_clear_bound(clnt->cl_xprt);
 742 }
 743 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 744
 745 /*
 746  * Restart an (async) RPC call from the call_prepare state.
 747  * Usually called from within the exit handler.
 748  */
 749 void
 750 rpc_restart_call_prepare(struct rpc_task *task)
 751 {
 752         if (RPC_ASSASSINATED(task))
 753                 return;
 754         task->tk_action = rpc_prepare_task;
 755 }
 756 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 757
 758 /*
 759  * Restart an (async) RPC call. Usually called from within the
 760  * exit handler.
 761  */
 762 void
 763 rpc_restart_call(struct rpc_task *task)
 764 {
 765         if (RPC_ASSASSINATED(task))
 766                 return;
 767
 768         task->tk_action = call_start;
 769 }
 770 EXPORT_SYMBOL_GPL(rpc_restart_call);
 771
 772 #ifdef RPC_DEBUG
 773 static const char *rpc_proc_name(const struct rpc_task *task)
 774 {
 775         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 776
 777         if (proc) {
 778                 if (proc->p_name)
 779                         return proc->p_name;
 780                 else
 781                         return "NULL";
 782         } else
 783                 return "no proc";
 784 }
 785 #endif
 786
 787 /*
 788  * 0.  Initial state
 789  *
 790  *     Other FSM states can be visited zero or more times, but
 791  *     this state is visited exactly once for each RPC.
 792  */
 793 static void
 794 call_start(struct rpc_task *task)
 795 {
 796         struct rpc_clnt *clnt = task->tk_client;
 797
 798         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 799                         clnt->cl_protname, clnt->cl_vers,
 800                         rpc_proc_name(task),
 801                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 802
 803         /* Increment call count */
 804         task->tk_msg.rpc_proc->p_count++;
 805         clnt->cl_stats->rpccnt++;
 806         task->tk_action = call_reserve;
 807 }
 808
 809 /*
 810  * 1.   Reserve an RPC call slot
 811  */
 812 static void
 813 call_reserve(struct rpc_task *task)
 814 {
 815         dprint_status(task);
 816
 817         if (!rpcauth_uptodatecred(task)) {
 818                 task->tk_action = call_refresh;
 819                 return;
 820         }
 821
 822         task->tk_status  = 0;
 823         task->tk_action  = call_reserveresult;
 824         xprt_reserve(task);
 825 }
 826
 827 /*
 828  * 1b.  Grok the result of xprt_reserve()
 829  */
 830 static void
 831 call_reserveresult(struct rpc_task *task)
 832 {
 833         int status = task->tk_status;
 834
 835         dprint_status(task);
 836
 837         /*
 838          * After a call to xprt_reserve(), we must have either
 839          * a request slot or else an error status.
 840          */
 841         task->tk_status = 0;
 842         if (status >= 0) {
 843                 if (task->tk_rqstp) {
 844                         task->tk_action = call_allocate;
 845                         return;
 846                 }
 847
 848                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 849                                 __func__, status);
 850                 rpc_exit(task, -EIO);
 851                 return;
 852         }
 853
 854         /*
 855          * Even though there was an error, we may have acquired
 856          * a request slot somehow.  Make sure not to leak it.
 857          */
 858         if (task->tk_rqstp) {
 859                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 860                                 __func__, status);
 861                 xprt_release(task);
 862         }
 863
 864         switch (status) {
 865         case -EAGAIN:   /* woken up; retry */
 866                 task->tk_action = call_reserve;
 867                 return;
 868         case -EIO:      /* probably a shutdown */
 869                 break;
 870         default:
 871                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 872                                 __func__, status);
 873                 break;
 874         }
 875         rpc_exit(task, status);
 876 }
 877
 878 /*
 879  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 880  *      (Note: buffer memory is freed in xprt_release).
