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_client(struct rpc_task *task)
 969 {
 970         struct rpc_clnt *clnt = task->tk_client;
 971         struct rpc_xprt *xprt = task->tk_xprt;
 972
 973         if (clnt != NULL) {
 974                 /* Remove from client task list */
 975                 spin_lock(&clnt->cl_lock);
 976                 list_del(&task->tk_task);
 977                 spin_unlock(&clnt->cl_lock);
 978                 task->tk_client = NULL;
 979
 980                 rpc_release_client(clnt);
 981         }
 982
 983         if (xprt != NULL) {
 984                 task->tk_xprt = NULL;
 985
 986                 xprt_put(xprt);
 987         }
 988 }
 989
 990 static
 991 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 992 {
 993
 994         if (clnt != NULL) {
 995                 if (task->tk_xprt == NULL)
 996                         task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
 997                 task->tk_client = clnt;
 998                 atomic_inc(&clnt->cl_count);
 999                 if (clnt->cl_softrtry)
1000                         task->tk_flags |= RPC_TASK_SOFT;
1001                 if (clnt->cl_noretranstimeo)
1002                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1003                 if (atomic_read(&clnt->cl_swapper))
1004                         task->tk_flags |= RPC_TASK_SWAPPER;
1005                 /* Add to the client's list of all tasks */
1006                 spin_lock(&clnt->cl_lock);
1007                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1008                 spin_unlock(&clnt->cl_lock);
1009         }
1010 }
1011
1012 static void
1013 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1014 {
1015         if (msg != NULL) {
1016                 task->tk_msg.rpc_proc = msg->rpc_proc;
1017                 task->tk_msg.rpc_argp = msg->rpc_argp;
1018                 task->tk_msg.rpc_resp = msg->rpc_resp;
1019                 if (msg->rpc_cred != NULL)
1020                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1021         }
1022 }
1023
1024 /*
1025  * Default callback for async RPC calls
1026  */
1027 static void
1028 rpc_default_callback(struct rpc_task *task, void *data)
1029 {
1030 }
1031
1032 static const struct rpc_call_ops rpc_default_ops = {
1033         .rpc_call_done = rpc_default_callback,
1034 };
1035
1036 /**
1037  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1038  * @task_setup_data: pointer to task initialisation data
1039  */
1040 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1041 {
1042         struct rpc_task *task;
1043
1044         task = rpc_new_task(task_setup_data);
1045         if (IS_ERR(task))
1046                 goto out;
1047
1048         rpc_task_set_client(task, task_setup_data->rpc_client);
1049         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1050
1051         if (task->tk_action == NULL)
1052                 rpc_call_start(task);
1053
1054         atomic_inc(&task->tk_count);
1055         rpc_execute(task);
1056 out:
1057         return task;
1058 }
1059 EXPORT_SYMBOL_GPL(rpc_run_task);
1060
1061 /**
1062  * rpc_call_sync - Perform a synchronous RPC call
1063  * @clnt: pointer to RPC client
1064  * @msg: RPC call parameters
1065  * @flags: RPC call flags
1066  */
1067 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1068 {
1069         struct rpc_task *task;
1070         struct rpc_task_setup task_setup_data = {
1071                 .rpc_client = clnt,
1072                 .rpc_message = msg,
1073                 .callback_ops = &rpc_default_ops,
1074                 .flags = flags,
1075         };
1076         int status;
1077
1078         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1079         if (flags & RPC_TASK_ASYNC) {
1080                 rpc_release_calldata(task_setup_data.callback_ops,
1081                         task_setup_data.callback_data);
1082                 return -EINVAL;
1083         }
1084
1085         task = rpc_run_task(&task_setup_data);
1086         if (IS_ERR(task))
1087                 return PTR_ERR(task);
1088         status = task->tk_status;
1089         rpc_put_task(task);
1090         return status;
1091 }
1092 EXPORT_SYMBOL_GPL(rpc_call_sync);
1093
1094 /**
1095  * rpc_call_async - Perform an asynchronous RPC call
1096  * @clnt: pointer to RPC client
1097  * @msg: RPC call parameters
1098  * @flags: RPC call flags
1099  * @tk_ops: RPC call ops
1100  * @data: user call data
1101  */
1102 int
1103 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1104                const struct rpc_call_ops *tk_ops, void *data)
1105 {
1106         struct rpc_task *task;
1107         struct rpc_task_setup task_setup_data = {
1108                 .rpc_client = clnt,
1109                 .rpc_message = msg,
1110                 .callback_ops = tk_ops,
1111                 .callback_data = data,
1112                 .flags = flags|RPC_TASK_ASYNC,
1113         };
1114
1115         task = rpc_run_task(&task_setup_data);
1116         if (IS_ERR(task))
1117                 return PTR_ERR(task);
1118         rpc_put_task(task);
1119         return 0;
1120 }
1121 EXPORT_SYMBOL_GPL(rpc_call_async);
1122
1123 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1124 /**
1125  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1126  * rpc_execute against it
1127  * @req: RPC request
1128  */
1129 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1130 {
1131         struct rpc_task *task;
1132         struct xdr_buf *xbufp = &req->rq_snd_buf;
1133         struct rpc_task_setup task_setup_data = {
1134                 .callback_ops = &rpc_default_ops,
1135                 .flags = RPC_TASK_SOFTCONN,
1136         };
1137
1138         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1139         /*
1140          * Create an rpc_task to send the data
1141          */
1142         task = rpc_new_task(&task_setup_data);
1143         if (IS_ERR(task)) {
1144                 xprt_free_bc_request(req);
1145                 goto out;
1146         }
1147         task->tk_rqstp = req;
1148
1149         /*
1150          * Set up the xdr_buf length.
1151          * This also indicates that the buffer is XDR encoded already.
1152          */
1153         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1154                         xbufp->tail[0].iov_len;
1155
1156         task->tk_action = call_bc_transmit;
1157         atomic_inc(&task->tk_count);
1158         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1159         rpc_execute(task);
1160
1161 out:
1162         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1163         return task;
1164 }
1165 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1166
1167 void
1168 rpc_call_start(struct rpc_task *task)
1169 {
1170         task->tk_action = call_start;
1171 }
1172 EXPORT_SYMBOL_GPL(rpc_call_start);
1173
1174 /**
1175  * rpc_peeraddr - extract remote peer address from clnt's xprt
1176  * @clnt: RPC client structure
1177  * @buf: target buffer
1178  * @bufsize: length of target buffer
1179  *
1180  * Returns the number of bytes that are actually in the stored address.
1181  */
1182 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1183 {
1184         size_t bytes;
1185         struct rpc_xprt *xprt;
1186
1187         rcu_read_lock();
1188         xprt = rcu_dereference(clnt->cl_xprt);
1189
1190         bytes = xprt->addrlen;
1191         if (bytes > bufsize)
1192                 bytes = bufsize;
1193         memcpy(buf, &xprt->addr, bytes);
1194         rcu_read_unlock();
1195
1196         return bytes;
1197 }
1198 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1199
1200 /**
1201  * rpc_peeraddr2str - return remote peer address in printable format
1202  * @clnt: RPC client structure
1203  * @format: address format
1204  *
1205  * NB: the lifetime of the memory referenced by the returned pointer is
1206  * the same as the rpc_xprt itself.  As long as the caller uses this
1207  * pointer, it must hold the RCU read lock.
