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/mm.h>
  29 #include <linux/slab.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/utsname.h>
  32 #include <linux/workqueue.h>
  33
  34 #include <linux/sunrpc/clnt.h>
  35 #include <linux/sunrpc/rpc_pipe_fs.h>
  36 #include <linux/sunrpc/metrics.h>
  37
  38
  39 #ifdef RPC_DEBUG
  40 # define RPCDBG_FACILITY        RPCDBG_CALL
  41 #endif
  42
  43 #define dprint_status(t)                                        \
  44         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  45                         __FUNCTION__, t->tk_status)
  46
  47 /*
  48  * All RPC clients are linked into this list
  49  */
  50 static LIST_HEAD(all_clients);
  51 static DEFINE_SPINLOCK(rpc_client_lock);
  52
  53 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  54
  55
  56 static void     call_start(struct rpc_task *task);
  57 static void     call_reserve(struct rpc_task *task);
  58 static void     call_reserveresult(struct rpc_task *task);
  59 static void     call_allocate(struct rpc_task *task);
  60 static void     call_encode(struct rpc_task *task);
  61 static void     call_decode(struct rpc_task *task);
  62 static void     call_bind(struct rpc_task *task);
  63 static void     call_bind_status(struct rpc_task *task);
  64 static void     call_transmit(struct rpc_task *task);
  65 static void     call_status(struct rpc_task *task);
  66 static void     call_transmit_status(struct rpc_task *task);
  67 static void     call_refresh(struct rpc_task *task);
  68 static void     call_refreshresult(struct rpc_task *task);
  69 static void     call_timeout(struct rpc_task *task);
  70 static void     call_connect(struct rpc_task *task);
  71 static void     call_connect_status(struct rpc_task *task);
  72 static __be32 * call_header(struct rpc_task *task);
  73 static __be32 * call_verify(struct rpc_task *task);
  74
  75 static void rpc_register_client(struct rpc_clnt *clnt)
  76 {
  77         spin_lock(&rpc_client_lock);
  78         list_add(&clnt->cl_clients, &all_clients);
  79         spin_unlock(&rpc_client_lock);
  80 }
  81
  82 static void rpc_unregister_client(struct rpc_clnt *clnt)
  83 {
  84         spin_lock(&rpc_client_lock);
  85         list_del(&clnt->cl_clients);
  86         spin_unlock(&rpc_client_lock);
  87 }
  88
  89 static int
  90 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  91 {
  92         static uint32_t clntid;
  93         int error;
  94
  95         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  96         clnt->cl_dentry = ERR_PTR(-ENOENT);
  97         if (dir_name == NULL)
  98                 return 0;
  99
 100         clnt->cl_vfsmnt = rpc_get_mount();
 101         if (IS_ERR(clnt->cl_vfsmnt))
 102                 return PTR_ERR(clnt->cl_vfsmnt);
 103
 104         for (;;) {
 105                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 106                                 "%s/clnt%x", dir_name,
 107                                 (unsigned int)clntid++);
 108                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 109                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 110                 if (!IS_ERR(clnt->cl_dentry))
 111                         return 0;
 112                 error = PTR_ERR(clnt->cl_dentry);
 113                 if (error != -EEXIST) {
 114                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 115                                         clnt->cl_pathname, error);
 116                         rpc_put_mount();
 117                         return error;
 118                 }
 119         }
 120 }
 121
 122 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
 123 {
 124         struct rpc_version      *version;
 125         struct rpc_clnt         *clnt = NULL;
 126         struct rpc_auth         *auth;
 127         int err;
 128         int len;
 129
 130         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 131                         program->name, servname, xprt);
 132
 133         err = rpciod_up();
 134         if (err)
 135                 goto out_no_rpciod;
 136         err = -EINVAL;
 137         if (!xprt)
 138                 goto out_no_xprt;
 139         if (vers >= program->nrvers || !(version = program->version[vers]))
 140                 goto out_err;
 141
 142         err = -ENOMEM;
 143         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 144         if (!clnt)
 145                 goto out_err;
 146         clnt->cl_parent = clnt;
 147
 148         clnt->cl_server = clnt->cl_inline_name;
 149         len = strlen(servname) + 1;
 150         if (len > sizeof(clnt->cl_inline_name)) {
 151                 char *buf = kmalloc(len, GFP_KERNEL);
 152                 if (buf != 0)
 153                         clnt->cl_server = buf;
 154                 else
 155                         len = sizeof(clnt->cl_inline_name);
 156         }
 157         strlcpy(clnt->cl_server, servname, len);
 158
 159         clnt->cl_xprt     = xprt;
 160         clnt->cl_procinfo = version->procs;
 161         clnt->cl_maxproc  = version->nrprocs;
 162         clnt->cl_protname = program->name;
 163         clnt->cl_prog     = program->number;
 164         clnt->cl_vers     = version->number;
 165         clnt->cl_stats    = program->stats;
 166         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 167         err = -ENOMEM;
 168         if (clnt->cl_metrics == NULL)
 169                 goto out_no_stats;
 170         clnt->cl_program  = program;
 171         INIT_LIST_HEAD(&clnt->cl_tasks);
 172         spin_lock_init(&clnt->cl_lock);
 173
 174         if (!xprt_bound(clnt->cl_xprt))
 175                 clnt->cl_autobind = 1;
 176
 177         clnt->cl_rtt = &clnt->cl_rtt_default;
 178         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 179
 180         kref_init(&clnt->cl_kref);
 181
 182         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 183         if (err < 0)
 184                 goto out_no_path;
 185
 186         auth = rpcauth_create(flavor, clnt);
 187         if (IS_ERR(auth)) {
 188                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 189                                 flavor);
 190                 err = PTR_ERR(auth);
 191                 goto out_no_auth;
 192         }
 193
 194         /* save the nodename */
 195         clnt->cl_nodelen = strlen(utsname()->nodename);
 196         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 197                 clnt->cl_nodelen = UNX_MAXNODENAME;
 198         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 199         rpc_register_client(clnt);
 200         return clnt;
 201
 202 out_no_auth:
 203         if (!IS_ERR(clnt->cl_dentry)) {
 204                 rpc_rmdir(clnt->cl_dentry);
 205                 rpc_put_mount();
 206         }
 207 out_no_path:
 208         rpc_free_iostats(clnt->cl_metrics);
 209 out_no_stats:
 210         if (clnt->cl_server != clnt->cl_inline_name)
 211                 kfree(clnt->cl_server);
 212         kfree(clnt);
 213 out_err:
 214         xprt_put(xprt);
 215 out_no_xprt:
 216         rpciod_down();
 217 out_no_rpciod:
 218         return ERR_PTR(err);
 219 }
 220
 221 /*
 222  * rpc_create - create an RPC client and transport with one call
 223  * @args: rpc_clnt create argument structure
 224  *
 225  * Creates and initializes an RPC transport and an RPC client.
