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 <[email protected]>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <[email protected]>
  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         err = rpciod_up();
 374         if (err)
 375                 goto out_no_rpciod;
 376
 377         err = -EINVAL;
 378         if (args->version >= program->nrvers)
 379                 goto out_err;
 380         version = program->version[args->version];
 381         if (version == NULL)
 382                 goto out_err;
 383
 384         err = -ENOMEM;
 385         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 386         if (!clnt)
 387                 goto out_err;
 388         clnt->cl_parent = parent ? : clnt;
 389
 390         err = rpc_alloc_clid(clnt);
 391         if (err)
 392                 goto out_no_clid;
 393
 394         clnt->cl_cred     = get_cred(args->cred);
 395         clnt->cl_procinfo = version->procs;
 396         clnt->cl_maxproc  = version->nrprocs;
 397         clnt->cl_prog     = args->prognumber ? : program->number;
 398         clnt->cl_vers     = version->number;
 399         clnt->cl_stats    = program->stats;
 400         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 401         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 402         err = -ENOMEM;
 403         if (clnt->cl_metrics == NULL)
 404                 goto out_no_stats;
 405         clnt->cl_program  = program;
 406         INIT_LIST_HEAD(&clnt->cl_tasks);
 407         spin_lock_init(&clnt->cl_lock);
 408
 409         timeout = xprt->timeout;
 410         if (args->timeout != NULL) {
 411                 memcpy(&clnt->cl_timeout_default, args->timeout,
 412                                 sizeof(clnt->cl_timeout_default));
 413                 timeout = &clnt->cl_timeout_default;
 414         }
 415
 416         rpc_clnt_set_transport(clnt, xprt, timeout);
 417         xprt_iter_init(&clnt->cl_xpi, xps);
 418         xprt_switch_put(xps);
 419
 420         clnt->cl_rtt = &clnt->cl_rtt_default;
 421         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 422
 423         atomic_set(&clnt->cl_count, 1);
 424
 425         if (nodename == NULL)
 426                 nodename = utsname()->nodename;
 427         /* save the nodename */
 428         rpc_clnt_set_nodename(clnt, nodename);
 429
 430         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 431         if (err)
 432                 goto out_no_path;
 433         if (parent)
 434                 atomic_inc(&parent->cl_count);
 435
 436         trace_rpc_clnt_new(clnt, xprt, program->name, args->servername);
 437         return clnt;
 438
 439 out_no_path:
 440         rpc_free_iostats(clnt->cl_metrics);
 441 out_no_stats:
 442         put_cred(clnt->cl_cred);
 443         rpc_free_clid(clnt);
 444 out_no_clid:
 445         kfree(clnt);
 446 out_err:
 447         rpciod_down();
 448 out_no_rpciod:
 449         xprt_switch_put(xps);
 450         xprt_put(xprt);
 451         trace_rpc_clnt_new_err(program->name, args->servername, err);
 452         return ERR_PTR(err);
 453 }
 454
 455 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 456                                         struct rpc_xprt *xprt)
 457 {
 458         struct rpc_clnt *clnt = NULL;
 459         struct rpc_xprt_switch *xps;
 460
 461         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 462                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 463                 xps = args->bc_xprt->xpt_bc_xps;
 464                 xprt_switch_get(xps);
 465         } else {
 466                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 467                 if (xps == NULL) {
 468                         xprt_put(xprt);
 469                         return ERR_PTR(-ENOMEM);
 470                 }
 471                 if (xprt->bc_xprt) {
 472                         xprt_switch_get(xps);
 473                         xprt->bc_xprt->xpt_bc_xps = xps;
 474                 }
 475         }
 476         clnt = rpc_new_client(args, xps, xprt, NULL);
 477         if (IS_ERR(clnt))
 478                 return clnt;
 479
 480         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 481                 int err = rpc_ping(clnt);
 482                 if (err != 0) {
 483                         rpc_shutdown_client(clnt);
 484                         return ERR_PTR(err);
 485                 }
 486         }
 487
 488         clnt->cl_softrtry = 1;
 489         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 490                 clnt->cl_softrtry = 0;
 491                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 492                         clnt->cl_softerr = 1;
 493         }
 494
 495         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 496                 clnt->cl_autobind = 1;
 497         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 498                 clnt->cl_noretranstimeo = 1;
 499         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 500                 clnt->cl_discrtry = 1;
 501         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 502                 clnt->cl_chatty = 1;
 503
 504         return clnt;
 505 }
 506
 507 /**
 508  * rpc_create - create an RPC client and transport with one call
 509  * @args: rpc_clnt create argument structure
 510  *
 511  * Creates and initializes an RPC transport and an RPC client.
 512  *
 513  * It can ping the server in order to determine if it is up, and to see if
 514  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 515  * this behavior so asynchronous tasks can also use rpc_create.
 516  */
 517 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 518 {
 519         struct rpc_xprt *xprt;
 520         struct xprt_create xprtargs = {
 521                 .net = args->net,
 522                 .ident = args->protocol,
 523                 .srcaddr = args->saddress,
 524                 .dstaddr = args->address,
 525                 .addrlen = args->addrsize,
 526                 .servername = args->servername,
 527                 .bc_xprt = args->bc_xprt,
 528         };
 529         char servername[48];
 530         struct rpc_clnt *clnt;
 531         int i;
 532
 533         if (args->bc_xprt) {
 534                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 535                 xprt = args->bc_xprt->xpt_bc_xprt;
 536                 if (xprt) {
 537                         xprt_get(xprt);
 538                         return rpc_create_xprt(args, xprt);
 539                 }
 540         }
 541
 542         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 543                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 544         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 545                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 546         /*
 547          * If the caller chooses not to specify a hostname, whip
 548          * up a string representation of the passed-in address.
 549          */
 550         if (xprtargs.servername == NULL) {
 551                 struct sockaddr_un *sun =
 552                                 (struct sockaddr_un *)args->address;
 553                 struct sockaddr_in *sin =
 554                                 (struct sockaddr_in *)args->address;
 555                 struct sockaddr_in6 *sin6 =
 556                                 (struct sockaddr_in6 *)args->address;
 557
 558                 servername[0] = '\0';
 559                 switch (args->address->sa_family) {
 560                 case AF_LOCAL:
 561                         snprintf(servername, sizeof(servername), "%s",
 562                                  sun->sun_path);
 563                         break;
 564                 case AF_INET:
 565                         snprintf(servername, sizeof(servername), "%pI4",
 566                                  &sin->sin_addr.s_addr);
 567                         break;
 568                 case AF_INET6:
 569                         snprintf(servername, sizeof(servername), "%pI6",
 570                                  &sin6->sin6_addr);
 571                         break;
 572                 default:
 573                         /* caller wants default server name, but
 574                          * address family isn't recognized. */
 575                         return ERR_PTR(-EINVAL);
 576                 }
 577                 xprtargs.servername = servername;
 578         }
 579
 580         xprt = xprt_create_transport(&xprtargs);
 581         if (IS_ERR(xprt))
 582                 return (struct rpc_clnt *)xprt;
 583
 584         /*
 585          * By default, kernel RPC client connects from a reserved port.
 586          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 587          * but it is always enabled for rpciod, which handles the connect
 588          * operation.
 589          */
 590         xprt->resvport = 1;
 591         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 592                 xprt->resvport = 0;
 593         xprt->reuseport = 0;
 594         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 595                 xprt->reuseport = 1;
 596
 597         clnt = rpc_create_xprt(args, xprt);
 598         if (IS_ERR(clnt) || args->nconnect <= 1)
 599                 return clnt;
 600
 601         for (i = 0; i < args->nconnect - 1; i++) {
 602                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 603                         break;
 604         }
 605         return clnt;
 606 }
 607 EXPORT_SYMBOL_GPL(rpc_create);
 608
 609 /*
 610  * This function clones the RPC client structure. It allows us to share the
 611  * same transport while varying parameters such as the authentication
 612  * flavour.
 613  */
 614 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 615                                            struct rpc_clnt *clnt)
 616 {
 617         struct rpc_xprt_switch *xps;
 618         struct rpc_xprt *xprt;
 619         struct rpc_clnt *new;
 620         int err;
 621
 622         err = -ENOMEM;
 623         rcu_read_lock();
 624         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 625         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 626         rcu_read_unlock();
 627         if (xprt == NULL || xps == NULL) {
 628                 xprt_put(xprt);
 629                 xprt_switch_put(xps);
 630                 goto out_err;
 631         }
 632         args->servername = xprt->servername;
 633         args->nodename = clnt->cl_nodename;
 634
 635         new = rpc_new_client(args, xps, xprt, clnt);
 636         if (IS_ERR(new))
 637                 return new;
 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         trace_rpc_clnt_clone_err(clnt, 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                 return PTR_ERR(xprt);
 725
 726         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 727         if (xps == NULL) {
 728                 xprt_put(xprt);
 729                 return -ENOMEM;
 730         }
 731
 732         pseudoflavor = clnt->cl_auth->au_flavor;
 733
 734         old_timeo = clnt->cl_timeout;
 735         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 736         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 737
 738         rpc_unregister_client(clnt);
 739         __rpc_clnt_remove_pipedir(clnt);
 740         rpc_clnt_debugfs_unregister(clnt);
 741
 742         /*
 743          * A new transport was created.  "clnt" therefore
 744          * becomes the root of a new cl_parent tree.  clnt's
 745          * children, if it has any, still point to the old xprt.
 746          */
 747         parent = clnt->cl_parent;
 748         clnt->cl_parent = clnt;
 749
 750         /*
 751          * The old rpc_auth cache cannot be re-used.  GSS
 752          * contexts in particular are between a single
 753          * client and server.
