net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/utsname.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/in.h>
  31 #include <linux/in6.h>
  32 #include <linux/un.h>
  33 #include <linux/rcupdate.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #include <trace/events/sunrpc.h>
  41
  42 #include "sunrpc.h"
  43 #include "netns.h"
  44
  45 #ifdef RPC_DEBUG
  46 # define RPCDBG_FACILITY        RPCDBG_CALL
  47 #endif
  48
  49 #define dprint_status(t)                                        \
  50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  51                         __func__, t->tk_status)
  52
  53 /*
  54  * All RPC clients are linked into this list
  55  */
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         struct net *net = rpc_net_ns(clnt);
  86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  87
  88         spin_lock(&sn->rpc_client_lock);
  89         list_add(&clnt->cl_clients, &sn->all_clients);
  90         spin_unlock(&sn->rpc_client_lock);
  91 }
  92
  93 static void rpc_unregister_client(struct rpc_clnt *clnt)
  94 {
  95         struct net *net = rpc_net_ns(clnt);
  96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  97
  98         spin_lock(&sn->rpc_client_lock);
  99         list_del(&clnt->cl_clients);
 100         spin_unlock(&sn->rpc_client_lock);
 101 }
 102
 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 104 {
 105         rpc_remove_client_dir(clnt);
 106 }
 107
 108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 109 {
 110         struct net *net = rpc_net_ns(clnt);
 111         struct super_block *pipefs_sb;
 112
 113         pipefs_sb = rpc_get_sb_net(net);
 114         if (pipefs_sb) {
 115                 __rpc_clnt_remove_pipedir(clnt);
 116                 rpc_put_sb_net(net);
 117         }
 118 }
 119
 120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 121                                     struct rpc_clnt *clnt)
 122 {
 123         static uint32_t clntid;
 124         const char *dir_name = clnt->cl_program->pipe_dir_name;
 125         char name[15];
 126         struct dentry *dir, *dentry;
 127
 128         dir = rpc_d_lookup_sb(sb, dir_name);
 129         if (dir == NULL) {
 130                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 131                 return dir;
 132         }
 133         for (;;) {
 134                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 135                 name[sizeof(name) - 1] = '\0';
 136                 dentry = rpc_create_client_dir(dir, name, clnt);
 137                 if (!IS_ERR(dentry))
 138                         break;
 139                 if (dentry == ERR_PTR(-EEXIST))
 140                         continue;
 141                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 142                                 " %s/%s, error %ld\n",
 143                                 dir_name, name, PTR_ERR(dentry));
 144                 break;
 145         }
 146         dput(dir);
 147         return dentry;
 148 }
 149
 150 static int
 151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 152 {
 153         struct dentry *dentry;
 154
 155         if (clnt->cl_program->pipe_dir_name != NULL) {
 156                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 157                 if (IS_ERR(dentry))
 158                         return PTR_ERR(dentry);
 159         }
 160         return 0;
 161 }
 162
 163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 164 {
 165         if (clnt->cl_program->pipe_dir_name == NULL)
 166                 return 1;
 167
 168         switch (event) {
 169         case RPC_PIPEFS_MOUNT:
 170                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 171                         return 1;
 172                 if (atomic_read(&clnt->cl_count) == 0)
 173                         return 1;
 174                 break;
 175         case RPC_PIPEFS_UMOUNT:
 176                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 177                         return 1;
 178                 break;
 179         }
 180         return 0;
 181 }
 182
 183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 184                                    struct super_block *sb)
 185 {
 186         struct dentry *dentry;
 187         int err = 0;
 188
 189         switch (event) {
 190         case RPC_PIPEFS_MOUNT:
 191                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 192                 if (!dentry)
 193                         return -ENOENT;
 194                 if (IS_ERR(dentry))
 195                         return PTR_ERR(dentry);
 196                 break;
 197         case RPC_PIPEFS_UMOUNT:
 198                 __rpc_clnt_remove_pipedir(clnt);
 199                 break;
 200         default:
 201                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 202                 return -ENOTSUPP;
 203         }
 204         return err;
 205 }
 206
 207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 208                                 struct super_block *sb)
 209 {
 210         int error = 0;
 211
 212         for (;; clnt = clnt->cl_parent) {
 213                 if (!rpc_clnt_skip_event(clnt, event))
 214                         error = __rpc_clnt_handle_event(clnt, event, sb);
 215                 if (error || clnt == clnt->cl_parent)
 216                         break;
 217         }
 218         return error;
 219 }
 220
 221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 222 {
 223         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 224         struct rpc_clnt *clnt;
 225
 226         spin_lock(&sn->rpc_client_lock);
 227         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 228                 if (rpc_clnt_skip_event(clnt, event))
 229                         continue;
 230                 spin_unlock(&sn->rpc_client_lock);
 231                 return clnt;
 232         }
 233         spin_unlock(&sn->rpc_client_lock);
 234         return NULL;
 235 }
 236
 237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 238                             void *ptr)
 239 {
 240         struct super_block *sb = ptr;
 241         struct rpc_clnt *clnt;
 242         int error = 0;
 243
 244         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 245                 error = __rpc_pipefs_event(clnt, event, sb);
 246                 if (error)
 247                         break;
 248         }
 249         return error;
 250 }
 251
 252 static struct notifier_block rpc_clients_block = {
 253         .notifier_call  = rpc_pipefs_event,
 254         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 255 };
 256
 257 int rpc_clients_notifier_register(void)
 258 {
 259         return rpc_pipefs_notifier_register(&rpc_clients_block);
 260 }
 261
 262 void rpc_clients_notifier_unregister(void)
 263 {
 264         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 265 }
 266
 267 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 268 {
 269         clnt->cl_nodelen = strlen(nodename);
 270         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 271                 clnt->cl_nodelen = UNX_MAXNODENAME;
 272         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 273 }
 274
 275 static int rpc_client_register(const struct rpc_create_args *args,
 276                                struct rpc_clnt *clnt)
 277 {
 278         struct rpc_auth_create_args auth_args = {
 279                 .pseudoflavor = args->authflavor,
 280                 .target_name = args->client_name,
 281         };
 282         struct rpc_auth *auth;
 283         struct net *net = rpc_net_ns(clnt);
 284         struct super_block *pipefs_sb;
 285         int err;
 286
 287         pipefs_sb = rpc_get_sb_net(net);
 288         if (pipefs_sb) {
 289                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 290                 if (err)
 291                         goto out;
 292         }
 293
 294         rpc_register_client(clnt);
 295         if (pipefs_sb)
 296                 rpc_put_sb_net(net);
 297
 298         auth = rpcauth_create(&auth_args, clnt);
 299         if (IS_ERR(auth)) {
 300                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 301                                 args->authflavor);
 302                 err = PTR_ERR(auth);
 303                 goto err_auth;
 304         }
 305         return 0;
 306 err_auth:
 307         pipefs_sb = rpc_get_sb_net(net);
 308         rpc_unregister_client(clnt);
 309         __rpc_clnt_remove_pipedir(clnt);
 310 out:
 311         if (pipefs_sb)
 312                 rpc_put_sb_net(net);
 313         return err;
 314 }
 315
 316 static DEFINE_IDA(rpc_clids);
 317
 318 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 319 {
 320         int clid;
 321
 322         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 323         if (clid < 0)
 324                 return clid;
 325         clnt->cl_clid = clid;
 326         return 0;
 327 }
 328
 329 static void rpc_free_clid(struct rpc_clnt *clnt)
 330 {
 331         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 332 }
 333
 334 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 335                 struct rpc_xprt *xprt,
 336                 struct rpc_clnt *parent)
 337 {
 338         const struct rpc_program *program = args->program;
 339         const struct rpc_version *version;
 340         struct rpc_clnt         *clnt = NULL;
 341         int err;
 342
 343         /* sanity check the name before trying to print it */
 344         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 345                         program->name, args->servername, xprt);
 346
 347         err = rpciod_up();
 348         if (err)
 349                 goto out_no_rpciod;
 350
 351         err = -EINVAL;
 352         if (args->version >= program->nrvers)
 353                 goto out_err;
 354         version = program->version[args->version];
 355         if (version == NULL)
 356                 goto out_err;
 357
 358         err = -ENOMEM;
 359         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 360         if (!clnt)
 361                 goto out_err;
 362         clnt->cl_parent = parent ? : clnt;
 363
 364         err = rpc_alloc_clid(clnt);
 365         if (err)
 366                 goto out_no_clid;
 367
 368         rcu_assign_pointer(clnt->cl_xprt, xprt);
 369         clnt->cl_procinfo = version->procs;
 370         clnt->cl_maxproc  = version->nrprocs;
 371         clnt->cl_prog     = args->prognumber ? : program->number;
 372         clnt->cl_vers     = version->number;
 373         clnt->cl_stats    = program->stats;
 374         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 375         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 376         err = -ENOMEM;
 377         if (clnt->cl_metrics == NULL)
 378                 goto out_no_stats;
 379         clnt->cl_program  = program;
 380         INIT_LIST_HEAD(&clnt->cl_tasks);
 381         spin_lock_init(&clnt->cl_lock);
 382
 383         if (!xprt_bound(xprt))
 384                 clnt->cl_autobind = 1;
 385
 386         clnt->cl_timeout = xprt->timeout;
 387         if (args->timeout != NULL) {
 388                 memcpy(&clnt->cl_timeout_default, args->timeout,
 389                                 sizeof(clnt->cl_timeout_default));
 390                 clnt->cl_timeout = &clnt->cl_timeout_default;
 391         }
 392
 393         clnt->cl_rtt = &clnt->cl_rtt_default;
 394         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 395
 396         atomic_set(&clnt->cl_count, 1);
 397
 398         /* save the nodename */
 399         rpc_clnt_set_nodename(clnt, utsname()->nodename);
 400
 401         err = rpc_client_register(args, clnt);
 402         if (err)
 403                 goto out_no_path;
 404         if (parent)
 405                 atomic_inc(&parent->cl_count);
 406         return clnt;
 407
 408 out_no_path:
 409         rpc_free_iostats(clnt->cl_metrics);
 410 out_no_stats:
 411         rpc_free_clid(clnt);
 412 out_no_clid:
 413         kfree(clnt);
 414 out_err:
 415         rpciod_down();
 416 out_no_rpciod:
 417         xprt_put(xprt);
 418         return ERR_PTR(err);
 419 }
 420
 421 /**
 422  * rpc_create - create an RPC client and transport with one call
 423  * @args: rpc_clnt create argument structure
 424  *
 425  * Creates and initializes an RPC transport and an RPC client.
