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