1208  */
1209 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1210                              enum rpc_display_format_t format)
1211 {
1212         struct rpc_xprt *xprt;
1213
1214         xprt = rcu_dereference(clnt->cl_xprt);
1215
1216         if (xprt->address_strings[format] != NULL)
1217                 return xprt->address_strings[format];
1218         else
1219                 return "unprintable";
1220 }
1221 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1222
1223 static const struct sockaddr_in rpc_inaddr_loopback = {
1224         .sin_family             = AF_INET,
1225         .sin_addr.s_addr        = htonl(INADDR_ANY),
1226 };
1227
1228 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1229         .sin6_family            = AF_INET6,
1230         .sin6_addr              = IN6ADDR_ANY_INIT,
1231 };
1232
1233 /*
1234  * Try a getsockname() on a connected datagram socket.  Using a
1235  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1236  * This conserves the ephemeral port number space.
1237  *
1238  * Returns zero and fills in "buf" if successful; otherwise, a
1239  * negative errno is returned.
1240  */
1241 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1242                         struct sockaddr *buf, int buflen)
1243 {
1244         struct socket *sock;
1245         int err;
1246
1247         err = __sock_create(net, sap->sa_family,
1248                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1249         if (err < 0) {
1250                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1251                 goto out;
1252         }
1253
1254         switch (sap->sa_family) {
1255         case AF_INET:
1256                 err = kernel_bind(sock,
1257                                 (struct sockaddr *)&rpc_inaddr_loopback,
1258                                 sizeof(rpc_inaddr_loopback));
1259                 break;
1260         case AF_INET6:
1261                 err = kernel_bind(sock,
1262                                 (struct sockaddr *)&rpc_in6addr_loopback,
1263                                 sizeof(rpc_in6addr_loopback));
1264                 break;
1265         default:
1266                 err = -EAFNOSUPPORT;
1267                 goto out;
1268         }
1269         if (err < 0) {
1270                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1271                 goto out_release;
1272         }
1273
1274         err = kernel_connect(sock, sap, salen, 0);
1275         if (err < 0) {
1276                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1277                 goto out_release;
1278         }
1279
1280         err = kernel_getsockname(sock, buf, &buflen);
1281         if (err < 0) {
1282                 dprintk("RPC:       getsockname failed (%d)\n", err);
1283                 goto out_release;
1284         }
1285
1286         err = 0;
1287         if (buf->sa_family == AF_INET6) {
1288                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1289                 sin6->sin6_scope_id = 0;
1290         }
1291         dprintk("RPC:       %s succeeded\n", __func__);
1292
1293 out_release:
1294         sock_release(sock);
1295 out:
1296         return err;
1297 }
1298
1299 /*
1300  * Scraping a connected socket failed, so we don't have a useable
1301  * local address.  Fallback: generate an address that will prevent
1302  * the server from calling us back.
1303  *
1304  * Returns zero and fills in "buf" if successful; otherwise, a
1305  * negative errno is returned.
1306  */
1307 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1308 {
1309         switch (family) {
1310         case AF_INET:
1311                 if (buflen < sizeof(rpc_inaddr_loopback))
1312                         return -EINVAL;
1313                 memcpy(buf, &rpc_inaddr_loopback,
1314                                 sizeof(rpc_inaddr_loopback));
1315                 break;
1316         case AF_INET6:
1317                 if (buflen < sizeof(rpc_in6addr_loopback))
1318                         return -EINVAL;
1319                 memcpy(buf, &rpc_in6addr_loopback,
1320                                 sizeof(rpc_in6addr_loopback));
1321                 break;
1322         default:
1323                 dprintk("RPC:       %s: address family not supported\n",
1324                         __func__);
1325                 return -EAFNOSUPPORT;
1326         }
1327         dprintk("RPC:       %s: succeeded\n", __func__);
1328         return 0;
1329 }
1330
1331 /**
1332  * rpc_localaddr - discover local endpoint address for an RPC client
1333  * @clnt: RPC client structure
1334  * @buf: target buffer
1335  * @buflen: size of target buffer, in bytes
1336  *
1337  * Returns zero and fills in "buf" and "buflen" if successful;
1338  * otherwise, a negative errno is returned.
1339  *
1340  * This works even if the underlying transport is not currently connected,
1341  * or if the upper layer never previously provided a source address.
1342  *
1343  * The result of this function call is transient: multiple calls in
1344  * succession may give different results, depending on how local
1345  * networking configuration changes over time.
1346  */
1347 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1348 {
1349         struct sockaddr_storage address;
1350         struct sockaddr *sap = (struct sockaddr *)&address;
1351         struct rpc_xprt *xprt;
1352         struct net *net;
1353         size_t salen;
1354         int err;
1355
1356         rcu_read_lock();
1357         xprt = rcu_dereference(clnt->cl_xprt);
1358         salen = xprt->addrlen;
1359         memcpy(sap, &xprt->addr, salen);
1360         net = get_net(xprt->xprt_net);
1361         rcu_read_unlock();
1362
1363         rpc_set_port(sap, 0);
1364         err = rpc_sockname(net, sap, salen, buf, buflen);
1365         put_net(net);
1366         if (err != 0)
1367                 /* Couldn't discover local address, return ANYADDR */
1368                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1369         return 0;
1370 }
1371 EXPORT_SYMBOL_GPL(rpc_localaddr);
1372
1373 void
1374 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1375 {
1376         struct rpc_xprt *xprt;
1377
1378         rcu_read_lock();
1379         xprt = rcu_dereference(clnt->cl_xprt);
1380         if (xprt->ops->set_buffer_size)
1381                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1382         rcu_read_unlock();
1383 }
1384 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1385
1386 /**
1387  * rpc_protocol - Get transport protocol number for an RPC client
1388  * @clnt: RPC client to query
1389  *
1390  */
1391 int rpc_protocol(struct rpc_clnt *clnt)
1392 {
1393         int protocol;
1394
1395         rcu_read_lock();
1396         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1397         rcu_read_unlock();
1398         return protocol;
1399 }
1400 EXPORT_SYMBOL_GPL(rpc_protocol);
1401
1402 /**
1403  * rpc_net_ns - Get the network namespace for this RPC client
1404  * @clnt: RPC client to query
1405  *
1406  */
1407 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1408 {
1409         struct net *ret;
1410
1411         rcu_read_lock();
1412         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1413         rcu_read_unlock();
1414         return ret;
1415 }
1416 EXPORT_SYMBOL_GPL(rpc_net_ns);
1417
1418 /**
1419  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1420  * @clnt: RPC client to query
1421  *
1422  * For stream transports, this is one RPC record fragment (see RFC
1423  * 1831), as we don't support multi-record requests yet.  For datagram
1424  * transports, this is the size of an IP packet minus the IP, UDP, and
1425  * RPC header sizes.
