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  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/utsname.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/in.h>
  31 #include <linux/in6.h>
  32 #include <linux/un.h>
  33 #include <linux/rcupdate.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/rpc_pipe_fs.h>
  37 #include <linux/sunrpc/metrics.h>
  38 #include <linux/sunrpc/bc_xprt.h>
  39 #include <trace/events/sunrpc.h>
  40
  41 #include "sunrpc.h"
  42 #include "netns.h"
  43
  44 #ifdef RPC_DEBUG
  45 # define RPCDBG_FACILITY        RPCDBG_CALL
  46 #endif
  47
  48 #define dprint_status(t)                                        \
  49         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  50                         __func__, t->tk_status)
  51
  52 /*
  53  * All RPC clients are linked into this list
  54  */
  55
  56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  57
  58
  59 static void     call_start(struct rpc_task *task);
  60 static void     call_reserve(struct rpc_task *task);
  61 static void     call_reserveresult(struct rpc_task *task);
  62 static void     call_allocate(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  68 static void     call_bc_transmit(struct rpc_task *task);
  69 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  70 static void     call_status(struct rpc_task *task);
  71 static void     call_transmit_status(struct rpc_task *task);
  72 static void     call_refresh(struct rpc_task *task);
  73 static void     call_refreshresult(struct rpc_task *task);
  74 static void     call_timeout(struct rpc_task *task);
  75 static void     call_connect(struct rpc_task *task);
  76 static void     call_connect_status(struct rpc_task *task);
  77
  78 static __be32   *rpc_encode_header(struct rpc_task *task);
  79 static __be32   *rpc_verify_header(struct rpc_task *task);
  80 static int      rpc_ping(struct rpc_clnt *clnt);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         if (clnt->cl_dentry) {
 105                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
 106                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
 107                 rpc_remove_client_dir(clnt->cl_dentry);
 108         }
 109         clnt->cl_dentry = NULL;
 110 }
 111
 112 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 113 {
 114         struct net *net = rpc_net_ns(clnt);
 115         struct super_block *pipefs_sb;
 116
 117         pipefs_sb = rpc_get_sb_net(net);
 118         if (pipefs_sb) {
 119                 __rpc_clnt_remove_pipedir(clnt);
 120                 rpc_put_sb_net(net);
 121         }
 122 }
 123
 124 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 125                                     struct rpc_clnt *clnt,
 126                                     const char *dir_name)
 127 {
 128         static uint32_t clntid;
 129         char name[15];
 130         struct qstr q = { .name = name };
 131         struct dentry *dir, *dentry;
 132         int error;
 133
 134         dir = rpc_d_lookup_sb(sb, dir_name);
 135         if (dir == NULL) {
 136                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 137                 return dir;
 138         }
 139         for (;;) {
 140                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 141                 name[sizeof(name) - 1] = '\0';
 142                 q.hash = full_name_hash(q.name, q.len);
 143                 dentry = rpc_create_client_dir(dir, &q, clnt);
 144                 if (!IS_ERR(dentry))
 145                         break;
 146                 error = PTR_ERR(dentry);
 147                 if (error != -EEXIST) {
 148                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 149                                         " %s/%s, error %d\n",
 150                                         dir_name, name, error);
 151                         break;
 152                 }
 153         }
 154         dput(dir);
 155         return dentry;
 156 }
 157
 158 static int
 159 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
 160 {
 161         struct net *net = rpc_net_ns(clnt);
 162         struct super_block *pipefs_sb;
 163         struct dentry *dentry;
 164
 165         clnt->cl_dentry = NULL;
 166         if (dir_name == NULL)
 167                 return 0;
 168         pipefs_sb = rpc_get_sb_net(net);
 169         if (!pipefs_sb)
 170                 return 0;
 171         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
 172         rpc_put_sb_net(net);
 173         if (IS_ERR(dentry))
 174                 return PTR_ERR(dentry);
 175         clnt->cl_dentry = dentry;
 176         return 0;
 177 }
 178
 179 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 180 {
 181         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 182             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 183                 return 1;
 184         return 0;
 185 }
 186
 187 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 188                                    struct super_block *sb)
 189 {
 190         struct dentry *dentry;
 191         int err = 0;
 192
 193         switch (event) {
 194         case RPC_PIPEFS_MOUNT:
 195                 dentry = rpc_setup_pipedir_sb(sb, clnt,
 196                                               clnt->cl_program->pipe_dir_name);
 197                 if (!dentry)
 198                         return -ENOENT;
 199                 if (IS_ERR(dentry))
 200                         return PTR_ERR(dentry);
 201                 clnt->cl_dentry = dentry;
 202                 if (clnt->cl_auth->au_ops->pipes_create) {
 203                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 204                         if (err)
 205                                 __rpc_clnt_remove_pipedir(clnt);
 206                 }
 207                 break;
 208         case RPC_PIPEFS_UMOUNT:
 209                 __rpc_clnt_remove_pipedir(clnt);
 210                 break;
 211         default:
 212                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 213                 return -ENOTSUPP;
 214         }
 215         return err;
 216 }
 217
 218 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 219                                 struct super_block *sb)
 220 {
 221         int error = 0;
 222
 223         for (;; clnt = clnt->cl_parent) {
 224                 if (!rpc_clnt_skip_event(clnt, event))
 225                         error = __rpc_clnt_handle_event(clnt, event, sb);
 226                 if (error || clnt == clnt->cl_parent)
 227                         break;
 228         }
 229         return error;
 230 }
 231
 232 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 233 {
 234         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 235         struct rpc_clnt *clnt;
 236
 237         spin_lock(&sn->rpc_client_lock);
 238         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 239                 if (clnt->cl_program->pipe_dir_name == NULL)
 240                         continue;
 241                 if (rpc_clnt_skip_event(clnt, event))
 242                         continue;
 243                 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
 244                         continue;
 245                 spin_unlock(&sn->rpc_client_lock);
 246                 return clnt;
 247         }
 248         spin_unlock(&sn->rpc_client_lock);
 249         return NULL;
 250 }
 251
 252 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 253                             void *ptr)
 254 {
 255         struct super_block *sb = ptr;
 256         struct rpc_clnt *clnt;
 257         int error = 0;
 258
 259         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 260                 error = __rpc_pipefs_event(clnt, event, sb);
 261                 rpc_release_client(clnt);
 262                 if (error)
 263                         break;
 264         }
 265         return error;
 266 }
 267
 268 static struct notifier_block rpc_clients_block = {
 269         .notifier_call  = rpc_pipefs_event,
 270         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 271 };
 272
 273 int rpc_clients_notifier_register(void)
 274 {
 275         return rpc_pipefs_notifier_register(&rpc_clients_block);
 276 }
 277
 278 void rpc_clients_notifier_unregister(void)
 279 {
 280         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 281 }
 282
 283 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 284 {
 285         clnt->cl_nodelen = strlen(nodename);
 286         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 287                 clnt->cl_nodelen = UNX_MAXNODENAME;
 288         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 289 }
 290
 291 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 292 {
 293         const struct rpc_program *program = args->program;
 294         const struct rpc_version *version;
 295         struct rpc_clnt         *clnt = NULL;
 296         struct rpc_auth         *auth;
 297         int err;
 298
 299         /* sanity check the name before trying to print it */
 300         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 301                         program->name, args->servername, xprt);
 302
 303         err = rpciod_up();
 304         if (err)
 305                 goto out_no_rpciod;
 306         err = -EINVAL;
 307         if (!xprt)
 308                 goto out_no_xprt;
 309
 310         if (args->version >= program->nrvers)
 311                 goto out_err;
 312         version = program->version[args->version];
 313         if (version == NULL)
 314                 goto out_err;
 315
 316         err = -ENOMEM;
 317         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 318         if (!clnt)
 319                 goto out_err;
 320         clnt->cl_parent = clnt;
 321
 322         rcu_assign_pointer(clnt->cl_xprt, xprt);
 323         clnt->cl_procinfo = version->procs;
 324         clnt->cl_maxproc  = version->nrprocs;
 325         clnt->cl_protname = program->name;
 326         clnt->cl_prog     = args->prognumber ? : program->number;
 327         clnt->cl_vers     = version->number;
 328         clnt->cl_stats    = program->stats;
 329         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 330         err = -ENOMEM;
 331         if (clnt->cl_metrics == NULL)
 332                 goto out_no_stats;
 333         clnt->cl_program  = program;
 334         INIT_LIST_HEAD(&clnt->cl_tasks);
 335         spin_lock_init(&clnt->cl_lock);
 336
 337         if (!xprt_bound(xprt))
 338                 clnt->cl_autobind = 1;
 339
 340         clnt->cl_timeout = xprt->timeout;
 341         if (args->timeout != NULL) {
 342                 memcpy(&clnt->cl_timeout_default, args->timeout,
 343                                 sizeof(clnt->cl_timeout_default));
 344                 clnt->cl_timeout = &clnt->cl_timeout_default;
 345         }
 346
 347         clnt->cl_rtt = &clnt->cl_rtt_default;
 348         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 349         clnt->cl_principal = NULL;
 350         if (args->client_name) {
 351                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 352                 if (!clnt->cl_principal)
 353                         goto out_no_principal;
 354         }
 355
 356         atomic_set(&clnt->cl_count, 1);
 357
 358         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 359         if (err < 0)
 360                 goto out_no_path;
 361
 362         auth = rpcauth_create(args->authflavor, clnt);
 363         if (IS_ERR(auth)) {
 364                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 365                                 args->authflavor);
 366                 err = PTR_ERR(auth);
 367                 goto out_no_auth;
 368         }
 369
 370         /* save the nodename */
 371         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 372         rpc_register_client(clnt);
 373         return clnt;
 374
 375 out_no_auth:
 376         rpc_clnt_remove_pipedir(clnt);
 377 out_no_path:
 378         kfree(clnt->cl_principal);
 379 out_no_principal:
 380         rpc_free_iostats(clnt->cl_metrics);
 381 out_no_stats:
 382         kfree(clnt);
 383 out_err:
 384         xprt_put(xprt);
 385 out_no_xprt:
 386         rpciod_down();
 387 out_no_rpciod:
 388         return ERR_PTR(err);
 389 }
 390
 391 /**
 392  * rpc_create - create an RPC client and transport with one call
 393  * @args: rpc_clnt create argument structure
 394  *
 395  * Creates and initializes an RPC transport and an RPC client.
