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/rcupdate.h>
  29 #include <linux/utsname.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/in.h>
  32 #include <linux/in6.h>
  33 #include <linux/un.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 #if IS_ENABLED(CONFIG_SUNRPC_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
 188         switch (event) {
 189         case RPC_PIPEFS_MOUNT:
 190                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 191                 if (!dentry)
 192                         return -ENOENT;
 193                 if (IS_ERR(dentry))
 194                         return PTR_ERR(dentry);
 195                 break;
 196         case RPC_PIPEFS_UMOUNT:
 197                 __rpc_clnt_remove_pipedir(clnt);
 198                 break;
 199         default:
 200                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 201                 return -ENOTSUPP;
 202         }
 203         return 0;
 204 }
 205
 206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 207                                 struct super_block *sb)
 208 {
 209         int error = 0;
 210
 211         for (;; clnt = clnt->cl_parent) {
 212                 if (!rpc_clnt_skip_event(clnt, event))
 213                         error = __rpc_clnt_handle_event(clnt, event, sb);
 214                 if (error || clnt == clnt->cl_parent)
 215                         break;
 216         }
 217         return error;
 218 }
 219
 220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 221 {
 222         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 223         struct rpc_clnt *clnt;
 224
 225         spin_lock(&sn->rpc_client_lock);
 226         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 227                 if (rpc_clnt_skip_event(clnt, event))
 228                         continue;
 229                 spin_unlock(&sn->rpc_client_lock);
 230                 return clnt;
 231         }
 232         spin_unlock(&sn->rpc_client_lock);
 233         return NULL;
 234 }
 235
 236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 237                             void *ptr)
 238 {
 239         struct super_block *sb = ptr;
 240         struct rpc_clnt *clnt;
 241         int error = 0;
 242
 243         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 244                 error = __rpc_pipefs_event(clnt, event, sb);
 245                 if (error)
 246                         break;
 247         }
 248         return error;
 249 }
 250
 251 static struct notifier_block rpc_clients_block = {
 252         .notifier_call  = rpc_pipefs_event,
 253         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 254 };
 255
 256 int rpc_clients_notifier_register(void)
 257 {
 258         return rpc_pipefs_notifier_register(&rpc_clients_block);
 259 }
 260
 261 void rpc_clients_notifier_unregister(void)
 262 {
 263         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 264 }
 265
 266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 267                 struct rpc_xprt *xprt,
 268                 const struct rpc_timeout *timeout)
 269 {
 270         struct rpc_xprt *old;
 271
 272         spin_lock(&clnt->cl_lock);
 273         old = rcu_dereference_protected(clnt->cl_xprt,
 274                         lockdep_is_held(&clnt->cl_lock));
 275
 276         if (!xprt_bound(xprt))
 277                 clnt->cl_autobind = 1;
 278
 279         clnt->cl_timeout = timeout;
 280         rcu_assign_pointer(clnt->cl_xprt, xprt);
 281         spin_unlock(&clnt->cl_lock);
 282
 283         return old;
 284 }
 285
 286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 287 {
 288         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 289                         nodename, sizeof(clnt->cl_nodename));
 290 }
 291
 292 static int rpc_client_register(struct rpc_clnt *clnt,
 293                                rpc_authflavor_t pseudoflavor,
 294                                const char *client_name)
 295 {
 296         struct rpc_auth_create_args auth_args = {
 297                 .pseudoflavor = pseudoflavor,
 298                 .target_name = client_name,
 299         };
 300         struct rpc_auth *auth;
 301         struct net *net = rpc_net_ns(clnt);
 302         struct super_block *pipefs_sb;
 303         int err;
 304
 305         rpc_clnt_debugfs_register(clnt);
 306
 307         pipefs_sb = rpc_get_sb_net(net);
 308         if (pipefs_sb) {
 309                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 310                 if (err)
 311                         goto out;
 312         }
 313
 314         rpc_register_client(clnt);
 315         if (pipefs_sb)
 316                 rpc_put_sb_net(net);
 317
 318         auth = rpcauth_create(&auth_args, clnt);
 319         if (IS_ERR(auth)) {
 320                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 321                                 pseudoflavor);
 322                 err = PTR_ERR(auth);
 323                 goto err_auth;
 324         }
 325         return 0;
 326 err_auth:
 327         pipefs_sb = rpc_get_sb_net(net);
 328         rpc_unregister_client(clnt);
 329         __rpc_clnt_remove_pipedir(clnt);
 330 out:
 331         if (pipefs_sb)
 332                 rpc_put_sb_net(net);
 333         rpc_clnt_debugfs_unregister(clnt);
 334         return err;
 335 }
 336
 337 static DEFINE_IDA(rpc_clids);
 338
 339 void rpc_cleanup_clids(void)
 340 {
 341         ida_destroy(&rpc_clids);
 342 }
 343
 344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 345 {
 346         int clid;
 347
 348         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 349         if (clid < 0)
 350                 return clid;
 351         clnt->cl_clid = clid;
 352         return 0;
 353 }
 354
 355 static void rpc_free_clid(struct rpc_clnt *clnt)
 356 {
 357         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 358 }
 359
 360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 361                 struct rpc_xprt_switch *xps,
 362                 struct rpc_xprt *xprt,
 363                 struct rpc_clnt *parent)
 364 {
 365         const struct rpc_program *program = args->program;
 366         const struct rpc_version *version;
 367         struct rpc_clnt *clnt = NULL;
 368         const struct rpc_timeout *timeout;
 369         const char *nodename = args->nodename;
 370         int err;
 371
 372         /* sanity check the name before trying to print it */
 373         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 374                         program->name, args->servername, xprt);
 375
 376         err = rpciod_up();
 377         if (err)
 378                 goto out_no_rpciod;
 379
 380         err = -EINVAL;
 381         if (args->version >= program->nrvers)
 382                 goto out_err;
 383         version = program->version[args->version];
 384         if (version == NULL)
 385                 goto out_err;
 386
 387         err = -ENOMEM;
 388         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 389         if (!clnt)
 390                 goto out_err;
 391         clnt->cl_parent = parent ? : clnt;
 392
 393         err = rpc_alloc_clid(clnt);
 394         if (err)
 395                 goto out_no_clid;
 396
 397         clnt->cl_procinfo = version->procs;
 398         clnt->cl_maxproc  = version->nrprocs;
 399         clnt->cl_prog     = args->prognumber ? : program->number;
 400         clnt->cl_vers     = version->number;
 401         clnt->cl_stats    = program->stats;
 402         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 403         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 404         err = -ENOMEM;
 405         if (clnt->cl_metrics == NULL)
 406                 goto out_no_stats;
 407         clnt->cl_program  = program;
 408         INIT_LIST_HEAD(&clnt->cl_tasks);
 409         spin_lock_init(&clnt->cl_lock);
 410
 411         timeout = xprt->timeout;
 412         if (args->timeout != NULL) {
 413                 memcpy(&clnt->cl_timeout_default, args->timeout,
 414                                 sizeof(clnt->cl_timeout_default));
 415                 timeout = &clnt->cl_timeout_default;
 416         }
 417
 418         rpc_clnt_set_transport(clnt, xprt, timeout);
 419         xprt_iter_init(&clnt->cl_xpi, xps);
 420         xprt_switch_put(xps);
 421
 422         clnt->cl_rtt = &clnt->cl_rtt_default;
 423         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 424
 425         atomic_set(&clnt->cl_count, 1);
 426
 427         if (nodename == NULL)
 428                 nodename = utsname()->nodename;
 429         /* save the nodename */
 430         rpc_clnt_set_nodename(clnt, nodename);
 431
 432         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 433         if (err)
 434                 goto out_no_path;
 435         if (parent)
 436                 atomic_inc(&parent->cl_count);
 437         return clnt;
 438
 439 out_no_path:
 440         rpc_free_iostats(clnt->cl_metrics);
 441 out_no_stats:
 442         rpc_free_clid(clnt);
 443 out_no_clid:
 444         kfree(clnt);
 445 out_err:
 446         rpciod_down();
 447 out_no_rpciod:
 448         xprt_switch_put(xps);
 449         xprt_put(xprt);
 450         return ERR_PTR(err);
 451 }
 452
 453 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 454                                         struct rpc_xprt *xprt)
 455 {
 456         struct rpc_clnt *clnt = NULL;
 457         struct rpc_xprt_switch *xps;
 458
 459         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 460                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 461                 xps = args->bc_xprt->xpt_bc_xps;
 462                 xprt_switch_get(xps);
 463         } else {
 464                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 465                 if (xps == NULL) {
 466                         xprt_put(xprt);
 467                         return ERR_PTR(-ENOMEM);
 468                 }
 469                 if (xprt->bc_xprt) {
 470                         xprt_switch_get(xps);
 471                         xprt->bc_xprt->xpt_bc_xps = xps;
 472                 }
 473         }
 474         clnt = rpc_new_client(args, xps, xprt, NULL);
 475         if (IS_ERR(clnt))
 476                 return clnt;
 477
 478         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 479                 int err = rpc_ping(clnt);
 480                 if (err != 0) {
 481                         rpc_shutdown_client(clnt);
 482                         return ERR_PTR(err);
 483                 }
 484         }
 485
 486         clnt->cl_softrtry = 1;
 487         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 488                 clnt->cl_softrtry = 0;
 489
 490         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 491                 clnt->cl_autobind = 1;
 492         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 493                 clnt->cl_noretranstimeo = 1;
 494         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 495                 clnt->cl_discrtry = 1;
 496         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 497                 clnt->cl_chatty = 1;
 498
 499         return clnt;
 500 }
 501
 502 /**
 503  * rpc_create - create an RPC client and transport with one call
 504  * @args: rpc_clnt create argument structure
 505  *
 506  * Creates and initializes an RPC transport and an RPC client.
 507  *
 508  * It can ping the server in order to determine if it is up, and to see if
 509  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 510  * this behavior so asynchronous tasks can also use rpc_create.
