linux/net/sunrpc/clnt.c
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   1/*
   2 *  linux/net/sunrpc/clnt.c
   3 *
   4 *  This file contains the high-level RPC interface.
   5 *  It is modeled as a finite state machine to support both synchronous
   6 *  and asynchronous requests.
   7 *
   8 *  -   RPC header generation and argument serialization.
   9 *  -   Credential refresh.
  10 *  -   TCP connect handling.
  11 *  -   Retry of operation when it is suspected the operation failed because
  12 *      of uid squashing on the server, or when the credentials were stale
  13 *      and need to be refreshed, or when a packet was damaged in transit.
  14 *      This may be have to be moved to the VFS layer.
  15 *
  16 *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17 *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18 */
  19
  20
  21#include <linux/module.h>
  22#include <linux/types.h>
  23#include <linux/kallsyms.h>
  24#include <linux/mm.h>
  25#include <linux/namei.h>
  26#include <linux/mount.h>
  27#include <linux/slab.h>
  28#include <linux/utsname.h>
  29#include <linux/workqueue.h>
  30#include <linux/in.h>
  31#include <linux/in6.h>
  32#include <linux/un.h>
  33#include <linux/rcupdate.h>
  34
  35#include <linux/sunrpc/clnt.h>
  36#include <linux/sunrpc/rpc_pipe_fs.h>
  37#include <linux/sunrpc/metrics.h>
  38#include <linux/sunrpc/bc_xprt.h>
  39#include <trace/events/sunrpc.h>
  40
  41#include "sunrpc.h"
  42#include "netns.h"
  43
  44#ifdef RPC_DEBUG
  45# define RPCDBG_FACILITY        RPCDBG_CALL
  46#endif
  47
  48#define dprint_status(t)                                        \
  49        dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  50                        __func__, t->tk_status)
  51
  52/*
  53 * All RPC clients are linked into this list
  54 */
  55
  56static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  57
  58
  59static void     call_start(struct rpc_task *task);
  60static void     call_reserve(struct rpc_task *task);
  61static void     call_reserveresult(struct rpc_task *task);
  62static void     call_allocate(struct rpc_task *task);
  63static void     call_decode(struct rpc_task *task);
  64static void     call_bind(struct rpc_task *task);
  65static void     call_bind_status(struct rpc_task *task);
  66static void     call_transmit(struct rpc_task *task);
  67#if defined(CONFIG_SUNRPC_BACKCHANNEL)
  68static void     call_bc_transmit(struct rpc_task *task);
  69#endif /* CONFIG_SUNRPC_BACKCHANNEL */
  70static void     call_status(struct rpc_task *task);
  71static void     call_transmit_status(struct rpc_task *task);
  72static void     call_refresh(struct rpc_task *task);
  73static void     call_refreshresult(struct rpc_task *task);
  74static void     call_timeout(struct rpc_task *task);
  75static void     call_connect(struct rpc_task *task);
  76static void     call_connect_status(struct rpc_task *task);
  77
  78static __be32   *rpc_encode_header(struct rpc_task *task);
  79static __be32   *rpc_verify_header(struct rpc_task *task);
  80static int      rpc_ping(struct rpc_clnt *clnt);
  81
  82static void rpc_register_client(struct rpc_clnt *clnt)
  83{
  84        struct net *net = rpc_net_ns(clnt);
  85        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87        spin_lock(&sn->rpc_client_lock);
  88        list_add(&clnt->cl_clients, &sn->all_clients);
  89        spin_unlock(&sn->rpc_client_lock);
  90}
  91
  92static void rpc_unregister_client(struct rpc_clnt *clnt)
  93{
  94        struct net *net = rpc_net_ns(clnt);
  95        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97        spin_lock(&sn->rpc_client_lock);
  98        list_del(&clnt->cl_clients);
  99        spin_unlock(&sn->rpc_client_lock);
 100}
 101
 102static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103{
 104        if (clnt->cl_dentry) {
 105                if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
 106                        clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
 107                rpc_remove_client_dir(clnt->cl_dentry);
 108        }
 109        clnt->cl_dentry = NULL;
 110}
 111
 112static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 113{
 114        struct net *net = rpc_net_ns(clnt);
 115        struct super_block *pipefs_sb;
 116
 117        pipefs_sb = rpc_get_sb_net(net);
 118        if (pipefs_sb) {
 119                __rpc_clnt_remove_pipedir(clnt);
 120                rpc_put_sb_net(net);
 121        }
 122}
 123
 124static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 125                                    struct rpc_clnt *clnt,
 126                                    const char *dir_name)
 127{
 128        static uint32_t clntid;
