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