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_get_timeout - Get timeout for transport in units of HZ
1457  * @clnt: RPC client to query
1458  */
1459 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1460 {
1461         unsigned long ret;
1462
1463         rcu_read_lock();
1464         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1465         rcu_read_unlock();
1466         return ret;
1467 }
1468 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1469
1470 /**
1471  * rpc_force_rebind - force transport to check that remote port is unchanged
1472  * @clnt: client to rebind
1473  *
1474  */
1475 void rpc_force_rebind(struct rpc_clnt *clnt)
1476 {
1477         if (clnt->cl_autobind) {
1478                 rcu_read_lock();
1479                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1480                 rcu_read_unlock();
1481         }
1482 }
1483 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1484
1485 /*
1486  * Restart an (async) RPC call from the call_prepare state.
1487  * Usually called from within the exit handler.
1488  */
1489 int
1490 rpc_restart_call_prepare(struct rpc_task *task)
1491 {
1492         if (RPC_ASSASSINATED(task))
1493                 return 0;
1494         task->tk_action = call_start;
1495         task->tk_status = 0;
1496         if (task->tk_ops->rpc_call_prepare != NULL)
1497                 task->tk_action = rpc_prepare_task;
1498         return 1;
1499 }
1500 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1501
1502 /*
1503  * Restart an (async) RPC call. Usually called from within the
1504  * exit handler.
1505  */
1506 int
1507 rpc_restart_call(struct rpc_task *task)
1508 {
1509         if (RPC_ASSASSINATED(task))
1510                 return 0;
1511         task->tk_action = call_start;
1512         task->tk_status = 0;
1513         return 1;
1514 }
1515 EXPORT_SYMBOL_GPL(rpc_restart_call);
1516
1517 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1518 const char
1519 *rpc_proc_name(const struct rpc_task *task)
1520 {
1521         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1522
1523         if (proc) {
1524                 if (proc->p_name)
1525                         return proc->p_name;
1526                 else
1527                         return "NULL";
1528         } else
1529                 return "no proc";
1530 }
1531 #endif
1532
1533 /*
1534  * 0.  Initial state
1535  *
1536  *     Other FSM states can be visited zero or more times, but
1537  *     this state is visited exactly once for each RPC.
1538  */
1539 static void
1540 call_start(struct rpc_task *task)
1541 {
1542         struct rpc_clnt *clnt = task->tk_client;
1543
1544         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1545                         clnt->cl_program->name, clnt->cl_vers,
1546                         rpc_proc_name(task),
1547                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1548
1549         /* Increment call count */
1550         task->tk_msg.rpc_proc->p_count++;
1551         clnt->cl_stats->rpccnt++;
1552         task->tk_action = call_reserve;
1553 }
1554
1555 /*
1556  * 1.   Reserve an RPC call slot
1557  */
1558 static void
1559 call_reserve(struct rpc_task *task)
1560 {
1561         dprint_status(task);
1562
1563         task->tk_status  = 0;
1564         task->tk_action  = call_reserveresult;
1565         xprt_reserve(task);
1566 }
1567
1568 static void call_retry_reserve(struct rpc_task *task);
1569
1570 /*
1571  * 1b.  Grok the result of xprt_reserve()
1572  */
1573 static void
1574 call_reserveresult(struct rpc_task *task)
1575 {
1576         int status = task->tk_status;
1577
1578         dprint_status(task);
1579
1580         /*
1581          * After a call to xprt_reserve(), we must have either
1582          * a request slot or else an error status.
1583          */
1584         task->tk_status = 0;
1585         if (status >= 0) {
1586                 if (task->tk_rqstp) {
1587                         task->tk_action = call_refresh;
1588                         return;
1589                 }
1590
1591                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1592                                 __func__, status);
1593                 rpc_exit(task, -EIO);
1594                 return;
1595         }
1596
1597         /*
1598          * Even though there was an error, we may have acquired
1599          * a request slot somehow.  Make sure not to leak it.
1600          */
1601         if (task->tk_rqstp) {
1602                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1603                                 __func__, status);
1604                 xprt_release(task);
1605         }
1606
1607         switch (status) {
1608         case -ENOMEM:
1609                 rpc_delay(task, HZ >> 2);
1610         case -EAGAIN:   /* woken up; retry */
1611                 task->tk_action = call_retry_reserve;
1612                 return;
1613         case -EIO:      /* probably a shutdown */
1614                 break;
1615         default:
1616                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1617                                 __func__, status);
1618                 break;
1619         }
1620         rpc_exit(task, status);
1621 }
1622
1623 /*
1624  * 1c.  Retry reserving an RPC call slot
1625  */
1626 static void
1627 call_retry_reserve(struct rpc_task *task)
1628 {
1629         dprint_status(task);
1630
1631         task->tk_status  = 0;
1632         task->tk_action  = call_reserveresult;
1633         xprt_retry_reserve(task);
1634 }
1635
1636 /*
1637  * 2.   Bind and/or refresh the credentials
1638  */
1639 static void
1640 call_refresh(struct rpc_task *task)
1641 {
1642         dprint_status(task);
1643
1644         task->tk_action = call_refreshresult;
1645         task->tk_status = 0;
1646         task->tk_client->cl_stats->rpcauthrefresh++;
1647         rpcauth_refreshcred(task);
1648 }
1649
1650 /*
1651  * 2a.  Process the results of a credential refresh
1652  */
1653 static void
1654 call_refreshresult(struct rpc_task *task)
1655 {
1656         int status = task->tk_status;
1657
1658         dprint_status(task);
1659
1660         task->tk_status = 0;
1661         task->tk_action = call_refresh;
1662         switch (status) {
1663         case 0:
1664                 if (rpcauth_uptodatecred(task)) {
1665                         task->tk_action = call_allocate;
1666                         return;
1667                 }
1668                 /* Use rate-limiting and a max number of retries if refresh
1669                  * had status 0 but failed to update the cred.