 396  *
 397  * It can ping the server in order to determine if it is up, and to see if
 398  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 399  * this behavior so asynchronous tasks can also use rpc_create.
 400  */
 401 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 402 {
 403         struct rpc_xprt *xprt;
 404         struct rpc_clnt *clnt;
 405         struct xprt_create xprtargs = {
 406                 .net = args->net,
 407                 .ident = args->protocol,
 408                 .srcaddr = args->saddress,
 409                 .dstaddr = args->address,
 410                 .addrlen = args->addrsize,
 411                 .servername = args->servername,
 412                 .bc_xprt = args->bc_xprt,
 413         };
 414         char servername[48];
 415
 416         /*
 417          * If the caller chooses not to specify a hostname, whip
 418          * up a string representation of the passed-in address.
 419          */
 420         if (xprtargs.servername == NULL) {
 421                 struct sockaddr_un *sun =
 422                                 (struct sockaddr_un *)args->address;
 423                 struct sockaddr_in *sin =
 424                                 (struct sockaddr_in *)args->address;
 425                 struct sockaddr_in6 *sin6 =
 426                                 (struct sockaddr_in6 *)args->address;
 427
 428                 servername[0] = '\0';
 429                 switch (args->address->sa_family) {
 430                 case AF_LOCAL:
 431                         snprintf(servername, sizeof(servername), "%s",
 432                                  sun->sun_path);
 433                         break;
 434                 case AF_INET:
 435                         snprintf(servername, sizeof(servername), "%pI4",
 436                                  &sin->sin_addr.s_addr);
 437                         break;
 438                 case AF_INET6:
 439                         snprintf(servername, sizeof(servername), "%pI6",
 440                                  &sin6->sin6_addr);
 441                         break;
 442                 default:
 443                         /* caller wants default server name, but
 444                          * address family isn't recognized. */
 445                         return ERR_PTR(-EINVAL);
 446                 }
 447                 xprtargs.servername = servername;
 448         }
 449
 450         xprt = xprt_create_transport(&xprtargs);
 451         if (IS_ERR(xprt))
 452                 return (struct rpc_clnt *)xprt;
 453
 454         /*
 455          * By default, kernel RPC client connects from a reserved port.
 456          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 457          * but it is always enabled for rpciod, which handles the connect
 458          * operation.
 459          */
 460         xprt->resvport = 1;
 461         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 462                 xprt->resvport = 0;
 463
 464         clnt = rpc_new_client(args, xprt);
 465         if (IS_ERR(clnt))
 466                 return clnt;
 467
 468         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 469                 int err = rpc_ping(clnt);
 470                 if (err != 0) {
 471                         rpc_shutdown_client(clnt);
 472                         return ERR_PTR(err);
 473                 }
 474         }
 475
 476         clnt->cl_softrtry = 1;
 477         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 478                 clnt->cl_softrtry = 0;
 479
 480         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 481                 clnt->cl_autobind = 1;
 482         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 483                 clnt->cl_discrtry = 1;
 484         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 485                 clnt->cl_chatty = 1;
 486
 487         return clnt;
 488 }
 489 EXPORT_SYMBOL_GPL(rpc_create);
 490
 491 /*
 492  * This function clones the RPC client structure. It allows us to share the
 493  * same transport while varying parameters such as the authentication
 494  * flavour.
 495  */
 496 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 497                                            struct rpc_clnt *clnt)
 498 {
 499         struct rpc_xprt *xprt;
 500         struct rpc_clnt *new;
 501         int err;
 502
 503         err = -ENOMEM;
 504         rcu_read_lock();
 505         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 506         rcu_read_unlock();
 507         if (xprt == NULL)
 508                 goto out_err;
 509         args->servername = xprt->servername;
 510
 511         new = rpc_new_client(args, xprt);
 512         if (IS_ERR(new)) {
 513                 err = PTR_ERR(new);
 514                 goto out_put;
 515         }
 516
 517         atomic_inc(&clnt->cl_count);
 518         new->cl_parent = clnt;
 519
 520         /* Turn off autobind on clones */
 521         new->cl_autobind = 0;
 522         new->cl_softrtry = clnt->cl_softrtry;
 523         new->cl_discrtry = clnt->cl_discrtry;
 524         new->cl_chatty = clnt->cl_chatty;
 525         return new;
 526
 527 out_put:
 528         xprt_put(xprt);
 529 out_err:
 530         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 531         return ERR_PTR(err);
 532 }
 533
 534 /**
 535  * rpc_clone_client - Clone an RPC client structure
 536  *
 537  * @clnt: RPC client whose parameters are copied
 538  *
 539  * Returns a fresh RPC client or an ERR_PTR.
 540  */
 541 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 542 {
 543         struct rpc_create_args args = {
 544                 .program        = clnt->cl_program,
 545                 .prognumber     = clnt->cl_prog,
 546                 .version        = clnt->cl_vers,
 547                 .authflavor     = clnt->cl_auth->au_flavor,
 548                 .client_name    = clnt->cl_principal,
 549         };
 550         return __rpc_clone_client(&args, clnt);
 551 }
 552 EXPORT_SYMBOL_GPL(rpc_clone_client);
 553
 554 /**
 555  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 556  *
 557  * @clnt: RPC client whose parameters are copied
 558  * @flavor: security flavor for new client
 559  *
 560  * Returns a fresh RPC client or an ERR_PTR.
 561  */
 562 struct rpc_clnt *
 563 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 564 {
 565         struct rpc_create_args args = {
 566                 .program        = clnt->cl_program,
 567                 .prognumber     = clnt->cl_prog,
 568                 .version        = clnt->cl_vers,
 569                 .authflavor     = flavor,
 570                 .client_name    = clnt->cl_principal,
 571         };
 572         return __rpc_clone_client(&args, clnt);
 573 }
 574 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 575
 576 /*
 577  * Kill all tasks for the given client.
 578  * XXX: kill their descendants as well?
 579  */
 580 void rpc_killall_tasks(struct rpc_clnt *clnt)
 581 {
 582         struct rpc_task *rovr;
 583
 584
 585         if (list_empty(&clnt->cl_tasks))
 586                 return;
 587         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 588         /*
 589          * Spin lock all_tasks to prevent changes...
 590          */
 591         spin_lock(&clnt->cl_lock);
 592         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 593                 if (!RPC_IS_ACTIVATED(rovr))
 594                         continue;
 595                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 596                         rovr->tk_flags |= RPC_TASK_KILLED;
 597                         rpc_exit(rovr, -EIO);
 598                         if (RPC_IS_QUEUED(rovr))
 599                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 600                                                         rovr);
 601                 }
 602         }
 603         spin_unlock(&clnt->cl_lock);
 604 }
 605 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 606
 607 /*
 608  * Properly shut down an RPC client, terminating all outstanding
 609  * requests.
