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_alloc(&rpc_clids, 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_free(&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  * rpc_cancel_tasks - try to cancel a set of RPC tasks
 878  * @clnt: Pointer to RPC client
 879  * @error: RPC task error value to set
 880  * @fnmatch: Pointer to selector function
 881  * @data: User data
 882  *
 883  * Uses @fnmatch to define a set of RPC tasks that are to be cancelled.
 884  * The argument @error must be a negative error value.
 885  */
 886 unsigned long rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
 887                                bool (*fnmatch)(const struct rpc_task *,
 888                                                const void *),
 889                                const void *data)
 890 {
 891         struct rpc_task *task;
 892         unsigned long count = 0;
 893
 894         if (list_empty(&clnt->cl_tasks))
 895                 return 0;
 896         /*
 897          * Spin lock all_tasks to prevent changes...
 898          */
 899         spin_lock(&clnt->cl_lock);
 900         list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
 901                 if (!RPC_IS_ACTIVATED(task))
 902                         continue;
 903                 if (!fnmatch(task, data))
 904                         continue;
 905                 rpc_task_try_cancel(task, error);
 906                 count++;
 907         }
 908         spin_unlock(&clnt->cl_lock);
 909         return count;
 910 }
 911 EXPORT_SYMBOL_GPL(rpc_cancel_tasks);
 912
 913 static int rpc_clnt_disconnect_xprt(struct rpc_clnt *clnt,
 914                                     struct rpc_xprt *xprt, void *dummy)
 915 {
 916         if (xprt_connected(xprt))
 917                 xprt_force_disconnect(xprt);
 918         return 0;
 919 }
 920
 921 void rpc_clnt_disconnect(struct rpc_clnt *clnt)
 922 {
 923         rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_disconnect_xprt, NULL);
 924 }
 925 EXPORT_SYMBOL_GPL(rpc_clnt_disconnect);
 926
 927 /*
 928  * Properly shut down an RPC client, terminating all outstanding
 929  * requests.
 930  */
 931 void rpc_shutdown_client(struct rpc_clnt *clnt)
 932 {
 933         might_sleep();
 934
 935         trace_rpc_clnt_shutdown(clnt);
 936
 937         while (!list_empty(&clnt->cl_tasks)) {
 938                 rpc_killall_tasks(clnt);
 939                 wait_event_timeout(destroy_wait,
 940                         list_empty(&clnt->cl_tasks), 1*HZ);
 941         }
 942
 943         rpc_release_client(clnt);
 944 }
 945 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 946
 947 /*
 948  * Free an RPC client
 949  */
 950 static void rpc_free_client_work(struct work_struct *work)
 951 {
 952         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 953
 954         trace_rpc_clnt_free(clnt);
 955
 956         /* These might block on processes that might allocate memory,
 957          * so they cannot be called in rpciod, so they are handled separately
 958          * here.
 959          */
 960         rpc_sysfs_client_destroy(clnt);
 961         rpc_clnt_debugfs_unregister(clnt);
 962         rpc_free_clid(clnt);
 963         rpc_clnt_remove_pipedir(clnt);
 964         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 965
 966         kfree(clnt);
 967         rpciod_down();
 968 }
 969 static struct rpc_clnt *
 970 rpc_free_client(struct rpc_clnt *clnt)
 971 {
 972         struct rpc_clnt *parent = NULL;
 973
 974         trace_rpc_clnt_release(clnt);
 975         if (clnt->cl_parent != clnt)
 976                 parent = clnt->cl_parent;
 977         rpc_unregister_client(clnt);
 978         rpc_free_iostats(clnt->cl_metrics);
 979         clnt->cl_metrics = NULL;
 980         xprt_iter_destroy(&clnt->cl_xpi);
 981         put_cred(clnt->cl_cred);
 982
 983         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 984         schedule_work(&clnt->cl_work);
 985         return parent;
 986 }
 987
 988 /*
 989  * Free an RPC client
 990  */
 991 static struct rpc_clnt *
 992 rpc_free_auth(struct rpc_clnt *clnt)
 993 {
 994         /*
 995          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 996          *       release remaining GSS contexts. This mechanism ensures
 997          *       that it can do so safely.
 998          */
 999         if (clnt->cl_auth != NULL) {
1000                 rpcauth_release(clnt->cl_auth);
1001                 clnt->cl_auth = NULL;
1002         }
1003         if (refcount_dec_and_test(&clnt->cl_count))
1004                 return rpc_free_client(clnt);
1005         return NULL;
1006 }
1007
1008 /*
1009  * Release reference to the RPC client
1010  */
1011 void
1012 rpc_release_client(struct rpc_clnt *clnt)
1013 {
1014         do {
1015                 if (list_empty(&clnt->cl_tasks))
1016                         wake_up(&destroy_wait);
1017                 if (refcount_dec_not_one(&clnt->cl_count))
1018                         break;
1019                 clnt = rpc_free_auth(clnt);
1020         } while (clnt != NULL);
1021 }
1022 EXPORT_SYMBOL_GPL(rpc_release_client);
1023
1024 /**
1025  * rpc_bind_new_program - bind a new RPC program to an existing client
1026  * @old: old rpc_client
1027  * @program: rpc program to set
1028  * @vers: rpc program version
1029  *
1030  * Clones the rpc client and sets up a new RPC program. This is mainly
1031  * of use for enabling different RPC programs to share the same transport.
1032  * The Sun NFSv2/v3 ACL protocol can do this.
1033  */
1034 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
1035                                       const struct rpc_program *program,
1036                                       u32 vers)
1037 {
1038         struct rpc_create_args args = {
1039                 .program        = program,
1040                 .prognumber     = program->number,
1041                 .version        = vers,
1042                 .authflavor     = old->cl_auth->au_flavor,
1043                 .cred           = old->cl_cred,
1044         };
1045         struct rpc_clnt *clnt;
1046         int err;
1047
1048         clnt = __rpc_clone_client(&args, old);
1049         if (IS_ERR(clnt))
1050                 goto out;
1051         err = rpc_ping(clnt);
1052         if (err != 0) {
1053                 rpc_shutdown_client(clnt);
1054                 clnt = ERR_PTR(err);
1055         }
1056 out:
1057         return clnt;
1058 }
1059 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
1060
1061 struct rpc_xprt *
1062 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1063 {
1064         struct rpc_xprt_switch *xps;
1065
1066         if (!xprt)
1067                 return NULL;
1068         rcu_read_lock();
1069         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1070         atomic_long_inc(&xps->xps_queuelen);
1071         rcu_read_unlock();
1072         atomic_long_inc(&xprt->queuelen);
1073
1074         return xprt;
1075 }
1076
1077 static void
1078 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1079 {
1080         struct rpc_xprt_switch *xps;
1081
1082         atomic_long_dec(&xprt->queuelen);
1083         rcu_read_lock();
1084         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1085         atomic_long_dec(&xps->xps_queuelen);
1086         rcu_read_unlock();
1087
1088         xprt_put(xprt);
1089 }
1090
1091 void rpc_task_release_transport(struct rpc_task *task)
1092 {
1093         struct rpc_xprt *xprt = task->tk_xprt;
1094
1095         if (xprt) {
1096                 task->tk_xprt = NULL;
1097                 if (task->tk_client)
1098                         rpc_task_release_xprt(task->tk_client, xprt);
1099                 else
1100                         xprt_put(xprt);
1101         }
1102 }
1103 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1104
1105 void rpc_task_release_client(struct rpc_task *task)
1106 {
1107         struct rpc_clnt *clnt = task->tk_client;
1108
1109         rpc_task_release_transport(task);
1110         if (clnt != NULL) {
1111                 /* Remove from client task list */
1112                 spin_lock(&clnt->cl_lock);
1113                 list_del(&task->tk_task);
1114                 spin_unlock(&clnt->cl_lock);
1115                 task->tk_client = NULL;
1116
1117                 rpc_release_client(clnt);
1118         }
1119 }
1120
1121 static struct rpc_xprt *
1122 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1123 {
1124         struct rpc_xprt *xprt;
1125
1126         rcu_read_lock();
1127         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1128         rcu_read_unlock();
1129         return rpc_task_get_xprt(clnt, xprt);
1130 }
1131
1132 static struct rpc_xprt *
1133 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1134 {
1135         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1136 }
1137
1138 static
1139 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1140 {
1141         if (task->tk_xprt) {
1142                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1143                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1144                         return;
1145                 xprt_release(task);
1146                 xprt_put(task->tk_xprt);
1147         }
1148         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1149                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1150         else
1151                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1152 }
1153
1154 static
1155 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1156 {
1157         rpc_task_set_transport(task, clnt);
1158         task->tk_client = clnt;
1159         refcount_inc(&clnt->cl_count);
1160         if (clnt->cl_softrtry)
1161                 task->tk_flags |= RPC_TASK_SOFT;
1162         if (clnt->cl_softerr)
1163                 task->tk_flags |= RPC_TASK_TIMEOUT;
1164         if (clnt->cl_noretranstimeo)
1165                 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1166         /* Add to the client's list of all tasks */
1167         spin_lock(&clnt->cl_lock);
1168         list_add_tail(&task->tk_task, &clnt->cl_tasks);
1169         spin_unlock(&clnt->cl_lock);
1170 }
1171
1172 static void
1173 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1174 {
1175         if (msg != NULL) {
1176                 task->tk_msg.rpc_proc = msg->rpc_proc;
1177                 task->tk_msg.rpc_argp = msg->rpc_argp;
