net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "netns.h"
  45
  46 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  47 # define RPCDBG_FACILITY        RPCDBG_CALL
  48 #endif
  49
  50 #define dprint_status(t)                                        \
  51         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  52                         __func__, t->tk_status)
  53
  54 /*
  55  * All RPC clients are linked into this list
  56  */
  57
  58 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  59
  60
  61 static void     call_start(struct rpc_task *task);
  62 static void     call_reserve(struct rpc_task *task);
  63 static void     call_reserveresult(struct rpc_task *task);
  64 static void     call_allocate(struct rpc_task *task);
  65 static void     call_encode(struct rpc_task *task);
  66 static void     call_decode(struct rpc_task *task);
  67 static void     call_bind(struct rpc_task *task);
  68 static void     call_bind_status(struct rpc_task *task);
  69 static void     call_transmit(struct rpc_task *task);
  70 static void     call_status(struct rpc_task *task);
  71 static void     call_transmit_status(struct rpc_task *task);
  72 static void     call_refresh(struct rpc_task *task);
  73 static void     call_refreshresult(struct rpc_task *task);
  74 static void     call_connect(struct rpc_task *task);
  75 static void     call_connect_status(struct rpc_task *task);
  76
  77 static int      rpc_encode_header(struct rpc_task *task,
  78                                   struct xdr_stream *xdr);
  79 static int      rpc_decode_header(struct rpc_task *task,
  80                                   struct xdr_stream *xdr);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82 static void     rpc_check_timeout(struct rpc_task *task);
  83
  84 static void rpc_register_client(struct rpc_clnt *clnt)
  85 {
  86         struct net *net = rpc_net_ns(clnt);
  87         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  88
  89         spin_lock(&sn->rpc_client_lock);
  90         list_add(&clnt->cl_clients, &sn->all_clients);
  91         spin_unlock(&sn->rpc_client_lock);
  92 }
  93
  94 static void rpc_unregister_client(struct rpc_clnt *clnt)
  95 {
  96         struct net *net = rpc_net_ns(clnt);
  97         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  98
  99         spin_lock(&sn->rpc_client_lock);
 100         list_del(&clnt->cl_clients);
 101         spin_unlock(&sn->rpc_client_lock);
 102 }
 103
 104 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 105 {
 106         rpc_remove_client_dir(clnt);
 107 }
 108
 109 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 110 {
 111         struct net *net = rpc_net_ns(clnt);
 112         struct super_block *pipefs_sb;
 113
 114         pipefs_sb = rpc_get_sb_net(net);
 115         if (pipefs_sb) {
 116                 __rpc_clnt_remove_pipedir(clnt);
 117                 rpc_put_sb_net(net);
 118         }
 119 }
 120
 121 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 122                                     struct rpc_clnt *clnt)
 123 {
 124         static uint32_t clntid;
 125         const char *dir_name = clnt->cl_program->pipe_dir_name;
 126         char name[15];
 127         struct dentry *dir, *dentry;
 128
 129         dir = rpc_d_lookup_sb(sb, dir_name);
 130         if (dir == NULL) {
 131                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 132                 return dir;
 133         }
 134         for (;;) {
 135                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 136                 name[sizeof(name) - 1] = '\0';
 137                 dentry = rpc_create_client_dir(dir, name, clnt);
 138                 if (!IS_ERR(dentry))
 139                         break;
 140                 if (dentry == ERR_PTR(-EEXIST))
 141                         continue;
 142                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 143                                 " %s/%s, error %ld\n",
 144                                 dir_name, name, PTR_ERR(dentry));
 145                 break;
 146         }
 147         dput(dir);
 148         return dentry;
 149 }
 150
 151 static int
 152 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 153 {
 154         struct dentry *dentry;
 155
 156         if (clnt->cl_program->pipe_dir_name != NULL) {
 157                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 158                 if (IS_ERR(dentry))
 159                         return PTR_ERR(dentry);
 160         }
 161         return 0;
 162 }
 163
 164 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 165 {
 166         if (clnt->cl_program->pipe_dir_name == NULL)
 167                 return 1;
 168
 169         switch (event) {
 170         case RPC_PIPEFS_MOUNT:
 171                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 172                         return 1;
 173                 if (atomic_read(&clnt->cl_count) == 0)
 174                         return 1;
 175                 break;
 176         case RPC_PIPEFS_UMOUNT:
 177                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 178                         return 1;
 179                 break;
 180         }
 181         return 0;
 182 }
 183
 184 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 185                                    struct super_block *sb)
 186 {
 187         struct dentry *dentry;
 188
 189         switch (event) {
 190         case RPC_PIPEFS_MOUNT:
 191                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 192                 if (!dentry)
 193                         return -ENOENT;
 194                 if (IS_ERR(dentry))
 195                         return PTR_ERR(dentry);
 196                 break;
 197         case RPC_PIPEFS_UMOUNT:
 198                 __rpc_clnt_remove_pipedir(clnt);
 199                 break;
 200         default:
 201                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 202                 return -ENOTSUPP;
 203         }
 204         return 0;
 205 }
 206
 207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 208                                 struct super_block *sb)
 209 {
 210         int error = 0;
 211
 212         for (;; clnt = clnt->cl_parent) {
 213                 if (!rpc_clnt_skip_event(clnt, event))
 214                         error = __rpc_clnt_handle_event(clnt, event, sb);
 215                 if (error || clnt == clnt->cl_parent)
 216                         break;
 217         }
 218         return error;
 219 }
 220
 221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 222 {
 223         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 224         struct rpc_clnt *clnt;
 225
 226         spin_lock(&sn->rpc_client_lock);
 227         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 228                 if (rpc_clnt_skip_event(clnt, event))
 229                         continue;
 230                 spin_unlock(&sn->rpc_client_lock);
 231                 return clnt;
 232         }
 233         spin_unlock(&sn->rpc_client_lock);
 234         return NULL;
 235 }
 236
 237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 238                             void *ptr)
 239 {
 240         struct super_block *sb = ptr;
 241         struct rpc_clnt *clnt;
 242         int error = 0;
 243
 244         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 245                 error = __rpc_pipefs_event(clnt, event, sb);
 246                 if (error)
 247                         break;
 248         }
 249         return error;
 250 }
 251
 252 static struct notifier_block rpc_clients_block = {
 253         .notifier_call  = rpc_pipefs_event,
 254         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 255 };
 256
 257 int rpc_clients_notifier_register(void)
 258 {
 259         return rpc_pipefs_notifier_register(&rpc_clients_block);
 260 }
 261
 262 void rpc_clients_notifier_unregister(void)
 263 {
 264         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 265 }
 266
 267 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 268                 struct rpc_xprt *xprt,
 269                 const struct rpc_timeout *timeout)
 270 {
 271         struct rpc_xprt *old;
 272
 273         spin_lock(&clnt->cl_lock);
 274         old = rcu_dereference_protected(clnt->cl_xprt,
 275                         lockdep_is_held(&clnt->cl_lock));
 276
 277         if (!xprt_bound(xprt))
 278                 clnt->cl_autobind = 1;
 279
 280         clnt->cl_timeout = timeout;
 281         rcu_assign_pointer(clnt->cl_xprt, xprt);
 282         spin_unlock(&clnt->cl_lock);
 283
 284         return old;
 285 }
 286
 287 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 288 {
 289         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 290                         nodename, sizeof(clnt->cl_nodename));
 291 }
 292
 293 static int rpc_client_register(struct rpc_clnt *clnt,
 294                                rpc_authflavor_t pseudoflavor,
 295                                const char *client_name)
 296 {
 297         struct rpc_auth_create_args auth_args = {
 298                 .pseudoflavor = pseudoflavor,
 299                 .target_name = client_name,
 300         };
 301         struct rpc_auth *auth;
 302         struct net *net = rpc_net_ns(clnt);
 303         struct super_block *pipefs_sb;
 304         int err;
 305
 306         rpc_clnt_debugfs_register(clnt);
 307
 308         pipefs_sb = rpc_get_sb_net(net);
 309         if (pipefs_sb) {
 310                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 311                 if (err)
 312                         goto out;
 313         }
 314
 315         rpc_register_client(clnt);
 316         if (pipefs_sb)
 317                 rpc_put_sb_net(net);
 318
 319         auth = rpcauth_create(&auth_args, clnt);
 320         if (IS_ERR(auth)) {
 321                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 322                                 pseudoflavor);
 323                 err = PTR_ERR(auth);
 324                 goto err_auth;
 325         }
 326         return 0;
 327 err_auth:
 328         pipefs_sb = rpc_get_sb_net(net);
 329         rpc_unregister_client(clnt);
 330         __rpc_clnt_remove_pipedir(clnt);
 331 out:
 332         if (pipefs_sb)
 333                 rpc_put_sb_net(net);
 334         rpc_clnt_debugfs_unregister(clnt);
 335         return err;
 336 }
 337
 338 static DEFINE_IDA(rpc_clids);
 339
 340 void rpc_cleanup_clids(void)
 341 {
 342         ida_destroy(&rpc_clids);
 343 }
 344
 345 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 346 {
 347         int clid;
 348
 349         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 350         if (clid < 0)
 351                 return clid;
 352         clnt->cl_clid = clid;
 353         return 0;
 354 }
 355
 356 static void rpc_free_clid(struct rpc_clnt *clnt)
 357 {
 358         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 359 }
 360
 361 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 362                 struct rpc_xprt_switch *xps,
 363                 struct rpc_xprt *xprt,
 364                 struct rpc_clnt *parent)
 365 {
 366         const struct rpc_program *program = args->program;
 367         const struct rpc_version *version;
 368         struct rpc_clnt *clnt = NULL;
 369         const struct rpc_timeout *timeout;
 370         const char *nodename = args->nodename;
 371         int err;
 372
 373         /* sanity check the name before trying to print it */
 374         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 375                         program->name, args->servername, xprt);
 376
 377         err = rpciod_up();
 378         if (err)
 379                 goto out_no_rpciod;
 380
 381         err = -EINVAL;
 382         if (args->version >= program->nrvers)
 383                 goto out_err;
 384         version = program->version[args->version];
 385         if (version == NULL)
 386                 goto out_err;
 387
 388         err = -ENOMEM;
 389         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 390         if (!clnt)
 391                 goto out_err;
 392         clnt->cl_parent = parent ? : clnt;
 393
 394         err = rpc_alloc_clid(clnt);
 395         if (err)
 396                 goto out_no_clid;
 397
 398         clnt->cl_cred     = get_cred(args->cred);
 399         clnt->cl_procinfo = version->procs;
 400         clnt->cl_maxproc  = version->nrprocs;
 401         clnt->cl_prog     = args->prognumber ? : program->number;
 402         clnt->cl_vers     = version->number;
 403         clnt->cl_stats    = program->stats;
 404         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 405         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 406         err = -ENOMEM;
 407         if (clnt->cl_metrics == NULL)
 408                 goto out_no_stats;
 409         clnt->cl_program  = program;
 410         INIT_LIST_HEAD(&clnt->cl_tasks);
 411         spin_lock_init(&clnt->cl_lock);
 412
 413         timeout = xprt->timeout;
 414         if (args->timeout != NULL) {
 415                 memcpy(&clnt->cl_timeout_default, args->timeout,
 416                                 sizeof(clnt->cl_timeout_default));
 417                 timeout = &clnt->cl_timeout_default;
 418         }
 419
 420         rpc_clnt_set_transport(clnt, xprt, timeout);
 421         xprt_iter_init(&clnt->cl_xpi, xps);
 422         xprt_switch_put(xps);
 423
 424         clnt->cl_rtt = &clnt->cl_rtt_default;
 425         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 426
 427         atomic_set(&clnt->cl_count, 1);
 428
 429         if (nodename == NULL)
 430                 nodename = utsname()->nodename;
 431         /* save the nodename */
 432         rpc_clnt_set_nodename(clnt, nodename);
 433
 434         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 435         if (err)
 436                 goto out_no_path;
 437         if (parent)
 438                 atomic_inc(&parent->cl_count);
 439         return clnt;
 440
 441 out_no_path:
 442         rpc_free_iostats(clnt->cl_metrics);
 443 out_no_stats:
 444         put_cred(clnt->cl_cred);
 445         rpc_free_clid(clnt);
 446 out_no_clid:
 447         kfree(clnt);
 448 out_err:
 449         rpciod_down();
 450 out_no_rpciod:
 451         xprt_switch_put(xps);
 452         xprt_put(xprt);
 453         return ERR_PTR(err);
 454 }
 455
 456 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 457                                         struct rpc_xprt *xprt)
 458 {
 459         struct rpc_clnt *clnt = NULL;
 460         struct rpc_xprt_switch *xps;
 461
 462         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 463                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 464                 xps = args->bc_xprt->xpt_bc_xps;
 465                 xprt_switch_get(xps);
 466         } else {
 467                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 468                 if (xps == NULL) {
 469                         xprt_put(xprt);
 470                         return ERR_PTR(-ENOMEM);
 471                 }
 472                 if (xprt->bc_xprt) {
 473                         xprt_switch_get(xps);
 474                         xprt->bc_xprt->xpt_bc_xps = xps;
 475                 }
 476         }
 477         clnt = rpc_new_client(args, xps, xprt, NULL);
 478         if (IS_ERR(clnt))
 479                 return clnt;
 480
 481         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 482                 int err = rpc_ping(clnt);
 483                 if (err != 0) {
 484                         rpc_shutdown_client(clnt);
 485                         return ERR_PTR(err);
 486                 }
 487         }
 488
 489         clnt->cl_softrtry = 1;
 490         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 491                 clnt->cl_softrtry = 0;
 492                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 493                         clnt->cl_softerr = 1;
 494         }
 495
 496         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 497                 clnt->cl_autobind = 1;
 498         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 499                 clnt->cl_noretranstimeo = 1;
 500         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 501                 clnt->cl_discrtry = 1;
 502         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 503                 clnt->cl_chatty = 1;
 504
 505         return clnt;
 506 }
 507
 508 /**
 509  * rpc_create - create an RPC client and transport with one call
 510  * @args: rpc_clnt create argument structure
 511  *
 512  * Creates and initializes an RPC transport and an RPC client.
