net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "sysfs.h"
  45 #include "netns.h"
  46
  47 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  48 # define RPCDBG_FACILITY        RPCDBG_CALL
  49 #endif
  50
  51 /*
  52  * All RPC clients are linked into this list
  53  */
  54
  55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  56
  57
  58 static void     call_start(struct rpc_task *task);
  59 static void     call_reserve(struct rpc_task *task);
  60 static void     call_reserveresult(struct rpc_task *task);
  61 static void     call_allocate(struct rpc_task *task);
  62 static void     call_encode(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 static void     call_status(struct rpc_task *task);
  68 static void     call_transmit_status(struct rpc_task *task);
  69 static void     call_refresh(struct rpc_task *task);
  70 static void     call_refreshresult(struct rpc_task *task);
  71 static void     call_connect(struct rpc_task *task);
  72 static void     call_connect_status(struct rpc_task *task);
  73
  74 static int      rpc_encode_header(struct rpc_task *task,
  75                                   struct xdr_stream *xdr);
  76 static int      rpc_decode_header(struct rpc_task *task,
  77                                   struct xdr_stream *xdr);
  78 static int      rpc_ping(struct rpc_clnt *clnt);
  79 static int      rpc_ping_noreply(struct rpc_clnt *clnt);
  80 static void     rpc_check_timeout(struct rpc_task *task);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         rpc_remove_client_dir(clnt);
 105 }
 106
 107 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 108 {
 109         struct net *net = rpc_net_ns(clnt);
 110         struct super_block *pipefs_sb;
 111
 112         pipefs_sb = rpc_get_sb_net(net);
 113         if (pipefs_sb) {
 114                 __rpc_clnt_remove_pipedir(clnt);
 115                 rpc_put_sb_net(net);
 116         }
 117 }
 118
 119 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 120                                     struct rpc_clnt *clnt)
 121 {
 122         static uint32_t clntid;
 123         const char *dir_name = clnt->cl_program->pipe_dir_name;
 124         char name[15];
 125         struct dentry *dir, *dentry;
 126
 127         dir = rpc_d_lookup_sb(sb, dir_name);
 128         if (dir == NULL) {
 129                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 130                 return dir;
 131         }
 132         for (;;) {
 133                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 134                 name[sizeof(name) - 1] = '\0';
 135                 dentry = rpc_create_client_dir(dir, name, clnt);
 136                 if (!IS_ERR(dentry))
 137                         break;
 138                 if (dentry == ERR_PTR(-EEXIST))
 139                         continue;
 140                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 141                                 " %s/%s, error %ld\n",
 142                                 dir_name, name, PTR_ERR(dentry));
 143                 break;
 144         }
 145         dput(dir);
 146         return dentry;
 147 }
 148
 149 static int
 150 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 151 {
 152         struct dentry *dentry;
 153
 154         if (clnt->cl_program->pipe_dir_name != NULL) {
 155                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 156                 if (IS_ERR(dentry))
 157                         return PTR_ERR(dentry);
 158         }
 159         return 0;
 160 }
 161
 162 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 163 {
 164         if (clnt->cl_program->pipe_dir_name == NULL)
 165                 return 1;
 166
 167         switch (event) {
 168         case RPC_PIPEFS_MOUNT:
 169                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 170                         return 1;
 171                 if (refcount_read(&clnt->cl_count) == 0)
 172                         return 1;
 173                 break;
 174         case RPC_PIPEFS_UMOUNT:
 175                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 176                         return 1;
 177                 break;
 178         }
 179         return 0;
 180 }
 181
 182 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 183                                    struct super_block *sb)
 184 {
 185         struct dentry *dentry;
 186
 187         switch (event) {
 188         case RPC_PIPEFS_MOUNT:
 189                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 190                 if (!dentry)
 191                         return -ENOENT;
 192                 if (IS_ERR(dentry))
 193                         return PTR_ERR(dentry);
 194                 break;
 195         case RPC_PIPEFS_UMOUNT:
 196                 __rpc_clnt_remove_pipedir(clnt);
 197                 break;
 198         default:
 199                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 200                 return -ENOTSUPP;
 201         }
 202         return 0;
 203 }
 204
 205 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 206                                 struct super_block *sb)
 207 {
 208         int error = 0;
 209
 210         for (;; clnt = clnt->cl_parent) {
 211                 if (!rpc_clnt_skip_event(clnt, event))
 212                         error = __rpc_clnt_handle_event(clnt, event, sb);
 213                 if (error || clnt == clnt->cl_parent)
 214                         break;
 215         }
 216         return error;
 217 }
 218
 219 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 220 {
 221         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 222         struct rpc_clnt *clnt;
 223
 224         spin_lock(&sn->rpc_client_lock);
 225         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 226                 if (rpc_clnt_skip_event(clnt, event))
 227                         continue;
 228                 spin_unlock(&sn->rpc_client_lock);
 229                 return clnt;
 230         }
 231         spin_unlock(&sn->rpc_client_lock);
 232         return NULL;
 233 }
 234
 235 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 236                             void *ptr)
 237 {
 238         struct super_block *sb = ptr;
 239         struct rpc_clnt *clnt;
 240         int error = 0;
 241
 242         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 243                 error = __rpc_pipefs_event(clnt, event, sb);
 244                 if (error)
 245                         break;
 246         }
 247         return error;
 248 }
 249
 250 static struct notifier_block rpc_clients_block = {
 251         .notifier_call  = rpc_pipefs_event,
 252         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 253 };
 254
 255 int rpc_clients_notifier_register(void)
 256 {
 257         return rpc_pipefs_notifier_register(&rpc_clients_block);
 258 }
 259
 260 void rpc_clients_notifier_unregister(void)
 261 {
 262         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 263 }
 264
 265 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 266                 struct rpc_xprt *xprt,
 267                 const struct rpc_timeout *timeout)
 268 {
 269         struct rpc_xprt *old;
 270
 271         spin_lock(&clnt->cl_lock);
 272         old = rcu_dereference_protected(clnt->cl_xprt,
 273                         lockdep_is_held(&clnt->cl_lock));
 274
 275         if (!xprt_bound(xprt))
 276                 clnt->cl_autobind = 1;
 277
 278         clnt->cl_timeout = timeout;
 279         rcu_assign_pointer(clnt->cl_xprt, xprt);
 280         spin_unlock(&clnt->cl_lock);
 281
 282         return old;
 283 }
 284
 285 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 286 {
 287         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 288                         nodename, sizeof(clnt->cl_nodename));
 289 }
 290
 291 static int rpc_client_register(struct rpc_clnt *clnt,
 292                                rpc_authflavor_t pseudoflavor,
 293                                const char *client_name)
 294 {
 295         struct rpc_auth_create_args auth_args = {
 296                 .pseudoflavor = pseudoflavor,
 297                 .target_name = client_name,
 298         };
 299         struct rpc_auth *auth;
 300         struct net *net = rpc_net_ns(clnt);
 301         struct super_block *pipefs_sb;
 302         int err;
 303
 304         rpc_clnt_debugfs_register(clnt);
 305
 306         pipefs_sb = rpc_get_sb_net(net);
 307         if (pipefs_sb) {
 308                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 309                 if (err)
 310                         goto out;
 311         }
 312
 313         rpc_register_client(clnt);
 314         if (pipefs_sb)
 315                 rpc_put_sb_net(net);
 316
 317         auth = rpcauth_create(&auth_args, clnt);
 318         if (IS_ERR(auth)) {
 319                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 320                                 pseudoflavor);
 321                 err = PTR_ERR(auth);
 322                 goto err_auth;
 323         }
 324         return 0;
 325 err_auth:
 326         pipefs_sb = rpc_get_sb_net(net);
 327         rpc_unregister_client(clnt);
 328         __rpc_clnt_remove_pipedir(clnt);
 329 out:
 330         if (pipefs_sb)
 331                 rpc_put_sb_net(net);
 332         rpc_sysfs_client_destroy(clnt);
 333         rpc_clnt_debugfs_unregister(clnt);
 334         return err;
 335 }
 336
 337 static DEFINE_IDA(rpc_clids);
 338
 339 void rpc_cleanup_clids(void)
 340 {
 341         ida_destroy(&rpc_clids);
 342 }
 343
 344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 345 {
 346         int clid;
 347
 348         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 349         if (clid < 0)
 350                 return clid;
 351         clnt->cl_clid = clid;
 352         return 0;
 353 }
 354
 355 static void rpc_free_clid(struct rpc_clnt *clnt)
 356 {
 357         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 358 }
 359
 360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 361                 struct rpc_xprt_switch *xps,
 362                 struct rpc_xprt *xprt,
 363                 struct rpc_clnt *parent)
 364 {
 365         const struct rpc_program *program = args->program;
 366         const struct rpc_version *version;
 367         struct rpc_clnt *clnt = NULL;
 368         const struct rpc_timeout *timeout;
 369         const char *nodename = args->nodename;
 370         int err;
 371
 372         err = rpciod_up();
 373         if (err)
 374                 goto out_no_rpciod;
 375
 376         err = -EINVAL;
 377         if (args->version >= program->nrvers)
 378                 goto out_err;
 379         version = program->version[args->version];
 380         if (version == NULL)
 381                 goto out_err;
 382
 383         err = -ENOMEM;
 384         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 385         if (!clnt)
 386                 goto out_err;
 387         clnt->cl_parent = parent ? : clnt;
 388
 389         err = rpc_alloc_clid(clnt);
 390         if (err)
 391                 goto out_no_clid;
 392
 393         clnt->cl_cred     = get_cred(args->cred);
 394         clnt->cl_procinfo = version->procs;
 395         clnt->cl_maxproc  = version->nrprocs;
 396         clnt->cl_prog     = args->prognumber ? : program->number;
 397         clnt->cl_vers     = version->number;
 398         clnt->cl_stats    = program->stats;
 399         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 400         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 401         err = -ENOMEM;
 402         if (clnt->cl_metrics == NULL)
 403                 goto out_no_stats;
 404         clnt->cl_program  = program;
 405         INIT_LIST_HEAD(&clnt->cl_tasks);
 406         spin_lock_init(&clnt->cl_lock);
 407
 408         timeout = xprt->timeout;
 409         if (args->timeout != NULL) {
 410                 memcpy(&clnt->cl_timeout_default, args->timeout,
 411                                 sizeof(clnt->cl_timeout_default));
 412                 timeout = &clnt->cl_timeout_default;
 413         }
 414
 415         rpc_clnt_set_transport(clnt, xprt, timeout);
 416         xprt->main = true;
 417         xprt_iter_init(&clnt->cl_xpi, xps);
 418         xprt_switch_put(xps);
 419
 420         clnt->cl_rtt = &clnt->cl_rtt_default;
 421         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 422
 423         refcount_set(&clnt->cl_count, 1);
 424
 425         if (nodename == NULL)
 426                 nodename = utsname()->nodename;
 427         /* save the nodename */
 428         rpc_clnt_set_nodename(clnt, nodename);
 429
 430         rpc_sysfs_client_setup(clnt, xps, rpc_net_ns(clnt));
 431         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 432         if (err)
 433                 goto out_no_path;
 434         if (parent)
 435                 refcount_inc(&parent->cl_count);
 436
 437         trace_rpc_clnt_new(clnt, xprt, program->name, args->servername);
 438         return clnt;
 439
 440 out_no_path:
 441         rpc_free_iostats(clnt->cl_metrics);
 442 out_no_stats:
 443         put_cred(clnt->cl_cred);
 444         rpc_free_clid(clnt);
 445 out_no_clid:
 446         kfree(clnt);
 447 out_err:
 448         rpciod_down();
 449 out_no_rpciod:
 450         xprt_switch_put(xps);
 451         xprt_put(xprt);
 452         trace_rpc_clnt_new_err(program->name, args->servername, err);
 453         return ERR_PTR(err);
 454 }
 455
 456 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 457                                         struct rpc_xprt *xprt)
 458 {
 459         struct rpc_clnt *clnt = NULL;
 460         struct rpc_xprt_switch *xps;
 461
 462         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 463                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 464                 xps = args->bc_xprt->xpt_bc_xps;
 465                 xprt_switch_get(xps);
 466         } else {
 467                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 468                 if (xps == NULL) {
 469                         xprt_put(xprt);
 470                         return ERR_PTR(-ENOMEM);
 471                 }
 472                 if (xprt->bc_xprt) {
 473                         xprt_switch_get(xps);
 474                         xprt->bc_xprt->xpt_bc_xps = xps;
 475                 }
 476         }
 477         clnt = rpc_new_client(args, xps, xprt, NULL);
 478         if (IS_ERR(clnt))
 479                 return clnt;
 480
 481         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 482                 int err = rpc_ping(clnt);
 483                 if (err != 0) {
 484                         rpc_shutdown_client(clnt);
 485                         return ERR_PTR(err);
 486                 }
 487         } else if (args->flags & RPC_CLNT_CREATE_CONNECTED) {
 488                 int err = rpc_ping_noreply(clnt);
 489                 if (err != 0) {
 490                         rpc_shutdown_client(clnt);
 491                         return ERR_PTR(err);
 492                 }
 493         }
 494
 495         clnt->cl_softrtry = 1;
 496         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 497                 clnt->cl_softrtry = 0;
 498                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 499                         clnt->cl_softerr = 1;
 500         }
 501
 502         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 503                 clnt->cl_autobind = 1;
 504         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 505                 clnt->cl_noretranstimeo = 1;
 506         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 507                 clnt->cl_discrtry = 1;
 508         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 509                 clnt->cl_chatty = 1;
 510
 511         return clnt;
 512 }
 513
 514 /**
 515  * rpc_create - create an RPC client and transport with one call
 516  * @args: rpc_clnt create argument structure
 517  *
 518  * Creates and initializes an RPC transport and an RPC client.