 754          */
 755         err = rpc_client_register(clnt, pseudoflavor, NULL);
 756         if (err)
 757                 goto out_revert;
 758
 759         synchronize_rcu();
 760         if (parent != clnt)
 761                 rpc_release_client(parent);
 762         xprt_switch_put(oldxps);
 763         xprt_put(old);
 764         trace_rpc_clnt_replace_xprt(clnt);
 765         return 0;
 766
 767 out_revert:
 768         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 769         rpc_clnt_set_transport(clnt, old, old_timeo);
 770         clnt->cl_parent = parent;
 771         rpc_client_register(clnt, pseudoflavor, NULL);
 772         xprt_switch_put(xps);
 773         xprt_put(xprt);
 774         trace_rpc_clnt_replace_xprt_err(clnt);
 775         return err;
 776 }
 777 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 778
 779 static
 780 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 781 {
 782         struct rpc_xprt_switch *xps;
 783
 784         rcu_read_lock();
 785         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 786         rcu_read_unlock();
 787         if (xps == NULL)
 788                 return -EAGAIN;
 789         xprt_iter_init_listall(xpi, xps);
 790         xprt_switch_put(xps);
 791         return 0;
 792 }
 793
 794 /**
 795  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 796  * @clnt: pointer to client
 797  * @fn: function to apply
 798  * @data: void pointer to function data
 799  *
 800  * Iterates through the list of RPC transports currently attached to the
 801  * client and applies the function fn(clnt, xprt, data).
 802  *
 803  * On error, the iteration stops, and the function returns the error value.
 804  */
 805 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 806                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 807                 void *data)
 808 {
 809         struct rpc_xprt_iter xpi;
 810         int ret;
 811
 812         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 813         if (ret)
 814                 return ret;
 815         for (;;) {
 816                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 817
 818                 if (!xprt)
 819                         break;
 820                 ret = fn(clnt, xprt, data);
 821                 xprt_put(xprt);
 822                 if (ret < 0)
 823                         break;
 824         }
 825         xprt_iter_destroy(&xpi);
 826         return ret;
 827 }
 828 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 829
 830 /*
 831  * Kill all tasks for the given client.
 832  * XXX: kill their descendants as well?
 833  */
 834 void rpc_killall_tasks(struct rpc_clnt *clnt)
 835 {
 836         struct rpc_task *rovr;
 837
 838
 839         if (list_empty(&clnt->cl_tasks))
 840                 return;
 841
 842         /*
 843          * Spin lock all_tasks to prevent changes...
 844          */
 845         trace_rpc_clnt_killall(clnt);
 846         spin_lock(&clnt->cl_lock);
 847         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 848                 rpc_signal_task(rovr);
 849         spin_unlock(&clnt->cl_lock);
 850 }
 851 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 852
 853 /*
 854  * Properly shut down an RPC client, terminating all outstanding
 855  * requests.
 856  */
 857 void rpc_shutdown_client(struct rpc_clnt *clnt)
 858 {
 859         might_sleep();
 860
 861         trace_rpc_clnt_shutdown(clnt);
 862
 863         while (!list_empty(&clnt->cl_tasks)) {
 864                 rpc_killall_tasks(clnt);
 865                 wait_event_timeout(destroy_wait,
 866                         list_empty(&clnt->cl_tasks), 1*HZ);
 867         }
 868
 869         rpc_release_client(clnt);
 870 }
 871 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 872
 873 /*
 874  * Free an RPC client
 875  */
 876 static void rpc_free_client_work(struct work_struct *work)
 877 {
 878         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 879
 880         trace_rpc_clnt_free(clnt);
 881
 882         /* These might block on processes that might allocate memory,
 883          * so they cannot be called in rpciod, so they are handled separately
 884          * here.
 885          */
 886         rpc_clnt_debugfs_unregister(clnt);
 887         rpc_free_clid(clnt);
 888         rpc_clnt_remove_pipedir(clnt);
 889         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 890
 891         kfree(clnt);
 892         rpciod_down();
 893 }
 894 static struct rpc_clnt *
 895 rpc_free_client(struct rpc_clnt *clnt)
 896 {
 897         struct rpc_clnt *parent = NULL;
 898
 899         trace_rpc_clnt_release(clnt);
 900         if (clnt->cl_parent != clnt)
 901                 parent = clnt->cl_parent;
 902         rpc_unregister_client(clnt);
 903         rpc_free_iostats(clnt->cl_metrics);
 904         clnt->cl_metrics = NULL;
 905         xprt_iter_destroy(&clnt->cl_xpi);
 906         put_cred(clnt->cl_cred);
 907
 908         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 909         schedule_work(&clnt->cl_work);
 910         return parent;
 911 }
 912
 913 /*
 914  * Free an RPC client
 915  */
 916 static struct rpc_clnt *
 917 rpc_free_auth(struct rpc_clnt *clnt)
 918 {
 919         if (clnt->cl_auth == NULL)
 920                 return rpc_free_client(clnt);
 921
 922         /*
 923          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 924          *       release remaining GSS contexts. This mechanism ensures
 925          *       that it can do so safely.
 926          */
 927         atomic_inc(&clnt->cl_count);
 928         rpcauth_release(clnt->cl_auth);
 929         clnt->cl_auth = NULL;
 930         if (atomic_dec_and_test(&clnt->cl_count))
 931                 return rpc_free_client(clnt);
 932         return NULL;
 933 }
 934
 935 /*
 936  * Release reference to the RPC client
 937  */
 938 void
 939 rpc_release_client(struct rpc_clnt *clnt)
 940 {
 941         do {
 942                 if (list_empty(&clnt->cl_tasks))
 943                         wake_up(&destroy_wait);
 944                 if (!atomic_dec_and_test(&clnt->cl_count))
 945                         break;
 946                 clnt = rpc_free_auth(clnt);
 947         } while (clnt != NULL);
 948 }
 949 EXPORT_SYMBOL_GPL(rpc_release_client);
 950
 951 /**
 952  * rpc_bind_new_program - bind a new RPC program to an existing client
 953  * @old: old rpc_client
 954  * @program: rpc program to set
 955  * @vers: rpc program version
 956  *
 957  * Clones the rpc client and sets up a new RPC program. This is mainly
 958  * of use for enabling different RPC programs to share the same transport.
 959  * The Sun NFSv2/v3 ACL protocol can do this.
 960  */
 961 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 962                                       const struct rpc_program *program,
 963                                       u32 vers)
 964 {
 965         struct rpc_create_args args = {
 966                 .program        = program,
 967                 .prognumber     = program->number,
 968                 .version        = vers,
 969                 .authflavor     = old->cl_auth->au_flavor,
 970                 .cred           = old->cl_cred,
 971         };
 972         struct rpc_clnt *clnt;
 973         int err;
 974
 975         clnt = __rpc_clone_client(&args, old);
 976         if (IS_ERR(clnt))
 977                 goto out;
 978         err = rpc_ping(clnt);
 979         if (err != 0) {
 980                 rpc_shutdown_client(clnt);
 981                 clnt = ERR_PTR(err);
 982         }
 983 out:
 984         return clnt;
 985 }
 986 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 987
 988 struct rpc_xprt *
 989 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 990 {
 991         struct rpc_xprt_switch *xps;
 992
 993         if (!xprt)
 994                 return NULL;
 995         rcu_read_lock();
 996         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
 997         atomic_long_inc(&xps->xps_queuelen);
 998         rcu_read_unlock();
 999         atomic_long_inc(&xprt->queuelen);
1000
1001         return xprt;
1002 }
1003
1004 static void
1005 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1006 {
1007         struct rpc_xprt_switch *xps;
1008
1009         atomic_long_dec(&xprt->queuelen);
1010         rcu_read_lock();
1011         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1012         atomic_long_dec(&xps->xps_queuelen);
1013         rcu_read_unlock();
1014
1015         xprt_put(xprt);
1016 }
1017
1018 void rpc_task_release_transport(struct rpc_task *task)
1019 {
1020         struct rpc_xprt *xprt = task->tk_xprt;
1021
1022         if (xprt) {
1023                 task->tk_xprt = NULL;
1024                 if (task->tk_client)
1025                         rpc_task_release_xprt(task->tk_client, xprt);
1026                 else
1027                         xprt_put(xprt);
1028         }
1029 }
1030 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1031
1032 void rpc_task_release_client(struct rpc_task *task)
1033 {
1034         struct rpc_clnt *clnt = task->tk_client;
1035
1036         rpc_task_release_transport(task);
1037         if (clnt != NULL) {
1038                 /* Remove from client task list */
1039                 spin_lock(&clnt->cl_lock);
1040                 list_del(&task->tk_task);
1041                 spin_unlock(&clnt->cl_lock);
1042                 task->tk_client = NULL;
1043
1044                 rpc_release_client(clnt);
1045         }
1046 }
1047
1048 static struct rpc_xprt *
1049 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1050 {
1051         struct rpc_xprt *xprt;
1052
1053         rcu_read_lock();
1054         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1055         rcu_read_unlock();
1056         return rpc_task_get_xprt(clnt, xprt);
1057 }
1058
1059 static struct rpc_xprt *
1060 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1061 {
1062         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1063 }
1064
1065 static
1066 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1067 {
1068         if (task->tk_xprt)
1069                 return;
1070         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1071                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1072         else
1073                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1074 }
1075
1076 static
1077 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1078 {
1079
1080         if (clnt != NULL) {
1081                 rpc_task_set_transport(task, clnt);
1082                 task->tk_client = clnt;
1083                 atomic_inc(&clnt->cl_count);
1084                 if (clnt->cl_softrtry)
1085                         task->tk_flags |= RPC_TASK_SOFT;
1086                 if (clnt->cl_softerr)
1087                         task->tk_flags |= RPC_TASK_TIMEOUT;
1088                 if (clnt->cl_noretranstimeo)
1089                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1090                 if (atomic_read(&clnt->cl_swapper))
1091                         task->tk_flags |= RPC_TASK_SWAPPER;
1092                 /* Add to the client's list of all tasks */
1093                 spin_lock(&clnt->cl_lock);
1094                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1095                 spin_unlock(&clnt->cl_lock);
1096         }
1097 }
1098
1099 static void
1100 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1101 {
1102         if (msg != NULL) {
1103                 task->tk_msg.rpc_proc = msg->rpc_proc;
1104                 task->tk_msg.rpc_argp = msg->rpc_argp;
1105                 task->tk_msg.rpc_resp = msg->rpc_resp;
