net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "sysfs.h"
  45 #include "netns.h"
  46
  47 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  48 # define RPCDBG_FACILITY        RPCDBG_CALL
  49 #endif
  50
  51 /*
  52  * All RPC clients are linked into this list
  53  */
  54
  55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  56
  57
  58 static void     call_start(struct rpc_task *task);
  59 static void     call_reserve(struct rpc_task *task);
  60 static void     call_reserveresult(struct rpc_task *task);
  61 static void     call_allocate(struct rpc_task *task);
  62 static void     call_encode(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 static void     call_status(struct rpc_task *task);
  68 static void     call_transmit_status(struct rpc_task *task);
  69 static void     call_refresh(struct rpc_task *task);
  70 static void     call_refreshresult(struct rpc_task *task);
  71 static void     call_connect(struct rpc_task *task);
  72 static void     call_connect_status(struct rpc_task *task);
  73
  74 static int      rpc_encode_header(struct rpc_task *task,
  75                                   struct xdr_stream *xdr);
  76 static int      rpc_decode_header(struct rpc_task *task,
  77                                   struct xdr_stream *xdr);
  78 static int      rpc_ping(struct rpc_clnt *clnt);
  79 static int      rpc_ping_noreply(struct rpc_clnt *clnt);
  80 static void     rpc_check_timeout(struct rpc_task *task);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         rpc_remove_client_dir(clnt);
 105 }
 106
 107 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 108 {
 109         struct net *net = rpc_net_ns(clnt);
 110         struct super_block *pipefs_sb;
 111
 112         pipefs_sb = rpc_get_sb_net(net);
 113         if (pipefs_sb) {
 114                 __rpc_clnt_remove_pipedir(clnt);
 115                 rpc_put_sb_net(net);
 116         }
 117 }
 118
 119 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 120                                     struct rpc_clnt *clnt)
 121 {
 122         static uint32_t clntid;
 123         const char *dir_name = clnt->cl_program->pipe_dir_name;
 124         char name[15];
 125         struct dentry *dir, *dentry;
 126
 127         dir = rpc_d_lookup_sb(sb, dir_name);
 128         if (dir == NULL) {
 129                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 130                 return dir;
 131         }
 132         for (;;) {
 133                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 134                 name[sizeof(name) - 1] = '\0';
 135                 dentry = rpc_create_client_dir(dir, name, clnt);
 136                 if (!IS_ERR(dentry))
 137                         break;
 138                 if (dentry == ERR_PTR(-EEXIST))
 139                         continue;
 140                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 141                                 " %s/%s, error %ld\n",
 142                                 dir_name, name, PTR_ERR(dentry));
 143                 break;
 144         }
 145         dput(dir);
 146         return dentry;
 147 }
 148
 149 static int
 150 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 151 {
 152         struct dentry *dentry;
 153
 154         if (clnt->cl_program->pipe_dir_name != NULL) {
 155                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 156                 if (IS_ERR(dentry))
 157                         return PTR_ERR(dentry);
 158         }
 159         return 0;
 160 }
 161
 162 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 163 {
 164         if (clnt->cl_program->pipe_dir_name == NULL)
 165                 return 1;
 166
 167         switch (event) {
 168         case RPC_PIPEFS_MOUNT:
 169                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 170                         return 1;
 171                 if (refcount_read(&clnt->cl_count) == 0)
 172                         return 1;
 173                 break;
 174         case RPC_PIPEFS_UMOUNT:
 175                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 176                         return 1;
 177                 break;
 178         }
 179         return 0;
 180 }
 181
 182 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 183                                    struct super_block *sb)
 184 {
 185         struct dentry *dentry;
 186
 187         switch (event) {
 188         case RPC_PIPEFS_MOUNT:
 189                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 190                 if (!dentry)
 191                         return -ENOENT;
 192                 if (IS_ERR(dentry))
 193                         return PTR_ERR(dentry);
 194                 break;
 195         case RPC_PIPEFS_UMOUNT:
 196                 __rpc_clnt_remove_pipedir(clnt);
 197                 break;
 198         default:
 199                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 200                 return -ENOTSUPP;
 201         }
 202         return 0;
 203 }
 204
 205 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 206                                 struct super_block *sb)
 207 {
 208         int error = 0;
 209
 210         for (;; clnt = clnt->cl_parent) {
 211                 if (!rpc_clnt_skip_event(clnt, event))
 212                         error = __rpc_clnt_handle_event(clnt, event, sb);
 213                 if (error || clnt == clnt->cl_parent)
 214                         break;
 215         }
 216         return error;
 217 }
 218
 219 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 220 {
 221         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 222         struct rpc_clnt *clnt;
 223
 224         spin_lock(&sn->rpc_client_lock);
 225         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 226                 if (rpc_clnt_skip_event(clnt, event))
 227                         continue;
 228                 spin_unlock(&sn->rpc_client_lock);
 229                 return clnt;
 230         }
 231         spin_unlock(&sn->rpc_client_lock);
 232         return NULL;
 233 }
 234
 235 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 236                             void *ptr)
 237 {
 238         struct super_block *sb = ptr;
 239         struct rpc_clnt *clnt;
 240         int error = 0;
 241
 242         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 243                 error = __rpc_pipefs_event(clnt, event, sb);
 244                 if (error)
 245                         break;
 246         }
 247         return error;
 248 }
 249
 250 static struct notifier_block rpc_clients_block = {
 251         .notifier_call  = rpc_pipefs_event,
 252         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 253 };
 254
 255 int rpc_clients_notifier_register(void)
 256 {
 257         return rpc_pipefs_notifier_register(&rpc_clients_block);
 258 }
 259
 260 void rpc_clients_notifier_unregister(void)
 261 {
 262         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 263 }
 264
 265 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 266                 struct rpc_xprt *xprt,
 267                 const struct rpc_timeout *timeout)
 268 {
 269         struct rpc_xprt *old;
 270
 271         spin_lock(&clnt->cl_lock);
 272         old = rcu_dereference_protected(clnt->cl_xprt,
 273                         lockdep_is_held(&clnt->cl_lock));
 274
 275         if (!xprt_bound(xprt))
 276                 clnt->cl_autobind = 1;
 277
 278         clnt->cl_timeout = timeout;
 279         rcu_assign_pointer(clnt->cl_xprt, xprt);
 280         spin_unlock(&clnt->cl_lock);
 281
 282         return old;
 283 }
 284
 285 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 286 {
 287         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 288                         nodename, sizeof(clnt->cl_nodename));
 289 }
 290
 291 static int rpc_client_register(struct rpc_clnt *clnt,
 292                                rpc_authflavor_t pseudoflavor,
 293                                const char *client_name)
 294 {
 295         struct rpc_auth_create_args auth_args = {
 296                 .pseudoflavor = pseudoflavor,
 297                 .target_name = client_name,
 298         };
 299         struct rpc_auth *auth;
 300         struct net *net = rpc_net_ns(clnt);
 301         struct super_block *pipefs_sb;
 302         int err;
 303
 304         rpc_clnt_debugfs_register(clnt);
 305
 306         pipefs_sb = rpc_get_sb_net(net);
 307         if (pipefs_sb) {
 308                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 309                 if (err)
 310                         goto out;
 311         }
 312
 313         rpc_register_client(clnt);
 314         if (pipefs_sb)
 315                 rpc_put_sb_net(net);
 316
 317         auth = rpcauth_create(&auth_args, clnt);
 318         if (IS_ERR(auth)) {
 319                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 320                                 pseudoflavor);
 321                 err = PTR_ERR(auth);
 322                 goto err_auth;
 323         }
 324         return 0;
 325 err_auth:
 326         pipefs_sb = rpc_get_sb_net(net);
 327         rpc_unregister_client(clnt);
 328         __rpc_clnt_remove_pipedir(clnt);
 329 out:
 330         if (pipefs_sb)
 331                 rpc_put_sb_net(net);
 332         rpc_sysfs_client_destroy(clnt);
 333         rpc_clnt_debugfs_unregister(clnt);
 334         return err;
 335 }
 336
 337 static DEFINE_IDA(rpc_clids);
 338
 339 void rpc_cleanup_clids(void)
 340 {
 341         ida_destroy(&rpc_clids);
 342 }
 343
 344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 345 {
 346         int clid;
 347
 348         clid = ida_alloc(&rpc_clids, GFP_KERNEL);
 349         if (clid < 0)
 350                 return clid;
 351         clnt->cl_clid = clid;
 352         return 0;
 353 }
 354
 355 static void rpc_free_clid(struct rpc_clnt *clnt)
 356 {
 357         ida_free(&rpc_clids, clnt->cl_clid);
 358 }
 359
 360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 361                 struct rpc_xprt_switch *xps,
 362                 struct rpc_xprt *xprt,
 363                 struct rpc_clnt *parent)
 364 {
 365         const struct rpc_program *program = args->program;
 366         const struct rpc_version *version;
 367         struct rpc_clnt *clnt = NULL;
 368         const struct rpc_timeout *timeout;
 369         const char *nodename = args->nodename;
 370         int err;
 371
 372         err = rpciod_up();
 373         if (err)
 374                 goto out_no_rpciod;
 375
 376         err = -EINVAL;
 377         if (args->version >= program->nrvers)
 378                 goto out_err;
 379         version = program->version[args->version];
 380         if (version == NULL)
 381                 goto out_err;
 382
 383         err = -ENOMEM;
 384         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 385         if (!clnt)
 386                 goto out_err;
 387         clnt->cl_parent = parent ? : clnt;
 388         clnt->cl_xprtsec = args->xprtsec;
 389
 390         err = rpc_alloc_clid(clnt);
 391         if (err)
 392                 goto out_no_clid;
 393
 394         clnt->cl_cred     = get_cred(args->cred);
 395         clnt->cl_procinfo = version->procs;
 396         clnt->cl_maxproc  = version->nrprocs;
 397         clnt->cl_prog     = args->prognumber ? : program->number;
 398         clnt->cl_vers     = version->number;
 399         clnt->cl_stats    = program->stats;
 400         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 401         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 402         err = -ENOMEM;
 403         if (clnt->cl_metrics == NULL)
 404                 goto out_no_stats;
 405         clnt->cl_program  = program;
 406         INIT_LIST_HEAD(&clnt->cl_tasks);
 407         spin_lock_init(&clnt->cl_lock);
 408
 409         timeout = xprt->timeout;
 410         if (args->timeout != NULL) {
 411                 memcpy(&clnt->cl_timeout_default, args->timeout,
 412                                 sizeof(clnt->cl_timeout_default));
 413                 timeout = &clnt->cl_timeout_default;
 414         }
 415
 416         rpc_clnt_set_transport(clnt, xprt, timeout);
 417         xprt->main = true;
 418         xprt_iter_init(&clnt->cl_xpi, xps);
 419         xprt_switch_put(xps);
 420
 421         clnt->cl_rtt = &clnt->cl_rtt_default;
 422         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 423
 424         refcount_set(&clnt->cl_count, 1);
 425
 426         if (nodename == NULL)
 427                 nodename = utsname()->nodename;
 428         /* save the nodename */
 429         rpc_clnt_set_nodename(clnt, nodename);
 430
 431         rpc_sysfs_client_setup(clnt, xps, rpc_net_ns(clnt));
 432         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 433         if (err)
 434                 goto out_no_path;
 435         if (parent)
 436                 refcount_inc(&parent->cl_count);
 437
 438         trace_rpc_clnt_new(clnt, xprt, args);
 439         return clnt;
 440
 441 out_no_path:
 442         rpc_free_iostats(clnt->cl_metrics);
 443 out_no_stats:
 444         put_cred(clnt->cl_cred);
 445         rpc_free_clid(clnt);
 446 out_no_clid:
 447         kfree(clnt);
 448 out_err:
 449         rpciod_down();
 450 out_no_rpciod:
 451         xprt_switch_put(xps);
 452         xprt_put(xprt);
 453         trace_rpc_clnt_new_err(program->name, args->servername, err);
 454         return ERR_PTR(err);
 455 }
 456
 457 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 458                                         struct rpc_xprt *xprt)
 459 {
 460         struct rpc_clnt *clnt = NULL;
 461         struct rpc_xprt_switch *xps;
 462
 463         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 464                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 465                 xps = args->bc_xprt->xpt_bc_xps;
 466                 xprt_switch_get(xps);
 467         } else {
 468                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 469                 if (xps == NULL) {
 470                         xprt_put(xprt);
 471                         return ERR_PTR(-ENOMEM);
 472                 }
 473                 if (xprt->bc_xprt) {
 474                         xprt_switch_get(xps);
 475                         xprt->bc_xprt->xpt_bc_xps = xps;
 476                 }
 477         }
 478         clnt = rpc_new_client(args, xps, xprt, NULL);
 479         if (IS_ERR(clnt))
 480                 return clnt;
 481
 482         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 483                 int err = rpc_ping(clnt);
 484                 if (err != 0) {
 485                         rpc_shutdown_client(clnt);
 486                         return ERR_PTR(err);
 487                 }
 488         } else if (args->flags & RPC_CLNT_CREATE_CONNECTED) {
 489                 int err = rpc_ping_noreply(clnt);
 490                 if (err != 0) {
 491                         rpc_shutdown_client(clnt);
 492                         return ERR_PTR(err);
 493                 }
 494         }
 495
 496         clnt->cl_softrtry = 1;
 497         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 498                 clnt->cl_softrtry = 0;
 499                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 500                         clnt->cl_softerr = 1;
 501         }
 502
 503         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 504                 clnt->cl_autobind = 1;
 505         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 506                 clnt->cl_noretranstimeo = 1;
 507         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 508                 clnt->cl_discrtry = 1;
 509         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 510                 clnt->cl_chatty = 1;
 511
 512         return clnt;
 513 }
 514
 515 /**
 516  * rpc_create - create an RPC client and transport with one call
 517  * @args: rpc_clnt create argument structure
 518  *
 519  * Creates and initializes an RPC transport and an RPC client.
