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 <[email protected]>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <[email protected]>
  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 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  52
  53 static void     call_start(struct rpc_task *task);
  54 static void     call_reserve(struct rpc_task *task);
  55 static void     call_reserveresult(struct rpc_task *task);
  56 static void     call_allocate(struct rpc_task *task);
  57 static void     call_encode(struct rpc_task *task);
  58 static void     call_decode(struct rpc_task *task);
  59 static void     call_bind(struct rpc_task *task);
  60 static void     call_bind_status(struct rpc_task *task);
  61 static void     call_transmit(struct rpc_task *task);
  62 static void     call_status(struct rpc_task *task);
  63 static void     call_transmit_status(struct rpc_task *task);
  64 static void     call_refresh(struct rpc_task *task);
  65 static void     call_refreshresult(struct rpc_task *task);
  66 static void     call_connect(struct rpc_task *task);
  67 static void     call_connect_status(struct rpc_task *task);
  68
  69 static int      rpc_encode_header(struct rpc_task *task,
  70                                   struct xdr_stream *xdr);
  71 static int      rpc_decode_header(struct rpc_task *task,
  72                                   struct xdr_stream *xdr);
  73 static int      rpc_ping(struct rpc_clnt *clnt);
  74 static int      rpc_ping_noreply(struct rpc_clnt *clnt);
  75 static void     rpc_check_timeout(struct rpc_task *task);
  76
  77 static void rpc_register_client(struct rpc_clnt *clnt)
  78 {
  79         struct net *net = rpc_net_ns(clnt);
  80         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  81
  82         spin_lock(&sn->rpc_client_lock);
  83         list_add(&clnt->cl_clients, &sn->all_clients);
  84         spin_unlock(&sn->rpc_client_lock);
  85 }
  86
  87 static void rpc_unregister_client(struct rpc_clnt *clnt)
  88 {
  89         struct net *net = rpc_net_ns(clnt);
  90         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  91
  92         spin_lock(&sn->rpc_client_lock);
  93         list_del(&clnt->cl_clients);
  94         spin_unlock(&sn->rpc_client_lock);
  95 }
  96
  97 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
  98 {
  99         rpc_remove_client_dir(clnt);
 100 }
 101
 102 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         struct net *net = rpc_net_ns(clnt);
 105         struct super_block *pipefs_sb;
 106
 107         pipefs_sb = rpc_get_sb_net(net);
 108         if (pipefs_sb) {
 109                 if (pipefs_sb == clnt->pipefs_sb)
 110                         __rpc_clnt_remove_pipedir(clnt);
 111                 rpc_put_sb_net(net);
 112         }
 113 }
 114
 115 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 116                                     struct rpc_clnt *clnt)
 117 {
 118         static uint32_t clntid;
 119         const char *dir_name = clnt->cl_program->pipe_dir_name;
 120         char name[15];
 121         struct dentry *dir, *dentry;
 122
 123         dir = rpc_d_lookup_sb(sb, dir_name);
 124         if (dir == NULL) {
 125                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 126                 return dir;
 127         }
 128         for (;;) {
 129                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 130                 name[sizeof(name) - 1] = '\0';
 131                 dentry = rpc_create_client_dir(dir, name, clnt);
 132                 if (!IS_ERR(dentry))
 133                         break;
 134                 if (dentry == ERR_PTR(-EEXIST))
 135                         continue;
 136                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 137                                 " %s/%s, error %ld\n",
 138                                 dir_name, name, PTR_ERR(dentry));
 139                 break;
 140         }
 141         dput(dir);
 142         return dentry;
 143 }
 144
 145 static int
 146 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 147 {
 148         struct dentry *dentry;
 149
 150         clnt->pipefs_sb = pipefs_sb;
 151
 152         if (clnt->cl_program->pipe_dir_name != NULL) {
 153                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 154                 if (IS_ERR(dentry))
 155                         return PTR_ERR(dentry);
 156         }
 157         return 0;
 158 }
 159
 160 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 161 {
 162         if (clnt->cl_program->pipe_dir_name == NULL)
 163                 return 1;
 164
 165         switch (event) {
 166         case RPC_PIPEFS_MOUNT:
 167                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 168                         return 1;
 169                 if (refcount_read(&clnt->cl_count) == 0)
 170                         return 1;
 171                 break;
 172         case RPC_PIPEFS_UMOUNT:
 173                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 174                         return 1;
 175                 break;
 176         }
 177         return 0;
 178 }
 179
 180 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 181                                    struct super_block *sb)
 182 {
 183         struct dentry *dentry;
 184
 185         switch (event) {
 186         case RPC_PIPEFS_MOUNT:
 187                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 188                 if (!dentry)
 189                         return -ENOENT;
 190                 if (IS_ERR(dentry))
 191                         return PTR_ERR(dentry);
 192                 break;
 193         case RPC_PIPEFS_UMOUNT:
 194                 __rpc_clnt_remove_pipedir(clnt);
 195                 break;
 196         default:
 197                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 198                 return -ENOTSUPP;
 199         }
 200         return 0;
 201 }
 202
 203 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 204                                 struct super_block *sb)
 205 {
 206         int error = 0;
 207
 208         for (;; clnt = clnt->cl_parent) {
 209                 if (!rpc_clnt_skip_event(clnt, event))
 210                         error = __rpc_clnt_handle_event(clnt, event, sb);
 211                 if (error || clnt == clnt->cl_parent)
 212                         break;
 213         }
 214         return error;
 215 }
 216
 217 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 218 {
 219         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 220         struct rpc_clnt *clnt;
 221
 222         spin_lock(&sn->rpc_client_lock);
 223         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 224                 if (rpc_clnt_skip_event(clnt, event))
 225                         continue;
 226                 spin_unlock(&sn->rpc_client_lock);
 227                 return clnt;
 228         }
 229         spin_unlock(&sn->rpc_client_lock);
 230         return NULL;
 231 }
 232
 233 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 234                             void *ptr)
 235 {
 236         struct super_block *sb = ptr;
 237         struct rpc_clnt *clnt;
 238         int error = 0;
 239
 240         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 241                 error = __rpc_pipefs_event(clnt, event, sb);
 242                 if (error)
 243                         break;
 244         }
 245         return error;
 246 }
 247
 248 static struct notifier_block rpc_clients_block = {
 249         .notifier_call  = rpc_pipefs_event,
 250         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 251 };
 252
 253 int rpc_clients_notifier_register(void)
 254 {
 255         return rpc_pipefs_notifier_register(&rpc_clients_block);
 256 }
 257
 258 void rpc_clients_notifier_unregister(void)
 259 {
 260         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 261 }
 262
 263 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 264                 struct rpc_xprt *xprt,
 265                 const struct rpc_timeout *timeout)
 266 {
 267         struct rpc_xprt *old;
 268
 269         spin_lock(&clnt->cl_lock);
 270         old = rcu_dereference_protected(clnt->cl_xprt,
 271                         lockdep_is_held(&clnt->cl_lock));
 272
 273         if (!xprt_bound(xprt))
 274                 clnt->cl_autobind = 1;
 275
 276         clnt->cl_timeout = timeout;
 277         rcu_assign_pointer(clnt->cl_xprt, xprt);
 278         spin_unlock(&clnt->cl_lock);
 279
 280         return old;
 281 }
 282
 283 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 284 {
 285         ssize_t copied;
 286
 287         copied = strscpy(clnt->cl_nodename,
 288                          nodename, sizeof(clnt->cl_nodename));
 289
 290         clnt->cl_nodelen = copied < 0
 291                                 ? sizeof(clnt->cl_nodename) - 1
 292                                 : copied;
 293 }
 294
 295 static int rpc_client_register(struct rpc_clnt *clnt,
 296                                rpc_authflavor_t pseudoflavor,
 297                                const char *client_name)
 298 {
 299         struct rpc_auth_create_args auth_args = {
 300                 .pseudoflavor = pseudoflavor,
 301                 .target_name = client_name,
 302         };
 303         struct rpc_auth *auth;
 304         struct net *net = rpc_net_ns(clnt);
 305         struct super_block *pipefs_sb;
 306         int err;
 307
 308         rpc_clnt_debugfs_register(clnt);
 309
 310         pipefs_sb = rpc_get_sb_net(net);
 311         if (pipefs_sb) {
 312                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 313                 if (err)
 314                         goto out;
 315         }
 316
 317         rpc_register_client(clnt);
 318         if (pipefs_sb)
 319                 rpc_put_sb_net(net);
 320
 321         auth = rpcauth_create(&auth_args, clnt);
 322         if (IS_ERR(auth)) {
 323                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 324                                 pseudoflavor);
 325                 err = PTR_ERR(auth);
 326                 goto err_auth;
 327         }
 328         return 0;
 329 err_auth:
 330         pipefs_sb = rpc_get_sb_net(net);
 331         rpc_unregister_client(clnt);
 332         __rpc_clnt_remove_pipedir(clnt);
 333 out:
 334         if (pipefs_sb)
 335                 rpc_put_sb_net(net);
 336         rpc_sysfs_client_destroy(clnt);
 337         rpc_clnt_debugfs_unregister(clnt);
 338         return err;
 339 }
 340
 341 static DEFINE_IDA(rpc_clids);
 342
 343 void rpc_cleanup_clids(void)
 344 {
 345         ida_destroy(&rpc_clids);
 346 }
 347
 348 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 349 {
 350         int clid;
 351
 352         clid = ida_alloc(&rpc_clids, GFP_KERNEL);
 353         if (clid < 0)
 354                 return clid;
 355         clnt->cl_clid = clid;
 356         return 0;
 357 }
 358
 359 static void rpc_free_clid(struct rpc_clnt *clnt)
 360 {
 361         ida_free(&rpc_clids, clnt->cl_clid);
 362 }
 363
 364 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 365                 struct rpc_xprt_switch *xps,
 366                 struct rpc_xprt *xprt,
 367                 struct rpc_clnt *parent)
 368 {
 369         const struct rpc_program *program = args->program;
 370         const struct rpc_version *version;
 371         struct rpc_clnt *clnt = NULL;
 372         const struct rpc_timeout *timeout;
 373         const char *nodename = args->nodename;
 374         int err;
 375
 376         err = rpciod_up();
 377         if (err)
 378                 goto out_no_rpciod;
 379
 380         err = -EINVAL;
 381         if (args->version >= program->nrvers)
 382                 goto out_err;
 383         version = program->version[args->version];
 384         if (version == NULL)
 385                 goto out_err;
 386
 387         err = -ENOMEM;
 388         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 389         if (!clnt)
 390                 goto out_err;
 391         clnt->cl_parent = parent ? : clnt;
 392         clnt->cl_xprtsec = args->xprtsec;
 393
 394         err = rpc_alloc_clid(clnt);
 395         if (err)
 396                 goto out_no_clid;
 397
 398         clnt->cl_cred     = get_cred(args->cred);
 399         clnt->cl_procinfo = version->procs;
 400         clnt->cl_maxproc  = version->nrprocs;
 401         clnt->cl_prog     = args->prognumber ? : program->number;
 402         clnt->cl_vers     = version->number;
 403         clnt->cl_stats    = args->stats ? : program->stats;
 404         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 405         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 406         err = -ENOMEM;
 407         if (clnt->cl_metrics == NULL)
 408                 goto out_no_stats;
 409         clnt->cl_program  = program;
 410         INIT_LIST_HEAD(&clnt->cl_tasks);
 411         spin_lock_init(&clnt->cl_lock);
 412
 413         timeout = xprt->timeout;
 414         if (args->timeout != NULL) {
 415                 memcpy(&clnt->cl_timeout_default, args->timeout,
 416                                 sizeof(clnt->cl_timeout_default));
 417                 timeout = &clnt->cl_timeout_default;
 418         }
 419
 420         rpc_clnt_set_transport(clnt, xprt, timeout);
 421         xprt->main = true;
 422         xprt_iter_init(&clnt->cl_xpi, xps);
 423         xprt_switch_put(xps);
 424
 425         clnt->cl_rtt = &clnt->cl_rtt_default;
 426         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 427
 428         refcount_set(&clnt->cl_count, 1);
 429
 430         if (nodename == NULL)
 431                 nodename = utsname()->nodename;
 432         /* save the nodename */
 433         rpc_clnt_set_nodename(clnt, nodename);
 434
 435         rpc_sysfs_client_setup(clnt, xps, rpc_net_ns(clnt));
 436         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 437         if (err)
 438                 goto out_no_path;
 439         if (parent)
 440                 refcount_inc(&parent->cl_count);
 441
 442         trace_rpc_clnt_new(clnt, xprt, args);
 443         return clnt;
 444
 445 out_no_path:
 446         rpc_free_iostats(clnt->cl_metrics);
 447 out_no_stats:
 448         put_cred(clnt->cl_cred);
 449         rpc_free_clid(clnt);
 450 out_no_clid:
 451         kfree(clnt);
 452 out_err:
 453         rpciod_down();
 454 out_no_rpciod:
 455         xprt_switch_put(xps);
 456         xprt_put(xprt);
 457         trace_rpc_clnt_new_err(program->name, args->servername, err);
 458         return ERR_PTR(err);
 459 }
 460
 461 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 462                                         struct rpc_xprt *xprt)
 463 {
 464         struct rpc_clnt *clnt = NULL;
 465         struct rpc_xprt_switch *xps;
 466
 467         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 468                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 469                 xps = args->bc_xprt->xpt_bc_xps;
 470                 xprt_switch_get(xps);
 471         } else {
 472                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 473                 if (xps == NULL) {
 474                         xprt_put(xprt);
 475                         return ERR_PTR(-ENOMEM);
 476                 }
 477                 if (xprt->bc_xprt) {
 478                         xprt_switch_get(xps);
 479                         xprt->bc_xprt->xpt_bc_xps = xps;
 480                 }
 481         }
 482         clnt = rpc_new_client(args, xps, xprt, NULL);
 483         if (IS_ERR(clnt))
 484                 return clnt;
 485
 486         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 487                 int err = rpc_ping(clnt);
 488                 if (err != 0) {
 489                         rpc_shutdown_client(clnt);
 490                         return ERR_PTR(err);
 491                 }
 492         } else if (args->flags & RPC_CLNT_CREATE_CONNECTED) {
 493                 int err = rpc_ping_noreply(clnt);
 494                 if (err != 0) {
 495                         rpc_shutdown_client(clnt);
 496                         return ERR_PTR(err);
 497                 }
 498         }
 499
 500         clnt->cl_softrtry = 1;
 501         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 502                 clnt->cl_softrtry = 0;
 503                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 504                         clnt->cl_softerr = 1;
 505         }
 506
 507         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 508                 clnt->cl_autobind = 1;
 509         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 510                 clnt->cl_noretranstimeo = 1;
 511         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 512                 clnt->cl_discrtry = 1;
 513         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 514                 clnt->cl_chatty = 1;
 515
 516         return clnt;
 517 }
 518
 519 /**
 520  * rpc_create - create an RPC client and transport with one call
 521  * @args: rpc_clnt create argument structure
 522  *
 523  * Creates and initializes an RPC transport and an RPC client.