1106                 task->tk_msg.rpc_cred = msg->rpc_cred;
1107                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1108                         get_cred(task->tk_msg.rpc_cred);
1109         }
1110 }
1111
1112 /*
1113  * Default callback for async RPC calls
1114  */
1115 static void
1116 rpc_default_callback(struct rpc_task *task, void *data)
1117 {
1118 }
1119
1120 static const struct rpc_call_ops rpc_default_ops = {
1121         .rpc_call_done = rpc_default_callback,
1122 };
1123
1124 /**
1125  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1126  * @task_setup_data: pointer to task initialisation data
1127  */
1128 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1129 {
1130         struct rpc_task *task;
1131
1132         task = rpc_new_task(task_setup_data);
1133
1134         if (!RPC_IS_ASYNC(task))
1135                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1136
1137         rpc_task_set_client(task, task_setup_data->rpc_client);
1138         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1139
1140         if (task->tk_action == NULL)
1141                 rpc_call_start(task);
1142
1143         atomic_inc(&task->tk_count);
1144         rpc_execute(task);
1145         return task;
1146 }
1147 EXPORT_SYMBOL_GPL(rpc_run_task);
1148
1149 /**
1150  * rpc_call_sync - Perform a synchronous RPC call
1151  * @clnt: pointer to RPC client
1152  * @msg: RPC call parameters
1153  * @flags: RPC call flags
1154  */
1155 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1156 {
1157         struct rpc_task *task;
1158         struct rpc_task_setup task_setup_data = {
1159                 .rpc_client = clnt,
1160                 .rpc_message = msg,
1161                 .callback_ops = &rpc_default_ops,
1162                 .flags = flags,
1163         };
1164         int status;
1165
1166         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1167         if (flags & RPC_TASK_ASYNC) {
1168                 rpc_release_calldata(task_setup_data.callback_ops,
1169                         task_setup_data.callback_data);
1170                 return -EINVAL;
1171         }
1172
1173         task = rpc_run_task(&task_setup_data);
1174         if (IS_ERR(task))
1175                 return PTR_ERR(task);
1176         status = task->tk_status;
1177         rpc_put_task(task);
1178         return status;
1179 }
1180 EXPORT_SYMBOL_GPL(rpc_call_sync);
1181
1182 /**
1183  * rpc_call_async - Perform an asynchronous RPC call
1184  * @clnt: pointer to RPC client
1185  * @msg: RPC call parameters
1186  * @flags: RPC call flags
1187  * @tk_ops: RPC call ops
1188  * @data: user call data
1189  */
1190 int
1191 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1192                const struct rpc_call_ops *tk_ops, void *data)
1193 {
1194         struct rpc_task *task;
1195         struct rpc_task_setup task_setup_data = {
1196                 .rpc_client = clnt,
1197                 .rpc_message = msg,
1198                 .callback_ops = tk_ops,
1199                 .callback_data = data,
1200                 .flags = flags|RPC_TASK_ASYNC,
1201         };
1202
1203         task = rpc_run_task(&task_setup_data);
1204         if (IS_ERR(task))
1205                 return PTR_ERR(task);
1206         rpc_put_task(task);
1207         return 0;
1208 }
1209 EXPORT_SYMBOL_GPL(rpc_call_async);
1210
1211 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1212 static void call_bc_encode(struct rpc_task *task);
1213
1214 /**
1215  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1216  * rpc_execute against it
1217  * @req: RPC request
1218  */
1219 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1220 {
1221         struct rpc_task *task;
1222         struct rpc_task_setup task_setup_data = {
1223                 .callback_ops = &rpc_default_ops,
1224                 .flags = RPC_TASK_SOFTCONN |
1225                         RPC_TASK_NO_RETRANS_TIMEOUT,
1226         };
1227
1228         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1229         /*
1230          * Create an rpc_task to send the data
1231          */
1232         task = rpc_new_task(&task_setup_data);
1233         xprt_init_bc_request(req, task);
1234
1235         task->tk_action = call_bc_encode;
1236         atomic_inc(&task->tk_count);
1237         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1238         rpc_execute(task);
1239
1240         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1241         return task;
1242 }
1243 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1244
1245 /**
1246  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1247  * @req: RPC request to prepare
1248  * @pages: vector of struct page pointers
1249  * @base: offset in first page where receive should start, in bytes
1250  * @len: expected size of the upper layer data payload, in bytes
1251  * @hdrsize: expected size of upper layer reply header, in XDR words
1252  *
1253  */
1254 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1255                              unsigned int base, unsigned int len,
1256                              unsigned int hdrsize)
1257 {
1258         /* Subtract one to force an extra word of buffer space for the
1259          * payload's XDR pad to fall into the rcv_buf's tail iovec.
1260          */
1261         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
1262
1263         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1264         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1265 }
1266 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1267
1268 void
1269 rpc_call_start(struct rpc_task *task)
1270 {
1271         task->tk_action = call_start;
1272 }
1273 EXPORT_SYMBOL_GPL(rpc_call_start);
1274
1275 /**
1276  * rpc_peeraddr - extract remote peer address from clnt's xprt
1277  * @clnt: RPC client structure
1278  * @buf: target buffer
1279  * @bufsize: length of target buffer
1280  *
1281  * Returns the number of bytes that are actually in the stored address.
1282  */
1283 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1284 {
1285         size_t bytes;
1286         struct rpc_xprt *xprt;
1287
1288         rcu_read_lock();
1289         xprt = rcu_dereference(clnt->cl_xprt);
1290
1291         bytes = xprt->addrlen;
1292         if (bytes > bufsize)
1293                 bytes = bufsize;
1294         memcpy(buf, &xprt->addr, bytes);
1295         rcu_read_unlock();
1296
1297         return bytes;
1298 }
1299 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1300
1301 /**
1302  * rpc_peeraddr2str - return remote peer address in printable format
1303  * @clnt: RPC client structure
1304  * @format: address format
1305  *
1306  * NB: the lifetime of the memory referenced by the returned pointer is
1307  * the same as the rpc_xprt itself.  As long as the caller uses this
1308  * pointer, it must hold the RCU read lock.
1309  */
1310 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1311                              enum rpc_display_format_t format)
1312 {
1313         struct rpc_xprt *xprt;
1314
1315         xprt = rcu_dereference(clnt->cl_xprt);
1316
1317         if (xprt->address_strings[format] != NULL)
1318                 return xprt->address_strings[format];
1319         else
1320                 return "unprintable";
1321 }
1322 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1323
1324 static const struct sockaddr_in rpc_inaddr_loopback = {
1325         .sin_family             = AF_INET,
1326         .sin_addr.s_addr        = htonl(INADDR_ANY),
1327 };
1328
1329 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1330         .sin6_family            = AF_INET6,
1331         .sin6_addr              = IN6ADDR_ANY_INIT,
1332 };
1333
1334 /*
1335  * Try a getsockname() on a connected datagram socket.  Using a
1336  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1337  * This conserves the ephemeral port number space.
1338  *
1339  * Returns zero and fills in "buf" if successful; otherwise, a
1340  * negative errno is returned.
1341  */
1342 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1343                         struct sockaddr *buf)
1344 {
1345         struct socket *sock;
1346         int err;
1347
1348         err = __sock_create(net, sap->sa_family,
1349                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1350         if (err < 0) {
1351                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1352                 goto out;
1353         }
1354
1355         switch (sap->sa_family) {
1356         case AF_INET:
1357                 err = kernel_bind(sock,
1358                                 (struct sockaddr *)&rpc_inaddr_loopback,
1359                                 sizeof(rpc_inaddr_loopback));
1360                 break;
1361         case AF_INET6:
1362                 err = kernel_bind(sock,
1363                                 (struct sockaddr *)&rpc_in6addr_loopback,
1364                                 sizeof(rpc_in6addr_loopback));
1365                 break;
1366         default:
1367                 err = -EAFNOSUPPORT;
1368                 goto out;
1369         }
1370         if (err < 0) {
1371                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1372                 goto out_release;
1373         }
1374
1375         err = kernel_connect(sock, sap, salen, 0);
1376         if (err < 0) {
1377                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1378                 goto out_release;
1379         }
1380
1381         err = kernel_getsockname(sock, buf);
1382         if (err < 0) {
1383                 dprintk("RPC:       getsockname failed (%d)\n", err);
1384                 goto out_release;
1385         }
1386
1387         err = 0;
1388         if (buf->sa_family == AF_INET6) {
1389                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1390                 sin6->sin6_scope_id = 0;
1391         }
1392         dprintk("RPC:       %s succeeded\n", __func__);
1393
1394 out_release:
1395         sock_release(sock);
1396 out:
1397         return err;
1398 }
1399
1400 /*
1401  * Scraping a connected socket failed, so we don't have a useable
1402  * local address.  Fallback: generate an address that will prevent
1403  * the server from calling us back.
1404  *
1405  * Returns zero and fills in "buf" if successful; otherwise, a
1406  * negative errno is returned.
1407  */
1408 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1409 {
1410         switch (family) {
1411         case AF_INET:
1412                 if (buflen < sizeof(rpc_inaddr_loopback))
1413                         return -EINVAL;
1414                 memcpy(buf, &rpc_inaddr_loopback,
1415                                 sizeof(rpc_inaddr_loopback));
1416                 break;
1417         case AF_INET6:
1418                 if (buflen < sizeof(rpc_in6addr_loopback))
1419                         return -EINVAL;
1420                 memcpy(buf, &rpc_in6addr_loopback,
1421                                 sizeof(rpc_in6addr_loopback));
1422                 break;
1423         default:
1424                 dprintk("RPC:       %s: address family not supported\n",
1425                         __func__);
1426                 return -EAFNOSUPPORT;
1427         }
1428         dprintk("RPC:       %s: succeeded\n", __func__);
1429         return 0;
1430 }
1431
1432 /**
1433  * rpc_localaddr - discover local endpoint address for an RPC client
1434  * @clnt: RPC client structure
1435  * @buf: target buffer
1436  * @buflen: size of target buffer, in bytes
1437  *
1438  * Returns zero and fills in "buf" and "buflen" if successful;
1439  * otherwise, a negative errno is returned.