1178                 task->tk_msg.rpc_resp = msg->rpc_resp;
1179                 task->tk_msg.rpc_cred = msg->rpc_cred;
1180                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1181                         get_cred(task->tk_msg.rpc_cred);
1182         }
1183 }
1184
1185 /*
1186  * Default callback for async RPC calls
1187  */
1188 static void
1189 rpc_default_callback(struct rpc_task *task, void *data)
1190 {
1191 }
1192
1193 static const struct rpc_call_ops rpc_default_ops = {
1194         .rpc_call_done = rpc_default_callback,
1195 };
1196
1197 /**
1198  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1199  * @task_setup_data: pointer to task initialisation data
1200  */
1201 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1202 {
1203         struct rpc_task *task;
1204
1205         task = rpc_new_task(task_setup_data);
1206         if (IS_ERR(task))
1207                 return task;
1208
1209         if (!RPC_IS_ASYNC(task))
1210                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1211
1212         rpc_task_set_client(task, task_setup_data->rpc_client);
1213         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1214
1215         if (task->tk_action == NULL)
1216                 rpc_call_start(task);
1217
1218         atomic_inc(&task->tk_count);
1219         rpc_execute(task);
1220         return task;
1221 }
1222 EXPORT_SYMBOL_GPL(rpc_run_task);
1223
1224 /**
1225  * rpc_call_sync - Perform a synchronous RPC call
1226  * @clnt: pointer to RPC client
1227  * @msg: RPC call parameters
1228  * @flags: RPC call flags
1229  */
1230 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1231 {
1232         struct rpc_task *task;
1233         struct rpc_task_setup task_setup_data = {
1234                 .rpc_client = clnt,
1235                 .rpc_message = msg,
1236                 .callback_ops = &rpc_default_ops,
1237                 .flags = flags,
1238         };
1239         int status;
1240
1241         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1242         if (flags & RPC_TASK_ASYNC) {
1243                 rpc_release_calldata(task_setup_data.callback_ops,
1244                         task_setup_data.callback_data);
1245                 return -EINVAL;
1246         }
1247
1248         task = rpc_run_task(&task_setup_data);
1249         if (IS_ERR(task))
1250                 return PTR_ERR(task);
1251         status = task->tk_status;
1252         rpc_put_task(task);
1253         return status;
1254 }
1255 EXPORT_SYMBOL_GPL(rpc_call_sync);
1256
1257 /**
1258  * rpc_call_async - Perform an asynchronous RPC call
1259  * @clnt: pointer to RPC client
1260  * @msg: RPC call parameters
1261  * @flags: RPC call flags
1262  * @tk_ops: RPC call ops
1263  * @data: user call data
1264  */
1265 int
1266 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1267                const struct rpc_call_ops *tk_ops, void *data)
1268 {
1269         struct rpc_task *task;
1270         struct rpc_task_setup task_setup_data = {
1271                 .rpc_client = clnt,
1272                 .rpc_message = msg,
1273                 .callback_ops = tk_ops,
1274                 .callback_data = data,
1275                 .flags = flags|RPC_TASK_ASYNC,
1276         };
1277
1278         task = rpc_run_task(&task_setup_data);
1279         if (IS_ERR(task))
1280                 return PTR_ERR(task);
1281         rpc_put_task(task);
1282         return 0;
1283 }
1284 EXPORT_SYMBOL_GPL(rpc_call_async);
1285
1286 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1287 static void call_bc_encode(struct rpc_task *task);
1288
1289 /**
1290  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1291  * rpc_execute against it
1292  * @req: RPC request
1293  */
1294 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1295 {
1296         struct rpc_task *task;
1297         struct rpc_task_setup task_setup_data = {
1298                 .callback_ops = &rpc_default_ops,
1299                 .flags = RPC_TASK_SOFTCONN |
1300                         RPC_TASK_NO_RETRANS_TIMEOUT,
1301         };
1302
1303         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1304         /*
1305          * Create an rpc_task to send the data
1306          */
1307         task = rpc_new_task(&task_setup_data);
1308         if (IS_ERR(task)) {
1309                 xprt_free_bc_request(req);
1310                 return task;
1311         }
1312
1313         xprt_init_bc_request(req, task);
1314
1315         task->tk_action = call_bc_encode;
1316         atomic_inc(&task->tk_count);
1317         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1318         rpc_execute(task);
1319
1320         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1321         return task;
1322 }
1323 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1324
1325 /**
1326  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1327  * @req: RPC request to prepare
1328  * @pages: vector of struct page pointers
1329  * @base: offset in first page where receive should start, in bytes
1330  * @len: expected size of the upper layer data payload, in bytes
1331  * @hdrsize: expected size of upper layer reply header, in XDR words
1332  *
1333  */
1334 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1335                              unsigned int base, unsigned int len,
1336                              unsigned int hdrsize)
1337 {
1338         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1339
1340         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1341         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1342 }
1343 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1344
1345 void
1346 rpc_call_start(struct rpc_task *task)
1347 {
1348         task->tk_action = call_start;
1349 }
1350 EXPORT_SYMBOL_GPL(rpc_call_start);
1351
1352 /**
1353  * rpc_peeraddr - extract remote peer address from clnt's xprt
1354  * @clnt: RPC client structure
1355  * @buf: target buffer
1356  * @bufsize: length of target buffer
1357  *
1358  * Returns the number of bytes that are actually in the stored address.
1359  */
1360 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1361 {
1362         size_t bytes;
1363         struct rpc_xprt *xprt;
1364
1365         rcu_read_lock();
1366         xprt = rcu_dereference(clnt->cl_xprt);
1367
1368         bytes = xprt->addrlen;
1369         if (bytes > bufsize)
1370                 bytes = bufsize;
1371         memcpy(buf, &xprt->addr, bytes);
1372         rcu_read_unlock();
1373
1374         return bytes;
1375 }
1376 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1377
1378 /**
1379  * rpc_peeraddr2str - return remote peer address in printable format
1380  * @clnt: RPC client structure
1381  * @format: address format
1382  *
1383  * NB: the lifetime of the memory referenced by the returned pointer is
1384  * the same as the rpc_xprt itself.  As long as the caller uses this
1385  * pointer, it must hold the RCU read lock.
1386  */
1387 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1388                              enum rpc_display_format_t format)
1389 {
1390         struct rpc_xprt *xprt;
1391
1392         xprt = rcu_dereference(clnt->cl_xprt);
1393
1394         if (xprt->address_strings[format] != NULL)
1395                 return xprt->address_strings[format];
1396         else
1397                 return "unprintable";
1398 }
1399 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1400
1401 static const struct sockaddr_in rpc_inaddr_loopback = {
1402         .sin_family             = AF_INET,
1403         .sin_addr.s_addr        = htonl(INADDR_ANY),
1404 };
1405
1406 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1407         .sin6_family            = AF_INET6,
1408         .sin6_addr              = IN6ADDR_ANY_INIT,
1409 };
1410
1411 /*
1412  * Try a getsockname() on a connected datagram socket.  Using a
1413  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1414  * This conserves the ephemeral port number space.
1415  *
1416  * Returns zero and fills in "buf" if successful; otherwise, a
1417  * negative errno is returned.
1418  */
1419 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1420                         struct sockaddr *buf)
1421 {
1422         struct socket *sock;
1423         int err;
1424
1425         err = __sock_create(net, sap->sa_family,
1426                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1427         if (err < 0) {
1428                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1429                 goto out;
1430         }
1431
1432         switch (sap->sa_family) {
1433         case AF_INET:
1434                 err = kernel_bind(sock,
1435                                 (struct sockaddr *)&rpc_inaddr_loopback,
1436                                 sizeof(rpc_inaddr_loopback));
1437                 break;
1438         case AF_INET6:
1439                 err = kernel_bind(sock,
1440                                 (struct sockaddr *)&rpc_in6addr_loopback,
1441                                 sizeof(rpc_in6addr_loopback));
1442                 break;
1443         default:
1444                 err = -EAFNOSUPPORT;
1445                 goto out_release;
1446         }
1447         if (err < 0) {
1448                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1449                 goto out_release;
1450         }
1451
1452         err = kernel_connect(sock, sap, salen, 0);
1453         if (err < 0) {
1454                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1455                 goto out_release;
1456         }
1457
1458         err = kernel_getsockname(sock, buf);
1459         if (err < 0) {
1460                 dprintk("RPC:       getsockname failed (%d)\n", err);
1461                 goto out_release;
1462         }
1463
1464         err = 0;
1465         if (buf->sa_family == AF_INET6) {
1466                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1467                 sin6->sin6_scope_id = 0;
1468         }
1469         dprintk("RPC:       %s succeeded\n", __func__);
1470
1471 out_release:
1472         sock_release(sock);
1473 out:
1474         return err;
1475 }
1476
1477 /*
1478  * Scraping a connected socket failed, so we don't have a useable
1479  * local address.  Fallback: generate an address that will prevent
1480  * the server from calling us back.
1481  *
1482  * Returns zero and fills in "buf" if successful; otherwise, a
1483  * negative errno is returned.