1426  */
1427 size_t rpc_max_payload(struct rpc_clnt *clnt)
1428 {
1429         size_t ret;
1430
1431         rcu_read_lock();
1432         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1433         rcu_read_unlock();
1434         return ret;
1435 }
1436 EXPORT_SYMBOL_GPL(rpc_max_payload);
1437
1438 /**
1439  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1440  * @clnt: RPC client to query
1441  */
1442 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1443 {
1444         struct rpc_xprt *xprt;
1445         size_t ret;
1446
1447         rcu_read_lock();
1448         xprt = rcu_dereference(clnt->cl_xprt);
1449         ret = xprt->ops->bc_maxpayload(xprt);
1450         rcu_read_unlock();
1451         return ret;
1452 }
1453 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1454
1455 /**
1456  * rpc_force_rebind - force transport to check that remote port is unchanged
1457  * @clnt: client to rebind
1458  *
1459  */
1460 void rpc_force_rebind(struct rpc_clnt *clnt)
1461 {
1462         if (clnt->cl_autobind) {
1463                 rcu_read_lock();
1464                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1465                 rcu_read_unlock();
1466         }
1467 }
1468 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1469
1470 /*
1471  * Restart an (async) RPC call from the call_prepare state.
1472  * Usually called from within the exit handler.
1473  */
1474 int
1475 rpc_restart_call_prepare(struct rpc_task *task)
1476 {
1477         if (RPC_ASSASSINATED(task))
1478                 return 0;
1479         task->tk_action = call_start;
1480         task->tk_status = 0;
1481         if (task->tk_ops->rpc_call_prepare != NULL)
1482                 task->tk_action = rpc_prepare_task;
1483         return 1;
1484 }
1485 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1486
1487 /*
1488  * Restart an (async) RPC call. Usually called from within the
1489  * exit handler.
1490  */
1491 int
1492 rpc_restart_call(struct rpc_task *task)
1493 {
1494         if (RPC_ASSASSINATED(task))
1495                 return 0;
1496         task->tk_action = call_start;
1497         task->tk_status = 0;
1498         return 1;
1499 }
1500 EXPORT_SYMBOL_GPL(rpc_restart_call);
1501
1502 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1503 const char
1504 *rpc_proc_name(const struct rpc_task *task)
1505 {
1506         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1507
1508         if (proc) {
1509                 if (proc->p_name)
1510                         return proc->p_name;
1511                 else
1512                         return "NULL";
1513         } else
1514                 return "no proc";
1515 }
1516 #endif
1517
1518 /*
1519  * 0.  Initial state
1520  *
1521  *     Other FSM states can be visited zero or more times, but
1522  *     this state is visited exactly once for each RPC.
1523  */
1524 static void
1525 call_start(struct rpc_task *task)
1526 {
1527         struct rpc_clnt *clnt = task->tk_client;
1528
1529         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1530                         clnt->cl_program->name, clnt->cl_vers,
1531                         rpc_proc_name(task),
1532                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1533
1534         /* Increment call count */
1535         task->tk_msg.rpc_proc->p_count++;
1536         clnt->cl_stats->rpccnt++;
1537         task->tk_action = call_reserve;
1538 }
1539
1540 /*
1541  * 1.   Reserve an RPC call slot
1542  */
1543 static void
1544 call_reserve(struct rpc_task *task)
1545 {
1546         dprint_status(task);
1547
1548         task->tk_status  = 0;
1549         task->tk_action  = call_reserveresult;
1550         xprt_reserve(task);
1551 }
1552
1553 static void call_retry_reserve(struct rpc_task *task);
1554
1555 /*
1556  * 1b.  Grok the result of xprt_reserve()
1557  */
1558 static void
1559 call_reserveresult(struct rpc_task *task)
1560 {
1561         int status = task->tk_status;
1562
1563         dprint_status(task);
1564
1565         /*
1566          * After a call to xprt_reserve(), we must have either
1567          * a request slot or else an error status.
1568          */
1569         task->tk_status = 0;
1570         if (status >= 0) {
1571                 if (task->tk_rqstp) {
1572                         task->tk_action = call_refresh;
1573                         return;
1574                 }
1575
1576                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1577                                 __func__, status);
1578                 rpc_exit(task, -EIO);
1579                 return;
1580         }
1581
1582         /*
1583          * Even though there was an error, we may have acquired
1584          * a request slot somehow.  Make sure not to leak it.
1585          */
1586         if (task->tk_rqstp) {
1587                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1588                                 __func__, status);
1589                 xprt_release(task);
1590         }
1591
1592         switch (status) {
1593         case -ENOMEM:
1594                 rpc_delay(task, HZ >> 2);
1595         case -EAGAIN:   /* woken up; retry */
1596                 task->tk_action = call_retry_reserve;
1597                 return;
1598         case -EIO:      /* probably a shutdown */
1599                 break;
1600         default:
1601                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1602                                 __func__, status);
1603                 break;
1604         }
1605         rpc_exit(task, status);
1606 }
1607
1608 /*
1609  * 1c.  Retry reserving an RPC call slot
1610  */
1611 static void
1612 call_retry_reserve(struct rpc_task *task)
1613 {
1614         dprint_status(task);
1615
1616         task->tk_status  = 0;
1617         task->tk_action  = call_reserveresult;
1618         xprt_retry_reserve(task);
1619 }
1620
1621 /*
1622  * 2.   Bind and/or refresh the credentials
1623  */
1624 static void
1625 call_refresh(struct rpc_task *task)
1626 {
1627         dprint_status(task);
1628
1629         task->tk_action = call_refreshresult;
1630         task->tk_status = 0;
1631         task->tk_client->cl_stats->rpcauthrefresh++;
1632         rpcauth_refreshcred(task);
1633 }
1634
1635 /*
1636  * 2a.  Process the results of a credential refresh
1637  */
1638 static void
1639 call_refreshresult(struct rpc_task *task)
1640 {
1641         int status = task->tk_status;
1642
1643         dprint_status(task);
1644
1645         task->tk_status = 0;
1646         task->tk_action = call_refresh;
1647         switch (status) {
1648         case 0:
1649                 if (rpcauth_uptodatecred(task)) {
1650                         task->tk_action = call_allocate;
1651                         return;
1652                 }
1653                 /* Use rate-limiting and a max number of retries if refresh
1654                  * had status 0 but failed to update the cred.
1655                  */
1656         case -ETIMEDOUT:
1657                 rpc_delay(task, 3*HZ);
1658         case -EAGAIN:
1659                 status = -EACCES;
1660         case -EKEYEXPIRED:
1661                 if (!task->tk_cred_retry)
1662                         break;
1663                 task->tk_cred_retry--;
1664                 dprintk("RPC: %5u %s: retry refresh creds\n",
1665                                 task->tk_pid, __func__);
1666                 return;
1667         }
1668         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1669                                 task->tk_pid, __func__, status);
1670         rpc_exit(task, status);
1671 }
1672
1673 /*
1674  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1675  *      (Note: buffer memory is freed in xprt_release).
1676  */
1677 static void
1678 call_allocate(struct rpc_task *task)
1679 {
1680         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1681         struct rpc_rqst *req = task->tk_rqstp;
1682         struct rpc_xprt *xprt = req->rq_xprt;
1683         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1684         int status;
1685
1686         dprint_status(task);
1687
1688         task->tk_status = 0;
1689         task->tk_action = call_bind;
1690
1691         if (req->rq_buffer)
1692                 return;
1693
1694         if (proc->p_proc != 0) {
1695                 BUG_ON(proc->p_arglen == 0);
1696                 if (proc->p_decode != NULL)
1697                         BUG_ON(proc->p_replen == 0);
1698         }
1699
1700         /*
1701          * Calculate the size (in quads) of the RPC call
1702          * and reply headers, and convert both values
1703          * to byte sizes.
