net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "sysfs.h"
  45 #include "netns.h"
  46
  47 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  48 # define RPCDBG_FACILITY        RPCDBG_CALL
  49 #endif
  50
  51 /*
  52  * All RPC clients are linked into this list
  53  */
  54
  55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  56
  57
  58 static void     call_start(struct rpc_task *task);
  59 static void     call_reserve(struct rpc_task *task);
  60 static void     call_reserveresult(struct rpc_task *task);
  61 static void     call_allocate(struct rpc_task *task);
  62 static void     call_encode(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 static void     call_status(struct rpc_task *task);
  68 static void     call_transmit_status(struct rpc_task *task);
  69 static void     call_refresh(struct rpc_task *task);
  70 static void     call_refreshresult(struct rpc_task *task);
  71 static void     call_connect(struct rpc_task *task);
  72 static void     call_connect_status(struct rpc_task *task);
  73
  74 static int      rpc_encode_header(struct rpc_task *task,
  75                                   struct xdr_stream *xdr);
  76 static int      rpc_decode_header(struct rpc_task *task,
  77                                   struct xdr_stream *xdr);
  78 static int      rpc_ping(struct rpc_clnt *clnt);
  79 static int      rpc_ping_noreply(struct rpc_clnt *clnt);
  80 static void     rpc_check_timeout(struct rpc_task *task);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         rpc_remove_client_dir(clnt);
 105 }
 106
 107 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 108 {
 109         struct net *net = rpc_net_ns(clnt);
 110         struct super_block *pipefs_sb;
 111
 112         pipefs_sb = rpc_get_sb_net(net);
 113         if (pipefs_sb) {
 114                 __rpc_clnt_remove_pipedir(clnt);
 115                 rpc_put_sb_net(net);
 116         }
 117 }
 118
 119 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 120                                     struct rpc_clnt *clnt)
 121 {
 122         static uint32_t clntid;
 123         const char *dir_name = clnt->cl_program->pipe_dir_name;
 124         char name[15];
 125         struct dentry *dir, *dentry;
 126
 127         dir = rpc_d_lookup_sb(sb, dir_name);
 128         if (dir == NULL) {
 129                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 130                 return dir;
 131         }
 132         for (;;) {
 133                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 134                 name[sizeof(name) - 1] = '\0';
 135                 dentry = rpc_create_client_dir(dir, name, clnt);
 136                 if (!IS_ERR(dentry))
 137                         break;
 138                 if (dentry == ERR_PTR(-EEXIST))
 139                         continue;
 140                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 141                                 " %s/%s, error %ld\n",
 142                                 dir_name, name, PTR_ERR(dentry));
 143                 break;
 144         }
 145         dput(dir);
 146         return dentry;
 147 }
 148
 149 static int
 150 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 151 {
 152         struct dentry *dentry;
 153
 154         if (clnt->cl_program->pipe_dir_name != NULL) {
 155                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 156                 if (IS_ERR(dentry))
 157                         return PTR_ERR(dentry);
 158         }
 159         return 0;
 160 }
 161
 162 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 163 {
 164         if (clnt->cl_program->pipe_dir_name == NULL)
 165                 return 1;
 166
 167         switch (event) {
 168         case RPC_PIPEFS_MOUNT:
 169                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 170                         return 1;
 171                 if (refcount_read(&clnt->cl_count) == 0)
 172                         return 1;
 173                 break;
 174         case RPC_PIPEFS_UMOUNT:
 175                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 176                         return 1;
 177                 break;
 178         }
 179         return 0;
 180 }
 181
 182 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 183                                    struct super_block *sb)
 184 {
 185         struct dentry *dentry;
 186
 187         switch (event) {
 188         case RPC_PIPEFS_MOUNT:
 189                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 190                 if (!dentry)
 191                         return -ENOENT;
 192                 if (IS_ERR(dentry))
 193                         return PTR_ERR(dentry);
 194                 break;
 195         case RPC_PIPEFS_UMOUNT:
 196                 __rpc_clnt_remove_pipedir(clnt);
 197                 break;
 198         default:
 199                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 200                 return -ENOTSUPP;
 201         }
 202         return 0;
 203 }
 204
 205 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 206                                 struct super_block *sb)
 207 {
 208         int error = 0;
 209
 210         for (;; clnt = clnt->cl_parent) {
 211                 if (!rpc_clnt_skip_event(clnt, event))
 212                         error = __rpc_clnt_handle_event(clnt, event, sb);
 213                 if (error || clnt == clnt->cl_parent)
 214                         break;
 215         }
 216         return error;
 217 }
 218
 219 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 220 {
 221         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 222         struct rpc_clnt *clnt;
 223
 224         spin_lock(&sn->rpc_client_lock);
 225         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 226                 if (rpc_clnt_skip_event(clnt, event))
 227                         continue;
 228                 spin_unlock(&sn->rpc_client_lock);
 229                 return clnt;
 230         }
 231         spin_unlock(&sn->rpc_client_lock);
 232         return NULL;
 233 }
 234
 235 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 236                             void *ptr)
 237 {
 238         struct super_block *sb = ptr;
 239         struct rpc_clnt *clnt;
 240         int error = 0;
 241
 242         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 243                 error = __rpc_pipefs_event(clnt, event, sb);
 244                 if (error)
 245                         break;
 246         }
 247         return error;
 248 }
 249
 250 static struct notifier_block rpc_clients_block = {
 251         .notifier_call  = rpc_pipefs_event,
 252         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 253 };
 254
 255 int rpc_clients_notifier_register(void)
 256 {
 257         return rpc_pipefs_notifier_register(&rpc_clients_block);
 258 }
 259
 260 void rpc_clients_notifier_unregister(void)
 261 {
 262         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 263 }
 264
 265 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 266                 struct rpc_xprt *xprt,
 267                 const struct rpc_timeout *timeout)
 268 {
 269         struct rpc_xprt *old;
 270
 271         spin_lock(&clnt->cl_lock);
 272         old = rcu_dereference_protected(clnt->cl_xprt,
 273                         lockdep_is_held(&clnt->cl_lock));
 274
 275         if (!xprt_bound(xprt))
 276                 clnt->cl_autobind = 1;
 277
 278         clnt->cl_timeout = timeout;
 279         rcu_assign_pointer(clnt->cl_xprt, xprt);
 280         spin_unlock(&clnt->cl_lock);
 281
 282         return old;
 283 }
 284
 285 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 286 {
 287         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 288                         nodename, sizeof(clnt->cl_nodename));
 289 }
 290
 291 static int rpc_client_register(struct rpc_clnt *clnt,
 292                                rpc_authflavor_t pseudoflavor,
 293                                const char *client_name)
 294 {
 295         struct rpc_auth_create_args auth_args = {
 296                 .pseudoflavor = pseudoflavor,
 297                 .target_name = client_name,
 298         };
 299         struct rpc_auth *auth;
 300         struct net *net = rpc_net_ns(clnt);
 301         struct super_block *pipefs_sb;
 302         int err;
 303
 304         rpc_clnt_debugfs_register(clnt);
 305
 306         pipefs_sb = rpc_get_sb_net(net);
 307         if (pipefs_sb) {
 308                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 309                 if (err)
 310                         goto out;
 311         }
 312
 313         rpc_register_client(clnt);
 314         if (pipefs_sb)
 315                 rpc_put_sb_net(net);
 316
 317         auth = rpcauth_create(&auth_args, clnt);
 318         if (IS_ERR(auth)) {
 319                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 320                                 pseudoflavor);
 321                 err = PTR_ERR(auth);
 322                 goto err_auth;
 323         }
 324         return 0;
 325 err_auth:
 326         pipefs_sb = rpc_get_sb_net(net);
 327         rpc_unregister_client(clnt);
 328         __rpc_clnt_remove_pipedir(clnt);
 329 out:
 330         if (pipefs_sb)
 331                 rpc_put_sb_net(net);
 332         rpc_sysfs_client_destroy(clnt);
 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         err = rpciod_up();
 373         if (err)
 374                 goto out_no_rpciod;
 375
 376         err = -EINVAL;
 377         if (args->version >= program->nrvers)
 378                 goto out_err;
 379         version = program->version[args->version];
 380         if (version == NULL)
 381                 goto out_err;
 382
 383         err = -ENOMEM;
 384         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 385         if (!clnt)
 386                 goto out_err;
 387         clnt->cl_parent = parent ? : clnt;
 388
 389         err = rpc_alloc_clid(clnt);
 390         if (err)
 391                 goto out_no_clid;
 392
 393         clnt->cl_cred     = get_cred(args->cred);
 394         clnt->cl_procinfo = version->procs;
 395         clnt->cl_maxproc  = version->nrprocs;
 396         clnt->cl_prog     = args->prognumber ? : program->number;
 397         clnt->cl_vers     = version->number;
 398         clnt->cl_stats    = program->stats;
 399         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 400         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 401         err = -ENOMEM;
 402         if (clnt->cl_metrics == NULL)
 403                 goto out_no_stats;
 404         clnt->cl_program  = program;
 405         INIT_LIST_HEAD(&clnt->cl_tasks);
 406         spin_lock_init(&clnt->cl_lock);
 407
 408         timeout = xprt->timeout;
 409         if (args->timeout != NULL) {
 410                 memcpy(&clnt->cl_timeout_default, args->timeout,
 411                                 sizeof(clnt->cl_timeout_default));
 412                 timeout = &clnt->cl_timeout_default;
 413         }
 414
 415         rpc_clnt_set_transport(clnt, xprt, timeout);
 416         xprt->main = true;
 417         xprt_iter_init(&clnt->cl_xpi, xps);
 418         xprt_switch_put(xps);
 419
 420         clnt->cl_rtt = &clnt->cl_rtt_default;
 421         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 422
 423         refcount_set(&clnt->cl_count, 1);
 424
 425         if (nodename == NULL)
 426                 nodename = utsname()->nodename;
 427         /* save the nodename */
 428         rpc_clnt_set_nodename(clnt, nodename);
 429
 430         rpc_sysfs_client_setup(clnt, xps, rpc_net_ns(clnt));
 431         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 432         if (err)
 433                 goto out_no_path;
 434         if (parent)
 435                 refcount_inc(&parent->cl_count);
 436
 437         trace_rpc_clnt_new(clnt, xprt, program->name, args->servername);
 438         return clnt;
 439
 440 out_no_path:
 441         rpc_free_iostats(clnt->cl_metrics);
 442 out_no_stats:
 443         put_cred(clnt->cl_cred);
 444         rpc_free_clid(clnt);
 445 out_no_clid:
 446         kfree(clnt);
 447 out_err:
 448         rpciod_down();
 449 out_no_rpciod:
 450         xprt_switch_put(xps);
 451         xprt_put(xprt);
 452         trace_rpc_clnt_new_err(program->name, args->servername, err);
 453         return ERR_PTR(err);
 454 }
 455
 456 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 457                                         struct rpc_xprt *xprt)
 458 {
 459         struct rpc_clnt *clnt = NULL;
 460         struct rpc_xprt_switch *xps;
 461
 462         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 463                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 464                 xps = args->bc_xprt->xpt_bc_xps;
 465                 xprt_switch_get(xps);
 466         } else {
 467                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 468                 if (xps == NULL) {
 469                         xprt_put(xprt);
 470                         return ERR_PTR(-ENOMEM);
 471                 }
 472                 if (xprt->bc_xprt) {
 473                         xprt_switch_get(xps);
 474                         xprt->bc_xprt->xpt_bc_xps = xps;
 475                 }
 476         }
 477         clnt = rpc_new_client(args, xps, xprt, NULL);
 478         if (IS_ERR(clnt))
 479                 return clnt;
 480
 481         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 482                 int err = rpc_ping(clnt);
 483                 if (err != 0) {
 484                         rpc_shutdown_client(clnt);
 485                         return ERR_PTR(err);
 486                 }
 487         } else if (args->flags & RPC_CLNT_CREATE_CONNECTED) {
 488                 int err = rpc_ping_noreply(clnt);
 489                 if (err != 0) {
 490                         rpc_shutdown_client(clnt);
 491                         return ERR_PTR(err);
 492                 }
 493         }
 494
 495         clnt->cl_softrtry = 1;
 496         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 497                 clnt->cl_softrtry = 0;
 498                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 499                         clnt->cl_softerr = 1;
 500         }
 501
 502         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 503                 clnt->cl_autobind = 1;
 504         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 505                 clnt->cl_noretranstimeo = 1;
 506         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 507                 clnt->cl_discrtry = 1;
 508         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 509                 clnt->cl_chatty = 1;
 510
 511         return clnt;
 512 }
 513
 514 /**
 515  * rpc_create - create an RPC client and transport with one call
 516  * @args: rpc_clnt create argument structure
 517  *
 518  * Creates and initializes an RPC transport and an RPC client.