 426  *
 427  * It can ping the server in order to determine if it is up, and to see if
 428  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 429  * this behavior so asynchronous tasks can also use rpc_create.
 430  */
 431 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 432 {
 433         struct rpc_xprt *xprt;
 434         struct rpc_clnt *clnt;
 435         struct xprt_create xprtargs = {
 436                 .net = args->net,
 437                 .ident = args->protocol,
 438                 .srcaddr = args->saddress,
 439                 .dstaddr = args->address,
 440                 .addrlen = args->addrsize,
 441                 .servername = args->servername,
 442                 .bc_xprt = args->bc_xprt,
 443         };
 444         char servername[48];
 445
 446         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 447                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 448         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 449                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 450         /*
 451          * If the caller chooses not to specify a hostname, whip
 452          * up a string representation of the passed-in address.
 453          */
 454         if (xprtargs.servername == NULL) {
 455                 struct sockaddr_un *sun =
 456                                 (struct sockaddr_un *)args->address;
 457                 struct sockaddr_in *sin =
 458                                 (struct sockaddr_in *)args->address;
 459                 struct sockaddr_in6 *sin6 =
 460                                 (struct sockaddr_in6 *)args->address;
 461
 462                 servername[0] = '\0';
 463                 switch (args->address->sa_family) {
 464                 case AF_LOCAL:
 465                         snprintf(servername, sizeof(servername), "%s",
 466                                  sun->sun_path);
 467                         break;
 468                 case AF_INET:
 469                         snprintf(servername, sizeof(servername), "%pI4",
 470                                  &sin->sin_addr.s_addr);
 471                         break;
 472                 case AF_INET6:
 473                         snprintf(servername, sizeof(servername), "%pI6",
 474                                  &sin6->sin6_addr);
 475                         break;
 476                 default:
 477                         /* caller wants default server name, but
 478                          * address family isn't recognized. */
 479                         return ERR_PTR(-EINVAL);
 480                 }
 481                 xprtargs.servername = servername;
 482         }
 483
 484         xprt = xprt_create_transport(&xprtargs);
 485         if (IS_ERR(xprt))
 486                 return (struct rpc_clnt *)xprt;
 487
 488         /*
 489          * By default, kernel RPC client connects from a reserved port.
 490          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 491          * but it is always enabled for rpciod, which handles the connect
 492          * operation.
 493          */
 494         xprt->resvport = 1;
 495         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 496                 xprt->resvport = 0;
 497
 498         clnt = rpc_new_client(args, xprt, NULL);
 499         if (IS_ERR(clnt))
 500                 return clnt;
 501
 502         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 503                 int err = rpc_ping(clnt);
 504                 if (err != 0) {
 505                         rpc_shutdown_client(clnt);
 506                         return ERR_PTR(err);
 507                 }
 508         }
 509
 510         clnt->cl_softrtry = 1;
 511         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 512                 clnt->cl_softrtry = 0;
 513
 514         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 515                 clnt->cl_autobind = 1;
 516         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 517                 clnt->cl_discrtry = 1;
 518         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 519                 clnt->cl_chatty = 1;
 520
 521         return clnt;
 522 }
 523 EXPORT_SYMBOL_GPL(rpc_create);
 524
 525 /*
 526  * This function clones the RPC client structure. It allows us to share the
 527  * same transport while varying parameters such as the authentication
 528  * flavour.
 529  */
 530 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 531                                            struct rpc_clnt *clnt)
 532 {
 533         struct rpc_xprt *xprt;
 534         struct rpc_clnt *new;
 535         int err;
 536
 537         err = -ENOMEM;
 538         rcu_read_lock();
 539         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 540         rcu_read_unlock();
 541         if (xprt == NULL)
 542                 goto out_err;
 543         args->servername = xprt->servername;
 544
 545         new = rpc_new_client(args, xprt, clnt);
 546         if (IS_ERR(new)) {
 547                 err = PTR_ERR(new);
 548                 goto out_err;
 549         }
 550
 551         /* Turn off autobind on clones */
 552         new->cl_autobind = 0;
 553         new->cl_softrtry = clnt->cl_softrtry;
 554         new->cl_discrtry = clnt->cl_discrtry;
 555         new->cl_chatty = clnt->cl_chatty;
 556         return new;
 557
 558 out_err:
 559         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 560         return ERR_PTR(err);
 561 }
 562
 563 /**
 564  * rpc_clone_client - Clone an RPC client structure
 565  *
 566  * @clnt: RPC client whose parameters are copied
 567  *
 568  * Returns a fresh RPC client or an ERR_PTR.
 569  */
 570 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 571 {
 572         struct rpc_create_args args = {
 573                 .program        = clnt->cl_program,
 574                 .prognumber     = clnt->cl_prog,
 575                 .version        = clnt->cl_vers,
 576                 .authflavor     = clnt->cl_auth->au_flavor,
 577         };
 578         return __rpc_clone_client(&args, clnt);
 579 }
 580 EXPORT_SYMBOL_GPL(rpc_clone_client);
 581
 582 /**
 583  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 584  *
 585  * @clnt: RPC client whose parameters are copied
 586  * @flavor: security flavor for new client
 587  *
 588  * Returns a fresh RPC client or an ERR_PTR.
 589  */
 590 struct rpc_clnt *
 591 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 592 {
 593         struct rpc_create_args args = {
 594                 .program        = clnt->cl_program,
 595                 .prognumber     = clnt->cl_prog,
 596                 .version        = clnt->cl_vers,
 597                 .authflavor     = flavor,
 598         };
 599         return __rpc_clone_client(&args, clnt);
 600 }
 601 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 602
 603 /*
 604  * Kill all tasks for the given client.
 605  * XXX: kill their descendants as well?
 606  */
 607 void rpc_killall_tasks(struct rpc_clnt *clnt)
 608 {
 609         struct rpc_task *rovr;
 610
 611
 612         if (list_empty(&clnt->cl_tasks))
 613                 return;
 614         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 615         /*
 616          * Spin lock all_tasks to prevent changes...
 617          */
 618         spin_lock(&clnt->cl_lock);
 619         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 620                 if (!RPC_IS_ACTIVATED(rovr))
 621                         continue;
 622                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 623                         rovr->tk_flags |= RPC_TASK_KILLED;
 624                         rpc_exit(rovr, -EIO);
 625                         if (RPC_IS_QUEUED(rovr))
 626                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 627                                                         rovr);
 628                 }
 629         }
 630         spin_unlock(&clnt->cl_lock);
 631 }
 632 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 633
 634 /*
 635  * Properly shut down an RPC client, terminating all outstanding
 636  * requests.
