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/addr.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #include <trace/events/sunrpc.h>
  41
  42 #include "sunrpc.h"
  43 #include "netns.h"
  44
  45 #ifdef RPC_DEBUG
  46 # define RPCDBG_FACILITY        RPCDBG_CALL
  47 #endif
  48
  49 #define dprint_status(t)                                        \
  50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  51                         __func__, t->tk_status)
  52
  53 /*
  54  * All RPC clients are linked into this list
  55  */
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         struct net *net = rpc_net_ns(clnt);
  86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  87
  88         spin_lock(&sn->rpc_client_lock);
  89         list_add(&clnt->cl_clients, &sn->all_clients);
  90         spin_unlock(&sn->rpc_client_lock);
  91 }
  92
  93 static void rpc_unregister_client(struct rpc_clnt *clnt)
  94 {
  95         struct net *net = rpc_net_ns(clnt);
  96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  97
  98         spin_lock(&sn->rpc_client_lock);
  99         list_del(&clnt->cl_clients);
 100         spin_unlock(&sn->rpc_client_lock);
 101 }
 102
 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 104 {
 105         if (clnt->cl_dentry) {
 106                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
 107                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
 108                 rpc_remove_client_dir(clnt->cl_dentry);
 109         }
 110         clnt->cl_dentry = NULL;
 111 }
 112
 113 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 114 {
 115         struct net *net = rpc_net_ns(clnt);
 116         struct super_block *pipefs_sb;
 117
 118         pipefs_sb = rpc_get_sb_net(net);
 119         if (pipefs_sb) {
 120                 __rpc_clnt_remove_pipedir(clnt);
 121                 rpc_put_sb_net(net);
 122         }
 123 }
 124
 125 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 126                                     struct rpc_clnt *clnt)
 127 {
 128         static uint32_t clntid;
 129         const char *dir_name = clnt->cl_program->pipe_dir_name;
 130         char name[15];
 131         struct dentry *dir, *dentry;
 132
 133         dir = rpc_d_lookup_sb(sb, dir_name);
 134         if (dir == NULL) {
 135                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 136                 return dir;
 137         }
 138         for (;;) {
 139                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 140                 name[sizeof(name) - 1] = '\0';
 141                 dentry = rpc_create_client_dir(dir, name, clnt);
 142                 if (!IS_ERR(dentry))
 143                         break;
 144                 if (dentry == ERR_PTR(-EEXIST))
 145                         continue;
 146                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 147                                 " %s/%s, error %ld\n",
 148                                 dir_name, name, PTR_ERR(dentry));
 149                 break;
 150         }
 151         dput(dir);
 152         return dentry;
 153 }
 154
 155 static int
 156 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 157 {
 158         struct dentry *dentry;
 159
 160         if (clnt->cl_program->pipe_dir_name == NULL)
 161                 goto out;
 162         clnt->cl_dentry = NULL;
 163         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 164         if (IS_ERR(dentry))
 165                 return PTR_ERR(dentry);
 166         clnt->cl_dentry = dentry;
 167 out:
 168         return 0;
 169 }
 170
 171 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 172 {
 173         if (clnt->cl_program->pipe_dir_name == NULL)
 174                 return 1;
 175
 176         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 177             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 178                 return 1;
 179         if ((event == RPC_PIPEFS_MOUNT) && atomic_read(&clnt->cl_count) == 0)
 180                 return 1;
 181         return 0;
 182 }
 183
 184 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 185                                    struct super_block *sb)
 186 {
 187         struct dentry *dentry;
 188         int err = 0;
 189
 190         switch (event) {
 191         case RPC_PIPEFS_MOUNT:
 192                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 193                 if (!dentry)
 194                         return -ENOENT;
 195                 if (IS_ERR(dentry))
 196                         return PTR_ERR(dentry);
 197                 clnt->cl_dentry = dentry;
 198                 if (clnt->cl_auth->au_ops->pipes_create) {
 199                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 200                         if (err)
 201                                 __rpc_clnt_remove_pipedir(clnt);
 202                 }
 203                 break;
 204         case RPC_PIPEFS_UMOUNT:
 205                 __rpc_clnt_remove_pipedir(clnt);
 206                 break;
 207         default:
 208                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 209                 return -ENOTSUPP;
 210         }
 211         return err;
 212 }
 213
 214 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 215                                 struct super_block *sb)
 216 {
 217         int error = 0;
 218
 219         for (;; clnt = clnt->cl_parent) {
 220                 if (!rpc_clnt_skip_event(clnt, event))
 221                         error = __rpc_clnt_handle_event(clnt, event, sb);
 222                 if (error || clnt == clnt->cl_parent)
 223                         break;
 224         }
 225         return error;
 226 }
 227
 228 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 229 {
 230         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 231         struct rpc_clnt *clnt;
 232
 233         spin_lock(&sn->rpc_client_lock);
 234         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 235                 if (rpc_clnt_skip_event(clnt, event))
 236                         continue;
 237                 spin_unlock(&sn->rpc_client_lock);
 238                 return clnt;
 239         }
 240         spin_unlock(&sn->rpc_client_lock);
 241         return NULL;
 242 }
 243
 244 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 245                             void *ptr)
 246 {
 247         struct super_block *sb = ptr;
 248         struct rpc_clnt *clnt;
 249         int error = 0;
 250
 251         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 252                 error = __rpc_pipefs_event(clnt, event, sb);
 253                 if (error)
 254                         break;
 255         }
 256         return error;
 257 }
 258
 259 static struct notifier_block rpc_clients_block = {
 260         .notifier_call  = rpc_pipefs_event,
 261         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 262 };
 263
 264 int rpc_clients_notifier_register(void)
 265 {
 266         return rpc_pipefs_notifier_register(&rpc_clients_block);
 267 }
 268
 269 void rpc_clients_notifier_unregister(void)
 270 {
 271         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 272 }
 273
 274 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 275 {
 276         clnt->cl_nodelen = strlen(nodename);
 277         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 278                 clnt->cl_nodelen = UNX_MAXNODENAME;
 279         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 280 }
 281
 282 static int rpc_client_register(const struct rpc_create_args *args,
 283                                struct rpc_clnt *clnt)
 284 {
 285         struct rpc_auth_create_args auth_args = {
 286                 .pseudoflavor = args->authflavor,
 287                 .target_name = args->client_name,
 288         };
 289         struct rpc_auth *auth;
 290         struct net *net = rpc_net_ns(clnt);
 291         struct super_block *pipefs_sb;
 292         int err;
 293
 294         pipefs_sb = rpc_get_sb_net(net);
 295         if (pipefs_sb) {
 296                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 297                 if (err)
 298                         goto out;
 299         }
 300
 301         rpc_register_client(clnt);
 302         if (pipefs_sb)
 303                 rpc_put_sb_net(net);
 304
 305         auth = rpcauth_create(&auth_args, clnt);
 306         if (IS_ERR(auth)) {
 307                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 308                                 args->authflavor);
 309                 err = PTR_ERR(auth);
 310                 goto err_auth;
 311         }
 312         return 0;
 313 err_auth:
 314         pipefs_sb = rpc_get_sb_net(net);
 315         rpc_unregister_client(clnt);
 316         __rpc_clnt_remove_pipedir(clnt);
 317 out:
 318         if (pipefs_sb)
 319                 rpc_put_sb_net(net);
 320         return err;
 321 }
 322
 323 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 324 {
 325         const struct rpc_program *program = args->program;
 326         const struct rpc_version *version;
 327         struct rpc_clnt         *clnt = NULL;
 328         int err;
 329
 330         /* sanity check the name before trying to print it */
 331         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 332                         program->name, args->servername, xprt);
 333
 334         err = rpciod_up();
 335         if (err)
 336                 goto out_no_rpciod;
 337
 338         err = -EINVAL;
 339         if (args->version >= program->nrvers)
 340                 goto out_err;
 341         version = program->version[args->version];
 342         if (version == NULL)
 343                 goto out_err;
 344
 345         err = -ENOMEM;
 346         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 347         if (!clnt)
 348                 goto out_err;
 349         clnt->cl_parent = clnt;
 350
 351         rcu_assign_pointer(clnt->cl_xprt, xprt);
 352         clnt->cl_procinfo = version->procs;
 353         clnt->cl_maxproc  = version->nrprocs;
 354         clnt->cl_prog     = args->prognumber ? : program->number;
 355         clnt->cl_vers     = version->number;
 356         clnt->cl_stats    = program->stats;
 357         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 358         err = -ENOMEM;
 359         if (clnt->cl_metrics == NULL)
 360                 goto out_no_stats;
 361         clnt->cl_program  = program;
 362         INIT_LIST_HEAD(&clnt->cl_tasks);
 363         spin_lock_init(&clnt->cl_lock);
 364
 365         if (!xprt_bound(xprt))
 366                 clnt->cl_autobind = 1;
 367
 368         clnt->cl_timeout = xprt->timeout;
 369         if (args->timeout != NULL) {
 370                 memcpy(&clnt->cl_timeout_default, args->timeout,
 371                                 sizeof(clnt->cl_timeout_default));
 372                 clnt->cl_timeout = &clnt->cl_timeout_default;
 373         }
 374
 375         clnt->cl_rtt = &clnt->cl_rtt_default;
 376         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 377
 378         atomic_set(&clnt->cl_count, 1);
 379
 380         /* save the nodename */
 381         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 382
 383         err = rpc_client_register(args, clnt);
 384         if (err)
 385                 goto out_no_path;
 386         return clnt;
 387
 388 out_no_path:
 389         rpc_free_iostats(clnt->cl_metrics);
 390 out_no_stats:
 391         kfree(clnt);
 392 out_err:
 393         rpciod_down();
 394 out_no_rpciod:
 395         xprt_put(xprt);
 396         return ERR_PTR(err);
 397 }
 398
 399 /**
 400  * rpc_create - create an RPC client and transport with one call
 401  * @args: rpc_clnt create argument structure
 402  *
 403  * Creates and initializes an RPC transport and an RPC client.