 610  */
 611 void rpc_shutdown_client(struct rpc_clnt *clnt)
 612 {
 613         might_sleep();
 614
 615         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 616                         clnt->cl_protname,
 617                         rcu_dereference(clnt->cl_xprt)->servername);
 618
 619         while (!list_empty(&clnt->cl_tasks)) {
 620                 rpc_killall_tasks(clnt);
 621                 wait_event_timeout(destroy_wait,
 622                         list_empty(&clnt->cl_tasks), 1*HZ);
 623         }
 624
 625         rpc_release_client(clnt);
 626 }
 627 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 628
 629 /*
 630  * Free an RPC client
 631  */
 632 static void
 633 rpc_free_client(struct rpc_clnt *clnt)
 634 {
 635         dprintk_rcu("RPC:       destroying %s client for %s\n",
 636                         clnt->cl_protname,
 637                         rcu_dereference(clnt->cl_xprt)->servername);
 638         if (clnt->cl_parent != clnt)
 639                 rpc_release_client(clnt->cl_parent);
 640         rpc_unregister_client(clnt);
 641         rpc_clnt_remove_pipedir(clnt);
 642         rpc_free_iostats(clnt->cl_metrics);
 643         kfree(clnt->cl_principal);
 644         clnt->cl_metrics = NULL;
 645         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 646         rpciod_down();
 647         kfree(clnt);
 648 }
 649
 650 /*
 651  * Free an RPC client
 652  */
 653 static void
 654 rpc_free_auth(struct rpc_clnt *clnt)
 655 {
 656         if (clnt->cl_auth == NULL) {
 657                 rpc_free_client(clnt);
 658                 return;
 659         }
 660
 661         /*
 662          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 663          *       release remaining GSS contexts. This mechanism ensures
 664          *       that it can do so safely.
 665          */
 666         atomic_inc(&clnt->cl_count);
 667         rpcauth_release(clnt->cl_auth);
 668         clnt->cl_auth = NULL;
 669         if (atomic_dec_and_test(&clnt->cl_count))
 670                 rpc_free_client(clnt);
 671 }
 672
 673 /*
 674  * Release reference to the RPC client
 675  */
 676 void
 677 rpc_release_client(struct rpc_clnt *clnt)
 678 {
 679         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 680
 681         if (list_empty(&clnt->cl_tasks))
 682                 wake_up(&destroy_wait);
 683         if (atomic_dec_and_test(&clnt->cl_count))
 684                 rpc_free_auth(clnt);
 685 }
 686
 687 /**
 688  * rpc_bind_new_program - bind a new RPC program to an existing client
 689  * @old: old rpc_client
 690  * @program: rpc program to set
 691  * @vers: rpc program version
 692  *
 693  * Clones the rpc client and sets up a new RPC program. This is mainly
 694  * of use for enabling different RPC programs to share the same transport.
 695  * The Sun NFSv2/v3 ACL protocol can do this.
 696  */
 697 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 698                                       const struct rpc_program *program,
 699                                       u32 vers)
 700 {
 701         struct rpc_create_args args = {
 702                 .program        = program,
 703                 .prognumber     = program->number,
 704                 .version        = vers,
 705                 .authflavor     = old->cl_auth->au_flavor,
 706                 .client_name    = old->cl_principal,
 707         };
 708         struct rpc_clnt *clnt;
 709         int err;
 710
 711         clnt = __rpc_clone_client(&args, old);
 712         if (IS_ERR(clnt))
 713                 goto out;
 714         err = rpc_ping(clnt);
 715         if (err != 0) {
 716                 rpc_shutdown_client(clnt);
 717                 clnt = ERR_PTR(err);
 718         }
 719 out:
 720         return clnt;
 721 }
 722 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 723
 724 void rpc_task_release_client(struct rpc_task *task)
 725 {
 726         struct rpc_clnt *clnt = task->tk_client;
 727
 728         if (clnt != NULL) {
 729                 /* Remove from client task list */
 730                 spin_lock(&clnt->cl_lock);
 731                 list_del(&task->tk_task);
 732                 spin_unlock(&clnt->cl_lock);
 733                 task->tk_client = NULL;
 734
 735                 rpc_release_client(clnt);
 736         }
 737 }
 738
 739 static
 740 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 741 {
 742         if (clnt != NULL) {
 743                 rpc_task_release_client(task);
 744                 task->tk_client = clnt;
 745                 atomic_inc(&clnt->cl_count);
 746                 if (clnt->cl_softrtry)
 747                         task->tk_flags |= RPC_TASK_SOFT;
 748                 if (sk_memalloc_socks()) {
 749                         struct rpc_xprt *xprt;
 750
 751                         rcu_read_lock();
 752                         xprt = rcu_dereference(clnt->cl_xprt);
 753                         if (xprt->swapper)
 754                                 task->tk_flags |= RPC_TASK_SWAPPER;
 755                         rcu_read_unlock();
 756                 }
 757                 /* Add to the client's list of all tasks */
 758                 spin_lock(&clnt->cl_lock);
 759                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 760                 spin_unlock(&clnt->cl_lock);
 761         }
 762 }
 763
 764 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 765 {
 766         rpc_task_release_client(task);
 767         rpc_task_set_client(task, clnt);
 768 }
 769 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 770
 771
 772 static void
 773 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 774 {
 775         if (msg != NULL) {
 776                 task->tk_msg.rpc_proc = msg->rpc_proc;
 777                 task->tk_msg.rpc_argp = msg->rpc_argp;
 778                 task->tk_msg.rpc_resp = msg->rpc_resp;
 779                 if (msg->rpc_cred != NULL)
 780                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 781         }
 782 }
 783
 784 /*
 785  * Default callback for async RPC calls
 786  */
 787 static void
 788 rpc_default_callback(struct rpc_task *task, void *data)
 789 {
 790 }
 791
 792 static const struct rpc_call_ops rpc_default_ops = {
 793         .rpc_call_done = rpc_default_callback,
 794 };
 795
 796 /**
 797  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 798  * @task_setup_data: pointer to task initialisation data
 799  */
 800 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 801 {
 802         struct rpc_task *task;
 803
 804         task = rpc_new_task(task_setup_data);
 805         if (IS_ERR(task))
 806                 goto out;
 807
 808         rpc_task_set_client(task, task_setup_data->rpc_client);
 809         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 810
 811         if (task->tk_action == NULL)
 812                 rpc_call_start(task);
 813
 814         atomic_inc(&task->tk_count);
 815         rpc_execute(task);
 816 out:
 817         return task;
 818 }
 819 EXPORT_SYMBOL_GPL(rpc_run_task);
 820
 821 /**
 822  * rpc_call_sync - Perform a synchronous RPC call
 823  * @clnt: pointer to RPC client
 824  * @msg: RPC call parameters
 825  * @flags: RPC call flags
 826  */
 827 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 828 {
 829         struct rpc_task *task;
 830         struct rpc_task_setup task_setup_data = {
 831                 .rpc_client = clnt,
 832                 .rpc_message = msg,
 833                 .callback_ops = &rpc_default_ops,
 834                 .flags = flags,
 835         };
 836         int status;
 837
 838         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 839         if (flags & RPC_TASK_ASYNC) {
 840                 rpc_release_calldata(task_setup_data.callback_ops,
 841                         task_setup_data.callback_data);
 842                 return -EINVAL;
 843         }
 844
 845         task = rpc_run_task(&task_setup_data);
 846         if (IS_ERR(task))
 847                 return PTR_ERR(task);
 848         status = task->tk_status;
 849         rpc_put_task(task);
 850         return status;
 851 }
 852 EXPORT_SYMBOL_GPL(rpc_call_sync);
 853
 854 /**
 855  * rpc_call_async - Perform an asynchronous RPC call
 856  * @clnt: pointer to RPC client
 857  * @msg: RPC call parameters
 858  * @flags: RPC call flags
 859  * @tk_ops: RPC call ops
 860  * @data: user call data
 861  */
 862 int
 863 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 864                const struct rpc_call_ops *tk_ops, void *data)
 865 {
 866         struct rpc_task *task;
 867         struct rpc_task_setup task_setup_data = {
 868                 .rpc_client = clnt,
 869                 .rpc_message = msg,
 870                 .callback_ops = tk_ops,
 871                 .callback_data = data,
 872                 .flags = flags|RPC_TASK_ASYNC,
 873         };
 874
 875         task = rpc_run_task(&task_setup_data);
 876         if (IS_ERR(task))
 877                 return PTR_ERR(task);
 878         rpc_put_task(task);
 879         return 0;
 880 }
 881 EXPORT_SYMBOL_GPL(rpc_call_async);
 882
 883 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 884 /**
 885  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 886  * rpc_execute against it
 887  * @req: RPC request
 888  * @tk_ops: RPC call ops
 889  */
 890 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 891                                 const struct rpc_call_ops *tk_ops)
 892 {
 893         struct rpc_task *task;
 894         struct xdr_buf *xbufp = &req->rq_snd_buf;
 895         struct rpc_task_setup task_setup_data = {
 896                 .callback_ops = tk_ops,
 897         };
 898
 899         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 900         /*
 901          * Create an rpc_task to send the data
 902          */
 903         task = rpc_new_task(&task_setup_data);
 904         if (IS_ERR(task)) {
 905                 xprt_free_bc_request(req);
 906                 goto out;
 907         }
 908         task->tk_rqstp = req;
 909
 910         /*
 911          * Set up the xdr_buf length.
