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 int      rpc_ping(struct rpc_clnt *clnt, int flags);
  76
  77 static void rpc_register_client(struct rpc_clnt *clnt)
  78 {
  79         spin_lock(&rpc_client_lock);
  80         list_add(&clnt->cl_clients, &all_clients);
  81         spin_unlock(&rpc_client_lock);
  82 }
  83
  84 static void rpc_unregister_client(struct rpc_clnt *clnt)
  85 {
  86         spin_lock(&rpc_client_lock);
  87         list_del(&clnt->cl_clients);
  88         spin_unlock(&rpc_client_lock);
  89 }
  90
  91 static int
  92 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
  93 {
  94         static uint32_t clntid;
  95         int error;
  96
  97         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
  98         clnt->cl_dentry = ERR_PTR(-ENOENT);
  99         if (dir_name == NULL)
 100                 return 0;
 101
 102         clnt->cl_vfsmnt = rpc_get_mount();
 103         if (IS_ERR(clnt->cl_vfsmnt))
 104                 return PTR_ERR(clnt->cl_vfsmnt);
 105
 106         for (;;) {
 107                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 108                                 "%s/clnt%x", dir_name,
 109                                 (unsigned int)clntid++);
 110                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
 111                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
 112                 if (!IS_ERR(clnt->cl_dentry))
 113                         return 0;
 114                 error = PTR_ERR(clnt->cl_dentry);
 115                 if (error != -EEXIST) {
 116                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 117                                         clnt->cl_pathname, error);
 118                         rpc_put_mount();
 119                         return error;
 120                 }
 121         }
 122 }
 123
 124 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
 125 {
 126         struct rpc_version      *version;
 127         struct rpc_clnt         *clnt = NULL;
 128         struct rpc_auth         *auth;
 129         int err;
 130         int len;
 131
 132         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 133                         program->name, servname, xprt);
 134
 135         err = rpciod_up();
 136         if (err)
 137                 goto out_no_rpciod;
 138         err = -EINVAL;
 139         if (!xprt)
 140                 goto out_no_xprt;
 141         if (vers >= program->nrvers || !(version = program->version[vers]))
 142                 goto out_err;
 143
 144         err = -ENOMEM;
 145         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 146         if (!clnt)
 147                 goto out_err;
 148         clnt->cl_parent = clnt;
 149
 150         clnt->cl_server = clnt->cl_inline_name;
 151         len = strlen(servname) + 1;
 152         if (len > sizeof(clnt->cl_inline_name)) {
 153                 char *buf = kmalloc(len, GFP_KERNEL);
 154                 if (buf != 0)
 155                         clnt->cl_server = buf;
 156                 else
 157                         len = sizeof(clnt->cl_inline_name);
 158         }
 159         strlcpy(clnt->cl_server, servname, len);
 160
 161         clnt->cl_xprt     = xprt;
 162         clnt->cl_procinfo = version->procs;
 163         clnt->cl_maxproc  = version->nrprocs;
 164         clnt->cl_protname = program->name;
 165         clnt->cl_prog     = program->number;
 166         clnt->cl_vers     = version->number;
 167         clnt->cl_stats    = program->stats;
 168         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 169         err = -ENOMEM;
 170         if (clnt->cl_metrics == NULL)
 171                 goto out_no_stats;
 172         clnt->cl_program  = program;
 173         INIT_LIST_HEAD(&clnt->cl_tasks);
 174         spin_lock_init(&clnt->cl_lock);
 175
 176         if (!xprt_bound(clnt->cl_xprt))
 177                 clnt->cl_autobind = 1;
 178
 179         clnt->cl_rtt = &clnt->cl_rtt_default;
 180         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 181
 182         kref_init(&clnt->cl_kref);
 183
 184         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 185         if (err < 0)
 186                 goto out_no_path;
 187
 188         auth = rpcauth_create(flavor, clnt);
 189         if (IS_ERR(auth)) {
 190                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 191                                 flavor);
 192                 err = PTR_ERR(auth);
 193                 goto out_no_auth;
 194         }
 195
 196         /* save the nodename */
 197         clnt->cl_nodelen = strlen(utsname()->nodename);
 198         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 199                 clnt->cl_nodelen = UNX_MAXNODENAME;
 200         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
 201         rpc_register_client(clnt);
 202         return clnt;
 203
 204 out_no_auth:
 205         if (!IS_ERR(clnt->cl_dentry)) {
 206                 rpc_rmdir(clnt->cl_dentry);
 207                 rpc_put_mount();
 208         }
 209 out_no_path:
 210         rpc_free_iostats(clnt->cl_metrics);
 211 out_no_stats:
 212         if (clnt->cl_server != clnt->cl_inline_name)
 213                 kfree(clnt->cl_server);
 214         kfree(clnt);
 215 out_err:
 216         xprt_put(xprt);
 217 out_no_xprt:
 218         rpciod_down();
 219 out_no_rpciod:
 220         return ERR_PTR(err);
 221 }
 222
 223 /*
 224  * rpc_create - create an RPC client and transport with one call
 225  * @args: rpc_clnt create argument structure
 226  *
 227  * Creates and initializes an RPC transport and an RPC client.
 228  *
 229  * It can ping the server in order to determine if it is up, and to see if
 230  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 231  * this behavior so asynchronous tasks can also use rpc_create.
 232  */
 233 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 234 {
 235         struct rpc_xprt *xprt;
 236         struct rpc_clnt *clnt;
 237
 238         xprt = xprt_create_transport(args->protocol, args->address,
 239                                         args->addrsize, args->timeout);
 240         if (IS_ERR(xprt))
 241                 return (struct rpc_clnt *)xprt;
 242
 243         /*
 244          * By default, kernel RPC client connects from a reserved port.