 404  *
 405  * It can ping the server in order to determine if it is up, and to see if
 406  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 407  * this behavior so asynchronous tasks can also use rpc_create.
 408  */
 409 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 410 {
 411         struct rpc_xprt *xprt;
 412         struct rpc_clnt *clnt;
 413         struct xprt_create xprtargs = {
 414                 .net = args->net,
 415                 .ident = args->protocol,
 416                 .srcaddr = args->saddress,
 417                 .dstaddr = args->address,
 418                 .addrlen = args->addrsize,
 419                 .servername = args->servername,
 420                 .bc_xprt = args->bc_xprt,
 421         };
 422         char servername[48];
 423
 424         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 425                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 426         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 427                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 428         /*
 429          * If the caller chooses not to specify a hostname, whip
 430          * up a string representation of the passed-in address.
 431          */
 432         if (xprtargs.servername == NULL) {
 433                 struct sockaddr_un *sun =
 434                                 (struct sockaddr_un *)args->address;
 435                 struct sockaddr_in *sin =
 436                                 (struct sockaddr_in *)args->address;
 437                 struct sockaddr_in6 *sin6 =
 438                                 (struct sockaddr_in6 *)args->address;
 439
 440                 servername[0] = '\0';
 441                 switch (args->address->sa_family) {
 442                 case AF_LOCAL:
 443                         snprintf(servername, sizeof(servername), "%s",
 444                                  sun->sun_path);
 445                         break;
 446                 case AF_INET:
 447                         snprintf(servername, sizeof(servername), "%pI4",
 448                                  &sin->sin_addr.s_addr);
 449                         break;
 450                 case AF_INET6:
 451                         snprintf(servername, sizeof(servername), "%pI6",
 452                                  &sin6->sin6_addr);
 453                         break;
 454                 default:
 455                         /* caller wants default server name, but
 456                          * address family isn't recognized. */
 457                         return ERR_PTR(-EINVAL);
 458                 }
 459                 xprtargs.servername = servername;
 460         }
 461
 462         xprt = xprt_create_transport(&xprtargs);
 463         if (IS_ERR(xprt))
 464                 return (struct rpc_clnt *)xprt;
 465
 466         /*
 467          * By default, kernel RPC client connects from a reserved port.
 468          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 469          * but it is always enabled for rpciod, which handles the connect
 470          * operation.
 471          */
 472         xprt->resvport = 1;
 473         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 474                 xprt->resvport = 0;
 475
 476         clnt = rpc_new_client(args, xprt);
 477         if (IS_ERR(clnt))
 478                 return clnt;
 479
 480         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 481                 int err = rpc_ping(clnt);
 482                 if (err != 0) {
 483                         rpc_shutdown_client(clnt);
 484                         return ERR_PTR(err);
 485                 }
 486         }
 487
 488         clnt->cl_softrtry = 1;
 489         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 490                 clnt->cl_softrtry = 0;
 491
 492         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 493                 clnt->cl_autobind = 1;
 494         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 495                 clnt->cl_discrtry = 1;
 496         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 497                 clnt->cl_chatty = 1;
 498
 499         return clnt;
 500 }
 501 EXPORT_SYMBOL_GPL(rpc_create);
 502
 503 /*
 504  * This function clones the RPC client structure. It allows us to share the
 505  * same transport while varying parameters such as the authentication
 506  * flavour.
 507  */
 508 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 509                                            struct rpc_clnt *clnt)
 510 {
 511         struct rpc_xprt *xprt;
 512         struct rpc_clnt *new;
 513         int err;
 514
 515         err = -ENOMEM;
 516         rcu_read_lock();
 517         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 518         rcu_read_unlock();
 519         if (xprt == NULL)
 520                 goto out_err;
 521         args->servername = xprt->servername;
 522
 523         new = rpc_new_client(args, xprt);
 524         if (IS_ERR(new)) {
 525                 err = PTR_ERR(new);
 526                 goto out_err;
 527         }
 528
 529         atomic_inc(&clnt->cl_count);
 530         new->cl_parent = clnt;
 531
 532         /* Turn off autobind on clones */
 533         new->cl_autobind = 0;
 534         new->cl_softrtry = clnt->cl_softrtry;
 535         new->cl_discrtry = clnt->cl_discrtry;
 536         new->cl_chatty = clnt->cl_chatty;
 537         return new;
 538
 539 out_err:
 540         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 541         return ERR_PTR(err);
 542 }
 543
 544 /**
 545  * rpc_clone_client - Clone an RPC client structure
 546  *
 547  * @clnt: RPC client whose parameters are copied
 548  *
 549  * Returns a fresh RPC client or an ERR_PTR.
 550  */
 551 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 552 {
 553         struct rpc_create_args args = {
 554                 .program        = clnt->cl_program,
 555                 .prognumber     = clnt->cl_prog,
 556                 .version        = clnt->cl_vers,
 557                 .authflavor     = clnt->cl_auth->au_flavor,
 558         };
 559         return __rpc_clone_client(&args, clnt);
 560 }
 561 EXPORT_SYMBOL_GPL(rpc_clone_client);
 562
 563 /**
 564  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 565  *
 566  * @clnt: RPC client whose parameters are copied
 567  * @flavor: security flavor for new client
 568  *
 569  * Returns a fresh RPC client or an ERR_PTR.
 570  */
 571 struct rpc_clnt *
 572 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 573 {
 574         struct rpc_create_args args = {
 575                 .program        = clnt->cl_program,
 576                 .prognumber     = clnt->cl_prog,
 577                 .version        = clnt->cl_vers,
 578                 .authflavor     = flavor,
 579         };
 580         return __rpc_clone_client(&args, clnt);
 581 }
 582 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 583
 584 /*
 585  * Kill all tasks for the given client.
 586  * XXX: kill their descendants as well?
 587  */
 588 void rpc_killall_tasks(struct rpc_clnt *clnt)
 589 {
 590         struct rpc_task *rovr;
 591
 592
 593         if (list_empty(&clnt->cl_tasks))
 594                 return;
 595         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 596         /*
 597          * Spin lock all_tasks to prevent changes...
 598          */
 599         spin_lock(&clnt->cl_lock);
 600         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 601                 if (!RPC_IS_ACTIVATED(rovr))
 602                         continue;
 603                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 604                         rovr->tk_flags |= RPC_TASK_KILLED;
 605                         rpc_exit(rovr, -EIO);
 606                         if (RPC_IS_QUEUED(rovr))
 607                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 608                                                         rovr);
 609                 }
 610         }
 611         spin_unlock(&clnt->cl_lock);
 612 }
 613 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 614
 615 /*
 616  * Properly shut down an RPC client, terminating all outstanding
 617  * requests.
