net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "netns.h"
  45
  46 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  47 # define RPCDBG_FACILITY        RPCDBG_CALL
  48 #endif
  49
  50 #define dprint_status(t)                                        \
  51         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  52                         __func__, t->tk_status)
  53
  54 /*
  55  * All RPC clients are linked into this list
  56  */
  57
  58 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  59
  60
  61 static void     call_start(struct rpc_task *task);
  62 static void     call_reserve(struct rpc_task *task);
  63 static void     call_reserveresult(struct rpc_task *task);
  64 static void     call_allocate(struct rpc_task *task);
  65 static void     call_encode(struct rpc_task *task);
  66 static void     call_decode(struct rpc_task *task);
  67 static void     call_bind(struct rpc_task *task);
  68 static void     call_bind_status(struct rpc_task *task);
  69 static void     call_transmit(struct rpc_task *task);
  70 static void     call_status(struct rpc_task *task);
  71 static void     call_transmit_status(struct rpc_task *task);
  72 static void     call_refresh(struct rpc_task *task);
  73 static void     call_refreshresult(struct rpc_task *task);
  74 static void     call_connect(struct rpc_task *task);
  75 static void     call_connect_status(struct rpc_task *task);
  76
  77 static int      rpc_encode_header(struct rpc_task *task,
  78                                   struct xdr_stream *xdr);
  79 static int      rpc_decode_header(struct rpc_task *task,
  80                                   struct xdr_stream *xdr);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82 static void     rpc_check_timeout(struct rpc_task *task);
  83
  84 static void rpc_register_client(struct rpc_clnt *clnt)
  85 {
  86         struct net *net = rpc_net_ns(clnt);
  87         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  88
  89         spin_lock(&sn->rpc_client_lock);
  90         list_add(&clnt->cl_clients, &sn->all_clients);
  91         spin_unlock(&sn->rpc_client_lock);
  92 }
  93
  94 static void rpc_unregister_client(struct rpc_clnt *clnt)
  95 {
  96         struct net *net = rpc_net_ns(clnt);
  97         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  98
  99         spin_lock(&sn->rpc_client_lock);
 100         list_del(&clnt->cl_clients);
 101         spin_unlock(&sn->rpc_client_lock);
 102 }
 103
 104 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 105 {
 106         rpc_remove_client_dir(clnt);
 107 }
 108
 109 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 110 {
 111         struct net *net = rpc_net_ns(clnt);
 112         struct super_block *pipefs_sb;
 113
 114         pipefs_sb = rpc_get_sb_net(net);
 115         if (pipefs_sb) {
 116                 __rpc_clnt_remove_pipedir(clnt);
 117                 rpc_put_sb_net(net);
 118         }
 119 }
 120
 121 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 122                                     struct rpc_clnt *clnt)
 123 {
 124         static uint32_t clntid;
 125         const char *dir_name = clnt->cl_program->pipe_dir_name;
 126         char name[15];
 127         struct dentry *dir, *dentry;
 128
 129         dir = rpc_d_lookup_sb(sb, dir_name);
 130         if (dir == NULL) {
 131                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 132                 return dir;
 133         }
 134         for (;;) {
 135                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 136                 name[sizeof(name) - 1] = '\0';
 137                 dentry = rpc_create_client_dir(dir, name, clnt);
 138                 if (!IS_ERR(dentry))
 139                         break;
 140                 if (dentry == ERR_PTR(-EEXIST))
 141                         continue;
 142                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 143                                 " %s/%s, error %ld\n",
 144                                 dir_name, name, PTR_ERR(dentry));
 145                 break;
 146         }
 147         dput(dir);
 148         return dentry;
 149 }
 150
 151 static int
 152 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 153 {
 154         struct dentry *dentry;
 155
 156         if (clnt->cl_program->pipe_dir_name != NULL) {
 157                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 158                 if (IS_ERR(dentry))
 159                         return PTR_ERR(dentry);
 160         }
 161         return 0;
 162 }
 163
 164 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 165 {
 166         if (clnt->cl_program->pipe_dir_name == NULL)
 167                 return 1;
 168
 169         switch (event) {
 170         case RPC_PIPEFS_MOUNT:
 171                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 172                         return 1;
 173                 if (atomic_read(&clnt->cl_count) == 0)
 174                         return 1;
 175                 break;
 176         case RPC_PIPEFS_UMOUNT:
 177                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 178                         return 1;
 179                 break;
 180         }
 181         return 0;
 182 }
 183
 184 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 185                                    struct super_block *sb)
 186 {
 187         struct dentry *dentry;
 188
 189         switch (event) {
 190         case RPC_PIPEFS_MOUNT:
 191                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 192                 if (!dentry)
 193                         return -ENOENT;
 194                 if (IS_ERR(dentry))
 195                         return PTR_ERR(dentry);
 196                 break;
 197         case RPC_PIPEFS_UMOUNT:
 198                 __rpc_clnt_remove_pipedir(clnt);
 199                 break;
 200         default:
 201                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 202                 return -ENOTSUPP;
 203         }
 204         return 0;
 205 }
 206
 207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 208                                 struct super_block *sb)
 209 {
 210         int error = 0;
 211
 212         for (;; clnt = clnt->cl_parent) {
 213                 if (!rpc_clnt_skip_event(clnt, event))
 214                         error = __rpc_clnt_handle_event(clnt, event, sb);
 215                 if (error || clnt == clnt->cl_parent)
 216                         break;
 217         }
 218         return error;
 219 }
 220
 221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 222 {
 223         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 224         struct rpc_clnt *clnt;
 225
 226         spin_lock(&sn->rpc_client_lock);
 227         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 228                 if (rpc_clnt_skip_event(clnt, event))
 229                         continue;
 230                 spin_unlock(&sn->rpc_client_lock);
 231                 return clnt;
 232         }
 233         spin_unlock(&sn->rpc_client_lock);
 234         return NULL;
 235 }
 236
 237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 238                             void *ptr)
 239 {
 240         struct super_block *sb = ptr;
 241         struct rpc_clnt *clnt;
 242         int error = 0;
 243
 244         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 245                 error = __rpc_pipefs_event(clnt, event, sb);
 246                 if (error)
 247                         break;
 248         }
 249         return error;
 250 }
 251
 252 static struct notifier_block rpc_clients_block = {
 253         .notifier_call  = rpc_pipefs_event,
 254         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 255 };
 256
 257 int rpc_clients_notifier_register(void)
 258 {
 259         return rpc_pipefs_notifier_register(&rpc_clients_block);
 260 }
 261
 262 void rpc_clients_notifier_unregister(void)
 263 {
 264         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 265 }
 266
 267 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 268                 struct rpc_xprt *xprt,
 269                 const struct rpc_timeout *timeout)
 270 {
 271         struct rpc_xprt *old;
 272
 273         spin_lock(&clnt->cl_lock);
 274         old = rcu_dereference_protected(clnt->cl_xprt,
 275                         lockdep_is_held(&clnt->cl_lock));
 276
 277         if (!xprt_bound(xprt))
 278                 clnt->cl_autobind = 1;
 279
 280         clnt->cl_timeout = timeout;
 281         rcu_assign_pointer(clnt->cl_xprt, xprt);
 282         spin_unlock(&clnt->cl_lock);
 283
 284         return old;
 285 }
 286
 287 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 288 {
 289         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 290                         nodename, sizeof(clnt->cl_nodename));
 291 }
 292
 293 static int rpc_client_register(struct rpc_clnt *clnt,
 294                                rpc_authflavor_t pseudoflavor,
 295                                const char *client_name)
 296 {
 297         struct rpc_auth_create_args auth_args = {
 298                 .pseudoflavor = pseudoflavor,
 299                 .target_name = client_name,
 300         };
 301         struct rpc_auth *auth;
 302         struct net *net = rpc_net_ns(clnt);
 303         struct super_block *pipefs_sb;
 304         int err;
 305
 306         rpc_clnt_debugfs_register(clnt);
 307
 308         pipefs_sb = rpc_get_sb_net(net);
 309         if (pipefs_sb) {
 310                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 311                 if (err)
 312                         goto out;
 313         }
 314
 315         rpc_register_client(clnt);
 316         if (pipefs_sb)
 317                 rpc_put_sb_net(net);
 318
 319         auth = rpcauth_create(&auth_args, clnt);
 320         if (IS_ERR(auth)) {
 321                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 322                                 pseudoflavor);
 323                 err = PTR_ERR(auth);
 324                 goto err_auth;
 325         }
 326         return 0;
 327 err_auth:
 328         pipefs_sb = rpc_get_sb_net(net);
 329         rpc_unregister_client(clnt);
 330         __rpc_clnt_remove_pipedir(clnt);
 331 out:
 332         if (pipefs_sb)
 333                 rpc_put_sb_net(net);
 334         rpc_clnt_debugfs_unregister(clnt);
 335         return err;
 336 }
 337
 338 static DEFINE_IDA(rpc_clids);
 339
 340 void rpc_cleanup_clids(void)
 341 {
 342         ida_destroy(&rpc_clids);
 343 }
 344
 345 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 346 {
 347         int clid;
 348
 349         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 350         if (clid < 0)
 351                 return clid;
 352         clnt->cl_clid = clid;
 353         return 0;
 354 }
 355
 356 static void rpc_free_clid(struct rpc_clnt *clnt)
 357 {
 358         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 359 }
 360
 361 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 362                 struct rpc_xprt_switch *xps,
 363                 struct rpc_xprt *xprt,
 364                 struct rpc_clnt *parent)
 365 {
 366         const struct rpc_program *program = args->program;
 367         const struct rpc_version *version;
 368         struct rpc_clnt *clnt = NULL;
 369         const struct rpc_timeout *timeout;
 370         const char *nodename = args->nodename;
 371         int err;
 372
 373         /* sanity check the name before trying to print it */
 374         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 375                         program->name, args->servername, xprt);
 376
 377         err = rpciod_up();
 378         if (err)
 379                 goto out_no_rpciod;
 380
 381         err = -EINVAL;
 382         if (args->version >= program->nrvers)
 383                 goto out_err;
 384         version = program->version[args->version];
 385         if (version == NULL)
 386                 goto out_err;
 387
 388         err = -ENOMEM;
 389         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 390         if (!clnt)
 391                 goto out_err;
 392         clnt->cl_parent = parent ? : clnt;
 393
 394         err = rpc_alloc_clid(clnt);
 395         if (err)
 396                 goto out_no_clid;
 397
 398         clnt->cl_cred     = get_cred(args->cred);
 399         clnt->cl_procinfo = version->procs;
 400         clnt->cl_maxproc  = version->nrprocs;
 401         clnt->cl_prog     = args->prognumber ? : program->number;
 402         clnt->cl_vers     = version->number;
 403         clnt->cl_stats    = program->stats;
 404         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 405         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 406         err = -ENOMEM;
 407         if (clnt->cl_metrics == NULL)
 408                 goto out_no_stats;
 409         clnt->cl_program  = program;
 410         INIT_LIST_HEAD(&clnt->cl_tasks);
 411         spin_lock_init(&clnt->cl_lock);
 412
 413         timeout = xprt->timeout;
 414         if (args->timeout != NULL) {
 415                 memcpy(&clnt->cl_timeout_default, args->timeout,
 416                                 sizeof(clnt->cl_timeout_default));
 417                 timeout = &clnt->cl_timeout_default;
 418         }
 419
 420         rpc_clnt_set_transport(clnt, xprt, timeout);
 421         xprt_iter_init(&clnt->cl_xpi, xps);
 422         xprt_switch_put(xps);
 423
 424         clnt->cl_rtt = &clnt->cl_rtt_default;
 425         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 426
 427         atomic_set(&clnt->cl_count, 1);
 428
 429         if (nodename == NULL)
 430                 nodename = utsname()->nodename;
 431         /* save the nodename */
 432         rpc_clnt_set_nodename(clnt, nodename);
 433
 434         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 435         if (err)
 436                 goto out_no_path;
 437         if (parent)
 438                 atomic_inc(&parent->cl_count);
 439         return clnt;
 440
 441 out_no_path:
 442         rpc_free_iostats(clnt->cl_metrics);
 443 out_no_stats:
 444         put_cred(clnt->cl_cred);
 445         rpc_free_clid(clnt);
 446 out_no_clid:
 447         kfree(clnt);
 448 out_err:
 449         rpciod_down();
 450 out_no_rpciod:
 451         xprt_switch_put(xps);
 452         xprt_put(xprt);
 453         return ERR_PTR(err);
 454 }
 455
 456 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 457                                         struct rpc_xprt *xprt)
 458 {
 459         struct rpc_clnt *clnt = NULL;
 460         struct rpc_xprt_switch *xps;
 461
 462         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 463                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 464                 xps = args->bc_xprt->xpt_bc_xps;
 465                 xprt_switch_get(xps);
 466         } else {
 467                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 468                 if (xps == NULL) {
 469                         xprt_put(xprt);
 470                         return ERR_PTR(-ENOMEM);
 471                 }
 472                 if (xprt->bc_xprt) {
 473                         xprt_switch_get(xps);
 474                         xprt->bc_xprt->xpt_bc_xps = xps;
 475                 }
 476         }
 477         clnt = rpc_new_client(args, xps, xprt, NULL);
 478         if (IS_ERR(clnt))
 479                 return clnt;
 480
 481         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 482                 int err = rpc_ping(clnt);
 483                 if (err != 0) {
 484                         rpc_shutdown_client(clnt);
 485                         return ERR_PTR(err);
 486                 }
 487         }
 488
 489         clnt->cl_softrtry = 1;
 490         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 491                 clnt->cl_softrtry = 0;
 492                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 493                         clnt->cl_softerr = 1;
 494         }
 495
 496         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 497                 clnt->cl_autobind = 1;
 498         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 499                 clnt->cl_noretranstimeo = 1;
 500         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 501                 clnt->cl_discrtry = 1;
 502         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 503                 clnt->cl_chatty = 1;
 504
 505         return clnt;
 506 }
 507
 508 /**
 509  * rpc_create - create an RPC client and transport with one call
 510  * @args: rpc_clnt create argument structure
 511  *
 512  * Creates and initializes an RPC transport and an RPC client.