 511  */
 512 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 513 {
 514         struct rpc_xprt *xprt;
 515         struct xprt_create xprtargs = {
 516                 .net = args->net,
 517                 .ident = args->protocol,
 518                 .srcaddr = args->saddress,
 519                 .dstaddr = args->address,
 520                 .addrlen = args->addrsize,
 521                 .servername = args->servername,
 522                 .bc_xprt = args->bc_xprt,
 523         };
 524         char servername[48];
 525
 526         if (args->bc_xprt) {
 527                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 528                 xprt = args->bc_xprt->xpt_bc_xprt;
 529                 if (xprt) {
 530                         xprt_get(xprt);
 531                         return rpc_create_xprt(args, xprt);
 532                 }
 533         }
 534
 535         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 536                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 537         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 538                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 539         /*
 540          * If the caller chooses not to specify a hostname, whip
 541          * up a string representation of the passed-in address.
 542          */
 543         if (xprtargs.servername == NULL) {
 544                 struct sockaddr_un *sun =
 545                                 (struct sockaddr_un *)args->address;
 546                 struct sockaddr_in *sin =
 547                                 (struct sockaddr_in *)args->address;
 548                 struct sockaddr_in6 *sin6 =
 549                                 (struct sockaddr_in6 *)args->address;
 550
 551                 servername[0] = '\0';
 552                 switch (args->address->sa_family) {
 553                 case AF_LOCAL:
 554                         snprintf(servername, sizeof(servername), "%s",
 555                                  sun->sun_path);
 556                         break;
 557                 case AF_INET:
 558                         snprintf(servername, sizeof(servername), "%pI4",
 559                                  &sin->sin_addr.s_addr);
 560                         break;
 561                 case AF_INET6:
 562                         snprintf(servername, sizeof(servername), "%pI6",
 563                                  &sin6->sin6_addr);
 564                         break;
 565                 default:
 566                         /* caller wants default server name, but
 567                          * address family isn't recognized. */
 568                         return ERR_PTR(-EINVAL);
 569                 }
 570                 xprtargs.servername = servername;
 571         }
 572
 573         xprt = xprt_create_transport(&xprtargs);
 574         if (IS_ERR(xprt))
 575                 return (struct rpc_clnt *)xprt;
 576
 577         /*
 578          * By default, kernel RPC client connects from a reserved port.
 579          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 580          * but it is always enabled for rpciod, which handles the connect
 581          * operation.
 582          */
 583         xprt->resvport = 1;
 584         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 585                 xprt->resvport = 0;
 586
 587         return rpc_create_xprt(args, xprt);
 588 }
 589 EXPORT_SYMBOL_GPL(rpc_create);
 590
 591 /*
 592  * This function clones the RPC client structure. It allows us to share the
 593  * same transport while varying parameters such as the authentication
 594  * flavour.
 595  */
 596 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 597                                            struct rpc_clnt *clnt)
 598 {
 599         struct rpc_xprt_switch *xps;
 600         struct rpc_xprt *xprt;
 601         struct rpc_clnt *new;
 602         int err;
 603
 604         err = -ENOMEM;
 605         rcu_read_lock();
 606         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 607         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 608         rcu_read_unlock();
 609         if (xprt == NULL || xps == NULL) {
 610                 xprt_put(xprt);
 611                 xprt_switch_put(xps);
 612                 goto out_err;
 613         }
 614         args->servername = xprt->servername;
 615         args->nodename = clnt->cl_nodename;
 616
 617         new = rpc_new_client(args, xps, xprt, clnt);
 618         if (IS_ERR(new)) {
 619                 err = PTR_ERR(new);
 620                 goto out_err;
 621         }
 622
 623         /* Turn off autobind on clones */
 624         new->cl_autobind = 0;
 625         new->cl_softrtry = clnt->cl_softrtry;
 626         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 627         new->cl_discrtry = clnt->cl_discrtry;
 628         new->cl_chatty = clnt->cl_chatty;
 629         return new;
 630
 631 out_err:
 632         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 633         return ERR_PTR(err);
 634 }
 635
 636 /**
 637  * rpc_clone_client - Clone an RPC client structure
 638  *
 639  * @clnt: RPC client whose parameters are copied
 640  *
 641  * Returns a fresh RPC client or an ERR_PTR.
 642  */
 643 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 644 {
 645         struct rpc_create_args args = {
 646                 .program        = clnt->cl_program,
 647                 .prognumber     = clnt->cl_prog,
 648                 .version        = clnt->cl_vers,
 649                 .authflavor     = clnt->cl_auth->au_flavor,
 650         };
 651         return __rpc_clone_client(&args, clnt);
 652 }
 653 EXPORT_SYMBOL_GPL(rpc_clone_client);
 654
 655 /**
 656  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 657  *
 658  * @clnt: RPC client whose parameters are copied
 659  * @flavor: security flavor for new client
 660  *
 661  * Returns a fresh RPC client or an ERR_PTR.
 662  */
 663 struct rpc_clnt *
 664 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 665 {
 666         struct rpc_create_args args = {
 667                 .program        = clnt->cl_program,
 668                 .prognumber     = clnt->cl_prog,
 669                 .version        = clnt->cl_vers,
 670                 .authflavor     = flavor,
 671         };
 672         return __rpc_clone_client(&args, clnt);
 673 }
 674 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 675
 676 /**
 677  * rpc_switch_client_transport: switch the RPC transport on the fly
 678  * @clnt: pointer to a struct rpc_clnt
 679  * @args: pointer to the new transport arguments
 680  * @timeout: pointer to the new timeout parameters
 681  *
 682  * This function allows the caller to switch the RPC transport for the
 683  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 684  * server, for instance.  It assumes that the caller has ensured that
 685  * there are no active RPC tasks by using some form of locking.
 686  *
 687  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 688  * negative errno is returned, and "clnt" continues to use the old
 689  * xprt.
 690  */
 691 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 692                 struct xprt_create *args,
 693                 const struct rpc_timeout *timeout)
 694 {
 695         const struct rpc_timeout *old_timeo;
 696         rpc_authflavor_t pseudoflavor;
 697         struct rpc_xprt_switch *xps, *oldxps;
 698         struct rpc_xprt *xprt, *old;
 699         struct rpc_clnt *parent;
 700         int err;
 701
 702         xprt = xprt_create_transport(args);
 703         if (IS_ERR(xprt)) {
 704                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 705                         clnt);
 706                 return PTR_ERR(xprt);
 707         }
 708
 709         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 710         if (xps == NULL) {
 711                 xprt_put(xprt);
 712                 return -ENOMEM;
 713         }
 714
 715         pseudoflavor = clnt->cl_auth->au_flavor;
 716
 717         old_timeo = clnt->cl_timeout;
 718         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 719         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 720
 721         rpc_unregister_client(clnt);
 722         __rpc_clnt_remove_pipedir(clnt);
 723         rpc_clnt_debugfs_unregister(clnt);
 724
 725         /*
 726          * A new transport was created.  "clnt" therefore
 727          * becomes the root of a new cl_parent tree.  clnt's
 728          * children, if it has any, still point to the old xprt.
 729          */
 730         parent = clnt->cl_parent;
 731         clnt->cl_parent = clnt;
 732
 733         /*
 734          * The old rpc_auth cache cannot be re-used.  GSS
 735          * contexts in particular are between a single
 736          * client and server.
 737          */
 738         err = rpc_client_register(clnt, pseudoflavor, NULL);
 739         if (err)
 740                 goto out_revert;
 741
 742         synchronize_rcu();
 743         if (parent != clnt)
 744                 rpc_release_client(parent);
 745         xprt_switch_put(oldxps);
 746         xprt_put(old);
 747         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 748         return 0;
 749
 750 out_revert:
 751         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 752         rpc_clnt_set_transport(clnt, old, old_timeo);
 753         clnt->cl_parent = parent;
 754         rpc_client_register(clnt, pseudoflavor, NULL);
 755         xprt_switch_put(xps);
 756         xprt_put(xprt);
 757         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 758         return err;
 759 }
 760 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 761
 762 static
 763 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 764 {
 765         struct rpc_xprt_switch *xps;
 766
 767         rcu_read_lock();
 768         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 769         rcu_read_unlock();
 770         if (xps == NULL)
 771                 return -EAGAIN;
 772         xprt_iter_init_listall(xpi, xps);
 773         xprt_switch_put(xps);
 774         return 0;
 775 }
 776
 777 /**
 778  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 779  * @clnt: pointer to client
 780  * @fn: function to apply
 781  * @data: void pointer to function data
 782  *
 783  * Iterates through the list of RPC transports currently attached to the
 784  * client and applies the function fn(clnt, xprt, data).
 785  *
 786  * On error, the iteration stops, and the function returns the error value.
 787  */
 788 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 789                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 790                 void *data)
 791 {
 792         struct rpc_xprt_iter xpi;
 793         int ret;
 794
 795         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 796         if (ret)
 797                 return ret;
 798         for (;;) {
 799                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 800
 801                 if (!xprt)
 802                         break;
 803                 ret = fn(clnt, xprt, data);
 804                 xprt_put(xprt);
 805                 if (ret < 0)
 806                         break;
 807         }
 808         xprt_iter_destroy(&xpi);
 809         return ret;
 810 }
 811 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 812
 813 /*
 814  * Kill all tasks for the given client.
 815  * XXX: kill their descendants as well?
 816  */
 817 void rpc_killall_tasks(struct rpc_clnt *clnt)
 818 {
 819         struct rpc_task *rovr;
 820
 821
 822         if (list_empty(&clnt->cl_tasks))
 823                 return;
 824         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 825         /*
 826          * Spin lock all_tasks to prevent changes...
 827          */
 828         spin_lock(&clnt->cl_lock);
 829         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 830                 if (!RPC_IS_ACTIVATED(rovr))
 831                         continue;
 832                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 833                         rovr->tk_flags |= RPC_TASK_KILLED;
 834                         rpc_exit(rovr, -EIO);
 835                         if (RPC_IS_QUEUED(rovr))
 836                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 837                                                         rovr);
 838                 }
 839         }
 840         spin_unlock(&clnt->cl_lock);
 841 }
 842 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 843
 844 /*
 845  * Properly shut down an RPC client, terminating all outstanding
 846  * requests.