 519  *
 520  * It can ping the server in order to determine if it is up, and to see if
 521  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 522  * this behavior so asynchronous tasks can also use rpc_create.
 523  */
 524 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 525 {
 526         struct rpc_xprt *xprt;
 527         struct xprt_create xprtargs = {
 528                 .net = args->net,
 529                 .ident = args->protocol,
 530                 .srcaddr = args->saddress,
 531                 .dstaddr = args->address,
 532                 .addrlen = args->addrsize,
 533                 .servername = args->servername,
 534                 .bc_xprt = args->bc_xprt,
 535         };
 536         char servername[48];
 537         struct rpc_clnt *clnt;
 538         int i;
 539
 540         if (args->bc_xprt) {
 541                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 542                 xprt = args->bc_xprt->xpt_bc_xprt;
 543                 if (xprt) {
 544                         xprt_get(xprt);
 545                         return rpc_create_xprt(args, xprt);
 546                 }
 547         }
 548
 549         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 550                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 551         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 552                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 553         /*
 554          * If the caller chooses not to specify a hostname, whip
 555          * up a string representation of the passed-in address.
 556          */
 557         if (xprtargs.servername == NULL) {
 558                 struct sockaddr_un *sun =
 559                                 (struct sockaddr_un *)args->address;
 560                 struct sockaddr_in *sin =
 561                                 (struct sockaddr_in *)args->address;
 562                 struct sockaddr_in6 *sin6 =
 563                                 (struct sockaddr_in6 *)args->address;
 564
 565                 servername[0] = '\0';
 566                 switch (args->address->sa_family) {
 567                 case AF_LOCAL:
 568                         snprintf(servername, sizeof(servername), "%s",
 569                                  sun->sun_path);
 570                         break;
 571                 case AF_INET:
 572                         snprintf(servername, sizeof(servername), "%pI4",
 573                                  &sin->sin_addr.s_addr);
 574                         break;
 575                 case AF_INET6:
 576                         snprintf(servername, sizeof(servername), "%pI6",
 577                                  &sin6->sin6_addr);
 578                         break;
 579                 default:
 580                         /* caller wants default server name, but
 581                          * address family isn't recognized. */
 582                         return ERR_PTR(-EINVAL);
 583                 }
 584                 xprtargs.servername = servername;
 585         }
 586
 587         xprt = xprt_create_transport(&xprtargs);
 588         if (IS_ERR(xprt))
 589                 return (struct rpc_clnt *)xprt;
 590
 591         /*
 592          * By default, kernel RPC client connects from a reserved port.
 593          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 594          * but it is always enabled for rpciod, which handles the connect
 595          * operation.
 596          */
 597         xprt->resvport = 1;
 598         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 599                 xprt->resvport = 0;
 600         xprt->reuseport = 0;
 601         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 602                 xprt->reuseport = 1;
 603
 604         clnt = rpc_create_xprt(args, xprt);
 605         if (IS_ERR(clnt) || args->nconnect <= 1)
 606                 return clnt;
 607
 608         for (i = 0; i < args->nconnect - 1; i++) {
 609                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 610                         break;
 611         }
 612         return clnt;
 613 }
 614 EXPORT_SYMBOL_GPL(rpc_create);
 615
 616 /*
 617  * This function clones the RPC client structure. It allows us to share the
 618  * same transport while varying parameters such as the authentication
 619  * flavour.
 620  */
 621 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 622                                            struct rpc_clnt *clnt)
 623 {
 624         struct rpc_xprt_switch *xps;
 625         struct rpc_xprt *xprt;
 626         struct rpc_clnt *new;
 627         int err;
 628
 629         err = -ENOMEM;
 630         rcu_read_lock();
 631         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 632         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 633         rcu_read_unlock();
 634         if (xprt == NULL || xps == NULL) {
 635                 xprt_put(xprt);
 636                 xprt_switch_put(xps);
 637                 goto out_err;
 638         }
 639         args->servername = xprt->servername;
 640         args->nodename = clnt->cl_nodename;
 641
 642         new = rpc_new_client(args, xps, xprt, clnt);
 643         if (IS_ERR(new))
 644                 return new;
 645
 646         /* Turn off autobind on clones */
 647         new->cl_autobind = 0;
 648         new->cl_softrtry = clnt->cl_softrtry;
 649         new->cl_softerr = clnt->cl_softerr;
 650         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 651         new->cl_discrtry = clnt->cl_discrtry;
 652         new->cl_chatty = clnt->cl_chatty;
 653         new->cl_principal = clnt->cl_principal;
 654         new->cl_max_connect = clnt->cl_max_connect;
 655         return new;
 656
 657 out_err:
 658         trace_rpc_clnt_clone_err(clnt, err);
 659         return ERR_PTR(err);
 660 }
 661
 662 /**
 663  * rpc_clone_client - Clone an RPC client structure
 664  *
 665  * @clnt: RPC client whose parameters are copied
 666  *
 667  * Returns a fresh RPC client or an ERR_PTR.
 668  */
 669 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 670 {
 671         struct rpc_create_args args = {
 672                 .program        = clnt->cl_program,
 673                 .prognumber     = clnt->cl_prog,
 674                 .version        = clnt->cl_vers,
 675                 .authflavor     = clnt->cl_auth->au_flavor,
 676                 .cred           = clnt->cl_cred,
 677         };
 678         return __rpc_clone_client(&args, clnt);
 679 }
 680 EXPORT_SYMBOL_GPL(rpc_clone_client);
 681
 682 /**
 683  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 684  *
 685  * @clnt: RPC client whose parameters are copied
 686  * @flavor: security flavor for new client
 687  *
 688  * Returns a fresh RPC client or an ERR_PTR.
 689  */
 690 struct rpc_clnt *
 691 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 692 {
 693         struct rpc_create_args args = {
 694                 .program        = clnt->cl_program,
 695                 .prognumber     = clnt->cl_prog,
 696                 .version        = clnt->cl_vers,
 697                 .authflavor     = flavor,
 698                 .cred           = clnt->cl_cred,
 699         };
 700         return __rpc_clone_client(&args, clnt);
 701 }
 702 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 703
 704 /**
 705  * rpc_switch_client_transport: switch the RPC transport on the fly
 706  * @clnt: pointer to a struct rpc_clnt
 707  * @args: pointer to the new transport arguments
 708  * @timeout: pointer to the new timeout parameters
 709  *
 710  * This function allows the caller to switch the RPC transport for the
 711  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 712  * server, for instance.  It assumes that the caller has ensured that
 713  * there are no active RPC tasks by using some form of locking.
 714  *
 715  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 716  * negative errno is returned, and "clnt" continues to use the old
 717  * xprt.
 718  */
 719 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 720                 struct xprt_create *args,
 721                 const struct rpc_timeout *timeout)
 722 {
 723         const struct rpc_timeout *old_timeo;
 724         rpc_authflavor_t pseudoflavor;
 725         struct rpc_xprt_switch *xps, *oldxps;
 726         struct rpc_xprt *xprt, *old;
 727         struct rpc_clnt *parent;
 728         int err;
 729
 730         xprt = xprt_create_transport(args);
 731         if (IS_ERR(xprt))
 732                 return PTR_ERR(xprt);
 733
 734         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 735         if (xps == NULL) {
 736                 xprt_put(xprt);
 737                 return -ENOMEM;
 738         }
 739
 740         pseudoflavor = clnt->cl_auth->au_flavor;
 741
 742         old_timeo = clnt->cl_timeout;
 743         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 744         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 745
 746         rpc_unregister_client(clnt);
 747         __rpc_clnt_remove_pipedir(clnt);
 748         rpc_sysfs_client_destroy(clnt);
 749         rpc_clnt_debugfs_unregister(clnt);
 750
 751         /*
 752          * A new transport was created.  "clnt" therefore
 753          * becomes the root of a new cl_parent tree.  clnt's
 754          * children, if it has any, still point to the old xprt.
 755          */
 756         parent = clnt->cl_parent;
 757         clnt->cl_parent = clnt;
 758
 759         /*
 760          * The old rpc_auth cache cannot be re-used.  GSS
 761          * contexts in particular are between a single
 762          * client and server.
 763          */
 764         err = rpc_client_register(clnt, pseudoflavor, NULL);
 765         if (err)
 766                 goto out_revert;
 767
 768         synchronize_rcu();
 769         if (parent != clnt)
 770                 rpc_release_client(parent);
 771         xprt_switch_put(oldxps);
 772         xprt_put(old);
 773         trace_rpc_clnt_replace_xprt(clnt);
 774         return 0;
 775
 776 out_revert:
 777         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 778         rpc_clnt_set_transport(clnt, old, old_timeo);
 779         clnt->cl_parent = parent;
 780         rpc_client_register(clnt, pseudoflavor, NULL);
 781         xprt_switch_put(xps);
 782         xprt_put(xprt);
 783         trace_rpc_clnt_replace_xprt_err(clnt);
 784         return err;
 785 }
 786 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 787
 788 static
 789 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 790 {
 791         struct rpc_xprt_switch *xps;
 792
 793         rcu_read_lock();
 794         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 795         rcu_read_unlock();
 796         if (xps == NULL)
 797                 return -EAGAIN;
 798         xprt_iter_init_listall(xpi, xps);
 799         xprt_switch_put(xps);
 800         return 0;
 801 }
 802
 803 /**
 804  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 805  * @clnt: pointer to client
 806  * @fn: function to apply
 807  * @data: void pointer to function data
 808  *
 809  * Iterates through the list of RPC transports currently attached to the
 810  * client and applies the function fn(clnt, xprt, data).
 811  *
 812  * On error, the iteration stops, and the function returns the error value.