1440  *
1441  * This works even if the underlying transport is not currently connected,
1442  * or if the upper layer never previously provided a source address.
1443  *
1444  * The result of this function call is transient: multiple calls in
1445  * succession may give different results, depending on how local
1446  * networking configuration changes over time.
1447  */
1448 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1449 {
1450         struct sockaddr_storage address;
1451         struct sockaddr *sap = (struct sockaddr *)&address;
1452         struct rpc_xprt *xprt;
1453         struct net *net;
1454         size_t salen;
1455         int err;
1456
1457         rcu_read_lock();
1458         xprt = rcu_dereference(clnt->cl_xprt);
1459         salen = xprt->addrlen;
1460         memcpy(sap, &xprt->addr, salen);
1461         net = get_net(xprt->xprt_net);
1462         rcu_read_unlock();
1463
1464         rpc_set_port(sap, 0);
1465         err = rpc_sockname(net, sap, salen, buf);
1466         put_net(net);
1467         if (err != 0)
1468                 /* Couldn't discover local address, return ANYADDR */
1469                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1470         return 0;
1471 }
1472 EXPORT_SYMBOL_GPL(rpc_localaddr);
1473
1474 void
1475 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1476 {
1477         struct rpc_xprt *xprt;
1478
1479         rcu_read_lock();
1480         xprt = rcu_dereference(clnt->cl_xprt);
1481         if (xprt->ops->set_buffer_size)
1482                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1483         rcu_read_unlock();
1484 }
1485 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1486
1487 /**
1488  * rpc_net_ns - Get the network namespace for this RPC client
1489  * @clnt: RPC client to query
1490  *
1491  */
1492 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1493 {
1494         struct net *ret;
1495
1496         rcu_read_lock();
1497         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1498         rcu_read_unlock();
1499         return ret;
1500 }
1501 EXPORT_SYMBOL_GPL(rpc_net_ns);
1502
1503 /**
1504  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1505  * @clnt: RPC client to query
1506  *
1507  * For stream transports, this is one RPC record fragment (see RFC
1508  * 1831), as we don't support multi-record requests yet.  For datagram
1509  * transports, this is the size of an IP packet minus the IP, UDP, and
1510  * RPC header sizes.
1511  */
1512 size_t rpc_max_payload(struct rpc_clnt *clnt)
1513 {
1514         size_t ret;
1515
1516         rcu_read_lock();
1517         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1518         rcu_read_unlock();
1519         return ret;
1520 }
1521 EXPORT_SYMBOL_GPL(rpc_max_payload);
1522
1523 /**
1524  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1525  * @clnt: RPC client to query
1526  */
1527 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1528 {
1529         struct rpc_xprt *xprt;
1530         size_t ret;
1531
1532         rcu_read_lock();
1533         xprt = rcu_dereference(clnt->cl_xprt);
1534         ret = xprt->ops->bc_maxpayload(xprt);
1535         rcu_read_unlock();
1536         return ret;
1537 }
1538 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1539
1540 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1541 {
1542         struct rpc_xprt *xprt;
1543         unsigned int ret;
1544
1545         rcu_read_lock();
1546         xprt = rcu_dereference(clnt->cl_xprt);
1547         ret = xprt->ops->bc_num_slots(xprt);
1548         rcu_read_unlock();
1549         return ret;
1550 }
1551 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1552
1553 /**
1554  * rpc_force_rebind - force transport to check that remote port is unchanged
1555  * @clnt: client to rebind
1556  *
1557  */
1558 void rpc_force_rebind(struct rpc_clnt *clnt)
1559 {
1560         if (clnt->cl_autobind) {
1561                 rcu_read_lock();
1562                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1563                 rcu_read_unlock();
1564         }
1565 }
1566 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1567
1568 static int
1569 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1570 {
1571         task->tk_status = 0;
1572         task->tk_rpc_status = 0;
1573         task->tk_action = action;
1574         return 1;
1575 }
1576
1577 /*
1578  * Restart an (async) RPC call. Usually called from within the
1579  * exit handler.
1580  */
1581 int
1582 rpc_restart_call(struct rpc_task *task)
1583 {
1584         return __rpc_restart_call(task, call_start);
1585 }
1586 EXPORT_SYMBOL_GPL(rpc_restart_call);
1587
1588 /*
1589  * Restart an (async) RPC call from the call_prepare state.
1590  * Usually called from within the exit handler.
1591  */
1592 int
1593 rpc_restart_call_prepare(struct rpc_task *task)
1594 {
1595         if (task->tk_ops->rpc_call_prepare != NULL)
1596                 return __rpc_restart_call(task, rpc_prepare_task);
1597         return rpc_restart_call(task);
1598 }
1599 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1600
1601 const char
1602 *rpc_proc_name(const struct rpc_task *task)
1603 {
1604         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1605
1606         if (proc) {
1607                 if (proc->p_name)
1608                         return proc->p_name;
1609                 else
1610                         return "NULL";
1611         } else
1612                 return "no proc";
1613 }
1614
1615 static void
1616 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1617 {
1618         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1619         task->tk_rpc_status = rpc_status;
1620         rpc_exit(task, tk_status);
1621 }
1622
1623 static void
1624 rpc_call_rpcerror(struct rpc_task *task, int status)
1625 {
1626         __rpc_call_rpcerror(task, status, status);
1627 }
1628
1629 /*
1630  * 0.  Initial state
1631  *
1632  *     Other FSM states can be visited zero or more times, but
1633  *     this state is visited exactly once for each RPC.
1634  */
1635 static void
1636 call_start(struct rpc_task *task)
1637 {
1638         struct rpc_clnt *clnt = task->tk_client;
1639         int idx = task->tk_msg.rpc_proc->p_statidx;
1640
1641         trace_rpc_request(task);
1642         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1643                         clnt->cl_program->name, clnt->cl_vers,
1644                         rpc_proc_name(task),
1645                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1646
1647         /* Increment call count (version might not be valid for ping) */
1648         if (clnt->cl_program->version[clnt->cl_vers])
1649                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1650         clnt->cl_stats->rpccnt++;
1651         task->tk_action = call_reserve;
1652         rpc_task_set_transport(task, clnt);
1653 }
1654
1655 /*
1656  * 1.   Reserve an RPC call slot
1657  */
1658 static void
1659 call_reserve(struct rpc_task *task)
1660 {
1661         dprint_status(task);
1662
1663         task->tk_status  = 0;
1664         task->tk_action  = call_reserveresult;
1665         xprt_reserve(task);
1666 }
1667
1668 static void call_retry_reserve(struct rpc_task *task);
1669
1670 /*
1671  * 1b.  Grok the result of xprt_reserve()
1672  */
1673 static void
1674 call_reserveresult(struct rpc_task *task)
1675 {
1676         int status = task->tk_status;
1677
1678         dprint_status(task);
1679
1680         /*
1681          * After a call to xprt_reserve(), we must have either
1682          * a request slot or else an error status.
1683          */
1684         task->tk_status = 0;
1685         if (status >= 0) {
1686                 if (task->tk_rqstp) {
1687                         task->tk_action = call_refresh;
1688                         return;
1689                 }
1690
1691                 rpc_call_rpcerror(task, -EIO);
1692                 return;
1693         }
1694
1695         /*
1696          * Even though there was an error, we may have acquired
1697          * a request slot somehow.  Make sure not to leak it.
1698          */
1699         if (task->tk_rqstp)
1700                 xprt_release(task);
1701
1702         switch (status) {
1703         case -ENOMEM:
1704                 rpc_delay(task, HZ >> 2);
1705                 /* fall through */
1706         case -EAGAIN:   /* woken up; retry */
1707                 task->tk_action = call_retry_reserve;
1708                 return;
1709         default:
1710                 rpc_call_rpcerror(task, status);
1711         }
1712 }
1713
1714 /*
1715  * 1c.  Retry reserving an RPC call slot
1716  */
1717 static void
1718 call_retry_reserve(struct rpc_task *task)
1719 {
1720         dprint_status(task);
1721
1722         task->tk_status  = 0;
1723         task->tk_action  = call_reserveresult;
1724         xprt_retry_reserve(task);
1725 }
1726
1727 /*
1728  * 2.   Bind and/or refresh the credentials
1729  */
1730 static void
1731 call_refresh(struct rpc_task *task)
1732 {
1733         dprint_status(task);
1734
1735         task->tk_action = call_refreshresult;
1736         task->tk_status = 0;
1737         task->tk_client->cl_stats->rpcauthrefresh++;
1738         rpcauth_refreshcred(task);
1739 }
1740
1741 /*
1742  * 2a.  Process the results of a credential refresh
1743  */
1744 static void
1745 call_refreshresult(struct rpc_task *task)
1746 {
1747         int status = task->tk_status;
1748
1749         dprint_status(task);
1750
1751         task->tk_status = 0;
1752         task->tk_action = call_refresh;
1753         switch (status) {
1754         case 0:
1755                 if (rpcauth_uptodatecred(task)) {
1756                         task->tk_action = call_allocate;
1757                         return;
1758                 }
1759                 /* Use rate-limiting and a max number of retries if refresh
1760                  * had status 0 but failed to update the cred.
1761                  */
1762                 /* fall through */
1763         case -ETIMEDOUT:
1764                 rpc_delay(task, 3*HZ);
1765                 /* fall through */
1766         case -EAGAIN:
1767                 status = -EACCES;
1768                 /* fall through */
1769         case -EKEYEXPIRED:
1770                 if (!task->tk_cred_retry)
1771                         break;
1772                 task->tk_cred_retry--;
1773                 dprintk("RPC: %5u %s: retry refresh creds\n",
1774                                 task->tk_pid, __func__);
1775                 return;
1776         }
1777         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1778                                 task->tk_pid, __func__, status);
1779         rpc_call_rpcerror(task, status);
1780 }
1781
1782 /*
1783  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1784  *      (Note: buffer memory is freed in xprt_release).