 245          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 246          * but it is always enabled for rpciod, which handles the connect
 247          * operation.
 248          */
 249         xprt->resvport = 1;
 250         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 251                 xprt->resvport = 0;
 252
 253         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 254                         args->program->name, args->servername, xprt);
 255
 256         clnt = rpc_new_client(xprt, args->servername, args->program,
 257                                 args->version, args->authflavor);
 258         if (IS_ERR(clnt))
 259                 return clnt;
 260
 261         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 262                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 263                 if (err != 0) {
 264                         rpc_shutdown_client(clnt);
 265                         return ERR_PTR(err);
 266                 }
 267         }
 268
 269         clnt->cl_softrtry = 1;
 270         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 271                 clnt->cl_softrtry = 0;
 272
 273         if (args->flags & RPC_CLNT_CREATE_INTR)
 274                 clnt->cl_intr = 1;
 275         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 276                 clnt->cl_autobind = 1;
 277         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 278                 clnt->cl_discrtry = 1;
 279
 280         return clnt;
 281 }
 282 EXPORT_SYMBOL_GPL(rpc_create);
 283
 284 /*
 285  * This function clones the RPC client structure. It allows us to share the
 286  * same transport while varying parameters such as the authentication
 287  * flavour.
 288  */
 289 struct rpc_clnt *
 290 rpc_clone_client(struct rpc_clnt *clnt)
 291 {
 292         struct rpc_clnt *new;
 293         int err = -ENOMEM;
 294
 295         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 296         if (!new)
 297                 goto out_no_clnt;
 298         new->cl_parent = clnt;
 299         /* Turn off autobind on clones */
 300         new->cl_autobind = 0;
 301         INIT_LIST_HEAD(&new->cl_tasks);
 302         spin_lock_init(&new->cl_lock);
 303         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 304         new->cl_metrics = rpc_alloc_iostats(clnt);
 305         if (new->cl_metrics == NULL)
 306                 goto out_no_stats;
 307         kref_init(&new->cl_kref);
 308         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 309         if (err != 0)
 310                 goto out_no_path;
 311         if (new->cl_auth)
 312                 atomic_inc(&new->cl_auth->au_count);
 313         xprt_get(clnt->cl_xprt);
 314         kref_get(&clnt->cl_kref);
 315         rpc_register_client(new);
 316         rpciod_up();
 317         return new;
 318 out_no_path:
 319         rpc_free_iostats(new->cl_metrics);
 320 out_no_stats:
 321         kfree(new);
 322 out_no_clnt:
 323         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
 324         return ERR_PTR(err);
 325 }
 326
 327 /*
 328  * Properly shut down an RPC client, terminating all outstanding
 329  * requests.
 330  */
 331 void rpc_shutdown_client(struct rpc_clnt *clnt)
 332 {
 333         dprintk("RPC:       shutting down %s client for %s\n",
 334                         clnt->cl_protname, clnt->cl_server);
 335
 336         while (!list_empty(&clnt->cl_tasks)) {
 337                 rpc_killall_tasks(clnt);
 338                 wait_event_timeout(destroy_wait,
 339                         list_empty(&clnt->cl_tasks), 1*HZ);
 340         }
 341
 342         rpc_release_client(clnt);
 343 }
 344
 345 /*
 346  * Free an RPC client
 347  */
 348 static void
 349 rpc_free_client(struct kref *kref)
 350 {
 351         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 352
 353         dprintk("RPC:       destroying %s client for %s\n",
 354                         clnt->cl_protname, clnt->cl_server);
 355         if (clnt->cl_auth) {
 356                 rpcauth_destroy(clnt->cl_auth);
 357                 clnt->cl_auth = NULL;
 358         }
 359         if (!IS_ERR(clnt->cl_dentry)) {
 360                 rpc_rmdir(clnt->cl_dentry);
 361                 rpc_put_mount();
 362         }
 363         if (clnt->cl_parent != clnt) {
 364                 rpc_release_client(clnt->cl_parent);
 365                 goto out_free;
 366         }
 367         if (clnt->cl_server != clnt->cl_inline_name)
 368                 kfree(clnt->cl_server);
 369 out_free:
 370         rpc_unregister_client(clnt);
 371         rpc_free_iostats(clnt->cl_metrics);
 372         clnt->cl_metrics = NULL;
 373         xprt_put(clnt->cl_xprt);
 374         rpciod_down();
 375         kfree(clnt);
 376 }
 377
 378 /*
 379  * Release reference to the RPC client
 380  */
 381 void
 382 rpc_release_client(struct rpc_clnt *clnt)
 383 {
 384         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 385
 386         if (list_empty(&clnt->cl_tasks))
 387                 wake_up(&destroy_wait);
 388         kref_put(&clnt->cl_kref, rpc_free_client);
 389 }
 390
 391 /**
 392  * rpc_bind_new_program - bind a new RPC program to an existing client
 393  * @old - old rpc_client
 394  * @program - rpc program to set
 395  * @vers - rpc program version
 396  *
 397  * Clones the rpc client and sets up a new RPC program. This is mainly
 398  * of use for enabling different RPC programs to share the same transport.
 399  * The Sun NFSv2/v3 ACL protocol can do this.