 881  */
 882 static void
 883 call_allocate(struct rpc_task *task)
 884 {
 885         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 886         struct rpc_rqst *req = task->tk_rqstp;
 887         struct rpc_xprt *xprt = task->tk_xprt;
 888         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 889
 890         dprint_status(task);
 891
 892         task->tk_status = 0;
 893         task->tk_action = call_bind;
 894
 895         if (req->rq_buffer)
 896                 return;
 897
 898         if (proc->p_proc != 0) {
 899                 BUG_ON(proc->p_arglen == 0);
 900                 if (proc->p_decode != NULL)
 901                         BUG_ON(proc->p_replen == 0);
 902         }
 903
 904         /*
 905          * Calculate the size (in quads) of the RPC call
 906          * and reply headers, and convert both values
 907          * to byte sizes.
 908          */
 909         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 910         req->rq_callsize <<= 2;
 911         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 912         req->rq_rcvsize <<= 2;
 913
 914         req->rq_buffer = xprt->ops->buf_alloc(task,
 915                                         req->rq_callsize + req->rq_rcvsize);
 916         if (req->rq_buffer != NULL)
 917                 return;
 918
 919         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 920
 921         if (RPC_IS_ASYNC(task) || !signalled()) {
 922                 task->tk_action = call_allocate;
 923                 rpc_delay(task, HZ>>4);
 924                 return;
 925         }
 926
 927         rpc_exit(task, -ERESTARTSYS);
 928 }
 929
 930 static inline int
 931 rpc_task_need_encode(struct rpc_task *task)
 932 {
 933         return task->tk_rqstp->rq_snd_buf.len == 0;
 934 }
 935
 936 static inline void
 937 rpc_task_force_reencode(struct rpc_task *task)
 938 {
 939         task->tk_rqstp->rq_snd_buf.len = 0;
 940 }
 941
 942 static inline void
 943 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 944 {
 945         buf->head[0].iov_base = start;
 946         buf->head[0].iov_len = len;
 947         buf->tail[0].iov_len = 0;
 948         buf->page_len = 0;
 949         buf->flags = 0;
 950         buf->len = 0;
 951         buf->buflen = len;
 952 }
 953
 954 /*
 955  * 3.   Encode arguments of an RPC call
 956  */
 957 static void
 958 rpc_xdr_encode(struct rpc_task *task)
 959 {
 960         struct rpc_rqst *req = task->tk_rqstp;
 961         kxdrproc_t      encode;
 962         __be32          *p;
 963
 964         dprint_status(task);
 965
 966         rpc_xdr_buf_init(&req->rq_snd_buf,
 967                          req->rq_buffer,
 968                          req->rq_callsize);
 969         rpc_xdr_buf_init(&req->rq_rcv_buf,
 970                          (char *)req->rq_buffer + req->rq_callsize,
 971                          req->rq_rcvsize);
 972
 973         p = rpc_encode_header(task);
 974         if (p == NULL) {
 975                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 976                 rpc_exit(task, -EIO);
 977                 return;
 978         }
 979
 980         encode = task->tk_msg.rpc_proc->p_encode;
 981         if (encode == NULL)
 982                 return;
 983
 984         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 985                         task->tk_msg.rpc_argp);
 986 }
 987
 988 /*
 989  * 4.   Get the server port number if not yet set
 990  */
 991 static void
 992 call_bind(struct rpc_task *task)
 993 {
 994         struct rpc_xprt *xprt = task->tk_xprt;
 995
 996         dprint_status(task);
 997
 998         task->tk_action = call_connect;
 999         if (!xprt_bound(xprt)) {
1000                 task->tk_action = call_bind_status;
1001                 task->tk_timeout = xprt->bind_timeout;
1002                 xprt->ops->rpcbind(task);
1003         }
1004 }
1005
1006 /*
1007  * 4a.  Sort out bind result
1008  */
1009 static void
1010 call_bind_status(struct rpc_task *task)
1011 {
1012         int status = -EIO;
1013
1014         if (task->tk_status >= 0) {
1015                 dprint_status(task);
1016                 task->tk_status = 0;
1017                 task->tk_action = call_connect;
1018                 return;
1019         }
1020
1021         switch (task->tk_status) {
1022         case -ENOMEM:
1023                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1024                 rpc_delay(task, HZ >> 2);
1025                 goto retry_timeout;