 513  *
 514  * It can ping the server in order to determine if it is up, and to see if
 515  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 516  * this behavior so asynchronous tasks can also use rpc_create.
 517  */
 518 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 519 {
 520         struct rpc_xprt *xprt;
 521         struct xprt_create xprtargs = {
 522                 .net = args->net,
 523                 .ident = args->protocol,
 524                 .srcaddr = args->saddress,
 525                 .dstaddr = args->address,
 526                 .addrlen = args->addrsize,
 527                 .servername = args->servername,
 528                 .bc_xprt = args->bc_xprt,
 529         };
 530         char servername[48];
 531         struct rpc_clnt *clnt;
 532         int i;
 533
 534         if (args->bc_xprt) {
 535                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 536                 xprt = args->bc_xprt->xpt_bc_xprt;
 537                 if (xprt) {
 538                         xprt_get(xprt);
 539                         return rpc_create_xprt(args, xprt);
 540                 }
 541         }
 542
 543         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 544                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 545         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 546                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 547         /*
 548          * If the caller chooses not to specify a hostname, whip
 549          * up a string representation of the passed-in address.
 550          */
 551         if (xprtargs.servername == NULL) {
 552                 struct sockaddr_un *sun =
 553                                 (struct sockaddr_un *)args->address;
 554                 struct sockaddr_in *sin =
 555                                 (struct sockaddr_in *)args->address;
 556                 struct sockaddr_in6 *sin6 =
 557                                 (struct sockaddr_in6 *)args->address;
 558
 559                 servername[0] = '\0';
 560                 switch (args->address->sa_family) {
 561                 case AF_LOCAL:
 562                         snprintf(servername, sizeof(servername), "%s",
 563                                  sun->sun_path);
 564                         break;
 565                 case AF_INET:
 566                         snprintf(servername, sizeof(servername), "%pI4",
 567                                  &sin->sin_addr.s_addr);
 568                         break;
 569                 case AF_INET6:
 570                         snprintf(servername, sizeof(servername), "%pI6",
 571                                  &sin6->sin6_addr);
 572                         break;
 573                 default:
 574                         /* caller wants default server name, but
 575                          * address family isn't recognized. */
 576                         return ERR_PTR(-EINVAL);
 577                 }
 578                 xprtargs.servername = servername;
 579         }
 580
 581         xprt = xprt_create_transport(&xprtargs);
 582         if (IS_ERR(xprt))
 583                 return (struct rpc_clnt *)xprt;
 584
 585         /*
 586          * By default, kernel RPC client connects from a reserved port.
 587          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 588          * but it is always enabled for rpciod, which handles the connect
 589          * operation.
 590          */
 591         xprt->resvport = 1;
 592         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 593                 xprt->resvport = 0;
 594         xprt->reuseport = 0;
 595         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 596                 xprt->reuseport = 1;
 597
 598         clnt = rpc_create_xprt(args, xprt);
 599         if (IS_ERR(clnt) || args->nconnect <= 1)
 600                 return clnt;
 601
 602         for (i = 0; i < args->nconnect - 1; i++) {
 603                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 604                         break;
 605         }
 606         return clnt;
 607 }
 608 EXPORT_SYMBOL_GPL(rpc_create);
 609
 610 /*
 611  * This function clones the RPC client structure. It allows us to share the
 612  * same transport while varying parameters such as the authentication
 613  * flavour.
 614  */
 615 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 616                                            struct rpc_clnt *clnt)
 617 {
 618         struct rpc_xprt_switch *xps;
 619         struct rpc_xprt *xprt;
 620         struct rpc_clnt *new;
 621         int err;
 622
 623         err = -ENOMEM;
 624         rcu_read_lock();
 625         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 626         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 627         rcu_read_unlock();
 628         if (xprt == NULL || xps == NULL) {
 629                 xprt_put(xprt);
 630                 xprt_switch_put(xps);
 631                 goto out_err;
 632         }
 633         args->servername = xprt->servername;
 634         args->nodename = clnt->cl_nodename;
 635
 636         new = rpc_new_client(args, xps, xprt, clnt);
 637         if (IS_ERR(new)) {
 638                 err = PTR_ERR(new);
 639                 goto out_err;
 640         }
 641
 642         /* Turn off autobind on clones */
 643         new->cl_autobind = 0;
 644         new->cl_softrtry = clnt->cl_softrtry;
 645         new->cl_softerr = clnt->cl_softerr;
 646         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 647         new->cl_discrtry = clnt->cl_discrtry;
 648         new->cl_chatty = clnt->cl_chatty;
 649         new->cl_principal = clnt->cl_principal;
 650         return new;
 651
 652 out_err:
 653         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 654         return ERR_PTR(err);
 655 }
 656
 657 /**
 658  * rpc_clone_client - Clone an RPC client structure
 659  *
 660  * @clnt: RPC client whose parameters are copied
 661  *
 662  * Returns a fresh RPC client or an ERR_PTR.
 663  */
 664 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 665 {
 666         struct rpc_create_args args = {
 667                 .program        = clnt->cl_program,
 668                 .prognumber     = clnt->cl_prog,
 669                 .version        = clnt->cl_vers,
 670                 .authflavor     = clnt->cl_auth->au_flavor,
 671                 .cred           = clnt->cl_cred,
 672         };
 673         return __rpc_clone_client(&args, clnt);
 674 }
 675 EXPORT_SYMBOL_GPL(rpc_clone_client);
 676
 677 /**
 678  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 679  *
 680  * @clnt: RPC client whose parameters are copied
 681  * @flavor: security flavor for new client
 682  *
 683  * Returns a fresh RPC client or an ERR_PTR.
 684  */
 685 struct rpc_clnt *
 686 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 687 {
 688         struct rpc_create_args args = {
 689                 .program        = clnt->cl_program,
 690                 .prognumber     = clnt->cl_prog,
 691                 .version        = clnt->cl_vers,
 692                 .authflavor     = flavor,
 693                 .cred           = clnt->cl_cred,
 694         };
 695         return __rpc_clone_client(&args, clnt);
 696 }
 697 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 698
 699 /**
 700  * rpc_switch_client_transport: switch the RPC transport on the fly
 701  * @clnt: pointer to a struct rpc_clnt
 702  * @args: pointer to the new transport arguments
 703  * @timeout: pointer to the new timeout parameters
 704  *
 705  * This function allows the caller to switch the RPC transport for the
 706  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 707  * server, for instance.  It assumes that the caller has ensured that
 708  * there are no active RPC tasks by using some form of locking.
 709  *
 710  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 711  * negative errno is returned, and "clnt" continues to use the old
 712  * xprt.
 713  */
 714 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 715                 struct xprt_create *args,
 716                 const struct rpc_timeout *timeout)
 717 {
 718         const struct rpc_timeout *old_timeo;
 719         rpc_authflavor_t pseudoflavor;
 720         struct rpc_xprt_switch *xps, *oldxps;
 721         struct rpc_xprt *xprt, *old;
 722         struct rpc_clnt *parent;
 723         int err;
 724
 725         xprt = xprt_create_transport(args);
 726         if (IS_ERR(xprt)) {
 727                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 728                         clnt);
 729                 return PTR_ERR(xprt);
 730         }
 731
 732         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 733         if (xps == NULL) {
 734                 xprt_put(xprt);
 735                 return -ENOMEM;
 736         }
 737
 738         pseudoflavor = clnt->cl_auth->au_flavor;
 739
 740         old_timeo = clnt->cl_timeout;
 741         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 742         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 743
 744         rpc_unregister_client(clnt);
 745         __rpc_clnt_remove_pipedir(clnt);
 746         rpc_clnt_debugfs_unregister(clnt);
 747
 748         /*
 749          * A new transport was created.  "clnt" therefore
 750          * becomes the root of a new cl_parent tree.  clnt's
 751          * children, if it has any, still point to the old xprt.
 752          */
 753         parent = clnt->cl_parent;
 754         clnt->cl_parent = clnt;
 755
 756         /*
 757          * The old rpc_auth cache cannot be re-used.  GSS
 758          * contexts in particular are between a single
 759          * client and server.
 760          */
 761         err = rpc_client_register(clnt, pseudoflavor, NULL);
 762         if (err)
 763                 goto out_revert;
 764
 765         synchronize_rcu();
 766         if (parent != clnt)
 767                 rpc_release_client(parent);
 768         xprt_switch_put(oldxps);
 769         xprt_put(old);
 770         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 771         return 0;
 772
 773 out_revert:
 774         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 775         rpc_clnt_set_transport(clnt, old, old_timeo);
 776         clnt->cl_parent = parent;
 777         rpc_client_register(clnt, pseudoflavor, NULL);
 778         xprt_switch_put(xps);
 779         xprt_put(xprt);
 780         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 781         return err;
 782 }
 783 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 784
 785 static
 786 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 787 {
 788         struct rpc_xprt_switch *xps;
 789
 790         rcu_read_lock();
 791         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 792         rcu_read_unlock();
 793         if (xps == NULL)
 794                 return -EAGAIN;
 795         xprt_iter_init_listall(xpi, xps);
 796         xprt_switch_put(xps);
 797         return 0;
 798 }
 799
 800 /**
 801  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 802  * @clnt: pointer to client
 803  * @fn: function to apply
 804  * @data: void pointer to function data
 805  *
 806  * Iterates through the list of RPC transports currently attached to the
 807  * client and applies the function fn(clnt, xprt, data).