 226  *
 227  * It can ping the server in order to determine if it is up, and to see if
 228  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 229  * this behavior so asynchronous tasks can also use rpc_create.
 230  */
 231 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 232 {
 233         struct rpc_xprt *xprt;
 234         struct rpc_clnt *clnt;
 235
 236         xprt = xprt_create_transport(args->protocol, args->address,
 237                                         args->addrsize, args->timeout);
 238         if (IS_ERR(xprt))
 239                 return (struct rpc_clnt *)xprt;
 240
 241         /*
 242          * By default, kernel RPC client connects from a reserved port.
 243          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 244          * but it is always enabled for rpciod, which handles the connect
 245          * operation.
 246          */
 247         xprt->resvport = 1;
 248         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 249                 xprt->resvport = 0;
 250
 251         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 252                         args->program->name, args->servername, xprt);
 253
 254         clnt = rpc_new_client(xprt, args->servername, args->program,
 255                                 args->version, args->authflavor);
 256         if (IS_ERR(clnt))
 257                 return clnt;
 258
 259         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 260                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 261                 if (err != 0) {
 262                         rpc_shutdown_client(clnt);
 263                         return ERR_PTR(err);
 264                 }
 265         }
 266
 267         clnt->cl_softrtry = 1;
 268         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 269                 clnt->cl_softrtry = 0;
 270
 271         if (args->flags & RPC_CLNT_CREATE_INTR)
 272                 clnt->cl_intr = 1;
 273         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 274                 clnt->cl_autobind = 1;
 275         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 276                 clnt->cl_discrtry = 1;
 277
 278         return clnt;
 279 }
 280 EXPORT_SYMBOL_GPL(rpc_create);
 281
 282 /*
 283  * This function clones the RPC client structure. It allows us to share the
 284  * same transport while varying parameters such as the authentication
 285  * flavour.
 286  */
 287 struct rpc_clnt *
 288 rpc_clone_client(struct rpc_clnt *clnt)
 289 {
 290         struct rpc_clnt *new;
 291         int err = -ENOMEM;
 292
 293         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 294         if (!new)
 295                 goto out_no_clnt;
 296         new->cl_parent = clnt;
 297         /* Turn off autobind on clones */
 298         new->cl_autobind = 0;
 299         INIT_LIST_HEAD(&new->cl_tasks);
 300         spin_lock_init(&new->cl_lock);
 301         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 302         new->cl_metrics = rpc_alloc_iostats(clnt);
 303         if (new->cl_metrics == NULL)
 304                 goto out_no_stats;
 305         kref_init(&new->cl_kref);
 306         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 307         if (err != 0)
 308                 goto out_no_path;
 309         if (new->cl_auth)
 310                 atomic_inc(&new->cl_auth->au_count);
 311         xprt_get(clnt->cl_xprt);
 312         kref_get(&clnt->cl_kref);
 313         rpc_register_client(new);
 314         rpciod_up();
 315         return new;
 316 out_no_path:
 317         rpc_free_iostats(new->cl_metrics);
 318 out_no_stats:
 319         kfree(new);
 320 out_no_clnt:
 321         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 322         return ERR_PTR(err);
 323 }
 324
 325 /*
 326  * Properly shut down an RPC client, terminating all outstanding
 327  * requests.
 328  */
 329 void rpc_shutdown_client(struct rpc_clnt *clnt)
 330 {
 331         dprintk("RPC:       shutting down %s client for %s\n",
 332                         clnt->cl_protname, clnt->cl_server);
 333
 334         while (!list_empty(&clnt->cl_tasks)) {
 335                 rpc_killall_tasks(clnt);
 336                 wait_event_timeout(destroy_wait,
 337                         list_empty(&clnt->cl_tasks), 1*HZ);
 338         }
 339
 340         rpc_release_client(clnt);
 341 }
 342
 343 /*
 344  * Free an RPC client
 345  */
 346 static void
 347 rpc_free_client(struct kref *kref)
 348 {
 349         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 350
 351         dprintk("RPC:       destroying %s client for %s\n",
 352                         clnt->cl_protname, clnt->cl_server);
 353         if (clnt->cl_auth) {
 354                 rpcauth_destroy(clnt->cl_auth);
 355                 clnt->cl_auth = NULL;
 356         }
 357         if (!IS_ERR(clnt->cl_dentry)) {
 358                 rpc_rmdir(clnt->cl_dentry);
 359                 rpc_put_mount();
 360         }
 361         if (clnt->cl_parent != clnt) {
 362                 rpc_release_client(clnt->cl_parent);
 363                 goto out_free;
 364         }
 365         if (clnt->cl_server != clnt->cl_inline_name)
 366                 kfree(clnt->cl_server);
 367 out_free:
 368         rpc_unregister_client(clnt);
 369         rpc_free_iostats(clnt->cl_metrics);
 370         clnt->cl_metrics = NULL;
 371         xprt_put(clnt->cl_xprt);
 372         rpciod_down();
 373         kfree(clnt);
 374 }
 375
 376 /*
 377  * Release reference to the RPC client
 378  */
 379 void
 380 rpc_release_client(struct rpc_clnt *clnt)
 381 {
 382         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 383
 384         if (list_empty(&clnt->cl_tasks))
 385                 wake_up(&destroy_wait);
 386         kref_put(&clnt->cl_kref, rpc_free_client);
 387 }
 388
 389 /**
 390  * rpc_bind_new_program - bind a new RPC program to an existing client
 391  * @old - old rpc_client
 392  * @program - rpc program to set
 393  * @vers - rpc program version
 394  *
 395  * Clones the rpc client and sets up a new RPC program. This is mainly
 396  * of use for enabling different RPC programs to share the same transport.