 520  *
 521  * It can ping the server in order to determine if it is up, and to see if
 522  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 523  * this behavior so asynchronous tasks can also use rpc_create.
 524  */
 525 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 526 {
 527         struct rpc_xprt *xprt;
 528         struct xprt_create xprtargs = {
 529                 .net = args->net,
 530                 .ident = args->protocol,
 531                 .srcaddr = args->saddress,
 532                 .dstaddr = args->address,
 533                 .addrlen = args->addrsize,
 534                 .servername = args->servername,
 535                 .bc_xprt = args->bc_xprt,
 536                 .xprtsec = args->xprtsec,
 537                 .connect_timeout = args->connect_timeout,
 538                 .reconnect_timeout = args->reconnect_timeout,
 539         };
 540         char servername[48];
 541         struct rpc_clnt *clnt;
 542         int i;
 543
 544         if (args->bc_xprt) {
 545                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 546                 xprt = args->bc_xprt->xpt_bc_xprt;
 547                 if (xprt) {
 548                         xprt_get(xprt);
 549                         return rpc_create_xprt(args, xprt);
 550                 }
 551         }
 552
 553         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 554                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 555         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 556                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 557         /*
 558          * If the caller chooses not to specify a hostname, whip
 559          * up a string representation of the passed-in address.
 560          */
 561         if (xprtargs.servername == NULL) {
 562                 struct sockaddr_un *sun =
 563                                 (struct sockaddr_un *)args->address;
 564                 struct sockaddr_in *sin =
 565                                 (struct sockaddr_in *)args->address;
 566                 struct sockaddr_in6 *sin6 =
 567                                 (struct sockaddr_in6 *)args->address;
 568
 569                 servername[0] = '\0';
 570                 switch (args->address->sa_family) {
 571                 case AF_LOCAL:
 572                         if (sun->sun_path[0])
 573                                 snprintf(servername, sizeof(servername), "%s",
 574                                          sun->sun_path);
 575                         else
 576                                 snprintf(servername, sizeof(servername), "@%s",
 577                                          sun->sun_path+1);
 578                         break;
 579                 case AF_INET:
 580                         snprintf(servername, sizeof(servername), "%pI4",
 581                                  &sin->sin_addr.s_addr);
 582                         break;
 583                 case AF_INET6:
 584                         snprintf(servername, sizeof(servername), "%pI6",
 585                                  &sin6->sin6_addr);
 586                         break;
 587                 default:
 588                         /* caller wants default server name, but
 589                          * address family isn't recognized. */
 590                         return ERR_PTR(-EINVAL);
 591                 }
 592                 xprtargs.servername = servername;
 593         }
 594
 595         xprt = xprt_create_transport(&xprtargs);
 596         if (IS_ERR(xprt))
 597                 return (struct rpc_clnt *)xprt;
 598
 599         /*
 600          * By default, kernel RPC client connects from a reserved port.
 601          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 602          * but it is always enabled for rpciod, which handles the connect
 603          * operation.
 604          */
 605         xprt->resvport = 1;
 606         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 607                 xprt->resvport = 0;
 608         xprt->reuseport = 0;
 609         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 610                 xprt->reuseport = 1;
 611
 612         clnt = rpc_create_xprt(args, xprt);
 613         if (IS_ERR(clnt) || args->nconnect <= 1)
 614                 return clnt;
 615
 616         for (i = 0; i < args->nconnect - 1; i++) {
 617                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 618                         break;
 619         }
 620         return clnt;
 621 }
 622 EXPORT_SYMBOL_GPL(rpc_create);
 623
 624 /*
 625  * This function clones the RPC client structure. It allows us to share the
 626  * same transport while varying parameters such as the authentication
 627  * flavour.
 628  */
 629 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 630                                            struct rpc_clnt *clnt)
 631 {
 632         struct rpc_xprt_switch *xps;
 633         struct rpc_xprt *xprt;
 634         struct rpc_clnt *new;
 635         int err;
 636
 637         err = -ENOMEM;
 638         rcu_read_lock();
 639         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 640         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 641         rcu_read_unlock();
 642         if (xprt == NULL || xps == NULL) {
 643                 xprt_put(xprt);
 644                 xprt_switch_put(xps);
 645                 goto out_err;
 646         }
 647         args->servername = xprt->servername;
 648         args->nodename = clnt->cl_nodename;
 649
 650         new = rpc_new_client(args, xps, xprt, clnt);
 651         if (IS_ERR(new))
 652                 return new;
 653
 654         /* Turn off autobind on clones */
 655         new->cl_autobind = 0;
 656         new->cl_softrtry = clnt->cl_softrtry;
 657         new->cl_softerr = clnt->cl_softerr;
 658         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 659         new->cl_discrtry = clnt->cl_discrtry;
 660         new->cl_chatty = clnt->cl_chatty;
 661         new->cl_principal = clnt->cl_principal;
 662         new->cl_max_connect = clnt->cl_max_connect;
 663         return new;
 664
 665 out_err:
 666         trace_rpc_clnt_clone_err(clnt, err);
 667         return ERR_PTR(err);
 668 }
 669
 670 /**
 671  * rpc_clone_client - Clone an RPC client structure
 672  *
 673  * @clnt: RPC client whose parameters are copied
 674  *
 675  * Returns a fresh RPC client or an ERR_PTR.
 676  */
 677 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 678 {
 679         struct rpc_create_args args = {
 680                 .program        = clnt->cl_program,
 681                 .prognumber     = clnt->cl_prog,
 682                 .version        = clnt->cl_vers,
 683                 .authflavor     = clnt->cl_auth->au_flavor,
 684                 .cred           = clnt->cl_cred,
 685         };
 686         return __rpc_clone_client(&args, clnt);
 687 }
 688 EXPORT_SYMBOL_GPL(rpc_clone_client);
 689
 690 /**
 691  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 692  *
 693  * @clnt: RPC client whose parameters are copied
 694  * @flavor: security flavor for new client
 695  *
 696  * Returns a fresh RPC client or an ERR_PTR.
 697  */
 698 struct rpc_clnt *
 699 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 700 {
 701         struct rpc_create_args args = {
 702                 .program        = clnt->cl_program,
 703                 .prognumber     = clnt->cl_prog,
 704                 .version        = clnt->cl_vers,
 705                 .authflavor     = flavor,
 706                 .cred           = clnt->cl_cred,
 707         };
 708         return __rpc_clone_client(&args, clnt);
 709 }
 710 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 711
 712 /**
 713  * rpc_switch_client_transport: switch the RPC transport on the fly
 714  * @clnt: pointer to a struct rpc_clnt
 715  * @args: pointer to the new transport arguments
 716  * @timeout: pointer to the new timeout parameters
 717  *
 718  * This function allows the caller to switch the RPC transport for the
 719  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 720  * server, for instance.  It assumes that the caller has ensured that
 721  * there are no active RPC tasks by using some form of locking.
 722  *
 723  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 724  * negative errno is returned, and "clnt" continues to use the old
 725  * xprt.
 726  */
 727 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 728                 struct xprt_create *args,
 729                 const struct rpc_timeout *timeout)
 730 {
 731         const struct rpc_timeout *old_timeo;
 732         rpc_authflavor_t pseudoflavor;
 733         struct rpc_xprt_switch *xps, *oldxps;
 734         struct rpc_xprt *xprt, *old;
 735         struct rpc_clnt *parent;
 736         int err;
 737
 738         args->xprtsec = clnt->cl_xprtsec;
 739         xprt = xprt_create_transport(args);
 740         if (IS_ERR(xprt))
 741                 return PTR_ERR(xprt);
 742
 743         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 744         if (xps == NULL) {
 745                 xprt_put(xprt);
 746                 return -ENOMEM;
 747         }
 748
 749         pseudoflavor = clnt->cl_auth->au_flavor;
 750
 751         old_timeo = clnt->cl_timeout;
 752         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 753         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 754
 755         rpc_unregister_client(clnt);
 756         __rpc_clnt_remove_pipedir(clnt);
 757         rpc_sysfs_client_destroy(clnt);
 758         rpc_clnt_debugfs_unregister(clnt);
 759
 760         /*
 761          * A new transport was created.  "clnt" therefore
 762          * becomes the root of a new cl_parent tree.  clnt's
 763          * children, if it has any, still point to the old xprt.
 764          */
 765         parent = clnt->cl_parent;
 766         clnt->cl_parent = clnt;
 767
 768         /*
 769          * The old rpc_auth cache cannot be re-used.  GSS
 770          * contexts in particular are between a single
 771          * client and server.
 772          */
 773         err = rpc_client_register(clnt, pseudoflavor, NULL);
 774         if (err)
 775                 goto out_revert;
 776
 777         synchronize_rcu();
 778         if (parent != clnt)
 779                 rpc_release_client(parent);
 780         xprt_switch_put(oldxps);
 781         xprt_put(old);
 782         trace_rpc_clnt_replace_xprt(clnt);
 783         return 0;
 784
 785 out_revert:
 786         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 787         rpc_clnt_set_transport(clnt, old, old_timeo);
 788         clnt->cl_parent = parent;
 789         rpc_client_register(clnt, pseudoflavor, NULL);
 790         xprt_switch_put(xps);
 791         xprt_put(xprt);
 792         trace_rpc_clnt_replace_xprt_err(clnt);
 793         return err;
 794 }
 795 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 796
 797 static
 798 int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi,
 799                              void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps))
 800 {
 801         struct rpc_xprt_switch *xps;
 802
 803         rcu_read_lock();
 804         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 805         rcu_read_unlock();
 806         if (xps == NULL)
 807                 return -EAGAIN;
 808         func(xpi, xps);
 809         xprt_switch_put(xps);
 810         return 0;
 811 }
 812
 813 static
 814 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 815 {
 816         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listall);
 817 }
 818
 819 static
 820 int rpc_clnt_xprt_iter_offline_init(struct rpc_clnt *clnt,
 821                                     struct rpc_xprt_iter *xpi)
 822 {
 823         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listoffline);
 824 }
 825
 826 /**
 827  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 828  * @clnt: pointer to client
 829  * @fn: function to apply
 830  * @data: void pointer to function data
 831  *
 832  * Iterates through the list of RPC transports currently attached to the
 833  * client and applies the function fn(clnt, xprt, data).
 834  *
 835  * On error, the iteration stops, and the function returns the error value.
 836  */
 837 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 838                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 839                 void *data)
 840 {
 841         struct rpc_xprt_iter xpi;
 842         int ret;
 843
 844         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 845         if (ret)
 846                 return ret;
 847         for (;;) {
 848                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 849
 850                 if (!xprt)
 851                         break;
 852                 ret = fn(clnt, xprt, data);
 853                 xprt_put(xprt);
 854                 if (ret < 0)
 855                         break;
 856         }
 857         xprt_iter_destroy(&xpi);
 858         return ret;
 859 }
 860 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 861
 862 /*
 863  * Kill all tasks for the given client.
 864  * XXX: kill their descendants as well?
 865  */
 866 void rpc_killall_tasks(struct rpc_clnt *clnt)
 867 {
 868         struct rpc_task *rovr;
 869
 870
 871         if (list_empty(&clnt->cl_tasks))
 872                 return;
 873
 874         /*
 875          * Spin lock all_tasks to prevent changes...
 876          */
 877         trace_rpc_clnt_killall(clnt);
 878         spin_lock(&clnt->cl_lock);
 879         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 880                 rpc_signal_task(rovr);
 881         spin_unlock(&clnt->cl_lock);
 882 }
 883 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 884
 885 /**
 886  * rpc_cancel_tasks - try to cancel a set of RPC tasks
 887  * @clnt: Pointer to RPC client
 888  * @error: RPC task error value to set
 889  * @fnmatch: Pointer to selector function
 890  * @data: User data
 891  *
 892  * Uses @fnmatch to define a set of RPC tasks that are to be cancelled.