 129        char name[15];
 130        struct qstr q = { .name = name };
 131        struct dentry *dir, *dentry;
 132        int error;
 133
 134        dir = rpc_d_lookup_sb(sb, dir_name);
 135        if (dir == NULL)
 136                return dir;
 137        for (;;) {
 138                q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 139                name[sizeof(name) - 1] = '\0';
 140                q.hash = full_name_hash(q.name, q.len);
 141                dentry = rpc_create_client_dir(dir, &q, clnt);
 142                if (!IS_ERR(dentry))
 143                        break;
 144                error = PTR_ERR(dentry);
 145                if (error != -EEXIST) {
 146                        printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 147                                        " %s/%s, error %d\n",
 148                                        dir_name, name, error);
 149                        break;
 150                }
 151        }
 152        dput(dir);
 153        return dentry;
 154}
 155
 156static int
 157rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
 158{
 159        struct net *net = rpc_net_ns(clnt);
 160        struct super_block *pipefs_sb;
 161        struct dentry *dentry;
 162
 163        clnt->cl_dentry = NULL;
 164        if (dir_name == NULL)
 165                return 0;
 166        pipefs_sb = rpc_get_sb_net(net);
 167        if (!pipefs_sb)
 168                return 0;
 169        dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
 170        rpc_put_sb_net(net);
 171        if (IS_ERR(dentry))
 172                return PTR_ERR(dentry);
 173        clnt->cl_dentry = dentry;
 174        return 0;
 175}
 176
 177static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 178{
 179        if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 180            ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 181                return 1;
 182        return 0;
 183}
 184
 185static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 186                                   struct super_block *sb)
 187{
 188        struct dentry *dentry;
 189        int err = 0;
 190
 191        switch (event) {
 192        case RPC_PIPEFS_MOUNT:
 193                dentry = rpc_setup_pipedir_sb(sb, clnt,
 194                                              clnt->cl_program->pipe_dir_name);
 195                BUG_ON(dentry == NULL);
 196                if (IS_ERR(dentry))
 197                        return PTR_ERR(dentry);
 198                clnt->cl_dentry = dentry;
 199                if (clnt->cl_auth->au_ops->pipes_create) {
 200                        err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
 201                        if (err)
 202                                __rpc_clnt_remove_pipedir(clnt);
 203                }
 204                break;
 205        case RPC_PIPEFS_UMOUNT:
 206                __rpc_clnt_remove_pipedir(clnt);
 207                break;
 208        default:
 209                printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 210                return -ENOTSUPP;
 211        }
 212        return err;
 213}
 214
 215static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 216                                struct super_block *sb)
 217{
 218        int error = 0;
 219
 220        for (;; clnt = clnt->cl_parent) {
 221                if (!rpc_clnt_skip_event(clnt, event))
 222                        error = __rpc_clnt_handle_event(clnt, event, sb);
 223                if (error || clnt == clnt->cl_parent)
 224                        break;
 225        }
 226        return error;
 227}
 228
 229static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 230{
 231        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 232        struct rpc_clnt *clnt;
 233
 234        spin_lock(&sn->rpc_client_lock);
 235        list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 236                if (clnt->cl_program->pipe_dir_name == NULL)
 237                        break;
 238                if (rpc_clnt_skip_event(clnt, event))
 239                        continue;
 240                if (atomic_inc_not_zero(&clnt->cl_count) == 0)
 241                        continue;
 242                spin_unlock(&sn->rpc_client_lock);
 243                return clnt;
 244        }
 245        spin_unlock(&sn->rpc_client_lock);
 246        return NULL;
 247}
 248
 249static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 250                            void *ptr)
 251{
 252        struct super_block *sb = ptr;
 253        struct rpc_clnt *clnt;
 254        int error = 0;
 255
 256        while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 257                error = __rpc_pipefs_event(clnt, event, sb);
