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_call_rpcerror(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_reply_bytes_recvd = 0;
1866         req->rq_snd_buf.head[0].iov_len = 0;
1867         xdr_init_encode(&xdr, &req->rq_snd_buf,
1868                         req->rq_snd_buf.head[0].iov_base, req);
1869         xdr_free_bvec(&req->rq_snd_buf);
1870         if (rpc_encode_header(task, &xdr))
1871                 return;
1872
1873         task->tk_status = rpcauth_wrap_req(task, &xdr);
1874 }
1875
1876 /*
1877  * 3.   Encode arguments of an RPC call
1878  */
1879 static void
1880 call_encode(struct rpc_task *task)
1881 {
1882         if (!rpc_task_need_encode(task))
1883                 goto out;
1884         dprint_status(task);
1885         /* Dequeue task from the receive queue while we're encoding */
1886         xprt_request_dequeue_xprt(task);
1887         /* Encode here so that rpcsec_gss can use correct sequence number. */
1888         rpc_xdr_encode(task);
1889         /* Did the encode result in an error condition? */
1890         if (task->tk_status != 0) {
1891                 /* Was the error nonfatal? */
1892                 switch (task->tk_status) {
1893                 case -EAGAIN:
1894                 case -ENOMEM:
1895                         rpc_delay(task, HZ >> 4);
1896                         break;
1897                 case -EKEYEXPIRED:
1898                         if (!task->tk_cred_retry) {
1899                                 rpc_exit(task, task->tk_status);
1900                         } else {
1901                                 task->tk_action = call_refresh;
1902                                 task->tk_cred_retry--;
1903                                 dprintk("RPC: %5u %s: retry refresh creds\n",
1904                                         task->tk_pid, __func__);
1905                         }
1906                         break;
1907                 default:
1908                         rpc_call_rpcerror(task, task->tk_status);
1909                 }
1910                 return;
1911         }
1912
1913         /* Add task to reply queue before transmission to avoid races */
1914         if (rpc_reply_expected(task))
1915                 xprt_request_enqueue_receive(task);
1916         xprt_request_enqueue_transmit(task);
1917 out:
1918         task->tk_action = call_transmit;
1919         /* Check that the connection is OK */
1920         if (!xprt_bound(task->tk_xprt))
1921                 task->tk_action = call_bind;
1922         else if (!xprt_connected(task->tk_xprt))
1923                 task->tk_action = call_connect;
1924 }
1925
1926 /*
1927  * Helpers to check if the task was already transmitted, and
1928  * to take action when that is the case.
1929  */
1930 static bool
1931 rpc_task_transmitted(struct rpc_task *task)
1932 {
1933         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1934 }
1935
1936 static void
1937 rpc_task_handle_transmitted(struct rpc_task *task)
1938 {
1939         xprt_end_transmit(task);
1940         task->tk_action = call_transmit_status;
1941 }
1942
1943 /*
1944  * 4.   Get the server port number if not yet set
1945  */
1946 static void
1947 call_bind(struct rpc_task *task)
1948 {
1949         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1950
1951         if (rpc_task_transmitted(task)) {
1952                 rpc_task_handle_transmitted(task);
1953                 return;
1954         }
1955
1956         if (xprt_bound(xprt)) {
1957                 task->tk_action = call_connect;
1958                 return;
1959         }
1960
1961         dprint_status(task);
1962
1963         task->tk_action = call_bind_status;
1964         if (!xprt_prepare_transmit(task))
1965                 return;
1966
1967         xprt->ops->rpcbind(task);
1968 }
1969
1970 /*
1971  * 4a.  Sort out bind result
1972  */
1973 static void
1974 call_bind_status(struct rpc_task *task)
1975 {
1976         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1977         int status = -EIO;
1978
1979         if (rpc_task_transmitted(task)) {
1980                 rpc_task_handle_transmitted(task);
1981                 return;
1982         }
1983
1984         dprint_status(task);
1985         trace_rpc_bind_status(task);
1986         if (task->tk_status >= 0)
1987                 goto out_next;
1988         if (xprt_bound(xprt)) {
1989                 task->tk_status = 0;
1990                 goto out_next;
1991         }
1992
1993         switch (task->tk_status) {
1994         case -ENOMEM:
1995                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1996                 rpc_delay(task, HZ >> 2);
1997                 goto retry_timeout;
1998         case -EACCES:
1999                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
2000                                 "unavailable\n", task->tk_pid);
2001                 /* fail immediately if this is an RPC ping */
2002                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2003                         status = -EOPNOTSUPP;
2004                         break;
2005                 }
2006                 if (task->tk_rebind_retry == 0)
2007                         break;
2008                 task->tk_rebind_retry--;
2009                 rpc_delay(task, 3*HZ);
2010                 goto retry_timeout;
2011         case -ENOBUFS:
2012                 rpc_delay(task, HZ >> 2);
2013                 goto retry_timeout;
2014         case -EAGAIN:
2015                 goto retry_timeout;
2016         case -ETIMEDOUT:
2017                 dprintk("RPC: %5u rpcbind request timed out\n",
2018                                 task->tk_pid);
2019                 goto retry_timeout;
2020         case -EPFNOSUPPORT:
2021                 /* server doesn't support any rpcbind version we know of */
2022                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
2023                                 task->tk_pid);
2024                 break;
2025         case -EPROTONOSUPPORT:
2026                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
2027                                 task->tk_pid);
2028                 goto retry_timeout;
2029         case -ECONNREFUSED:             /* connection problems */
2030         case -ECONNRESET:
2031         case -ECONNABORTED:
2032         case -ENOTCONN:
2033         case -EHOSTDOWN:
2034         case -ENETDOWN:
2035         case -EHOSTUNREACH:
2036         case -ENETUNREACH:
2037         case -EPIPE:
2038                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
2039                                 task->tk_pid, task->tk_status);
2040                 if (!RPC_IS_SOFTCONN(task)) {
2041                         rpc_delay(task, 5*HZ);
2042                         goto retry_timeout;
2043                 }
2044                 status = task->tk_status;
2045                 break;
2046         default:
2047                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
2048                                 task->tk_pid, -task->tk_status);
2049         }
2050
2051         rpc_call_rpcerror(task, status);
2052         return;
2053 out_next:
2054         task->tk_action = call_connect;
2055         return;
2056 retry_timeout:
2057         task->tk_status = 0;
2058         task->tk_action = call_bind;
2059         rpc_check_timeout(task);
2060 }
2061
2062 /*
2063  * 4b.  Connect to the RPC server
2064  */
2065 static void
2066 call_connect(struct rpc_task *task)
2067 {
2068         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2069
2070         if (rpc_task_transmitted(task)) {
2071                 rpc_task_handle_transmitted(task);
2072                 return;
2073         }
2074
2075         if (xprt_connected(xprt)) {
2076                 task->tk_action = call_transmit;
2077                 return;
2078         }
2079
2080         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
2081                         task->tk_pid, xprt,
2082                         (xprt_connected(xprt) ? "is" : "is not"));
2083
2084         task->tk_action = call_connect_status;
2085         if (task->tk_status < 0)
2086                 return;
2087         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2088                 rpc_call_rpcerror(task, -ENOTCONN);
2089                 return;
2090         }
2091         if (!xprt_prepare_transmit(task))
2092                 return;
2093         xprt_connect(task);
2094 }
2095
2096 /*
2097  * 4c.  Sort out connect result
2098  */
2099 static void
2100 call_connect_status(struct rpc_task *task)
2101 {
2102         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2103         struct rpc_clnt *clnt = task->tk_client;
2104         int status = task->tk_status;
2105
2106         if (rpc_task_transmitted(task)) {
2107                 rpc_task_handle_transmitted(task);
2108                 return;
2109         }
2110
2111         dprint_status(task);
2112         trace_rpc_connect_status(task);
2113
2114         if (task->tk_status == 0) {
2115                 clnt->cl_stats->netreconn++;
2116                 goto out_next;
2117         }
2118         if (xprt_connected(xprt)) {
2119                 task->tk_status = 0;
2120                 goto out_next;
2121         }
2122
2123         task->tk_status = 0;
2124         switch (status) {
2125         case -ECONNREFUSED:
2126                 /* A positive refusal suggests a rebind is needed. */
2127                 if (RPC_IS_SOFTCONN(task))
2128                         break;
2129                 if (clnt->cl_autobind) {
2130                         rpc_force_rebind(clnt);
2131                         goto out_retry;
2132                 }
2133                 /* fall through */
2134         case -ECONNRESET:
2135         case -ECONNABORTED:
2136         case -ENETDOWN:
2137         case -ENETUNREACH:
2138         case -EHOSTUNREACH:
2139         case -EPIPE:
2140                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2141                                             task->tk_rqstp->rq_connect_cookie);
2142                 if (RPC_IS_SOFTCONN(task))
2143                         break;
2144                 /* retry with existing socket, after a delay */
2145                 rpc_delay(task, 3*HZ);
2146                 /* fall through */
2147         case -EADDRINUSE:
2148         case -ENOTCONN:
2149         case -EAGAIN:
2150         case -ETIMEDOUT:
2151                 goto out_retry;
2152         case -ENOBUFS:
2153                 rpc_delay(task, HZ >> 2);
2154                 goto out_retry;
2155         }
2156         rpc_call_rpcerror(task, status);
2157         return;
2158 out_next:
2159         task->tk_action = call_transmit;
2160         return;
2161 out_retry:
2162         /* Check for timeouts before looping back to call_bind */
2163         task->tk_action = call_bind;
2164         rpc_check_timeout(task);
2165 }
2166
2167 /*
2168  * 5.   Transmit the RPC request, and wait for reply
2169  */
2170 static void
2171 call_transmit(struct rpc_task *task)
2172 {
2173         if (rpc_task_transmitted(task)) {
2174                 rpc_task_handle_transmitted(task);
2175                 return;
2176         }
2177
2178         dprint_status(task);
2179
2180         task->tk_action = call_transmit_status;
2181         if (!xprt_prepare_transmit(task))
2182                 return;
2183         task->tk_status = 0;
2184         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2185                 if (!xprt_connected(task->tk_xprt)) {
2186                         task->tk_status = -ENOTCONN;
2187                         return;
2188                 }
2189                 xprt_transmit(task);
2190         }
2191         xprt_end_transmit(task);
2192 }
2193
2194 /*
2195  * 5a.  Handle cleanup after a transmission
2196  */
2197 static void
2198 call_transmit_status(struct rpc_task *task)
2199 {
2200         task->tk_action = call_status;
2201
2202         /*
2203          * Common case: success.  Force the compiler to put this
2204          * test first.