 813  */
 814 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 815                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 816                 void *data)
 817 {
 818         struct rpc_xprt_iter xpi;
 819         int ret;
 820
 821         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 822         if (ret)
 823                 return ret;
 824         for (;;) {
 825                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 826
 827                 if (!xprt)
 828                         break;
 829                 ret = fn(clnt, xprt, data);
 830                 xprt_put(xprt);
 831                 if (ret < 0)
 832                         break;
 833         }
 834         xprt_iter_destroy(&xpi);
 835         return ret;
 836 }
 837 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 838
 839 /*
 840  * Kill all tasks for the given client.
 841  * XXX: kill their descendants as well?
 842  */
 843 void rpc_killall_tasks(struct rpc_clnt *clnt)
 844 {
 845         struct rpc_task *rovr;
 846
 847
 848         if (list_empty(&clnt->cl_tasks))
 849                 return;
 850
 851         /*
 852          * Spin lock all_tasks to prevent changes...
 853          */
 854         trace_rpc_clnt_killall(clnt);
 855         spin_lock(&clnt->cl_lock);
 856         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 857                 rpc_signal_task(rovr);
 858         spin_unlock(&clnt->cl_lock);
 859 }
 860 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 861
 862 /*
 863  * Properly shut down an RPC client, terminating all outstanding
 864  * requests.
 865  */
 866 void rpc_shutdown_client(struct rpc_clnt *clnt)
 867 {
 868         might_sleep();
 869
 870         trace_rpc_clnt_shutdown(clnt);
 871
 872         while (!list_empty(&clnt->cl_tasks)) {
 873                 rpc_killall_tasks(clnt);
 874                 wait_event_timeout(destroy_wait,
 875                         list_empty(&clnt->cl_tasks), 1*HZ);
 876         }
 877
 878         rpc_release_client(clnt);
 879 }
 880 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 881
 882 /*
 883  * Free an RPC client
 884  */
 885 static void rpc_free_client_work(struct work_struct *work)
 886 {
 887         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 888
 889         trace_rpc_clnt_free(clnt);
 890
 891         /* These might block on processes that might allocate memory,
 892          * so they cannot be called in rpciod, so they are handled separately
 893          * here.
 894          */
 895         rpc_sysfs_client_destroy(clnt);
 896         rpc_clnt_debugfs_unregister(clnt);
 897         rpc_free_clid(clnt);
 898         rpc_clnt_remove_pipedir(clnt);
 899         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 900
 901         kfree(clnt);
 902         rpciod_down();
 903 }
 904 static struct rpc_clnt *
 905 rpc_free_client(struct rpc_clnt *clnt)
 906 {
 907         struct rpc_clnt *parent = NULL;
 908
 909         trace_rpc_clnt_release(clnt);
 910         if (clnt->cl_parent != clnt)
 911                 parent = clnt->cl_parent;
 912         rpc_unregister_client(clnt);
 913         rpc_free_iostats(clnt->cl_metrics);
 914         clnt->cl_metrics = NULL;
 915         xprt_iter_destroy(&clnt->cl_xpi);
 916         put_cred(clnt->cl_cred);
 917
 918         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 919         schedule_work(&clnt->cl_work);
 920         return parent;
 921 }
 922
 923 /*
 924  * Free an RPC client
 925  */
 926 static struct rpc_clnt *
 927 rpc_free_auth(struct rpc_clnt *clnt)
 928 {
 929         /*
 930          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 931          *       release remaining GSS contexts. This mechanism ensures
 932          *       that it can do so safely.
 933          */
 934         if (clnt->cl_auth != NULL) {
 935                 rpcauth_release(clnt->cl_auth);
 936                 clnt->cl_auth = NULL;
 937         }
 938         if (refcount_dec_and_test(&clnt->cl_count))
 939                 return rpc_free_client(clnt);
 940         return NULL;
 941 }
 942
 943 /*
 944  * Release reference to the RPC client
 945  */
 946 void
 947 rpc_release_client(struct rpc_clnt *clnt)
 948 {
 949         do {
 950                 if (list_empty(&clnt->cl_tasks))
 951                         wake_up(&destroy_wait);
 952                 if (refcount_dec_not_one(&clnt->cl_count))
 953                         break;
 954                 clnt = rpc_free_auth(clnt);
 955         } while (clnt != NULL);
 956 }
 957 EXPORT_SYMBOL_GPL(rpc_release_client);
 958
 959 /**
 960  * rpc_bind_new_program - bind a new RPC program to an existing client
 961  * @old: old rpc_client
 962  * @program: rpc program to set
 963  * @vers: rpc program version
 964  *
 965  * Clones the rpc client and sets up a new RPC program. This is mainly
 966  * of use for enabling different RPC programs to share the same transport.
 967  * The Sun NFSv2/v3 ACL protocol can do this.
 968  */
 969 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 970                                       const struct rpc_program *program,
 971                                       u32 vers)
 972 {
 973         struct rpc_create_args args = {
 974                 .program        = program,
 975                 .prognumber     = program->number,
 976                 .version        = vers,
 977                 .authflavor     = old->cl_auth->au_flavor,
 978                 .cred           = old->cl_cred,
 979         };
 980         struct rpc_clnt *clnt;
 981         int err;
 982
 983         clnt = __rpc_clone_client(&args, old);
 984         if (IS_ERR(clnt))
 985                 goto out;
 986         err = rpc_ping(clnt);
 987         if (err != 0) {
 988                 rpc_shutdown_client(clnt);
 989                 clnt = ERR_PTR(err);
 990         }
 991 out:
 992         return clnt;
 993 }
 994 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 995
 996 struct rpc_xprt *
 997 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 998 {
 999         struct rpc_xprt_switch *xps;
1000
1001         if (!xprt)
1002                 return NULL;
1003         rcu_read_lock();
1004         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1005         atomic_long_inc(&xps->xps_queuelen);
1006         rcu_read_unlock();
1007         atomic_long_inc(&xprt->queuelen);
1008
1009         return xprt;
1010 }
1011
1012 static void
1013 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1014 {
1015         struct rpc_xprt_switch *xps;
1016
1017         atomic_long_dec(&xprt->queuelen);
1018         rcu_read_lock();
1019         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1020         atomic_long_dec(&xps->xps_queuelen);
1021         rcu_read_unlock();
1022
1023         xprt_put(xprt);
1024 }
1025
1026 void rpc_task_release_transport(struct rpc_task *task)
1027 {
1028         struct rpc_xprt *xprt = task->tk_xprt;
1029
1030         if (xprt) {
1031                 task->tk_xprt = NULL;
1032                 if (task->tk_client)
1033                         rpc_task_release_xprt(task->tk_client, xprt);
1034                 else
1035                         xprt_put(xprt);
1036         }
1037 }
1038 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1039
1040 void rpc_task_release_client(struct rpc_task *task)
1041 {
1042         struct rpc_clnt *clnt = task->tk_client;
1043
1044         rpc_task_release_transport(task);
1045         if (clnt != NULL) {
1046                 /* Remove from client task list */
1047                 spin_lock(&clnt->cl_lock);
1048                 list_del(&task->tk_task);
1049                 spin_unlock(&clnt->cl_lock);
1050                 task->tk_client = NULL;
1051
1052                 rpc_release_client(clnt);
1053         }
1054 }
1055
1056 static struct rpc_xprt *
1057 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1058 {
1059         struct rpc_xprt *xprt;
1060
1061         rcu_read_lock();
1062         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1063         rcu_read_unlock();
1064         return rpc_task_get_xprt(clnt, xprt);
1065 }
1066
1067 static struct rpc_xprt *
1068 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1069 {
1070         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1071 }
1072
1073 static
1074 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1075 {
1076         if (task->tk_xprt) {
1077                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1078                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1079                         return;
1080                 xprt_release(task);
1081                 xprt_put(task->tk_xprt);
1082         }
1083         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1084                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1085         else
1086                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1087 }
1088
1089 static
1090 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1091 {
1092
1093         if (clnt != NULL) {
1094                 rpc_task_set_transport(task, clnt);
1095                 task->tk_client = clnt;
1096                 refcount_inc(&clnt->cl_count);
1097                 if (clnt->cl_softrtry)
1098                         task->tk_flags |= RPC_TASK_SOFT;
1099                 if (clnt->cl_softerr)
1100                         task->tk_flags |= RPC_TASK_TIMEOUT;
1101                 if (clnt->cl_noretranstimeo)
1102                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1103                 if (atomic_read(&clnt->cl_swapper))
1104                         task->tk_flags |= RPC_TASK_SWAPPER;
1105                 /* Add to the client's list of all tasks */
1106                 spin_lock(&clnt->cl_lock);
1107                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1108                 spin_unlock(&clnt->cl_lock);
1109         }
1110 }
1111
1112 static void
1113 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1114 {
1115         if (msg != NULL) {
1116                 task->tk_msg.rpc_proc = msg->rpc_proc;
1117                 task->tk_msg.rpc_argp = msg->rpc_argp;
1118                 task->tk_msg.rpc_resp = msg->rpc_resp;
1119                 task->tk_msg.rpc_cred = msg->rpc_cred;
1120                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1121                         get_cred(task->tk_msg.rpc_cred);
1122         }
1123 }
1124
1125 /*
1126  * Default callback for async RPC calls
1127  */
1128 static void
1129 rpc_default_callback(struct rpc_task *task, void *data)
1130 {
1131 }
1132
1133 static const struct rpc_call_ops rpc_default_ops = {
1134         .rpc_call_done = rpc_default_callback,
1135 };
1136
1137 /**
1138  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1139  * @task_setup_data: pointer to task initialisation data
1140  */
1141 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1142 {
1143         struct rpc_task *task;
1144
1145         task = rpc_new_task(task_setup_data);
1146
1147         if (!RPC_IS_ASYNC(task))
1148                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1149
1150         rpc_task_set_client(task, task_setup_data->rpc_client);
1151         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1152
1153         if (task->tk_action == NULL)
1154                 rpc_call_start(task);
1155
1156         atomic_inc(&task->tk_count);
1157         rpc_execute(task);
1158         return task;
1159 }
1160 EXPORT_SYMBOL_GPL(rpc_run_task);
1161
1162 /**
1163  * rpc_call_sync - Perform a synchronous RPC call
1164  * @clnt: pointer to RPC client
1165  * @msg: RPC call parameters
1166  * @flags: RPC call flags
1167  */
1168 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1169 {
1170         struct rpc_task *task;
1171         struct rpc_task_setup task_setup_data = {
1172                 .rpc_client = clnt,
1173                 .rpc_message = msg,
1174                 .callback_ops = &rpc_default_ops,
1175                 .flags = flags,
1176         };
1177         int status;
1178
1179         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1180         if (flags & RPC_TASK_ASYNC) {
1181                 rpc_release_calldata(task_setup_data.callback_ops,
1182                         task_setup_data.callback_data);
1183                 return -EINVAL;
1184         }
1185
1186         task = rpc_run_task(&task_setup_data);
1187         if (IS_ERR(task))
1188                 return PTR_ERR(task);
1189         status = task->tk_status;
1190         rpc_put_task(task);
1191         return status;
1192 }
1193 EXPORT_SYMBOL_GPL(rpc_call_sync);
1194
1195 /**
1196  * rpc_call_async - Perform an asynchronous RPC call
1197  * @clnt: pointer to RPC client
1198  * @msg: RPC call parameters
1199  * @flags: RPC call flags
1200  * @tk_ops: RPC call ops
1201  * @data: user call data
1202  */
1203 int
1204 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1205                const struct rpc_call_ops *tk_ops, void *data)
1206 {
1207         struct rpc_task *task;
1208         struct rpc_task_setup task_setup_data = {
1209                 .rpc_client = clnt,
1210                 .rpc_message = msg,
1211                 .callback_ops = tk_ops,
1212                 .callback_data = data,
1213                 .flags = flags|RPC_TASK_ASYNC,
1214         };
1215
1216         task = rpc_run_task(&task_setup_data);
1217         if (IS_ERR(task))
1218                 return PTR_ERR(task);
1219         rpc_put_task(task);
1220         return 0;
1221 }
1222 EXPORT_SYMBOL_GPL(rpc_call_async);
1223
1224 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1225 static void call_bc_encode(struct rpc_task *task);
1226
1227 /**
1228  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1229  * rpc_execute against it
1230  * @req: RPC request
1231  */
1232 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1233 {
1234         struct rpc_task *task;
1235         struct rpc_task_setup task_setup_data = {
1236                 .callback_ops = &rpc_default_ops,
1237                 .flags = RPC_TASK_SOFTCONN |
1238                         RPC_TASK_NO_RETRANS_TIMEOUT,
1239         };
1240
1241         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1242         /*
1243          * Create an rpc_task to send the data
1244          */
1245         task = rpc_new_task(&task_setup_data);
1246         xprt_init_bc_request(req, task);
1247
1248         task->tk_action = call_bc_encode;
1249         atomic_inc(&task->tk_count);
1250         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1251         rpc_execute(task);
1252
1253         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1254         return task;
1255 }
1256 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1257
1258 /**
1259  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1260  * @req: RPC request to prepare
1261  * @pages: vector of struct page pointers
1262  * @base: offset in first page where receive should start, in bytes
1263  * @len: expected size of the upper layer data payload, in bytes
1264  * @hdrsize: expected size of upper layer reply header, in XDR words
1265  *
1266  */
1267 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1268                              unsigned int base, unsigned int len,
1269                              unsigned int hdrsize)
1270 {
1271         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1272
1273         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1274         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1275 }
1276 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1277
1278 void
1279 rpc_call_start(struct rpc_task *task)
1280 {
1281         task->tk_action = call_start;
1282 }
1283 EXPORT_SYMBOL_GPL(rpc_call_start);
1284
1285 /**
1286  * rpc_peeraddr - extract remote peer address from clnt's xprt
1287  * @clnt: RPC client structure
1288  * @buf: target buffer
1289  * @bufsize: length of target buffer
1290  *
1291  * Returns the number of bytes that are actually in the stored address.