 400  */
 401 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 402                                       struct rpc_program *program,
 403                                       int vers)
 404 {
 405         struct rpc_clnt *clnt;
 406         struct rpc_version *version;
 407         int err;
 408
 409         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 410         version = program->version[vers];
 411         clnt = rpc_clone_client(old);
 412         if (IS_ERR(clnt))
 413                 goto out;
 414         clnt->cl_procinfo = version->procs;
 415         clnt->cl_maxproc  = version->nrprocs;
 416         clnt->cl_protname = program->name;
 417         clnt->cl_prog     = program->number;
 418         clnt->cl_vers     = version->number;
 419         clnt->cl_stats    = program->stats;
 420         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
 421         if (err != 0) {
 422                 rpc_shutdown_client(clnt);
 423                 clnt = ERR_PTR(err);
 424         }
 425 out:
 426         return clnt;
 427 }
 428
 429 /*
 430  * Default callback for async RPC calls
 431  */
 432 static void
 433 rpc_default_callback(struct rpc_task *task, void *data)
 434 {
 435 }
 436
 437 static const struct rpc_call_ops rpc_default_ops = {
 438         .rpc_call_done = rpc_default_callback,
 439 };
 440
 441 /*
 442  *      Export the signal mask handling for synchronous code that
 443  *      sleeps on RPC calls
 444  */
 445 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
 446
 447 static void rpc_save_sigmask(sigset_t *oldset, int intr)
 448 {
 449         unsigned long   sigallow = sigmask(SIGKILL);
 450         sigset_t sigmask;
 451
 452         /* Block all signals except those listed in sigallow */
 453         if (intr)
 454                 sigallow |= RPC_INTR_SIGNALS;
 455         siginitsetinv(&sigmask, sigallow);
 456         sigprocmask(SIG_BLOCK, &sigmask, oldset);
 457 }
 458
 459 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
 460 {
 461         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
 462 }
 463
 464 static inline void rpc_restore_sigmask(sigset_t *oldset)
 465 {
 466         sigprocmask(SIG_SETMASK, oldset, NULL);
 467 }
 468
 469 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
 470 {
 471         rpc_save_sigmask(oldset, clnt->cl_intr);
 472 }
 473
 474 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
 475 {
 476         rpc_restore_sigmask(oldset);
 477 }
 478
 479 static
 480 struct rpc_task *rpc_do_run_task(struct rpc_clnt *clnt,
 481                 struct rpc_message *msg,
 482                 int flags,
 483                 const struct rpc_call_ops *ops,
 484                 void *data)
 485 {
 486         struct rpc_task *task, *ret;
 487         sigset_t oldset;
 488
 489         task = rpc_new_task(clnt, flags, ops, data);
 490         if (task == NULL) {
 491                 rpc_release_calldata(ops, data);
 492                 return ERR_PTR(-ENOMEM);
 493         }
 494
 495         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
 496         rpc_task_sigmask(task, &oldset);
 497         if (msg != NULL) {
 498                 rpc_call_setup(task, msg, 0);
 499                 if (task->tk_status != 0) {
 500                         ret = ERR_PTR(task->tk_status);
 501                         rpc_put_task(task);
 502                         goto out;
 503                 }
 504         }
 505         atomic_inc(&task->tk_count);
 506         rpc_execute(task);
 507         ret = task;
 508 out:
 509         rpc_restore_sigmask(&oldset);
 510         return ret;
 511 }
 512
 513 /**
 514  * rpc_call_sync - Perform a synchronous RPC call
 515  * @clnt: pointer to RPC client
 516  * @msg: RPC call parameters
 517  * @flags: RPC call flags
 518  */
 519 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
 520 {
 521         struct rpc_task *task;
 522         int status;
 523
 524         BUG_ON(flags & RPC_TASK_ASYNC);
 525
 526         task = rpc_do_run_task(clnt, msg, flags, &rpc_default_ops, NULL);
 527         if (IS_ERR(task))
 528                 return PTR_ERR(task);
 529         status = task->tk_status;
 530         rpc_put_task(task);
 531         return status;
 532 }
 533
 534 /**
 535  * rpc_call_async - Perform an asynchronous RPC call
 536  * @clnt: pointer to RPC client
 537  * @msg: RPC call parameters
 538  * @flags: RPC call flags
 539  * @ops: RPC call ops
 540  * @data: user call data
 541  */
 542 int
 543 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
 544                const struct rpc_call_ops *tk_ops, void *data)
 545 {
 546         struct rpc_task *task;
 547
 548         task = rpc_do_run_task(clnt, msg, flags|RPC_TASK_ASYNC, tk_ops, data);
 549         if (IS_ERR(task))
 550                 return PTR_ERR(task);
 551         rpc_put_task(task);
 552         return 0;
 553 }
 554
 555 /**
 556  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 557  * @clnt: pointer to RPC client
 558  * @flags: RPC flags
 559  * @ops: RPC call ops
 560  * @data: user call data
 561  */
 562 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
 563                                         const struct rpc_call_ops *tk_ops,
 564                                         void *data)
 565 {
 566         return rpc_do_run_task(clnt, NULL, flags, tk_ops, data);
 567 }
 568 EXPORT_SYMBOL(rpc_run_task);
 569
 570 void
 571 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
 572 {
 573         task->tk_msg   = *msg;
 574         task->tk_flags |= flags;
 575         /* Bind the user cred */
 576         if (task->tk_msg.rpc_cred != NULL)
 577                 rpcauth_holdcred(task);
 578         else
 579                 rpcauth_bindcred(task);
 580
 581         if (task->tk_status == 0)
 582                 task->tk_action = call_start;
 583         else
 584                 task->tk_action = rpc_exit_task;
 585 }
 586
 587 /**
 588  * rpc_peeraddr - extract remote peer address from clnt's xprt
 589  * @clnt: RPC client structure
 590  * @buf: target buffer
 591  * @size: length of target buffer
 592  *
 593  * Returns the number of bytes that are actually in the stored address.