 258                rpc_release_client(clnt);
 259                if (error)
 260                        break;
 261        }
 262        return error;
 263}
 264
 265static struct notifier_block rpc_clients_block = {
 266        .notifier_call  = rpc_pipefs_event,
 267        .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 268};
 269
 270int rpc_clients_notifier_register(void)
 271{
 272        return rpc_pipefs_notifier_register(&rpc_clients_block);
 273}
 274
 275void rpc_clients_notifier_unregister(void)
 276{
 277        return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 278}
 279
 280static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 281{
 282        clnt->cl_nodelen = strlen(nodename);
 283        if (clnt->cl_nodelen > UNX_MAXNODENAME)
 284                clnt->cl_nodelen = UNX_MAXNODENAME;
 285        memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 286}
 287
 288static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 289{
 290        const struct rpc_program *program = args->program;
 291        const struct rpc_version *version;
 292        struct rpc_clnt         *clnt = NULL;
 293        struct rpc_auth         *auth;
 294        int err;
 295
 296        /* sanity check the name before trying to print it */
 297        dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 298                        program->name, args->servername, xprt);
 299
 300        err = rpciod_up();
 301        if (err)
 302                goto out_no_rpciod;
 303        err = -EINVAL;
 304        if (!xprt)
 305                goto out_no_xprt;
 306
 307        if (args->version >= program->nrvers)
 308                goto out_err;
 309        version = program->version[args->version];
 310        if (version == NULL)
 311                goto out_err;
 312
 313        err = -ENOMEM;
 314        clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 315        if (!clnt)
 316                goto out_err;
 317        clnt->cl_parent = clnt;
 318
 319        rcu_assign_pointer(clnt->cl_xprt, xprt);
 320        clnt->cl_procinfo = version->procs;
 321        clnt->cl_maxproc  = version->nrprocs;
 322        clnt->cl_protname = program->name;
 323        clnt->cl_prog     = args->prognumber ? : program->number;
 324        clnt->cl_vers     = version->number;
 325        clnt->cl_stats    = program->stats;
 326        clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 327        err = -ENOMEM;
 328        if (clnt->cl_metrics == NULL)
 329                goto out_no_stats;
 330        clnt->cl_program  = program;
 331        INIT_LIST_HEAD(&clnt->cl_tasks);
 332        spin_lock_init(&clnt->cl_lock);
 333
 334        if (!xprt_bound(xprt))
 335                clnt->cl_autobind = 1;
 336
 337        clnt->cl_timeout = xprt->timeout;
 338        if (args->timeout != NULL) {
 339                memcpy(&clnt->cl_timeout_default, args->timeout,
 340                                sizeof(clnt->cl_timeout_default));
 341                clnt->cl_timeout = &clnt->cl_timeout_default;
 342        }
 343
 344        clnt->cl_rtt = &clnt->cl_rtt_default;
 345        rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 346        clnt->cl_principal = NULL;
 347        if (args->client_name) {
 348                clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 349                if (!clnt->cl_principal)
 350                        goto out_no_principal;
 351        }
 352
 353        atomic_set(&clnt->cl_count, 1);
 354
 355        err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 356        if (err < 0)
 357                goto out_no_path;
 358
 359        auth = rpcauth_create(args->authflavor, clnt);
 360        if (IS_ERR(auth)) {
 361                printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 362                                args->authflavor);
 363                err = PTR_ERR(auth);
 364                goto out_no_auth;
 365        }
 366
 367        /* save the nodename */
 368        rpc_clnt_set_nodename(clnt, utsname()->nodename);
 369        rpc_register_client(clnt);
 370        return clnt;
 371
 372out_no_auth:
 373        rpc_clnt_remove_pipedir(clnt);
 374out_no_path:
 375        kfree(clnt->cl_principal);
 376out_no_principal:
 377        rpc_free_iostats(clnt->cl_metrics);
 378out_no_stats:
 379        kfree(clnt);
 380out_err:
 381        xprt_put(xprt);
 382out_no_xprt:
 383        rpciod_down();
 384out_no_rpciod:
 385        return ERR_PTR(err);
 386}
 387
 388/**
 389 * rpc_create - create an RPC client and transport with one call
 390 * @args: rpc_clnt create argument structure
 391 *
 392 * Creates and initializes an RPC transport and an RPC client.