1292  */
1293 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1294 {
1295         size_t bytes;
1296         struct rpc_xprt *xprt;
1297
1298         rcu_read_lock();
1299         xprt = rcu_dereference(clnt->cl_xprt);
1300
1301         bytes = xprt->addrlen;
1302         if (bytes > bufsize)
1303                 bytes = bufsize;
1304         memcpy(buf, &xprt->addr, bytes);
1305         rcu_read_unlock();
1306
1307         return bytes;
1308 }
1309 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1310
1311 /**
1312  * rpc_peeraddr2str - return remote peer address in printable format
1313  * @clnt: RPC client structure
1314  * @format: address format
1315  *
1316  * NB: the lifetime of the memory referenced by the returned pointer is
1317  * the same as the rpc_xprt itself.  As long as the caller uses this
1318  * pointer, it must hold the RCU read lock.
1319  */
1320 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1321                              enum rpc_display_format_t format)
1322 {
1323         struct rpc_xprt *xprt;
1324
1325         xprt = rcu_dereference(clnt->cl_xprt);
1326
1327         if (xprt->address_strings[format] != NULL)
1328                 return xprt->address_strings[format];
1329         else
1330                 return "unprintable";
1331 }
1332 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1333
1334 static const struct sockaddr_in rpc_inaddr_loopback = {
1335         .sin_family             = AF_INET,
1336         .sin_addr.s_addr        = htonl(INADDR_ANY),
1337 };
1338
1339 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1340         .sin6_family            = AF_INET6,
1341         .sin6_addr              = IN6ADDR_ANY_INIT,
1342 };
1343
1344 /*
1345  * Try a getsockname() on a connected datagram socket.  Using a
1346  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1347  * This conserves the ephemeral port number space.
1348  *
1349  * Returns zero and fills in "buf" if successful; otherwise, a
1350  * negative errno is returned.
1351  */
1352 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1353                         struct sockaddr *buf)
1354 {
1355         struct socket *sock;
1356         int err;
1357
1358         err = __sock_create(net, sap->sa_family,
1359                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1360         if (err < 0) {
1361                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1362                 goto out;
1363         }
1364
1365         switch (sap->sa_family) {
1366         case AF_INET:
1367                 err = kernel_bind(sock,
1368                                 (struct sockaddr *)&rpc_inaddr_loopback,
1369                                 sizeof(rpc_inaddr_loopback));
1370                 break;
1371         case AF_INET6:
1372                 err = kernel_bind(sock,
1373                                 (struct sockaddr *)&rpc_in6addr_loopback,
1374                                 sizeof(rpc_in6addr_loopback));
1375                 break;
1376         default:
1377                 err = -EAFNOSUPPORT;
1378                 goto out_release;
1379         }
1380         if (err < 0) {
1381                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1382                 goto out_release;
1383         }
1384
1385         err = kernel_connect(sock, sap, salen, 0);
1386         if (err < 0) {
1387                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1388                 goto out_release;
1389         }
1390
1391         err = kernel_getsockname(sock, buf);
1392         if (err < 0) {
1393                 dprintk("RPC:       getsockname failed (%d)\n", err);
1394                 goto out_release;
1395         }
1396
1397         err = 0;
1398         if (buf->sa_family == AF_INET6) {
1399                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1400                 sin6->sin6_scope_id = 0;
1401         }
1402         dprintk("RPC:       %s succeeded\n", __func__);
1403
1404 out_release:
1405         sock_release(sock);
1406 out:
1407         return err;
1408 }
1409
1410 /*
1411  * Scraping a connected socket failed, so we don't have a useable
1412  * local address.  Fallback: generate an address that will prevent
1413  * the server from calling us back.
1414  *
1415  * Returns zero and fills in "buf" if successful; otherwise, a
1416  * negative errno is returned.
1417  */
1418 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1419 {
1420         switch (family) {
1421         case AF_INET:
1422                 if (buflen < sizeof(rpc_inaddr_loopback))
1423                         return -EINVAL;
1424                 memcpy(buf, &rpc_inaddr_loopback,
1425                                 sizeof(rpc_inaddr_loopback));
1426                 break;
1427         case AF_INET6:
1428                 if (buflen < sizeof(rpc_in6addr_loopback))
1429                         return -EINVAL;
1430                 memcpy(buf, &rpc_in6addr_loopback,
1431                                 sizeof(rpc_in6addr_loopback));
1432                 break;
1433         default:
1434                 dprintk("RPC:       %s: address family not supported\n",
1435                         __func__);
1436                 return -EAFNOSUPPORT;
1437         }
1438         dprintk("RPC:       %s: succeeded\n", __func__);
1439         return 0;
1440 }
1441
1442 /**
1443  * rpc_localaddr - discover local endpoint address for an RPC client
1444  * @clnt: RPC client structure
1445  * @buf: target buffer
1446  * @buflen: size of target buffer, in bytes
1447  *
1448  * Returns zero and fills in "buf" and "buflen" if successful;
1449  * otherwise, a negative errno is returned.
1450  *
1451  * This works even if the underlying transport is not currently connected,
1452  * or if the upper layer never previously provided a source address.
1453  *
1454  * The result of this function call is transient: multiple calls in
1455  * succession may give different results, depending on how local
1456  * networking configuration changes over time.
1457  */
1458 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1459 {
1460         struct sockaddr_storage address;
1461         struct sockaddr *sap = (struct sockaddr *)&address;
1462         struct rpc_xprt *xprt;
1463         struct net *net;
1464         size_t salen;
1465         int err;
1466
1467         rcu_read_lock();
1468         xprt = rcu_dereference(clnt->cl_xprt);
1469         salen = xprt->addrlen;
1470         memcpy(sap, &xprt->addr, salen);
1471         net = get_net(xprt->xprt_net);
1472         rcu_read_unlock();
1473
1474         rpc_set_port(sap, 0);
1475         err = rpc_sockname(net, sap, salen, buf);
1476         put_net(net);
1477         if (err != 0)
1478                 /* Couldn't discover local address, return ANYADDR */
1479                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1480         return 0;
1481 }
1482 EXPORT_SYMBOL_GPL(rpc_localaddr);
1483
1484 void
1485 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1486 {
1487         struct rpc_xprt *xprt;
1488
1489         rcu_read_lock();
1490         xprt = rcu_dereference(clnt->cl_xprt);
1491         if (xprt->ops->set_buffer_size)
1492                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1493         rcu_read_unlock();
1494 }
1495 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1496
1497 /**
1498  * rpc_net_ns - Get the network namespace for this RPC client
1499  * @clnt: RPC client to query
1500  *
1501  */
1502 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1503 {
1504         struct net *ret;
1505
1506         rcu_read_lock();
1507         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1508         rcu_read_unlock();
1509         return ret;
1510 }
1511 EXPORT_SYMBOL_GPL(rpc_net_ns);
1512
1513 /**
1514  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1515  * @clnt: RPC client to query
1516  *
1517  * For stream transports, this is one RPC record fragment (see RFC
1518  * 1831), as we don't support multi-record requests yet.  For datagram
1519  * transports, this is the size of an IP packet minus the IP, UDP, and
1520  * RPC header sizes.
1521  */
1522 size_t rpc_max_payload(struct rpc_clnt *clnt)
1523 {
1524         size_t ret;
1525
1526         rcu_read_lock();
1527         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1528         rcu_read_unlock();
1529         return ret;
1530 }
1531 EXPORT_SYMBOL_GPL(rpc_max_payload);
1532
1533 /**
1534  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1535  * @clnt: RPC client to query
1536  */
1537 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1538 {
1539         struct rpc_xprt *xprt;
1540         size_t ret;
1541
1542         rcu_read_lock();
1543         xprt = rcu_dereference(clnt->cl_xprt);
1544         ret = xprt->ops->bc_maxpayload(xprt);
1545         rcu_read_unlock();
1546         return ret;
1547 }
1548 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1549
1550 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1551 {
1552         struct rpc_xprt *xprt;
1553         unsigned int ret;
1554
1555         rcu_read_lock();
1556         xprt = rcu_dereference(clnt->cl_xprt);
1557         ret = xprt->ops->bc_num_slots(xprt);
1558         rcu_read_unlock();
1559         return ret;
1560 }
1561 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1562
1563 /**
1564  * rpc_force_rebind - force transport to check that remote port is unchanged
1565  * @clnt: client to rebind
1566  *
1567  */
1568 void rpc_force_rebind(struct rpc_clnt *clnt)
1569 {
1570         if (clnt->cl_autobind) {
1571                 rcu_read_lock();
1572                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1573                 rcu_read_unlock();
1574         }
1575 }
1576 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1577
1578 static int
1579 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1580 {
1581         task->tk_status = 0;
1582         task->tk_rpc_status = 0;
1583         task->tk_action = action;
1584         return 1;
1585 }
1586
1587 /*
1588  * Restart an (async) RPC call. Usually called from within the
1589  * exit handler.
1590  */
1591 int
1592 rpc_restart_call(struct rpc_task *task)
1593 {
1594         return __rpc_restart_call(task, call_start);
1595 }
1596 EXPORT_SYMBOL_GPL(rpc_restart_call);
1597
1598 /*
1599  * Restart an (async) RPC call from the call_prepare state.
1600  * Usually called from within the exit handler.