 637  */
 638 void rpc_shutdown_client(struct rpc_clnt *clnt)
 639 {
 640         might_sleep();
 641
 642         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 643                         clnt->cl_program->name,
 644                         rcu_dereference(clnt->cl_xprt)->servername);
 645
 646         while (!list_empty(&clnt->cl_tasks)) {
 647                 rpc_killall_tasks(clnt);
 648                 wait_event_timeout(destroy_wait,
 649                         list_empty(&clnt->cl_tasks), 1*HZ);
 650         }
 651
 652         rpc_release_client(clnt);
 653 }
 654 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 655
 656 /*
 657  * Free an RPC client
 658  */
 659 static void
 660 rpc_free_client(struct rpc_clnt *clnt)
 661 {
 662         dprintk_rcu("RPC:       destroying %s client for %s\n",
 663                         clnt->cl_program->name,
 664                         rcu_dereference(clnt->cl_xprt)->servername);
 665         if (clnt->cl_parent != clnt)
 666                 rpc_release_client(clnt->cl_parent);
 667         rpc_clnt_remove_pipedir(clnt);
 668         rpc_unregister_client(clnt);
 669         rpc_free_iostats(clnt->cl_metrics);
 670         clnt->cl_metrics = NULL;
 671         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 672         rpciod_down();
 673         rpc_free_clid(clnt);
 674         kfree(clnt);
 675 }
 676
 677 /*
 678  * Free an RPC client
 679  */
 680 static void
 681 rpc_free_auth(struct rpc_clnt *clnt)
 682 {
 683         if (clnt->cl_auth == NULL) {
 684                 rpc_free_client(clnt);
 685                 return;
 686         }
 687
 688         /*
 689          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 690          *       release remaining GSS contexts. This mechanism ensures
 691          *       that it can do so safely.
 692          */
 693         atomic_inc(&clnt->cl_count);
 694         rpcauth_release(clnt->cl_auth);
 695         clnt->cl_auth = NULL;
 696         if (atomic_dec_and_test(&clnt->cl_count))
 697                 rpc_free_client(clnt);
 698 }
 699
 700 /*
 701  * Release reference to the RPC client
 702  */
 703 void
 704 rpc_release_client(struct rpc_clnt *clnt)
 705 {
 706         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 707
 708         if (list_empty(&clnt->cl_tasks))
 709                 wake_up(&destroy_wait);
 710         if (atomic_dec_and_test(&clnt->cl_count))
 711                 rpc_free_auth(clnt);
 712 }
 713 EXPORT_SYMBOL_GPL(rpc_release_client);
 714
 715 /**
 716  * rpc_bind_new_program - bind a new RPC program to an existing client
 717  * @old: old rpc_client
 718  * @program: rpc program to set
 719  * @vers: rpc program version
 720  *
 721  * Clones the rpc client and sets up a new RPC program. This is mainly
 722  * of use for enabling different RPC programs to share the same transport.
 723  * The Sun NFSv2/v3 ACL protocol can do this.
 724  */
 725 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 726                                       const struct rpc_program *program,
 727                                       u32 vers)
 728 {
 729         struct rpc_create_args args = {
 730                 .program        = program,
 731                 .prognumber     = program->number,
 732                 .version        = vers,
 733                 .authflavor     = old->cl_auth->au_flavor,
 734         };
 735         struct rpc_clnt *clnt;
 736         int err;
 737
 738         clnt = __rpc_clone_client(&args, old);
 739         if (IS_ERR(clnt))
 740                 goto out;
 741         err = rpc_ping(clnt);
 742         if (err != 0) {
 743                 rpc_shutdown_client(clnt);
 744                 clnt = ERR_PTR(err);
 745         }
 746 out:
 747         return clnt;
 748 }
 749 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 750
 751 void rpc_task_release_client(struct rpc_task *task)
 752 {
 753         struct rpc_clnt *clnt = task->tk_client;
 754
 755         if (clnt != NULL) {
 756                 /* Remove from client task list */
 757                 spin_lock(&clnt->cl_lock);
 758                 list_del(&task->tk_task);
 759                 spin_unlock(&clnt->cl_lock);
 760                 task->tk_client = NULL;
 761
 762                 rpc_release_client(clnt);
 763         }
 764 }
 765
 766 static
 767 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 768 {
 769         if (clnt != NULL) {
 770                 rpc_task_release_client(task);
 771                 task->tk_client = clnt;
 772                 atomic_inc(&clnt->cl_count);
 773                 if (clnt->cl_softrtry)
 774                         task->tk_flags |= RPC_TASK_SOFT;
 775                 if (sk_memalloc_socks()) {
 776                         struct rpc_xprt *xprt;
 777
 778                         rcu_read_lock();
 779                         xprt = rcu_dereference(clnt->cl_xprt);
 780                         if (xprt->swapper)
 781                                 task->tk_flags |= RPC_TASK_SWAPPER;
 782                         rcu_read_unlock();
 783                 }
 784                 /* Add to the client's list of all tasks */
 785                 spin_lock(&clnt->cl_lock);
 786                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 787                 spin_unlock(&clnt->cl_lock);
 788         }
 789 }
 790
 791 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 792 {
 793         rpc_task_release_client(task);
 794         rpc_task_set_client(task, clnt);
 795 }
 796 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 797
 798
 799 static void
 800 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 801 {
 802         if (msg != NULL) {
 803                 task->tk_msg.rpc_proc = msg->rpc_proc;
 804                 task->tk_msg.rpc_argp = msg->rpc_argp;
 805                 task->tk_msg.rpc_resp = msg->rpc_resp;
 806                 if (msg->rpc_cred != NULL)
 807                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 808         }
 809 }
 810
 811 /*
 812  * Default callback for async RPC calls
 813  */
 814 static void
 815 rpc_default_callback(struct rpc_task *task, void *data)
 816 {
 817 }
 818
 819 static const struct rpc_call_ops rpc_default_ops = {
 820         .rpc_call_done = rpc_default_callback,
 821 };
 822
 823 /**
 824  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 825  * @task_setup_data: pointer to task initialisation data
 826  */
 827 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 828 {
 829         struct rpc_task *task;
 830
 831         task = rpc_new_task(task_setup_data);
 832         if (IS_ERR(task))
 833                 goto out;
 834
 835         rpc_task_set_client(task, task_setup_data->rpc_client);
 836         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 837
 838         if (task->tk_action == NULL)
 839                 rpc_call_start(task);
 840
 841         atomic_inc(&task->tk_count);
 842         rpc_execute(task);
 843 out:
 844         return task;
 845 }
 846 EXPORT_SYMBOL_GPL(rpc_run_task);
 847
 848 /**
 849  * rpc_call_sync - Perform a synchronous RPC call
 850  * @clnt: pointer to RPC client
 851  * @msg: RPC call parameters
 852  * @flags: RPC call flags
 853  */
 854 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 855 {
 856         struct rpc_task *task;
 857         struct rpc_task_setup task_setup_data = {
 858                 .rpc_client = clnt,
 859                 .rpc_message = msg,
 860                 .callback_ops = &rpc_default_ops,
 861                 .flags = flags,
 862         };
 863         int status;
 864
 865         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
 866         if (flags & RPC_TASK_ASYNC) {
 867                 rpc_release_calldata(task_setup_data.callback_ops,
 868                         task_setup_data.callback_data);
 869                 return -EINVAL;
 870         }
 871
 872         task = rpc_run_task(&task_setup_data);
 873         if (IS_ERR(task))
 874                 return PTR_ERR(task);
 875         status = task->tk_status;
 876         rpc_put_task(task);
 877         return status;
 878 }
 879 EXPORT_SYMBOL_GPL(rpc_call_sync);
 880
 881 /**
 882  * rpc_call_async - Perform an asynchronous RPC call
 883  * @clnt: pointer to RPC client
 884  * @msg: RPC call parameters
 885  * @flags: RPC call flags
 886  * @tk_ops: RPC call ops
 887  * @data: user call data
 888  */
 889 int
 890 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 891                const struct rpc_call_ops *tk_ops, void *data)
 892 {
 893         struct rpc_task *task;
 894         struct rpc_task_setup task_setup_data = {
 895                 .rpc_client = clnt,
 896                 .rpc_message = msg,
 897                 .callback_ops = tk_ops,
 898                 .callback_data = data,
 899                 .flags = flags|RPC_TASK_ASYNC,
 900         };
 901
 902         task = rpc_run_task(&task_setup_data);
 903         if (IS_ERR(task))
 904                 return PTR_ERR(task);
 905         rpc_put_task(task);
 906         return 0;
 907 }
 908 EXPORT_SYMBOL_GPL(rpc_call_async);
 909
 910 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 911 /**
 912  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 913  * rpc_execute against it
 914  * @req: RPC request
 915  * @tk_ops: RPC call ops
 916  */
 917 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 918                                 const struct rpc_call_ops *tk_ops)
 919 {
 920         struct rpc_task *task;
 921         struct xdr_buf *xbufp = &req->rq_snd_buf;
 922         struct rpc_task_setup task_setup_data = {
 923                 .callback_ops = tk_ops,
 924         };
 925
 926         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 927         /*
 928          * Create an rpc_task to send the data
 929          */
 930         task = rpc_new_task(&task_setup_data);
 931         if (IS_ERR(task)) {
 932                 xprt_free_bc_request(req);
 933                 goto out;
 934         }
 935         task->tk_rqstp = req;
 936
 937         /*
 938          * Set up the xdr_buf length.