1785  */
1786 static void
1787 call_allocate(struct rpc_task *task)
1788 {
1789         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1790         struct rpc_rqst *req = task->tk_rqstp;
1791         struct rpc_xprt *xprt = req->rq_xprt;
1792         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1793         int status;
1794
1795         dprint_status(task);
1796
1797         task->tk_status = 0;
1798         task->tk_action = call_encode;
1799
1800         if (req->rq_buffer)
1801                 return;
1802
1803         if (proc->p_proc != 0) {
1804                 BUG_ON(proc->p_arglen == 0);
1805                 if (proc->p_decode != NULL)
1806                         BUG_ON(proc->p_replen == 0);
1807         }
1808
1809         /*
1810          * Calculate the size (in quads) of the RPC call
1811          * and reply headers, and convert both values
1812          * to byte sizes.
1813          */
1814         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1815                            proc->p_arglen;
1816         req->rq_callsize <<= 2;
1817         /*
1818          * Note: the reply buffer must at minimum allocate enough space
1819          * for the 'struct accepted_reply' from RFC5531.
1820          */
1821         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1822                         max_t(size_t, proc->p_replen, 2);
1823         req->rq_rcvsize <<= 2;
1824
1825         status = xprt->ops->buf_alloc(task);
1826         xprt_inject_disconnect(xprt);
1827         if (status == 0)
1828                 return;
1829         if (status != -ENOMEM) {
1830                 rpc_call_rpcerror(task, status);
1831                 return;
1832         }
1833
1834         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1835
1836         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1837                 task->tk_action = call_allocate;
1838                 rpc_delay(task, HZ>>4);
1839                 return;
1840         }
1841
1842         rpc_call_rpcerror(task, -ERESTARTSYS);
1843 }
1844
1845 static int
1846 rpc_task_need_encode(struct rpc_task *task)
1847 {
1848         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1849                 (!(task->tk_flags & RPC_TASK_SENT) ||
1850                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1851                  xprt_request_need_retransmit(task));
1852 }
1853
1854 static void
1855 rpc_xdr_encode(struct rpc_task *task)
1856 {
1857         struct rpc_rqst *req = task->tk_rqstp;
1858         struct xdr_stream xdr;
1859
1860         xdr_buf_init(&req->rq_snd_buf,
1861                      req->rq_buffer,
1862                      req->rq_callsize);
1863         xdr_buf_init(&req->rq_rcv_buf,
1864                      req->rq_rbuffer,
1865                      req->rq_rcvsize);
1866
1867         req->rq_reply_bytes_recvd = 0;
1868         req->rq_snd_buf.head[0].iov_len = 0;
1869         xdr_init_encode(&xdr, &req->rq_snd_buf,
1870                         req->rq_snd_buf.head[0].iov_base, req);
1871         xdr_free_bvec(&req->rq_snd_buf);
1872         if (rpc_encode_header(task, &xdr))
1873                 return;
1874
1875         task->tk_status = rpcauth_wrap_req(task, &xdr);
1876 }
1877
1878 /*
1879  * 3.   Encode arguments of an RPC call
1880  */
1881 static void
1882 call_encode(struct rpc_task *task)
1883 {
1884         if (!rpc_task_need_encode(task))
1885                 goto out;
1886         dprint_status(task);
1887         /* Dequeue task from the receive queue while we're encoding */
1888         xprt_request_dequeue_xprt(task);
1889         /* Encode here so that rpcsec_gss can use correct sequence number. */
1890         rpc_xdr_encode(task);
1891         /* Did the encode result in an error condition? */
1892         if (task->tk_status != 0) {
1893                 /* Was the error nonfatal? */
1894                 switch (task->tk_status) {
1895                 case -EAGAIN:
1896                 case -ENOMEM:
1897                         rpc_delay(task, HZ >> 4);
1898                         break;
1899                 case -EKEYEXPIRED:
1900                         if (!task->tk_cred_retry) {
1901                                 rpc_exit(task, task->tk_status);
1902                         } else {
1903                                 task->tk_action = call_refresh;
1904                                 task->tk_cred_retry--;
1905                                 dprintk("RPC: %5u %s: retry refresh creds\n",
1906                                         task->tk_pid, __func__);
1907                         }
1908                         break;
1909                 default:
1910                         rpc_call_rpcerror(task, task->tk_status);
1911                 }
1912                 return;
1913         }
1914
1915         /* Add task to reply queue before transmission to avoid races */
1916         if (rpc_reply_expected(task))
1917                 xprt_request_enqueue_receive(task);
1918         xprt_request_enqueue_transmit(task);
1919 out:
1920         task->tk_action = call_transmit;
1921         /* Check that the connection is OK */
1922         if (!xprt_bound(task->tk_xprt))
1923                 task->tk_action = call_bind;
1924         else if (!xprt_connected(task->tk_xprt))
1925                 task->tk_action = call_connect;
1926 }
1927
1928 /*
1929  * Helpers to check if the task was already transmitted, and
1930  * to take action when that is the case.
1931  */
1932 static bool
1933 rpc_task_transmitted(struct rpc_task *task)
1934 {
1935         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1936 }
1937
1938 static void
1939 rpc_task_handle_transmitted(struct rpc_task *task)
1940 {
1941         xprt_end_transmit(task);
1942         task->tk_action = call_transmit_status;
1943 }
1944
1945 /*
1946  * 4.   Get the server port number if not yet set
1947  */
1948 static void
1949 call_bind(struct rpc_task *task)
1950 {
1951         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1952
1953         if (rpc_task_transmitted(task)) {
1954                 rpc_task_handle_transmitted(task);
1955                 return;
1956         }
1957
1958         if (xprt_bound(xprt)) {
1959                 task->tk_action = call_connect;
1960                 return;
1961         }
1962
1963         dprint_status(task);
1964
1965         task->tk_action = call_bind_status;
1966         if (!xprt_prepare_transmit(task))
1967                 return;
1968
1969         xprt->ops->rpcbind(task);
1970 }
1971
1972 /*
1973  * 4a.  Sort out bind result
1974  */
1975 static void
1976 call_bind_status(struct rpc_task *task)
1977 {
1978         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1979         int status = -EIO;
1980
1981         if (rpc_task_transmitted(task)) {
1982                 rpc_task_handle_transmitted(task);
1983                 return;
1984         }
1985
1986         dprint_status(task);
1987         trace_rpc_bind_status(task);
1988         if (task->tk_status >= 0)
1989                 goto out_next;
1990         if (xprt_bound(xprt)) {
1991                 task->tk_status = 0;
1992                 goto out_next;
1993         }
1994
1995         switch (task->tk_status) {
1996         case -ENOMEM:
1997                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1998                 rpc_delay(task, HZ >> 2);
1999                 goto retry_timeout;
2000         case -EACCES:
2001                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
2002                                 "unavailable\n", task->tk_pid);
2003                 /* fail immediately if this is an RPC ping */
2004                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2005                         status = -EOPNOTSUPP;
2006                         break;
2007                 }
2008                 if (task->tk_rebind_retry == 0)
2009                         break;
2010                 task->tk_rebind_retry--;
2011                 rpc_delay(task, 3*HZ);
2012                 goto retry_timeout;
2013         case -ENOBUFS:
2014                 rpc_delay(task, HZ >> 2);
2015                 goto retry_timeout;
2016         case -EAGAIN:
2017                 goto retry_timeout;
2018         case -ETIMEDOUT:
2019                 dprintk("RPC: %5u rpcbind request timed out\n",
2020                                 task->tk_pid);
2021                 goto retry_timeout;
2022         case -EPFNOSUPPORT:
2023                 /* server doesn't support any rpcbind version we know of */
2024                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
2025                                 task->tk_pid);
2026                 break;
2027         case -EPROTONOSUPPORT:
2028                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
2029                                 task->tk_pid);
2030                 goto retry_timeout;
2031         case -ECONNREFUSED:             /* connection problems */
2032         case -ECONNRESET:
2033         case -ECONNABORTED:
2034         case -ENOTCONN:
2035         case -EHOSTDOWN:
2036         case -ENETDOWN:
2037         case -EHOSTUNREACH:
2038         case -ENETUNREACH:
2039         case -EPIPE:
2040                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
2041                                 task->tk_pid, task->tk_status);
2042                 if (!RPC_IS_SOFTCONN(task)) {
2043                         rpc_delay(task, 5*HZ);
2044                         goto retry_timeout;
2045                 }
2046                 status = task->tk_status;
2047                 break;
2048         default:
2049                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
2050                                 task->tk_pid, -task->tk_status);
2051         }
2052
2053         rpc_call_rpcerror(task, status);
2054         return;
2055 out_next:
2056         task->tk_action = call_connect;
2057         return;
2058 retry_timeout:
2059         task->tk_status = 0;
2060         task->tk_action = call_bind;
2061         rpc_check_timeout(task);
2062 }
2063
2064 /*
2065  * 4b.  Connect to the RPC server
2066  */
2067 static void
2068 call_connect(struct rpc_task *task)
2069 {
2070         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2071
2072         if (rpc_task_transmitted(task)) {
2073                 rpc_task_handle_transmitted(task);
2074                 return;
2075         }
2076
2077         if (xprt_connected(xprt)) {
2078                 task->tk_action = call_transmit;
2079                 return;
2080         }
2081
2082         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
2083                         task->tk_pid, xprt,
2084                         (xprt_connected(xprt) ? "is" : "is not"));
2085
2086         task->tk_action = call_connect_status;
2087         if (task->tk_status < 0)
2088                 return;
2089         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2090                 rpc_call_rpcerror(task, -ENOTCONN);
2091                 return;
2092         }
2093         if (!xprt_prepare_transmit(task))
2094                 return;
2095         xprt_connect(task);
2096 }
2097
2098 /*
2099  * 4c.  Sort out connect result
2100  */
2101 static void
2102 call_connect_status(struct rpc_task *task)
2103 {
2104         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2105         struct rpc_clnt *clnt = task->tk_client;
2106         int status = task->tk_status;
2107
2108         if (rpc_task_transmitted(task)) {
2109                 rpc_task_handle_transmitted(task);
2110                 return;
2111         }
2112
2113         dprint_status(task);
