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         new->cl_principal = clnt->cl_principal;
 631         return new;
 632
 633 out_err:
 634         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 635         return ERR_PTR(err);
 636 }
 637
 638 /**
 639  * rpc_clone_client - Clone an RPC client structure
 640  *
 641  * @clnt: RPC client whose parameters are copied
 642  *
 643  * Returns a fresh RPC client or an ERR_PTR.
 644  */
 645 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 646 {
 647         struct rpc_create_args args = {
 648                 .program        = clnt->cl_program,
 649                 .prognumber     = clnt->cl_prog,
 650                 .version        = clnt->cl_vers,
 651                 .authflavor     = clnt->cl_auth->au_flavor,
 652         };
 653         return __rpc_clone_client(&args, clnt);
 654 }
 655 EXPORT_SYMBOL_GPL(rpc_clone_client);
 656
 657 /**
 658  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 659  *
 660  * @clnt: RPC client whose parameters are copied
 661  * @flavor: security flavor for new client
 662  *
 663  * Returns a fresh RPC client or an ERR_PTR.
 664  */
 665 struct rpc_clnt *
 666 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 667 {
 668         struct rpc_create_args args = {
 669                 .program        = clnt->cl_program,
 670                 .prognumber     = clnt->cl_prog,
 671                 .version        = clnt->cl_vers,
 672                 .authflavor     = flavor,
 673         };
 674         return __rpc_clone_client(&args, clnt);
 675 }
 676 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 677
 678 /**
 679  * rpc_switch_client_transport: switch the RPC transport on the fly
 680  * @clnt: pointer to a struct rpc_clnt
 681  * @args: pointer to the new transport arguments
 682  * @timeout: pointer to the new timeout parameters
 683  *
 684  * This function allows the caller to switch the RPC transport for the
 685  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 686  * server, for instance.  It assumes that the caller has ensured that
 687  * there are no active RPC tasks by using some form of locking.
 688  *
 689  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 690  * negative errno is returned, and "clnt" continues to use the old
 691  * xprt.
 692  */
 693 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 694                 struct xprt_create *args,
 695                 const struct rpc_timeout *timeout)
 696 {
 697         const struct rpc_timeout *old_timeo;
 698         rpc_authflavor_t pseudoflavor;
 699         struct rpc_xprt_switch *xps, *oldxps;
 700         struct rpc_xprt *xprt, *old;
 701         struct rpc_clnt *parent;
 702         int err;
 703
 704         xprt = xprt_create_transport(args);
 705         if (IS_ERR(xprt)) {
 706                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 707                         clnt);
 708                 return PTR_ERR(xprt);
 709         }
 710
 711         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 712         if (xps == NULL) {
 713                 xprt_put(xprt);
 714                 return -ENOMEM;
 715         }
 716
 717         pseudoflavor = clnt->cl_auth->au_flavor;
 718
 719         old_timeo = clnt->cl_timeout;
 720         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 721         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 722
 723         rpc_unregister_client(clnt);
 724         __rpc_clnt_remove_pipedir(clnt);
 725         rpc_clnt_debugfs_unregister(clnt);
 726
 727         /*
 728          * A new transport was created.  "clnt" therefore
 729          * becomes the root of a new cl_parent tree.  clnt's
 730          * children, if it has any, still point to the old xprt.
 731          */
 732         parent = clnt->cl_parent;
 733         clnt->cl_parent = clnt;
 734
 735         /*
 736          * The old rpc_auth cache cannot be re-used.  GSS
 737          * contexts in particular are between a single
 738          * client and server.
 739          */
 740         err = rpc_client_register(clnt, pseudoflavor, NULL);
 741         if (err)
 742                 goto out_revert;
 743
 744         synchronize_rcu();
 745         if (parent != clnt)
 746                 rpc_release_client(parent);
 747         xprt_switch_put(oldxps);
 748         xprt_put(old);
 749         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 750         return 0;
 751
 752 out_revert:
 753         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 754         rpc_clnt_set_transport(clnt, old, old_timeo);
 755         clnt->cl_parent = parent;
 756         rpc_client_register(clnt, pseudoflavor, NULL);
 757         xprt_switch_put(xps);
 758         xprt_put(xprt);
 759         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 760         return err;
 761 }
 762 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 763
 764 static
 765 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 766 {
 767         struct rpc_xprt_switch *xps;
 768
 769         rcu_read_lock();
 770         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 771         rcu_read_unlock();
 772         if (xps == NULL)
 773                 return -EAGAIN;
 774         xprt_iter_init_listall(xpi, xps);
 775         xprt_switch_put(xps);
 776         return 0;
 777 }
 778
 779 /**
 780  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 781  * @clnt: pointer to client
 782  * @fn: function to apply
 783  * @data: void pointer to function data
 784  *
 785  * Iterates through the list of RPC transports currently attached to the
 786  * client and applies the function fn(clnt, xprt, data).
 787  *
 788  * On error, the iteration stops, and the function returns the error value.
 789  */
 790 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 791                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 792                 void *data)
 793 {
 794         struct rpc_xprt_iter xpi;
 795         int ret;
 796
 797         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 798         if (ret)
 799                 return ret;
 800         for (;;) {
 801                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 802
 803                 if (!xprt)
 804                         break;
 805                 ret = fn(clnt, xprt, data);
 806                 xprt_put(xprt);
 807                 if (ret < 0)
 808                         break;
 809         }
 810         xprt_iter_destroy(&xpi);
 811         return ret;
 812 }
 813 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 814
 815 /*
 816  * Kill all tasks for the given client.
 817  * XXX: kill their descendants as well?
 818  */
 819 void rpc_killall_tasks(struct rpc_clnt *clnt)
 820 {
 821         struct rpc_task *rovr;
 822
 823
 824         if (list_empty(&clnt->cl_tasks))
 825                 return;
 826         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 827         /*
 828          * Spin lock all_tasks to prevent changes...
 829          */
 830         spin_lock(&clnt->cl_lock);
 831         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 832                 if (!RPC_IS_ACTIVATED(rovr))
 833                         continue;
 834                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 835                         rovr->tk_flags |= RPC_TASK_KILLED;
 836                         rpc_exit(rovr, -EIO);
 837                         if (RPC_IS_QUEUED(rovr))
 838                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 839                                                         rovr);
 840                 }
 841         }
 842         spin_unlock(&clnt->cl_lock);
 843 }
 844 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 845
 846 /*
 847  * Properly shut down an RPC client, terminating all outstanding
 848  * requests.
 849  */
 850 void rpc_shutdown_client(struct rpc_clnt *clnt)
 851 {
 852         might_sleep();
 853
 854         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 855                         clnt->cl_program->name,
 856                         rcu_dereference(clnt->cl_xprt)->servername);
 857
 858         while (!list_empty(&clnt->cl_tasks)) {
 859                 rpc_killall_tasks(clnt);
 860                 wait_event_timeout(destroy_wait,
 861                         list_empty(&clnt->cl_tasks), 1*HZ);
 862         }
 863
 864         rpc_release_client(clnt);
 865 }
 866 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 867
 868 /*
 869  * Free an RPC client
 870  */
 871 static struct rpc_clnt *
 872 rpc_free_client(struct rpc_clnt *clnt)
 873 {
 874         struct rpc_clnt *parent = NULL;
 875
 876         dprintk_rcu("RPC:       destroying %s client for %s\n",
 877                         clnt->cl_program->name,
 878                         rcu_dereference(clnt->cl_xprt)->servername);
 879         if (clnt->cl_parent != clnt)
 880                 parent = clnt->cl_parent;
 881         rpc_clnt_debugfs_unregister(clnt);
 882         rpc_clnt_remove_pipedir(clnt);
 883         rpc_unregister_client(clnt);
 884         rpc_free_iostats(clnt->cl_metrics);
 885         clnt->cl_metrics = NULL;
 886         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 887         xprt_iter_destroy(&clnt->cl_xpi);
 888         rpciod_down();
 889         rpc_free_clid(clnt);
 890         kfree(clnt);
 891         return parent;
 892 }
 893
 894 /*
 895  * Free an RPC client
 896  */
 897 static struct rpc_clnt *
 898 rpc_free_auth(struct rpc_clnt *clnt)
 899 {
 900         if (clnt->cl_auth == NULL)
 901                 return rpc_free_client(clnt);
 902
 903         /*
 904          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 905          *       release remaining GSS contexts. This mechanism ensures
 906          *       that it can do so safely.
