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         return new;
 655
 656 out_err:
 657         trace_rpc_clnt_clone_err(clnt, err);
 658         return ERR_PTR(err);
 659 }
 660
 661 /**
 662  * rpc_clone_client - Clone an RPC client structure
 663  *
 664  * @clnt: RPC client whose parameters are copied
 665  *
 666  * Returns a fresh RPC client or an ERR_PTR.
 667  */
 668 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 669 {
 670         struct rpc_create_args args = {
 671                 .program        = clnt->cl_program,
 672                 .prognumber     = clnt->cl_prog,
 673                 .version        = clnt->cl_vers,
 674                 .authflavor     = clnt->cl_auth->au_flavor,
 675                 .cred           = clnt->cl_cred,
 676         };
 677         return __rpc_clone_client(&args, clnt);
 678 }
 679 EXPORT_SYMBOL_GPL(rpc_clone_client);
 680
 681 /**
 682  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 683  *
 684  * @clnt: RPC client whose parameters are copied
 685  * @flavor: security flavor for new client
 686  *
 687  * Returns a fresh RPC client or an ERR_PTR.
 688  */
 689 struct rpc_clnt *
 690 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 691 {
 692         struct rpc_create_args args = {
 693                 .program        = clnt->cl_program,
 694                 .prognumber     = clnt->cl_prog,
 695                 .version        = clnt->cl_vers,
 696                 .authflavor     = flavor,
 697                 .cred           = clnt->cl_cred,
 698         };
 699         return __rpc_clone_client(&args, clnt);
 700 }
 701 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 702
 703 /**
 704  * rpc_switch_client_transport: switch the RPC transport on the fly
 705  * @clnt: pointer to a struct rpc_clnt
 706  * @args: pointer to the new transport arguments
 707  * @timeout: pointer to the new timeout parameters
 708  *
 709  * This function allows the caller to switch the RPC transport for the
 710  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 711  * server, for instance.  It assumes that the caller has ensured that
 712  * there are no active RPC tasks by using some form of locking.
 713  *
 714  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 715  * negative errno is returned, and "clnt" continues to use the old
 716  * xprt.
 717  */
 718 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 719                 struct xprt_create *args,
 720                 const struct rpc_timeout *timeout)
 721 {
 722         const struct rpc_timeout *old_timeo;
 723         rpc_authflavor_t pseudoflavor;
 724         struct rpc_xprt_switch *xps, *oldxps;
 725         struct rpc_xprt *xprt, *old;
 726         struct rpc_clnt *parent;
 727         int err;
 728
 729         xprt = xprt_create_transport(args);
 730         if (IS_ERR(xprt))
 731                 return PTR_ERR(xprt);
 732
 733         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 734         if (xps == NULL) {
 735                 xprt_put(xprt);
 736                 return -ENOMEM;
 737         }
 738
 739         pseudoflavor = clnt->cl_auth->au_flavor;
 740
 741         old_timeo = clnt->cl_timeout;
 742         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 743         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 744
 745         rpc_unregister_client(clnt);
 746         __rpc_clnt_remove_pipedir(clnt);
 747         rpc_sysfs_client_destroy(clnt);
 748         rpc_clnt_debugfs_unregister(clnt);
 749
 750         /*
 751          * A new transport was created.  "clnt" therefore
 752          * becomes the root of a new cl_parent tree.  clnt's
 753          * children, if it has any, still point to the old xprt.
 754          */
 755         parent = clnt->cl_parent;
 756         clnt->cl_parent = clnt;
 757
 758         /*
 759          * The old rpc_auth cache cannot be re-used.  GSS
 760          * contexts in particular are between a single
 761          * client and server.
 762          */
 763         err = rpc_client_register(clnt, pseudoflavor, NULL);
 764         if (err)
 765                 goto out_revert;
 766
 767         synchronize_rcu();
 768         if (parent != clnt)
 769                 rpc_release_client(parent);
 770         xprt_switch_put(oldxps);
 771         xprt_put(old);
 772         trace_rpc_clnt_replace_xprt(clnt);
 773         return 0;
 774
 775 out_revert:
 776         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 777         rpc_clnt_set_transport(clnt, old, old_timeo);
 778         clnt->cl_parent = parent;
 779         rpc_client_register(clnt, pseudoflavor, NULL);
 780         xprt_switch_put(xps);
 781         xprt_put(xprt);
 782         trace_rpc_clnt_replace_xprt_err(clnt);
 783         return err;
 784 }
 785 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 786
 787 static
 788 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 789 {
 790         struct rpc_xprt_switch *xps;
 791
 792         rcu_read_lock();
 793         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 794         rcu_read_unlock();
 795         if (xps == NULL)
 796                 return -EAGAIN;
 797         xprt_iter_init_listall(xpi, xps);
 798         xprt_switch_put(xps);
 799         return 0;
 800 }
 801
 802 /**
 803  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 804  * @clnt: pointer to client
 805  * @fn: function to apply
 806  * @data: void pointer to function data
 807  *
 808  * Iterates through the list of RPC transports currently attached to the
 809  * client and applies the function fn(clnt, xprt, data).
 810  *
 811  * On error, the iteration stops, and the function returns the error value.
 812  */
 813 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 814                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 815                 void *data)
 816 {
 817         struct rpc_xprt_iter xpi;
 818         int ret;
 819
 820         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 821         if (ret)
 822                 return ret;
 823         for (;;) {
 824                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 825
 826                 if (!xprt)
 827                         break;
 828                 ret = fn(clnt, xprt, data);
 829                 xprt_put(xprt);
 830                 if (ret < 0)
 831                         break;
 832         }
 833         xprt_iter_destroy(&xpi);
 834         return ret;
 835 }
 836 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 837
 838 /*
 839  * Kill all tasks for the given client.
 840  * XXX: kill their descendants as well?
 841  */
 842 void rpc_killall_tasks(struct rpc_clnt *clnt)
 843 {
 844         struct rpc_task *rovr;
 845
 846
 847         if (list_empty(&clnt->cl_tasks))
 848                 return;
 849
 850         /*
 851          * Spin lock all_tasks to prevent changes...
 852          */
 853         trace_rpc_clnt_killall(clnt);
 854         spin_lock(&clnt->cl_lock);
 855         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 856                 rpc_signal_task(rovr);
 857         spin_unlock(&clnt->cl_lock);
 858 }
 859 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 860
 861 /*
 862  * Properly shut down an RPC client, terminating all outstanding
 863  * requests.
 864  */
 865 void rpc_shutdown_client(struct rpc_clnt *clnt)
 866 {
 867         might_sleep();
 868
 869         trace_rpc_clnt_shutdown(clnt);
 870
 871         while (!list_empty(&clnt->cl_tasks)) {
 872                 rpc_killall_tasks(clnt);
 873                 wait_event_timeout(destroy_wait,
 874                         list_empty(&clnt->cl_tasks), 1*HZ);
 875         }
 876
 877         rpc_release_client(clnt);
 878 }
 879 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 880
 881 /*
 882  * Free an RPC client
 883  */
 884 static void rpc_free_client_work(struct work_struct *work)
 885 {
 886         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 887
 888         trace_rpc_clnt_free(clnt);
 889
 890         /* These might block on processes that might allocate memory,
 891          * so they cannot be called in rpciod, so they are handled separately
 892          * here.
 893          */
 894         rpc_sysfs_client_destroy(clnt);
 895         rpc_clnt_debugfs_unregister(clnt);
 896         rpc_free_clid(clnt);
 897         rpc_clnt_remove_pipedir(clnt);
 898         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 899
 900         kfree(clnt);
 901         rpciod_down();
 902 }
 903 static struct rpc_clnt *
 904 rpc_free_client(struct rpc_clnt *clnt)
 905 {
 906         struct rpc_clnt *parent = NULL;
 907
 908         trace_rpc_clnt_release(clnt);
 909         if (clnt->cl_parent != clnt)
 910                 parent = clnt->cl_parent;
 911         rpc_unregister_client(clnt);
 912         rpc_free_iostats(clnt->cl_metrics);
 913         clnt->cl_metrics = NULL;
 914         xprt_iter_destroy(&clnt->cl_xpi);
 915         put_cred(clnt->cl_cred);
 916
 917         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 918         schedule_work(&clnt->cl_work);
 919         return parent;
 920 }
 921
 922 /*
 923  * Free an RPC client
 924  */
 925 static struct rpc_clnt *
 926 rpc_free_auth(struct rpc_clnt *clnt)
 927 {
 928         /*
 929          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 930          *       release remaining GSS contexts. This mechanism ensures
 931          *       that it can do so safely.
 932          */
 933         if (clnt->cl_auth != NULL) {
 934                 rpcauth_release(clnt->cl_auth);
 935                 clnt->cl_auth = NULL;
 936         }
 937         if (refcount_dec_and_test(&clnt->cl_count))
 938                 return rpc_free_client(clnt);
 939         return NULL;
 940 }
 941
 942 /*
 943  * Release reference to the RPC client
 944  */
 945 void
 946 rpc_release_client(struct rpc_clnt *clnt)
 947 {
 948         do {
 949                 if (list_empty(&clnt->cl_tasks))
 950                         wake_up(&destroy_wait);
 951                 if (refcount_dec_not_one(&clnt->cl_count))
 952                         break;
 953                 clnt = rpc_free_auth(clnt);
 954         } while (clnt != NULL);
 955 }
 956 EXPORT_SYMBOL_GPL(rpc_release_client);
 957
 958 /**
 959  * rpc_bind_new_program - bind a new RPC program to an existing client
 960  * @old: old rpc_client
 961  * @program: rpc program to set
 962  * @vers: rpc program version
 963  *
 964  * Clones the rpc client and sets up a new RPC program. This is mainly
 965  * of use for enabling different RPC programs to share the same transport.