 594  */
 595 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 596 {
 597         size_t bytes;
 598         struct rpc_xprt *xprt = clnt->cl_xprt;
 599
 600         bytes = sizeof(xprt->addr);
 601         if (bytes > bufsize)
 602                 bytes = bufsize;
 603         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 604         return xprt->addrlen;
 605 }
 606 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 607
 608 /**
 609  * rpc_peeraddr2str - return remote peer address in printable format
 610  * @clnt: RPC client structure
 611  * @format: address format
 612  *
 613  */
 614 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
 615 {
 616         struct rpc_xprt *xprt = clnt->cl_xprt;
 617
 618         if (xprt->address_strings[format] != NULL)
 619                 return xprt->address_strings[format];
 620         else
 621                 return "unprintable";
 622 }
 623 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 624
 625 void
 626 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 627 {
 628         struct rpc_xprt *xprt = clnt->cl_xprt;
 629         if (xprt->ops->set_buffer_size)
 630                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 631 }
 632
 633 /*
 634  * Return size of largest payload RPC client can support, in bytes
 635  *
 636  * For stream transports, this is one RPC record fragment (see RFC
 637  * 1831), as we don't support multi-record requests yet.  For datagram
 638  * transports, this is the size of an IP packet minus the IP, UDP, and
 639  * RPC header sizes.
 640  */
 641 size_t rpc_max_payload(struct rpc_clnt *clnt)
 642 {
 643         return clnt->cl_xprt->max_payload;
 644 }
 645 EXPORT_SYMBOL_GPL(rpc_max_payload);
 646
 647 /**
 648  * rpc_force_rebind - force transport to check that remote port is unchanged
 649  * @clnt: client to rebind
 650  *
 651  */
 652 void rpc_force_rebind(struct rpc_clnt *clnt)
 653 {
 654         if (clnt->cl_autobind)
 655                 xprt_clear_bound(clnt->cl_xprt);
 656 }
 657 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 658
 659 /*
 660  * Restart an (async) RPC call. Usually called from within the
 661  * exit handler.
 662  */
 663 void
 664 rpc_restart_call(struct rpc_task *task)
 665 {
 666         if (RPC_ASSASSINATED(task))
 667                 return;
 668
 669         task->tk_action = call_start;
 670 }
 671
 672 /*
 673  * 0.  Initial state
 674  *
 675  *     Other FSM states can be visited zero or more times, but
 676  *     this state is visited exactly once for each RPC.
 677  */
 678 static void
 679 call_start(struct rpc_task *task)
 680 {
 681         struct rpc_clnt *clnt = task->tk_client;
 682
 683         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
 684                         clnt->cl_protname, clnt->cl_vers,
 685                         task->tk_msg.rpc_proc->p_proc,
 686                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 687
 688         /* Increment call count */
 689         task->tk_msg.rpc_proc->p_count++;
 690         clnt->cl_stats->rpccnt++;
 691         task->tk_action = call_reserve;
 692 }
 693
 694 /*
 695  * 1.   Reserve an RPC call slot
 696  */
 697 static void
 698 call_reserve(struct rpc_task *task)
 699 {
 700         dprint_status(task);
 701
 702         if (!rpcauth_uptodatecred(task)) {
 703                 task->tk_action = call_refresh;
 704                 return;
 705         }
 706
 707         task->tk_status  = 0;
 708         task->tk_action  = call_reserveresult;
 709         xprt_reserve(task);
 710 }
 711
 712 /*
 713  * 1b.  Grok the result of xprt_reserve()
 714  */
 715 static void
 716 call_reserveresult(struct rpc_task *task)
 717 {
 718         int status = task->tk_status;
 719
 720         dprint_status(task);
 721
 722         /*
 723          * After a call to xprt_reserve(), we must have either
 724          * a request slot or else an error status.
 725          */
 726         task->tk_status = 0;
 727         if (status >= 0) {
 728                 if (task->tk_rqstp) {
 729                         task->tk_action = call_allocate;
 730                         return;
 731                 }
 732
 733                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 734                                 __FUNCTION__, status);
 735                 rpc_exit(task, -EIO);
 736                 return;
 737         }
 738
 739         /*
 740          * Even though there was an error, we may have acquired
 741          * a request slot somehow.  Make sure not to leak it.
 742          */
 743         if (task->tk_rqstp) {
 744                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 745                                 __FUNCTION__, status);
 746                 xprt_release(task);
 747         }
 748
 749         switch (status) {
 750         case -EAGAIN:   /* woken up; retry */
 751                 task->tk_action = call_reserve;
 752                 return;
 753         case -EIO:      /* probably a shutdown */
 754                 break;
 755         default:
 756                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 757                                 __FUNCTION__, status);
 758                 break;
 759         }
 760         rpc_exit(task, status);
 761 }
 762
 763 /*
 764  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 765  *      (Note: buffer memory is freed in xprt_release).
 766  */
 767 static void
 768 call_allocate(struct rpc_task *task)
 769 {
 770         unsigned int slack = task->tk_auth->au_cslack;
 771         struct rpc_rqst *req = task->tk_rqstp;
 772         struct rpc_xprt *xprt = task->tk_xprt;
 773         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 774
 775         dprint_status(task);
 776
 777         task->tk_status = 0;
 778         task->tk_action = call_bind;
 779
 780         if (req->rq_buffer)
 781                 return;
 782
 783         if (proc->p_proc != 0) {
 784                 BUG_ON(proc->p_arglen == 0);
 785                 if (proc->p_decode != NULL)
 786                         BUG_ON(proc->p_replen == 0);
 787         }
 788
 789         /*
 790          * Calculate the size (in quads) of the RPC call
 791          * and reply headers, and convert both values
 792          * to byte sizes.