 397  * The Sun NFSv2/v3 ACL protocol can do this.
 398  */
 399 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 400                                       struct rpc_program *program,
 401                                       int vers)
 402 {
 403         struct rpc_clnt *clnt;
 404         struct rpc_version *version;
 405         int err;
 406
 407         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 408         version = program->version[vers];
 409         clnt = rpc_clone_client(old);
 410         if (IS_ERR(clnt))
 411                 goto out;
 412         clnt->cl_procinfo = version->procs;
 413         clnt->cl_maxproc  = version->nrprocs;
 414         clnt->cl_protname = program->name;
 415         clnt->cl_prog     = program->number;
 416         clnt->cl_vers     = version->number;
 417         clnt->cl_stats    = program->stats;
 418         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 419         if (err != 0) {
 420                 rpc_shutdown_client(clnt);
 421                 clnt = ERR_PTR(err);
 422         }
 423 out:
 424         return clnt;
 425 }
 426
 427 /*
 428  * Default callback for async RPC calls
 429  */
 430 static void
 431 rpc_default_callback(struct rpc_task *task, void *data)
 432 {
 433 }
 434
 435 static const struct rpc_call_ops rpc_default_ops = {
 436         .rpc_call_done = rpc_default_callback,
 437 };
 438
 439 /*
 440  *      Export the signal mask handling for synchronous code that
 441  *      sleeps on RPC calls
 442  */
 443 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 444
 445 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 446 {
 447         unsigned long   sigallow = sigmask(SIGKILL);
 448         sigset_t sigmask;
 449
 450         /* Block all signals except those listed in sigallow */
 451         if (intr)
 452                 sigallow |= RPC_INTR_SIGNALS;
 453         siginitsetinv(&sigmask, sigallow);
 454         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 455 }
 456
 457 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 458 {
 459         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 460 }
 461
 462 static inline void rpc_restore_sigmask(sigset_t *oldset)
 463 {
 464         sigprocmask(SIG_SETMASK, oldset, NULL);
 465 }
 466
 467 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 468 {
 469         rpc_save_sigmask(oldset, clnt->cl_intr);
 470 }
 471
 472 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 473 {
 474         rpc_restore_sigmask(oldset);
 475 }
 476
 477 /*
 478  * New rpc_call implementation
 479  */
 480 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 481 {
 482         struct rpc_task *task;
 483         sigset_t        oldset;
 484         int             status;
 485
 486         BUG_ON(flags & RPC_TASK_ASYNC);
 487
 488         task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
 489         if (task == NULL)
 490                 return -ENOMEM;
 491
 492         /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
 493         rpc_task_sigmask(task, &oldset);
 494
 495         /* Set up the call info struct and execute the task */
 496         rpc_call_setup(task, msg, 0);
 497         if (task->tk_status == 0) {
 498                 atomic_inc(&task->tk_count);
 499                 rpc_execute(task);
 500         }
 501         status = task->tk_status;
 502         rpc_put_task(task);
 503         rpc_restore_sigmask(&oldset);
 504         return status;
 505 }
 506
 507 /*
 508  * New rpc_call implementation
 509  */
 510 int
 511 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 512                const struct rpc_call_ops *tk_ops, void *data)
 513 {
 514         struct rpc_task *task;
 515         sigset_t        oldset;
 516         int             status;
 517
 518         flags |= RPC_TASK_ASYNC;
 519
 520         /* Create/initialize a new RPC task */
 521         status = -ENOMEM;
 522         if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
 523                 goto out_release;
 524
 525         /* Mask signals on GSS_AUTH upcalls */
 526         rpc_task_sigmask(task, &oldset);
 527
 528         rpc_call_setup(task, msg, 0);
 529
 530         /* Set up the call info struct and execute the task */
 531         status = task->tk_status;
 532         if (status == 0)
 533                 rpc_execute(task);
 534         else
 535                 rpc_put_task(task);
 536
 537         rpc_restore_sigmask(&oldset);
 538         return status;
 539 out_release:
 540         rpc_release_calldata(tk_ops, data);
 541         return status;
 542 }
 543
 544
 545 void
 546 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 547 {
 548         task->tk_msg   = *msg;
 549         task->tk_flags |= flags;
 550         /* Bind the user cred */
 551         if (task->tk_msg.rpc_cred != NULL)
 552                 rpcauth_holdcred(task);
 553         else
 554                 rpcauth_bindcred(task);
 555
 556         if (task->tk_status == 0)
 557                 task->tk_action = call_start;
 558         else
 559                 task->tk_action = rpc_exit_task;
 560 }
 561
 562 /**
 563  * rpc_peeraddr - extract remote peer address from clnt's xprt
 564  * @clnt: RPC client structure
 565  * @buf: target buffer
 566  * @size: length of target buffer
 567  *
 568  * Returns the number of bytes that are actually in the stored address.