 966  * The Sun NFSv2/v3 ACL protocol can do this.
 967  */
 968 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 969                                       const struct rpc_program *program,
 970                                       u32 vers)
 971 {
 972         struct rpc_create_args args = {
 973                 .program        = program,
 974                 .prognumber     = program->number,
 975                 .version        = vers,
 976                 .authflavor     = old->cl_auth->au_flavor,
 977                 .cred           = old->cl_cred,
 978         };
 979         struct rpc_clnt *clnt;
 980         int err;
 981
 982         clnt = __rpc_clone_client(&args, old);
 983         if (IS_ERR(clnt))
 984                 goto out;
 985         err = rpc_ping(clnt);
 986         if (err != 0) {
 987                 rpc_shutdown_client(clnt);
 988                 clnt = ERR_PTR(err);
 989         }
 990 out:
 991         return clnt;
 992 }
 993 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 994
 995 struct rpc_xprt *
 996 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 997 {
 998         struct rpc_xprt_switch *xps;
 999
1000         if (!xprt)
1001                 return NULL;
1002         rcu_read_lock();
1003         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1004         atomic_long_inc(&xps->xps_queuelen);
1005         rcu_read_unlock();
1006         atomic_long_inc(&xprt->queuelen);
1007
1008         return xprt;
1009 }
1010
1011 static void
1012 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1013 {
1014         struct rpc_xprt_switch *xps;
1015
1016         atomic_long_dec(&xprt->queuelen);
1017         rcu_read_lock();
1018         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1019         atomic_long_dec(&xps->xps_queuelen);
1020         rcu_read_unlock();
1021
1022         xprt_put(xprt);
1023 }
1024
1025 void rpc_task_release_transport(struct rpc_task *task)
1026 {
1027         struct rpc_xprt *xprt = task->tk_xprt;
1028
1029         if (xprt) {
1030                 task->tk_xprt = NULL;
1031                 if (task->tk_client)
1032                         rpc_task_release_xprt(task->tk_client, xprt);
1033                 else
1034                         xprt_put(xprt);
1035         }
1036 }
1037 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1038
1039 void rpc_task_release_client(struct rpc_task *task)
1040 {
1041         struct rpc_clnt *clnt = task->tk_client;
1042
1043         rpc_task_release_transport(task);
1044         if (clnt != NULL) {
1045                 /* Remove from client task list */
1046                 spin_lock(&clnt->cl_lock);
1047                 list_del(&task->tk_task);
1048                 spin_unlock(&clnt->cl_lock);
1049                 task->tk_client = NULL;
1050
1051                 rpc_release_client(clnt);
1052         }
1053 }
1054
1055 static struct rpc_xprt *
1056 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1057 {
1058         struct rpc_xprt *xprt;
1059
1060         rcu_read_lock();
1061         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1062         rcu_read_unlock();
1063         return rpc_task_get_xprt(clnt, xprt);
1064 }
1065
1066 static struct rpc_xprt *
1067 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1068 {
1069         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1070 }
1071
1072 static
1073 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1074 {
1075         if (task->tk_xprt) {
1076                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1077                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1078                         return;
1079                 xprt_release(task);
1080                 xprt_put(task->tk_xprt);
1081         }
1082         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1083                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1084         else
1085                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1086 }
1087
1088 static
1089 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1090 {
1091         rpc_task_set_transport(task, clnt);
1092         task->tk_client = clnt;
1093         refcount_inc(&clnt->cl_count);
1094         if (clnt->cl_softrtry)
1095                 task->tk_flags |= RPC_TASK_SOFT;
1096         if (clnt->cl_softerr)
1097                 task->tk_flags |= RPC_TASK_TIMEOUT;
1098         if (clnt->cl_noretranstimeo)
1099                 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1100         /* Add to the client's list of all tasks */
1101         spin_lock(&clnt->cl_lock);
1102         list_add_tail(&task->tk_task, &clnt->cl_tasks);
1103         spin_unlock(&clnt->cl_lock);
1104 }
1105
1106 static void
1107 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1108 {
1109         if (msg != NULL) {
1110                 task->tk_msg.rpc_proc = msg->rpc_proc;
1111                 task->tk_msg.rpc_argp = msg->rpc_argp;
1112                 task->tk_msg.rpc_resp = msg->rpc_resp;
1113                 task->tk_msg.rpc_cred = msg->rpc_cred;
1114                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1115                         get_cred(task->tk_msg.rpc_cred);
1116         }
1117 }
1118
1119 /*
1120  * Default callback for async RPC calls
1121  */
1122 static void
1123 rpc_default_callback(struct rpc_task *task, void *data)
1124 {
1125 }
1126
1127 static const struct rpc_call_ops rpc_default_ops = {
1128         .rpc_call_done = rpc_default_callback,
1129 };
1130
1131 /**
1132  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1133  * @task_setup_data: pointer to task initialisation data
1134  */
1135 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1136 {
1137         struct rpc_task *task;
1138
1139         task = rpc_new_task(task_setup_data);
1140         if (IS_ERR(task))
1141                 return task;
1142
1143         if (!RPC_IS_ASYNC(task))
1144                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1145
1146         rpc_task_set_client(task, task_setup_data->rpc_client);
1147         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1148
1149         if (task->tk_action == NULL)
1150                 rpc_call_start(task);
1151
1152         atomic_inc(&task->tk_count);
1153         rpc_execute(task);
1154         return task;
1155 }
1156 EXPORT_SYMBOL_GPL(rpc_run_task);
1157
1158 /**
1159  * rpc_call_sync - Perform a synchronous RPC call
1160  * @clnt: pointer to RPC client
1161  * @msg: RPC call parameters
1162  * @flags: RPC call flags
1163  */
1164 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1165 {
1166         struct rpc_task *task;
1167         struct rpc_task_setup task_setup_data = {
1168                 .rpc_client = clnt,
1169                 .rpc_message = msg,
1170                 .callback_ops = &rpc_default_ops,
1171                 .flags = flags,
1172         };
1173         int status;
1174
1175         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1176         if (flags & RPC_TASK_ASYNC) {
1177                 rpc_release_calldata(task_setup_data.callback_ops,
1178                         task_setup_data.callback_data);
1179                 return -EINVAL;
1180         }
1181
1182         task = rpc_run_task(&task_setup_data);
1183         if (IS_ERR(task))
1184                 return PTR_ERR(task);
1185         status = task->tk_status;
1186         rpc_put_task(task);
1187         return status;
1188 }
1189 EXPORT_SYMBOL_GPL(rpc_call_sync);
1190
1191 /**
1192  * rpc_call_async - Perform an asynchronous RPC call
1193  * @clnt: pointer to RPC client
1194  * @msg: RPC call parameters
1195  * @flags: RPC call flags
1196  * @tk_ops: RPC call ops
1197  * @data: user call data
1198  */
1199 int
1200 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1201                const struct rpc_call_ops *tk_ops, void *data)
1202 {
1203         struct rpc_task *task;
1204         struct rpc_task_setup task_setup_data = {
1205                 .rpc_client = clnt,
1206                 .rpc_message = msg,
1207                 .callback_ops = tk_ops,
1208                 .callback_data = data,
1209                 .flags = flags|RPC_TASK_ASYNC,
1210         };
1211
1212         task = rpc_run_task(&task_setup_data);
1213         if (IS_ERR(task))
1214                 return PTR_ERR(task);
1215         rpc_put_task(task);
1216         return 0;
1217 }
1218 EXPORT_SYMBOL_GPL(rpc_call_async);
1219
1220 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1221 static void call_bc_encode(struct rpc_task *task);
1222
1223 /**
1224  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1225  * rpc_execute against it
1226  * @req: RPC request
1227  */
1228 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1229 {
1230         struct rpc_task *task;
1231         struct rpc_task_setup task_setup_data = {
1232                 .callback_ops = &rpc_default_ops,
1233                 .flags = RPC_TASK_SOFTCONN |
1234                         RPC_TASK_NO_RETRANS_TIMEOUT,
1235         };
1236
1237         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1238         /*
1239          * Create an rpc_task to send the data
1240          */
1241         task = rpc_new_task(&task_setup_data);
1242         if (IS_ERR(task)) {
1243                 xprt_free_bc_request(req);
1244                 return task;
1245         }
1246
1247         xprt_init_bc_request(req, task);
1248
1249         task->tk_action = call_bc_encode;
1250         atomic_inc(&task->tk_count);
1251         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1252         rpc_execute(task);
1253
1254         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1255         return task;
1256 }
1257 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1258
1259 /**
1260  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1261  * @req: RPC request to prepare
1262  * @pages: vector of struct page pointers
1263  * @base: offset in first page where receive should start, in bytes
1264  * @len: expected size of the upper layer data payload, in bytes
1265  * @hdrsize: expected size of upper layer reply header, in XDR words
1266  *
1267  */
1268 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1269                              unsigned int base, unsigned int len,
1270                              unsigned int hdrsize)
1271 {
1272         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1273
1274         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1275         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1276 }
1277 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1278
1279 void
1280 rpc_call_start(struct rpc_task *task)
1281 {
1282         task->tk_action = call_start;
1283 }
1284 EXPORT_SYMBOL_GPL(rpc_call_start);
1285
1286 /**
1287  * rpc_peeraddr - extract remote peer address from clnt's xprt
1288  * @clnt: RPC client structure
1289  * @buf: target buffer
1290  * @bufsize: length of target buffer
1291  *
1292  * Returns the number of bytes that are actually in the stored address.