 893  * The argument @error must be a negative error value.
 894  */
 895 unsigned long rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
 896                                bool (*fnmatch)(const struct rpc_task *,
 897                                                const void *),
 898                                const void *data)
 899 {
 900         struct rpc_task *task;
 901         unsigned long count = 0;
 902
 903         if (list_empty(&clnt->cl_tasks))
 904                 return 0;
 905         /*
 906          * Spin lock all_tasks to prevent changes...
 907          */
 908         spin_lock(&clnt->cl_lock);
 909         list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
 910                 if (!RPC_IS_ACTIVATED(task))
 911                         continue;
 912                 if (!fnmatch(task, data))
 913                         continue;
 914                 rpc_task_try_cancel(task, error);
 915                 count++;
 916         }
 917         spin_unlock(&clnt->cl_lock);
 918         return count;
 919 }
 920 EXPORT_SYMBOL_GPL(rpc_cancel_tasks);
 921
 922 static int rpc_clnt_disconnect_xprt(struct rpc_clnt *clnt,
 923                                     struct rpc_xprt *xprt, void *dummy)
 924 {
 925         if (xprt_connected(xprt))
 926                 xprt_force_disconnect(xprt);
 927         return 0;
 928 }
 929
 930 void rpc_clnt_disconnect(struct rpc_clnt *clnt)
 931 {
 932         rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_disconnect_xprt, NULL);
 933 }
 934 EXPORT_SYMBOL_GPL(rpc_clnt_disconnect);
 935
 936 /*
 937  * Properly shut down an RPC client, terminating all outstanding
 938  * requests.
 939  */
 940 void rpc_shutdown_client(struct rpc_clnt *clnt)
 941 {
 942         might_sleep();
 943
 944         trace_rpc_clnt_shutdown(clnt);
 945
 946         while (!list_empty(&clnt->cl_tasks)) {
 947                 rpc_killall_tasks(clnt);
 948                 wait_event_timeout(destroy_wait,
 949                         list_empty(&clnt->cl_tasks), 1*HZ);
 950         }
 951
 952         rpc_release_client(clnt);
 953 }
 954 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 955
 956 /*
 957  * Free an RPC client
 958  */
 959 static void rpc_free_client_work(struct work_struct *work)
 960 {
 961         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 962
 963         trace_rpc_clnt_free(clnt);
 964
 965         /* These might block on processes that might allocate memory,
 966          * so they cannot be called in rpciod, so they are handled separately
 967          * here.
 968          */
 969         rpc_sysfs_client_destroy(clnt);
 970         rpc_clnt_debugfs_unregister(clnt);
 971         rpc_free_clid(clnt);
 972         rpc_clnt_remove_pipedir(clnt);
 973         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 974
 975         kfree(clnt);
 976         rpciod_down();
 977 }
 978 static struct rpc_clnt *
 979 rpc_free_client(struct rpc_clnt *clnt)
 980 {
 981         struct rpc_clnt *parent = NULL;
 982
 983         trace_rpc_clnt_release(clnt);
 984         if (clnt->cl_parent != clnt)
 985                 parent = clnt->cl_parent;
 986         rpc_unregister_client(clnt);
 987         rpc_free_iostats(clnt->cl_metrics);
 988         clnt->cl_metrics = NULL;
 989         xprt_iter_destroy(&clnt->cl_xpi);
 990         put_cred(clnt->cl_cred);
 991
 992         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 993         schedule_work(&clnt->cl_work);
 994         return parent;
 995 }
 996
 997 /*
 998  * Free an RPC client
 999  */
1000 static struct rpc_clnt *
1001 rpc_free_auth(struct rpc_clnt *clnt)
1002 {
1003         /*
1004          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
1005          *       release remaining GSS contexts. This mechanism ensures
1006          *       that it can do so safely.
1007          */
1008         if (clnt->cl_auth != NULL) {
1009                 rpcauth_release(clnt->cl_auth);
1010                 clnt->cl_auth = NULL;
1011         }
1012         if (refcount_dec_and_test(&clnt->cl_count))
1013                 return rpc_free_client(clnt);
1014         return NULL;
1015 }
1016
1017 /*
1018  * Release reference to the RPC client
1019  */
1020 void
1021 rpc_release_client(struct rpc_clnt *clnt)
1022 {
1023         do {
1024                 if (list_empty(&clnt->cl_tasks))
1025                         wake_up(&destroy_wait);
1026                 if (refcount_dec_not_one(&clnt->cl_count))
1027                         break;
1028                 clnt = rpc_free_auth(clnt);
1029         } while (clnt != NULL);
1030 }
1031 EXPORT_SYMBOL_GPL(rpc_release_client);
1032
1033 /**
1034  * rpc_bind_new_program - bind a new RPC program to an existing client
1035  * @old: old rpc_client
1036  * @program: rpc program to set
1037  * @vers: rpc program version
1038  *
1039  * Clones the rpc client and sets up a new RPC program. This is mainly
1040  * of use for enabling different RPC programs to share the same transport.
1041  * The Sun NFSv2/v3 ACL protocol can do this.
1042  */
1043 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
1044                                       const struct rpc_program *program,
1045                                       u32 vers)
1046 {
1047         struct rpc_create_args args = {
1048                 .program        = program,
1049                 .prognumber     = program->number,
1050                 .version        = vers,
1051                 .authflavor     = old->cl_auth->au_flavor,
1052                 .cred           = old->cl_cred,
1053         };
1054         struct rpc_clnt *clnt;
1055         int err;
1056
1057         clnt = __rpc_clone_client(&args, old);
1058         if (IS_ERR(clnt))
1059                 goto out;
1060         err = rpc_ping(clnt);
1061         if (err != 0) {
1062                 rpc_shutdown_client(clnt);
1063                 clnt = ERR_PTR(err);
1064         }
1065 out:
1066         return clnt;
1067 }
1068 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
1069
1070 struct rpc_xprt *
1071 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1072 {
1073         struct rpc_xprt_switch *xps;
1074
1075         if (!xprt)
1076                 return NULL;
1077         rcu_read_lock();
1078         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1079         atomic_long_inc(&xps->xps_queuelen);
1080         rcu_read_unlock();
1081         atomic_long_inc(&xprt->queuelen);
1082
1083         return xprt;
1084 }
1085
1086 static void
1087 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1088 {
1089         struct rpc_xprt_switch *xps;
1090
1091         atomic_long_dec(&xprt->queuelen);
1092         rcu_read_lock();
1093         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1094         atomic_long_dec(&xps->xps_queuelen);
1095         rcu_read_unlock();
1096
1097         xprt_put(xprt);
1098 }
1099
1100 void rpc_task_release_transport(struct rpc_task *task)
1101 {
1102         struct rpc_xprt *xprt = task->tk_xprt;
1103
1104         if (xprt) {
1105                 task->tk_xprt = NULL;
1106                 if (task->tk_client)
1107                         rpc_task_release_xprt(task->tk_client, xprt);
1108                 else
1109                         xprt_put(xprt);
1110         }
1111 }
1112 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1113
1114 void rpc_task_release_client(struct rpc_task *task)
1115 {
1116         struct rpc_clnt *clnt = task->tk_client;
1117
1118         rpc_task_release_transport(task);
1119         if (clnt != NULL) {
1120                 /* Remove from client task list */
1121                 spin_lock(&clnt->cl_lock);
1122                 list_del(&task->tk_task);
1123                 spin_unlock(&clnt->cl_lock);
1124                 task->tk_client = NULL;
1125
1126                 rpc_release_client(clnt);
1127         }
1128 }
1129
1130 static struct rpc_xprt *
1131 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1132 {
1133         struct rpc_xprt *xprt;
1134
1135         rcu_read_lock();
1136         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1137         rcu_read_unlock();
1138         return rpc_task_get_xprt(clnt, xprt);
1139 }
1140
1141 static struct rpc_xprt *
1142 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1143 {
1144         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1145 }
1146
1147 static
1148 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1149 {
1150         if (task->tk_xprt) {
1151                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1152                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1153                         return;
1154                 xprt_release(task);
1155                 xprt_put(task->tk_xprt);
1156         }
1157         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1158                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1159         else
1160                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1161 }
1162
1163 static
1164 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1165 {
1166         rpc_task_set_transport(task, clnt);
1167         task->tk_client = clnt;
1168         refcount_inc(&clnt->cl_count);
1169         if (clnt->cl_softrtry)
1170                 task->tk_flags |= RPC_TASK_SOFT;
1171         if (clnt->cl_softerr)
1172                 task->tk_flags |= RPC_TASK_TIMEOUT;
1173         if (clnt->cl_noretranstimeo)
1174                 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1175         /* Add to the client's list of all tasks */
1176         spin_lock(&clnt->cl_lock);
1177         list_add_tail(&task->tk_task, &clnt->cl_tasks);
1178         spin_unlock(&clnt->cl_lock);
1179 }
1180
1181 static void
1182 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1183 {
1184         if (msg != NULL) {
1185                 task->tk_msg.rpc_proc = msg->rpc_proc;
1186                 task->tk_msg.rpc_argp = msg->rpc_argp;
1187                 task->tk_msg.rpc_resp = msg->rpc_resp;
1188                 task->tk_msg.rpc_cred = msg->rpc_cred;
1189                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1190                         get_cred(task->tk_msg.rpc_cred);
1191         }
1192 }
1193
1194 /*
1195  * Default callback for async RPC calls
1196  */
1197 static void
1198 rpc_default_callback(struct rpc_task *task, void *data)
1199 {
1200 }
1201
1202 static const struct rpc_call_ops rpc_default_ops = {
1203         .rpc_call_done = rpc_default_callback,
1204 };
1205
1206 /**
1207  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1208  * @task_setup_data: pointer to task initialisation data
1209  */
1210 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1211 {
1212         struct rpc_task *task;
1213
1214         task = rpc_new_task(task_setup_data);
1215         if (IS_ERR(task))
1216                 return task;
1217
1218         if (!RPC_IS_ASYNC(task))
1219                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1220
1221         rpc_task_set_client(task, task_setup_data->rpc_client);
1222         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1223
1224         if (task->tk_action == NULL)
1225                 rpc_call_start(task);
1226
1227         atomic_inc(&task->tk_count);
1228         rpc_execute(task);
1229         return task;
1230 }
1231 EXPORT_SYMBOL_GPL(rpc_run_task);
1232
1233 /**
1234  * rpc_call_sync - Perform a synchronous RPC call
1235  * @clnt: pointer to RPC client
1236  * @msg: RPC call parameters
1237  * @flags: RPC call flags
1238  */
1239 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1240 {
1241         struct rpc_task *task;
1242         struct rpc_task_setup task_setup_data = {
1243                 .rpc_client = clnt,
1244                 .rpc_message = msg,
1245                 .callback_ops = &rpc_default_ops,
1246                 .flags = flags,
1247         };
1248         int status;
1249
1250         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1251         if (flags & RPC_TASK_ASYNC) {
1252                 rpc_release_calldata(task_setup_data.callback_ops,
1253                         task_setup_data.callback_data);
1254                 return -EINVAL;
1255         }
1256
1257         task = rpc_run_task(&task_setup_data);
1258         if (IS_ERR(task))
1259                 return PTR_ERR(task);
1260         status = task->tk_status;
1261         rpc_put_task(task);
1262         return status;
1263 }
1264 EXPORT_SYMBOL_GPL(rpc_call_sync);
1265
1266 /**
1267  * rpc_call_async - Perform an asynchronous RPC call
1268  * @clnt: pointer to RPC client
1269  * @msg: RPC call parameters
1270  * @flags: RPC call flags
1271  * @tk_ops: RPC call ops
1272  * @data: user call data
1273  */
1274 int
1275 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1276                const struct rpc_call_ops *tk_ops, void *data)
1277 {
1278         struct rpc_task *task;
1279         struct rpc_task_setup task_setup_data = {
1280                 .rpc_client = clnt,
1281                 .rpc_message = msg,
1282                 .callback_ops = tk_ops,
1283                 .callback_data = data,
1284                 .flags = flags|RPC_TASK_ASYNC,
1285         };
1286
1287         task = rpc_run_task(&task_setup_data);
1288         if (IS_ERR(task))
1289                 return PTR_ERR(task);
1290         rpc_put_task(task);
1291         return 0;
1292 }
1293 EXPORT_SYMBOL_GPL(rpc_call_async);
1294
1295 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1296 static void call_bc_encode(struct rpc_task *task);
1297
1298 /**
1299  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1300  * rpc_execute against it
1301  * @req: RPC request
1302  */
1303 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1304 {
1305         struct rpc_task *task;
1306         struct rpc_task_setup task_setup_data = {
1307                 .callback_ops = &rpc_default_ops,
1308                 .flags = RPC_TASK_SOFTCONN |
1309                         RPC_TASK_NO_RETRANS_TIMEOUT,
1310         };
1311
1312         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1313         /*
1314          * Create an rpc_task to send the data
1315          */
1316         task = rpc_new_task(&task_setup_data);
1317         if (IS_ERR(task)) {
1318                 xprt_free_bc_request(req);
1319                 return task;
1320         }
1321
1322         xprt_init_bc_request(req, task);
1323
1324         task->tk_action = call_bc_encode;
1325         atomic_inc(&task->tk_count);
1326         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1327         rpc_execute(task);
1328
1329         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1330         return task;
1331 }
1332 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1333
1334 /**
1335  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1336  * @req: RPC request to prepare
1337  * @pages: vector of struct page pointers
1338  * @base: offset in first page where receive should start, in bytes
1339  * @len: expected size of the upper layer data payload, in bytes
1340  * @hdrsize: expected size of upper layer reply header, in XDR words
1341  *
1342  */
1343 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1344                              unsigned int base, unsigned int len,
1345                              unsigned int hdrsize)
1346 {
1347         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1348
1349         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1350         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1351 }
1352 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1353
1354 void
1355 rpc_call_start(struct rpc_task *task)
1356 {
1357         task->tk_action = call_start;
1358 }
1359 EXPORT_SYMBOL_GPL(rpc_call_start);
1360
1361 /**
1362  * rpc_peeraddr - extract remote peer address from clnt's xprt
1363  * @clnt: RPC client structure
1364  * @buf: target buffer
1365  * @bufsize: length of target buffer
1366  *
1367  * Returns the number of bytes that are actually in the stored address.