 939          * This also indicates that the buffer is XDR encoded already.
 940          */
 941         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 942                         xbufp->tail[0].iov_len;
 943
 944         task->tk_action = call_bc_transmit;
 945         atomic_inc(&task->tk_count);
 946         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 947         rpc_execute(task);
 948
 949 out:
 950         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 951         return task;
 952 }
 953 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 954
 955 void
 956 rpc_call_start(struct rpc_task *task)
 957 {
 958         task->tk_action = call_start;
 959 }
 960 EXPORT_SYMBOL_GPL(rpc_call_start);
 961
 962 /**
 963  * rpc_peeraddr - extract remote peer address from clnt's xprt
 964  * @clnt: RPC client structure
 965  * @buf: target buffer
 966  * @bufsize: length of target buffer
 967  *
 968  * Returns the number of bytes that are actually in the stored address.
 969  */
 970 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 971 {
 972         size_t bytes;
 973         struct rpc_xprt *xprt;
 974
 975         rcu_read_lock();
 976         xprt = rcu_dereference(clnt->cl_xprt);
 977
 978         bytes = xprt->addrlen;
 979         if (bytes > bufsize)
 980                 bytes = bufsize;
 981         memcpy(buf, &xprt->addr, bytes);
 982         rcu_read_unlock();
 983
 984         return bytes;
 985 }
 986 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 987
 988 /**
 989  * rpc_peeraddr2str - return remote peer address in printable format
 990  * @clnt: RPC client structure
 991  * @format: address format
 992  *
 993  * NB: the lifetime of the memory referenced by the returned pointer is
 994  * the same as the rpc_xprt itself.  As long as the caller uses this
 995  * pointer, it must hold the RCU read lock.
 996  */
 997 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 998                              enum rpc_display_format_t format)
 999 {
1000         struct rpc_xprt *xprt;
1001
1002         xprt = rcu_dereference(clnt->cl_xprt);
1003
1004         if (xprt->address_strings[format] != NULL)
1005                 return xprt->address_strings[format];
1006         else
1007                 return "unprintable";
1008 }
1009 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1010
1011 static const struct sockaddr_in rpc_inaddr_loopback = {
1012         .sin_family             = AF_INET,
1013         .sin_addr.s_addr        = htonl(INADDR_ANY),
1014 };
1015
1016 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1017         .sin6_family            = AF_INET6,
1018         .sin6_addr              = IN6ADDR_ANY_INIT,
1019 };
1020
1021 /*
1022  * Try a getsockname() on a connected datagram socket.  Using a
1023  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1024  * This conserves the ephemeral port number space.
1025  *
1026  * Returns zero and fills in "buf" if successful; otherwise, a
1027  * negative errno is returned.
1028  */
1029 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1030                         struct sockaddr *buf, int buflen)
1031 {
1032         struct socket *sock;
1033         int err;
1034
1035         err = __sock_create(net, sap->sa_family,
1036                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1037         if (err < 0) {
1038                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1039                 goto out;
1040         }
1041
1042         switch (sap->sa_family) {
1043         case AF_INET:
1044                 err = kernel_bind(sock,
1045                                 (struct sockaddr *)&rpc_inaddr_loopback,
1046                                 sizeof(rpc_inaddr_loopback));
1047                 break;
1048         case AF_INET6:
1049                 err = kernel_bind(sock,
1050                                 (struct sockaddr *)&rpc_in6addr_loopback,
1051                                 sizeof(rpc_in6addr_loopback));
1052                 break;
1053         default:
1054                 err = -EAFNOSUPPORT;
1055                 goto out;
1056         }
1057         if (err < 0) {
1058                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1059                 goto out_release;
1060         }
1061
1062         err = kernel_connect(sock, sap, salen, 0);
1063         if (err < 0) {
1064                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1065                 goto out_release;
1066         }
1067
1068         err = kernel_getsockname(sock, buf, &buflen);
1069         if (err < 0) {
1070                 dprintk("RPC:       getsockname failed (%d)\n", err);
1071                 goto out_release;
1072         }
1073
1074         err = 0;
1075         if (buf->sa_family == AF_INET6) {
1076                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1077                 sin6->sin6_scope_id = 0;
1078         }
1079         dprintk("RPC:       %s succeeded\n", __func__);
1080
1081 out_release:
1082         sock_release(sock);
1083 out:
1084         return err;
1085 }
1086
1087 /*
1088  * Scraping a connected socket failed, so we don't have a useable
1089  * local address.  Fallback: generate an address that will prevent
1090  * the server from calling us back.
1091  *
1092  * Returns zero and fills in "buf" if successful; otherwise, a
1093  * negative errno is returned.
1094  */
1095 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1096 {
1097         switch (family) {
1098         case AF_INET:
1099                 if (buflen < sizeof(rpc_inaddr_loopback))
1100                         return -EINVAL;
1101                 memcpy(buf, &rpc_inaddr_loopback,
1102                                 sizeof(rpc_inaddr_loopback));
1103                 break;
1104         case AF_INET6:
1105                 if (buflen < sizeof(rpc_in6addr_loopback))
1106                         return -EINVAL;
1107                 memcpy(buf, &rpc_in6addr_loopback,
1108                                 sizeof(rpc_in6addr_loopback));
1109         default:
1110                 dprintk("RPC:       %s: address family not supported\n",
1111                         __func__);
1112                 return -EAFNOSUPPORT;
1113         }
1114         dprintk("RPC:       %s: succeeded\n", __func__);
1115         return 0;
1116 }
1117
1118 /**
1119  * rpc_localaddr - discover local endpoint address for an RPC client
1120  * @clnt: RPC client structure
1121  * @buf: target buffer
1122  * @buflen: size of target buffer, in bytes
1123  *
1124  * Returns zero and fills in "buf" and "buflen" if successful;
1125  * otherwise, a negative errno is returned.
1126  *
1127  * This works even if the underlying transport is not currently connected,
1128  * or if the upper layer never previously provided a source address.
1129  *
1130  * The result of this function call is transient: multiple calls in
1131  * succession may give different results, depending on how local
1132  * networking configuration changes over time.
1133  */
1134 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1135 {
1136         struct sockaddr_storage address;
1137         struct sockaddr *sap = (struct sockaddr *)&address;
1138         struct rpc_xprt *xprt;
1139         struct net *net;
1140         size_t salen;
1141         int err;
1142
1143         rcu_read_lock();
1144         xprt = rcu_dereference(clnt->cl_xprt);
1145         salen = xprt->addrlen;
1146         memcpy(sap, &xprt->addr, salen);
1147         net = get_net(xprt->xprt_net);
1148         rcu_read_unlock();
1149
1150         rpc_set_port(sap, 0);
1151         err = rpc_sockname(net, sap, salen, buf, buflen);
1152         put_net(net);
1153         if (err != 0)
1154                 /* Couldn't discover local address, return ANYADDR */
1155                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1156         return 0;
1157 }
1158 EXPORT_SYMBOL_GPL(rpc_localaddr);
1159
1160 void
1161 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1162 {
1163         struct rpc_xprt *xprt;
1164
1165         rcu_read_lock();
1166         xprt = rcu_dereference(clnt->cl_xprt);
1167         if (xprt->ops->set_buffer_size)
1168                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1169         rcu_read_unlock();
1170 }
1171 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1172
1173 /**
1174  * rpc_protocol - Get transport protocol number for an RPC client
1175  * @clnt: RPC client to query
1176  *
1177  */
1178 int rpc_protocol(struct rpc_clnt *clnt)
1179 {
1180         int protocol;
1181
1182         rcu_read_lock();
1183         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1184         rcu_read_unlock();
1185         return protocol;
1186 }
1187 EXPORT_SYMBOL_GPL(rpc_protocol);
1188
1189 /**
1190  * rpc_net_ns - Get the network namespace for this RPC client
1191  * @clnt: RPC client to query
1192  *
1193  */
1194 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1195 {
1196         struct net *ret;
1197
1198         rcu_read_lock();
1199         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1200         rcu_read_unlock();
1201         return ret;
1202 }
1203 EXPORT_SYMBOL_GPL(rpc_net_ns);
1204
1205 /**
1206  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1207  * @clnt: RPC client to query
1208  *
1209  * For stream transports, this is one RPC record fragment (see RFC
1210  * 1831), as we don't support multi-record requests yet.  For datagram
1211  * transports, this is the size of an IP packet minus the IP, UDP, and
1212  * RPC header sizes.