1026         case -EACCES:
1027                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1028                                 "unavailable\n", task->tk_pid);
1029                 /* fail immediately if this is an RPC ping */
1030                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1031                         status = -EOPNOTSUPP;
1032                         break;
1033                 }
1034                 rpc_delay(task, 3*HZ);
1035                 goto retry_timeout;
1036         case -ETIMEDOUT:
1037                 dprintk("RPC: %5u rpcbind request timed out\n",
1038                                 task->tk_pid);
1039                 goto retry_timeout;
1040         case -EPFNOSUPPORT:
1041                 /* server doesn't support any rpcbind version we know of */
1042                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1043                                 task->tk_pid);
1044                 break;
1045         case -EPROTONOSUPPORT:
1046                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1047                                 task->tk_pid);
1048                 task->tk_status = 0;
1049                 task->tk_action = call_bind;
1050                 return;
1051         default:
1052                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1053                                 task->tk_pid, -task->tk_status);
1054         }
1055
1056         rpc_exit(task, status);
1057         return;
1058
1059 retry_timeout:
1060         task->tk_action = call_timeout;
1061 }
1062
1063 /*
1064  * 4b.  Connect to the RPC server
1065  */
1066 static void
1067 call_connect(struct rpc_task *task)
1068 {
1069         struct rpc_xprt *xprt = task->tk_xprt;
1070
1071         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1072                         task->tk_pid, xprt,
1073                         (xprt_connected(xprt) ? "is" : "is not"));
1074
1075         task->tk_action = call_transmit;
1076         if (!xprt_connected(xprt)) {
1077                 task->tk_action = call_connect_status;
1078                 if (task->tk_status < 0)
1079                         return;
1080                 xprt_connect(task);
1081         }
1082 }
1083
1084 /*
1085  * 4c.  Sort out connect result
1086  */
1087 static void
1088 call_connect_status(struct rpc_task *task)
1089 {
1090         struct rpc_clnt *clnt = task->tk_client;
1091         int status = task->tk_status;
1092
1093         dprint_status(task);
1094
1095         task->tk_status = 0;
1096         if (status >= 0 || status == -EAGAIN) {
1097                 clnt->cl_stats->netreconn++;
1098                 task->tk_action = call_transmit;
1099                 return;
1100         }
1101
1102         switch (status) {
1103                 /* if soft mounted, test if we've timed out */
1104         case -ETIMEDOUT:
1105                 task->tk_action = call_timeout;
1106                 break;
1107         default:
1108                 rpc_exit(task, -EIO);
1109         }
1110 }
1111
1112 /*
1113  * 5.   Transmit the RPC request, and wait for reply
1114  */
1115 static void
1116 call_transmit(struct rpc_task *task)
1117 {
1118         dprint_status(task);
1119
1120         task->tk_action = call_status;
1121         if (task->tk_status < 0)
1122                 return;
1123         task->tk_status = xprt_prepare_transmit(task);
1124         if (task->tk_status != 0)
1125                 return;
1126         task->tk_action = call_transmit_status;
1127         /* Encode here so that rpcsec_gss can use correct sequence number. */
1128         if (rpc_task_need_encode(task)) {
1129                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1130                 rpc_xdr_encode(task);
1131                 /* Did the encode result in an error condition? */
1132                 if (task->tk_status != 0) {
1133                         /* Was the error nonfatal? */
1134                         if (task->tk_status == -EAGAIN)
1135                                 rpc_delay(task, HZ >> 4);
1136                         else
1137                                 rpc_exit(task, task->tk_status);
1138                         return;
1139                 }
1140         }
1141         xprt_transmit(task);
1142         if (task->tk_status < 0)
1143                 return;
1144         /*
1145          * On success, ensure that we call xprt_end_transmit() before sleeping
1146          * in order to allow access to the socket to other RPC requests.