 513  *
 514  * It can ping the server in order to determine if it is up, and to see if
 515  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 516  * this behavior so asynchronous tasks can also use rpc_create.
 517  */
 518 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 519 {
 520         struct rpc_xprt *xprt;
 521         struct xprt_create xprtargs = {
 522                 .net = args->net,
 523                 .ident = args->protocol,
 524                 .srcaddr = args->saddress,
 525                 .dstaddr = args->address,
 526                 .addrlen = args->addrsize,
 527                 .servername = args->servername,
 528                 .bc_xprt = args->bc_xprt,
 529         };
 530         char servername[48];
 531         struct rpc_clnt *clnt;
 532         int i;
 533
 534         if (args->bc_xprt) {
 535                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 536                 xprt = args->bc_xprt->xpt_bc_xprt;
 537                 if (xprt) {
 538                         xprt_get(xprt);
 539                         return rpc_create_xprt(args, xprt);
 540                 }
 541         }
 542
 543         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 544                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 545         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 546                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 547         /*
 548          * If the caller chooses not to specify a hostname, whip
 549          * up a string representation of the passed-in address.
 550          */
 551         if (xprtargs.servername == NULL) {
 552                 struct sockaddr_un *sun =
 553                                 (struct sockaddr_un *)args->address;
 554                 struct sockaddr_in *sin =
 555                                 (struct sockaddr_in *)args->address;
 556                 struct sockaddr_in6 *sin6 =
 557                                 (struct sockaddr_in6 *)args->address;
 558
 559                 servername[0] = '\0';
 560                 switch (args->address->sa_family) {
 561                 case AF_LOCAL:
 562                         snprintf(servername, sizeof(servername), "%s",
 563                                  sun->sun_path);
 564                         break;
 565                 case AF_INET:
 566                         snprintf(servername, sizeof(servername), "%pI4",
 567                                  &sin->sin_addr.s_addr);
 568                         break;
 569                 case AF_INET6:
 570                         snprintf(servername, sizeof(servername), "%pI6",
 571                                  &sin6->sin6_addr);
 572                         break;
 573                 default:
 574                         /* caller wants default server name, but
 575                          * address family isn't recognized. */
 576                         return ERR_PTR(-EINVAL);
 577                 }
 578                 xprtargs.servername = servername;
 579         }
 580
 581         xprt = xprt_create_transport(&xprtargs);
 582         if (IS_ERR(xprt))
 583                 return (struct rpc_clnt *)xprt;
 584
 585         /*
 586          * By default, kernel RPC client connects from a reserved port.
 587          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 588          * but it is always enabled for rpciod, which handles the connect
 589          * operation.
 590          */
 591         xprt->resvport = 1;
 592         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 593                 xprt->resvport = 0;
 594         xprt->reuseport = 0;
 595         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 596                 xprt->reuseport = 1;
 597
 598         clnt = rpc_create_xprt(args, xprt);
 599         if (IS_ERR(clnt) || args->nconnect <= 1)
 600                 return clnt;
 601
 602         for (i = 0; i < args->nconnect - 1; i++) {
 603                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 604                         break;
 605         }
 606         return clnt;
 607 }
 608 EXPORT_SYMBOL_GPL(rpc_create);
 609
 610 /*
 611  * This function clones the RPC client structure. It allows us to share the
 612  * same transport while varying parameters such as the authentication
 613  * flavour.
 614  */
 615 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 616                                            struct rpc_clnt *clnt)
 617 {
 618         struct rpc_xprt_switch *xps;
 619         struct rpc_xprt *xprt;
 620         struct rpc_clnt *new;
 621         int err;
 622
 623         err = -ENOMEM;
 624         rcu_read_lock();
 625         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 626         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 627         rcu_read_unlock();
 628         if (xprt == NULL || xps == NULL) {
 629                 xprt_put(xprt);
 630                 xprt_switch_put(xps);
 631                 goto out_err;
 632         }
 633         args->servername = xprt->servername;
 634         args->nodename = clnt->cl_nodename;
 635
 636         new = rpc_new_client(args, xps, xprt, clnt);
 637         if (IS_ERR(new)) {
 638                 err = PTR_ERR(new);
 639                 goto out_err;
 640         }
 641
 642         /* Turn off autobind on clones */
 643         new->cl_autobind = 0;
 644         new->cl_softrtry = clnt->cl_softrtry;
 645         new->cl_softerr = clnt->cl_softerr;
 646         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 647         new->cl_discrtry = clnt->cl_discrtry;
 648         new->cl_chatty = clnt->cl_chatty;
 649         new->cl_principal = clnt->cl_principal;
 650         return new;
 651
 652 out_err:
 653         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 654         return ERR_PTR(err);
 655 }
 656
 657 /**
 658  * rpc_clone_client - Clone an RPC client structure
 659  *
 660  * @clnt: RPC client whose parameters are copied
 661  *
 662  * Returns a fresh RPC client or an ERR_PTR.
 663  */
 664 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 665 {
 666         struct rpc_create_args args = {
 667                 .program        = clnt->cl_program,
 668                 .prognumber     = clnt->cl_prog,
 669                 .version        = clnt->cl_vers,
 670                 .authflavor     = clnt->cl_auth->au_flavor,
 671                 .cred           = clnt->cl_cred,
 672         };
 673         return __rpc_clone_client(&args, clnt);
 674 }
 675 EXPORT_SYMBOL_GPL(rpc_clone_client);
 676
 677 /**
 678  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 679  *
 680  * @clnt: RPC client whose parameters are copied
 681  * @flavor: security flavor for new client
 682  *
 683  * Returns a fresh RPC client or an ERR_PTR.
 684  */
 685 struct rpc_clnt *
 686 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 687 {
 688         struct rpc_create_args args = {
 689                 .program        = clnt->cl_program,
 690                 .prognumber     = clnt->cl_prog,
 691                 .version        = clnt->cl_vers,
 692                 .authflavor     = flavor,
 693                 .cred           = clnt->cl_cred,
 694         };
 695         return __rpc_clone_client(&args, clnt);
 696 }
 697 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 698
 699 /**
 700  * rpc_switch_client_transport: switch the RPC transport on the fly
 701  * @clnt: pointer to a struct rpc_clnt
 702  * @args: pointer to the new transport arguments
 703  * @timeout: pointer to the new timeout parameters
 704  *
 705  * This function allows the caller to switch the RPC transport for the
 706  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 707  * server, for instance.  It assumes that the caller has ensured that
 708  * there are no active RPC tasks by using some form of locking.
 709  *
 710  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 711  * negative errno is returned, and "clnt" continues to use the old
 712  * xprt.
 713  */
 714 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 715                 struct xprt_create *args,
 716                 const struct rpc_timeout *timeout)
 717 {
 718         const struct rpc_timeout *old_timeo;
 719         rpc_authflavor_t pseudoflavor;
 720         struct rpc_xprt_switch *xps, *oldxps;
 721         struct rpc_xprt *xprt, *old;
 722         struct rpc_clnt *parent;
 723         int err;
 724
 725         xprt = xprt_create_transport(args);
 726         if (IS_ERR(xprt)) {
 727                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 728                         clnt);
 729                 return PTR_ERR(xprt);
 730         }
 731
 732         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 733         if (xps == NULL) {
 734                 xprt_put(xprt);
 735                 return -ENOMEM;
 736         }
 737
 738         pseudoflavor = clnt->cl_auth->au_flavor;
 739
 740         old_timeo = clnt->cl_timeout;
 741         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 742         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 743
 744         rpc_unregister_client(clnt);
 745         __rpc_clnt_remove_pipedir(clnt);
 746         rpc_clnt_debugfs_unregister(clnt);
 747
 748         /*
 749          * A new transport was created.  "clnt" therefore
 750          * becomes the root of a new cl_parent tree.  clnt's
 751          * children, if it has any, still point to the old xprt.
 752          */
 753         parent = clnt->cl_parent;
 754         clnt->cl_parent = clnt;
 755
 756         /*
 757          * The old rpc_auth cache cannot be re-used.  GSS
 758          * contexts in particular are between a single
 759          * client and server.
 760          */
 761         err = rpc_client_register(clnt, pseudoflavor, NULL);
 762         if (err)
 763                 goto out_revert;
 764
 765         synchronize_rcu();
 766         if (parent != clnt)
 767                 rpc_release_client(parent);
 768         xprt_switch_put(oldxps);
 769         xprt_put(old);
 770         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 771         return 0;
 772
 773 out_revert:
 774         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 775         rpc_clnt_set_transport(clnt, old, old_timeo);
 776         clnt->cl_parent = parent;
 777         rpc_client_register(clnt, pseudoflavor, NULL);
 778         xprt_switch_put(xps);
 779         xprt_put(xprt);
 780         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 781         return err;
 782 }
 783 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 784
 785 static
 786 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 787 {
 788         struct rpc_xprt_switch *xps;
 789
 790         rcu_read_lock();
 791         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 792         rcu_read_unlock();
 793         if (xps == NULL)
 794                 return -EAGAIN;
 795         xprt_iter_init_listall(xpi, xps);
 796         xprt_switch_put(xps);
 797         return 0;
 798 }
 799
 800 /**
 801  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 802  * @clnt: pointer to client
 803  * @fn: function to apply
 804  * @data: void pointer to function data
 805  *
 806  * Iterates through the list of RPC transports currently attached to the
 807  * client and applies the function fn(clnt, xprt, data).