 847  */
 848 void rpc_shutdown_client(struct rpc_clnt *clnt)
 849 {
 850         might_sleep();
 851
 852         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 853                         clnt->cl_program->name,
 854                         rcu_dereference(clnt->cl_xprt)->servername);
 855
 856         while (!list_empty(&clnt->cl_tasks)) {
 857                 rpc_killall_tasks(clnt);
 858                 wait_event_timeout(destroy_wait,
 859                         list_empty(&clnt->cl_tasks), 1*HZ);
 860         }
 861
 862         rpc_release_client(clnt);
 863 }
 864 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 865
 866 /*
 867  * Free an RPC client
 868  */
 869 static struct rpc_clnt *
 870 rpc_free_client(struct rpc_clnt *clnt)
 871 {
 872         struct rpc_clnt *parent = NULL;
 873
 874         dprintk_rcu("RPC:       destroying %s client for %s\n",
 875                         clnt->cl_program->name,
 876                         rcu_dereference(clnt->cl_xprt)->servername);
 877         if (clnt->cl_parent != clnt)
 878                 parent = clnt->cl_parent;
 879         rpc_clnt_debugfs_unregister(clnt);
 880         rpc_clnt_remove_pipedir(clnt);
 881         rpc_unregister_client(clnt);
 882         rpc_free_iostats(clnt->cl_metrics);
 883         clnt->cl_metrics = NULL;
 884         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 885         xprt_iter_destroy(&clnt->cl_xpi);
 886         rpciod_down();
 887         rpc_free_clid(clnt);
 888         kfree(clnt);
 889         return parent;
 890 }
 891
 892 /*
 893  * Free an RPC client
 894  */
 895 static struct rpc_clnt *
 896 rpc_free_auth(struct rpc_clnt *clnt)
 897 {
 898         if (clnt->cl_auth == NULL)
 899                 return rpc_free_client(clnt);
 900
 901         /*
 902          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 903          *       release remaining GSS contexts. This mechanism ensures
 904          *       that it can do so safely.
 905          */
 906         atomic_inc(&clnt->cl_count);
 907         rpcauth_release(clnt->cl_auth);
 908         clnt->cl_auth = NULL;
 909         if (atomic_dec_and_test(&clnt->cl_count))
 910                 return rpc_free_client(clnt);
 911         return NULL;
 912 }
 913
 914 /*
 915  * Release reference to the RPC client
 916  */
 917 void
 918 rpc_release_client(struct rpc_clnt *clnt)
 919 {
 920         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 921
 922         do {
 923                 if (list_empty(&clnt->cl_tasks))
 924                         wake_up(&destroy_wait);
 925                 if (!atomic_dec_and_test(&clnt->cl_count))
 926                         break;
 927                 clnt = rpc_free_auth(clnt);
 928         } while (clnt != NULL);
 929 }
 930 EXPORT_SYMBOL_GPL(rpc_release_client);
 931
 932 /**
 933  * rpc_bind_new_program - bind a new RPC program to an existing client
 934  * @old: old rpc_client
 935  * @program: rpc program to set
 936  * @vers: rpc program version
 937  *
 938  * Clones the rpc client and sets up a new RPC program. This is mainly
 939  * of use for enabling different RPC programs to share the same transport.
 940  * The Sun NFSv2/v3 ACL protocol can do this.
 941  */
 942 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 943                                       const struct rpc_program *program,
 944                                       u32 vers)
 945 {
 946         struct rpc_create_args args = {
 947                 .program        = program,
 948                 .prognumber     = program->number,
 949                 .version        = vers,
 950                 .authflavor     = old->cl_auth->au_flavor,
 951         };
 952         struct rpc_clnt *clnt;
 953         int err;
 954
 955         clnt = __rpc_clone_client(&args, old);
 956         if (IS_ERR(clnt))
 957                 goto out;
 958         err = rpc_ping(clnt);
 959         if (err != 0) {
 960                 rpc_shutdown_client(clnt);
 961                 clnt = ERR_PTR(err);
 962         }
 963 out:
 964         return clnt;
 965 }
 966 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 967
 968 void rpc_task_release_transport(struct rpc_task *task)
 969 {
 970         struct rpc_xprt *xprt = task->tk_xprt;
 971
 972         if (xprt) {
 973                 task->tk_xprt = NULL;
 974                 xprt_put(xprt);
 975         }
 976 }
 977 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
 978
 979 void rpc_task_release_client(struct rpc_task *task)
 980 {
 981         struct rpc_clnt *clnt = task->tk_client;
 982
 983         if (clnt != NULL) {
 984                 /* Remove from client task list */
 985                 spin_lock(&clnt->cl_lock);
 986                 list_del(&task->tk_task);
 987                 spin_unlock(&clnt->cl_lock);
 988                 task->tk_client = NULL;
 989
 990                 rpc_release_client(clnt);
 991         }
 992         rpc_task_release_transport(task);
 993 }
 994
 995 static
 996 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 997 {
 998         if (!task->tk_xprt)
 999                 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
1000 }
1001
1002 static
1003 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1004 {
1005
1006         if (clnt != NULL) {
1007                 rpc_task_set_transport(task, clnt);
1008                 task->tk_client = clnt;
1009                 atomic_inc(&clnt->cl_count);
1010                 if (clnt->cl_softrtry)
1011                         task->tk_flags |= RPC_TASK_SOFT;
1012                 if (clnt->cl_noretranstimeo)
1013                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1014                 if (atomic_read(&clnt->cl_swapper))
1015                         task->tk_flags |= RPC_TASK_SWAPPER;
1016                 /* Add to the client's list of all tasks */
1017                 spin_lock(&clnt->cl_lock);
1018                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1019                 spin_unlock(&clnt->cl_lock);
1020         }
1021 }
1022
1023 static void
1024 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1025 {
1026         if (msg != NULL) {
1027                 task->tk_msg.rpc_proc = msg->rpc_proc;
1028                 task->tk_msg.rpc_argp = msg->rpc_argp;
1029                 task->tk_msg.rpc_resp = msg->rpc_resp;
1030                 if (msg->rpc_cred != NULL)
1031                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1032         }
1033 }
1034
1035 /*
1036  * Default callback for async RPC calls
1037  */
1038 static void
1039 rpc_default_callback(struct rpc_task *task, void *data)
1040 {
1041 }
1042
1043 static const struct rpc_call_ops rpc_default_ops = {
1044         .rpc_call_done = rpc_default_callback,
1045 };
1046
1047 /**
1048  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1049  * @task_setup_data: pointer to task initialisation data
1050  */
1051 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1052 {
1053         struct rpc_task *task;
1054
1055         task = rpc_new_task(task_setup_data);
1056
1057         rpc_task_set_client(task, task_setup_data->rpc_client);
1058         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1059
1060         if (task->tk_action == NULL)
1061                 rpc_call_start(task);
1062
1063         atomic_inc(&task->tk_count);
1064         rpc_execute(task);
1065         return task;
1066 }
1067 EXPORT_SYMBOL_GPL(rpc_run_task);
1068
1069 /**
1070  * rpc_call_sync - Perform a synchronous RPC call
1071  * @clnt: pointer to RPC client
1072  * @msg: RPC call parameters
1073  * @flags: RPC call flags
1074  */
1075 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1076 {
1077         struct rpc_task *task;
1078         struct rpc_task_setup task_setup_data = {
1079                 .rpc_client = clnt,
1080                 .rpc_message = msg,
1081                 .callback_ops = &rpc_default_ops,
1082                 .flags = flags,
1083         };
1084         int status;
1085
1086         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1087         if (flags & RPC_TASK_ASYNC) {
1088                 rpc_release_calldata(task_setup_data.callback_ops,
1089                         task_setup_data.callback_data);
1090                 return -EINVAL;
1091         }
1092
1093         task = rpc_run_task(&task_setup_data);
1094         if (IS_ERR(task))
1095                 return PTR_ERR(task);
1096         status = task->tk_status;
1097         rpc_put_task(task);
1098         return status;
1099 }
1100 EXPORT_SYMBOL_GPL(rpc_call_sync);
1101
1102 /**
1103  * rpc_call_async - Perform an asynchronous RPC call
1104  * @clnt: pointer to RPC client
1105  * @msg: RPC call parameters
1106  * @flags: RPC call flags
1107  * @tk_ops: RPC call ops
1108  * @data: user call data
1109  */
1110 int
1111 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1112                const struct rpc_call_ops *tk_ops, void *data)
1113 {
1114         struct rpc_task *task;
1115         struct rpc_task_setup task_setup_data = {
1116                 .rpc_client = clnt,
1117                 .rpc_message = msg,
1118                 .callback_ops = tk_ops,
1119                 .callback_data = data,
1120                 .flags = flags|RPC_TASK_ASYNC,
1121         };
1122
1123         task = rpc_run_task(&task_setup_data);
1124         if (IS_ERR(task))
1125                 return PTR_ERR(task);
1126         rpc_put_task(task);
1127         return 0;
1128 }
1129 EXPORT_SYMBOL_GPL(rpc_call_async);
1130
1131 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1132 /**
1133  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1134  * rpc_execute against it
1135  * @req: RPC request
1136  */
1137 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1138 {
1139         struct rpc_task *task;
1140         struct xdr_buf *xbufp = &req->rq_snd_buf;
1141         struct rpc_task_setup task_setup_data = {
1142                 .callback_ops = &rpc_default_ops,
1143                 .flags = RPC_TASK_SOFTCONN,
1144         };
1145
1146         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1147         /*
1148          * Create an rpc_task to send the data
1149          */
1150         task = rpc_new_task(&task_setup_data);
1151         task->tk_rqstp = req;
1152
1153         /*
1154          * Set up the xdr_buf length.
1155          * This also indicates that the buffer is XDR encoded already.
1156          */
1157         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1158                         xbufp->tail[0].iov_len;
1159
1160         task->tk_action = call_bc_transmit;
1161         atomic_inc(&task->tk_count);
1162         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1163         rpc_execute(task);
1164
1165         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1166         return task;
1167 }
1168 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1169
1170 void
1171 rpc_call_start(struct rpc_task *task)
1172 {
1173         task->tk_action = call_start;
1174 }
1175 EXPORT_SYMBOL_GPL(rpc_call_start);
1176
1177 /**
1178  * rpc_peeraddr - extract remote peer address from clnt's xprt
1179  * @clnt: RPC client structure
1180  * @buf: target buffer
1181  * @bufsize: length of target buffer
1182  *
1183  * Returns the number of bytes that are actually in the stored address.