1670                  */
1671         case -ETIMEDOUT:
1672                 rpc_delay(task, 3*HZ);
1673         case -EAGAIN:
1674                 status = -EACCES;
1675         case -EKEYEXPIRED:
1676                 if (!task->tk_cred_retry)
1677                         break;
1678                 task->tk_cred_retry--;
1679                 dprintk("RPC: %5u %s: retry refresh creds\n",
1680                                 task->tk_pid, __func__);
1681                 return;
1682         }
1683         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1684                                 task->tk_pid, __func__, status);
1685         rpc_exit(task, status);
1686 }
1687
1688 /*
1689  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1690  *      (Note: buffer memory is freed in xprt_release).
1691  */
1692 static void
1693 call_allocate(struct rpc_task *task)
1694 {
1695         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1696         struct rpc_rqst *req = task->tk_rqstp;
1697         struct rpc_xprt *xprt = req->rq_xprt;
1698         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1699         int status;
1700
1701         dprint_status(task);
1702
1703         task->tk_status = 0;
1704         task->tk_action = call_bind;
1705
1706         if (req->rq_buffer)
1707                 return;
1708
1709         if (proc->p_proc != 0) {
1710                 BUG_ON(proc->p_arglen == 0);
1711                 if (proc->p_decode != NULL)
1712                         BUG_ON(proc->p_replen == 0);
1713         }
1714
1715         /*
1716          * Calculate the size (in quads) of the RPC call
1717          * and reply headers, and convert both values
1718          * to byte sizes.
1719          */
1720         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1721         req->rq_callsize <<= 2;
1722         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1723         req->rq_rcvsize <<= 2;
1724
1725         status = xprt->ops->buf_alloc(task);
1726         xprt_inject_disconnect(xprt);
1727         if (status == 0)
1728                 return;
1729         if (status != -ENOMEM) {
1730                 rpc_exit(task, status);
1731                 return;
1732         }
1733
1734         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1735
1736         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1737                 task->tk_action = call_allocate;
1738                 rpc_delay(task, HZ>>4);
1739                 return;
1740         }
1741
1742         rpc_exit(task, -ERESTARTSYS);
1743 }
1744
1745 static inline int
1746 rpc_task_need_encode(struct rpc_task *task)
1747 {
1748         return task->tk_rqstp->rq_snd_buf.len == 0;
1749 }
1750
1751 static inline void
1752 rpc_task_force_reencode(struct rpc_task *task)
1753 {
1754         task->tk_rqstp->rq_snd_buf.len = 0;
1755         task->tk_rqstp->rq_bytes_sent = 0;
1756 }
1757
1758 /*
1759  * 3.   Encode arguments of an RPC call
1760  */
1761 static void
1762 rpc_xdr_encode(struct rpc_task *task)
1763 {
1764         struct rpc_rqst *req = task->tk_rqstp;
1765         kxdreproc_t     encode;
1766         __be32          *p;
1767
1768         dprint_status(task);
1769
1770         xdr_buf_init(&req->rq_snd_buf,
1771                      req->rq_buffer,
1772                      req->rq_callsize);
1773         xdr_buf_init(&req->rq_rcv_buf,
1774                      req->rq_rbuffer,
1775                      req->rq_rcvsize);
1776
1777         p = rpc_encode_header(task);
1778         if (p == NULL) {
1779                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1780                 rpc_exit(task, -EIO);
1781                 return;
1782         }
1783
1784         encode = task->tk_msg.rpc_proc->p_encode;
1785         if (encode == NULL)
1786                 return;
1787
1788         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1789                         task->tk_msg.rpc_argp);
1790 }
1791
1792 /*
1793  * 4.   Get the server port number if not yet set
1794  */
1795 static void
1796 call_bind(struct rpc_task *task)
1797 {
1798         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1799
1800         dprint_status(task);
1801
1802         task->tk_action = call_connect;
1803         if (!xprt_bound(xprt)) {
1804                 task->tk_action = call_bind_status;
1805                 task->tk_timeout = xprt->bind_timeout;
1806                 xprt->ops->rpcbind(task);
1807         }
1808 }
1809
1810 /*
1811  * 4a.  Sort out bind result
1812  */
1813 static void
1814 call_bind_status(struct rpc_task *task)
1815 {
1816         int status = -EIO;
1817
1818         if (task->tk_status >= 0) {
1819                 dprint_status(task);
1820                 task->tk_status = 0;
1821                 task->tk_action = call_connect;
1822                 return;
1823         }
1824
1825         trace_rpc_bind_status(task);
1826         switch (task->tk_status) {
1827         case -ENOMEM:
1828                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1829                 rpc_delay(task, HZ >> 2);
1830                 goto retry_timeout;
1831         case -EACCES:
1832                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1833                                 "unavailable\n", task->tk_pid);
1834                 /* fail immediately if this is an RPC ping */
1835                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1836                         status = -EOPNOTSUPP;
1837                         break;
1838                 }
1839                 if (task->tk_rebind_retry == 0)
1840                         break;
1841                 task->tk_rebind_retry--;
1842                 rpc_delay(task, 3*HZ);
1843                 goto retry_timeout;
1844         case -ETIMEDOUT:
1845                 dprintk("RPC: %5u rpcbind request timed out\n",
1846                                 task->tk_pid);