 524  *
 525  * It can ping the server in order to determine if it is up, and to see if
 526  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 527  * this behavior so asynchronous tasks can also use rpc_create.
 528  */
 529 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 530 {
 531         struct rpc_xprt *xprt;
 532         struct xprt_create xprtargs = {
 533                 .net = args->net,
 534                 .ident = args->protocol,
 535                 .srcaddr = args->saddress,
 536                 .dstaddr = args->address,
 537                 .addrlen = args->addrsize,
 538                 .servername = args->servername,
 539                 .bc_xprt = args->bc_xprt,
 540                 .xprtsec = args->xprtsec,
 541                 .connect_timeout = args->connect_timeout,
 542                 .reconnect_timeout = args->reconnect_timeout,
 543         };
 544         char servername[RPC_MAXNETNAMELEN];
 545         struct rpc_clnt *clnt;
 546         int i;
 547
 548         if (args->bc_xprt) {
 549                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 550                 xprt = args->bc_xprt->xpt_bc_xprt;
 551                 if (xprt) {
 552                         xprt_get(xprt);
 553                         return rpc_create_xprt(args, xprt);
 554                 }
 555         }
 556
 557         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 558                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 559         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 560                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 561         /*
 562          * If the caller chooses not to specify a hostname, whip
 563          * up a string representation of the passed-in address.
 564          */
 565         if (xprtargs.servername == NULL) {
 566                 struct sockaddr_un *sun =
 567                                 (struct sockaddr_un *)args->address;
 568                 struct sockaddr_in *sin =
 569                                 (struct sockaddr_in *)args->address;
 570                 struct sockaddr_in6 *sin6 =
 571                                 (struct sockaddr_in6 *)args->address;
 572
 573                 servername[0] = '\0';
 574                 switch (args->address->sa_family) {
 575                 case AF_LOCAL:
 576                         if (sun->sun_path[0])
 577                                 snprintf(servername, sizeof(servername), "%s",
 578                                          sun->sun_path);
 579                         else
 580                                 snprintf(servername, sizeof(servername), "@%s",
 581                                          sun->sun_path+1);
 582                         break;
 583                 case AF_INET:
 584                         snprintf(servername, sizeof(servername), "%pI4",
 585                                  &sin->sin_addr.s_addr);
 586                         break;
 587                 case AF_INET6:
 588                         snprintf(servername, sizeof(servername), "%pI6",
 589                                  &sin6->sin6_addr);
 590                         break;
 591                 default:
 592                         /* caller wants default server name, but
 593                          * address family isn't recognized. */
 594                         return ERR_PTR(-EINVAL);
 595                 }
 596                 xprtargs.servername = servername;
 597         }
 598
 599         xprt = xprt_create_transport(&xprtargs);
 600         if (IS_ERR(xprt))
 601                 return (struct rpc_clnt *)xprt;
 602
 603         /*
 604          * By default, kernel RPC client connects from a reserved port.
 605          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 606          * but it is always enabled for rpciod, which handles the connect
 607          * operation.
 608          */
 609         xprt->resvport = 1;
 610         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 611                 xprt->resvport = 0;
 612         xprt->reuseport = 0;
 613         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 614                 xprt->reuseport = 1;
 615
 616         clnt = rpc_create_xprt(args, xprt);
 617         if (IS_ERR(clnt) || args->nconnect <= 1)
 618                 return clnt;
 619
 620         for (i = 0; i < args->nconnect - 1; i++) {
 621                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 622                         break;
 623         }
 624         return clnt;
 625 }
 626 EXPORT_SYMBOL_GPL(rpc_create);
 627
 628 /*
 629  * This function clones the RPC client structure. It allows us to share the
 630  * same transport while varying parameters such as the authentication
 631  * flavour.
 632  */
 633 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 634                                            struct rpc_clnt *clnt)
 635 {
 636         struct rpc_xprt_switch *xps;
 637         struct rpc_xprt *xprt;
 638         struct rpc_clnt *new;
 639         int err;
 640
 641         err = -ENOMEM;
 642         rcu_read_lock();
 643         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 644         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 645         rcu_read_unlock();
 646         if (xprt == NULL || xps == NULL) {
 647                 xprt_put(xprt);
 648                 xprt_switch_put(xps);
 649                 goto out_err;
 650         }
 651         args->servername = xprt->servername;
 652         args->nodename = clnt->cl_nodename;
 653
 654         new = rpc_new_client(args, xps, xprt, clnt);
 655         if (IS_ERR(new))
 656                 return new;
 657
 658         /* Turn off autobind on clones */
 659         new->cl_autobind = 0;
 660         new->cl_softrtry = clnt->cl_softrtry;
 661         new->cl_softerr = clnt->cl_softerr;
 662         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 663         new->cl_discrtry = clnt->cl_discrtry;
 664         new->cl_chatty = clnt->cl_chatty;
 665         new->cl_principal = clnt->cl_principal;
 666         new->cl_max_connect = clnt->cl_max_connect;
 667         return new;
 668
 669 out_err:
 670         trace_rpc_clnt_clone_err(clnt, err);
 671         return ERR_PTR(err);
 672 }
 673
 674 /**
 675  * rpc_clone_client - Clone an RPC client structure
 676  *
 677  * @clnt: RPC client whose parameters are copied
 678  *
 679  * Returns a fresh RPC client or an ERR_PTR.
 680  */
 681 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 682 {
 683         struct rpc_create_args args = {
 684                 .program        = clnt->cl_program,
 685                 .prognumber     = clnt->cl_prog,
 686                 .version        = clnt->cl_vers,
 687                 .authflavor     = clnt->cl_auth->au_flavor,
 688                 .cred           = clnt->cl_cred,
 689                 .stats          = clnt->cl_stats,
 690         };
 691         return __rpc_clone_client(&args, clnt);
 692 }
 693 EXPORT_SYMBOL_GPL(rpc_clone_client);
 694
 695 /**
 696  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 697  *
 698  * @clnt: RPC client whose parameters are copied
 699  * @flavor: security flavor for new client
 700  *
 701  * Returns a fresh RPC client or an ERR_PTR.
 702  */
 703 struct rpc_clnt *
 704 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 705 {
 706         struct rpc_create_args args = {
 707                 .program        = clnt->cl_program,
 708                 .prognumber     = clnt->cl_prog,
 709                 .version        = clnt->cl_vers,
 710                 .authflavor     = flavor,
 711                 .cred           = clnt->cl_cred,
 712                 .stats          = clnt->cl_stats,
 713         };
 714         return __rpc_clone_client(&args, clnt);
 715 }
 716 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 717
 718 /**
 719  * rpc_switch_client_transport: switch the RPC transport on the fly
 720  * @clnt: pointer to a struct rpc_clnt
 721  * @args: pointer to the new transport arguments
 722  * @timeout: pointer to the new timeout parameters
 723  *
 724  * This function allows the caller to switch the RPC transport for the
 725  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 726  * server, for instance.  It assumes that the caller has ensured that
 727  * there are no active RPC tasks by using some form of locking.
 728  *
 729  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 730  * negative errno is returned, and "clnt" continues to use the old
 731  * xprt.
 732  */
 733 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 734                 struct xprt_create *args,
 735                 const struct rpc_timeout *timeout)
 736 {
 737         const struct rpc_timeout *old_timeo;
 738         rpc_authflavor_t pseudoflavor;
 739         struct rpc_xprt_switch *xps, *oldxps;
 740         struct rpc_xprt *xprt, *old;
 741         struct rpc_clnt *parent;
 742         int err;
 743
 744         args->xprtsec = clnt->cl_xprtsec;
 745         xprt = xprt_create_transport(args);
 746         if (IS_ERR(xprt))
 747                 return PTR_ERR(xprt);
 748
 749         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 750         if (xps == NULL) {
 751                 xprt_put(xprt);
 752                 return -ENOMEM;
 753         }
 754
 755         pseudoflavor = clnt->cl_auth->au_flavor;
 756
 757         old_timeo = clnt->cl_timeout;
 758         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 759         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 760
 761         rpc_unregister_client(clnt);
 762         __rpc_clnt_remove_pipedir(clnt);
 763         rpc_sysfs_client_destroy(clnt);
 764         rpc_clnt_debugfs_unregister(clnt);
 765
 766         /*
 767          * A new transport was created.  "clnt" therefore
 768          * becomes the root of a new cl_parent tree.  clnt's
 769          * children, if it has any, still point to the old xprt.
 770          */
 771         parent = clnt->cl_parent;
 772         clnt->cl_parent = clnt;
 773
 774         /*
 775          * The old rpc_auth cache cannot be re-used.  GSS
 776          * contexts in particular are between a single
 777          * client and server.
 778          */
 779         err = rpc_client_register(clnt, pseudoflavor, NULL);
 780         if (err)
 781                 goto out_revert;
 782
 783         synchronize_rcu();
 784         if (parent != clnt)
 785                 rpc_release_client(parent);
 786         xprt_switch_put(oldxps);
 787         xprt_put(old);
 788         trace_rpc_clnt_replace_xprt(clnt);
 789         return 0;
 790
 791 out_revert:
 792         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 793         rpc_clnt_set_transport(clnt, old, old_timeo);
 794         clnt->cl_parent = parent;
 795         rpc_client_register(clnt, pseudoflavor, NULL);
 796         xprt_switch_put(xps);
 797         xprt_put(xprt);
 798         trace_rpc_clnt_replace_xprt_err(clnt);
 799         return err;
 800 }
 801 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 802
 803 static struct rpc_xprt_switch *rpc_clnt_xprt_switch_get(struct rpc_clnt *clnt)
 804 {
 805         struct rpc_xprt_switch *xps;
 806
 807         rcu_read_lock();
 808         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 809         rcu_read_unlock();
 810
 811         return xps;
 812 }
 813
 814 static
 815 int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi,
 816                              void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps))
 817 {
 818         struct rpc_xprt_switch *xps;
 819
 820         xps = rpc_clnt_xprt_switch_get(clnt);
 821         if (xps == NULL)
 822                 return -EAGAIN;
 823         func(xpi, xps);
 824         xprt_switch_put(xps);
 825         return 0;
 826 }
 827
 828 static
 829 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 830 {
 831         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listall);
 832 }
 833
 834 static
 835 int rpc_clnt_xprt_iter_offline_init(struct rpc_clnt *clnt,
 836                                     struct rpc_xprt_iter *xpi)
 837 {
 838         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listoffline);
 839 }
 840
 841 /**
 842  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 843  * @clnt: pointer to client
 844  * @fn: function to apply
 845  * @data: void pointer to function data
 846  *
 847  * Iterates through the list of RPC transports currently attached to the
 848  * client and applies the function fn(clnt, xprt, data).
 849  *
 850  * On error, the iteration stops, and the function returns the error value.