 569  */
 570 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 571 {
 572         size_t bytes;
 573         struct rpc_xprt *xprt = clnt->cl_xprt;
 574
 575         bytes = sizeof(xprt->addr);
 576         if (bytes > bufsize)
 577                 bytes = bufsize;
 578         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 579         return xprt->addrlen;
 580 }
 581 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 582
 583 /**
 584  * rpc_peeraddr2str - return remote peer address in printable format
 585  * @clnt: RPC client structure
 586  * @format: address format
 587  *
 588  */
 589 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 590 {
 591         struct rpc_xprt *xprt = clnt->cl_xprt;
 592
 593         if (xprt->address_strings[format] != NULL)
 594                 return xprt->address_strings[format];
 595         else
 596                 return "unprintable";
 597 }
 598 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 599
 600 void
 601 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 602 {
 603         struct rpc_xprt *xprt = clnt->cl_xprt;
 604         if (xprt->ops->set_buffer_size)
 605                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 606 }
 607
 608 /*
 609  * Return size of largest payload RPC client can support, in bytes
 610  *
 611  * For stream transports, this is one RPC record fragment (see RFC
 612  * 1831), as we don't support multi-record requests yet.  For datagram
 613  * transports, this is the size of an IP packet minus the IP, UDP, and
 614  * RPC header sizes.
 615  */
 616 size_t rpc_max_payload(struct rpc_clnt *clnt)
 617 {
 618         return clnt->cl_xprt->max_payload;
 619 }
 620 EXPORT_SYMBOL_GPL(rpc_max_payload);
 621
 622 /**
 623  * rpc_force_rebind - force transport to check that remote port is unchanged
 624  * @clnt: client to rebind
 625  *
 626  */
 627 void rpc_force_rebind(struct rpc_clnt *clnt)
 628 {
 629         if (clnt->cl_autobind)
 630                 xprt_clear_bound(clnt->cl_xprt);
 631 }
 632 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 633
 634 /*
 635  * Restart an (async) RPC call. Usually called from within the
 636  * exit handler.
 637  */
 638 void
 639 rpc_restart_call(struct rpc_task *task)
 640 {
 641         if (RPC_ASSASSINATED(task))
 642                 return;
 643
 644         task->tk_action = call_start;
 645 }
 646
 647 /*
 648  * 0.  Initial state
 649  *
 650  *     Other FSM states can be visited zero or more times, but
 651  *     this state is visited exactly once for each RPC.
 652  */
 653 static void
 654 call_start(struct rpc_task *task)
 655 {
 656         struct rpc_clnt *clnt = task->tk_client;
 657
 658         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 659                         clnt->cl_protname, clnt->cl_vers,
 660                         task->tk_msg.rpc_proc->p_proc,
 661                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 662
 663         /* Increment call count */
 664         task->tk_msg.rpc_proc->p_count++;
 665         clnt->cl_stats->rpccnt++;
 666         task->tk_action = call_reserve;
 667 }
 668
 669 /*
 670  * 1.   Reserve an RPC call slot
 671  */
 672 static void
 673 call_reserve(struct rpc_task *task)
 674 {
 675         dprint_status(task);
 676
 677         if (!rpcauth_uptodatecred(task)) {
 678                 task->tk_action = call_refresh;
 679                 return;
 680         }
 681
 682         task->tk_status  = 0;
 683         task->tk_action  = call_reserveresult;
 684         xprt_reserve(task);
 685 }
 686
 687 /*
 688  * 1b.  Grok the result of xprt_reserve()
 689  */
 690 static void
 691 call_reserveresult(struct rpc_task *task)
 692 {
 693         int status = task->tk_status;
 694
 695         dprint_status(task);
 696
 697         /*
 698          * After a call to xprt_reserve(), we must have either
 699          * a request slot or else an error status.
 700          */
 701         task->tk_status = 0;
 702         if (status >= 0) {
 703                 if (task->tk_rqstp) {
 704                         task->tk_action = call_allocate;
 705                         return;
 706                 }
 707
 708                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 709                                 __FUNCTION__, status);
 710                 rpc_exit(task, -EIO);
 711                 return;
 712         }
 713
 714         /*
 715          * Even though there was an error, we may have acquired
 716          * a request slot somehow.  Make sure not to leak it.
 717          */
 718         if (task->tk_rqstp) {
 719                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 720                                 __FUNCTION__, status);
 721                 xprt_release(task);
 722         }
 723
 724         switch (status) {
 725         case -EAGAIN:   /* woken up; retry */
 726                 task->tk_action = call_reserve;
 727                 return;
 728         case -EIO:      /* probably a shutdown */
 729                 break;
 730         default:
 731                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 732                                 __FUNCTION__, status);
 733                 break;
 734         }
 735         rpc_exit(task, status);
 736 }
 737
 738 /*
 739  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 740  *      (Note: buffer memory is freed in xprt_release).
 741  */
 742 static void
 743 call_allocate(struct rpc_task *task)
 744 {
 745         unsigned int slack = task->tk_auth->au_cslack;
 746         struct rpc_rqst *req = task->tk_rqstp;
 747         struct rpc_xprt *xprt = task->tk_xprt;
 748         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 749
 750         dprint_status(task);
 751
 752         task->tk_status = 0;
 753         task->tk_action = call_bind;
 754
 755         if (req->rq_buffer)
 756                 return;
 757
 758         if (proc->p_proc != 0) {
 759                 BUG_ON(proc->p_arglen == 0);
 760                 if (proc->p_decode != NULL)
 761                         BUG_ON(proc->p_replen == 0);
 762         }
 763
 764         /*
 765          * Calculate the size (in quads) of the RPC call
 766          * and reply headers, and convert both values
 767          * to byte sizes.