2205          */
2206         if (rpc_task_transmitted(task)) {
2207                 task->tk_status = 0;
2208                 xprt_request_wait_receive(task);
2209                 return;
2210         }
2211
2212         switch (task->tk_status) {
2213         default:
2214                 dprint_status(task);
2215                 break;
2216         case -EBADMSG:
2217                 task->tk_status = 0;
2218                 task->tk_action = call_encode;
2219                 break;
2220                 /*
2221                  * Special cases: if we've been waiting on the
2222                  * socket's write_space() callback, or if the
2223                  * socket just returned a connection error,
2224                  * then hold onto the transport lock.
2225                  */
2226         case -ENOBUFS:
2227                 rpc_delay(task, HZ>>2);
2228                 /* fall through */
2229         case -EBADSLT:
2230         case -EAGAIN:
2231                 task->tk_action = call_transmit;
2232                 task->tk_status = 0;
2233                 break;
2234         case -ECONNREFUSED:
2235         case -EHOSTDOWN:
2236         case -ENETDOWN:
2237         case -EHOSTUNREACH:
2238         case -ENETUNREACH:
2239         case -EPERM:
2240                 if (RPC_IS_SOFTCONN(task)) {
2241                         if (!task->tk_msg.rpc_proc->p_proc)
2242                                 trace_xprt_ping(task->tk_xprt,
2243                                                 task->tk_status);
2244                         rpc_call_rpcerror(task, task->tk_status);
2245                         return;
2246                 }
2247                 /* fall through */
2248         case -ECONNRESET:
2249         case -ECONNABORTED:
2250         case -EADDRINUSE:
2251         case -ENOTCONN:
2252         case -EPIPE:
2253                 task->tk_action = call_bind;
2254                 task->tk_status = 0;
2255                 break;
2256         }
2257         rpc_check_timeout(task);
2258 }
2259
2260 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2261 static void call_bc_transmit(struct rpc_task *task);
2262 static void call_bc_transmit_status(struct rpc_task *task);
2263
2264 static void
2265 call_bc_encode(struct rpc_task *task)
2266 {
2267         xprt_request_enqueue_transmit(task);
2268         task->tk_action = call_bc_transmit;
2269 }
2270
2271 /*
2272  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2273  * addition, disconnect on connectivity errors.
2274  */
2275 static void
2276 call_bc_transmit(struct rpc_task *task)
2277 {
2278         task->tk_action = call_bc_transmit_status;
2279         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2280                 if (!xprt_prepare_transmit(task))
2281                         return;
2282                 task->tk_status = 0;
2283                 xprt_transmit(task);
2284         }
2285         xprt_end_transmit(task);
2286 }
2287
2288 static void
2289 call_bc_transmit_status(struct rpc_task *task)
2290 {
2291         struct rpc_rqst *req = task->tk_rqstp;
2292
2293         if (rpc_task_transmitted(task))
2294                 task->tk_status = 0;
2295
2296         dprint_status(task);
2297
2298         switch (task->tk_status) {
2299         case 0:
2300                 /* Success */
2301         case -ENETDOWN:
2302         case -EHOSTDOWN:
2303         case -EHOSTUNREACH:
2304         case -ENETUNREACH:
2305         case -ECONNRESET:
2306         case -ECONNREFUSED:
2307         case -EADDRINUSE:
2308         case -ENOTCONN:
2309         case -EPIPE:
2310                 break;
2311         case -ENOBUFS:
2312                 rpc_delay(task, HZ>>2);
2313                 /* fall through */
2314         case -EBADSLT:
2315         case -EAGAIN:
2316                 task->tk_status = 0;
2317                 task->tk_action = call_bc_transmit;
2318                 return;
2319         case -ETIMEDOUT:
2320                 /*
2321                  * Problem reaching the server.  Disconnect and let the
2322                  * forechannel reestablish the connection.  The server will
2323                  * have to retransmit the backchannel request and we'll
2324                  * reprocess it.  Since these ops are idempotent, there's no
2325                  * need to cache our reply at this time.