 618  */
 619 void rpc_shutdown_client(struct rpc_clnt *clnt)
 620 {
 621         might_sleep();
 622
 623         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 624                         clnt->cl_program->name,
 625                         rcu_dereference(clnt->cl_xprt)->servername);
 626
 627         while (!list_empty(&clnt->cl_tasks)) {
 628                 rpc_killall_tasks(clnt);
 629                 wait_event_timeout(destroy_wait,
 630                         list_empty(&clnt->cl_tasks), 1*HZ);
 631         }
 632
 633         rpc_release_client(clnt);
 634 }
 635 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 636
 637 /*
 638  * Free an RPC client
 639  */
 640 static void
 641 rpc_free_client(struct rpc_clnt *clnt)
 642 {
 643         dprintk_rcu("RPC:       destroying %s client for %s\n",
 644                         clnt->cl_program->name,
 645                         rcu_dereference(clnt->cl_xprt)->servername);
 646         if (clnt->cl_parent != clnt)
 647                 rpc_release_client(clnt->cl_parent);
 648         rpc_clnt_remove_pipedir(clnt);
 649         rpc_unregister_client(clnt);
 650         rpc_free_iostats(clnt->cl_metrics);
 651         clnt->cl_metrics = NULL;
 652         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 653         rpciod_down();
 654         kfree(clnt);
 655 }
 656
 657 /*
 658  * Free an RPC client
 659  */
 660 static void
 661 rpc_free_auth(struct rpc_clnt *clnt)
 662 {
 663         if (clnt->cl_auth == NULL) {
 664                 rpc_free_client(clnt);
 665                 return;
 666         }
 667
 668         /*
 669          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 670          *       release remaining GSS contexts. This mechanism ensures
 671          *       that it can do so safely.
 672          */
 673         atomic_inc(&clnt->cl_count);
 674         rpcauth_release(clnt->cl_auth);
 675         clnt->cl_auth = NULL;
 676         if (atomic_dec_and_test(&clnt->cl_count))
 677                 rpc_free_client(clnt);
 678 }
 679
 680 /*
 681  * Release reference to the RPC client
 682  */
 683 void
 684 rpc_release_client(struct rpc_clnt *clnt)
 685 {
 686         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 687
 688         if (list_empty(&clnt->cl_tasks))
 689                 wake_up(&destroy_wait);
 690         if (atomic_dec_and_test(&clnt->cl_count))
 691                 rpc_free_auth(clnt);
 692 }
 693 EXPORT_SYMBOL_GPL(rpc_release_client);
 694
 695 /**
 696  * rpc_bind_new_program - bind a new RPC program to an existing client
 697  * @old: old rpc_client
 698  * @program: rpc program to set
 699  * @vers: rpc program version
 700  *
 701  * Clones the rpc client and sets up a new RPC program. This is mainly
 702  * of use for enabling different RPC programs to share the same transport.
 703  * The Sun NFSv2/v3 ACL protocol can do this.
 704  */
 705 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 706                                       const struct rpc_program *program,
 707                                       u32 vers)
 708 {
 709         struct rpc_create_args args = {
 710                 .program        = program,
 711                 .prognumber     = program->number,
 712                 .version        = vers,
 713                 .authflavor     = old->cl_auth->au_flavor,
 714         };
 715         struct rpc_clnt *clnt;
 716         int err;
 717
 718         clnt = __rpc_clone_client(&args, old);
 719         if (IS_ERR(clnt))
 720                 goto out;
 721         err = rpc_ping(clnt);
 722         if (err != 0) {
 723                 rpc_shutdown_client(clnt);
 724                 clnt = ERR_PTR(err);
 725         }
 726 out:
 727         return clnt;
 728 }
 729 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 730
 731 void rpc_task_release_client(struct rpc_task *task)
 732 {
 733         struct rpc_clnt *clnt = task->tk_client;
 734
 735         if (clnt != NULL) {
 736                 /* Remove from client task list */
 737                 spin_lock(&clnt->cl_lock);
 738                 list_del(&task->tk_task);
 739                 spin_unlock(&clnt->cl_lock);
 740                 task->tk_client = NULL;
 741
 742                 rpc_release_client(clnt);
 743         }
 744 }
 745
 746 static
 747 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 748 {
 749         if (clnt != NULL) {
 750                 rpc_task_release_client(task);
 751                 task->tk_client = clnt;
 752                 atomic_inc(&clnt->cl_count);
 753                 if (clnt->cl_softrtry)
 754                         task->tk_flags |= RPC_TASK_SOFT;
 755                 if (sk_memalloc_socks()) {
 756                         struct rpc_xprt *xprt;
 757
 758                         rcu_read_lock();
 759                         xprt = rcu_dereference(clnt->cl_xprt);
 760                         if (xprt->swapper)
 761                                 task->tk_flags |= RPC_TASK_SWAPPER;
 762                         rcu_read_unlock();
 763                 }
 764                 /* Add to the client's list of all tasks */
 765                 spin_lock(&clnt->cl_lock);
 766                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 767                 spin_unlock(&clnt->cl_lock);
 768         }
 769 }
 770
 771 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 772 {
 773         rpc_task_release_client(task);
 774         rpc_task_set_client(task, clnt);
 775 }
 776 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 777
 778
 779 static void
 780 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 781 {
 782         if (msg != NULL) {
 783                 task->tk_msg.rpc_proc = msg->rpc_proc;
 784                 task->tk_msg.rpc_argp = msg->rpc_argp;
 785                 task->tk_msg.rpc_resp = msg->rpc_resp;
 786                 if (msg->rpc_cred != NULL)
 787                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 788         }
 789 }
 790
 791 /*
 792  * Default callback for async RPC calls
 793  */
 794 static void
 795 rpc_default_callback(struct rpc_task *task, void *data)
 796 {
 797 }
 798
 799 static const struct rpc_call_ops rpc_default_ops = {
 800         .rpc_call_done = rpc_default_callback,
 801 };
 802
 803 /**
 804  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 805  * @task_setup_data: pointer to task initialisation data
 806  */
 807 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 808 {
 809         struct rpc_task *task;
 810
 811         task = rpc_new_task(task_setup_data);
 812         if (IS_ERR(task))
 813                 goto out;
 814
 815         rpc_task_set_client(task, task_setup_data->rpc_client);
 816         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 817
 818         if (task->tk_action == NULL)
 819                 rpc_call_start(task);
 820
 821         atomic_inc(&task->tk_count);
 822         rpc_execute(task);
 823 out:
 824         return task;
 825 }
 826 EXPORT_SYMBOL_GPL(rpc_run_task);
 827
 828 /**
 829  * rpc_call_sync - Perform a synchronous RPC call
 830  * @clnt: pointer to RPC client
 831  * @msg: RPC call parameters
 832  * @flags: RPC call flags
 833  */
 834 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 835 {
 836         struct rpc_task *task;
 837         struct rpc_task_setup task_setup_data = {
 838                 .rpc_client = clnt,
 839                 .rpc_message = msg,
 840                 .callback_ops = &rpc_default_ops,
 841                 .flags = flags,
 842         };
 843         int status;
 844
 845         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 846         if (flags & RPC_TASK_ASYNC) {
 847                 rpc_release_calldata(task_setup_data.callback_ops,
 848                         task_setup_data.callback_data);
 849                 return -EINVAL;
 850         }
 851
 852         task = rpc_run_task(&task_setup_data);
 853         if (IS_ERR(task))
 854                 return PTR_ERR(task);
 855         status = task->tk_status;
 856         rpc_put_task(task);
 857         return status;
 858 }
 859 EXPORT_SYMBOL_GPL(rpc_call_sync);
 860
 861 /**
 862  * rpc_call_async - Perform an asynchronous RPC call
 863  * @clnt: pointer to RPC client
 864  * @msg: RPC call parameters
 865  * @flags: RPC call flags
 866  * @tk_ops: RPC call ops
 867  * @data: user call data
 868  */
 869 int
 870 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 871                const struct rpc_call_ops *tk_ops, void *data)
 872 {
 873         struct rpc_task *task;
 874         struct rpc_task_setup task_setup_data = {
 875                 .rpc_client = clnt,
 876                 .rpc_message = msg,
 877                 .callback_ops = tk_ops,
 878                 .callback_data = data,
 879                 .flags = flags|RPC_TASK_ASYNC,
 880         };
 881
 882         task = rpc_run_task(&task_setup_data);
 883         if (IS_ERR(task))
 884                 return PTR_ERR(task);
 885         rpc_put_task(task);
 886         return 0;
 887 }
 888 EXPORT_SYMBOL_GPL(rpc_call_async);
 889
 890 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 891 /**
 892  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 893  * rpc_execute against it
 894  * @req: RPC request
 895  * @tk_ops: RPC call ops
 896  */
 897 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 898                                 const struct rpc_call_ops *tk_ops)
 899 {
 900         struct rpc_task *task;
 901         struct xdr_buf *xbufp = &req->rq_snd_buf;
 902         struct rpc_task_setup task_setup_data = {
 903                 .callback_ops = tk_ops,
 904         };
 905
 906         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 907         /*
 908          * Create an rpc_task to send the data
 909          */
 910         task = rpc_new_task(&task_setup_data);
 911         if (IS_ERR(task)) {
 912                 xprt_free_bc_request(req);
 913                 goto out;
 914         }
 915         task->tk_rqstp = req;
 916
 917         /*
 918          * Set up the xdr_buf length.