1184  */
1185 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1186 {
1187         size_t bytes;
1188         struct rpc_xprt *xprt;
1189
1190         rcu_read_lock();
1191         xprt = rcu_dereference(clnt->cl_xprt);
1192
1193         bytes = xprt->addrlen;
1194         if (bytes > bufsize)
1195                 bytes = bufsize;
1196         memcpy(buf, &xprt->addr, bytes);
1197         rcu_read_unlock();
1198
1199         return bytes;
1200 }
1201 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1202
1203 /**
1204  * rpc_peeraddr2str - return remote peer address in printable format
1205  * @clnt: RPC client structure
1206  * @format: address format
1207  *
1208  * NB: the lifetime of the memory referenced by the returned pointer is
1209  * the same as the rpc_xprt itself.  As long as the caller uses this
1210  * pointer, it must hold the RCU read lock.
1211  */
1212 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1213                              enum rpc_display_format_t format)
1214 {
1215         struct rpc_xprt *xprt;
1216
1217         xprt = rcu_dereference(clnt->cl_xprt);
1218
1219         if (xprt->address_strings[format] != NULL)
1220                 return xprt->address_strings[format];
1221         else
1222                 return "unprintable";
1223 }
1224 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1225
1226 static const struct sockaddr_in rpc_inaddr_loopback = {
1227         .sin_family             = AF_INET,
1228         .sin_addr.s_addr        = htonl(INADDR_ANY),
1229 };
1230
1231 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1232         .sin6_family            = AF_INET6,
1233         .sin6_addr              = IN6ADDR_ANY_INIT,
1234 };
1235
1236 /*
1237  * Try a getsockname() on a connected datagram socket.  Using a
1238  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1239  * This conserves the ephemeral port number space.
1240  *
1241  * Returns zero and fills in "buf" if successful; otherwise, a
1242  * negative errno is returned.
1243  */
1244 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1245                         struct sockaddr *buf)
1246 {
1247         struct socket *sock;
1248         int err;
1249
1250         err = __sock_create(net, sap->sa_family,
1251                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1252         if (err < 0) {
1253                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1254                 goto out;
1255         }
1256
1257         switch (sap->sa_family) {
1258         case AF_INET:
1259                 err = kernel_bind(sock,
1260                                 (struct sockaddr *)&rpc_inaddr_loopback,
1261                                 sizeof(rpc_inaddr_loopback));
1262                 break;
1263         case AF_INET6:
1264                 err = kernel_bind(sock,
1265                                 (struct sockaddr *)&rpc_in6addr_loopback,
1266                                 sizeof(rpc_in6addr_loopback));
1267                 break;
1268         default:
1269                 err = -EAFNOSUPPORT;
1270                 goto out_release;
1271         }
1272         if (err < 0) {
1273                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1274                 goto out_release;
1275         }
1276
1277         err = kernel_connect(sock, sap, salen, 0);
1278         if (err < 0) {
1279                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1280                 goto out_release;
1281         }
1282
1283         err = kernel_getsockname(sock, buf);
1284         if (err < 0) {
1285                 dprintk("RPC:       getsockname failed (%d)\n", err);
1286                 goto out_release;
1287         }
1288
1289         err = 0;
1290         if (buf->sa_family == AF_INET6) {
1291                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1292                 sin6->sin6_scope_id = 0;
1293         }
1294         dprintk("RPC:       %s succeeded\n", __func__);
1295
1296 out_release:
1297         sock_release(sock);
1298 out:
1299         return err;
1300 }
1301
1302 /*
1303  * Scraping a connected socket failed, so we don't have a useable
1304  * local address.  Fallback: generate an address that will prevent
1305  * the server from calling us back.
1306  *
1307  * Returns zero and fills in "buf" if successful; otherwise, a
1308  * negative errno is returned.
1309  */
1310 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1311 {
1312         switch (family) {
1313         case AF_INET:
1314                 if (buflen < sizeof(rpc_inaddr_loopback))
1315                         return -EINVAL;
1316                 memcpy(buf, &rpc_inaddr_loopback,
1317                                 sizeof(rpc_inaddr_loopback));
1318                 break;
1319         case AF_INET6:
1320                 if (buflen < sizeof(rpc_in6addr_loopback))
1321                         return -EINVAL;
1322                 memcpy(buf, &rpc_in6addr_loopback,
1323                                 sizeof(rpc_in6addr_loopback));
1324                 break;
1325         default:
1326                 dprintk("RPC:       %s: address family not supported\n",
1327                         __func__);
1328                 return -EAFNOSUPPORT;
1329         }
1330         dprintk("RPC:       %s: succeeded\n", __func__);
1331         return 0;
1332 }
1333
1334 /**
1335  * rpc_localaddr - discover local endpoint address for an RPC client
1336  * @clnt: RPC client structure
1337  * @buf: target buffer
1338  * @buflen: size of target buffer, in bytes
1339  *
1340  * Returns zero and fills in "buf" and "buflen" if successful;
1341  * otherwise, a negative errno is returned.
1342  *
1343  * This works even if the underlying transport is not currently connected,
1344  * or if the upper layer never previously provided a source address.
1345  *
1346  * The result of this function call is transient: multiple calls in
1347  * succession may give different results, depending on how local
1348  * networking configuration changes over time.
1349  */
1350 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1351 {
1352         struct sockaddr_storage address;
1353         struct sockaddr *sap = (struct sockaddr *)&address;
1354         struct rpc_xprt *xprt;
1355         struct net *net;
1356         size_t salen;
1357         int err;
1358
1359         rcu_read_lock();
1360         xprt = rcu_dereference(clnt->cl_xprt);
1361         salen = xprt->addrlen;
1362         memcpy(sap, &xprt->addr, salen);
1363         net = get_net(xprt->xprt_net);
1364         rcu_read_unlock();
1365
1366         rpc_set_port(sap, 0);
1367         err = rpc_sockname(net, sap, salen, buf);
1368         put_net(net);
1369         if (err != 0)
1370                 /* Couldn't discover local address, return ANYADDR */
1371                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1372         return 0;
1373 }
1374 EXPORT_SYMBOL_GPL(rpc_localaddr);
1375
1376 void
1377 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1378 {
1379         struct rpc_xprt *xprt;
1380
1381         rcu_read_lock();
1382         xprt = rcu_dereference(clnt->cl_xprt);
1383         if (xprt->ops->set_buffer_size)
1384                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1385         rcu_read_unlock();
1386 }
1387 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1388
1389 /**
1390  * rpc_net_ns - Get the network namespace for this RPC client
1391  * @clnt: RPC client to query
1392  *
1393  */
1394 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1395 {
1396         struct net *ret;
1397
1398         rcu_read_lock();
1399         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1400         rcu_read_unlock();
1401         return ret;
1402 }
1403 EXPORT_SYMBOL_GPL(rpc_net_ns);
1404
1405 /**
1406  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1407  * @clnt: RPC client to query
1408  *
1409  * For stream transports, this is one RPC record fragment (see RFC
1410  * 1831), as we don't support multi-record requests yet.  For datagram
1411  * transports, this is the size of an IP packet minus the IP, UDP, and
1412  * RPC header sizes.
1413  */
1414 size_t rpc_max_payload(struct rpc_clnt *clnt)
1415 {
1416         size_t ret;
1417
1418         rcu_read_lock();
1419         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1420         rcu_read_unlock();
1421         return ret;
1422 }
1423 EXPORT_SYMBOL_GPL(rpc_max_payload);
1424
1425 /**
1426  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1427  * @clnt: RPC client to query
1428  */
1429 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1430 {
1431         struct rpc_xprt *xprt;
1432         size_t ret;
1433
1434         rcu_read_lock();
1435         xprt = rcu_dereference(clnt->cl_xprt);
1436         ret = xprt->ops->bc_maxpayload(xprt);
1437         rcu_read_unlock();
1438         return ret;
1439 }
1440 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1441
1442 /**
1443  * rpc_force_rebind - force transport to check that remote port is unchanged
1444  * @clnt: client to rebind
1445  *
1446  */
1447 void rpc_force_rebind(struct rpc_clnt *clnt)
1448 {
1449         if (clnt->cl_autobind) {
1450                 rcu_read_lock();
1451                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1452                 rcu_read_unlock();
1453         }
1454 }
1455 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1456
1457 /*
1458  * Restart an (async) RPC call from the call_prepare state.
1459  * Usually called from within the exit handler.
1460  */
1461 int
1462 rpc_restart_call_prepare(struct rpc_task *task)
1463 {
1464         if (RPC_ASSASSINATED(task))
1465                 return 0;
1466         task->tk_action = call_start;
1467         task->tk_status = 0;
1468         if (task->tk_ops->rpc_call_prepare != NULL)
1469                 task->tk_action = rpc_prepare_task;
1470         return 1;
1471 }
1472 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1473
1474 /*
1475  * Restart an (async) RPC call. Usually called from within the
1476  * exit handler.
1477  */
1478 int
1479 rpc_restart_call(struct rpc_task *task)
1480 {
1481         if (RPC_ASSASSINATED(task))
1482                 return 0;
1483         task->tk_action = call_start;
1484         task->tk_status = 0;
1485         return 1;
1486 }
1487 EXPORT_SYMBOL_GPL(rpc_restart_call);
1488
1489 const char
1490 *rpc_proc_name(const struct rpc_task *task)
1491 {
1492         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1493
1494         if (proc) {
1495                 if (proc->p_name)
1496                         return proc->p_name;
1497                 else
1498                         return "NULL";
1499         } else
1500                 return "no proc";
1501 }
1502
1503 /*
1504  * 0.  Initial state
1505  *
1506  *     Other FSM states can be visited zero or more times, but
1507  *     this state is visited exactly once for each RPC.
1508  */
1509 static void
1510 call_start(struct rpc_task *task)
1511 {
1512         struct rpc_clnt *clnt = task->tk_client;
1513         int idx = task->tk_msg.rpc_proc->p_statidx;
1514
1515         trace_rpc_request(task);
1516         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1517                         clnt->cl_program->name, clnt->cl_vers,
1518                         rpc_proc_name(task),
1519                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1520
1521         /* Increment call count (version might not be valid for ping) */
1522         if (clnt->cl_program->version[clnt->cl_vers])
1523                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1524         clnt->cl_stats->rpccnt++;
1525         task->tk_action = call_reserve;
1526         rpc_task_set_transport(task, clnt);
1527 }
1528
1529 /*
1530  * 1.   Reserve an RPC call slot
1531  */
1532 static void
1533 call_reserve(struct rpc_task *task)
1534 {
1535         dprint_status(task);
1536
1537         task->tk_status  = 0;
1538         task->tk_action  = call_reserveresult;
1539         xprt_reserve(task);
1540 }
1541
1542 static void call_retry_reserve(struct rpc_task *task);
1543
1544 /*
1545  * 1b.  Grok the result of xprt_reserve()
1546  */
1547 static void
1548 call_reserveresult(struct rpc_task *task)
1549 {
1550         int status = task->tk_status;
1551
1552         dprint_status(task);
1553
1554         /*
1555          * After a call to xprt_reserve(), we must have either
1556          * a request slot or else an error status.