2326                  */
2327                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2328                         "error: %d\n", task->tk_status);
2329                 xprt_conditional_disconnect(req->rq_xprt,
2330                         req->rq_connect_cookie);
2331                 break;
2332         default:
2333                 /*
2334                  * We were unable to reply and will have to drop the
2335                  * request.  The server should reconnect and retransmit.
2336                  */
2337                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2338                         "error: %d\n", task->tk_status);
2339                 break;
2340         }
2341         task->tk_action = rpc_exit_task;
2342 }
2343 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2344
2345 /*
2346  * 6.   Sort out the RPC call status
2347  */
2348 static void
2349 call_status(struct rpc_task *task)
2350 {
2351         struct rpc_clnt *clnt = task->tk_client;
2352         int             status;
2353
2354         if (!task->tk_msg.rpc_proc->p_proc)
2355                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2356
2357         dprint_status(task);
2358
2359         status = task->tk_status;
2360         if (status >= 0) {
2361                 task->tk_action = call_decode;
2362                 return;
2363         }
2364
2365         trace_rpc_call_status(task);
2366         task->tk_status = 0;
2367         switch(status) {
2368         case -EHOSTDOWN:
2369         case -ENETDOWN:
2370         case -EHOSTUNREACH:
2371         case -ENETUNREACH:
2372         case -EPERM:
2373                 if (RPC_IS_SOFTCONN(task))
2374                         goto out_exit;
2375                 /*
2376                  * Delay any retries for 3 seconds, then handle as if it
2377                  * were a timeout.
2378                  */
2379                 rpc_delay(task, 3*HZ);
2380                 /* fall through */
2381         case -ETIMEDOUT:
2382                 break;
2383         case -ECONNREFUSED:
2384         case -ECONNRESET:
2385         case -ECONNABORTED:
2386         case -ENOTCONN:
2387                 rpc_force_rebind(clnt);
2388                 break;
2389         case -EADDRINUSE:
2390                 rpc_delay(task, 3*HZ);
2391                 /* fall through */
2392         case -EPIPE:
2393         case -EAGAIN:
2394                 break;
2395         case -EIO:
2396                 /* shutdown or soft timeout */
2397                 goto out_exit;
2398         default:
2399                 if (clnt->cl_chatty)
2400                         printk("%s: RPC call returned error %d\n",
2401                                clnt->cl_program->name, -status);
2402                 goto out_exit;
2403         }
2404         task->tk_action = call_encode;
2405         rpc_check_timeout(task);
2406         return;
2407 out_exit:
2408         rpc_call_rpcerror(task, status);
2409 }
2410
2411 static bool
2412 rpc_check_connected(const struct rpc_rqst *req)
2413 {
2414         /* No allocated request or transport? return true */
2415         if (!req || !req->rq_xprt)
2416                 return true;
2417         return xprt_connected(req->rq_xprt);
2418 }
2419
2420 static void
2421 rpc_check_timeout(struct rpc_task *task)
2422 {
2423         struct rpc_clnt *clnt = task->tk_client;
2424
2425         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2426                 return;
2427
2428         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2429         task->tk_timeouts++;
2430
2431         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2432                 rpc_call_rpcerror(task, -ETIMEDOUT);
2433                 return;
2434         }
2435
2436         if (RPC_IS_SOFT(task)) {
2437                 /*
2438                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2439                  * been sent, it should time out only if the transport
2440                  * connection gets terminally broken.
2441                  */
2442                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2443                     rpc_check_connected(task->tk_rqstp))
2444                         return;
2445
2446                 if (clnt->cl_chatty) {
2447                         pr_notice_ratelimited(
2448                                 "%s: server %s not responding, timed out\n",
2449                                 clnt->cl_program->name,
2450                                 task->tk_xprt->servername);
2451                 }
2452                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2453                         rpc_call_rpcerror(task, -ETIMEDOUT);
2454                 else
2455                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2456                 return;
2457         }
2458
2459         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2460                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2461                 if (clnt->cl_chatty) {
2462                         pr_notice_ratelimited(
2463                                 "%s: server %s not responding, still trying\n",
2464                                 clnt->cl_program->name,
2465                                 task->tk_xprt->servername);
2466                 }
2467         }
2468         rpc_force_rebind(clnt);
2469         /*
2470          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2471          * event? RFC2203 requires the server to drop all such requests.