1213  */
1214 size_t rpc_max_payload(struct rpc_clnt *clnt)
1215 {
1216         size_t ret;
1217
1218         rcu_read_lock();
1219         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1220         rcu_read_unlock();
1221         return ret;
1222 }
1223 EXPORT_SYMBOL_GPL(rpc_max_payload);
1224
1225 /**
1226  * rpc_get_timeout - Get timeout for transport in units of HZ
1227  * @clnt: RPC client to query
1228  */
1229 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1230 {
1231         unsigned long ret;
1232
1233         rcu_read_lock();
1234         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1235         rcu_read_unlock();
1236         return ret;
1237 }
1238 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1239
1240 /**
1241  * rpc_force_rebind - force transport to check that remote port is unchanged
1242  * @clnt: client to rebind
1243  *
1244  */
1245 void rpc_force_rebind(struct rpc_clnt *clnt)
1246 {
1247         if (clnt->cl_autobind) {
1248                 rcu_read_lock();
1249                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1250                 rcu_read_unlock();
1251         }
1252 }
1253 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1254
1255 /*
1256  * Restart an (async) RPC call from the call_prepare state.
1257  * Usually called from within the exit handler.
1258  */
1259 int
1260 rpc_restart_call_prepare(struct rpc_task *task)
1261 {
1262         if (RPC_ASSASSINATED(task))
1263                 return 0;
1264         task->tk_action = call_start;
1265         if (task->tk_ops->rpc_call_prepare != NULL)
1266                 task->tk_action = rpc_prepare_task;
1267         return 1;
1268 }
1269 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1270
1271 /*
1272  * Restart an (async) RPC call. Usually called from within the
1273  * exit handler.
1274  */
1275 int
1276 rpc_restart_call(struct rpc_task *task)
1277 {
1278         if (RPC_ASSASSINATED(task))
1279                 return 0;
1280         task->tk_action = call_start;
1281         return 1;
1282 }
1283 EXPORT_SYMBOL_GPL(rpc_restart_call);
1284
1285 #ifdef RPC_DEBUG
1286 static const char *rpc_proc_name(const struct rpc_task *task)
1287 {
1288         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1289
1290         if (proc) {
1291                 if (proc->p_name)
1292                         return proc->p_name;
1293                 else
1294                         return "NULL";
1295         } else
1296                 return "no proc";
1297 }
1298 #endif
1299
1300 /*
1301  * 0.  Initial state
1302  *
1303  *     Other FSM states can be visited zero or more times, but
1304  *     this state is visited exactly once for each RPC.
1305  */
1306 static void
1307 call_start(struct rpc_task *task)
1308 {
1309         struct rpc_clnt *clnt = task->tk_client;
1310
1311         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1312                         clnt->cl_program->name, clnt->cl_vers,
1313                         rpc_proc_name(task),
1314                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1315
1316         /* Increment call count */
1317         task->tk_msg.rpc_proc->p_count++;
1318         clnt->cl_stats->rpccnt++;
1319         task->tk_action = call_reserve;
1320 }
1321
1322 /*
1323  * 1.   Reserve an RPC call slot
1324  */
1325 static void
1326 call_reserve(struct rpc_task *task)
1327 {
1328         dprint_status(task);
1329
1330         task->tk_status  = 0;
1331         task->tk_action  = call_reserveresult;
1332         xprt_reserve(task);
1333 }
1334
1335 static void call_retry_reserve(struct rpc_task *task);
1336
1337 /*
1338  * 1b.  Grok the result of xprt_reserve()
1339  */
1340 static void
1341 call_reserveresult(struct rpc_task *task)
1342 {
1343         int status = task->tk_status;
1344
1345         dprint_status(task);
1346
1347         /*
1348          * After a call to xprt_reserve(), we must have either
1349          * a request slot or else an error status.
1350          */
1351         task->tk_status = 0;
1352         if (status >= 0) {
1353                 if (task->tk_rqstp) {
1354                         task->tk_action = call_refresh;
1355                         return;
1356                 }
1357
1358                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1359                                 __func__, status);
1360                 rpc_exit(task, -EIO);
1361                 return;
1362         }
1363
1364         /*
1365          * Even though there was an error, we may have acquired
1366          * a request slot somehow.  Make sure not to leak it.
1367          */
1368         if (task->tk_rqstp) {
1369                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1370                                 __func__, status);
1371                 xprt_release(task);
1372         }
1373
1374         switch (status) {
1375         case -ENOMEM:
1376                 rpc_delay(task, HZ >> 2);
1377         case -EAGAIN:   /* woken up; retry */
1378                 task->tk_action = call_retry_reserve;
1379                 return;
1380         case -EIO:      /* probably a shutdown */
1381                 break;
1382         default:
1383                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1384                                 __func__, status);
1385                 break;
1386         }
1387         rpc_exit(task, status);
1388 }
1389
1390 /*
1391  * 1c.  Retry reserving an RPC call slot
1392  */
1393 static void
1394 call_retry_reserve(struct rpc_task *task)
1395 {
1396         dprint_status(task);
1397
1398         task->tk_status  = 0;
1399         task->tk_action  = call_reserveresult;
1400         xprt_retry_reserve(task);
1401 }
1402
1403 /*
1404  * 2.   Bind and/or refresh the credentials
1405  */
1406 static void
1407 call_refresh(struct rpc_task *task)
1408 {
1409         dprint_status(task);
1410
1411         task->tk_action = call_refreshresult;
1412         task->tk_status = 0;
1413         task->tk_client->cl_stats->rpcauthrefresh++;
1414         rpcauth_refreshcred(task);
1415 }
1416
1417 /*
1418  * 2a.  Process the results of a credential refresh
1419  */
1420 static void
1421 call_refreshresult(struct rpc_task *task)
1422 {
1423         int status = task->tk_status;
1424
1425         dprint_status(task);
1426
1427         task->tk_status = 0;
1428         task->tk_action = call_refresh;
1429         switch (status) {
1430         case 0:
1431                 if (rpcauth_uptodatecred(task))
1432                         task->tk_action = call_allocate;
1433                 return;
1434         case -ETIMEDOUT:
1435                 rpc_delay(task, 3*HZ);
1436         case -EAGAIN:
1437                 status = -EACCES;
1438         case -EKEYEXPIRED:
1439                 if (!task->tk_cred_retry)
1440                         break;
1441                 task->tk_cred_retry--;
1442                 dprintk("RPC: %5u %s: retry refresh creds\n",
1443                                 task->tk_pid, __func__);
1444                 return;
1445         }
1446         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1447                                 task->tk_pid, __func__, status);
1448         rpc_exit(task, status);
1449 }
1450
1451 /*
1452  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1453  *      (Note: buffer memory is freed in xprt_release).
1454  */
1455 static void
1456 call_allocate(struct rpc_task *task)
1457 {
1458         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1459         struct rpc_rqst *req = task->tk_rqstp;
1460         struct rpc_xprt *xprt = req->rq_xprt;
1461         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1462
1463         dprint_status(task);
1464
1465         task->tk_status = 0;
1466         task->tk_action = call_bind;
1467
1468         if (req->rq_buffer)
1469                 return;
1470
1471         if (proc->p_proc != 0) {
1472                 BUG_ON(proc->p_arglen == 0);
1473                 if (proc->p_decode != NULL)
1474                         BUG_ON(proc->p_replen == 0);
1475         }
1476
1477         /*
1478          * Calculate the size (in quads) of the RPC call
1479          * and reply headers, and convert both values
1480          * to byte sizes.