1484  */
1485 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1486 {
1487         switch (family) {
1488         case AF_INET:
1489                 if (buflen < sizeof(rpc_inaddr_loopback))
1490                         return -EINVAL;
1491                 memcpy(buf, &rpc_inaddr_loopback,
1492                                 sizeof(rpc_inaddr_loopback));
1493                 break;
1494         case AF_INET6:
1495                 if (buflen < sizeof(rpc_in6addr_loopback))
1496                         return -EINVAL;
1497                 memcpy(buf, &rpc_in6addr_loopback,
1498                                 sizeof(rpc_in6addr_loopback));
1499                 break;
1500         default:
1501                 dprintk("RPC:       %s: address family not supported\n",
1502                         __func__);
1503                 return -EAFNOSUPPORT;
1504         }
1505         dprintk("RPC:       %s: succeeded\n", __func__);
1506         return 0;
1507 }
1508
1509 /**
1510  * rpc_localaddr - discover local endpoint address for an RPC client
1511  * @clnt: RPC client structure
1512  * @buf: target buffer
1513  * @buflen: size of target buffer, in bytes
1514  *
1515  * Returns zero and fills in "buf" and "buflen" if successful;
1516  * otherwise, a negative errno is returned.
1517  *
1518  * This works even if the underlying transport is not currently connected,
1519  * or if the upper layer never previously provided a source address.
1520  *
1521  * The result of this function call is transient: multiple calls in
1522  * succession may give different results, depending on how local
1523  * networking configuration changes over time.
1524  */
1525 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1526 {
1527         struct sockaddr_storage address;
1528         struct sockaddr *sap = (struct sockaddr *)&address;
1529         struct rpc_xprt *xprt;
1530         struct net *net;
1531         size_t salen;
1532         int err;
1533
1534         rcu_read_lock();
1535         xprt = rcu_dereference(clnt->cl_xprt);
1536         salen = xprt->addrlen;
1537         memcpy(sap, &xprt->addr, salen);
1538         net = get_net(xprt->xprt_net);
1539         rcu_read_unlock();
1540
1541         rpc_set_port(sap, 0);
1542         err = rpc_sockname(net, sap, salen, buf);
1543         put_net(net);
1544         if (err != 0)
1545                 /* Couldn't discover local address, return ANYADDR */
1546                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1547         return 0;
1548 }
1549 EXPORT_SYMBOL_GPL(rpc_localaddr);
1550
1551 void
1552 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1553 {
1554         struct rpc_xprt *xprt;
1555
1556         rcu_read_lock();
1557         xprt = rcu_dereference(clnt->cl_xprt);
1558         if (xprt->ops->set_buffer_size)
1559                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1560         rcu_read_unlock();
1561 }
1562 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1563
1564 /**
1565  * rpc_net_ns - Get the network namespace for this RPC client
1566  * @clnt: RPC client to query
1567  *
1568  */
1569 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1570 {
1571         struct net *ret;
1572
1573         rcu_read_lock();
1574         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1575         rcu_read_unlock();
1576         return ret;
1577 }
1578 EXPORT_SYMBOL_GPL(rpc_net_ns);
1579
1580 /**
1581  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1582  * @clnt: RPC client to query
1583  *
1584  * For stream transports, this is one RPC record fragment (see RFC
1585  * 1831), as we don't support multi-record requests yet.  For datagram
1586  * transports, this is the size of an IP packet minus the IP, UDP, and
1587  * RPC header sizes.
1588  */
1589 size_t rpc_max_payload(struct rpc_clnt *clnt)
1590 {
1591         size_t ret;
1592
1593         rcu_read_lock();
1594         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1595         rcu_read_unlock();
1596         return ret;
1597 }
1598 EXPORT_SYMBOL_GPL(rpc_max_payload);
1599
1600 /**
1601  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1602  * @clnt: RPC client to query
1603  */
1604 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1605 {
1606         struct rpc_xprt *xprt;
1607         size_t ret;
1608
1609         rcu_read_lock();
1610         xprt = rcu_dereference(clnt->cl_xprt);
1611         ret = xprt->ops->bc_maxpayload(xprt);
1612         rcu_read_unlock();
1613         return ret;
1614 }
1615 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1616
1617 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1618 {
1619         struct rpc_xprt *xprt;
1620         unsigned int ret;
1621
1622         rcu_read_lock();
1623         xprt = rcu_dereference(clnt->cl_xprt);
1624         ret = xprt->ops->bc_num_slots(xprt);
1625         rcu_read_unlock();
1626         return ret;
1627 }
1628 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1629
1630 /**
1631  * rpc_force_rebind - force transport to check that remote port is unchanged
1632  * @clnt: client to rebind
1633  *
1634  */
1635 void rpc_force_rebind(struct rpc_clnt *clnt)
1636 {
1637         if (clnt->cl_autobind) {
1638                 rcu_read_lock();
1639                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1640                 rcu_read_unlock();
1641         }
1642 }
1643 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1644
1645 static int
1646 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1647 {
1648         task->tk_status = 0;
1649         task->tk_rpc_status = 0;
1650         task->tk_action = action;
1651         return 1;
1652 }
1653
1654 /*
1655  * Restart an (async) RPC call. Usually called from within the
1656  * exit handler.
1657  */
1658 int
1659 rpc_restart_call(struct rpc_task *task)
1660 {
1661         return __rpc_restart_call(task, call_start);
1662 }
1663 EXPORT_SYMBOL_GPL(rpc_restart_call);
1664
1665 /*
1666  * Restart an (async) RPC call from the call_prepare state.
1667  * Usually called from within the exit handler.
1668  */
1669 int
1670 rpc_restart_call_prepare(struct rpc_task *task)
1671 {
1672         if (task->tk_ops->rpc_call_prepare != NULL)
1673                 return __rpc_restart_call(task, rpc_prepare_task);
1674         return rpc_restart_call(task);
1675 }
1676 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1677
1678 const char
1679 *rpc_proc_name(const struct rpc_task *task)
1680 {
1681         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1682
1683         if (proc) {
1684                 if (proc->p_name)
1685                         return proc->p_name;
1686                 else
1687                         return "NULL";
1688         } else
1689                 return "no proc";
1690 }
1691
1692 static void
1693 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1694 {
1695         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1696         rpc_task_set_rpc_status(task, rpc_status);
1697         rpc_exit(task, tk_status);
1698 }
1699
1700 static void
1701 rpc_call_rpcerror(struct rpc_task *task, int status)
1702 {
1703         __rpc_call_rpcerror(task, status, status);
1704 }
1705
1706 /*
1707  * 0.  Initial state
1708  *
1709  *     Other FSM states can be visited zero or more times, but
1710  *     this state is visited exactly once for each RPC.
1711  */
1712 static void
1713 call_start(struct rpc_task *task)
1714 {
1715         struct rpc_clnt *clnt = task->tk_client;
1716         int idx = task->tk_msg.rpc_proc->p_statidx;
1717
1718         trace_rpc_request(task);
1719
1720         /* Increment call count (version might not be valid for ping) */
1721         if (clnt->cl_program->version[clnt->cl_vers])
1722                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1723         clnt->cl_stats->rpccnt++;
1724         task->tk_action = call_reserve;
1725         rpc_task_set_transport(task, clnt);
1726 }
1727
1728 /*
1729  * 1.   Reserve an RPC call slot
1730  */
1731 static void
1732 call_reserve(struct rpc_task *task)
1733 {
1734         task->tk_status  = 0;
1735         task->tk_action  = call_reserveresult;
1736         xprt_reserve(task);
1737 }
1738
1739 static void call_retry_reserve(struct rpc_task *task);
1740
1741 /*
1742  * 1b.  Grok the result of xprt_reserve()
1743  */
1744 static void
1745 call_reserveresult(struct rpc_task *task)
1746 {
1747         int status = task->tk_status;
1748
1749         /*
1750          * After a call to xprt_reserve(), we must have either
1751          * a request slot or else an error status.
1752          */
1753         task->tk_status = 0;
1754         if (status >= 0) {
1755                 if (task->tk_rqstp) {
1756                         task->tk_action = call_refresh;
1757                         return;
1758                 }
1759
1760                 rpc_call_rpcerror(task, -EIO);
1761                 return;
1762         }
1763
1764         switch (status) {
1765         case -ENOMEM:
1766                 rpc_delay(task, HZ >> 2);
1767                 fallthrough;
1768         case -EAGAIN:   /* woken up; retry */
1769                 task->tk_action = call_retry_reserve;
1770                 return;
1771         default:
1772                 rpc_call_rpcerror(task, status);
1773         }
1774 }
1775
1776 /*
1777  * 1c.  Retry reserving an RPC call slot
1778  */
1779 static void
1780 call_retry_reserve(struct rpc_task *task)
1781 {
1782         task->tk_status  = 0;
1783         task->tk_action  = call_reserveresult;
1784         xprt_retry_reserve(task);
1785 }
1786
1787 /*
1788  * 2.   Bind and/or refresh the credentials
1789  */
1790 static void
1791 call_refresh(struct rpc_task *task)
1792 {
1793         task->tk_action = call_refreshresult;
1794         task->tk_status = 0;
1795         task->tk_client->cl_stats->rpcauthrefresh++;
1796         rpcauth_refreshcred(task);
1797 }
1798
1799 /*
1800  * 2a.  Process the results of a credential refresh
1801  */
1802 static void
1803 call_refreshresult(struct rpc_task *task)
1804 {
1805         int status = task->tk_status;
1806
1807         task->tk_status = 0;
1808         task->tk_action = call_refresh;
1809         switch (status) {
1810         case 0:
1811                 if (rpcauth_uptodatecred(task)) {
1812                         task->tk_action = call_allocate;
1813                         return;
1814                 }
1815                 /* Use rate-limiting and a max number of retries if refresh
1816                  * had status 0 but failed to update the cred.