1704          */
1705         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1706         req->rq_callsize <<= 2;
1707         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1708         req->rq_rcvsize <<= 2;
1709
1710         status = xprt->ops->buf_alloc(task);
1711         xprt_inject_disconnect(xprt);
1712         if (status == 0)
1713                 return;
1714         if (status != -ENOMEM) {
1715                 rpc_exit(task, status);
1716                 return;
1717         }
1718
1719         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1720
1721         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1722                 task->tk_action = call_allocate;
1723                 rpc_delay(task, HZ>>4);
1724                 return;
1725         }
1726
1727         rpc_exit(task, -ERESTARTSYS);
1728 }
1729
1730 static inline int
1731 rpc_task_need_encode(struct rpc_task *task)
1732 {
1733         return task->tk_rqstp->rq_snd_buf.len == 0;
1734 }
1735
1736 static inline void
1737 rpc_task_force_reencode(struct rpc_task *task)
1738 {
1739         task->tk_rqstp->rq_snd_buf.len = 0;
1740         task->tk_rqstp->rq_bytes_sent = 0;
1741 }
1742
1743 /*
1744  * 3.   Encode arguments of an RPC call
1745  */
1746 static void
1747 rpc_xdr_encode(struct rpc_task *task)
1748 {
1749         struct rpc_rqst *req = task->tk_rqstp;
1750         kxdreproc_t     encode;
1751         __be32          *p;
1752
1753         dprint_status(task);
1754
1755         xdr_buf_init(&req->rq_snd_buf,
1756                      req->rq_buffer,
1757                      req->rq_callsize);
1758         xdr_buf_init(&req->rq_rcv_buf,
1759                      req->rq_rbuffer,
1760                      req->rq_rcvsize);
1761
1762         p = rpc_encode_header(task);
1763         if (p == NULL) {
1764                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1765                 rpc_exit(task, -EIO);
1766                 return;
1767         }
1768
1769         encode = task->tk_msg.rpc_proc->p_encode;
1770         if (encode == NULL)
1771                 return;
1772
1773         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1774                         task->tk_msg.rpc_argp);
1775 }
1776
1777 /*
1778  * 4.   Get the server port number if not yet set
1779  */
1780 static void
1781 call_bind(struct rpc_task *task)
1782 {
1783         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1784
1785         dprint_status(task);
1786
1787         task->tk_action = call_connect;
1788         if (!xprt_bound(xprt)) {
1789                 task->tk_action = call_bind_status;
1790                 task->tk_timeout = xprt->bind_timeout;
1791                 xprt->ops->rpcbind(task);
1792         }
1793 }
1794
1795 /*
1796  * 4a.  Sort out bind result
1797  */
1798 static void
1799 call_bind_status(struct rpc_task *task)
1800 {
1801         int status = -EIO;
1802
1803         if (task->tk_status >= 0) {
1804                 dprint_status(task);
1805                 task->tk_status = 0;
1806                 task->tk_action = call_connect;
1807                 return;
1808         }
1809
1810         trace_rpc_bind_status(task);
1811         switch (task->tk_status) {
1812         case -ENOMEM:
1813                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1814                 rpc_delay(task, HZ >> 2);
1815                 goto retry_timeout;
1816         case -EACCES:
1817                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1818                                 "unavailable\n", task->tk_pid);
1819                 /* fail immediately if this is an RPC ping */
1820                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1821                         status = -EOPNOTSUPP;
1822                         break;
1823                 }
1824                 if (task->tk_rebind_retry == 0)
1825                         break;
1826                 task->tk_rebind_retry--;
1827                 rpc_delay(task, 3*HZ);
1828                 goto retry_timeout;
1829         case -ETIMEDOUT:
1830                 dprintk("RPC: %5u rpcbind request timed out\n",
1831                                 task->tk_pid);
1832                 goto retry_timeout;
1833         case -EPFNOSUPPORT:
1834                 /* server doesn't support any rpcbind version we know of */
1835                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1836                                 task->tk_pid);
1837                 break;
1838         case -EPROTONOSUPPORT:
1839                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1840                                 task->tk_pid);
1841                 goto retry_timeout;
1842         case -ECONNREFUSED:             /* connection problems */
1843         case -ECONNRESET:
1844         case -ECONNABORTED:
1845         case -ENOTCONN:
1846         case -EHOSTDOWN:
1847         case -EHOSTUNREACH:
1848         case -ENETUNREACH:
1849         case -ENOBUFS:
1850         case -EPIPE:
1851                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1852                                 task->tk_pid, task->tk_status);
1853                 if (!RPC_IS_SOFTCONN(task)) {
1854                         rpc_delay(task, 5*HZ);
1855                         goto retry_timeout;
1856                 }
1857                 status = task->tk_status;
1858                 break;
1859         default:
1860                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1861                                 task->tk_pid, -task->tk_status);
1862         }
1863
1864         rpc_exit(task, status);
1865         return;
1866
1867 retry_timeout:
1868         task->tk_status = 0;
1869         task->tk_action = call_timeout;
1870 }
1871
1872 /*
1873  * 4b.  Connect to the RPC server
1874  */
1875 static void
1876 call_connect(struct rpc_task *task)
1877 {
1878         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1879
1880         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1881                         task->tk_pid, xprt,
1882                         (xprt_connected(xprt) ? "is" : "is not"));
1883
1884         task->tk_action = call_transmit;
1885         if (!xprt_connected(xprt)) {
1886                 task->tk_action = call_connect_status;
1887                 if (task->tk_status < 0)
1888                         return;
1889                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1890                         rpc_exit(task, -ENOTCONN);
1891                         return;
1892                 }
1893                 xprt_connect(task);
1894         }
1895 }
1896
1897 /*
1898  * 4c.  Sort out connect result
1899  */
1900 static void
1901 call_connect_status(struct rpc_task *task)
1902 {
1903         struct rpc_clnt *clnt = task->tk_client;
1904         int status = task->tk_status;
1905
1906         dprint_status(task);
1907
1908         trace_rpc_connect_status(task, status);
1909         task->tk_status = 0;
1910         switch (status) {
1911         case -ECONNREFUSED:
1912         case -ECONNRESET:
1913         case -ECONNABORTED:
1914         case -ENETUNREACH:
1915         case -EHOSTUNREACH:
1916         case -EADDRINUSE:
1917         case -ENOBUFS:
1918         case -EPIPE:
1919                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1920                                             task->tk_rqstp->rq_connect_cookie);
1921                 if (RPC_IS_SOFTCONN(task))
1922                         break;
1923                 /* retry with existing socket, after a delay */
1924                 rpc_delay(task, 3*HZ);
1925         case -EAGAIN:
1926                 /* Check for timeouts before looping back to call_bind */
1927         case -ETIMEDOUT:
1928                 task->tk_action = call_timeout;
1929                 return;
1930         case 0:
1931                 clnt->cl_stats->netreconn++;
1932                 task->tk_action = call_transmit;
1933                 return;
1934         }
1935         rpc_exit(task, status);
1936 }
1937
1938 /*
1939  * 5.   Transmit the RPC request, and wait for reply
1940  */
1941 static void
1942 call_transmit(struct rpc_task *task)
1943 {
1944         int is_retrans = RPC_WAS_SENT(task);
1945
1946         dprint_status(task);
1947
1948         task->tk_action = call_status;
1949         if (task->tk_status < 0)
1950                 return;
1951         if (!xprt_prepare_transmit(task))
1952                 return;
1953         task->tk_action = call_transmit_status;
1954         /* Encode here so that rpcsec_gss can use correct sequence number. */
1955         if (rpc_task_need_encode(task)) {
1956                 rpc_xdr_encode(task);
1957                 /* Did the encode result in an error condition? */
1958                 if (task->tk_status != 0) {
1959                         /* Was the error nonfatal? */
1960                         if (task->tk_status == -EAGAIN)
1961                                 rpc_delay(task, HZ >> 4);
1962                         else
1963                                 rpc_exit(task, task->tk_status);
1964                         return;
1965                 }
1966         }
1967         xprt_transmit(task);
1968         if (task->tk_status < 0)
1969                 return;
1970         if (is_retrans)
1971                 task->tk_client->cl_stats->rpcretrans++;
1972         /*
1973          * On success, ensure that we call xprt_end_transmit() before sleeping
1974          * in order to allow access to the socket to other RPC requests.