1147          */
1148         call_transmit_status(task);
1149         if (rpc_reply_expected(task))
1150                 return;
1151         task->tk_action = rpc_exit_task;
1152         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1153 }
1154
1155 /*
1156  * 5a.  Handle cleanup after a transmission
1157  */
1158 static void
1159 call_transmit_status(struct rpc_task *task)
1160 {
1161         task->tk_action = call_status;
1162         switch (task->tk_status) {
1163         case -EAGAIN:
1164                 break;
1165         default:
1166                 xprt_end_transmit(task);
1167                 /*
1168                  * Special cases: if we've been waiting on the
1169                  * socket's write_space() callback, or if the
1170                  * socket just returned a connection error,
1171                  * then hold onto the transport lock.
1172                  */
1173         case -ECONNREFUSED:
1174         case -ECONNRESET:
1175         case -ENOTCONN:
1176         case -EHOSTDOWN:
1177         case -EHOSTUNREACH:
1178         case -ENETUNREACH:
1179         case -EPIPE:
1180                 rpc_task_force_reencode(task);
1181         }
1182 }
1183
1184 #if defined(CONFIG_NFS_V4_1)
1185 /*
1186  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1187  * addition, disconnect on connectivity errors.
1188  */
1189 static void
1190 call_bc_transmit(struct rpc_task *task)
1191 {
1192         struct rpc_rqst *req = task->tk_rqstp;
1193
1194         BUG_ON(task->tk_status != 0);
1195         task->tk_status = xprt_prepare_transmit(task);
1196         if (task->tk_status == -EAGAIN) {
1197                 /*
1198                  * Could not reserve the transport. Try again after the
1199                  * transport is released.
1200                  */
1201                 task->tk_status = 0;
1202                 task->tk_action = call_bc_transmit;
1203                 return;
1204         }
1205
1206         task->tk_action = rpc_exit_task;
1207         if (task->tk_status < 0) {
1208                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1209                         "error: %d\n", task->tk_status);
1210                 return;
1211         }
1212
1213         xprt_transmit(task);
1214         xprt_end_transmit(task);
1215         dprint_status(task);
1216         switch (task->tk_status) {
1217         case 0:
1218                 /* Success */
1219                 break;
1220         case -EHOSTDOWN:
1221         case -EHOSTUNREACH:
1222         case -ENETUNREACH:
1223         case -ETIMEDOUT:
1224                 /*
1225                  * Problem reaching the server.  Disconnect and let the
1226                  * forechannel reestablish the connection.  The server will
1227                  * have to retransmit the backchannel request and we'll
1228                  * reprocess it.  Since these ops are idempotent, there's no
1229                  * need to cache our reply at this time.
1230                  */
1231                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1232                         "error: %d\n", task->tk_status);
1233                 xprt_conditional_disconnect(task->tk_xprt,
1234                         req->rq_connect_cookie);
1235                 break;
1236         default:
1237                 /*
1238                  * We were unable to reply and will have to drop the
1239                  * request.  The server should reconnect and retransmit.
1240                  */
1241                 BUG_ON(task->tk_status == -EAGAIN);
1242                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1243                         "error: %d\n", task->tk_status);
1244                 break;
1245         }
1246         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1247 }
1248 #endif /* CONFIG_NFS_V4_1 */
1249
1250 /*
1251  * 6.   Sort out the RPC call status
1252  */
1253 static void
1254 call_status(struct rpc_task *task)
1255 {
1256         struct rpc_clnt *clnt = task->tk_client;
1257         struct rpc_rqst *req = task->tk_rqstp;
1258         int             status;
1259
1260         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1261                 task->tk_status = req->rq_reply_bytes_recvd;
1262
1263         dprint_status(task);
1264
1265         status = task->tk_status;
1266         if (status >= 0) {
1267                 task->tk_action = call_decode;
1268                 return;
1269         }
1270
1271         task->tk_status = 0;
1272         switch(status) {
1273         case -EHOSTDOWN:
1274         case -EHOSTUNREACH:
1275         case -ENETUNREACH:
1276                 /*
1277                  * Delay any retries for 3 seconds, then handle as if it
1278                  * were a timeout.