1293  */
1294 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1295 {
1296         size_t bytes;
1297         struct rpc_xprt *xprt;
1298
1299         rcu_read_lock();
1300         xprt = rcu_dereference(clnt->cl_xprt);
1301
1302         bytes = xprt->addrlen;
1303         if (bytes > bufsize)
1304                 bytes = bufsize;
1305         memcpy(buf, &xprt->addr, bytes);
1306         rcu_read_unlock();
1307
1308         return bytes;
1309 }
1310 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1311
1312 /**
1313  * rpc_peeraddr2str - return remote peer address in printable format
1314  * @clnt: RPC client structure
1315  * @format: address format
1316  *
1317  * NB: the lifetime of the memory referenced by the returned pointer is
1318  * the same as the rpc_xprt itself.  As long as the caller uses this
1319  * pointer, it must hold the RCU read lock.
1320  */
1321 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1322                              enum rpc_display_format_t format)
1323 {
1324         struct rpc_xprt *xprt;
1325
1326         xprt = rcu_dereference(clnt->cl_xprt);
1327
1328         if (xprt->address_strings[format] != NULL)
1329                 return xprt->address_strings[format];
1330         else
1331                 return "unprintable";
1332 }
1333 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1334
1335 static const struct sockaddr_in rpc_inaddr_loopback = {
1336         .sin_family             = AF_INET,
1337         .sin_addr.s_addr        = htonl(INADDR_ANY),
1338 };
1339
1340 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1341         .sin6_family            = AF_INET6,
1342         .sin6_addr              = IN6ADDR_ANY_INIT,
1343 };
1344
1345 /*
1346  * Try a getsockname() on a connected datagram socket.  Using a
1347  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1348  * This conserves the ephemeral port number space.
1349  *
1350  * Returns zero and fills in "buf" if successful; otherwise, a
1351  * negative errno is returned.
1352  */
1353 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1354                         struct sockaddr *buf)
1355 {
1356         struct socket *sock;
1357         int err;
1358
1359         err = __sock_create(net, sap->sa_family,
1360                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1361         if (err < 0) {
1362                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1363                 goto out;
1364         }
1365
1366         switch (sap->sa_family) {
1367         case AF_INET:
1368                 err = kernel_bind(sock,
1369                                 (struct sockaddr *)&rpc_inaddr_loopback,
1370                                 sizeof(rpc_inaddr_loopback));
1371                 break;
1372         case AF_INET6:
1373                 err = kernel_bind(sock,
1374                                 (struct sockaddr *)&rpc_in6addr_loopback,
1375                                 sizeof(rpc_in6addr_loopback));
1376                 break;
1377         default:
1378                 err = -EAFNOSUPPORT;
1379                 goto out;
1380         }
1381         if (err < 0) {
1382                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1383                 goto out_release;
1384         }
1385
1386         err = kernel_connect(sock, sap, salen, 0);
1387         if (err < 0) {
1388                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1389                 goto out_release;
1390         }
1391
1392         err = kernel_getsockname(sock, buf);
1393         if (err < 0) {
1394                 dprintk("RPC:       getsockname failed (%d)\n", err);
1395                 goto out_release;
1396         }
1397
1398         err = 0;
1399         if (buf->sa_family == AF_INET6) {
1400                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1401                 sin6->sin6_scope_id = 0;
1402         }
1403         dprintk("RPC:       %s succeeded\n", __func__);
1404
1405 out_release:
1406         sock_release(sock);
1407 out:
1408         return err;
1409 }
1410
1411 /*
1412  * Scraping a connected socket failed, so we don't have a useable
1413  * local address.  Fallback: generate an address that will prevent
1414  * the server from calling us back.
1415  *
1416  * Returns zero and fills in "buf" if successful; otherwise, a
1417  * negative errno is returned.
1418  */
1419 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1420 {
1421         switch (family) {
1422         case AF_INET:
1423                 if (buflen < sizeof(rpc_inaddr_loopback))
1424                         return -EINVAL;
1425                 memcpy(buf, &rpc_inaddr_loopback,
1426                                 sizeof(rpc_inaddr_loopback));
1427                 break;
1428         case AF_INET6:
1429                 if (buflen < sizeof(rpc_in6addr_loopback))
1430                         return -EINVAL;
1431                 memcpy(buf, &rpc_in6addr_loopback,
1432                                 sizeof(rpc_in6addr_loopback));
1433                 break;
1434         default:
1435                 dprintk("RPC:       %s: address family not supported\n",
1436                         __func__);
1437                 return -EAFNOSUPPORT;
1438         }
1439         dprintk("RPC:       %s: succeeded\n", __func__);
1440         return 0;
1441 }
1442
1443 /**
1444  * rpc_localaddr - discover local endpoint address for an RPC client
1445  * @clnt: RPC client structure
1446  * @buf: target buffer
1447  * @buflen: size of target buffer, in bytes
1448  *
1449  * Returns zero and fills in "buf" and "buflen" if successful;
1450  * otherwise, a negative errno is returned.
1451  *
1452  * This works even if the underlying transport is not currently connected,
1453  * or if the upper layer never previously provided a source address.
1454  *
1455  * The result of this function call is transient: multiple calls in
1456  * succession may give different results, depending on how local
1457  * networking configuration changes over time.
1458  */
1459 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1460 {
1461         struct sockaddr_storage address;
1462         struct sockaddr *sap = (struct sockaddr *)&address;
1463         struct rpc_xprt *xprt;
1464         struct net *net;
1465         size_t salen;
1466         int err;
1467
1468         rcu_read_lock();
1469         xprt = rcu_dereference(clnt->cl_xprt);
1470         salen = xprt->addrlen;
1471         memcpy(sap, &xprt->addr, salen);
1472         net = get_net(xprt->xprt_net);
1473         rcu_read_unlock();
1474
1475         rpc_set_port(sap, 0);
1476         err = rpc_sockname(net, sap, salen, buf);
1477         put_net(net);
1478         if (err != 0)
1479                 /* Couldn't discover local address, return ANYADDR */
1480                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1481         return 0;
1482 }
1483 EXPORT_SYMBOL_GPL(rpc_localaddr);
1484
1485 void
1486 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1487 {
1488         struct rpc_xprt *xprt;
1489
1490         rcu_read_lock();
1491         xprt = rcu_dereference(clnt->cl_xprt);
1492         if (xprt->ops->set_buffer_size)
1493                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1494         rcu_read_unlock();
1495 }
1496 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1497
1498 /**
1499  * rpc_net_ns - Get the network namespace for this RPC client
1500  * @clnt: RPC client to query
1501  *
1502  */
1503 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1504 {
1505         struct net *ret;
1506
1507         rcu_read_lock();
1508         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1509         rcu_read_unlock();
1510         return ret;
1511 }
1512 EXPORT_SYMBOL_GPL(rpc_net_ns);
1513
1514 /**
1515  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1516  * @clnt: RPC client to query
1517  *
1518  * For stream transports, this is one RPC record fragment (see RFC
1519  * 1831), as we don't support multi-record requests yet.  For datagram
1520  * transports, this is the size of an IP packet minus the IP, UDP, and
1521  * RPC header sizes.
1522  */
1523 size_t rpc_max_payload(struct rpc_clnt *clnt)
1524 {
1525         size_t ret;
1526
1527         rcu_read_lock();
1528         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1529         rcu_read_unlock();
1530         return ret;
1531 }
1532 EXPORT_SYMBOL_GPL(rpc_max_payload);
1533
1534 /**
1535  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1536  * @clnt: RPC client to query
1537  */
1538 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1539 {
1540         struct rpc_xprt *xprt;
1541         size_t ret;
1542
1543         rcu_read_lock();
1544         xprt = rcu_dereference(clnt->cl_xprt);
1545         ret = xprt->ops->bc_maxpayload(xprt);
1546         rcu_read_unlock();
1547         return ret;
1548 }
1549 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1550
1551 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1552 {
1553         struct rpc_xprt *xprt;
1554         unsigned int ret;
1555
1556         rcu_read_lock();
1557         xprt = rcu_dereference(clnt->cl_xprt);
1558         ret = xprt->ops->bc_num_slots(xprt);
1559         rcu_read_unlock();
1560         return ret;
1561 }
1562 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1563
1564 /**
1565  * rpc_force_rebind - force transport to check that remote port is unchanged
1566  * @clnt: client to rebind
1567  *
1568  */
1569 void rpc_force_rebind(struct rpc_clnt *clnt)
1570 {
1571         if (clnt->cl_autobind) {
1572                 rcu_read_lock();
1573                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1574                 rcu_read_unlock();
1575         }
1576 }
1577 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1578
1579 static int
1580 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1581 {
1582         task->tk_status = 0;
1583         task->tk_rpc_status = 0;
1584         task->tk_action = action;
1585         return 1;
1586 }
1587
1588 /*
1589  * Restart an (async) RPC call. Usually called from within the
1590  * exit handler.
1591  */
1592 int
1593 rpc_restart_call(struct rpc_task *task)
1594 {
1595         return __rpc_restart_call(task, call_start);
1596 }
1597 EXPORT_SYMBOL_GPL(rpc_restart_call);
1598
1599 /*
1600  * Restart an (async) RPC call from the call_prepare state.
1601  * Usually called from within the exit handler.