1601  */
1602 int
1603 rpc_restart_call_prepare(struct rpc_task *task)
1604 {
1605         if (task->tk_ops->rpc_call_prepare != NULL)
1606                 return __rpc_restart_call(task, rpc_prepare_task);
1607         return rpc_restart_call(task);
1608 }
1609 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1610
1611 const char
1612 *rpc_proc_name(const struct rpc_task *task)
1613 {
1614         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1615
1616         if (proc) {
1617                 if (proc->p_name)
1618                         return proc->p_name;
1619                 else
1620                         return "NULL";
1621         } else
1622                 return "no proc";
1623 }
1624
1625 static void
1626 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1627 {
1628         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1629         task->tk_rpc_status = rpc_status;
1630         rpc_exit(task, tk_status);
1631 }
1632
1633 static void
1634 rpc_call_rpcerror(struct rpc_task *task, int status)
1635 {
1636         __rpc_call_rpcerror(task, status, status);
1637 }
1638
1639 /*
1640  * 0.  Initial state
1641  *
1642  *     Other FSM states can be visited zero or more times, but
1643  *     this state is visited exactly once for each RPC.
1644  */
1645 static void
1646 call_start(struct rpc_task *task)
1647 {
1648         struct rpc_clnt *clnt = task->tk_client;
1649         int idx = task->tk_msg.rpc_proc->p_statidx;
1650
1651         trace_rpc_request(task);
1652
1653         /* Increment call count (version might not be valid for ping) */
1654         if (clnt->cl_program->version[clnt->cl_vers])
1655                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1656         clnt->cl_stats->rpccnt++;
1657         task->tk_action = call_reserve;
1658         rpc_task_set_transport(task, clnt);
1659 }
1660
1661 /*
1662  * 1.   Reserve an RPC call slot
1663  */
1664 static void
1665 call_reserve(struct rpc_task *task)
1666 {
1667         task->tk_status  = 0;
1668         task->tk_action  = call_reserveresult;
1669         xprt_reserve(task);
1670 }
1671
1672 static void call_retry_reserve(struct rpc_task *task);
1673
1674 /*
1675  * 1b.  Grok the result of xprt_reserve()
1676  */
1677 static void
1678 call_reserveresult(struct rpc_task *task)
1679 {
1680         int status = task->tk_status;
1681
1682         /*
1683          * After a call to xprt_reserve(), we must have either
1684          * a request slot or else an error status.
1685          */
1686         task->tk_status = 0;
1687         if (status >= 0) {
1688                 if (task->tk_rqstp) {
1689                         task->tk_action = call_refresh;
1690                         return;
1691                 }
1692
1693                 rpc_call_rpcerror(task, -EIO);
1694                 return;
1695         }
1696
1697         switch (status) {
1698         case -ENOMEM:
1699                 rpc_delay(task, HZ >> 2);
1700                 fallthrough;
1701         case -EAGAIN:   /* woken up; retry */
1702                 task->tk_action = call_retry_reserve;
1703                 return;
1704         default:
1705                 rpc_call_rpcerror(task, status);
1706         }
1707 }
1708
1709 /*
1710  * 1c.  Retry reserving an RPC call slot
1711  */
1712 static void
1713 call_retry_reserve(struct rpc_task *task)
1714 {
1715         task->tk_status  = 0;
1716         task->tk_action  = call_reserveresult;
1717         xprt_retry_reserve(task);
1718 }
1719
1720 /*
1721  * 2.   Bind and/or refresh the credentials
1722  */
1723 static void
1724 call_refresh(struct rpc_task *task)
1725 {
1726         task->tk_action = call_refreshresult;
1727         task->tk_status = 0;
1728         task->tk_client->cl_stats->rpcauthrefresh++;
1729         rpcauth_refreshcred(task);
1730 }
1731
1732 /*
1733  * 2a.  Process the results of a credential refresh
1734  */
1735 static void
1736 call_refreshresult(struct rpc_task *task)
1737 {
1738         int status = task->tk_status;
1739
1740         task->tk_status = 0;
1741         task->tk_action = call_refresh;
1742         switch (status) {
1743         case 0:
1744                 if (rpcauth_uptodatecred(task)) {
1745                         task->tk_action = call_allocate;
1746                         return;
1747                 }
1748                 /* Use rate-limiting and a max number of retries if refresh
1749                  * had status 0 but failed to update the cred.
1750                  */
1751                 fallthrough;
1752         case -ETIMEDOUT:
1753                 rpc_delay(task, 3*HZ);
1754                 fallthrough;
1755         case -EAGAIN:
1756                 status = -EACCES;
1757                 fallthrough;
1758         case -EKEYEXPIRED:
1759                 if (!task->tk_cred_retry)
1760                         break;
1761                 task->tk_cred_retry--;
1762                 trace_rpc_retry_refresh_status(task);
1763                 return;
1764         }
1765         trace_rpc_refresh_status(task);
1766         rpc_call_rpcerror(task, status);
1767 }
1768
1769 /*
1770  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1771  *      (Note: buffer memory is freed in xprt_release).
1772  */
1773 static void
1774 call_allocate(struct rpc_task *task)
1775 {
1776         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1777         struct rpc_rqst *req = task->tk_rqstp;
1778         struct rpc_xprt *xprt = req->rq_xprt;
1779         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1780         int status;
1781
1782         task->tk_status = 0;
1783         task->tk_action = call_encode;
1784
1785         if (req->rq_buffer)
1786                 return;
1787
1788         if (proc->p_proc != 0) {
1789                 BUG_ON(proc->p_arglen == 0);
1790                 if (proc->p_decode != NULL)
1791                         BUG_ON(proc->p_replen == 0);
1792         }
1793
1794         /*
1795          * Calculate the size (in quads) of the RPC call
1796          * and reply headers, and convert both values
1797          * to byte sizes.
1798          */
1799         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1800                            proc->p_arglen;
1801         req->rq_callsize <<= 2;
1802         /*
1803          * Note: the reply buffer must at minimum allocate enough space
1804          * for the 'struct accepted_reply' from RFC5531.
1805          */
1806         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1807                         max_t(size_t, proc->p_replen, 2);
1808         req->rq_rcvsize <<= 2;
1809
1810         status = xprt->ops->buf_alloc(task);
1811         trace_rpc_buf_alloc(task, status);
1812         if (status == 0)
1813                 return;
1814         if (status != -ENOMEM) {
1815                 rpc_call_rpcerror(task, status);
1816                 return;
1817         }
1818
1819         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1820                 task->tk_action = call_allocate;
1821                 rpc_delay(task, HZ>>4);
1822                 return;
1823         }
1824
1825         rpc_call_rpcerror(task, -ERESTARTSYS);
1826 }
1827
1828 static int
1829 rpc_task_need_encode(struct rpc_task *task)
1830 {
1831         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1832                 (!(task->tk_flags & RPC_TASK_SENT) ||
1833                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1834                  xprt_request_need_retransmit(task));
1835 }
1836
1837 static void
1838 rpc_xdr_encode(struct rpc_task *task)
1839 {
1840         struct rpc_rqst *req = task->tk_rqstp;
1841         struct xdr_stream xdr;
1842
1843         xdr_buf_init(&req->rq_snd_buf,
1844                      req->rq_buffer,
1845                      req->rq_callsize);
1846         xdr_buf_init(&req->rq_rcv_buf,
1847                      req->rq_rbuffer,
1848                      req->rq_rcvsize);
1849
1850         req->rq_reply_bytes_recvd = 0;
1851         req->rq_snd_buf.head[0].iov_len = 0;
1852         xdr_init_encode(&xdr, &req->rq_snd_buf,
1853                         req->rq_snd_buf.head[0].iov_base, req);
1854         xdr_free_bvec(&req->rq_snd_buf);
1855         if (rpc_encode_header(task, &xdr))
1856                 return;
1857
1858         task->tk_status = rpcauth_wrap_req(task, &xdr);
1859 }
1860
1861 /*
1862  * 3.   Encode arguments of an RPC call
1863  */
1864 static void
1865 call_encode(struct rpc_task *task)
1866 {
1867         if (!rpc_task_need_encode(task))
1868                 goto out;
1869
1870         /* Dequeue task from the receive queue while we're encoding */
1871         xprt_request_dequeue_xprt(task);
1872         /* Encode here so that rpcsec_gss can use correct sequence number. */
1873         rpc_xdr_encode(task);
1874         /* Did the encode result in an error condition? */
1875         if (task->tk_status != 0) {
1876                 /* Was the error nonfatal? */
1877                 switch (task->tk_status) {
1878                 case -EAGAIN:
1879                 case -ENOMEM:
1880                         rpc_delay(task, HZ >> 4);
1881                         break;
1882                 case -EKEYEXPIRED:
1883                         if (!task->tk_cred_retry) {
1884                                 rpc_call_rpcerror(task, task->tk_status);
1885                         } else {
1886                                 task->tk_action = call_refresh;
1887                                 task->tk_cred_retry--;
1888                                 trace_rpc_retry_refresh_status(task);
1889                         }
1890                         break;
1891                 default:
1892                         rpc_call_rpcerror(task, task->tk_status);
1893                 }
1894                 return;
1895         }
1896
1897         /* Add task to reply queue before transmission to avoid races */
1898         if (rpc_reply_expected(task))
1899                 xprt_request_enqueue_receive(task);
1900         xprt_request_enqueue_transmit(task);
1901 out:
1902         task->tk_action = call_transmit;
1903         /* Check that the connection is OK */
1904         if (!xprt_bound(task->tk_xprt))
1905                 task->tk_action = call_bind;
1906         else if (!xprt_connected(task->tk_xprt))
1907                 task->tk_action = call_connect;
1908 }
1909
1910 /*
1911  * Helpers to check if the task was already transmitted, and
1912  * to take action when that is the case.