1975          */
1976         call_transmit_status(task);
1977         if (rpc_reply_expected(task))
1978                 return;
1979         task->tk_action = rpc_exit_task;
1980         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1981 }
1982
1983 /*
1984  * 5a.  Handle cleanup after a transmission
1985  */
1986 static void
1987 call_transmit_status(struct rpc_task *task)
1988 {
1989         task->tk_action = call_status;
1990
1991         /*
1992          * Common case: success.  Force the compiler to put this
1993          * test first.
1994          */
1995         if (task->tk_status == 0) {
1996                 xprt_end_transmit(task);
1997                 rpc_task_force_reencode(task);
1998                 return;
1999         }
2000
2001         switch (task->tk_status) {
2002         case -EAGAIN:
2003         case -ENOBUFS:
2004                 break;
2005         default:
2006                 dprint_status(task);
2007                 xprt_end_transmit(task);
2008                 rpc_task_force_reencode(task);
2009                 break;
2010                 /*
2011                  * Special cases: if we've been waiting on the
2012                  * socket's write_space() callback, or if the
2013                  * socket just returned a connection error,
2014                  * then hold onto the transport lock.
2015                  */
2016         case -ECONNREFUSED:
2017         case -EHOSTDOWN:
2018         case -EHOSTUNREACH:
2019         case -ENETUNREACH:
2020         case -EPERM:
2021                 if (RPC_IS_SOFTCONN(task)) {
2022                         xprt_end_transmit(task);
2023                         rpc_exit(task, task->tk_status);
2024                         break;
2025                 }
2026         case -ECONNRESET:
2027         case -ECONNABORTED:
2028         case -EADDRINUSE:
2029         case -ENOTCONN:
2030         case -EPIPE:
2031                 rpc_task_force_reencode(task);
2032         }
2033 }
2034
2035 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2036 /*
2037  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2038  * addition, disconnect on connectivity errors.
2039  */
2040 static void
2041 call_bc_transmit(struct rpc_task *task)
2042 {
2043         struct rpc_rqst *req = task->tk_rqstp;
2044
2045         if (!xprt_prepare_transmit(task))
2046                 goto out_retry;
2047
2048         if (task->tk_status < 0) {
2049                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2050                         "error: %d\n", task->tk_status);
2051                 goto out_done;
2052         }
2053         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2054                 req->rq_bytes_sent = 0;
2055
2056         xprt_transmit(task);
2057
2058         if (task->tk_status == -EAGAIN)
2059                 goto out_nospace;
2060
2061         xprt_end_transmit(task);
2062         dprint_status(task);
2063         switch (task->tk_status) {
2064         case 0:
2065                 /* Success */
2066         case -EHOSTDOWN:
2067         case -EHOSTUNREACH:
2068         case -ENETUNREACH:
2069         case -ECONNRESET:
2070         case -ECONNREFUSED:
2071         case -EADDRINUSE:
2072         case -ENOTCONN:
2073         case -EPIPE:
2074                 break;
2075         case -ETIMEDOUT:
2076                 /*
2077                  * Problem reaching the server.  Disconnect and let the
2078                  * forechannel reestablish the connection.  The server will
2079                  * have to retransmit the backchannel request and we'll
2080                  * reprocess it.  Since these ops are idempotent, there's no
2081                  * need to cache our reply at this time.
2082                  */
2083                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2084                         "error: %d\n", task->tk_status);
2085                 xprt_conditional_disconnect(req->rq_xprt,
2086                         req->rq_connect_cookie);
2087                 break;
2088         default:
2089                 /*
2090                  * We were unable to reply and will have to drop the
2091                  * request.  The server should reconnect and retransmit.
2092                  */
2093                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2094                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2095                         "error: %d\n", task->tk_status);
2096                 break;
2097         }
2098         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2099 out_done:
2100         task->tk_action = rpc_exit_task;
2101         return;
2102 out_nospace:
2103         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2104 out_retry:
2105         task->tk_status = 0;
2106 }
2107 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2108
2109 /*
2110  * 6.   Sort out the RPC call status
2111  */
2112 static void
2113 call_status(struct rpc_task *task)
2114 {
2115         struct rpc_clnt *clnt = task->tk_client;
2116         struct rpc_rqst *req = task->tk_rqstp;
2117         int             status;
2118
2119         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2120                 task->tk_status = req->rq_reply_bytes_recvd;
2121
2122         dprint_status(task);
2123
2124         status = task->tk_status;
2125         if (status >= 0) {
2126                 task->tk_action = call_decode;
2127                 return;
2128         }
2129
2130         trace_rpc_call_status(task);
2131         task->tk_status = 0;
2132         switch(status) {
2133         case -EHOSTDOWN:
2134         case -EHOSTUNREACH:
2135         case -ENETUNREACH:
2136         case -EPERM:
2137                 if (RPC_IS_SOFTCONN(task)) {
2138                         rpc_exit(task, status);
2139                         break;
2140                 }
2141                 /*
2142                  * Delay any retries for 3 seconds, then handle as if it
2143                  * were a timeout.
2144                  */
2145                 rpc_delay(task, 3*HZ);
2146         case -ETIMEDOUT:
2147                 task->tk_action = call_timeout;
2148                 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2149                     && task->tk_client->cl_discrtry)
2150                         xprt_conditional_disconnect(req->rq_xprt,
2151                                         req->rq_connect_cookie);
2152                 break;
2153         case -ECONNREFUSED:
2154         case -ECONNRESET:
2155         case -ECONNABORTED:
2156                 rpc_force_rebind(clnt);
2157         case -EADDRINUSE:
2158                 rpc_delay(task, 3*HZ);
2159         case -EPIPE:
2160         case -ENOTCONN:
2161                 task->tk_action = call_bind;
2162                 break;
2163         case -ENOBUFS:
2164                 rpc_delay(task, HZ>>2);
2165         case -EAGAIN:
2166                 task->tk_action = call_transmit;
2167                 break;
2168         case -EIO:
2169                 /* shutdown or soft timeout */
2170                 rpc_exit(task, status);
2171                 break;
2172         default:
2173                 if (clnt->cl_chatty)
2174                         printk("%s: RPC call returned error %d\n",
2175                                clnt->cl_program->name, -status);
2176                 rpc_exit(task, status);
2177         }
2178 }
2179
2180 /*
2181  * 6a.  Handle RPC timeout
2182  *      We do not release the request slot, so we keep using the
2183  *      same XID for all retransmits.