1817                  */
1818                 fallthrough;
1819         case -ETIMEDOUT:
1820                 rpc_delay(task, 3*HZ);
1821                 fallthrough;
1822         case -EAGAIN:
1823                 status = -EACCES;
1824                 fallthrough;
1825         case -EKEYEXPIRED:
1826                 if (!task->tk_cred_retry)
1827                         break;
1828                 task->tk_cred_retry--;
1829                 trace_rpc_retry_refresh_status(task);
1830                 return;
1831         case -ENOMEM:
1832                 rpc_delay(task, HZ >> 4);
1833                 return;
1834         }
1835         trace_rpc_refresh_status(task);
1836         rpc_call_rpcerror(task, status);
1837 }
1838
1839 /*
1840  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1841  *      (Note: buffer memory is freed in xprt_release).
1842  */
1843 static void
1844 call_allocate(struct rpc_task *task)
1845 {
1846         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1847         struct rpc_rqst *req = task->tk_rqstp;
1848         struct rpc_xprt *xprt = req->rq_xprt;
1849         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1850         int status;
1851
1852         task->tk_status = 0;
1853         task->tk_action = call_encode;
1854
1855         if (req->rq_buffer)
1856                 return;
1857
1858         if (proc->p_proc != 0) {
1859                 BUG_ON(proc->p_arglen == 0);
1860                 if (proc->p_decode != NULL)
1861                         BUG_ON(proc->p_replen == 0);
1862         }
1863
1864         /*
1865          * Calculate the size (in quads) of the RPC call
1866          * and reply headers, and convert both values
1867          * to byte sizes.
1868          */
1869         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1870                            proc->p_arglen;
1871         req->rq_callsize <<= 2;
1872         /*
1873          * Note: the reply buffer must at minimum allocate enough space
1874          * for the 'struct accepted_reply' from RFC5531.
1875          */
1876         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1877                         max_t(size_t, proc->p_replen, 2);
1878         req->rq_rcvsize <<= 2;
1879
1880         status = xprt->ops->buf_alloc(task);
1881         trace_rpc_buf_alloc(task, status);
1882         if (status == 0)
1883                 return;
1884         if (status != -ENOMEM) {
1885                 rpc_call_rpcerror(task, status);
1886                 return;
1887         }
1888
1889         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1890                 task->tk_action = call_allocate;
1891                 rpc_delay(task, HZ>>4);
1892                 return;
1893         }
1894
1895         rpc_call_rpcerror(task, -ERESTARTSYS);
1896 }
1897
1898 static int
1899 rpc_task_need_encode(struct rpc_task *task)
1900 {
1901         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1902                 (!(task->tk_flags & RPC_TASK_SENT) ||
1903                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1904                  xprt_request_need_retransmit(task));
1905 }
1906
1907 static void
1908 rpc_xdr_encode(struct rpc_task *task)
1909 {
1910         struct rpc_rqst *req = task->tk_rqstp;
1911         struct xdr_stream xdr;
1912
1913         xdr_buf_init(&req->rq_snd_buf,
1914                      req->rq_buffer,
1915                      req->rq_callsize);
1916         xdr_buf_init(&req->rq_rcv_buf,
1917                      req->rq_rbuffer,
1918                      req->rq_rcvsize);
1919
1920         req->rq_reply_bytes_recvd = 0;
1921         req->rq_snd_buf.head[0].iov_len = 0;
1922         xdr_init_encode(&xdr, &req->rq_snd_buf,
1923                         req->rq_snd_buf.head[0].iov_base, req);
1924         if (rpc_encode_header(task, &xdr))
1925                 return;
1926
1927         task->tk_status = rpcauth_wrap_req(task, &xdr);
1928 }
1929
1930 /*
1931  * 3.   Encode arguments of an RPC call
1932  */
1933 static void
1934 call_encode(struct rpc_task *task)
1935 {
1936         if (!rpc_task_need_encode(task))
1937                 goto out;
1938
1939         /* Dequeue task from the receive queue while we're encoding */
1940         xprt_request_dequeue_xprt(task);
1941         /* Encode here so that rpcsec_gss can use correct sequence number. */
1942         rpc_xdr_encode(task);
1943         /* Add task to reply queue before transmission to avoid races */
1944         if (task->tk_status == 0 && rpc_reply_expected(task))
1945                 task->tk_status = xprt_request_enqueue_receive(task);
1946         /* Did the encode result in an error condition? */
1947         if (task->tk_status != 0) {
1948                 /* Was the error nonfatal? */
1949                 switch (task->tk_status) {
1950                 case -EAGAIN:
1951                 case -ENOMEM:
1952                         rpc_delay(task, HZ >> 4);
1953                         break;
1954                 case -EKEYEXPIRED:
1955                         if (!task->tk_cred_retry) {
1956                                 rpc_call_rpcerror(task, task->tk_status);
1957                         } else {
1958                                 task->tk_action = call_refresh;
1959                                 task->tk_cred_retry--;
1960                                 trace_rpc_retry_refresh_status(task);
1961                         }
1962                         break;
1963                 default:
1964                         rpc_call_rpcerror(task, task->tk_status);
1965                 }
1966                 return;
1967         }
1968
1969         xprt_request_enqueue_transmit(task);
1970 out:
1971         task->tk_action = call_transmit;
1972         /* Check that the connection is OK */
1973         if (!xprt_bound(task->tk_xprt))
1974                 task->tk_action = call_bind;
1975         else if (!xprt_connected(task->tk_xprt))
1976                 task->tk_action = call_connect;
1977 }
1978
1979 /*
1980  * Helpers to check if the task was already transmitted, and
1981  * to take action when that is the case.
1982  */
1983 static bool
1984 rpc_task_transmitted(struct rpc_task *task)
1985 {
1986         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1987 }
1988
1989 static void
1990 rpc_task_handle_transmitted(struct rpc_task *task)
1991 {
1992         xprt_end_transmit(task);
1993         task->tk_action = call_transmit_status;
1994 }
1995
1996 /*
1997  * 4.   Get the server port number if not yet set
1998  */
1999 static void
2000 call_bind(struct rpc_task *task)
2001 {
2002         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2003
2004         if (rpc_task_transmitted(task)) {
2005                 rpc_task_handle_transmitted(task);
2006                 return;
2007         }
2008
2009         if (xprt_bound(xprt)) {
2010                 task->tk_action = call_connect;
2011                 return;
2012         }
2013
2014         task->tk_action = call_bind_status;
2015         if (!xprt_prepare_transmit(task))
2016                 return;
2017
2018         xprt->ops->rpcbind(task);
2019 }
2020
2021 /*
2022  * 4a.  Sort out bind result
2023  */
2024 static void
2025 call_bind_status(struct rpc_task *task)
2026 {
2027         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2028         int status = -EIO;
2029
2030         if (rpc_task_transmitted(task)) {
2031                 rpc_task_handle_transmitted(task);
2032                 return;
2033         }
2034
2035         if (task->tk_status >= 0)
2036                 goto out_next;
2037         if (xprt_bound(xprt)) {
2038                 task->tk_status = 0;
2039                 goto out_next;
2040         }
2041
2042         switch (task->tk_status) {
2043         case -ENOMEM:
2044                 rpc_delay(task, HZ >> 2);
2045                 goto retry_timeout;
2046         case -EACCES:
2047                 trace_rpcb_prog_unavail_err(task);
2048                 /* fail immediately if this is an RPC ping */
2049                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2050                         status = -EOPNOTSUPP;
2051                         break;
2052                 }
2053                 rpc_delay(task, 3*HZ);
2054                 goto retry_timeout;
2055         case -ENOBUFS:
2056                 rpc_delay(task, HZ >> 2);
2057                 goto retry_timeout;
2058         case -EAGAIN:
2059                 goto retry_timeout;
2060         case -ETIMEDOUT:
2061                 trace_rpcb_timeout_err(task);
2062                 goto retry_timeout;
2063         case -EPFNOSUPPORT:
2064                 /* server doesn't support any rpcbind version we know of */
2065                 trace_rpcb_bind_version_err(task);
2066                 break;
2067         case -EPROTONOSUPPORT:
2068                 trace_rpcb_bind_version_err(task);
2069                 goto retry_timeout;
2070         case -ECONNREFUSED:             /* connection problems */
2071         case -ECONNRESET:
2072         case -ECONNABORTED:
2073         case -ENOTCONN:
2074         case -EHOSTDOWN:
2075         case -ENETDOWN:
2076         case -EHOSTUNREACH:
2077         case -ENETUNREACH:
2078         case -EPIPE:
2079                 trace_rpcb_unreachable_err(task);
2080                 if (!RPC_IS_SOFTCONN(task)) {
2081                         rpc_delay(task, 5*HZ);
2082                         goto retry_timeout;
2083                 }
2084                 status = task->tk_status;
2085                 break;
2086         default:
2087                 trace_rpcb_unrecognized_err(task);
2088         }
2089
2090         rpc_call_rpcerror(task, status);
2091         return;
2092 out_next:
2093         task->tk_action = call_connect;
2094         return;
2095 retry_timeout:
2096         task->tk_status = 0;
2097         task->tk_action = call_bind;
2098         rpc_check_timeout(task);
2099 }
2100
2101 /*
2102  * 4b.  Connect to the RPC server
2103  */
2104 static void
2105 call_connect(struct rpc_task *task)
2106 {
2107         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2108
2109         if (rpc_task_transmitted(task)) {
2110                 rpc_task_handle_transmitted(task);
2111                 return;
2112         }
2113
2114         if (xprt_connected(xprt)) {
2115                 task->tk_action = call_transmit;
2116                 return;
2117         }
2118
2119         task->tk_action = call_connect_status;
2120         if (task->tk_status < 0)
2121                 return;
2122         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2123                 rpc_call_rpcerror(task, -ENOTCONN);
2124                 return;
2125         }
2126         if (!xprt_prepare_transmit(task))
2127                 return;
2128         xprt_connect(task);
2129 }
2130
2131 /*
2132  * 4c.  Sort out connect result
2133  */
2134 static void
2135 call_connect_status(struct rpc_task *task)