 519  *
 520  * It can ping the server in order to determine if it is up, and to see if
 521  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 522  * this behavior so asynchronous tasks can also use rpc_create.
 523  */
 524 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 525 {
 526         struct rpc_xprt *xprt;
 527         struct xprt_create xprtargs = {
 528                 .net = args->net,
 529                 .ident = args->protocol,
 530                 .srcaddr = args->saddress,
 531                 .dstaddr = args->address,
 532                 .addrlen = args->addrsize,
 533                 .servername = args->servername,
 534                 .bc_xprt = args->bc_xprt,
 535         };
 536         char servername[48];
 537         struct rpc_clnt *clnt;
 538         int i;
 539
 540         if (args->bc_xprt) {
 541                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 542                 xprt = args->bc_xprt->xpt_bc_xprt;
 543                 if (xprt) {
 544                         xprt_get(xprt);
 545                         return rpc_create_xprt(args, xprt);
 546                 }
 547         }
 548
 549         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 550                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 551         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 552                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 553         /*
 554          * If the caller chooses not to specify a hostname, whip
 555          * up a string representation of the passed-in address.
 556          */
 557         if (xprtargs.servername == NULL) {
 558                 struct sockaddr_un *sun =
 559                                 (struct sockaddr_un *)args->address;
 560                 struct sockaddr_in *sin =
 561                                 (struct sockaddr_in *)args->address;
 562                 struct sockaddr_in6 *sin6 =
 563                                 (struct sockaddr_in6 *)args->address;
 564
 565                 servername[0] = '\0';
 566                 switch (args->address->sa_family) {
 567                 case AF_LOCAL:
 568                         snprintf(servername, sizeof(servername), "%s",
 569                                  sun->sun_path);
 570                         break;
 571                 case AF_INET:
 572                         snprintf(servername, sizeof(servername), "%pI4",
 573                                  &sin->sin_addr.s_addr);
 574                         break;
 575                 case AF_INET6:
 576                         snprintf(servername, sizeof(servername), "%pI6",
 577                                  &sin6->sin6_addr);
 578                         break;
 579                 default:
 580                         /* caller wants default server name, but
 581                          * address family isn't recognized. */
 582                         return ERR_PTR(-EINVAL);
 583                 }
 584                 xprtargs.servername = servername;
 585         }
 586
 587         xprt = xprt_create_transport(&xprtargs);
 588         if (IS_ERR(xprt))
 589                 return (struct rpc_clnt *)xprt;
 590
 591         /*
 592          * By default, kernel RPC client connects from a reserved port.
 593          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 594          * but it is always enabled for rpciod, which handles the connect
 595          * operation.
 596          */
 597         xprt->resvport = 1;
 598         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 599                 xprt->resvport = 0;
 600         xprt->reuseport = 0;
 601         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 602                 xprt->reuseport = 1;
 603
 604         clnt = rpc_create_xprt(args, xprt);
 605         if (IS_ERR(clnt) || args->nconnect <= 1)
 606                 return clnt;
 607
 608         for (i = 0; i < args->nconnect - 1; i++) {
 609                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 610                         break;
 611         }
 612         return clnt;
 613 }
 614 EXPORT_SYMBOL_GPL(rpc_create);
 615
 616 /*
 617  * This function clones the RPC client structure. It allows us to share the
 618  * same transport while varying parameters such as the authentication
 619  * flavour.
 620  */
 621 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 622                                            struct rpc_clnt *clnt)
 623 {
 624         struct rpc_xprt_switch *xps;
 625         struct rpc_xprt *xprt;
 626         struct rpc_clnt *new;
 627         int err;
 628
 629         err = -ENOMEM;
 630         rcu_read_lock();
 631         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 632         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 633         rcu_read_unlock();
 634         if (xprt == NULL || xps == NULL) {
 635                 xprt_put(xprt);
 636                 xprt_switch_put(xps);
 637                 goto out_err;
 638         }
 639         args->servername = xprt->servername;
 640         args->nodename = clnt->cl_nodename;
 641
 642         new = rpc_new_client(args, xps, xprt, clnt);
 643         if (IS_ERR(new))
 644                 return new;
 645
 646         /* Turn off autobind on clones */
 647         new->cl_autobind = 0;
 648         new->cl_softrtry = clnt->cl_softrtry;
 649         new->cl_softerr = clnt->cl_softerr;
 650         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 651         new->cl_discrtry = clnt->cl_discrtry;
 652         new->cl_chatty = clnt->cl_chatty;
 653         new->cl_principal = clnt->cl_principal;
 654         new->cl_max_connect = clnt->cl_max_connect;
 655         return new;
 656
 657 out_err:
 658         trace_rpc_clnt_clone_err(clnt, err);
 659         return ERR_PTR(err);
 660 }
 661
 662 /**
 663  * rpc_clone_client - Clone an RPC client structure
 664  *
 665  * @clnt: RPC client whose parameters are copied
 666  *
 667  * Returns a fresh RPC client or an ERR_PTR.
 668  */
 669 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 670 {
 671         struct rpc_create_args args = {
 672                 .program        = clnt->cl_program,
 673                 .prognumber     = clnt->cl_prog,
 674                 .version        = clnt->cl_vers,
 675                 .authflavor     = clnt->cl_auth->au_flavor,
 676                 .cred           = clnt->cl_cred,
 677         };
 678         return __rpc_clone_client(&args, clnt);
 679 }
 680 EXPORT_SYMBOL_GPL(rpc_clone_client);
 681
 682 /**
 683  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 684  *
 685  * @clnt: RPC client whose parameters are copied
 686  * @flavor: security flavor for new client
 687  *
 688  * Returns a fresh RPC client or an ERR_PTR.
 689  */
 690 struct rpc_clnt *
 691 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 692 {
 693         struct rpc_create_args args = {
 694                 .program        = clnt->cl_program,
 695                 .prognumber     = clnt->cl_prog,
 696                 .version        = clnt->cl_vers,
 697                 .authflavor     = flavor,
 698                 .cred           = clnt->cl_cred,
 699         };
 700         return __rpc_clone_client(&args, clnt);
 701 }
 702 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 703
 704 /**
 705  * rpc_switch_client_transport: switch the RPC transport on the fly
 706  * @clnt: pointer to a struct rpc_clnt
 707  * @args: pointer to the new transport arguments
 708  * @timeout: pointer to the new timeout parameters
 709  *
 710  * This function allows the caller to switch the RPC transport for the
 711  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 712  * server, for instance.  It assumes that the caller has ensured that
 713  * there are no active RPC tasks by using some form of locking.
 714  *
 715  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 716  * negative errno is returned, and "clnt" continues to use the old
 717  * xprt.
 718  */
 719 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 720                 struct xprt_create *args,
 721                 const struct rpc_timeout *timeout)
 722 {
 723         const struct rpc_timeout *old_timeo;
 724         rpc_authflavor_t pseudoflavor;
 725         struct rpc_xprt_switch *xps, *oldxps;
 726         struct rpc_xprt *xprt, *old;
 727         struct rpc_clnt *parent;
 728         int err;
 729
 730         xprt = xprt_create_transport(args);
 731         if (IS_ERR(xprt))
 732                 return PTR_ERR(xprt);
 733
 734         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 735         if (xps == NULL) {
 736                 xprt_put(xprt);
 737                 return -ENOMEM;
 738         }
 739
 740         pseudoflavor = clnt->cl_auth->au_flavor;
 741
 742         old_timeo = clnt->cl_timeout;
 743         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 744         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 745
 746         rpc_unregister_client(clnt);
 747         __rpc_clnt_remove_pipedir(clnt);
 748         rpc_sysfs_client_destroy(clnt);
 749         rpc_clnt_debugfs_unregister(clnt);
 750
 751         /*
 752          * A new transport was created.  "clnt" therefore
 753          * becomes the root of a new cl_parent tree.  clnt's
 754          * children, if it has any, still point to the old xprt.
 755          */
 756         parent = clnt->cl_parent;
 757         clnt->cl_parent = clnt;
 758
 759         /*
 760          * The old rpc_auth cache cannot be re-used.  GSS
 761          * contexts in particular are between a single
 762          * client and server.
 763          */
 764         err = rpc_client_register(clnt, pseudoflavor, NULL);
 765         if (err)
 766                 goto out_revert;
 767
 768         synchronize_rcu();
 769         if (parent != clnt)
 770                 rpc_release_client(parent);
 771         xprt_switch_put(oldxps);
 772         xprt_put(old);
 773         trace_rpc_clnt_replace_xprt(clnt);
 774         return 0;
 775
 776 out_revert:
 777         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 778         rpc_clnt_set_transport(clnt, old, old_timeo);
 779         clnt->cl_parent = parent;
 780         rpc_client_register(clnt, pseudoflavor, NULL);
 781         xprt_switch_put(xps);
 782         xprt_put(xprt);
 783         trace_rpc_clnt_replace_xprt_err(clnt);
 784         return err;
 785 }
 786 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 787
 788 static
 789 int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi,
 790                              void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps))
 791 {
 792         struct rpc_xprt_switch *xps;
 793
 794         rcu_read_lock();
 795         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 796         rcu_read_unlock();
 797         if (xps == NULL)
 798                 return -EAGAIN;
 799         func(xpi, xps);
 800         xprt_switch_put(xps);
 801         return 0;
 802 }
 803
 804 static
 805 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 806 {
 807         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listall);
 808 }
 809
 810 static
 811 int rpc_clnt_xprt_iter_offline_init(struct rpc_clnt *clnt,
 812                                     struct rpc_xprt_iter *xpi)
 813 {
 814         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listoffline);
 815 }
 816
 817 /**
 818  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 819  * @clnt: pointer to client
 820  * @fn: function to apply
 821  * @data: void pointer to function data
 822  *
 823  * Iterates through the list of RPC transports currently attached to the
 824  * client and applies the function fn(clnt, xprt, data).
 825  *
 826  * On error, the iteration stops, and the function returns the error value.
 827  */
 828 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 829                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 830                 void *data)
 831 {
 832         struct rpc_xprt_iter xpi;
 833         int ret;
 834
 835         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 836         if (ret)
 837                 return ret;
 838         for (;;) {
 839                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 840
 841                 if (!xprt)
 842                         break;
 843                 ret = fn(clnt, xprt, data);
 844                 xprt_put(xprt);
 845                 if (ret < 0)
 846                         break;
 847         }
 848         xprt_iter_destroy(&xpi);
 849         return ret;
 850 }
 851 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 852
 853 /*
 854  * Kill all tasks for the given client.
 855  * XXX: kill their descendants as well?
 856  */
 857 void rpc_killall_tasks(struct rpc_clnt *clnt)
 858 {
 859         struct rpc_task *rovr;
 860
 861
 862         if (list_empty(&clnt->cl_tasks))
 863                 return;
 864
 865         /*
 866          * Spin lock all_tasks to prevent changes...
 867          */
 868         trace_rpc_clnt_killall(clnt);
 869         spin_lock(&clnt->cl_lock);
 870         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 871                 rpc_signal_task(rovr);
 872         spin_unlock(&clnt->cl_lock);
 873 }
 874 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 875
 876 /*
 877  * Properly shut down an RPC client, terminating all outstanding
 878  * requests.
 879  */
 880 void rpc_shutdown_client(struct rpc_clnt *clnt)
 881 {
 882         might_sleep();
 883
 884         trace_rpc_clnt_shutdown(clnt);
 885
 886         while (!list_empty(&clnt->cl_tasks)) {
 887                 rpc_killall_tasks(clnt);
 888                 wait_event_timeout(destroy_wait,
 889                         list_empty(&clnt->cl_tasks), 1*HZ);
 890         }
 891
 892         rpc_release_client(clnt);
 893 }
 894 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 895
 896 /*
 897  * Free an RPC client
 898  */
 899 static void rpc_free_client_work(struct work_struct *work)
 900 {
 901         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 902
 903         trace_rpc_clnt_free(clnt);
 904
 905         /* These might block on processes that might allocate memory,
 906          * so they cannot be called in rpciod, so they are handled separately
 907          * here.