 768          */
 769         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 770         req->rq_callsize <<= 2;
 771         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 772         req->rq_rcvsize <<= 2;
 773
 774         req->rq_buffer = xprt->ops->buf_alloc(task,
 775                                         req->rq_callsize + req->rq_rcvsize);
 776         if (req->rq_buffer != NULL)
 777                 return;
 778
 779         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 780
 781         if (RPC_IS_ASYNC(task) || !signalled()) {
 782                 xprt_release(task);
 783                 task->tk_action = call_reserve;
 784                 rpc_delay(task, HZ>>4);
 785                 return;
 786         }
 787
 788         rpc_exit(task, -ERESTARTSYS);
 789 }
 790
 791 static inline int
 792 rpc_task_need_encode(struct rpc_task *task)
 793 {
 794         return task->tk_rqstp->rq_snd_buf.len == 0;
 795 }
 796
 797 static inline void
 798 rpc_task_force_reencode(struct rpc_task *task)
 799 {
 800         task->tk_rqstp->rq_snd_buf.len = 0;
 801 }
 802
 803 static inline void
 804 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 805 {
 806         buf->head[0].iov_base = start;
 807         buf->head[0].iov_len = len;
 808         buf->tail[0].iov_len = 0;
 809         buf->page_len = 0;
 810         buf->len = 0;
 811         buf->buflen = len;
 812 }
 813
 814 /*
 815  * 3.   Encode arguments of an RPC call
 816  */
 817 static void
 818 call_encode(struct rpc_task *task)
 819 {
 820         struct rpc_rqst *req = task->tk_rqstp;
 821         kxdrproc_t      encode;
 822         __be32          *p;
 823
 824         dprint_status(task);
 825
 826         rpc_xdr_buf_init(&req->rq_snd_buf,
 827                          req->rq_buffer,
 828                          req->rq_callsize);
 829         rpc_xdr_buf_init(&req->rq_rcv_buf,
 830                          (char *)req->rq_buffer + req->rq_callsize,
 831                          req->rq_rcvsize);
 832
 833         /* Encode header and provided arguments */
 834         encode = task->tk_msg.rpc_proc->p_encode;
 835         if (!(p = call_header(task))) {
 836                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 837                 rpc_exit(task, -EIO);
 838                 return;
 839         }
 840         if (encode == NULL)
 841                 return;
 842
 843         lock_kernel();
 844         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 845                         task->tk_msg.rpc_argp);
 846         unlock_kernel();
 847         if (task->tk_status == -ENOMEM) {
 848                 /* XXX: Is this sane? */
 849                 rpc_delay(task, 3*HZ);
 850                 task->tk_status = -EAGAIN;
 851         }
 852 }
 853
 854 /*
 855  * 4.   Get the server port number if not yet set
 856  */
 857 static void
 858 call_bind(struct rpc_task *task)
 859 {
 860         struct rpc_xprt *xprt = task->tk_xprt;
 861
 862         dprint_status(task);
 863
 864         task->tk_action = call_connect;
 865         if (!xprt_bound(xprt)) {
 866                 task->tk_action = call_bind_status;
 867                 task->tk_timeout = xprt->bind_timeout;
 868                 xprt->ops->rpcbind(task);
 869         }
 870 }
 871
 872 /*
 873  * 4a.  Sort out bind result
 874  */
 875 static void
 876 call_bind_status(struct rpc_task *task)
 877 {
 878         int status = -EACCES;
 879
 880         if (task->tk_status >= 0) {
 881                 dprint_status(task);
 882                 task->tk_status = 0;
 883                 task->tk_action = call_connect;
 884                 return;
 885         }
 886
 887         switch (task->tk_status) {
 888         case -EACCES:
 889                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 890                                 "unavailable\n", task->tk_pid);
 891                 rpc_delay(task, 3*HZ);
 892                 goto retry_timeout;
 893         case -ETIMEDOUT:
 894                 dprintk("RPC: %5u rpcbind request timed out\n",
 895                                 task->tk_pid);
 896                 goto retry_timeout;
 897         case -EPFNOSUPPORT:
 898                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 899                                 task->tk_pid);
 900                 break;
 901         case -EPROTONOSUPPORT:
 902                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 903                                 task->tk_pid);
 904                 task->tk_status = 0;
 905                 task->tk_action = call_bind;
 906                 return;
 907         default:
 908                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
 909                                 task->tk_pid, -task->tk_status);
 910                 status = -EIO;
 911         }
 912
 913         rpc_exit(task, status);
 914         return;
 915
 916 retry_timeout:
 917         task->tk_action = call_timeout;
 918 }
 919
 920 /*
 921  * 4b.  Connect to the RPC server
 922  */
 923 static void
 924 call_connect(struct rpc_task *task)
 925 {
 926         struct rpc_xprt *xprt = task->tk_xprt;
 927
 928         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
 929                         task->tk_pid, xprt,
 930                         (xprt_connected(xprt) ? "is" : "is not"));
 931
 932         task->tk_action = call_transmit;
 933         if (!xprt_connected(xprt)) {
 934                 task->tk_action = call_connect_status;
 935                 if (task->tk_status < 0)
 936                         return;
 937                 xprt_connect(task);
 938         }
 939 }
 940
 941 /*
 942  * 4c.  Sort out connect result
 943  */
 944 static void
 945 call_connect_status(struct rpc_task *task)
 946 {
 947         struct rpc_clnt *clnt = task->tk_client;
 948         int status = task->tk_status;
 949
 950         dprint_status(task);
 951
 952         task->tk_status = 0;
 953         if (status >= 0) {
 954                 clnt->cl_stats->netreconn++;
 955                 task->tk_action = call_transmit;
 956                 return;
 957         }
 958
 959         /* Something failed: remote service port may have changed */
 960         rpc_force_rebind(clnt);
 961
 962         switch (status) {
 963         case -ENOTCONN:
 964         case -EAGAIN:
 965                 task->tk_action = call_bind;
 966                 if (!RPC_IS_SOFT(task))
 967                         return;
 968                 /* if soft mounted, test if we've timed out */
 969         case -ETIMEDOUT:
 970                 task->tk_action = call_timeout;
 971                 return;
 972         }
 973         rpc_exit(task, -EIO);
 974 }
 975
 976 /*
 977  * 5.   Transmit the RPC request, and wait for reply
 978  */
 979 static void
 980 call_transmit(struct rpc_task *task)
 981 {
 982         dprint_status(task);
 983
 984         task->tk_action = call_status;
 985         if (task->tk_status < 0)
 986                 return;
 987         task->tk_status = xprt_prepare_transmit(task);
 988         if (task->tk_status != 0)
 989                 return;
 990         task->tk_action = call_transmit_status;
 991         /* Encode here so that rpcsec_gss can use correct sequence number. */
 992         if (rpc_task_need_encode(task)) {
 993                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
 994                 call_encode(task);
 995                 /* Did the encode result in an error condition? */
 996                 if (task->tk_status != 0)
 997                         return;
 998         }
 999         xprt_transmit(task);
1000         if (task->tk_status < 0)
1001                 return;
1002         /*
1003          * On success, ensure that we call xprt_end_transmit() before sleeping
1004          * in order to allow access to the socket to other RPC requests.