2114         trace_rpc_connect_status(task);
2115
2116         if (task->tk_status == 0) {
2117                 clnt->cl_stats->netreconn++;
2118                 goto out_next;
2119         }
2120         if (xprt_connected(xprt)) {
2121                 task->tk_status = 0;
2122                 goto out_next;
2123         }
2124
2125         task->tk_status = 0;
2126         switch (status) {
2127         case -ECONNREFUSED:
2128                 /* A positive refusal suggests a rebind is needed. */
2129                 if (RPC_IS_SOFTCONN(task))
2130                         break;
2131                 if (clnt->cl_autobind) {
2132                         rpc_force_rebind(clnt);
2133                         goto out_retry;
2134                 }
2135                 /* fall through */
2136         case -ECONNRESET:
2137         case -ECONNABORTED:
2138         case -ENETDOWN:
2139         case -ENETUNREACH:
2140         case -EHOSTUNREACH:
2141         case -EPIPE:
2142         case -EPROTO:
2143                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2144                                             task->tk_rqstp->rq_connect_cookie);
2145                 if (RPC_IS_SOFTCONN(task))
2146                         break;
2147                 /* retry with existing socket, after a delay */
2148                 rpc_delay(task, 3*HZ);
2149                 /* fall through */
2150         case -EADDRINUSE:
2151         case -ENOTCONN:
2152         case -EAGAIN:
2153         case -ETIMEDOUT:
2154                 goto out_retry;
2155         case -ENOBUFS:
2156                 rpc_delay(task, HZ >> 2);
2157                 goto out_retry;
2158         }
2159         rpc_call_rpcerror(task, status);
2160         return;
2161 out_next:
2162         task->tk_action = call_transmit;
2163         return;
2164 out_retry:
2165         /* Check for timeouts before looping back to call_bind */
2166         task->tk_action = call_bind;
2167         rpc_check_timeout(task);
2168 }
2169
2170 /*
2171  * 5.   Transmit the RPC request, and wait for reply
2172  */
2173 static void
2174 call_transmit(struct rpc_task *task)
2175 {
2176         if (rpc_task_transmitted(task)) {
2177                 rpc_task_handle_transmitted(task);
2178                 return;
2179         }
2180
2181         dprint_status(task);
2182
2183         task->tk_action = call_transmit_status;
2184         if (!xprt_prepare_transmit(task))
2185                 return;
2186         task->tk_status = 0;
2187         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2188                 if (!xprt_connected(task->tk_xprt)) {
2189                         task->tk_status = -ENOTCONN;
2190                         return;
2191                 }
2192                 xprt_transmit(task);
2193         }
2194         xprt_end_transmit(task);
2195 }
2196
2197 /*
2198  * 5a.  Handle cleanup after a transmission
2199  */
2200 static void
2201 call_transmit_status(struct rpc_task *task)
2202 {
2203         task->tk_action = call_status;
2204
2205         /*
2206          * Common case: success.  Force the compiler to put this
2207          * test first.
2208          */
2209         if (rpc_task_transmitted(task)) {
2210                 task->tk_status = 0;
2211                 xprt_request_wait_receive(task);
2212                 return;
2213         }
2214
2215         switch (task->tk_status) {
2216         default:
2217                 dprint_status(task);
2218                 break;
2219         case -EBADMSG:
2220                 task->tk_status = 0;
2221                 task->tk_action = call_encode;
2222                 break;
2223                 /*
2224                  * Special cases: if we've been waiting on the
2225                  * socket's write_space() callback, or if the
2226                  * socket just returned a connection error,
2227                  * then hold onto the transport lock.
2228                  */
2229         case -ENOBUFS:
2230                 rpc_delay(task, HZ>>2);
2231                 /* fall through */
2232         case -EBADSLT:
2233         case -EAGAIN:
2234                 task->tk_action = call_transmit;
2235                 task->tk_status = 0;
2236                 break;
2237         case -ECONNREFUSED:
2238         case -EHOSTDOWN:
2239         case -ENETDOWN:
2240         case -EHOSTUNREACH:
2241         case -ENETUNREACH:
2242         case -EPERM:
2243                 if (RPC_IS_SOFTCONN(task)) {
2244                         if (!task->tk_msg.rpc_proc->p_proc)
2245                                 trace_xprt_ping(task->tk_xprt,
2246                                                 task->tk_status);
2247                         rpc_call_rpcerror(task, task->tk_status);
2248                         return;
2249                 }
2250                 /* fall through */
2251         case -ECONNRESET:
2252         case -ECONNABORTED:
2253         case -EADDRINUSE:
2254         case -ENOTCONN:
2255         case -EPIPE:
2256                 task->tk_action = call_bind;
2257                 task->tk_status = 0;
2258                 break;
2259         }
2260         rpc_check_timeout(task);
2261 }
2262
2263 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2264 static void call_bc_transmit(struct rpc_task *task);
2265 static void call_bc_transmit_status(struct rpc_task *task);
2266
2267 static void
2268 call_bc_encode(struct rpc_task *task)
2269 {
2270         xprt_request_enqueue_transmit(task);
2271         task->tk_action = call_bc_transmit;
2272 }
2273
2274 /*
2275  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2276  * addition, disconnect on connectivity errors.
2277  */
2278 static void
2279 call_bc_transmit(struct rpc_task *task)
2280 {
2281         task->tk_action = call_bc_transmit_status;
2282         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2283                 if (!xprt_prepare_transmit(task))
2284                         return;
2285                 task->tk_status = 0;
2286                 xprt_transmit(task);
2287         }
2288         xprt_end_transmit(task);
2289 }
2290
2291 static void
2292 call_bc_transmit_status(struct rpc_task *task)
2293 {
2294         struct rpc_rqst *req = task->tk_rqstp;
2295
2296         if (rpc_task_transmitted(task))
2297                 task->tk_status = 0;
2298
2299         dprint_status(task);
2300
2301         switch (task->tk_status) {
2302         case 0:
2303                 /* Success */
2304         case -ENETDOWN:
2305         case -EHOSTDOWN:
2306         case -EHOSTUNREACH:
2307         case -ENETUNREACH:
2308         case -ECONNRESET:
2309         case -ECONNREFUSED:
2310         case -EADDRINUSE:
2311         case -ENOTCONN:
2312         case -EPIPE:
2313                 break;
2314         case -ENOBUFS:
2315                 rpc_delay(task, HZ>>2);
2316                 /* fall through */
2317         case -EBADSLT:
2318         case -EAGAIN:
2319                 task->tk_status = 0;
2320                 task->tk_action = call_bc_transmit;
2321                 return;
2322         case -ETIMEDOUT:
2323                 /*
2324                  * Problem reaching the server.  Disconnect and let the
2325                  * forechannel reestablish the connection.  The server will
2326                  * have to retransmit the backchannel request and we'll
2327                  * reprocess it.  Since these ops are idempotent, there's no
2328                  * need to cache our reply at this time.
2329                  */
2330                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2331                         "error: %d\n", task->tk_status);
2332                 xprt_conditional_disconnect(req->rq_xprt,
2333                         req->rq_connect_cookie);
2334                 break;
2335         default:
2336                 /*
2337                  * We were unable to reply and will have to drop the
2338                  * request.  The server should reconnect and retransmit.
2339                  */
2340                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2341                         "error: %d\n", task->tk_status);
2342                 break;
2343         }
2344         task->tk_action = rpc_exit_task;
2345 }
2346 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2347
2348 /*
2349  * 6.   Sort out the RPC call status
2350  */
2351 static void
2352 call_status(struct rpc_task *task)
2353 {
2354         struct rpc_clnt *clnt = task->tk_client;
2355         int             status;
2356
2357         if (!task->tk_msg.rpc_proc->p_proc)
2358                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2359
2360         dprint_status(task);
2361
2362         status = task->tk_status;
2363         if (status >= 0) {
2364                 task->tk_action = call_decode;
2365                 return;
2366         }
2367
2368         trace_rpc_call_status(task);
2369         task->tk_status = 0;
2370         switch(status) {
2371         case -EHOSTDOWN:
2372         case -ENETDOWN:
2373         case -EHOSTUNREACH:
2374         case -ENETUNREACH:
2375         case -EPERM:
2376                 if (RPC_IS_SOFTCONN(task))
2377                         goto out_exit;
2378                 /*
2379                  * Delay any retries for 3 seconds, then handle as if it
2380                  * were a timeout.
2381                  */
2382                 rpc_delay(task, 3*HZ);
2383                 /* fall through */
2384         case -ETIMEDOUT:
2385                 break;
2386         case -ECONNREFUSED:
2387         case -ECONNRESET:
2388         case -ECONNABORTED:
2389         case -ENOTCONN:
2390                 rpc_force_rebind(clnt);
2391                 break;
2392         case -EADDRINUSE:
2393                 rpc_delay(task, 3*HZ);
2394                 /* fall through */
2395         case -EPIPE:
2396         case -EAGAIN:
2397                 break;
2398         case -EIO:
2399                 /* shutdown or soft timeout */
2400                 goto out_exit;
2401         default:
2402                 if (clnt->cl_chatty)
2403                         printk("%s: RPC call returned error %d\n",
2404                                clnt->cl_program->name, -status);
2405                 goto out_exit;
2406         }
2407         task->tk_action = call_encode;
2408         rpc_check_timeout(task);
2409         return;
2410 out_exit:
2411         rpc_call_rpcerror(task, status);
2412 }
2413
2414 static bool
2415 rpc_check_connected(const struct rpc_rqst *req)
2416 {
2417         /* No allocated request or transport? return true */
2418         if (!req || !req->rq_xprt)
2419                 return true;
2420         return xprt_connected(req->rq_xprt);
2421 }
2422
2423 static void
2424 rpc_check_timeout(struct rpc_task *task)
2425 {
2426         struct rpc_clnt *clnt = task->tk_client;
2427
2428         if (RPC_SIGNALLED(task)) {
2429                 rpc_call_rpcerror(task, -ERESTARTSYS);
2430                 return;
2431         }
2432
2433         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2434                 return;
2435
2436         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2437         task->tk_timeouts++;
2438
2439         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2440                 rpc_call_rpcerror(task, -ETIMEDOUT);
2441                 return;
2442         }
2443
2444         if (RPC_IS_SOFT(task)) {
2445                 /*
2446                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2447                  * been sent, it should time out only if the transport
2448                  * connection gets terminally broken.
