net/sunrpc/clnt.c

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