 912          * This also indicates that the buffer is XDR encoded already.
 913          */
 914         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 915                         xbufp->tail[0].iov_len;
 916
 917         task->tk_action = call_bc_transmit;
 918         atomic_inc(&task->tk_count);
 919         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 920         rpc_execute(task);
 921
 922 out:
 923         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 924         return task;
 925 }
 926 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 927
 928 void
 929 rpc_call_start(struct rpc_task *task)
 930 {
 931         task->tk_action = call_start;
 932 }
 933 EXPORT_SYMBOL_GPL(rpc_call_start);
 934
 935 /**
 936  * rpc_peeraddr - extract remote peer address from clnt's xprt
 937  * @clnt: RPC client structure
 938  * @buf: target buffer
 939  * @bufsize: length of target buffer
 940  *
 941  * Returns the number of bytes that are actually in the stored address.
 942  */
 943 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 944 {
 945         size_t bytes;
 946         struct rpc_xprt *xprt;
 947
 948         rcu_read_lock();
 949         xprt = rcu_dereference(clnt->cl_xprt);
 950
 951         bytes = xprt->addrlen;
 952         if (bytes > bufsize)
 953                 bytes = bufsize;
 954         memcpy(buf, &xprt->addr, bytes);
 955         rcu_read_unlock();
 956
 957         return bytes;
 958 }
 959 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 960
 961 /**
 962  * rpc_peeraddr2str - return remote peer address in printable format
 963  * @clnt: RPC client structure
 964  * @format: address format
 965  *
 966  * NB: the lifetime of the memory referenced by the returned pointer is
 967  * the same as the rpc_xprt itself.  As long as the caller uses this
 968  * pointer, it must hold the RCU read lock.
 969  */
 970 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 971                              enum rpc_display_format_t format)
 972 {
 973         struct rpc_xprt *xprt;
 974
 975         xprt = rcu_dereference(clnt->cl_xprt);
 976
 977         if (xprt->address_strings[format] != NULL)
 978                 return xprt->address_strings[format];
 979         else
 980                 return "unprintable";
 981 }
 982 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 983
 984 static const struct sockaddr_in rpc_inaddr_loopback = {
 985         .sin_family             = AF_INET,
 986         .sin_addr.s_addr        = htonl(INADDR_ANY),
 987 };
 988
 989 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 990         .sin6_family            = AF_INET6,
 991         .sin6_addr              = IN6ADDR_ANY_INIT,
 992 };
 993
 994 /*
 995  * Try a getsockname() on a connected datagram socket.  Using a
 996  * connected datagram socket prevents leaving a socket in TIME_WAIT.
 997  * This conserves the ephemeral port number space.
 998  *
 999  * Returns zero and fills in "buf" if successful; otherwise, a
1000  * negative errno is returned.
1001  */
1002 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1003                         struct sockaddr *buf, int buflen)
1004 {
1005         struct socket *sock;
1006         int err;
1007
1008         err = __sock_create(net, sap->sa_family,
1009                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1010         if (err < 0) {
1011                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1012                 goto out;
1013         }
1014
1015         switch (sap->sa_family) {
1016         case AF_INET:
1017                 err = kernel_bind(sock,
1018                                 (struct sockaddr *)&rpc_inaddr_loopback,
1019                                 sizeof(rpc_inaddr_loopback));
1020                 break;
1021         case AF_INET6:
1022                 err = kernel_bind(sock,
1023                                 (struct sockaddr *)&rpc_in6addr_loopback,
1024                                 sizeof(rpc_in6addr_loopback));
1025                 break;
1026         default:
1027                 err = -EAFNOSUPPORT;
1028                 goto out;
1029         }
1030         if (err < 0) {
1031                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1032                 goto out_release;
1033         }
1034
1035         err = kernel_connect(sock, sap, salen, 0);
1036         if (err < 0) {
1037                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1038                 goto out_release;
1039         }
1040
1041         err = kernel_getsockname(sock, buf, &buflen);
1042         if (err < 0) {
1043                 dprintk("RPC:       getsockname failed (%d)\n", err);
1044                 goto out_release;
1045         }
1046
1047         err = 0;
1048         if (buf->sa_family == AF_INET6) {
1049                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1050                 sin6->sin6_scope_id = 0;
1051         }
1052         dprintk("RPC:       %s succeeded\n", __func__);
1053
1054 out_release:
1055         sock_release(sock);
1056 out:
1057         return err;
1058 }
1059
1060 /*
1061  * Scraping a connected socket failed, so we don't have a useable
1062  * local address.  Fallback: generate an address that will prevent
1063  * the server from calling us back.
1064  *
1065  * Returns zero and fills in "buf" if successful; otherwise, a
1066  * negative errno is returned.
1067  */
1068 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1069 {
1070         switch (family) {
1071         case AF_INET:
1072                 if (buflen < sizeof(rpc_inaddr_loopback))
1073                         return -EINVAL;
1074                 memcpy(buf, &rpc_inaddr_loopback,
1075                                 sizeof(rpc_inaddr_loopback));
1076                 break;
1077         case AF_INET6:
1078                 if (buflen < sizeof(rpc_in6addr_loopback))
1079                         return -EINVAL;
1080                 memcpy(buf, &rpc_in6addr_loopback,
1081                                 sizeof(rpc_in6addr_loopback));
1082         default:
1083                 dprintk("RPC:       %s: address family not supported\n",
1084                         __func__);
1085                 return -EAFNOSUPPORT;
1086         }
1087         dprintk("RPC:       %s: succeeded\n", __func__);
1088         return 0;
1089 }
1090
1091 /**
1092  * rpc_localaddr - discover local endpoint address for an RPC client
1093  * @clnt: RPC client structure
1094  * @buf: target buffer
1095  * @buflen: size of target buffer, in bytes
1096  *
1097  * Returns zero and fills in "buf" and "buflen" if successful;
1098  * otherwise, a negative errno is returned.
1099  *
1100  * This works even if the underlying transport is not currently connected,
1101  * or if the upper layer never previously provided a source address.
1102  *
1103  * The result of this function call is transient: multiple calls in
1104  * succession may give different results, depending on how local
1105  * networking configuration changes over time.
1106  */
1107 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1108 {
1109         struct sockaddr_storage address;
1110         struct sockaddr *sap = (struct sockaddr *)&address;
1111         struct rpc_xprt *xprt;
1112         struct net *net;
1113         size_t salen;
1114         int err;
1115
1116         rcu_read_lock();
1117         xprt = rcu_dereference(clnt->cl_xprt);
1118         salen = xprt->addrlen;
1119         memcpy(sap, &xprt->addr, salen);
1120         net = get_net(xprt->xprt_net);
1121         rcu_read_unlock();
1122
1123         rpc_set_port(sap, 0);
1124         err = rpc_sockname(net, sap, salen, buf, buflen);
1125         put_net(net);
1126         if (err != 0)
1127                 /* Couldn't discover local address, return ANYADDR */
1128                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1129         return 0;
1130 }
1131 EXPORT_SYMBOL_GPL(rpc_localaddr);
1132
1133 void
1134 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1135 {
1136         struct rpc_xprt *xprt;
1137
1138         rcu_read_lock();
1139         xprt = rcu_dereference(clnt->cl_xprt);
1140         if (xprt->ops->set_buffer_size)
1141                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1142         rcu_read_unlock();
1143 }
1144 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1145
1146 /**
1147  * rpc_protocol - Get transport protocol number for an RPC client
1148  * @clnt: RPC client to query
1149  *
1150  */
1151 int rpc_protocol(struct rpc_clnt *clnt)
1152 {
1153         int protocol;
1154
1155         rcu_read_lock();
1156         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1157         rcu_read_unlock();
1158         return protocol;
1159 }
1160 EXPORT_SYMBOL_GPL(rpc_protocol);
1161
1162 /**
1163  * rpc_net_ns - Get the network namespace for this RPC client
1164  * @clnt: RPC client to query
1165  *
1166  */
1167 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1168 {
1169         struct net *ret;
1170
1171         rcu_read_lock();
1172         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1173         rcu_read_unlock();
1174         return ret;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_net_ns);
1177
1178 /**
1179  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1180  * @clnt: RPC client to query
1181  *
1182  * For stream transports, this is one RPC record fragment (see RFC
1183  * 1831), as we don't support multi-record requests yet.  For datagram
1184  * transports, this is the size of an IP packet minus the IP, UDP, and
1185  * RPC header sizes.