 907          */
 908         atomic_inc(&clnt->cl_count);
 909         rpcauth_release(clnt->cl_auth);
 910         clnt->cl_auth = NULL;
 911         if (atomic_dec_and_test(&clnt->cl_count))
 912                 return rpc_free_client(clnt);
 913         return NULL;
 914 }
 915
 916 /*
 917  * Release reference to the RPC client
 918  */
 919 void
 920 rpc_release_client(struct rpc_clnt *clnt)
 921 {
 922         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 923
 924         do {
 925                 if (list_empty(&clnt->cl_tasks))
 926                         wake_up(&destroy_wait);
 927                 if (!atomic_dec_and_test(&clnt->cl_count))
 928                         break;
 929                 clnt = rpc_free_auth(clnt);
 930         } while (clnt != NULL);
 931 }
 932 EXPORT_SYMBOL_GPL(rpc_release_client);
 933
 934 /**
 935  * rpc_bind_new_program - bind a new RPC program to an existing client
 936  * @old: old rpc_client
 937  * @program: rpc program to set
 938  * @vers: rpc program version
 939  *
 940  * Clones the rpc client and sets up a new RPC program. This is mainly
 941  * of use for enabling different RPC programs to share the same transport.
 942  * The Sun NFSv2/v3 ACL protocol can do this.
 943  */
 944 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 945                                       const struct rpc_program *program,
 946                                       u32 vers)
 947 {
 948         struct rpc_create_args args = {
 949                 .program        = program,
 950                 .prognumber     = program->number,
 951                 .version        = vers,
 952                 .authflavor     = old->cl_auth->au_flavor,
 953         };
 954         struct rpc_clnt *clnt;
 955         int err;
 956
 957         clnt = __rpc_clone_client(&args, old);
 958         if (IS_ERR(clnt))
 959                 goto out;
 960         err = rpc_ping(clnt);
 961         if (err != 0) {
 962                 rpc_shutdown_client(clnt);
 963                 clnt = ERR_PTR(err);
 964         }
 965 out:
 966         return clnt;
 967 }
 968 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 969
 970 void rpc_task_release_transport(struct rpc_task *task)
 971 {
 972         struct rpc_xprt *xprt = task->tk_xprt;
 973
 974         if (xprt) {
 975                 task->tk_xprt = NULL;
 976                 xprt_put(xprt);
 977         }
 978 }
 979 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
 980
 981 void rpc_task_release_client(struct rpc_task *task)
 982 {
 983         struct rpc_clnt *clnt = task->tk_client;
 984
 985         if (clnt != NULL) {
 986                 /* Remove from client task list */
 987                 spin_lock(&clnt->cl_lock);
 988                 list_del(&task->tk_task);
 989                 spin_unlock(&clnt->cl_lock);
 990                 task->tk_client = NULL;
 991
 992                 rpc_release_client(clnt);
 993         }
 994         rpc_task_release_transport(task);
 995 }
 996
 997 static
 998 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 999 {
1000         if (!task->tk_xprt)
1001                 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
1002 }
1003
1004 static
1005 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1006 {
1007
1008         if (clnt != NULL) {
1009                 rpc_task_set_transport(task, clnt);
1010                 task->tk_client = clnt;
1011                 atomic_inc(&clnt->cl_count);
1012                 if (clnt->cl_softrtry)
1013                         task->tk_flags |= RPC_TASK_SOFT;
1014                 if (clnt->cl_noretranstimeo)
1015                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1016                 if (atomic_read(&clnt->cl_swapper))
1017                         task->tk_flags |= RPC_TASK_SWAPPER;
1018                 /* Add to the client's list of all tasks */
1019                 spin_lock(&clnt->cl_lock);
1020                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1021                 spin_unlock(&clnt->cl_lock);
1022         }
1023 }
1024
1025 static void
1026 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1027 {
1028         if (msg != NULL) {
1029                 task->tk_msg.rpc_proc = msg->rpc_proc;
1030                 task->tk_msg.rpc_argp = msg->rpc_argp;
1031                 task->tk_msg.rpc_resp = msg->rpc_resp;
1032                 if (msg->rpc_cred != NULL)
1033                         task->tk_msg.rpc_cred = get_cred(msg->rpc_cred);
1034         }
1035 }
1036
1037 /*
1038  * Default callback for async RPC calls
1039  */
1040 static void
1041 rpc_default_callback(struct rpc_task *task, void *data)
1042 {
1043 }
1044
1045 static const struct rpc_call_ops rpc_default_ops = {
1046         .rpc_call_done = rpc_default_callback,
1047 };
1048
1049 /**
1050  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1051  * @task_setup_data: pointer to task initialisation data
1052  */
1053 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1054 {
1055         struct rpc_task *task;
1056
1057         task = rpc_new_task(task_setup_data);
1058
1059         rpc_task_set_client(task, task_setup_data->rpc_client);
1060         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1061
1062         if (task->tk_action == NULL)
1063                 rpc_call_start(task);
1064
1065         atomic_inc(&task->tk_count);
1066         rpc_execute(task);
1067         return task;
1068 }
1069 EXPORT_SYMBOL_GPL(rpc_run_task);
1070
1071 /**
1072  * rpc_call_sync - Perform a synchronous RPC call
1073  * @clnt: pointer to RPC client
1074  * @msg: RPC call parameters
1075  * @flags: RPC call flags
1076  */
1077 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1078 {
1079         struct rpc_task *task;
1080         struct rpc_task_setup task_setup_data = {
1081                 .rpc_client = clnt,
1082                 .rpc_message = msg,
1083                 .callback_ops = &rpc_default_ops,
1084                 .flags = flags,
1085         };
1086         int status;
1087
1088         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1089         if (flags & RPC_TASK_ASYNC) {
1090                 rpc_release_calldata(task_setup_data.callback_ops,
1091                         task_setup_data.callback_data);
1092                 return -EINVAL;
1093         }
1094
1095         task = rpc_run_task(&task_setup_data);
1096         if (IS_ERR(task))
1097                 return PTR_ERR(task);
1098         status = task->tk_status;
1099         rpc_put_task(task);
1100         return status;
1101 }
1102 EXPORT_SYMBOL_GPL(rpc_call_sync);
1103
1104 /**
1105  * rpc_call_async - Perform an asynchronous RPC call
1106  * @clnt: pointer to RPC client
1107  * @msg: RPC call parameters
1108  * @flags: RPC call flags
1109  * @tk_ops: RPC call ops
1110  * @data: user call data
1111  */
1112 int
1113 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1114                const struct rpc_call_ops *tk_ops, void *data)
1115 {
1116         struct rpc_task *task;
1117         struct rpc_task_setup task_setup_data = {
1118                 .rpc_client = clnt,
1119                 .rpc_message = msg,
1120                 .callback_ops = tk_ops,
1121                 .callback_data = data,
1122                 .flags = flags|RPC_TASK_ASYNC,
1123         };
1124
1125         task = rpc_run_task(&task_setup_data);
1126         if (IS_ERR(task))
1127                 return PTR_ERR(task);
1128         rpc_put_task(task);
1129         return 0;
1130 }
1131 EXPORT_SYMBOL_GPL(rpc_call_async);
1132
1133 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1134 /**
1135  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1136  * rpc_execute against it
1137  * @req: RPC request
1138  */
1139 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1140 {
1141         struct rpc_task *task;
1142         struct rpc_task_setup task_setup_data = {
1143                 .callback_ops = &rpc_default_ops,
1144                 .flags = RPC_TASK_SOFTCONN |
1145                         RPC_TASK_NO_RETRANS_TIMEOUT,
1146         };
1147
1148         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1149         /*
1150          * Create an rpc_task to send the data
1151          */
1152         task = rpc_new_task(&task_setup_data);
1153         xprt_init_bc_request(req, task);
1154
1155         task->tk_action = call_bc_transmit;
1156         atomic_inc(&task->tk_count);
1157         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1158         rpc_execute(task);
1159
1160         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1161         return task;
1162 }
1163 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1164
1165 void
1166 rpc_call_start(struct rpc_task *task)
1167 {
1168         task->tk_action = call_start;
1169 }
1170 EXPORT_SYMBOL_GPL(rpc_call_start);
1171
1172 /**
1173  * rpc_peeraddr - extract remote peer address from clnt's xprt
1174  * @clnt: RPC client structure
1175  * @buf: target buffer
1176  * @bufsize: length of target buffer
1177  *
1178  * Returns the number of bytes that are actually in the stored address.