 808  *
 809  * On error, the iteration stops, and the function returns the error value.
 810  */
 811 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 812                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 813                 void *data)
 814 {
 815         struct rpc_xprt_iter xpi;
 816         int ret;
 817
 818         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 819         if (ret)
 820                 return ret;
 821         for (;;) {
 822                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 823
 824                 if (!xprt)
 825                         break;
 826                 ret = fn(clnt, xprt, data);
 827                 xprt_put(xprt);
 828                 if (ret < 0)
 829                         break;
 830         }
 831         xprt_iter_destroy(&xpi);
 832         return ret;
 833 }
 834 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 835
 836 /*
 837  * Kill all tasks for the given client.
 838  * XXX: kill their descendants as well?
 839  */
 840 void rpc_killall_tasks(struct rpc_clnt *clnt)
 841 {
 842         struct rpc_task *rovr;
 843
 844
 845         if (list_empty(&clnt->cl_tasks))
 846                 return;
 847         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 848         /*
 849          * Spin lock all_tasks to prevent changes...
 850          */
 851         spin_lock(&clnt->cl_lock);
 852         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 853                 rpc_signal_task(rovr);
 854         spin_unlock(&clnt->cl_lock);
 855 }
 856 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 857
 858 /*
 859  * Properly shut down an RPC client, terminating all outstanding
 860  * requests.
 861  */
 862 void rpc_shutdown_client(struct rpc_clnt *clnt)
 863 {
 864         might_sleep();
 865
 866         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 867                         clnt->cl_program->name,
 868                         rcu_dereference(clnt->cl_xprt)->servername);
 869
 870         while (!list_empty(&clnt->cl_tasks)) {
 871                 rpc_killall_tasks(clnt);
 872                 wait_event_timeout(destroy_wait,
 873                         list_empty(&clnt->cl_tasks), 1*HZ);
 874         }
 875
 876         rpc_release_client(clnt);
 877 }
 878 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 879
 880 /*
 881  * Free an RPC client
 882  */
 883 static struct rpc_clnt *
 884 rpc_free_client(struct rpc_clnt *clnt)
 885 {
 886         struct rpc_clnt *parent = NULL;
 887
 888         dprintk_rcu("RPC:       destroying %s client for %s\n",
 889                         clnt->cl_program->name,
 890                         rcu_dereference(clnt->cl_xprt)->servername);
 891         if (clnt->cl_parent != clnt)
 892                 parent = clnt->cl_parent;
 893         rpc_clnt_debugfs_unregister(clnt);
 894         rpc_clnt_remove_pipedir(clnt);
 895         rpc_unregister_client(clnt);
 896         rpc_free_iostats(clnt->cl_metrics);
 897         clnt->cl_metrics = NULL;
 898         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 899         xprt_iter_destroy(&clnt->cl_xpi);
 900         rpciod_down();
 901         put_cred(clnt->cl_cred);
 902         rpc_free_clid(clnt);
 903         kfree(clnt);
 904         return parent;
 905 }
 906
 907 /*
 908  * Free an RPC client
 909  */
 910 static struct rpc_clnt *
 911 rpc_free_auth(struct rpc_clnt *clnt)
 912 {
 913         if (clnt->cl_auth == NULL)
 914                 return rpc_free_client(clnt);
 915
 916         /*
 917          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 918          *       release remaining GSS contexts. This mechanism ensures
 919          *       that it can do so safely.
 920          */
 921         atomic_inc(&clnt->cl_count);
 922         rpcauth_release(clnt->cl_auth);
 923         clnt->cl_auth = NULL;
 924         if (atomic_dec_and_test(&clnt->cl_count))
 925                 return rpc_free_client(clnt);
 926         return NULL;
 927 }
 928
 929 /*
 930  * Release reference to the RPC client
 931  */
 932 void
 933 rpc_release_client(struct rpc_clnt *clnt)
 934 {
 935         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 936
 937         do {
 938                 if (list_empty(&clnt->cl_tasks))
 939                         wake_up(&destroy_wait);
 940                 if (!atomic_dec_and_test(&clnt->cl_count))
 941                         break;
 942                 clnt = rpc_free_auth(clnt);
 943         } while (clnt != NULL);
 944 }
 945 EXPORT_SYMBOL_GPL(rpc_release_client);
 946
 947 /**
 948  * rpc_bind_new_program - bind a new RPC program to an existing client
 949  * @old: old rpc_client
 950  * @program: rpc program to set
 951  * @vers: rpc program version
 952  *
 953  * Clones the rpc client and sets up a new RPC program. This is mainly
 954  * of use for enabling different RPC programs to share the same transport.
 955  * The Sun NFSv2/v3 ACL protocol can do this.
 956  */
 957 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 958                                       const struct rpc_program *program,
 959                                       u32 vers)
 960 {
 961         struct rpc_create_args args = {
 962                 .program        = program,
 963                 .prognumber     = program->number,
 964                 .version        = vers,
 965                 .authflavor     = old->cl_auth->au_flavor,
 966                 .cred           = old->cl_cred,
 967         };
 968         struct rpc_clnt *clnt;
 969         int err;
 970
 971         clnt = __rpc_clone_client(&args, old);
 972         if (IS_ERR(clnt))
 973                 goto out;
 974         err = rpc_ping(clnt);
 975         if (err != 0) {
 976                 rpc_shutdown_client(clnt);
 977                 clnt = ERR_PTR(err);
 978         }
 979 out:
 980         return clnt;
 981 }
 982 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 983
 984 struct rpc_xprt *
 985 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 986 {
 987         struct rpc_xprt_switch *xps;
 988
 989         if (!xprt)
 990                 return NULL;
 991         rcu_read_lock();
 992         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
 993         atomic_long_inc(&xps->xps_queuelen);
 994         rcu_read_unlock();
 995         atomic_long_inc(&xprt->queuelen);
 996
 997         return xprt;
 998 }
 999
1000 static void
1001 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1002 {
1003         struct rpc_xprt_switch *xps;
1004
1005         atomic_long_dec(&xprt->queuelen);
1006         rcu_read_lock();
1007         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1008         atomic_long_dec(&xps->xps_queuelen);
1009         rcu_read_unlock();
1010
1011         xprt_put(xprt);
1012 }
1013
1014 void rpc_task_release_transport(struct rpc_task *task)
1015 {
1016         struct rpc_xprt *xprt = task->tk_xprt;
1017
1018         if (xprt) {
1019                 task->tk_xprt = NULL;
1020                 if (task->tk_client)
1021                         rpc_task_release_xprt(task->tk_client, xprt);
1022                 else
1023                         xprt_put(xprt);
1024         }
1025 }
1026 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1027
1028 void rpc_task_release_client(struct rpc_task *task)
1029 {
1030         struct rpc_clnt *clnt = task->tk_client;
1031
1032         rpc_task_release_transport(task);
1033         if (clnt != NULL) {
1034                 /* Remove from client task list */
1035                 spin_lock(&clnt->cl_lock);
1036                 list_del(&task->tk_task);
1037                 spin_unlock(&clnt->cl_lock);
1038                 task->tk_client = NULL;
1039
1040                 rpc_release_client(clnt);
1041         }
1042 }
1043
1044 static struct rpc_xprt *
1045 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1046 {
1047         struct rpc_xprt *xprt;
1048
1049         rcu_read_lock();
1050         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1051         rcu_read_unlock();
1052         return rpc_task_get_xprt(clnt, xprt);
1053 }
1054
1055 static struct rpc_xprt *
1056 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1057 {
1058         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1059 }
1060
1061 static
1062 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1063 {
1064         if (task->tk_xprt)
1065                 return;
1066         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1067                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1068         else
1069                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1070 }
1071
1072 static
1073 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1074 {
1075
1076         if (clnt != NULL) {
1077                 rpc_task_set_transport(task, clnt);
1078                 task->tk_client = clnt;
1079                 atomic_inc(&clnt->cl_count);
1080                 if (clnt->cl_softrtry)
1081                         task->tk_flags |= RPC_TASK_SOFT;
1082                 if (clnt->cl_softerr)
1083                         task->tk_flags |= RPC_TASK_TIMEOUT;
1084                 if (clnt->cl_noretranstimeo)
1085                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1086                 if (atomic_read(&clnt->cl_swapper))
1087                         task->tk_flags |= RPC_TASK_SWAPPER;
1088                 /* Add to the client's list of all tasks */
1089                 spin_lock(&clnt->cl_lock);
1090                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1091                 spin_unlock(&clnt->cl_lock);
1092         }
1093 }
1094
1095 static void
1096 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1097 {
1098         if (msg != NULL) {
1099                 task->tk_msg.rpc_proc = msg->rpc_proc;
1100                 task->tk_msg.rpc_argp = msg->rpc_argp;
1101                 task->tk_msg.rpc_resp = msg->rpc_resp;
1102                 task->tk_msg.rpc_cred = msg->rpc_cred;
1103                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1104                         get_cred(task->tk_msg.rpc_cred);
1105         }
1106 }
1107
1108 /*
1109  * Default callback for async RPC calls
1110  */
1111 static void
1112 rpc_default_callback(struct rpc_task *task, void *data)
1113 {
1114 }
1115
1116 static const struct rpc_call_ops rpc_default_ops = {
1117         .rpc_call_done = rpc_default_callback,
1118 };
1119
1120 /**
1121  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1122  * @task_setup_data: pointer to task initialisation data
1123  */
1124 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1125 {
1126         struct rpc_task *task;
1127
1128         task = rpc_new_task(task_setup_data);
1129
1130         if (!RPC_IS_ASYNC(task))
1131                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1132
1133         rpc_task_set_client(task, task_setup_data->rpc_client);
1134         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1135
1136         if (task->tk_action == NULL)
1137                 rpc_call_start(task);
1138
1139         atomic_inc(&task->tk_count);
1140         rpc_execute(task);
1141         return task;
1142 }
1143 EXPORT_SYMBOL_GPL(rpc_run_task);
1144
1145 /**
1146  * rpc_call_sync - Perform a synchronous RPC call
1147  * @clnt: pointer to RPC client
1148  * @msg: RPC call parameters
1149  * @flags: RPC call flags
1150  */
1151 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1152 {
1153         struct rpc_task *task;
1154         struct rpc_task_setup task_setup_data = {
1155                 .rpc_client = clnt,
1156                 .rpc_message = msg,
1157                 .callback_ops = &rpc_default_ops,
1158                 .flags = flags,
1159         };
1160         int status;
1161
1162         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1163         if (flags & RPC_TASK_ASYNC) {
1164                 rpc_release_calldata(task_setup_data.callback_ops,
1165                         task_setup_data.callback_data);
1166                 return -EINVAL;
1167         }
1168
1169         task = rpc_run_task(&task_setup_data);
1170         if (IS_ERR(task))
1171                 return PTR_ERR(task);
1172         status = task->tk_status;
1173         rpc_put_task(task);
1174         return status;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_call_sync);
1177
1178 /**
1179  * rpc_call_async - Perform an asynchronous RPC call
1180  * @clnt: pointer to RPC client
1181  * @msg: RPC call parameters
1182  * @flags: RPC call flags
1183  * @tk_ops: RPC call ops
1184  * @data: user call data
1185  */
1186 int
1187 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1188                const struct rpc_call_ops *tk_ops, void *data)
1189 {
1190         struct rpc_task *task;
1191         struct rpc_task_setup task_setup_data = {
1192                 .rpc_client = clnt,
1193                 .rpc_message = msg,
1194                 .callback_ops = tk_ops,
1195                 .callback_data = data,
1196                 .flags = flags|RPC_TASK_ASYNC,
1197         };
1198
1199         task = rpc_run_task(&task_setup_data);
1200         if (IS_ERR(task))
1201                 return PTR_ERR(task);
1202         rpc_put_task(task);
1203         return 0;
1204 }
1205 EXPORT_SYMBOL_GPL(rpc_call_async);
1206
1207 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1208 static void call_bc_encode(struct rpc_task *task);
1209
1210 /**
1211  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1212  * rpc_execute against it
1213  * @req: RPC request
1214  */
1215 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1216 {
1217         struct rpc_task *task;
1218         struct rpc_task_setup task_setup_data = {
1219                 .callback_ops = &rpc_default_ops,
1220                 .flags = RPC_TASK_SOFTCONN |
1221                         RPC_TASK_NO_RETRANS_TIMEOUT,
1222         };
1223
1224         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1225         /*
1226          * Create an rpc_task to send the data
1227          */
1228         task = rpc_new_task(&task_setup_data);
1229         xprt_init_bc_request(req, task);
1230
1231         task->tk_action = call_bc_encode;
1232         atomic_inc(&task->tk_count);
1233         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1234         rpc_execute(task);
1235
1236         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1237         return task;
1238 }
1239 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1240
1241 /**
1242  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1243  * @req: RPC request to prepare
1244  * @pages: vector of struct page pointers
1245  * @base: offset in first page where receive should start, in bytes
1246  * @len: expected size of the upper layer data payload, in bytes
1247  * @hdrsize: expected size of upper layer reply header, in XDR words
1248  *
1249  */
1250 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1251                              unsigned int base, unsigned int len,
1252                              unsigned int hdrsize)
1253 {
1254         /* Subtract one to force an extra word of buffer space for the
1255          * payload's XDR pad to fall into the rcv_buf's tail iovec.