 793          */
 794         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 795         req->rq_callsize <<= 2;
 796         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 797         req->rq_rcvsize <<= 2;
 798
 799         req->rq_buffer = xprt->ops->buf_alloc(task,
 800                                         req->rq_callsize + req->rq_rcvsize);
 801         if (req->rq_buffer != NULL)
 802                 return;
 803
 804         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 805
 806         if (RPC_IS_ASYNC(task) || !signalled()) {
 807                 xprt_release(task);
 808                 task->tk_action = call_reserve;
 809                 rpc_delay(task, HZ>>4);
 810                 return;
 811         }
 812
 813         rpc_exit(task, -ERESTARTSYS);
 814 }
 815
 816 static inline int
 817 rpc_task_need_encode(struct rpc_task *task)
 818 {
 819         return task->tk_rqstp->rq_snd_buf.len == 0;
 820 }
 821
 822 static inline void
 823 rpc_task_force_reencode(struct rpc_task *task)
 824 {
 825         task->tk_rqstp->rq_snd_buf.len = 0;
 826 }
 827
 828 static inline void
 829 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 830 {
 831         buf->head[0].iov_base = start;
 832         buf->head[0].iov_len = len;
 833         buf->tail[0].iov_len = 0;
 834         buf->page_len = 0;
 835         buf->len = 0;
 836         buf->buflen = len;
 837 }
 838
 839 /*
 840  * 3.   Encode arguments of an RPC call
 841  */
 842 static void
 843 call_encode(struct rpc_task *task)
 844 {
 845         struct rpc_rqst *req = task->tk_rqstp;
 846         kxdrproc_t      encode;
 847         __be32          *p;
 848
 849         dprint_status(task);
 850
 851         rpc_xdr_buf_init(&req->rq_snd_buf,
 852                          req->rq_buffer,
 853                          req->rq_callsize);
 854         rpc_xdr_buf_init(&req->rq_rcv_buf,
 855                          (char *)req->rq_buffer + req->rq_callsize,
 856                          req->rq_rcvsize);
 857
 858         /* Encode header and provided arguments */
 859         encode = task->tk_msg.rpc_proc->p_encode;
 860         if (!(p = call_header(task))) {
 861                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
 862                 rpc_exit(task, -EIO);
 863                 return;
 864         }
 865         if (encode == NULL)
 866                 return;
 867
 868         lock_kernel();
 869         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 870                         task->tk_msg.rpc_argp);
 871         unlock_kernel();
 872         if (task->tk_status == -ENOMEM) {
 873                 /* XXX: Is this sane? */
 874                 rpc_delay(task, 3*HZ);
 875                 task->tk_status = -EAGAIN;
 876         }
 877 }
 878
 879 /*
 880  * 4.   Get the server port number if not yet set
 881  */
 882 static void
 883 call_bind(struct rpc_task *task)
 884 {
 885         struct rpc_xprt *xprt = task->tk_xprt;
 886
 887         dprint_status(task);
 888
 889         task->tk_action = call_connect;
 890         if (!xprt_bound(xprt)) {
 891                 task->tk_action = call_bind_status;
 892                 task->tk_timeout = xprt->bind_timeout;
 893                 xprt->ops->rpcbind(task);
 894         }
 895 }
 896
 897 /*
 898  * 4a.  Sort out bind result
 899  */
 900 static void
 901 call_bind_status(struct rpc_task *task)
 902 {
 903         int status = -EACCES;
 904
 905         if (task->tk_status >= 0) {
 906                 dprint_status(task);
 907                 task->tk_status = 0;
 908                 task->tk_action = call_connect;
 909                 return;
 910         }
 911
 912         switch (task->tk_status) {
 913         case -EACCES:
 914                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
 915                                 "unavailable\n", task->tk_pid);
 916                 rpc_delay(task, 3*HZ);
 917                 goto retry_timeout;
 918         case -ETIMEDOUT:
 919                 dprintk("RPC: %5u rpcbind request timed out\n",
 920                                 task->tk_pid);
 921                 goto retry_timeout;
 922         case -EPFNOSUPPORT:
 923                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
 924                                 task->tk_pid);
 925                 break;
 926         case -EPROTONOSUPPORT:
 927                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
 928                                 task->tk_pid);
 929                 task->tk_status = 0;
 930                 task->tk_action = call_bind;
 931                 return;
 932         default:
 933                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
 934                                 task->tk_pid, -task->tk_status);
 935                 status = -EIO;
 936         }
 937
 938         rpc_exit(task, status);
 939         return;
 940
 941 retry_timeout:
 942         task->tk_action = call_timeout;
 943 }
 944
 945 /*
 946  * 4b.  Connect to the RPC server
 947  */
 948 static void
 949 call_connect(struct rpc_task *task)
 950 {
 951         struct rpc_xprt *xprt = task->tk_xprt;
 952
 953         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
 954                         task->tk_pid, xprt,
 955                         (xprt_connected(xprt) ? "is" : "is not"));
 956
 957         task->tk_action = call_transmit;
 958         if (!xprt_connected(xprt)) {
 959                 task->tk_action = call_connect_status;
 960                 if (task->tk_status < 0)
 961                         return;
 962                 xprt_connect(task);
 963         }
 964 }
 965
 966 /*
 967  * 4c.  Sort out connect result
 968  */
 969 static void
 970 call_connect_status(struct rpc_task *task)
 971 {
 972         struct rpc_clnt *clnt = task->tk_client;
 973         int status = task->tk_status;
 974
 975         dprint_status(task);
 976
 977         task->tk_status = 0;
 978         if (status >= 0) {
 979                 clnt->cl_stats->netreconn++;
 980                 task->tk_action = call_transmit;
 981                 return;
 982         }
 983
 984         /* Something failed: remote service port may have changed */
 985         rpc_force_rebind(clnt);
 986
 987         switch (status) {
 988         case -ENOTCONN:
 989         case -EAGAIN:
 990                 task->tk_action = call_bind;
 991                 if (!RPC_IS_SOFT(task))
 992                         return;
 993                 /* if soft mounted, test if we've timed out */
 994         case -ETIMEDOUT:
 995                 task->tk_action = call_timeout;
 996                 return;
 997         }
 998         rpc_exit(task, -EIO);
 999 }
1000
1001 /*
1002  * 5.   Transmit the RPC request, and wait for reply
1003  */
1004 static void
1005 call_transmit(struct rpc_task *task)
1006 {
1007         dprint_status(task);
1008
1009         task->tk_action = call_status;
1010         if (task->tk_status < 0)
1011                 return;
1012         task->tk_status = xprt_prepare_transmit(task);
1013         if (task->tk_status != 0)
1014                 return;
1015         task->tk_action = call_transmit_status;
1016         /* Encode here so that rpcsec_gss can use correct sequence number. */
1017         if (rpc_task_need_encode(task)) {
1018                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1019                 call_encode(task);
1020                 /* Did the encode result in an error condition? */
1021                 if (task->tk_status != 0)
1022                         return;
1023         }
1024         xprt_transmit(task);
1025         if (task->tk_status < 0)
1026                 return;
1027         /*
1028          * On success, ensure that we call xprt_end_transmit() before sleeping
1029          * in order to allow access to the socket to other RPC requests.