 908          */
 909         rpc_sysfs_client_destroy(clnt);
 910         rpc_clnt_debugfs_unregister(clnt);
 911         rpc_free_clid(clnt);
 912         rpc_clnt_remove_pipedir(clnt);
 913         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 914
 915         kfree(clnt);
 916         rpciod_down();
 917 }
 918 static struct rpc_clnt *
 919 rpc_free_client(struct rpc_clnt *clnt)
 920 {
 921         struct rpc_clnt *parent = NULL;
 922
 923         trace_rpc_clnt_release(clnt);
 924         if (clnt->cl_parent != clnt)
 925                 parent = clnt->cl_parent;
 926         rpc_unregister_client(clnt);
 927         rpc_free_iostats(clnt->cl_metrics);
 928         clnt->cl_metrics = NULL;
 929         xprt_iter_destroy(&clnt->cl_xpi);
 930         put_cred(clnt->cl_cred);
 931
 932         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 933         schedule_work(&clnt->cl_work);
 934         return parent;
 935 }
 936
 937 /*
 938  * Free an RPC client
 939  */
 940 static struct rpc_clnt *
 941 rpc_free_auth(struct rpc_clnt *clnt)
 942 {
 943         /*
 944          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 945          *       release remaining GSS contexts. This mechanism ensures
 946          *       that it can do so safely.
 947          */
 948         if (clnt->cl_auth != NULL) {
 949                 rpcauth_release(clnt->cl_auth);
 950                 clnt->cl_auth = NULL;
 951         }
 952         if (refcount_dec_and_test(&clnt->cl_count))
 953                 return rpc_free_client(clnt);
 954         return NULL;
 955 }
 956
 957 /*
 958  * Release reference to the RPC client
 959  */
 960 void
 961 rpc_release_client(struct rpc_clnt *clnt)
 962 {
 963         do {
 964                 if (list_empty(&clnt->cl_tasks))
 965                         wake_up(&destroy_wait);
 966                 if (refcount_dec_not_one(&clnt->cl_count))
 967                         break;
 968                 clnt = rpc_free_auth(clnt);
 969         } while (clnt != NULL);
 970 }
 971 EXPORT_SYMBOL_GPL(rpc_release_client);
 972
 973 /**
 974  * rpc_bind_new_program - bind a new RPC program to an existing client
 975  * @old: old rpc_client
 976  * @program: rpc program to set
 977  * @vers: rpc program version
 978  *
 979  * Clones the rpc client and sets up a new RPC program. This is mainly
 980  * of use for enabling different RPC programs to share the same transport.
 981  * The Sun NFSv2/v3 ACL protocol can do this.
 982  */
 983 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 984                                       const struct rpc_program *program,
 985                                       u32 vers)
 986 {
 987         struct rpc_create_args args = {
 988                 .program        = program,
 989                 .prognumber     = program->number,
 990                 .version        = vers,
 991                 .authflavor     = old->cl_auth->au_flavor,
 992                 .cred           = old->cl_cred,
 993         };
 994         struct rpc_clnt *clnt;
 995         int err;
 996
 997         clnt = __rpc_clone_client(&args, old);
 998         if (IS_ERR(clnt))
 999                 goto out;
1000         err = rpc_ping(clnt);
1001         if (err != 0) {
1002                 rpc_shutdown_client(clnt);
1003                 clnt = ERR_PTR(err);
1004         }
1005 out:
1006         return clnt;
1007 }
1008 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
1009
1010 struct rpc_xprt *
1011 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1012 {
1013         struct rpc_xprt_switch *xps;
1014
1015         if (!xprt)
1016                 return NULL;
1017         rcu_read_lock();
1018         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1019         atomic_long_inc(&xps->xps_queuelen);
1020         rcu_read_unlock();
1021         atomic_long_inc(&xprt->queuelen);
1022
1023         return xprt;
1024 }
1025
1026 static void
1027 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1028 {
1029         struct rpc_xprt_switch *xps;
1030
1031         atomic_long_dec(&xprt->queuelen);
1032         rcu_read_lock();
1033         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1034         atomic_long_dec(&xps->xps_queuelen);
1035         rcu_read_unlock();
1036
1037         xprt_put(xprt);
1038 }
1039
1040 void rpc_task_release_transport(struct rpc_task *task)
1041 {
1042         struct rpc_xprt *xprt = task->tk_xprt;
1043
1044         if (xprt) {
1045                 task->tk_xprt = NULL;
1046                 if (task->tk_client)
1047                         rpc_task_release_xprt(task->tk_client, xprt);
1048                 else
1049                         xprt_put(xprt);
1050         }
1051 }
1052 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1053
1054 void rpc_task_release_client(struct rpc_task *task)
1055 {
1056         struct rpc_clnt *clnt = task->tk_client;
1057
1058         rpc_task_release_transport(task);
1059         if (clnt != NULL) {
1060                 /* Remove from client task list */
1061                 spin_lock(&clnt->cl_lock);
1062                 list_del(&task->tk_task);
1063                 spin_unlock(&clnt->cl_lock);
1064                 task->tk_client = NULL;
1065
1066                 rpc_release_client(clnt);
1067         }
1068 }
1069
1070 static struct rpc_xprt *
1071 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1072 {
1073         struct rpc_xprt *xprt;
1074
1075         rcu_read_lock();
1076         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1077         rcu_read_unlock();
1078         return rpc_task_get_xprt(clnt, xprt);
1079 }
1080
1081 static struct rpc_xprt *
1082 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1083 {
1084         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1085 }
1086
1087 static
1088 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1089 {
1090         if (task->tk_xprt) {
1091                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1092                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1093                         return;
1094                 xprt_release(task);
1095                 xprt_put(task->tk_xprt);
1096         }
1097         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1098                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1099         else
1100                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1101 }
1102
1103 static
1104 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1105 {
1106         rpc_task_set_transport(task, clnt);
1107         task->tk_client = clnt;
1108         refcount_inc(&clnt->cl_count);
1109         if (clnt->cl_softrtry)
1110                 task->tk_flags |= RPC_TASK_SOFT;
1111         if (clnt->cl_softerr)
1112                 task->tk_flags |= RPC_TASK_TIMEOUT;
1113         if (clnt->cl_noretranstimeo)
1114                 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1115         /* Add to the client's list of all tasks */
1116         spin_lock(&clnt->cl_lock);
1117         list_add_tail(&task->tk_task, &clnt->cl_tasks);
1118         spin_unlock(&clnt->cl_lock);
1119 }
1120
1121 static void
1122 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1123 {
1124         if (msg != NULL) {
1125                 task->tk_msg.rpc_proc = msg->rpc_proc;
1126                 task->tk_msg.rpc_argp = msg->rpc_argp;
1127                 task->tk_msg.rpc_resp = msg->rpc_resp;
1128                 task->tk_msg.rpc_cred = msg->rpc_cred;
1129                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1130                         get_cred(task->tk_msg.rpc_cred);
1131         }
1132 }
1133
1134 /*
1135  * Default callback for async RPC calls
1136  */
1137 static void
1138 rpc_default_callback(struct rpc_task *task, void *data)
1139 {
1140 }
1141
1142 static const struct rpc_call_ops rpc_default_ops = {
1143         .rpc_call_done = rpc_default_callback,
1144 };
1145
1146 /**
1147  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1148  * @task_setup_data: pointer to task initialisation data
1149  */
1150 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1151 {
1152         struct rpc_task *task;
1153
1154         task = rpc_new_task(task_setup_data);
1155         if (IS_ERR(task))
1156                 return task;
1157
1158         if (!RPC_IS_ASYNC(task))
1159                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1160
1161         rpc_task_set_client(task, task_setup_data->rpc_client);
1162         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1163
1164         if (task->tk_action == NULL)
1165                 rpc_call_start(task);
1166
1167         atomic_inc(&task->tk_count);
1168         rpc_execute(task);
1169         return task;
1170 }
1171 EXPORT_SYMBOL_GPL(rpc_run_task);
1172
1173 /**
1174  * rpc_call_sync - Perform a synchronous RPC call
1175  * @clnt: pointer to RPC client
1176  * @msg: RPC call parameters
1177  * @flags: RPC call flags
1178  */
1179 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1180 {
1181         struct rpc_task *task;
1182         struct rpc_task_setup task_setup_data = {
1183                 .rpc_client = clnt,
1184                 .rpc_message = msg,
1185                 .callback_ops = &rpc_default_ops,
1186                 .flags = flags,
1187         };
1188         int status;
1189
1190         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1191         if (flags & RPC_TASK_ASYNC) {
1192                 rpc_release_calldata(task_setup_data.callback_ops,
1193                         task_setup_data.callback_data);
1194                 return -EINVAL;
1195         }
1196
1197         task = rpc_run_task(&task_setup_data);
1198         if (IS_ERR(task))
1199                 return PTR_ERR(task);
1200         status = task->tk_status;
1201         rpc_put_task(task);
1202         return status;
1203 }
1204 EXPORT_SYMBOL_GPL(rpc_call_sync);
1205
1206 /**
1207  * rpc_call_async - Perform an asynchronous RPC call
1208  * @clnt: pointer to RPC client
1209  * @msg: RPC call parameters
1210  * @flags: RPC call flags
1211  * @tk_ops: RPC call ops
1212  * @data: user call data
1213  */
1214 int
1215 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1216                const struct rpc_call_ops *tk_ops, void *data)
1217 {
1218         struct rpc_task *task;
1219         struct rpc_task_setup task_setup_data = {
1220                 .rpc_client = clnt,
1221                 .rpc_message = msg,
1222                 .callback_ops = tk_ops,
1223                 .callback_data = data,
1224                 .flags = flags|RPC_TASK_ASYNC,
1225         };
1226
1227         task = rpc_run_task(&task_setup_data);
1228         if (IS_ERR(task))
1229                 return PTR_ERR(task);
1230         rpc_put_task(task);
1231         return 0;
1232 }
1233 EXPORT_SYMBOL_GPL(rpc_call_async);
1234
1235 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1236 static void call_bc_encode(struct rpc_task *task);
1237
1238 /**
1239  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1240  * rpc_execute against it
1241  * @req: RPC request
1242  */
1243 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1244 {
1245         struct rpc_task *task;
1246         struct rpc_task_setup task_setup_data = {
1247                 .callback_ops = &rpc_default_ops,
1248                 .flags = RPC_TASK_SOFTCONN |
1249                         RPC_TASK_NO_RETRANS_TIMEOUT,
1250         };
1251
1252         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1253         /*
1254          * Create an rpc_task to send the data
1255          */
1256         task = rpc_new_task(&task_setup_data);
1257         if (IS_ERR(task)) {
1258                 xprt_free_bc_request(req);
1259                 return task;
1260         }
1261
1262         xprt_init_bc_request(req, task);
1263
1264         task->tk_action = call_bc_encode;
1265         atomic_inc(&task->tk_count);
1266         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1267         rpc_execute(task);
1268
1269         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1270         return task;
1271 }
1272 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1273
1274 /**
1275  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1276  * @req: RPC request to prepare
1277  * @pages: vector of struct page pointers
1278  * @base: offset in first page where receive should start, in bytes
1279  * @len: expected size of the upper layer data payload, in bytes
1280  * @hdrsize: expected size of upper layer reply header, in XDR words
1281  *
1282  */
1283 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1284                              unsigned int base, unsigned int len,
1285                              unsigned int hdrsize)
1286 {
1287         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1288
1289         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1290         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1291 }
1292 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1293
1294 void
1295 rpc_call_start(struct rpc_task *task)
1296 {
1297         task->tk_action = call_start;
1298 }
1299 EXPORT_SYMBOL_GPL(rpc_call_start);
1300
1301 /**
1302  * rpc_peeraddr - extract remote peer address from clnt's xprt
1303  * @clnt: RPC client structure
1304  * @buf: target buffer
1305  * @bufsize: length of target buffer
1306  *
1307  * Returns the number of bytes that are actually in the stored address.