2136 {
2137         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2138         struct rpc_clnt *clnt = task->tk_client;
2139         int status = task->tk_status;
2140
2141         if (rpc_task_transmitted(task)) {
2142                 rpc_task_handle_transmitted(task);
2143                 return;
2144         }
2145
2146         trace_rpc_connect_status(task);
2147
2148         if (task->tk_status == 0) {
2149                 clnt->cl_stats->netreconn++;
2150                 goto out_next;
2151         }
2152         if (xprt_connected(xprt)) {
2153                 task->tk_status = 0;
2154                 goto out_next;
2155         }
2156
2157         task->tk_status = 0;
2158         switch (status) {
2159         case -ECONNREFUSED:
2160                 /* A positive refusal suggests a rebind is needed. */
2161                 if (RPC_IS_SOFTCONN(task))
2162                         break;
2163                 if (clnt->cl_autobind) {
2164                         rpc_force_rebind(clnt);
2165                         goto out_retry;
2166                 }
2167                 fallthrough;
2168         case -ECONNRESET:
2169         case -ECONNABORTED:
2170         case -ENETDOWN:
2171         case -ENETUNREACH:
2172         case -EHOSTUNREACH:
2173         case -EPIPE:
2174         case -EPROTO:
2175                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2176                                             task->tk_rqstp->rq_connect_cookie);
2177                 if (RPC_IS_SOFTCONN(task))
2178                         break;
2179                 /* retry with existing socket, after a delay */
2180                 rpc_delay(task, 3*HZ);
2181                 fallthrough;
2182         case -EADDRINUSE:
2183         case -ENOTCONN:
2184         case -EAGAIN:
2185         case -ETIMEDOUT:
2186                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2187                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2188                     test_bit(XPRT_REMOVE, &xprt->state)) {
2189                         struct rpc_xprt *saved = task->tk_xprt;
2190                         struct rpc_xprt_switch *xps;
2191
2192                         rcu_read_lock();
2193                         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2194                         rcu_read_unlock();
2195                         if (xps->xps_nxprts > 1) {
2196                                 long value;
2197
2198                                 xprt_release(task);
2199                                 value = atomic_long_dec_return(&xprt->queuelen);
2200                                 if (value == 0)
2201                                         rpc_xprt_switch_remove_xprt(xps, saved,
2202                                                                     true);
2203                                 xprt_put(saved);
2204                                 task->tk_xprt = NULL;
2205                                 task->tk_action = call_start;
2206                         }
2207                         xprt_switch_put(xps);
2208                         if (!task->tk_xprt)
2209                                 return;
2210                 }
2211                 goto out_retry;
2212         case -ENOBUFS:
2213                 rpc_delay(task, HZ >> 2);
2214                 goto out_retry;
2215         }
2216         rpc_call_rpcerror(task, status);
2217         return;
2218 out_next:
2219         task->tk_action = call_transmit;
2220         return;
2221 out_retry:
2222         /* Check for timeouts before looping back to call_bind */
2223         task->tk_action = call_bind;
2224         rpc_check_timeout(task);
2225 }
2226
2227 /*
2228  * 5.   Transmit the RPC request, and wait for reply
2229  */
2230 static void
2231 call_transmit(struct rpc_task *task)
2232 {
2233         if (rpc_task_transmitted(task)) {
2234                 rpc_task_handle_transmitted(task);
2235                 return;
2236         }
2237
2238         task->tk_action = call_transmit_status;
2239         if (!xprt_prepare_transmit(task))
2240                 return;
2241         task->tk_status = 0;
2242         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2243                 if (!xprt_connected(task->tk_xprt)) {
2244                         task->tk_status = -ENOTCONN;
2245                         return;
2246                 }
2247                 xprt_transmit(task);
2248         }
2249         xprt_end_transmit(task);
2250 }
2251
2252 /*
2253  * 5a.  Handle cleanup after a transmission
2254  */
2255 static void
2256 call_transmit_status(struct rpc_task *task)
2257 {
2258         task->tk_action = call_status;
2259
2260         /*
2261          * Common case: success.  Force the compiler to put this
2262          * test first.
2263          */
2264         if (rpc_task_transmitted(task)) {
2265                 task->tk_status = 0;
2266                 xprt_request_wait_receive(task);
2267                 return;
2268         }
2269
2270         switch (task->tk_status) {
2271         default:
2272                 break;
2273         case -EBADMSG:
2274                 task->tk_status = 0;
2275                 task->tk_action = call_encode;
2276                 break;
2277                 /*
2278                  * Special cases: if we've been waiting on the
2279                  * socket's write_space() callback, or if the
2280                  * socket just returned a connection error,
2281                  * then hold onto the transport lock.
2282                  */
2283         case -ENOMEM:
2284         case -ENOBUFS:
2285                 rpc_delay(task, HZ>>2);
2286                 fallthrough;
2287         case -EBADSLT:
2288         case -EAGAIN:
2289                 task->tk_action = call_transmit;
2290                 task->tk_status = 0;
2291                 break;
2292         case -ECONNREFUSED:
2293         case -EHOSTDOWN:
2294         case -ENETDOWN:
2295         case -EHOSTUNREACH:
2296         case -ENETUNREACH:
2297         case -EPERM:
2298                 if (RPC_IS_SOFTCONN(task)) {
2299                         if (!task->tk_msg.rpc_proc->p_proc)
2300                                 trace_xprt_ping(task->tk_xprt,
2301                                                 task->tk_status);
2302                         rpc_call_rpcerror(task, task->tk_status);
2303                         return;
2304                 }
2305                 fallthrough;
2306         case -ECONNRESET:
2307         case -ECONNABORTED:
2308         case -EADDRINUSE:
2309         case -ENOTCONN:
2310         case -EPIPE:
2311                 task->tk_action = call_bind;
2312                 task->tk_status = 0;
2313                 break;
2314         }
2315         rpc_check_timeout(task);
2316 }
2317
2318 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2319 static void call_bc_transmit(struct rpc_task *task);
2320 static void call_bc_transmit_status(struct rpc_task *task);
2321
2322 static void
2323 call_bc_encode(struct rpc_task *task)
2324 {
2325         xprt_request_enqueue_transmit(task);
2326         task->tk_action = call_bc_transmit;
2327 }
2328
2329 /*
2330  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2331  * addition, disconnect on connectivity errors.
2332  */
2333 static void
2334 call_bc_transmit(struct rpc_task *task)
2335 {
2336         task->tk_action = call_bc_transmit_status;
2337         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2338                 if (!xprt_prepare_transmit(task))
2339                         return;
2340                 task->tk_status = 0;
2341                 xprt_transmit(task);
2342         }
2343         xprt_end_transmit(task);
2344 }
2345
2346 static void
2347 call_bc_transmit_status(struct rpc_task *task)
2348 {
2349         struct rpc_rqst *req = task->tk_rqstp;
2350
2351         if (rpc_task_transmitted(task))
2352                 task->tk_status = 0;
2353
2354         switch (task->tk_status) {
2355         case 0:
2356                 /* Success */
2357         case -ENETDOWN:
2358         case -EHOSTDOWN:
2359         case -EHOSTUNREACH:
2360         case -ENETUNREACH:
2361         case -ECONNRESET:
2362         case -ECONNREFUSED:
2363         case -EADDRINUSE:
2364         case -ENOTCONN:
2365         case -EPIPE:
2366                 break;
2367         case -ENOMEM:
2368         case -ENOBUFS:
2369                 rpc_delay(task, HZ>>2);
2370                 fallthrough;
2371         case -EBADSLT:
2372         case -EAGAIN:
2373                 task->tk_status = 0;
2374                 task->tk_action = call_bc_transmit;
2375                 return;
2376         case -ETIMEDOUT:
2377                 /*
2378                  * Problem reaching the server.  Disconnect and let the
2379                  * forechannel reestablish the connection.  The server will
2380                  * have to retransmit the backchannel request and we'll
2381                  * reprocess it.  Since these ops are idempotent, there's no
2382                  * need to cache our reply at this time.
2383                  */
2384                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2385                         "error: %d\n", task->tk_status);
2386                 xprt_conditional_disconnect(req->rq_xprt,
2387                         req->rq_connect_cookie);
2388                 break;
2389         default:
2390                 /*
2391                  * We were unable to reply and will have to drop the
2392                  * request.  The server should reconnect and retransmit.
2393                  */
2394                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2395                         "error: %d\n", task->tk_status);
2396                 break;
2397         }
2398         task->tk_action = rpc_exit_task;
2399 }
2400 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2401
2402 /*
2403  * 6.   Sort out the RPC call status
2404  */
2405 static void
2406 call_status(struct rpc_task *task)
2407 {
2408         struct rpc_clnt *clnt = task->tk_client;
2409         int             status;
2410
2411         if (!task->tk_msg.rpc_proc->p_proc)
2412                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2413
2414         status = task->tk_status;
2415         if (status >= 0) {
2416                 task->tk_action = call_decode;
2417                 return;
2418         }
2419
2420         trace_rpc_call_status(task);
2421         task->tk_status = 0;
2422         switch(status) {
2423         case -EHOSTDOWN:
2424         case -ENETDOWN:
2425         case -EHOSTUNREACH:
2426         case -ENETUNREACH:
2427         case -EPERM:
2428                 if (RPC_IS_SOFTCONN(task))
2429                         goto out_exit;
2430                 /*
2431                  * Delay any retries for 3 seconds, then handle as if it
2432                  * were a timeout.