1179  */
1180 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1181 {
1182         size_t bytes;
1183         struct rpc_xprt *xprt;
1184
1185         rcu_read_lock();
1186         xprt = rcu_dereference(clnt->cl_xprt);
1187
1188         bytes = xprt->addrlen;
1189         if (bytes > bufsize)
1190                 bytes = bufsize;
1191         memcpy(buf, &xprt->addr, bytes);
1192         rcu_read_unlock();
1193
1194         return bytes;
1195 }
1196 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1197
1198 /**
1199  * rpc_peeraddr2str - return remote peer address in printable format
1200  * @clnt: RPC client structure
1201  * @format: address format
1202  *
1203  * NB: the lifetime of the memory referenced by the returned pointer is
1204  * the same as the rpc_xprt itself.  As long as the caller uses this
1205  * pointer, it must hold the RCU read lock.
1206  */
1207 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1208                              enum rpc_display_format_t format)
1209 {
1210         struct rpc_xprt *xprt;
1211
1212         xprt = rcu_dereference(clnt->cl_xprt);
1213
1214         if (xprt->address_strings[format] != NULL)
1215                 return xprt->address_strings[format];
1216         else
1217                 return "unprintable";
1218 }
1219 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1220
1221 static const struct sockaddr_in rpc_inaddr_loopback = {
1222         .sin_family             = AF_INET,
1223         .sin_addr.s_addr        = htonl(INADDR_ANY),
1224 };
1225
1226 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1227         .sin6_family            = AF_INET6,
1228         .sin6_addr              = IN6ADDR_ANY_INIT,
1229 };
1230
1231 /*
1232  * Try a getsockname() on a connected datagram socket.  Using a
1233  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1234  * This conserves the ephemeral port number space.
1235  *
1236  * Returns zero and fills in "buf" if successful; otherwise, a
1237  * negative errno is returned.
1238  */
1239 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1240                         struct sockaddr *buf)
1241 {
1242         struct socket *sock;
1243         int err;
1244
1245         err = __sock_create(net, sap->sa_family,
1246                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1247         if (err < 0) {
1248                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1249                 goto out;
1250         }
1251
1252         switch (sap->sa_family) {
1253         case AF_INET:
1254                 err = kernel_bind(sock,
1255                                 (struct sockaddr *)&rpc_inaddr_loopback,
1256                                 sizeof(rpc_inaddr_loopback));
1257                 break;
1258         case AF_INET6:
1259                 err = kernel_bind(sock,
1260                                 (struct sockaddr *)&rpc_in6addr_loopback,
1261                                 sizeof(rpc_in6addr_loopback));
1262                 break;
1263         default:
1264                 err = -EAFNOSUPPORT;
1265                 goto out;
1266         }
1267         if (err < 0) {
1268                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1269                 goto out_release;
1270         }
1271
1272         err = kernel_connect(sock, sap, salen, 0);
1273         if (err < 0) {
1274                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1275                 goto out_release;
1276         }
1277
1278         err = kernel_getsockname(sock, buf);
1279         if (err < 0) {
1280                 dprintk("RPC:       getsockname failed (%d)\n", err);
1281                 goto out_release;
1282         }
1283
1284         err = 0;
1285         if (buf->sa_family == AF_INET6) {
1286                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1287                 sin6->sin6_scope_id = 0;
1288         }
1289         dprintk("RPC:       %s succeeded\n", __func__);
1290
1291 out_release:
1292         sock_release(sock);
1293 out:
1294         return err;
1295 }
1296
1297 /*
1298  * Scraping a connected socket failed, so we don't have a useable
1299  * local address.  Fallback: generate an address that will prevent
1300  * the server from calling us back.
1301  *
1302  * Returns zero and fills in "buf" if successful; otherwise, a
1303  * negative errno is returned.
1304  */
1305 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1306 {
1307         switch (family) {
1308         case AF_INET:
1309                 if (buflen < sizeof(rpc_inaddr_loopback))
1310                         return -EINVAL;
1311                 memcpy(buf, &rpc_inaddr_loopback,
1312                                 sizeof(rpc_inaddr_loopback));
1313                 break;
1314         case AF_INET6:
1315                 if (buflen < sizeof(rpc_in6addr_loopback))
1316                         return -EINVAL;
1317                 memcpy(buf, &rpc_in6addr_loopback,
1318                                 sizeof(rpc_in6addr_loopback));
1319                 break;
1320         default:
1321                 dprintk("RPC:       %s: address family not supported\n",
1322                         __func__);
1323                 return -EAFNOSUPPORT;
1324         }
1325         dprintk("RPC:       %s: succeeded\n", __func__);
1326         return 0;
1327 }
1328
1329 /**
1330  * rpc_localaddr - discover local endpoint address for an RPC client
1331  * @clnt: RPC client structure
1332  * @buf: target buffer
1333  * @buflen: size of target buffer, in bytes
1334  *
1335  * Returns zero and fills in "buf" and "buflen" if successful;
1336  * otherwise, a negative errno is returned.
1337  *
1338  * This works even if the underlying transport is not currently connected,
1339  * or if the upper layer never previously provided a source address.
1340  *
1341  * The result of this function call is transient: multiple calls in
1342  * succession may give different results, depending on how local
1343  * networking configuration changes over time.
1344  */
1345 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1346 {
1347         struct sockaddr_storage address;
1348         struct sockaddr *sap = (struct sockaddr *)&address;
1349         struct rpc_xprt *xprt;
1350         struct net *net;
1351         size_t salen;
1352         int err;
1353
1354         rcu_read_lock();
1355         xprt = rcu_dereference(clnt->cl_xprt);
1356         salen = xprt->addrlen;
1357         memcpy(sap, &xprt->addr, salen);
1358         net = get_net(xprt->xprt_net);
1359         rcu_read_unlock();
1360
1361         rpc_set_port(sap, 0);
1362         err = rpc_sockname(net, sap, salen, buf);
1363         put_net(net);
1364         if (err != 0)
1365                 /* Couldn't discover local address, return ANYADDR */
1366                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1367         return 0;
1368 }
1369 EXPORT_SYMBOL_GPL(rpc_localaddr);
1370
1371 void
1372 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1373 {
1374         struct rpc_xprt *xprt;
1375
1376         rcu_read_lock();
1377         xprt = rcu_dereference(clnt->cl_xprt);
1378         if (xprt->ops->set_buffer_size)
1379                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1380         rcu_read_unlock();
1381 }
1382 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1383
1384 /**
1385  * rpc_net_ns - Get the network namespace for this RPC client
1386  * @clnt: RPC client to query
1387  *
1388  */
1389 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1390 {
1391         struct net *ret;
1392
1393         rcu_read_lock();
1394         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1395         rcu_read_unlock();
1396         return ret;
1397 }
1398 EXPORT_SYMBOL_GPL(rpc_net_ns);
1399
1400 /**
1401  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1402  * @clnt: RPC client to query
1403  *
1404  * For stream transports, this is one RPC record fragment (see RFC
1405  * 1831), as we don't support multi-record requests yet.  For datagram
1406  * transports, this is the size of an IP packet minus the IP, UDP, and
1407  * RPC header sizes.
1408  */
1409 size_t rpc_max_payload(struct rpc_clnt *clnt)
1410 {
1411         size_t ret;
1412
1413         rcu_read_lock();
1414         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1415         rcu_read_unlock();
1416         return ret;
1417 }
1418 EXPORT_SYMBOL_GPL(rpc_max_payload);
1419
1420 /**
1421  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1422  * @clnt: RPC client to query
1423  */
1424 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1425 {
1426         struct rpc_xprt *xprt;
1427         size_t ret;
1428
1429         rcu_read_lock();
1430         xprt = rcu_dereference(clnt->cl_xprt);
1431         ret = xprt->ops->bc_maxpayload(xprt);
1432         rcu_read_unlock();
1433         return ret;
1434 }
1435 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1436
1437 /**
1438  * rpc_force_rebind - force transport to check that remote port is unchanged
1439  * @clnt: client to rebind
1440  *
1441  */
1442 void rpc_force_rebind(struct rpc_clnt *clnt)
1443 {
1444         if (clnt->cl_autobind) {
1445                 rcu_read_lock();
1446                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1447                 rcu_read_unlock();
1448         }
1449 }
1450 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1451
1452 /*
1453  * Restart an (async) RPC call from the call_prepare state.
1454  * Usually called from within the exit handler.
1455  */
1456 int
1457 rpc_restart_call_prepare(struct rpc_task *task)
1458 {
1459         if (RPC_ASSASSINATED(task))
1460                 return 0;
1461         task->tk_action = call_start;
1462         task->tk_status = 0;
1463         if (task->tk_ops->rpc_call_prepare != NULL)
1464                 task->tk_action = rpc_prepare_task;
1465         return 1;
1466 }
1467 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1468
1469 /*
1470  * Restart an (async) RPC call. Usually called from within the
1471  * exit handler.