1847                 goto retry_timeout;
1848         case -EPFNOSUPPORT:
1849                 /* server doesn't support any rpcbind version we know of */
1850                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1851                                 task->tk_pid);
1852                 break;
1853         case -EPROTONOSUPPORT:
1854                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1855                                 task->tk_pid);
1856                 goto retry_timeout;
1857         case -ECONNREFUSED:             /* connection problems */
1858         case -ECONNRESET:
1859         case -ECONNABORTED:
1860         case -ENOTCONN:
1861         case -EHOSTDOWN:
1862         case -EHOSTUNREACH:
1863         case -ENETUNREACH:
1864         case -ENOBUFS:
1865         case -EPIPE:
1866                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1867                                 task->tk_pid, task->tk_status);
1868                 if (!RPC_IS_SOFTCONN(task)) {
1869                         rpc_delay(task, 5*HZ);
1870                         goto retry_timeout;
1871                 }
1872                 status = task->tk_status;
1873                 break;
1874         default:
1875                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1876                                 task->tk_pid, -task->tk_status);
1877         }
1878
1879         rpc_exit(task, status);
1880         return;
1881
1882 retry_timeout:
1883         task->tk_status = 0;
1884         task->tk_action = call_timeout;
1885 }
1886
1887 /*
1888  * 4b.  Connect to the RPC server
1889  */
1890 static void
1891 call_connect(struct rpc_task *task)
1892 {
1893         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1894
1895         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1896                         task->tk_pid, xprt,
1897                         (xprt_connected(xprt) ? "is" : "is not"));
1898
1899         task->tk_action = call_transmit;
1900         if (!xprt_connected(xprt)) {
1901                 task->tk_action = call_connect_status;
1902                 if (task->tk_status < 0)
1903                         return;
1904                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1905                         rpc_exit(task, -ENOTCONN);
1906                         return;
1907                 }
1908                 xprt_connect(task);
1909         }
1910 }
1911
1912 /*
1913  * 4c.  Sort out connect result
1914  */
1915 static void
1916 call_connect_status(struct rpc_task *task)
1917 {
1918         struct rpc_clnt *clnt = task->tk_client;
1919         int status = task->tk_status;
1920
1921         dprint_status(task);
1922
1923         trace_rpc_connect_status(task, status);
1924         task->tk_status = 0;
1925         switch (status) {
1926         case -ECONNREFUSED:
1927         case -ECONNRESET:
1928         case -ECONNABORTED:
1929         case -ENETUNREACH:
1930         case -EHOSTUNREACH:
1931         case -EADDRINUSE:
1932         case -ENOBUFS:
1933         case -EPIPE:
1934                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1935                                             task->tk_rqstp->rq_connect_cookie);
1936                 if (RPC_IS_SOFTCONN(task))
1937                         break;
1938                 /* retry with existing socket, after a delay */
1939                 rpc_delay(task, 3*HZ);
1940         case -EAGAIN:
1941                 /* Check for timeouts before looping back to call_bind */
1942         case -ETIMEDOUT:
1943                 task->tk_action = call_timeout;
1944                 return;
1945         case 0:
1946                 clnt->cl_stats->netreconn++;
1947                 task->tk_action = call_transmit;
1948                 return;
1949         }
1950         rpc_exit(task, status);
1951 }
1952
1953 /*
1954  * 5.   Transmit the RPC request, and wait for reply
1955  */
1956 static void
1957 call_transmit(struct rpc_task *task)
1958 {
1959         int is_retrans = RPC_WAS_SENT(task);
1960
1961         dprint_status(task);
1962
1963         task->tk_action = call_status;
1964         if (task->tk_status < 0)
1965                 return;
1966         if (!xprt_prepare_transmit(task))
1967                 return;
1968         task->tk_action = call_transmit_status;
1969         /* Encode here so that rpcsec_gss can use correct sequence number. */
1970         if (rpc_task_need_encode(task)) {
1971                 rpc_xdr_encode(task);
1972                 /* Did the encode result in an error condition? */
1973                 if (task->tk_status != 0) {
1974                         /* Was the error nonfatal? */
1975                         if (task->tk_status == -EAGAIN)
1976                                 rpc_delay(task, HZ >> 4);
1977                         else
1978                                 rpc_exit(task, task->tk_status);
1979                         return;
1980                 }
1981         }
1982         xprt_transmit(task);
1983         if (task->tk_status < 0)
1984                 return;
1985         if (is_retrans)
1986                 task->tk_client->cl_stats->rpcretrans++;
1987         /*
1988          * On success, ensure that we call xprt_end_transmit() before sleeping
1989          * in order to allow access to the socket to other RPC requests.
1990          */
1991         call_transmit_status(task);
1992         if (rpc_reply_expected(task))
1993                 return;
1994         task->tk_action = rpc_exit_task;
1995         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1996 }
1997
1998 /*
1999  * 5a.  Handle cleanup after a transmission
2000  */
2001 static void
2002 call_transmit_status(struct rpc_task *task)
2003 {
2004         task->tk_action = call_status;
2005
2006         /*
2007          * Common case: success.  Force the compiler to put this
2008          * test first.