1256          */
1257         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
1258
1259         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1260         trace_rpc_reply_pages(req);
1261 }
1262 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1263
1264 void
1265 rpc_call_start(struct rpc_task *task)
1266 {
1267         task->tk_action = call_start;
1268 }
1269 EXPORT_SYMBOL_GPL(rpc_call_start);
1270
1271 /**
1272  * rpc_peeraddr - extract remote peer address from clnt's xprt
1273  * @clnt: RPC client structure
1274  * @buf: target buffer
1275  * @bufsize: length of target buffer
1276  *
1277  * Returns the number of bytes that are actually in the stored address.
1278  */
1279 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1280 {
1281         size_t bytes;
1282         struct rpc_xprt *xprt;
1283
1284         rcu_read_lock();
1285         xprt = rcu_dereference(clnt->cl_xprt);
1286
1287         bytes = xprt->addrlen;
1288         if (bytes > bufsize)
1289                 bytes = bufsize;
1290         memcpy(buf, &xprt->addr, bytes);
1291         rcu_read_unlock();
1292
1293         return bytes;
1294 }
1295 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1296
1297 /**
1298  * rpc_peeraddr2str - return remote peer address in printable format
1299  * @clnt: RPC client structure
1300  * @format: address format
1301  *
1302  * NB: the lifetime of the memory referenced by the returned pointer is
1303  * the same as the rpc_xprt itself.  As long as the caller uses this
1304  * pointer, it must hold the RCU read lock.
1305  */
1306 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1307                              enum rpc_display_format_t format)
1308 {
1309         struct rpc_xprt *xprt;
1310
1311         xprt = rcu_dereference(clnt->cl_xprt);
1312
1313         if (xprt->address_strings[format] != NULL)
1314                 return xprt->address_strings[format];
1315         else
1316                 return "unprintable";
1317 }
1318 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1319
1320 static const struct sockaddr_in rpc_inaddr_loopback = {
1321         .sin_family             = AF_INET,
1322         .sin_addr.s_addr        = htonl(INADDR_ANY),
1323 };
1324
1325 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1326         .sin6_family            = AF_INET6,
1327         .sin6_addr              = IN6ADDR_ANY_INIT,
1328 };
1329
1330 /*
1331  * Try a getsockname() on a connected datagram socket.  Using a
1332  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1333  * This conserves the ephemeral port number space.
1334  *
1335  * Returns zero and fills in "buf" if successful; otherwise, a
1336  * negative errno is returned.
1337  */
1338 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1339                         struct sockaddr *buf)
1340 {
1341         struct socket *sock;
1342         int err;
1343
1344         err = __sock_create(net, sap->sa_family,
1345                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1346         if (err < 0) {
1347                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1348                 goto out;
1349         }
1350
1351         switch (sap->sa_family) {
1352         case AF_INET:
1353                 err = kernel_bind(sock,
1354                                 (struct sockaddr *)&rpc_inaddr_loopback,
1355                                 sizeof(rpc_inaddr_loopback));
1356                 break;
1357         case AF_INET6:
1358                 err = kernel_bind(sock,
1359                                 (struct sockaddr *)&rpc_in6addr_loopback,
1360                                 sizeof(rpc_in6addr_loopback));
1361                 break;
1362         default:
1363                 err = -EAFNOSUPPORT;
1364                 goto out;
1365         }
1366         if (err < 0) {
1367                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1368                 goto out_release;
1369         }
1370
1371         err = kernel_connect(sock, sap, salen, 0);
1372         if (err < 0) {
1373                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1374                 goto out_release;
1375         }
1376
1377         err = kernel_getsockname(sock, buf);
1378         if (err < 0) {
1379                 dprintk("RPC:       getsockname failed (%d)\n", err);
1380                 goto out_release;
1381         }
1382
1383         err = 0;
1384         if (buf->sa_family == AF_INET6) {
1385                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1386                 sin6->sin6_scope_id = 0;
1387         }
1388         dprintk("RPC:       %s succeeded\n", __func__);
1389
1390 out_release:
1391         sock_release(sock);
1392 out:
1393         return err;
1394 }
1395
1396 /*
1397  * Scraping a connected socket failed, so we don't have a useable
1398  * local address.  Fallback: generate an address that will prevent
1399  * the server from calling us back.
1400  *
1401  * Returns zero and fills in "buf" if successful; otherwise, a
1402  * negative errno is returned.
1403  */
1404 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1405 {
1406         switch (family) {
1407         case AF_INET:
1408                 if (buflen < sizeof(rpc_inaddr_loopback))
1409                         return -EINVAL;
1410                 memcpy(buf, &rpc_inaddr_loopback,
1411                                 sizeof(rpc_inaddr_loopback));
1412                 break;
1413         case AF_INET6:
1414                 if (buflen < sizeof(rpc_in6addr_loopback))
1415                         return -EINVAL;
1416                 memcpy(buf, &rpc_in6addr_loopback,
1417                                 sizeof(rpc_in6addr_loopback));
1418                 break;
1419         default:
1420                 dprintk("RPC:       %s: address family not supported\n",
1421                         __func__);
1422                 return -EAFNOSUPPORT;
1423         }
1424         dprintk("RPC:       %s: succeeded\n", __func__);
1425         return 0;
1426 }
1427
1428 /**
1429  * rpc_localaddr - discover local endpoint address for an RPC client
1430  * @clnt: RPC client structure
1431  * @buf: target buffer
1432  * @buflen: size of target buffer, in bytes
1433  *
1434  * Returns zero and fills in "buf" and "buflen" if successful;
1435  * otherwise, a negative errno is returned.
1436  *
1437  * This works even if the underlying transport is not currently connected,
1438  * or if the upper layer never previously provided a source address.
1439  *
1440  * The result of this function call is transient: multiple calls in
1441  * succession may give different results, depending on how local
1442  * networking configuration changes over time.
1443  */
1444 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1445 {
1446         struct sockaddr_storage address;
1447         struct sockaddr *sap = (struct sockaddr *)&address;
1448         struct rpc_xprt *xprt;
1449         struct net *net;
1450         size_t salen;
1451         int err;
1452
1453         rcu_read_lock();
1454         xprt = rcu_dereference(clnt->cl_xprt);
1455         salen = xprt->addrlen;
1456         memcpy(sap, &xprt->addr, salen);
1457         net = get_net(xprt->xprt_net);
1458         rcu_read_unlock();
1459
1460         rpc_set_port(sap, 0);
1461         err = rpc_sockname(net, sap, salen, buf);
1462         put_net(net);
1463         if (err != 0)
1464                 /* Couldn't discover local address, return ANYADDR */
1465                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1466         return 0;
1467 }
1468 EXPORT_SYMBOL_GPL(rpc_localaddr);
1469
1470 void
1471 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1472 {
1473         struct rpc_xprt *xprt;
1474
1475         rcu_read_lock();
1476         xprt = rcu_dereference(clnt->cl_xprt);
1477         if (xprt->ops->set_buffer_size)
1478                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1479         rcu_read_unlock();
1480 }
1481 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1482
1483 /**
1484  * rpc_net_ns - Get the network namespace for this RPC client
1485  * @clnt: RPC client to query
1486  *
1487  */
1488 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1489 {
1490         struct net *ret;
1491
1492         rcu_read_lock();
1493         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1494         rcu_read_unlock();
1495         return ret;
1496 }
1497 EXPORT_SYMBOL_GPL(rpc_net_ns);
1498
1499 /**
1500  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1501  * @clnt: RPC client to query
1502  *
1503  * For stream transports, this is one RPC record fragment (see RFC
1504  * 1831), as we don't support multi-record requests yet.  For datagram
1505  * transports, this is the size of an IP packet minus the IP, UDP, and
1506  * RPC header sizes.
1507  */
1508 size_t rpc_max_payload(struct rpc_clnt *clnt)
1509 {
1510         size_t ret;
1511
1512         rcu_read_lock();
1513         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1514         rcu_read_unlock();
1515         return ret;
1516 }
1517 EXPORT_SYMBOL_GPL(rpc_max_payload);
1518
1519 /**
1520  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1521  * @clnt: RPC client to query
1522  */
1523 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1524 {
1525         struct rpc_xprt *xprt;
1526         size_t ret;
1527
1528         rcu_read_lock();
1529         xprt = rcu_dereference(clnt->cl_xprt);
1530         ret = xprt->ops->bc_maxpayload(xprt);
1531         rcu_read_unlock();
1532         return ret;
1533 }
1534 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1535
1536 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1537 {
1538         struct rpc_xprt *xprt;
1539         unsigned int ret;
1540
1541         rcu_read_lock();
1542         xprt = rcu_dereference(clnt->cl_xprt);
1543         ret = xprt->ops->bc_num_slots(xprt);
1544         rcu_read_unlock();
1545         return ret;
1546 }
1547 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1548
1549 /**
1550  * rpc_force_rebind - force transport to check that remote port is unchanged
1551  * @clnt: client to rebind
1552  *
1553  */
1554 void rpc_force_rebind(struct rpc_clnt *clnt)
1555 {
1556         if (clnt->cl_autobind) {
1557                 rcu_read_lock();
1558                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1559                 rcu_read_unlock();
1560         }
1561 }
1562 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1563
1564 static int
1565 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1566 {
1567         task->tk_status = 0;
1568         task->tk_rpc_status = 0;
1569         task->tk_action = action;
1570         return 1;
1571 }
1572
1573 /*
1574  * Restart an (async) RPC call. Usually called from within the
1575  * exit handler.