1481          */
1482         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1483         req->rq_callsize <<= 2;
1484         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1485         req->rq_rcvsize <<= 2;
1486
1487         req->rq_buffer = xprt->ops->buf_alloc(task,
1488                                         req->rq_callsize + req->rq_rcvsize);
1489         if (req->rq_buffer != NULL)
1490                 return;
1491
1492         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1493
1494         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1495                 task->tk_action = call_allocate;
1496                 rpc_delay(task, HZ>>4);
1497                 return;
1498         }
1499
1500         rpc_exit(task, -ERESTARTSYS);
1501 }
1502
1503 static inline int
1504 rpc_task_need_encode(struct rpc_task *task)
1505 {
1506         return task->tk_rqstp->rq_snd_buf.len == 0;
1507 }
1508
1509 static inline void
1510 rpc_task_force_reencode(struct rpc_task *task)
1511 {
1512         task->tk_rqstp->rq_snd_buf.len = 0;
1513         task->tk_rqstp->rq_bytes_sent = 0;
1514 }
1515
1516 static inline void
1517 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1518 {
1519         buf->head[0].iov_base = start;
1520         buf->head[0].iov_len = len;
1521         buf->tail[0].iov_len = 0;
1522         buf->page_len = 0;
1523         buf->flags = 0;
1524         buf->len = 0;
1525         buf->buflen = len;
1526 }
1527
1528 /*
1529  * 3.   Encode arguments of an RPC call
1530  */
1531 static void
1532 rpc_xdr_encode(struct rpc_task *task)
1533 {
1534         struct rpc_rqst *req = task->tk_rqstp;
1535         kxdreproc_t     encode;
1536         __be32          *p;
1537
1538         dprint_status(task);
1539
1540         rpc_xdr_buf_init(&req->rq_snd_buf,
1541                          req->rq_buffer,
1542                          req->rq_callsize);
1543         rpc_xdr_buf_init(&req->rq_rcv_buf,
1544                          (char *)req->rq_buffer + req->rq_callsize,
1545                          req->rq_rcvsize);
1546
1547         p = rpc_encode_header(task);
1548         if (p == NULL) {
1549                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1550                 rpc_exit(task, -EIO);
1551                 return;
1552         }
1553
1554         encode = task->tk_msg.rpc_proc->p_encode;
1555         if (encode == NULL)
1556                 return;
1557
1558         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1559                         task->tk_msg.rpc_argp);
1560 }
1561
1562 /*
1563  * 4.   Get the server port number if not yet set
1564  */
1565 static void
1566 call_bind(struct rpc_task *task)
1567 {
1568         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1569
1570         dprint_status(task);
1571
1572         task->tk_action = call_connect;
1573         if (!xprt_bound(xprt)) {
1574                 task->tk_action = call_bind_status;
1575                 task->tk_timeout = xprt->bind_timeout;
1576                 xprt->ops->rpcbind(task);
1577         }
1578 }
1579
1580 /*
1581  * 4a.  Sort out bind result
1582  */
1583 static void
1584 call_bind_status(struct rpc_task *task)
1585 {
1586         int status = -EIO;
1587
1588         if (task->tk_status >= 0) {
1589                 dprint_status(task);
1590                 task->tk_status = 0;
1591                 task->tk_action = call_connect;
1592                 return;
1593         }
1594
1595         trace_rpc_bind_status(task);
1596         switch (task->tk_status) {
1597         case -ENOMEM:
1598                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1599                 rpc_delay(task, HZ >> 2);
1600                 goto retry_timeout;
1601         case -EACCES:
1602                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1603                                 "unavailable\n", task->tk_pid);
1604                 /* fail immediately if this is an RPC ping */
1605                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1606                         status = -EOPNOTSUPP;
1607                         break;
1608                 }
1609                 if (task->tk_rebind_retry == 0)
1610                         break;
1611                 task->tk_rebind_retry--;
1612                 rpc_delay(task, 3*HZ);
1613                 goto retry_timeout;
1614         case -ETIMEDOUT:
1615                 dprintk("RPC: %5u rpcbind request timed out\n",
1616                                 task->tk_pid);
1617                 goto retry_timeout;
1618         case -EPFNOSUPPORT:
1619                 /* server doesn't support any rpcbind version we know of */
1620                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1621                                 task->tk_pid);
1622                 break;
1623         case -EPROTONOSUPPORT:
1624                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1625                                 task->tk_pid);
1626                 task->tk_status = 0;
1627                 task->tk_action = call_bind;
1628                 return;
1629         case -ECONNREFUSED:             /* connection problems */
1630         case -ECONNRESET:
1631         case -ENOTCONN:
1632         case -EHOSTDOWN:
1633         case -EHOSTUNREACH:
1634         case -ENETUNREACH:
1635         case -EPIPE:
1636                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1637                                 task->tk_pid, task->tk_status);
1638                 if (!RPC_IS_SOFTCONN(task)) {
1639                         rpc_delay(task, 5*HZ);
1640                         goto retry_timeout;
1641                 }
1642                 status = task->tk_status;
1643                 break;
1644         default:
1645                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1646                                 task->tk_pid, -task->tk_status);
1647         }
1648
1649         rpc_exit(task, status);
1650         return;
1651
1652 retry_timeout:
1653         task->tk_action = call_timeout;
1654 }
1655
1656 /*
1657  * 4b.  Connect to the RPC server
1658  */
1659 static void
1660 call_connect(struct rpc_task *task)
1661 {
1662         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1663
1664         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1665                         task->tk_pid, xprt,
1666                         (xprt_connected(xprt) ? "is" : "is not"));
1667
1668         task->tk_action = call_transmit;
1669         if (!xprt_connected(xprt)) {
1670                 task->tk_action = call_connect_status;
1671                 if (task->tk_status < 0)
1672                         return;
1673                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1674                         rpc_exit(task, -ENOTCONN);
1675                         return;
1676                 }
1677                 xprt_connect(task);
1678         }
1679 }
1680
1681 /*
1682  * 4c.  Sort out connect result
1683  */
1684 static void
1685 call_connect_status(struct rpc_task *task)
1686 {
1687         struct rpc_clnt *clnt = task->tk_client;
1688         int status = task->tk_status;
1689
1690         dprint_status(task);
1691
1692         trace_rpc_connect_status(task, status);
1693         switch (status) {
1694                 /* if soft mounted, test if we've timed out */
1695         case -ETIMEDOUT:
1696                 task->tk_action = call_timeout;
1697                 return;
1698         case -ECONNREFUSED:
1699         case -ECONNRESET:
1700         case -ENETUNREACH:
1701                 if (RPC_IS_SOFTCONN(task))
1702                         break;
1703                 /* retry with existing socket, after a delay */
1704         case 0:
1705         case -EAGAIN:
1706                 task->tk_status = 0;
1707                 clnt->cl_stats->netreconn++;
1708                 task->tk_action = call_transmit;
1709                 return;
1710         }
1711         rpc_exit(task, status);
1712 }
1713
1714 /*
1715  * 5.   Transmit the RPC request, and wait for reply
1716  */
1717 static void
1718 call_transmit(struct rpc_task *task)
1719 {
1720         dprint_status(task);
1721
1722         task->tk_action = call_status;
1723         if (task->tk_status < 0)
1724                 return;
1725         task->tk_status = xprt_prepare_transmit(task);
1726         if (task->tk_status != 0)
1727                 return;
1728         task->tk_action = call_transmit_status;
1729         /* Encode here so that rpcsec_gss can use correct sequence number. */
1730         if (rpc_task_need_encode(task)) {
1731                 rpc_xdr_encode(task);
1732                 /* Did the encode result in an error condition? */
1733                 if (task->tk_status != 0) {
1734                         /* Was the error nonfatal? */
1735                         if (task->tk_status == -EAGAIN)
1736                                 rpc_delay(task, HZ >> 4);
1737                         else
1738                                 rpc_exit(task, task->tk_status);
1739                         return;
1740                 }
1741         }
1742         xprt_transmit(task);
1743         if (task->tk_status < 0)
1744                 return;
1745         /*
1746          * On success, ensure that we call xprt_end_transmit() before sleeping
1747          * in order to allow access to the socket to other RPC requests.
1748          */
1749         call_transmit_status(task);
1750         if (rpc_reply_expected(task))
1751                 return;
1752         task->tk_action = rpc_exit_task;
1753         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1754 }
1755
1756 /*
1757  * 5a.  Handle cleanup after a transmission
1758  */
1759 static void
1760 call_transmit_status(struct rpc_task *task)
1761 {
1762         task->tk_action = call_status;
1763
1764         /*
1765          * Common case: success.  Force the compiler to put this
1766          * test first.
1767          */
1768         if (task->tk_status == 0) {
1769                 xprt_end_transmit(task);
1770                 rpc_task_force_reencode(task);
1771                 return;
1772         }
1773
1774         switch (task->tk_status) {
1775         case -EAGAIN:
1776                 break;
1777         default:
1778                 dprint_status(task);
1779                 xprt_end_transmit(task);
1780                 rpc_task_force_reencode(task);
1781                 break;
1782                 /*
1783                  * Special cases: if we've been waiting on the
1784                  * socket's write_space() callback, or if the
1785                  * socket just returned a connection error,
1786                  * then hold onto the transport lock.
1787                  */
1788         case -ECONNREFUSED:
1789         case -EHOSTDOWN:
1790         case -EHOSTUNREACH:
1791         case -ENETUNREACH:
1792                 if (RPC_IS_SOFTCONN(task)) {
1793                         xprt_end_transmit(task);
1794                         rpc_exit(task, task->tk_status);
1795                         break;
1796                 }
1797         case -ECONNRESET:
1798         case -ENOTCONN:
1799         case -EPIPE:
1800                 rpc_task_force_reencode(task);
1801         }
1802 }
1803
1804 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1805 /*
1806  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1807  * addition, disconnect on connectivity errors.