2009          */
2010         if (task->tk_status == 0) {
2011                 xprt_end_transmit(task);
2012                 rpc_task_force_reencode(task);
2013                 return;
2014         }
2015
2016         switch (task->tk_status) {
2017         case -EAGAIN:
2018         case -ENOBUFS:
2019                 break;
2020         default:
2021                 dprint_status(task);
2022                 xprt_end_transmit(task);
2023                 rpc_task_force_reencode(task);
2024                 break;
2025                 /*
2026                  * Special cases: if we've been waiting on the
2027                  * socket's write_space() callback, or if the
2028                  * socket just returned a connection error,
2029                  * then hold onto the transport lock.
2030                  */
2031         case -ECONNREFUSED:
2032         case -EHOSTDOWN:
2033         case -EHOSTUNREACH:
2034         case -ENETUNREACH:
2035         case -EPERM:
2036                 if (RPC_IS_SOFTCONN(task)) {
2037                         xprt_end_transmit(task);
2038                         rpc_exit(task, task->tk_status);
2039                         break;
2040                 }
2041         case -ECONNRESET:
2042         case -ECONNABORTED:
2043         case -EADDRINUSE:
2044         case -ENOTCONN:
2045         case -EPIPE:
2046                 rpc_task_force_reencode(task);
2047         }
2048 }
2049
2050 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2051 /*
2052  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2053  * addition, disconnect on connectivity errors.
2054  */
2055 static void
2056 call_bc_transmit(struct rpc_task *task)
2057 {
2058         struct rpc_rqst *req = task->tk_rqstp;
2059
2060         if (!xprt_prepare_transmit(task))
2061                 goto out_retry;
2062
2063         if (task->tk_status < 0) {
2064                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2065                         "error: %d\n", task->tk_status);
2066                 goto out_done;
2067         }
2068         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2069                 req->rq_bytes_sent = 0;
2070
2071         xprt_transmit(task);
2072
2073         if (task->tk_status == -EAGAIN)
2074                 goto out_nospace;
2075
2076         xprt_end_transmit(task);
2077         dprint_status(task);
2078         switch (task->tk_status) {
2079         case 0:
2080                 /* Success */
2081         case -EHOSTDOWN:
2082         case -EHOSTUNREACH:
2083         case -ENETUNREACH:
2084         case -ECONNRESET:
2085         case -ECONNREFUSED:
2086         case -EADDRINUSE:
2087         case -ENOTCONN:
2088         case -EPIPE:
2089                 break;
2090         case -ETIMEDOUT:
2091                 /*
2092                  * Problem reaching the server.  Disconnect and let the
2093                  * forechannel reestablish the connection.  The server will
2094                  * have to retransmit the backchannel request and we'll
2095                  * reprocess it.  Since these ops are idempotent, there's no
2096                  * need to cache our reply at this time.
2097                  */
2098                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2099                         "error: %d\n", task->tk_status);
2100                 xprt_conditional_disconnect(req->rq_xprt,
2101                         req->rq_connect_cookie);
2102                 break;
2103         default:
2104                 /*
2105                  * We were unable to reply and will have to drop the
2106                  * request.  The server should reconnect and retransmit.
2107                  */
2108                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2109                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2110                         "error: %d\n", task->tk_status);
2111                 break;
2112         }
2113         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2114 out_done:
2115         task->tk_action = rpc_exit_task;
2116         return;
2117 out_nospace:
2118         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2119 out_retry:
2120         task->tk_status = 0;
2121 }
2122 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2123
2124 /*
2125  * 6.   Sort out the RPC call status
2126  */
2127 static void
2128 call_status(struct rpc_task *task)
2129 {
2130         struct rpc_clnt *clnt = task->tk_client;
2131         struct rpc_rqst *req = task->tk_rqstp;
2132         int             status;
2133
2134         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2135                 task->tk_status = req->rq_reply_bytes_recvd;
2136
2137         dprint_status(task);
2138
2139         status = task->tk_status;
2140         if (status >= 0) {
2141                 task->tk_action = call_decode;
2142                 return;
2143         }
2144
2145         trace_rpc_call_status(task);
2146         task->tk_status = 0;
2147         switch(status) {
2148         case -EHOSTDOWN:
2149         case -EHOSTUNREACH:
2150         case -ENETUNREACH:
2151         case -EPERM:
2152                 if (RPC_IS_SOFTCONN(task)) {
2153                         rpc_exit(task, status);
2154                         break;
2155                 }
2156                 /*
2157                  * Delay any retries for 3 seconds, then handle as if it
2158                  * were a timeout.
2159                  */
2160                 rpc_delay(task, 3*HZ);
2161         case -ETIMEDOUT:
2162                 task->tk_action = call_timeout;
2163                 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2164                     && task->tk_client->cl_discrtry)
2165                         xprt_conditional_disconnect(req->rq_xprt,
2166                                         req->rq_connect_cookie);
2167                 break;
2168         case -ECONNREFUSED:
2169         case -ECONNRESET:
2170         case -ECONNABORTED:
2171                 rpc_force_rebind(clnt);
2172         case -EADDRINUSE:
2173                 rpc_delay(task, 3*HZ);
2174         case -EPIPE:
2175         case -ENOTCONN:
2176                 task->tk_action = call_bind;
2177                 break;
2178         case -ENOBUFS:
2179                 rpc_delay(task, HZ>>2);
2180         case -EAGAIN:
2181                 task->tk_action = call_transmit;
2182                 break;
2183         case -EIO:
2184                 /* shutdown or soft timeout */
2185                 rpc_exit(task, status);
2186                 break;
2187         default:
2188                 if (clnt->cl_chatty)
2189                         printk("%s: RPC call returned error %d\n",
2190                                clnt->cl_program->name, -status);
2191                 rpc_exit(task, status);
2192         }
2193 }
2194
2195 /*
2196  * 6a.  Handle RPC timeout
2197  *      We do not release the request slot, so we keep using the
2198  *      same XID for all retransmits.