1005          */
1006         call_transmit_status(task);
1007         if (task->tk_msg.rpc_proc->p_decode != NULL)
1008                 return;
1009         task->tk_action = rpc_exit_task;
1010         rpc_wake_up_task(task);
1011 }
1012
1013 /*
1014  * 5a.  Handle cleanup after a transmission
1015  */
1016 static void
1017 call_transmit_status(struct rpc_task *task)
1018 {
1019         task->tk_action = call_status;
1020         /*
1021          * Special case: if we've been waiting on the socket's write_space()
1022          * callback, then don't call xprt_end_transmit().
1023          */
1024         if (task->tk_status == -EAGAIN)
1025                 return;
1026         xprt_end_transmit(task);
1027         rpc_task_force_reencode(task);
1028 }
1029
1030 /*
1031  * 6.   Sort out the RPC call status
1032  */
1033 static void
1034 call_status(struct rpc_task *task)
1035 {
1036         struct rpc_clnt *clnt = task->tk_client;
1037         struct rpc_rqst *req = task->tk_rqstp;
1038         int             status;
1039
1040         if (req->rq_received > 0 && !req->rq_bytes_sent)
1041                 task->tk_status = req->rq_received;
1042
1043         dprint_status(task);
1044
1045         status = task->tk_status;
1046         if (status >= 0) {
1047                 task->tk_action = call_decode;
1048                 return;
1049         }
1050
1051         task->tk_status = 0;
1052         switch(status) {
1053         case -EHOSTDOWN:
1054         case -EHOSTUNREACH:
1055         case -ENETUNREACH:
1056                 /*
1057                  * Delay any retries for 3 seconds, then handle as if it
1058                  * were a timeout.
1059                  */
1060                 rpc_delay(task, 3*HZ);
1061         case -ETIMEDOUT:
1062                 task->tk_action = call_timeout;
1063                 if (task->tk_client->cl_discrtry)
1064                         xprt_disconnect(task->tk_xprt);
1065                 break;
1066         case -ECONNREFUSED:
1067         case -ENOTCONN:
1068                 rpc_force_rebind(clnt);
1069                 task->tk_action = call_bind;
1070                 break;
1071         case -EAGAIN:
1072                 task->tk_action = call_transmit;
1073                 break;
1074         case -EIO:
1075                 /* shutdown or soft timeout */
1076                 rpc_exit(task, status);
1077                 break;
1078         default:
1079                 printk("%s: RPC call returned error %d\n",
1080                                clnt->cl_protname, -status);
1081                 rpc_exit(task, status);
1082         }
1083 }
1084
1085 /*
1086  * 6a.  Handle RPC timeout
1087  *      We do not release the request slot, so we keep using the
1088  *      same XID for all retransmits.
1089  */
1090 static void
1091 call_timeout(struct rpc_task *task)
1092 {
1093         struct rpc_clnt *clnt = task->tk_client;
1094
1095         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1096                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1097                 goto retry;
1098         }
1099
1100         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1101         task->tk_timeouts++;
1102
1103         if (RPC_IS_SOFT(task)) {
1104                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1105                                 clnt->cl_protname, clnt->cl_server);
1106                 rpc_exit(task, -EIO);
1107                 return;
1108         }
1109
1110         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1111                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1112                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1113                         clnt->cl_protname, clnt->cl_server);
1114         }
1115         rpc_force_rebind(clnt);
1116
1117 retry:
1118         clnt->cl_stats->rpcretrans++;
1119         task->tk_action = call_bind;
1120         task->tk_status = 0;
1121 }
1122
1123 /*
1124  * 7.   Decode the RPC reply
1125  */
1126 static void
1127 call_decode(struct rpc_task *task)
1128 {
1129         struct rpc_clnt *clnt = task->tk_client;
1130         struct rpc_rqst *req = task->tk_rqstp;
1131         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1132         __be32          *p;
1133
1134         dprintk("RPC: %5u call_decode (status %d)\n",
1135                         task->tk_pid, task->tk_status);
1136
1137         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1138                 printk(KERN_NOTICE "%s: server %s OK\n",
1139                         clnt->cl_protname, clnt->cl_server);
1140                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1141         }
1142
1143         if (task->tk_status < 12) {
1144                 if (!RPC_IS_SOFT(task)) {
1145                         task->tk_action = call_bind;
1146                         clnt->cl_stats->rpcretrans++;
1147                         goto out_retry;
1148                 }
1149                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1150                                 clnt->cl_protname, task->tk_status);
1151                 task->tk_action = call_timeout;
1152                 goto out_retry;
1153         }
1154
1155         /*
1156          * Ensure that we see all writes made by xprt_complete_rqst()
1157          * before it changed req->rq_received.