1368  */
1369 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1370 {
1371         size_t bytes;
1372         struct rpc_xprt *xprt;
1373
1374         rcu_read_lock();
1375         xprt = rcu_dereference(clnt->cl_xprt);
1376
1377         bytes = xprt->addrlen;
1378         if (bytes > bufsize)
1379                 bytes = bufsize;
1380         memcpy(buf, &xprt->addr, bytes);
1381         rcu_read_unlock();
1382
1383         return bytes;
1384 }
1385 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1386
1387 /**
1388  * rpc_peeraddr2str - return remote peer address in printable format
1389  * @clnt: RPC client structure
1390  * @format: address format
1391  *
1392  * NB: the lifetime of the memory referenced by the returned pointer is
1393  * the same as the rpc_xprt itself.  As long as the caller uses this
1394  * pointer, it must hold the RCU read lock.
1395  */
1396 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1397                              enum rpc_display_format_t format)
1398 {
1399         struct rpc_xprt *xprt;
1400
1401         xprt = rcu_dereference(clnt->cl_xprt);
1402
1403         if (xprt->address_strings[format] != NULL)
1404                 return xprt->address_strings[format];
1405         else
1406                 return "unprintable";
1407 }
1408 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1409
1410 static const struct sockaddr_in rpc_inaddr_loopback = {
1411         .sin_family             = AF_INET,
1412         .sin_addr.s_addr        = htonl(INADDR_ANY),
1413 };
1414
1415 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1416         .sin6_family            = AF_INET6,
1417         .sin6_addr              = IN6ADDR_ANY_INIT,
1418 };
1419
1420 /*
1421  * Try a getsockname() on a connected datagram socket.  Using a
1422  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1423  * This conserves the ephemeral port number space.
1424  *
1425  * Returns zero and fills in "buf" if successful; otherwise, a
1426  * negative errno is returned.
1427  */
1428 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1429                         struct sockaddr *buf)
1430 {
1431         struct socket *sock;
1432         int err;
1433
1434         err = __sock_create(net, sap->sa_family,
1435                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1436         if (err < 0) {
1437                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1438                 goto out;
1439         }
1440
1441         switch (sap->sa_family) {
1442         case AF_INET:
1443                 err = kernel_bind(sock,
1444                                 (struct sockaddr *)&rpc_inaddr_loopback,
1445                                 sizeof(rpc_inaddr_loopback));
1446                 break;
1447         case AF_INET6:
1448                 err = kernel_bind(sock,
1449                                 (struct sockaddr *)&rpc_in6addr_loopback,
1450                                 sizeof(rpc_in6addr_loopback));
1451                 break;
1452         default:
1453                 err = -EAFNOSUPPORT;
1454                 goto out_release;
1455         }
1456         if (err < 0) {
1457                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1458                 goto out_release;
1459         }
1460
1461         err = kernel_connect(sock, sap, salen, 0);
1462         if (err < 0) {
1463                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1464                 goto out_release;
1465         }
1466
1467         err = kernel_getsockname(sock, buf);
1468         if (err < 0) {
1469                 dprintk("RPC:       getsockname failed (%d)\n", err);
1470                 goto out_release;
1471         }
1472
1473         err = 0;
1474         if (buf->sa_family == AF_INET6) {
1475                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1476                 sin6->sin6_scope_id = 0;
1477         }
1478         dprintk("RPC:       %s succeeded\n", __func__);
1479
1480 out_release:
1481         sock_release(sock);
1482 out:
1483         return err;
1484 }
1485
1486 /*
1487  * Scraping a connected socket failed, so we don't have a useable
1488  * local address.  Fallback: generate an address that will prevent
1489  * the server from calling us back.
1490  *
1491  * Returns zero and fills in "buf" if successful; otherwise, a
1492  * negative errno is returned.
1493  */
1494 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1495 {
1496         switch (family) {
1497         case AF_INET:
1498                 if (buflen < sizeof(rpc_inaddr_loopback))
1499                         return -EINVAL;
1500                 memcpy(buf, &rpc_inaddr_loopback,
1501                                 sizeof(rpc_inaddr_loopback));
1502                 break;
1503         case AF_INET6:
1504                 if (buflen < sizeof(rpc_in6addr_loopback))
1505                         return -EINVAL;
1506                 memcpy(buf, &rpc_in6addr_loopback,
1507                                 sizeof(rpc_in6addr_loopback));
1508                 break;
1509         default:
1510                 dprintk("RPC:       %s: address family not supported\n",
1511                         __func__);
1512                 return -EAFNOSUPPORT;
1513         }
1514         dprintk("RPC:       %s: succeeded\n", __func__);
1515         return 0;
1516 }
1517
1518 /**
1519  * rpc_localaddr - discover local endpoint address for an RPC client
1520  * @clnt: RPC client structure
1521  * @buf: target buffer
1522  * @buflen: size of target buffer, in bytes
1523  *
1524  * Returns zero and fills in "buf" and "buflen" if successful;
1525  * otherwise, a negative errno is returned.
1526  *
1527  * This works even if the underlying transport is not currently connected,
1528  * or if the upper layer never previously provided a source address.
1529  *
1530  * The result of this function call is transient: multiple calls in
1531  * succession may give different results, depending on how local
1532  * networking configuration changes over time.
1533  */
1534 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1535 {
1536         struct sockaddr_storage address;
1537         struct sockaddr *sap = (struct sockaddr *)&address;
1538         struct rpc_xprt *xprt;
1539         struct net *net;
1540         size_t salen;
1541         int err;
1542
1543         rcu_read_lock();
1544         xprt = rcu_dereference(clnt->cl_xprt);
1545         salen = xprt->addrlen;
1546         memcpy(sap, &xprt->addr, salen);
1547         net = get_net(xprt->xprt_net);
1548         rcu_read_unlock();
1549
1550         rpc_set_port(sap, 0);
1551         err = rpc_sockname(net, sap, salen, buf);
1552         put_net(net);
1553         if (err != 0)
1554                 /* Couldn't discover local address, return ANYADDR */
1555                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1556         return 0;
1557 }
1558 EXPORT_SYMBOL_GPL(rpc_localaddr);
1559
1560 void
1561 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1562 {
1563         struct rpc_xprt *xprt;
1564
1565         rcu_read_lock();
1566         xprt = rcu_dereference(clnt->cl_xprt);
1567         if (xprt->ops->set_buffer_size)
1568                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1569         rcu_read_unlock();
1570 }
1571 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1572
1573 /**
1574  * rpc_net_ns - Get the network namespace for this RPC client
1575  * @clnt: RPC client to query
1576  *
1577  */
1578 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1579 {
1580         struct net *ret;
1581
1582         rcu_read_lock();
1583         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1584         rcu_read_unlock();
1585         return ret;
1586 }
1587 EXPORT_SYMBOL_GPL(rpc_net_ns);
1588
1589 /**
1590  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1591  * @clnt: RPC client to query
1592  *
1593  * For stream transports, this is one RPC record fragment (see RFC
1594  * 1831), as we don't support multi-record requests yet.  For datagram
1595  * transports, this is the size of an IP packet minus the IP, UDP, and
1596  * RPC header sizes.
1597  */
1598 size_t rpc_max_payload(struct rpc_clnt *clnt)
1599 {
1600         size_t ret;
1601
1602         rcu_read_lock();
1603         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1604         rcu_read_unlock();
1605         return ret;
1606 }
1607 EXPORT_SYMBOL_GPL(rpc_max_payload);
1608
1609 /**
1610  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1611  * @clnt: RPC client to query
1612  */
1613 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1614 {
1615         struct rpc_xprt *xprt;
1616         size_t ret;
1617
1618         rcu_read_lock();
1619         xprt = rcu_dereference(clnt->cl_xprt);
1620         ret = xprt->ops->bc_maxpayload(xprt);
1621         rcu_read_unlock();
1622         return ret;
1623 }
1624 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1625
1626 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1627 {
1628         struct rpc_xprt *xprt;
1629         unsigned int ret;
1630
1631         rcu_read_lock();
1632         xprt = rcu_dereference(clnt->cl_xprt);
1633         ret = xprt->ops->bc_num_slots(xprt);
1634         rcu_read_unlock();
1635         return ret;
1636 }
1637 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1638
1639 /**
1640  * rpc_force_rebind - force transport to check that remote port is unchanged
1641  * @clnt: client to rebind
1642  *
1643  */
1644 void rpc_force_rebind(struct rpc_clnt *clnt)
1645 {
1646         if (clnt->cl_autobind) {
1647                 rcu_read_lock();
1648                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1649                 rcu_read_unlock();
1650         }
1651 }
1652 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1653
1654 static int
1655 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1656 {
1657         task->tk_status = 0;
1658         task->tk_rpc_status = 0;
1659         task->tk_action = action;
1660         return 1;
1661 }
1662
1663 /*
1664  * Restart an (async) RPC call. Usually called from within the
1665  * exit handler.
1666  */
1667 int
1668 rpc_restart_call(struct rpc_task *task)
1669 {
1670         return __rpc_restart_call(task, call_start);
1671 }
1672 EXPORT_SYMBOL_GPL(rpc_restart_call);
1673
1674 /*
1675  * Restart an (async) RPC call from the call_prepare state.
1676  * Usually called from within the exit handler.
1677  */
1678 int
1679 rpc_restart_call_prepare(struct rpc_task *task)
1680 {
1681         if (task->tk_ops->rpc_call_prepare != NULL)
1682                 return __rpc_restart_call(task, rpc_prepare_task);
1683         return rpc_restart_call(task);
1684 }
1685 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1686
1687 const char
1688 *rpc_proc_name(const struct rpc_task *task)
1689 {
1690         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1691
1692         if (proc) {
1693                 if (proc->p_name)
1694                         return proc->p_name;
1695                 else
1696                         return "NULL";
1697         } else
1698                 return "no proc";
1699 }
1700
1701 static void
1702 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1703 {
1704         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1705         rpc_task_set_rpc_status(task, rpc_status);
1706         rpc_exit(task, tk_status);
1707 }
1708
1709 static void
1710 rpc_call_rpcerror(struct rpc_task *task, int status)
1711 {
1712         __rpc_call_rpcerror(task, status, status);
1713 }
1714
1715 /*
1716  * 0.  Initial state
1717  *
1718  *     Other FSM states can be visited zero or more times, but
1719  *     this state is visited exactly once for each RPC.