 808  *
 809  * On error, the iteration stops, and the function returns the error value.
 810  */
 811 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 812                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 813                 void *data)
 814 {
 815         struct rpc_xprt_iter xpi;
 816         int ret;
 817
 818         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 819         if (ret)
 820                 return ret;
 821         for (;;) {
 822                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 823
 824                 if (!xprt)
 825                         break;
 826                 ret = fn(clnt, xprt, data);
 827                 xprt_put(xprt);
 828                 if (ret < 0)
 829                         break;
 830         }
 831         xprt_iter_destroy(&xpi);
 832         return ret;
 833 }
 834 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 835
 836 /*
 837  * Kill all tasks for the given client.
 838  * XXX: kill their descendants as well?
 839  */
 840 void rpc_killall_tasks(struct rpc_clnt *clnt)
 841 {
 842         struct rpc_task *rovr;
 843
 844
 845         if (list_empty(&clnt->cl_tasks))
 846                 return;
 847         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 848         /*
 849          * Spin lock all_tasks to prevent changes...
 850          */
 851         spin_lock(&clnt->cl_lock);
 852         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 853                 rpc_signal_task(rovr);
 854         spin_unlock(&clnt->cl_lock);
 855 }
 856 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 857
 858 /*
 859  * Properly shut down an RPC client, terminating all outstanding
 860  * requests.
 861  */
 862 void rpc_shutdown_client(struct rpc_clnt *clnt)
 863 {
 864         might_sleep();
 865
 866         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 867                         clnt->cl_program->name,
 868                         rcu_dereference(clnt->cl_xprt)->servername);
 869
 870         while (!list_empty(&clnt->cl_tasks)) {
 871                 rpc_killall_tasks(clnt);
 872                 wait_event_timeout(destroy_wait,
 873                         list_empty(&clnt->cl_tasks), 1*HZ);
 874         }
 875
 876         rpc_release_client(clnt);
 877 }
 878 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 879
 880 /*
 881  * Free an RPC client
 882  */
 883 static struct rpc_clnt *
 884 rpc_free_client(struct rpc_clnt *clnt)
 885 {
 886         struct rpc_clnt *parent = NULL;
 887
 888         dprintk_rcu("RPC:       destroying %s client for %s\n",
 889                         clnt->cl_program->name,
 890                         rcu_dereference(clnt->cl_xprt)->servername);
 891         if (clnt->cl_parent != clnt)
 892                 parent = clnt->cl_parent;
 893         rpc_clnt_debugfs_unregister(clnt);
 894         rpc_clnt_remove_pipedir(clnt);
 895         rpc_unregister_client(clnt);
 896         rpc_free_iostats(clnt->cl_metrics);
 897         clnt->cl_metrics = NULL;
 898         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 899         xprt_iter_destroy(&clnt->cl_xpi);
 900         rpciod_down();
 901         put_cred(clnt->cl_cred);
 902         rpc_free_clid(clnt);
 903         kfree(clnt);
 904         return parent;
 905 }
 906
 907 /*
 908  * Free an RPC client
 909  */
 910 static struct rpc_clnt *
 911 rpc_free_auth(struct rpc_clnt *clnt)
 912 {
 913         if (clnt->cl_auth == NULL)
 914                 return rpc_free_client(clnt);
 915
 916         /*
 917          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 918          *       release remaining GSS contexts. This mechanism ensures
 919          *       that it can do so safely.
 920          */
 921         atomic_inc(&clnt->cl_count);
 922         rpcauth_release(clnt->cl_auth);
 923         clnt->cl_auth = NULL;
 924         if (atomic_dec_and_test(&clnt->cl_count))
 925                 return rpc_free_client(clnt);
 926         return NULL;
 927 }
 928
 929 /*
 930  * Release reference to the RPC client
 931  */
 932 void
 933 rpc_release_client(struct rpc_clnt *clnt)
 934 {
 935         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 936
 937         do {
 938                 if (list_empty(&clnt->cl_tasks))
 939                         wake_up(&destroy_wait);
 940                 if (!atomic_dec_and_test(&clnt->cl_count))
 941                         break;
 942                 clnt = rpc_free_auth(clnt);
 943         } while (clnt != NULL);
 944 }
 945 EXPORT_SYMBOL_GPL(rpc_release_client);
 946
 947 /**
 948  * rpc_bind_new_program - bind a new RPC program to an existing client
 949  * @old: old rpc_client
 950  * @program: rpc program to set
 951  * @vers: rpc program version
 952  *
 953  * Clones the rpc client and sets up a new RPC program. This is mainly
 954  * of use for enabling different RPC programs to share the same transport.
 955  * The Sun NFSv2/v3 ACL protocol can do this.
 956  */
 957 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 958                                       const struct rpc_program *program,
 959                                       u32 vers)
 960 {
 961         struct rpc_create_args args = {
 962                 .program        = program,
 963                 .prognumber     = program->number,
 964                 .version        = vers,
 965                 .authflavor     = old->cl_auth->au_flavor,
 966                 .cred           = old->cl_cred,
 967         };
 968         struct rpc_clnt *clnt;
 969         int err;
 970
 971         clnt = __rpc_clone_client(&args, old);
 972         if (IS_ERR(clnt))
 973                 goto out;
 974         err = rpc_ping(clnt);
 975         if (err != 0) {
 976                 rpc_shutdown_client(clnt);
 977                 clnt = ERR_PTR(err);
 978         }
 979 out:
 980         return clnt;
 981 }
 982 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 983
 984 struct rpc_xprt *
 985 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 986 {
 987         struct rpc_xprt_switch *xps;
 988
 989         if (!xprt)
 990                 return NULL;
 991         rcu_read_lock();
 992         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
 993         atomic_long_inc(&xps->xps_queuelen);
 994         rcu_read_unlock();
 995         atomic_long_inc(&xprt->queuelen);
 996
 997         return xprt;
 998 }
 999
1000 static void
1001 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1002 {
1003         struct rpc_xprt_switch *xps;
1004
1005         atomic_long_dec(&xprt->queuelen);
1006         rcu_read_lock();
1007         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1008         atomic_long_dec(&xps->xps_queuelen);
1009         rcu_read_unlock();
1010
1011         xprt_put(xprt);
1012 }
1013
1014 void rpc_task_release_transport(struct rpc_task *task)
1015 {
1016         struct rpc_xprt *xprt = task->tk_xprt;
1017
1018         if (xprt) {
1019                 task->tk_xprt = NULL;
1020                 if (task->tk_client)
1021                         rpc_task_release_xprt(task->tk_client, xprt);
1022                 else
1023                         xprt_put(xprt);
1024         }
1025 }
1026 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1027
1028 void rpc_task_release_client(struct rpc_task *task)
1029 {
1030         struct rpc_clnt *clnt = task->tk_client;
1031
1032         rpc_task_release_transport(task);
1033         if (clnt != NULL) {
1034                 /* Remove from client task list */
1035                 spin_lock(&clnt->cl_lock);
1036                 list_del(&task->tk_task);
1037                 spin_unlock(&clnt->cl_lock);
1038                 task->tk_client = NULL;
1039
1040                 rpc_release_client(clnt);
1041         }
1042 }
1043
1044 static struct rpc_xprt *
1045 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1046 {
1047         struct rpc_xprt *xprt;
1048
1049         rcu_read_lock();
1050         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1051         rcu_read_unlock();
1052         return rpc_task_get_xprt(clnt, xprt);
1053 }
1054
1055 static struct rpc_xprt *
1056 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1057 {
1058         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1059 }
1060
1061 static
1062 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1063 {
1064         if (task->tk_xprt)
1065                 return;
1066         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1067                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1068         else
1069                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1070 }
1071
1072 static
1073 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1074 {
1075
1076         if (clnt != NULL) {
1077                 rpc_task_set_transport(task, clnt);
1078                 task->tk_client = clnt;
1079                 atomic_inc(&clnt->cl_count);
1080                 if (clnt->cl_softrtry)
1081                         task->tk_flags |= RPC_TASK_SOFT;
1082                 if (clnt->cl_softerr)
1083                         task->tk_flags |= RPC_TASK_TIMEOUT;
1084                 if (clnt->cl_noretranstimeo)
1085                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1086                 if (atomic_read(&clnt->cl_swapper))
1087                         task->tk_flags |= RPC_TASK_SWAPPER;
1088                 /* Add to the client's list of all tasks */
1089                 spin_lock(&clnt->cl_lock);
1090                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1091                 spin_unlock(&clnt->cl_lock);
1092         }
1093 }
1094
1095 static void
1096 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1097 {
1098         if (msg != NULL) {
1099                 task->tk_msg.rpc_proc = msg->rpc_proc;
1100                 task->tk_msg.rpc_argp = msg->rpc_argp;
1101                 task->tk_msg.rpc_resp = msg->rpc_resp;
1102                 if (msg->rpc_cred != NULL)
1103                         task->tk_msg.rpc_cred = get_cred(msg->rpc_cred);
1104         }
1105 }
1106
1107 /*
1108  * Default callback for async RPC calls
1109  */
1110 static void
1111 rpc_default_callback(struct rpc_task *task, void *data)
1112 {
1113 }
1114
1115 static const struct rpc_call_ops rpc_default_ops = {
1116         .rpc_call_done = rpc_default_callback,
1117 };
1118
1119 /**
1120  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1121  * @task_setup_data: pointer to task initialisation data
1122  */
1123 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1124 {
1125         struct rpc_task *task;
1126
1127         task = rpc_new_task(task_setup_data);
1128
1129         rpc_task_set_client(task, task_setup_data->rpc_client);
1130         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1131
1132         if (task->tk_action == NULL)
1133                 rpc_call_start(task);
1134
1135         atomic_inc(&task->tk_count);
1136         rpc_execute(task);
1137         return task;
1138 }
1139 EXPORT_SYMBOL_GPL(rpc_run_task);
1140
1141 /**
1142  * rpc_call_sync - Perform a synchronous RPC call
1143  * @clnt: pointer to RPC client
1144  * @msg: RPC call parameters
1145  * @flags: RPC call flags
1146  */
1147 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1148 {
1149         struct rpc_task *task;
1150         struct rpc_task_setup task_setup_data = {
1151                 .rpc_client = clnt,
1152                 .rpc_message = msg,
1153                 .callback_ops = &rpc_default_ops,
1154                 .flags = flags,
1155         };
1156         int status;
1157
1158         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1159         if (flags & RPC_TASK_ASYNC) {
1160                 rpc_release_calldata(task_setup_data.callback_ops,
1161                         task_setup_data.callback_data);
1162                 return -EINVAL;
1163         }
1164
1165         task = rpc_run_task(&task_setup_data);
1166         if (IS_ERR(task))
1167                 return PTR_ERR(task);
1168         status = task->tk_status;
1169         rpc_put_task(task);
1170         return status;
1171 }
1172 EXPORT_SYMBOL_GPL(rpc_call_sync);
1173
1174 /**
1175  * rpc_call_async - Perform an asynchronous RPC call
1176  * @clnt: pointer to RPC client
1177  * @msg: RPC call parameters
1178  * @flags: RPC call flags
1179  * @tk_ops: RPC call ops
1180  * @data: user call data
1181  */
1182 int
1183 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1184                const struct rpc_call_ops *tk_ops, void *data)
1185 {
1186         struct rpc_task *task;
1187         struct rpc_task_setup task_setup_data = {
1188                 .rpc_client = clnt,
1189                 .rpc_message = msg,
1190                 .callback_ops = tk_ops,
1191                 .callback_data = data,
1192                 .flags = flags|RPC_TASK_ASYNC,
1193         };
1194
1195         task = rpc_run_task(&task_setup_data);
1196         if (IS_ERR(task))
1197                 return PTR_ERR(task);
1198         rpc_put_task(task);
1199         return 0;
1200 }
1201 EXPORT_SYMBOL_GPL(rpc_call_async);
1202
1203 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1204 static void call_bc_encode(struct rpc_task *task);
1205
1206 /**
1207  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1208  * rpc_execute against it
1209  * @req: RPC request
1210  */
1211 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1212 {
1213         struct rpc_task *task;
1214         struct rpc_task_setup task_setup_data = {
1215                 .callback_ops = &rpc_default_ops,
1216                 .flags = RPC_TASK_SOFTCONN |
1217                         RPC_TASK_NO_RETRANS_TIMEOUT,
1218         };
1219
1220         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1221         /*
1222          * Create an rpc_task to send the data
1223          */
1224         task = rpc_new_task(&task_setup_data);
1225         xprt_init_bc_request(req, task);
1226
1227         task->tk_action = call_bc_encode;
1228         atomic_inc(&task->tk_count);
1229         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1230         rpc_execute(task);
1231
1232         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1233         return task;
1234 }
1235 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1236
1237 /**
1238  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1239  * @req: RPC request to prepare
1240  * @pages: vector of struct page pointers
1241  * @base: offset in first page where receive should start, in bytes
1242  * @len: expected size of the upper layer data payload, in bytes
1243  * @hdrsize: expected size of upper layer reply header, in XDR words
1244  *
1245  */
1246 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1247                              unsigned int base, unsigned int len,
1248                              unsigned int hdrsize)
1249 {
1250         /* Subtract one to force an extra word of buffer space for the
1251          * payload's XDR pad to fall into the rcv_buf's tail iovec.