1913  */
1914 static bool
1915 rpc_task_transmitted(struct rpc_task *task)
1916 {
1917         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1918 }
1919
1920 static void
1921 rpc_task_handle_transmitted(struct rpc_task *task)
1922 {
1923         xprt_end_transmit(task);
1924         task->tk_action = call_transmit_status;
1925 }
1926
1927 /*
1928  * 4.   Get the server port number if not yet set
1929  */
1930 static void
1931 call_bind(struct rpc_task *task)
1932 {
1933         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1934
1935         if (rpc_task_transmitted(task)) {
1936                 rpc_task_handle_transmitted(task);
1937                 return;
1938         }
1939
1940         if (xprt_bound(xprt)) {
1941                 task->tk_action = call_connect;
1942                 return;
1943         }
1944
1945         task->tk_action = call_bind_status;
1946         if (!xprt_prepare_transmit(task))
1947                 return;
1948
1949         xprt->ops->rpcbind(task);
1950 }
1951
1952 /*
1953  * 4a.  Sort out bind result
1954  */
1955 static void
1956 call_bind_status(struct rpc_task *task)
1957 {
1958         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1959         int status = -EIO;
1960
1961         if (rpc_task_transmitted(task)) {
1962                 rpc_task_handle_transmitted(task);
1963                 return;
1964         }
1965
1966         if (task->tk_status >= 0)
1967                 goto out_next;
1968         if (xprt_bound(xprt)) {
1969                 task->tk_status = 0;
1970                 goto out_next;
1971         }
1972
1973         switch (task->tk_status) {
1974         case -ENOMEM:
1975                 rpc_delay(task, HZ >> 2);
1976                 goto retry_timeout;
1977         case -EACCES:
1978                 trace_rpcb_prog_unavail_err(task);
1979                 /* fail immediately if this is an RPC ping */
1980                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1981                         status = -EOPNOTSUPP;
1982                         break;
1983                 }
1984                 if (task->tk_rebind_retry == 0)
1985                         break;
1986                 task->tk_rebind_retry--;
1987                 rpc_delay(task, 3*HZ);
1988                 goto retry_timeout;
1989         case -ENOBUFS:
1990                 rpc_delay(task, HZ >> 2);
1991                 goto retry_timeout;
1992         case -EAGAIN:
1993                 goto retry_timeout;
1994         case -ETIMEDOUT:
1995                 trace_rpcb_timeout_err(task);
1996                 goto retry_timeout;
1997         case -EPFNOSUPPORT:
1998                 /* server doesn't support any rpcbind version we know of */
1999                 trace_rpcb_bind_version_err(task);
2000                 break;
2001         case -EPROTONOSUPPORT:
2002                 trace_rpcb_bind_version_err(task);
2003                 goto retry_timeout;
2004         case -ECONNREFUSED:             /* connection problems */
2005         case -ECONNRESET:
2006         case -ECONNABORTED:
2007         case -ENOTCONN:
2008         case -EHOSTDOWN:
2009         case -ENETDOWN:
2010         case -EHOSTUNREACH:
2011         case -ENETUNREACH:
2012         case -EPIPE:
2013                 trace_rpcb_unreachable_err(task);
2014                 if (!RPC_IS_SOFTCONN(task)) {
2015                         rpc_delay(task, 5*HZ);
2016                         goto retry_timeout;
2017                 }
2018                 status = task->tk_status;
2019                 break;
2020         default:
2021                 trace_rpcb_unrecognized_err(task);
2022         }
2023
2024         rpc_call_rpcerror(task, status);
2025         return;
2026 out_next:
2027         task->tk_action = call_connect;
2028         return;
2029 retry_timeout:
2030         task->tk_status = 0;
2031         task->tk_action = call_bind;
2032         rpc_check_timeout(task);
2033 }
2034
2035 /*
2036  * 4b.  Connect to the RPC server
2037  */
2038 static void
2039 call_connect(struct rpc_task *task)
2040 {
2041         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2042
2043         if (rpc_task_transmitted(task)) {
2044                 rpc_task_handle_transmitted(task);
2045                 return;
2046         }
2047
2048         if (xprt_connected(xprt)) {
2049                 task->tk_action = call_transmit;
2050                 return;
2051         }
2052
2053         task->tk_action = call_connect_status;
2054         if (task->tk_status < 0)
2055                 return;
2056         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2057                 rpc_call_rpcerror(task, -ENOTCONN);
2058                 return;
2059         }
2060         if (!xprt_prepare_transmit(task))
2061                 return;
2062         xprt_connect(task);
2063 }
2064
2065 /*
2066  * 4c.  Sort out connect result
2067  */
2068 static void
2069 call_connect_status(struct rpc_task *task)
2070 {
2071         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2072         struct rpc_clnt *clnt = task->tk_client;
2073         int status = task->tk_status;
2074
2075         if (rpc_task_transmitted(task)) {
2076                 rpc_task_handle_transmitted(task);
2077                 return;
2078         }
2079
2080         trace_rpc_connect_status(task);
2081
2082         if (task->tk_status == 0) {
2083                 clnt->cl_stats->netreconn++;
2084                 goto out_next;
2085         }
2086         if (xprt_connected(xprt)) {
2087                 task->tk_status = 0;
2088                 goto out_next;
2089         }
2090
2091         task->tk_status = 0;
2092         switch (status) {
2093         case -ECONNREFUSED:
2094                 /* A positive refusal suggests a rebind is needed. */
2095                 if (RPC_IS_SOFTCONN(task))
2096                         break;
2097                 if (clnt->cl_autobind) {
2098                         rpc_force_rebind(clnt);
2099                         goto out_retry;
2100                 }
2101                 fallthrough;
2102         case -ECONNRESET:
2103         case -ECONNABORTED:
2104         case -ENETDOWN:
2105         case -ENETUNREACH:
2106         case -EHOSTUNREACH:
2107         case -EPIPE:
2108         case -EPROTO:
2109                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2110                                             task->tk_rqstp->rq_connect_cookie);
2111                 if (RPC_IS_SOFTCONN(task))
2112                         break;
2113                 /* retry with existing socket, after a delay */
2114                 rpc_delay(task, 3*HZ);
2115                 fallthrough;
2116         case -EADDRINUSE:
2117         case -ENOTCONN:
2118         case -EAGAIN:
2119         case -ETIMEDOUT:
2120                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2121                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2122                     test_bit(XPRT_REMOVE, &xprt->state)) {
2123                         struct rpc_xprt *saved = task->tk_xprt;
2124                         struct rpc_xprt_switch *xps;
2125
2126                         rcu_read_lock();
2127                         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2128                         rcu_read_unlock();
2129                         if (xps->xps_nxprts > 1) {
2130                                 long value;
2131
2132                                 xprt_release(task);
2133                                 value = atomic_long_dec_return(&xprt->queuelen);
2134                                 if (value == 0)
2135                                         rpc_xprt_switch_remove_xprt(xps, saved);
2136                                 xprt_put(saved);
2137                                 task->tk_xprt = NULL;
2138                                 task->tk_action = call_start;
2139                         }
2140                         xprt_switch_put(xps);
2141                         if (!task->tk_xprt)
2142                                 return;
2143                 }
2144                 goto out_retry;
2145         case -ENOBUFS:
2146                 rpc_delay(task, HZ >> 2);
2147                 goto out_retry;
2148         }
2149         rpc_call_rpcerror(task, status);
2150         return;
2151 out_next:
2152         task->tk_action = call_transmit;
2153         return;
2154 out_retry:
2155         /* Check for timeouts before looping back to call_bind */
2156         task->tk_action = call_bind;
2157         rpc_check_timeout(task);
2158 }
2159
2160 /*
2161  * 5.   Transmit the RPC request, and wait for reply
2162  */
2163 static void
2164 call_transmit(struct rpc_task *task)
2165 {
2166         if (rpc_task_transmitted(task)) {
2167                 rpc_task_handle_transmitted(task);
2168                 return;
2169         }
2170
2171         task->tk_action = call_transmit_status;
2172         if (!xprt_prepare_transmit(task))
2173                 return;
2174         task->tk_status = 0;
2175         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2176                 if (!xprt_connected(task->tk_xprt)) {
2177                         task->tk_status = -ENOTCONN;
2178                         return;
2179                 }
2180                 xprt_transmit(task);
2181         }
2182         xprt_end_transmit(task);
2183 }
2184
2185 /*
2186  * 5a.  Handle cleanup after a transmission
2187  */
2188 static void
2189 call_transmit_status(struct rpc_task *task)
2190 {
2191         task->tk_action = call_status;
2192
2193         /*
2194          * Common case: success.  Force the compiler to put this
2195          * test first.
2196          */
2197         if (rpc_task_transmitted(task)) {
2198                 task->tk_status = 0;
2199                 xprt_request_wait_receive(task);
2200                 return;
2201         }
2202
2203         switch (task->tk_status) {
2204         default:
2205                 break;
2206         case -EBADMSG:
2207                 task->tk_status = 0;
2208                 task->tk_action = call_encode;
2209                 break;
2210                 /*
2211                  * Special cases: if we've been waiting on the
2212                  * socket's write_space() callback, or if the
2213                  * socket just returned a connection error,
2214                  * then hold onto the transport lock.
2215                  */
2216         case -ENOMEM:
2217         case -ENOBUFS:
2218                 rpc_delay(task, HZ>>2);
2219                 fallthrough;
2220         case -EBADSLT:
2221         case -EAGAIN:
2222                 task->tk_action = call_transmit;
2223                 task->tk_status = 0;
2224                 break;
2225         case -ECONNREFUSED:
2226         case -EHOSTDOWN:
2227         case -ENETDOWN:
2228         case -EHOSTUNREACH:
2229         case -ENETUNREACH:
2230         case -EPERM:
2231                 if (RPC_IS_SOFTCONN(task)) {
2232                         if (!task->tk_msg.rpc_proc->p_proc)
2233                                 trace_xprt_ping(task->tk_xprt,
2234                                                 task->tk_status);
2235                         rpc_call_rpcerror(task, task->tk_status);
2236                         return;
2237                 }
2238                 fallthrough;
2239         case -ECONNRESET:
2240         case -ECONNABORTED:
2241         case -EADDRINUSE:
2242         case -ENOTCONN:
2243         case -EPIPE:
2244                 task->tk_action = call_bind;
2245                 task->tk_status = 0;
2246                 break;
2247         }
2248         rpc_check_timeout(task);
2249 }
2250
2251 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2252 static void call_bc_transmit(struct rpc_task *task);
2253 static void call_bc_transmit_status(struct rpc_task *task);
2254
2255 static void
2256 call_bc_encode(struct rpc_task *task)
2257 {
2258         xprt_request_enqueue_transmit(task);
2259         task->tk_action = call_bc_transmit;
2260 }
2261
2262 /*
2263  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2264  * addition, disconnect on connectivity errors.
2265  */
2266 static void
2267 call_bc_transmit(struct rpc_task *task)
2268 {
2269         task->tk_action = call_bc_transmit_status;
2270         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2271                 if (!xprt_prepare_transmit(task))
2272                         return;
2273                 task->tk_status = 0;
2274                 xprt_transmit(task);
2275         }
2276         xprt_end_transmit(task);
2277 }
2278
2279 static void
2280 call_bc_transmit_status(struct rpc_task *task)
2281 {
2282         struct rpc_rqst *req = task->tk_rqstp;
2283
2284         if (rpc_task_transmitted(task))
2285                 task->tk_status = 0;
2286
2287         switch (task->tk_status) {
2288         case 0:
2289                 /* Success */
2290         case -ENETDOWN:
2291         case -EHOSTDOWN:
2292         case -EHOSTUNREACH:
2293         case -ENETUNREACH:
2294         case -ECONNRESET:
2295         case -ECONNREFUSED:
2296         case -EADDRINUSE:
2297         case -ENOTCONN:
2298         case -EPIPE:
2299                 break;
2300         case -ENOMEM:
2301         case -ENOBUFS:
2302                 rpc_delay(task, HZ>>2);
2303                 fallthrough;
2304         case -EBADSLT:
2305         case -EAGAIN:
2306                 task->tk_status = 0;
2307                 task->tk_action = call_bc_transmit;
2308                 return;
2309         case -ETIMEDOUT:
2310                 /*
2311                  * Problem reaching the server.  Disconnect and let the
2312                  * forechannel reestablish the connection.  The server will
2313                  * have to retransmit the backchannel request and we'll
2314                  * reprocess it.  Since these ops are idempotent, there's no
2315                  * need to cache our reply at this time.
2316                  */
2317                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2318                         "error: %d\n", task->tk_status);
2319                 xprt_conditional_disconnect(req->rq_xprt,
2320                         req->rq_connect_cookie);
2321                 break;
2322         default:
2323                 /*
2324                  * We were unable to reply and will have to drop the
2325                  * request.  The server should reconnect and retransmit.
2326                  */
2327                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2328                         "error: %d\n", task->tk_status);
2329                 break;
2330         }
2331         task->tk_action = rpc_exit_task;
2332 }
2333 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2334
2335 /*
2336  * 6.   Sort out the RPC call status
2337  */
2338 static void
2339 call_status(struct rpc_task *task)
2340 {
2341         struct rpc_clnt *clnt = task->tk_client;
2342         int             status;
2343
2344         if (!task->tk_msg.rpc_proc->p_proc)
2345                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2346
2347         status = task->tk_status;
2348         if (status >= 0) {
2349                 task->tk_action = call_decode;
2350                 return;
2351         }
2352
2353         trace_rpc_call_status(task);
2354         task->tk_status = 0;
2355         switch(status) {
2356         case -EHOSTDOWN:
2357         case -ENETDOWN:
2358         case -EHOSTUNREACH:
2359         case -ENETUNREACH:
2360         case -EPERM:
2361                 if (RPC_IS_SOFTCONN(task))
2362                         goto out_exit;
2363                 /*
2364                  * Delay any retries for 3 seconds, then handle as if it
2365                  * were a timeout.