1557          */
1558         task->tk_status = 0;
1559         if (status >= 0) {
1560                 if (task->tk_rqstp) {
1561                         task->tk_action = call_refresh;
1562                         return;
1563                 }
1564
1565                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1566                                 __func__, status);
1567                 rpc_exit(task, -EIO);
1568                 return;
1569         }
1570
1571         /*
1572          * Even though there was an error, we may have acquired
1573          * a request slot somehow.  Make sure not to leak it.
1574          */
1575         if (task->tk_rqstp) {
1576                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1577                                 __func__, status);
1578                 xprt_release(task);
1579         }
1580
1581         switch (status) {
1582         case -ENOMEM:
1583                 rpc_delay(task, HZ >> 2);
1584                 /* fall through */
1585         case -EAGAIN:   /* woken up; retry */
1586                 task->tk_action = call_retry_reserve;
1587                 return;
1588         case -EIO:      /* probably a shutdown */
1589                 break;
1590         default:
1591                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1592                                 __func__, status);
1593                 break;
1594         }
1595         rpc_exit(task, status);
1596 }
1597
1598 /*
1599  * 1c.  Retry reserving an RPC call slot
1600  */
1601 static void
1602 call_retry_reserve(struct rpc_task *task)
1603 {
1604         dprint_status(task);
1605
1606         task->tk_status  = 0;
1607         task->tk_action  = call_reserveresult;
1608         xprt_retry_reserve(task);
1609 }
1610
1611 /*
1612  * 2.   Bind and/or refresh the credentials
1613  */
1614 static void
1615 call_refresh(struct rpc_task *task)
1616 {
1617         dprint_status(task);
1618
1619         task->tk_action = call_refreshresult;
1620         task->tk_status = 0;
1621         task->tk_client->cl_stats->rpcauthrefresh++;
1622         rpcauth_refreshcred(task);
1623 }
1624
1625 /*
1626  * 2a.  Process the results of a credential refresh
1627  */
1628 static void
1629 call_refreshresult(struct rpc_task *task)
1630 {
1631         int status = task->tk_status;
1632
1633         dprint_status(task);
1634
1635         task->tk_status = 0;
1636         task->tk_action = call_refresh;
1637         switch (status) {
1638         case 0:
1639                 if (rpcauth_uptodatecred(task)) {
1640                         task->tk_action = call_allocate;
1641                         return;
1642                 }
1643                 /* Use rate-limiting and a max number of retries if refresh
1644                  * had status 0 but failed to update the cred.
1645                  */
1646                 /* fall through */
1647         case -ETIMEDOUT:
1648                 rpc_delay(task, 3*HZ);
1649                 /* fall through */
1650         case -EAGAIN:
1651                 status = -EACCES;
1652                 /* fall through */
1653         case -EKEYEXPIRED:
1654                 if (!task->tk_cred_retry)
1655                         break;
1656                 task->tk_cred_retry--;
1657                 dprintk("RPC: %5u %s: retry refresh creds\n",
1658                                 task->tk_pid, __func__);
1659                 return;
1660         }
1661         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1662                                 task->tk_pid, __func__, status);
1663         rpc_exit(task, status);
1664 }
1665
1666 /*
1667  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1668  *      (Note: buffer memory is freed in xprt_release).
1669  */
1670 static void
1671 call_allocate(struct rpc_task *task)
1672 {
1673         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1674         struct rpc_rqst *req = task->tk_rqstp;
1675         struct rpc_xprt *xprt = req->rq_xprt;
1676         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1677         int status;
1678
1679         dprint_status(task);
1680
1681         task->tk_status = 0;
1682         task->tk_action = call_bind;
1683
1684         if (req->rq_buffer)
1685                 return;
1686
1687         if (proc->p_proc != 0) {
1688                 BUG_ON(proc->p_arglen == 0);
1689                 if (proc->p_decode != NULL)
1690                         BUG_ON(proc->p_replen == 0);
1691         }
1692
1693         /*
1694          * Calculate the size (in quads) of the RPC call
1695          * and reply headers, and convert both values
1696          * to byte sizes.
1697          */
1698         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1699         req->rq_callsize <<= 2;
1700         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1701         req->rq_rcvsize <<= 2;
1702
1703         status = xprt->ops->buf_alloc(task);
1704         xprt_inject_disconnect(xprt);
1705         if (status == 0)
1706                 return;
1707         if (status != -ENOMEM) {
1708                 rpc_exit(task, status);
1709                 return;
1710         }
1711
1712         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1713
1714         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1715                 task->tk_action = call_allocate;
1716                 rpc_delay(task, HZ>>4);
1717                 return;
1718         }
1719
1720         rpc_exit(task, -ERESTARTSYS);
1721 }
1722
1723 static inline int
1724 rpc_task_need_encode(struct rpc_task *task)
1725 {
1726         return task->tk_rqstp->rq_snd_buf.len == 0;
1727 }
1728
1729 static inline void
1730 rpc_task_force_reencode(struct rpc_task *task)
1731 {
1732         task->tk_rqstp->rq_snd_buf.len = 0;
1733         task->tk_rqstp->rq_bytes_sent = 0;
1734 }
1735
1736 /*
1737  * 3.   Encode arguments of an RPC call
1738  */
1739 static void
1740 rpc_xdr_encode(struct rpc_task *task)
1741 {
1742         struct rpc_rqst *req = task->tk_rqstp;
1743         kxdreproc_t     encode;
1744         __be32          *p;
1745
1746         dprint_status(task);
1747
1748         xdr_buf_init(&req->rq_snd_buf,
1749                      req->rq_buffer,
1750                      req->rq_callsize);
1751         xdr_buf_init(&req->rq_rcv_buf,
1752                      req->rq_rbuffer,
1753                      req->rq_rcvsize);
1754
1755         p = rpc_encode_header(task);
1756         if (p == NULL) {
1757                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1758                 rpc_exit(task, -EIO);
1759                 return;
1760         }
1761
1762         encode = task->tk_msg.rpc_proc->p_encode;
1763         if (encode == NULL)
1764                 return;
1765
1766         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1767                         task->tk_msg.rpc_argp);
1768 }
1769
1770 /*
1771  * 4.   Get the server port number if not yet set
1772  */
1773 static void
1774 call_bind(struct rpc_task *task)
1775 {
1776         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1777
1778         dprint_status(task);
1779
1780         task->tk_action = call_connect;
1781         if (!xprt_bound(xprt)) {
1782                 task->tk_action = call_bind_status;
1783                 task->tk_timeout = xprt->bind_timeout;
1784                 xprt->ops->rpcbind(task);
1785         }
1786 }
1787
1788 /*
1789  * 4a.  Sort out bind result
1790  */
1791 static void
1792 call_bind_status(struct rpc_task *task)
1793 {
1794         int status = -EIO;
1795
1796         if (task->tk_status >= 0) {
1797                 dprint_status(task);
1798                 task->tk_status = 0;
1799                 task->tk_action = call_connect;
1800                 return;
1801         }
1802
1803         trace_rpc_bind_status(task);
1804         switch (task->tk_status) {
1805         case -ENOMEM:
1806                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1807                 rpc_delay(task, HZ >> 2);
1808                 goto retry_timeout;
1809         case -EACCES:
1810                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1811                                 "unavailable\n", task->tk_pid);
1812                 /* fail immediately if this is an RPC ping */
1813                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1814                         status = -EOPNOTSUPP;
1815                         break;
1816                 }
1817                 rpc_delay(task, 3*HZ);
1818                 goto retry_timeout;
1819         case -ETIMEDOUT:
1820                 dprintk("RPC: %5u rpcbind request timed out\n",
1821                                 task->tk_pid);
1822                 goto retry_timeout;
1823         case -EPFNOSUPPORT:
1824                 /* server doesn't support any rpcbind version we know of */
1825                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1826                                 task->tk_pid);
1827                 break;
1828         case -EPROTONOSUPPORT:
1829                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1830                                 task->tk_pid);
1831                 goto retry_timeout;
1832         case -ECONNREFUSED:             /* connection problems */
1833         case -ECONNRESET:
1834         case -ECONNABORTED:
1835         case -ENOTCONN:
1836         case -EHOSTDOWN:
1837         case -ENETDOWN:
1838         case -EHOSTUNREACH:
1839         case -ENETUNREACH:
1840         case -ENOBUFS:
1841         case -EPIPE:
1842                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1843                                 task->tk_pid, task->tk_status);
1844                 if (!RPC_IS_SOFTCONN(task)) {
1845                         rpc_delay(task, 5*HZ);
1846                         goto retry_timeout;
1847                 }
1848                 status = task->tk_status;
1849                 break;
1850         default:
1851                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1852                                 task->tk_pid, -task->tk_status);
1853         }
1854
1855         rpc_exit(task, status);
1856         return;
1857
1858 retry_timeout:
1859         task->tk_status = 0;
1860         task->tk_action = call_timeout;
1861 }
1862
1863 /*
1864  * 4b.  Connect to the RPC server
1865  */
1866 static void
1867 call_connect(struct rpc_task *task)
1868 {
1869         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1870
1871         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1872                         task->tk_pid, xprt,
1873                         (xprt_connected(xprt) ? "is" : "is not"));
1874
1875         task->tk_action = call_transmit;
1876         if (!xprt_connected(xprt)) {
1877                 task->tk_action = call_connect_status;
1878                 if (task->tk_status < 0)
1879                         return;
1880                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1881                         rpc_exit(task, -ENOTCONN);
1882                         return;
1883                 }
1884                 xprt_connect(task);
1885         }
1886 }
1887
1888 /*
1889  * 4c.  Sort out connect result
1890  */
1891 static void
1892 call_connect_status(struct rpc_task *task)
1893 {
1894         struct rpc_clnt *clnt = task->tk_client;
1895         int status = task->tk_status;
1896
1897         dprint_status(task);
1898
1899         trace_rpc_connect_status(task);
1900         task->tk_status = 0;
1901         switch (status) {
1902         case -ECONNREFUSED:
1903                 /* A positive refusal suggests a rebind is needed. */
1904                 if (RPC_IS_SOFTCONN(task))
1905                         break;
1906                 if (clnt->cl_autobind) {
1907                         rpc_force_rebind(clnt);
1908                         task->tk_action = call_bind;
1909                         return;
1910                 }
1911                 /* fall through */
1912         case -ECONNRESET:
1913         case -ECONNABORTED:
1914         case -ENETDOWN:
1915         case -ENETUNREACH:
1916         case -EHOSTUNREACH:
1917         case -EADDRINUSE:
1918         case -ENOBUFS:
1919         case -EPIPE:
1920                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1921                                             task->tk_rqstp->rq_connect_cookie);
1922                 if (RPC_IS_SOFTCONN(task))
1923                         break;
1924                 /* retry with existing socket, after a delay */
1925                 rpc_delay(task, 3*HZ);
1926                 /* fall through */
1927         case -EAGAIN:
1928                 /* Check for timeouts before looping back to call_bind */
1929         case -ETIMEDOUT:
1930                 task->tk_action = call_timeout;
1931                 return;
1932         case 0:
1933                 clnt->cl_stats->netreconn++;
1934                 task->tk_action = call_transmit;
1935                 return;
1936         }
1937         rpc_exit(task, status);
1938 }
1939
1940 /*
1941  * 5.   Transmit the RPC request, and wait for reply
1942  */
1943 static void
1944 call_transmit(struct rpc_task *task)
1945 {
1946         int is_retrans = RPC_WAS_SENT(task);
1947
1948         dprint_status(task);
1949
1950         task->tk_action = call_status;
1951         if (task->tk_status < 0)
1952                 return;
1953         if (!xprt_prepare_transmit(task))
1954                 return;
1955         task->tk_action = call_transmit_status;
1956         /* Encode here so that rpcsec_gss can use correct sequence number. */
1957         if (rpc_task_need_encode(task)) {
1958                 rpc_xdr_encode(task);
1959                 /* Did the encode result in an error condition? */
1960                 if (task->tk_status != 0) {
1961                         /* Was the error nonfatal? */
1962                         if (task->tk_status == -EAGAIN)
1963                                 rpc_delay(task, HZ >> 4);
1964                         else
1965                                 rpc_exit(task, task->tk_status);
1966                         return;
1967                 }
1968         }
1969         xprt_transmit(task);
1970         if (task->tk_status < 0)
1971                 return;
1972         if (is_retrans)
1973                 task->tk_client->cl_stats->rpcretrans++;
1974         /*
1975          * On success, ensure that we call xprt_end_transmit() before sleeping
1976          * in order to allow access to the socket to other RPC requests.