 851  */
 852 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 853                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 854                 void *data)
 855 {
 856         struct rpc_xprt_iter xpi;
 857         int ret;
 858
 859         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 860         if (ret)
 861                 return ret;
 862         for (;;) {
 863                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 864
 865                 if (!xprt)
 866                         break;
 867                 ret = fn(clnt, xprt, data);
 868                 xprt_put(xprt);
 869                 if (ret < 0)
 870                         break;
 871         }
 872         xprt_iter_destroy(&xpi);
 873         return ret;
 874 }
 875 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 876
 877 /*
 878  * Kill all tasks for the given client.
 879  * XXX: kill their descendants as well?
 880  */
 881 void rpc_killall_tasks(struct rpc_clnt *clnt)
 882 {
 883         struct rpc_task *rovr;
 884
 885
 886         if (list_empty(&clnt->cl_tasks))
 887                 return;
 888
 889         /*
 890          * Spin lock all_tasks to prevent changes...
 891          */
 892         trace_rpc_clnt_killall(clnt);
 893         spin_lock(&clnt->cl_lock);
 894         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 895                 rpc_signal_task(rovr);
 896         spin_unlock(&clnt->cl_lock);
 897 }
 898 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 899
 900 /**
 901  * rpc_cancel_tasks - try to cancel a set of RPC tasks
 902  * @clnt: Pointer to RPC client
 903  * @error: RPC task error value to set
 904  * @fnmatch: Pointer to selector function
 905  * @data: User data
 906  *
 907  * Uses @fnmatch to define a set of RPC tasks that are to be cancelled.
 908  * The argument @error must be a negative error value.
 909  */
 910 unsigned long rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
 911                                bool (*fnmatch)(const struct rpc_task *,
 912                                                const void *),
 913                                const void *data)
 914 {
 915         struct rpc_task *task;
 916         unsigned long count = 0;
 917
 918         if (list_empty(&clnt->cl_tasks))
 919                 return 0;
 920         /*
 921          * Spin lock all_tasks to prevent changes...
 922          */
 923         spin_lock(&clnt->cl_lock);
 924         list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
 925                 if (!RPC_IS_ACTIVATED(task))
 926                         continue;
 927                 if (!fnmatch(task, data))
 928                         continue;
 929                 rpc_task_try_cancel(task, error);
 930                 count++;
 931         }
 932         spin_unlock(&clnt->cl_lock);
 933         return count;
 934 }
 935 EXPORT_SYMBOL_GPL(rpc_cancel_tasks);
 936
 937 static int rpc_clnt_disconnect_xprt(struct rpc_clnt *clnt,
 938                                     struct rpc_xprt *xprt, void *dummy)
 939 {
 940         if (xprt_connected(xprt))
 941                 xprt_force_disconnect(xprt);
 942         return 0;
 943 }
 944
 945 void rpc_clnt_disconnect(struct rpc_clnt *clnt)
 946 {
 947         rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_disconnect_xprt, NULL);
 948 }
 949 EXPORT_SYMBOL_GPL(rpc_clnt_disconnect);
 950
 951 /*
 952  * Properly shut down an RPC client, terminating all outstanding
 953  * requests.
 954  */
 955 void rpc_shutdown_client(struct rpc_clnt *clnt)
 956 {
 957         might_sleep();
 958
 959         trace_rpc_clnt_shutdown(clnt);
 960
 961         while (!list_empty(&clnt->cl_tasks)) {
 962                 rpc_killall_tasks(clnt);
 963                 wait_event_timeout(destroy_wait,
 964                         list_empty(&clnt->cl_tasks), 1*HZ);
 965         }
 966
 967         rpc_release_client(clnt);
 968 }
 969 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 970
 971 /*
 972  * Free an RPC client
 973  */
 974 static void rpc_free_client_work(struct work_struct *work)
 975 {
 976         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 977
 978         trace_rpc_clnt_free(clnt);
 979
 980         /* These might block on processes that might allocate memory,
 981          * so they cannot be called in rpciod, so they are handled separately
 982          * here.
 983          */
 984         rpc_sysfs_client_destroy(clnt);
 985         rpc_clnt_debugfs_unregister(clnt);
 986         rpc_free_clid(clnt);
 987         rpc_clnt_remove_pipedir(clnt);
 988         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 989
 990         kfree(clnt);
 991         rpciod_down();
 992 }
 993 static struct rpc_clnt *
 994 rpc_free_client(struct rpc_clnt *clnt)
 995 {
 996         struct rpc_clnt *parent = NULL;
 997
 998         trace_rpc_clnt_release(clnt);
 999         if (clnt->cl_parent != clnt)
1000                 parent = clnt->cl_parent;
1001         rpc_unregister_client(clnt);
1002         rpc_free_iostats(clnt->cl_metrics);
1003         clnt->cl_metrics = NULL;
1004         xprt_iter_destroy(&clnt->cl_xpi);
1005         put_cred(clnt->cl_cred);
1006
1007         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
1008         schedule_work(&clnt->cl_work);
1009         return parent;
1010 }
1011
1012 /*
1013  * Free an RPC client
1014  */
1015 static struct rpc_clnt *
1016 rpc_free_auth(struct rpc_clnt *clnt)
1017 {
1018         /*
1019          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
1020          *       release remaining GSS contexts. This mechanism ensures
1021          *       that it can do so safely.
1022          */
1023         if (clnt->cl_auth != NULL) {
1024                 rpcauth_release(clnt->cl_auth);
1025                 clnt->cl_auth = NULL;
1026         }
1027         if (refcount_dec_and_test(&clnt->cl_count))
1028                 return rpc_free_client(clnt);
1029         return NULL;
1030 }
1031
1032 /*
1033  * Release reference to the RPC client
1034  */
1035 void
1036 rpc_release_client(struct rpc_clnt *clnt)
1037 {
1038         do {
1039                 if (list_empty(&clnt->cl_tasks))
1040                         wake_up(&destroy_wait);
1041                 if (refcount_dec_not_one(&clnt->cl_count))
1042                         break;
1043                 clnt = rpc_free_auth(clnt);
1044         } while (clnt != NULL);
1045 }
1046 EXPORT_SYMBOL_GPL(rpc_release_client);
1047
1048 /**
1049  * rpc_bind_new_program - bind a new RPC program to an existing client
1050  * @old: old rpc_client
1051  * @program: rpc program to set
1052  * @vers: rpc program version
1053  *
1054  * Clones the rpc client and sets up a new RPC program. This is mainly
1055  * of use for enabling different RPC programs to share the same transport.
1056  * The Sun NFSv2/v3 ACL protocol can do this.
1057  */
1058 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
1059                                       const struct rpc_program *program,
1060                                       u32 vers)
1061 {
1062         struct rpc_create_args args = {
1063                 .program        = program,
1064                 .prognumber     = program->number,
1065                 .version        = vers,
1066                 .authflavor     = old->cl_auth->au_flavor,
1067                 .cred           = old->cl_cred,
1068                 .stats          = old->cl_stats,
1069                 .timeout        = old->cl_timeout,
1070         };
1071         struct rpc_clnt *clnt;
1072         int err;
1073
1074         clnt = __rpc_clone_client(&args, old);
1075         if (IS_ERR(clnt))
1076                 goto out;
1077         err = rpc_ping(clnt);
1078         if (err != 0) {
1079                 rpc_shutdown_client(clnt);
1080                 clnt = ERR_PTR(err);
1081         }
1082 out:
1083         return clnt;
1084 }
1085 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
1086
1087 struct rpc_xprt *
1088 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1089 {
1090         struct rpc_xprt_switch *xps;
1091
1092         if (!xprt)
1093                 return NULL;
1094         rcu_read_lock();
1095         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1096         atomic_long_inc(&xps->xps_queuelen);
1097         rcu_read_unlock();
1098         atomic_long_inc(&xprt->queuelen);
1099
1100         return xprt;
1101 }
1102
1103 static void
1104 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1105 {
1106         struct rpc_xprt_switch *xps;
1107
1108         atomic_long_dec(&xprt->queuelen);
1109         rcu_read_lock();
1110         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1111         atomic_long_dec(&xps->xps_queuelen);
1112         rcu_read_unlock();
1113
1114         xprt_put(xprt);
1115 }
1116
1117 void rpc_task_release_transport(struct rpc_task *task)
1118 {
1119         struct rpc_xprt *xprt = task->tk_xprt;
1120
1121         if (xprt) {
1122                 task->tk_xprt = NULL;
1123                 if (task->tk_client)
1124                         rpc_task_release_xprt(task->tk_client, xprt);
1125                 else
1126                         xprt_put(xprt);
1127         }
1128 }
1129 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1130
1131 void rpc_task_release_client(struct rpc_task *task)
1132 {
1133         struct rpc_clnt *clnt = task->tk_client;
1134
1135         rpc_task_release_transport(task);
1136         if (clnt != NULL) {
1137                 /* Remove from client task list */
1138                 spin_lock(&clnt->cl_lock);
1139                 list_del(&task->tk_task);
1140                 spin_unlock(&clnt->cl_lock);
1141                 task->tk_client = NULL;
1142
1143                 rpc_release_client(clnt);
1144         }
1145 }
1146
1147 static struct rpc_xprt *
1148 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1149 {
1150         struct rpc_xprt *xprt;
1151
1152         rcu_read_lock();
1153         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1154         rcu_read_unlock();
1155         return rpc_task_get_xprt(clnt, xprt);
1156 }
1157
1158 static struct rpc_xprt *
1159 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1160 {
1161         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1162 }
1163
1164 static
1165 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1166 {
1167         if (task->tk_xprt) {
1168                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1169                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1170                         return;
1171                 xprt_release(task);
1172                 xprt_put(task->tk_xprt);
1173         }
1174         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1175                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1176         else
1177                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1178 }
1179
1180 static
1181 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1182 {
1183         rpc_task_set_transport(task, clnt);
1184         task->tk_client = clnt;
1185         refcount_inc(&clnt->cl_count);
1186         if (clnt->cl_softrtry)
1187                 task->tk_flags |= RPC_TASK_SOFT;
1188         if (clnt->cl_softerr)
1189                 task->tk_flags |= RPC_TASK_TIMEOUT;
1190         if (clnt->cl_noretranstimeo)
1191                 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1192         /* Add to the client's list of all tasks */
1193         spin_lock(&clnt->cl_lock);
1194         list_add_tail(&task->tk_task, &clnt->cl_tasks);
1195         spin_unlock(&clnt->cl_lock);
1196 }
1197
1198 static void
1199 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1200 {
1201         if (msg != NULL) {
1202                 task->tk_msg.rpc_proc = msg->rpc_proc;
1203                 task->tk_msg.rpc_argp = msg->rpc_argp;
1204                 task->tk_msg.rpc_resp = msg->rpc_resp;
1205                 task->tk_msg.rpc_cred = msg->rpc_cred;
1206                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1207                         get_cred(task->tk_msg.rpc_cred);
1208         }
1209 }
1210
1211 /*
1212  * Default callback for async RPC calls
1213  */
1214 static void
1215 rpc_default_callback(struct rpc_task *task, void *data)
1216 {
1217 }
1218
1219 static const struct rpc_call_ops rpc_default_ops = {
1220         .rpc_call_done = rpc_default_callback,
1221 };
1222
1223 /**
1224  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1225  * @task_setup_data: pointer to task initialisation data
1226  */
1227 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1228 {
1229         struct rpc_task *task;
1230
1231         task = rpc_new_task(task_setup_data);
1232         if (IS_ERR(task))
1233                 return task;
1234
1235         if (!RPC_IS_ASYNC(task))
1236                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1237
1238         rpc_task_set_client(task, task_setup_data->rpc_client);
1239         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1240
1241         if (task->tk_action == NULL)
1242                 rpc_call_start(task);
1243
1244         atomic_inc(&task->tk_count);
1245         rpc_execute(task);
1246         return task;
1247 }
1248 EXPORT_SYMBOL_GPL(rpc_run_task);
1249
1250 /**
1251  * rpc_call_sync - Perform a synchronous RPC call
1252  * @clnt: pointer to RPC client
1253  * @msg: RPC call parameters
1254  * @flags: RPC call flags
1255  */
1256 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1257 {
1258         struct rpc_task *task;
1259         struct rpc_task_setup task_setup_data = {
1260                 .rpc_client = clnt,
1261                 .rpc_message = msg,
1262                 .callback_ops = &rpc_default_ops,
1263                 .flags = flags,
1264         };
1265         int status;
1266
1267         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1268         if (flags & RPC_TASK_ASYNC) {
1269                 rpc_release_calldata(task_setup_data.callback_ops,
1270                         task_setup_data.callback_data);
1271                 return -EINVAL;
1272         }
1273
1274         task = rpc_run_task(&task_setup_data);
1275         if (IS_ERR(task))
1276                 return PTR_ERR(task);
1277         status = task->tk_status;
1278         rpc_put_task(task);
1279         return status;
1280 }
1281 EXPORT_SYMBOL_GPL(rpc_call_sync);
1282
1283 /**
1284  * rpc_call_async - Perform an asynchronous RPC call
1285  * @clnt: pointer to RPC client
1286  * @msg: RPC call parameters
1287  * @flags: RPC call flags
1288  * @tk_ops: RPC call ops
1289  * @data: user call data
1290  */
1291 int
1292 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1293                const struct rpc_call_ops *tk_ops, void *data)
1294 {
1295         struct rpc_task *task;
1296         struct rpc_task_setup task_setup_data = {
1297                 .rpc_client = clnt,
1298                 .rpc_message = msg,
1299                 .callback_ops = tk_ops,
1300                 .callback_data = data,
1301                 .flags = flags|RPC_TASK_ASYNC,
1302         };
1303
1304         task = rpc_run_task(&task_setup_data);
1305         if (IS_ERR(task))
1306                 return PTR_ERR(task);
1307         rpc_put_task(task);
1308         return 0;
1309 }
1310 EXPORT_SYMBOL_GPL(rpc_call_async);
1311
1312 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1313 static void call_bc_encode(struct rpc_task *task);
1314
1315 /**
1316  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1317  * rpc_execute against it
1318  * @req: RPC request
1319  * @timeout: timeout values to use for this task
1320  */
1321 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
1322                 struct rpc_timeout *timeout)
1323 {
1324         struct rpc_task *task;
1325         struct rpc_task_setup task_setup_data = {
1326                 .callback_ops = &rpc_default_ops,
1327                 .flags = RPC_TASK_SOFTCONN |
1328                         RPC_TASK_NO_RETRANS_TIMEOUT,
1329         };
1330
1331         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1332         /*
1333          * Create an rpc_task to send the data
1334          */
1335         task = rpc_new_task(&task_setup_data);
1336         if (IS_ERR(task)) {
1337                 xprt_free_bc_request(req);
1338                 return task;
1339         }
1340
1341         xprt_init_bc_request(req, task, timeout);
1342
1343         task->tk_action = call_bc_encode;
1344         atomic_inc(&task->tk_count);
1345         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1346         rpc_execute(task);
1347
1348         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1349         return task;
1350 }
1351 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1352
1353 /**
1354  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1355  * @req: RPC request to prepare
1356  * @pages: vector of struct page pointers
1357  * @base: offset in first page where receive should start, in bytes
1358  * @len: expected size of the upper layer data payload, in bytes
1359  * @hdrsize: expected size of upper layer reply header, in XDR words
1360  *
1361  */
1362 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1363                              unsigned int base, unsigned int len,
1364                              unsigned int hdrsize)
1365 {
1366         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1367
1368         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1369         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1370 }
1371 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1372
1373 void
1374 rpc_call_start(struct rpc_task *task)
1375 {
1376         task->tk_action = call_start;
1377 }
1378 EXPORT_SYMBOL_GPL(rpc_call_start);
1379
1380 /**
1381  * rpc_peeraddr - extract remote peer address from clnt's xprt
1382  * @clnt: RPC client structure
1383  * @buf: target buffer
1384  * @bufsize: length of target buffer
1385  *
1386  * Returns the number of bytes that are actually in the stored address.