 919          * This also indicates that the buffer is XDR encoded already.
 920          */
 921         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 922                         xbufp->tail[0].iov_len;
 923
 924         task->tk_action = call_bc_transmit;
 925         atomic_inc(&task->tk_count);
 926         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 927         rpc_execute(task);
 928
 929 out:
 930         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 931         return task;
 932 }
 933 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 934
 935 void
 936 rpc_call_start(struct rpc_task *task)
 937 {
 938         task->tk_action = call_start;
 939 }
 940 EXPORT_SYMBOL_GPL(rpc_call_start);
 941
 942 /**
 943  * rpc_peeraddr - extract remote peer address from clnt's xprt
 944  * @clnt: RPC client structure
 945  * @buf: target buffer
 946  * @bufsize: length of target buffer
 947  *
 948  * Returns the number of bytes that are actually in the stored address.
 949  */
 950 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 951 {
 952         size_t bytes;
 953         struct rpc_xprt *xprt;
 954
 955         rcu_read_lock();
 956         xprt = rcu_dereference(clnt->cl_xprt);
 957
 958         bytes = xprt->addrlen;
 959         if (bytes > bufsize)
 960                 bytes = bufsize;
 961         memcpy(buf, &xprt->addr, bytes);
 962         rcu_read_unlock();
 963
 964         return bytes;
 965 }
 966 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 967
 968 /**
 969  * rpc_peeraddr2str - return remote peer address in printable format
 970  * @clnt: RPC client structure
 971  * @format: address format
 972  *
 973  * NB: the lifetime of the memory referenced by the returned pointer is
 974  * the same as the rpc_xprt itself.  As long as the caller uses this
 975  * pointer, it must hold the RCU read lock.
 976  */
 977 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 978                              enum rpc_display_format_t format)
 979 {
 980         struct rpc_xprt *xprt;
 981
 982         xprt = rcu_dereference(clnt->cl_xprt);
 983
 984         if (xprt->address_strings[format] != NULL)
 985                 return xprt->address_strings[format];
 986         else
 987                 return "unprintable";
 988 }
 989 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 990
 991 static const struct sockaddr_in rpc_inaddr_loopback = {
 992         .sin_family             = AF_INET,
 993         .sin_addr.s_addr        = htonl(INADDR_ANY),
 994 };
 995
 996 static const struct sockaddr_in6 rpc_in6addr_loopback = {
 997         .sin6_family            = AF_INET6,
 998         .sin6_addr              = IN6ADDR_ANY_INIT,
 999 };
1000
1001 /*
1002  * Try a getsockname() on a connected datagram socket.  Using a
1003  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1004  * This conserves the ephemeral port number space.
1005  *
1006  * Returns zero and fills in "buf" if successful; otherwise, a
1007  * negative errno is returned.
1008  */
1009 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1010                         struct sockaddr *buf, int buflen)
1011 {
1012         struct socket *sock;
1013         int err;
1014
1015         err = __sock_create(net, sap->sa_family,
1016                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1017         if (err < 0) {
1018                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1019                 goto out;
1020         }
1021
1022         switch (sap->sa_family) {
1023         case AF_INET:
1024                 err = kernel_bind(sock,
1025                                 (struct sockaddr *)&rpc_inaddr_loopback,
1026                                 sizeof(rpc_inaddr_loopback));
1027                 break;
1028         case AF_INET6:
1029                 err = kernel_bind(sock,
1030                                 (struct sockaddr *)&rpc_in6addr_loopback,
1031                                 sizeof(rpc_in6addr_loopback));
1032                 break;
1033         default:
1034                 err = -EAFNOSUPPORT;
1035                 goto out;
1036         }
1037         if (err < 0) {
1038                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1039                 goto out_release;
1040         }
1041
1042         err = kernel_connect(sock, sap, salen, 0);
1043         if (err < 0) {
1044                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1045                 goto out_release;
1046         }
1047
1048         err = kernel_getsockname(sock, buf, &buflen);
1049         if (err < 0) {
1050                 dprintk("RPC:       getsockname failed (%d)\n", err);
1051                 goto out_release;
1052         }
1053
1054         err = 0;
1055         if (buf->sa_family == AF_INET6) {
1056                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1057                 sin6->sin6_scope_id = 0;
1058         }
1059         dprintk("RPC:       %s succeeded\n", __func__);
1060
1061 out_release:
1062         sock_release(sock);
1063 out:
1064         return err;
1065 }
1066
1067 /*
1068  * Scraping a connected socket failed, so we don't have a useable
1069  * local address.  Fallback: generate an address that will prevent
1070  * the server from calling us back.
1071  *
1072  * Returns zero and fills in "buf" if successful; otherwise, a
1073  * negative errno is returned.
1074  */
1075 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1076 {
1077         switch (family) {
1078         case AF_INET:
1079                 if (buflen < sizeof(rpc_inaddr_loopback))
1080                         return -EINVAL;
1081                 memcpy(buf, &rpc_inaddr_loopback,
1082                                 sizeof(rpc_inaddr_loopback));
1083                 break;
1084         case AF_INET6:
1085                 if (buflen < sizeof(rpc_in6addr_loopback))
1086                         return -EINVAL;
1087                 memcpy(buf, &rpc_in6addr_loopback,
1088                                 sizeof(rpc_in6addr_loopback));
1089         default:
1090                 dprintk("RPC:       %s: address family not supported\n",
1091                         __func__);
1092                 return -EAFNOSUPPORT;
1093         }
1094         dprintk("RPC:       %s: succeeded\n", __func__);
1095         return 0;
1096 }
1097
1098 /**
1099  * rpc_localaddr - discover local endpoint address for an RPC client
1100  * @clnt: RPC client structure
1101  * @buf: target buffer
1102  * @buflen: size of target buffer, in bytes
1103  *
1104  * Returns zero and fills in "buf" and "buflen" if successful;
1105  * otherwise, a negative errno is returned.
1106  *
1107  * This works even if the underlying transport is not currently connected,
1108  * or if the upper layer never previously provided a source address.
1109  *
1110  * The result of this function call is transient: multiple calls in
1111  * succession may give different results, depending on how local
1112  * networking configuration changes over time.
1113  */
1114 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1115 {
1116         struct sockaddr_storage address;
1117         struct sockaddr *sap = (struct sockaddr *)&address;
1118         struct rpc_xprt *xprt;
1119         struct net *net;
1120         size_t salen;
1121         int err;
1122
1123         rcu_read_lock();
1124         xprt = rcu_dereference(clnt->cl_xprt);
1125         salen = xprt->addrlen;
1126         memcpy(sap, &xprt->addr, salen);
1127         net = get_net(xprt->xprt_net);
1128         rcu_read_unlock();
1129
1130         rpc_set_port(sap, 0);
1131         err = rpc_sockname(net, sap, salen, buf, buflen);
1132         put_net(net);
1133         if (err != 0)
1134                 /* Couldn't discover local address, return ANYADDR */
1135                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1136         return 0;
1137 }
1138 EXPORT_SYMBOL_GPL(rpc_localaddr);
1139
1140 void
1141 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1142 {
1143         struct rpc_xprt *xprt;
1144
1145         rcu_read_lock();
1146         xprt = rcu_dereference(clnt->cl_xprt);
1147         if (xprt->ops->set_buffer_size)
1148                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1149         rcu_read_unlock();
1150 }
1151 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1152
1153 /**
1154  * rpc_protocol - Get transport protocol number for an RPC client
1155  * @clnt: RPC client to query
1156  *
1157  */
1158 int rpc_protocol(struct rpc_clnt *clnt)
1159 {
1160         int protocol;
1161
1162         rcu_read_lock();
1163         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1164         rcu_read_unlock();
1165         return protocol;
1166 }
1167 EXPORT_SYMBOL_GPL(rpc_protocol);
1168
1169 /**
1170  * rpc_net_ns - Get the network namespace for this RPC client
1171  * @clnt: RPC client to query
1172  *
1173  */
1174 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1175 {
1176         struct net *ret;
1177
1178         rcu_read_lock();
1179         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1180         rcu_read_unlock();
1181         return ret;
1182 }
1183 EXPORT_SYMBOL_GPL(rpc_net_ns);
1184
1185 /**
1186  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1187  * @clnt: RPC client to query
1188  *
1189  * For stream transports, this is one RPC record fragment (see RFC
1190  * 1831), as we don't support multi-record requests yet.  For datagram
1191  * transports, this is the size of an IP packet minus the IP, UDP, and
1192  * RPC header sizes.