1602  */
1603 int
1604 rpc_restart_call_prepare(struct rpc_task *task)
1605 {
1606         if (task->tk_ops->rpc_call_prepare != NULL)
1607                 return __rpc_restart_call(task, rpc_prepare_task);
1608         return rpc_restart_call(task);
1609 }
1610 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1611
1612 const char
1613 *rpc_proc_name(const struct rpc_task *task)
1614 {
1615         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1616
1617         if (proc) {
1618                 if (proc->p_name)
1619                         return proc->p_name;
1620                 else
1621                         return "NULL";
1622         } else
1623                 return "no proc";
1624 }
1625
1626 static void
1627 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1628 {
1629         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1630         task->tk_rpc_status = rpc_status;
1631         rpc_exit(task, tk_status);
1632 }
1633
1634 static void
1635 rpc_call_rpcerror(struct rpc_task *task, int status)
1636 {
1637         __rpc_call_rpcerror(task, status, status);
1638 }
1639
1640 /*
1641  * 0.  Initial state
1642  *
1643  *     Other FSM states can be visited zero or more times, but
1644  *     this state is visited exactly once for each RPC.
1645  */
1646 static void
1647 call_start(struct rpc_task *task)
1648 {
1649         struct rpc_clnt *clnt = task->tk_client;
1650         int idx = task->tk_msg.rpc_proc->p_statidx;
1651
1652         trace_rpc_request(task);
1653
1654         /* Increment call count (version might not be valid for ping) */
1655         if (clnt->cl_program->version[clnt->cl_vers])
1656                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1657         clnt->cl_stats->rpccnt++;
1658         task->tk_action = call_reserve;
1659         rpc_task_set_transport(task, clnt);
1660 }
1661
1662 /*
1663  * 1.   Reserve an RPC call slot
1664  */
1665 static void
1666 call_reserve(struct rpc_task *task)
1667 {
1668         task->tk_status  = 0;
1669         task->tk_action  = call_reserveresult;
1670         xprt_reserve(task);
1671 }
1672
1673 static void call_retry_reserve(struct rpc_task *task);
1674
1675 /*
1676  * 1b.  Grok the result of xprt_reserve()
1677  */
1678 static void
1679 call_reserveresult(struct rpc_task *task)
1680 {
1681         int status = task->tk_status;
1682
1683         /*
1684          * After a call to xprt_reserve(), we must have either
1685          * a request slot or else an error status.
1686          */
1687         task->tk_status = 0;
1688         if (status >= 0) {
1689                 if (task->tk_rqstp) {
1690                         task->tk_action = call_refresh;
1691                         return;
1692                 }
1693
1694                 rpc_call_rpcerror(task, -EIO);
1695                 return;
1696         }
1697
1698         switch (status) {
1699         case -ENOMEM:
1700                 rpc_delay(task, HZ >> 2);
1701                 fallthrough;
1702         case -EAGAIN:   /* woken up; retry */
1703                 task->tk_action = call_retry_reserve;
1704                 return;
1705         default:
1706                 rpc_call_rpcerror(task, status);
1707         }
1708 }
1709
1710 /*
1711  * 1c.  Retry reserving an RPC call slot
1712  */
1713 static void
1714 call_retry_reserve(struct rpc_task *task)
1715 {
1716         task->tk_status  = 0;
1717         task->tk_action  = call_reserveresult;
1718         xprt_retry_reserve(task);
1719 }
1720
1721 /*
1722  * 2.   Bind and/or refresh the credentials
1723  */
1724 static void
1725 call_refresh(struct rpc_task *task)
1726 {
1727         task->tk_action = call_refreshresult;
1728         task->tk_status = 0;
1729         task->tk_client->cl_stats->rpcauthrefresh++;
1730         rpcauth_refreshcred(task);
1731 }
1732
1733 /*
1734  * 2a.  Process the results of a credential refresh
1735  */
1736 static void
1737 call_refreshresult(struct rpc_task *task)
1738 {
1739         int status = task->tk_status;
1740
1741         task->tk_status = 0;
1742         task->tk_action = call_refresh;
1743         switch (status) {
1744         case 0:
1745                 if (rpcauth_uptodatecred(task)) {
1746                         task->tk_action = call_allocate;
1747                         return;
1748                 }
1749                 /* Use rate-limiting and a max number of retries if refresh
1750                  * had status 0 but failed to update the cred.
1751                  */
1752                 fallthrough;
1753         case -ETIMEDOUT:
1754                 rpc_delay(task, 3*HZ);
1755                 fallthrough;
1756         case -EAGAIN:
1757                 status = -EACCES;
1758                 fallthrough;
1759         case -EKEYEXPIRED:
1760                 if (!task->tk_cred_retry)
1761                         break;
1762                 task->tk_cred_retry--;
1763                 trace_rpc_retry_refresh_status(task);
1764                 return;
1765         case -ENOMEM:
1766                 rpc_delay(task, HZ >> 4);
1767                 return;
1768         }
1769         trace_rpc_refresh_status(task);
1770         rpc_call_rpcerror(task, status);
1771 }
1772
1773 /*
1774  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1775  *      (Note: buffer memory is freed in xprt_release).
1776  */
1777 static void
1778 call_allocate(struct rpc_task *task)
1779 {
1780         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1781         struct rpc_rqst *req = task->tk_rqstp;
1782         struct rpc_xprt *xprt = req->rq_xprt;
1783         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1784         int status;
1785
1786         task->tk_status = 0;
1787         task->tk_action = call_encode;
1788
1789         if (req->rq_buffer)
1790                 return;
1791
1792         if (proc->p_proc != 0) {
1793                 BUG_ON(proc->p_arglen == 0);
1794                 if (proc->p_decode != NULL)
1795                         BUG_ON(proc->p_replen == 0);
1796         }
1797
1798         /*
1799          * Calculate the size (in quads) of the RPC call
1800          * and reply headers, and convert both values
1801          * to byte sizes.
1802          */
1803         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1804                            proc->p_arglen;
1805         req->rq_callsize <<= 2;
1806         /*
1807          * Note: the reply buffer must at minimum allocate enough space
1808          * for the 'struct accepted_reply' from RFC5531.
1809          */
1810         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1811                         max_t(size_t, proc->p_replen, 2);
1812         req->rq_rcvsize <<= 2;
1813
1814         status = xprt->ops->buf_alloc(task);
1815         trace_rpc_buf_alloc(task, status);
1816         if (status == 0)
1817                 return;
1818         if (status != -ENOMEM) {
1819                 rpc_call_rpcerror(task, status);
1820                 return;
1821         }
1822
1823         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1824                 task->tk_action = call_allocate;
1825                 rpc_delay(task, HZ>>4);
1826                 return;
1827         }
1828
1829         rpc_call_rpcerror(task, -ERESTARTSYS);
1830 }
1831
1832 static int
1833 rpc_task_need_encode(struct rpc_task *task)
1834 {
1835         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1836                 (!(task->tk_flags & RPC_TASK_SENT) ||
1837                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1838                  xprt_request_need_retransmit(task));
1839 }
1840
1841 static void
1842 rpc_xdr_encode(struct rpc_task *task)
1843 {
1844         struct rpc_rqst *req = task->tk_rqstp;
1845         struct xdr_stream xdr;
1846
1847         xdr_buf_init(&req->rq_snd_buf,
1848                      req->rq_buffer,
1849                      req->rq_callsize);
1850         xdr_buf_init(&req->rq_rcv_buf,
1851                      req->rq_rbuffer,
1852                      req->rq_rcvsize);
1853
1854         req->rq_reply_bytes_recvd = 0;
1855         req->rq_snd_buf.head[0].iov_len = 0;
1856         xdr_init_encode(&xdr, &req->rq_snd_buf,
1857                         req->rq_snd_buf.head[0].iov_base, req);
1858         xdr_free_bvec(&req->rq_snd_buf);
1859         if (rpc_encode_header(task, &xdr))
1860                 return;
1861
1862         task->tk_status = rpcauth_wrap_req(task, &xdr);
1863 }
1864
1865 /*
1866  * 3.   Encode arguments of an RPC call
1867  */
1868 static void
1869 call_encode(struct rpc_task *task)
1870 {
1871         if (!rpc_task_need_encode(task))
1872                 goto out;
1873
1874         /* Dequeue task from the receive queue while we're encoding */
1875         xprt_request_dequeue_xprt(task);
1876         /* Encode here so that rpcsec_gss can use correct sequence number. */
1877         rpc_xdr_encode(task);
1878         /* Add task to reply queue before transmission to avoid races */
1879         if (task->tk_status == 0 && rpc_reply_expected(task))
1880                 task->tk_status = xprt_request_enqueue_receive(task);
1881         /* Did the encode result in an error condition? */
1882         if (task->tk_status != 0) {
1883                 /* Was the error nonfatal? */
1884                 switch (task->tk_status) {
1885                 case -EAGAIN:
1886                 case -ENOMEM:
1887                         rpc_delay(task, HZ >> 4);
1888                         break;
1889                 case -EKEYEXPIRED:
1890                         if (!task->tk_cred_retry) {
1891                                 rpc_exit(task, task->tk_status);
1892                         } else {
1893                                 task->tk_action = call_refresh;
1894                                 task->tk_cred_retry--;
1895                                 trace_rpc_retry_refresh_status(task);
1896                         }
1897                         break;
1898                 default:
1899                         rpc_call_rpcerror(task, task->tk_status);
1900                 }
1901                 return;
1902         }
1903
1904         xprt_request_enqueue_transmit(task);
1905 out:
1906         task->tk_action = call_transmit;
1907         /* Check that the connection is OK */
1908         if (!xprt_bound(task->tk_xprt))
1909                 task->tk_action = call_bind;
1910         else if (!xprt_connected(task->tk_xprt))
1911                 task->tk_action = call_connect;
1912 }
1913
1914 /*
1915  * Helpers to check if the task was already transmitted, and
1916  * to take action when that is the case.