1308  */
1309 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1310 {
1311         size_t bytes;
1312         struct rpc_xprt *xprt;
1313
1314         rcu_read_lock();
1315         xprt = rcu_dereference(clnt->cl_xprt);
1316
1317         bytes = xprt->addrlen;
1318         if (bytes > bufsize)
1319                 bytes = bufsize;
1320         memcpy(buf, &xprt->addr, bytes);
1321         rcu_read_unlock();
1322
1323         return bytes;
1324 }
1325 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1326
1327 /**
1328  * rpc_peeraddr2str - return remote peer address in printable format
1329  * @clnt: RPC client structure
1330  * @format: address format
1331  *
1332  * NB: the lifetime of the memory referenced by the returned pointer is
1333  * the same as the rpc_xprt itself.  As long as the caller uses this
1334  * pointer, it must hold the RCU read lock.
1335  */
1336 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1337                              enum rpc_display_format_t format)
1338 {
1339         struct rpc_xprt *xprt;
1340
1341         xprt = rcu_dereference(clnt->cl_xprt);
1342
1343         if (xprt->address_strings[format] != NULL)
1344                 return xprt->address_strings[format];
1345         else
1346                 return "unprintable";
1347 }
1348 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1349
1350 static const struct sockaddr_in rpc_inaddr_loopback = {
1351         .sin_family             = AF_INET,
1352         .sin_addr.s_addr        = htonl(INADDR_ANY),
1353 };
1354
1355 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1356         .sin6_family            = AF_INET6,
1357         .sin6_addr              = IN6ADDR_ANY_INIT,
1358 };
1359
1360 /*
1361  * Try a getsockname() on a connected datagram socket.  Using a
1362  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1363  * This conserves the ephemeral port number space.
1364  *
1365  * Returns zero and fills in "buf" if successful; otherwise, a
1366  * negative errno is returned.
1367  */
1368 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1369                         struct sockaddr *buf)
1370 {
1371         struct socket *sock;
1372         int err;
1373
1374         err = __sock_create(net, sap->sa_family,
1375                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1376         if (err < 0) {
1377                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1378                 goto out;
1379         }
1380
1381         switch (sap->sa_family) {
1382         case AF_INET:
1383                 err = kernel_bind(sock,
1384                                 (struct sockaddr *)&rpc_inaddr_loopback,
1385                                 sizeof(rpc_inaddr_loopback));
1386                 break;
1387         case AF_INET6:
1388                 err = kernel_bind(sock,
1389                                 (struct sockaddr *)&rpc_in6addr_loopback,
1390                                 sizeof(rpc_in6addr_loopback));
1391                 break;
1392         default:
1393                 err = -EAFNOSUPPORT;
1394                 goto out;
1395         }
1396         if (err < 0) {
1397                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1398                 goto out_release;
1399         }
1400
1401         err = kernel_connect(sock, sap, salen, 0);
1402         if (err < 0) {
1403                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1404                 goto out_release;
1405         }
1406
1407         err = kernel_getsockname(sock, buf);
1408         if (err < 0) {
1409                 dprintk("RPC:       getsockname failed (%d)\n", err);
1410                 goto out_release;
1411         }
1412
1413         err = 0;
1414         if (buf->sa_family == AF_INET6) {
1415                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1416                 sin6->sin6_scope_id = 0;
1417         }
1418         dprintk("RPC:       %s succeeded\n", __func__);
1419
1420 out_release:
1421         sock_release(sock);
1422 out:
1423         return err;
1424 }
1425
1426 /*
1427  * Scraping a connected socket failed, so we don't have a useable
1428  * local address.  Fallback: generate an address that will prevent
1429  * the server from calling us back.
1430  *
1431  * Returns zero and fills in "buf" if successful; otherwise, a
1432  * negative errno is returned.
1433  */
1434 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1435 {
1436         switch (family) {
1437         case AF_INET:
1438                 if (buflen < sizeof(rpc_inaddr_loopback))
1439                         return -EINVAL;
1440                 memcpy(buf, &rpc_inaddr_loopback,
1441                                 sizeof(rpc_inaddr_loopback));
1442                 break;
1443         case AF_INET6:
1444                 if (buflen < sizeof(rpc_in6addr_loopback))
1445                         return -EINVAL;
1446                 memcpy(buf, &rpc_in6addr_loopback,
1447                                 sizeof(rpc_in6addr_loopback));
1448                 break;
1449         default:
1450                 dprintk("RPC:       %s: address family not supported\n",
1451                         __func__);
1452                 return -EAFNOSUPPORT;
1453         }
1454         dprintk("RPC:       %s: succeeded\n", __func__);
1455         return 0;
1456 }
1457
1458 /**
1459  * rpc_localaddr - discover local endpoint address for an RPC client
1460  * @clnt: RPC client structure
1461  * @buf: target buffer
1462  * @buflen: size of target buffer, in bytes
1463  *
1464  * Returns zero and fills in "buf" and "buflen" if successful;
1465  * otherwise, a negative errno is returned.
1466  *
1467  * This works even if the underlying transport is not currently connected,
1468  * or if the upper layer never previously provided a source address.
1469  *
1470  * The result of this function call is transient: multiple calls in
1471  * succession may give different results, depending on how local
1472  * networking configuration changes over time.
1473  */
1474 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1475 {
1476         struct sockaddr_storage address;
1477         struct sockaddr *sap = (struct sockaddr *)&address;
1478         struct rpc_xprt *xprt;
1479         struct net *net;
1480         size_t salen;
1481         int err;
1482
1483         rcu_read_lock();
1484         xprt = rcu_dereference(clnt->cl_xprt);
1485         salen = xprt->addrlen;
1486         memcpy(sap, &xprt->addr, salen);
1487         net = get_net(xprt->xprt_net);
1488         rcu_read_unlock();
1489
1490         rpc_set_port(sap, 0);
1491         err = rpc_sockname(net, sap, salen, buf);
1492         put_net(net);
1493         if (err != 0)
1494                 /* Couldn't discover local address, return ANYADDR */
1495                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1496         return 0;
1497 }
1498 EXPORT_SYMBOL_GPL(rpc_localaddr);
1499
1500 void
1501 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1502 {
1503         struct rpc_xprt *xprt;
1504
1505         rcu_read_lock();
1506         xprt = rcu_dereference(clnt->cl_xprt);
1507         if (xprt->ops->set_buffer_size)
1508                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1509         rcu_read_unlock();
1510 }
1511 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1512
1513 /**
1514  * rpc_net_ns - Get the network namespace for this RPC client
1515  * @clnt: RPC client to query
1516  *
1517  */
1518 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1519 {
1520         struct net *ret;
1521
1522         rcu_read_lock();
1523         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1524         rcu_read_unlock();
1525         return ret;
1526 }
1527 EXPORT_SYMBOL_GPL(rpc_net_ns);
1528
1529 /**
1530  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1531  * @clnt: RPC client to query
1532  *
1533  * For stream transports, this is one RPC record fragment (see RFC
1534  * 1831), as we don't support multi-record requests yet.  For datagram
1535  * transports, this is the size of an IP packet minus the IP, UDP, and
1536  * RPC header sizes.
1537  */
1538 size_t rpc_max_payload(struct rpc_clnt *clnt)
1539 {
1540         size_t ret;
1541
1542         rcu_read_lock();
1543         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1544         rcu_read_unlock();
1545         return ret;
1546 }
1547 EXPORT_SYMBOL_GPL(rpc_max_payload);
1548
1549 /**
1550  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1551  * @clnt: RPC client to query
1552  */
1553 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1554 {
1555         struct rpc_xprt *xprt;
1556         size_t ret;
1557
1558         rcu_read_lock();
1559         xprt = rcu_dereference(clnt->cl_xprt);
1560         ret = xprt->ops->bc_maxpayload(xprt);
1561         rcu_read_unlock();
1562         return ret;
1563 }
1564 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1565
1566 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1567 {
1568         struct rpc_xprt *xprt;
1569         unsigned int ret;
1570
1571         rcu_read_lock();
1572         xprt = rcu_dereference(clnt->cl_xprt);
1573         ret = xprt->ops->bc_num_slots(xprt);
1574         rcu_read_unlock();
1575         return ret;
1576 }
1577 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1578
1579 /**
1580  * rpc_force_rebind - force transport to check that remote port is unchanged
1581  * @clnt: client to rebind
1582  *
1583  */
1584 void rpc_force_rebind(struct rpc_clnt *clnt)
1585 {
1586         if (clnt->cl_autobind) {
1587                 rcu_read_lock();
1588                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1589                 rcu_read_unlock();
1590         }
1591 }
1592 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1593
1594 static int
1595 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1596 {
1597         task->tk_status = 0;
1598         task->tk_rpc_status = 0;
1599         task->tk_action = action;
1600         return 1;
1601 }
1602
1603 /*
1604  * Restart an (async) RPC call. Usually called from within the
1605  * exit handler.
1606  */
1607 int
1608 rpc_restart_call(struct rpc_task *task)
1609 {
1610         return __rpc_restart_call(task, call_start);
1611 }
1612 EXPORT_SYMBOL_GPL(rpc_restart_call);
1613
1614 /*
1615  * Restart an (async) RPC call from the call_prepare state.
1616  * Usually called from within the exit handler.
1617  */
1618 int
1619 rpc_restart_call_prepare(struct rpc_task *task)
1620 {
1621         if (task->tk_ops->rpc_call_prepare != NULL)
1622                 return __rpc_restart_call(task, rpc_prepare_task);
1623         return rpc_restart_call(task);
1624 }
1625 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1626
1627 const char
1628 *rpc_proc_name(const struct rpc_task *task)
1629 {
1630         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1631
1632         if (proc) {
1633                 if (proc->p_name)
1634                         return proc->p_name;
1635                 else
1636                         return "NULL";
1637         } else
1638                 return "no proc";
1639 }
1640
1641 static void
1642 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1643 {
1644         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1645         task->tk_rpc_status = rpc_status;
1646         rpc_exit(task, tk_status);
1647 }
1648
1649 static void
1650 rpc_call_rpcerror(struct rpc_task *task, int status)
1651 {
1652         __rpc_call_rpcerror(task, status, status);
1653 }
1654
1655 /*
1656  * 0.  Initial state
1657  *
1658  *     Other FSM states can be visited zero or more times, but
1659  *     this state is visited exactly once for each RPC.
1660  */
1661 static void
1662 call_start(struct rpc_task *task)
1663 {
1664         struct rpc_clnt *clnt = task->tk_client;
1665         int idx = task->tk_msg.rpc_proc->p_statidx;
1666
1667         trace_rpc_request(task);
1668
1669         /* Increment call count (version might not be valid for ping) */
1670         if (clnt->cl_program->version[clnt->cl_vers])
1671                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1672         clnt->cl_stats->rpccnt++;
1673         task->tk_action = call_reserve;
1674         rpc_task_set_transport(task, clnt);
1675 }
1676
1677 /*
1678  * 1.   Reserve an RPC call slot
1679  */
1680 static void
1681 call_reserve(struct rpc_task *task)
1682 {
1683         task->tk_status  = 0;
1684         task->tk_action  = call_reserveresult;
1685         xprt_reserve(task);
1686 }
1687
1688 static void call_retry_reserve(struct rpc_task *task);
1689
1690 /*
1691  * 1b.  Grok the result of xprt_reserve()
1692  */
1693 static void
1694 call_reserveresult(struct rpc_task *task)
1695 {
1696         int status = task->tk_status;
1697
1698         /*
1699          * After a call to xprt_reserve(), we must have either
1700          * a request slot or else an error status.