2184  */
2185 static void
2186 call_timeout(struct rpc_task *task)
2187 {
2188         struct rpc_clnt *clnt = task->tk_client;
2189
2190         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2191                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2192                 goto retry;
2193         }
2194
2195         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2196         task->tk_timeouts++;
2197
2198         if (RPC_IS_SOFTCONN(task)) {
2199                 rpc_exit(task, -ETIMEDOUT);
2200                 return;
2201         }
2202         if (RPC_IS_SOFT(task)) {
2203                 if (clnt->cl_chatty) {
2204                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2205                                 clnt->cl_program->name,
2206                                 task->tk_xprt->servername);
2207                 }
2208                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2209                         rpc_exit(task, -ETIMEDOUT);
2210                 else
2211                         rpc_exit(task, -EIO);
2212                 return;
2213         }
2214
2215         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2216                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2217                 if (clnt->cl_chatty) {
2218                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2219                         clnt->cl_program->name,
2220                         task->tk_xprt->servername);
2221                 }
2222         }
2223         rpc_force_rebind(clnt);
2224         /*
2225          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2226          * event? RFC2203 requires the server to drop all such requests.
2227          */
2228         rpcauth_invalcred(task);
2229
2230 retry:
2231         task->tk_action = call_bind;
2232         task->tk_status = 0;
2233 }
2234
2235 /*
2236  * 7.   Decode the RPC reply
2237  */
2238 static void
2239 call_decode(struct rpc_task *task)
2240 {
2241         struct rpc_clnt *clnt = task->tk_client;
2242         struct rpc_rqst *req = task->tk_rqstp;
2243         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2244         __be32          *p;
2245
2246         dprint_status(task);
2247
2248         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2249                 if (clnt->cl_chatty) {
2250                         printk(KERN_NOTICE "%s: server %s OK\n",
2251                                 clnt->cl_program->name,
2252                                 task->tk_xprt->servername);
2253                 }
2254                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2255         }
2256
2257         /*
2258          * Ensure that we see all writes made by xprt_complete_rqst()
2259          * before it changed req->rq_reply_bytes_recvd.
2260          */
2261         smp_rmb();
2262         req->rq_rcv_buf.len = req->rq_private_buf.len;
2263
2264         /* Check that the softirq receive buffer is valid */
2265         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2266                                 sizeof(req->rq_rcv_buf)) != 0);
2267
2268         if (req->rq_rcv_buf.len < 12) {
2269                 if (!RPC_IS_SOFT(task)) {
2270                         task->tk_action = call_bind;
2271                         goto out_retry;
2272                 }
2273                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2274                                 clnt->cl_program->name, task->tk_status);
2275                 task->tk_action = call_timeout;
2276                 goto out_retry;
2277         }
2278
2279         p = rpc_verify_header(task);
2280         if (IS_ERR(p)) {
2281                 if (p == ERR_PTR(-EAGAIN))
2282                         goto out_retry;
2283                 return;
2284         }
2285
2286         task->tk_action = rpc_exit_task;
2287
2288         if (decode) {
2289                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2290                                                       task->tk_msg.rpc_resp);
2291         }
2292         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2293                         task->tk_status);
2294         return;
2295 out_retry:
2296         task->tk_status = 0;
2297         /* Note: rpc_verify_header() may have freed the RPC slot */
2298         if (task->tk_rqstp == req) {
2299                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2300                 if (task->tk_client->cl_discrtry)
2301                         xprt_conditional_disconnect(req->rq_xprt,
2302                                         req->rq_connect_cookie);
2303         }
2304 }
2305
2306 static __be32 *
2307 rpc_encode_header(struct rpc_task *task)
2308 {
2309         struct rpc_clnt *clnt = task->tk_client;
2310         struct rpc_rqst *req = task->tk_rqstp;
2311         __be32          *p = req->rq_svec[0].iov_base;
2312
2313         /* FIXME: check buffer size? */
2314
2315         p = xprt_skip_transport_header(req->rq_xprt, p);
2316         *p++ = req->rq_xid;             /* XID */
2317         *p++ = htonl(RPC_CALL);         /* CALL */
2318         *p++ = htonl(RPC_VERSION);      /* RPC version */
2319         *p++ = htonl(clnt->cl_prog);    /* program number */
2320         *p++ = htonl(clnt->cl_vers);    /* program version */
2321         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2322         p = rpcauth_marshcred(task, p);
2323         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2324         return p;
2325 }
2326
2327 static __be32 *
2328 rpc_verify_header(struct rpc_task *task)
2329 {
2330         struct rpc_clnt *clnt = task->tk_client;
2331         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2332         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2333         __be32  *p = iov->iov_base;
2334         u32 n;
2335         int error = -EACCES;
2336
2337         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2338                 /* RFC-1014 says that the representation of XDR data must be a
2339                  * multiple of four bytes
2340                  * - if it isn't pointer subtraction in the NFS client may give
2341                  *   undefined results
2342                  */
2343                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2344                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2345                        task->tk_rqstp->rq_rcv_buf.len);
2346                 error = -EIO;
2347                 goto out_err;
2348         }
2349         if ((len -= 3) < 0)
2350                 goto out_overflow;
2351
2352         p += 1; /* skip XID */
2353         if ((n = ntohl(*p++)) != RPC_REPLY) {
2354                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2355                         task->tk_pid, __func__, n);
2356                 error = -EIO;
2357                 goto out_garbage;
2358         }
2359
2360         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2361                 if (--len < 0)
2362                         goto out_overflow;
2363                 switch ((n = ntohl(*p++))) {
2364                 case RPC_AUTH_ERROR:
2365                         break;
2366                 case RPC_MISMATCH:
2367                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2368                                 task->tk_pid, __func__);
2369                         error = -EPROTONOSUPPORT;
2370                         goto out_err;
2371                 default:
2372                         dprintk("RPC: %5u %s: RPC call rejected, "
2373                                 "unknown error: %x\n",
2374                                 task->tk_pid, __func__, n);
2375                         error = -EIO;
2376                         goto out_err;
2377                 }
2378                 if (--len < 0)
2379                         goto out_overflow;
2380                 switch ((n = ntohl(*p++))) {
2381                 case RPC_AUTH_REJECTEDCRED:
2382                 case RPC_AUTH_REJECTEDVERF:
2383                 case RPCSEC_GSS_CREDPROBLEM:
2384                 case RPCSEC_GSS_CTXPROBLEM:
2385                         if (!task->tk_cred_retry)
2386                                 break;
2387                         task->tk_cred_retry--;
2388                         dprintk("RPC: %5u %s: retry stale creds\n",
2389                                         task->tk_pid, __func__);
2390                         rpcauth_invalcred(task);
2391                         /* Ensure we obtain a new XID! */