1193  */
1194 size_t rpc_max_payload(struct rpc_clnt *clnt)
1195 {
1196         size_t ret;
1197
1198         rcu_read_lock();
1199         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1200         rcu_read_unlock();
1201         return ret;
1202 }
1203 EXPORT_SYMBOL_GPL(rpc_max_payload);
1204
1205 /**
1206  * rpc_get_timeout - Get timeout for transport in units of HZ
1207  * @clnt: RPC client to query
1208  */
1209 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1210 {
1211         unsigned long ret;
1212
1213         rcu_read_lock();
1214         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1215         rcu_read_unlock();
1216         return ret;
1217 }
1218 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1219
1220 /**
1221  * rpc_force_rebind - force transport to check that remote port is unchanged
1222  * @clnt: client to rebind
1223  *
1224  */
1225 void rpc_force_rebind(struct rpc_clnt *clnt)
1226 {
1227         if (clnt->cl_autobind) {
1228                 rcu_read_lock();
1229                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1230                 rcu_read_unlock();
1231         }
1232 }
1233 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1234
1235 /*
1236  * Restart an (async) RPC call from the call_prepare state.
1237  * Usually called from within the exit handler.
1238  */
1239 int
1240 rpc_restart_call_prepare(struct rpc_task *task)
1241 {
1242         if (RPC_ASSASSINATED(task))
1243                 return 0;
1244         task->tk_action = call_start;
1245         if (task->tk_ops->rpc_call_prepare != NULL)
1246                 task->tk_action = rpc_prepare_task;
1247         return 1;
1248 }
1249 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1250
1251 /*
1252  * Restart an (async) RPC call. Usually called from within the
1253  * exit handler.
1254  */
1255 int
1256 rpc_restart_call(struct rpc_task *task)
1257 {
1258         if (RPC_ASSASSINATED(task))
1259                 return 0;
1260         task->tk_action = call_start;
1261         return 1;
1262 }
1263 EXPORT_SYMBOL_GPL(rpc_restart_call);
1264
1265 #ifdef RPC_DEBUG
1266 static const char *rpc_proc_name(const struct rpc_task *task)
1267 {
1268         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1269
1270         if (proc) {
1271                 if (proc->p_name)
1272                         return proc->p_name;
1273                 else
1274                         return "NULL";
1275         } else
1276                 return "no proc";
1277 }
1278 #endif
1279
1280 /*
1281  * 0.  Initial state
1282  *
1283  *     Other FSM states can be visited zero or more times, but
1284  *     this state is visited exactly once for each RPC.
1285  */
1286 static void
1287 call_start(struct rpc_task *task)
1288 {
1289         struct rpc_clnt *clnt = task->tk_client;
1290
1291         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1292                         clnt->cl_program->name, clnt->cl_vers,
1293                         rpc_proc_name(task),
1294                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1295
1296         /* Increment call count */
1297         task->tk_msg.rpc_proc->p_count++;
1298         clnt->cl_stats->rpccnt++;
1299         task->tk_action = call_reserve;
1300 }
1301
1302 /*
1303  * 1.   Reserve an RPC call slot
1304  */
1305 static void
1306 call_reserve(struct rpc_task *task)
1307 {
1308         dprint_status(task);
1309
1310         task->tk_status  = 0;
1311         task->tk_action  = call_reserveresult;
1312         xprt_reserve(task);
1313 }
1314
1315 static void call_retry_reserve(struct rpc_task *task);
1316
1317 /*
1318  * 1b.  Grok the result of xprt_reserve()
1319  */
1320 static void
1321 call_reserveresult(struct rpc_task *task)
1322 {
1323         int status = task->tk_status;
1324
1325         dprint_status(task);
1326
1327         /*
1328          * After a call to xprt_reserve(), we must have either
1329          * a request slot or else an error status.
1330          */
1331         task->tk_status = 0;
1332         if (status >= 0) {
1333                 if (task->tk_rqstp) {
1334                         task->tk_action = call_refresh;
1335                         return;
1336                 }
1337
1338                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1339                                 __func__, status);
1340                 rpc_exit(task, -EIO);
1341                 return;
1342         }
1343
1344         /*
1345          * Even though there was an error, we may have acquired
1346          * a request slot somehow.  Make sure not to leak it.
1347          */
1348         if (task->tk_rqstp) {
1349                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1350                                 __func__, status);
1351                 xprt_release(task);
1352         }
1353
1354         switch (status) {
1355         case -ENOMEM:
1356                 rpc_delay(task, HZ >> 2);
1357         case -EAGAIN:   /* woken up; retry */
1358                 task->tk_action = call_retry_reserve;
1359                 return;
1360         case -EIO:      /* probably a shutdown */
1361                 break;
1362         default:
1363                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1364                                 __func__, status);
1365                 break;
1366         }
1367         rpc_exit(task, status);
1368 }
1369
1370 /*
1371  * 1c.  Retry reserving an RPC call slot
1372  */
1373 static void
1374 call_retry_reserve(struct rpc_task *task)
1375 {
1376         dprint_status(task);
1377
1378         task->tk_status  = 0;
1379         task->tk_action  = call_reserveresult;
1380         xprt_retry_reserve(task);
1381 }
1382
1383 /*
1384  * 2.   Bind and/or refresh the credentials
1385  */
1386 static void
1387 call_refresh(struct rpc_task *task)
1388 {
1389         dprint_status(task);
1390
1391         task->tk_action = call_refreshresult;
1392         task->tk_status = 0;
1393         task->tk_client->cl_stats->rpcauthrefresh++;
1394         rpcauth_refreshcred(task);
1395 }
1396
1397 /*
1398  * 2a.  Process the results of a credential refresh
1399  */
1400 static void
1401 call_refreshresult(struct rpc_task *task)
1402 {
1403         int status = task->tk_status;
1404
1405         dprint_status(task);
1406
1407         task->tk_status = 0;
1408         task->tk_action = call_refresh;
1409         switch (status) {
1410         case 0:
1411                 if (rpcauth_uptodatecred(task))
1412                         task->tk_action = call_allocate;
1413                 return;
1414         case -ETIMEDOUT:
1415                 rpc_delay(task, 3*HZ);
1416         case -EKEYEXPIRED:
1417         case -EAGAIN:
1418                 status = -EACCES;
1419                 if (!task->tk_cred_retry)
1420                         break;
1421                 task->tk_cred_retry--;
1422                 dprintk("RPC: %5u %s: retry refresh creds\n",
1423                                 task->tk_pid, __func__);
1424                 return;
1425         }
1426         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1427                                 task->tk_pid, __func__, status);
1428         rpc_exit(task, status);
1429 }
1430
1431 /*
1432  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1433  *      (Note: buffer memory is freed in xprt_release).
1434  */
1435 static void
1436 call_allocate(struct rpc_task *task)
1437 {
1438         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1439         struct rpc_rqst *req = task->tk_rqstp;
1440         struct rpc_xprt *xprt = req->rq_xprt;
1441         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1442
1443         dprint_status(task);
1444
1445         task->tk_status = 0;
1446         task->tk_action = call_bind;
1447
1448         if (req->rq_buffer)
1449                 return;
1450
1451         if (proc->p_proc != 0) {
1452                 BUG_ON(proc->p_arglen == 0);
1453                 if (proc->p_decode != NULL)
1454                         BUG_ON(proc->p_replen == 0);
1455         }
1456
1457         /*
1458          * Calculate the size (in quads) of the RPC call
1459          * and reply headers, and convert both values
1460          * to byte sizes.