 393 *
 394 * It can ping the server in order to determine if it is up, and to see if
 395 * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 396 * this behavior so asynchronous tasks can also use rpc_create.
 397 */
 398struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 399{
 400        struct rpc_xprt *xprt;
 401        struct rpc_clnt *clnt;
 402        struct xprt_create xprtargs = {
 403                .net = args->net,
 404                .ident = args->protocol,
 405                .srcaddr = args->saddress,
 406                .dstaddr = args->address,
 407                .addrlen = args->addrsize,
 408                .servername = args->servername,
 409                .bc_xprt = args->bc_xprt,
 410        };
 411        char servername[48];
 412
 413        /*
 414         * If the caller chooses not to specify a hostname, whip
 415         * up a string representation of the passed-in address.
 416         */
 417        if (xprtargs.servername == NULL) {
 418                struct sockaddr_un *sun =
 419                                (struct sockaddr_un *)args->address;
 420                struct sockaddr_in *sin =
 421                                (struct sockaddr_in *)args->address;
 422                struct sockaddr_in6 *sin6 =
 423                                (struct sockaddr_in6 *)args->address;
 424
 425                servername[0] = '\0';
 426                switch (args->address->sa_family) {
 427                case AF_LOCAL:
 428                        snprintf(servername, sizeof(servername), "%s",
 429                                 sun->sun_path);
 430                        break;
 431                case AF_INET:
 432                        snprintf(servername, sizeof(servername), "%pI4",
 433                                 &sin->sin_addr.s_addr);
 434                        break;
 435                case AF_INET6:
 436                        snprintf(servername, sizeof(servername), "%pI6",
 437                                 &sin6->sin6_addr);
 438                        break;
 439                default:
 440                        /* caller wants default server name, but
 441                         * address family isn't recognized. */
 442                        return ERR_PTR(-EINVAL);
 443                }
 444                xprtargs.servername = servername;
 445        }
 446
 447        xprt = xprt_create_transport(&xprtargs);
 448        if (IS_ERR(xprt))
 449                return (struct rpc_clnt *)xprt;
 450
 451        /*
 452         * By default, kernel RPC client connects from a reserved port.
 453         * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 454         * but it is always enabled for rpciod, which handles the connect
 455         * operation.
 456         */
 457        xprt->resvport = 1;
 458        if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 459                xprt->resvport = 0;
 460
 461        clnt = rpc_new_client(args, xprt);
 462        if (IS_ERR(clnt))
 463                return clnt;
 464
 465        if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 466                int err = rpc_ping(clnt);
 467                if (err != 0) {
 468                        rpc_shutdown_client(clnt);
 469                        return ERR_PTR(err);
 470                }
 471        }
 472
 473        clnt->cl_softrtry = 1;
 474        if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 475                clnt->cl_softrtry = 0;
 476
 477        if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 478                clnt->cl_autobind = 1;
 479        if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 480                clnt->cl_discrtry = 1;
 481        if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 482                clnt->cl_chatty = 1;
 483
 484        return clnt;
 485}
 486EXPORT_SYMBOL_GPL(rpc_create);
 487
 488/*
 489 * This function clones the RPC client structure. It allows us to share the
 490 * same transport while varying parameters such as the authentication
 491 * flavour.