1472  */
1473 int
1474 rpc_restart_call(struct rpc_task *task)
1475 {
1476         if (RPC_ASSASSINATED(task))
1477                 return 0;
1478         task->tk_action = call_start;
1479         task->tk_status = 0;
1480         return 1;
1481 }
1482 EXPORT_SYMBOL_GPL(rpc_restart_call);
1483
1484 const char
1485 *rpc_proc_name(const struct rpc_task *task)
1486 {
1487         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1488
1489         if (proc) {
1490                 if (proc->p_name)
1491                         return proc->p_name;
1492                 else
1493                         return "NULL";
1494         } else
1495                 return "no proc";
1496 }
1497
1498 /*
1499  * 0.  Initial state
1500  *
1501  *     Other FSM states can be visited zero or more times, but
1502  *     this state is visited exactly once for each RPC.
1503  */
1504 static void
1505 call_start(struct rpc_task *task)
1506 {
1507         struct rpc_clnt *clnt = task->tk_client;
1508         int idx = task->tk_msg.rpc_proc->p_statidx;
1509
1510         trace_rpc_request(task);
1511         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1512                         clnt->cl_program->name, clnt->cl_vers,
1513                         rpc_proc_name(task),
1514                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1515
1516         /* Increment call count (version might not be valid for ping) */
1517         if (clnt->cl_program->version[clnt->cl_vers])
1518                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1519         clnt->cl_stats->rpccnt++;
1520         task->tk_action = call_reserve;
1521         rpc_task_set_transport(task, clnt);
1522 }
1523
1524 /*
1525  * 1.   Reserve an RPC call slot
1526  */
1527 static void
1528 call_reserve(struct rpc_task *task)
1529 {
1530         dprint_status(task);
1531
1532         task->tk_status  = 0;
1533         task->tk_action  = call_reserveresult;
1534         xprt_reserve(task);
1535 }
1536
1537 static void call_retry_reserve(struct rpc_task *task);
1538
1539 /*
1540  * 1b.  Grok the result of xprt_reserve()
1541  */
1542 static void
1543 call_reserveresult(struct rpc_task *task)
1544 {
1545         int status = task->tk_status;
1546
1547         dprint_status(task);
1548
1549         /*
1550          * After a call to xprt_reserve(), we must have either
1551          * a request slot or else an error status.
1552          */
1553         task->tk_status = 0;
1554         if (status >= 0) {
1555                 if (task->tk_rqstp) {
1556                         task->tk_action = call_refresh;
1557                         return;
1558                 }
1559
1560                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1561                                 __func__, status);
1562                 rpc_exit(task, -EIO);
1563                 return;
1564         }
1565
1566         /*
1567          * Even though there was an error, we may have acquired
1568          * a request slot somehow.  Make sure not to leak it.
1569          */
1570         if (task->tk_rqstp) {
1571                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1572                                 __func__, status);
1573                 xprt_release(task);
1574         }
1575
1576         switch (status) {
1577         case -ENOMEM:
1578                 rpc_delay(task, HZ >> 2);
1579                 /* fall through */
1580         case -EAGAIN:   /* woken up; retry */
1581                 task->tk_action = call_retry_reserve;
1582                 return;
1583         case -EIO:      /* probably a shutdown */
1584                 break;
1585         default:
1586                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1587                                 __func__, status);
1588                 break;
1589         }
1590         rpc_exit(task, status);
1591 }
1592
1593 /*
1594  * 1c.  Retry reserving an RPC call slot
1595  */
1596 static void
1597 call_retry_reserve(struct rpc_task *task)
1598 {
1599         dprint_status(task);
1600
1601         task->tk_status  = 0;
1602         task->tk_action  = call_reserveresult;
1603         xprt_retry_reserve(task);
1604 }
1605
1606 /*
1607  * 2.   Bind and/or refresh the credentials
1608  */
1609 static void
1610 call_refresh(struct rpc_task *task)
1611 {
1612         dprint_status(task);
1613
1614         task->tk_action = call_refreshresult;
1615         task->tk_status = 0;
1616         task->tk_client->cl_stats->rpcauthrefresh++;
1617         rpcauth_refreshcred(task);
1618 }
1619
1620 /*
1621  * 2a.  Process the results of a credential refresh
1622  */
1623 static void
1624 call_refreshresult(struct rpc_task *task)
1625 {
1626         int status = task->tk_status;
1627
1628         dprint_status(task);
1629
1630         task->tk_status = 0;
1631         task->tk_action = call_refresh;
1632         switch (status) {
1633         case 0:
1634                 if (rpcauth_uptodatecred(task)) {
1635                         task->tk_action = call_allocate;
1636                         return;
1637                 }
1638                 /* Use rate-limiting and a max number of retries if refresh
1639                  * had status 0 but failed to update the cred.
1640                  */
1641                 /* fall through */
1642         case -ETIMEDOUT:
1643                 rpc_delay(task, 3*HZ);
1644                 /* fall through */
1645         case -EAGAIN:
1646                 status = -EACCES;
1647                 /* fall through */
1648         case -EKEYEXPIRED:
1649                 if (!task->tk_cred_retry)
1650                         break;
1651                 task->tk_cred_retry--;
1652                 dprintk("RPC: %5u %s: retry refresh creds\n",
1653                                 task->tk_pid, __func__);
1654                 return;
1655         }
1656         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1657                                 task->tk_pid, __func__, status);
1658         rpc_exit(task, status);
1659 }
1660
1661 /*
1662  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1663  *      (Note: buffer memory is freed in xprt_release).
1664  */
1665 static void
1666 call_allocate(struct rpc_task *task)
1667 {
1668         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1669         struct rpc_rqst *req = task->tk_rqstp;
1670         struct rpc_xprt *xprt = req->rq_xprt;
1671         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1672         int status;
1673
1674         dprint_status(task);
1675
1676         task->tk_status = 0;
1677         task->tk_action = call_encode;
1678
1679         if (req->rq_buffer)
1680                 return;
1681
1682         if (proc->p_proc != 0) {
1683                 BUG_ON(proc->p_arglen == 0);
1684                 if (proc->p_decode != NULL)
1685                         BUG_ON(proc->p_replen == 0);
1686         }
1687
1688         /*
1689          * Calculate the size (in quads) of the RPC call
1690          * and reply headers, and convert both values
1691          * to byte sizes.