1461          */
1462         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1463         req->rq_callsize <<= 2;
1464         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1465         req->rq_rcvsize <<= 2;
1466
1467         req->rq_buffer = xprt->ops->buf_alloc(task,
1468                                         req->rq_callsize + req->rq_rcvsize);
1469         if (req->rq_buffer != NULL)
1470                 return;
1471
1472         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1473
1474         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1475                 task->tk_action = call_allocate;
1476                 rpc_delay(task, HZ>>4);
1477                 return;
1478         }
1479
1480         rpc_exit(task, -ERESTARTSYS);
1481 }
1482
1483 static inline int
1484 rpc_task_need_encode(struct rpc_task *task)
1485 {
1486         return task->tk_rqstp->rq_snd_buf.len == 0;
1487 }
1488
1489 static inline void
1490 rpc_task_force_reencode(struct rpc_task *task)
1491 {
1492         task->tk_rqstp->rq_snd_buf.len = 0;
1493         task->tk_rqstp->rq_bytes_sent = 0;
1494 }
1495
1496 static inline void
1497 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1498 {
1499         buf->head[0].iov_base = start;
1500         buf->head[0].iov_len = len;
1501         buf->tail[0].iov_len = 0;
1502         buf->page_len = 0;
1503         buf->flags = 0;
1504         buf->len = 0;
1505         buf->buflen = len;
1506 }
1507
1508 /*
1509  * 3.   Encode arguments of an RPC call
1510  */
1511 static void
1512 rpc_xdr_encode(struct rpc_task *task)
1513 {
1514         struct rpc_rqst *req = task->tk_rqstp;
1515         kxdreproc_t     encode;
1516         __be32          *p;
1517
1518         dprint_status(task);
1519
1520         rpc_xdr_buf_init(&req->rq_snd_buf,
1521                          req->rq_buffer,
1522                          req->rq_callsize);
1523         rpc_xdr_buf_init(&req->rq_rcv_buf,
1524                          (char *)req->rq_buffer + req->rq_callsize,
1525                          req->rq_rcvsize);
1526
1527         p = rpc_encode_header(task);
1528         if (p == NULL) {
1529                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1530                 rpc_exit(task, -EIO);
1531                 return;
1532         }
1533
1534         encode = task->tk_msg.rpc_proc->p_encode;
1535         if (encode == NULL)
1536                 return;
1537
1538         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1539                         task->tk_msg.rpc_argp);
1540 }
1541
1542 /*
1543  * 4.   Get the server port number if not yet set
1544  */
1545 static void
1546 call_bind(struct rpc_task *task)
1547 {
1548         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1549
1550         dprint_status(task);
1551
1552         task->tk_action = call_connect;
1553         if (!xprt_bound(xprt)) {
1554                 task->tk_action = call_bind_status;
1555                 task->tk_timeout = xprt->bind_timeout;
1556                 xprt->ops->rpcbind(task);
1557         }
1558 }
1559
1560 /*
1561  * 4a.  Sort out bind result
1562  */
1563 static void
1564 call_bind_status(struct rpc_task *task)
1565 {
1566         int status = -EIO;
1567
1568         if (task->tk_status >= 0) {
1569                 dprint_status(task);
1570                 task->tk_status = 0;
1571                 task->tk_action = call_connect;
1572                 return;
1573         }
1574
1575         trace_rpc_bind_status(task);
1576         switch (task->tk_status) {
1577         case -ENOMEM:
1578                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1579                 rpc_delay(task, HZ >> 2);
1580                 goto retry_timeout;
1581         case -EACCES:
1582                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1583                                 "unavailable\n", task->tk_pid);
1584                 /* fail immediately if this is an RPC ping */
1585                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1586                         status = -EOPNOTSUPP;
1587                         break;
1588                 }
1589                 if (task->tk_rebind_retry == 0)
1590                         break;
1591                 task->tk_rebind_retry--;
1592                 rpc_delay(task, 3*HZ);
1593                 goto retry_timeout;
1594         case -ETIMEDOUT:
1595                 dprintk("RPC: %5u rpcbind request timed out\n",
1596                                 task->tk_pid);
1597                 goto retry_timeout;
1598         case -EPFNOSUPPORT:
1599                 /* server doesn't support any rpcbind version we know of */
1600                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1601                                 task->tk_pid);
1602                 break;
1603         case -EPROTONOSUPPORT:
1604                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1605                                 task->tk_pid);
1606                 task->tk_status = 0;
1607                 task->tk_action = call_bind;
1608                 return;
1609         case -ECONNREFUSED:             /* connection problems */
1610         case -ECONNRESET:
1611         case -ENOTCONN:
1612         case -EHOSTDOWN:
1613         case -EHOSTUNREACH:
1614         case -ENETUNREACH:
1615         case -EPIPE:
1616                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1617                                 task->tk_pid, task->tk_status);
1618                 if (!RPC_IS_SOFTCONN(task)) {
1619                         rpc_delay(task, 5*HZ);
1620                         goto retry_timeout;
1621                 }
1622                 status = task->tk_status;
1623                 break;
1624         default:
1625                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1626                                 task->tk_pid, -task->tk_status);
1627         }
1628
1629         rpc_exit(task, status);
1630         return;
1631
1632 retry_timeout:
1633         task->tk_action = call_timeout;
1634 }
1635
1636 /*
1637  * 4b.  Connect to the RPC server
1638  */
1639 static void
1640 call_connect(struct rpc_task *task)
1641 {
1642         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1643
1644         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1645                         task->tk_pid, xprt,
1646                         (xprt_connected(xprt) ? "is" : "is not"));
1647
1648         task->tk_action = call_transmit;
1649         if (!xprt_connected(xprt)) {
1650                 task->tk_action = call_connect_status;
1651                 if (task->tk_status < 0)
1652                         return;
1653                 xprt_connect(task);
1654         }
1655 }
1656
1657 /*
1658  * 4c.  Sort out connect result
1659  */
1660 static void
1661 call_connect_status(struct rpc_task *task)
1662 {
1663         struct rpc_clnt *clnt = task->tk_client;
1664         int status = task->tk_status;
1665
1666         dprint_status(task);
1667
1668         trace_rpc_connect_status(task, status);
1669         switch (status) {
1670                 /* if soft mounted, test if we've timed out */
1671         case -ETIMEDOUT:
1672                 task->tk_action = call_timeout;
1673                 return;
1674         case -ECONNREFUSED:
1675         case -ECONNRESET:
1676         case -ENETUNREACH:
1677                 if (RPC_IS_SOFTCONN(task))
1678                         break;
1679                 /* retry with existing socket, after a delay */
1680         case 0:
1681         case -EAGAIN:
1682                 task->tk_status = 0;
1683                 clnt->cl_stats->netreconn++;
1684                 task->tk_action = call_transmit;
1685                 return;
1686         }
1687         rpc_exit(task, status);
1688 }
1689
1690 /*
1691  * 5.   Transmit the RPC request, and wait for reply
1692  */
1693 static void
1694 call_transmit(struct rpc_task *task)
1695 {
1696         dprint_status(task);
1697
1698         task->tk_action = call_status;
1699         if (task->tk_status < 0)
1700                 return;
1701         task->tk_status = xprt_prepare_transmit(task);
1702         if (task->tk_status != 0)
1703                 return;
1704         task->tk_action = call_transmit_status;
1705         /* Encode here so that rpcsec_gss can use correct sequence number. */
1706         if (rpc_task_need_encode(task)) {
1707                 rpc_xdr_encode(task);
1708                 /* Did the encode result in an error condition? */
1709                 if (task->tk_status != 0) {
1710                         /* Was the error nonfatal? */
1711                         if (task->tk_status == -EAGAIN)
1712                                 rpc_delay(task, HZ >> 4);
1713                         else
1714                                 rpc_exit(task, task->tk_status);
1715                         return;
1716                 }
1717         }
1718         xprt_transmit(task);
1719         if (task->tk_status < 0)
1720                 return;
1721         /*
1722          * On success, ensure that we call xprt_end_transmit() before sleeping
1723          * in order to allow access to the socket to other RPC requests.
1724          */
1725         call_transmit_status(task);
1726         if (rpc_reply_expected(task))
1727                 return;
1728         task->tk_action = rpc_exit_task;
1729         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1730 }
1731
1732 /*
1733  * 5a.  Handle cleanup after a transmission
1734  */
1735 static void
1736 call_transmit_status(struct rpc_task *task)
1737 {
1738         task->tk_action = call_status;
1739
1740         /*
1741          * Common case: success.  Force the compiler to put this
1742          * test first.
1743          */
1744         if (task->tk_status == 0) {
1745                 xprt_end_transmit(task);
1746                 rpc_task_force_reencode(task);
1747                 return;
1748         }
1749
1750         switch (task->tk_status) {
1751         case -EAGAIN:
1752                 break;
1753         default:
1754                 dprint_status(task);
1755                 xprt_end_transmit(task);
1756                 rpc_task_force_reencode(task);
1757                 break;
1758                 /*
1759                  * Special cases: if we've been waiting on the
1760                  * socket's write_space() callback, or if the
1761                  * socket just returned a connection error,
1762                  * then hold onto the transport lock.
1763                  */
1764         case -ECONNREFUSED:
1765         case -EHOSTDOWN:
1766         case -EHOSTUNREACH:
1767         case -ENETUNREACH:
1768                 if (RPC_IS_SOFTCONN(task)) {
1769                         xprt_end_transmit(task);
1770                         rpc_exit(task, task->tk_status);
1771                         break;
1772                 }
1773         case -ECONNRESET:
1774         case -ENOTCONN:
1775         case -EPIPE:
1776                 rpc_task_force_reencode(task);
1777         }
1778 }
1779
1780 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1781 /*
1782  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1783  * addition, disconnect on connectivity errors.