1720  */
1721 static void
1722 call_start(struct rpc_task *task)
1723 {
1724         struct rpc_clnt *clnt = task->tk_client;
1725         int idx = task->tk_msg.rpc_proc->p_statidx;
1726
1727         trace_rpc_request(task);
1728
1729         if (task->tk_client->cl_shutdown) {
1730                 rpc_call_rpcerror(task, -EIO);
1731                 return;
1732         }
1733
1734         /* Increment call count (version might not be valid for ping) */
1735         if (clnt->cl_program->version[clnt->cl_vers])
1736                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1737         clnt->cl_stats->rpccnt++;
1738         task->tk_action = call_reserve;
1739         rpc_task_set_transport(task, clnt);
1740 }
1741
1742 /*
1743  * 1.   Reserve an RPC call slot
1744  */
1745 static void
1746 call_reserve(struct rpc_task *task)
1747 {
1748         task->tk_status  = 0;
1749         task->tk_action  = call_reserveresult;
1750         xprt_reserve(task);
1751 }
1752
1753 static void call_retry_reserve(struct rpc_task *task);
1754
1755 /*
1756  * 1b.  Grok the result of xprt_reserve()
1757  */
1758 static void
1759 call_reserveresult(struct rpc_task *task)
1760 {
1761         int status = task->tk_status;
1762
1763         /*
1764          * After a call to xprt_reserve(), we must have either
1765          * a request slot or else an error status.
1766          */
1767         task->tk_status = 0;
1768         if (status >= 0) {
1769                 if (task->tk_rqstp) {
1770                         task->tk_action = call_refresh;
1771                         return;
1772                 }
1773
1774                 rpc_call_rpcerror(task, -EIO);
1775                 return;
1776         }
1777
1778         switch (status) {
1779         case -ENOMEM:
1780                 rpc_delay(task, HZ >> 2);
1781                 fallthrough;
1782         case -EAGAIN:   /* woken up; retry */
1783                 task->tk_action = call_retry_reserve;
1784                 return;
1785         default:
1786                 rpc_call_rpcerror(task, status);
1787         }
1788 }
1789
1790 /*
1791  * 1c.  Retry reserving an RPC call slot
1792  */
1793 static void
1794 call_retry_reserve(struct rpc_task *task)
1795 {
1796         task->tk_status  = 0;
1797         task->tk_action  = call_reserveresult;
1798         xprt_retry_reserve(task);
1799 }
1800
1801 /*
1802  * 2.   Bind and/or refresh the credentials
1803  */
1804 static void
1805 call_refresh(struct rpc_task *task)
1806 {
1807         task->tk_action = call_refreshresult;
1808         task->tk_status = 0;
1809         task->tk_client->cl_stats->rpcauthrefresh++;
1810         rpcauth_refreshcred(task);
1811 }
1812
1813 /*
1814  * 2a.  Process the results of a credential refresh
1815  */
1816 static void
1817 call_refreshresult(struct rpc_task *task)
1818 {
1819         int status = task->tk_status;
1820
1821         task->tk_status = 0;
1822         task->tk_action = call_refresh;
1823         switch (status) {
1824         case 0:
1825                 if (rpcauth_uptodatecred(task)) {
1826                         task->tk_action = call_allocate;
1827                         return;
1828                 }
1829                 /* Use rate-limiting and a max number of retries if refresh
1830                  * had status 0 but failed to update the cred.
1831                  */
1832                 fallthrough;
1833         case -ETIMEDOUT:
1834                 rpc_delay(task, 3*HZ);
1835                 fallthrough;
1836         case -EAGAIN:
1837                 status = -EACCES;
1838                 fallthrough;
1839         case -EKEYEXPIRED:
1840                 if (!task->tk_cred_retry)
1841                         break;
1842                 task->tk_cred_retry--;
1843                 trace_rpc_retry_refresh_status(task);
1844                 return;
1845         case -ENOMEM:
1846                 rpc_delay(task, HZ >> 4);
1847                 return;
1848         }
1849         trace_rpc_refresh_status(task);
1850         rpc_call_rpcerror(task, status);
1851 }
1852
1853 /*
1854  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1855  *      (Note: buffer memory is freed in xprt_release).
1856  */
1857 static void
1858 call_allocate(struct rpc_task *task)
1859 {
1860         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1861         struct rpc_rqst *req = task->tk_rqstp;
1862         struct rpc_xprt *xprt = req->rq_xprt;
1863         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1864         int status;
1865
1866         task->tk_status = 0;
1867         task->tk_action = call_encode;
1868
1869         if (req->rq_buffer)
1870                 return;
1871
1872         if (proc->p_proc != 0) {
1873                 BUG_ON(proc->p_arglen == 0);
1874                 if (proc->p_decode != NULL)
1875                         BUG_ON(proc->p_replen == 0);
1876         }
1877
1878         /*
1879          * Calculate the size (in quads) of the RPC call
1880          * and reply headers, and convert both values
1881          * to byte sizes.
1882          */
1883         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1884                            proc->p_arglen;
1885         req->rq_callsize <<= 2;
1886         /*
1887          * Note: the reply buffer must at minimum allocate enough space
1888          * for the 'struct accepted_reply' from RFC5531.
1889          */
1890         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1891                         max_t(size_t, proc->p_replen, 2);
1892         req->rq_rcvsize <<= 2;
1893
1894         status = xprt->ops->buf_alloc(task);
1895         trace_rpc_buf_alloc(task, status);
1896         if (status == 0)
1897                 return;
1898         if (status != -ENOMEM) {
1899                 rpc_call_rpcerror(task, status);
1900                 return;
1901         }
1902
1903         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1904                 task->tk_action = call_allocate;
1905                 rpc_delay(task, HZ>>4);
1906                 return;
1907         }
1908
1909         rpc_call_rpcerror(task, -ERESTARTSYS);
1910 }
1911
1912 static int
1913 rpc_task_need_encode(struct rpc_task *task)
1914 {
1915         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1916                 (!(task->tk_flags & RPC_TASK_SENT) ||
1917                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1918                  xprt_request_need_retransmit(task));
1919 }
1920
1921 static void
1922 rpc_xdr_encode(struct rpc_task *task)
1923 {
1924         struct rpc_rqst *req = task->tk_rqstp;
1925         struct xdr_stream xdr;
1926
1927         xdr_buf_init(&req->rq_snd_buf,
1928                      req->rq_buffer,
1929                      req->rq_callsize);
1930         xdr_buf_init(&req->rq_rcv_buf,
1931                      req->rq_rbuffer,
1932                      req->rq_rcvsize);
1933
1934         req->rq_reply_bytes_recvd = 0;
1935         req->rq_snd_buf.head[0].iov_len = 0;
1936         xdr_init_encode(&xdr, &req->rq_snd_buf,
1937                         req->rq_snd_buf.head[0].iov_base, req);
1938         if (rpc_encode_header(task, &xdr))
1939                 return;
1940
1941         task->tk_status = rpcauth_wrap_req(task, &xdr);
1942 }
1943
1944 /*
1945  * 3.   Encode arguments of an RPC call
1946  */
1947 static void
1948 call_encode(struct rpc_task *task)
1949 {
1950         if (!rpc_task_need_encode(task))
1951                 goto out;
1952
1953         /* Dequeue task from the receive queue while we're encoding */
1954         xprt_request_dequeue_xprt(task);
1955         /* Encode here so that rpcsec_gss can use correct sequence number. */
1956         rpc_xdr_encode(task);
1957         /* Add task to reply queue before transmission to avoid races */
1958         if (task->tk_status == 0 && rpc_reply_expected(task))
1959                 task->tk_status = xprt_request_enqueue_receive(task);
1960         /* Did the encode result in an error condition? */
1961         if (task->tk_status != 0) {
1962                 /* Was the error nonfatal? */
1963                 switch (task->tk_status) {
1964                 case -EAGAIN:
1965                 case -ENOMEM:
1966                         rpc_delay(task, HZ >> 4);
1967                         break;
1968                 case -EKEYEXPIRED:
1969                         if (!task->tk_cred_retry) {
1970                                 rpc_call_rpcerror(task, task->tk_status);
1971                         } else {
1972                                 task->tk_action = call_refresh;
1973                                 task->tk_cred_retry--;
1974                                 trace_rpc_retry_refresh_status(task);
1975                         }
1976                         break;
1977                 default:
1978                         rpc_call_rpcerror(task, task->tk_status);
1979                 }
1980                 return;
1981         }
1982
1983         xprt_request_enqueue_transmit(task);
1984 out:
1985         task->tk_action = call_transmit;
1986         /* Check that the connection is OK */
1987         if (!xprt_bound(task->tk_xprt))
1988                 task->tk_action = call_bind;
1989         else if (!xprt_connected(task->tk_xprt))
1990                 task->tk_action = call_connect;
1991 }
1992
1993 /*
1994  * Helpers to check if the task was already transmitted, and
1995  * to take action when that is the case.
1996  */
1997 static bool
1998 rpc_task_transmitted(struct rpc_task *task)
1999 {
2000         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
2001 }
2002
2003 static void
2004 rpc_task_handle_transmitted(struct rpc_task *task)
2005 {
2006         xprt_end_transmit(task);
2007         task->tk_action = call_transmit_status;
2008 }
2009
2010 /*
2011  * 4.   Get the server port number if not yet set
2012  */
2013 static void
2014 call_bind(struct rpc_task *task)
2015 {
2016         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2017
2018         if (rpc_task_transmitted(task)) {
2019                 rpc_task_handle_transmitted(task);
2020                 return;
2021         }
2022
2023         if (xprt_bound(xprt)) {
2024                 task->tk_action = call_connect;
2025                 return;
2026         }
2027
2028         task->tk_action = call_bind_status;
2029         if (!xprt_prepare_transmit(task))
2030                 return;
2031
2032         xprt->ops->rpcbind(task);
2033 }
2034
2035 /*
2036  * 4a.  Sort out bind result
2037  */
2038 static void
2039 call_bind_status(struct rpc_task *task)
2040 {
2041         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2042         int status = -EIO;
2043
2044         if (rpc_task_transmitted(task)) {
2045                 rpc_task_handle_transmitted(task);
2046                 return;
2047         }
2048
2049         if (task->tk_status >= 0)
2050                 goto out_next;
2051         if (xprt_bound(xprt)) {
2052                 task->tk_status = 0;
2053                 goto out_next;
2054         }
2055
2056         switch (task->tk_status) {
2057         case -ENOMEM:
2058                 rpc_delay(task, HZ >> 2);
2059                 goto retry_timeout;
2060         case -EACCES:
2061                 trace_rpcb_prog_unavail_err(task);
2062                 /* fail immediately if this is an RPC ping */
2063                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2064                         status = -EOPNOTSUPP;
2065                         break;
2066                 }
2067                 rpc_delay(task, 3*HZ);
2068                 goto retry_timeout;
2069         case -ENOBUFS:
2070                 rpc_delay(task, HZ >> 2);
2071                 goto retry_timeout;
2072         case -EAGAIN:
2073                 goto retry_timeout;
2074         case -ETIMEDOUT:
2075                 trace_rpcb_timeout_err(task);
2076                 goto retry_timeout;
2077         case -EPFNOSUPPORT:
2078                 /* server doesn't support any rpcbind version we know of */
2079                 trace_rpcb_bind_version_err(task);
2080                 break;
2081         case -EPROTONOSUPPORT:
2082                 trace_rpcb_bind_version_err(task);
2083                 goto retry_timeout;
2084         case -ECONNREFUSED:             /* connection problems */
2085         case -ECONNRESET:
2086         case -ECONNABORTED:
2087         case -ENOTCONN:
2088         case -EHOSTDOWN:
2089         case -ENETDOWN:
2090         case -EHOSTUNREACH:
2091         case -ENETUNREACH:
2092         case -EPIPE:
2093                 trace_rpcb_unreachable_err(task);
2094                 if (!RPC_IS_SOFTCONN(task)) {
2095                         rpc_delay(task, 5*HZ);
2096                         goto retry_timeout;
2097                 }
2098                 status = task->tk_status;
2099                 break;
2100         default:
2101                 trace_rpcb_unrecognized_err(task);
2102         }
2103
2104         rpc_call_rpcerror(task, status);
2105         return;
2106 out_next:
2107         task->tk_action = call_connect;
2108         return;
2109 retry_timeout:
2110         task->tk_status = 0;
2111         task->tk_action = call_bind;
2112         rpc_check_timeout(task);
2113 }
2114
2115 /*
2116  * 4b.  Connect to the RPC server
2117  */
2118 static void
2119 call_connect(struct rpc_task *task)
2120 {
2121         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2122
2123         if (rpc_task_transmitted(task)) {
2124                 rpc_task_handle_transmitted(task);
2125                 return;
2126         }
2127
2128         if (xprt_connected(xprt)) {
2129                 task->tk_action = call_transmit;
2130                 return;
2131         }
2132
2133         task->tk_action = call_connect_status;
2134         if (task->tk_status < 0)
2135                 return;
2136         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2137                 rpc_call_rpcerror(task, -ENOTCONN);
2138                 return;
2139         }
2140         if (!xprt_prepare_transmit(task))
2141                 return;
2142         xprt_connect(task);
2143 }
2144
2145 /*
2146  * 4c.  Sort out connect result
2147  */
2148 static void
2149 call_connect_status(struct rpc_task *task)
2150 {
2151         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2152         struct rpc_clnt *clnt = task->tk_client;
2153         int status = task->tk_status;
2154
2155         if (rpc_task_transmitted(task)) {
2156                 rpc_task_handle_transmitted(task);