1977          */
1978         call_transmit_status(task);
1979         if (rpc_reply_expected(task))
1980                 return;
1981         task->tk_action = rpc_exit_task;
1982         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1983 }
1984
1985 /*
1986  * 5a.  Handle cleanup after a transmission
1987  */
1988 static void
1989 call_transmit_status(struct rpc_task *task)
1990 {
1991         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1992         task->tk_action = call_status;
1993
1994         /*
1995          * Common case: success.  Force the compiler to put this
1996          * test first.  Or, if any error and xprt_close_wait,
1997          * release the xprt lock so the socket can close.
1998          */
1999         if (task->tk_status == 0 || xprt_close_wait(xprt)) {
2000                 xprt_end_transmit(task);
2001                 rpc_task_force_reencode(task);
2002                 return;
2003         }
2004
2005         switch (task->tk_status) {
2006         case -EAGAIN:
2007         case -ENOBUFS:
2008                 break;
2009         default:
2010                 dprint_status(task);
2011                 xprt_end_transmit(task);
2012                 rpc_task_force_reencode(task);
2013                 break;
2014                 /*
2015                  * Special cases: if we've been waiting on the
2016                  * socket's write_space() callback, or if the
2017                  * socket just returned a connection error,
2018                  * then hold onto the transport lock.
2019                  */
2020         case -ECONNREFUSED:
2021         case -EHOSTDOWN:
2022         case -ENETDOWN:
2023         case -EHOSTUNREACH:
2024         case -ENETUNREACH:
2025         case -EPERM:
2026                 if (RPC_IS_SOFTCONN(task)) {
2027                         xprt_end_transmit(task);
2028                         if (!task->tk_msg.rpc_proc->p_proc)
2029                                 trace_xprt_ping(task->tk_xprt,
2030                                                 task->tk_status);
2031                         rpc_exit(task, task->tk_status);
2032                         break;
2033                 }
2034                 /* fall through */
2035         case -ECONNRESET:
2036         case -ECONNABORTED:
2037         case -EADDRINUSE:
2038         case -ENOTCONN:
2039         case -EPIPE:
2040                 rpc_task_force_reencode(task);
2041         }
2042 }
2043
2044 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2045 /*
2046  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2047  * addition, disconnect on connectivity errors.
2048  */
2049 static void
2050 call_bc_transmit(struct rpc_task *task)
2051 {
2052         struct rpc_rqst *req = task->tk_rqstp;
2053
2054         if (!xprt_prepare_transmit(task))
2055                 goto out_retry;
2056
2057         if (task->tk_status < 0) {
2058                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2059                         "error: %d\n", task->tk_status);
2060                 goto out_done;
2061         }
2062         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2063                 req->rq_bytes_sent = 0;
2064
2065         xprt_transmit(task);
2066
2067         if (task->tk_status == -EAGAIN)
2068                 goto out_nospace;
2069
2070         xprt_end_transmit(task);
2071         dprint_status(task);
2072         switch (task->tk_status) {
2073         case 0:
2074                 /* Success */
2075         case -ENETDOWN:
2076         case -EHOSTDOWN:
2077         case -EHOSTUNREACH:
2078         case -ENETUNREACH:
2079         case -ECONNRESET:
2080         case -ECONNREFUSED:
2081         case -EADDRINUSE:
2082         case -ENOTCONN:
2083         case -EPIPE:
2084                 break;
2085         case -ETIMEDOUT:
2086                 /*
2087                  * Problem reaching the server.  Disconnect and let the
2088                  * forechannel reestablish the connection.  The server will
2089                  * have to retransmit the backchannel request and we'll
2090                  * reprocess it.  Since these ops are idempotent, there's no
2091                  * need to cache our reply at this time.
2092                  */
2093                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2094                         "error: %d\n", task->tk_status);
2095                 xprt_conditional_disconnect(req->rq_xprt,
2096                         req->rq_connect_cookie);
2097                 break;
2098         default:
2099                 /*
2100                  * We were unable to reply and will have to drop the
2101                  * request.  The server should reconnect and retransmit.
2102                  */
2103                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2104                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2105                         "error: %d\n", task->tk_status);
2106                 break;
2107         }
2108         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2109 out_done:
2110         task->tk_action = rpc_exit_task;
2111         return;
2112 out_nospace:
2113         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2114 out_retry:
2115         task->tk_status = 0;
2116 }
2117 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2118
2119 /*
2120  * 6.   Sort out the RPC call status
2121  */
2122 static void
2123 call_status(struct rpc_task *task)
2124 {
2125         struct rpc_clnt *clnt = task->tk_client;
2126         struct rpc_rqst *req = task->tk_rqstp;
2127         int             status;
2128
2129         if (!task->tk_msg.rpc_proc->p_proc)
2130                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2131
2132         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2133                 task->tk_status = req->rq_reply_bytes_recvd;
2134
2135         dprint_status(task);
2136
2137         status = task->tk_status;
2138         if (status >= 0) {
2139                 task->tk_action = call_decode;
2140                 return;
2141         }
2142
2143         trace_rpc_call_status(task);
2144         task->tk_status = 0;
2145         switch(status) {
2146         case -EHOSTDOWN:
2147         case -ENETDOWN:
2148         case -EHOSTUNREACH:
2149         case -ENETUNREACH:
2150         case -EPERM:
2151                 if (RPC_IS_SOFTCONN(task)) {
2152                         rpc_exit(task, status);
2153                         break;
2154                 }
2155                 /*
2156                  * Delay any retries for 3 seconds, then handle as if it
2157                  * were a timeout.
2158                  */
2159                 rpc_delay(task, 3*HZ);
2160                 /* fall through */
2161         case -ETIMEDOUT:
2162                 task->tk_action = call_timeout;
2163                 break;
2164         case -ECONNREFUSED:
2165         case -ECONNRESET:
2166         case -ECONNABORTED:
2167                 rpc_force_rebind(clnt);
2168                 /* fall through */
2169         case -EADDRINUSE:
2170                 rpc_delay(task, 3*HZ);
2171                 /* fall through */
2172         case -EPIPE:
2173         case -ENOTCONN:
2174                 task->tk_action = call_bind;
2175                 break;
2176         case -ENOBUFS:
2177                 rpc_delay(task, HZ>>2);
2178                 /* fall through */
2179         case -EAGAIN:
2180                 task->tk_action = call_transmit;
2181                 break;
2182         case -EIO:
2183                 /* shutdown or soft timeout */
2184                 rpc_exit(task, status);
2185                 break;
2186         default:
2187                 if (clnt->cl_chatty)
2188                         printk("%s: RPC call returned error %d\n",
2189                                clnt->cl_program->name, -status);
2190                 rpc_exit(task, status);
2191         }
2192 }
2193
2194 /*
2195  * 6a.  Handle RPC timeout
2196  *      We do not release the request slot, so we keep using the
2197  *      same XID for all retransmits.
2198  */
2199 static void
2200 call_timeout(struct rpc_task *task)
2201 {
2202         struct rpc_clnt *clnt = task->tk_client;
2203
2204         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2205                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2206                 goto retry;
2207         }
2208
2209         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2210         task->tk_timeouts++;
2211
2212         if (RPC_IS_SOFTCONN(task)) {
2213                 rpc_exit(task, -ETIMEDOUT);
2214                 return;
2215         }
2216         if (RPC_IS_SOFT(task)) {
2217                 if (clnt->cl_chatty) {
2218                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2219                                 clnt->cl_program->name,
2220                                 task->tk_xprt->servername);
2221                 }
2222                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2223                         rpc_exit(task, -ETIMEDOUT);
2224                 else
2225                         rpc_exit(task, -EIO);
2226                 return;
2227         }
2228
2229         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2230                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2231                 if (clnt->cl_chatty) {
2232                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2233                         clnt->cl_program->name,
2234                         task->tk_xprt->servername);
2235                 }
2236         }
2237         rpc_force_rebind(clnt);
2238         /*
2239          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2240          * event? RFC2203 requires the server to drop all such requests.