1808  */
1809 static void
1810 call_bc_transmit(struct rpc_task *task)
1811 {
1812         struct rpc_rqst *req = task->tk_rqstp;
1813
1814         task->tk_status = xprt_prepare_transmit(task);
1815         if (task->tk_status == -EAGAIN) {
1816                 /*
1817                  * Could not reserve the transport. Try again after the
1818                  * transport is released.
1819                  */
1820                 task->tk_status = 0;
1821                 task->tk_action = call_bc_transmit;
1822                 return;
1823         }
1824
1825         task->tk_action = rpc_exit_task;
1826         if (task->tk_status < 0) {
1827                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1828                         "error: %d\n", task->tk_status);
1829                 return;
1830         }
1831
1832         xprt_transmit(task);
1833         xprt_end_transmit(task);
1834         dprint_status(task);
1835         switch (task->tk_status) {
1836         case 0:
1837                 /* Success */
1838                 break;
1839         case -EHOSTDOWN:
1840         case -EHOSTUNREACH:
1841         case -ENETUNREACH:
1842         case -ETIMEDOUT:
1843                 /*
1844                  * Problem reaching the server.  Disconnect and let the
1845                  * forechannel reestablish the connection.  The server will
1846                  * have to retransmit the backchannel request and we'll
1847                  * reprocess it.  Since these ops are idempotent, there's no
1848                  * need to cache our reply at this time.
1849                  */
1850                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1851                         "error: %d\n", task->tk_status);
1852                 xprt_conditional_disconnect(req->rq_xprt,
1853                         req->rq_connect_cookie);
1854                 break;
1855         default:
1856                 /*
1857                  * We were unable to reply and will have to drop the
1858                  * request.  The server should reconnect and retransmit.
1859                  */
1860                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1861                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1862                         "error: %d\n", task->tk_status);
1863                 break;
1864         }
1865         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1866 }
1867 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1868
1869 /*
1870  * 6.   Sort out the RPC call status
1871  */
1872 static void
1873 call_status(struct rpc_task *task)
1874 {
1875         struct rpc_clnt *clnt = task->tk_client;
1876         struct rpc_rqst *req = task->tk_rqstp;
1877         int             status;
1878
1879         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1880                 task->tk_status = req->rq_reply_bytes_recvd;
1881
1882         dprint_status(task);
1883
1884         status = task->tk_status;
1885         if (status >= 0) {
1886                 task->tk_action = call_decode;
1887                 return;
1888         }
1889
1890         trace_rpc_call_status(task);
1891         task->tk_status = 0;
1892         switch(status) {
1893         case -EHOSTDOWN:
1894         case -EHOSTUNREACH:
1895         case -ENETUNREACH:
1896                 /*
1897                  * Delay any retries for 3 seconds, then handle as if it
1898                  * were a timeout.
1899                  */
1900                 rpc_delay(task, 3*HZ);
1901         case -ETIMEDOUT:
1902                 task->tk_action = call_timeout;
1903                 if (task->tk_client->cl_discrtry)
1904                         xprt_conditional_disconnect(req->rq_xprt,
1905                                         req->rq_connect_cookie);
1906                 break;
1907         case -ECONNRESET:
1908         case -ECONNREFUSED:
1909                 rpc_force_rebind(clnt);
1910                 rpc_delay(task, 3*HZ);
1911         case -EPIPE:
1912         case -ENOTCONN:
1913                 task->tk_action = call_bind;
1914                 break;
1915         case -EAGAIN:
1916                 task->tk_action = call_transmit;
1917                 break;
1918         case -EIO:
1919                 /* shutdown or soft timeout */
1920                 rpc_exit(task, status);
1921                 break;
1922         default:
1923                 if (clnt->cl_chatty)
1924                         printk("%s: RPC call returned error %d\n",
1925                                clnt->cl_program->name, -status);
1926                 rpc_exit(task, status);
1927         }
1928 }
1929
1930 /*
1931  * 6a.  Handle RPC timeout
1932  *      We do not release the request slot, so we keep using the
1933  *      same XID for all retransmits.
1934  */
1935 static void
1936 call_timeout(struct rpc_task *task)
1937 {
1938         struct rpc_clnt *clnt = task->tk_client;
1939
1940         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1941                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1942                 goto retry;
1943         }
1944
1945         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1946         task->tk_timeouts++;
1947
1948         if (RPC_IS_SOFTCONN(task)) {
1949                 rpc_exit(task, -ETIMEDOUT);
1950                 return;
1951         }
1952         if (RPC_IS_SOFT(task)) {
1953                 if (clnt->cl_chatty) {
1954                         rcu_read_lock();
1955                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1956                                 clnt->cl_program->name,
1957                                 rcu_dereference(clnt->cl_xprt)->servername);
1958                         rcu_read_unlock();
1959                 }
1960                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1961                         rpc_exit(task, -ETIMEDOUT);
1962                 else
1963                         rpc_exit(task, -EIO);
1964                 return;
1965         }
1966
1967         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1968                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1969                 if (clnt->cl_chatty) {
1970                         rcu_read_lock();
1971                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1972                         clnt->cl_program->name,
1973                         rcu_dereference(clnt->cl_xprt)->servername);
1974                         rcu_read_unlock();
1975                 }
1976         }
1977         rpc_force_rebind(clnt);
1978         /*
1979          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1980          * event? RFC2203 requires the server to drop all such requests.
1981          */
1982         rpcauth_invalcred(task);
1983
1984 retry:
1985         clnt->cl_stats->rpcretrans++;
1986         task->tk_action = call_bind;
1987         task->tk_status = 0;
1988 }
1989
1990 /*
1991  * 7.   Decode the RPC reply
1992  */
1993 static void
1994 call_decode(struct rpc_task *task)
1995 {
1996         struct rpc_clnt *clnt = task->tk_client;
1997         struct rpc_rqst *req = task->tk_rqstp;
1998         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1999         __be32          *p;
2000
2001         dprint_status(task);
2002
2003         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2004                 if (clnt->cl_chatty) {
2005                         rcu_read_lock();
2006                         printk(KERN_NOTICE "%s: server %s OK\n",
2007                                 clnt->cl_program->name,
2008                                 rcu_dereference(clnt->cl_xprt)->servername);
2009                         rcu_read_unlock();
2010                 }
2011                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2012         }
2013
2014         /*
2015          * Ensure that we see all writes made by xprt_complete_rqst()
2016          * before it changed req->rq_reply_bytes_recvd.