1252          */
1253         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
1254
1255         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1256         trace_rpc_reply_pages(req);
1257 }
1258 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1259
1260 void
1261 rpc_call_start(struct rpc_task *task)
1262 {
1263         task->tk_action = call_start;
1264 }
1265 EXPORT_SYMBOL_GPL(rpc_call_start);
1266
1267 /**
1268  * rpc_peeraddr - extract remote peer address from clnt's xprt
1269  * @clnt: RPC client structure
1270  * @buf: target buffer
1271  * @bufsize: length of target buffer
1272  *
1273  * Returns the number of bytes that are actually in the stored address.
1274  */
1275 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1276 {
1277         size_t bytes;
1278         struct rpc_xprt *xprt;
1279
1280         rcu_read_lock();
1281         xprt = rcu_dereference(clnt->cl_xprt);
1282
1283         bytes = xprt->addrlen;
1284         if (bytes > bufsize)
1285                 bytes = bufsize;
1286         memcpy(buf, &xprt->addr, bytes);
1287         rcu_read_unlock();
1288
1289         return bytes;
1290 }
1291 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1292
1293 /**
1294  * rpc_peeraddr2str - return remote peer address in printable format
1295  * @clnt: RPC client structure
1296  * @format: address format
1297  *
1298  * NB: the lifetime of the memory referenced by the returned pointer is
1299  * the same as the rpc_xprt itself.  As long as the caller uses this
1300  * pointer, it must hold the RCU read lock.
1301  */
1302 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1303                              enum rpc_display_format_t format)
1304 {
1305         struct rpc_xprt *xprt;
1306
1307         xprt = rcu_dereference(clnt->cl_xprt);
1308
1309         if (xprt->address_strings[format] != NULL)
1310                 return xprt->address_strings[format];
1311         else
1312                 return "unprintable";
1313 }
1314 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1315
1316 static const struct sockaddr_in rpc_inaddr_loopback = {
1317         .sin_family             = AF_INET,
1318         .sin_addr.s_addr        = htonl(INADDR_ANY),
1319 };
1320
1321 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1322         .sin6_family            = AF_INET6,
1323         .sin6_addr              = IN6ADDR_ANY_INIT,
1324 };
1325
1326 /*
1327  * Try a getsockname() on a connected datagram socket.  Using a
1328  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1329  * This conserves the ephemeral port number space.
1330  *
1331  * Returns zero and fills in "buf" if successful; otherwise, a
1332  * negative errno is returned.
1333  */
1334 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1335                         struct sockaddr *buf)
1336 {
1337         struct socket *sock;
1338         int err;
1339
1340         err = __sock_create(net, sap->sa_family,
1341                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1342         if (err < 0) {
1343                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1344                 goto out;
1345         }
1346
1347         switch (sap->sa_family) {
1348         case AF_INET:
1349                 err = kernel_bind(sock,
1350                                 (struct sockaddr *)&rpc_inaddr_loopback,
1351                                 sizeof(rpc_inaddr_loopback));
1352                 break;
1353         case AF_INET6:
1354                 err = kernel_bind(sock,
1355                                 (struct sockaddr *)&rpc_in6addr_loopback,
1356                                 sizeof(rpc_in6addr_loopback));
1357                 break;
1358         default:
1359                 err = -EAFNOSUPPORT;
1360                 goto out;
1361         }
1362         if (err < 0) {
1363                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1364                 goto out_release;
1365         }
1366
1367         err = kernel_connect(sock, sap, salen, 0);
1368         if (err < 0) {
1369                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1370                 goto out_release;
1371         }
1372
1373         err = kernel_getsockname(sock, buf);
1374         if (err < 0) {
1375                 dprintk("RPC:       getsockname failed (%d)\n", err);
1376                 goto out_release;
1377         }
1378
1379         err = 0;
1380         if (buf->sa_family == AF_INET6) {
1381                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1382                 sin6->sin6_scope_id = 0;
1383         }
1384         dprintk("RPC:       %s succeeded\n", __func__);
1385
1386 out_release:
1387         sock_release(sock);
1388 out:
1389         return err;
1390 }
1391
1392 /*
1393  * Scraping a connected socket failed, so we don't have a useable
1394  * local address.  Fallback: generate an address that will prevent
1395  * the server from calling us back.
1396  *
1397  * Returns zero and fills in "buf" if successful; otherwise, a
1398  * negative errno is returned.
1399  */
1400 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1401 {
1402         switch (family) {
1403         case AF_INET:
1404                 if (buflen < sizeof(rpc_inaddr_loopback))
1405                         return -EINVAL;
1406                 memcpy(buf, &rpc_inaddr_loopback,
1407                                 sizeof(rpc_inaddr_loopback));
1408                 break;
1409         case AF_INET6:
1410                 if (buflen < sizeof(rpc_in6addr_loopback))
1411                         return -EINVAL;
1412                 memcpy(buf, &rpc_in6addr_loopback,
1413                                 sizeof(rpc_in6addr_loopback));
1414                 break;
1415         default:
1416                 dprintk("RPC:       %s: address family not supported\n",
1417                         __func__);
1418                 return -EAFNOSUPPORT;
1419         }
1420         dprintk("RPC:       %s: succeeded\n", __func__);
1421         return 0;
1422 }
1423
1424 /**
1425  * rpc_localaddr - discover local endpoint address for an RPC client
1426  * @clnt: RPC client structure
1427  * @buf: target buffer
1428  * @buflen: size of target buffer, in bytes
1429  *
1430  * Returns zero and fills in "buf" and "buflen" if successful;
1431  * otherwise, a negative errno is returned.
1432  *
1433  * This works even if the underlying transport is not currently connected,
1434  * or if the upper layer never previously provided a source address.
1435  *
1436  * The result of this function call is transient: multiple calls in
1437  * succession may give different results, depending on how local
1438  * networking configuration changes over time.
1439  */
1440 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1441 {
1442         struct sockaddr_storage address;
1443         struct sockaddr *sap = (struct sockaddr *)&address;
1444         struct rpc_xprt *xprt;
1445         struct net *net;
1446         size_t salen;
1447         int err;
1448
1449         rcu_read_lock();
1450         xprt = rcu_dereference(clnt->cl_xprt);
1451         salen = xprt->addrlen;
1452         memcpy(sap, &xprt->addr, salen);
1453         net = get_net(xprt->xprt_net);
1454         rcu_read_unlock();
1455
1456         rpc_set_port(sap, 0);
1457         err = rpc_sockname(net, sap, salen, buf);
1458         put_net(net);
1459         if (err != 0)
1460                 /* Couldn't discover local address, return ANYADDR */
1461                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1462         return 0;
1463 }
1464 EXPORT_SYMBOL_GPL(rpc_localaddr);
1465
1466 void
1467 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1468 {
1469         struct rpc_xprt *xprt;
1470
1471         rcu_read_lock();
1472         xprt = rcu_dereference(clnt->cl_xprt);
1473         if (xprt->ops->set_buffer_size)
1474                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1475         rcu_read_unlock();
1476 }
1477 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1478
1479 /**
1480  * rpc_net_ns - Get the network namespace for this RPC client
1481  * @clnt: RPC client to query
1482  *
1483  */
1484 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1485 {
1486         struct net *ret;
1487
1488         rcu_read_lock();
1489         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1490         rcu_read_unlock();
1491         return ret;
1492 }
1493 EXPORT_SYMBOL_GPL(rpc_net_ns);
1494
1495 /**
1496  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1497  * @clnt: RPC client to query
1498  *
1499  * For stream transports, this is one RPC record fragment (see RFC
1500  * 1831), as we don't support multi-record requests yet.  For datagram
1501  * transports, this is the size of an IP packet minus the IP, UDP, and
1502  * RPC header sizes.
1503  */
1504 size_t rpc_max_payload(struct rpc_clnt *clnt)
1505 {
1506         size_t ret;
1507
1508         rcu_read_lock();
1509         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1510         rcu_read_unlock();
1511         return ret;
1512 }
1513 EXPORT_SYMBOL_GPL(rpc_max_payload);
1514
1515 /**
1516  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1517  * @clnt: RPC client to query
1518  */
1519 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1520 {
1521         struct rpc_xprt *xprt;
1522         size_t ret;
1523
1524         rcu_read_lock();
1525         xprt = rcu_dereference(clnt->cl_xprt);
1526         ret = xprt->ops->bc_maxpayload(xprt);
1527         rcu_read_unlock();
1528         return ret;
1529 }
1530 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1531
1532 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1533 {
1534         struct rpc_xprt *xprt;
1535         unsigned int ret;
1536
1537         rcu_read_lock();
1538         xprt = rcu_dereference(clnt->cl_xprt);
1539         ret = xprt->ops->bc_num_slots(xprt);
1540         rcu_read_unlock();
1541         return ret;
1542 }
1543 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1544
1545 /**
1546  * rpc_force_rebind - force transport to check that remote port is unchanged
1547  * @clnt: client to rebind
1548  *
1549  */
1550 void rpc_force_rebind(struct rpc_clnt *clnt)
1551 {
1552         if (clnt->cl_autobind) {
1553                 rcu_read_lock();
1554                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1555                 rcu_read_unlock();
1556         }
1557 }
1558 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1559
1560 static int
1561 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1562 {
1563         task->tk_status = 0;
1564         task->tk_rpc_status = 0;
1565         task->tk_action = action;
1566         return 1;
1567 }
1568
1569 /*
1570  * Restart an (async) RPC call. Usually called from within the
1571  * exit handler.