1917  */
1918 static bool
1919 rpc_task_transmitted(struct rpc_task *task)
1920 {
1921         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1922 }
1923
1924 static void
1925 rpc_task_handle_transmitted(struct rpc_task *task)
1926 {
1927         xprt_end_transmit(task);
1928         task->tk_action = call_transmit_status;
1929 }
1930
1931 /*
1932  * 4.   Get the server port number if not yet set
1933  */
1934 static void
1935 call_bind(struct rpc_task *task)
1936 {
1937         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1938
1939         if (rpc_task_transmitted(task)) {
1940                 rpc_task_handle_transmitted(task);
1941                 return;
1942         }
1943
1944         if (xprt_bound(xprt)) {
1945                 task->tk_action = call_connect;
1946                 return;
1947         }
1948
1949         task->tk_action = call_bind_status;
1950         if (!xprt_prepare_transmit(task))
1951                 return;
1952
1953         xprt->ops->rpcbind(task);
1954 }
1955
1956 /*
1957  * 4a.  Sort out bind result
1958  */
1959 static void
1960 call_bind_status(struct rpc_task *task)
1961 {
1962         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1963         int status = -EIO;
1964
1965         if (rpc_task_transmitted(task)) {
1966                 rpc_task_handle_transmitted(task);
1967                 return;
1968         }
1969
1970         if (task->tk_status >= 0)
1971                 goto out_next;
1972         if (xprt_bound(xprt)) {
1973                 task->tk_status = 0;
1974                 goto out_next;
1975         }
1976
1977         switch (task->tk_status) {
1978         case -ENOMEM:
1979                 rpc_delay(task, HZ >> 2);
1980                 goto retry_timeout;
1981         case -EACCES:
1982                 trace_rpcb_prog_unavail_err(task);
1983                 /* fail immediately if this is an RPC ping */
1984                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1985                         status = -EOPNOTSUPP;
1986                         break;
1987                 }
1988                 if (task->tk_rebind_retry == 0)
1989                         break;
1990                 task->tk_rebind_retry--;
1991                 rpc_delay(task, 3*HZ);
1992                 goto retry_timeout;
1993         case -ENOBUFS:
1994                 rpc_delay(task, HZ >> 2);
1995                 goto retry_timeout;
1996         case -EAGAIN:
1997                 goto retry_timeout;
1998         case -ETIMEDOUT:
1999                 trace_rpcb_timeout_err(task);
2000                 goto retry_timeout;
2001         case -EPFNOSUPPORT:
2002                 /* server doesn't support any rpcbind version we know of */
2003                 trace_rpcb_bind_version_err(task);
2004                 break;
2005         case -EPROTONOSUPPORT:
2006                 trace_rpcb_bind_version_err(task);
2007                 goto retry_timeout;
2008         case -ECONNREFUSED:             /* connection problems */
2009         case -ECONNRESET:
2010         case -ECONNABORTED:
2011         case -ENOTCONN:
2012         case -EHOSTDOWN:
2013         case -ENETDOWN:
2014         case -EHOSTUNREACH:
2015         case -ENETUNREACH:
2016         case -EPIPE:
2017                 trace_rpcb_unreachable_err(task);
2018                 if (!RPC_IS_SOFTCONN(task)) {
2019                         rpc_delay(task, 5*HZ);
2020                         goto retry_timeout;
2021                 }
2022                 status = task->tk_status;
2023                 break;
2024         default:
2025                 trace_rpcb_unrecognized_err(task);
2026         }
2027
2028         rpc_call_rpcerror(task, status);
2029         return;
2030 out_next:
2031         task->tk_action = call_connect;
2032         return;
2033 retry_timeout:
2034         task->tk_status = 0;
2035         task->tk_action = call_bind;
2036         rpc_check_timeout(task);
2037 }
2038
2039 /*
2040  * 4b.  Connect to the RPC server
2041  */
2042 static void
2043 call_connect(struct rpc_task *task)
2044 {
2045         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2046
2047         if (rpc_task_transmitted(task)) {
2048                 rpc_task_handle_transmitted(task);
2049                 return;
2050         }
2051
2052         if (xprt_connected(xprt)) {
2053                 task->tk_action = call_transmit;
2054                 return;
2055         }
2056
2057         task->tk_action = call_connect_status;
2058         if (task->tk_status < 0)
2059                 return;
2060         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2061                 rpc_call_rpcerror(task, -ENOTCONN);
2062                 return;
2063         }
2064         if (!xprt_prepare_transmit(task))
2065                 return;
2066         xprt_connect(task);
2067 }
2068
2069 /*
2070  * 4c.  Sort out connect result
2071  */
2072 static void
2073 call_connect_status(struct rpc_task *task)
2074 {
2075         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2076         struct rpc_clnt *clnt = task->tk_client;
2077         int status = task->tk_status;
2078
2079         if (rpc_task_transmitted(task)) {
2080                 rpc_task_handle_transmitted(task);
2081                 return;
2082         }
2083
2084         trace_rpc_connect_status(task);
2085
2086         if (task->tk_status == 0) {
2087                 clnt->cl_stats->netreconn++;
2088                 goto out_next;
2089         }
2090         if (xprt_connected(xprt)) {
2091                 task->tk_status = 0;
2092                 goto out_next;
2093         }
2094
2095         task->tk_status = 0;
2096         switch (status) {
2097         case -ECONNREFUSED:
2098                 /* A positive refusal suggests a rebind is needed. */
2099                 if (RPC_IS_SOFTCONN(task))
2100                         break;
2101                 if (clnt->cl_autobind) {
2102                         rpc_force_rebind(clnt);
2103                         goto out_retry;
2104                 }
2105                 fallthrough;
2106         case -ECONNRESET:
2107         case -ECONNABORTED:
2108         case -ENETDOWN:
2109         case -ENETUNREACH:
2110         case -EHOSTUNREACH:
2111         case -EPIPE:
2112         case -EPROTO:
2113                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2114                                             task->tk_rqstp->rq_connect_cookie);
2115                 if (RPC_IS_SOFTCONN(task))
2116                         break;
2117                 /* retry with existing socket, after a delay */
2118                 rpc_delay(task, 3*HZ);
2119                 fallthrough;
2120         case -EADDRINUSE:
2121         case -ENOTCONN:
2122         case -EAGAIN:
2123         case -ETIMEDOUT:
2124                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2125                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2126                     test_bit(XPRT_REMOVE, &xprt->state)) {
2127                         struct rpc_xprt *saved = task->tk_xprt;
2128                         struct rpc_xprt_switch *xps;
2129
2130                         rcu_read_lock();
2131                         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2132                         rcu_read_unlock();
2133                         if (xps->xps_nxprts > 1) {
2134                                 long value;
2135
2136                                 xprt_release(task);
2137                                 value = atomic_long_dec_return(&xprt->queuelen);
2138                                 if (value == 0)
2139                                         rpc_xprt_switch_remove_xprt(xps, saved);
2140                                 xprt_put(saved);
2141                                 task->tk_xprt = NULL;
2142                                 task->tk_action = call_start;
2143                         }
2144                         xprt_switch_put(xps);
2145                         if (!task->tk_xprt)
2146                                 return;
2147                 }
2148                 goto out_retry;
2149         case -ENOBUFS:
2150                 rpc_delay(task, HZ >> 2);
2151                 goto out_retry;
2152         }
2153         rpc_call_rpcerror(task, status);
2154         return;
2155 out_next:
2156         task->tk_action = call_transmit;
2157         return;
2158 out_retry:
2159         /* Check for timeouts before looping back to call_bind */
2160         task->tk_action = call_bind;
2161         rpc_check_timeout(task);
2162 }
2163
2164 /*
2165  * 5.   Transmit the RPC request, and wait for reply
2166  */
2167 static void
2168 call_transmit(struct rpc_task *task)
2169 {
2170         if (rpc_task_transmitted(task)) {
2171                 rpc_task_handle_transmitted(task);
2172                 return;
2173         }
2174
2175         task->tk_action = call_transmit_status;
2176         if (!xprt_prepare_transmit(task))
2177                 return;
2178         task->tk_status = 0;
2179         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2180                 if (!xprt_connected(task->tk_xprt)) {
2181                         task->tk_status = -ENOTCONN;
2182                         return;
2183                 }
2184                 xprt_transmit(task);
2185         }
2186         xprt_end_transmit(task);
2187 }
2188
2189 /*
2190  * 5a.  Handle cleanup after a transmission
2191  */
2192 static void
2193 call_transmit_status(struct rpc_task *task)
2194 {
2195         task->tk_action = call_status;
2196
2197         /*
2198          * Common case: success.  Force the compiler to put this
2199          * test first.
2200          */
2201         if (rpc_task_transmitted(task)) {
2202                 task->tk_status = 0;
2203                 xprt_request_wait_receive(task);
2204                 return;
2205         }
2206
2207         switch (task->tk_status) {
2208         default:
2209                 break;
2210         case -EBADMSG:
2211                 task->tk_status = 0;
2212                 task->tk_action = call_encode;
2213                 break;
2214                 /*
2215                  * Special cases: if we've been waiting on the
2216                  * socket's write_space() callback, or if the
2217                  * socket just returned a connection error,
2218                  * then hold onto the transport lock.
