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