1387  */
1388 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1389 {
1390         size_t bytes;
1391         struct rpc_xprt *xprt;
1392
1393         rcu_read_lock();
1394         xprt = rcu_dereference(clnt->cl_xprt);
1395
1396         bytes = xprt->addrlen;
1397         if (bytes > bufsize)
1398                 bytes = bufsize;
1399         memcpy(buf, &xprt->addr, bytes);
1400         rcu_read_unlock();
1401
1402         return bytes;
1403 }
1404 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1405
1406 /**
1407  * rpc_peeraddr2str - return remote peer address in printable format
1408  * @clnt: RPC client structure
1409  * @format: address format
1410  *
1411  * NB: the lifetime of the memory referenced by the returned pointer is
1412  * the same as the rpc_xprt itself.  As long as the caller uses this
1413  * pointer, it must hold the RCU read lock.
1414  */
1415 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1416                              enum rpc_display_format_t format)
1417 {
1418         struct rpc_xprt *xprt;
1419
1420         xprt = rcu_dereference(clnt->cl_xprt);
1421
1422         if (xprt->address_strings[format] != NULL)
1423                 return xprt->address_strings[format];
1424         else
1425                 return "unprintable";
1426 }
1427 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1428
1429 static const struct sockaddr_in rpc_inaddr_loopback = {
1430         .sin_family             = AF_INET,
1431         .sin_addr.s_addr        = htonl(INADDR_ANY),
1432 };
1433
1434 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1435         .sin6_family            = AF_INET6,
1436         .sin6_addr              = IN6ADDR_ANY_INIT,
1437 };
1438
1439 /*
1440  * Try a getsockname() on a connected datagram socket.  Using a
1441  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1442  * This conserves the ephemeral port number space.
1443  *
1444  * Returns zero and fills in "buf" if successful; otherwise, a
1445  * negative errno is returned.
1446  */
1447 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1448                         struct sockaddr *buf)
1449 {
1450         struct socket *sock;
1451         int err;
1452
1453         err = __sock_create(net, sap->sa_family,
1454                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1455         if (err < 0) {
1456                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1457                 goto out;
1458         }
1459
1460         switch (sap->sa_family) {
1461         case AF_INET:
1462                 err = kernel_bind(sock,
1463                                 (struct sockaddr *)&rpc_inaddr_loopback,
1464                                 sizeof(rpc_inaddr_loopback));
1465                 break;
1466         case AF_INET6:
1467                 err = kernel_bind(sock,
1468                                 (struct sockaddr *)&rpc_in6addr_loopback,
1469                                 sizeof(rpc_in6addr_loopback));
1470                 break;
1471         default:
1472                 err = -EAFNOSUPPORT;
1473                 goto out_release;
1474         }
1475         if (err < 0) {
1476                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1477                 goto out_release;
1478         }
1479
1480         err = kernel_connect(sock, sap, salen, 0);
1481         if (err < 0) {
1482                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1483                 goto out_release;
1484         }
1485
1486         err = kernel_getsockname(sock, buf);
1487         if (err < 0) {
1488                 dprintk("RPC:       getsockname failed (%d)\n", err);
1489                 goto out_release;
1490         }
1491
1492         err = 0;
1493         if (buf->sa_family == AF_INET6) {
1494                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1495                 sin6->sin6_scope_id = 0;
1496         }
1497         dprintk("RPC:       %s succeeded\n", __func__);
1498
1499 out_release:
1500         sock_release(sock);
1501 out:
1502         return err;
1503 }
1504
1505 /*
1506  * Scraping a connected socket failed, so we don't have a useable
1507  * local address.  Fallback: generate an address that will prevent
1508  * the server from calling us back.
1509  *
1510  * Returns zero and fills in "buf" if successful; otherwise, a
1511  * negative errno is returned.
1512  */
1513 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1514 {
1515         switch (family) {
1516         case AF_INET:
1517                 if (buflen < sizeof(rpc_inaddr_loopback))
1518                         return -EINVAL;
1519                 memcpy(buf, &rpc_inaddr_loopback,
1520                                 sizeof(rpc_inaddr_loopback));
1521                 break;
1522         case AF_INET6:
1523                 if (buflen < sizeof(rpc_in6addr_loopback))
1524                         return -EINVAL;
1525                 memcpy(buf, &rpc_in6addr_loopback,
1526                                 sizeof(rpc_in6addr_loopback));
1527                 break;
1528         default:
1529                 dprintk("RPC:       %s: address family not supported\n",
1530                         __func__);
1531                 return -EAFNOSUPPORT;
1532         }
1533         dprintk("RPC:       %s: succeeded\n", __func__);
1534         return 0;
1535 }
1536
1537 /**
1538  * rpc_localaddr - discover local endpoint address for an RPC client
1539  * @clnt: RPC client structure
1540  * @buf: target buffer
1541  * @buflen: size of target buffer, in bytes
1542  *
1543  * Returns zero and fills in "buf" and "buflen" if successful;
1544  * otherwise, a negative errno is returned.
1545  *
1546  * This works even if the underlying transport is not currently connected,
1547  * or if the upper layer never previously provided a source address.
1548  *
1549  * The result of this function call is transient: multiple calls in
1550  * succession may give different results, depending on how local
1551  * networking configuration changes over time.
1552  */
1553 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1554 {
1555         struct sockaddr_storage address;
1556         struct sockaddr *sap = (struct sockaddr *)&address;
1557         struct rpc_xprt *xprt;
1558         struct net *net;
1559         size_t salen;
1560         int err;
1561
1562         rcu_read_lock();
1563         xprt = rcu_dereference(clnt->cl_xprt);
1564         salen = xprt->addrlen;
1565         memcpy(sap, &xprt->addr, salen);
1566         net = get_net(xprt->xprt_net);
1567         rcu_read_unlock();
1568
1569         rpc_set_port(sap, 0);
1570         err = rpc_sockname(net, sap, salen, buf);
1571         put_net(net);
1572         if (err != 0)
1573                 /* Couldn't discover local address, return ANYADDR */
1574                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1575         return 0;
1576 }
1577 EXPORT_SYMBOL_GPL(rpc_localaddr);
1578
1579 void
1580 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1581 {
1582         struct rpc_xprt *xprt;
1583
1584         rcu_read_lock();
1585         xprt = rcu_dereference(clnt->cl_xprt);
1586         if (xprt->ops->set_buffer_size)
1587                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1588         rcu_read_unlock();
1589 }
1590 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1591
1592 /**
1593  * rpc_net_ns - Get the network namespace for this RPC client
1594  * @clnt: RPC client to query
1595  *
1596  */
1597 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1598 {
1599         struct net *ret;
1600
1601         rcu_read_lock();
1602         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1603         rcu_read_unlock();
1604         return ret;
1605 }
1606 EXPORT_SYMBOL_GPL(rpc_net_ns);
1607
1608 /**
1609  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1610  * @clnt: RPC client to query
1611  *
1612  * For stream transports, this is one RPC record fragment (see RFC
1613  * 1831), as we don't support multi-record requests yet.  For datagram
1614  * transports, this is the size of an IP packet minus the IP, UDP, and
1615  * RPC header sizes.
1616  */
1617 size_t rpc_max_payload(struct rpc_clnt *clnt)
1618 {
1619         size_t ret;
1620
1621         rcu_read_lock();
1622         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1623         rcu_read_unlock();
1624         return ret;
1625 }
1626 EXPORT_SYMBOL_GPL(rpc_max_payload);
1627
1628 /**
1629  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1630  * @clnt: RPC client to query
1631  */
1632 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1633 {
1634         struct rpc_xprt *xprt;
1635         size_t ret;
1636
1637         rcu_read_lock();
1638         xprt = rcu_dereference(clnt->cl_xprt);
1639         ret = xprt->ops->bc_maxpayload(xprt);
1640         rcu_read_unlock();
1641         return ret;
1642 }
1643 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1644
1645 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1646 {
1647         struct rpc_xprt *xprt;
1648         unsigned int ret;
1649
1650         rcu_read_lock();
1651         xprt = rcu_dereference(clnt->cl_xprt);
1652         ret = xprt->ops->bc_num_slots(xprt);
1653         rcu_read_unlock();
1654         return ret;
1655 }
1656 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1657
1658 /**
1659  * rpc_force_rebind - force transport to check that remote port is unchanged
1660  * @clnt: client to rebind
1661  *
1662  */
1663 void rpc_force_rebind(struct rpc_clnt *clnt)
1664 {
1665         if (clnt->cl_autobind) {
1666                 rcu_read_lock();
1667                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1668                 rcu_read_unlock();
1669         }
1670 }
1671 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1672
1673 static int
1674 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1675 {
1676         task->tk_status = 0;
1677         task->tk_rpc_status = 0;
1678         task->tk_action = action;
1679         return 1;
1680 }
1681
1682 /*
1683  * Restart an (async) RPC call. Usually called from within the
1684  * exit handler.
1685  */
1686 int
1687 rpc_restart_call(struct rpc_task *task)
1688 {
1689         return __rpc_restart_call(task, call_start);
1690 }
1691 EXPORT_SYMBOL_GPL(rpc_restart_call);
1692
1693 /*
1694  * Restart an (async) RPC call from the call_prepare state.
1695  * Usually called from within the exit handler.
1696  */
1697 int
1698 rpc_restart_call_prepare(struct rpc_task *task)
1699 {
1700         if (task->tk_ops->rpc_call_prepare != NULL)
1701                 return __rpc_restart_call(task, rpc_prepare_task);
1702         return rpc_restart_call(task);
1703 }
1704 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1705
1706 const char
1707 *rpc_proc_name(const struct rpc_task *task)
1708 {
1709         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1710
1711         if (proc) {
1712                 if (proc->p_name)
1713                         return proc->p_name;
1714                 else
1715                         return "NULL";
1716         } else
1717                 return "no proc";
1718 }
1719
1720 static void
1721 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1722 {
1723         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1724         rpc_task_set_rpc_status(task, rpc_status);
1725         rpc_exit(task, tk_status);
1726 }
1727
1728 static void
1729 rpc_call_rpcerror(struct rpc_task *task, int status)
1730 {
1731         __rpc_call_rpcerror(task, status, status);
1732 }
1733
1734 /*
1735  * 0.  Initial state
1736  *
1737  *     Other FSM states can be visited zero or more times, but
1738  *     this state is visited exactly once for each RPC.