2392                         xprt_release(task);
2393                         task->tk_action = call_reserve;
2394                         goto out_retry;
2395                 case RPC_AUTH_BADCRED:
2396                 case RPC_AUTH_BADVERF:
2397                         /* possibly garbled cred/verf? */
2398                         if (!task->tk_garb_retry)
2399                                 break;
2400                         task->tk_garb_retry--;
2401                         dprintk("RPC: %5u %s: retry garbled creds\n",
2402                                         task->tk_pid, __func__);
2403                         task->tk_action = call_bind;
2404                         goto out_retry;
2405                 case RPC_AUTH_TOOWEAK:
2406                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2407                                "authentication.\n",
2408                                task->tk_xprt->servername);
2409                         break;
2410                 default:
2411                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2412                                         task->tk_pid, __func__, n);
2413                         error = -EIO;
2414                 }
2415                 dprintk("RPC: %5u %s: call rejected %d\n",
2416                                 task->tk_pid, __func__, n);
2417                 goto out_err;
2418         }
2419         p = rpcauth_checkverf(task, p);
2420         if (IS_ERR(p)) {
2421                 error = PTR_ERR(p);
2422                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2423                                 task->tk_pid, __func__, error);
2424                 goto out_garbage;               /* bad verifier, retry */
2425         }
2426         len = p - (__be32 *)iov->iov_base - 1;
2427         if (len < 0)
2428                 goto out_overflow;
2429         switch ((n = ntohl(*p++))) {
2430         case RPC_SUCCESS:
2431                 return p;
2432         case RPC_PROG_UNAVAIL:
2433                 dprintk("RPC: %5u %s: program %u is unsupported "
2434                                 "by server %s\n", task->tk_pid, __func__,
2435                                 (unsigned int)clnt->cl_prog,
2436                                 task->tk_xprt->servername);
2437                 error = -EPFNOSUPPORT;
2438                 goto out_err;
2439         case RPC_PROG_MISMATCH:
2440                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2441                                 "by server %s\n", task->tk_pid, __func__,
2442                                 (unsigned int)clnt->cl_prog,
2443                                 (unsigned int)clnt->cl_vers,
2444                                 task->tk_xprt->servername);
2445                 error = -EPROTONOSUPPORT;
2446                 goto out_err;
2447         case RPC_PROC_UNAVAIL:
2448                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2449                                 "version %u on server %s\n",
2450                                 task->tk_pid, __func__,
2451                                 rpc_proc_name(task),
2452                                 clnt->cl_prog, clnt->cl_vers,
2453                                 task->tk_xprt->servername);
2454                 error = -EOPNOTSUPP;
2455                 goto out_err;
2456         case RPC_GARBAGE_ARGS:
2457                 dprintk("RPC: %5u %s: server saw garbage\n",
2458                                 task->tk_pid, __func__);
2459                 break;                  /* retry */
2460         default:
2461                 dprintk("RPC: %5u %s: server accept status: %x\n",
2462                                 task->tk_pid, __func__, n);
2463                 /* Also retry */
2464         }
2465
2466 out_garbage:
2467         clnt->cl_stats->rpcgarbage++;
2468         if (task->tk_garb_retry) {
2469                 task->tk_garb_retry--;
2470                 dprintk("RPC: %5u %s: retrying\n",
2471                                 task->tk_pid, __func__);
2472                 task->tk_action = call_bind;
2473 out_retry:
2474                 return ERR_PTR(-EAGAIN);
2475         }
2476 out_err:
2477         rpc_exit(task, error);
2478         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2479                         __func__, error);
2480         return ERR_PTR(error);
2481 out_overflow:
2482         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2483                         __func__);
2484         goto out_garbage;
2485 }
2486
2487 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2488 {
2489 }
2490
2491 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2492 {
2493         return 0;
2494 }
2495
2496 static struct rpc_procinfo rpcproc_null = {
2497         .p_encode = rpcproc_encode_null,
2498         .p_decode = rpcproc_decode_null,
2499 };
2500
2501 static int rpc_ping(struct rpc_clnt *clnt)
2502 {
2503         struct rpc_message msg = {
2504                 .rpc_proc = &rpcproc_null,
2505         };
2506         int err;
2507         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2508         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2509         put_rpccred(msg.rpc_cred);
2510         return err;
2511 }
2512
2513 static
2514 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2515                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2516                 const struct rpc_call_ops *ops, void *data)
2517 {
2518         struct rpc_message msg = {
2519                 .rpc_proc = &rpcproc_null,
2520                 .rpc_cred = cred,
2521         };
2522         struct rpc_task_setup task_setup_data = {
2523                 .rpc_client = clnt,
2524                 .rpc_xprt = xprt,
2525                 .rpc_message = &msg,
2526                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2527                 .callback_data = data,
2528                 .flags = flags,
2529         };
2530
2531         return rpc_run_task(&task_setup_data);
2532 }
2533
2534 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2535 {
2536         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2537 }
2538 EXPORT_SYMBOL_GPL(rpc_call_null);
2539
2540 struct rpc_cb_add_xprt_calldata {
2541         struct rpc_xprt_switch *xps;
2542         struct rpc_xprt *xprt;
2543 };
2544
2545 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2546 {
2547         struct rpc_cb_add_xprt_calldata *data = calldata;
2548
2549         if (task->tk_status == 0)
2550                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2551 }
2552
2553 static void rpc_cb_add_xprt_release(void *calldata)
2554 {
2555         struct rpc_cb_add_xprt_calldata *data = calldata;
2556
2557         xprt_put(data->xprt);
2558         xprt_switch_put(data->xps);
2559         kfree(data);
2560 }
2561
2562 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2563         .rpc_call_done = rpc_cb_add_xprt_done,
2564         .rpc_release = rpc_cb_add_xprt_release,
2565 };
2566
2567 /**
2568  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2569  * @clnt: pointer to struct rpc_clnt
2570  * @xps: pointer to struct rpc_xprt_switch,
2571  * @xprt: pointer struct rpc_xprt
2572  * @dummy: unused
2573  */
2574 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2575                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2576                 void *dummy)
2577 {
2578         struct rpc_cb_add_xprt_calldata *data;
2579         struct rpc_cred *cred;
2580         struct rpc_task *task;
2581
2582         data = kmalloc(sizeof(*data), GFP_NOFS);
2583         if (!data)
2584                 return -ENOMEM;
2585         data->xps = xprt_switch_get(xps);
2586         data->xprt = xprt_get(xprt);
2587
2588         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2589         task = rpc_call_null_helper(clnt, xprt, cred,
2590                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2591                         &rpc_cb_add_xprt_call_ops, data);
2592         put_rpccred(cred);
2593         if (IS_ERR(task))
2594                 return PTR_ERR(task);
2595         rpc_put_task(task);
2596         return 1;
2597 }
2598 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2599
2600 /**
2601  * rpc_clnt_setup_test_and_add_xprt()
2602  *
2603  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2604  *   1) caller of the test function must dereference the rpc_xprt_switch
2605  *   and the rpc_xprt.
2606  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2607  *   the rpc_call_done routine.