1701          */
1702         task->tk_status = 0;
1703         if (status >= 0) {
1704                 if (task->tk_rqstp) {
1705                         task->tk_action = call_refresh;
1706                         return;
1707                 }
1708
1709                 rpc_call_rpcerror(task, -EIO);
1710                 return;
1711         }
1712
1713         switch (status) {
1714         case -ENOMEM:
1715                 rpc_delay(task, HZ >> 2);
1716                 fallthrough;
1717         case -EAGAIN:   /* woken up; retry */
1718                 task->tk_action = call_retry_reserve;
1719                 return;
1720         default:
1721                 rpc_call_rpcerror(task, status);
1722         }
1723 }
1724
1725 /*
1726  * 1c.  Retry reserving an RPC call slot
1727  */
1728 static void
1729 call_retry_reserve(struct rpc_task *task)
1730 {
1731         task->tk_status  = 0;
1732         task->tk_action  = call_reserveresult;
1733         xprt_retry_reserve(task);
1734 }
1735
1736 /*
1737  * 2.   Bind and/or refresh the credentials
1738  */
1739 static void
1740 call_refresh(struct rpc_task *task)
1741 {
1742         task->tk_action = call_refreshresult;
1743         task->tk_status = 0;
1744         task->tk_client->cl_stats->rpcauthrefresh++;
1745         rpcauth_refreshcred(task);
1746 }
1747
1748 /*
1749  * 2a.  Process the results of a credential refresh
1750  */
1751 static void
1752 call_refreshresult(struct rpc_task *task)
1753 {
1754         int status = task->tk_status;
1755
1756         task->tk_status = 0;
1757         task->tk_action = call_refresh;
1758         switch (status) {
1759         case 0:
1760                 if (rpcauth_uptodatecred(task)) {
1761                         task->tk_action = call_allocate;
1762                         return;
1763                 }
1764                 /* Use rate-limiting and a max number of retries if refresh
1765                  * had status 0 but failed to update the cred.
1766                  */
1767                 fallthrough;
1768         case -ETIMEDOUT:
1769                 rpc_delay(task, 3*HZ);
1770                 fallthrough;
1771         case -EAGAIN:
1772                 status = -EACCES;
1773                 fallthrough;
1774         case -EKEYEXPIRED:
1775                 if (!task->tk_cred_retry)
1776                         break;
1777                 task->tk_cred_retry--;
1778                 trace_rpc_retry_refresh_status(task);
1779                 return;
1780         case -ENOMEM:
1781                 rpc_delay(task, HZ >> 4);
1782                 return;
1783         }
1784         trace_rpc_refresh_status(task);
1785         rpc_call_rpcerror(task, status);
1786 }
1787
1788 /*
1789  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1790  *      (Note: buffer memory is freed in xprt_release).
1791  */
1792 static void
1793 call_allocate(struct rpc_task *task)
1794 {
1795         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1796         struct rpc_rqst *req = task->tk_rqstp;
1797         struct rpc_xprt *xprt = req->rq_xprt;
1798         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1799         int status;
1800
1801         task->tk_status = 0;
1802         task->tk_action = call_encode;
1803
1804         if (req->rq_buffer)
1805                 return;
1806
1807         if (proc->p_proc != 0) {
1808                 BUG_ON(proc->p_arglen == 0);
1809                 if (proc->p_decode != NULL)
1810                         BUG_ON(proc->p_replen == 0);
1811         }
1812
1813         /*
1814          * Calculate the size (in quads) of the RPC call
1815          * and reply headers, and convert both values
1816          * to byte sizes.
1817          */
1818         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1819                            proc->p_arglen;
1820         req->rq_callsize <<= 2;
1821         /*
1822          * Note: the reply buffer must at minimum allocate enough space
1823          * for the 'struct accepted_reply' from RFC5531.
1824          */
1825         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1826                         max_t(size_t, proc->p_replen, 2);
1827         req->rq_rcvsize <<= 2;
1828
1829         status = xprt->ops->buf_alloc(task);
1830         trace_rpc_buf_alloc(task, status);
1831         if (status == 0)
1832                 return;
1833         if (status != -ENOMEM) {
1834                 rpc_call_rpcerror(task, status);
1835                 return;
1836         }
1837
1838         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1839                 task->tk_action = call_allocate;
1840                 rpc_delay(task, HZ>>4);
1841                 return;
1842         }
1843
1844         rpc_call_rpcerror(task, -ERESTARTSYS);
1845 }
1846
1847 static int
1848 rpc_task_need_encode(struct rpc_task *task)
1849 {
1850         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1851                 (!(task->tk_flags & RPC_TASK_SENT) ||
1852                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1853                  xprt_request_need_retransmit(task));
1854 }
1855
1856 static void
1857 rpc_xdr_encode(struct rpc_task *task)
1858 {
1859         struct rpc_rqst *req = task->tk_rqstp;
1860         struct xdr_stream xdr;
1861
1862         xdr_buf_init(&req->rq_snd_buf,
1863                      req->rq_buffer,
1864                      req->rq_callsize);
1865         xdr_buf_init(&req->rq_rcv_buf,
1866                      req->rq_rbuffer,
1867                      req->rq_rcvsize);
1868
1869         req->rq_reply_bytes_recvd = 0;
1870         req->rq_snd_buf.head[0].iov_len = 0;
1871         xdr_init_encode(&xdr, &req->rq_snd_buf,
1872                         req->rq_snd_buf.head[0].iov_base, req);
1873         if (rpc_encode_header(task, &xdr))
1874                 return;
1875
1876         task->tk_status = rpcauth_wrap_req(task, &xdr);
1877 }
1878
1879 /*
1880  * 3.   Encode arguments of an RPC call
1881  */
1882 static void
1883 call_encode(struct rpc_task *task)
1884 {
1885         if (!rpc_task_need_encode(task))
1886                 goto out;
1887
1888         /* Dequeue task from the receive queue while we're encoding */
1889         xprt_request_dequeue_xprt(task);
1890         /* Encode here so that rpcsec_gss can use correct sequence number. */
1891         rpc_xdr_encode(task);
1892         /* Add task to reply queue before transmission to avoid races */
1893         if (task->tk_status == 0 && rpc_reply_expected(task))
1894                 task->tk_status = xprt_request_enqueue_receive(task);
1895         /* Did the encode result in an error condition? */
1896         if (task->tk_status != 0) {
1897                 /* Was the error nonfatal? */
1898                 switch (task->tk_status) {
1899                 case -EAGAIN:
1900                 case -ENOMEM:
1901                         rpc_delay(task, HZ >> 4);
1902                         break;
1903                 case -EKEYEXPIRED:
1904                         if (!task->tk_cred_retry) {
1905                                 rpc_call_rpcerror(task, task->tk_status);
1906                         } else {
1907                                 task->tk_action = call_refresh;
1908                                 task->tk_cred_retry--;
1909                                 trace_rpc_retry_refresh_status(task);
1910                         }
1911                         break;
1912                 default:
1913                         rpc_call_rpcerror(task, task->tk_status);
1914                 }
1915                 return;
1916         }
1917
1918         xprt_request_enqueue_transmit(task);
1919 out:
1920         task->tk_action = call_transmit;
1921         /* Check that the connection is OK */
1922         if (!xprt_bound(task->tk_xprt))
1923                 task->tk_action = call_bind;
1924         else if (!xprt_connected(task->tk_xprt))
1925                 task->tk_action = call_connect;
1926 }
1927
1928 /*
1929  * Helpers to check if the task was already transmitted, and
1930  * to take action when that is the case.
1931  */
1932 static bool
1933 rpc_task_transmitted(struct rpc_task *task)
1934 {
1935         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1936 }
1937
1938 static void
1939 rpc_task_handle_transmitted(struct rpc_task *task)
1940 {
1941         xprt_end_transmit(task);
1942         task->tk_action = call_transmit_status;
1943 }
1944
1945 /*
1946  * 4.   Get the server port number if not yet set
1947  */
1948 static void
1949 call_bind(struct rpc_task *task)
1950 {
1951         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1952
1953         if (rpc_task_transmitted(task)) {
1954                 rpc_task_handle_transmitted(task);
1955                 return;
1956         }
1957
1958         if (xprt_bound(xprt)) {
1959                 task->tk_action = call_connect;
1960                 return;
1961         }
1962
1963         task->tk_action = call_bind_status;
1964         if (!xprt_prepare_transmit(task))
1965                 return;
1966
1967         xprt->ops->rpcbind(task);
1968 }
1969
1970 /*
1971  * 4a.  Sort out bind result
1972  */
1973 static void
1974 call_bind_status(struct rpc_task *task)
1975 {
1976         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1977         int status = -EIO;
1978
1979         if (rpc_task_transmitted(task)) {
1980                 rpc_task_handle_transmitted(task);
1981                 return;
1982         }
1983
1984         if (task->tk_status >= 0)
1985                 goto out_next;
1986         if (xprt_bound(xprt)) {
1987                 task->tk_status = 0;
1988                 goto out_next;
1989         }
1990
1991         switch (task->tk_status) {
1992         case -ENOMEM:
1993                 rpc_delay(task, HZ >> 2);
1994                 goto retry_timeout;
1995         case -EACCES:
1996                 trace_rpcb_prog_unavail_err(task);
1997                 /* fail immediately if this is an RPC ping */
1998                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1999                         status = -EOPNOTSUPP;
2000                         break;
2001                 }
2002                 if (task->tk_rebind_retry == 0)
2003                         break;
2004                 task->tk_rebind_retry--;
2005                 rpc_delay(task, 3*HZ);
2006                 goto retry_timeout;
2007         case -ENOBUFS:
2008                 rpc_delay(task, HZ >> 2);
2009                 goto retry_timeout;
2010         case -EAGAIN:
2011                 goto retry_timeout;
2012         case -ETIMEDOUT:
2013                 trace_rpcb_timeout_err(task);
2014                 goto retry_timeout;
2015         case -EPFNOSUPPORT:
2016                 /* server doesn't support any rpcbind version we know of */
2017                 trace_rpcb_bind_version_err(task);
2018                 break;
2019         case -EPROTONOSUPPORT:
2020                 trace_rpcb_bind_version_err(task);
2021                 goto retry_timeout;
2022         case -ECONNREFUSED:             /* connection problems */
2023         case -ECONNRESET:
2024         case -ECONNABORTED:
2025         case -ENOTCONN:
2026         case -EHOSTDOWN:
2027         case -ENETDOWN:
2028         case -EHOSTUNREACH:
2029         case -ENETUNREACH:
2030         case -EPIPE:
2031                 trace_rpcb_unreachable_err(task);
2032                 if (!RPC_IS_SOFTCONN(task)) {
2033                         rpc_delay(task, 5*HZ);
2034                         goto retry_timeout;
2035                 }
2036                 status = task->tk_status;
2037                 break;
2038         default:
2039                 trace_rpcb_unrecognized_err(task);
2040         }
2041
2042         rpc_call_rpcerror(task, status);
2043         return;
2044 out_next:
2045         task->tk_action = call_connect;
2046         return;
2047 retry_timeout:
2048         task->tk_status = 0;
2049         task->tk_action = call_bind;
2050         rpc_check_timeout(task);
2051 }
2052
2053 /*
2054  * 4b.  Connect to the RPC server
2055  */
2056 static void
2057 call_connect(struct rpc_task *task)
2058 {
2059         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2060
2061         if (rpc_task_transmitted(task)) {
2062                 rpc_task_handle_transmitted(task);
2063                 return;
2064         }
2065
2066         if (xprt_connected(xprt)) {
2067                 task->tk_action = call_transmit;
2068                 return;
2069         }
2070
2071         task->tk_action = call_connect_status;
2072         if (task->tk_status < 0)
2073                 return;
2074         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2075                 rpc_call_rpcerror(task, -ENOTCONN);
2076                 return;
2077         }
2078         if (!xprt_prepare_transmit(task))
2079                 return;
2080         xprt_connect(task);
2081 }
2082
2083 /*
2084  * 4c.  Sort out connect result
2085  */
2086 static void
2087 call_connect_status(struct rpc_task *task)
2088 {
2089         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2090         struct rpc_clnt *clnt = task->tk_client;
2091         int status = task->tk_status;
2092
2093         if (rpc_task_transmitted(task)) {
2094                 rpc_task_handle_transmitted(task);
2095                 return;
2096         }
2097
2098         trace_rpc_connect_status(task);
2099
2100         if (task->tk_status == 0) {
2101                 clnt->cl_stats->netreconn++;
2102                 goto out_next;
2103         }
2104         if (xprt_connected(xprt)) {
2105                 task->tk_status = 0;
2106                 goto out_next;
2107         }
2108
2109         task->tk_status = 0;
2110         switch (status) {
2111         case -ECONNREFUSED:
2112                 /* A positive refusal suggests a rebind is needed. */
2113                 if (RPC_IS_SOFTCONN(task))
2114                         break;
2115                 if (clnt->cl_autobind) {
2116                         rpc_force_rebind(clnt);
2117                         goto out_retry;
2118                 }
2119                 fallthrough;
2120         case -ECONNRESET:
2121         case -ECONNABORTED:
2122         case -ENETDOWN:
2123         case -ENETUNREACH:
2124         case -EHOSTUNREACH:
2125         case -EPIPE:
2126         case -EPROTO:
2127                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2128                                             task->tk_rqstp->rq_connect_cookie);
2129                 if (RPC_IS_SOFTCONN(task))
2130                         break;
2131                 /* retry with existing socket, after a delay */
2132                 rpc_delay(task, 3*HZ);
2133                 fallthrough;
2134         case -EADDRINUSE:
2135         case -ENOTCONN:
2136         case -EAGAIN:
2137         case -ETIMEDOUT:
2138                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2139                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2140                     test_bit(XPRT_REMOVE, &xprt->state)) {
2141                         struct rpc_xprt *saved = task->tk_xprt;
2142                         struct rpc_xprt_switch *xps;
2143
2144                         rcu_read_lock();
2145                         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2146                         rcu_read_unlock();
2147                         if (xps->xps_nxprts > 1) {
2148                                 long value;
2149
2150                                 xprt_release(task);
2151                                 value = atomic_long_dec_return(&xprt->queuelen);
2152                                 if (value == 0)
2153                                         rpc_xprt_switch_remove_xprt(xps, saved,
2154                                                                     true);
2155                                 xprt_put(saved);
2156                                 task->tk_xprt = NULL;
2157                                 task->tk_action = call_start;
2158                         }
2159                         xprt_switch_put(xps);
2160                         if (!task->tk_xprt)
2161                                 return;
2162                 }
2163                 goto out_retry;
2164         case -ENOBUFS:
2165                 rpc_delay(task, HZ >> 2);
2166                 goto out_retry;
2167         }
2168         rpc_call_rpcerror(task, status);
2169         return;
2170 out_next:
2171         task->tk_action = call_transmit;
2172         return;
2173 out_retry:
2174         /* Check for timeouts before looping back to call_bind */
2175         task->tk_action = call_bind;
2176         rpc_check_timeout(task);
2177 }
2178
2179 /*
2180  * 5.   Transmit the RPC request, and wait for reply
2181  */
2182 static void
2183 call_transmit(struct rpc_task *task)
2184 {
2185         if (rpc_task_transmitted(task)) {
2186                 rpc_task_handle_transmitted(task);
2187                 return;
2188         }
2189
2190         task->tk_action = call_transmit_status;
2191         if (!xprt_prepare_transmit(task))
2192                 return;
2193         task->tk_status = 0;
2194         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2195                 if (!xprt_connected(task->tk_xprt)) {
2196                         task->tk_status = -ENOTCONN;
2197                         return;
2198                 }
2199                 xprt_transmit(task);
2200         }
2201         xprt_end_transmit(task);
2202 }
2203
2204 /*
2205  * 5a.  Handle cleanup after a transmission
2206  */
2207 static void
2208 call_transmit_status(struct rpc_task *task)
2209 {
2210         task->tk_action = call_status;
2211
2212         /*
2213          * Common case: success.  Force the compiler to put this
2214          * test first.