1739  */
1740 static void
1741 call_start(struct rpc_task *task)
1742 {
1743         struct rpc_clnt *clnt = task->tk_client;
1744         int idx = task->tk_msg.rpc_proc->p_statidx;
1745
1746         trace_rpc_request(task);
1747
1748         if (task->tk_client->cl_shutdown) {
1749                 rpc_call_rpcerror(task, -EIO);
1750                 return;
1751         }
1752
1753         /* Increment call count (version might not be valid for ping) */
1754         if (clnt->cl_program->version[clnt->cl_vers])
1755                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1756         clnt->cl_stats->rpccnt++;
1757         task->tk_action = call_reserve;
1758         rpc_task_set_transport(task, clnt);
1759 }
1760
1761 /*
1762  * 1.   Reserve an RPC call slot
1763  */
1764 static void
1765 call_reserve(struct rpc_task *task)
1766 {
1767         task->tk_status  = 0;
1768         task->tk_action  = call_reserveresult;
1769         xprt_reserve(task);
1770 }
1771
1772 static void call_retry_reserve(struct rpc_task *task);
1773
1774 /*
1775  * 1b.  Grok the result of xprt_reserve()
1776  */
1777 static void
1778 call_reserveresult(struct rpc_task *task)
1779 {
1780         int status = task->tk_status;
1781
1782         /*
1783          * After a call to xprt_reserve(), we must have either
1784          * a request slot or else an error status.
1785          */
1786         task->tk_status = 0;
1787         if (status >= 0) {
1788                 if (task->tk_rqstp) {
1789                         task->tk_action = call_refresh;
1790                         return;
1791                 }
1792
1793                 rpc_call_rpcerror(task, -EIO);
1794                 return;
1795         }
1796
1797         switch (status) {
1798         case -ENOMEM:
1799                 rpc_delay(task, HZ >> 2);
1800                 fallthrough;
1801         case -EAGAIN:   /* woken up; retry */
1802                 task->tk_action = call_retry_reserve;
1803                 return;
1804         default:
1805                 rpc_call_rpcerror(task, status);
1806         }
1807 }
1808
1809 /*
1810  * 1c.  Retry reserving an RPC call slot
1811  */
1812 static void
1813 call_retry_reserve(struct rpc_task *task)
1814 {
1815         task->tk_status  = 0;
1816         task->tk_action  = call_reserveresult;
1817         xprt_retry_reserve(task);
1818 }
1819
1820 /*
1821  * 2.   Bind and/or refresh the credentials
1822  */
1823 static void
1824 call_refresh(struct rpc_task *task)
1825 {
1826         task->tk_action = call_refreshresult;
1827         task->tk_status = 0;
1828         task->tk_client->cl_stats->rpcauthrefresh++;
1829         rpcauth_refreshcred(task);
1830 }
1831
1832 /*
1833  * 2a.  Process the results of a credential refresh
1834  */
1835 static void
1836 call_refreshresult(struct rpc_task *task)
1837 {
1838         int status = task->tk_status;
1839
1840         task->tk_status = 0;
1841         task->tk_action = call_refresh;
1842         switch (status) {
1843         case 0:
1844                 if (rpcauth_uptodatecred(task)) {
1845                         task->tk_action = call_allocate;
1846                         return;
1847                 }
1848                 /* Use rate-limiting and a max number of retries if refresh
1849                  * had status 0 but failed to update the cred.
1850                  */
1851                 fallthrough;
1852         case -ETIMEDOUT:
1853                 rpc_delay(task, 3*HZ);
1854                 fallthrough;
1855         case -EAGAIN:
1856                 status = -EACCES;
1857                 fallthrough;
1858         case -EKEYEXPIRED:
1859                 if (!task->tk_cred_retry)
1860                         break;
1861                 task->tk_cred_retry--;
1862                 trace_rpc_retry_refresh_status(task);
1863                 return;
1864         case -ENOMEM:
1865                 rpc_delay(task, HZ >> 4);
1866                 return;
1867         }
1868         trace_rpc_refresh_status(task);
1869         rpc_call_rpcerror(task, status);
1870 }
1871
1872 /*
1873  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1874  *      (Note: buffer memory is freed in xprt_release).
1875  */
1876 static void
1877 call_allocate(struct rpc_task *task)
1878 {
1879         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1880         struct rpc_rqst *req = task->tk_rqstp;
1881         struct rpc_xprt *xprt = req->rq_xprt;
1882         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1883         int status;
1884
1885         task->tk_status = 0;
1886         task->tk_action = call_encode;
1887
1888         if (req->rq_buffer)
1889                 return;
1890
1891         /*
1892          * Calculate the size (in quads) of the RPC call
1893          * and reply headers, and convert both values
1894          * to byte sizes.
1895          */
1896         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1897                            proc->p_arglen;
1898         req->rq_callsize <<= 2;
1899         /*
1900          * Note: the reply buffer must at minimum allocate enough space
1901          * for the 'struct accepted_reply' from RFC5531.
1902          */
1903         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1904                         max_t(size_t, proc->p_replen, 2);
1905         req->rq_rcvsize <<= 2;
1906
1907         status = xprt->ops->buf_alloc(task);
1908         trace_rpc_buf_alloc(task, status);
1909         if (status == 0)
1910                 return;
1911         if (status != -ENOMEM) {
1912                 rpc_call_rpcerror(task, status);
1913                 return;
1914         }
1915
1916         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1917                 task->tk_action = call_allocate;
1918                 rpc_delay(task, HZ>>4);
1919                 return;
1920         }
1921
1922         rpc_call_rpcerror(task, -ERESTARTSYS);
1923 }
1924
1925 static int
1926 rpc_task_need_encode(struct rpc_task *task)
1927 {
1928         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1929                 (!(task->tk_flags & RPC_TASK_SENT) ||
1930                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1931                  xprt_request_need_retransmit(task));
1932 }
1933
1934 static void
1935 rpc_xdr_encode(struct rpc_task *task)
1936 {
1937         struct rpc_rqst *req = task->tk_rqstp;
1938         struct xdr_stream xdr;
1939
1940         xdr_buf_init(&req->rq_snd_buf,
1941                      req->rq_buffer,
1942                      req->rq_callsize);
1943         xdr_buf_init(&req->rq_rcv_buf,
1944                      req->rq_rbuffer,
1945                      req->rq_rcvsize);
1946
1947         req->rq_reply_bytes_recvd = 0;
1948         req->rq_snd_buf.head[0].iov_len = 0;
1949         xdr_init_encode(&xdr, &req->rq_snd_buf,
1950                         req->rq_snd_buf.head[0].iov_base, req);
1951         if (rpc_encode_header(task, &xdr))
1952                 return;
1953
1954         task->tk_status = rpcauth_wrap_req(task, &xdr);
1955 }
1956
1957 /*
1958  * 3.   Encode arguments of an RPC call
1959  */
1960 static void
1961 call_encode(struct rpc_task *task)
1962 {
1963         if (!rpc_task_need_encode(task))
1964                 goto out;
1965
1966         /* Dequeue task from the receive queue while we're encoding */
1967         xprt_request_dequeue_xprt(task);
1968         /* Encode here so that rpcsec_gss can use correct sequence number. */
1969         rpc_xdr_encode(task);
1970         /* Add task to reply queue before transmission to avoid races */
1971         if (task->tk_status == 0 && rpc_reply_expected(task))
1972                 task->tk_status = xprt_request_enqueue_receive(task);
1973         /* Did the encode result in an error condition? */
1974         if (task->tk_status != 0) {
1975                 /* Was the error nonfatal? */
1976                 switch (task->tk_status) {
1977                 case -EAGAIN:
1978                 case -ENOMEM:
1979                         rpc_delay(task, HZ >> 4);
1980                         break;
1981                 case -EKEYEXPIRED:
1982                         if (!task->tk_cred_retry) {
1983                                 rpc_call_rpcerror(task, task->tk_status);
1984                         } else {
1985                                 task->tk_action = call_refresh;
1986                                 task->tk_cred_retry--;
1987                                 trace_rpc_retry_refresh_status(task);
1988                         }
1989                         break;
1990                 default:
1991                         rpc_call_rpcerror(task, task->tk_status);
1992                 }
1993                 return;
1994         }
1995
1996         xprt_request_enqueue_transmit(task);
1997 out:
1998         task->tk_action = call_transmit;
1999         /* Check that the connection is OK */
2000         if (!xprt_bound(task->tk_xprt))
2001                 task->tk_action = call_bind;
2002         else if (!xprt_connected(task->tk_xprt))
2003                 task->tk_action = call_connect;
2004 }
2005
2006 /*
2007  * Helpers to check if the task was already transmitted, and
2008  * to take action when that is the case.
2009  */
2010 static bool
2011 rpc_task_transmitted(struct rpc_task *task)
2012 {
2013         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
2014 }
2015
2016 static void
2017 rpc_task_handle_transmitted(struct rpc_task *task)
2018 {
2019         xprt_end_transmit(task);
2020         task->tk_action = call_transmit_status;
2021 }
2022
2023 /*
2024  * 4.   Get the server port number if not yet set
2025  */
2026 static void
2027 call_bind(struct rpc_task *task)
2028 {
2029         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2030
2031         if (rpc_task_transmitted(task)) {
2032                 rpc_task_handle_transmitted(task);
2033                 return;
2034         }
2035
2036         if (xprt_bound(xprt)) {
2037                 task->tk_action = call_connect;
2038                 return;
2039         }
2040
2041         task->tk_action = call_bind_status;
2042         if (!xprt_prepare_transmit(task))
2043                 return;
2044
2045         xprt->ops->rpcbind(task);
2046 }
2047
2048 /*
2049  * 4a.  Sort out bind result
2050  */
2051 static void
2052 call_bind_status(struct rpc_task *task)
2053 {
2054         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2055         int status = -EIO;
2056
2057         if (rpc_task_transmitted(task)) {
2058                 rpc_task_handle_transmitted(task);
2059                 return;
2060         }
2061
2062         if (task->tk_status >= 0)
2063                 goto out_next;
2064         if (xprt_bound(xprt)) {
2065                 task->tk_status = 0;
2066                 goto out_next;
2067         }
2068
2069         switch (task->tk_status) {
2070         case -ENOMEM:
2071                 rpc_delay(task, HZ >> 2);
2072                 goto retry_timeout;
2073         case -EACCES:
2074                 trace_rpcb_prog_unavail_err(task);
2075                 /* fail immediately if this is an RPC ping */
2076                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2077                         status = -EOPNOTSUPP;
2078                         break;
2079                 }
2080                 rpc_delay(task, 3*HZ);
2081                 goto retry_timeout;
2082         case -ENOBUFS:
2083                 rpc_delay(task, HZ >> 2);
2084                 goto retry_timeout;
2085         case -EAGAIN:
2086                 goto retry_timeout;
2087         case -ETIMEDOUT:
2088                 trace_rpcb_timeout_err(task);
2089                 goto retry_timeout;
2090         case -EPFNOSUPPORT:
2091                 /* server doesn't support any rpcbind version we know of */
2092                 trace_rpcb_bind_version_err(task);
2093                 break;
2094         case -EPROTONOSUPPORT:
2095                 trace_rpcb_bind_version_err(task);
2096                 goto retry_timeout;
2097         case -ECONNREFUSED:             /* connection problems */
2098         case -ECONNRESET:
2099         case -ECONNABORTED:
2100         case -ENOTCONN:
2101         case -EHOSTDOWN:
2102         case -ENETDOWN:
2103         case -EHOSTUNREACH:
2104         case -ENETUNREACH:
2105         case -EPIPE:
2106                 trace_rpcb_unreachable_err(task);
2107                 if (!RPC_IS_SOFTCONN(task)) {
2108                         rpc_delay(task, 5*HZ);
2109                         goto retry_timeout;
2110                 }
2111                 status = task->tk_status;
2112                 break;
2113         default:
2114                 trace_rpcb_unrecognized_err(task);
2115         }
2116
2117         rpc_call_rpcerror(task, status);
2118         return;
2119 out_next:
2120         task->tk_action = call_connect;
2121         return;
2122 retry_timeout:
2123         task->tk_status = 0;
2124         task->tk_action = call_bind;
2125         rpc_check_timeout(task);
2126 }
2127
2128 /*
2129  * 4b.  Connect to the RPC server
2130  */
2131 static void
2132 call_connect(struct rpc_task *task)
2133 {
2134         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2135
2136         if (rpc_task_transmitted(task)) {
2137                 rpc_task_handle_transmitted(task);
2138                 return;
2139         }
2140
2141         if (xprt_connected(xprt)) {
2142                 task->tk_action = call_transmit;
2143                 return;
2144         }
2145
2146         task->tk_action = call_connect_status;
2147         if (task->tk_status < 0)
2148                 return;
2149         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2150                 rpc_call_rpcerror(task, -ENOTCONN);
2151                 return;
2152         }
2153         if (!xprt_prepare_transmit(task))
2154                 return;
2155         xprt_connect(task);
2156 }
2157
2158 /*
2159  * 4c.  Sort out connect result
2160  */
2161 static void
2162 call_connect_status(struct rpc_task *task)
2163 {
2164         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2165         struct rpc_clnt *clnt = task->tk_client;
2166         int status = task->tk_status;
2167
2168         if (rpc_task_transmitted(task)) {
2169                 rpc_task_handle_transmitted(task);
2170                 return;