1692          */
1693         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1694         req->rq_callsize <<= 2;
1695         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1696         req->rq_rcvsize <<= 2;
1697
1698         status = xprt->ops->buf_alloc(task);
1699         xprt_inject_disconnect(xprt);
1700         if (status == 0)
1701                 return;
1702         if (status != -ENOMEM) {
1703                 rpc_exit(task, status);
1704                 return;
1705         }
1706
1707         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1708
1709         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1710                 task->tk_action = call_allocate;
1711                 rpc_delay(task, HZ>>4);
1712                 return;
1713         }
1714
1715         rpc_exit(task, -ERESTARTSYS);
1716 }
1717
1718 static int
1719 rpc_task_need_encode(struct rpc_task *task)
1720 {
1721         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1722                 (!(task->tk_flags & RPC_TASK_SENT) ||
1723                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1724                  xprt_request_need_retransmit(task));
1725 }
1726
1727 static void
1728 rpc_xdr_encode(struct rpc_task *task)
1729 {
1730         struct rpc_rqst *req = task->tk_rqstp;
1731         kxdreproc_t     encode;
1732         __be32          *p;
1733
1734         dprint_status(task);
1735
1736         xdr_buf_init(&req->rq_snd_buf,
1737                      req->rq_buffer,
1738                      req->rq_callsize);
1739         xdr_buf_init(&req->rq_rcv_buf,
1740                      req->rq_rbuffer,
1741                      req->rq_rcvsize);
1742
1743         p = rpc_encode_header(task);
1744         if (p == NULL)
1745                 return;
1746
1747         encode = task->tk_msg.rpc_proc->p_encode;
1748         if (encode == NULL)
1749                 return;
1750
1751         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1752                         task->tk_msg.rpc_argp);
1753         if (task->tk_status == 0)
1754                 xprt_request_prepare(req);
1755 }
1756
1757 /*
1758  * 3.   Encode arguments of an RPC call
1759  */
1760 static void
1761 call_encode(struct rpc_task *task)
1762 {
1763         if (!rpc_task_need_encode(task))
1764                 goto out;
1765         /* Encode here so that rpcsec_gss can use correct sequence number. */
1766         rpc_xdr_encode(task);
1767         /* Did the encode result in an error condition? */
1768         if (task->tk_status != 0) {
1769                 /* Was the error nonfatal? */
1770                 switch (task->tk_status) {
1771                 case -EAGAIN:
1772                 case -ENOMEM:
1773                         rpc_delay(task, HZ >> 4);
1774                         break;
1775                 case -EKEYEXPIRED:
1776                         task->tk_action = call_refresh;
1777                         break;
1778                 default:
1779                         rpc_exit(task, task->tk_status);
1780                 }
1781                 return;
1782         }
1783
1784         /* Add task to reply queue before transmission to avoid races */
1785         if (rpc_reply_expected(task))
1786                 xprt_request_enqueue_receive(task);
1787         xprt_request_enqueue_transmit(task);
1788 out:
1789         task->tk_action = call_bind;
1790 }
1791
1792 /*
1793  * 4.   Get the server port number if not yet set
1794  */
1795 static void
1796 call_bind(struct rpc_task *task)
1797 {
1798         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1799
1800         dprint_status(task);
1801
1802         task->tk_action = call_connect;
1803         if (!xprt_bound(xprt)) {
1804                 task->tk_action = call_bind_status;
1805                 task->tk_timeout = xprt->bind_timeout;
1806                 xprt->ops->rpcbind(task);
1807         }
1808 }
1809
1810 /*
1811  * 4a.  Sort out bind result
1812  */
1813 static void
1814 call_bind_status(struct rpc_task *task)
1815 {
1816         int status = -EIO;
1817
1818         if (task->tk_status >= 0) {
1819                 dprint_status(task);
1820                 task->tk_status = 0;
1821                 task->tk_action = call_connect;
1822                 return;
1823         }
1824
1825         trace_rpc_bind_status(task);
1826         switch (task->tk_status) {
1827         case -ENOMEM:
1828                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1829                 rpc_delay(task, HZ >> 2);
1830                 goto retry_timeout;
1831         case -EACCES:
1832                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1833                                 "unavailable\n", task->tk_pid);
1834                 /* fail immediately if this is an RPC ping */
1835                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1836                         status = -EOPNOTSUPP;
1837                         break;
1838                 }
1839                 if (task->tk_rebind_retry == 0)
1840                         break;
1841                 task->tk_rebind_retry--;
1842                 rpc_delay(task, 3*HZ);
1843                 goto retry_timeout;
1844         case -ETIMEDOUT:
1845                 dprintk("RPC: %5u rpcbind request timed out\n",
1846                                 task->tk_pid);
1847                 goto retry_timeout;
1848         case -EPFNOSUPPORT:
1849                 /* server doesn't support any rpcbind version we know of */
1850                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1851                                 task->tk_pid);
1852                 break;
1853         case -EPROTONOSUPPORT:
1854                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1855                                 task->tk_pid);
1856                 goto retry_timeout;
1857         case -ECONNREFUSED:             /* connection problems */
1858         case -ECONNRESET:
1859         case -ECONNABORTED:
1860         case -ENOTCONN:
1861         case -EHOSTDOWN:
1862         case -ENETDOWN:
1863         case -EHOSTUNREACH:
1864         case -ENETUNREACH:
1865         case -ENOBUFS:
1866         case -EPIPE:
1867                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1868                                 task->tk_pid, task->tk_status);
1869                 if (!RPC_IS_SOFTCONN(task)) {
1870                         rpc_delay(task, 5*HZ);
1871                         goto retry_timeout;
1872                 }
1873                 status = task->tk_status;
1874                 break;
1875         default:
1876                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1877                                 task->tk_pid, -task->tk_status);
1878         }
1879
1880         rpc_exit(task, status);
1881         return;
1882
1883 retry_timeout:
1884         task->tk_status = 0;
1885         task->tk_action = call_timeout;
1886 }
1887
1888 /*
1889  * 4b.  Connect to the RPC server
1890  */
1891 static void
1892 call_connect(struct rpc_task *task)
1893 {
1894         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1895
1896         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1897                         task->tk_pid, xprt,
1898                         (xprt_connected(xprt) ? "is" : "is not"));
1899
1900         task->tk_action = call_transmit;
1901         if (!xprt_connected(xprt)) {
1902                 task->tk_action = call_connect_status;
1903                 if (task->tk_status < 0)
1904                         return;
1905                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1906                         rpc_exit(task, -ENOTCONN);
1907                         return;
1908                 }
1909                 xprt_connect(task);
1910         }
1911 }
1912
1913 /*
1914  * 4c.  Sort out connect result
1915  */
1916 static void
1917 call_connect_status(struct rpc_task *task)
1918 {
1919         struct rpc_clnt *clnt = task->tk_client;
1920         int status = task->tk_status;
1921
1922         /* Check if the task was already transmitted */
1923         if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
1924                 xprt_end_transmit(task);
1925                 task->tk_action = call_transmit_status;
1926                 return;
1927         }
1928
1929         dprint_status(task);
1930
1931         trace_rpc_connect_status(task);
1932         task->tk_status = 0;
1933         switch (status) {
1934         case -ECONNREFUSED:
1935                 /* A positive refusal suggests a rebind is needed. */
1936                 if (RPC_IS_SOFTCONN(task))
1937                         break;
1938                 if (clnt->cl_autobind) {
1939                         rpc_force_rebind(clnt);
1940                         task->tk_action = call_bind;
1941                         return;
1942                 }
1943                 /* fall through */
1944         case -ECONNRESET:
1945         case -ECONNABORTED:
1946         case -ENETDOWN:
1947         case -ENETUNREACH:
1948         case -EHOSTUNREACH:
1949         case -EADDRINUSE:
1950         case -ENOBUFS:
1951         case -EPIPE:
1952                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1953                                             task->tk_rqstp->rq_connect_cookie);
1954                 if (RPC_IS_SOFTCONN(task))
1955                         break;
1956                 /* retry with existing socket, after a delay */
1957                 rpc_delay(task, 3*HZ);
1958                 /* fall through */
1959         case -ENOTCONN:
1960         case -EAGAIN:
1961                 /* Check for timeouts before looping back to call_bind */
1962         case -ETIMEDOUT:
1963                 task->tk_action = call_timeout;
1964                 return;
1965         case 0:
1966                 clnt->cl_stats->netreconn++;
1967                 task->tk_action = call_transmit;
1968                 return;
1969         }
1970         rpc_exit(task, status);
1971 }
1972
1973 /*
1974  * 5.   Transmit the RPC request, and wait for reply
1975  */
1976 static void
1977 call_transmit(struct rpc_task *task)
1978 {
1979         dprint_status(task);
1980
1981         task->tk_status = 0;
1982         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
1983                 if (!xprt_prepare_transmit(task))
1984                         return;
1985                 xprt_transmit(task);
1986         }
1987         task->tk_action = call_transmit_status;
1988         xprt_end_transmit(task);
1989 }
1990
1991 /*
1992  * 5a.  Handle cleanup after a transmission
1993  */
1994 static void
1995 call_transmit_status(struct rpc_task *task)
1996 {
1997         task->tk_action = call_status;
1998
1999         /*
2000          * Common case: success.  Force the compiler to put this
2001          * test first.
2002          */
2003         if (task->tk_status == 0) {
2004                 xprt_request_wait_receive(task);
2005                 return;
2006         }
2007
2008         switch (task->tk_status) {
2009         default:
2010                 dprint_status(task);
2011                 break;
2012         case -EBADMSG:
2013                 task->tk_status = 0;
2014                 task->tk_action = call_encode;
2015                 break;
2016                 /*
2017                  * Special cases: if we've been waiting on the
2018                  * socket's write_space() callback, or if the
2019                  * socket just returned a connection error,
2020                  * then hold onto the transport lock.
2021                  */
2022         case -ENOBUFS:
2023                 rpc_delay(task, HZ>>2);
2024                 /* fall through */
2025         case -EBADSLT:
2026         case -EAGAIN:
2027                 task->tk_action = call_transmit;
2028                 task->tk_status = 0;
2029                 break;
2030         case -ECONNREFUSED:
2031         case -EHOSTDOWN:
2032         case -ENETDOWN:
2033         case -EHOSTUNREACH:
2034         case -ENETUNREACH:
2035         case -EPERM:
2036                 if (RPC_IS_SOFTCONN(task)) {
2037                         if (!task->tk_msg.rpc_proc->p_proc)
2038                                 trace_xprt_ping(task->tk_xprt,
2039                                                 task->tk_status);
2040                         rpc_exit(task, task->tk_status);
2041                         break;
2042                 }
2043                 /* fall through */
2044         case -ECONNRESET:
2045         case -ECONNABORTED:
2046         case -EADDRINUSE:
2047         case -ENOTCONN:
2048         case -EPIPE:
2049                 break;
2050         }
2051 }
2052
2053 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2054 /*
2055  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2056  * addition, disconnect on connectivity errors.