1784  */
1785 static void
1786 call_bc_transmit(struct rpc_task *task)
1787 {
1788         struct rpc_rqst *req = task->tk_rqstp;
1789
1790         task->tk_status = xprt_prepare_transmit(task);
1791         if (task->tk_status == -EAGAIN) {
1792                 /*
1793                  * Could not reserve the transport. Try again after the
1794                  * transport is released.
1795                  */
1796                 task->tk_status = 0;
1797                 task->tk_action = call_bc_transmit;
1798                 return;
1799         }
1800
1801         task->tk_action = rpc_exit_task;
1802         if (task->tk_status < 0) {
1803                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1804                         "error: %d\n", task->tk_status);
1805                 return;
1806         }
1807
1808         xprt_transmit(task);
1809         xprt_end_transmit(task);
1810         dprint_status(task);
1811         switch (task->tk_status) {
1812         case 0:
1813                 /* Success */
1814                 break;
1815         case -EHOSTDOWN:
1816         case -EHOSTUNREACH:
1817         case -ENETUNREACH:
1818         case -ETIMEDOUT:
1819                 /*
1820                  * Problem reaching the server.  Disconnect and let the
1821                  * forechannel reestablish the connection.  The server will
1822                  * have to retransmit the backchannel request and we'll
1823                  * reprocess it.  Since these ops are idempotent, there's no
1824                  * need to cache our reply at this time.
1825                  */
1826                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1827                         "error: %d\n", task->tk_status);
1828                 xprt_conditional_disconnect(req->rq_xprt,
1829                         req->rq_connect_cookie);
1830                 break;
1831         default:
1832                 /*
1833                  * We were unable to reply and will have to drop the
1834                  * request.  The server should reconnect and retransmit.
1835                  */
1836                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1837                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1838                         "error: %d\n", task->tk_status);
1839                 break;
1840         }
1841         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1842 }
1843 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1844
1845 /*
1846  * 6.   Sort out the RPC call status
1847  */
1848 static void
1849 call_status(struct rpc_task *task)
1850 {
1851         struct rpc_clnt *clnt = task->tk_client;
1852         struct rpc_rqst *req = task->tk_rqstp;
1853         int             status;
1854
1855         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1856                 task->tk_status = req->rq_reply_bytes_recvd;
1857
1858         dprint_status(task);
1859
1860         status = task->tk_status;
1861         if (status >= 0) {
1862                 task->tk_action = call_decode;
1863                 return;
1864         }
1865
1866         trace_rpc_call_status(task);
1867         task->tk_status = 0;
1868         switch(status) {
1869         case -EHOSTDOWN:
1870         case -EHOSTUNREACH:
1871         case -ENETUNREACH:
1872                 /*
1873                  * Delay any retries for 3 seconds, then handle as if it
1874                  * were a timeout.
1875                  */
1876                 rpc_delay(task, 3*HZ);
1877         case -ETIMEDOUT:
1878                 task->tk_action = call_timeout;
1879                 if (task->tk_client->cl_discrtry)
1880                         xprt_conditional_disconnect(req->rq_xprt,
1881                                         req->rq_connect_cookie);
1882                 break;
1883         case -ECONNRESET:
1884         case -ECONNREFUSED:
1885                 rpc_force_rebind(clnt);
1886                 rpc_delay(task, 3*HZ);
1887         case -EPIPE:
1888         case -ENOTCONN:
1889                 task->tk_action = call_bind;
1890                 break;
1891         case -EAGAIN:
1892                 task->tk_action = call_transmit;
1893                 break;
1894         case -EIO:
1895                 /* shutdown or soft timeout */
1896                 rpc_exit(task, status);
1897                 break;
1898         default:
1899                 if (clnt->cl_chatty)
1900                         printk("%s: RPC call returned error %d\n",
1901                                clnt->cl_program->name, -status);
1902                 rpc_exit(task, status);
1903         }
1904 }
1905
1906 /*
1907  * 6a.  Handle RPC timeout
1908  *      We do not release the request slot, so we keep using the
1909  *      same XID for all retransmits.
1910  */
1911 static void
1912 call_timeout(struct rpc_task *task)
1913 {
1914         struct rpc_clnt *clnt = task->tk_client;
1915
1916         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1917                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1918                 goto retry;
1919         }
1920
1921         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1922         task->tk_timeouts++;
1923
1924         if (RPC_IS_SOFTCONN(task)) {
1925                 rpc_exit(task, -ETIMEDOUT);
1926                 return;
1927         }
1928         if (RPC_IS_SOFT(task)) {
1929                 if (clnt->cl_chatty) {
1930                         rcu_read_lock();
1931                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1932                                 clnt->cl_program->name,
1933                                 rcu_dereference(clnt->cl_xprt)->servername);
1934                         rcu_read_unlock();
1935                 }
1936                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1937                         rpc_exit(task, -ETIMEDOUT);
1938                 else
1939                         rpc_exit(task, -EIO);
1940                 return;
1941         }
1942
1943         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1944                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1945                 if (clnt->cl_chatty) {
1946                         rcu_read_lock();
1947                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1948                         clnt->cl_program->name,
1949                         rcu_dereference(clnt->cl_xprt)->servername);
1950                         rcu_read_unlock();
1951                 }
1952         }
1953         rpc_force_rebind(clnt);
1954         /*
1955          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1956          * event? RFC2203 requires the server to drop all such requests.
1957          */
1958         rpcauth_invalcred(task);
1959
1960 retry:
1961         clnt->cl_stats->rpcretrans++;
1962         task->tk_action = call_bind;
1963         task->tk_status = 0;
1964 }
1965
1966 /*
1967  * 7.   Decode the RPC reply
1968  */
1969 static void
1970 call_decode(struct rpc_task *task)
1971 {
1972         struct rpc_clnt *clnt = task->tk_client;
1973         struct rpc_rqst *req = task->tk_rqstp;
1974         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1975         __be32          *p;
1976
1977         dprint_status(task);
1978
1979         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1980                 if (clnt->cl_chatty) {
1981                         rcu_read_lock();
1982                         printk(KERN_NOTICE "%s: server %s OK\n",
1983                                 clnt->cl_program->name,
1984                                 rcu_dereference(clnt->cl_xprt)->servername);
1985                         rcu_read_unlock();
1986                 }
1987                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1988         }
1989
1990         /*
1991          * Ensure that we see all writes made by xprt_complete_rqst()
1992          * before it changed req->rq_reply_bytes_recvd.