2241          */
2242         rpcauth_invalcred(task);
2243
2244 retry:
2245         task->tk_action = call_bind;
2246         task->tk_status = 0;
2247 }
2248
2249 /*
2250  * 7.   Decode the RPC reply
2251  */
2252 static void
2253 call_decode(struct rpc_task *task)
2254 {
2255         struct rpc_clnt *clnt = task->tk_client;
2256         struct rpc_rqst *req = task->tk_rqstp;
2257         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2258         __be32          *p;
2259
2260         dprint_status(task);
2261
2262         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2263                 if (clnt->cl_chatty) {
2264                         printk(KERN_NOTICE "%s: server %s OK\n",
2265                                 clnt->cl_program->name,
2266                                 task->tk_xprt->servername);
2267                 }
2268                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2269         }
2270
2271         /*
2272          * Ensure that we see all writes made by xprt_complete_rqst()
2273          * before it changed req->rq_reply_bytes_recvd.
2274          */
2275         smp_rmb();
2276         req->rq_rcv_buf.len = req->rq_private_buf.len;
2277
2278         /* Check that the softirq receive buffer is valid */
2279         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2280                                 sizeof(req->rq_rcv_buf)) != 0);
2281
2282         if (req->rq_rcv_buf.len < 12) {
2283                 if (!RPC_IS_SOFT(task)) {
2284                         task->tk_action = call_bind;
2285                         goto out_retry;
2286                 }
2287                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2288                                 clnt->cl_program->name, task->tk_status);
2289                 task->tk_action = call_timeout;
2290                 goto out_retry;
2291         }
2292
2293         p = rpc_verify_header(task);
2294         if (IS_ERR(p)) {
2295                 if (p == ERR_PTR(-EAGAIN))
2296                         goto out_retry;
2297                 return;
2298         }
2299
2300         task->tk_action = rpc_exit_task;
2301
2302         if (decode) {
2303                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2304                                                       task->tk_msg.rpc_resp);
2305         }
2306         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2307                         task->tk_status);
2308         return;
2309 out_retry:
2310         task->tk_status = 0;
2311         /* Note: rpc_verify_header() may have freed the RPC slot */
2312         if (task->tk_rqstp == req) {
2313                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2314                 if (task->tk_client->cl_discrtry)
2315                         xprt_conditional_disconnect(req->rq_xprt,
2316                                         req->rq_connect_cookie);
2317         }
2318 }
2319
2320 static __be32 *
2321 rpc_encode_header(struct rpc_task *task)
2322 {
2323         struct rpc_clnt *clnt = task->tk_client;
2324         struct rpc_rqst *req = task->tk_rqstp;
2325         __be32          *p = req->rq_svec[0].iov_base;
2326
2327         /* FIXME: check buffer size? */
2328
2329         p = xprt_skip_transport_header(req->rq_xprt, p);
2330         *p++ = req->rq_xid;             /* XID */
2331         *p++ = htonl(RPC_CALL);         /* CALL */
2332         *p++ = htonl(RPC_VERSION);      /* RPC version */
2333         *p++ = htonl(clnt->cl_prog);    /* program number */
2334         *p++ = htonl(clnt->cl_vers);    /* program version */
2335         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2336         p = rpcauth_marshcred(task, p);
2337         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2338         return p;
2339 }
2340
2341 static __be32 *
2342 rpc_verify_header(struct rpc_task *task)
2343 {
2344         struct rpc_clnt *clnt = task->tk_client;
2345         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2346         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2347         __be32  *p = iov->iov_base;
2348         u32 n;
2349         int error = -EACCES;
2350
2351         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2352                 /* RFC-1014 says that the representation of XDR data must be a
2353                  * multiple of four bytes
2354                  * - if it isn't pointer subtraction in the NFS client may give
2355                  *   undefined results
2356                  */
2357                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2358                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2359                        task->tk_rqstp->rq_rcv_buf.len);
2360                 error = -EIO;
2361                 goto out_err;
2362         }
2363         if ((len -= 3) < 0)
2364                 goto out_overflow;
2365
2366         p += 1; /* skip XID */
2367         if ((n = ntohl(*p++)) != RPC_REPLY) {
2368                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2369                         task->tk_pid, __func__, n);
2370                 error = -EIO;
2371                 goto out_garbage;
2372         }
2373
2374         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2375                 if (--len < 0)
2376                         goto out_overflow;
2377                 switch ((n = ntohl(*p++))) {
2378                 case RPC_AUTH_ERROR:
2379                         break;
2380                 case RPC_MISMATCH:
2381                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2382                                 task->tk_pid, __func__);
2383                         error = -EPROTONOSUPPORT;
2384                         goto out_err;
2385                 default:
2386                         dprintk("RPC: %5u %s: RPC call rejected, "
2387                                 "unknown error: %x\n",
2388                                 task->tk_pid, __func__, n);
2389                         error = -EIO;
2390                         goto out_err;
2391                 }
2392                 if (--len < 0)
2393                         goto out_overflow;
2394                 switch ((n = ntohl(*p++))) {
2395                 case RPC_AUTH_REJECTEDCRED:
2396                 case RPC_AUTH_REJECTEDVERF:
2397                 case RPCSEC_GSS_CREDPROBLEM:
2398                 case RPCSEC_GSS_CTXPROBLEM:
2399                         if (!task->tk_cred_retry)
2400                                 break;
2401                         task->tk_cred_retry--;
2402                         dprintk("RPC: %5u %s: retry stale creds\n",
2403                                         task->tk_pid, __func__);
2404                         rpcauth_invalcred(task);
2405                         /* Ensure we obtain a new XID! */
2406                         xprt_release(task);
2407                         task->tk_action = call_reserve;
2408                         goto out_retry;
2409                 case RPC_AUTH_BADCRED:
2410                 case RPC_AUTH_BADVERF:
2411                         /* possibly garbled cred/verf? */
2412                         if (!task->tk_garb_retry)
2413                                 break;
2414                         task->tk_garb_retry--;
2415                         dprintk("RPC: %5u %s: retry garbled creds\n",
2416                                         task->tk_pid, __func__);
2417                         task->tk_action = call_bind;
2418                         goto out_retry;
2419                 case RPC_AUTH_TOOWEAK:
2420                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2421                                "authentication.\n",
2422                                task->tk_xprt->servername);
2423                         break;
2424                 default:
2425                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2426                                         task->tk_pid, __func__, n);
2427                         error = -EIO;
2428                 }
2429                 dprintk("RPC: %5u %s: call rejected %d\n",
2430                                 task->tk_pid, __func__, n);
2431                 goto out_err;
2432         }
2433         p = rpcauth_checkverf(task, p);
2434         if (IS_ERR(p)) {
2435                 error = PTR_ERR(p);
2436                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2437                                 task->tk_pid, __func__, error);
2438                 goto out_garbage;               /* bad verifier, retry */
2439         }
2440         len = p - (__be32 *)iov->iov_base - 1;
2441         if (len < 0)
2442                 goto out_overflow;
2443         switch ((n = ntohl(*p++))) {
2444         case RPC_SUCCESS:
2445                 return p;
2446         case RPC_PROG_UNAVAIL:
2447                 dprintk("RPC: %5u %s: program %u is unsupported "
2448                                 "by server %s\n", task->tk_pid, __func__,
2449                                 (unsigned int)clnt->cl_prog,
2450                                 task->tk_xprt->servername);
2451                 error = -EPFNOSUPPORT;
2452                 goto out_err;
2453         case RPC_PROG_MISMATCH:
2454                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2455                                 "by server %s\n", task->tk_pid, __func__,
2456                                 (unsigned int)clnt->cl_prog,
2457                                 (unsigned int)clnt->cl_vers,
2458                                 task->tk_xprt->servername);
2459                 error = -EPROTONOSUPPORT;
2460                 goto out_err;
2461         case RPC_PROC_UNAVAIL:
2462                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2463                                 "version %u on server %s\n",
2464                                 task->tk_pid, __func__,
2465                                 rpc_proc_name(task),
2466                                 clnt->cl_prog, clnt->cl_vers,
2467                                 task->tk_xprt->servername);
2468                 error = -EOPNOTSUPP;
2469                 goto out_err;
2470         case RPC_GARBAGE_ARGS:
2471                 dprintk("RPC: %5u %s: server saw garbage\n",
2472                                 task->tk_pid, __func__);
2473                 break;                  /* retry */
2474         default:
2475                 dprintk("RPC: %5u %s: server accept status: %x\n",
2476                                 task->tk_pid, __func__, n);
2477                 /* Also retry */
2478         }
2479
2480 out_garbage:
2481         clnt->cl_stats->rpcgarbage++;
2482         if (task->tk_garb_retry) {
2483                 task->tk_garb_retry--;
2484                 dprintk("RPC: %5u %s: retrying\n",
2485                                 task->tk_pid, __func__);
2486                 task->tk_action = call_bind;
2487 out_retry:
2488                 return ERR_PTR(-EAGAIN);
2489         }
2490 out_err:
2491         rpc_exit(task, error);
2492         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2493                         __func__, error);
2494         return ERR_PTR(error);
2495 out_overflow:
2496         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2497                         __func__);
2498         goto out_garbage;
2499 }
2500
2501 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2502                 const void *obj)
2503 {
2504 }
2505
2506 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2507                 void *obj)
2508 {
2509         return 0;
2510 }
2511
2512 static const struct rpc_procinfo rpcproc_null = {
2513         .p_encode = rpcproc_encode_null,
2514         .p_decode = rpcproc_decode_null,
2515 };
2516
2517 static int rpc_ping(struct rpc_clnt *clnt)
2518 {
2519         struct rpc_message msg = {
2520                 .rpc_proc = &rpcproc_null,
2521         };
2522         int err;
2523         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2524         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2525         put_rpccred(msg.rpc_cred);
2526         return err;
2527 }
2528
2529 static
2530 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2531                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2532                 const struct rpc_call_ops *ops, void *data)
2533 {
2534         struct rpc_message msg = {
2535                 .rpc_proc = &rpcproc_null,
2536                 .rpc_cred = cred,
2537         };
2538         struct rpc_task_setup task_setup_data = {
2539                 .rpc_client = clnt,
2540                 .rpc_xprt = xprt,
2541                 .rpc_message = &msg,
2542                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2543                 .callback_data = data,
2544                 .flags = flags,
2545         };
2546
2547         return rpc_run_task(&task_setup_data);
2548 }
2549
2550 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2551 {
2552         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2553 }
2554 EXPORT_SYMBOL_GPL(rpc_call_null);
2555
2556 struct rpc_cb_add_xprt_calldata {
2557         struct rpc_xprt_switch *xps;
2558         struct rpc_xprt *xprt;
2559 };
2560
2561 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2562 {
2563         struct rpc_cb_add_xprt_calldata *data = calldata;
2564
2565         if (task->tk_status == 0)
2566                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2567 }
2568
2569 static void rpc_cb_add_xprt_release(void *calldata)
2570 {
2571         struct rpc_cb_add_xprt_calldata *data = calldata;
2572
2573         xprt_put(data->xprt);
2574         xprt_switch_put(data->xps);
2575         kfree(data);
2576 }
2577
2578 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2579         .rpc_call_done = rpc_cb_add_xprt_done,
2580         .rpc_release = rpc_cb_add_xprt_release,
2581 };
2582
2583 /**
2584  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2585  * @clnt: pointer to struct rpc_clnt
2586  * @xps: pointer to struct rpc_xprt_switch,
2587  * @xprt: pointer struct rpc_xprt
2588  * @dummy: unused
2589  */
2590 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2591                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2592                 void *dummy)
2593 {
2594         struct rpc_cb_add_xprt_calldata *data;
2595         struct rpc_cred *cred;
2596         struct rpc_task *task;
2597
2598         data = kmalloc(sizeof(*data), GFP_NOFS);
2599         if (!data)
2600                 return -ENOMEM;
2601         data->xps = xprt_switch_get(xps);
2602         data->xprt = xprt_get(xprt);
2603
2604         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2605         task = rpc_call_null_helper(clnt, xprt, cred,
2606                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2607                         &rpc_cb_add_xprt_call_ops, data);
2608         put_rpccred(cred);
2609         if (IS_ERR(task))
2610                 return PTR_ERR(task);
2611         rpc_put_task(task);
2612         return 1;
2613 }
2614 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2615
2616 /**
2617  * rpc_clnt_setup_test_and_add_xprt()
2618  *
2619  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2620  *   1) caller of the test function must dereference the rpc_xprt_switch
2621  *   and the rpc_xprt.