1279                  */
1280                 rpc_delay(task, 3*HZ);
1281         case -ETIMEDOUT:
1282                 task->tk_action = call_timeout;
1283                 if (task->tk_client->cl_discrtry)
1284                         xprt_conditional_disconnect(task->tk_xprt,
1285                                         req->rq_connect_cookie);
1286                 break;
1287         case -ECONNRESET:
1288         case -ECONNREFUSED:
1289                 rpc_force_rebind(clnt);
1290                 rpc_delay(task, 3*HZ);
1291         case -EPIPE:
1292         case -ENOTCONN:
1293                 task->tk_action = call_bind;
1294                 break;
1295         case -EAGAIN:
1296                 task->tk_action = call_transmit;
1297                 break;
1298         case -EIO:
1299                 /* shutdown or soft timeout */
1300                 rpc_exit(task, status);
1301                 break;
1302         default:
1303                 if (clnt->cl_chatty)
1304                         printk("%s: RPC call returned error %d\n",
1305                                clnt->cl_protname, -status);
1306                 rpc_exit(task, status);
1307         }
1308 }
1309
1310 /*
1311  * 6a.  Handle RPC timeout
1312  *      We do not release the request slot, so we keep using the
1313  *      same XID for all retransmits.
1314  */
1315 static void
1316 call_timeout(struct rpc_task *task)
1317 {
1318         struct rpc_clnt *clnt = task->tk_client;
1319
1320         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1321                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1322                 goto retry;
1323         }
1324
1325         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1326         task->tk_timeouts++;
1327
1328         if (RPC_IS_SOFT(task)) {
1329                 if (clnt->cl_chatty)
1330                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1331                                 clnt->cl_protname, clnt->cl_server);
1332                 rpc_exit(task, -EIO);
1333                 return;
1334         }
1335
1336         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1337                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1338                 if (clnt->cl_chatty)
1339                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1340                         clnt->cl_protname, clnt->cl_server);
1341         }
1342         rpc_force_rebind(clnt);
1343         /*
1344          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1345          * event? RFC2203 requires the server to drop all such requests.
1346          */
1347         rpcauth_invalcred(task);
1348
1349 retry:
1350         clnt->cl_stats->rpcretrans++;
1351         task->tk_action = call_bind;
1352         task->tk_status = 0;
1353 }
1354
1355 /*
1356  * 7.   Decode the RPC reply
1357  */
1358 static void
1359 call_decode(struct rpc_task *task)
1360 {
1361         struct rpc_clnt *clnt = task->tk_client;
1362         struct rpc_rqst *req = task->tk_rqstp;
1363         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1364         __be32          *p;
1365
1366         dprintk("RPC: %5u call_decode (status %d)\n",
1367                         task->tk_pid, task->tk_status);
1368
1369         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1370                 if (clnt->cl_chatty)
1371                         printk(KERN_NOTICE "%s: server %s OK\n",
1372                                 clnt->cl_protname, clnt->cl_server);
1373                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1374         }
1375
1376         /*
1377          * Ensure that we see all writes made by xprt_complete_rqst()
1378          * before it changed req->rq_reply_bytes_recvd.