1572  */
1573 int
1574 rpc_restart_call(struct rpc_task *task)
1575 {
1576         return __rpc_restart_call(task, call_start);
1577 }
1578 EXPORT_SYMBOL_GPL(rpc_restart_call);
1579
1580 /*
1581  * Restart an (async) RPC call from the call_prepare state.
1582  * Usually called from within the exit handler.
1583  */
1584 int
1585 rpc_restart_call_prepare(struct rpc_task *task)
1586 {
1587         if (task->tk_ops->rpc_call_prepare != NULL)
1588                 return __rpc_restart_call(task, rpc_prepare_task);
1589         return rpc_restart_call(task);
1590 }
1591 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1592
1593 const char
1594 *rpc_proc_name(const struct rpc_task *task)
1595 {
1596         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1597
1598         if (proc) {
1599                 if (proc->p_name)
1600                         return proc->p_name;
1601                 else
1602                         return "NULL";
1603         } else
1604                 return "no proc";
1605 }
1606
1607 static void
1608 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1609 {
1610         task->tk_rpc_status = rpc_status;
1611         rpc_exit(task, tk_status);
1612 }
1613
1614 static void
1615 rpc_call_rpcerror(struct rpc_task *task, int status)
1616 {
1617         __rpc_call_rpcerror(task, status, status);
1618 }
1619
1620 /*
1621  * 0.  Initial state
1622  *
1623  *     Other FSM states can be visited zero or more times, but
1624  *     this state is visited exactly once for each RPC.
1625  */
1626 static void
1627 call_start(struct rpc_task *task)
1628 {
1629         struct rpc_clnt *clnt = task->tk_client;
1630         int idx = task->tk_msg.rpc_proc->p_statidx;
1631
1632         trace_rpc_request(task);
1633         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1634                         clnt->cl_program->name, clnt->cl_vers,
1635                         rpc_proc_name(task),
1636                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1637
1638         /* Increment call count (version might not be valid for ping) */
1639         if (clnt->cl_program->version[clnt->cl_vers])
1640                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1641         clnt->cl_stats->rpccnt++;
1642         task->tk_action = call_reserve;
1643         rpc_task_set_transport(task, clnt);
1644 }
1645
1646 /*
1647  * 1.   Reserve an RPC call slot
1648  */
1649 static void
1650 call_reserve(struct rpc_task *task)
1651 {
1652         dprint_status(task);
1653
1654         task->tk_status  = 0;
1655         task->tk_action  = call_reserveresult;
1656         xprt_reserve(task);
1657 }
1658
1659 static void call_retry_reserve(struct rpc_task *task);
1660
1661 /*
1662  * 1b.  Grok the result of xprt_reserve()
1663  */
1664 static void
1665 call_reserveresult(struct rpc_task *task)
1666 {
1667         int status = task->tk_status;
1668
1669         dprint_status(task);
1670
1671         /*
1672          * After a call to xprt_reserve(), we must have either
1673          * a request slot or else an error status.
1674          */
1675         task->tk_status = 0;
1676         if (status >= 0) {
1677                 if (task->tk_rqstp) {
1678                         task->tk_action = call_refresh;
1679                         return;
1680                 }
1681
1682                 rpc_call_rpcerror(task, -EIO);
1683                 return;
1684         }
1685
1686         /*
1687          * Even though there was an error, we may have acquired
1688          * a request slot somehow.  Make sure not to leak it.
1689          */
1690         if (task->tk_rqstp)
1691                 xprt_release(task);
1692
1693         switch (status) {
1694         case -ENOMEM:
1695                 rpc_delay(task, HZ >> 2);
1696                 /* fall through */
1697         case -EAGAIN:   /* woken up; retry */
1698                 task->tk_action = call_retry_reserve;
1699                 return;
1700         default:
1701                 rpc_call_rpcerror(task, status);
1702         }
1703 }
1704
1705 /*
1706  * 1c.  Retry reserving an RPC call slot
1707  */
1708 static void
1709 call_retry_reserve(struct rpc_task *task)
1710 {
1711         dprint_status(task);
1712
1713         task->tk_status  = 0;
1714         task->tk_action  = call_reserveresult;
1715         xprt_retry_reserve(task);
1716 }
1717
1718 /*
1719  * 2.   Bind and/or refresh the credentials
1720  */
1721 static void
1722 call_refresh(struct rpc_task *task)
1723 {
1724         dprint_status(task);
1725
1726         task->tk_action = call_refreshresult;
1727         task->tk_status = 0;
1728         task->tk_client->cl_stats->rpcauthrefresh++;
1729         rpcauth_refreshcred(task);
1730 }
1731
1732 /*
1733  * 2a.  Process the results of a credential refresh
1734  */
1735 static void
1736 call_refreshresult(struct rpc_task *task)
1737 {
1738         int status = task->tk_status;
1739
1740         dprint_status(task);
1741
1742         task->tk_status = 0;
1743         task->tk_action = call_refresh;
1744         switch (status) {
1745         case 0:
1746                 if (rpcauth_uptodatecred(task)) {
1747                         task->tk_action = call_allocate;
1748                         return;
1749                 }
1750                 /* Use rate-limiting and a max number of retries if refresh
1751                  * had status 0 but failed to update the cred.
1752                  */
1753                 /* fall through */
1754         case -ETIMEDOUT:
1755                 rpc_delay(task, 3*HZ);
1756                 /* fall through */
1757         case -EAGAIN:
1758                 status = -EACCES;
1759                 /* fall through */
1760         case -EKEYEXPIRED:
1761                 if (!task->tk_cred_retry)
1762                         break;
1763                 task->tk_cred_retry--;
1764                 dprintk("RPC: %5u %s: retry refresh creds\n",
1765                                 task->tk_pid, __func__);
1766                 return;
1767         }
1768         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1769                                 task->tk_pid, __func__, status);
1770         rpc_call_rpcerror(task, status);
1771 }
1772
1773 /*
1774  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1775  *      (Note: buffer memory is freed in xprt_release).
1776  */
1777 static void
1778 call_allocate(struct rpc_task *task)
1779 {
1780         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1781         struct rpc_rqst *req = task->tk_rqstp;
1782         struct rpc_xprt *xprt = req->rq_xprt;
1783         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1784         int status;
1785
1786         dprint_status(task);
1787
1788         task->tk_status = 0;
1789         task->tk_action = call_encode;
1790
1791         if (req->rq_buffer)
1792                 return;
1793
1794         if (proc->p_proc != 0) {
1795                 BUG_ON(proc->p_arglen == 0);
1796                 if (proc->p_decode != NULL)
1797                         BUG_ON(proc->p_replen == 0);
1798         }
1799
1800         /*
1801          * Calculate the size (in quads) of the RPC call
1802          * and reply headers, and convert both values
1803          * to byte sizes.
1804          */
1805         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1806                            proc->p_arglen;
1807         req->rq_callsize <<= 2;
1808         /*
1809          * Note: the reply buffer must at minimum allocate enough space
1810          * for the 'struct accepted_reply' from RFC5531.
1811          */
1812         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1813                         max_t(size_t, proc->p_replen, 2);
1814         req->rq_rcvsize <<= 2;
1815
1816         status = xprt->ops->buf_alloc(task);
1817         xprt_inject_disconnect(xprt);
1818         if (status == 0)
1819                 return;
1820         if (status != -ENOMEM) {
1821                 rpc_call_rpcerror(task, status);
1822                 return;
1823         }
1824
1825         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1826
1827         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1828                 task->tk_action = call_allocate;
1829                 rpc_delay(task, HZ>>4);
1830                 return;
1831         }
1832
1833         rpc_call_rpcerror(task, -ERESTARTSYS);
1834 }
1835
1836 static int
1837 rpc_task_need_encode(struct rpc_task *task)
1838 {
1839         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1840                 (!(task->tk_flags & RPC_TASK_SENT) ||
1841                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1842                  xprt_request_need_retransmit(task));
1843 }
1844
1845 static void
1846 rpc_xdr_encode(struct rpc_task *task)
1847 {
1848         struct rpc_rqst *req = task->tk_rqstp;
1849         struct xdr_stream xdr;
1850
1851         xdr_buf_init(&req->rq_snd_buf,
1852                      req->rq_buffer,
1853                      req->rq_callsize);
1854         xdr_buf_init(&req->rq_rcv_buf,
1855                      req->rq_rbuffer,
1856                      req->rq_rcvsize);
1857
1858         req->rq_reply_bytes_recvd = 0;
1859         req->rq_snd_buf.head[0].iov_len = 0;
1860         xdr_init_encode(&xdr, &req->rq_snd_buf,
1861                         req->rq_snd_buf.head[0].iov_base, req);
1862         xdr_free_bvec(&req->rq_snd_buf);
1863         if (rpc_encode_header(task, &xdr))
1864                 return;
1865
1866         task->tk_status = rpcauth_wrap_req(task, &xdr);
1867 }
1868
1869 /*
1870  * 3.   Encode arguments of an RPC call
1871  */
1872 static void
1873 call_encode(struct rpc_task *task)
1874 {
1875         if (!rpc_task_need_encode(task))
1876                 goto out;
1877         dprint_status(task);
1878         /* Dequeue task from the receive queue while we're encoding */
1879         xprt_request_dequeue_xprt(task);
1880         /* Encode here so that rpcsec_gss can use correct sequence number. */
1881         rpc_xdr_encode(task);
1882         /* Did the encode result in an error condition? */
1883         if (task->tk_status != 0) {
1884                 /* Was the error nonfatal? */
1885                 switch (task->tk_status) {
1886                 case -EAGAIN:
1887                 case -ENOMEM:
1888                         rpc_delay(task, HZ >> 4);
1889                         break;
1890                 case -EKEYEXPIRED:
1891                         if (!task->tk_cred_retry) {
1892                                 rpc_exit(task, task->tk_status);
1893                         } else {
1894                                 task->tk_action = call_refresh;
1895                                 task->tk_cred_retry--;
1896                                 dprintk("RPC: %5u %s: retry refresh creds\n",
1897                                         task->tk_pid, __func__);
1898                         }
1899                         break;
1900                 default:
1901                         rpc_call_rpcerror(task, task->tk_status);
1902                 }
1903                 return;
1904         }
1905
1906         /* Add task to reply queue before transmission to avoid races */
1907         if (rpc_reply_expected(task))
1908                 xprt_request_enqueue_receive(task);
1909         xprt_request_enqueue_transmit(task);
1910 out:
1911         task->tk_action = call_transmit;
1912         /* Check that the connection is OK */
1913         if (!xprt_bound(task->tk_xprt))
1914                 task->tk_action = call_bind;
1915         else if (!xprt_connected(task->tk_xprt))
1916                 task->tk_action = call_connect;
1917 }
1918
1919 /*
1920  * Helpers to check if the task was already transmitted, and
1921  * to take action when that is the case.
