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