2171         }
2172
2173         trace_rpc_connect_status(task);
2174
2175         if (task->tk_status == 0) {
2176                 clnt->cl_stats->netreconn++;
2177                 goto out_next;
2178         }
2179         if (xprt_connected(xprt)) {
2180                 task->tk_status = 0;
2181                 goto out_next;
2182         }
2183
2184         task->tk_status = 0;
2185         switch (status) {
2186         case -ECONNREFUSED:
2187         case -ECONNRESET:
2188                 /* A positive refusal suggests a rebind is needed. */
2189                 if (RPC_IS_SOFTCONN(task))
2190                         break;
2191                 if (clnt->cl_autobind) {
2192                         rpc_force_rebind(clnt);
2193                         goto out_retry;
2194                 }
2195                 fallthrough;
2196         case -ECONNABORTED:
2197         case -ENETDOWN:
2198         case -ENETUNREACH:
2199         case -EHOSTUNREACH:
2200         case -EPIPE:
2201         case -EPROTO:
2202                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2203                                             task->tk_rqstp->rq_connect_cookie);
2204                 if (RPC_IS_SOFTCONN(task))
2205                         break;
2206                 /* retry with existing socket, after a delay */
2207                 rpc_delay(task, 3*HZ);
2208                 fallthrough;
2209         case -EADDRINUSE:
2210         case -ENOTCONN:
2211         case -EAGAIN:
2212         case -ETIMEDOUT:
2213                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2214                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2215                     test_bit(XPRT_REMOVE, &xprt->state)) {
2216                         struct rpc_xprt *saved = task->tk_xprt;
2217                         struct rpc_xprt_switch *xps;
2218
2219                         xps = rpc_clnt_xprt_switch_get(clnt);
2220                         if (xps->xps_nxprts > 1) {
2221                                 long value;
2222
2223                                 xprt_release(task);
2224                                 value = atomic_long_dec_return(&xprt->queuelen);
2225                                 if (value == 0)
2226                                         rpc_xprt_switch_remove_xprt(xps, saved,
2227                                                                     true);
2228                                 xprt_put(saved);
2229                                 task->tk_xprt = NULL;
2230                                 task->tk_action = call_start;
2231                         }
2232                         xprt_switch_put(xps);
2233                         if (!task->tk_xprt)
2234                                 goto out;
2235                 }
2236                 goto out_retry;
2237         case -ENOBUFS:
2238                 rpc_delay(task, HZ >> 2);
2239                 goto out_retry;
2240         }
2241         rpc_call_rpcerror(task, status);
2242         return;
2243 out_next:
2244         task->tk_action = call_transmit;
2245         return;
2246 out_retry:
2247         /* Check for timeouts before looping back to call_bind */
2248         task->tk_action = call_bind;
2249 out:
2250         rpc_check_timeout(task);
2251 }
2252
2253 /*
2254  * 5.   Transmit the RPC request, and wait for reply
2255  */
2256 static void
2257 call_transmit(struct rpc_task *task)
2258 {
2259         if (rpc_task_transmitted(task)) {
2260                 rpc_task_handle_transmitted(task);
2261                 return;
2262         }
2263
2264         task->tk_action = call_transmit_status;
2265         if (!xprt_prepare_transmit(task))
2266                 return;
2267         task->tk_status = 0;
2268         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2269                 if (!xprt_connected(task->tk_xprt)) {
2270                         task->tk_status = -ENOTCONN;
2271                         return;
2272                 }
2273                 xprt_transmit(task);
2274         }
2275         xprt_end_transmit(task);
2276 }
2277
2278 /*
2279  * 5a.  Handle cleanup after a transmission
2280  */
2281 static void
2282 call_transmit_status(struct rpc_task *task)
2283 {
2284         task->tk_action = call_status;
2285
2286         /*
2287          * Common case: success.  Force the compiler to put this
2288          * test first.
2289          */
2290         if (rpc_task_transmitted(task)) {
2291                 task->tk_status = 0;
2292                 xprt_request_wait_receive(task);
2293                 return;
2294         }
2295
2296         switch (task->tk_status) {
2297         default:
2298                 break;
2299         case -EBADMSG:
2300                 task->tk_status = 0;
2301                 task->tk_action = call_encode;
2302                 break;
2303                 /*
2304                  * Special cases: if we've been waiting on the
2305                  * socket's write_space() callback, or if the
2306                  * socket just returned a connection error,
2307                  * then hold onto the transport lock.
2308                  */
2309         case -ENOMEM:
2310         case -ENOBUFS:
2311                 rpc_delay(task, HZ>>2);
2312                 fallthrough;
2313         case -EBADSLT:
2314         case -EAGAIN:
2315                 task->tk_action = call_transmit;
2316                 task->tk_status = 0;
2317                 break;
2318         case -EHOSTDOWN:
2319         case -ENETDOWN:
2320         case -EHOSTUNREACH:
2321         case -ENETUNREACH:
2322         case -EPERM:
2323                 break;
2324         case -ECONNREFUSED:
2325                 if (RPC_IS_SOFTCONN(task)) {
2326                         if (!task->tk_msg.rpc_proc->p_proc)
2327                                 trace_xprt_ping(task->tk_xprt,
2328                                                 task->tk_status);
2329                         rpc_call_rpcerror(task, task->tk_status);
2330                         return;
2331                 }
2332                 fallthrough;
2333         case -ECONNRESET:
2334         case -ECONNABORTED:
2335         case -EADDRINUSE:
2336         case -ENOTCONN:
2337         case -EPIPE:
2338                 task->tk_action = call_bind;
2339                 task->tk_status = 0;
2340                 break;
2341         }
2342         rpc_check_timeout(task);
2343 }
2344
2345 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2346 static void call_bc_transmit(struct rpc_task *task);
2347 static void call_bc_transmit_status(struct rpc_task *task);
2348
2349 static void
2350 call_bc_encode(struct rpc_task *task)
2351 {
2352         xprt_request_enqueue_transmit(task);
2353         task->tk_action = call_bc_transmit;
2354 }
2355
2356 /*
2357  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2358  * addition, disconnect on connectivity errors.
2359  */
2360 static void
2361 call_bc_transmit(struct rpc_task *task)
2362 {
2363         task->tk_action = call_bc_transmit_status;
2364         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2365                 if (!xprt_prepare_transmit(task))
2366                         return;
2367                 task->tk_status = 0;
2368                 xprt_transmit(task);
2369         }
2370         xprt_end_transmit(task);
2371 }
2372
2373 static void
2374 call_bc_transmit_status(struct rpc_task *task)
2375 {
2376         struct rpc_rqst *req = task->tk_rqstp;
2377
2378         if (rpc_task_transmitted(task))
2379                 task->tk_status = 0;
2380
2381         switch (task->tk_status) {
2382         case 0:
2383                 /* Success */
2384         case -ENETDOWN:
2385         case -EHOSTDOWN:
2386         case -EHOSTUNREACH:
2387         case -ENETUNREACH:
2388         case -ECONNRESET:
2389         case -ECONNREFUSED:
2390         case -EADDRINUSE:
2391         case -ENOTCONN:
2392         case -EPIPE:
2393                 break;
2394         case -ENOMEM:
2395         case -ENOBUFS:
2396                 rpc_delay(task, HZ>>2);
2397                 fallthrough;
2398         case -EBADSLT:
2399         case -EAGAIN:
2400                 task->tk_status = 0;
2401                 task->tk_action = call_bc_transmit;
2402                 return;
2403         case -ETIMEDOUT:
2404                 /*
2405                  * Problem reaching the server.  Disconnect and let the
2406                  * forechannel reestablish the connection.  The server will
2407                  * have to retransmit the backchannel request and we'll
2408                  * reprocess it.  Since these ops are idempotent, there's no
2409                  * need to cache our reply at this time.
2410                  */
2411                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2412                         "error: %d\n", task->tk_status);
2413                 xprt_conditional_disconnect(req->rq_xprt,
2414                         req->rq_connect_cookie);
2415                 break;
2416         default:
2417                 /*
2418                  * We were unable to reply and will have to drop the
2419                  * request.  The server should reconnect and retransmit.
2420                  */
2421                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2422                         "error: %d\n", task->tk_status);
2423                 break;
2424         }
2425         task->tk_action = rpc_exit_task;
2426 }
2427 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2428
2429 /*
2430  * 6.   Sort out the RPC call status
2431  */
2432 static void
2433 call_status(struct rpc_task *task)
2434 {
2435         struct rpc_clnt *clnt = task->tk_client;
2436         int             status;
2437
2438         if (!task->tk_msg.rpc_proc->p_proc)
2439                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2440
2441         status = task->tk_status;
2442         if (status >= 0) {
2443                 task->tk_action = call_decode;
2444                 return;
2445         }
2446
2447         trace_rpc_call_status(task);
2448         task->tk_status = 0;
2449         switch(status) {
2450         case -EHOSTDOWN:
2451         case -ENETDOWN:
2452         case -EHOSTUNREACH:
2453         case -ENETUNREACH:
2454         case -EPERM:
2455                 if (RPC_IS_SOFTCONN(task))
2456                         goto out_exit;
2457                 /*
2458                  * Delay any retries for 3 seconds, then handle as if it
2459                  * were a timeout.
2460                  */
2461                 rpc_delay(task, 3*HZ);
2462                 fallthrough;
2463         case -ETIMEDOUT:
2464                 break;
2465         case -ECONNREFUSED:
2466         case -ECONNRESET:
2467         case -ECONNABORTED:
2468         case -ENOTCONN:
2469                 rpc_force_rebind(clnt);
2470                 break;
2471         case -EADDRINUSE:
2472                 rpc_delay(task, 3*HZ);
2473                 fallthrough;
2474         case -EPIPE:
2475         case -EAGAIN:
2476                 break;
2477         case -ENFILE:
2478         case -ENOBUFS:
2479         case -ENOMEM:
2480                 rpc_delay(task, HZ>>2);
2481                 break;
2482         case -EIO:
2483                 /* shutdown or soft timeout */
2484                 goto out_exit;
2485         default:
2486                 if (clnt->cl_chatty)
2487                         printk("%s: RPC call returned error %d\n",
2488                                clnt->cl_program->name, -status);
2489                 goto out_exit;
2490         }
2491         task->tk_action = call_encode;
2492         rpc_check_timeout(task);
2493         return;
2494 out_exit:
2495         rpc_call_rpcerror(task, status);
2496 }
2497
2498 static bool
2499 rpc_check_connected(const struct rpc_rqst *req)
2500 {
2501         /* No allocated request or transport? return true */
2502         if (!req || !req->rq_xprt)
2503                 return true;
2504         return xprt_connected(req->rq_xprt);
2505 }
2506
2507 static void
2508 rpc_check_timeout(struct rpc_task *task)
2509 {
2510         struct rpc_clnt *clnt = task->tk_client;
2511
2512         if (RPC_SIGNALLED(task))
2513                 return;
2514
2515         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2516                 return;
2517
2518         trace_rpc_timeout_status(task);
2519         task->tk_timeouts++;
2520
2521         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2522                 rpc_call_rpcerror(task, -ETIMEDOUT);
2523                 return;
2524         }
2525
2526         if (RPC_IS_SOFT(task)) {
2527                 /*
2528                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2529                  * been sent, it should time out only if the transport
2530                  * connection gets terminally broken.
2531                  */
2532                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2533                     rpc_check_connected(task->tk_rqstp))
2534                         return;
2535
2536                 if (clnt->cl_chatty) {
2537                         pr_notice_ratelimited(
2538                                 "%s: server %s not responding, timed out\n",
2539                                 clnt->cl_program->name,
2540                                 task->tk_xprt->servername);
2541                 }
2542                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2543                         rpc_call_rpcerror(task, -ETIMEDOUT);
2544                 else
2545                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2546                 return;
2547         }
2548
2549         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2550                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2551                 if (clnt->cl_chatty) {
2552                         pr_notice_ratelimited(
2553                                 "%s: server %s not responding, still trying\n",
2554                                 clnt->cl_program->name,
2555                                 task->tk_xprt->servername);
2556                 }
2557         }
2558         rpc_force_rebind(clnt);
2559         /*
2560          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2561          * event? RFC2203 requires the server to drop all such requests.