1379          */
1380         smp_rmb();
1381         req->rq_rcv_buf.len = req->rq_private_buf.len;
1382
1383         /* Check that the softirq receive buffer is valid */
1384         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1385                                 sizeof(req->rq_rcv_buf)) != 0);
1386
1387         if (req->rq_rcv_buf.len < 12) {
1388                 if (!RPC_IS_SOFT(task)) {
1389                         task->tk_action = call_bind;
1390                         clnt->cl_stats->rpcretrans++;
1391                         goto out_retry;
1392                 }
1393                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1394                                 clnt->cl_protname, task->tk_status);
1395                 task->tk_action = call_timeout;
1396                 goto out_retry;
1397         }
1398
1399         p = rpc_verify_header(task);
1400         if (IS_ERR(p)) {
1401                 if (p == ERR_PTR(-EAGAIN))
1402                         goto out_retry;
1403                 return;
1404         }
1405
1406         task->tk_action = rpc_exit_task;
1407
1408         if (decode) {
1409                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1410                                                       task->tk_msg.rpc_resp);
1411         }
1412         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1413                         task->tk_status);
1414         return;
1415 out_retry:
1416         task->tk_status = 0;
1417         /* Note: rpc_verify_header() may have freed the RPC slot */
1418         if (task->tk_rqstp == req) {
1419                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1420                 if (task->tk_client->cl_discrtry)
1421                         xprt_conditional_disconnect(task->tk_xprt,
1422                                         req->rq_connect_cookie);
1423         }
1424 }
1425
1426 /*
1427  * 8.   Refresh the credentials if rejected by the server
1428  */
1429 static void
1430 call_refresh(struct rpc_task *task)
1431 {
1432         dprint_status(task);
1433
1434         task->tk_action = call_refreshresult;
1435         task->tk_status = 0;
1436         task->tk_client->cl_stats->rpcauthrefresh++;
1437         rpcauth_refreshcred(task);
1438 }
1439
1440 /*
1441  * 8a.  Process the results of a credential refresh
1442  */
1443 static void
1444 call_refreshresult(struct rpc_task *task)
1445 {
1446         int status = task->tk_status;
1447
1448         dprint_status(task);
1449
1450         task->tk_status = 0;
1451         task->tk_action = call_reserve;
1452         if (status >= 0 && rpcauth_uptodatecred(task))
1453                 return;
1454         if (status == -EACCES) {
1455                 rpc_exit(task, -EACCES);
1456                 return;
1457         }
1458         task->tk_action = call_refresh;
1459         if (status != -ETIMEDOUT)
1460                 rpc_delay(task, 3*HZ);
1461         return;
1462 }
1463
1464 static __be32 *
1465 rpc_encode_header(struct rpc_task *task)
1466 {
1467         struct rpc_clnt *clnt = task->tk_client;
1468         struct rpc_rqst *req = task->tk_rqstp;
1469         __be32          *p = req->rq_svec[0].iov_base;
1470
1471         /* FIXME: check buffer size? */
1472
1473         p = xprt_skip_transport_header(task->tk_xprt, p);
1474         *p++ = req->rq_xid;             /* XID */
1475         *p++ = htonl(RPC_CALL);         /* CALL */
1476         *p++ = htonl(RPC_VERSION);      /* RPC version */
1477         *p++ = htonl(clnt->cl_prog);    /* program number */
1478         *p++ = htonl(clnt->cl_vers);    /* program version */
1479         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1480         p = rpcauth_marshcred(task, p);
1481         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1482         return p;
1483 }
1484
1485 static __be32 *
1486 rpc_verify_header(struct rpc_task *task)
1487 {
1488         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1489         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1490         __be32  *p = iov->iov_base;
1491         u32 n;
1492         int error = -EACCES;
1493
1494         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1495                 /* RFC-1014 says that the representation of XDR data must be a
1496                  * multiple of four bytes
1497                  * - if it isn't pointer subtraction in the NFS client may give
1498                  *   undefined results
1499                  */
1500                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1501                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1502                        task->tk_rqstp->rq_rcv_buf.len);
1503                 goto out_eio;
1504         }
1505         if ((len -= 3) < 0)
1506                 goto out_overflow;
1507
1508         p += 1; /* skip XID */