2472          */
2473         rpcauth_invalcred(task);
2474 }
2475
2476 /*
2477  * 7.   Decode the RPC reply
2478  */
2479 static void
2480 call_decode(struct rpc_task *task)
2481 {
2482         struct rpc_clnt *clnt = task->tk_client;
2483         struct rpc_rqst *req = task->tk_rqstp;
2484         struct xdr_stream xdr;
2485         int err;
2486
2487         dprint_status(task);
2488
2489         if (!task->tk_msg.rpc_proc->p_decode) {
2490                 task->tk_action = rpc_exit_task;
2491                 return;
2492         }
2493
2494         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2495                 if (clnt->cl_chatty) {
2496                         pr_notice_ratelimited("%s: server %s OK\n",
2497                                 clnt->cl_program->name,
2498                                 task->tk_xprt->servername);
2499                 }
2500                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2501         }
2502
2503         /*
2504          * Ensure that we see all writes made by xprt_complete_rqst()
2505          * before it changed req->rq_reply_bytes_recvd.
2506          */
2507         smp_rmb();
2508
2509         /*
2510          * Did we ever call xprt_complete_rqst()? If not, we should assume
2511          * the message is incomplete.
2512          */
2513         err = -EAGAIN;
2514         if (!req->rq_reply_bytes_recvd)
2515                 goto out;
2516
2517         req->rq_rcv_buf.len = req->rq_private_buf.len;
2518
2519         /* Check that the softirq receive buffer is valid */
2520         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2521                                 sizeof(req->rq_rcv_buf)) != 0);
2522
2523         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2524                         req->rq_rcv_buf.head[0].iov_base, req);
2525         err = rpc_decode_header(task, &xdr);
2526 out:
2527         switch (err) {
2528         case 0:
2529                 task->tk_action = rpc_exit_task;
2530                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2531                 dprintk("RPC: %5u %s result %d\n",
2532                         task->tk_pid, __func__, task->tk_status);
2533                 return;
2534         case -EAGAIN:
2535                 task->tk_status = 0;
2536                 if (task->tk_client->cl_discrtry)
2537                         xprt_conditional_disconnect(req->rq_xprt,
2538                                                     req->rq_connect_cookie);
2539                 task->tk_action = call_encode;
2540                 rpc_check_timeout(task);
2541                 break;
2542         case -EKEYREJECTED:
2543                 task->tk_action = call_reserve;
2544                 rpc_check_timeout(task);
2545                 rpcauth_invalcred(task);
2546                 /* Ensure we obtain a new XID if we retry! */
2547                 xprt_release(task);
2548         }
2549 }
2550
2551 static int
2552 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2553 {
2554         struct rpc_clnt *clnt = task->tk_client;
2555         struct rpc_rqst *req = task->tk_rqstp;
2556         __be32 *p;
2557         int error;
2558
2559         error = -EMSGSIZE;
2560         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2561         if (!p)
2562                 goto out_fail;
2563         *p++ = req->rq_xid;
2564         *p++ = rpc_call;
2565         *p++ = cpu_to_be32(RPC_VERSION);
2566         *p++ = cpu_to_be32(clnt->cl_prog);
2567         *p++ = cpu_to_be32(clnt->cl_vers);
2568         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2569
2570         error = rpcauth_marshcred(task, xdr);
2571         if (error < 0)
2572                 goto out_fail;
2573         return 0;
2574 out_fail:
2575         trace_rpc_bad_callhdr(task);
2576         rpc_call_rpcerror(task, error);
2577         return error;
2578 }
2579
2580 static noinline int
2581 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2582 {
2583         struct rpc_clnt *clnt = task->tk_client;
2584         int error;
2585         __be32 *p;
2586
2587         /* RFC-1014 says that the representation of XDR data must be a
2588          * multiple of four bytes
2589          * - if it isn't pointer subtraction in the NFS client may give
2590          *   undefined results
2591          */
2592         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2593                 goto out_unparsable;
2594
2595         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2596         if (!p)
2597                 goto out_unparsable;
2598         p++;    /* skip XID */
2599         if (*p++ != rpc_reply)
2600                 goto out_unparsable;
2601         if (*p++ != rpc_msg_accepted)
2602                 goto out_msg_denied;
2603
2604         error = rpcauth_checkverf(task, xdr);
2605         if (error)
2606                 goto out_verifier;
2607
2608         p = xdr_inline_decode(xdr, sizeof(*p));
2609         if (!p)