1186  */
1187 size_t rpc_max_payload(struct rpc_clnt *clnt)
1188 {
1189         size_t ret;
1190
1191         rcu_read_lock();
1192         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1193         rcu_read_unlock();
1194         return ret;
1195 }
1196 EXPORT_SYMBOL_GPL(rpc_max_payload);
1197
1198 /**
1199  * rpc_force_rebind - force transport to check that remote port is unchanged
1200  * @clnt: client to rebind
1201  *
1202  */
1203 void rpc_force_rebind(struct rpc_clnt *clnt)
1204 {
1205         if (clnt->cl_autobind) {
1206                 rcu_read_lock();
1207                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1208                 rcu_read_unlock();
1209         }
1210 }
1211 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1212
1213 /*
1214  * Restart an (async) RPC call from the call_prepare state.
1215  * Usually called from within the exit handler.
1216  */
1217 int
1218 rpc_restart_call_prepare(struct rpc_task *task)
1219 {
1220         if (RPC_ASSASSINATED(task))
1221                 return 0;
1222         task->tk_action = call_start;
1223         if (task->tk_ops->rpc_call_prepare != NULL)
1224                 task->tk_action = rpc_prepare_task;
1225         return 1;
1226 }
1227 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1228
1229 /*
1230  * Restart an (async) RPC call. Usually called from within the
1231  * exit handler.
1232  */
1233 int
1234 rpc_restart_call(struct rpc_task *task)
1235 {
1236         if (RPC_ASSASSINATED(task))
1237                 return 0;
1238         task->tk_action = call_start;
1239         return 1;
1240 }
1241 EXPORT_SYMBOL_GPL(rpc_restart_call);
1242
1243 #ifdef RPC_DEBUG
1244 static const char *rpc_proc_name(const struct rpc_task *task)
1245 {
1246         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1247
1248         if (proc) {
1249                 if (proc->p_name)
1250                         return proc->p_name;
1251                 else
1252                         return "NULL";
1253         } else
1254                 return "no proc";
1255 }
1256 #endif
1257
1258 /*
1259  * 0.  Initial state
1260  *
1261  *     Other FSM states can be visited zero or more times, but
1262  *     this state is visited exactly once for each RPC.
1263  */
1264 static void
1265 call_start(struct rpc_task *task)
1266 {
1267         struct rpc_clnt *clnt = task->tk_client;
1268
1269         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1270                         clnt->cl_protname, clnt->cl_vers,
1271                         rpc_proc_name(task),
1272                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1273
1274         /* Increment call count */
1275         task->tk_msg.rpc_proc->p_count++;
1276         clnt->cl_stats->rpccnt++;
1277         task->tk_action = call_reserve;
1278 }
1279
1280 /*
1281  * 1.   Reserve an RPC call slot
1282  */
1283 static void
1284 call_reserve(struct rpc_task *task)
1285 {
1286         dprint_status(task);
1287
1288         task->tk_status  = 0;
1289         task->tk_action  = call_reserveresult;
1290         xprt_reserve(task);
1291 }
1292
1293 /*
1294  * 1b.  Grok the result of xprt_reserve()
1295  */
1296 static void
1297 call_reserveresult(struct rpc_task *task)
1298 {
1299         int status = task->tk_status;
1300
1301         dprint_status(task);
1302
1303         /*
1304          * After a call to xprt_reserve(), we must have either
1305          * a request slot or else an error status.
1306          */
1307         task->tk_status = 0;
1308         if (status >= 0) {
1309                 if (task->tk_rqstp) {
1310                         task->tk_action = call_refresh;
1311                         return;
1312                 }
1313
1314                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1315                                 __func__, status);
1316                 rpc_exit(task, -EIO);
1317                 return;
1318         }
1319
1320         /*
1321          * Even though there was an error, we may have acquired
1322          * a request slot somehow.  Make sure not to leak it.
1323          */
1324         if (task->tk_rqstp) {
1325                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1326                                 __func__, status);
1327                 xprt_release(task);
1328         }
1329
1330         switch (status) {
1331         case -ENOMEM:
1332                 rpc_delay(task, HZ >> 2);
1333         case -EAGAIN:   /* woken up; retry */
1334                 task->tk_action = call_reserve;
1335                 return;
1336         case -EIO:      /* probably a shutdown */
1337                 break;
1338         default:
1339                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1340                                 __func__, status);
1341                 break;
1342         }
1343         rpc_exit(task, status);
1344 }
1345
1346 /*
1347  * 2.   Bind and/or refresh the credentials
1348  */
1349 static void
1350 call_refresh(struct rpc_task *task)
1351 {
1352         dprint_status(task);
1353
1354         task->tk_action = call_refreshresult;
1355         task->tk_status = 0;
1356         task->tk_client->cl_stats->rpcauthrefresh++;
1357         rpcauth_refreshcred(task);
1358 }
1359
1360 /*
1361  * 2a.  Process the results of a credential refresh
1362  */
1363 static void
1364 call_refreshresult(struct rpc_task *task)
1365 {
1366         int status = task->tk_status;
1367
1368         dprint_status(task);
1369
1370         task->tk_status = 0;
1371         task->tk_action = call_refresh;
1372         switch (status) {
1373         case 0:
1374                 if (rpcauth_uptodatecred(task))
1375                         task->tk_action = call_allocate;
1376                 return;
1377         case -ETIMEDOUT:
1378                 rpc_delay(task, 3*HZ);
1379         case -EKEYEXPIRED:
1380         case -EAGAIN:
1381                 status = -EACCES;
1382                 if (!task->tk_cred_retry)
1383                         break;
1384                 task->tk_cred_retry--;
1385                 dprintk("RPC: %5u %s: retry refresh creds\n",
1386                                 task->tk_pid, __func__);
1387                 return;
1388         }
1389         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1390                                 task->tk_pid, __func__, status);
1391         rpc_exit(task, status);
1392 }
1393
1394 /*
1395  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1396  *      (Note: buffer memory is freed in xprt_release).
1397  */
1398 static void
1399 call_allocate(struct rpc_task *task)
1400 {
1401         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1402         struct rpc_rqst *req = task->tk_rqstp;
1403         struct rpc_xprt *xprt = task->tk_xprt;
1404         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1405
1406         dprint_status(task);
1407
1408         task->tk_status = 0;
1409         task->tk_action = call_bind;
1410
1411         if (req->rq_buffer)
1412                 return;
1413
1414         if (proc->p_proc != 0) {
1415                 BUG_ON(proc->p_arglen == 0);
1416                 if (proc->p_decode != NULL)
1417                         BUG_ON(proc->p_replen == 0);
1418         }
1419
1420         /*
1421          * Calculate the size (in quads) of the RPC call
1422          * and reply headers, and convert both values
1423          * to byte sizes.