2157                 return;
2158         }
2159
2160         trace_rpc_connect_status(task);
2161
2162         if (task->tk_status == 0) {
2163                 clnt->cl_stats->netreconn++;
2164                 goto out_next;
2165         }
2166         if (xprt_connected(xprt)) {
2167                 task->tk_status = 0;
2168                 goto out_next;
2169         }
2170
2171         task->tk_status = 0;
2172         switch (status) {
2173         case -ECONNREFUSED:
2174                 /* A positive refusal suggests a rebind is needed. */
2175                 if (RPC_IS_SOFTCONN(task))
2176                         break;
2177                 if (clnt->cl_autobind) {
2178                         rpc_force_rebind(clnt);
2179                         goto out_retry;
2180                 }
2181                 fallthrough;
2182         case -ECONNRESET:
2183         case -ECONNABORTED:
2184         case -ENETDOWN:
2185         case -ENETUNREACH:
2186         case -EHOSTUNREACH:
2187         case -EPIPE:
2188         case -EPROTO:
2189                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2190                                             task->tk_rqstp->rq_connect_cookie);
2191                 if (RPC_IS_SOFTCONN(task))
2192                         break;
2193                 /* retry with existing socket, after a delay */
2194                 rpc_delay(task, 3*HZ);
2195                 fallthrough;
2196         case -EADDRINUSE:
2197         case -ENOTCONN:
2198         case -EAGAIN:
2199         case -ETIMEDOUT:
2200                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2201                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2202                     test_bit(XPRT_REMOVE, &xprt->state)) {
2203                         struct rpc_xprt *saved = task->tk_xprt;
2204                         struct rpc_xprt_switch *xps;
2205
2206                         rcu_read_lock();
2207                         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2208                         rcu_read_unlock();
2209                         if (xps->xps_nxprts > 1) {
2210                                 long value;
2211
2212                                 xprt_release(task);
2213                                 value = atomic_long_dec_return(&xprt->queuelen);
2214                                 if (value == 0)
2215                                         rpc_xprt_switch_remove_xprt(xps, saved,
2216                                                                     true);
2217                                 xprt_put(saved);
2218                                 task->tk_xprt = NULL;
2219                                 task->tk_action = call_start;
2220                         }
2221                         xprt_switch_put(xps);
2222                         if (!task->tk_xprt)
2223                                 return;
2224                 }
2225                 goto out_retry;
2226         case -ENOBUFS:
2227                 rpc_delay(task, HZ >> 2);
2228                 goto out_retry;
2229         }
2230         rpc_call_rpcerror(task, status);
2231         return;
2232 out_next:
2233         task->tk_action = call_transmit;
2234         return;
2235 out_retry:
2236         /* Check for timeouts before looping back to call_bind */
2237         task->tk_action = call_bind;
2238         rpc_check_timeout(task);
2239 }
2240
2241 /*
2242  * 5.   Transmit the RPC request, and wait for reply
2243  */
2244 static void
2245 call_transmit(struct rpc_task *task)
2246 {
2247         if (rpc_task_transmitted(task)) {
2248                 rpc_task_handle_transmitted(task);
2249                 return;
2250         }
2251
2252         task->tk_action = call_transmit_status;
2253         if (!xprt_prepare_transmit(task))
2254                 return;
2255         task->tk_status = 0;
2256         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2257                 if (!xprt_connected(task->tk_xprt)) {
2258                         task->tk_status = -ENOTCONN;
2259                         return;
2260                 }
2261                 xprt_transmit(task);
2262         }
2263         xprt_end_transmit(task);
2264 }
2265
2266 /*
2267  * 5a.  Handle cleanup after a transmission
2268  */
2269 static void
2270 call_transmit_status(struct rpc_task *task)
2271 {
2272         task->tk_action = call_status;
2273
2274         /*
2275          * Common case: success.  Force the compiler to put this
2276          * test first.
2277          */
2278         if (rpc_task_transmitted(task)) {
2279                 task->tk_status = 0;
2280                 xprt_request_wait_receive(task);
2281                 return;
2282         }
2283
2284         switch (task->tk_status) {
2285         default:
2286                 break;
2287         case -EBADMSG:
2288                 task->tk_status = 0;
2289                 task->tk_action = call_encode;
2290                 break;
2291                 /*
2292                  * Special cases: if we've been waiting on the
2293                  * socket's write_space() callback, or if the
2294                  * socket just returned a connection error,
2295                  * then hold onto the transport lock.
2296                  */
2297         case -ENOMEM:
2298         case -ENOBUFS:
2299                 rpc_delay(task, HZ>>2);
2300                 fallthrough;
2301         case -EBADSLT:
2302         case -EAGAIN:
2303                 task->tk_action = call_transmit;
2304                 task->tk_status = 0;
2305                 break;
2306         case -ECONNREFUSED:
2307         case -EHOSTDOWN:
2308         case -ENETDOWN:
2309         case -EHOSTUNREACH:
2310         case -ENETUNREACH:
2311         case -EPERM:
2312                 if (RPC_IS_SOFTCONN(task)) {
2313                         if (!task->tk_msg.rpc_proc->p_proc)
2314                                 trace_xprt_ping(task->tk_xprt,
2315                                                 task->tk_status);
2316                         rpc_call_rpcerror(task, task->tk_status);
2317                         return;
2318                 }
2319                 fallthrough;
2320         case -ECONNRESET:
2321         case -ECONNABORTED:
2322         case -EADDRINUSE:
2323         case -ENOTCONN:
2324         case -EPIPE:
2325                 task->tk_action = call_bind;
2326                 task->tk_status = 0;
2327                 break;
2328         }
2329         rpc_check_timeout(task);
2330 }
2331
2332 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2333 static void call_bc_transmit(struct rpc_task *task);
2334 static void call_bc_transmit_status(struct rpc_task *task);
2335
2336 static void
2337 call_bc_encode(struct rpc_task *task)
2338 {
2339         xprt_request_enqueue_transmit(task);
2340         task->tk_action = call_bc_transmit;
2341 }
2342
2343 /*
2344  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2345  * addition, disconnect on connectivity errors.
2346  */
2347 static void
2348 call_bc_transmit(struct rpc_task *task)
2349 {
2350         task->tk_action = call_bc_transmit_status;
2351         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2352                 if (!xprt_prepare_transmit(task))
2353                         return;
2354                 task->tk_status = 0;
2355                 xprt_transmit(task);
2356         }
2357         xprt_end_transmit(task);
2358 }
2359
2360 static void
2361 call_bc_transmit_status(struct rpc_task *task)
2362 {
2363         struct rpc_rqst *req = task->tk_rqstp;
2364
2365         if (rpc_task_transmitted(task))
2366                 task->tk_status = 0;
2367
2368         switch (task->tk_status) {
2369         case 0:
2370                 /* Success */
2371         case -ENETDOWN:
2372         case -EHOSTDOWN:
2373         case -EHOSTUNREACH:
2374         case -ENETUNREACH:
2375         case -ECONNRESET:
2376         case -ECONNREFUSED:
2377         case -EADDRINUSE:
2378         case -ENOTCONN:
2379         case -EPIPE:
2380                 break;
2381         case -ENOMEM:
2382         case -ENOBUFS:
2383                 rpc_delay(task, HZ>>2);
2384                 fallthrough;
2385         case -EBADSLT:
2386         case -EAGAIN:
2387                 task->tk_status = 0;
2388                 task->tk_action = call_bc_transmit;
2389                 return;
2390         case -ETIMEDOUT:
2391                 /*
2392                  * Problem reaching the server.  Disconnect and let the
2393                  * forechannel reestablish the connection.  The server will
2394                  * have to retransmit the backchannel request and we'll
2395                  * reprocess it.  Since these ops are idempotent, there's no
2396                  * need to cache our reply at this time.
2397                  */
2398                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2399                         "error: %d\n", task->tk_status);
2400                 xprt_conditional_disconnect(req->rq_xprt,
2401                         req->rq_connect_cookie);
2402                 break;
2403         default:
2404                 /*
2405                  * We were unable to reply and will have to drop the
2406                  * request.  The server should reconnect and retransmit.
2407                  */
2408                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2409                         "error: %d\n", task->tk_status);
2410                 break;
2411         }
2412         task->tk_action = rpc_exit_task;
2413 }
2414 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2415
2416 /*
2417  * 6.   Sort out the RPC call status
2418  */
2419 static void
2420 call_status(struct rpc_task *task)
2421 {
2422         struct rpc_clnt *clnt = task->tk_client;
2423         int             status;
2424
2425         if (!task->tk_msg.rpc_proc->p_proc)
2426                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2427
2428         status = task->tk_status;
2429         if (status >= 0) {
2430                 task->tk_action = call_decode;
2431                 return;
2432         }
2433
2434         trace_rpc_call_status(task);
2435         task->tk_status = 0;
2436         switch(status) {
2437         case -EHOSTDOWN:
2438         case -ENETDOWN:
2439         case -EHOSTUNREACH:
2440         case -ENETUNREACH:
2441         case -EPERM:
2442                 if (RPC_IS_SOFTCONN(task))
2443                         goto out_exit;
2444                 /*
2445                  * Delay any retries for 3 seconds, then handle as if it
2446                  * were a timeout.
2447                  */
2448                 rpc_delay(task, 3*HZ);
2449                 fallthrough;
2450         case -ETIMEDOUT:
2451                 break;
2452         case -ECONNREFUSED:
2453         case -ECONNRESET:
2454         case -ECONNABORTED:
2455         case -ENOTCONN:
2456                 rpc_force_rebind(clnt);
2457                 break;
2458         case -EADDRINUSE:
2459                 rpc_delay(task, 3*HZ);
2460                 fallthrough;
2461         case -EPIPE:
2462         case -EAGAIN:
2463                 break;
2464         case -ENFILE:
2465         case -ENOBUFS:
2466         case -ENOMEM:
2467                 rpc_delay(task, HZ>>2);
2468                 break;
2469         case -EIO:
2470                 /* shutdown or soft timeout */
2471                 goto out_exit;
2472         default:
2473                 if (clnt->cl_chatty)
2474                         printk("%s: RPC call returned error %d\n",
2475                                clnt->cl_program->name, -status);
2476                 goto out_exit;
2477         }
2478         task->tk_action = call_encode;
2479         if (status != -ECONNRESET && status != -ECONNABORTED)
2480                 rpc_check_timeout(task);
2481         return;
2482 out_exit:
2483         rpc_call_rpcerror(task, status);
2484 }
2485
2486 static bool
2487 rpc_check_connected(const struct rpc_rqst *req)
2488 {
2489         /* No allocated request or transport? return true */
2490         if (!req || !req->rq_xprt)
2491                 return true;
2492         return xprt_connected(req->rq_xprt);
2493 }
2494
2495 static void
2496 rpc_check_timeout(struct rpc_task *task)
2497 {
2498         struct rpc_clnt *clnt = task->tk_client;
2499
2500         if (RPC_SIGNALLED(task))
2501                 return;
2502
2503         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2504                 return;
2505
2506         trace_rpc_timeout_status(task);
2507         task->tk_timeouts++;
2508
2509         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2510                 rpc_call_rpcerror(task, -ETIMEDOUT);
2511                 return;
2512         }
2513
2514         if (RPC_IS_SOFT(task)) {
2515                 /*
2516                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2517                  * been sent, it should time out only if the transport
2518                  * connection gets terminally broken.
2519                  */
2520                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2521                     rpc_check_connected(task->tk_rqstp))
2522                         return;
2523
2524                 if (clnt->cl_chatty) {
2525                         pr_notice_ratelimited(
2526                                 "%s: server %s not responding, timed out\n",
2527                                 clnt->cl_program->name,
2528                                 task->tk_xprt->servername);
2529                 }
2530                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2531                         rpc_call_rpcerror(task, -ETIMEDOUT);
2532                 else
2533                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2534                 return;
2535         }
2536
2537         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2538                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2539                 if (clnt->cl_chatty) {
2540                         pr_notice_ratelimited(
2541                                 "%s: server %s not responding, still trying\n",
2542                                 clnt->cl_program->name,
2543                                 task->tk_xprt->servername);
2544                 }
2545         }
2546         rpc_force_rebind(clnt);
2547         /*
2548          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2549          * event? RFC2203 requires the server to drop all such requests.