1922  */
1923 static bool
1924 rpc_task_transmitted(struct rpc_task *task)
1925 {
1926         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1927 }
1928
1929 static void
1930 rpc_task_handle_transmitted(struct rpc_task *task)
1931 {
1932         xprt_end_transmit(task);
1933         task->tk_action = call_transmit_status;
1934 }
1935
1936 /*
1937  * 4.   Get the server port number if not yet set
1938  */
1939 static void
1940 call_bind(struct rpc_task *task)
1941 {
1942         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1943
1944         if (rpc_task_transmitted(task)) {
1945                 rpc_task_handle_transmitted(task);
1946                 return;
1947         }
1948
1949         if (xprt_bound(xprt)) {
1950                 task->tk_action = call_connect;
1951                 return;
1952         }
1953
1954         dprint_status(task);
1955
1956         task->tk_action = call_bind_status;
1957         if (!xprt_prepare_transmit(task))
1958                 return;
1959
1960         xprt->ops->rpcbind(task);
1961 }
1962
1963 /*
1964  * 4a.  Sort out bind result
1965  */
1966 static void
1967 call_bind_status(struct rpc_task *task)
1968 {
1969         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1970         int status = -EIO;
1971
1972         if (rpc_task_transmitted(task)) {
1973                 rpc_task_handle_transmitted(task);
1974                 return;
1975         }
1976
1977         dprint_status(task);
1978         trace_rpc_bind_status(task);
1979         if (task->tk_status >= 0)
1980                 goto out_next;
1981         if (xprt_bound(xprt)) {
1982                 task->tk_status = 0;
1983                 goto out_next;
1984         }
1985
1986         switch (task->tk_status) {
1987         case -ENOMEM:
1988                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1989                 rpc_delay(task, HZ >> 2);
1990                 goto retry_timeout;
1991         case -EACCES:
1992                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1993                                 "unavailable\n", task->tk_pid);
1994                 /* fail immediately if this is an RPC ping */
1995                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1996                         status = -EOPNOTSUPP;
1997                         break;
1998                 }
1999                 if (task->tk_rebind_retry == 0)
2000                         break;
2001                 task->tk_rebind_retry--;
2002                 rpc_delay(task, 3*HZ);
2003                 goto retry_timeout;
2004         case -ENOBUFS:
2005                 rpc_delay(task, HZ >> 2);
2006                 goto retry_timeout;
2007         case -EAGAIN:
2008                 goto retry_timeout;
2009         case -ETIMEDOUT:
2010                 dprintk("RPC: %5u rpcbind request timed out\n",
2011                                 task->tk_pid);
2012                 goto retry_timeout;
2013         case -EPFNOSUPPORT:
2014                 /* server doesn't support any rpcbind version we know of */
2015                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
2016                                 task->tk_pid);
2017                 break;
2018         case -EPROTONOSUPPORT:
2019                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
2020                                 task->tk_pid);
2021                 goto retry_timeout;
2022         case -ECONNREFUSED:             /* connection problems */
2023         case -ECONNRESET:
2024         case -ECONNABORTED:
2025         case -ENOTCONN:
2026         case -EHOSTDOWN:
2027         case -ENETDOWN:
2028         case -EHOSTUNREACH:
2029         case -ENETUNREACH:
2030         case -EPIPE:
2031                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
2032                                 task->tk_pid, task->tk_status);
2033                 if (!RPC_IS_SOFTCONN(task)) {
2034                         rpc_delay(task, 5*HZ);
2035                         goto retry_timeout;
2036                 }
2037                 status = task->tk_status;
2038                 break;
2039         default:
2040                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
2041                                 task->tk_pid, -task->tk_status);
2042         }
2043
2044         rpc_call_rpcerror(task, status);
2045         return;
2046 out_next:
2047         task->tk_action = call_connect;
2048         return;
2049 retry_timeout:
2050         task->tk_status = 0;
2051         task->tk_action = call_bind;
2052         rpc_check_timeout(task);
2053 }
2054
2055 /*
2056  * 4b.  Connect to the RPC server
2057  */
2058 static void
2059 call_connect(struct rpc_task *task)
2060 {
2061         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2062
2063         if (rpc_task_transmitted(task)) {
2064                 rpc_task_handle_transmitted(task);
2065                 return;
2066         }
2067
2068         if (xprt_connected(xprt)) {
2069                 task->tk_action = call_transmit;
2070                 return;
2071         }
2072
2073         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
2074                         task->tk_pid, xprt,
2075                         (xprt_connected(xprt) ? "is" : "is not"));
2076
2077         task->tk_action = call_connect_status;
2078         if (task->tk_status < 0)
2079                 return;
2080         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2081                 rpc_call_rpcerror(task, -ENOTCONN);
2082                 return;
2083         }
2084         if (!xprt_prepare_transmit(task))
2085                 return;
2086         xprt_connect(task);
2087 }
2088
2089 /*
2090  * 4c.  Sort out connect result
2091  */
2092 static void
2093 call_connect_status(struct rpc_task *task)
2094 {
2095         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2096         struct rpc_clnt *clnt = task->tk_client;
2097         int status = task->tk_status;
2098
2099         if (rpc_task_transmitted(task)) {
2100                 rpc_task_handle_transmitted(task);
2101                 return;
2102         }
2103
2104         dprint_status(task);
2105         trace_rpc_connect_status(task);
2106
2107         if (task->tk_status == 0) {
2108                 clnt->cl_stats->netreconn++;
2109                 goto out_next;
2110         }
2111         if (xprt_connected(xprt)) {
2112                 task->tk_status = 0;
2113                 goto out_next;
2114         }
2115
2116         task->tk_status = 0;
2117         switch (status) {
2118         case -ECONNREFUSED:
2119                 /* A positive refusal suggests a rebind is needed. */
2120                 if (RPC_IS_SOFTCONN(task))
2121                         break;
2122                 if (clnt->cl_autobind) {
2123                         rpc_force_rebind(clnt);
2124                         goto out_retry;
2125                 }
2126                 /* fall through */
2127         case -ECONNRESET:
2128         case -ECONNABORTED:
2129         case -ENETDOWN:
2130         case -ENETUNREACH:
2131         case -EHOSTUNREACH:
2132         case -EPIPE:
2133         case -EPROTO:
2134                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2135                                             task->tk_rqstp->rq_connect_cookie);
2136                 if (RPC_IS_SOFTCONN(task))
2137                         break;
2138                 /* retry with existing socket, after a delay */
2139                 rpc_delay(task, 3*HZ);
2140                 /* fall through */
2141         case -EADDRINUSE:
2142         case -ENOTCONN:
2143         case -EAGAIN:
2144         case -ETIMEDOUT:
2145                 goto out_retry;
2146         case -ENOBUFS:
2147                 rpc_delay(task, HZ >> 2);
2148                 goto out_retry;
2149         }
2150         rpc_call_rpcerror(task, status);
2151         return;
2152 out_next:
2153         task->tk_action = call_transmit;
2154         return;
2155 out_retry:
2156         /* Check for timeouts before looping back to call_bind */
2157         task->tk_action = call_bind;
2158         rpc_check_timeout(task);
2159 }
2160
2161 /*
2162  * 5.   Transmit the RPC request, and wait for reply
2163  */
2164 static void
2165 call_transmit(struct rpc_task *task)
2166 {
2167         if (rpc_task_transmitted(task)) {
2168                 rpc_task_handle_transmitted(task);
2169                 return;
2170         }
2171
2172         dprint_status(task);
2173
2174         task->tk_action = call_transmit_status;
2175         if (!xprt_prepare_transmit(task))
2176                 return;
2177         task->tk_status = 0;
2178         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2179                 if (!xprt_connected(task->tk_xprt)) {
2180                         task->tk_status = -ENOTCONN;
2181                         return;
2182                 }
2183                 xprt_transmit(task);
2184         }
2185         xprt_end_transmit(task);
2186 }
2187
2188 /*
2189  * 5a.  Handle cleanup after a transmission
2190  */
2191 static void
2192 call_transmit_status(struct rpc_task *task)
2193 {
2194         task->tk_action = call_status;
2195
2196         /*
2197          * Common case: success.  Force the compiler to put this
2198          * test first.
2199          */
2200         if (rpc_task_transmitted(task)) {
2201                 task->tk_status = 0;
2202                 xprt_request_wait_receive(task);
2203                 return;
2204         }
2205
2206         switch (task->tk_status) {
2207         default:
2208                 dprint_status(task);
2209                 break;
2210         case -EBADMSG:
2211                 task->tk_status = 0;
2212                 task->tk_action = call_encode;
2213                 break;
2214                 /*
2215                  * Special cases: if we've been waiting on the
2216                  * socket's write_space() callback, or if the
2217                  * socket just returned a connection error,
2218                  * then hold onto the transport lock.
2219                  */
2220         case -ENOBUFS:
2221                 rpc_delay(task, HZ>>2);
2222                 /* fall through */
2223         case -EBADSLT:
2224         case -EAGAIN:
2225                 task->tk_action = call_transmit;
2226                 task->tk_status = 0;
2227                 break;
2228         case -ECONNREFUSED:
2229         case -EHOSTDOWN:
2230         case -ENETDOWN:
2231         case -EHOSTUNREACH:
2232         case -ENETUNREACH:
2233         case -EPERM:
2234                 if (RPC_IS_SOFTCONN(task)) {
2235                         if (!task->tk_msg.rpc_proc->p_proc)
2236                                 trace_xprt_ping(task->tk_xprt,
2237                                                 task->tk_status);
2238                         rpc_call_rpcerror(task, task->tk_status);
2239                         return;
2240                 }
2241                 /* fall through */
2242         case -ECONNRESET:
2243         case -ECONNABORTED:
2244         case -EADDRINUSE:
2245         case -ENOTCONN:
2246         case -EPIPE:
2247                 task->tk_action = call_bind;
2248                 task->tk_status = 0;
2249                 break;
2250         }
2251         rpc_check_timeout(task);
2252 }
2253
2254 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2255 static void call_bc_transmit(struct rpc_task *task);
2256 static void call_bc_transmit_status(struct rpc_task *task);
2257
2258 static void
2259 call_bc_encode(struct rpc_task *task)
2260 {
2261         xprt_request_enqueue_transmit(task);
2262         task->tk_action = call_bc_transmit;
2263 }
2264
2265 /*
2266  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2267  * addition, disconnect on connectivity errors.
2268  */
2269 static void
2270 call_bc_transmit(struct rpc_task *task)
2271 {
2272         task->tk_action = call_bc_transmit_status;
2273         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2274                 if (!xprt_prepare_transmit(task))
2275                         return;
2276                 task->tk_status = 0;
2277                 xprt_transmit(task);
2278         }
2279         xprt_end_transmit(task);
2280 }
2281
2282 static void
2283 call_bc_transmit_status(struct rpc_task *task)
2284 {
2285         struct rpc_rqst *req = task->tk_rqstp;
2286
2287         if (rpc_task_transmitted(task))
2288                 task->tk_status = 0;
2289
2290         dprint_status(task);
2291
2292         switch (task->tk_status) {
2293         case 0:
2294                 /* Success */
2295         case -ENETDOWN:
2296         case -EHOSTDOWN:
2297         case -EHOSTUNREACH:
2298         case -ENETUNREACH:
2299         case -ECONNRESET:
2300         case -ECONNREFUSED:
2301         case -EADDRINUSE:
2302         case -ENOTCONN:
2303         case -EPIPE:
2304                 break;
2305         case -ENOBUFS:
2306                 rpc_delay(task, HZ>>2);
2307                 /* fall through */
2308         case -EBADSLT:
2309         case -EAGAIN:
2310                 task->tk_status = 0;
2311                 task->tk_action = call_bc_transmit;
2312                 return;
2313         case -ETIMEDOUT:
2314                 /*
2315                  * Problem reaching the server.  Disconnect and let the
2316                  * forechannel reestablish the connection.  The server will
2317                  * have to retransmit the backchannel request and we'll
2318                  * reprocess it.  Since these ops are idempotent, there's no
2319                  * need to cache our reply at this time.