2562          */
2563         rpcauth_invalcred(task);
2564 }
2565
2566 /*
2567  * 7.   Decode the RPC reply
2568  */
2569 static void
2570 call_decode(struct rpc_task *task)
2571 {
2572         struct rpc_clnt *clnt = task->tk_client;
2573         struct rpc_rqst *req = task->tk_rqstp;
2574         struct xdr_stream xdr;
2575         int err;
2576
2577         if (!task->tk_msg.rpc_proc->p_decode) {
2578                 task->tk_action = rpc_exit_task;
2579                 return;
2580         }
2581
2582         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2583                 if (clnt->cl_chatty) {
2584                         pr_notice_ratelimited("%s: server %s OK\n",
2585                                 clnt->cl_program->name,
2586                                 task->tk_xprt->servername);
2587                 }
2588                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2589         }
2590
2591         /*
2592          * Did we ever call xprt_complete_rqst()? If not, we should assume
2593          * the message is incomplete.
2594          */
2595         err = -EAGAIN;
2596         if (!req->rq_reply_bytes_recvd)
2597                 goto out;
2598
2599         /* Ensure that we see all writes made by xprt_complete_rqst()
2600          * before it changed req->rq_reply_bytes_recvd.
2601          */
2602         smp_rmb();
2603
2604         req->rq_rcv_buf.len = req->rq_private_buf.len;
2605         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2606
2607         /* Check that the softirq receive buffer is valid */
2608         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2609                                 sizeof(req->rq_rcv_buf)) != 0);
2610
2611         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2612                         req->rq_rcv_buf.head[0].iov_base, req);
2613         err = rpc_decode_header(task, &xdr);
2614 out:
2615         switch (err) {
2616         case 0:
2617                 task->tk_action = rpc_exit_task;
2618                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2619                 xdr_finish_decode(&xdr);
2620                 return;
2621         case -EAGAIN:
2622                 task->tk_status = 0;
2623                 if (task->tk_client->cl_discrtry)
2624                         xprt_conditional_disconnect(req->rq_xprt,
2625                                                     req->rq_connect_cookie);
2626                 task->tk_action = call_encode;
2627                 rpc_check_timeout(task);
2628                 break;
2629         case -EKEYREJECTED:
2630                 task->tk_action = call_reserve;
2631                 rpc_check_timeout(task);
2632                 rpcauth_invalcred(task);
2633                 /* Ensure we obtain a new XID if we retry! */
2634                 xprt_release(task);
2635         }
2636 }
2637
2638 static int
2639 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2640 {
2641         struct rpc_clnt *clnt = task->tk_client;
2642         struct rpc_rqst *req = task->tk_rqstp;
2643         __be32 *p;
2644         int error;
2645
2646         error = -EMSGSIZE;
2647         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2648         if (!p)
2649                 goto out_fail;
2650         *p++ = req->rq_xid;
2651         *p++ = rpc_call;
2652         *p++ = cpu_to_be32(RPC_VERSION);
2653         *p++ = cpu_to_be32(clnt->cl_prog);
2654         *p++ = cpu_to_be32(clnt->cl_vers);
2655         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2656
2657         error = rpcauth_marshcred(task, xdr);
2658         if (error < 0)
2659                 goto out_fail;
2660         return 0;
2661 out_fail:
2662         trace_rpc_bad_callhdr(task);
2663         rpc_call_rpcerror(task, error);
2664         return error;
2665 }
2666
2667 static noinline int
2668 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2669 {
2670         struct rpc_clnt *clnt = task->tk_client;
2671         int error;
2672         __be32 *p;
2673
2674         /* RFC-1014 says that the representation of XDR data must be a
2675          * multiple of four bytes
2676          * - if it isn't pointer subtraction in the NFS client may give
2677          *   undefined results
2678          */
2679         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2680                 goto out_unparsable;
2681
2682         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2683         if (!p)
2684                 goto out_unparsable;
2685         p++;    /* skip XID */
2686         if (*p++ != rpc_reply)
2687                 goto out_unparsable;
2688         if (*p++ != rpc_msg_accepted)
2689                 goto out_msg_denied;
2690
2691         error = rpcauth_checkverf(task, xdr);
2692         if (error) {
2693                 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
2694
2695                 if (!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
2696                         rpcauth_invalcred(task);
2697                         if (!task->tk_cred_retry)
2698                                 goto out_err;
2699                         task->tk_cred_retry--;
2700                         trace_rpc__stale_creds(task);
2701                         return -EKEYREJECTED;
2702                 }
2703                 goto out_verifier;
2704         }
2705
2706         p = xdr_inline_decode(xdr, sizeof(*p));
2707         if (!p)
2708                 goto out_unparsable;
2709         switch (*p) {
2710         case rpc_success:
2711                 return 0;
2712         case rpc_prog_unavail:
2713                 trace_rpc__prog_unavail(task);
2714                 error = -EPFNOSUPPORT;
2715                 goto out_err;
2716         case rpc_prog_mismatch:
2717                 trace_rpc__prog_mismatch(task);
2718                 error = -EPROTONOSUPPORT;
2719                 goto out_err;
2720         case rpc_proc_unavail:
2721                 trace_rpc__proc_unavail(task);
2722                 error = -EOPNOTSUPP;
2723                 goto out_err;
2724         case rpc_garbage_args:
2725         case rpc_system_err:
2726                 trace_rpc__garbage_args(task);
2727                 error = -EIO;
2728                 break;
2729         default:
2730                 goto out_unparsable;
2731         }
2732
2733 out_garbage:
2734         clnt->cl_stats->rpcgarbage++;
2735         if (task->tk_garb_retry) {
2736                 task->tk_garb_retry--;
2737                 task->tk_action = call_encode;
2738                 return -EAGAIN;
2739         }
2740 out_err:
2741         rpc_call_rpcerror(task, error);
2742         return error;
2743
2744 out_unparsable:
2745         trace_rpc__unparsable(task);
2746         error = -EIO;
2747         goto out_garbage;
2748
2749 out_verifier:
2750         trace_rpc_bad_verifier(task);
2751         switch (error) {
2752         case -EPROTONOSUPPORT:
2753                 goto out_err;
2754         case -EACCES:
2755                 /* Re-encode with a fresh cred */
2756                 fallthrough;
2757         default:
2758                 goto out_garbage;
2759         }
2760
2761 out_msg_denied:
2762         error = -EACCES;
2763         p = xdr_inline_decode(xdr, sizeof(*p));
2764         if (!p)
2765                 goto out_unparsable;
2766         switch (*p++) {
2767         case rpc_auth_error:
2768                 break;
2769         case rpc_mismatch:
2770                 trace_rpc__mismatch(task);
2771                 error = -EPROTONOSUPPORT;
2772                 goto out_err;
2773         default:
2774                 goto out_unparsable;
2775         }
2776
2777         p = xdr_inline_decode(xdr, sizeof(*p));
2778         if (!p)
2779                 goto out_unparsable;
2780         switch (*p++) {
2781         case rpc_autherr_rejectedcred:
2782         case rpc_autherr_rejectedverf:
2783         case rpcsec_gsserr_credproblem:
2784         case rpcsec_gsserr_ctxproblem:
2785                 rpcauth_invalcred(task);
2786                 if (!task->tk_cred_retry)
2787                         break;
2788                 task->tk_cred_retry--;
2789                 trace_rpc__stale_creds(task);
2790                 return -EKEYREJECTED;
2791         case rpc_autherr_badcred:
2792         case rpc_autherr_badverf:
2793                 /* possibly garbled cred/verf? */
2794                 if (!task->tk_garb_retry)
2795                         break;
2796                 task->tk_garb_retry--;
2797                 trace_rpc__bad_creds(task);
2798                 task->tk_action = call_encode;
2799                 return -EAGAIN;
2800         case rpc_autherr_tooweak:
2801                 trace_rpc__auth_tooweak(task);
2802                 pr_warn("RPC: server %s requires stronger authentication.\n",
2803                         task->tk_xprt->servername);
2804                 break;
2805         default:
2806                 goto out_unparsable;
2807         }
2808         goto out_err;
2809 }
2810
2811 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2812                 const void *obj)
2813 {
2814 }
2815
2816 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2817                 void *obj)
2818 {
2819         return 0;
2820 }
2821
2822 static const struct rpc_procinfo rpcproc_null = {
2823         .p_encode = rpcproc_encode_null,
2824         .p_decode = rpcproc_decode_null,
2825 };
2826
2827 static const struct rpc_procinfo rpcproc_null_noreply = {
2828         .p_encode = rpcproc_encode_null,
2829 };
2830
2831 static void
2832 rpc_null_call_prepare(struct rpc_task *task, void *data)
2833 {
2834         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2835         rpc_call_start(task);
2836 }
2837
2838 static const struct rpc_call_ops rpc_null_ops = {
2839         .rpc_call_prepare = rpc_null_call_prepare,
2840         .rpc_call_done = rpc_default_callback,
2841 };
2842
2843 static
2844 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2845                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2846                 const struct rpc_call_ops *ops, void *data)
2847 {
2848         struct rpc_message msg = {
2849                 .rpc_proc = &rpcproc_null,
2850         };
2851         struct rpc_task_setup task_setup_data = {
2852                 .rpc_client = clnt,
2853                 .rpc_xprt = xprt,
2854                 .rpc_message = &msg,
2855                 .rpc_op_cred = cred,
2856                 .callback_ops = ops ?: &rpc_null_ops,
2857                 .callback_data = data,
2858                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2859                          RPC_TASK_NULLCREDS,
2860         };
2861
2862         return rpc_run_task(&task_setup_data);
2863 }
2864
2865 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2866 {
2867         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2868 }
2869 EXPORT_SYMBOL_GPL(rpc_call_null);
2870
2871 static int rpc_ping(struct rpc_clnt *clnt)
2872 {
2873         struct rpc_task *task;
2874         int status;
2875
2876         if (clnt->cl_auth->au_ops->ping)
2877                 return clnt->cl_auth->au_ops->ping(clnt);
2878
2879         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2880         if (IS_ERR(task))
2881                 return PTR_ERR(task);
2882         status = task->tk_status;
2883         rpc_put_task(task);
2884         return status;
2885 }
2886
2887 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2888 {
2889         struct rpc_message msg = {
2890                 .rpc_proc = &rpcproc_null_noreply,
2891         };
2892         struct rpc_task_setup task_setup_data = {
2893                 .rpc_client = clnt,
2894                 .rpc_message = &msg,
2895                 .callback_ops = &rpc_null_ops,
2896                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2897         };
2898         struct rpc_task *task;
2899         int status;
2900
2901         task = rpc_run_task(&task_setup_data);
2902         if (IS_ERR(task))
2903                 return PTR_ERR(task);
2904         status = task->tk_status;
2905         rpc_put_task(task);
2906         return status;
2907 }
2908
2909 struct rpc_cb_add_xprt_calldata {
2910         struct rpc_xprt_switch *xps;
2911         struct rpc_xprt *xprt;
2912 };
2913
2914 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2915 {
2916         struct rpc_cb_add_xprt_calldata *data = calldata;
2917
2918         if (task->tk_status == 0)
2919                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2920 }
2921
2922 static void rpc_cb_add_xprt_release(void *calldata)
2923 {
2924         struct rpc_cb_add_xprt_calldata *data = calldata;
2925
2926         xprt_put(data->xprt);
2927         xprt_switch_put(data->xps);
2928         kfree(data);
2929 }
2930
2931 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2932         .rpc_call_prepare = rpc_null_call_prepare,
2933         .rpc_call_done = rpc_cb_add_xprt_done,
2934         .rpc_release = rpc_cb_add_xprt_release,
2935 };
2936
2937 /**
2938  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2939  * @clnt: pointer to struct rpc_clnt
2940  * @xps: pointer to struct rpc_xprt_switch,
2941  * @xprt: pointer struct rpc_xprt
2942  * @in_max_connect: pointer to the max_connect value for the passed in xprt transport
2943  */
2944 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2945                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2946                 void *in_max_connect)
2947 {
2948         struct rpc_cb_add_xprt_calldata *data;
2949         struct rpc_task *task;
2950         int max_connect = clnt->cl_max_connect;
2951
2952         if (in_max_connect)
2953                 max_connect = *(int *)in_max_connect;
2954         if (xps->xps_nunique_destaddr_xprts + 1 > max_connect) {
2955                 rcu_read_lock();
2956                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2957                         "transport to server: %s\n", max_connect,
2958                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2959                 rcu_read_unlock();
2960                 return -EINVAL;
2961         }
2962
2963         data = kmalloc(sizeof(*data), GFP_KERNEL);
2964         if (!data)
2965                 return -ENOMEM;
2966         data->xps = xprt_switch_get(xps);
2967         data->xprt = xprt_get(xprt);
2968         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2969                 rpc_cb_add_xprt_release(data);
2970                 goto success;
2971         }
2972
2973         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2974                         &rpc_cb_add_xprt_call_ops, data);
2975         if (IS_ERR(task))
2976                 return PTR_ERR(task);
2977
2978         data->xps->xps_nunique_destaddr_xprts++;
2979         rpc_put_task(task);
2980 success:
2981         return 1;
2982 }
2983 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2984
2985 static int rpc_clnt_add_xprt_helper(struct rpc_clnt *clnt,
2986                                     struct rpc_xprt *xprt,
2987                                     struct rpc_add_xprt_test *data)
2988 {
2989         struct rpc_task *task;
2990         int status = -EADDRINUSE;
2991
2992         /* Test the connection */
2993         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2994         if (IS_ERR(task))
2995                 return PTR_ERR(task);
2996
2997         status = task->tk_status;
2998         rpc_put_task(task);
2999
3000         if (status < 0)
3001                 return status;
3002
3003         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
3004         data->add_xprt_test(clnt, xprt, data->data);
3005
3006         return 0;
3007 }
3008
3009 /**
3010  * rpc_clnt_setup_test_and_add_xprt()
3011  *
3012  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
3013  *   1) caller of the test function must dereference the rpc_xprt_switch
3014  *   and the rpc_xprt.