 492 */
 493struct rpc_clnt *
 494rpc_clone_client(struct rpc_clnt *clnt)
 495{
 496        struct rpc_clnt *new;
 497        struct rpc_xprt *xprt;
 498        int err = -ENOMEM;
 499
 500        new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 501        if (!new)
 502                goto out_no_clnt;
 503        new->cl_parent = clnt;
 504        /* Turn off autobind on clones */
 505        new->cl_autobind = 0;
 506        INIT_LIST_HEAD(&new->cl_tasks);
 507        spin_lock_init(&new->cl_lock);
 508        rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 509        new->cl_metrics = rpc_alloc_iostats(clnt);
 510        if (new->cl_metrics == NULL)
 511                goto out_no_stats;
 512        if (clnt->cl_principal) {
 513                new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
 514                if (new->cl_principal == NULL)
 515                        goto out_no_principal;
 516        }
 517        rcu_read_lock();
 518        xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 519        rcu_read_unlock();
 520        if (xprt == NULL)
 521                goto out_no_transport;
 522        rcu_assign_pointer(new->cl_xprt, xprt);
 523        atomic_set(&new->cl_count, 1);
 524        err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 525        if (err != 0)
 526                goto out_no_path;
 527        rpc_clnt_set_nodename(new, utsname()->nodename);
 528        if (new->cl_auth)
 529                atomic_inc(&new->cl_auth->au_count);
 530        atomic_inc(&clnt->cl_count);
 531        rpc_register_client(new);
 532        rpciod_up();
 533        return new;
 534out_no_path:
 535        xprt_put(xprt);
 536out_no_transport:
 537        kfree(new->cl_principal);
 538out_no_principal:
 539        rpc_free_iostats(new->cl_metrics);
 540out_no_stats:
 541        kfree(new);
 542out_no_clnt:
 543        dprintk("RPC:       %s: returned error %d\n", __func__, err);
 544        return ERR_PTR(err);
 545}
 546EXPORT_SYMBOL_GPL(rpc_clone_client);
 547
 548/*
 549 * Kill all tasks for the given client.
 550 * XXX: kill their descendants as well?
 551 */
 552void rpc_killall_tasks(struct rpc_clnt *clnt)
 553{
 554        struct rpc_task *rovr;
 555
 556
 557        if (list_empty(&clnt->cl_tasks))
 558                return;
 559        dprintk("RPC:       killing all tasks for client %p\n", clnt);
 560        /*
 561         * Spin lock all_tasks to prevent changes...
 562         */
 563        spin_lock(&clnt->cl_lock);
 564        list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 565                if (!RPC_IS_ACTIVATED(rovr))
 566                        continue;
 567                if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 568                        rovr->tk_flags |= RPC_TASK_KILLED;
 569                        rpc_exit(rovr, -EIO);
 570                        if (RPC_IS_QUEUED(rovr))
 571                                rpc_wake_up_queued_task(rovr->tk_waitqueue,
 572                                                        rovr);
 573                }
 574        }
 575        spin_unlock(&clnt->cl_lock);
 576}
 577EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 578
 579/*
 580 * Properly shut down an RPC client, terminating all outstanding
 581 * requests.
 582 */
 583void rpc_shutdown_client(struct rpc_clnt *clnt)
 584{
 585        dprintk_rcu("RPC:       shutting down %s client for %s\n",
 586                        clnt->cl_protname,
 587                        rcu_dereference(clnt->cl_xprt)->servername);
 588
 589        while (!list_empty(&clnt->cl_tasks)) {
 590                rpc_killall_tasks(clnt);
 591                wait_event_timeout(destroy_wait,
 592                        list_empty(&clnt->cl_tasks), 1*HZ);
 593        }
 594
 595        rpc_release_client(clnt);
 596}
 597EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 598
 599/*
 600 * Free an RPC client
 601 */
 602static void
 603rpc_free_client(struct rpc_clnt *clnt)
 604{
 605        dprintk_rcu("RPC:       destroying %s client for %s\n",
 606                        clnt->cl_protname,
 607                        rcu_dereference(clnt->cl_xprt)->servername);
 608        if (clnt->cl_parent != clnt)
 609                rpc_release_client(clnt->cl_parent);
 610        rpc_unregister_client(clnt);
 611        rpc_clnt_remove_pipedir(clnt);
 612        rpc_free_iostats(clnt->cl_metrics);
 613        kfree(clnt->cl_principal);
 614        clnt->cl_metrics = NULL;
 615        xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 616        rpciod_down();
 617        kfree(clnt);
 618}
 619
 620/*
 621 * Free an RPC client
 622 */
 623static void
 624rpc_free_auth(struct rpc_clnt *clnt)
 625{
 626        if (clnt->cl_auth == NULL) {
 627                rpc_free_client(clnt);
 628                return;
 629        }
 630
 631        /*
 632         * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 633         *       release remaining GSS contexts. This mechanism ensures
 634         *       that it can do so safely.