2320                  */
2321                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2322                         "error: %d\n", task->tk_status);
2323                 xprt_conditional_disconnect(req->rq_xprt,
2324                         req->rq_connect_cookie);
2325                 break;
2326         default:
2327                 /*
2328                  * We were unable to reply and will have to drop the
2329                  * request.  The server should reconnect and retransmit.
2330                  */
2331                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2332                         "error: %d\n", task->tk_status);
2333                 break;
2334         }
2335         task->tk_action = rpc_exit_task;
2336 }
2337 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2338
2339 /*
2340  * 6.   Sort out the RPC call status
2341  */
2342 static void
2343 call_status(struct rpc_task *task)
2344 {
2345         struct rpc_clnt *clnt = task->tk_client;
2346         int             status;
2347
2348         if (!task->tk_msg.rpc_proc->p_proc)
2349                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2350
2351         dprint_status(task);
2352
2353         status = task->tk_status;
2354         if (status >= 0) {
2355                 task->tk_action = call_decode;
2356                 return;
2357         }
2358
2359         trace_rpc_call_status(task);
2360         task->tk_status = 0;
2361         switch(status) {
2362         case -EHOSTDOWN:
2363         case -ENETDOWN:
2364         case -EHOSTUNREACH:
2365         case -ENETUNREACH:
2366         case -EPERM:
2367                 if (RPC_IS_SOFTCONN(task))
2368                         goto out_exit;
2369                 /*
2370                  * Delay any retries for 3 seconds, then handle as if it
2371                  * were a timeout.
2372                  */
2373                 rpc_delay(task, 3*HZ);
2374                 /* fall through */
2375         case -ETIMEDOUT:
2376                 break;
2377         case -ECONNREFUSED:
2378         case -ECONNRESET:
2379         case -ECONNABORTED:
2380         case -ENOTCONN:
2381                 rpc_force_rebind(clnt);
2382                 break;
2383         case -EADDRINUSE:
2384                 rpc_delay(task, 3*HZ);
2385                 /* fall through */
2386         case -EPIPE:
2387         case -EAGAIN:
2388                 break;
2389         case -EIO:
2390                 /* shutdown or soft timeout */
2391                 goto out_exit;
2392         default:
2393                 if (clnt->cl_chatty)
2394                         printk("%s: RPC call returned error %d\n",
2395                                clnt->cl_program->name, -status);
2396                 goto out_exit;
2397         }
2398         task->tk_action = call_encode;
2399         rpc_check_timeout(task);
2400         return;
2401 out_exit:
2402         rpc_call_rpcerror(task, status);
2403 }
2404
2405 static bool
2406 rpc_check_connected(const struct rpc_rqst *req)
2407 {
2408         /* No allocated request or transport? return true */
2409         if (!req || !req->rq_xprt)
2410                 return true;
2411         return xprt_connected(req->rq_xprt);
2412 }
2413
2414 static void
2415 rpc_check_timeout(struct rpc_task *task)
2416 {
2417         struct rpc_clnt *clnt = task->tk_client;
2418
2419         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2420                 return;
2421
2422         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2423         task->tk_timeouts++;
2424
2425         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2426                 rpc_call_rpcerror(task, -ETIMEDOUT);
2427                 return;
2428         }
2429
2430         if (RPC_IS_SOFT(task)) {
2431                 /*
2432                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2433                  * been sent, it should time out only if the transport
2434                  * connection gets terminally broken.
2435                  */
2436                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2437                     rpc_check_connected(task->tk_rqstp))
2438                         return;
2439
2440                 if (clnt->cl_chatty) {
2441                         pr_notice_ratelimited(
2442                                 "%s: server %s not responding, timed out\n",
2443                                 clnt->cl_program->name,
2444                                 task->tk_xprt->servername);
2445                 }
2446                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2447                         rpc_call_rpcerror(task, -ETIMEDOUT);
2448                 else
2449                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2450                 return;
2451         }
2452
2453         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2454                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2455                 if (clnt->cl_chatty) {
2456                         pr_notice_ratelimited(
2457                                 "%s: server %s not responding, still trying\n",
2458                                 clnt->cl_program->name,
2459                                 task->tk_xprt->servername);
2460                 }
2461         }
2462         rpc_force_rebind(clnt);
2463         /*
2464          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2465          * event? RFC2203 requires the server to drop all such requests.
2466          */
2467         rpcauth_invalcred(task);
2468 }
2469
2470 /*
2471  * 7.   Decode the RPC reply
2472  */
2473 static void
2474 call_decode(struct rpc_task *task)
2475 {
2476         struct rpc_clnt *clnt = task->tk_client;
2477         struct rpc_rqst *req = task->tk_rqstp;
2478         struct xdr_stream xdr;
2479         int err;
2480
2481         dprint_status(task);
2482
2483         if (!task->tk_msg.rpc_proc->p_decode) {
2484                 task->tk_action = rpc_exit_task;
2485                 return;
2486         }
2487
2488         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2489                 if (clnt->cl_chatty) {
2490                         pr_notice_ratelimited("%s: server %s OK\n",
2491                                 clnt->cl_program->name,
2492                                 task->tk_xprt->servername);
2493                 }
2494                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2495         }
2496
2497         /*
2498          * Ensure that we see all writes made by xprt_complete_rqst()
2499          * before it changed req->rq_reply_bytes_recvd.
2500          */
2501         smp_rmb();
2502
2503         /*
2504          * Did we ever call xprt_complete_rqst()? If not, we should assume
2505          * the message is incomplete.
2506          */
2507         err = -EAGAIN;
2508         if (!req->rq_reply_bytes_recvd)
2509                 goto out;
2510
2511         req->rq_rcv_buf.len = req->rq_private_buf.len;
2512         trace_xprt_recvfrom(&req->rq_rcv_buf);
2513
2514         /* Check that the softirq receive buffer is valid */
2515         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2516                                 sizeof(req->rq_rcv_buf)) != 0);
2517
2518         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2519                         req->rq_rcv_buf.head[0].iov_base, req);
2520         err = rpc_decode_header(task, &xdr);
2521 out:
2522         switch (err) {
2523         case 0:
2524                 task->tk_action = rpc_exit_task;
2525                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2526                 dprintk("RPC: %5u %s result %d\n",
2527                         task->tk_pid, __func__, task->tk_status);
2528                 return;
2529         case -EAGAIN:
2530                 task->tk_status = 0;
2531                 if (task->tk_client->cl_discrtry)
2532                         xprt_conditional_disconnect(req->rq_xprt,
2533                                                     req->rq_connect_cookie);
2534                 task->tk_action = call_encode;
2535                 rpc_check_timeout(task);
2536                 break;
2537         case -EKEYREJECTED:
2538                 task->tk_action = call_reserve;
2539                 rpc_check_timeout(task);
2540                 rpcauth_invalcred(task);
2541                 /* Ensure we obtain a new XID if we retry! */
2542                 xprt_release(task);
2543         }
2544 }
2545
2546 static int
2547 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2548 {
2549         struct rpc_clnt *clnt = task->tk_client;
2550         struct rpc_rqst *req = task->tk_rqstp;
2551         __be32 *p;
2552         int error;
2553
2554         error = -EMSGSIZE;
2555         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2556         if (!p)
2557                 goto out_fail;
2558         *p++ = req->rq_xid;
2559         *p++ = rpc_call;
2560         *p++ = cpu_to_be32(RPC_VERSION);
2561         *p++ = cpu_to_be32(clnt->cl_prog);
2562         *p++ = cpu_to_be32(clnt->cl_vers);
2563         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2564
2565         error = rpcauth_marshcred(task, xdr);
2566         if (error < 0)
2567                 goto out_fail;
2568         return 0;
2569 out_fail:
2570         trace_rpc_bad_callhdr(task);
2571         rpc_call_rpcerror(task, error);
2572         return error;
2573 }
2574
2575 static noinline int
2576 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2577 {
2578         struct rpc_clnt *clnt = task->tk_client;
2579         int error;
2580         __be32 *p;
2581
2582         /* RFC-1014 says that the representation of XDR data must be a
2583          * multiple of four bytes
2584          * - if it isn't pointer subtraction in the NFS client may give
2585          *   undefined results
2586          */
2587         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2588                 goto out_unparsable;
2589
2590         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2591         if (!p)
2592                 goto out_unparsable;
2593         p++;    /* skip XID */
2594         if (*p++ != rpc_reply)
2595                 goto out_unparsable;
2596         if (*p++ != rpc_msg_accepted)
2597                 goto out_msg_denied;
2598
2599         error = rpcauth_checkverf(task, xdr);
2600         if (error)
2601                 goto out_verifier;
2602
2603         p = xdr_inline_decode(xdr, sizeof(*p));
2604         if (!p)
2605                 goto out_unparsable;
2606         switch (*p) {
2607         case rpc_success:
2608                 return 0;
2609         case rpc_prog_unavail:
2610                 trace_rpc__prog_unavail(task);
2611                 error = -EPFNOSUPPORT;
2612                 goto out_err;
2613         case rpc_prog_mismatch:
2614                 trace_rpc__prog_mismatch(task);
2615                 error = -EPROTONOSUPPORT;
2616                 goto out_err;
2617         case rpc_proc_unavail:
2618                 trace_rpc__proc_unavail(task);
2619                 error = -EOPNOTSUPP;
2620                 goto out_err;
2621         case rpc_garbage_args:
2622         case rpc_system_err:
2623                 trace_rpc__garbage_args(task);
2624                 error = -EIO;
2625                 break;
2626         default:
2627                 goto out_unparsable;
2628         }
2629
2630 out_garbage:
2631         clnt->cl_stats->rpcgarbage++;
2632         if (task->tk_garb_retry) {
2633                 task->tk_garb_retry--;
2634                 task->tk_action = call_encode;
2635                 return -EAGAIN;
2636         }
2637 out_err:
2638         rpc_call_rpcerror(task, error);
2639         return error;
2640
2641 out_unparsable:
2642         trace_rpc__unparsable(task);
2643         error = -EIO;
2644         goto out_garbage;
2645
2646 out_verifier:
2647         trace_rpc_bad_verifier(task);
2648         goto out_garbage;
2649
2650 out_msg_denied:
2651         error = -EACCES;
2652         p = xdr_inline_decode(xdr, sizeof(*p));
2653         if (!p)
2654                 goto out_unparsable;
2655         switch (*p++) {
2656         case rpc_auth_error:
2657                 break;
2658         case rpc_mismatch:
2659                 trace_rpc__mismatch(task);
2660                 error = -EPROTONOSUPPORT;
2661                 goto out_err;
2662         default:
2663                 goto out_unparsable;
2664         }
2665
2666         p = xdr_inline_decode(xdr, sizeof(*p));
2667         if (!p)
2668                 goto out_unparsable;
2669         switch (*p++) {
2670         case rpc_autherr_rejectedcred:
2671         case rpc_autherr_rejectedverf:
2672         case rpcsec_gsserr_credproblem:
2673         case rpcsec_gsserr_ctxproblem:
2674                 if (!task->tk_cred_retry)
2675                         break;
2676                 task->tk_cred_retry--;
2677                 trace_rpc__stale_creds(task);
2678                 return -EKEYREJECTED;
2679         case rpc_autherr_badcred:
2680         case rpc_autherr_badverf:
2681                 /* possibly garbled cred/verf? */
2682                 if (!task->tk_garb_retry)
2683                         break;
2684                 task->tk_garb_retry--;
2685                 trace_rpc__bad_creds(task);
2686                 task->tk_action = call_encode;
2687                 return -EAGAIN;
2688         case rpc_autherr_tooweak:
2689                 trace_rpc__auth_tooweak(task);
2690                 pr_warn("RPC: server %s requires stronger authentication.\n",
2691                         task->tk_xprt->servername);
2692                 break;
2693         default:
2694                 goto out_unparsable;
2695         }
2696         goto out_err;
2697 }
2698
2699 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2700                 const void *obj)
2701 {
2702 }
2703
