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