2550          */
2551         rpcauth_invalcred(task);
2552 }
2553
2554 /*
2555  * 7.   Decode the RPC reply
2556  */
2557 static void
2558 call_decode(struct rpc_task *task)
2559 {
2560         struct rpc_clnt *clnt = task->tk_client;
2561         struct rpc_rqst *req = task->tk_rqstp;
2562         struct xdr_stream xdr;
2563         int err;
2564
2565         if (!task->tk_msg.rpc_proc->p_decode) {
2566                 task->tk_action = rpc_exit_task;
2567                 return;
2568         }
2569
2570         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2571                 if (clnt->cl_chatty) {
2572                         pr_notice_ratelimited("%s: server %s OK\n",
2573                                 clnt->cl_program->name,
2574                                 task->tk_xprt->servername);
2575                 }
2576                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2577         }
2578
2579         /*
2580          * Did we ever call xprt_complete_rqst()? If not, we should assume
2581          * the message is incomplete.
2582          */
2583         err = -EAGAIN;
2584         if (!req->rq_reply_bytes_recvd)
2585                 goto out;
2586
2587         /* Ensure that we see all writes made by xprt_complete_rqst()
2588          * before it changed req->rq_reply_bytes_recvd.
2589          */
2590         smp_rmb();
2591
2592         req->rq_rcv_buf.len = req->rq_private_buf.len;
2593         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2594
2595         /* Check that the softirq receive buffer is valid */
2596         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2597                                 sizeof(req->rq_rcv_buf)) != 0);
2598
2599         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2600                         req->rq_rcv_buf.head[0].iov_base, req);
2601         err = rpc_decode_header(task, &xdr);
2602 out:
2603         switch (err) {
2604         case 0:
2605                 task->tk_action = rpc_exit_task;
2606                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2607                 xdr_finish_decode(&xdr);
2608                 return;
2609         case -EAGAIN:
2610                 task->tk_status = 0;
2611                 if (task->tk_client->cl_discrtry)
2612                         xprt_conditional_disconnect(req->rq_xprt,
2613                                                     req->rq_connect_cookie);
2614                 task->tk_action = call_encode;
2615                 rpc_check_timeout(task);
2616                 break;
2617         case -EKEYREJECTED:
2618                 task->tk_action = call_reserve;
2619                 rpc_check_timeout(task);
2620                 rpcauth_invalcred(task);
2621                 /* Ensure we obtain a new XID if we retry! */
2622                 xprt_release(task);
2623         }
2624 }
2625
2626 static int
2627 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2628 {
2629         struct rpc_clnt *clnt = task->tk_client;
2630         struct rpc_rqst *req = task->tk_rqstp;
2631         __be32 *p;
2632         int error;
2633
2634         error = -EMSGSIZE;
2635         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2636         if (!p)
2637                 goto out_fail;
2638         *p++ = req->rq_xid;
2639         *p++ = rpc_call;
2640         *p++ = cpu_to_be32(RPC_VERSION);
2641         *p++ = cpu_to_be32(clnt->cl_prog);
2642         *p++ = cpu_to_be32(clnt->cl_vers);
2643         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2644
2645         error = rpcauth_marshcred(task, xdr);
2646         if (error < 0)
2647                 goto out_fail;
2648         return 0;
2649 out_fail:
2650         trace_rpc_bad_callhdr(task);
2651         rpc_call_rpcerror(task, error);
2652         return error;
2653 }
2654
2655 static noinline int
2656 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2657 {
2658         struct rpc_clnt *clnt = task->tk_client;
2659         int error;
2660         __be32 *p;
2661
2662         /* RFC-1014 says that the representation of XDR data must be a
2663          * multiple of four bytes
2664          * - if it isn't pointer subtraction in the NFS client may give
2665          *   undefined results
2666          */
2667         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2668                 goto out_unparsable;
2669
2670         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2671         if (!p)
2672                 goto out_unparsable;
2673         p++;    /* skip XID */
2674         if (*p++ != rpc_reply)
2675                 goto out_unparsable;
2676         if (*p++ != rpc_msg_accepted)
2677                 goto out_msg_denied;
2678
2679         error = rpcauth_checkverf(task, xdr);
2680         if (error)
2681                 goto out_verifier;
2682
2683         p = xdr_inline_decode(xdr, sizeof(*p));
2684         if (!p)
2685                 goto out_unparsable;
2686         switch (*p) {
2687         case rpc_success:
2688                 return 0;
2689         case rpc_prog_unavail:
2690                 trace_rpc__prog_unavail(task);
2691                 error = -EPFNOSUPPORT;
2692                 goto out_err;
2693         case rpc_prog_mismatch:
2694                 trace_rpc__prog_mismatch(task);
2695                 error = -EPROTONOSUPPORT;
2696                 goto out_err;
2697         case rpc_proc_unavail:
2698                 trace_rpc__proc_unavail(task);
2699                 error = -EOPNOTSUPP;
2700                 goto out_err;
2701         case rpc_garbage_args:
2702         case rpc_system_err:
2703                 trace_rpc__garbage_args(task);
2704                 error = -EIO;
2705                 break;
2706         default:
2707                 goto out_unparsable;
2708         }
2709
2710 out_garbage:
2711         clnt->cl_stats->rpcgarbage++;
2712         if (task->tk_garb_retry) {
2713                 task->tk_garb_retry--;
2714                 task->tk_action = call_encode;
2715                 return -EAGAIN;
2716         }
2717 out_err:
2718         rpc_call_rpcerror(task, error);
2719         return error;
2720
2721 out_unparsable:
2722         trace_rpc__unparsable(task);
2723         error = -EIO;
2724         goto out_garbage;
2725
2726 out_verifier:
2727         trace_rpc_bad_verifier(task);
2728         goto out_garbage;
2729
2730 out_msg_denied:
2731         error = -EACCES;
2732         p = xdr_inline_decode(xdr, sizeof(*p));
2733         if (!p)
2734                 goto out_unparsable;
2735         switch (*p++) {
2736         case rpc_auth_error:
2737                 break;
2738         case rpc_mismatch:
2739                 trace_rpc__mismatch(task);
2740                 error = -EPROTONOSUPPORT;
2741                 goto out_err;
2742         default:
2743                 goto out_unparsable;
2744         }
2745
2746         p = xdr_inline_decode(xdr, sizeof(*p));
2747         if (!p)
2748                 goto out_unparsable;
2749         switch (*p++) {
2750         case rpc_autherr_rejectedcred:
2751         case rpc_autherr_rejectedverf:
2752         case rpcsec_gsserr_credproblem:
2753         case rpcsec_gsserr_ctxproblem:
2754                 rpcauth_invalcred(task);
2755                 if (!task->tk_cred_retry)
2756                         break;
2757                 task->tk_cred_retry--;
2758                 trace_rpc__stale_creds(task);
2759                 return -EKEYREJECTED;
2760         case rpc_autherr_badcred:
2761         case rpc_autherr_badverf:
2762                 /* possibly garbled cred/verf? */
2763                 if (!task->tk_garb_retry)
2764                         break;
2765                 task->tk_garb_retry--;
2766                 trace_rpc__bad_creds(task);
2767                 task->tk_action = call_encode;
2768                 return -EAGAIN;
2769         case rpc_autherr_tooweak:
2770                 trace_rpc__auth_tooweak(task);
2771                 pr_warn("RPC: server %s requires stronger authentication.\n",
2772                         task->tk_xprt->servername);
2773                 break;
2774         default:
2775                 goto out_unparsable;
2776         }
2777         goto out_err;
2778 }
2779
2780 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2781                 const void *obj)
2782 {
2783 }
2784
2785 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2786                 void *obj)
2787 {
2788         return 0;
2789 }
2790
2791 static const struct rpc_procinfo rpcproc_null = {
2792         .p_encode = rpcproc_encode_null,
2793         .p_decode = rpcproc_decode_null,
2794 };
2795
2796 static const struct rpc_procinfo rpcproc_null_noreply = {
2797         .p_encode = rpcproc_encode_null,
2798 };
2799
2800 static void
2801 rpc_null_call_prepare(struct rpc_task *task, void *data)
2802 {
2803         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2804         rpc_call_start(task);
2805 }
2806
2807 static const struct rpc_call_ops rpc_null_ops = {
2808         .rpc_call_prepare = rpc_null_call_prepare,
2809         .rpc_call_done = rpc_default_callback,
2810 };
2811
2812 static
2813 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2814                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2815                 const struct rpc_call_ops *ops, void *data)
2816 {
2817         struct rpc_message msg = {
2818                 .rpc_proc = &rpcproc_null,
2819         };
2820         struct rpc_task_setup task_setup_data = {
2821                 .rpc_client = clnt,
2822                 .rpc_xprt = xprt,
2823                 .rpc_message = &msg,
2824                 .rpc_op_cred = cred,
2825                 .callback_ops = ops ?: &rpc_null_ops,
2826                 .callback_data = data,
2827                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2828                          RPC_TASK_NULLCREDS,
2829         };
2830
2831         return rpc_run_task(&task_setup_data);
2832 }
2833
2834 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2835 {
2836         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2837 }
2838 EXPORT_SYMBOL_GPL(rpc_call_null);
2839
2840 static int rpc_ping(struct rpc_clnt *clnt)
2841 {
2842         struct rpc_task *task;
2843         int status;
2844
2845         if (clnt->cl_auth->au_ops->ping)
2846                 return clnt->cl_auth->au_ops->ping(clnt);
2847
2848         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2849         if (IS_ERR(task))
2850                 return PTR_ERR(task);
2851         status = task->tk_status;
2852         rpc_put_task(task);
2853         return status;
2854 }
2855
2856 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2857 {
2858         struct rpc_message msg = {
2859                 .rpc_proc = &rpcproc_null_noreply,
2860         };
2861         struct rpc_task_setup task_setup_data = {
2862                 .rpc_client = clnt,
2863                 .rpc_message = &msg,
2864                 .callback_ops = &rpc_null_ops,
2865                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2866         };
2867         struct rpc_task *task;
2868         int status;
2869
2870         task = rpc_run_task(&task_setup_data);
2871         if (IS_ERR(task))
2872                 return PTR_ERR(task);
2873         status = task->tk_status;
2874         rpc_put_task(task);
2875         return status;
2876 }
2877
2878 struct rpc_cb_add_xprt_calldata {
2879         struct rpc_xprt_switch *xps;
2880         struct rpc_xprt *xprt;
2881 };
2882
2883 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2884 {
2885         struct rpc_cb_add_xprt_calldata *data = calldata;
2886
2887         if (task->tk_status == 0)
2888                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2889 }
2890
2891 static void rpc_cb_add_xprt_release(void *calldata)
2892 {
2893         struct rpc_cb_add_xprt_calldata *data = calldata;
2894
2895         xprt_put(data->xprt);
2896         xprt_switch_put(data->xps);
2897         kfree(data);
2898 }
2899
2900 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2901         .rpc_call_prepare = rpc_null_call_prepare,
2902         .rpc_call_done = rpc_cb_add_xprt_done,
2903         .rpc_release = rpc_cb_add_xprt_release,
2904 };
2905
2906 /**
2907  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2908  * @clnt: pointer to struct rpc_clnt
2909  * @xps: pointer to struct rpc_xprt_switch,
2910  * @xprt: pointer struct rpc_xprt
2911  * @in_max_connect: pointer to the max_connect value for the passed in xprt transport
2912  */
2913 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2914                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2915                 void *in_max_connect)
2916 {
2917         struct rpc_cb_add_xprt_calldata *data;
2918         struct rpc_task *task;
2919         int max_connect = clnt->cl_max_connect;
2920
2921         if (in_max_connect)
2922                 max_connect = *(int *)in_max_connect;
2923         if (xps->xps_nunique_destaddr_xprts + 1 > max_connect) {
2924                 rcu_read_lock();
2925                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2926                         "transport to server: %s\n", max_connect,
2927                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2928                 rcu_read_unlock();
2929                 return -EINVAL;
2930         }
2931
2932         data = kmalloc(sizeof(*data), GFP_KERNEL);
2933         if (!data)
2934                 return -ENOMEM;
2935         data->xps = xprt_switch_get(xps);
2936         data->xprt = xprt_get(xprt);
2937         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2938                 rpc_cb_add_xprt_release(data);
2939                 goto success;
2940         }
2941
2942         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2943                         &rpc_cb_add_xprt_call_ops, data);
2944         if (IS_ERR(task))
2945                 return PTR_ERR(task);
2946
2947         data->xps->xps_nunique_destaddr_xprts++;
2948         rpc_put_task(task);
2949 success:
2950         return 1;
2951 }
2952 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2953
2954 static int rpc_clnt_add_xprt_helper(struct rpc_clnt *clnt,
2955                                     struct rpc_xprt *xprt,
2956                                     struct rpc_add_xprt_test *data)
2957 {
2958         struct rpc_task *task;
2959         int status = -EADDRINUSE;
2960
2961         /* Test the connection */
2962         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2963         if (IS_ERR(task))
2964                 return PTR_ERR(task);
2965
2966         status = task->tk_status;
2967         rpc_put_task(task);
2968
2969         if (status < 0)
2970                 return status;
2971
2972         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2973         data->add_xprt_test(clnt, xprt, data->data);
2974
2975         return 0;
2976 }
2977
2978 /**
2979  * rpc_clnt_setup_test_and_add_xprt()
2980  *
2981  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2982  *   1) caller of the test function must dereference the rpc_xprt_switch
2983  *   and the rpc_xprt.