2610                 goto out_unparsable;
2611         switch (*p) {
2612         case rpc_success:
2613                 return 0;
2614         case rpc_prog_unavail:
2615                 trace_rpc__prog_unavail(task);
2616                 error = -EPFNOSUPPORT;
2617                 goto out_err;
2618         case rpc_prog_mismatch:
2619                 trace_rpc__prog_mismatch(task);
2620                 error = -EPROTONOSUPPORT;
2621                 goto out_err;
2622         case rpc_proc_unavail:
2623                 trace_rpc__proc_unavail(task);
2624                 error = -EOPNOTSUPP;
2625                 goto out_err;
2626         case rpc_garbage_args:
2627         case rpc_system_err:
2628                 trace_rpc__garbage_args(task);
2629                 error = -EIO;
2630                 break;
2631         default:
2632                 goto out_unparsable;
2633         }
2634
2635 out_garbage:
2636         clnt->cl_stats->rpcgarbage++;
2637         if (task->tk_garb_retry) {
2638                 task->tk_garb_retry--;
2639                 task->tk_action = call_encode;
2640                 return -EAGAIN;
2641         }
2642 out_err:
2643         rpc_call_rpcerror(task, error);
2644         return error;
2645
2646 out_unparsable:
2647         trace_rpc__unparsable(task);
2648         error = -EIO;
2649         goto out_garbage;
2650
2651 out_verifier:
2652         trace_rpc_bad_verifier(task);
2653         goto out_garbage;
2654
2655 out_msg_denied:
2656         error = -EACCES;
2657         p = xdr_inline_decode(xdr, sizeof(*p));
2658         if (!p)
2659                 goto out_unparsable;
2660         switch (*p++) {
2661         case rpc_auth_error:
2662                 break;
2663         case rpc_mismatch:
2664                 trace_rpc__mismatch(task);
2665                 error = -EPROTONOSUPPORT;
2666                 goto out_err;
2667         default:
2668                 goto out_unparsable;
2669         }
2670
2671         p = xdr_inline_decode(xdr, sizeof(*p));
2672         if (!p)
2673                 goto out_unparsable;
2674         switch (*p++) {
2675         case rpc_autherr_rejectedcred:
2676         case rpc_autherr_rejectedverf:
2677         case rpcsec_gsserr_credproblem:
2678         case rpcsec_gsserr_ctxproblem:
2679                 if (!task->tk_cred_retry)
2680                         break;
2681                 task->tk_cred_retry--;
2682                 trace_rpc__stale_creds(task);
2683                 return -EKEYREJECTED;
2684         case rpc_autherr_badcred:
2685         case rpc_autherr_badverf:
2686                 /* possibly garbled cred/verf? */
2687                 if (!task->tk_garb_retry)
2688                         break;
2689                 task->tk_garb_retry--;
2690                 trace_rpc__bad_creds(task);
2691                 task->tk_action = call_encode;
2692                 return -EAGAIN;
2693         case rpc_autherr_tooweak:
2694                 trace_rpc__auth_tooweak(task);
2695                 pr_warn("RPC: server %s requires stronger authentication.\n",
2696                         task->tk_xprt->servername);
2697                 break;
2698         default:
2699                 goto out_unparsable;
2700         }
2701         goto out_err;
2702 }
2703
2704 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2705                 const void *obj)
2706 {
2707 }
2708
2709 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2710                 void *obj)
2711 {
2712         return 0;
2713 }
2714
2715 static const struct rpc_procinfo rpcproc_null = {
2716         .p_encode = rpcproc_encode_null,
2717         .p_decode = rpcproc_decode_null,
2718 };
2719
2720 static int rpc_ping(struct rpc_clnt *clnt)
2721 {
2722         struct rpc_message msg = {
2723                 .rpc_proc = &rpcproc_null,
2724         };
2725         int err;
2726         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2727                             RPC_TASK_NULLCREDS);
2728         return err;
2729 }
2730
2731 static
2732 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2733                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2734                 const struct rpc_call_ops *ops, void *data)
2735 {
2736         struct rpc_message msg = {
2737                 .rpc_proc = &rpcproc_null,
2738         };
2739         struct rpc_task_setup task_setup_data = {
2740                 .rpc_client = clnt,
2741                 .rpc_xprt = xprt,
2742                 .rpc_message = &msg,
2743                 .rpc_op_cred = cred,
2744                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2745                 .callback_data = data,
2746                 .flags = flags | RPC_TASK_NULLCREDS,
2747         };
2748
2749         return rpc_run_task(&task_setup_data);
2750 }
2751
2752 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2753 {
2754         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2755 }
2756 EXPORT_SYMBOL_GPL(rpc_call_null);