1509         if ((n = ntohl(*p++)) != RPC_REPLY) {
1510                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1511                         task->tk_pid, __func__, n);
1512                 goto out_garbage;
1513         }
1514
1515         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1516                 if (--len < 0)
1517                         goto out_overflow;
1518                 switch ((n = ntohl(*p++))) {
1519                         case RPC_AUTH_ERROR:
1520                                 break;
1521                         case RPC_MISMATCH:
1522                                 dprintk("RPC: %5u %s: RPC call version "
1523                                                 "mismatch!\n",
1524                                                 task->tk_pid, __func__);
1525                                 error = -EPROTONOSUPPORT;
1526                                 goto out_err;
1527                         default:
1528                                 dprintk("RPC: %5u %s: RPC call rejected, "
1529                                                 "unknown error: %x\n",
1530                                                 task->tk_pid, __func__, n);
1531                                 goto out_eio;
1532                 }
1533                 if (--len < 0)
1534                         goto out_overflow;
1535                 switch ((n = ntohl(*p++))) {
1536                 case RPC_AUTH_REJECTEDCRED:
1537                 case RPC_AUTH_REJECTEDVERF:
1538                 case RPCSEC_GSS_CREDPROBLEM:
1539                 case RPCSEC_GSS_CTXPROBLEM:
1540                         if (!task->tk_cred_retry)
1541                                 break;
1542                         task->tk_cred_retry--;
1543                         dprintk("RPC: %5u %s: retry stale creds\n",
1544                                         task->tk_pid, __func__);
1545                         rpcauth_invalcred(task);
1546                         /* Ensure we obtain a new XID! */
1547                         xprt_release(task);
1548                         task->tk_action = call_refresh;
1549                         goto out_retry;
1550                 case RPC_AUTH_BADCRED:
1551                 case RPC_AUTH_BADVERF:
1552                         /* possibly garbled cred/verf? */
1553                         if (!task->tk_garb_retry)
1554                                 break;
1555                         task->tk_garb_retry--;
1556                         dprintk("RPC: %5u %s: retry garbled creds\n",
1557                                         task->tk_pid, __func__);
1558                         task->tk_action = call_bind;
1559                         goto out_retry;
1560                 case RPC_AUTH_TOOWEAK:
1561                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1562                                "authentication.\n", task->tk_client->cl_server);
1563                         break;
1564                 default:
1565                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1566                                         task->tk_pid, __func__, n);
1567                         error = -EIO;
1568                 }
1569                 dprintk("RPC: %5u %s: call rejected %d\n",
1570                                 task->tk_pid, __func__, n);
1571                 goto out_err;
1572         }
1573         if (!(p = rpcauth_checkverf(task, p))) {
1574                 dprintk("RPC: %5u %s: auth check failed\n",
1575                                 task->tk_pid, __func__);
1576                 goto out_garbage;               /* bad verifier, retry */
1577         }
1578         len = p - (__be32 *)iov->iov_base - 1;
1579         if (len < 0)
1580                 goto out_overflow;
1581         switch ((n = ntohl(*p++))) {
1582         case RPC_SUCCESS:
1583                 return p;
1584         case RPC_PROG_UNAVAIL:
1585                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1586                                 task->tk_pid, __func__,
1587                                 (unsigned int)task->tk_client->cl_prog,
1588                                 task->tk_client->cl_server);
1589                 error = -EPFNOSUPPORT;
1590                 goto out_err;
1591         case RPC_PROG_MISMATCH:
1592                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1593                                 "server %s\n", task->tk_pid, __func__,
1594                                 (unsigned int)task->tk_client->cl_prog,
1595                                 (unsigned int)task->tk_client->cl_vers,
1596                                 task->tk_client->cl_server);
1597                 error = -EPROTONOSUPPORT;
1598                 goto out_err;
1599         case RPC_PROC_UNAVAIL:
1600                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1601                                 "version %u on server %s\n",