2199  */
2200 static void
2201 call_timeout(struct rpc_task *task)
2202 {
2203         struct rpc_clnt *clnt = task->tk_client;
2204
2205         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2206                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2207                 goto retry;
2208         }
2209
2210         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2211         task->tk_timeouts++;
2212
2213         if (RPC_IS_SOFTCONN(task)) {
2214                 rpc_exit(task, -ETIMEDOUT);
2215                 return;
2216         }
2217         if (RPC_IS_SOFT(task)) {
2218                 if (clnt->cl_chatty) {
2219                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2220                                 clnt->cl_program->name,
2221                                 task->tk_xprt->servername);
2222                 }
2223                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2224                         rpc_exit(task, -ETIMEDOUT);
2225                 else
2226                         rpc_exit(task, -EIO);
2227                 return;
2228         }
2229
2230         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2231                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2232                 if (clnt->cl_chatty) {
2233                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2234                         clnt->cl_program->name,
2235                         task->tk_xprt->servername);
2236                 }
2237         }
2238         rpc_force_rebind(clnt);
2239         /*
2240          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2241          * event? RFC2203 requires the server to drop all such requests.
2242          */
2243         rpcauth_invalcred(task);
2244
2245 retry:
2246         task->tk_action = call_bind;
2247         task->tk_status = 0;
2248 }
2249
2250 /*
2251  * 7.   Decode the RPC reply
2252  */
2253 static void
2254 call_decode(struct rpc_task *task)
2255 {
2256         struct rpc_clnt *clnt = task->tk_client;
2257         struct rpc_rqst *req = task->tk_rqstp;
2258         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2259         __be32          *p;
2260
2261         dprint_status(task);
2262
2263         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2264                 if (clnt->cl_chatty) {
2265                         printk(KERN_NOTICE "%s: server %s OK\n",
2266                                 clnt->cl_program->name,
2267                                 task->tk_xprt->servername);
2268                 }
2269                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2270         }
2271
2272         /*
2273          * Ensure that we see all writes made by xprt_complete_rqst()
2274          * before it changed req->rq_reply_bytes_recvd.
2275          */
2276         smp_rmb();
2277         req->rq_rcv_buf.len = req->rq_private_buf.len;
2278
2279         /* Check that the softirq receive buffer is valid */
2280         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2281                                 sizeof(req->rq_rcv_buf)) != 0);
2282
2283         if (req->rq_rcv_buf.len < 12) {
2284                 if (!RPC_IS_SOFT(task)) {
2285                         task->tk_action = call_bind;
2286                         goto out_retry;
2287                 }
2288                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2289                                 clnt->cl_program->name, task->tk_status);
2290                 task->tk_action = call_timeout;
2291                 goto out_retry;
2292         }
2293
2294         p = rpc_verify_header(task);
2295         if (IS_ERR(p)) {
2296                 if (p == ERR_PTR(-EAGAIN))
2297                         goto out_retry;
2298                 return;
2299         }
2300
2301         task->tk_action = rpc_exit_task;
2302
2303         if (decode) {
2304                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2305                                                       task->tk_msg.rpc_resp);
2306         }
2307         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2308                         task->tk_status);
2309         return;
2310 out_retry:
2311         task->tk_status = 0;
2312         /* Note: rpc_verify_header() may have freed the RPC slot */
2313         if (task->tk_rqstp == req) {
2314                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2315                 if (task->tk_client->cl_discrtry)
2316                         xprt_conditional_disconnect(req->rq_xprt,
2317                                         req->rq_connect_cookie);
2318         }
2319 }
2320
2321 static __be32 *
2322 rpc_encode_header(struct rpc_task *task)
2323 {
2324         struct rpc_clnt *clnt = task->tk_client;
2325         struct rpc_rqst *req = task->tk_rqstp;
2326         __be32          *p = req->rq_svec[0].iov_base;
2327
2328         /* FIXME: check buffer size? */
2329
2330         p = xprt_skip_transport_header(req->rq_xprt, p);
2331         *p++ = req->rq_xid;             /* XID */
2332         *p++ = htonl(RPC_CALL);         /* CALL */
2333         *p++ = htonl(RPC_VERSION);      /* RPC version */
2334         *p++ = htonl(clnt->cl_prog);    /* program number */
2335         *p++ = htonl(clnt->cl_vers);    /* program version */
2336         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2337         p = rpcauth_marshcred(task, p);
2338         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2339         return p;
2340 }
2341
2342 static __be32 *
2343 rpc_verify_header(struct rpc_task *task)
2344 {
2345         struct rpc_clnt *clnt = task->tk_client;
2346         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2347         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2348         __be32  *p = iov->iov_base;
2349         u32 n;
2350         int error = -EACCES;
2351
2352         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2353                 /* RFC-1014 says that the representation of XDR data must be a
2354                  * multiple of four bytes
2355                  * - if it isn't pointer subtraction in the NFS client may give
2356                  *   undefined results
2357                  */
2358                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2359                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2360                        task->tk_rqstp->rq_rcv_buf.len);
2361                 error = -EIO;
2362                 goto out_err;
2363         }