2219                  */
2220         case -ENOMEM:
2221         case -ENOBUFS:
2222                 rpc_delay(task, HZ>>2);
2223                 fallthrough;
2224         case -EBADSLT:
2225         case -EAGAIN:
2226                 task->tk_action = call_transmit;
2227                 task->tk_status = 0;
2228                 break;
2229         case -ECONNREFUSED:
2230         case -EHOSTDOWN:
2231         case -ENETDOWN:
2232         case -EHOSTUNREACH:
2233         case -ENETUNREACH:
2234         case -EPERM:
2235                 if (RPC_IS_SOFTCONN(task)) {
2236                         if (!task->tk_msg.rpc_proc->p_proc)
2237                                 trace_xprt_ping(task->tk_xprt,
2238                                                 task->tk_status);
2239                         rpc_call_rpcerror(task, task->tk_status);
2240                         return;
2241                 }
2242                 fallthrough;
2243         case -ECONNRESET:
2244         case -ECONNABORTED:
2245         case -EADDRINUSE:
2246         case -ENOTCONN:
2247         case -EPIPE:
2248                 task->tk_action = call_bind;
2249                 task->tk_status = 0;
2250                 break;
2251         }
2252         rpc_check_timeout(task);
2253 }
2254
2255 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2256 static void call_bc_transmit(struct rpc_task *task);
2257 static void call_bc_transmit_status(struct rpc_task *task);
2258
2259 static void
2260 call_bc_encode(struct rpc_task *task)
2261 {
2262         xprt_request_enqueue_transmit(task);
2263         task->tk_action = call_bc_transmit;
2264 }
2265
2266 /*
2267  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2268  * addition, disconnect on connectivity errors.
2269  */
2270 static void
2271 call_bc_transmit(struct rpc_task *task)
2272 {
2273         task->tk_action = call_bc_transmit_status;
2274         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2275                 if (!xprt_prepare_transmit(task))
2276                         return;
2277                 task->tk_status = 0;
2278                 xprt_transmit(task);
2279         }
2280         xprt_end_transmit(task);
2281 }
2282
2283 static void
2284 call_bc_transmit_status(struct rpc_task *task)
2285 {
2286         struct rpc_rqst *req = task->tk_rqstp;
2287
2288         if (rpc_task_transmitted(task))
2289                 task->tk_status = 0;
2290
2291         switch (task->tk_status) {
2292         case 0:
2293                 /* Success */
2294         case -ENETDOWN:
2295         case -EHOSTDOWN:
2296         case -EHOSTUNREACH:
2297         case -ENETUNREACH:
2298         case -ECONNRESET:
2299         case -ECONNREFUSED:
2300         case -EADDRINUSE:
2301         case -ENOTCONN:
2302         case -EPIPE:
2303                 break;
2304         case -ENOMEM:
2305         case -ENOBUFS:
2306                 rpc_delay(task, HZ>>2);
2307                 fallthrough;
2308         case -EBADSLT:
2309         case -EAGAIN:
2310                 task->tk_status = 0;
2311                 task->tk_action = call_bc_transmit;
2312                 return;
2313         case -ETIMEDOUT:
2314                 /*
2315                  * Problem reaching the server.  Disconnect and let the
2316                  * forechannel reestablish the connection.  The server will
2317                  * have to retransmit the backchannel request and we'll
2318                  * reprocess it.  Since these ops are idempotent, there's no
2319                  * need to cache our reply at this time.
2320                  */
2321                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2322                         "error: %d\n", task->tk_status);
2323                 xprt_conditional_disconnect(req->rq_xprt,
2324                         req->rq_connect_cookie);
2325                 break;
2326         default:
2327                 /*
2328                  * We were unable to reply and will have to drop the
2329                  * request.  The server should reconnect and retransmit.
2330                  */
2331                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2332                         "error: %d\n", task->tk_status);
2333                 break;
2334         }
2335         task->tk_action = rpc_exit_task;
2336 }
2337 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2338
2339 /*
2340  * 6.   Sort out the RPC call status
2341  */
2342 static void
2343 call_status(struct rpc_task *task)
2344 {
2345         struct rpc_clnt *clnt = task->tk_client;
2346         int             status;
2347
2348         if (!task->tk_msg.rpc_proc->p_proc)
2349                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2350
2351         status = task->tk_status;
2352         if (status >= 0) {
2353                 task->tk_action = call_decode;
2354                 return;
2355         }
2356
2357         trace_rpc_call_status(task);
2358         task->tk_status = 0;
2359         switch(status) {
2360         case -EHOSTDOWN:
2361         case -ENETDOWN:
2362         case -EHOSTUNREACH:
2363         case -ENETUNREACH:
2364         case -EPERM:
2365                 if (RPC_IS_SOFTCONN(task))
2366                         goto out_exit;
2367                 /*
2368                  * Delay any retries for 3 seconds, then handle as if it
2369                  * were a timeout.
2370                  */
2371                 rpc_delay(task, 3*HZ);
2372                 fallthrough;
2373         case -ETIMEDOUT:
2374                 break;
2375         case -ECONNREFUSED:
2376         case -ECONNRESET:
2377         case -ECONNABORTED:
2378         case -ENOTCONN:
2379                 rpc_force_rebind(clnt);
2380                 break;
2381         case -EADDRINUSE:
2382                 rpc_delay(task, 3*HZ);
2383                 fallthrough;
2384         case -EPIPE:
2385         case -EAGAIN:
2386                 break;
2387         case -ENFILE:
2388         case -ENOBUFS:
2389         case -ENOMEM:
2390                 rpc_delay(task, HZ>>2);
2391                 break;
2392         case -EIO:
2393                 /* shutdown or soft timeout */
2394                 goto out_exit;
2395         default:
2396                 if (clnt->cl_chatty)
2397                         printk("%s: RPC call returned error %d\n",
2398                                clnt->cl_program->name, -status);
2399                 goto out_exit;
2400         }
2401         task->tk_action = call_encode;
2402         if (status != -ECONNRESET && status != -ECONNABORTED)
2403                 rpc_check_timeout(task);
2404         return;
2405 out_exit:
2406         rpc_call_rpcerror(task, status);
2407 }
2408
2409 static bool
2410 rpc_check_connected(const struct rpc_rqst *req)
2411 {
2412         /* No allocated request or transport? return true */
2413         if (!req || !req->rq_xprt)
2414                 return true;
2415         return xprt_connected(req->rq_xprt);
2416 }
2417
2418 static void
2419 rpc_check_timeout(struct rpc_task *task)
2420 {
2421         struct rpc_clnt *clnt = task->tk_client;
2422
2423         if (RPC_SIGNALLED(task)) {
2424                 rpc_call_rpcerror(task, -ERESTARTSYS);
2425                 return;
2426         }
2427
2428         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2429                 return;
2430
2431         trace_rpc_timeout_status(task);
2432         task->tk_timeouts++;
2433
2434         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2435                 rpc_call_rpcerror(task, -ETIMEDOUT);
2436                 return;
2437         }
2438
2439         if (RPC_IS_SOFT(task)) {
2440                 /*
2441                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2442                  * been sent, it should time out only if the transport
2443                  * connection gets terminally broken.
2444                  */
2445                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2446                     rpc_check_connected(task->tk_rqstp))
2447                         return;
2448
2449                 if (clnt->cl_chatty) {
2450                         pr_notice_ratelimited(
2451                                 "%s: server %s not responding, timed out\n",
2452                                 clnt->cl_program->name,
2453                                 task->tk_xprt->servername);
2454                 }
2455                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2456                         rpc_call_rpcerror(task, -ETIMEDOUT);
2457                 else
2458                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2459                 return;
2460         }
2461
2462         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2463                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2464                 if (clnt->cl_chatty) {
2465                         pr_notice_ratelimited(
2466                                 "%s: server %s not responding, still trying\n",
2467                                 clnt->cl_program->name,
2468                                 task->tk_xprt->servername);
2469                 }
2470         }
2471         rpc_force_rebind(clnt);
2472         /*
2473          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2474          * event? RFC2203 requires the server to drop all such requests.
2475          */
2476         rpcauth_invalcred(task);
2477 }
2478
2479 /*
2480  * 7.   Decode the RPC reply
2481  */
2482 static void
2483 call_decode(struct rpc_task *task)
2484 {
2485         struct rpc_clnt *clnt = task->tk_client;
2486         struct rpc_rqst *req = task->tk_rqstp;
2487         struct xdr_stream xdr;
2488         int err;
2489
2490         if (!task->tk_msg.rpc_proc->p_decode) {
2491                 task->tk_action = rpc_exit_task;
2492                 return;
2493         }
2494
2495         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2496                 if (clnt->cl_chatty) {
2497                         pr_notice_ratelimited("%s: server %s OK\n",
2498                                 clnt->cl_program->name,
2499                                 task->tk_xprt->servername);
2500                 }
2501                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2502         }
2503
2504         /*
2505          * Did we ever call xprt_complete_rqst()? If not, we should assume
2506          * the message is incomplete.
2507          */
2508         err = -EAGAIN;
2509         if (!req->rq_reply_bytes_recvd)
2510                 goto out;
2511
2512         /* Ensure that we see all writes made by xprt_complete_rqst()
2513          * before it changed req->rq_reply_bytes_recvd.