2622  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2623  *   the rpc_call_done routine.
2624  *
2625  * Upon success (return of 1), the test function adds the new
2626  * transport to the rpc_clnt xprt switch
2627  *
2628  * @clnt: struct rpc_clnt to get the new transport
2629  * @xps:  the rpc_xprt_switch to hold the new transport
2630  * @xprt: the rpc_xprt to test
2631  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2632  *        and test function call data
2633  */
2634 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2635                                      struct rpc_xprt_switch *xps,
2636                                      struct rpc_xprt *xprt,
2637                                      void *data)
2638 {
2639         struct rpc_cred *cred;
2640         struct rpc_task *task;
2641         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2642         int status = -EADDRINUSE;
2643
2644         xprt = xprt_get(xprt);
2645         xprt_switch_get(xps);
2646
2647         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2648                 goto out_err;
2649
2650         /* Test the connection */
2651         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2652         task = rpc_call_null_helper(clnt, xprt, cred,
2653                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2654                                     NULL, NULL);
2655         put_rpccred(cred);
2656         if (IS_ERR(task)) {
2657                 status = PTR_ERR(task);
2658                 goto out_err;
2659         }
2660         status = task->tk_status;
2661         rpc_put_task(task);
2662
2663         if (status < 0)
2664                 goto out_err;
2665
2666         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2667         xtest->add_xprt_test(clnt, xprt, xtest->data);
2668
2669         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2670         return 1;
2671 out_err:
2672         xprt_put(xprt);
2673         xprt_switch_put(xps);
2674         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2675                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2676         return status;
2677 }
2678 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2679
2680 /**
2681  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2682  * @clnt: pointer to struct rpc_clnt
2683  * @xprtargs: pointer to struct xprt_create
2684  * @setup: callback to test and/or set up the connection
2685  * @data: pointer to setup function data
2686  *
2687  * Creates a new transport using the parameters set in args and
2688  * adds it to clnt.
2689  * If ping is set, then test that connectivity succeeds before
2690  * adding the new transport.
2691  *
2692  */
2693 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2694                 struct xprt_create *xprtargs,
2695                 int (*setup)(struct rpc_clnt *,
2696                         struct rpc_xprt_switch *,
2697                         struct rpc_xprt *,
2698                         void *),
2699                 void *data)
2700 {
2701         struct rpc_xprt_switch *xps;
2702         struct rpc_xprt *xprt;
2703         unsigned long connect_timeout;
2704         unsigned long reconnect_timeout;
2705         unsigned char resvport;
2706         int ret = 0;
2707
2708         rcu_read_lock();
2709         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2710         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2711         if (xps == NULL || xprt == NULL) {
2712                 rcu_read_unlock();
2713                 xprt_switch_put(xps);
2714                 return -EAGAIN;
2715         }
2716         resvport = xprt->resvport;
2717         connect_timeout = xprt->connect_timeout;
2718         reconnect_timeout = xprt->max_reconnect_timeout;
2719         rcu_read_unlock();
2720
2721         xprt = xprt_create_transport(xprtargs);
2722         if (IS_ERR(xprt)) {
2723                 ret = PTR_ERR(xprt);
2724                 goto out_put_switch;
2725         }
2726         xprt->resvport = resvport;
2727         if (xprt->ops->set_connect_timeout != NULL)
2728                 xprt->ops->set_connect_timeout(xprt,
2729                                 connect_timeout,
2730                                 reconnect_timeout);
2731
2732         rpc_xprt_switch_set_roundrobin(xps);
2733         if (setup) {
2734                 ret = setup(clnt, xps, xprt, data);
2735                 if (ret != 0)
2736                         goto out_put_xprt;
2737         }
2738         rpc_xprt_switch_add_xprt(xps, xprt);
2739 out_put_xprt:
2740         xprt_put(xprt);
2741 out_put_switch:
2742         xprt_switch_put(xps);
2743         return ret;
2744 }
2745 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2746
2747 struct connect_timeout_data {
2748         unsigned long connect_timeout;
2749         unsigned long reconnect_timeout;
2750 };
2751
2752 static int
2753 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2754                 struct rpc_xprt *xprt,
2755                 void *data)
2756 {
2757         struct connect_timeout_data *timeo = data;
2758
2759         if (xprt->ops->set_connect_timeout)
2760                 xprt->ops->set_connect_timeout(xprt,
2761                                 timeo->connect_timeout,
2762                                 timeo->reconnect_timeout);
2763         return 0;
2764 }
2765
2766 void
2767 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2768                 unsigned long connect_timeout,
2769                 unsigned long reconnect_timeout)
2770 {
2771         struct connect_timeout_data timeout = {
2772                 .connect_timeout = connect_timeout,
2773                 .reconnect_timeout = reconnect_timeout,
2774         };
2775         rpc_clnt_iterate_for_each_xprt(clnt,
2776                         rpc_xprt_set_connect_timeout,
2777                         &timeout);
2778 }
2779 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2780
2781 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2782 {
2783         rcu_read_lock();
2784         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2785         rcu_read_unlock();
2786 }
2787 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2788
2789 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2790 {
2791         rcu_read_lock();
2792         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2793                                  xprt);
2794         rcu_read_unlock();
2795 }
2796 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2797
2798 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2799                                    const struct sockaddr *sap)
2800 {
2801         struct rpc_xprt_switch *xps;
2802         bool ret;
2803
2804         rcu_read_lock();
2805         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2806         ret = rpc_xprt_switch_has_addr(xps, sap);
2807         rcu_read_unlock();
2808         return ret;
2809 }
2810 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2811
2812 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2813 static void rpc_show_header(void)
2814 {
2815         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2816                 "-timeout ---ops--\n");
2817 }
2818
2819 static void rpc_show_task(const struct rpc_clnt *clnt,
2820                           const struct rpc_task *task)
2821 {
2822         const char *rpc_waitq = "none";
2823
2824         if (RPC_IS_QUEUED(task))
2825                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2826
2827         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2828                 task->tk_pid, task->tk_flags, task->tk_status,
2829                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2830                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2831                 task->tk_action, rpc_waitq);
2832 }
2833
2834 void rpc_show_tasks(struct net *net)
2835 {
2836         struct rpc_clnt *clnt;
2837         struct rpc_task *task;
2838         int header = 0;
2839         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2840
2841         spin_lock(&sn->rpc_client_lock);
2842         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2843                 spin_lock(&clnt->cl_lock);
2844                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2845                         if (!header) {
2846                                 rpc_show_header();
2847                                 header++;
2848                         }
2849                         rpc_show_task(clnt, task);
2850                 }
2851                 spin_unlock(&clnt->cl_lock);
2852         }
2853         spin_unlock(&sn->rpc_client_lock);
2854 }
2855 #endif
2856
2857 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2858 static int
2859 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2860                 struct rpc_xprt *xprt,
2861                 void *dummy)
2862 {
2863         return xprt_enable_swap(xprt);
2864 }
2865
2866 int
2867 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2868 {
2869         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2870                 return rpc_clnt_iterate_for_each_xprt(clnt,
2871                                 rpc_clnt_swap_activate_callback, NULL);
2872         return 0;
2873 }
2874 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2875
2876 static int
2877 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2878                 struct rpc_xprt *xprt,
2879                 void *dummy)
2880 {
2881         xprt_disable_swap(xprt);
2882         return 0;
2883 }
2884
2885 void
2886 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2887 {
2888         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2889                 rpc_clnt_iterate_for_each_xprt(clnt,
2890                                 rpc_clnt_swap_deactivate_callback, NULL);
2891 }
2892 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2893 #endif /* CONFIG_SUNRPC_SWAP */