1602                                 task->tk_pid, __func__,
1603                                 rpc_proc_name(task),
1604                                 task->tk_client->cl_prog,
1605                                 task->tk_client->cl_vers,
1606                                 task->tk_client->cl_server);
1607                 error = -EOPNOTSUPP;
1608                 goto out_err;
1609         case RPC_GARBAGE_ARGS:
1610                 dprintk("RPC: %5u %s: server saw garbage\n",
1611                                 task->tk_pid, __func__);
1612                 break;                  /* retry */
1613         default:
1614                 dprintk("RPC: %5u %s: server accept status: %x\n",
1615                                 task->tk_pid, __func__, n);
1616                 /* Also retry */
1617         }
1618
1619 out_garbage:
1620         task->tk_client->cl_stats->rpcgarbage++;
1621         if (task->tk_garb_retry) {
1622                 task->tk_garb_retry--;
1623                 dprintk("RPC: %5u %s: retrying\n",
1624                                 task->tk_pid, __func__);
1625                 task->tk_action = call_bind;
1626 out_retry:
1627                 return ERR_PTR(-EAGAIN);
1628         }
1629 out_eio:
1630         error = -EIO;
1631 out_err:
1632         rpc_exit(task, error);
1633         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1634                         __func__, error);
1635         return ERR_PTR(error);
1636 out_overflow:
1637         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1638                         __func__);
1639         goto out_garbage;
1640 }
1641
1642 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1643 {
1644         return 0;
1645 }
1646
1647 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1648 {
1649         return 0;
1650 }
1651
1652 static struct rpc_procinfo rpcproc_null = {
1653         .p_encode = rpcproc_encode_null,
1654         .p_decode = rpcproc_decode_null,
1655 };
1656
1657 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1658 {
1659         struct rpc_message msg = {
1660                 .rpc_proc = &rpcproc_null,
1661         };
1662         int err;
1663         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1664         err = rpc_call_sync(clnt, &msg, flags);
1665         put_rpccred(msg.rpc_cred);
1666         return err;
1667 }
1668
1669 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1670 {
1671         struct rpc_message msg = {
1672                 .rpc_proc = &rpcproc_null,
1673                 .rpc_cred = cred,
1674         };
1675         struct rpc_task_setup task_setup_data = {
1676                 .rpc_client = clnt,
1677                 .rpc_message = &msg,
1678                 .callback_ops = &rpc_default_ops,
1679                 .flags = flags,
1680         };
1681         return rpc_run_task(&task_setup_data);
1682 }
1683 EXPORT_SYMBOL_GPL(rpc_call_null);
1684
1685 #ifdef RPC_DEBUG
1686 static void rpc_show_header(void)
1687 {
1688         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1689                 "-timeout ---ops--\n");
1690 }
1691
1692 static void rpc_show_task(const struct rpc_clnt *clnt,
1693                           const struct rpc_task *task)
1694 {
1695         const char *rpc_waitq = "none";
1696         char *p, action[KSYM_SYMBOL_LEN];
1697
1698         if (RPC_IS_QUEUED(task))
1699                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1700
1701         /* map tk_action pointer to a function name; then trim off
1702          * the "+0x0 [sunrpc]" */
1703         sprint_symbol(action, (unsigned long)task->tk_action);
1704         p = strchr(action, '+');
1705         if (p)
1706                 *p = '\0';
1707
1708         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1709                 task->tk_pid, task->tk_flags, task->tk_status,
1710                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1711                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1712                 action, rpc_waitq);
1713 }
1714
1715 void rpc_show_tasks(void)
1716 {
1717         struct rpc_clnt *clnt;
1718         struct rpc_task *task;
1719         int header = 0;
1720
1721         spin_lock(&rpc_client_lock);
1722         list_for_each_entry(clnt, &all_clients, cl_clients) {
1723                 spin_lock(&clnt->cl_lock);
1724                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1725                         if (!header) {
1726                                 rpc_show_header();
1727                                 header++;
1728                         }
1729                         rpc_show_task(clnt, task);
1730                 }
1731                 spin_unlock(&clnt->cl_lock);
1732         }
1733         spin_unlock(&rpc_client_lock);
1734 }
1735 #endif