2017          */
2018         smp_rmb();
2019         req->rq_rcv_buf.len = req->rq_private_buf.len;
2020
2021         /* Check that the softirq receive buffer is valid */
2022         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2023                                 sizeof(req->rq_rcv_buf)) != 0);
2024
2025         if (req->rq_rcv_buf.len < 12) {
2026                 if (!RPC_IS_SOFT(task)) {
2027                         task->tk_action = call_bind;
2028                         clnt->cl_stats->rpcretrans++;
2029                         goto out_retry;
2030                 }
2031                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2032                                 clnt->cl_program->name, task->tk_status);
2033                 task->tk_action = call_timeout;
2034                 goto out_retry;
2035         }
2036
2037         p = rpc_verify_header(task);
2038         if (IS_ERR(p)) {
2039                 if (p == ERR_PTR(-EAGAIN))
2040                         goto out_retry;
2041                 return;
2042         }
2043
2044         task->tk_action = rpc_exit_task;
2045
2046         if (decode) {
2047                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2048                                                       task->tk_msg.rpc_resp);
2049         }
2050         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2051                         task->tk_status);
2052         return;
2053 out_retry:
2054         task->tk_status = 0;
2055         /* Note: rpc_verify_header() may have freed the RPC slot */
2056         if (task->tk_rqstp == req) {
2057                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2058                 if (task->tk_client->cl_discrtry)
2059                         xprt_conditional_disconnect(req->rq_xprt,
2060                                         req->rq_connect_cookie);
2061         }
2062 }
2063
2064 static __be32 *
2065 rpc_encode_header(struct rpc_task *task)
2066 {
2067         struct rpc_clnt *clnt = task->tk_client;
2068         struct rpc_rqst *req = task->tk_rqstp;
2069         __be32          *p = req->rq_svec[0].iov_base;
2070
2071         /* FIXME: check buffer size? */
2072
2073         p = xprt_skip_transport_header(req->rq_xprt, p);
2074         *p++ = req->rq_xid;             /* XID */
2075         *p++ = htonl(RPC_CALL);         /* CALL */
2076         *p++ = htonl(RPC_VERSION);      /* RPC version */
2077         *p++ = htonl(clnt->cl_prog);    /* program number */
2078         *p++ = htonl(clnt->cl_vers);    /* program version */
2079         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2080         p = rpcauth_marshcred(task, p);
2081         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2082         return p;
2083 }
2084
2085 static __be32 *
2086 rpc_verify_header(struct rpc_task *task)
2087 {
2088         struct rpc_clnt *clnt = task->tk_client;
2089         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2090         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2091         __be32  *p = iov->iov_base;
2092         u32 n;
2093         int error = -EACCES;
2094
2095         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2096                 /* RFC-1014 says that the representation of XDR data must be a
2097                  * multiple of four bytes
2098                  * - if it isn't pointer subtraction in the NFS client may give
2099                  *   undefined results
2100                  */
2101                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2102                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2103                        task->tk_rqstp->rq_rcv_buf.len);
2104                 error = -EIO;
2105                 goto out_err;
2106         }
2107         if ((len -= 3) < 0)
2108                 goto out_overflow;
2109
2110         p += 1; /* skip XID */
2111         if ((n = ntohl(*p++)) != RPC_REPLY) {
2112                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2113                         task->tk_pid, __func__, n);
2114                 error = -EIO;
2115                 goto out_garbage;
2116         }
2117
2118         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2119                 if (--len < 0)
2120                         goto out_overflow;
2121                 switch ((n = ntohl(*p++))) {
2122                 case RPC_AUTH_ERROR:
2123                         break;
2124                 case RPC_MISMATCH:
2125                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2126                                 task->tk_pid, __func__);
2127                         error = -EPROTONOSUPPORT;
2128                         goto out_err;
2129                 default:
2130                         dprintk("RPC: %5u %s: RPC call rejected, "
2131                                 "unknown error: %x\n",
2132                                 task->tk_pid, __func__, n);
2133                         error = -EIO;
2134                         goto out_err;
2135                 }
2136                 if (--len < 0)
2137                         goto out_overflow;
2138                 switch ((n = ntohl(*p++))) {
2139                 case RPC_AUTH_REJECTEDCRED:
2140                 case RPC_AUTH_REJECTEDVERF:
2141                 case RPCSEC_GSS_CREDPROBLEM:
2142                 case RPCSEC_GSS_CTXPROBLEM:
2143                         if (!task->tk_cred_retry)
2144                                 break;
2145                         task->tk_cred_retry--;
2146                         dprintk("RPC: %5u %s: retry stale creds\n",
2147                                         task->tk_pid, __func__);
2148                         rpcauth_invalcred(task);
2149                         /* Ensure we obtain a new XID! */
2150                         xprt_release(task);
2151                         task->tk_action = call_reserve;
2152                         goto out_retry;
2153                 case RPC_AUTH_BADCRED:
2154                 case RPC_AUTH_BADVERF:
2155                         /* possibly garbled cred/verf? */
2156                         if (!task->tk_garb_retry)
2157                                 break;
2158                         task->tk_garb_retry--;
2159                         dprintk("RPC: %5u %s: retry garbled creds\n",
2160                                         task->tk_pid, __func__);
2161                         task->tk_action = call_bind;
2162                         goto out_retry;
2163                 case RPC_AUTH_TOOWEAK:
2164                         rcu_read_lock();
2165                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2166                                "authentication.\n",
2167                                rcu_dereference(clnt->cl_xprt)->servername);
2168                         rcu_read_unlock();
2169                         break;
2170                 default:
2171                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2172                                         task->tk_pid, __func__, n);
2173                         error = -EIO;
2174                 }
2175                 dprintk("RPC: %5u %s: call rejected %d\n",
2176                                 task->tk_pid, __func__, n);
2177                 goto out_err;
2178         }
2179         p = rpcauth_checkverf(task, p);
2180         if (IS_ERR(p)) {
2181                 error = PTR_ERR(p);
2182                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2183                                 task->tk_pid, __func__, error);
2184                 goto out_garbage;               /* bad verifier, retry */
2185         }
2186         len = p - (__be32 *)iov->iov_base - 1;
2187         if (len < 0)
2188                 goto out_overflow;
2189         switch ((n = ntohl(*p++))) {
2190         case RPC_SUCCESS:
2191                 return p;
2192         case RPC_PROG_UNAVAIL:
2193                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2194                                 "by server %s\n", task->tk_pid, __func__,
2195                                 (unsigned int)clnt->cl_prog,
2196                                 rcu_dereference(clnt->cl_xprt)->servername);
2197                 error = -EPFNOSUPPORT;
2198                 goto out_err;
2199         case RPC_PROG_MISMATCH:
2200                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2201                                 "by server %s\n", task->tk_pid, __func__,
2202                                 (unsigned int)clnt->cl_prog,
2203                                 (unsigned int)clnt->cl_vers,
2204                                 rcu_dereference(clnt->cl_xprt)->servername);
2205                 error = -EPROTONOSUPPORT;
2206                 goto out_err;
2207         case RPC_PROC_UNAVAIL:
2208                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2209                                 "version %u on server %s\n",
2210                                 task->tk_pid, __func__,
2211                                 rpc_proc_name(task),
2212                                 clnt->cl_prog, clnt->cl_vers,
2213                                 rcu_dereference(clnt->cl_xprt)->servername);
2214                 error = -EOPNOTSUPP;
2215                 goto out_err;
2216         case RPC_GARBAGE_ARGS:
2217                 dprintk("RPC: %5u %s: server saw garbage\n",
2218                                 task->tk_pid, __func__);
2219                 break;                  /* retry */
2220         default:
2221                 dprintk("RPC: %5u %s: server accept status: %x\n",
2222                                 task->tk_pid, __func__, n);
2223                 /* Also retry */
2224         }
2225
2226 out_garbage:
2227         clnt->cl_stats->rpcgarbage++;
2228         if (task->tk_garb_retry) {
2229                 task->tk_garb_retry--;
2230                 dprintk("RPC: %5u %s: retrying\n",
2231                                 task->tk_pid, __func__);
2232                 task->tk_action = call_bind;
2233 out_retry:
2234                 return ERR_PTR(-EAGAIN);
2235         }
2236 out_err:
2237         rpc_exit(task, error);
2238         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2239                         __func__, error);
2240         return ERR_PTR(error);
2241 out_overflow:
2242         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2243                         __func__);
2244         goto out_garbage;
2245 }
2246
2247 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2248 {
2249 }
2250
2251 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2252 {
2253         return 0;
2254 }
2255
2256 static struct rpc_procinfo rpcproc_null = {
2257         .p_encode = rpcproc_encode_null,
2258         .p_decode = rpcproc_decode_null,
2259 };
2260
2261 static int rpc_ping(struct rpc_clnt *clnt)
2262 {
2263         struct rpc_message msg = {
2264                 .rpc_proc = &rpcproc_null,
2265         };
2266         int err;
2267         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2268         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2269         put_rpccred(msg.rpc_cred);
2270         return err;
2271 }
2272
2273 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2274 {
2275         struct rpc_message msg = {
2276                 .rpc_proc = &rpcproc_null,
2277                 .rpc_cred = cred,
2278         };
2279         struct rpc_task_setup task_setup_data = {
2280                 .rpc_client = clnt,
2281                 .rpc_message = &msg,
2282                 .callback_ops = &rpc_default_ops,
2283                 .flags = flags,
2284         };
2285         return rpc_run_task(&task_setup_data);
2286 }
2287 EXPORT_SYMBOL_GPL(rpc_call_null);
2288
2289 #ifdef RPC_DEBUG
2290 static void rpc_show_header(void)
2291 {
2292         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2293                 "-timeout ---ops--\n");
2294 }
2295
2296 static void rpc_show_task(const struct rpc_clnt *clnt,
2297                           const struct rpc_task *task)
2298 {
2299         const char *rpc_waitq = "none";
2300
2301         if (RPC_IS_QUEUED(task))
2302                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2303
2304         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2305                 task->tk_pid, task->tk_flags, task->tk_status,
2306                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2307                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2308                 task->tk_action, rpc_waitq);
2309 }
2310
2311 void rpc_show_tasks(struct net *net)
2312 {
2313         struct rpc_clnt *clnt;
2314         struct rpc_task *task;
2315         int header = 0;
2316         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2317
2318         spin_lock(&sn->rpc_client_lock);
2319         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2320                 spin_lock(&clnt->cl_lock);
2321                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2322                         if (!header) {
2323                                 rpc_show_header();
2324                                 header++;
2325                         }
2326                         rpc_show_task(clnt, task);
2327                 }
2328                 spin_unlock(&clnt->cl_lock);
2329         }
2330         spin_unlock(&sn->rpc_client_lock);
2331 }
2332 #endif