2608  *
2609  * Upon success (return of 1), the test function adds the new
2610  * transport to the rpc_clnt xprt switch
2611  *
2612  * @clnt: struct rpc_clnt to get the new transport
2613  * @xps:  the rpc_xprt_switch to hold the new transport
2614  * @xprt: the rpc_xprt to test
2615  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2616  *        and test function call data
2617  */
2618 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2619                                      struct rpc_xprt_switch *xps,
2620                                      struct rpc_xprt *xprt,
2621                                      void *data)
2622 {
2623         struct rpc_cred *cred;
2624         struct rpc_task *task;
2625         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2626         int status = -EADDRINUSE;
2627
2628         xprt = xprt_get(xprt);
2629         xprt_switch_get(xps);
2630
2631         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2632                 goto out_err;
2633
2634         /* Test the connection */
2635         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2636         task = rpc_call_null_helper(clnt, xprt, cred,
2637                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2638                                     NULL, NULL);
2639         put_rpccred(cred);
2640         if (IS_ERR(task)) {
2641                 status = PTR_ERR(task);
2642                 goto out_err;
2643         }
2644         status = task->tk_status;
2645         rpc_put_task(task);
2646
2647         if (status < 0)
2648                 goto out_err;
2649
2650         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2651         xtest->add_xprt_test(clnt, xprt, xtest->data);
2652
2653         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2654         return 1;
2655 out_err:
2656         xprt_put(xprt);
2657         xprt_switch_put(xps);
2658         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2659                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2660         return status;
2661 }
2662 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2663
2664 /**
2665  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2666  * @clnt: pointer to struct rpc_clnt
2667  * @xprtargs: pointer to struct xprt_create
2668  * @setup: callback to test and/or set up the connection
2669  * @data: pointer to setup function data
2670  *
2671  * Creates a new transport using the parameters set in args and
2672  * adds it to clnt.
2673  * If ping is set, then test that connectivity succeeds before
2674  * adding the new transport.
2675  *
2676  */
2677 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2678                 struct xprt_create *xprtargs,
2679                 int (*setup)(struct rpc_clnt *,
2680                         struct rpc_xprt_switch *,
2681                         struct rpc_xprt *,
2682                         void *),
2683                 void *data)
2684 {
2685         struct rpc_xprt_switch *xps;
2686         struct rpc_xprt *xprt;
2687         unsigned long connect_timeout;
2688         unsigned long reconnect_timeout;
2689         unsigned char resvport;
2690         int ret = 0;
2691
2692         rcu_read_lock();
2693         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2694         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2695         if (xps == NULL || xprt == NULL) {
2696                 rcu_read_unlock();
2697                 return -EAGAIN;
2698         }
2699         resvport = xprt->resvport;
2700         connect_timeout = xprt->connect_timeout;
2701         reconnect_timeout = xprt->max_reconnect_timeout;
2702         rcu_read_unlock();
2703
2704         xprt = xprt_create_transport(xprtargs);
2705         if (IS_ERR(xprt)) {
2706                 ret = PTR_ERR(xprt);
2707                 goto out_put_switch;
2708         }
2709         xprt->resvport = resvport;
2710         if (xprt->ops->set_connect_timeout != NULL)
2711                 xprt->ops->set_connect_timeout(xprt,
2712                                 connect_timeout,
2713                                 reconnect_timeout);
2714
2715         rpc_xprt_switch_set_roundrobin(xps);
2716         if (setup) {
2717                 ret = setup(clnt, xps, xprt, data);
2718                 if (ret != 0)
2719                         goto out_put_xprt;
2720         }
2721         rpc_xprt_switch_add_xprt(xps, xprt);
2722 out_put_xprt:
2723         xprt_put(xprt);
2724 out_put_switch:
2725         xprt_switch_put(xps);
2726         return ret;
2727 }
2728 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2729
2730 struct connect_timeout_data {
2731         unsigned long connect_timeout;
2732         unsigned long reconnect_timeout;
2733 };
2734
2735 static int
2736 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2737                 struct rpc_xprt *xprt,
2738                 void *data)
2739 {
2740         struct connect_timeout_data *timeo = data;
2741
2742         if (xprt->ops->set_connect_timeout)
2743                 xprt->ops->set_connect_timeout(xprt,
2744                                 timeo->connect_timeout,
2745                                 timeo->reconnect_timeout);
2746         return 0;
2747 }
2748
2749 void
2750 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2751                 unsigned long connect_timeout,
2752                 unsigned long reconnect_timeout)
2753 {
2754         struct connect_timeout_data timeout = {
2755                 .connect_timeout = connect_timeout,
2756                 .reconnect_timeout = reconnect_timeout,
2757         };
2758         rpc_clnt_iterate_for_each_xprt(clnt,
2759                         rpc_xprt_set_connect_timeout,
2760                         &timeout);
2761 }
2762 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2763
2764 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2765 {
2766         rcu_read_lock();
2767         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2768         rcu_read_unlock();
2769 }
2770 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2771
2772 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2773 {
2774         rcu_read_lock();
2775         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2776                                  xprt);
2777         rcu_read_unlock();
2778 }
2779 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2780
2781 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2782                                    const struct sockaddr *sap)
2783 {
2784         struct rpc_xprt_switch *xps;
2785         bool ret;
2786
2787         rcu_read_lock();
2788         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2789         ret = rpc_xprt_switch_has_addr(xps, sap);
2790         rcu_read_unlock();
2791         return ret;
2792 }
2793 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2794
2795 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2796 static void rpc_show_header(void)
2797 {
2798         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2799                 "-timeout ---ops--\n");
2800 }
2801
2802 static void rpc_show_task(const struct rpc_clnt *clnt,
2803                           const struct rpc_task *task)
2804 {
2805         const char *rpc_waitq = "none";
2806
2807         if (RPC_IS_QUEUED(task))
2808                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2809
2810         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2811                 task->tk_pid, task->tk_flags, task->tk_status,
2812                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2813                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2814                 task->tk_action, rpc_waitq);
2815 }
2816
2817 void rpc_show_tasks(struct net *net)
2818 {
2819         struct rpc_clnt *clnt;
2820         struct rpc_task *task;
2821         int header = 0;
2822         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2823
2824         spin_lock(&sn->rpc_client_lock);
2825         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2826                 spin_lock(&clnt->cl_lock);
2827                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2828                         if (!header) {
2829                                 rpc_show_header();
2830                                 header++;
2831                         }
2832                         rpc_show_task(clnt, task);
2833                 }
2834                 spin_unlock(&clnt->cl_lock);
2835         }
2836         spin_unlock(&sn->rpc_client_lock);
2837 }
2838 #endif
2839
2840 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2841 static int
2842 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2843                 struct rpc_xprt *xprt,
2844                 void *dummy)
2845 {
2846         return xprt_enable_swap(xprt);
2847 }
2848
2849 int
2850 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2851 {
2852         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2853                 return rpc_clnt_iterate_for_each_xprt(clnt,
2854                                 rpc_clnt_swap_activate_callback, NULL);
2855         return 0;
2856 }
2857 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2858
2859 static int
2860 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2861                 struct rpc_xprt *xprt,
2862                 void *dummy)
2863 {
2864         xprt_disable_swap(xprt);
2865         return 0;
2866 }
2867
2868 void
2869 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2870 {
2871         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2872                 rpc_clnt_iterate_for_each_xprt(clnt,
2873                                 rpc_clnt_swap_deactivate_callback, NULL);
2874 }
2875 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2876 #endif /* CONFIG_SUNRPC_SWAP */