3015  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
3016  *   the rpc_call_done routine.
3017  *
3018  * Upon success (return of 1), the test function adds the new
3019  * transport to the rpc_clnt xprt switch
3020  *
3021  * @clnt: struct rpc_clnt to get the new transport
3022  * @xps:  the rpc_xprt_switch to hold the new transport
3023  * @xprt: the rpc_xprt to test
3024  * @data: a struct rpc_add_xprt_test pointer that holds the test function
3025  *        and test function call data
3026  */
3027 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
3028                                      struct rpc_xprt_switch *xps,
3029                                      struct rpc_xprt *xprt,
3030                                      void *data)
3031 {
3032         int status = -EADDRINUSE;
3033
3034         xprt = xprt_get(xprt);
3035         xprt_switch_get(xps);
3036
3037         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
3038                 goto out_err;
3039
3040         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3041         if (status < 0)
3042                 goto out_err;
3043
3044         status = 1;
3045 out_err:
3046         xprt_put(xprt);
3047         xprt_switch_put(xps);
3048         if (status < 0)
3049                 pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not "
3050                         "added\n", status,
3051                         xprt->address_strings[RPC_DISPLAY_ADDR]);
3052         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
3053         return status;
3054 }
3055 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
3056
3057 /**
3058  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
3059  * @clnt: pointer to struct rpc_clnt
3060  * @xprtargs: pointer to struct xprt_create
3061  * @setup: callback to test and/or set up the connection
3062  * @data: pointer to setup function data
3063  *
3064  * Creates a new transport using the parameters set in args and
3065  * adds it to clnt.
3066  * If ping is set, then test that connectivity succeeds before
3067  * adding the new transport.
3068  *
3069  */
3070 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
3071                 struct xprt_create *xprtargs,
3072                 int (*setup)(struct rpc_clnt *,
3073                         struct rpc_xprt_switch *,
3074                         struct rpc_xprt *,
3075                         void *),
3076                 void *data)
3077 {
3078         struct rpc_xprt_switch *xps;
3079         struct rpc_xprt *xprt;
3080         unsigned long connect_timeout;
3081         unsigned long reconnect_timeout;
3082         unsigned char resvport, reuseport;
3083         int ret = 0, ident;
3084
3085         rcu_read_lock();
3086         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3087         xprt = xprt_iter_xprt(&clnt->cl_xpi);
3088         if (xps == NULL || xprt == NULL) {
3089                 rcu_read_unlock();
3090                 xprt_switch_put(xps);
3091                 return -EAGAIN;
3092         }
3093         resvport = xprt->resvport;
3094         reuseport = xprt->reuseport;
3095         connect_timeout = xprt->connect_timeout;
3096         reconnect_timeout = xprt->max_reconnect_timeout;
3097         ident = xprt->xprt_class->ident;
3098         rcu_read_unlock();
3099
3100         if (!xprtargs->ident)
3101                 xprtargs->ident = ident;
3102         xprtargs->xprtsec = clnt->cl_xprtsec;
3103         xprt = xprt_create_transport(xprtargs);
3104         if (IS_ERR(xprt)) {
3105                 ret = PTR_ERR(xprt);
3106                 goto out_put_switch;
3107         }
3108         xprt->resvport = resvport;
3109         xprt->reuseport = reuseport;
3110
3111         if (xprtargs->connect_timeout)
3112                 connect_timeout = xprtargs->connect_timeout;
3113         if (xprtargs->reconnect_timeout)
3114                 reconnect_timeout = xprtargs->reconnect_timeout;
3115         if (xprt->ops->set_connect_timeout != NULL)
3116                 xprt->ops->set_connect_timeout(xprt,
3117                                 connect_timeout,
3118                                 reconnect_timeout);
3119
3120         rpc_xprt_switch_set_roundrobin(xps);
3121         if (setup) {
3122                 ret = setup(clnt, xps, xprt, data);
3123                 if (ret != 0)
3124                         goto out_put_xprt;
3125         }
3126         rpc_xprt_switch_add_xprt(xps, xprt);
3127 out_put_xprt:
3128         xprt_put(xprt);
3129 out_put_switch:
3130         xprt_switch_put(xps);
3131         return ret;
3132 }
3133 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
3134
3135 static int rpc_xprt_probe_trunked(struct rpc_clnt *clnt,
3136                                   struct rpc_xprt *xprt,
3137                                   struct rpc_add_xprt_test *data)
3138 {
3139         struct rpc_xprt *main_xprt;
3140         int status = 0;
3141
3142         xprt_get(xprt);
3143
3144         rcu_read_lock();
3145         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3146         status = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3147                                    (struct sockaddr *)&main_xprt->addr);
3148         rcu_read_unlock();
3149         xprt_put(main_xprt);
3150         if (status || !test_bit(XPRT_OFFLINE, &xprt->state))
3151                 goto out;
3152
3153         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3154 out:
3155         xprt_put(xprt);
3156         return status;
3157 }
3158
3159 /* rpc_clnt_probe_trunked_xprt -- probe offlined transport for session trunking
3160  * @clnt rpc_clnt structure
3161  *
3162  * For each offlined transport found in the rpc_clnt structure call
3163  * the function rpc_xprt_probe_trunked() which will determine if this
3164  * transport still belongs to the trunking group.
3165  */
3166 void rpc_clnt_probe_trunked_xprts(struct rpc_clnt *clnt,
3167                                   struct rpc_add_xprt_test *data)
3168 {
3169         struct rpc_xprt_iter xpi;
3170         int ret;
3171
3172         ret = rpc_clnt_xprt_iter_offline_init(clnt, &xpi);
3173         if (ret)
3174                 return;
3175         for (;;) {
3176                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
3177
3178                 if (!xprt)
3179                         break;
3180                 ret = rpc_xprt_probe_trunked(clnt, xprt, data);
3181                 xprt_put(xprt);
3182                 if (ret < 0)
3183                         break;
3184                 xprt_iter_rewind(&xpi);
3185         }
3186         xprt_iter_destroy(&xpi);
3187 }
3188 EXPORT_SYMBOL_GPL(rpc_clnt_probe_trunked_xprts);
3189
3190 static int rpc_xprt_offline(struct rpc_clnt *clnt,
3191                             struct rpc_xprt *xprt,
3192                             void *data)
3193 {
3194         struct rpc_xprt *main_xprt;
3195         struct rpc_xprt_switch *xps;
3196         int err = 0;
3197
3198         xprt_get(xprt);
3199
3200         rcu_read_lock();
3201         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3202         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3203         err = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3204                                 (struct sockaddr *)&main_xprt->addr);
3205         rcu_read_unlock();
3206         xprt_put(main_xprt);
3207         if (err)
3208                 goto out;
3209
3210         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
3211                 err = -EINTR;
3212                 goto out;
3213         }
3214         xprt_set_offline_locked(xprt, xps);
3215
3216         xprt_release_write(xprt, NULL);
3217 out:
3218         xprt_put(xprt);
3219         xprt_switch_put(xps);
3220         return err;
3221 }
3222
3223 /* rpc_clnt_manage_trunked_xprts -- offline trunked transports
3224  * @clnt rpc_clnt structure
3225  *
3226  * For each active transport found in the rpc_clnt structure call
3227  * the function rpc_xprt_offline() which will identify trunked transports
3228  * and will mark them offline.
3229  */
3230 void rpc_clnt_manage_trunked_xprts(struct rpc_clnt *clnt)
3231 {
3232         rpc_clnt_iterate_for_each_xprt(clnt, rpc_xprt_offline, NULL);
3233 }
3234 EXPORT_SYMBOL_GPL(rpc_clnt_manage_trunked_xprts);
3235
3236 struct connect_timeout_data {
3237         unsigned long connect_timeout;
3238         unsigned long reconnect_timeout;
3239 };
3240
3241 static int
3242 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3243                 struct rpc_xprt *xprt,
3244                 void *data)
3245 {
3246         struct connect_timeout_data *timeo = data;
3247
3248         if (xprt->ops->set_connect_timeout)
3249                 xprt->ops->set_connect_timeout(xprt,
3250                                 timeo->connect_timeout,
3251                                 timeo->reconnect_timeout);
3252         return 0;
3253 }
3254
3255 void
3256 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3257                 unsigned long connect_timeout,
3258                 unsigned long reconnect_timeout)
3259 {
3260         struct connect_timeout_data timeout = {
3261                 .connect_timeout = connect_timeout,
3262                 .reconnect_timeout = reconnect_timeout,
3263         };
3264         rpc_clnt_iterate_for_each_xprt(clnt,
3265                         rpc_xprt_set_connect_timeout,
3266                         &timeout);
3267 }
3268 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3269
3270 void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3271 {
3272         struct rpc_xprt_switch *xps;
3273
3274         xps = rpc_clnt_xprt_switch_get(clnt);
3275         xprt_set_online_locked(xprt, xps);
3276         xprt_switch_put(xps);
3277 }
3278
3279 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3280 {
3281         struct rpc_xprt_switch *xps;
3282
3283         if (rpc_clnt_xprt_switch_has_addr(clnt,
3284                 (const struct sockaddr *)&xprt->addr)) {
3285                 return rpc_clnt_xprt_set_online(clnt, xprt);
3286         }
3287
3288         xps = rpc_clnt_xprt_switch_get(clnt);
3289         rpc_xprt_switch_add_xprt(xps, xprt);
3290         xprt_switch_put(xps);
3291 }
3292 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3293
3294 void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3295 {
3296         struct rpc_xprt_switch *xps;
3297
3298         rcu_read_lock();
3299         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3300         rpc_xprt_switch_remove_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3301                                     xprt, 0);
3302         xps->xps_nunique_destaddr_xprts--;
3303         rcu_read_unlock();
3304 }
3305 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_remove_xprt);
3306
3307 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3308                                    const struct sockaddr *sap)
3309 {
3310         struct rpc_xprt_switch *xps;
3311         bool ret;
3312
3313         rcu_read_lock();
3314         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3315         ret = rpc_xprt_switch_has_addr(xps, sap);
3316         rcu_read_unlock();
3317         return ret;
3318 }
3319 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3320
3321 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3322 static void rpc_show_header(void)
3323 {
3324         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3325                 "-timeout ---ops--\n");
3326 }
3327
3328 static void rpc_show_task(const struct rpc_clnt *clnt,
3329                           const struct rpc_task *task)
3330 {
3331         const char *rpc_waitq = "none";
3332
3333         if (RPC_IS_QUEUED(task))
3334                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3335
3336         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3337                 task->tk_pid, task->tk_flags, task->tk_status,
3338                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3339                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3340                 task->tk_action, rpc_waitq);
3341 }
3342
3343 void rpc_show_tasks(struct net *net)
3344 {
3345         struct rpc_clnt *clnt;
3346         struct rpc_task *task;
3347         int header = 0;
3348         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3349
3350         spin_lock(&sn->rpc_client_lock);
3351         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3352                 spin_lock(&clnt->cl_lock);
3353                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3354                         if (!header) {
3355                                 rpc_show_header();
3356                                 header++;
3357                         }
3358                         rpc_show_task(clnt, task);
3359                 }
3360                 spin_unlock(&clnt->cl_lock);
3361         }
3362         spin_unlock(&sn->rpc_client_lock);
3363 }
3364 #endif
3365
3366 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3367 static int
3368 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3369                 struct rpc_xprt *xprt,
3370                 void *dummy)
3371 {
3372         return xprt_enable_swap(xprt);
3373 }
3374
3375 int
3376 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3377 {
3378         while (clnt != clnt->cl_parent)
3379                 clnt = clnt->cl_parent;
3380         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3381                 return rpc_clnt_iterate_for_each_xprt(clnt,
3382                                 rpc_clnt_swap_activate_callback, NULL);
3383         return 0;
3384 }
3385 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3386
3387 static int
3388 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3389                 struct rpc_xprt *xprt,
3390                 void *dummy)
3391 {
3392         xprt_disable_swap(xprt);
3393         return 0;
3394 }
3395
3396 void
3397 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3398 {
3399         while (clnt != clnt->cl_parent)
3400                 clnt = clnt->cl_parent;
3401         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3402                 rpc_clnt_iterate_for_each_xprt(clnt,
3403                                 rpc_clnt_swap_deactivate_callback, NULL);
3404 }
3405 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3406 #endif /* CONFIG_SUNRPC_SWAP */