2057  */
2058 static void
2059 call_bc_transmit(struct rpc_task *task)
2060 {
2061         struct rpc_rqst *req = task->tk_rqstp;
2062
2063         if (rpc_task_need_encode(task))
2064                 xprt_request_enqueue_transmit(task);
2065         if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate))
2066                 goto out_wakeup;
2067
2068         if (!xprt_prepare_transmit(task))
2069                 goto out_retry;
2070
2071         if (task->tk_status < 0) {
2072                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2073                         "error: %d\n", task->tk_status);
2074                 goto out_done;
2075         }
2076
2077         xprt_transmit(task);
2078
2079         xprt_end_transmit(task);
2080         dprint_status(task);
2081         switch (task->tk_status) {
2082         case 0:
2083                 /* Success */
2084         case -ENETDOWN:
2085         case -EHOSTDOWN:
2086         case -EHOSTUNREACH:
2087         case -ENETUNREACH:
2088         case -ECONNRESET:
2089         case -ECONNREFUSED:
2090         case -EADDRINUSE:
2091         case -ENOTCONN:
2092         case -EPIPE:
2093                 break;
2094         case -EAGAIN:
2095                 goto out_retry;
2096         case -ETIMEDOUT:
2097                 /*
2098                  * Problem reaching the server.  Disconnect and let the
2099                  * forechannel reestablish the connection.  The server will
2100                  * have to retransmit the backchannel request and we'll
2101                  * reprocess it.  Since these ops are idempotent, there's no
2102                  * need to cache our reply at this time.
2103                  */
2104                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2105                         "error: %d\n", task->tk_status);
2106                 xprt_conditional_disconnect(req->rq_xprt,
2107                         req->rq_connect_cookie);
2108                 break;
2109         default:
2110                 /*
2111                  * We were unable to reply and will have to drop the
2112                  * request.  The server should reconnect and retransmit.
2113                  */
2114                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2115                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2116                         "error: %d\n", task->tk_status);
2117                 break;
2118         }
2119 out_wakeup:
2120         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2121 out_done:
2122         task->tk_action = rpc_exit_task;
2123         return;
2124 out_retry:
2125         task->tk_status = 0;
2126 }
2127 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2128
2129 /*
2130  * 6.   Sort out the RPC call status
2131  */
2132 static void
2133 call_status(struct rpc_task *task)
2134 {
2135         struct rpc_clnt *clnt = task->tk_client;
2136         int             status;
2137
2138         if (!task->tk_msg.rpc_proc->p_proc)
2139                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2140
2141         dprint_status(task);
2142
2143         status = task->tk_status;
2144         if (status >= 0) {
2145                 task->tk_action = call_decode;
2146                 return;
2147         }
2148
2149         trace_rpc_call_status(task);
2150         task->tk_status = 0;
2151         switch(status) {
2152         case -EHOSTDOWN:
2153         case -ENETDOWN:
2154         case -EHOSTUNREACH:
2155         case -ENETUNREACH:
2156         case -EPERM:
2157                 if (RPC_IS_SOFTCONN(task)) {
2158                         rpc_exit(task, status);
2159                         break;
2160                 }
2161                 /*
2162                  * Delay any retries for 3 seconds, then handle as if it
2163                  * were a timeout.
2164                  */
2165                 rpc_delay(task, 3*HZ);
2166                 /* fall through */
2167         case -ETIMEDOUT:
2168                 task->tk_action = call_timeout;
2169                 break;
2170         case -ECONNREFUSED:
2171         case -ECONNRESET:
2172         case -ECONNABORTED:
2173                 rpc_force_rebind(clnt);
2174                 /* fall through */
2175         case -EADDRINUSE:
2176                 rpc_delay(task, 3*HZ);
2177                 /* fall through */
2178         case -EPIPE:
2179         case -ENOTCONN:
2180         case -EAGAIN:
2181                 task->tk_action = call_encode;
2182                 break;
2183         case -EIO:
2184                 /* shutdown or soft timeout */
2185                 rpc_exit(task, status);
2186                 break;
2187         default:
2188                 if (clnt->cl_chatty)
2189                         printk("%s: RPC call returned error %d\n",
2190                                clnt->cl_program->name, -status);
2191                 rpc_exit(task, status);
2192         }
2193 }
2194
2195 /*
2196  * 6a.  Handle RPC timeout
2197  *      We do not release the request slot, so we keep using the
2198  *      same XID for all retransmits.
2199  */
2200 static void
2201 call_timeout(struct rpc_task *task)
2202 {
2203         struct rpc_clnt *clnt = task->tk_client;
2204
2205         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2206                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2207                 goto retry;
2208         }
2209
2210         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2211         task->tk_timeouts++;
2212
2213         if (RPC_IS_SOFTCONN(task)) {
2214                 rpc_exit(task, -ETIMEDOUT);
2215                 return;
2216         }
2217         if (RPC_IS_SOFT(task)) {
2218                 if (clnt->cl_chatty) {
2219                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2220                                 clnt->cl_program->name,
2221                                 task->tk_xprt->servername);
2222                 }
2223                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2224                         rpc_exit(task, -ETIMEDOUT);
2225                 else
2226                         rpc_exit(task, -EIO);
2227                 return;
2228         }
2229
2230         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2231                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2232                 if (clnt->cl_chatty) {
2233                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2234                         clnt->cl_program->name,
2235                         task->tk_xprt->servername);
2236                 }
2237         }
2238         rpc_force_rebind(clnt);
2239         /*
2240          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2241          * event? RFC2203 requires the server to drop all such requests.
2242          */
2243         rpcauth_invalcred(task);
2244
2245 retry:
2246         task->tk_action = call_encode;
2247         task->tk_status = 0;
2248 }
2249
2250 /*
2251  * 7.   Decode the RPC reply
2252  */
2253 static void
2254 call_decode(struct rpc_task *task)
2255 {
2256         struct rpc_clnt *clnt = task->tk_client;
2257         struct rpc_rqst *req = task->tk_rqstp;
2258         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2259         __be32          *p;
2260
2261         dprint_status(task);
2262
2263         if (!decode) {
2264                 task->tk_action = rpc_exit_task;
2265                 return;
2266         }
2267
2268         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2269                 if (clnt->cl_chatty) {
2270                         printk(KERN_NOTICE "%s: server %s OK\n",
2271                                 clnt->cl_program->name,
2272                                 task->tk_xprt->servername);
2273                 }
2274                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2275         }
2276
2277         /*
2278          * Ensure that we see all writes made by xprt_complete_rqst()
2279          * before it changed req->rq_reply_bytes_recvd.