1424          */
1425         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1426         req->rq_callsize <<= 2;
1427         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1428         req->rq_rcvsize <<= 2;
1429
1430         req->rq_buffer = xprt->ops->buf_alloc(task,
1431                                         req->rq_callsize + req->rq_rcvsize);
1432         if (req->rq_buffer != NULL)
1433                 return;
1434
1435         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1436
1437         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1438                 task->tk_action = call_allocate;
1439                 rpc_delay(task, HZ>>4);
1440                 return;
1441         }
1442
1443         rpc_exit(task, -ERESTARTSYS);
1444 }
1445
1446 static inline int
1447 rpc_task_need_encode(struct rpc_task *task)
1448 {
1449         return task->tk_rqstp->rq_snd_buf.len == 0;
1450 }
1451
1452 static inline void
1453 rpc_task_force_reencode(struct rpc_task *task)
1454 {
1455         task->tk_rqstp->rq_snd_buf.len = 0;
1456         task->tk_rqstp->rq_bytes_sent = 0;
1457 }
1458
1459 static inline void
1460 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1461 {
1462         buf->head[0].iov_base = start;
1463         buf->head[0].iov_len = len;
1464         buf->tail[0].iov_len = 0;
1465         buf->page_len = 0;
1466         buf->flags = 0;
1467         buf->len = 0;
1468         buf->buflen = len;
1469 }
1470
1471 /*
1472  * 3.   Encode arguments of an RPC call
1473  */
1474 static void
1475 rpc_xdr_encode(struct rpc_task *task)
1476 {
1477         struct rpc_rqst *req = task->tk_rqstp;
1478         kxdreproc_t     encode;
1479         __be32          *p;
1480
1481         dprint_status(task);
1482
1483         rpc_xdr_buf_init(&req->rq_snd_buf,
1484                          req->rq_buffer,
1485                          req->rq_callsize);
1486         rpc_xdr_buf_init(&req->rq_rcv_buf,
1487                          (char *)req->rq_buffer + req->rq_callsize,
1488                          req->rq_rcvsize);
1489
1490         p = rpc_encode_header(task);
1491         if (p == NULL) {
1492                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1493                 rpc_exit(task, -EIO);
1494                 return;
1495         }
1496
1497         encode = task->tk_msg.rpc_proc->p_encode;
1498         if (encode == NULL)
1499                 return;
1500
1501         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1502                         task->tk_msg.rpc_argp);
1503 }
1504
1505 /*
1506  * 4.   Get the server port number if not yet set
1507  */
1508 static void
1509 call_bind(struct rpc_task *task)
1510 {
1511         struct rpc_xprt *xprt = task->tk_xprt;
1512
1513         dprint_status(task);
1514
1515         task->tk_action = call_connect;
1516         if (!xprt_bound(xprt)) {
1517                 task->tk_action = call_bind_status;
1518                 task->tk_timeout = xprt->bind_timeout;
1519                 xprt->ops->rpcbind(task);
1520         }
1521 }
1522
1523 /*
1524  * 4a.  Sort out bind result
1525  */
1526 static void
1527 call_bind_status(struct rpc_task *task)
1528 {
1529         int status = -EIO;
1530
1531         if (task->tk_status >= 0) {
1532                 dprint_status(task);
1533                 task->tk_status = 0;
1534                 task->tk_action = call_connect;
1535                 return;
1536         }
1537
1538         trace_rpc_bind_status(task);
1539         switch (task->tk_status) {
1540         case -ENOMEM:
1541                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1542                 rpc_delay(task, HZ >> 2);
1543                 goto retry_timeout;
1544         case -EACCES:
1545                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1546                                 "unavailable\n", task->tk_pid);
1547                 /* fail immediately if this is an RPC ping */
1548                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1549                         status = -EOPNOTSUPP;
1550                         break;
1551                 }
1552                 if (task->tk_rebind_retry == 0)
1553                         break;
1554                 task->tk_rebind_retry--;
1555                 rpc_delay(task, 3*HZ);
1556                 goto retry_timeout;
1557         case -ETIMEDOUT:
1558                 dprintk("RPC: %5u rpcbind request timed out\n",
1559                                 task->tk_pid);
1560                 goto retry_timeout;
1561         case -EPFNOSUPPORT:
1562                 /* server doesn't support any rpcbind version we know of */
1563                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1564                                 task->tk_pid);
1565                 break;
1566         case -EPROTONOSUPPORT:
1567                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1568                                 task->tk_pid);
1569                 task->tk_status = 0;
1570                 task->tk_action = call_bind;
1571                 return;
1572         case -ECONNREFUSED:             /* connection problems */
1573         case -ECONNRESET:
1574         case -ENOTCONN:
1575         case -EHOSTDOWN:
1576         case -EHOSTUNREACH:
1577         case -ENETUNREACH:
1578         case -EPIPE:
1579                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1580                                 task->tk_pid, task->tk_status);
1581                 if (!RPC_IS_SOFTCONN(task)) {
1582                         rpc_delay(task, 5*HZ);
1583                         goto retry_timeout;
1584                 }
1585                 status = task->tk_status;
1586                 break;
1587         default:
1588                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1589                                 task->tk_pid, -task->tk_status);
1590         }
1591
1592         rpc_exit(task, status);
1593         return;
1594
1595 retry_timeout:
1596         task->tk_action = call_timeout;
1597 }
1598
1599 /*
1600  * 4b.  Connect to the RPC server
1601  */
1602 static void
1603 call_connect(struct rpc_task *task)
1604 {
1605         struct rpc_xprt *xprt = task->tk_xprt;
1606
1607         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1608                         task->tk_pid, xprt,
1609                         (xprt_connected(xprt) ? "is" : "is not"));
1610
1611         task->tk_action = call_transmit;
1612         if (!xprt_connected(xprt)) {
1613                 task->tk_action = call_connect_status;
1614                 if (task->tk_status < 0)
1615                         return;
1616                 xprt_connect(task);
1617         }
1618 }
1619
1620 /*
1621  * 4c.  Sort out connect result
1622  */
1623 static void
1624 call_connect_status(struct rpc_task *task)
1625 {
1626         struct rpc_clnt *clnt = task->tk_client;
1627         int status = task->tk_status;
1628
1629         dprint_status(task);
1630
1631         task->tk_status = 0;
1632         if (status >= 0 || status == -EAGAIN) {
1633                 clnt->cl_stats->netreconn++;
1634                 task->tk_action = call_transmit;
1635                 return;
1636         }
1637
1638         trace_rpc_connect_status(task, status);
1639         switch (status) {
1640                 /* if soft mounted, test if we've timed out */
1641         case -ETIMEDOUT:
1642                 task->tk_action = call_timeout;
1643                 break;
1644         default:
1645                 rpc_exit(task, -EIO);
1646         }
1647 }
1648
1649 /*
1650  * 5.   Transmit the RPC request, and wait for reply
1651  */
1652 static void
1653 call_transmit(struct rpc_task *task)
1654 {
1655         dprint_status(task);
1656
1657         task->tk_action = call_status;
1658         if (task->tk_status < 0)
1659                 return;
1660         task->tk_status = xprt_prepare_transmit(task);
1661         if (task->tk_status != 0)
1662                 return;
1663         task->tk_action = call_transmit_status;
1664         /* Encode here so that rpcsec_gss can use correct sequence number. */
1665         if (rpc_task_need_encode(task)) {
1666                 rpc_xdr_encode(task);
1667                 /* Did the encode result in an error condition? */
1668                 if (task->tk_status != 0) {
1669                         /* Was the error nonfatal? */
1670                         if (task->tk_status == -EAGAIN)
1671                                 rpc_delay(task, HZ >> 4);
1672                         else
1673                                 rpc_exit(task, task->tk_status);
1674                         return;
1675                 }
1676         }
1677         xprt_transmit(task);
1678         if (task->tk_status < 0)
1679                 return;
1680         /*
1681          * On success, ensure that we call xprt_end_transmit() before sleeping
1682          * in order to allow access to the socket to other RPC requests.
1683          */
1684         call_transmit_status(task);
1685         if (rpc_reply_expected(task))
1686                 return;
1687         task->tk_action = rpc_exit_task;
1688         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1689 }
1690
1691 /*
1692  * 5a.  Handle cleanup after a transmission
1693  */
1694 static void
1695 call_transmit_status(struct rpc_task *task)
1696 {
1697         task->tk_action = call_status;
1698
1699         /*
1700          * Common case: success.  Force the compiler to put this
1701          * test first.
1702          */
1703         if (task->tk_status == 0) {
1704                 xprt_end_transmit(task);
1705                 rpc_task_force_reencode(task);
1706                 return;
1707         }
1708
1709         switch (task->tk_status) {
1710         case -EAGAIN:
1711                 break;
1712         default:
1713                 dprint_status(task);
1714                 xprt_end_transmit(task);
1715                 rpc_task_force_reencode(task);
1716                 break;
1717                 /*
1718                  * Special cases: if we've been waiting on the
1719                  * socket's write_space() callback, or if the
1720                  * socket just returned a connection error,
1721                  * then hold onto the transport lock.
1722                  */
1723         case -ECONNREFUSED:
1724         case -EHOSTDOWN:
1725         case -EHOSTUNREACH:
1726         case -ENETUNREACH:
1727                 if (RPC_IS_SOFTCONN(task)) {
1728                         xprt_end_transmit(task);
1729                         rpc_exit(task, task->tk_status);
1730                         break;
1731                 }
1732         case -ECONNRESET:
1733         case -ENOTCONN:
1734         case -EPIPE:
1735                 rpc_task_force_reencode(task);
1736         }
1737 }
1738
1739 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1740 /*
1741  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1742  * addition, disconnect on connectivity errors.