2366                  */
2367                 rpc_delay(task, 3*HZ);
2368                 fallthrough;
2369         case -ETIMEDOUT:
2370                 break;
2371         case -ECONNREFUSED:
2372         case -ECONNRESET:
2373         case -ECONNABORTED:
2374         case -ENOTCONN:
2375                 rpc_force_rebind(clnt);
2376                 break;
2377         case -EADDRINUSE:
2378                 rpc_delay(task, 3*HZ);
2379                 fallthrough;
2380         case -EPIPE:
2381         case -EAGAIN:
2382                 break;
2383         case -ENFILE:
2384         case -ENOBUFS:
2385         case -ENOMEM:
2386                 rpc_delay(task, HZ>>2);
2387                 break;
2388         case -EIO:
2389                 /* shutdown or soft timeout */
2390                 goto out_exit;
2391         default:
2392                 if (clnt->cl_chatty)
2393                         printk("%s: RPC call returned error %d\n",
2394                                clnt->cl_program->name, -status);
2395                 goto out_exit;
2396         }
2397         task->tk_action = call_encode;
2398         if (status != -ECONNRESET && status != -ECONNABORTED)
2399                 rpc_check_timeout(task);
2400         return;
2401 out_exit:
2402         rpc_call_rpcerror(task, status);
2403 }
2404
2405 static bool
2406 rpc_check_connected(const struct rpc_rqst *req)
2407 {
2408         /* No allocated request or transport? return true */
2409         if (!req || !req->rq_xprt)
2410                 return true;
2411         return xprt_connected(req->rq_xprt);
2412 }
2413
2414 static void
2415 rpc_check_timeout(struct rpc_task *task)
2416 {
2417         struct rpc_clnt *clnt = task->tk_client;
2418
2419         if (RPC_SIGNALLED(task)) {
2420                 rpc_call_rpcerror(task, -ERESTARTSYS);
2421                 return;
2422         }
2423
2424         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2425                 return;
2426
2427         trace_rpc_timeout_status(task);
2428         task->tk_timeouts++;
2429
2430         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2431                 rpc_call_rpcerror(task, -ETIMEDOUT);
2432                 return;
2433         }
2434
2435         if (RPC_IS_SOFT(task)) {
2436                 /*
2437                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2438                  * been sent, it should time out only if the transport
2439                  * connection gets terminally broken.
2440                  */
2441                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2442                     rpc_check_connected(task->tk_rqstp))
2443                         return;
2444
2445                 if (clnt->cl_chatty) {
2446                         pr_notice_ratelimited(
2447                                 "%s: server %s not responding, timed out\n",
2448                                 clnt->cl_program->name,
2449                                 task->tk_xprt->servername);
2450                 }
2451                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2452                         rpc_call_rpcerror(task, -ETIMEDOUT);
2453                 else
2454                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2455                 return;
2456         }
2457
2458         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2459                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2460                 if (clnt->cl_chatty) {
2461                         pr_notice_ratelimited(
2462                                 "%s: server %s not responding, still trying\n",
2463                                 clnt->cl_program->name,
2464                                 task->tk_xprt->servername);
2465                 }
2466         }
2467         rpc_force_rebind(clnt);
2468         /*
2469          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2470          * event? RFC2203 requires the server to drop all such requests.
2471          */
2472         rpcauth_invalcred(task);
2473 }
2474
2475 /*
2476  * 7.   Decode the RPC reply
2477  */
2478 static void
2479 call_decode(struct rpc_task *task)
2480 {
2481         struct rpc_clnt *clnt = task->tk_client;
2482         struct rpc_rqst *req = task->tk_rqstp;
2483         struct xdr_stream xdr;
2484         int err;
2485
2486         if (!task->tk_msg.rpc_proc->p_decode) {
2487                 task->tk_action = rpc_exit_task;
2488                 return;
2489         }
2490
2491         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2492                 if (clnt->cl_chatty) {
2493                         pr_notice_ratelimited("%s: server %s OK\n",
2494                                 clnt->cl_program->name,
2495                                 task->tk_xprt->servername);
2496                 }
2497                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2498         }
2499
2500         /*
2501          * Did we ever call xprt_complete_rqst()? If not, we should assume
2502          * the message is incomplete.
2503          */
2504         err = -EAGAIN;
2505         if (!req->rq_reply_bytes_recvd)
2506                 goto out;
2507
2508         /* Ensure that we see all writes made by xprt_complete_rqst()
2509          * before it changed req->rq_reply_bytes_recvd.
2510          */
2511         smp_rmb();
2512
2513         req->rq_rcv_buf.len = req->rq_private_buf.len;
2514         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2515
2516         /* Check that the softirq receive buffer is valid */
2517         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2518                                 sizeof(req->rq_rcv_buf)) != 0);
2519
2520         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2521                         req->rq_rcv_buf.head[0].iov_base, req);
2522         err = rpc_decode_header(task, &xdr);
2523 out:
2524         switch (err) {
2525         case 0:
2526                 task->tk_action = rpc_exit_task;
2527                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2528                 return;
2529         case -EAGAIN:
2530                 task->tk_status = 0;
2531                 if (task->tk_client->cl_discrtry)
2532                         xprt_conditional_disconnect(req->rq_xprt,
2533                                                     req->rq_connect_cookie);
2534                 task->tk_action = call_encode;
2535                 rpc_check_timeout(task);
2536                 break;
2537         case -EKEYREJECTED:
2538                 task->tk_action = call_reserve;
2539                 rpc_check_timeout(task);
2540                 rpcauth_invalcred(task);
2541                 /* Ensure we obtain a new XID if we retry! */
2542                 xprt_release(task);
2543         }
2544 }
2545
2546 static int
2547 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2548 {
2549         struct rpc_clnt *clnt = task->tk_client;
2550         struct rpc_rqst *req = task->tk_rqstp;
2551         __be32 *p;
2552         int error;
2553
2554         error = -EMSGSIZE;
2555         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2556         if (!p)
2557                 goto out_fail;
2558         *p++ = req->rq_xid;
2559         *p++ = rpc_call;
2560         *p++ = cpu_to_be32(RPC_VERSION);
2561         *p++ = cpu_to_be32(clnt->cl_prog);
2562         *p++ = cpu_to_be32(clnt->cl_vers);
2563         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2564
2565         error = rpcauth_marshcred(task, xdr);
2566         if (error < 0)
2567                 goto out_fail;
2568         return 0;
2569 out_fail:
2570         trace_rpc_bad_callhdr(task);
2571         rpc_call_rpcerror(task, error);
2572         return error;
2573 }
2574
2575 static noinline int
2576 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2577 {
2578         struct rpc_clnt *clnt = task->tk_client;
2579         int error;
2580         __be32 *p;
2581
2582         /* RFC-1014 says that the representation of XDR data must be a
2583          * multiple of four bytes
2584          * - if it isn't pointer subtraction in the NFS client may give
2585          *   undefined results
2586          */
2587         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2588                 goto out_unparsable;
2589
2590         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2591         if (!p)
2592                 goto out_unparsable;
2593         p++;    /* skip XID */
2594         if (*p++ != rpc_reply)
2595                 goto out_unparsable;
2596         if (*p++ != rpc_msg_accepted)
2597                 goto out_msg_denied;
2598
2599         error = rpcauth_checkverf(task, xdr);
2600         if (error)
2601                 goto out_verifier;
2602
2603         p = xdr_inline_decode(xdr, sizeof(*p));
2604         if (!p)
2605                 goto out_unparsable;
2606         switch (*p) {
2607         case rpc_success:
2608                 return 0;
2609         case rpc_prog_unavail:
2610                 trace_rpc__prog_unavail(task);
2611                 error = -EPFNOSUPPORT;
2612                 goto out_err;
2613         case rpc_prog_mismatch:
2614                 trace_rpc__prog_mismatch(task);
2615                 error = -EPROTONOSUPPORT;
2616                 goto out_err;
2617         case rpc_proc_unavail:
2618                 trace_rpc__proc_unavail(task);
2619                 error = -EOPNOTSUPP;
2620                 goto out_err;
2621         case rpc_garbage_args:
2622         case rpc_system_err:
2623                 trace_rpc__garbage_args(task);
2624                 error = -EIO;
2625                 break;
2626         default:
2627                 goto out_unparsable;
2628         }
2629
2630 out_garbage:
2631         clnt->cl_stats->rpcgarbage++;
2632         if (task->tk_garb_retry) {
2633                 task->tk_garb_retry--;
2634                 task->tk_action = call_encode;
2635                 return -EAGAIN;
2636         }
2637 out_err:
2638         rpc_call_rpcerror(task, error);
2639         return error;
2640
2641 out_unparsable:
2642         trace_rpc__unparsable(task);
2643         error = -EIO;
2644         goto out_garbage;
2645
2646 out_verifier:
2647         trace_rpc_bad_verifier(task);
2648         goto out_garbage;
2649
2650 out_msg_denied:
2651         error = -EACCES;
2652         p = xdr_inline_decode(xdr, sizeof(*p));
2653         if (!p)
2654                 goto out_unparsable;
2655         switch (*p++) {
2656         case rpc_auth_error:
2657                 break;
2658         case rpc_mismatch:
2659                 trace_rpc__mismatch(task);
2660                 error = -EPROTONOSUPPORT;
2661                 goto out_err;
2662         default:
2663                 goto out_unparsable;
2664         }
2665
2666         p = xdr_inline_decode(xdr, sizeof(*p));
2667         if (!p)
2668                 goto out_unparsable;
2669         switch (*p++) {
2670         case rpc_autherr_rejectedcred:
2671         case rpc_autherr_rejectedverf:
2672         case rpcsec_gsserr_credproblem:
2673         case rpcsec_gsserr_ctxproblem:
2674                 if (!task->tk_cred_retry)
2675                         break;
2676                 task->tk_cred_retry--;
2677                 trace_rpc__stale_creds(task);
2678                 return -EKEYREJECTED;
2679         case rpc_autherr_badcred:
2680         case rpc_autherr_badverf:
2681                 /* possibly garbled cred/verf? */
2682                 if (!task->tk_garb_retry)
2683                         break;
2684                 task->tk_garb_retry--;
2685                 trace_rpc__bad_creds(task);
2686                 task->tk_action = call_encode;
2687                 return -EAGAIN;
2688         case rpc_autherr_tooweak:
2689                 trace_rpc__auth_tooweak(task);
2690                 pr_warn("RPC: server %s requires stronger authentication.\n",
2691                         task->tk_xprt->servername);
2692                 break;
2693         default:
2694                 goto out_unparsable;
2695         }
2696         goto out_err;
2697 }
2698
2699 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2700                 const void *obj)
2701 {
2702 }
2703
2704 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2705                 void *obj)
2706 {
2707         return 0;
2708 }
2709
2710 static const struct rpc_procinfo rpcproc_null = {
2711         .p_encode = rpcproc_encode_null,
2712         .p_decode = rpcproc_decode_null,
2713 };
2714
2715 static const struct rpc_procinfo rpcproc_null_noreply = {
2716         .p_encode = rpcproc_encode_null,
2717 };
2718
2719 static void
2720 rpc_null_call_prepare(struct rpc_task *task, void *data)
2721 {
2722         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2723         rpc_call_start(task);
2724 }
2725
2726 static const struct rpc_call_ops rpc_null_ops = {
2727         .rpc_call_prepare = rpc_null_call_prepare,
2728         .rpc_call_done = rpc_default_callback,
2729 };
2730
2731 static
2732 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2733                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2734                 const struct rpc_call_ops *ops, void *data)
2735 {
2736         struct rpc_message msg = {
2737                 .rpc_proc = &rpcproc_null,
2738         };
2739         struct rpc_task_setup task_setup_data = {
2740                 .rpc_client = clnt,
2741                 .rpc_xprt = xprt,
2742                 .rpc_message = &msg,
2743                 .rpc_op_cred = cred,
2744                 .callback_ops = ops ?: &rpc_null_ops,
2745                 .callback_data = data,
2746                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2747                          RPC_TASK_NULLCREDS,
2748         };
2749
2750         return rpc_run_task(&task_setup_data);
2751 }
2752
2753 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2754 {