2280          */
2281         smp_rmb();
2282         req->rq_rcv_buf.len = req->rq_private_buf.len;
2283
2284         /* Check that the softirq receive buffer is valid */
2285         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2286                                 sizeof(req->rq_rcv_buf)) != 0);
2287
2288         if (req->rq_rcv_buf.len < 12) {
2289                 if (!RPC_IS_SOFT(task)) {
2290                         task->tk_action = call_encode;
2291                         goto out_retry;
2292                 }
2293                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2294                                 clnt->cl_program->name, task->tk_status);
2295                 task->tk_action = call_timeout;
2296                 goto out_retry;
2297         }
2298
2299         p = rpc_verify_header(task);
2300         if (IS_ERR(p)) {
2301                 if (p == ERR_PTR(-EAGAIN))
2302                         goto out_retry;
2303                 return;
2304         }
2305         task->tk_action = rpc_exit_task;
2306
2307         task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2308                                               task->tk_msg.rpc_resp);
2309
2310         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2311                         task->tk_status);
2312         return;
2313 out_retry:
2314         task->tk_status = 0;
2315         /* Note: rpc_verify_header() may have freed the RPC slot */
2316         if (task->tk_rqstp == req) {
2317                 xdr_free_bvec(&req->rq_rcv_buf);
2318                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2319                 if (task->tk_client->cl_discrtry)
2320                         xprt_conditional_disconnect(req->rq_xprt,
2321                                         req->rq_connect_cookie);
2322         }
2323 }
2324
2325 static __be32 *
2326 rpc_encode_header(struct rpc_task *task)
2327 {
2328         struct rpc_clnt *clnt = task->tk_client;
2329         struct rpc_rqst *req = task->tk_rqstp;
2330         __be32          *p = req->rq_svec[0].iov_base;
2331
2332         /* FIXME: check buffer size? */
2333
2334         p = xprt_skip_transport_header(req->rq_xprt, p);
2335         *p++ = req->rq_xid;             /* XID */
2336         *p++ = htonl(RPC_CALL);         /* CALL */
2337         *p++ = htonl(RPC_VERSION);      /* RPC version */
2338         *p++ = htonl(clnt->cl_prog);    /* program number */
2339         *p++ = htonl(clnt->cl_vers);    /* program version */
2340         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2341         p = rpcauth_marshcred(task, p);
2342         if (p)
2343                 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2344         return p;
2345 }
2346
2347 static __be32 *
2348 rpc_verify_header(struct rpc_task *task)
2349 {
2350         struct rpc_clnt *clnt = task->tk_client;
2351         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2352         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2353         __be32  *p = iov->iov_base;
2354         u32 n;
2355         int error = -EACCES;
2356
2357         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2358                 /* RFC-1014 says that the representation of XDR data must be a
2359                  * multiple of four bytes
2360                  * - if it isn't pointer subtraction in the NFS client may give
2361                  *   undefined results
2362                  */
2363                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2364                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2365                        task->tk_rqstp->rq_rcv_buf.len);
2366                 error = -EIO;
2367                 goto out_err;
2368         }
2369         if ((len -= 3) < 0)
2370                 goto out_overflow;
2371
2372         p += 1; /* skip XID */
2373         if ((n = ntohl(*p++)) != RPC_REPLY) {
2374                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2375                         task->tk_pid, __func__, n);
2376                 error = -EIO;
2377                 goto out_garbage;
2378         }
2379
2380         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2381                 if (--len < 0)
2382                         goto out_overflow;
2383                 switch ((n = ntohl(*p++))) {
2384                 case RPC_AUTH_ERROR:
2385                         break;
2386                 case RPC_MISMATCH:
2387                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2388                                 task->tk_pid, __func__);
2389                         error = -EPROTONOSUPPORT;
2390                         goto out_err;
2391                 default:
2392                         dprintk("RPC: %5u %s: RPC call rejected, "
2393                                 "unknown error: %x\n",
2394                                 task->tk_pid, __func__, n);
2395                         error = -EIO;
2396                         goto out_err;
2397                 }
2398                 if (--len < 0)
2399                         goto out_overflow;
2400                 switch ((n = ntohl(*p++))) {
2401                 case RPC_AUTH_REJECTEDCRED:
2402                 case RPC_AUTH_REJECTEDVERF:
2403                 case RPCSEC_GSS_CREDPROBLEM:
2404                 case RPCSEC_GSS_CTXPROBLEM:
2405                         if (!task->tk_cred_retry)
2406                                 break;
2407                         task->tk_cred_retry--;
2408                         dprintk("RPC: %5u %s: retry stale creds\n",
2409                                         task->tk_pid, __func__);
2410                         rpcauth_invalcred(task);
2411                         /* Ensure we obtain a new XID! */
2412                         xprt_release(task);
2413                         task->tk_action = call_reserve;
2414                         goto out_retry;
2415                 case RPC_AUTH_BADCRED:
2416                 case RPC_AUTH_BADVERF:
2417                         /* possibly garbled cred/verf? */
2418                         if (!task->tk_garb_retry)
2419                                 break;
2420                         task->tk_garb_retry--;
2421                         dprintk("RPC: %5u %s: retry garbled creds\n",
2422                                         task->tk_pid, __func__);
2423                         task->tk_action = call_encode;
2424                         goto out_retry;
2425                 case RPC_AUTH_TOOWEAK:
2426                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2427                                "authentication.\n",
2428                                task->tk_xprt->servername);
2429                         break;
2430                 default:
2431                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2432                                         task->tk_pid, __func__, n);
2433                         error = -EIO;
2434                 }
2435                 dprintk("RPC: %5u %s: call rejected %d\n",
2436                                 task->tk_pid, __func__, n);
2437                 goto out_err;
2438         }
2439         p = rpcauth_checkverf(task, p);
2440         if (IS_ERR(p)) {
2441                 error = PTR_ERR(p);
2442                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2443                                 task->tk_pid, __func__, error);
2444                 goto out_garbage;               /* bad verifier, retry */
2445         }
2446         len = p - (__be32 *)iov->iov_base - 1;
2447         if (len < 0)
2448                 goto out_overflow;
2449         switch ((n = ntohl(*p++))) {
2450         case RPC_SUCCESS:
2451                 return p;
2452         case RPC_PROG_UNAVAIL:
2453                 dprintk("RPC: %5u %s: program %u is unsupported "
2454                                 "by server %s\n", task->tk_pid, __func__,
2455                                 (unsigned int)clnt->cl_prog,
2456                                 task->tk_xprt->servername);
2457                 error = -EPFNOSUPPORT;
2458                 goto out_err;
2459         case RPC_PROG_MISMATCH:
2460                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2461                                 "by server %s\n", task->tk_pid, __func__,
2462                                 (unsigned int)clnt->cl_prog,
2463                                 (unsigned int)clnt->cl_vers,
2464                                 task->tk_xprt->servername);
2465                 error = -EPROTONOSUPPORT;
2466                 goto out_err;
2467         case RPC_PROC_UNAVAIL:
2468                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2469                                 "version %u on server %s\n",
2470                                 task->tk_pid, __func__,
2471                                 rpc_proc_name(task),
2472                                 clnt->cl_prog, clnt->cl_vers,
2473                                 task->tk_xprt->servername);
2474                 error = -EOPNOTSUPP;
2475                 goto out_err;
2476         case RPC_GARBAGE_ARGS:
2477                 dprintk("RPC: %5u %s: server saw garbage\n",
2478                                 task->tk_pid, __func__);
2479                 break;                  /* retry */
2480         default:
2481                 dprintk("RPC: %5u %s: server accept status: %x\n",
2482                                 task->tk_pid, __func__, n);
2483                 /* Also retry */
2484         }
2485
2486 out_garbage:
2487         clnt->cl_stats->rpcgarbage++;
2488         if (task->tk_garb_retry) {
2489                 task->tk_garb_retry--;
2490                 dprintk("RPC: %5u %s: retrying\n",
2491                                 task->tk_pid, __func__);
2492                 task->tk_action = call_encode;
2493 out_retry:
2494                 return ERR_PTR(-EAGAIN);
2495         }
2496 out_err:
2497         rpc_exit(task, error);
2498         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2499                         __func__, error);
2500         return ERR_PTR(error);
2501 out_overflow:
2502         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2503                         __func__);
2504         goto out_garbage;
2505 }
2506
2507 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2508                 const void *obj)
2509 {
2510 }
2511
2512 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2513                 void *obj)
2514 {
2515         return 0;
2516 }
2517
2518 static const struct rpc_procinfo rpcproc_null = {
2519         .p_encode = rpcproc_encode_null,
2520         .p_decode = rpcproc_decode_null,
2521 };
2522
2523 static int rpc_ping(struct rpc_clnt *clnt)
2524 {
2525         struct rpc_message msg = {
2526                 .rpc_proc = &rpcproc_null,
2527         };
2528         int err;
2529         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2530                             RPC_TASK_NULLCREDS);
2531         return err;
2532 }
2533
2534 static
2535 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2536                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2537                 const struct rpc_call_ops *ops, void *data)
2538 {
2539         struct rpc_message msg = {
2540                 .rpc_proc = &rpcproc_null,
2541         };
2542         struct rpc_task_setup task_setup_data = {
2543                 .rpc_client = clnt,
2544                 .rpc_xprt = xprt,
2545                 .rpc_message = &msg,
2546                 .rpc_op_cred = cred,
2547                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2548                 .callback_data = data,
2549                 .flags = flags | RPC_TASK_NULLCREDS,
2550         };
2551
2552         return rpc_run_task(&task_setup_data);
2553 }
2554
2555 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2556 {
2557         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2558 }
2559 EXPORT_SYMBOL_GPL(rpc_call_null);
2560
2561 struct rpc_cb_add_xprt_calldata {
2562         struct rpc_xprt_switch *xps;
2563         struct rpc_xprt *xprt;
2564 };
2565
2566 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2567 {
2568         struct rpc_cb_add_xprt_calldata *data = calldata;
2569
2570         if (task->tk_status == 0)
2571                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2572 }
2573
2574 static void rpc_cb_add_xprt_release(void *calldata)
2575 {
2576         struct rpc_cb_add_xprt_calldata *data = calldata;
2577
2578         xprt_put(data->xprt);
2579         xprt_switch_put(data->xps);
2580         kfree(data);
2581 }
2582
2583 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2584         .rpc_call_done = rpc_cb_add_xprt_done,
2585         .rpc_release = rpc_cb_add_xprt_release,
2586 };
2587
2588 /**
2589  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2590  * @clnt: pointer to struct rpc_clnt
2591  * @xps: pointer to struct rpc_xprt_switch,
2592  * @xprt: pointer struct rpc_xprt
2593  * @dummy: unused
2594  */
2595 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2596                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2597                 void *dummy)
2598 {
2599         struct rpc_cb_add_xprt_calldata *data;
2600         struct rpc_task *task;
2601
2602         data = kmalloc(sizeof(*data), GFP_NOFS);
2603         if (!data)
2604                 return -ENOMEM;
2605         data->xps = xprt_switch_get(xps);
2606         data->xprt = xprt_get(xprt);
2607
2608         task = rpc_call_null_helper(clnt, xprt, NULL,
2609                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
2610                         &rpc_cb_add_xprt_call_ops, data);
2611         if (IS_ERR(task))
2612                 return PTR_ERR(task);
2613         rpc_put_task(task);
2614         return 1;
2615 }
2616 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2617
2618 /**
2619  * rpc_clnt_setup_test_and_add_xprt()
2620  *
2621  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2622  *   1) caller of the test function must dereference the rpc_xprt_switch
2623  *   and the rpc_xprt.