1743  */
1744 static void
1745 call_bc_transmit(struct rpc_task *task)
1746 {
1747         struct rpc_rqst *req = task->tk_rqstp;
1748
1749         task->tk_status = xprt_prepare_transmit(task);
1750         if (task->tk_status == -EAGAIN) {
1751                 /*
1752                  * Could not reserve the transport. Try again after the
1753                  * transport is released.
1754                  */
1755                 task->tk_status = 0;
1756                 task->tk_action = call_bc_transmit;
1757                 return;
1758         }
1759
1760         task->tk_action = rpc_exit_task;
1761         if (task->tk_status < 0) {
1762                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1763                         "error: %d\n", task->tk_status);
1764                 return;
1765         }
1766
1767         xprt_transmit(task);
1768         xprt_end_transmit(task);
1769         dprint_status(task);
1770         switch (task->tk_status) {
1771         case 0:
1772                 /* Success */
1773                 break;
1774         case -EHOSTDOWN:
1775         case -EHOSTUNREACH:
1776         case -ENETUNREACH:
1777         case -ETIMEDOUT:
1778                 /*
1779                  * Problem reaching the server.  Disconnect and let the
1780                  * forechannel reestablish the connection.  The server will
1781                  * have to retransmit the backchannel request and we'll
1782                  * reprocess it.  Since these ops are idempotent, there's no
1783                  * need to cache our reply at this time.
1784                  */
1785                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1786                         "error: %d\n", task->tk_status);
1787                 xprt_conditional_disconnect(task->tk_xprt,
1788                         req->rq_connect_cookie);
1789                 break;
1790         default:
1791                 /*
1792                  * We were unable to reply and will have to drop the
1793                  * request.  The server should reconnect and retransmit.
1794                  */
1795                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1796                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1797                         "error: %d\n", task->tk_status);
1798                 break;
1799         }
1800         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1801 }
1802 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1803
1804 /*
1805  * 6.   Sort out the RPC call status
1806  */
1807 static void
1808 call_status(struct rpc_task *task)
1809 {
1810         struct rpc_clnt *clnt = task->tk_client;
1811         struct rpc_rqst *req = task->tk_rqstp;
1812         int             status;
1813
1814         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1815                 task->tk_status = req->rq_reply_bytes_recvd;
1816
1817         dprint_status(task);
1818
1819         status = task->tk_status;
1820         if (status >= 0) {
1821                 task->tk_action = call_decode;
1822                 return;
1823         }
1824
1825         trace_rpc_call_status(task);
1826         task->tk_status = 0;
1827         switch(status) {
1828         case -EHOSTDOWN:
1829         case -EHOSTUNREACH:
1830         case -ENETUNREACH:
1831                 /*
1832                  * Delay any retries for 3 seconds, then handle as if it
1833                  * were a timeout.
1834                  */
1835                 rpc_delay(task, 3*HZ);
1836         case -ETIMEDOUT:
1837                 task->tk_action = call_timeout;
1838                 if (task->tk_client->cl_discrtry)
1839                         xprt_conditional_disconnect(task->tk_xprt,
1840                                         req->rq_connect_cookie);
1841                 break;
1842         case -ECONNRESET:
1843         case -ECONNREFUSED:
1844                 rpc_force_rebind(clnt);
1845                 rpc_delay(task, 3*HZ);
1846         case -EPIPE:
1847         case -ENOTCONN:
1848                 task->tk_action = call_bind;
1849                 break;
1850         case -EAGAIN:
1851                 task->tk_action = call_transmit;
1852                 break;
1853         case -EIO:
1854                 /* shutdown or soft timeout */
1855                 rpc_exit(task, status);
1856                 break;
1857         default:
1858                 if (clnt->cl_chatty)
1859                         printk("%s: RPC call returned error %d\n",
1860                                clnt->cl_protname, -status);
1861                 rpc_exit(task, status);
1862         }
1863 }
1864
1865 /*
1866  * 6a.  Handle RPC timeout
1867  *      We do not release the request slot, so we keep using the
1868  *      same XID for all retransmits.
1869  */
1870 static void
1871 call_timeout(struct rpc_task *task)
1872 {
1873         struct rpc_clnt *clnt = task->tk_client;
1874
1875         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1876                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1877                 goto retry;
1878         }
1879
1880         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1881         task->tk_timeouts++;
1882
1883         if (RPC_IS_SOFTCONN(task)) {
1884                 rpc_exit(task, -ETIMEDOUT);
1885                 return;
1886         }
1887         if (RPC_IS_SOFT(task)) {
1888                 if (clnt->cl_chatty) {
1889                         rcu_read_lock();
1890                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1891                                 clnt->cl_protname,
1892                                 rcu_dereference(clnt->cl_xprt)->servername);
1893                         rcu_read_unlock();
1894                 }
1895                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1896                         rpc_exit(task, -ETIMEDOUT);
1897                 else
1898                         rpc_exit(task, -EIO);
1899                 return;
1900         }
1901
1902         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1903                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1904                 if (clnt->cl_chatty) {
1905                         rcu_read_lock();
1906                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1907                         clnt->cl_protname,
1908                         rcu_dereference(clnt->cl_xprt)->servername);
1909                         rcu_read_unlock();
1910                 }
1911         }
1912         rpc_force_rebind(clnt);
1913         /*
1914          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1915          * event? RFC2203 requires the server to drop all such requests.
1916          */
1917         rpcauth_invalcred(task);
1918
1919 retry:
1920         clnt->cl_stats->rpcretrans++;
1921         task->tk_action = call_bind;
1922         task->tk_status = 0;
1923 }
1924
1925 /*
1926  * 7.   Decode the RPC reply
1927  */
1928 static void
1929 call_decode(struct rpc_task *task)
1930 {
1931         struct rpc_clnt *clnt = task->tk_client;
1932         struct rpc_rqst *req = task->tk_rqstp;
1933         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1934         __be32          *p;
1935
1936         dprint_status(task);
1937
1938         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1939                 if (clnt->cl_chatty) {
1940                         rcu_read_lock();
1941                         printk(KERN_NOTICE "%s: server %s OK\n",
1942                                 clnt->cl_protname,
1943                                 rcu_dereference(clnt->cl_xprt)->servername);
1944                         rcu_read_unlock();
1945                 }
1946                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1947         }
1948
1949         /*
1950          * Ensure that we see all writes made by xprt_complete_rqst()
1951          * before it changed req->rq_reply_bytes_recvd.