1030          */
1031         call_transmit_status(task);
1032         if (task->tk_msg.rpc_proc->p_decode != NULL)
1033                 return;
1034         task->tk_action = rpc_exit_task;
1035         rpc_wake_up_task(task);
1036 }
1037
1038 /*
1039  * 5a.  Handle cleanup after a transmission
1040  */
1041 static void
1042 call_transmit_status(struct rpc_task *task)
1043 {
1044         task->tk_action = call_status;
1045         /*
1046          * Special case: if we've been waiting on the socket's write_space()
1047          * callback, then don't call xprt_end_transmit().
1048          */
1049         if (task->tk_status == -EAGAIN)
1050                 return;
1051         xprt_end_transmit(task);
1052         rpc_task_force_reencode(task);
1053 }
1054
1055 /*
1056  * 6.   Sort out the RPC call status
1057  */
1058 static void
1059 call_status(struct rpc_task *task)
1060 {
1061         struct rpc_clnt *clnt = task->tk_client;
1062         struct rpc_rqst *req = task->tk_rqstp;
1063         int             status;
1064
1065         if (req->rq_received > 0 && !req->rq_bytes_sent)
1066                 task->tk_status = req->rq_received;
1067
1068         dprint_status(task);
1069
1070         status = task->tk_status;
1071         if (status >= 0) {
1072                 task->tk_action = call_decode;
1073                 return;
1074         }
1075
1076         task->tk_status = 0;
1077         switch(status) {
1078         case -EHOSTDOWN:
1079         case -EHOSTUNREACH:
1080         case -ENETUNREACH:
1081                 /*
1082                  * Delay any retries for 3 seconds, then handle as if it
1083                  * were a timeout.
1084                  */
1085                 rpc_delay(task, 3*HZ);
1086         case -ETIMEDOUT:
1087                 task->tk_action = call_timeout;
1088                 if (task->tk_client->cl_discrtry)
1089                         xprt_disconnect(task->tk_xprt);
1090                 break;
1091         case -ECONNREFUSED:
1092         case -ENOTCONN:
1093                 rpc_force_rebind(clnt);
1094                 task->tk_action = call_bind;
1095                 break;
1096         case -EAGAIN:
1097                 task->tk_action = call_transmit;
1098                 break;
1099         case -EIO:
1100                 /* shutdown or soft timeout */
1101                 rpc_exit(task, status);
1102                 break;
1103         default:
1104                 printk("%s: RPC call returned error %d\n",
1105                                clnt->cl_protname, -status);
1106                 rpc_exit(task, status);
1107         }
1108 }
1109
1110 /*
1111  * 6a.  Handle RPC timeout
1112  *      We do not release the request slot, so we keep using the
1113  *      same XID for all retransmits.
1114  */
1115 static void
1116 call_timeout(struct rpc_task *task)
1117 {
1118         struct rpc_clnt *clnt = task->tk_client;
1119
1120         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1121                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1122                 goto retry;
1123         }
1124
1125         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1126         task->tk_timeouts++;
1127
1128         if (RPC_IS_SOFT(task)) {
1129                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1130                                 clnt->cl_protname, clnt->cl_server);
1131                 rpc_exit(task, -EIO);
1132                 return;
1133         }
1134
1135         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1136                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1137                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1138                         clnt->cl_protname, clnt->cl_server);
1139         }
1140         rpc_force_rebind(clnt);
1141
1142 retry:
1143         clnt->cl_stats->rpcretrans++;
1144         task->tk_action = call_bind;
1145         task->tk_status = 0;
1146 }
1147
1148 /*
1149  * 7.   Decode the RPC reply
1150  */
1151 static void
1152 call_decode(struct rpc_task *task)
1153 {
1154         struct rpc_clnt *clnt = task->tk_client;
1155         struct rpc_rqst *req = task->tk_rqstp;
1156         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1157         __be32          *p;
1158
1159         dprintk("RPC: %5u call_decode (status %d)\n",
1160                         task->tk_pid, task->tk_status);
1161
1162         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1163                 printk(KERN_NOTICE "%s: server %s OK\n",
1164                         clnt->cl_protname, clnt->cl_server);
1165                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1166         }
1167
1168         if (task->tk_status < 12) {
1169                 if (!RPC_IS_SOFT(task)) {
1170                         task->tk_action = call_bind;
1171                         clnt->cl_stats->rpcretrans++;
1172                         goto out_retry;
1173                 }
1174                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1175                                 clnt->cl_protname, task->tk_status);
1176                 task->tk_action = call_timeout;
1177                 goto out_retry;
1178         }
1179
1180         /*
1181          * Ensure that we see all writes made by xprt_complete_rqst()
1182          * before it changed req->rq_received.