2449                  */
2450                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2451                     rpc_check_connected(task->tk_rqstp))
2452                         return;
2453
2454                 if (clnt->cl_chatty) {
2455                         pr_notice_ratelimited(
2456                                 "%s: server %s not responding, timed out\n",
2457                                 clnt->cl_program->name,
2458                                 task->tk_xprt->servername);
2459                 }
2460                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2461                         rpc_call_rpcerror(task, -ETIMEDOUT);
2462                 else
2463                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2464                 return;
2465         }
2466
2467         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2468                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2469                 if (clnt->cl_chatty) {
2470                         pr_notice_ratelimited(
2471                                 "%s: server %s not responding, still trying\n",
2472                                 clnt->cl_program->name,
2473                                 task->tk_xprt->servername);
2474                 }
2475         }
2476         rpc_force_rebind(clnt);
2477         /*
2478          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2479          * event? RFC2203 requires the server to drop all such requests.
2480          */
2481         rpcauth_invalcred(task);
2482 }
2483
2484 /*
2485  * 7.   Decode the RPC reply
2486  */
2487 static void
2488 call_decode(struct rpc_task *task)
2489 {
2490         struct rpc_clnt *clnt = task->tk_client;
2491         struct rpc_rqst *req = task->tk_rqstp;
2492         struct xdr_stream xdr;
2493         int err;
2494
2495         dprint_status(task);
2496
2497         if (!task->tk_msg.rpc_proc->p_decode) {
2498                 task->tk_action = rpc_exit_task;
2499                 return;
2500         }
2501
2502         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2503                 if (clnt->cl_chatty) {
2504                         pr_notice_ratelimited("%s: server %s OK\n",
2505                                 clnt->cl_program->name,
2506                                 task->tk_xprt->servername);
2507                 }
2508                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2509         }
2510
2511         /*
2512          * Ensure that we see all writes made by xprt_complete_rqst()
2513          * before it changed req->rq_reply_bytes_recvd.
2514          */
2515         smp_rmb();
2516
2517         /*
2518          * Did we ever call xprt_complete_rqst()? If not, we should assume
2519          * the message is incomplete.
2520          */
2521         err = -EAGAIN;
2522         if (!req->rq_reply_bytes_recvd)
2523                 goto out;
2524
2525         req->rq_rcv_buf.len = req->rq_private_buf.len;
2526         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2527
2528         /* Check that the softirq receive buffer is valid */
2529         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2530                                 sizeof(req->rq_rcv_buf)) != 0);
2531
2532         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2533                         req->rq_rcv_buf.head[0].iov_base, req);
2534         err = rpc_decode_header(task, &xdr);
2535 out:
2536         switch (err) {
2537         case 0:
2538                 task->tk_action = rpc_exit_task;
2539                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2540                 dprintk("RPC: %5u %s result %d\n",
2541                         task->tk_pid, __func__, task->tk_status);
2542                 return;
2543         case -EAGAIN:
2544                 task->tk_status = 0;
2545                 if (task->tk_client->cl_discrtry)
2546                         xprt_conditional_disconnect(req->rq_xprt,
2547                                                     req->rq_connect_cookie);
2548                 task->tk_action = call_encode;
2549                 rpc_check_timeout(task);
2550                 break;
2551         case -EKEYREJECTED:
2552                 task->tk_action = call_reserve;
2553                 rpc_check_timeout(task);
2554                 rpcauth_invalcred(task);
2555                 /* Ensure we obtain a new XID if we retry! */
2556                 xprt_release(task);
2557         }
2558 }
2559
2560 static int
2561 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2562 {
2563         struct rpc_clnt *clnt = task->tk_client;
2564         struct rpc_rqst *req = task->tk_rqstp;
2565         __be32 *p;
2566         int error;
2567
2568         error = -EMSGSIZE;
2569         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2570         if (!p)
2571                 goto out_fail;
2572         *p++ = req->rq_xid;
2573         *p++ = rpc_call;
2574         *p++ = cpu_to_be32(RPC_VERSION);
2575         *p++ = cpu_to_be32(clnt->cl_prog);
2576         *p++ = cpu_to_be32(clnt->cl_vers);
2577         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2578
2579         error = rpcauth_marshcred(task, xdr);
2580         if (error < 0)
2581                 goto out_fail;
2582         return 0;
2583 out_fail:
2584         trace_rpc_bad_callhdr(task);
2585         rpc_call_rpcerror(task, error);
2586         return error;
2587 }
2588
2589 static noinline int
2590 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2591 {
2592         struct rpc_clnt *clnt = task->tk_client;
2593         int error;
2594         __be32 *p;
2595
2596         /* RFC-1014 says that the representation of XDR data must be a
2597          * multiple of four bytes
2598          * - if it isn't pointer subtraction in the NFS client may give
2599          *   undefined results
2600          */
2601         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2602                 goto out_unparsable;
2603
2604         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2605         if (!p)
2606                 goto out_unparsable;
2607         p++;    /* skip XID */
2608         if (*p++ != rpc_reply)
2609                 goto out_unparsable;
2610         if (*p++ != rpc_msg_accepted)
2611                 goto out_msg_denied;
2612
2613         error = rpcauth_checkverf(task, xdr);
2614         if (error)
2615                 goto out_verifier;
2616
2617         p = xdr_inline_decode(xdr, sizeof(*p));
2618         if (!p)
2619                 goto out_unparsable;
2620         switch (*p) {
2621         case rpc_success:
2622                 return 0;
2623         case rpc_prog_unavail:
2624                 trace_rpc__prog_unavail(task);
2625                 error = -EPFNOSUPPORT;
2626                 goto out_err;
2627         case rpc_prog_mismatch:
2628                 trace_rpc__prog_mismatch(task);
2629                 error = -EPROTONOSUPPORT;
2630                 goto out_err;
2631         case rpc_proc_unavail:
2632                 trace_rpc__proc_unavail(task);
2633                 error = -EOPNOTSUPP;
2634                 goto out_err;
2635         case rpc_garbage_args:
2636         case rpc_system_err:
2637                 trace_rpc__garbage_args(task);
2638                 error = -EIO;
2639                 break;
2640         default:
2641                 goto out_unparsable;
2642         }
2643
2644 out_garbage:
2645         clnt->cl_stats->rpcgarbage++;
2646         if (task->tk_garb_retry) {
2647                 task->tk_garb_retry--;
2648                 task->tk_action = call_encode;
2649                 return -EAGAIN;
2650         }
2651 out_err:
2652         rpc_call_rpcerror(task, error);
2653         return error;
2654
2655 out_unparsable:
2656         trace_rpc__unparsable(task);
2657         error = -EIO;
2658         goto out_garbage;
2659
2660 out_verifier:
2661         trace_rpc_bad_verifier(task);
2662         goto out_garbage;
2663
2664 out_msg_denied:
2665         error = -EACCES;
2666         p = xdr_inline_decode(xdr, sizeof(*p));
2667         if (!p)
2668                 goto out_unparsable;
2669         switch (*p++) {
2670         case rpc_auth_error:
2671                 break;
2672         case rpc_mismatch:
2673                 trace_rpc__mismatch(task);
2674                 error = -EPROTONOSUPPORT;
2675                 goto out_err;
2676         default:
2677                 goto out_unparsable;
2678         }
2679
2680         p = xdr_inline_decode(xdr, sizeof(*p));
2681         if (!p)
2682                 goto out_unparsable;
2683         switch (*p++) {
2684         case rpc_autherr_rejectedcred:
2685         case rpc_autherr_rejectedverf:
2686         case rpcsec_gsserr_credproblem:
2687         case rpcsec_gsserr_ctxproblem:
2688                 if (!task->tk_cred_retry)
2689                         break;
2690                 task->tk_cred_retry--;
2691                 trace_rpc__stale_creds(task);
2692                 return -EKEYREJECTED;
2693         case rpc_autherr_badcred:
2694         case rpc_autherr_badverf:
2695                 /* possibly garbled cred/verf? */
2696                 if (!task->tk_garb_retry)
2697                         break;
2698                 task->tk_garb_retry--;
2699                 trace_rpc__bad_creds(task);
2700                 task->tk_action = call_encode;
2701                 return -EAGAIN;
2702         case rpc_autherr_tooweak:
2703                 trace_rpc__auth_tooweak(task);
2704                 pr_warn("RPC: server %s requires stronger authentication.\n",
2705                         task->tk_xprt->servername);
2706                 break;
2707         default:
2708                 goto out_unparsable;
2709         }
2710         goto out_err;
2711 }
2712
2713 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2714                 const void *obj)
2715 {
2716 }
2717
2718 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2719                 void *obj)
2720 {
2721         return 0;
2722 }
2723
2724 static const struct rpc_procinfo rpcproc_null = {
2725         .p_encode = rpcproc_encode_null,
2726         .p_decode = rpcproc_decode_null,
2727 };
2728
2729 static int rpc_ping(struct rpc_clnt *clnt)
2730 {
2731         struct rpc_message msg = {
2732                 .rpc_proc = &rpcproc_null,
2733         };
2734         int err;
2735         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2736                             RPC_TASK_NULLCREDS);
2737         return err;
2738 }
2739
2740 static
2741 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2742                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2743                 const struct rpc_call_ops *ops, void *data)
2744 {
2745         struct rpc_message msg = {
2746                 .rpc_proc = &rpcproc_null,
2747         };
2748         struct rpc_task_setup task_setup_data = {
2749                 .rpc_client = clnt,
2750                 .rpc_xprt = xprt,
2751                 .rpc_message = &msg,
2752                 .rpc_op_cred = cred,
2753                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2754                 .callback_data = data,
2755                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2756                          RPC_TASK_NULLCREDS,
2757         };
2758
2759         return rpc_run_task(&task_setup_data);
2760 }
2761
2762 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2763 {
2764         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2765 }
2766 EXPORT_SYMBOL_GPL(rpc_call_null);
2767
2768 struct rpc_cb_add_xprt_calldata {
2769         struct rpc_xprt_switch *xps;
2770         struct rpc_xprt *xprt;
2771 };
2772
2773 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2774 {
2775         struct rpc_cb_add_xprt_calldata *data = calldata;
2776
2777         if (task->tk_status == 0)
2778                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2779 }
2780
2781 static void rpc_cb_add_xprt_release(void *calldata)
2782 {
2783         struct rpc_cb_add_xprt_calldata *data = calldata;
2784
2785         xprt_put(data->xprt);
2786         xprt_switch_put(data->xps);
2787         kfree(data);
2788 }
2789
2790 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2791         .rpc_call_done = rpc_cb_add_xprt_done,
2792         .rpc_release = rpc_cb_add_xprt_release,
2793 };
2794
2795 /**
2796  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2797  * @clnt: pointer to struct rpc_clnt
2798  * @xps: pointer to struct rpc_xprt_switch,
2799  * @xprt: pointer struct rpc_xprt
2800  * @dummy: unused
2801  */
2802 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2803                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2804                 void *dummy)
2805 {
2806         struct rpc_cb_add_xprt_calldata *data;
2807         struct rpc_task *task;
2808
2809         data = kmalloc(sizeof(*data), GFP_NOFS);
2810         if (!data)
2811                 return -ENOMEM;
2812         data->xps = xprt_switch_get(xps);
2813         data->xprt = xprt_get(xprt);
2814         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2815                 rpc_cb_add_xprt_release(data);
2816                 goto success;
2817         }
2818
2819         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2820                         &rpc_cb_add_xprt_call_ops, data);
2821
2822         rpc_put_task(task);
2823 success:
2824         return 1;
2825 }
2826 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2827
2828 /**
2829  * rpc_clnt_setup_test_and_add_xprt()
2830  *
2831  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2832  *   1) caller of the test function must dereference the rpc_xprt_switch
2833  *   and the rpc_xprt.