2757
2758 struct rpc_cb_add_xprt_calldata {
2759         struct rpc_xprt_switch *xps;
2760         struct rpc_xprt *xprt;
2761 };
2762
2763 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2764 {
2765         struct rpc_cb_add_xprt_calldata *data = calldata;
2766
2767         if (task->tk_status == 0)
2768                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2769 }
2770
2771 static void rpc_cb_add_xprt_release(void *calldata)
2772 {
2773         struct rpc_cb_add_xprt_calldata *data = calldata;
2774
2775         xprt_put(data->xprt);
2776         xprt_switch_put(data->xps);
2777         kfree(data);
2778 }
2779
2780 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2781         .rpc_call_done = rpc_cb_add_xprt_done,
2782         .rpc_release = rpc_cb_add_xprt_release,
2783 };
2784
2785 /**
2786  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2787  * @clnt: pointer to struct rpc_clnt
2788  * @xps: pointer to struct rpc_xprt_switch,
2789  * @xprt: pointer struct rpc_xprt
2790  * @dummy: unused
2791  */
2792 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2793                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2794                 void *dummy)
2795 {
2796         struct rpc_cb_add_xprt_calldata *data;
2797         struct rpc_task *task;
2798
2799         data = kmalloc(sizeof(*data), GFP_NOFS);
2800         if (!data)
2801                 return -ENOMEM;
2802         data->xps = xprt_switch_get(xps);
2803         data->xprt = xprt_get(xprt);
2804         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2805                 rpc_cb_add_xprt_release(data);
2806                 goto success;
2807         }
2808
2809         task = rpc_call_null_helper(clnt, xprt, NULL,
2810                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
2811                         &rpc_cb_add_xprt_call_ops, data);
2812         if (IS_ERR(task))
2813                 return PTR_ERR(task);
2814         rpc_put_task(task);
2815 success:
2816         return 1;
2817 }
2818 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2819
2820 /**
2821  * rpc_clnt_setup_test_and_add_xprt()
2822  *
2823  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2824  *   1) caller of the test function must dereference the rpc_xprt_switch
2825  *   and the rpc_xprt.
2826  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2827  *   the rpc_call_done routine.
2828  *
2829  * Upon success (return of 1), the test function adds the new
2830  * transport to the rpc_clnt xprt switch
2831  *
2832  * @clnt: struct rpc_clnt to get the new transport
2833  * @xps:  the rpc_xprt_switch to hold the new transport
2834  * @xprt: the rpc_xprt to test
2835  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2836  *        and test function call data
2837  */
2838 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2839                                      struct rpc_xprt_switch *xps,
2840                                      struct rpc_xprt *xprt,
2841                                      void *data)
2842 {
2843         struct rpc_task *task;
2844         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2845         int status = -EADDRINUSE;
2846
2847         xprt = xprt_get(xprt);
2848         xprt_switch_get(xps);
2849
2850         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2851                 goto out_err;
2852
2853         /* Test the connection */
2854         task = rpc_call_null_helper(clnt, xprt, NULL,
2855                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2856                                     NULL, NULL);
2857         if (IS_ERR(task)) {
2858                 status = PTR_ERR(task);
2859                 goto out_err;
2860         }
2861         status = task->tk_status;
2862         rpc_put_task(task);
2863
2864         if (status < 0)
2865                 goto out_err;
2866
2867         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2868         xtest->add_xprt_test(clnt, xprt, xtest->data);
2869
2870         xprt_put(xprt);
2871         xprt_switch_put(xps);
2872
2873         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2874         return 1;
2875 out_err:
2876         xprt_put(xprt);
2877         xprt_switch_put(xps);
2878         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2879                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2880         return status;
2881 }
2882 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2883
2884 /**
2885  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2886  * @clnt: pointer to struct rpc_clnt
2887  * @xprtargs: pointer to struct xprt_create
2888  * @setup: callback to test and/or set up the connection
2889  * @data: pointer to setup function data
2890  *
2891  * Creates a new transport using the parameters set in args and
2892  * adds it to clnt.
2893  * If ping is set, then test that connectivity succeeds before
2894  * adding the new transport.
