net/sunrpc/clnt.c

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