1993          */
1994         smp_rmb();
1995         req->rq_rcv_buf.len = req->rq_private_buf.len;
1996
1997         /* Check that the softirq receive buffer is valid */
1998         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1999                                 sizeof(req->rq_rcv_buf)) != 0);
2000
2001         if (req->rq_rcv_buf.len < 12) {
2002                 if (!RPC_IS_SOFT(task)) {
2003                         task->tk_action = call_bind;
2004                         clnt->cl_stats->rpcretrans++;
2005                         goto out_retry;
2006                 }
2007                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2008                                 clnt->cl_program->name, task->tk_status);
2009                 task->tk_action = call_timeout;
2010                 goto out_retry;
2011         }
2012
2013         p = rpc_verify_header(task);
2014         if (IS_ERR(p)) {
2015                 if (p == ERR_PTR(-EAGAIN))
2016                         goto out_retry;
2017                 return;
2018         }
2019
2020         task->tk_action = rpc_exit_task;
2021
2022         if (decode) {
2023                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2024                                                       task->tk_msg.rpc_resp);
2025         }
2026         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2027                         task->tk_status);
2028         return;
2029 out_retry:
2030         task->tk_status = 0;
2031         /* Note: rpc_verify_header() may have freed the RPC slot */
2032         if (task->tk_rqstp == req) {
2033                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2034                 if (task->tk_client->cl_discrtry)
2035                         xprt_conditional_disconnect(req->rq_xprt,
2036                                         req->rq_connect_cookie);
2037         }
2038 }
2039
2040 static __be32 *
2041 rpc_encode_header(struct rpc_task *task)
2042 {
2043         struct rpc_clnt *clnt = task->tk_client;
2044         struct rpc_rqst *req = task->tk_rqstp;
2045         __be32          *p = req->rq_svec[0].iov_base;
2046
2047         /* FIXME: check buffer size? */
2048
2049         p = xprt_skip_transport_header(req->rq_xprt, p);
2050         *p++ = req->rq_xid;             /* XID */
2051         *p++ = htonl(RPC_CALL);         /* CALL */
2052         *p++ = htonl(RPC_VERSION);      /* RPC version */
2053         *p++ = htonl(clnt->cl_prog);    /* program number */
2054         *p++ = htonl(clnt->cl_vers);    /* program version */
2055         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2056         p = rpcauth_marshcred(task, p);
2057         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2058         return p;
2059 }
2060
2061 static __be32 *
2062 rpc_verify_header(struct rpc_task *task)
2063 {
2064         struct rpc_clnt *clnt = task->tk_client;
2065         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2066         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2067         __be32  *p = iov->iov_base;
2068         u32 n;
2069         int error = -EACCES;
2070
2071         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2072                 /* RFC-1014 says that the representation of XDR data must be a
2073                  * multiple of four bytes
2074                  * - if it isn't pointer subtraction in the NFS client may give
2075                  *   undefined results
2076                  */
2077                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2078                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2079                        task->tk_rqstp->rq_rcv_buf.len);
2080                 goto out_eio;
2081         }
2082         if ((len -= 3) < 0)
2083                 goto out_overflow;
2084
2085         p += 1; /* skip XID */
2086         if ((n = ntohl(*p++)) != RPC_REPLY) {
2087                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2088                         task->tk_pid, __func__, n);
2089                 goto out_garbage;
2090         }
2091
2092         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2093                 if (--len < 0)
2094                         goto out_overflow;
2095                 switch ((n = ntohl(*p++))) {
2096                 case RPC_AUTH_ERROR:
2097                         break;
2098                 case RPC_MISMATCH:
2099                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2100                                 task->tk_pid, __func__);
2101                         error = -EPROTONOSUPPORT;
2102                         goto out_err;
2103                 default:
2104                         dprintk("RPC: %5u %s: RPC call rejected, "
2105                                 "unknown error: %x\n",
2106                                 task->tk_pid, __func__, n);
2107                         goto out_eio;
2108                 }
2109                 if (--len < 0)
2110                         goto out_overflow;
2111                 switch ((n = ntohl(*p++))) {
2112                 case RPC_AUTH_REJECTEDCRED:
2113                 case RPC_AUTH_REJECTEDVERF:
2114                 case RPCSEC_GSS_CREDPROBLEM:
2115                 case RPCSEC_GSS_CTXPROBLEM:
2116                         if (!task->tk_cred_retry)
2117                                 break;
2118                         task->tk_cred_retry--;
2119                         dprintk("RPC: %5u %s: retry stale creds\n",
2120                                         task->tk_pid, __func__);
2121                         rpcauth_invalcred(task);
2122                         /* Ensure we obtain a new XID! */
2123                         xprt_release(task);
2124                         task->tk_action = call_reserve;
2125                         goto out_retry;
2126                 case RPC_AUTH_BADCRED:
2127                 case RPC_AUTH_BADVERF:
2128                         /* possibly garbled cred/verf? */
2129                         if (!task->tk_garb_retry)
2130                                 break;
2131                         task->tk_garb_retry--;
2132                         dprintk("RPC: %5u %s: retry garbled creds\n",
2133                                         task->tk_pid, __func__);
2134                         task->tk_action = call_bind;
2135                         goto out_retry;
2136                 case RPC_AUTH_TOOWEAK:
2137                         rcu_read_lock();
2138                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2139                                "authentication.\n",
2140                                rcu_dereference(clnt->cl_xprt)->servername);
2141                         rcu_read_unlock();
2142                         break;
2143                 default:
2144                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2145                                         task->tk_pid, __func__, n);
2146                         error = -EIO;
2147                 }
2148                 dprintk("RPC: %5u %s: call rejected %d\n",
2149                                 task->tk_pid, __func__, n);
2150                 goto out_err;
2151         }
2152         if (!(p = rpcauth_checkverf(task, p))) {
2153                 dprintk("RPC: %5u %s: auth check failed\n",
2154                                 task->tk_pid, __func__);
2155                 goto out_garbage;               /* bad verifier, retry */
2156         }
2157         len = p - (__be32 *)iov->iov_base - 1;
2158         if (len < 0)
2159                 goto out_overflow;
2160         switch ((n = ntohl(*p++))) {
2161         case RPC_SUCCESS:
2162                 return p;
2163         case RPC_PROG_UNAVAIL:
2164                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2165                                 "by server %s\n", task->tk_pid, __func__,
2166                                 (unsigned int)clnt->cl_prog,
2167                                 rcu_dereference(clnt->cl_xprt)->servername);
2168                 error = -EPFNOSUPPORT;
2169                 goto out_err;
2170         case RPC_PROG_MISMATCH:
2171                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2172                                 "by server %s\n", task->tk_pid, __func__,
2173                                 (unsigned int)clnt->cl_prog,
2174                                 (unsigned int)clnt->cl_vers,
2175                                 rcu_dereference(clnt->cl_xprt)->servername);
2176                 error = -EPROTONOSUPPORT;
2177                 goto out_err;
2178         case RPC_PROC_UNAVAIL:
2179                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2180                                 "version %u on server %s\n",
2181                                 task->tk_pid, __func__,
2182                                 rpc_proc_name(task),
2183                                 clnt->cl_prog, clnt->cl_vers,
2184                                 rcu_dereference(clnt->cl_xprt)->servername);
2185                 error = -EOPNOTSUPP;
2186                 goto out_err;
2187         case RPC_GARBAGE_ARGS:
2188                 dprintk("RPC: %5u %s: server saw garbage\n",
2189                                 task->tk_pid, __func__);
2190                 break;                  /* retry */
2191         default:
2192                 dprintk("RPC: %5u %s: server accept status: %x\n",
2193                                 task->tk_pid, __func__, n);
2194                 /* Also retry */
2195         }
2196
2197 out_garbage:
2198         clnt->cl_stats->rpcgarbage++;
2199         if (task->tk_garb_retry) {
2200                 task->tk_garb_retry--;
2201                 dprintk("RPC: %5u %s: retrying\n",
2202                                 task->tk_pid, __func__);
2203                 task->tk_action = call_bind;
2204 out_retry:
2205                 return ERR_PTR(-EAGAIN);
2206         }
2207 out_eio:
2208         error = -EIO;
2209 out_err:
2210         rpc_exit(task, error);
2211         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2212                         __func__, error);
2213         return ERR_PTR(error);
2214 out_overflow:
2215         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2216                         __func__);
2217         goto out_garbage;
2218 }
2219
2220 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2221 {
2222 }
2223
2224 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2225 {
2226         return 0;
2227 }
2228
2229 static struct rpc_procinfo rpcproc_null = {
2230         .p_encode = rpcproc_encode_null,
2231         .p_decode = rpcproc_decode_null,
2232 };
2233
2234 static int rpc_ping(struct rpc_clnt *clnt)
2235 {
2236         struct rpc_message msg = {
2237                 .rpc_proc = &rpcproc_null,
2238         };
2239         int err;
2240         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2241         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2242         put_rpccred(msg.rpc_cred);
2243         return err;
2244 }
2245
2246 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2247 {
2248         struct rpc_message msg = {
2249                 .rpc_proc = &rpcproc_null,
2250                 .rpc_cred = cred,
2251         };
2252         struct rpc_task_setup task_setup_data = {
2253                 .rpc_client = clnt,
2254                 .rpc_message = &msg,
2255                 .callback_ops = &rpc_default_ops,
2256                 .flags = flags,
2257         };
2258         return rpc_run_task(&task_setup_data);
2259 }
2260 EXPORT_SYMBOL_GPL(rpc_call_null);
2261
2262 #ifdef RPC_DEBUG
2263 static void rpc_show_header(void)
2264 {
2265         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2266                 "-timeout ---ops--\n");
2267 }
2268
2269 static void rpc_show_task(const struct rpc_clnt *clnt,
2270                           const struct rpc_task *task)
2271 {
2272         const char *rpc_waitq = "none";
2273
2274         if (RPC_IS_QUEUED(task))
2275                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2276
2277         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2278                 task->tk_pid, task->tk_flags, task->tk_status,
2279                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2280                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2281                 task->tk_action, rpc_waitq);
2282 }
2283
2284 void rpc_show_tasks(struct net *net)
2285 {
2286         struct rpc_clnt *clnt;
2287         struct rpc_task *task;
2288         int header = 0;
2289         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2290
2291         spin_lock(&sn->rpc_client_lock);
2292         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2293                 spin_lock(&clnt->cl_lock);
2294                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2295                         if (!header) {
2296                                 rpc_show_header();
2297                                 header++;
2298                         }
2299                         rpc_show_task(clnt, task);
2300                 }
2301                 spin_unlock(&clnt->cl_lock);
2302         }
2303         spin_unlock(&sn->rpc_client_lock);
2304 }
2305 #endif