2514          */
2515         smp_rmb();
2516
2517         req->rq_rcv_buf.len = req->rq_private_buf.len;
2518         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2519
2520         /* Check that the softirq receive buffer is valid */
2521         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2522                                 sizeof(req->rq_rcv_buf)) != 0);
2523
2524         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2525                         req->rq_rcv_buf.head[0].iov_base, req);
2526         err = rpc_decode_header(task, &xdr);
2527 out:
2528         switch (err) {
2529         case 0:
2530                 task->tk_action = rpc_exit_task;
2531                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2532                 return;
2533         case -EAGAIN:
2534                 task->tk_status = 0;
2535                 if (task->tk_client->cl_discrtry)
2536                         xprt_conditional_disconnect(req->rq_xprt,
2537                                                     req->rq_connect_cookie);
2538                 task->tk_action = call_encode;
2539                 rpc_check_timeout(task);
2540                 break;
2541         case -EKEYREJECTED:
2542                 task->tk_action = call_reserve;
2543                 rpc_check_timeout(task);
2544                 rpcauth_invalcred(task);
2545                 /* Ensure we obtain a new XID if we retry! */
2546                 xprt_release(task);
2547         }
2548 }
2549
2550 static int
2551 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2552 {
2553         struct rpc_clnt *clnt = task->tk_client;
2554         struct rpc_rqst *req = task->tk_rqstp;
2555         __be32 *p;
2556         int error;
2557
2558         error = -EMSGSIZE;
2559         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2560         if (!p)
2561                 goto out_fail;
2562         *p++ = req->rq_xid;
2563         *p++ = rpc_call;
2564         *p++ = cpu_to_be32(RPC_VERSION);
2565         *p++ = cpu_to_be32(clnt->cl_prog);
2566         *p++ = cpu_to_be32(clnt->cl_vers);
2567         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2568
2569         error = rpcauth_marshcred(task, xdr);
2570         if (error < 0)
2571                 goto out_fail;
2572         return 0;
2573 out_fail:
2574         trace_rpc_bad_callhdr(task);
2575         rpc_call_rpcerror(task, error);
2576         return error;
2577 }
2578
2579 static noinline int
2580 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2581 {
2582         struct rpc_clnt *clnt = task->tk_client;
2583         int error;
2584         __be32 *p;
2585
2586         /* RFC-1014 says that the representation of XDR data must be a
2587          * multiple of four bytes
2588          * - if it isn't pointer subtraction in the NFS client may give
2589          *   undefined results
2590          */
2591         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2592                 goto out_unparsable;
2593
2594         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2595         if (!p)
2596                 goto out_unparsable;
2597         p++;    /* skip XID */
2598         if (*p++ != rpc_reply)
2599                 goto out_unparsable;
2600         if (*p++ != rpc_msg_accepted)
2601                 goto out_msg_denied;
2602
2603         error = rpcauth_checkverf(task, xdr);
2604         if (error)
2605                 goto out_verifier;
2606
2607         p = xdr_inline_decode(xdr, sizeof(*p));
2608         if (!p)
2609                 goto out_unparsable;
2610         switch (*p) {
2611         case rpc_success:
2612                 return 0;
2613         case rpc_prog_unavail:
2614                 trace_rpc__prog_unavail(task);
2615                 error = -EPFNOSUPPORT;
2616                 goto out_err;
2617         case rpc_prog_mismatch:
2618                 trace_rpc__prog_mismatch(task);
2619                 error = -EPROTONOSUPPORT;
2620                 goto out_err;
2621         case rpc_proc_unavail:
2622                 trace_rpc__proc_unavail(task);
2623                 error = -EOPNOTSUPP;
2624                 goto out_err;
2625         case rpc_garbage_args:
2626         case rpc_system_err:
2627                 trace_rpc__garbage_args(task);
2628                 error = -EIO;
2629                 break;
2630         default:
2631                 goto out_unparsable;
2632         }
2633
2634 out_garbage:
2635         clnt->cl_stats->rpcgarbage++;
2636         if (task->tk_garb_retry) {
2637                 task->tk_garb_retry--;
2638                 task->tk_action = call_encode;
2639                 return -EAGAIN;
2640         }
2641 out_err:
2642         rpc_call_rpcerror(task, error);
2643         return error;
2644
2645 out_unparsable:
2646         trace_rpc__unparsable(task);
2647         error = -EIO;
2648         goto out_garbage;
2649
2650 out_verifier:
2651         trace_rpc_bad_verifier(task);
2652         goto out_garbage;
2653
2654 out_msg_denied:
2655         error = -EACCES;
2656         p = xdr_inline_decode(xdr, sizeof(*p));
2657         if (!p)
2658                 goto out_unparsable;
2659         switch (*p++) {
2660         case rpc_auth_error:
2661                 break;
2662         case rpc_mismatch:
2663                 trace_rpc__mismatch(task);
2664                 error = -EPROTONOSUPPORT;
2665                 goto out_err;
2666         default:
2667                 goto out_unparsable;
2668         }
2669
2670         p = xdr_inline_decode(xdr, sizeof(*p));
2671         if (!p)
2672                 goto out_unparsable;
2673         switch (*p++) {
2674         case rpc_autherr_rejectedcred:
2675         case rpc_autherr_rejectedverf:
2676         case rpcsec_gsserr_credproblem:
2677         case rpcsec_gsserr_ctxproblem:
2678                 if (!task->tk_cred_retry)
2679                         break;
2680                 task->tk_cred_retry--;
2681                 trace_rpc__stale_creds(task);
2682                 return -EKEYREJECTED;
2683         case rpc_autherr_badcred:
2684         case rpc_autherr_badverf:
2685                 /* possibly garbled cred/verf? */
2686                 if (!task->tk_garb_retry)
2687                         break;
2688                 task->tk_garb_retry--;
2689                 trace_rpc__bad_creds(task);
2690                 task->tk_action = call_encode;
2691                 return -EAGAIN;
2692         case rpc_autherr_tooweak:
2693                 trace_rpc__auth_tooweak(task);
2694                 pr_warn("RPC: server %s requires stronger authentication.\n",
2695                         task->tk_xprt->servername);
2696                 break;
2697         default:
2698                 goto out_unparsable;
2699         }
2700         goto out_err;
2701 }
2702
2703 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2704                 const void *obj)
2705 {
2706 }
2707
2708 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2709                 void *obj)
2710 {
2711         return 0;
2712 }
2713
2714 static const struct rpc_procinfo rpcproc_null = {
2715         .p_encode = rpcproc_encode_null,
2716         .p_decode = rpcproc_decode_null,
2717 };
2718
2719 static const struct rpc_procinfo rpcproc_null_noreply = {
2720         .p_encode = rpcproc_encode_null,
2721 };
2722
2723 static void
2724 rpc_null_call_prepare(struct rpc_task *task, void *data)
2725 {
2726         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2727         rpc_call_start(task);
2728 }
2729
2730 static const struct rpc_call_ops rpc_null_ops = {
2731         .rpc_call_prepare = rpc_null_call_prepare,
2732         .rpc_call_done = rpc_default_callback,
2733 };
2734
2735 static
2736 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2737                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2738                 const struct rpc_call_ops *ops, void *data)
2739 {
2740         struct rpc_message msg = {
2741                 .rpc_proc = &rpcproc_null,
2742         };
2743         struct rpc_task_setup task_setup_data = {
2744                 .rpc_client = clnt,
2745                 .rpc_xprt = xprt,
2746                 .rpc_message = &msg,
2747                 .rpc_op_cred = cred,
2748                 .callback_ops = ops ?: &rpc_null_ops,
2749                 .callback_data = data,
2750                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2751                          RPC_TASK_NULLCREDS,
2752         };
2753
2754         return rpc_run_task(&task_setup_data);
2755 }
2756
2757 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2758 {
2759         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2760 }
2761 EXPORT_SYMBOL_GPL(rpc_call_null);
2762
2763 static int rpc_ping(struct rpc_clnt *clnt)
2764 {
2765         struct rpc_task *task;
2766         int status;
2767
2768         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2769         if (IS_ERR(task))
2770                 return PTR_ERR(task);
2771         status = task->tk_status;
2772         rpc_put_task(task);
2773         return status;
2774 }
2775
2776 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2777 {
2778         struct rpc_message msg = {
2779                 .rpc_proc = &rpcproc_null_noreply,
2780         };
2781         struct rpc_task_setup task_setup_data = {
2782                 .rpc_client = clnt,
2783                 .rpc_message = &msg,
2784                 .callback_ops = &rpc_null_ops,
2785                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2786         };
2787         struct rpc_task *task;
2788         int status;
2789
2790         task = rpc_run_task(&task_setup_data);
2791         if (IS_ERR(task))
2792                 return PTR_ERR(task);
2793         status = task->tk_status;
2794         rpc_put_task(task);
2795         return status;
2796 }
2797
2798 struct rpc_cb_add_xprt_calldata {
2799         struct rpc_xprt_switch *xps;
2800         struct rpc_xprt *xprt;
2801 };
2802
2803 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2804 {
2805         struct rpc_cb_add_xprt_calldata *data = calldata;
2806
2807         if (task->tk_status == 0)
2808                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2809 }
2810
2811 static void rpc_cb_add_xprt_release(void *calldata)
2812 {
2813         struct rpc_cb_add_xprt_calldata *data = calldata;
2814
2815         xprt_put(data->xprt);
2816         xprt_switch_put(data->xps);
2817         kfree(data);
2818 }
2819
2820 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2821         .rpc_call_prepare = rpc_null_call_prepare,
2822         .rpc_call_done = rpc_cb_add_xprt_done,
2823         .rpc_release = rpc_cb_add_xprt_release,
2824 };
2825
2826 /**
2827  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2828  * @clnt: pointer to struct rpc_clnt
2829  * @xps: pointer to struct rpc_xprt_switch,
2830  * @xprt: pointer struct rpc_xprt
2831  * @dummy: unused
2832  */
2833 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2834                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2835                 void *dummy)
2836 {
2837         struct rpc_cb_add_xprt_calldata *data;
2838         struct rpc_task *task;
2839
2840         if (xps->xps_nunique_destaddr_xprts + 1 > clnt->cl_max_connect) {
2841                 rcu_read_lock();
2842                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2843                         "transport to server: %s\n", clnt->cl_max_connect,
2844                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2845                 rcu_read_unlock();
2846                 return -EINVAL;
2847         }
2848
2849         data = kmalloc(sizeof(*data), GFP_KERNEL);
2850         if (!data)
2851                 return -ENOMEM;
2852         data->xps = xprt_switch_get(xps);
2853         data->xprt = xprt_get(xprt);
2854         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2855                 rpc_cb_add_xprt_release(data);
2856                 goto success;
2857         }
2858
2859         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2860                         &rpc_cb_add_xprt_call_ops, data);
2861         data->xps->xps_nunique_destaddr_xprts++;
2862         rpc_put_task(task);
2863 success:
2864         return 1;
2865 }
2866 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2867
2868 /**
2869  * rpc_clnt_setup_test_and_add_xprt()
2870  *
2871  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2872  *   1) caller of the test function must dereference the rpc_xprt_switch
2873  *   and the rpc_xprt.