2215          */
2216         if (rpc_task_transmitted(task)) {
2217                 task->tk_status = 0;
2218                 xprt_request_wait_receive(task);
2219                 return;
2220         }
2221
2222         switch (task->tk_status) {
2223         default:
2224                 break;
2225         case -EBADMSG:
2226                 task->tk_status = 0;
2227                 task->tk_action = call_encode;
2228                 break;
2229                 /*
2230                  * Special cases: if we've been waiting on the
2231                  * socket's write_space() callback, or if the
2232                  * socket just returned a connection error,
2233                  * then hold onto the transport lock.
2234                  */
2235         case -ENOMEM:
2236         case -ENOBUFS:
2237                 rpc_delay(task, HZ>>2);
2238                 fallthrough;
2239         case -EBADSLT:
2240         case -EAGAIN:
2241                 task->tk_action = call_transmit;
2242                 task->tk_status = 0;
2243                 break;
2244         case -ECONNREFUSED:
2245         case -EHOSTDOWN:
2246         case -ENETDOWN:
2247         case -EHOSTUNREACH:
2248         case -ENETUNREACH:
2249         case -EPERM:
2250                 if (RPC_IS_SOFTCONN(task)) {
2251                         if (!task->tk_msg.rpc_proc->p_proc)
2252                                 trace_xprt_ping(task->tk_xprt,
2253                                                 task->tk_status);
2254                         rpc_call_rpcerror(task, task->tk_status);
2255                         return;
2256                 }
2257                 fallthrough;
2258         case -ECONNRESET:
2259         case -ECONNABORTED:
2260         case -EADDRINUSE:
2261         case -ENOTCONN:
2262         case -EPIPE:
2263                 task->tk_action = call_bind;
2264                 task->tk_status = 0;
2265                 break;
2266         }
2267         rpc_check_timeout(task);
2268 }
2269
2270 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2271 static void call_bc_transmit(struct rpc_task *task);
2272 static void call_bc_transmit_status(struct rpc_task *task);
2273
2274 static void
2275 call_bc_encode(struct rpc_task *task)
2276 {
2277         xprt_request_enqueue_transmit(task);
2278         task->tk_action = call_bc_transmit;
2279 }
2280
2281 /*
2282  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2283  * addition, disconnect on connectivity errors.
2284  */
2285 static void
2286 call_bc_transmit(struct rpc_task *task)
2287 {
2288         task->tk_action = call_bc_transmit_status;
2289         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2290                 if (!xprt_prepare_transmit(task))
2291                         return;
2292                 task->tk_status = 0;
2293                 xprt_transmit(task);
2294         }
2295         xprt_end_transmit(task);
2296 }
2297
2298 static void
2299 call_bc_transmit_status(struct rpc_task *task)
2300 {
2301         struct rpc_rqst *req = task->tk_rqstp;
2302
2303         if (rpc_task_transmitted(task))
2304                 task->tk_status = 0;
2305
2306         switch (task->tk_status) {
2307         case 0:
2308                 /* Success */
2309         case -ENETDOWN:
2310         case -EHOSTDOWN:
2311         case -EHOSTUNREACH:
2312         case -ENETUNREACH:
2313         case -ECONNRESET:
2314         case -ECONNREFUSED:
2315         case -EADDRINUSE:
2316         case -ENOTCONN:
2317         case -EPIPE:
2318                 break;
2319         case -ENOMEM:
2320         case -ENOBUFS:
2321                 rpc_delay(task, HZ>>2);
2322                 fallthrough;
2323         case -EBADSLT:
2324         case -EAGAIN:
2325                 task->tk_status = 0;
2326                 task->tk_action = call_bc_transmit;
2327                 return;
2328         case -ETIMEDOUT:
2329                 /*
2330                  * Problem reaching the server.  Disconnect and let the
2331                  * forechannel reestablish the connection.  The server will
2332                  * have to retransmit the backchannel request and we'll
2333                  * reprocess it.  Since these ops are idempotent, there's no
2334                  * need to cache our reply at this time.
2335                  */
2336                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2337                         "error: %d\n", task->tk_status);
2338                 xprt_conditional_disconnect(req->rq_xprt,
2339                         req->rq_connect_cookie);
2340                 break;
2341         default:
2342                 /*
2343                  * We were unable to reply and will have to drop the
2344                  * request.  The server should reconnect and retransmit.
2345                  */
2346                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2347                         "error: %d\n", task->tk_status);
2348                 break;
2349         }
2350         task->tk_action = rpc_exit_task;
2351 }
2352 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2353
2354 /*
2355  * 6.   Sort out the RPC call status
2356  */
2357 static void
2358 call_status(struct rpc_task *task)
2359 {
2360         struct rpc_clnt *clnt = task->tk_client;
2361         int             status;
2362
2363         if (!task->tk_msg.rpc_proc->p_proc)
2364                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2365
2366         status = task->tk_status;
2367         if (status >= 0) {
2368                 task->tk_action = call_decode;
2369                 return;
2370         }
2371
2372         trace_rpc_call_status(task);
2373         task->tk_status = 0;
2374         switch(status) {
2375         case -EHOSTDOWN:
2376         case -ENETDOWN:
2377         case -EHOSTUNREACH:
2378         case -ENETUNREACH:
2379         case -EPERM:
2380                 if (RPC_IS_SOFTCONN(task))
2381                         goto out_exit;
2382                 /*
2383                  * Delay any retries for 3 seconds, then handle as if it
2384                  * were a timeout.
2385                  */
2386                 rpc_delay(task, 3*HZ);
2387                 fallthrough;
2388         case -ETIMEDOUT:
2389                 break;
2390         case -ECONNREFUSED:
2391         case -ECONNRESET:
2392         case -ECONNABORTED:
2393         case -ENOTCONN:
2394                 rpc_force_rebind(clnt);
2395                 break;
2396         case -EADDRINUSE:
2397                 rpc_delay(task, 3*HZ);
2398                 fallthrough;
2399         case -EPIPE:
2400         case -EAGAIN:
2401                 break;
2402         case -ENFILE:
2403         case -ENOBUFS:
2404         case -ENOMEM:
2405                 rpc_delay(task, HZ>>2);
2406                 break;
2407         case -EIO:
2408                 /* shutdown or soft timeout */
2409                 goto out_exit;
2410         default:
2411                 if (clnt->cl_chatty)
2412                         printk("%s: RPC call returned error %d\n",
2413                                clnt->cl_program->name, -status);
2414                 goto out_exit;
2415         }
2416         task->tk_action = call_encode;
2417         if (status != -ECONNRESET && status != -ECONNABORTED)
2418                 rpc_check_timeout(task);
2419         return;
2420 out_exit:
2421         rpc_call_rpcerror(task, status);
2422 }
2423
2424 static bool
2425 rpc_check_connected(const struct rpc_rqst *req)
2426 {
2427         /* No allocated request or transport? return true */
2428         if (!req || !req->rq_xprt)
2429                 return true;
2430         return xprt_connected(req->rq_xprt);
2431 }
2432
2433 static void
2434 rpc_check_timeout(struct rpc_task *task)
2435 {
2436         struct rpc_clnt *clnt = task->tk_client;
2437
2438         if (RPC_SIGNALLED(task)) {
2439                 rpc_call_rpcerror(task, -ERESTARTSYS);
2440                 return;
2441         }
2442
2443         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2444                 return;
2445
2446         trace_rpc_timeout_status(task);
2447         task->tk_timeouts++;
2448
2449         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2450                 rpc_call_rpcerror(task, -ETIMEDOUT);
2451                 return;
2452         }
2453
2454         if (RPC_IS_SOFT(task)) {
2455                 /*
2456                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2457                  * been sent, it should time out only if the transport
2458                  * connection gets terminally broken.
2459                  */
2460                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2461                     rpc_check_connected(task->tk_rqstp))
2462                         return;
2463
2464                 if (clnt->cl_chatty) {
2465                         pr_notice_ratelimited(
2466                                 "%s: server %s not responding, timed out\n",
2467                                 clnt->cl_program->name,
2468                                 task->tk_xprt->servername);
2469                 }
2470                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2471                         rpc_call_rpcerror(task, -ETIMEDOUT);
2472                 else
2473                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2474                 return;
2475         }
2476
2477         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2478                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2479                 if (clnt->cl_chatty) {
2480                         pr_notice_ratelimited(
2481                                 "%s: server %s not responding, still trying\n",
2482                                 clnt->cl_program->name,
2483                                 task->tk_xprt->servername);
2484                 }
2485         }
2486         rpc_force_rebind(clnt);
2487         /*
2488          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2489          * event? RFC2203 requires the server to drop all such requests.