2755         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2756 }
2757 EXPORT_SYMBOL_GPL(rpc_call_null);
2758
2759 static int rpc_ping(struct rpc_clnt *clnt)
2760 {
2761         struct rpc_task *task;
2762         int status;
2763
2764         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2765         if (IS_ERR(task))
2766                 return PTR_ERR(task);
2767         status = task->tk_status;
2768         rpc_put_task(task);
2769         return status;
2770 }
2771
2772 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2773 {
2774         struct rpc_message msg = {
2775                 .rpc_proc = &rpcproc_null_noreply,
2776         };
2777         struct rpc_task_setup task_setup_data = {
2778                 .rpc_client = clnt,
2779                 .rpc_message = &msg,
2780                 .callback_ops = &rpc_null_ops,
2781                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2782         };
2783         struct rpc_task *task;
2784         int status;
2785
2786         task = rpc_run_task(&task_setup_data);
2787         if (IS_ERR(task))
2788                 return PTR_ERR(task);
2789         status = task->tk_status;
2790         rpc_put_task(task);
2791         return status;
2792 }
2793
2794 struct rpc_cb_add_xprt_calldata {
2795         struct rpc_xprt_switch *xps;
2796         struct rpc_xprt *xprt;
2797 };
2798
2799 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2800 {
2801         struct rpc_cb_add_xprt_calldata *data = calldata;
2802
2803         if (task->tk_status == 0)
2804                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2805 }
2806
2807 static void rpc_cb_add_xprt_release(void *calldata)
2808 {
2809         struct rpc_cb_add_xprt_calldata *data = calldata;
2810
2811         xprt_put(data->xprt);
2812         xprt_switch_put(data->xps);
2813         kfree(data);
2814 }
2815
2816 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2817         .rpc_call_prepare = rpc_null_call_prepare,
2818         .rpc_call_done = rpc_cb_add_xprt_done,
2819         .rpc_release = rpc_cb_add_xprt_release,
2820 };
2821
2822 /**
2823  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2824  * @clnt: pointer to struct rpc_clnt
2825  * @xps: pointer to struct rpc_xprt_switch,
2826  * @xprt: pointer struct rpc_xprt
2827  * @dummy: unused
2828  */
2829 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2830                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2831                 void *dummy)
2832 {
2833         struct rpc_cb_add_xprt_calldata *data;
2834         struct rpc_task *task;
2835
2836         if (xps->xps_nunique_destaddr_xprts + 1 > clnt->cl_max_connect) {
2837                 rcu_read_lock();
2838                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2839                         "transport to server: %s\n", clnt->cl_max_connect,
2840                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2841                 rcu_read_unlock();
2842                 return -EINVAL;
2843         }
2844
2845         data = kmalloc(sizeof(*data), GFP_NOFS);
2846         if (!data)
2847                 return -ENOMEM;
2848         data->xps = xprt_switch_get(xps);
2849         data->xprt = xprt_get(xprt);
2850         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2851                 rpc_cb_add_xprt_release(data);
2852                 goto success;
2853         }
2854
2855         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2856                         &rpc_cb_add_xprt_call_ops, data);
2857         data->xps->xps_nunique_destaddr_xprts++;
2858         rpc_put_task(task);
2859 success:
2860         return 1;
2861 }
2862 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2863
2864 /**
2865  * rpc_clnt_setup_test_and_add_xprt()
2866  *
2867  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2868  *   1) caller of the test function must dereference the rpc_xprt_switch
2869  *   and the rpc_xprt.
2870  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2871  *   the rpc_call_done routine.
2872  *
2873  * Upon success (return of 1), the test function adds the new
2874  * transport to the rpc_clnt xprt switch
2875  *
2876  * @clnt: struct rpc_clnt to get the new transport
2877  * @xps:  the rpc_xprt_switch to hold the new transport
2878  * @xprt: the rpc_xprt to test
2879  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2880  *        and test function call data
2881  */
2882 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2883                                      struct rpc_xprt_switch *xps,
2884                                      struct rpc_xprt *xprt,
2885                                      void *data)
2886 {
2887         struct rpc_task *task;
2888         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2889         int status = -EADDRINUSE;
2890
2891         xprt = xprt_get(xprt);
2892         xprt_switch_get(xps);
2893
2894         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2895                 goto out_err;
2896
2897         /* Test the connection */
2898         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2899         if (IS_ERR(task)) {
2900                 status = PTR_ERR(task);
2901                 goto out_err;
2902         }
2903         status = task->tk_status;
2904         rpc_put_task(task);
2905
2906         if (status < 0)
2907                 goto out_err;
2908
2909         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2910         xtest->add_xprt_test(clnt, xprt, xtest->data);
2911
2912         xprt_put(xprt);
2913         xprt_switch_put(xps);
2914
2915         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2916         return 1;
2917 out_err:
2918         xprt_put(xprt);
2919         xprt_switch_put(xps);
2920         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2921                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2922         return status;
2923 }
2924 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2925
2926 /**
2927  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2928  * @clnt: pointer to struct rpc_clnt
2929  * @xprtargs: pointer to struct xprt_create
2930  * @setup: callback to test and/or set up the connection
2931  * @data: pointer to setup function data
2932  *
2933  * Creates a new transport using the parameters set in args and
2934  * adds it to clnt.
2935  * If ping is set, then test that connectivity succeeds before
2936  * adding the new transport.
2937  *
2938  */
2939 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2940                 struct xprt_create *xprtargs,
2941                 int (*setup)(struct rpc_clnt *,
2942                         struct rpc_xprt_switch *,
2943                         struct rpc_xprt *,
2944                         void *),
2945                 void *data)
2946 {
2947         struct rpc_xprt_switch *xps;
2948         struct rpc_xprt *xprt;
2949         unsigned long connect_timeout;
2950         unsigned long reconnect_timeout;
2951         unsigned char resvport, reuseport;
2952         int ret = 0, ident;
2953
2954         rcu_read_lock();
2955         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2956         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2957         if (xps == NULL || xprt == NULL) {
2958                 rcu_read_unlock();
2959                 xprt_switch_put(xps);
2960                 return -EAGAIN;
2961         }
2962         resvport = xprt->resvport;
2963         reuseport = xprt->reuseport;
2964         connect_timeout = xprt->connect_timeout;
2965         reconnect_timeout = xprt->max_reconnect_timeout;
2966         ident = xprt->xprt_class->ident;
2967         rcu_read_unlock();
2968
2969         if (!xprtargs->ident)
2970                 xprtargs->ident = ident;
2971         xprt = xprt_create_transport(xprtargs);
2972         if (IS_ERR(xprt)) {
2973                 ret = PTR_ERR(xprt);
2974                 goto out_put_switch;
2975         }
2976         xprt->resvport = resvport;
2977         xprt->reuseport = reuseport;
2978         if (xprt->ops->set_connect_timeout != NULL)
2979                 xprt->ops->set_connect_timeout(xprt,
2980                                 connect_timeout,
2981                                 reconnect_timeout);
2982
2983         rpc_xprt_switch_set_roundrobin(xps);
2984         if (setup) {
2985                 ret = setup(clnt, xps, xprt, data);
2986                 if (ret != 0)
2987                         goto out_put_xprt;
2988         }
2989         rpc_xprt_switch_add_xprt(xps, xprt);
2990 out_put_xprt:
2991         xprt_put(xprt);
2992 out_put_switch:
2993         xprt_switch_put(xps);
2994         return ret;
2995 }
2996 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2997
2998 struct connect_timeout_data {
2999         unsigned long connect_timeout;
3000         unsigned long reconnect_timeout;
3001 };
3002
3003 static int
3004 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3005                 struct rpc_xprt *xprt,
3006                 void *data)
3007 {
3008         struct connect_timeout_data *timeo = data;
3009
3010         if (xprt->ops->set_connect_timeout)
3011                 xprt->ops->set_connect_timeout(xprt,
3012                                 timeo->connect_timeout,
3013                                 timeo->reconnect_timeout);
3014         return 0;
3015 }
3016
3017 void
3018 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3019                 unsigned long connect_timeout,
3020                 unsigned long reconnect_timeout)
3021 {
3022         struct connect_timeout_data timeout = {
3023                 .connect_timeout = connect_timeout,
3024                 .reconnect_timeout = reconnect_timeout,
3025         };
3026         rpc_clnt_iterate_for_each_xprt(clnt,
3027                         rpc_xprt_set_connect_timeout,
3028                         &timeout);
3029 }
3030 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3031
3032 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
3033 {
3034         rcu_read_lock();
3035         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3036         rcu_read_unlock();
3037 }
3038 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
3039
3040 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3041 {
3042         rcu_read_lock();
3043         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3044                                  xprt);
3045         rcu_read_unlock();
3046 }
3047 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3048
3049 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3050                                    const struct sockaddr *sap)
3051 {
3052         struct rpc_xprt_switch *xps;
3053         bool ret;
3054
3055         rcu_read_lock();
3056         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3057         ret = rpc_xprt_switch_has_addr(xps, sap);
3058         rcu_read_unlock();
3059         return ret;
3060 }
3061 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3062
3063 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3064 static void rpc_show_header(void)
3065 {
3066         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3067                 "-timeout ---ops--\n");
3068 }
3069
3070 static void rpc_show_task(const struct rpc_clnt *clnt,
3071                           const struct rpc_task *task)
3072 {
3073         const char *rpc_waitq = "none";
3074
3075         if (RPC_IS_QUEUED(task))
3076                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3077
3078         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3079                 task->tk_pid, task->tk_flags, task->tk_status,
3080                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3081                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3082                 task->tk_action, rpc_waitq);
3083 }
3084
3085 void rpc_show_tasks(struct net *net)
3086 {
3087         struct rpc_clnt *clnt;
3088         struct rpc_task *task;
3089         int header = 0;
3090         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3091
3092         spin_lock(&sn->rpc_client_lock);
3093         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3094                 spin_lock(&clnt->cl_lock);
3095                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3096                         if (!header) {
3097                                 rpc_show_header();
3098                                 header++;
3099                         }
3100                         rpc_show_task(clnt, task);
3101                 }
3102                 spin_unlock(&clnt->cl_lock);
3103         }
3104         spin_unlock(&sn->rpc_client_lock);
3105 }
3106 #endif
3107
3108 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3109 static int
3110 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3111                 struct rpc_xprt *xprt,
3112                 void *dummy)
3113 {
3114         return xprt_enable_swap(xprt);
3115 }
3116
3117 int
3118 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3119 {
3120         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3121                 return rpc_clnt_iterate_for_each_xprt(clnt,
3122                                 rpc_clnt_swap_activate_callback, NULL);
3123         return 0;
3124 }
3125 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3126
3127 static int
3128 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3129                 struct rpc_xprt *xprt,
3130                 void *dummy)
3131 {
3132         xprt_disable_swap(xprt);
3133         return 0;
3134 }
3135
3136 void
3137 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3138 {
3139         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3140                 rpc_clnt_iterate_for_each_xprt(clnt,
3141                                 rpc_clnt_swap_deactivate_callback, NULL);
3142 }
3143 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3144 #endif /* CONFIG_SUNRPC_SWAP */