2433                  */
2434                 rpc_delay(task, 3*HZ);
2435                 fallthrough;
2436         case -ETIMEDOUT:
2437                 break;
2438         case -ECONNREFUSED:
2439         case -ECONNRESET:
2440         case -ECONNABORTED:
2441         case -ENOTCONN:
2442                 rpc_force_rebind(clnt);
2443                 break;
2444         case -EADDRINUSE:
2445                 rpc_delay(task, 3*HZ);
2446                 fallthrough;
2447         case -EPIPE:
2448         case -EAGAIN:
2449                 break;
2450         case -ENFILE:
2451         case -ENOBUFS:
2452         case -ENOMEM:
2453                 rpc_delay(task, HZ>>2);
2454                 break;
2455         case -EIO:
2456                 /* shutdown or soft timeout */
2457                 goto out_exit;
2458         default:
2459                 if (clnt->cl_chatty)
2460                         printk("%s: RPC call returned error %d\n",
2461                                clnt->cl_program->name, -status);
2462                 goto out_exit;
2463         }
2464         task->tk_action = call_encode;
2465         if (status != -ECONNRESET && status != -ECONNABORTED)
2466                 rpc_check_timeout(task);
2467         return;
2468 out_exit:
2469         rpc_call_rpcerror(task, status);
2470 }
2471
2472 static bool
2473 rpc_check_connected(const struct rpc_rqst *req)
2474 {
2475         /* No allocated request or transport? return true */
2476         if (!req || !req->rq_xprt)
2477                 return true;
2478         return xprt_connected(req->rq_xprt);
2479 }
2480
2481 static void
2482 rpc_check_timeout(struct rpc_task *task)
2483 {
2484         struct rpc_clnt *clnt = task->tk_client;
2485
2486         if (RPC_SIGNALLED(task))
2487                 return;
2488
2489         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2490                 return;
2491
2492         trace_rpc_timeout_status(task);
2493         task->tk_timeouts++;
2494
2495         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2496                 rpc_call_rpcerror(task, -ETIMEDOUT);
2497                 return;
2498         }
2499
2500         if (RPC_IS_SOFT(task)) {
2501                 /*
2502                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2503                  * been sent, it should time out only if the transport
2504                  * connection gets terminally broken.
2505                  */
2506                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2507                     rpc_check_connected(task->tk_rqstp))
2508                         return;
2509
2510                 if (clnt->cl_chatty) {
2511                         pr_notice_ratelimited(
2512                                 "%s: server %s not responding, timed out\n",
2513                                 clnt->cl_program->name,
2514                                 task->tk_xprt->servername);
2515                 }
2516                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2517                         rpc_call_rpcerror(task, -ETIMEDOUT);
2518                 else
2519                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2520                 return;
2521         }
2522
2523         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2524                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2525                 if (clnt->cl_chatty) {
2526                         pr_notice_ratelimited(
2527                                 "%s: server %s not responding, still trying\n",
2528                                 clnt->cl_program->name,
2529                                 task->tk_xprt->servername);
2530                 }
2531         }
2532         rpc_force_rebind(clnt);
2533         /*
2534          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2535          * event? RFC2203 requires the server to drop all such requests.
2536          */
2537         rpcauth_invalcred(task);
2538 }
2539
2540 /*
2541  * 7.   Decode the RPC reply
2542  */
2543 static void
2544 call_decode(struct rpc_task *task)
2545 {
2546         struct rpc_clnt *clnt = task->tk_client;
2547         struct rpc_rqst *req = task->tk_rqstp;
2548         struct xdr_stream xdr;
2549         int err;
2550
2551         if (!task->tk_msg.rpc_proc->p_decode) {
2552                 task->tk_action = rpc_exit_task;
2553                 return;
2554         }
2555
2556         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2557                 if (clnt->cl_chatty) {
2558                         pr_notice_ratelimited("%s: server %s OK\n",
2559                                 clnt->cl_program->name,
2560                                 task->tk_xprt->servername);
2561                 }
2562                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2563         }
2564
2565         /*
2566          * Did we ever call xprt_complete_rqst()? If not, we should assume
2567          * the message is incomplete.
2568          */
2569         err = -EAGAIN;
2570         if (!req->rq_reply_bytes_recvd)
2571                 goto out;
2572
2573         /* Ensure that we see all writes made by xprt_complete_rqst()
2574          * before it changed req->rq_reply_bytes_recvd.
2575          */
2576         smp_rmb();
2577
2578         req->rq_rcv_buf.len = req->rq_private_buf.len;
2579         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2580
2581         /* Check that the softirq receive buffer is valid */
2582         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2583                                 sizeof(req->rq_rcv_buf)) != 0);
2584
2585         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2586                         req->rq_rcv_buf.head[0].iov_base, req);
2587         err = rpc_decode_header(task, &xdr);
2588 out:
2589         switch (err) {
2590         case 0:
2591                 task->tk_action = rpc_exit_task;
2592                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2593                 return;
2594         case -EAGAIN:
2595                 task->tk_status = 0;
2596                 if (task->tk_client->cl_discrtry)
2597                         xprt_conditional_disconnect(req->rq_xprt,
2598                                                     req->rq_connect_cookie);
2599                 task->tk_action = call_encode;
2600                 rpc_check_timeout(task);
2601                 break;
2602         case -EKEYREJECTED:
2603                 task->tk_action = call_reserve;
2604                 rpc_check_timeout(task);
2605                 rpcauth_invalcred(task);
2606                 /* Ensure we obtain a new XID if we retry! */
2607                 xprt_release(task);
2608         }
2609 }
2610
2611 static int
2612 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2613 {
2614         struct rpc_clnt *clnt = task->tk_client;
2615         struct rpc_rqst *req = task->tk_rqstp;
2616         __be32 *p;
2617         int error;
2618
2619         error = -EMSGSIZE;
2620         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2621         if (!p)
2622                 goto out_fail;
2623         *p++ = req->rq_xid;
2624         *p++ = rpc_call;
2625         *p++ = cpu_to_be32(RPC_VERSION);
2626         *p++ = cpu_to_be32(clnt->cl_prog);
2627         *p++ = cpu_to_be32(clnt->cl_vers);
2628         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2629
2630         error = rpcauth_marshcred(task, xdr);
2631         if (error < 0)
2632                 goto out_fail;
2633         return 0;
2634 out_fail:
2635         trace_rpc_bad_callhdr(task);
2636         rpc_call_rpcerror(task, error);
2637         return error;
2638 }
2639
2640 static noinline int
2641 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2642 {
2643         struct rpc_clnt *clnt = task->tk_client;
2644         int error;
2645         __be32 *p;
2646
2647         /* RFC-1014 says that the representation of XDR data must be a
2648          * multiple of four bytes
2649          * - if it isn't pointer subtraction in the NFS client may give
2650          *   undefined results
2651          */
2652         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2653                 goto out_unparsable;
2654
2655         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2656         if (!p)
2657                 goto out_unparsable;
2658         p++;    /* skip XID */
2659         if (*p++ != rpc_reply)
2660                 goto out_unparsable;
2661         if (*p++ != rpc_msg_accepted)
2662                 goto out_msg_denied;
2663
2664         error = rpcauth_checkverf(task, xdr);
2665         if (error)
2666                 goto out_verifier;
2667
2668         p = xdr_inline_decode(xdr, sizeof(*p));
2669         if (!p)
2670                 goto out_unparsable;
2671         switch (*p) {
2672         case rpc_success:
2673                 return 0;
2674         case rpc_prog_unavail:
2675                 trace_rpc__prog_unavail(task);
2676                 error = -EPFNOSUPPORT;
2677                 goto out_err;
2678         case rpc_prog_mismatch:
2679                 trace_rpc__prog_mismatch(task);
2680                 error = -EPROTONOSUPPORT;
2681                 goto out_err;
2682         case rpc_proc_unavail:
2683                 trace_rpc__proc_unavail(task);
2684                 error = -EOPNOTSUPP;
2685                 goto out_err;
2686         case rpc_garbage_args:
2687         case rpc_system_err:
2688                 trace_rpc__garbage_args(task);
2689                 error = -EIO;
2690                 break;
2691         default:
2692                 goto out_unparsable;
2693         }
2694
2695 out_garbage:
2696         clnt->cl_stats->rpcgarbage++;
2697         if (task->tk_garb_retry) {
2698                 task->tk_garb_retry--;
2699                 task->tk_action = call_encode;
2700                 return -EAGAIN;
2701         }
2702 out_err:
2703         rpc_call_rpcerror(task, error);
2704         return error;
2705
2706 out_unparsable:
2707         trace_rpc__unparsable(task);
2708         error = -EIO;
2709         goto out_garbage;
2710
2711 out_verifier:
2712         trace_rpc_bad_verifier(task);
2713         goto out_err;
2714
2715 out_msg_denied:
2716         error = -EACCES;
2717         p = xdr_inline_decode(xdr, sizeof(*p));
2718         if (!p)
2719                 goto out_unparsable;