2490          */
2491         rpcauth_invalcred(task);
2492 }
2493
2494 /*
2495  * 7.   Decode the RPC reply
2496  */
2497 static void
2498 call_decode(struct rpc_task *task)
2499 {
2500         struct rpc_clnt *clnt = task->tk_client;
2501         struct rpc_rqst *req = task->tk_rqstp;
2502         struct xdr_stream xdr;
2503         int err;
2504
2505         if (!task->tk_msg.rpc_proc->p_decode) {
2506                 task->tk_action = rpc_exit_task;
2507                 return;
2508         }
2509
2510         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2511                 if (clnt->cl_chatty) {
2512                         pr_notice_ratelimited("%s: server %s OK\n",
2513                                 clnt->cl_program->name,
2514                                 task->tk_xprt->servername);
2515                 }
2516                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2517         }
2518
2519         /*
2520          * Did we ever call xprt_complete_rqst()? If not, we should assume
2521          * the message is incomplete.
2522          */
2523         err = -EAGAIN;
2524         if (!req->rq_reply_bytes_recvd)
2525                 goto out;
2526
2527         /* Ensure that we see all writes made by xprt_complete_rqst()
2528          * before it changed req->rq_reply_bytes_recvd.
2529          */
2530         smp_rmb();
2531
2532         req->rq_rcv_buf.len = req->rq_private_buf.len;
2533         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2534
2535         /* Check that the softirq receive buffer is valid */
2536         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2537                                 sizeof(req->rq_rcv_buf)) != 0);
2538
2539         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2540                         req->rq_rcv_buf.head[0].iov_base, req);
2541         err = rpc_decode_header(task, &xdr);
2542 out:
2543         switch (err) {
2544         case 0:
2545                 task->tk_action = rpc_exit_task;
2546                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2547                 return;
2548         case -EAGAIN:
2549                 task->tk_status = 0;
2550                 if (task->tk_client->cl_discrtry)
2551                         xprt_conditional_disconnect(req->rq_xprt,
2552                                                     req->rq_connect_cookie);
2553                 task->tk_action = call_encode;
2554                 rpc_check_timeout(task);
2555                 break;
2556         case -EKEYREJECTED:
2557                 task->tk_action = call_reserve;
2558                 rpc_check_timeout(task);
2559                 rpcauth_invalcred(task);
2560                 /* Ensure we obtain a new XID if we retry! */
2561                 xprt_release(task);
2562         }
2563 }
2564
2565 static int
2566 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2567 {
2568         struct rpc_clnt *clnt = task->tk_client;
2569         struct rpc_rqst *req = task->tk_rqstp;
2570         __be32 *p;
2571         int error;
2572
2573         error = -EMSGSIZE;
2574         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2575         if (!p)
2576                 goto out_fail;
2577         *p++ = req->rq_xid;
2578         *p++ = rpc_call;
2579         *p++ = cpu_to_be32(RPC_VERSION);
2580         *p++ = cpu_to_be32(clnt->cl_prog);
2581         *p++ = cpu_to_be32(clnt->cl_vers);
2582         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2583
2584         error = rpcauth_marshcred(task, xdr);
2585         if (error < 0)
2586                 goto out_fail;
2587         return 0;
2588 out_fail:
2589         trace_rpc_bad_callhdr(task);
2590         rpc_call_rpcerror(task, error);
2591         return error;
2592 }
2593
2594 static noinline int
2595 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2596 {
2597         struct rpc_clnt *clnt = task->tk_client;
2598         int error;
2599         __be32 *p;
2600
2601         /* RFC-1014 says that the representation of XDR data must be a
2602          * multiple of four bytes
2603          * - if it isn't pointer subtraction in the NFS client may give
2604          *   undefined results
2605          */
2606         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2607                 goto out_unparsable;
2608
2609         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2610         if (!p)
2611                 goto out_unparsable;
2612         p++;    /* skip XID */
2613         if (*p++ != rpc_reply)
2614                 goto out_unparsable;
2615         if (*p++ != rpc_msg_accepted)
2616                 goto out_msg_denied;
2617
2618         error = rpcauth_checkverf(task, xdr);
2619         if (error)
2620                 goto out_verifier;
2621
2622         p = xdr_inline_decode(xdr, sizeof(*p));
2623         if (!p)
2624                 goto out_unparsable;
2625         switch (*p) {
2626         case rpc_success:
2627                 return 0;
2628         case rpc_prog_unavail:
2629                 trace_rpc__prog_unavail(task);
2630                 error = -EPFNOSUPPORT;
2631                 goto out_err;
2632         case rpc_prog_mismatch:
2633                 trace_rpc__prog_mismatch(task);
2634                 error = -EPROTONOSUPPORT;
2635                 goto out_err;
2636         case rpc_proc_unavail:
2637                 trace_rpc__proc_unavail(task);
2638                 error = -EOPNOTSUPP;
2639                 goto out_err;
2640         case rpc_garbage_args:
2641         case rpc_system_err:
2642                 trace_rpc__garbage_args(task);
2643                 error = -EIO;
2644                 break;
2645         default:
2646                 goto out_unparsable;
2647         }
2648
2649 out_garbage:
2650         clnt->cl_stats->rpcgarbage++;
2651         if (task->tk_garb_retry) {
2652                 task->tk_garb_retry--;
2653                 task->tk_action = call_encode;
2654                 return -EAGAIN;
2655         }
2656 out_err:
2657         rpc_call_rpcerror(task, error);
2658         return error;
2659
2660 out_unparsable:
2661         trace_rpc__unparsable(task);
2662         error = -EIO;
2663         goto out_garbage;
2664
2665 out_verifier:
2666         trace_rpc_bad_verifier(task);
2667         goto out_err;
2668
2669 out_msg_denied:
2670         error = -EACCES;
2671         p = xdr_inline_decode(xdr, sizeof(*p));
2672         if (!p)
2673                 goto out_unparsable;
2674         switch (*p++) {
2675         case rpc_auth_error:
2676                 break;
2677         case rpc_mismatch:
2678                 trace_rpc__mismatch(task);
2679                 error = -EPROTONOSUPPORT;
2680                 goto out_err;
2681         default:
2682                 goto out_unparsable;
2683         }
2684
2685         p = xdr_inline_decode(xdr, sizeof(*p));
2686         if (!p)
2687                 goto out_unparsable;
2688         switch (*p++) {
2689         case rpc_autherr_rejectedcred:
2690         case rpc_autherr_rejectedverf:
2691         case rpcsec_gsserr_credproblem:
2692         case rpcsec_gsserr_ctxproblem:
2693                 if (!task->tk_cred_retry)
2694                         break;
2695                 task->tk_cred_retry--;
2696                 trace_rpc__stale_creds(task);
2697                 return -EKEYREJECTED;
2698         case rpc_autherr_badcred:
2699         case rpc_autherr_badverf:
2700                 /* possibly garbled cred/verf? */
2701                 if (!task->tk_garb_retry)
2702                         break;
2703                 task->tk_garb_retry--;
2704                 trace_rpc__bad_creds(task);
2705                 task->tk_action = call_encode;
2706                 return -EAGAIN;
2707         case rpc_autherr_tooweak:
2708                 trace_rpc__auth_tooweak(task);
2709                 pr_warn("RPC: server %s requires stronger authentication.\n",
2710                         task->tk_xprt->servername);
2711                 break;
2712         default:
2713                 goto out_unparsable;
2714         }
2715         goto out_err;
2716 }
2717
2718 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2719                 const void *obj)
2720 {
2721 }
2722
2723 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2724                 void *obj)
2725 {
2726         return 0;
2727 }
2728
2729 static const struct rpc_procinfo rpcproc_null = {
2730         .p_encode = rpcproc_encode_null,
2731         .p_decode = rpcproc_decode_null,
2732 };
2733
2734 static const struct rpc_procinfo rpcproc_null_noreply = {
2735         .p_encode = rpcproc_encode_null,
2736 };
2737
2738 static void
2739 rpc_null_call_prepare(struct rpc_task *task, void *data)
2740 {
2741         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2742         rpc_call_start(task);
2743 }
2744
2745 static const struct rpc_call_ops rpc_null_ops = {
2746         .rpc_call_prepare = rpc_null_call_prepare,
2747         .rpc_call_done = rpc_default_callback,
2748 };
2749
2750 static
2751 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2752                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2753                 const struct rpc_call_ops *ops, void *data)
2754 {
2755         struct rpc_message msg = {
2756                 .rpc_proc = &rpcproc_null,
2757         };
2758         struct rpc_task_setup task_setup_data = {
2759                 .rpc_client = clnt,
2760                 .rpc_xprt = xprt,
2761                 .rpc_message = &msg,
2762                 .rpc_op_cred = cred,
2763                 .callback_ops = ops ?: &rpc_null_ops,
2764                 .callback_data = data,
2765                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2766                          RPC_TASK_NULLCREDS,
2767         };
2768
2769         return rpc_run_task(&task_setup_data);
2770 }
2771
2772 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2773 {
2774         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2775 }
2776 EXPORT_SYMBOL_GPL(rpc_call_null);
2777
2778 static int rpc_ping(struct rpc_clnt *clnt)
2779 {
2780         struct rpc_task *task;
2781         int status;
2782
2783         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2784         if (IS_ERR(task))
2785                 return PTR_ERR(task);
2786         status = task->tk_status;
2787         rpc_put_task(task);
2788         return status;
2789 }
2790
2791 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2792 {
2793         struct rpc_message msg = {
2794                 .rpc_proc = &rpcproc_null_noreply,
2795         };
2796         struct rpc_task_setup task_setup_data = {
2797                 .rpc_client = clnt,
2798                 .rpc_message = &msg,
2799                 .callback_ops = &rpc_null_ops,
2800                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2801         };
2802         struct rpc_task *task;
2803         int status;
2804
2805         task = rpc_run_task(&task_setup_data);
2806         if (IS_ERR(task))
2807                 return PTR_ERR(task);
2808         status = task->tk_status;
2809         rpc_put_task(task);
2810         return status;
2811 }
2812
2813 struct rpc_cb_add_xprt_calldata {
2814         struct rpc_xprt_switch *xps;
2815         struct rpc_xprt *xprt;
2816 };
2817
2818 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2819 {
2820         struct rpc_cb_add_xprt_calldata *data = calldata;
2821
2822         if (task->tk_status == 0)
2823                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2824 }
2825
2826 static void rpc_cb_add_xprt_release(void *calldata)
2827 {
2828         struct rpc_cb_add_xprt_calldata *data = calldata;
2829
2830         xprt_put(data->xprt);
2831         xprt_switch_put(data->xps);
2832         kfree(data);
2833 }
2834
2835 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2836         .rpc_call_prepare = rpc_null_call_prepare,
2837         .rpc_call_done = rpc_cb_add_xprt_done,
2838         .rpc_release = rpc_cb_add_xprt_release,
2839 };
2840
2841 /**
2842  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2843  * @clnt: pointer to struct rpc_clnt
2844  * @xps: pointer to struct rpc_xprt_switch,
2845  * @xprt: pointer struct rpc_xprt
2846  * @dummy: unused
2847  */
2848 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2849                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2850                 void *dummy)
2851 {
2852         struct rpc_cb_add_xprt_calldata *data;
2853         struct rpc_task *task;
2854
2855         if (xps->xps_nunique_destaddr_xprts + 1 > clnt->cl_max_connect) {
2856                 rcu_read_lock();
2857                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2858                         "transport to server: %s\n", clnt->cl_max_connect,
2859                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2860                 rcu_read_unlock();
2861                 return -EINVAL;
2862         }
2863
2864         data = kmalloc(sizeof(*data), GFP_KERNEL);
2865         if (!data)
2866                 return -ENOMEM;
2867         data->xps = xprt_switch_get(xps);
2868         data->xprt = xprt_get(xprt);
2869         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2870                 rpc_cb_add_xprt_release(data);
2871                 goto success;
2872         }
2873
2874         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2875                         &rpc_cb_add_xprt_call_ops, data);
2876         if (IS_ERR(task))
2877                 return PTR_ERR(task);
2878
2879         data->xps->xps_nunique_destaddr_xprts++;
2880         rpc_put_task(task);
2881 success:
2882         return 1;
2883 }
2884 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2885
2886 static int rpc_clnt_add_xprt_helper(struct rpc_clnt *clnt,
2887                                     struct rpc_xprt *xprt,
2888                                     struct rpc_add_xprt_test *data)
2889 {
2890         struct rpc_task *task;
2891         int status = -EADDRINUSE;
2892
2893         /* Test the connection */
2894         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2895         if (IS_ERR(task))
2896                 return PTR_ERR(task);
2897
2898         status = task->tk_status;
2899         rpc_put_task(task);
2900
2901         if (status < 0)
2902                 return status;
2903
2904         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2905         data->add_xprt_test(clnt, xprt, data->data);
2906
2907         return 0;
2908 }
2909
2910 /**
2911  * rpc_clnt_setup_test_and_add_xprt()
2912  *
2913  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2914  *   1) caller of the test function must dereference the rpc_xprt_switch
2915  *   and the rpc_xprt.