2364         if ((len -= 3) < 0)
2365                 goto out_overflow;
2366
2367         p += 1; /* skip XID */
2368         if ((n = ntohl(*p++)) != RPC_REPLY) {
2369                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2370                         task->tk_pid, __func__, n);
2371                 error = -EIO;
2372                 goto out_garbage;
2373         }
2374
2375         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2376                 if (--len < 0)
2377                         goto out_overflow;
2378                 switch ((n = ntohl(*p++))) {
2379                 case RPC_AUTH_ERROR:
2380                         break;
2381                 case RPC_MISMATCH:
2382                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2383                                 task->tk_pid, __func__);
2384                         error = -EPROTONOSUPPORT;
2385                         goto out_err;
2386                 default:
2387                         dprintk("RPC: %5u %s: RPC call rejected, "
2388                                 "unknown error: %x\n",
2389                                 task->tk_pid, __func__, n);
2390                         error = -EIO;
2391                         goto out_err;
2392                 }
2393                 if (--len < 0)
2394                         goto out_overflow;
2395                 switch ((n = ntohl(*p++))) {
2396                 case RPC_AUTH_REJECTEDCRED:
2397                 case RPC_AUTH_REJECTEDVERF:
2398                 case RPCSEC_GSS_CREDPROBLEM:
2399                 case RPCSEC_GSS_CTXPROBLEM:
2400                         if (!task->tk_cred_retry)
2401                                 break;
2402                         task->tk_cred_retry--;
2403                         dprintk("RPC: %5u %s: retry stale creds\n",
2404                                         task->tk_pid, __func__);
2405                         rpcauth_invalcred(task);
2406                         /* Ensure we obtain a new XID! */
2407                         xprt_release(task);
2408                         task->tk_action = call_reserve;
2409                         goto out_retry;
2410                 case RPC_AUTH_BADCRED:
2411                 case RPC_AUTH_BADVERF:
2412                         /* possibly garbled cred/verf? */
2413                         if (!task->tk_garb_retry)
2414                                 break;
2415                         task->tk_garb_retry--;
2416                         dprintk("RPC: %5u %s: retry garbled creds\n",
2417                                         task->tk_pid, __func__);
2418                         task->tk_action = call_bind;
2419                         goto out_retry;
2420                 case RPC_AUTH_TOOWEAK:
2421                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2422                                "authentication.\n",
2423                                task->tk_xprt->servername);
2424                         break;
2425                 default:
2426                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2427                                         task->tk_pid, __func__, n);
2428                         error = -EIO;
2429                 }
2430                 dprintk("RPC: %5u %s: call rejected %d\n",
2431                                 task->tk_pid, __func__, n);
2432                 goto out_err;
2433         }
2434         p = rpcauth_checkverf(task, p);
2435         if (IS_ERR(p)) {
2436                 error = PTR_ERR(p);
2437                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2438                                 task->tk_pid, __func__, error);
2439                 goto out_garbage;               /* bad verifier, retry */
2440         }
2441         len = p - (__be32 *)iov->iov_base - 1;
2442         if (len < 0)
2443                 goto out_overflow;
2444         switch ((n = ntohl(*p++))) {
2445         case RPC_SUCCESS:
2446                 return p;
2447         case RPC_PROG_UNAVAIL:
2448                 dprintk("RPC: %5u %s: program %u is unsupported "
2449                                 "by server %s\n", task->tk_pid, __func__,
2450                                 (unsigned int)clnt->cl_prog,
2451                                 task->tk_xprt->servername);
2452                 error = -EPFNOSUPPORT;
2453                 goto out_err;
2454         case RPC_PROG_MISMATCH:
2455                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2456                                 "by server %s\n", task->tk_pid, __func__,
2457                                 (unsigned int)clnt->cl_prog,
2458                                 (unsigned int)clnt->cl_vers,
2459                                 task->tk_xprt->servername);
2460                 error = -EPROTONOSUPPORT;
2461                 goto out_err;
2462         case RPC_PROC_UNAVAIL:
2463                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2464                                 "version %u on server %s\n",
2465                                 task->tk_pid, __func__,
2466                                 rpc_proc_name(task),
2467                                 clnt->cl_prog, clnt->cl_vers,
2468                                 task->tk_xprt->servername);
2469                 error = -EOPNOTSUPP;
2470                 goto out_err;
2471         case RPC_GARBAGE_ARGS:
2472                 dprintk("RPC: %5u %s: server saw garbage\n",
2473                                 task->tk_pid, __func__);
2474                 break;                  /* retry */
2475         default:
2476                 dprintk("RPC: %5u %s: server accept status: %x\n",
2477                                 task->tk_pid, __func__, n);
2478                 /* Also retry */
2479         }
2480
2481 out_garbage:
2482         clnt->cl_stats->rpcgarbage++;
2483         if (task->tk_garb_retry) {
2484                 task->tk_garb_retry--;
2485                 dprintk("RPC: %5u %s: retrying\n",
2486                                 task->tk_pid, __func__);
2487                 task->tk_action = call_bind;
2488 out_retry:
2489                 return ERR_PTR(-EAGAIN);
2490         }
2491 out_err:
2492         rpc_exit(task, error);
2493         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2494                         __func__, error);
2495         return ERR_PTR(error);
2496 out_overflow:
2497         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2498                         __func__);
2499         goto out_garbage;
2500 }
2501