2720         switch (*p++) {
2721         case rpc_auth_error:
2722                 break;
2723         case rpc_mismatch:
2724                 trace_rpc__mismatch(task);
2725                 error = -EPROTONOSUPPORT;
2726                 goto out_err;
2727         default:
2728                 goto out_unparsable;
2729         }
2730
2731         p = xdr_inline_decode(xdr, sizeof(*p));
2732         if (!p)
2733                 goto out_unparsable;
2734         switch (*p++) {
2735         case rpc_autherr_rejectedcred:
2736         case rpc_autherr_rejectedverf:
2737         case rpcsec_gsserr_credproblem:
2738         case rpcsec_gsserr_ctxproblem:
2739                 if (!task->tk_cred_retry)
2740                         break;
2741                 task->tk_cred_retry--;
2742                 trace_rpc__stale_creds(task);
2743                 return -EKEYREJECTED;
2744         case rpc_autherr_badcred:
2745         case rpc_autherr_badverf:
2746                 /* possibly garbled cred/verf? */
2747                 if (!task->tk_garb_retry)
2748                         break;
2749                 task->tk_garb_retry--;
2750                 trace_rpc__bad_creds(task);
2751                 task->tk_action = call_encode;
2752                 return -EAGAIN;
2753         case rpc_autherr_tooweak:
2754                 trace_rpc__auth_tooweak(task);
2755                 pr_warn("RPC: server %s requires stronger authentication.\n",
2756                         task->tk_xprt->servername);
2757                 break;
2758         default:
2759                 goto out_unparsable;
2760         }
2761         goto out_err;
2762 }
2763
2764 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2765                 const void *obj)
2766 {
2767 }
2768
2769 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2770                 void *obj)
2771 {
2772         return 0;
2773 }
2774
2775 static const struct rpc_procinfo rpcproc_null = {
2776         .p_encode = rpcproc_encode_null,
2777         .p_decode = rpcproc_decode_null,
2778 };
2779
2780 static const struct rpc_procinfo rpcproc_null_noreply = {
2781         .p_encode = rpcproc_encode_null,
2782 };
2783
2784 static void
2785 rpc_null_call_prepare(struct rpc_task *task, void *data)
2786 {
2787         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2788         rpc_call_start(task);
2789 }
2790
2791 static const struct rpc_call_ops rpc_null_ops = {
2792         .rpc_call_prepare = rpc_null_call_prepare,
2793         .rpc_call_done = rpc_default_callback,
2794 };
2795
2796 static
2797 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2798                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2799                 const struct rpc_call_ops *ops, void *data)
2800 {
2801         struct rpc_message msg = {
2802                 .rpc_proc = &rpcproc_null,
2803         };
2804         struct rpc_task_setup task_setup_data = {
2805                 .rpc_client = clnt,
2806                 .rpc_xprt = xprt,
2807                 .rpc_message = &msg,
2808                 .rpc_op_cred = cred,
2809                 .callback_ops = ops ?: &rpc_null_ops,
2810                 .callback_data = data,
2811                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2812                          RPC_TASK_NULLCREDS,
2813         };
2814
2815         return rpc_run_task(&task_setup_data);
2816 }
2817
2818 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2819 {
2820         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2821 }
2822 EXPORT_SYMBOL_GPL(rpc_call_null);
2823
2824 static int rpc_ping(struct rpc_clnt *clnt)
2825 {
2826         struct rpc_task *task;
2827         int status;
2828
2829         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2830         if (IS_ERR(task))
2831                 return PTR_ERR(task);
2832         status = task->tk_status;
2833         rpc_put_task(task);
2834         return status;
2835 }
2836
2837 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2838 {
2839         struct rpc_message msg = {
2840                 .rpc_proc = &rpcproc_null_noreply,
2841         };
2842         struct rpc_task_setup task_setup_data = {
2843                 .rpc_client = clnt,
2844                 .rpc_message = &msg,
2845                 .callback_ops = &rpc_null_ops,
2846                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2847         };
2848         struct rpc_task *task;
2849         int status;
2850
2851         task = rpc_run_task(&task_setup_data);
2852         if (IS_ERR(task))
2853                 return PTR_ERR(task);
2854         status = task->tk_status;
2855         rpc_put_task(task);
2856         return status;
2857 }
2858
2859 struct rpc_cb_add_xprt_calldata {
2860         struct rpc_xprt_switch *xps;
2861         struct rpc_xprt *xprt;
2862 };
2863
2864 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2865 {
2866         struct rpc_cb_add_xprt_calldata *data = calldata;
2867
2868         if (task->tk_status == 0)
2869                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2870 }
2871
2872 static void rpc_cb_add_xprt_release(void *calldata)
2873 {
2874         struct rpc_cb_add_xprt_calldata *data = calldata;
2875
2876         xprt_put(data->xprt);
2877         xprt_switch_put(data->xps);
2878         kfree(data);
2879 }
2880
2881 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2882         .rpc_call_prepare = rpc_null_call_prepare,
2883         .rpc_call_done = rpc_cb_add_xprt_done,
2884         .rpc_release = rpc_cb_add_xprt_release,
2885 };
2886
2887 /**
2888  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2889  * @clnt: pointer to struct rpc_clnt
2890  * @xps: pointer to struct rpc_xprt_switch,
2891  * @xprt: pointer struct rpc_xprt
2892  * @dummy: unused
2893  */
2894 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2895                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2896                 void *dummy)
2897 {
2898         struct rpc_cb_add_xprt_calldata *data;
2899         struct rpc_task *task;
2900
2901         if (xps->xps_nunique_destaddr_xprts + 1 > clnt->cl_max_connect) {
2902                 rcu_read_lock();
2903                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2904                         "transport to server: %s\n", clnt->cl_max_connect,
2905                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2906                 rcu_read_unlock();
2907                 return -EINVAL;
2908         }
2909
2910         data = kmalloc(sizeof(*data), GFP_KERNEL);
2911         if (!data)
2912                 return -ENOMEM;
2913         data->xps = xprt_switch_get(xps);
2914         data->xprt = xprt_get(xprt);
2915         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2916                 rpc_cb_add_xprt_release(data);
2917                 goto success;
2918         }
2919
2920         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2921                         &rpc_cb_add_xprt_call_ops, data);
2922         if (IS_ERR(task))
2923                 return PTR_ERR(task);
2924
2925         data->xps->xps_nunique_destaddr_xprts++;
2926         rpc_put_task(task);
2927 success:
2928         return 1;
2929 }
2930 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2931
2932 static int rpc_clnt_add_xprt_helper(struct rpc_clnt *clnt,
2933                                     struct rpc_xprt *xprt,
2934                                     struct rpc_add_xprt_test *data)
2935 {
2936         struct rpc_task *task;
2937         int status = -EADDRINUSE;
2938
2939         /* Test the connection */
2940         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2941         if (IS_ERR(task))
2942                 return PTR_ERR(task);
2943
2944         status = task->tk_status;
2945         rpc_put_task(task);
2946
2947         if (status < 0)
2948                 return status;
2949
2950         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2951         data->add_xprt_test(clnt, xprt, data->data);
2952
2953         return 0;
2954 }
2955
2956 /**
2957  * rpc_clnt_setup_test_and_add_xprt()
2958  *
2959  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2960  *   1) caller of the test function must dereference the rpc_xprt_switch
2961  *   and the rpc_xprt.
2962  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2963  *   the rpc_call_done routine.
2964  *
2965  * Upon success (return of 1), the test function adds the new
2966  * transport to the rpc_clnt xprt switch
2967  *
2968  * @clnt: struct rpc_clnt to get the new transport
2969  * @xps:  the rpc_xprt_switch to hold the new transport
2970  * @xprt: the rpc_xprt to test
2971  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2972  *        and test function call data
2973  */
2974 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2975                                      struct rpc_xprt_switch *xps,
2976                                      struct rpc_xprt *xprt,
2977                                      void *data)
2978 {
2979         int status = -EADDRINUSE;
2980
2981         xprt = xprt_get(xprt);
2982         xprt_switch_get(xps);
2983
2984         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2985                 goto out_err;
2986
2987         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
2988         if (status < 0)
2989                 goto out_err;
2990
2991         status = 1;
2992 out_err:
2993         xprt_put(xprt);
2994         xprt_switch_put(xps);
2995         if (status < 0)
2996                 pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not "
2997                         "added\n", status,
2998                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2999         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
3000         return status;
3001 }
3002 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
3003
3004 /**
3005  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
3006  * @clnt: pointer to struct rpc_clnt
3007  * @xprtargs: pointer to struct xprt_create
3008  * @setup: callback to test and/or set up the connection
3009  * @data: pointer to setup function data
3010  *
3011  * Creates a new transport using the parameters set in args and
3012  * adds it to clnt.
3013  * If ping is set, then test that connectivity succeeds before
3014  * adding the new transport.