2984  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2985  *   the rpc_call_done routine.
2986  *
2987  * Upon success (return of 1), the test function adds the new
2988  * transport to the rpc_clnt xprt switch
2989  *
2990  * @clnt: struct rpc_clnt to get the new transport
2991  * @xps:  the rpc_xprt_switch to hold the new transport
2992  * @xprt: the rpc_xprt to test
2993  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2994  *        and test function call data
2995  */
2996 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2997                                      struct rpc_xprt_switch *xps,
2998                                      struct rpc_xprt *xprt,
2999                                      void *data)
3000 {
3001         int status = -EADDRINUSE;
3002
3003         xprt = xprt_get(xprt);
3004         xprt_switch_get(xps);
3005
3006         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
3007                 goto out_err;
3008
3009         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3010         if (status < 0)
3011                 goto out_err;
3012
3013         status = 1;
3014 out_err:
3015         xprt_put(xprt);
3016         xprt_switch_put(xps);
3017         if (status < 0)
3018                 pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not "
3019                         "added\n", status,
3020                         xprt->address_strings[RPC_DISPLAY_ADDR]);
3021         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
3022         return status;
3023 }
3024 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
3025
3026 /**
3027  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
3028  * @clnt: pointer to struct rpc_clnt
3029  * @xprtargs: pointer to struct xprt_create
3030  * @setup: callback to test and/or set up the connection
3031  * @data: pointer to setup function data
3032  *
3033  * Creates a new transport using the parameters set in args and
3034  * adds it to clnt.
3035  * If ping is set, then test that connectivity succeeds before
3036  * adding the new transport.
3037  *
3038  */
3039 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
3040                 struct xprt_create *xprtargs,
3041                 int (*setup)(struct rpc_clnt *,
3042                         struct rpc_xprt_switch *,
3043                         struct rpc_xprt *,
3044                         void *),
3045                 void *data)
3046 {
3047         struct rpc_xprt_switch *xps;
3048         struct rpc_xprt *xprt;
3049         unsigned long connect_timeout;
3050         unsigned long reconnect_timeout;
3051         unsigned char resvport, reuseport;
3052         int ret = 0, ident;
3053
3054         rcu_read_lock();
3055         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3056         xprt = xprt_iter_xprt(&clnt->cl_xpi);
3057         if (xps == NULL || xprt == NULL) {
3058                 rcu_read_unlock();
3059                 xprt_switch_put(xps);
3060                 return -EAGAIN;
3061         }
3062         resvport = xprt->resvport;
3063         reuseport = xprt->reuseport;
3064         connect_timeout = xprt->connect_timeout;
3065         reconnect_timeout = xprt->max_reconnect_timeout;
3066         ident = xprt->xprt_class->ident;
3067         rcu_read_unlock();
3068
3069         if (!xprtargs->ident)
3070                 xprtargs->ident = ident;
3071         xprtargs->xprtsec = clnt->cl_xprtsec;
3072         xprt = xprt_create_transport(xprtargs);
3073         if (IS_ERR(xprt)) {
3074                 ret = PTR_ERR(xprt);
3075                 goto out_put_switch;
3076         }
3077         xprt->resvport = resvport;
3078         xprt->reuseport = reuseport;
3079
3080         if (xprtargs->connect_timeout)
3081                 connect_timeout = xprtargs->connect_timeout;
3082         if (xprtargs->reconnect_timeout)
3083                 reconnect_timeout = xprtargs->reconnect_timeout;
3084         if (xprt->ops->set_connect_timeout != NULL)
3085                 xprt->ops->set_connect_timeout(xprt,
3086                                 connect_timeout,
3087                                 reconnect_timeout);
3088
3089         rpc_xprt_switch_set_roundrobin(xps);
3090         if (setup) {
3091                 ret = setup(clnt, xps, xprt, data);
3092                 if (ret != 0)
3093                         goto out_put_xprt;
3094         }
3095         rpc_xprt_switch_add_xprt(xps, xprt);
3096 out_put_xprt:
3097         xprt_put(xprt);
3098 out_put_switch:
3099         xprt_switch_put(xps);
3100         return ret;
3101 }
3102 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
3103
3104 static int rpc_xprt_probe_trunked(struct rpc_clnt *clnt,
3105                                   struct rpc_xprt *xprt,
3106                                   struct rpc_add_xprt_test *data)
3107 {
3108         struct rpc_xprt_switch *xps;
3109         struct rpc_xprt *main_xprt;
3110         int status = 0;
3111
3112         xprt_get(xprt);
3113
3114         rcu_read_lock();
3115         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3116         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3117         status = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3118                                    (struct sockaddr *)&main_xprt->addr);
3119         rcu_read_unlock();
3120         xprt_put(main_xprt);
3121         if (status || !test_bit(XPRT_OFFLINE, &xprt->state))
3122                 goto out;
3123
3124         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3125 out:
3126         xprt_put(xprt);
3127         xprt_switch_put(xps);
3128         return status;
3129 }
3130
3131 /* rpc_clnt_probe_trunked_xprt -- probe offlined transport for session trunking
3132  * @clnt rpc_clnt structure
3133  *
3134  * For each offlined transport found in the rpc_clnt structure call
3135  * the function rpc_xprt_probe_trunked() which will determine if this
3136  * transport still belongs to the trunking group.
3137  */
3138 void rpc_clnt_probe_trunked_xprts(struct rpc_clnt *clnt,
3139                                   struct rpc_add_xprt_test *data)
3140 {
3141         struct rpc_xprt_iter xpi;
3142         int ret;
3143
3144         ret = rpc_clnt_xprt_iter_offline_init(clnt, &xpi);
3145         if (ret)
3146                 return;
3147         for (;;) {
3148                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
3149
3150                 if (!xprt)
3151                         break;
3152                 ret = rpc_xprt_probe_trunked(clnt, xprt, data);
3153                 xprt_put(xprt);
3154                 if (ret < 0)
3155                         break;
3156                 xprt_iter_rewind(&xpi);
3157         }
3158         xprt_iter_destroy(&xpi);
3159 }
3160 EXPORT_SYMBOL_GPL(rpc_clnt_probe_trunked_xprts);
3161
3162 static int rpc_xprt_offline(struct rpc_clnt *clnt,
3163                             struct rpc_xprt *xprt,
3164                             void *data)
3165 {
3166         struct rpc_xprt *main_xprt;
3167         struct rpc_xprt_switch *xps;
3168         int err = 0;
3169
3170         xprt_get(xprt);
3171
3172         rcu_read_lock();
3173         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3174         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3175         err = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3176                                 (struct sockaddr *)&main_xprt->addr);
3177         rcu_read_unlock();
3178         xprt_put(main_xprt);
3179         if (err)
3180                 goto out;
3181
3182         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
3183                 err = -EINTR;
3184                 goto out;
3185         }
3186         xprt_set_offline_locked(xprt, xps);
3187
3188         xprt_release_write(xprt, NULL);
3189 out:
3190         xprt_put(xprt);
3191         xprt_switch_put(xps);
3192         return err;
3193 }
3194
3195 /* rpc_clnt_manage_trunked_xprts -- offline trunked transports
3196  * @clnt rpc_clnt structure
3197  *
3198  * For each active transport found in the rpc_clnt structure call
3199  * the function rpc_xprt_offline() which will identify trunked transports
3200  * and will mark them offline.
3201  */
3202 void rpc_clnt_manage_trunked_xprts(struct rpc_clnt *clnt)
3203 {
3204         rpc_clnt_iterate_for_each_xprt(clnt, rpc_xprt_offline, NULL);
3205 }
3206 EXPORT_SYMBOL_GPL(rpc_clnt_manage_trunked_xprts);
3207
3208 struct connect_timeout_data {
3209         unsigned long connect_timeout;
3210         unsigned long reconnect_timeout;
3211 };
3212
3213 static int
3214 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3215                 struct rpc_xprt *xprt,
3216                 void *data)
3217 {
3218         struct connect_timeout_data *timeo = data;
3219
3220         if (xprt->ops->set_connect_timeout)
3221                 xprt->ops->set_connect_timeout(xprt,
3222                                 timeo->connect_timeout,
3223                                 timeo->reconnect_timeout);
3224         return 0;
3225 }
3226
3227 void
3228 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3229                 unsigned long connect_timeout,
3230                 unsigned long reconnect_timeout)
3231 {
3232         struct connect_timeout_data timeout = {
3233                 .connect_timeout = connect_timeout,
3234                 .reconnect_timeout = reconnect_timeout,
3235         };
3236         rpc_clnt_iterate_for_each_xprt(clnt,
3237                         rpc_xprt_set_connect_timeout,
3238                         &timeout);
3239 }
3240 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3241
3242 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
3243 {
3244         rcu_read_lock();
3245         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3246         rcu_read_unlock();
3247 }
3248 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
3249
3250 void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3251 {
3252         struct rpc_xprt_switch *xps;
3253
3254         rcu_read_lock();
3255         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3256         rcu_read_unlock();
3257         xprt_set_online_locked(xprt, xps);
3258 }
3259
3260 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3261 {
3262         if (rpc_clnt_xprt_switch_has_addr(clnt,
3263                 (const struct sockaddr *)&xprt->addr)) {
3264                 return rpc_clnt_xprt_set_online(clnt, xprt);
3265         }
3266         rcu_read_lock();
3267         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3268                                  xprt);
3269         rcu_read_unlock();
3270 }
3271 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3272
3273 void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3274 {
3275         struct rpc_xprt_switch *xps;
3276
3277         rcu_read_lock();
3278         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3279         rpc_xprt_switch_remove_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3280                                     xprt, 0);
3281         xps->xps_nunique_destaddr_xprts--;
3282         rcu_read_unlock();
3283 }
3284 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_remove_xprt);
3285
3286 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3287                                    const struct sockaddr *sap)
3288 {
3289         struct rpc_xprt_switch *xps;
3290         bool ret;
3291
3292         rcu_read_lock();
3293         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3294         ret = rpc_xprt_switch_has_addr(xps, sap);
3295         rcu_read_unlock();
3296         return ret;
3297 }
3298 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3299
3300 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3301 static void rpc_show_header(void)
3302 {
3303         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3304                 "-timeout ---ops--\n");
3305 }
3306
3307 static void rpc_show_task(const struct rpc_clnt *clnt,
3308                           const struct rpc_task *task)
3309 {
3310         const char *rpc_waitq = "none";
3311
3312         if (RPC_IS_QUEUED(task))
3313                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3314
3315         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3316                 task->tk_pid, task->tk_flags, task->tk_status,
3317                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3318                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3319                 task->tk_action, rpc_waitq);
3320 }
3321
3322 void rpc_show_tasks(struct net *net)
3323 {
3324         struct rpc_clnt *clnt;
3325         struct rpc_task *task;
3326         int header = 0;
3327         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3328
3329         spin_lock(&sn->rpc_client_lock);
3330         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3331                 spin_lock(&clnt->cl_lock);
3332                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3333                         if (!header) {
3334                                 rpc_show_header();
3335                                 header++;
3336                         }
3337                         rpc_show_task(clnt, task);
3338                 }
3339                 spin_unlock(&clnt->cl_lock);
3340         }
3341         spin_unlock(&sn->rpc_client_lock);
3342 }
3343 #endif
3344
3345 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3346 static int
3347 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3348                 struct rpc_xprt *xprt,
3349                 void *dummy)
3350 {
3351         return xprt_enable_swap(xprt);
3352 }
3353
3354 int
3355 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3356 {
3357         while (clnt != clnt->cl_parent)
3358                 clnt = clnt->cl_parent;
3359         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3360                 return rpc_clnt_iterate_for_each_xprt(clnt,
3361                                 rpc_clnt_swap_activate_callback, NULL);
3362         return 0;
3363 }
3364 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3365
3366 static int
3367 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3368                 struct rpc_xprt *xprt,
3369                 void *dummy)
3370 {
3371         xprt_disable_swap(xprt);
3372         return 0;
3373 }
3374
3375 void
3376 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3377 {
3378         while (clnt != clnt->cl_parent)
3379                 clnt = clnt->cl_parent;
3380         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3381                 rpc_clnt_iterate_for_each_xprt(clnt,
3382                                 rpc_clnt_swap_deactivate_callback, NULL);
3383 }
3384 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3385 #endif /* CONFIG_SUNRPC_SWAP */