2502 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2503 {
2504 }
2505
2506 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2507 {
2508         return 0;
2509 }
2510
2511 static struct rpc_procinfo rpcproc_null = {
2512         .p_encode = rpcproc_encode_null,
2513         .p_decode = rpcproc_decode_null,
2514 };
2515
2516 static int rpc_ping(struct rpc_clnt *clnt)
2517 {
2518         struct rpc_message msg = {
2519                 .rpc_proc = &rpcproc_null,
2520         };
2521         int err;
2522         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2523         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2524         put_rpccred(msg.rpc_cred);
2525         return err;
2526 }
2527
2528 static
2529 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2530                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2531                 const struct rpc_call_ops *ops, void *data)
2532 {
2533         struct rpc_message msg = {
2534                 .rpc_proc = &rpcproc_null,
2535                 .rpc_cred = cred,
2536         };
2537         struct rpc_task_setup task_setup_data = {
2538                 .rpc_client = clnt,
2539                 .rpc_xprt = xprt,
2540                 .rpc_message = &msg,
2541                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2542                 .callback_data = data,
2543                 .flags = flags,
2544         };
2545
2546         return rpc_run_task(&task_setup_data);
2547 }
2548
2549 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2550 {
2551         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2552 }
2553 EXPORT_SYMBOL_GPL(rpc_call_null);
2554
2555 struct rpc_cb_add_xprt_calldata {
2556         struct rpc_xprt_switch *xps;
2557         struct rpc_xprt *xprt;
2558 };
2559
2560 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2561 {
2562         struct rpc_cb_add_xprt_calldata *data = calldata;
2563
2564         if (task->tk_status == 0)
2565                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2566 }
2567
2568 static void rpc_cb_add_xprt_release(void *calldata)
2569 {
2570         struct rpc_cb_add_xprt_calldata *data = calldata;
2571
2572         xprt_put(data->xprt);
2573         xprt_switch_put(data->xps);
2574         kfree(data);
2575 }
2576
2577 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2578         .rpc_call_done = rpc_cb_add_xprt_done,
2579         .rpc_release = rpc_cb_add_xprt_release,
2580 };
2581
2582 /**
2583  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2584  * @clnt: pointer to struct rpc_clnt
2585  * @xps: pointer to struct rpc_xprt_switch,
2586  * @xprt: pointer struct rpc_xprt
2587  * @dummy: unused
2588  */
2589 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2590                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2591                 void *dummy)
2592 {
2593         struct rpc_cb_add_xprt_calldata *data;
2594         struct rpc_cred *cred;
2595         struct rpc_task *task;
2596
2597         data = kmalloc(sizeof(*data), GFP_NOFS);
2598         if (!data)
2599                 return -ENOMEM;
2600         data->xps = xprt_switch_get(xps);
2601         data->xprt = xprt_get(xprt);
2602
2603         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2604         task = rpc_call_null_helper(clnt, xprt, cred,
2605                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2606                         &rpc_cb_add_xprt_call_ops, data);
2607         put_rpccred(cred);
2608         if (IS_ERR(task))
2609                 return PTR_ERR(task);
2610         rpc_put_task(task);
2611         return 1;
2612 }
2613 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2614
2615 /**
2616  * rpc_clnt_setup_test_and_add_xprt()
2617  *
2618  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2619  *   1) caller of the test function must dereference the rpc_xprt_switch
2620  *   and the rpc_xprt.
2621  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2622  *   the rpc_call_done routine.
2623  *
2624  * Upon success (return of 1), the test function adds the new
2625  * transport to the rpc_clnt xprt switch
2626  *
2627  * @clnt: struct rpc_clnt to get the new transport
2628  * @xps:  the rpc_xprt_switch to hold the new transport
2629  * @xprt: the rpc_xprt to test
2630  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2631  *        and test function call data
2632  */
2633 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2634                                      struct rpc_xprt_switch *xps,
2635                                      struct rpc_xprt *xprt,
2636                                      void *data)
2637 {
2638         struct rpc_cred *cred;
2639         struct rpc_task *task;
2640         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2641         int status = -EADDRINUSE;
2642
2643         xprt = xprt_get(xprt);
2644         xprt_switch_get(xps);
2645
2646         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2647                 goto out_err;
2648
2649         /* Test the connection */
2650         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2651         task = rpc_call_null_helper(clnt, xprt, cred,
2652                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2653                                     NULL, NULL);
2654         put_rpccred(cred);
2655         if (IS_ERR(task)) {
2656                 status = PTR_ERR(task);
2657                 goto out_err;
2658         }
2659         status = task->tk_status;
2660         rpc_put_task(task);
2661
2662         if (status < 0)
2663                 goto out_err;
2664
2665         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2666         xtest->add_xprt_test(clnt, xprt, xtest->data);
2667
2668         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2669         return 1;
2670 out_err:
2671         xprt_put(xprt);
2672         xprt_switch_put(xps);
2673         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2674                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2675         return status;
2676 }
2677 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2678
2679 /**
2680  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2681  * @clnt: pointer to struct rpc_clnt
2682  * @xprtargs: pointer to struct xprt_create
2683  * @setup: callback to test and/or set up the connection
2684  * @data: pointer to setup function data
2685  *
2686  * Creates a new transport using the parameters set in args and
2687  * adds it to clnt.