2624  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2625  *   the rpc_call_done routine.
2626  *
2627  * Upon success (return of 1), the test function adds the new
2628  * transport to the rpc_clnt xprt switch
2629  *
2630  * @clnt: struct rpc_clnt to get the new transport
2631  * @xps:  the rpc_xprt_switch to hold the new transport
2632  * @xprt: the rpc_xprt to test
2633  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2634  *        and test function call data
2635  */
2636 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2637                                      struct rpc_xprt_switch *xps,
2638                                      struct rpc_xprt *xprt,
2639                                      void *data)
2640 {
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         task = rpc_call_null_helper(clnt, xprt, NULL,
2653                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2654                                     NULL, NULL);
2655         if (IS_ERR(task)) {
2656                 status = PTR_ERR(task);
2657                 goto out_err;
2658         }
2659         status = task->tk_status;
2660         rpc_put_task(task);
2661
2662         if (status < 0)
2663                 goto out_err;
2664
2665         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2666         xtest->add_xprt_test(clnt, xprt, xtest->data);
2667
2668         xprt_put(xprt);
2669         xprt_switch_put(xps);
2670
2671         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2672         return 1;
2673 out_err:
2674         xprt_put(xprt);
2675         xprt_switch_put(xps);
2676         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2677                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2678         return status;
2679 }
2680 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2681
2682 /**
2683  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2684  * @clnt: pointer to struct rpc_clnt
2685  * @xprtargs: pointer to struct xprt_create
2686  * @setup: callback to test and/or set up the connection
2687  * @data: pointer to setup function data
2688  *
2689  * Creates a new transport using the parameters set in args and
2690  * adds it to clnt.
2691  * If ping is set, then test that connectivity succeeds before
2692  * adding the new transport.
2693  *
2694  */
2695 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2696                 struct xprt_create *xprtargs,
2697                 int (*setup)(struct rpc_clnt *,
2698                         struct rpc_xprt_switch *,
2699                         struct rpc_xprt *,
2700                         void *),
2701                 void *data)
2702 {
2703         struct rpc_xprt_switch *xps;
2704         struct rpc_xprt *xprt;
2705         unsigned long connect_timeout;
2706         unsigned long reconnect_timeout;
2707         unsigned char resvport;
2708         int ret = 0;
2709
2710         rcu_read_lock();
2711         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2712         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2713         if (xps == NULL || xprt == NULL) {
2714                 rcu_read_unlock();
2715                 return -EAGAIN;
2716         }
2717         resvport = xprt->resvport;
2718         connect_timeout = xprt->connect_timeout;
2719         reconnect_timeout = xprt->max_reconnect_timeout;
2720         rcu_read_unlock();
2721
2722         xprt = xprt_create_transport(xprtargs);
2723         if (IS_ERR(xprt)) {
2724                 ret = PTR_ERR(xprt);
2725                 goto out_put_switch;
2726         }
2727         xprt->resvport = resvport;
2728         if (xprt->ops->set_connect_timeout != NULL)
2729                 xprt->ops->set_connect_timeout(xprt,
2730                                 connect_timeout,
2731                                 reconnect_timeout);
2732
2733         rpc_xprt_switch_set_roundrobin(xps);
2734         if (setup) {
2735                 ret = setup(clnt, xps, xprt, data);
2736                 if (ret != 0)
2737                         goto out_put_xprt;
2738         }
2739         rpc_xprt_switch_add_xprt(xps, xprt);
2740 out_put_xprt:
2741         xprt_put(xprt);
2742 out_put_switch:
2743         xprt_switch_put(xps);
2744         return ret;
2745 }
2746 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2747
2748 struct connect_timeout_data {
2749         unsigned long connect_timeout;
2750         unsigned long reconnect_timeout;
2751 };
2752
2753 static int
2754 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2755                 struct rpc_xprt *xprt,
2756                 void *data)
2757 {
2758         struct connect_timeout_data *timeo = data;
2759
2760         if (xprt->ops->set_connect_timeout)
2761                 xprt->ops->set_connect_timeout(xprt,
2762                                 timeo->connect_timeout,
2763                                 timeo->reconnect_timeout);
2764         return 0;
2765 }
2766
2767 void
2768 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2769                 unsigned long connect_timeout,
2770                 unsigned long reconnect_timeout)
2771 {
2772         struct connect_timeout_data timeout = {
2773                 .connect_timeout = connect_timeout,
2774                 .reconnect_timeout = reconnect_timeout,
2775         };
2776         rpc_clnt_iterate_for_each_xprt(clnt,
2777                         rpc_xprt_set_connect_timeout,
2778                         &timeout);
2779 }
2780 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2781
2782 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2783 {
2784         rcu_read_lock();
2785         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2786         rcu_read_unlock();
2787 }
2788 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2789
2790 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2791 {
2792         rcu_read_lock();
2793         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2794                                  xprt);
2795         rcu_read_unlock();
2796 }
2797 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2798
2799 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2800                                    const struct sockaddr *sap)
2801 {
2802         struct rpc_xprt_switch *xps;
2803         bool ret;
2804
2805         rcu_read_lock();
2806         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2807         ret = rpc_xprt_switch_has_addr(xps, sap);
2808         rcu_read_unlock();
2809         return ret;
2810 }
2811 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2812
2813 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2814 static void rpc_show_header(void)
2815 {
2816         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2817                 "-timeout ---ops--\n");
2818 }
2819
2820 static void rpc_show_task(const struct rpc_clnt *clnt,
2821                           const struct rpc_task *task)
2822 {
2823         const char *rpc_waitq = "none";
2824
2825         if (RPC_IS_QUEUED(task))
2826                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2827
2828         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2829                 task->tk_pid, task->tk_flags, task->tk_status,
2830                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2831                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2832                 task->tk_action, rpc_waitq);
2833 }
2834
2835 void rpc_show_tasks(struct net *net)
2836 {
2837         struct rpc_clnt *clnt;
2838         struct rpc_task *task;
2839         int header = 0;
2840         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2841
2842         spin_lock(&sn->rpc_client_lock);
2843         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2844                 spin_lock(&clnt->cl_lock);
2845                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2846                         if (!header) {
2847                                 rpc_show_header();
2848                                 header++;
2849                         }
2850                         rpc_show_task(clnt, task);
2851                 }
2852                 spin_unlock(&clnt->cl_lock);
2853         }
2854         spin_unlock(&sn->rpc_client_lock);
2855 }
2856 #endif
2857
2858 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2859 static int
2860 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2861                 struct rpc_xprt *xprt,
2862                 void *dummy)
2863 {
2864         return xprt_enable_swap(xprt);
2865 }
2866
2867 int
2868 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2869 {
2870         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2871                 return rpc_clnt_iterate_for_each_xprt(clnt,
2872                                 rpc_clnt_swap_activate_callback, NULL);
2873         return 0;
2874 }
2875 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2876
2877 static int
2878 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2879                 struct rpc_xprt *xprt,
2880                 void *dummy)
2881 {
2882         xprt_disable_swap(xprt);
2883         return 0;
2884 }
2885
2886 void
2887 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2888 {
2889         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2890                 rpc_clnt_iterate_for_each_xprt(clnt,
2891                                 rpc_clnt_swap_deactivate_callback, NULL);
2892 }
2893 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2894 #endif /* CONFIG_SUNRPC_SWAP */