2874  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2875  *   the rpc_call_done routine.
2876  *
2877  * Upon success (return of 1), the test function adds the new
2878  * transport to the rpc_clnt xprt switch
2879  *
2880  * @clnt: struct rpc_clnt to get the new transport
2881  * @xps:  the rpc_xprt_switch to hold the new transport
2882  * @xprt: the rpc_xprt to test
2883  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2884  *        and test function call data
2885  */
2886 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2887                                      struct rpc_xprt_switch *xps,
2888                                      struct rpc_xprt *xprt,
2889                                      void *data)
2890 {
2891         struct rpc_task *task;
2892         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2893         int status = -EADDRINUSE;
2894
2895         xprt = xprt_get(xprt);
2896         xprt_switch_get(xps);
2897
2898         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2899                 goto out_err;
2900
2901         /* Test the connection */
2902         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2903         if (IS_ERR(task)) {
2904                 status = PTR_ERR(task);
2905                 goto out_err;
2906         }
2907         status = task->tk_status;
2908         rpc_put_task(task);
2909
2910         if (status < 0)
2911                 goto out_err;
2912
2913         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2914         xtest->add_xprt_test(clnt, xprt, xtest->data);
2915
2916         xprt_put(xprt);
2917         xprt_switch_put(xps);
2918
2919         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2920         return 1;
2921 out_err:
2922         xprt_put(xprt);
2923         xprt_switch_put(xps);
2924         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2925                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2926         return status;
2927 }
2928 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2929
2930 /**
2931  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2932  * @clnt: pointer to struct rpc_clnt
2933  * @xprtargs: pointer to struct xprt_create
2934  * @setup: callback to test and/or set up the connection
2935  * @data: pointer to setup function data
2936  *
2937  * Creates a new transport using the parameters set in args and
2938  * adds it to clnt.
2939  * If ping is set, then test that connectivity succeeds before
2940  * adding the new transport.
2941  *
2942  */
2943 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2944                 struct xprt_create *xprtargs,
2945                 int (*setup)(struct rpc_clnt *,
2946                         struct rpc_xprt_switch *,
2947                         struct rpc_xprt *,
2948                         void *),
2949                 void *data)
2950 {
2951         struct rpc_xprt_switch *xps;
2952         struct rpc_xprt *xprt;
2953         unsigned long connect_timeout;
2954         unsigned long reconnect_timeout;
2955         unsigned char resvport, reuseport;
2956         int ret = 0, ident;
2957
2958         rcu_read_lock();
2959         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2960         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2961         if (xps == NULL || xprt == NULL) {
2962                 rcu_read_unlock();
2963                 xprt_switch_put(xps);
2964                 return -EAGAIN;
2965         }
2966         resvport = xprt->resvport;
2967         reuseport = xprt->reuseport;
2968         connect_timeout = xprt->connect_timeout;
2969         reconnect_timeout = xprt->max_reconnect_timeout;
2970         ident = xprt->xprt_class->ident;
2971         rcu_read_unlock();
2972
2973         if (!xprtargs->ident)
2974                 xprtargs->ident = ident;
2975         xprt = xprt_create_transport(xprtargs);
2976         if (IS_ERR(xprt)) {
2977                 ret = PTR_ERR(xprt);
2978                 goto out_put_switch;
2979         }
2980         xprt->resvport = resvport;
2981         xprt->reuseport = reuseport;
2982         if (xprt->ops->set_connect_timeout != NULL)
2983                 xprt->ops->set_connect_timeout(xprt,
2984                                 connect_timeout,
2985                                 reconnect_timeout);
2986
2987         rpc_xprt_switch_set_roundrobin(xps);
2988         if (setup) {
2989                 ret = setup(clnt, xps, xprt, data);
2990                 if (ret != 0)
2991                         goto out_put_xprt;
2992         }
2993         rpc_xprt_switch_add_xprt(xps, xprt);
2994 out_put_xprt:
2995         xprt_put(xprt);
2996 out_put_switch:
2997         xprt_switch_put(xps);
2998         return ret;
2999 }
3000 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
3001
3002 struct connect_timeout_data {
3003         unsigned long connect_timeout;
3004         unsigned long reconnect_timeout;
3005 };
3006
3007 static int
3008 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3009                 struct rpc_xprt *xprt,
3010                 void *data)
3011 {
3012         struct connect_timeout_data *timeo = data;
3013
3014         if (xprt->ops->set_connect_timeout)
3015                 xprt->ops->set_connect_timeout(xprt,
3016                                 timeo->connect_timeout,
3017                                 timeo->reconnect_timeout);
3018         return 0;
3019 }
3020
3021 void
3022 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3023                 unsigned long connect_timeout,
3024                 unsigned long reconnect_timeout)
3025 {
3026         struct connect_timeout_data timeout = {
3027                 .connect_timeout = connect_timeout,
3028                 .reconnect_timeout = reconnect_timeout,
3029         };
3030         rpc_clnt_iterate_for_each_xprt(clnt,
3031                         rpc_xprt_set_connect_timeout,
3032                         &timeout);
3033 }
3034 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3035
3036 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
3037 {
3038         rcu_read_lock();
3039         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3040         rcu_read_unlock();
3041 }
3042 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
3043
3044 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3045 {
3046         rcu_read_lock();
3047         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3048                                  xprt);
3049         rcu_read_unlock();
3050 }
3051 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3052
3053 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3054                                    const struct sockaddr *sap)
3055 {
3056         struct rpc_xprt_switch *xps;
3057         bool ret;
3058
3059         rcu_read_lock();
3060         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3061         ret = rpc_xprt_switch_has_addr(xps, sap);
3062         rcu_read_unlock();
3063         return ret;
3064 }
3065 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3066
3067 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3068 static void rpc_show_header(void)
3069 {
3070         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3071                 "-timeout ---ops--\n");
3072 }
3073
3074 static void rpc_show_task(const struct rpc_clnt *clnt,
3075                           const struct rpc_task *task)
3076 {
3077         const char *rpc_waitq = "none";
3078
3079         if (RPC_IS_QUEUED(task))
3080                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3081
3082         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3083                 task->tk_pid, task->tk_flags, task->tk_status,
3084                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3085                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3086                 task->tk_action, rpc_waitq);
3087 }
3088
3089 void rpc_show_tasks(struct net *net)
3090 {
3091         struct rpc_clnt *clnt;
3092         struct rpc_task *task;
3093         int header = 0;
3094         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3095
3096         spin_lock(&sn->rpc_client_lock);
3097         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3098                 spin_lock(&clnt->cl_lock);
3099                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3100                         if (!header) {
3101                                 rpc_show_header();
3102                                 header++;
3103                         }
3104                         rpc_show_task(clnt, task);
3105                 }
3106                 spin_unlock(&clnt->cl_lock);
3107         }
3108         spin_unlock(&sn->rpc_client_lock);
3109 }
3110 #endif
3111
3112 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3113 static int
3114 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3115                 struct rpc_xprt *xprt,
3116                 void *dummy)
3117 {
3118         return xprt_enable_swap(xprt);
3119 }
3120
3121 int
3122 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3123 {
3124         while (clnt != clnt->cl_parent)
3125                 clnt = clnt->cl_parent;
3126         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3127                 return rpc_clnt_iterate_for_each_xprt(clnt,
3128                                 rpc_clnt_swap_activate_callback, NULL);
3129         return 0;
3130 }
3131 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3132
3133 static int
3134 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3135                 struct rpc_xprt *xprt,
3136                 void *dummy)
3137 {
3138         xprt_disable_swap(xprt);
3139         return 0;
3140 }
3141
3142 void
3143 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3144 {
3145         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3146                 rpc_clnt_iterate_for_each_xprt(clnt,
3147                                 rpc_clnt_swap_deactivate_callback, NULL);
3148 }
3149 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3150 #endif /* CONFIG_SUNRPC_SWAP */