2704 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2705                 void *obj)
2706 {
2707         return 0;
2708 }
2709
2710 static const struct rpc_procinfo rpcproc_null = {
2711         .p_encode = rpcproc_encode_null,
2712         .p_decode = rpcproc_decode_null,
2713 };
2714
2715 static int rpc_ping(struct rpc_clnt *clnt)
2716 {
2717         struct rpc_message msg = {
2718                 .rpc_proc = &rpcproc_null,
2719         };
2720         int err;
2721         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2722                             RPC_TASK_NULLCREDS);
2723         return err;
2724 }
2725
2726 static
2727 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2728                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2729                 const struct rpc_call_ops *ops, void *data)
2730 {
2731         struct rpc_message msg = {
2732                 .rpc_proc = &rpcproc_null,
2733         };
2734         struct rpc_task_setup task_setup_data = {
2735                 .rpc_client = clnt,
2736                 .rpc_xprt = xprt,
2737                 .rpc_message = &msg,
2738                 .rpc_op_cred = cred,
2739                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2740                 .callback_data = data,
2741                 .flags = flags | RPC_TASK_NULLCREDS,
2742         };
2743
2744         return rpc_run_task(&task_setup_data);
2745 }
2746
2747 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2748 {
2749         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2750 }
2751 EXPORT_SYMBOL_GPL(rpc_call_null);
2752
2753 struct rpc_cb_add_xprt_calldata {
2754         struct rpc_xprt_switch *xps;
2755         struct rpc_xprt *xprt;
2756 };
2757
2758 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2759 {
2760         struct rpc_cb_add_xprt_calldata *data = calldata;
2761
2762         if (task->tk_status == 0)
2763                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2764 }
2765
2766 static void rpc_cb_add_xprt_release(void *calldata)
2767 {
2768         struct rpc_cb_add_xprt_calldata *data = calldata;
2769
2770         xprt_put(data->xprt);
2771         xprt_switch_put(data->xps);
2772         kfree(data);
2773 }
2774
2775 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2776         .rpc_call_done = rpc_cb_add_xprt_done,
2777         .rpc_release = rpc_cb_add_xprt_release,
2778 };
2779
2780 /**
2781  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2782  * @clnt: pointer to struct rpc_clnt
2783  * @xps: pointer to struct rpc_xprt_switch,
2784  * @xprt: pointer struct rpc_xprt
2785  * @dummy: unused
2786  */
2787 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2788                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2789                 void *dummy)
2790 {
2791         struct rpc_cb_add_xprt_calldata *data;
2792         struct rpc_task *task;
2793
2794         data = kmalloc(sizeof(*data), GFP_NOFS);
2795         if (!data)
2796                 return -ENOMEM;
2797         data->xps = xprt_switch_get(xps);
2798         data->xprt = xprt_get(xprt);
2799         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2800                 rpc_cb_add_xprt_release(data);
2801                 goto success;
2802         }
2803
2804         task = rpc_call_null_helper(clnt, xprt, NULL,
2805                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
2806                         &rpc_cb_add_xprt_call_ops, data);
2807         if (IS_ERR(task))
2808                 return PTR_ERR(task);
2809         rpc_put_task(task);
2810 success:
2811         return 1;
2812 }
2813 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2814
2815 /**
2816  * rpc_clnt_setup_test_and_add_xprt()
2817  *
2818  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2819  *   1) caller of the test function must dereference the rpc_xprt_switch
2820  *   and the rpc_xprt.
2821  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2822  *   the rpc_call_done routine.
2823  *
2824  * Upon success (return of 1), the test function adds the new
2825  * transport to the rpc_clnt xprt switch
2826  *
2827  * @clnt: struct rpc_clnt to get the new transport
2828  * @xps:  the rpc_xprt_switch to hold the new transport
2829  * @xprt: the rpc_xprt to test
2830  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2831  *        and test function call data
2832  */
2833 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2834                                      struct rpc_xprt_switch *xps,
2835                                      struct rpc_xprt *xprt,
2836                                      void *data)
2837 {
2838         struct rpc_task *task;
2839         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2840         int status = -EADDRINUSE;
2841
2842         xprt = xprt_get(xprt);
2843         xprt_switch_get(xps);
2844
2845         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2846                 goto out_err;
2847
2848         /* Test the connection */
2849         task = rpc_call_null_helper(clnt, xprt, NULL,
2850                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2851                                     NULL, NULL);
2852         if (IS_ERR(task)) {
2853                 status = PTR_ERR(task);
2854                 goto out_err;
2855         }
2856         status = task->tk_status;
2857         rpc_put_task(task);
2858
2859         if (status < 0)
2860                 goto out_err;
2861
2862         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2863         xtest->add_xprt_test(clnt, xprt, xtest->data);
2864
2865         xprt_put(xprt);
2866         xprt_switch_put(xps);
2867
2868         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2869         return 1;
2870 out_err:
2871         xprt_put(xprt);
2872         xprt_switch_put(xps);
2873         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2874                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2875         return status;
2876 }
2877 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2878
2879 /**
2880  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2881  * @clnt: pointer to struct rpc_clnt
2882  * @xprtargs: pointer to struct xprt_create
2883  * @setup: callback to test and/or set up the connection
2884  * @data: pointer to setup function data
2885  *
2886  * Creates a new transport using the parameters set in args and
2887  * adds it to clnt.
2888  * If ping is set, then test that connectivity succeeds before
2889  * adding the new transport.
2890  *
2891  */
2892 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2893                 struct xprt_create *xprtargs,
2894                 int (*setup)(struct rpc_clnt *,
2895                         struct rpc_xprt_switch *,
2896                         struct rpc_xprt *,
2897                         void *),
2898                 void *data)
2899 {
2900         struct rpc_xprt_switch *xps;
2901         struct rpc_xprt *xprt;
2902         unsigned long connect_timeout;
2903         unsigned long reconnect_timeout;
2904         unsigned char resvport, reuseport;
2905         int ret = 0;
2906
2907         rcu_read_lock();
2908         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2909         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2910         if (xps == NULL || xprt == NULL) {
2911                 rcu_read_unlock();
2912                 xprt_switch_put(xps);
2913                 return -EAGAIN;
2914         }
2915         resvport = xprt->resvport;
2916         reuseport = xprt->reuseport;
2917         connect_timeout = xprt->connect_timeout;
2918         reconnect_timeout = xprt->max_reconnect_timeout;
2919         rcu_read_unlock();
2920
2921         xprt = xprt_create_transport(xprtargs);
2922         if (IS_ERR(xprt)) {
2923                 ret = PTR_ERR(xprt);
2924                 goto out_put_switch;
2925         }
2926         xprt->resvport = resvport;
2927         xprt->reuseport = reuseport;
2928         if (xprt->ops->set_connect_timeout != NULL)
2929                 xprt->ops->set_connect_timeout(xprt,
2930                                 connect_timeout,
2931                                 reconnect_timeout);
2932
2933         rpc_xprt_switch_set_roundrobin(xps);
2934         if (setup) {
2935                 ret = setup(clnt, xps, xprt, data);
2936                 if (ret != 0)
2937                         goto out_put_xprt;
2938         }
2939         rpc_xprt_switch_add_xprt(xps, xprt);
2940 out_put_xprt:
2941         xprt_put(xprt);
2942 out_put_switch:
2943         xprt_switch_put(xps);
2944         return ret;
2945 }
2946 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2947
2948 struct connect_timeout_data {
2949         unsigned long connect_timeout;
2950         unsigned long reconnect_timeout;
2951 };
2952
2953 static int
2954 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2955                 struct rpc_xprt *xprt,
2956                 void *data)
2957 {
2958         struct connect_timeout_data *timeo = data;
2959
2960         if (xprt->ops->set_connect_timeout)
2961                 xprt->ops->set_connect_timeout(xprt,
2962                                 timeo->connect_timeout,
2963                                 timeo->reconnect_timeout);
2964         return 0;
2965 }
2966
2967 void
2968 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2969                 unsigned long connect_timeout,
2970                 unsigned long reconnect_timeout)
2971 {
2972         struct connect_timeout_data timeout = {
2973                 .connect_timeout = connect_timeout,
2974                 .reconnect_timeout = reconnect_timeout,
2975         };
2976         rpc_clnt_iterate_for_each_xprt(clnt,
2977                         rpc_xprt_set_connect_timeout,
2978                         &timeout);
2979 }
2980 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2981
2982 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2983 {
2984         rcu_read_lock();
2985         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2986         rcu_read_unlock();
2987 }
2988 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2989
2990 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2991 {
2992         rcu_read_lock();
2993         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2994                                  xprt);
2995         rcu_read_unlock();
2996 }
2997 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2998
2999 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3000                                    const struct sockaddr *sap)
3001 {
3002         struct rpc_xprt_switch *xps;
3003         bool ret;
3004
3005         rcu_read_lock();
3006         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3007         ret = rpc_xprt_switch_has_addr(xps, sap);
3008         rcu_read_unlock();
3009         return ret;
3010 }
3011 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3012
3013 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3014 static void rpc_show_header(void)
3015 {
3016         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3017                 "-timeout ---ops--\n");
3018 }
3019
3020 static void rpc_show_task(const struct rpc_clnt *clnt,
3021                           const struct rpc_task *task)
3022 {
3023         const char *rpc_waitq = "none";
3024
3025         if (RPC_IS_QUEUED(task))
3026                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3027
3028         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3029                 task->tk_pid, task->tk_flags, task->tk_status,
3030                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3031                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3032                 task->tk_action, rpc_waitq);
3033 }
3034
3035 void rpc_show_tasks(struct net *net)
3036 {
3037         struct rpc_clnt *clnt;
3038         struct rpc_task *task;
3039         int header = 0;
3040         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3041
3042         spin_lock(&sn->rpc_client_lock);
3043         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3044                 spin_lock(&clnt->cl_lock);
3045                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3046                         if (!header) {
3047                                 rpc_show_header();
3048                                 header++;
3049                         }
3050                         rpc_show_task(clnt, task);
3051                 }
3052                 spin_unlock(&clnt->cl_lock);
3053         }
3054         spin_unlock(&sn->rpc_client_lock);
3055 }
3056 #endif
3057
3058 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3059 static int
3060 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3061                 struct rpc_xprt *xprt,
3062                 void *dummy)
3063 {
3064         return xprt_enable_swap(xprt);
3065 }
3066
3067 int
3068 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3069 {
3070         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3071                 return rpc_clnt_iterate_for_each_xprt(clnt,
3072                                 rpc_clnt_swap_activate_callback, NULL);
3073         return 0;
3074 }
3075 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3076
3077 static int
3078 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3079                 struct rpc_xprt *xprt,
3080                 void *dummy)
3081 {
3082         xprt_disable_swap(xprt);
3083         return 0;
3084 }
3085
3086 void
3087 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3088 {
3089         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3090                 rpc_clnt_iterate_for_each_xprt(clnt,
3091                                 rpc_clnt_swap_deactivate_callback, NULL);
3092 }
3093 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3094 #endif /* CONFIG_SUNRPC_SWAP */