net/sunrpc/clnt.c

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