2688  * If ping is set, then test that connectivity succeeds before
2689  * adding the new transport.
2690  *
2691  */
2692 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2693                 struct xprt_create *xprtargs,
2694                 int (*setup)(struct rpc_clnt *,
2695                         struct rpc_xprt_switch *,
2696                         struct rpc_xprt *,
2697                         void *),
2698                 void *data)
2699 {
2700         struct rpc_xprt_switch *xps;
2701         struct rpc_xprt *xprt;
2702         unsigned long reconnect_timeout;
2703         unsigned char resvport;
2704         int ret = 0;
2705
2706         rcu_read_lock();
2707         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2708         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2709         if (xps == NULL || xprt == NULL) {
2710                 rcu_read_unlock();
2711                 return -EAGAIN;
2712         }
2713         resvport = xprt->resvport;
2714         reconnect_timeout = xprt->max_reconnect_timeout;
2715         rcu_read_unlock();
2716
2717         xprt = xprt_create_transport(xprtargs);
2718         if (IS_ERR(xprt)) {
2719                 ret = PTR_ERR(xprt);
2720                 goto out_put_switch;
2721         }
2722         xprt->resvport = resvport;
2723         xprt->max_reconnect_timeout = reconnect_timeout;
2724
2725         rpc_xprt_switch_set_roundrobin(xps);
2726         if (setup) {
2727                 ret = setup(clnt, xps, xprt, data);
2728                 if (ret != 0)
2729                         goto out_put_xprt;
2730         }
2731         rpc_xprt_switch_add_xprt(xps, xprt);
2732 out_put_xprt:
2733         xprt_put(xprt);
2734 out_put_switch:
2735         xprt_switch_put(xps);
2736         return ret;
2737 }
2738 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2739
2740 static int
2741 rpc_xprt_cap_max_reconnect_timeout(struct rpc_clnt *clnt,
2742                 struct rpc_xprt *xprt,
2743                 void *data)
2744 {
2745         unsigned long timeout = *((unsigned long *)data);
2746
2747         if (timeout < xprt->max_reconnect_timeout)
2748                 xprt->max_reconnect_timeout = timeout;
2749         return 0;
2750 }
2751
2752 void
2753 rpc_cap_max_reconnect_timeout(struct rpc_clnt *clnt, unsigned long timeo)
2754 {
2755         rpc_clnt_iterate_for_each_xprt(clnt,
2756                         rpc_xprt_cap_max_reconnect_timeout,
2757                         &timeo);
2758 }
2759 EXPORT_SYMBOL_GPL(rpc_cap_max_reconnect_timeout);
2760
2761 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2762 {
2763         rcu_read_lock();
2764         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2765         rcu_read_unlock();
2766 }
2767 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2768
2769 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2770 {
2771         rcu_read_lock();
2772         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2773                                  xprt);
2774         rcu_read_unlock();
2775 }
2776 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2777
2778 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2779                                    const struct sockaddr *sap)
2780 {
2781         struct rpc_xprt_switch *xps;
2782         bool ret;
2783
2784         rcu_read_lock();
2785         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2786         ret = rpc_xprt_switch_has_addr(xps, sap);
2787         rcu_read_unlock();
2788         return ret;
2789 }
2790 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2791
2792 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2793 static void rpc_show_header(void)
2794 {
2795         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2796                 "-timeout ---ops--\n");
2797 }
2798
2799 static void rpc_show_task(const struct rpc_clnt *clnt,
2800                           const struct rpc_task *task)
2801 {
2802         const char *rpc_waitq = "none";
2803
2804         if (RPC_IS_QUEUED(task))
2805                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2806
2807         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2808                 task->tk_pid, task->tk_flags, task->tk_status,
2809                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2810                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2811                 task->tk_action, rpc_waitq);
2812 }
2813
2814 void rpc_show_tasks(struct net *net)
2815 {
2816         struct rpc_clnt *clnt;
2817         struct rpc_task *task;
2818         int header = 0;
2819         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2820
2821         spin_lock(&sn->rpc_client_lock);
2822         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2823                 spin_lock(&clnt->cl_lock);
2824                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2825                         if (!header) {
2826                                 rpc_show_header();
2827                                 header++;
2828                         }
2829                         rpc_show_task(clnt, task);
2830                 }
2831                 spin_unlock(&clnt->cl_lock);
2832         }
2833         spin_unlock(&sn->rpc_client_lock);
2834 }
2835 #endif
2836
2837 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2838 static int
2839 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2840                 struct rpc_xprt *xprt,
2841                 void *dummy)
2842 {
2843         return xprt_enable_swap(xprt);
2844 }
2845
2846 int
2847 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2848 {
2849         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2850                 return rpc_clnt_iterate_for_each_xprt(clnt,
2851                                 rpc_clnt_swap_activate_callback, NULL);
2852         return 0;
2853 }
2854 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2855
2856 static int
2857 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2858                 struct rpc_xprt *xprt,
2859                 void *dummy)
2860 {
2861         xprt_disable_swap(xprt);
2862         return 0;
2863 }
2864
2865 void
2866 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2867 {
2868         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2869                 rpc_clnt_iterate_for_each_xprt(clnt,
2870                                 rpc_clnt_swap_deactivate_callback, NULL);
2871 }
2872 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2873 #endif /* CONFIG_SUNRPC_SWAP */