2916  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2917  *   the rpc_call_done routine.
2918  *
2919  * Upon success (return of 1), the test function adds the new
2920  * transport to the rpc_clnt xprt switch
2921  *
2922  * @clnt: struct rpc_clnt to get the new transport
2923  * @xps:  the rpc_xprt_switch to hold the new transport
2924  * @xprt: the rpc_xprt to test
2925  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2926  *        and test function call data
2927  */
2928 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2929                                      struct rpc_xprt_switch *xps,
2930                                      struct rpc_xprt *xprt,
2931                                      void *data)
2932 {
2933         int status = -EADDRINUSE;
2934
2935         xprt = xprt_get(xprt);
2936         xprt_switch_get(xps);
2937
2938         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2939                 goto out_err;
2940
2941         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
2942         if (status < 0)
2943                 goto out_err;
2944
2945         status = 1;
2946 out_err:
2947         xprt_put(xprt);
2948         xprt_switch_put(xps);
2949         if (status < 0)
2950                 pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not "
2951                         "added\n", status,
2952                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2953         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2954         return status;
2955 }
2956 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2957
2958 /**
2959  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2960  * @clnt: pointer to struct rpc_clnt
2961  * @xprtargs: pointer to struct xprt_create
2962  * @setup: callback to test and/or set up the connection
2963  * @data: pointer to setup function data
2964  *
2965  * Creates a new transport using the parameters set in args and
2966  * adds it to clnt.
2967  * If ping is set, then test that connectivity succeeds before
2968  * adding the new transport.
2969  *
2970  */
2971 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2972                 struct xprt_create *xprtargs,
2973                 int (*setup)(struct rpc_clnt *,
2974                         struct rpc_xprt_switch *,
2975                         struct rpc_xprt *,
2976                         void *),
2977                 void *data)
2978 {
2979         struct rpc_xprt_switch *xps;
2980         struct rpc_xprt *xprt;
2981         unsigned long connect_timeout;
2982         unsigned long reconnect_timeout;
2983         unsigned char resvport, reuseport;
2984         int ret = 0, ident;
2985
2986         rcu_read_lock();
2987         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2988         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2989         if (xps == NULL || xprt == NULL) {
2990                 rcu_read_unlock();
2991                 xprt_switch_put(xps);
2992                 return -EAGAIN;
2993         }
2994         resvport = xprt->resvport;
2995         reuseport = xprt->reuseport;
2996         connect_timeout = xprt->connect_timeout;
2997         reconnect_timeout = xprt->max_reconnect_timeout;
2998         ident = xprt->xprt_class->ident;
2999         rcu_read_unlock();
3000
3001         if (!xprtargs->ident)
3002                 xprtargs->ident = ident;
3003         xprt = xprt_create_transport(xprtargs);
3004         if (IS_ERR(xprt)) {
3005                 ret = PTR_ERR(xprt);
3006                 goto out_put_switch;
3007         }
3008         xprt->resvport = resvport;
3009         xprt->reuseport = reuseport;
3010         if (xprt->ops->set_connect_timeout != NULL)
3011                 xprt->ops->set_connect_timeout(xprt,
3012                                 connect_timeout,
3013                                 reconnect_timeout);
3014
3015         rpc_xprt_switch_set_roundrobin(xps);
3016         if (setup) {
3017                 ret = setup(clnt, xps, xprt, data);
3018                 if (ret != 0)
3019                         goto out_put_xprt;
3020         }
3021         rpc_xprt_switch_add_xprt(xps, xprt);
3022 out_put_xprt:
3023         xprt_put(xprt);
3024 out_put_switch:
3025         xprt_switch_put(xps);
3026         return ret;
3027 }
3028 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
3029
3030 static int rpc_xprt_probe_trunked(struct rpc_clnt *clnt,
3031                                   struct rpc_xprt *xprt,
3032                                   struct rpc_add_xprt_test *data)
3033 {
3034         struct rpc_xprt_switch *xps;
3035         struct rpc_xprt *main_xprt;
3036         int status = 0;
3037
3038         xprt_get(xprt);
3039
3040         rcu_read_lock();
3041         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3042         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3043         status = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3044                                    (struct sockaddr *)&main_xprt->addr);
3045         rcu_read_unlock();
3046         xprt_put(main_xprt);
3047         if (status || !test_bit(XPRT_OFFLINE, &xprt->state))
3048                 goto out;
3049
3050         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3051 out:
3052         xprt_put(xprt);
3053         xprt_switch_put(xps);
3054         return status;
3055 }
3056
3057 /* rpc_clnt_probe_trunked_xprt -- probe offlined transport for session trunking
3058  * @clnt rpc_clnt structure
3059  *
3060  * For each offlined transport found in the rpc_clnt structure call
3061  * the function rpc_xprt_probe_trunked() which will determine if this
3062  * transport still belongs to the trunking group.
3063  */
3064 void rpc_clnt_probe_trunked_xprts(struct rpc_clnt *clnt,
3065                                   struct rpc_add_xprt_test *data)
3066 {
3067         struct rpc_xprt_iter xpi;
3068         int ret;
3069
3070         ret = rpc_clnt_xprt_iter_offline_init(clnt, &xpi);
3071         if (ret)
3072                 return;
3073         for (;;) {
3074                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
3075
3076                 if (!xprt)
3077                         break;
3078                 ret = rpc_xprt_probe_trunked(clnt, xprt, data);
3079                 xprt_put(xprt);
3080                 if (ret < 0)
3081                         break;
3082                 xprt_iter_rewind(&xpi);
3083         }
3084         xprt_iter_destroy(&xpi);
3085 }
3086 EXPORT_SYMBOL_GPL(rpc_clnt_probe_trunked_xprts);
3087
3088 static int rpc_xprt_offline(struct rpc_clnt *clnt,
3089                             struct rpc_xprt *xprt,
3090                             void *data)
3091 {
3092         struct rpc_xprt *main_xprt;
3093         struct rpc_xprt_switch *xps;
3094         int err = 0;
3095
3096         xprt_get(xprt);
3097
3098         rcu_read_lock();
3099         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3100         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3101         err = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3102                                 (struct sockaddr *)&main_xprt->addr);
3103         rcu_read_unlock();
3104         xprt_put(main_xprt);
3105         if (err)
3106                 goto out;
3107
3108         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
3109                 err = -EINTR;
3110                 goto out;
3111         }
3112         xprt_set_offline_locked(xprt, xps);
3113
3114         xprt_release_write(xprt, NULL);
3115 out:
3116         xprt_put(xprt);
3117         xprt_switch_put(xps);
3118         return err;
3119 }
3120
3121 /* rpc_clnt_manage_trunked_xprts -- offline trunked transports
3122  * @clnt rpc_clnt structure
3123  *
3124  * For each active transport found in the rpc_clnt structure call
3125  * the function rpc_xprt_offline() which will identify trunked transports
3126  * and will mark them offline.
3127  */
3128 void rpc_clnt_manage_trunked_xprts(struct rpc_clnt *clnt)
3129 {
3130         rpc_clnt_iterate_for_each_xprt(clnt, rpc_xprt_offline, NULL);
3131 }
3132 EXPORT_SYMBOL_GPL(rpc_clnt_manage_trunked_xprts);
3133
3134 struct connect_timeout_data {
3135         unsigned long connect_timeout;
3136         unsigned long reconnect_timeout;
3137 };
3138
3139 static int
3140 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3141                 struct rpc_xprt *xprt,
3142                 void *data)
3143 {
3144         struct connect_timeout_data *timeo = data;
3145
3146         if (xprt->ops->set_connect_timeout)
3147                 xprt->ops->set_connect_timeout(xprt,
3148                                 timeo->connect_timeout,
3149                                 timeo->reconnect_timeout);
3150         return 0;
3151 }
3152
3153 void
3154 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3155                 unsigned long connect_timeout,
3156                 unsigned long reconnect_timeout)
3157 {
3158         struct connect_timeout_data timeout = {
3159                 .connect_timeout = connect_timeout,
3160                 .reconnect_timeout = reconnect_timeout,
3161         };
3162         rpc_clnt_iterate_for_each_xprt(clnt,
3163                         rpc_xprt_set_connect_timeout,
3164                         &timeout);
3165 }
3166 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3167
3168 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
3169 {
3170         rcu_read_lock();
3171         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3172         rcu_read_unlock();
3173 }
3174 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
3175
3176 void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3177 {
3178         struct rpc_xprt_switch *xps;
3179
3180         rcu_read_lock();
3181         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3182         rcu_read_unlock();
3183         xprt_set_online_locked(xprt, xps);
3184 }
3185
3186 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3187 {
3188         if (rpc_clnt_xprt_switch_has_addr(clnt,
3189                 (const struct sockaddr *)&xprt->addr)) {
3190                 return rpc_clnt_xprt_set_online(clnt, xprt);
3191         }
3192         rcu_read_lock();
3193         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3194                                  xprt);
3195         rcu_read_unlock();
3196 }
3197 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3198
3199 void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3200 {
3201         struct rpc_xprt_switch *xps;
3202
3203         rcu_read_lock();
3204         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3205         rpc_xprt_switch_remove_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3206                                     xprt, 0);
3207         xps->xps_nunique_destaddr_xprts--;
3208         rcu_read_unlock();
3209 }
3210 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_remove_xprt);
3211
3212 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3213                                    const struct sockaddr *sap)
3214 {
3215         struct rpc_xprt_switch *xps;
3216         bool ret;
3217
3218         rcu_read_lock();
3219         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3220         ret = rpc_xprt_switch_has_addr(xps, sap);
3221         rcu_read_unlock();
3222         return ret;
3223 }
3224 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3225
3226 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3227 static void rpc_show_header(void)
3228 {
3229         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3230                 "-timeout ---ops--\n");
3231 }
3232
3233 static void rpc_show_task(const struct rpc_clnt *clnt,
3234                           const struct rpc_task *task)
3235 {
3236         const char *rpc_waitq = "none";
3237
3238         if (RPC_IS_QUEUED(task))
3239                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3240
3241         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3242                 task->tk_pid, task->tk_flags, task->tk_status,
3243                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3244                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3245                 task->tk_action, rpc_waitq);
3246 }
3247
3248 void rpc_show_tasks(struct net *net)
3249 {
3250         struct rpc_clnt *clnt;
3251         struct rpc_task *task;
3252         int header = 0;
3253         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3254
3255         spin_lock(&sn->rpc_client_lock);
3256         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3257                 spin_lock(&clnt->cl_lock);
3258                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3259                         if (!header) {
3260                                 rpc_show_header();
3261                                 header++;
3262                         }
3263                         rpc_show_task(clnt, task);
3264                 }
3265                 spin_unlock(&clnt->cl_lock);
3266         }
3267         spin_unlock(&sn->rpc_client_lock);
3268 }
3269 #endif
3270
3271 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3272 static int
3273 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3274                 struct rpc_xprt *xprt,
3275                 void *dummy)
3276 {
3277         return xprt_enable_swap(xprt);
3278 }
3279
3280 int
3281 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3282 {
3283         while (clnt != clnt->cl_parent)
3284                 clnt = clnt->cl_parent;
3285         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3286                 return rpc_clnt_iterate_for_each_xprt(clnt,
3287                                 rpc_clnt_swap_activate_callback, NULL);
3288         return 0;
3289 }
3290 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3291
3292 static int
3293 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3294                 struct rpc_xprt *xprt,
3295                 void *dummy)
3296 {
3297         xprt_disable_swap(xprt);
3298         return 0;
3299 }
3300
3301 void
3302 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3303 {
3304         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3305                 rpc_clnt_iterate_for_each_xprt(clnt,
3306                                 rpc_clnt_swap_deactivate_callback, NULL);
3307 }
3308 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3309 #endif /* CONFIG_SUNRPC_SWAP */