3015  *
3016  */
3017 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
3018                 struct xprt_create *xprtargs,
3019                 int (*setup)(struct rpc_clnt *,
3020                         struct rpc_xprt_switch *,
3021                         struct rpc_xprt *,
3022                         void *),
3023                 void *data)
3024 {
3025         struct rpc_xprt_switch *xps;
3026         struct rpc_xprt *xprt;
3027         unsigned long connect_timeout;
3028         unsigned long reconnect_timeout;
3029         unsigned char resvport, reuseport;
3030         int ret = 0, ident;
3031
3032         rcu_read_lock();
3033         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3034         xprt = xprt_iter_xprt(&clnt->cl_xpi);
3035         if (xps == NULL || xprt == NULL) {
3036                 rcu_read_unlock();
3037                 xprt_switch_put(xps);
3038                 return -EAGAIN;
3039         }
3040         resvport = xprt->resvport;
3041         reuseport = xprt->reuseport;
3042         connect_timeout = xprt->connect_timeout;
3043         reconnect_timeout = xprt->max_reconnect_timeout;
3044         ident = xprt->xprt_class->ident;
3045         rcu_read_unlock();
3046
3047         if (!xprtargs->ident)
3048                 xprtargs->ident = ident;
3049         xprt = xprt_create_transport(xprtargs);
3050         if (IS_ERR(xprt)) {
3051                 ret = PTR_ERR(xprt);
3052                 goto out_put_switch;
3053         }
3054         xprt->resvport = resvport;
3055         xprt->reuseport = reuseport;
3056         if (xprt->ops->set_connect_timeout != NULL)
3057                 xprt->ops->set_connect_timeout(xprt,
3058                                 connect_timeout,
3059                                 reconnect_timeout);
3060
3061         rpc_xprt_switch_set_roundrobin(xps);
3062         if (setup) {
3063                 ret = setup(clnt, xps, xprt, data);
3064                 if (ret != 0)
3065                         goto out_put_xprt;
3066         }
3067         rpc_xprt_switch_add_xprt(xps, xprt);
3068 out_put_xprt:
3069         xprt_put(xprt);
3070 out_put_switch:
3071         xprt_switch_put(xps);
3072         return ret;
3073 }
3074 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
3075
3076 static int rpc_xprt_probe_trunked(struct rpc_clnt *clnt,
3077                                   struct rpc_xprt *xprt,
3078                                   struct rpc_add_xprt_test *data)
3079 {
3080         struct rpc_xprt_switch *xps;
3081         struct rpc_xprt *main_xprt;
3082         int status = 0;
3083
3084         xprt_get(xprt);
3085
3086         rcu_read_lock();
3087         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3088         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3089         status = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3090                                    (struct sockaddr *)&main_xprt->addr);
3091         rcu_read_unlock();
3092         xprt_put(main_xprt);
3093         if (status || !test_bit(XPRT_OFFLINE, &xprt->state))
3094                 goto out;
3095
3096         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3097 out:
3098         xprt_put(xprt);
3099         xprt_switch_put(xps);
3100         return status;
3101 }
3102
3103 /* rpc_clnt_probe_trunked_xprt -- probe offlined transport for session trunking
3104  * @clnt rpc_clnt structure
3105  *
3106  * For each offlined transport found in the rpc_clnt structure call
3107  * the function rpc_xprt_probe_trunked() which will determine if this
3108  * transport still belongs to the trunking group.
3109  */
3110 void rpc_clnt_probe_trunked_xprts(struct rpc_clnt *clnt,
3111                                   struct rpc_add_xprt_test *data)
3112 {
3113         struct rpc_xprt_iter xpi;
3114         int ret;
3115
3116         ret = rpc_clnt_xprt_iter_offline_init(clnt, &xpi);
3117         if (ret)
3118                 return;
3119         for (;;) {
3120                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
3121
3122                 if (!xprt)
3123                         break;
3124                 ret = rpc_xprt_probe_trunked(clnt, xprt, data);
3125                 xprt_put(xprt);
3126                 if (ret < 0)
3127                         break;
3128                 xprt_iter_rewind(&xpi);
3129         }
3130         xprt_iter_destroy(&xpi);
3131 }
3132 EXPORT_SYMBOL_GPL(rpc_clnt_probe_trunked_xprts);
3133
3134 static int rpc_xprt_offline(struct rpc_clnt *clnt,
3135                             struct rpc_xprt *xprt,
3136                             void *data)
3137 {
3138         struct rpc_xprt *main_xprt;
3139         struct rpc_xprt_switch *xps;
3140         int err = 0;
3141
3142         xprt_get(xprt);
3143
3144         rcu_read_lock();
3145         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3146         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3147         err = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3148                                 (struct sockaddr *)&main_xprt->addr);
3149         rcu_read_unlock();
3150         xprt_put(main_xprt);
3151         if (err)
3152                 goto out;
3153
3154         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
3155                 err = -EINTR;
3156                 goto out;
3157         }
3158         xprt_set_offline_locked(xprt, xps);
3159
3160         xprt_release_write(xprt, NULL);
3161 out:
3162         xprt_put(xprt);
3163         xprt_switch_put(xps);
3164         return err;
3165 }
3166
3167 /* rpc_clnt_manage_trunked_xprts -- offline trunked transports
3168  * @clnt rpc_clnt structure
3169  *
3170  * For each active transport found in the rpc_clnt structure call
3171  * the function rpc_xprt_offline() which will identify trunked transports
3172  * and will mark them offline.
3173  */
3174 void rpc_clnt_manage_trunked_xprts(struct rpc_clnt *clnt)
3175 {
3176         rpc_clnt_iterate_for_each_xprt(clnt, rpc_xprt_offline, NULL);
3177 }
3178 EXPORT_SYMBOL_GPL(rpc_clnt_manage_trunked_xprts);
3179
3180 struct connect_timeout_data {
3181         unsigned long connect_timeout;
3182         unsigned long reconnect_timeout;
3183 };
3184
3185 static int
3186 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3187                 struct rpc_xprt *xprt,
3188                 void *data)
3189 {
3190         struct connect_timeout_data *timeo = data;
3191
3192         if (xprt->ops->set_connect_timeout)
3193                 xprt->ops->set_connect_timeout(xprt,
3194                                 timeo->connect_timeout,
3195                                 timeo->reconnect_timeout);
3196         return 0;
3197 }
3198
3199 void
3200 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3201                 unsigned long connect_timeout,
3202                 unsigned long reconnect_timeout)
3203 {
3204         struct connect_timeout_data timeout = {
3205                 .connect_timeout = connect_timeout,
3206                 .reconnect_timeout = reconnect_timeout,
3207         };
3208         rpc_clnt_iterate_for_each_xprt(clnt,
3209                         rpc_xprt_set_connect_timeout,
3210                         &timeout);
3211 }
3212 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3213
3214 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
3215 {
3216         rcu_read_lock();
3217         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3218         rcu_read_unlock();
3219 }
3220 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
3221
3222 void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3223 {
3224         struct rpc_xprt_switch *xps;
3225
3226         rcu_read_lock();
3227         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3228         rcu_read_unlock();
3229         xprt_set_online_locked(xprt, xps);
3230 }
3231
3232 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3233 {
3234         if (rpc_clnt_xprt_switch_has_addr(clnt,
3235                 (const struct sockaddr *)&xprt->addr)) {
3236                 return rpc_clnt_xprt_set_online(clnt, xprt);
3237         }
3238         rcu_read_lock();
3239         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3240                                  xprt);
3241         rcu_read_unlock();
3242 }
3243 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3244
3245 void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3246 {
3247         struct rpc_xprt_switch *xps;
3248
3249         rcu_read_lock();
3250         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3251         rpc_xprt_switch_remove_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3252                                     xprt, 0);
3253         xps->xps_nunique_destaddr_xprts--;
3254         rcu_read_unlock();
3255 }
3256 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_remove_xprt);
3257
3258 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3259                                    const struct sockaddr *sap)
3260 {
3261         struct rpc_xprt_switch *xps;
3262         bool ret;
3263
3264         rcu_read_lock();
3265         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3266         ret = rpc_xprt_switch_has_addr(xps, sap);
3267         rcu_read_unlock();
3268         return ret;
3269 }
3270 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3271
3272 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3273 static void rpc_show_header(void)
3274 {
3275         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3276                 "-timeout ---ops--\n");
3277 }
3278
3279 static void rpc_show_task(const struct rpc_clnt *clnt,
3280                           const struct rpc_task *task)
3281 {
3282         const char *rpc_waitq = "none";
3283
3284         if (RPC_IS_QUEUED(task))
3285                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3286
3287         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3288                 task->tk_pid, task->tk_flags, task->tk_status,
3289                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3290                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3291                 task->tk_action, rpc_waitq);
3292 }
3293
3294 void rpc_show_tasks(struct net *net)
3295 {
3296         struct rpc_clnt *clnt;
3297         struct rpc_task *task;
3298         int header = 0;
3299         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3300
3301         spin_lock(&sn->rpc_client_lock);
3302         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3303                 spin_lock(&clnt->cl_lock);
3304                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3305                         if (!header) {
3306                                 rpc_show_header();
3307                                 header++;
3308                         }
3309                         rpc_show_task(clnt, task);
3310                 }
3311                 spin_unlock(&clnt->cl_lock);
3312         }
3313         spin_unlock(&sn->rpc_client_lock);
3314 }
3315 #endif
3316
3317 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3318 static int
3319 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3320                 struct rpc_xprt *xprt,
3321                 void *dummy)
3322 {
3323         return xprt_enable_swap(xprt);
3324 }
3325
3326 int
3327 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3328 {
3329         while (clnt != clnt->cl_parent)
3330                 clnt = clnt->cl_parent;
3331         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3332                 return rpc_clnt_iterate_for_each_xprt(clnt,
3333                                 rpc_clnt_swap_activate_callback, NULL);
3334         return 0;
3335 }
3336 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3337
3338 static int
3339 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3340                 struct rpc_xprt *xprt,
3341                 void *dummy)
3342 {
3343         xprt_disable_swap(xprt);
3344         return 0;
3345 }
3346
3347 void
3348 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3349 {
3350         while (clnt != clnt->cl_parent)
3351                 clnt = clnt->cl_parent;
3352         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3353                 rpc_clnt_iterate_for_each_xprt(clnt,
3354                                 rpc_clnt_swap_deactivate_callback, NULL);
3355 }
3356 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3357 #endif /* CONFIG_SUNRPC_SWAP */