2834  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2835  *   the rpc_call_done routine.
2836  *
2837  * Upon success (return of 1), the test function adds the new
2838  * transport to the rpc_clnt xprt switch
2839  *
2840  * @clnt: struct rpc_clnt to get the new transport
2841  * @xps:  the rpc_xprt_switch to hold the new transport
2842  * @xprt: the rpc_xprt to test
2843  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2844  *        and test function call data
2845  */
2846 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2847                                      struct rpc_xprt_switch *xps,
2848                                      struct rpc_xprt *xprt,
2849                                      void *data)
2850 {
2851         struct rpc_task *task;
2852         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2853         int status = -EADDRINUSE;
2854
2855         xprt = xprt_get(xprt);
2856         xprt_switch_get(xps);
2857
2858         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2859                 goto out_err;
2860
2861         /* Test the connection */
2862         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2863         if (IS_ERR(task)) {
2864                 status = PTR_ERR(task);
2865                 goto out_err;
2866         }
2867         status = task->tk_status;
2868         rpc_put_task(task);
2869
2870         if (status < 0)
2871                 goto out_err;
2872
2873         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2874         xtest->add_xprt_test(clnt, xprt, xtest->data);
2875
2876         xprt_put(xprt);
2877         xprt_switch_put(xps);
2878
2879         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2880         return 1;
2881 out_err:
2882         xprt_put(xprt);
2883         xprt_switch_put(xps);
2884         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2885                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2886         return status;
2887 }
2888 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2889
2890 /**
2891  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2892  * @clnt: pointer to struct rpc_clnt
2893  * @xprtargs: pointer to struct xprt_create
2894  * @setup: callback to test and/or set up the connection
2895  * @data: pointer to setup function data
2896  *
2897  * Creates a new transport using the parameters set in args and
2898  * adds it to clnt.
2899  * If ping is set, then test that connectivity succeeds before
2900  * adding the new transport.
2901  *
2902  */
2903 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2904                 struct xprt_create *xprtargs,
2905                 int (*setup)(struct rpc_clnt *,
2906                         struct rpc_xprt_switch *,
2907                         struct rpc_xprt *,
2908                         void *),
2909                 void *data)
2910 {
2911         struct rpc_xprt_switch *xps;
2912         struct rpc_xprt *xprt;
2913         unsigned long connect_timeout;
2914         unsigned long reconnect_timeout;
2915         unsigned char resvport, reuseport;
2916         int ret = 0;
2917
2918         rcu_read_lock();
2919         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2920         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2921         if (xps == NULL || xprt == NULL) {
2922                 rcu_read_unlock();
2923                 xprt_switch_put(xps);
2924                 return -EAGAIN;
2925         }
2926         resvport = xprt->resvport;
2927         reuseport = xprt->reuseport;
2928         connect_timeout = xprt->connect_timeout;
2929         reconnect_timeout = xprt->max_reconnect_timeout;
2930         rcu_read_unlock();
2931
2932         xprt = xprt_create_transport(xprtargs);
2933         if (IS_ERR(xprt)) {
2934                 ret = PTR_ERR(xprt);
2935                 goto out_put_switch;
2936         }
2937         xprt->resvport = resvport;
2938         xprt->reuseport = reuseport;
2939         if (xprt->ops->set_connect_timeout != NULL)
2940                 xprt->ops->set_connect_timeout(xprt,
2941                                 connect_timeout,
2942                                 reconnect_timeout);
2943
2944         rpc_xprt_switch_set_roundrobin(xps);
2945         if (setup) {
2946                 ret = setup(clnt, xps, xprt, data);
2947                 if (ret != 0)
2948                         goto out_put_xprt;
2949         }
2950         rpc_xprt_switch_add_xprt(xps, xprt);
2951 out_put_xprt:
2952         xprt_put(xprt);
2953 out_put_switch:
2954         xprt_switch_put(xps);
2955         return ret;
2956 }
2957 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2958
2959 struct connect_timeout_data {
2960         unsigned long connect_timeout;
2961         unsigned long reconnect_timeout;
2962 };
2963
2964 static int
2965 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2966                 struct rpc_xprt *xprt,
2967                 void *data)
2968 {
2969         struct connect_timeout_data *timeo = data;
2970
2971         if (xprt->ops->set_connect_timeout)
2972                 xprt->ops->set_connect_timeout(xprt,
2973                                 timeo->connect_timeout,
2974                                 timeo->reconnect_timeout);
2975         return 0;
2976 }
2977
2978 void
2979 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2980                 unsigned long connect_timeout,
2981                 unsigned long reconnect_timeout)
2982 {
2983         struct connect_timeout_data timeout = {
2984                 .connect_timeout = connect_timeout,
2985                 .reconnect_timeout = reconnect_timeout,
2986         };
2987         rpc_clnt_iterate_for_each_xprt(clnt,
2988                         rpc_xprt_set_connect_timeout,
2989                         &timeout);
2990 }
2991 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2992
2993 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2994 {
2995         rcu_read_lock();
2996         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2997         rcu_read_unlock();
2998 }
2999 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
3000
3001 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3002 {
3003         rcu_read_lock();
3004         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3005                                  xprt);
3006         rcu_read_unlock();
3007 }
3008 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3009
3010 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3011                                    const struct sockaddr *sap)
3012 {
3013         struct rpc_xprt_switch *xps;
3014         bool ret;
3015
3016         rcu_read_lock();
3017         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3018         ret = rpc_xprt_switch_has_addr(xps, sap);
3019         rcu_read_unlock();
3020         return ret;
3021 }
3022 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3023
3024 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3025 static void rpc_show_header(void)
3026 {
3027         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3028                 "-timeout ---ops--\n");
3029 }
3030
3031 static void rpc_show_task(const struct rpc_clnt *clnt,
3032                           const struct rpc_task *task)
3033 {
3034         const char *rpc_waitq = "none";
3035
3036         if (RPC_IS_QUEUED(task))
3037                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3038
3039         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3040                 task->tk_pid, task->tk_flags, task->tk_status,
3041                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3042                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3043                 task->tk_action, rpc_waitq);
3044 }
3045
3046 void rpc_show_tasks(struct net *net)
3047 {
3048         struct rpc_clnt *clnt;
3049         struct rpc_task *task;
3050         int header = 0;
3051         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3052
3053         spin_lock(&sn->rpc_client_lock);
3054         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3055                 spin_lock(&clnt->cl_lock);
3056                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3057                         if (!header) {
3058                                 rpc_show_header();
3059                                 header++;
3060                         }
3061                         rpc_show_task(clnt, task);
3062                 }
3063                 spin_unlock(&clnt->cl_lock);
3064         }
3065         spin_unlock(&sn->rpc_client_lock);
3066 }
3067 #endif
3068
3069 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3070 static int
3071 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3072                 struct rpc_xprt *xprt,
3073                 void *dummy)
3074 {
3075         return xprt_enable_swap(xprt);
3076 }
3077
3078 int
3079 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3080 {
3081         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3082                 return rpc_clnt_iterate_for_each_xprt(clnt,
3083                                 rpc_clnt_swap_activate_callback, NULL);
3084         return 0;
3085 }
3086 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3087
3088 static int
3089 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3090                 struct rpc_xprt *xprt,
3091                 void *dummy)
3092 {
3093         xprt_disable_swap(xprt);
3094         return 0;
3095 }
3096
3097 void
3098 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3099 {
3100         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3101                 rpc_clnt_iterate_for_each_xprt(clnt,
3102                                 rpc_clnt_swap_deactivate_callback, NULL);
3103 }
3104 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3105 #endif /* CONFIG_SUNRPC_SWAP */