net/sunrpc/clnt.c

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