1576  */
1577 int
1578 rpc_restart_call(struct rpc_task *task)
1579 {
1580         return __rpc_restart_call(task, call_start);
1581 }
1582 EXPORT_SYMBOL_GPL(rpc_restart_call);
1583
1584 /*
1585  * Restart an (async) RPC call from the call_prepare state.
1586  * Usually called from within the exit handler.
1587  */
1588 int
1589 rpc_restart_call_prepare(struct rpc_task *task)
1590 {
1591         if (task->tk_ops->rpc_call_prepare != NULL)
1592                 return __rpc_restart_call(task, rpc_prepare_task);
1593         return rpc_restart_call(task);
1594 }
1595 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1596
1597 const char
1598 *rpc_proc_name(const struct rpc_task *task)
1599 {
1600         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1601
1602         if (proc) {
1603                 if (proc->p_name)
1604                         return proc->p_name;
1605                 else
1606                         return "NULL";
1607         } else
1608                 return "no proc";
1609 }
1610
1611 static void
1612 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1613 {
1614         task->tk_rpc_status = rpc_status;
1615         rpc_exit(task, tk_status);
1616 }
1617
1618 static void
1619 rpc_call_rpcerror(struct rpc_task *task, int status)
1620 {
1621         __rpc_call_rpcerror(task, status, status);
1622 }
1623
1624 /*
1625  * 0.  Initial state
1626  *
1627  *     Other FSM states can be visited zero or more times, but
1628  *     this state is visited exactly once for each RPC.
1629  */
1630 static void
1631 call_start(struct rpc_task *task)
1632 {
1633         struct rpc_clnt *clnt = task->tk_client;
1634         int idx = task->tk_msg.rpc_proc->p_statidx;
1635
1636         trace_rpc_request(task);
1637         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1638                         clnt->cl_program->name, clnt->cl_vers,
1639                         rpc_proc_name(task),
1640                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1641
1642         /* Increment call count (version might not be valid for ping) */
1643         if (clnt->cl_program->version[clnt->cl_vers])
1644                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1645         clnt->cl_stats->rpccnt++;
1646         task->tk_action = call_reserve;
1647         rpc_task_set_transport(task, clnt);
1648 }
1649
1650 /*
1651  * 1.   Reserve an RPC call slot
1652  */
1653 static void
1654 call_reserve(struct rpc_task *task)
1655 {
1656         dprint_status(task);
1657
1658         task->tk_status  = 0;
1659         task->tk_action  = call_reserveresult;
1660         xprt_reserve(task);
1661 }
1662
1663 static void call_retry_reserve(struct rpc_task *task);
1664
1665 /*
1666  * 1b.  Grok the result of xprt_reserve()
1667  */
1668 static void
1669 call_reserveresult(struct rpc_task *task)
1670 {
1671         int status = task->tk_status;
1672
1673         dprint_status(task);
1674
1675         /*
1676          * After a call to xprt_reserve(), we must have either
1677          * a request slot or else an error status.
1678          */
1679         task->tk_status = 0;
1680         if (status >= 0) {
1681                 if (task->tk_rqstp) {
1682                         task->tk_action = call_refresh;
1683                         return;
1684                 }
1685
1686                 rpc_call_rpcerror(task, -EIO);
1687                 return;
1688         }
1689
1690         /*
1691          * Even though there was an error, we may have acquired
1692          * a request slot somehow.  Make sure not to leak it.
1693          */
1694         if (task->tk_rqstp)
1695                 xprt_release(task);
1696
1697         switch (status) {
1698         case -ENOMEM:
1699                 rpc_delay(task, HZ >> 2);
1700                 /* fall through */
1701         case -EAGAIN:   /* woken up; retry */
1702                 task->tk_action = call_retry_reserve;
1703                 return;
1704         default:
1705                 rpc_call_rpcerror(task, status);
1706         }
1707 }
1708
1709 /*
1710  * 1c.  Retry reserving an RPC call slot
1711  */
1712 static void
1713 call_retry_reserve(struct rpc_task *task)
1714 {
1715         dprint_status(task);
1716
1717         task->tk_status  = 0;
1718         task->tk_action  = call_reserveresult;
1719         xprt_retry_reserve(task);
1720 }
1721
1722 /*
1723  * 2.   Bind and/or refresh the credentials
1724  */
1725 static void
1726 call_refresh(struct rpc_task *task)
1727 {
1728         dprint_status(task);
1729
1730         task->tk_action = call_refreshresult;
1731         task->tk_status = 0;
1732         task->tk_client->cl_stats->rpcauthrefresh++;
1733         rpcauth_refreshcred(task);
1734 }
1735
1736 /*
1737  * 2a.  Process the results of a credential refresh
1738  */
1739 static void
1740 call_refreshresult(struct rpc_task *task)
1741 {
1742         int status = task->tk_status;
1743
1744         dprint_status(task);
1745
1746         task->tk_status = 0;
1747         task->tk_action = call_refresh;
1748         switch (status) {
1749         case 0:
1750                 if (rpcauth_uptodatecred(task)) {
1751                         task->tk_action = call_allocate;
1752                         return;
1753                 }
1754                 /* Use rate-limiting and a max number of retries if refresh
1755                  * had status 0 but failed to update the cred.
1756                  */
1757                 /* fall through */
1758         case -ETIMEDOUT:
1759                 rpc_delay(task, 3*HZ);
1760                 /* fall through */
1761         case -EAGAIN:
1762                 status = -EACCES;
1763                 /* fall through */
1764         case -EKEYEXPIRED:
1765                 if (!task->tk_cred_retry)
1766                         break;
1767                 task->tk_cred_retry--;
1768                 dprintk("RPC: %5u %s: retry refresh creds\n",
1769                                 task->tk_pid, __func__);
1770                 return;
1771         }
1772         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1773                                 task->tk_pid, __func__, status);
1774         rpc_call_rpcerror(task, status);
1775 }
1776
1777 /*
1778  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1779  *      (Note: buffer memory is freed in xprt_release).
1780  */
1781 static void
1782 call_allocate(struct rpc_task *task)
1783 {
1784         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1785         struct rpc_rqst *req = task->tk_rqstp;
1786         struct rpc_xprt *xprt = req->rq_xprt;
1787         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1788         int status;
1789
1790         dprint_status(task);
1791
1792         task->tk_status = 0;
1793         task->tk_action = call_encode;
1794
1795         if (req->rq_buffer)
1796                 return;
1797
1798         if (proc->p_proc != 0) {
1799                 BUG_ON(proc->p_arglen == 0);
1800                 if (proc->p_decode != NULL)
1801                         BUG_ON(proc->p_replen == 0);
1802         }
1803
1804         /*
1805          * Calculate the size (in quads) of the RPC call
1806          * and reply headers, and convert both values
1807          * to byte sizes.
1808          */
1809         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1810                            proc->p_arglen;
1811         req->rq_callsize <<= 2;
1812         /*
1813          * Note: the reply buffer must at minimum allocate enough space
1814          * for the 'struct accepted_reply' from RFC5531.
1815          */
1816         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1817                         max_t(size_t, proc->p_replen, 2);
1818         req->rq_rcvsize <<= 2;
1819
1820         status = xprt->ops->buf_alloc(task);
1821         xprt_inject_disconnect(xprt);
1822         if (status == 0)
1823                 return;
1824         if (status != -ENOMEM) {
1825                 rpc_call_rpcerror(task, status);
1826                 return;
1827         }
1828
1829         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1830
1831         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1832                 task->tk_action = call_allocate;
1833                 rpc_delay(task, HZ>>4);
1834                 return;
1835         }
1836
1837         rpc_call_rpcerror(task, -ERESTARTSYS);
1838 }
1839
1840 static int
1841 rpc_task_need_encode(struct rpc_task *task)
1842 {
1843         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1844                 (!(task->tk_flags & RPC_TASK_SENT) ||
1845                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1846                  xprt_request_need_retransmit(task));
1847 }
1848
1849 static void
1850 rpc_xdr_encode(struct rpc_task *task)
1851 {
1852         struct rpc_rqst *req = task->tk_rqstp;
1853         struct xdr_stream xdr;
1854
1855         xdr_buf_init(&req->rq_snd_buf,
1856                      req->rq_buffer,
1857                      req->rq_callsize);
1858         xdr_buf_init(&req->rq_rcv_buf,
1859                      req->rq_rbuffer,
1860                      req->rq_rcvsize);
1861
1862         req->rq_reply_bytes_recvd = 0;
1863         req->rq_snd_buf.head[0].iov_len = 0;
1864         xdr_init_encode(&xdr, &req->rq_snd_buf,
1865                         req->rq_snd_buf.head[0].iov_base, req);
1866         xdr_free_bvec(&req->rq_snd_buf);
1867         if (rpc_encode_header(task, &xdr))
1868                 return;
1869
1870         task->tk_status = rpcauth_wrap_req(task, &xdr);
1871 }
1872
1873 /*
1874  * 3.   Encode arguments of an RPC call
1875  */
1876 static void
1877 call_encode(struct rpc_task *task)
1878 {
1879         if (!rpc_task_need_encode(task))
1880                 goto out;
1881         dprint_status(task);
1882         /* Dequeue task from the receive queue while we're encoding */
1883         xprt_request_dequeue_xprt(task);
1884         /* Encode here so that rpcsec_gss can use correct sequence number. */
1885         rpc_xdr_encode(task);
1886         /* Did the encode result in an error condition? */
1887         if (task->tk_status != 0) {
1888                 /* Was the error nonfatal? */
1889                 switch (task->tk_status) {
1890                 case -EAGAIN:
1891                 case -ENOMEM:
1892                         rpc_delay(task, HZ >> 4);
1893                         break;
1894                 case -EKEYEXPIRED:
1895                         if (!task->tk_cred_retry) {
1896                                 rpc_exit(task, task->tk_status);
1897                         } else {
1898                                 task->tk_action = call_refresh;
1899                                 task->tk_cred_retry--;
1900                                 dprintk("RPC: %5u %s: retry refresh creds\n",
1901                                         task->tk_pid, __func__);
1902                         }
1903                         break;
1904                 default:
1905                         rpc_call_rpcerror(task, task->tk_status);
1906                 }
1907                 return;
1908         }
1909
1910         /* Add task to reply queue before transmission to avoid races */
1911         if (rpc_reply_expected(task))
1912                 xprt_request_enqueue_receive(task);
1913         xprt_request_enqueue_transmit(task);
1914 out:
1915         task->tk_action = call_transmit;
1916         /* Check that the connection is OK */
1917         if (!xprt_bound(task->tk_xprt))
1918                 task->tk_action = call_bind;
1919         else if (!xprt_connected(task->tk_xprt))
1920                 task->tk_action = call_connect;
1921 }
1922
1923 /*
1924  * Helpers to check if the task was already transmitted, and
1925  * to take action when that is the case.