1183          */
1184         smp_rmb();
1185         req->rq_rcv_buf.len = req->rq_private_buf.len;
1186
1187         /* Check that the softirq receive buffer is valid */
1188         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1189                                 sizeof(req->rq_rcv_buf)) != 0);
1190
1191         /* Verify the RPC header */
1192         p = call_verify(task);
1193         if (IS_ERR(p)) {
1194                 if (p == ERR_PTR(-EAGAIN))
1195                         goto out_retry;
1196                 return;
1197         }
1198
1199         task->tk_action = rpc_exit_task;
1200
1201         if (decode) {
1202                 lock_kernel();
1203                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1204                                                       task->tk_msg.rpc_resp);
1205                 unlock_kernel();
1206         }
1207         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1208                         task->tk_status);
1209         return;
1210 out_retry:
1211         req->rq_received = req->rq_private_buf.len = 0;
1212         task->tk_status = 0;
1213         if (task->tk_client->cl_discrtry)
1214                 xprt_disconnect(task->tk_xprt);
1215 }
1216
1217 /*
1218  * 8.   Refresh the credentials if rejected by the server
1219  */
1220 static void
1221 call_refresh(struct rpc_task *task)
1222 {
1223         dprint_status(task);
1224
1225         xprt_release(task);     /* Must do to obtain new XID */
1226         task->tk_action = call_refreshresult;
1227         task->tk_status = 0;
1228         task->tk_client->cl_stats->rpcauthrefresh++;
1229         rpcauth_refreshcred(task);
1230 }
1231
1232 /*
1233  * 8a.  Process the results of a credential refresh
1234  */
1235 static void
1236 call_refreshresult(struct rpc_task *task)
1237 {
1238         int status = task->tk_status;
1239
1240         dprint_status(task);
1241
1242         task->tk_status = 0;
1243         task->tk_action = call_reserve;
1244         if (status >= 0 && rpcauth_uptodatecred(task))
1245                 return;
1246         if (status == -EACCES) {
1247                 rpc_exit(task, -EACCES);
1248                 return;
1249         }
1250         task->tk_action = call_refresh;
1251         if (status != -ETIMEDOUT)
1252                 rpc_delay(task, 3*HZ);
1253         return;
1254 }
1255
1256 /*
1257  * Call header serialization
1258  */
1259 static __be32 *
1260 call_header(struct rpc_task *task)
1261 {
1262         struct rpc_clnt *clnt = task->tk_client;
1263         struct rpc_rqst *req = task->tk_rqstp;
1264         __be32          *p = req->rq_svec[0].iov_base;
1265
1266         /* FIXME: check buffer size? */
1267
1268         p = xprt_skip_transport_header(task->tk_xprt, p);
1269         *p++ = req->rq_xid;             /* XID */
1270         *p++ = htonl(RPC_CALL);         /* CALL */
1271         *p++ = htonl(RPC_VERSION);      /* RPC version */
1272         *p++ = htonl(clnt->cl_prog);    /* program number */
1273         *p++ = htonl(clnt->cl_vers);    /* program version */
1274         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1275         p = rpcauth_marshcred(task, p);
1276         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1277         return p;
1278 }
1279
1280 /*
1281  * Reply header verification
1282  */
1283 static __be32 *
1284 call_verify(struct rpc_task *task)
1285 {
1286         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1287         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1288         __be32  *p = iov->iov_base;
1289         u32 n;
1290         int error = -EACCES;
1291
1292         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1293                 /* RFC-1014 says that the representation of XDR data must be a
1294                  * multiple of four bytes
1295                  * - if it isn't pointer subtraction in the NFS client may give
1296                  *   undefined results
1297                  */
1298                 printk(KERN_WARNING
1299                        "call_verify: XDR representation not a multiple of"
1300                        " 4 bytes: 0x%x\n", task->tk_rqstp->rq_rcv_buf.len);
1301                 goto out_eio;
1302         }
1303         if ((len -= 3) < 0)
1304                 goto out_overflow;
1305         p += 1; /* skip XID */
1306
1307         if ((n = ntohl(*p++)) != RPC_REPLY) {
1308                 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1309                 goto out_garbage;
1310         }
1311         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1312                 if (--len < 0)
1313                         goto out_overflow;
1314                 switch ((n = ntohl(*p++))) {
1315                         case RPC_AUTH_ERROR:
1316                                 break;
1317                         case RPC_MISMATCH:
1318                                 dprintk("RPC: %5u %s: RPC call version "
1319                                                 "mismatch!\n",
1320                                                 task->tk_pid, __FUNCTION__);
1321                                 error = -EPROTONOSUPPORT;
1322                                 goto out_err;
1323                         default:
1324                                 dprintk("RPC: %5u %s: RPC call rejected, "
1325                                                 "unknown error: %x\n",
1326                                                 task->tk_pid, __FUNCTION__, n);
1327                                 goto out_eio;
1328                 }
1329                 if (--len < 0)
1330                         goto out_overflow;
1331                 switch ((n = ntohl(*p++))) {
1332                 case RPC_AUTH_REJECTEDCRED:
1333                 case RPC_AUTH_REJECTEDVERF:
1334                 case RPCSEC_GSS_CREDPROBLEM:
1335                 case RPCSEC_GSS_CTXPROBLEM:
1336                         if (!task->tk_cred_retry)
1337                                 break;
1338                         task->tk_cred_retry--;
1339                         dprintk("RPC: %5u %s: retry stale creds\n",
1340                                         task->tk_pid, __FUNCTION__);
1341                         rpcauth_invalcred(task);
1342                         task->tk_action = call_refresh;
1343                         goto out_retry;
1344                 case RPC_AUTH_BADCRED:
1345                 case RPC_AUTH_BADVERF:
1346                         /* possibly garbled cred/verf? */
1347                         if (!task->tk_garb_retry)
1348                                 break;
1349                         task->tk_garb_retry--;
1350                         dprintk("RPC: %5u %s: retry garbled creds\n",
1351                                         task->tk_pid, __FUNCTION__);
1352                         task->tk_action = call_bind;
1353                         goto out_retry;
1354                 case RPC_AUTH_TOOWEAK:
1355                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1356                                "authentication.\n", task->tk_client->cl_server);
1357                         break;
1358                 default:
1359                         printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1360                         error = -EIO;
1361                 }
1362                 dprintk("RPC: %5u %s: call rejected %d\n",
1363                                 task->tk_pid, __FUNCTION__, n);
1364                 goto out_err;
1365         }
1366         if (!(p = rpcauth_checkverf(task, p))) {
1367                 printk(KERN_WARNING "call_verify: auth check failed\n");
1368                 goto out_garbage;               /* bad verifier, retry */
1369         }
1370         len = p - (__be32 *)iov->iov_base - 1;
1371         if (len < 0)
1372                 goto out_overflow;
1373         switch ((n = ntohl(*p++))) {
1374         case RPC_SUCCESS:
1375                 return p;
1376         case RPC_PROG_UNAVAIL:
1377                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1378                                 task->tk_pid, __FUNCTION__,
1379                                 (unsigned int)task->tk_client->cl_prog,
1380                                 task->tk_client->cl_server);
1381                 error = -EPFNOSUPPORT;
1382                 goto out_err;
1383         case RPC_PROG_MISMATCH:
1384                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1385                                 "server %s\n", task->tk_pid, __FUNCTION__,
1386                                 (unsigned int)task->tk_client->cl_prog,
1387                                 (unsigned int)task->tk_client->cl_vers,
1388                                 task->tk_client->cl_server);
1389                 error = -EPROTONOSUPPORT;
1390                 goto out_err;
1391         case RPC_PROC_UNAVAIL:
1392                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1393                                 "version %u on server %s\n",
1394                                 task->tk_pid, __FUNCTION__,
1395                                 task->tk_msg.rpc_proc,
1396                                 task->tk_client->cl_prog,
1397                                 task->tk_client->cl_vers,
1398                                 task->tk_client->cl_server);
1399                 error = -EOPNOTSUPP;
1400                 goto out_err;
1401         case RPC_GARBAGE_ARGS:
1402                 dprintk("RPC: %5u %s: server saw garbage\n",
1403                                 task->tk_pid, __FUNCTION__);
1404                 break;                  /* retry */
1405         default:
1406                 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1407                 /* Also retry */
1408         }
1409
1410 out_garbage:
1411         task->tk_client->cl_stats->rpcgarbage++;
1412         if (task->tk_garb_retry) {
1413                 task->tk_garb_retry--;
1414                 dprintk("RPC: %5u %s: retrying\n",
1415                                 task->tk_pid, __FUNCTION__);
1416                 task->tk_action = call_bind;
1417 out_retry:
1418                 return ERR_PTR(-EAGAIN);
1419         }
1420         printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1421 out_eio:
1422         error = -EIO;
1423 out_err:
1424         rpc_exit(task, error);
1425         return ERR_PTR(error);
1426 out_overflow:
1427         printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1428         goto out_garbage;
1429 }
1430
1431 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1432 {
1433         return 0;
1434 }
1435
1436 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1437 {
1438         return 0;
1439 }
1440
1441 static struct rpc_procinfo rpcproc_null = {
1442         .p_encode = rpcproc_encode_null,
1443         .p_decode = rpcproc_decode_null,
1444 };
1445
1446 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1447 {
1448         struct rpc_message msg = {
1449                 .rpc_proc = &rpcproc_null,
1450         };
1451         int err;
1452         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1453         err = rpc_call_sync(clnt, &msg, flags);
1454         put_rpccred(msg.rpc_cred);
1455         return err;
1456 }
1457
1458 #ifdef RPC_DEBUG
1459 void rpc_show_tasks(void)
1460 {
1461         struct rpc_clnt *clnt;
1462         struct rpc_task *t;
1463
1464         spin_lock(&rpc_client_lock);
1465         if (list_empty(&all_clients))
1466                 goto out;
1467         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1468                 "-rpcwait -action- ---ops--\n");
1469         list_for_each_entry(clnt, &all_clients, cl_clients) {
1470                 if (list_empty(&clnt->cl_tasks))
1471                         continue;
1472                 spin_lock(&clnt->cl_lock);
1473                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1474                         const char *rpc_waitq = "none";
1475
1476                         if (RPC_IS_QUEUED(t))
1477                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1478
1479                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1480                                 t->tk_pid,
1481                                 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1482                                 t->tk_flags, t->tk_status,
1483                                 t->tk_client,
1484                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1485                                 t->tk_rqstp, t->tk_timeout,
1486                                 rpc_waitq,
1487                                 t->tk_action, t->tk_ops);
1488                 }
1489                 spin_unlock(&clnt->cl_lock);
1490         }
1491 out:
1492         spin_unlock(&rpc_client_lock);
1493 }
1494 #endif