1158          */
1159         smp_rmb();
1160         req->rq_rcv_buf.len = req->rq_private_buf.len;
1161
1162         /* Check that the softirq receive buffer is valid */
1163         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1164                                 sizeof(req->rq_rcv_buf)) != 0);
1165
1166         /* Verify the RPC header */
1167         p = call_verify(task);
1168         if (IS_ERR(p)) {
1169                 if (p == ERR_PTR(-EAGAIN))
1170                         goto out_retry;
1171                 return;
1172         }
1173
1174         task->tk_action = rpc_exit_task;
1175
1176         if (decode) {
1177                 lock_kernel();
1178                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1179                                                       task->tk_msg.rpc_resp);
1180                 unlock_kernel();
1181         }
1182         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1183                         task->tk_status);
1184         return;
1185 out_retry:
1186         req->rq_received = req->rq_private_buf.len = 0;
1187         task->tk_status = 0;
1188         if (task->tk_client->cl_discrtry)
1189                 xprt_disconnect(task->tk_xprt);
1190 }
1191
1192 /*
1193  * 8.   Refresh the credentials if rejected by the server
1194  */
1195 static void
1196 call_refresh(struct rpc_task *task)
1197 {
1198         dprint_status(task);
1199
1200         xprt_release(task);     /* Must do to obtain new XID */
1201         task->tk_action = call_refreshresult;
1202         task->tk_status = 0;
1203         task->tk_client->cl_stats->rpcauthrefresh++;
1204         rpcauth_refreshcred(task);
1205 }
1206
1207 /*
1208  * 8a.  Process the results of a credential refresh
1209  */
1210 static void
1211 call_refreshresult(struct rpc_task *task)
1212 {
1213         int status = task->tk_status;
1214
1215         dprint_status(task);
1216
1217         task->tk_status = 0;
1218         task->tk_action = call_reserve;
1219         if (status >= 0 && rpcauth_uptodatecred(task))
1220                 return;
1221         if (status == -EACCES) {
1222                 rpc_exit(task, -EACCES);
1223                 return;
1224         }
1225         task->tk_action = call_refresh;
1226         if (status != -ETIMEDOUT)
1227                 rpc_delay(task, 3*HZ);
1228         return;
1229 }
1230
1231 /*
1232  * Call header serialization
1233  */
1234 static __be32 *
1235 call_header(struct rpc_task *task)
1236 {
1237         struct rpc_clnt *clnt = task->tk_client;
1238         struct rpc_rqst *req = task->tk_rqstp;
1239         __be32          *p = req->rq_svec[0].iov_base;
1240
1241         /* FIXME: check buffer size? */
1242
1243         p = xprt_skip_transport_header(task->tk_xprt, p);
1244         *p++ = req->rq_xid;             /* XID */
1245         *p++ = htonl(RPC_CALL);         /* CALL */
1246         *p++ = htonl(RPC_VERSION);      /* RPC version */
1247         *p++ = htonl(clnt->cl_prog);    /* program number */
1248         *p++ = htonl(clnt->cl_vers);    /* program version */
1249         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1250         p = rpcauth_marshcred(task, p);
1251         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1252         return p;
1253 }
1254
1255 /*
1256  * Reply header verification
1257  */
1258 static __be32 *
1259 call_verify(struct rpc_task *task)
1260 {
1261         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1262         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1263         __be32  *p = iov->iov_base;
1264         u32 n;
1265         int error = -EACCES;
1266
1267         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1268                 /* RFC-1014 says that the representation of XDR data must be a
1269                  * multiple of four bytes
1270                  * - if it isn't pointer subtraction in the NFS client may give
1271                  *   undefined results
1272                  */
1273                 printk(KERN_WARNING
1274                        "call_verify: XDR representation not a multiple of"
1275                        " 4 bytes: 0x%x\n", task->tk_rqstp->rq_rcv_buf.len);
1276                 goto out_eio;
1277         }
1278         if ((len -= 3) < 0)
1279                 goto out_overflow;
1280         p += 1; /* skip XID */
1281
1282         if ((n = ntohl(*p++)) != RPC_REPLY) {
1283                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1284                 goto out_garbage;
1285         }
1286         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1287                 if (--len < 0)
1288                         goto out_overflow;
1289                 switch ((n = ntohl(*p++))) {
1290                         case RPC_AUTH_ERROR:
1291                                 break;
1292                         case RPC_MISMATCH:
1293                                 dprintk("RPC: %5u %s: RPC call version "
1294                                                 "mismatch!\n",
1295                                                 task->tk_pid, __FUNCTION__);
1296                                 error = -EPROTONOSUPPORT;
1297                                 goto out_err;
1298                         default:
1299                                 dprintk("RPC: %5u %s: RPC call rejected, "
1300                                                 "unknown error: %x\n",
1301                                                 task->tk_pid, __FUNCTION__, n);
1302                                 goto out_eio;
1303                 }
1304                 if (--len < 0)
1305                         goto out_overflow;
1306                 switch ((n = ntohl(*p++))) {
1307                 case RPC_AUTH_REJECTEDCRED:
1308                 case RPC_AUTH_REJECTEDVERF:
1309                 case RPCSEC_GSS_CREDPROBLEM:
1310                 case RPCSEC_GSS_CTXPROBLEM:
1311                         if (!task->tk_cred_retry)
1312                                 break;
1313                         task->tk_cred_retry--;
1314                         dprintk("RPC: %5u %s: retry stale creds\n",
1315                                         task->tk_pid, __FUNCTION__);
1316                         rpcauth_invalcred(task);
1317                         task->tk_action = call_refresh;
1318                         goto out_retry;
1319                 case RPC_AUTH_BADCRED:
1320                 case RPC_AUTH_BADVERF:
1321                         /* possibly garbled cred/verf? */
1322                         if (!task->tk_garb_retry)
1323                                 break;
1324                         task->tk_garb_retry--;
1325                         dprintk("RPC: %5u %s: retry garbled creds\n",
1326                                         task->tk_pid, __FUNCTION__);
1327                         task->tk_action = call_bind;
1328                         goto out_retry;
1329                 case RPC_AUTH_TOOWEAK:
1330                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1331                                "authentication.\n", task->tk_client->cl_server);
1332                         break;
1333                 default:
1334                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1335                         error = -EIO;
1336                 }
1337                 dprintk("RPC: %5u %s: call rejected %d\n",
1338                                 task->tk_pid, __FUNCTION__, n);
1339                 goto out_err;
1340         }
1341         if (!(p = rpcauth_checkverf(task, p))) {
1342                 printk(KERN_WARNING "call_verify: auth check failed\n");
1343                 goto out_garbage;               /* bad verifier, retry */
1344         }
1345         len = p - (__be32 *)iov->iov_base - 1;
1346         if (len < 0)
1347                 goto out_overflow;
1348         switch ((n = ntohl(*p++))) {
1349         case RPC_SUCCESS:
1350                 return p;
1351         case RPC_PROG_UNAVAIL:
1352                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1353                                 task->tk_pid, __FUNCTION__,
1354                                 (unsigned int)task->tk_client->cl_prog,
1355                                 task->tk_client->cl_server);
1356                 error = -EPFNOSUPPORT;
1357                 goto out_err;
1358         case RPC_PROG_MISMATCH:
1359                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1360                                 "server %s\n", task->tk_pid, __FUNCTION__,
1361                                 (unsigned int)task->tk_client->cl_prog,
1362                                 (unsigned int)task->tk_client->cl_vers,
1363                                 task->tk_client->cl_server);
1364                 error = -EPROTONOSUPPORT;
1365                 goto out_err;
1366         case RPC_PROC_UNAVAIL:
1367                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1368                                 "version %u on server %s\n",
1369                                 task->tk_pid, __FUNCTION__,
1370                                 task->tk_msg.rpc_proc,
1371                                 task->tk_client->cl_prog,
1372                                 task->tk_client->cl_vers,
1373                                 task->tk_client->cl_server);
1374                 error = -EOPNOTSUPP;
1375                 goto out_err;
1376         case RPC_GARBAGE_ARGS:
1377                 dprintk("RPC: %5u %s: server saw garbage\n",
1378                                 task->tk_pid, __FUNCTION__);
1379                 break;                  /* retry */
1380         default:
1381                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1382                 /* Also retry */
1383         }
1384
1385 out_garbage:
1386         task->tk_client->cl_stats->rpcgarbage++;
1387         if (task->tk_garb_retry) {
1388                 task->tk_garb_retry--;
1389                 dprintk("RPC: %5u %s: retrying\n",
1390                                 task->tk_pid, __FUNCTION__);
1391                 task->tk_action = call_bind;
1392 out_retry:
1393                 return ERR_PTR(-EAGAIN);
1394         }
1395         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1396 out_eio:
1397         error = -EIO;
1398 out_err:
1399         rpc_exit(task, error);
1400         return ERR_PTR(error);
1401 out_overflow:
1402         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1403         goto out_garbage;
1404 }
1405
1406 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1407 {
1408         return 0;
1409 }
1410
1411 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1412 {
1413         return 0;
1414 }
1415
1416 static struct rpc_procinfo rpcproc_null = {
1417         .p_encode = rpcproc_encode_null,
1418         .p_decode = rpcproc_decode_null,
1419 };
1420
1421 int rpc_ping(struct rpc_clnt *clnt, int flags)
1422 {
1423         struct rpc_message msg = {
1424                 .rpc_proc = &rpcproc_null,
1425         };
1426         int err;
1427         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1428         err = rpc_call_sync(clnt, &msg, flags);
1429         put_rpccred(msg.rpc_cred);
1430         return err;
1431 }
1432
1433 #ifdef RPC_DEBUG
1434 void rpc_show_tasks(void)
1435 {
1436         struct rpc_clnt *clnt;
1437         struct rpc_task *t;
1438
1439         spin_lock(&rpc_client_lock);
1440         if (list_empty(&all_clients))
1441                 goto out;
1442         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1443                 "-rpcwait -action- ---ops--\n");
1444         list_for_each_entry(clnt, &all_clients, cl_clients) {
1445                 if (list_empty(&clnt->cl_tasks))
1446                         continue;
1447                 spin_lock(&clnt->cl_lock);
1448                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1449                         const char *rpc_waitq = "none";
1450
1451                         if (RPC_IS_QUEUED(t))
1452                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1453
1454                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1455                                 t->tk_pid,
1456                                 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1457                                 t->tk_flags, t->tk_status,
1458                                 t->tk_client,
1459                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1460                                 t->tk_rqstp, t->tk_timeout,
1461                                 rpc_waitq,
1462                                 t->tk_action, t->tk_ops);
1463                 }
1464                 spin_unlock(&clnt->cl_lock);
1465         }
1466 out:
1467         spin_unlock(&rpc_client_lock);
1468 }
1469 #endif