1926  */
1927 static bool
1928 rpc_task_transmitted(struct rpc_task *task)
1929 {
1930         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1931 }
1932
1933 static void
1934 rpc_task_handle_transmitted(struct rpc_task *task)
1935 {
1936         xprt_end_transmit(task);
1937         task->tk_action = call_transmit_status;
1938 }
1939
1940 /*
1941  * 4.   Get the server port number if not yet set
1942  */
1943 static void
1944 call_bind(struct rpc_task *task)
1945 {
1946         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1947
1948         if (rpc_task_transmitted(task)) {
1949                 rpc_task_handle_transmitted(task);
1950                 return;
1951         }
1952
1953         if (xprt_bound(xprt)) {
1954                 task->tk_action = call_connect;
1955                 return;
1956         }
1957
1958         dprint_status(task);
1959
1960         task->tk_action = call_bind_status;
1961         if (!xprt_prepare_transmit(task))
1962                 return;
1963
1964         xprt->ops->rpcbind(task);
1965 }
1966
1967 /*
1968  * 4a.  Sort out bind result
1969  */
1970 static void
1971 call_bind_status(struct rpc_task *task)
1972 {
1973         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1974         int status = -EIO;
1975
1976         if (rpc_task_transmitted(task)) {
1977                 rpc_task_handle_transmitted(task);
1978                 return;
1979         }
1980
1981         dprint_status(task);
1982         trace_rpc_bind_status(task);
1983         if (task->tk_status >= 0)
1984                 goto out_next;
1985         if (xprt_bound(xprt)) {
1986                 task->tk_status = 0;
1987                 goto out_next;
1988         }
1989
1990         switch (task->tk_status) {
1991         case -ENOMEM:
1992                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1993                 rpc_delay(task, HZ >> 2);
1994                 goto retry_timeout;
1995         case -EACCES:
1996                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1997                                 "unavailable\n", task->tk_pid);
1998                 /* fail immediately if this is an RPC ping */
1999                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2000                         status = -EOPNOTSUPP;
2001                         break;
2002                 }
2003                 if (task->tk_rebind_retry == 0)
2004                         break;
2005                 task->tk_rebind_retry--;
2006                 rpc_delay(task, 3*HZ);
2007                 goto retry_timeout;
2008         case -ENOBUFS:
2009                 rpc_delay(task, HZ >> 2);
2010                 goto retry_timeout;
2011         case -EAGAIN:
2012                 goto retry_timeout;
2013         case -ETIMEDOUT:
2014                 dprintk("RPC: %5u rpcbind request timed out\n",
2015                                 task->tk_pid);
2016                 goto retry_timeout;
2017         case -EPFNOSUPPORT:
2018                 /* server doesn't support any rpcbind version we know of */
2019                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
2020                                 task->tk_pid);
2021                 break;
2022         case -EPROTONOSUPPORT:
2023                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
2024                                 task->tk_pid);
2025                 goto retry_timeout;
2026         case -ECONNREFUSED:             /* connection problems */
2027         case -ECONNRESET:
2028         case -ECONNABORTED:
2029         case -ENOTCONN:
2030         case -EHOSTDOWN:
2031         case -ENETDOWN:
2032         case -EHOSTUNREACH:
2033         case -ENETUNREACH:
2034         case -EPIPE:
2035                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
2036                                 task->tk_pid, task->tk_status);
2037                 if (!RPC_IS_SOFTCONN(task)) {
2038                         rpc_delay(task, 5*HZ);
2039                         goto retry_timeout;
2040                 }
2041                 status = task->tk_status;
2042                 break;
2043         default:
2044                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
2045                                 task->tk_pid, -task->tk_status);
2046         }
2047
2048         rpc_call_rpcerror(task, status);
2049         return;
2050 out_next:
2051         task->tk_action = call_connect;
2052         return;
2053 retry_timeout:
2054         task->tk_status = 0;
2055         task->tk_action = call_bind;
2056         rpc_check_timeout(task);
2057 }
2058
2059 /*
2060  * 4b.  Connect to the RPC server
2061  */
2062 static void
2063 call_connect(struct rpc_task *task)
2064 {
2065         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2066
2067         if (rpc_task_transmitted(task)) {
2068                 rpc_task_handle_transmitted(task);
2069                 return;
2070         }
2071
2072         if (xprt_connected(xprt)) {
2073                 task->tk_action = call_transmit;
2074                 return;
2075         }
2076
2077         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
2078                         task->tk_pid, xprt,
2079                         (xprt_connected(xprt) ? "is" : "is not"));
2080
2081         task->tk_action = call_connect_status;
2082         if (task->tk_status < 0)
2083                 return;
2084         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2085                 rpc_call_rpcerror(task, -ENOTCONN);
2086                 return;
2087         }
2088         if (!xprt_prepare_transmit(task))
2089                 return;
2090         xprt_connect(task);
2091 }
2092
2093 /*
2094  * 4c.  Sort out connect result
2095  */
2096 static void
2097 call_connect_status(struct rpc_task *task)
2098 {
2099         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2100         struct rpc_clnt *clnt = task->tk_client;
2101         int status = task->tk_status;
2102
2103         if (rpc_task_transmitted(task)) {
2104                 rpc_task_handle_transmitted(task);
2105                 return;
2106         }
2107
2108         dprint_status(task);
2109         trace_rpc_connect_status(task);
2110
2111         if (task->tk_status == 0) {
2112                 clnt->cl_stats->netreconn++;
2113                 goto out_next;
2114         }
2115         if (xprt_connected(xprt)) {
2116                 task->tk_status = 0;
2117                 goto out_next;
2118         }
2119
2120         task->tk_status = 0;
2121         switch (status) {
2122         case -ECONNREFUSED:
2123                 /* A positive refusal suggests a rebind is needed. */
2124                 if (RPC_IS_SOFTCONN(task))
2125                         break;
2126                 if (clnt->cl_autobind) {
2127                         rpc_force_rebind(clnt);
2128                         goto out_retry;
2129                 }
2130                 /* fall through */
2131         case -ECONNRESET:
2132         case -ECONNABORTED:
2133         case -ENETDOWN:
2134         case -ENETUNREACH:
2135         case -EHOSTUNREACH:
2136         case -EPIPE:
2137         case -EPROTO:
2138                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2139                                             task->tk_rqstp->rq_connect_cookie);
2140                 if (RPC_IS_SOFTCONN(task))
2141                         break;
2142                 /* retry with existing socket, after a delay */
2143                 rpc_delay(task, 3*HZ);
2144                 /* fall through */
2145         case -EADDRINUSE:
2146         case -ENOTCONN:
2147         case -EAGAIN:
2148         case -ETIMEDOUT:
2149                 goto out_retry;
2150         case -ENOBUFS:
2151                 rpc_delay(task, HZ >> 2);
2152                 goto out_retry;
2153         }
2154         rpc_call_rpcerror(task, status);
2155         return;
2156 out_next:
2157         task->tk_action = call_transmit;
2158         return;
2159 out_retry:
2160         /* Check for timeouts before looping back to call_bind */
2161         task->tk_action = call_bind;
2162         rpc_check_timeout(task);
2163 }
2164
2165 /*
2166  * 5.   Transmit the RPC request, and wait for reply
2167  */
2168 static void
2169 call_transmit(struct rpc_task *task)
2170 {
2171         if (rpc_task_transmitted(task)) {
2172                 rpc_task_handle_transmitted(task);
2173                 return;
2174         }
2175
2176         dprint_status(task);
2177
2178         task->tk_action = call_transmit_status;
2179         if (!xprt_prepare_transmit(task))
2180                 return;
2181         task->tk_status = 0;
2182         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2183                 if (!xprt_connected(task->tk_xprt)) {
2184                         task->tk_status = -ENOTCONN;
2185                         return;
2186                 }
2187                 xprt_transmit(task);
2188         }
2189         xprt_end_transmit(task);
2190 }
2191
2192 /*
2193  * 5a.  Handle cleanup after a transmission
2194  */
2195 static void
2196 call_transmit_status(struct rpc_task *task)
2197 {
2198         task->tk_action = call_status;
2199
2200         /*
2201          * Common case: success.  Force the compiler to put this
2202          * test first.
2203          */
2204         if (rpc_task_transmitted(task)) {
2205                 task->tk_status = 0;
2206                 xprt_request_wait_receive(task);
2207                 return;
2208         }
2209
2210         switch (task->tk_status) {
2211         default:
2212                 dprint_status(task);
2213                 break;
2214         case -EBADMSG:
2215                 task->tk_status = 0;
2216                 task->tk_action = call_encode;
2217                 break;
2218                 /*
2219                  * Special cases: if we've been waiting on the
2220                  * socket's write_space() callback, or if the
2221                  * socket just returned a connection error,
2222                  * then hold onto the transport lock.
2223                  */
2224         case -ENOBUFS:
2225                 rpc_delay(task, HZ>>2);
2226                 /* fall through */
2227         case -EBADSLT:
2228         case -EAGAIN:
2229                 task->tk_action = call_transmit;
2230                 task->tk_status = 0;
2231                 break;
2232         case -ECONNREFUSED:
2233         case -EHOSTDOWN:
2234         case -ENETDOWN:
2235         case -EHOSTUNREACH:
2236         case -ENETUNREACH:
2237         case -EPERM:
2238                 if (RPC_IS_SOFTCONN(task)) {
2239                         if (!task->tk_msg.rpc_proc->p_proc)
2240                                 trace_xprt_ping(task->tk_xprt,
2241                                                 task->tk_status);
2242                         rpc_call_rpcerror(task, task->tk_status);
2243                         return;
2244                 }
2245                 /* fall through */
2246         case -ECONNRESET:
2247         case -ECONNABORTED:
2248         case -EADDRINUSE:
2249         case -ENOTCONN:
2250         case -EPIPE:
2251                 task->tk_action = call_bind;
2252                 task->tk_status = 0;
2253                 break;
2254         }
2255         rpc_check_timeout(task);
2256 }
2257
2258 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2259 static void call_bc_transmit(struct rpc_task *task);
2260 static void call_bc_transmit_status(struct rpc_task *task);
2261
2262 static void
2263 call_bc_encode(struct rpc_task *task)
2264 {
2265         xprt_request_enqueue_transmit(task);
2266         task->tk_action = call_bc_transmit;
2267 }
2268
2269 /*
2270  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2271  * addition, disconnect on connectivity errors.
2272  */
2273 static void
2274 call_bc_transmit(struct rpc_task *task)
2275 {
2276         task->tk_action = call_bc_transmit_status;
2277         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2278                 if (!xprt_prepare_transmit(task))
2279                         return;
2280                 task->tk_status = 0;
2281                 xprt_transmit(task);
2282         }
2283         xprt_end_transmit(task);
2284 }
2285
2286 static void
2287 call_bc_transmit_status(struct rpc_task *task)
2288 {
2289         struct rpc_rqst *req = task->tk_rqstp;
2290
2291         if (rpc_task_transmitted(task))
2292                 task->tk_status = 0;
2293
2294         dprint_status(task);
2295
2296         switch (task->tk_status) {
2297         case 0:
2298                 /* Success */
2299         case -ENETDOWN:
2300         case -EHOSTDOWN:
2301         case -EHOSTUNREACH:
2302         case -ENETUNREACH:
2303         case -ECONNRESET:
2304         case -ECONNREFUSED:
2305         case -EADDRINUSE:
2306         case -ENOTCONN:
2307         case -EPIPE:
2308                 break;
2309         case -ENOBUFS:
2310                 rpc_delay(task, HZ>>2);
2311                 /* fall through */
2312         case -EBADSLT:
2313         case -EAGAIN:
2314                 task->tk_status = 0;
2315                 task->tk_action = call_bc_transmit;
2316                 return;
2317         case -ETIMEDOUT:
2318                 /*
2319                  * Problem reaching the server.  Disconnect and let the
2320                  * forechannel reestablish the connection.  The server will
2321                  * have to retransmit the backchannel request and we'll
2322                  * reprocess it.  Since these ops are idempotent, there's no
2323                  * need to cache our reply at this time.