1952          */
1953         smp_rmb();
1954         req->rq_rcv_buf.len = req->rq_private_buf.len;
1955
1956         /* Check that the softirq receive buffer is valid */
1957         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1958                                 sizeof(req->rq_rcv_buf)) != 0);
1959
1960         if (req->rq_rcv_buf.len < 12) {
1961                 if (!RPC_IS_SOFT(task)) {
1962                         task->tk_action = call_bind;
1963                         clnt->cl_stats->rpcretrans++;
1964                         goto out_retry;
1965                 }
1966                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1967                                 clnt->cl_protname, task->tk_status);
1968                 task->tk_action = call_timeout;
1969                 goto out_retry;
1970         }
1971
1972         p = rpc_verify_header(task);
1973         if (IS_ERR(p)) {
1974                 if (p == ERR_PTR(-EAGAIN))
1975                         goto out_retry;
1976                 return;
1977         }
1978
1979         task->tk_action = rpc_exit_task;
1980
1981         if (decode) {
1982                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1983                                                       task->tk_msg.rpc_resp);
1984         }
1985         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1986                         task->tk_status);
1987         return;
1988 out_retry:
1989         task->tk_status = 0;
1990         /* Note: rpc_verify_header() may have freed the RPC slot */
1991         if (task->tk_rqstp == req) {
1992                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1993                 if (task->tk_client->cl_discrtry)
1994                         xprt_conditional_disconnect(task->tk_xprt,
1995                                         req->rq_connect_cookie);
1996         }
1997 }
1998
1999 static __be32 *
2000 rpc_encode_header(struct rpc_task *task)
2001 {
2002         struct rpc_clnt *clnt = task->tk_client;
2003         struct rpc_rqst *req = task->tk_rqstp;
2004         __be32          *p = req->rq_svec[0].iov_base;
2005
2006         /* FIXME: check buffer size? */
2007
2008         p = xprt_skip_transport_header(task->tk_xprt, p);
2009         *p++ = req->rq_xid;             /* XID */
2010         *p++ = htonl(RPC_CALL);         /* CALL */
2011         *p++ = htonl(RPC_VERSION);      /* RPC version */
2012         *p++ = htonl(clnt->cl_prog);    /* program number */
2013         *p++ = htonl(clnt->cl_vers);    /* program version */
2014         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2015         p = rpcauth_marshcred(task, p);
2016         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2017         return p;
2018 }
2019
2020 static __be32 *
2021 rpc_verify_header(struct rpc_task *task)
2022 {
2023         struct rpc_clnt *clnt = task->tk_client;
2024         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2025         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2026         __be32  *p = iov->iov_base;
2027         u32 n;
2028         int error = -EACCES;
2029
2030         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2031                 /* RFC-1014 says that the representation of XDR data must be a
2032                  * multiple of four bytes
2033                  * - if it isn't pointer subtraction in the NFS client may give
2034                  *   undefined results
2035                  */
2036                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2037                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2038                        task->tk_rqstp->rq_rcv_buf.len);
2039                 goto out_eio;
2040         }
2041         if ((len -= 3) < 0)
2042                 goto out_overflow;
2043
2044         p += 1; /* skip XID */
2045         if ((n = ntohl(*p++)) != RPC_REPLY) {
2046                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2047                         task->tk_pid, __func__, n);
2048                 goto out_garbage;
2049         }
2050
2051         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2052                 if (--len < 0)
2053                         goto out_overflow;
2054                 switch ((n = ntohl(*p++))) {
2055                 case RPC_AUTH_ERROR:
2056                         break;
2057                 case RPC_MISMATCH:
2058                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2059                                 task->tk_pid, __func__);
2060                         error = -EPROTONOSUPPORT;
2061                         goto out_err;
2062                 default:
2063                         dprintk("RPC: %5u %s: RPC call rejected, "
2064                                 "unknown error: %x\n",
2065                                 task->tk_pid, __func__, n);
2066                         goto out_eio;
2067                 }
2068                 if (--len < 0)
2069                         goto out_overflow;
2070                 switch ((n = ntohl(*p++))) {
2071                 case RPC_AUTH_REJECTEDCRED:
2072                 case RPC_AUTH_REJECTEDVERF:
2073                 case RPCSEC_GSS_CREDPROBLEM:
2074                 case RPCSEC_GSS_CTXPROBLEM:
2075                         if (!task->tk_cred_retry)
2076                                 break;
2077                         task->tk_cred_retry--;
2078                         dprintk("RPC: %5u %s: retry stale creds\n",
2079                                         task->tk_pid, __func__);
2080                         rpcauth_invalcred(task);
2081                         /* Ensure we obtain a new XID! */
2082                         xprt_release(task);
2083                         task->tk_action = call_reserve;
2084                         goto out_retry;
2085                 case RPC_AUTH_BADCRED:
2086                 case RPC_AUTH_BADVERF:
2087                         /* possibly garbled cred/verf? */
2088                         if (!task->tk_garb_retry)
2089                                 break;
2090                         task->tk_garb_retry--;
2091                         dprintk("RPC: %5u %s: retry garbled creds\n",
2092                                         task->tk_pid, __func__);
2093                         task->tk_action = call_bind;
2094                         goto out_retry;
2095                 case RPC_AUTH_TOOWEAK:
2096                         rcu_read_lock();
2097                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2098                                "authentication.\n",
2099                                rcu_dereference(clnt->cl_xprt)->servername);
2100                         rcu_read_unlock();
2101                         break;
2102                 default:
2103                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2104                                         task->tk_pid, __func__, n);
2105                         error = -EIO;
2106                 }
2107                 dprintk("RPC: %5u %s: call rejected %d\n",
2108                                 task->tk_pid, __func__, n);
2109                 goto out_err;
2110         }
2111         if (!(p = rpcauth_checkverf(task, p))) {
2112                 dprintk("RPC: %5u %s: auth check failed\n",
2113                                 task->tk_pid, __func__);
2114                 goto out_garbage;               /* bad verifier, retry */
2115         }
2116         len = p - (__be32 *)iov->iov_base - 1;
2117         if (len < 0)
2118                 goto out_overflow;
2119         switch ((n = ntohl(*p++))) {
2120         case RPC_SUCCESS:
2121                 return p;
2122         case RPC_PROG_UNAVAIL:
2123                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2124                                 "by server %s\n", task->tk_pid, __func__,
2125                                 (unsigned int)clnt->cl_prog,
2126                                 rcu_dereference(clnt->cl_xprt)->servername);
2127                 error = -EPFNOSUPPORT;
2128                 goto out_err;
2129         case RPC_PROG_MISMATCH:
2130                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2131                                 "by server %s\n", task->tk_pid, __func__,
2132                                 (unsigned int)clnt->cl_prog,
2133                                 (unsigned int)clnt->cl_vers,
2134                                 rcu_dereference(clnt->cl_xprt)->servername);
2135                 error = -EPROTONOSUPPORT;
2136                 goto out_err;
2137         case RPC_PROC_UNAVAIL:
2138                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2139                                 "version %u on server %s\n",
2140                                 task->tk_pid, __func__,
2141                                 rpc_proc_name(task),
2142                                 clnt->cl_prog, clnt->cl_vers,
2143                                 rcu_dereference(clnt->cl_xprt)->servername);
2144                 error = -EOPNOTSUPP;
2145                 goto out_err;
2146         case RPC_GARBAGE_ARGS:
2147                 dprintk("RPC: %5u %s: server saw garbage\n",
2148                                 task->tk_pid, __func__);
2149                 break;                  /* retry */
2150         default:
2151                 dprintk("RPC: %5u %s: server accept status: %x\n",
2152                                 task->tk_pid, __func__, n);
2153                 /* Also retry */
2154         }
2155
2156 out_garbage:
2157         clnt->cl_stats->rpcgarbage++;
2158         if (task->tk_garb_retry) {
2159                 task->tk_garb_retry--;
2160                 dprintk("RPC: %5u %s: retrying\n",
2161                                 task->tk_pid, __func__);
2162                 task->tk_action = call_bind;
2163 out_retry:
2164                 return ERR_PTR(-EAGAIN);
2165         }
2166 out_eio:
2167         error = -EIO;
2168 out_err:
2169         rpc_exit(task, error);
2170         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2171                         __func__, error);
2172         return ERR_PTR(error);
2173 out_overflow:
2174         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2175                         __func__);
2176         goto out_garbage;
2177 }
2178
2179 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2180 {
2181 }
2182
2183 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2184 {
2185         return 0;
2186 }
2187
2188 static struct rpc_procinfo rpcproc_null = {
2189         .p_encode = rpcproc_encode_null,
2190         .p_decode = rpcproc_decode_null,
2191 };
2192
2193 static int rpc_ping(struct rpc_clnt *clnt)
2194 {
2195         struct rpc_message msg = {
2196                 .rpc_proc = &rpcproc_null,
2197         };
2198         int err;
2199         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2200         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2201         put_rpccred(msg.rpc_cred);
2202         return err;
2203 }
2204
2205 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2206 {
2207         struct rpc_message msg = {
2208                 .rpc_proc = &rpcproc_null,
2209                 .rpc_cred = cred,
2210         };
2211         struct rpc_task_setup task_setup_data = {
2212                 .rpc_client = clnt,
2213                 .rpc_message = &msg,
2214                 .callback_ops = &rpc_default_ops,
2215                 .flags = flags,
2216         };
2217         return rpc_run_task(&task_setup_data);
2218 }
2219 EXPORT_SYMBOL_GPL(rpc_call_null);
2220
2221 #ifdef RPC_DEBUG
2222 static void rpc_show_header(void)
2223 {
2224         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2225                 "-timeout ---ops--\n");
2226 }
2227
2228 static void rpc_show_task(const struct rpc_clnt *clnt,
2229                           const struct rpc_task *task)
2230 {
2231         const char *rpc_waitq = "none";
2232
2233         if (RPC_IS_QUEUED(task))
2234                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2235
2236         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2237                 task->tk_pid, task->tk_flags, task->tk_status,
2238                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2239                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2240                 task->tk_action, rpc_waitq);
2241 }
2242
2243 void rpc_show_tasks(struct net *net)
2244 {
2245         struct rpc_clnt *clnt;
2246         struct rpc_task *task;
2247         int header = 0;
2248         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2249
2250         spin_lock(&sn->rpc_client_lock);
2251         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2252                 spin_lock(&clnt->cl_lock);
2253                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2254                         if (!header) {
2255                                 rpc_show_header();
2256                                 header++;
2257                         }
2258                         rpc_show_task(clnt, task);
2259                 }
2260                 spin_unlock(&clnt->cl_lock);
2261         }
2262         spin_unlock(&sn->rpc_client_lock);
2263 }
2264 #endif