2895  *
2896  */
2897 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2898                 struct xprt_create *xprtargs,
2899                 int (*setup)(struct rpc_clnt *,
2900                         struct rpc_xprt_switch *,
2901                         struct rpc_xprt *,
2902                         void *),
2903                 void *data)
2904 {
2905         struct rpc_xprt_switch *xps;
2906         struct rpc_xprt *xprt;
2907         unsigned long connect_timeout;
2908         unsigned long reconnect_timeout;
2909         unsigned char resvport;
2910         int ret = 0;
2911
2912         rcu_read_lock();
2913         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2914         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2915         if (xps == NULL || xprt == NULL) {
2916                 rcu_read_unlock();
2917                 xprt_switch_put(xps);
2918                 return -EAGAIN;
2919         }
2920         resvport = xprt->resvport;
2921         connect_timeout = xprt->connect_timeout;
2922         reconnect_timeout = xprt->max_reconnect_timeout;
2923         rcu_read_unlock();
2924
2925         xprt = xprt_create_transport(xprtargs);
2926         if (IS_ERR(xprt)) {
2927                 ret = PTR_ERR(xprt);
2928                 goto out_put_switch;
2929         }
2930         xprt->resvport = resvport;
2931         if (xprt->ops->set_connect_timeout != NULL)
2932                 xprt->ops->set_connect_timeout(xprt,
2933                                 connect_timeout,
2934                                 reconnect_timeout);
2935
2936         rpc_xprt_switch_set_roundrobin(xps);
2937         if (setup) {
2938                 ret = setup(clnt, xps, xprt, data);
2939                 if (ret != 0)
2940                         goto out_put_xprt;
2941         }
2942         rpc_xprt_switch_add_xprt(xps, xprt);
2943 out_put_xprt:
2944         xprt_put(xprt);
2945 out_put_switch:
2946         xprt_switch_put(xps);
2947         return ret;
2948 }
2949 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2950
2951 struct connect_timeout_data {
2952         unsigned long connect_timeout;
2953         unsigned long reconnect_timeout;
2954 };
2955
2956 static int
2957 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2958                 struct rpc_xprt *xprt,
2959                 void *data)
2960 {
2961         struct connect_timeout_data *timeo = data;
2962
2963         if (xprt->ops->set_connect_timeout)
2964                 xprt->ops->set_connect_timeout(xprt,
2965                                 timeo->connect_timeout,
2966                                 timeo->reconnect_timeout);
2967         return 0;
2968 }
2969
2970 void
2971 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2972                 unsigned long connect_timeout,
2973                 unsigned long reconnect_timeout)
2974 {
2975         struct connect_timeout_data timeout = {
2976                 .connect_timeout = connect_timeout,
2977                 .reconnect_timeout = reconnect_timeout,
2978         };
2979         rpc_clnt_iterate_for_each_xprt(clnt,
2980                         rpc_xprt_set_connect_timeout,
2981                         &timeout);
2982 }
2983 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2984
2985 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2986 {
2987         rcu_read_lock();
2988         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2989         rcu_read_unlock();
2990 }
2991 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2992
2993 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2994 {
2995         rcu_read_lock();
2996         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2997                                  xprt);
2998         rcu_read_unlock();
2999 }
3000 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3001
3002 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3003                                    const struct sockaddr *sap)
3004 {
3005         struct rpc_xprt_switch *xps;
3006         bool ret;
3007
3008         rcu_read_lock();
3009         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3010         ret = rpc_xprt_switch_has_addr(xps, sap);
3011         rcu_read_unlock();
3012         return ret;
3013 }
3014 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3015
3016 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3017 static void rpc_show_header(void)
3018 {
3019         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3020                 "-timeout ---ops--\n");
3021 }
3022
3023 static void rpc_show_task(const struct rpc_clnt *clnt,
3024                           const struct rpc_task *task)
3025 {
3026         const char *rpc_waitq = "none";
3027
3028         if (RPC_IS_QUEUED(task))
3029                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3030
3031         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3032                 task->tk_pid, task->tk_flags, task->tk_status,
3033                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3034                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3035                 task->tk_action, rpc_waitq);
3036 }
3037
3038 void rpc_show_tasks(struct net *net)
3039 {
3040         struct rpc_clnt *clnt;
3041         struct rpc_task *task;
3042         int header = 0;
3043         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3044
3045         spin_lock(&sn->rpc_client_lock);
3046         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3047                 spin_lock(&clnt->cl_lock);
3048                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3049                         if (!header) {
3050                                 rpc_show_header();
3051                                 header++;
3052                         }
3053                         rpc_show_task(clnt, task);
3054                 }
3055                 spin_unlock(&clnt->cl_lock);
3056         }
3057         spin_unlock(&sn->rpc_client_lock);
3058 }
3059 #endif
3060
3061 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3062 static int
3063 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3064                 struct rpc_xprt *xprt,
3065                 void *dummy)
3066 {
3067         return xprt_enable_swap(xprt);
3068 }
3069
3070 int
3071 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3072 {
3073         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3074                 return rpc_clnt_iterate_for_each_xprt(clnt,
3075                                 rpc_clnt_swap_activate_callback, NULL);
3076         return 0;
3077 }
3078 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3079
3080 static int
3081 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3082                 struct rpc_xprt *xprt,
3083                 void *dummy)
3084 {
3085         xprt_disable_swap(xprt);
3086         return 0;
3087 }
3088
3089 void
3090 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3091 {
3092         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3093                 rpc_clnt_iterate_for_each_xprt(clnt,
3094                                 rpc_clnt_swap_deactivate_callback, NULL);
3095 }
3096 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3097 #endif /* CONFIG_SUNRPC_SWAP */