2324                  */
2325                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2326                         "error: %d\n", task->tk_status);
2327                 xprt_conditional_disconnect(req->rq_xprt,
2328                         req->rq_connect_cookie);
2329                 break;
2330         default:
2331                 /*
2332                  * We were unable to reply and will have to drop the
2333                  * request.  The server should reconnect and retransmit.
2334                  */
2335                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2336                         "error: %d\n", task->tk_status);
2337                 break;
2338         }
2339         task->tk_action = rpc_exit_task;
2340 }
2341 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2342
2343 /*
2344  * 6.   Sort out the RPC call status
2345  */
2346 static void
2347 call_status(struct rpc_task *task)
2348 {
2349         struct rpc_clnt *clnt = task->tk_client;
2350         int             status;
2351
2352         if (!task->tk_msg.rpc_proc->p_proc)
2353                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2354
2355         dprint_status(task);
2356
2357         status = task->tk_status;
2358         if (status >= 0) {
2359                 task->tk_action = call_decode;
2360                 return;
2361         }
2362
2363         trace_rpc_call_status(task);
2364         task->tk_status = 0;
2365         switch(status) {
2366         case -EHOSTDOWN:
2367         case -ENETDOWN:
2368         case -EHOSTUNREACH:
2369         case -ENETUNREACH:
2370         case -EPERM:
2371                 if (RPC_IS_SOFTCONN(task))
2372                         goto out_exit;
2373                 /*
2374                  * Delay any retries for 3 seconds, then handle as if it
2375                  * were a timeout.
2376                  */
2377                 rpc_delay(task, 3*HZ);
2378                 /* fall through */
2379         case -ETIMEDOUT:
2380                 break;
2381         case -ECONNREFUSED:
2382         case -ECONNRESET:
2383         case -ECONNABORTED:
2384         case -ENOTCONN:
2385                 rpc_force_rebind(clnt);
2386                 break;
2387         case -EADDRINUSE:
2388                 rpc_delay(task, 3*HZ);
2389                 /* fall through */
2390         case -EPIPE:
2391         case -EAGAIN:
2392                 break;
2393         case -EIO:
2394                 /* shutdown or soft timeout */
2395                 goto out_exit;
2396         default:
2397                 if (clnt->cl_chatty)
2398                         printk("%s: RPC call returned error %d\n",
2399                                clnt->cl_program->name, -status);
2400                 goto out_exit;
2401         }
2402         task->tk_action = call_encode;
2403         rpc_check_timeout(task);
2404         return;
2405 out_exit:
2406         rpc_call_rpcerror(task, status);
2407 }
2408
2409 static bool
2410 rpc_check_connected(const struct rpc_rqst *req)
2411 {
2412         /* No allocated request or transport? return true */
2413         if (!req || !req->rq_xprt)
2414                 return true;
2415         return xprt_connected(req->rq_xprt);
2416 }
2417
2418 static void
2419 rpc_check_timeout(struct rpc_task *task)
2420 {
2421         struct rpc_clnt *clnt = task->tk_client;
2422
2423         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2424                 return;
2425
2426         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2427         task->tk_timeouts++;
2428
2429         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2430                 rpc_call_rpcerror(task, -ETIMEDOUT);
2431                 return;
2432         }
2433
2434         if (RPC_IS_SOFT(task)) {
2435                 /*
2436                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2437                  * been sent, it should time out only if the transport
2438                  * connection gets terminally broken.
2439                  */
2440                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2441                     rpc_check_connected(task->tk_rqstp))
2442                         return;
2443
2444                 if (clnt->cl_chatty) {
2445                         pr_notice_ratelimited(
2446                                 "%s: server %s not responding, timed out\n",
2447                                 clnt->cl_program->name,
2448                                 task->tk_xprt->servername);
2449                 }
2450                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2451                         rpc_call_rpcerror(task, -ETIMEDOUT);
2452                 else
2453                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2454                 return;
2455         }
2456
2457         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2458                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2459                 if (clnt->cl_chatty) {
2460                         pr_notice_ratelimited(
2461                                 "%s: server %s not responding, still trying\n",
2462                                 clnt->cl_program->name,
2463                                 task->tk_xprt->servername);
2464                 }
2465         }
2466         rpc_force_rebind(clnt);
2467         /*
2468          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2469          * event? RFC2203 requires the server to drop all such requests.
2470          */
2471         rpcauth_invalcred(task);
2472 }
2473
2474 /*
2475  * 7.   Decode the RPC reply
2476  */
2477 static void
2478 call_decode(struct rpc_task *task)
2479 {
2480         struct rpc_clnt *clnt = task->tk_client;
2481         struct rpc_rqst *req = task->tk_rqstp;
2482         struct xdr_stream xdr;
2483         int err;
2484
2485         dprint_status(task);
2486
2487         if (!task->tk_msg.rpc_proc->p_decode) {
2488                 task->tk_action = rpc_exit_task;
2489                 return;
2490         }
2491
2492         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2493                 if (clnt->cl_chatty) {
2494                         pr_notice_ratelimited("%s: server %s OK\n",
2495                                 clnt->cl_program->name,
2496                                 task->tk_xprt->servername);
2497                 }
2498                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2499         }
2500
2501         /*
2502          * Ensure that we see all writes made by xprt_complete_rqst()
2503          * before it changed req->rq_reply_bytes_recvd.
2504          */
2505         smp_rmb();
2506
2507         /*
2508          * Did we ever call xprt_complete_rqst()? If not, we should assume
2509          * the message is incomplete.
2510          */
2511         err = -EAGAIN;
2512         if (!req->rq_reply_bytes_recvd)
2513                 goto out;
2514
2515         req->rq_rcv_buf.len = req->rq_private_buf.len;
2516         trace_xprt_recvfrom(&req->rq_rcv_buf);
2517
2518         /* Check that the softirq receive buffer is valid */
2519         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2520                                 sizeof(req->rq_rcv_buf)) != 0);
2521
2522         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2523                         req->rq_rcv_buf.head[0].iov_base, req);
2524         err = rpc_decode_header(task, &xdr);
2525 out:
2526         switch (err) {
2527         case 0:
2528                 task->tk_action = rpc_exit_task;
2529                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2530                 dprintk("RPC: %5u %s result %d\n",
2531                         task->tk_pid, __func__, task->tk_status);
2532                 return;
2533         case -EAGAIN:
2534                 task->tk_status = 0;
2535                 if (task->tk_client->cl_discrtry)
2536                         xprt_conditional_disconnect(req->rq_xprt,
2537                                                     req->rq_connect_cookie);
2538                 task->tk_action = call_encode;
2539                 rpc_check_timeout(task);
2540                 break;
2541         case -EKEYREJECTED:
2542                 task->tk_action = call_reserve;
2543                 rpc_check_timeout(task);
2544                 rpcauth_invalcred(task);
2545                 /* Ensure we obtain a new XID if we retry! */
2546                 xprt_release(task);
2547         }
2548 }
2549
2550 static int
2551 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2552 {
2553         struct rpc_clnt *clnt = task->tk_client;
2554         struct rpc_rqst *req = task->tk_rqstp;
2555         __be32 *p;
2556         int error;
2557
2558         error = -EMSGSIZE;
2559         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2560         if (!p)
2561                 goto out_fail;
2562         *p++ = req->rq_xid;
2563         *p++ = rpc_call;
2564         *p++ = cpu_to_be32(RPC_VERSION);
2565         *p++ = cpu_to_be32(clnt->cl_prog);
2566         *p++ = cpu_to_be32(clnt->cl_vers);
2567         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2568
2569         error = rpcauth_marshcred(task, xdr);
2570         if (error < 0)
2571                 goto out_fail;
2572         return 0;
2573 out_fail:
2574         trace_rpc_bad_callhdr(task);
2575         rpc_call_rpcerror(task, error);
2576         return error;
2577 }
2578
2579 static noinline int
2580 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2581 {
2582         struct rpc_clnt *clnt = task->tk_client;
2583         int error;
2584         __be32 *p;
2585
2586         /* RFC-1014 says that the representation of XDR data must be a
2587          * multiple of four bytes
2588          * - if it isn't pointer subtraction in the NFS client may give
2589          *   undefined results
2590          */
2591         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2592                 goto out_unparsable;
2593
2594         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2595         if (!p)
2596                 goto out_unparsable;
2597         p++;    /* skip XID */
2598         if (*p++ != rpc_reply)
2599                 goto out_unparsable;
2600         if (*p++ != rpc_msg_accepted)
2601                 goto out_msg_denied;
2602
2603         error = rpcauth_checkverf(task, xdr);
2604         if (error)
2605                 goto out_verifier;
2606
2607         p = xdr_inline_decode(xdr, sizeof(*p));
2608         if (!p)
2609                 goto out_unparsable;
2610         switch (*p) {
2611         case rpc_success:
2612                 return 0;
2613         case rpc_prog_unavail:
2614                 trace_rpc__prog_unavail(task);
2615                 error = -EPFNOSUPPORT;
2616                 goto out_err;
2617         case rpc_prog_mismatch:
2618                 trace_rpc__prog_mismatch(task);
2619                 error = -EPROTONOSUPPORT;
2620                 goto out_err;
2621         case rpc_proc_unavail:
2622                 trace_rpc__proc_unavail(task);
2623                 error = -EOPNOTSUPP;
2624                 goto out_err;
2625         case rpc_garbage_args:
2626         case rpc_system_err:
2627                 trace_rpc__garbage_args(task);
2628                 error = -EIO;
2629                 break;
2630         default:
2631                 goto out_unparsable;
2632         }
2633
2634 out_garbage:
2635         clnt->cl_stats->rpcgarbage++;
2636         if (task->tk_garb_retry) {
2637                 task->tk_garb_retry--;
2638                 task->tk_action = call_encode;
2639                 return -EAGAIN;
2640         }
2641 out_err:
2642         rpc_call_rpcerror(task, error);
2643         return error;
2644
2645 out_unparsable:
2646         trace_rpc__unparsable(task);
2647         error = -EIO;
2648         goto out_garbage;
2649
2650 out_verifier:
2651         trace_rpc_bad_verifier(task);
2652         goto out_garbage;
2653
2654 out_msg_denied:
2655         error = -EACCES;
2656         p = xdr_inline_decode(xdr, sizeof(*p));
2657         if (!p)
2658                 goto out_unparsable;
2659         switch (*p++) {
2660         case rpc_auth_error:
2661                 break;
2662         case rpc_mismatch:
2663                 trace_rpc__mismatch(task);
2664                 error = -EPROTONOSUPPORT;
2665                 goto out_err;
2666         default:
2667                 goto out_unparsable;
2668         }
2669
2670         p = xdr_inline_decode(xdr, sizeof(*p));
2671         if (!p)
2672                 goto out_unparsable;
2673         switch (*p++) {
2674         case rpc_autherr_rejectedcred:
2675         case rpc_autherr_rejectedverf:
2676         case rpcsec_gsserr_credproblem:
2677         case rpcsec_gsserr_ctxproblem:
2678                 if (!task->tk_cred_retry)
2679                         break;
2680                 task->tk_cred_retry--;
2681                 trace_rpc__stale_creds(task);
2682                 return -EKEYREJECTED;
2683         case rpc_autherr_badcred:
2684         case rpc_autherr_badverf:
2685                 /* possibly garbled cred/verf? */
2686                 if (!task->tk_garb_retry)
2687                         break;
2688                 task->tk_garb_retry--;
2689                 trace_rpc__bad_creds(task);
2690                 task->tk_action = call_encode;
2691                 return -EAGAIN;
2692         case rpc_autherr_tooweak:
2693                 trace_rpc__auth_tooweak(task);
2694                 pr_warn("RPC: server %s requires stronger authentication.\n",
2695                         task->tk_xprt->servername);
2696                 break;
2697         default:
2698                 goto out_unparsable;
2699         }
2700         goto out_err;
2701 }
2702
2703 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2704                 const void *obj)
2705 {
2706 }
2707
2708 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2709                 void *obj)
2710 {
2711         return 0;
2712 }
2713
2714 static const struct rpc_procinfo rpcproc_null = {
2715         .p_encode = rpcproc_encode_null,
2716         .p_decode = rpcproc_decode_null,
2717 };
2718
2719 static int rpc_ping(struct rpc_clnt *clnt)
2720 {
2721         struct rpc_message msg = {
2722                 .rpc_proc = &rpcproc_null,
2723         };
2724         int err;
2725         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2726                             RPC_TASK_NULLCREDS);
2727         return err;
2728 }
2729
2730 static
2731 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2732                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2733                 const struct rpc_call_ops *ops, void *data)
2734 {
2735         struct rpc_message msg = {
2736                 .rpc_proc = &rpcproc_null,
2737         };
2738         struct rpc_task_setup task_setup_data = {
2739                 .rpc_client = clnt,
2740                 .rpc_xprt = xprt,
2741                 .rpc_message = &msg,
2742                 .rpc_op_cred = cred,
2743                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2744                 .callback_data = data,
2745                 .flags = flags | RPC_TASK_NULLCREDS,
2746         };
2747
2748         return rpc_run_task(&task_setup_data);
2749 }
2750
2751 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2752 {
2753         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2754 }
2755 EXPORT_SYMBOL_GPL(rpc_call_null);
2756
2757 struct rpc_cb_add_xprt_calldata {
2758         struct rpc_xprt_switch *xps;
2759         struct rpc_xprt *xprt;
2760 };
2761
2762 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2763 {
2764         struct rpc_cb_add_xprt_calldata *data = calldata;
2765
2766         if (task->tk_status == 0)
2767                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2768 }
2769
2770 static void rpc_cb_add_xprt_release(void *calldata)
2771 {
2772         struct rpc_cb_add_xprt_calldata *data = calldata;
2773
2774         xprt_put(data->xprt);
2775         xprt_switch_put(data->xps);
2776         kfree(data);
2777 }
2778
2779 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2780         .rpc_call_done = rpc_cb_add_xprt_done,
2781         .rpc_release = rpc_cb_add_xprt_release,
2782 };
2783
2784 /**
2785  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2786  * @clnt: pointer to struct rpc_clnt
2787  * @xps: pointer to struct rpc_xprt_switch,
2788  * @xprt: pointer struct rpc_xprt
2789  * @dummy: unused
2790  */
2791 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2792                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2793                 void *dummy)
2794 {
2795         struct rpc_cb_add_xprt_calldata *data;
2796         struct rpc_task *task;
2797
2798         data = kmalloc(sizeof(*data), GFP_NOFS);
2799         if (!data)
2800                 return -ENOMEM;
2801         data->xps = xprt_switch_get(xps);
2802         data->xprt = xprt_get(xprt);
2803         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2804                 rpc_cb_add_xprt_release(data);
2805                 goto success;
2806         }
2807
2808         task = rpc_call_null_helper(clnt, xprt, NULL,
2809                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
2810                         &rpc_cb_add_xprt_call_ops, data);
2811         if (IS_ERR(task))
2812                 return PTR_ERR(task);
2813         rpc_put_task(task);
2814 success:
2815         return 1;
2816 }
2817 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2818
2819 /**
2820  * rpc_clnt_setup_test_and_add_xprt()
2821  *
2822  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2823  *   1) caller of the test function must dereference the rpc_xprt_switch
2824  *   and the rpc_xprt.
2825  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2826  *   the rpc_call_done routine.
2827  *
2828  * Upon success (return of 1), the test function adds the new
2829  * transport to the rpc_clnt xprt switch
2830  *
2831  * @clnt: struct rpc_clnt to get the new transport
2832  * @xps:  the rpc_xprt_switch to hold the new transport
2833  * @xprt: the rpc_xprt to test
2834  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2835  *        and test function call data
2836  */
2837 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2838                                      struct rpc_xprt_switch *xps,
2839                                      struct rpc_xprt *xprt,
2840                                      void *data)
2841 {
2842         struct rpc_task *task;
2843         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2844         int status = -EADDRINUSE;
2845
2846         xprt = xprt_get(xprt);
2847         xprt_switch_get(xps);
2848
2849         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2850                 goto out_err;
2851
2852         /* Test the connection */
2853         task = rpc_call_null_helper(clnt, xprt, NULL,
2854                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2855                                     NULL, NULL);
2856         if (IS_ERR(task)) {
2857                 status = PTR_ERR(task);
2858                 goto out_err;
2859         }
2860         status = task->tk_status;
2861         rpc_put_task(task);
2862
2863         if (status < 0)
2864                 goto out_err;
2865
2866         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2867         xtest->add_xprt_test(clnt, xprt, xtest->data);
2868
2869         xprt_put(xprt);
2870         xprt_switch_put(xps);
2871
2872         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2873         return 1;
2874 out_err:
2875         xprt_put(xprt);
2876         xprt_switch_put(xps);
2877         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2878                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2879         return status;
2880 }
2881 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2882
2883 /**
2884  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2885  * @clnt: pointer to struct rpc_clnt
2886  * @xprtargs: pointer to struct xprt_create
2887  * @setup: callback to test and/or set up the connection
2888  * @data: pointer to setup function data
2889  *
2890  * Creates a new transport using the parameters set in args and
2891  * adds it to clnt.
2892  * If ping is set, then test that connectivity succeeds before
2893  * adding the new transport.
2894  *
2895  */
2896 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2897                 struct xprt_create *xprtargs,
2898                 int (*setup)(struct rpc_clnt *,
2899                         struct rpc_xprt_switch *,
2900                         struct rpc_xprt *,
2901                         void *),
2902                 void *data)
2903 {
2904         struct rpc_xprt_switch *xps;
2905         struct rpc_xprt *xprt;
2906         unsigned long connect_timeout;
2907         unsigned long reconnect_timeout;
2908         unsigned char resvport, reuseport;
2909         int ret = 0;
2910
2911         rcu_read_lock();
2912         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2913         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2914         if (xps == NULL || xprt == NULL) {
2915                 rcu_read_unlock();
2916                 xprt_switch_put(xps);
2917                 return -EAGAIN;
2918         }
2919         resvport = xprt->resvport;
2920         reuseport = xprt->reuseport;
2921         connect_timeout = xprt->connect_timeout;
2922         reconnect_timeout = xprt->max_reconnect_timeout;
2923         rcu_read_unlock();
2924
2925         xprt = xprt_create_transport(xprtargs);
2926         if (IS_ERR(xprt)) {
2927                 ret = PTR_ERR(xprt);
2928                 goto out_put_switch;
2929         }
2930         xprt->resvport = resvport;
2931         xprt->reuseport = reuseport;
2932         if (xprt->ops->set_connect_timeout != NULL)
2933                 xprt->ops->set_connect_timeout(xprt,
2934                                 connect_timeout,
2935                                 reconnect_timeout);
2936
2937         rpc_xprt_switch_set_roundrobin(xps);
2938         if (setup) {
2939                 ret = setup(clnt, xps, xprt, data);
2940                 if (ret != 0)
2941                         goto out_put_xprt;
2942         }
2943         rpc_xprt_switch_add_xprt(xps, xprt);
2944 out_put_xprt:
2945         xprt_put(xprt);
2946 out_put_switch:
2947         xprt_switch_put(xps);
2948         return ret;
2949 }
2950 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2951
2952 struct connect_timeout_data {
2953         unsigned long connect_timeout;
2954         unsigned long reconnect_timeout;
2955 };
2956
2957 static int
2958 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2959                 struct rpc_xprt *xprt,
2960                 void *data)
2961 {
2962         struct connect_timeout_data *timeo = data;
2963
2964         if (xprt->ops->set_connect_timeout)
2965                 xprt->ops->set_connect_timeout(xprt,
2966                                 timeo->connect_timeout,
2967                                 timeo->reconnect_timeout);
2968         return 0;
2969 }
2970
2971 void
2972 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2973                 unsigned long connect_timeout,
2974                 unsigned long reconnect_timeout)
2975 {
2976         struct connect_timeout_data timeout = {
2977                 .connect_timeout = connect_timeout,
2978                 .reconnect_timeout = reconnect_timeout,
2979         };
2980         rpc_clnt_iterate_for_each_xprt(clnt,
2981                         rpc_xprt_set_connect_timeout,
2982                         &timeout);
2983 }
2984 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2985
2986 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2987 {
2988         rcu_read_lock();
2989         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2990         rcu_read_unlock();
2991 }
2992 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2993
2994 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2995 {
2996         rcu_read_lock();
2997         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2998                                  xprt);
2999         rcu_read_unlock();
3000 }
3001 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3002
3003 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3004                                    const struct sockaddr *sap)
3005 {
3006         struct rpc_xprt_switch *xps;
3007         bool ret;
3008
3009         rcu_read_lock();
3010         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3011         ret = rpc_xprt_switch_has_addr(xps, sap);
3012         rcu_read_unlock();
3013         return ret;
3014 }
3015 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3016
3017 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3018 static void rpc_show_header(void)
3019 {
3020         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3021                 "-timeout ---ops--\n");
3022 }
3023
3024 static void rpc_show_task(const struct rpc_clnt *clnt,
3025                           const struct rpc_task *task)
3026 {
3027         const char *rpc_waitq = "none";
3028
3029         if (RPC_IS_QUEUED(task))
3030                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3031
3032         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3033                 task->tk_pid, task->tk_flags, task->tk_status,
3034                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3035                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3036                 task->tk_action, rpc_waitq);
3037 }
3038
3039 void rpc_show_tasks(struct net *net)
3040 {
3041         struct rpc_clnt *clnt;
3042         struct rpc_task *task;
3043         int header = 0;
3044         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3045
3046         spin_lock(&sn->rpc_client_lock);
3047         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3048                 spin_lock(&clnt->cl_lock);
3049                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3050                         if (!header) {
3051                                 rpc_show_header();
3052                                 header++;
3053                         }
3054                         rpc_show_task(clnt, task);
3055                 }
3056                 spin_unlock(&clnt->cl_lock);
3057         }
3058         spin_unlock(&sn->rpc_client_lock);
3059 }
3060 #endif
3061
3062 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3063 static int
3064 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3065                 struct rpc_xprt *xprt,
3066                 void *dummy)
3067 {
3068         return xprt_enable_swap(xprt);
3069 }
3070
3071 int
3072 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3073 {
3074         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3075                 return rpc_clnt_iterate_for_each_xprt(clnt,
3076                                 rpc_clnt_swap_activate_callback, NULL);
3077         return 0;
3078 }
3079 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3080
3081 static int
3082 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3083                 struct rpc_xprt *xprt,
3084                 void *dummy)
3085 {
3086         xprt_disable_swap(xprt);
3087         return 0;
3088 }
3089
3090 void
3091 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3092 {
3093         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3094                 rpc_clnt_iterate_for_each_xprt(clnt,
3095                                 rpc_clnt_swap_deactivate_callback, NULL);
3096 }
3097 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3098 #endif /* CONFIG_SUNRPC_SWAP */