 635         */
 636        atomic_inc(&clnt->cl_count);
 637        rpcauth_release(clnt->cl_auth);
 638        clnt->cl_auth = NULL;
 639        if (atomic_dec_and_test(&clnt->cl_count))
 640                rpc_free_client(clnt);
 641}
 642
 643/*
 644 * Release reference to the RPC client
 645 */
 646void
 647rpc_release_client(struct rpc_clnt *clnt)
 648{
 649        dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 650
 651        if (list_empty(&clnt->cl_tasks))
 652                wake_up(&destroy_wait);
 653        if (atomic_dec_and_test(&clnt->cl_count))
 654                rpc_free_auth(clnt);
 655}
 656
 657/**
 658 * rpc_bind_new_program - bind a new RPC program to an existing client
 659 * @old: old rpc_client
 660 * @program: rpc program to set
 661 * @vers: rpc program version
 662 *
 663 * Clones the rpc client and sets up a new RPC program. This is mainly
 664 * of use for enabling different RPC programs to share the same transport.
 665 * The Sun NFSv2/v3 ACL protocol can do this.
 666 */
 667struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 668                                      const struct rpc_program *program,
 669                                      u32 vers)
 670{
 671        struct rpc_clnt *clnt;
 672        const struct rpc_version *version;
 673        int err;
 674
 675        BUG_ON(vers >= program->nrvers || !program->version[vers]);
 676        version = program->version[vers];
 677        clnt = rpc_clone_client(old);
 678        if (IS_ERR(clnt))
 679                goto out;
 680        clnt->cl_procinfo = version->procs;
 681        clnt->cl_maxproc  = version->nrprocs;
 682        clnt->cl_protname = program->name;
 683        clnt->cl_prog     = program->number;
 684        clnt->cl_vers     = version->number;
 685        clnt->cl_stats    = program->stats;
 686        err = rpc_ping(clnt);
 687        if (err != 0) {
 688                rpc_shutdown_client(clnt);
 689                clnt = ERR_PTR(err);
 690        }
 691out:
 692        return clnt;
 693}
 694EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 695
 696void rpc_task_release_client(struct rpc_task *task)
 697{
 698        struct rpc_clnt *clnt = task->tk_client;
 699
 700        if (clnt != NULL) {
 701                /* Remove from client task list */
 702                spin_lock(&clnt->cl_lock);
 703                list_del(&task->tk_task);
 704                spin_unlock(&clnt->cl_lock);
 705                task->tk_client = NULL;
 706
 707                rpc_release_client(clnt);
 708        }
 709}
 710
 711static
 712void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 713{
 714        if (clnt != NULL) {
 715                rpc_task_release_client(task);
 716                task->tk_client = clnt;
 717                atomic_inc(&clnt->cl_count);
 718                if (clnt->cl_softrtry)
 719                        task->tk_flags |= RPC_TASK_SOFT;
 720                if (sk_memalloc_socks()) {
 721                        struct rpc_xprt *xprt;
 722
 723                        rcu_read_lock();
 724                        xprt = rcu_dereference(clnt->cl_xprt);
 725                        if (xprt->swapper)
 726                                task->tk_flags |= RPC_TASK_SWAPPER;
 727                        rcu_read_unlock();
 728                }
 729                /* Add to the client's list of all tasks */
 730                spin_lock(&clnt->cl_lock);
 731                list_add_tail(&task->tk_task, &clnt->cl_tasks);
 732                spin_unlock(&clnt->cl_lock);
 733        }
 734}
 735
 736void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
 737{
 738        rpc_task_release_client(task);
 739        rpc_task_set_client(task, clnt);
 740}
 741EXPORT_SYMBOL_GPL(rpc_task_reset_client);
 742
 743
 744static void
 745rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 746{
 747        if (msg != NULL) {
 748                task->tk_msg.rpc_proc = msg->rpc_proc;
 749                task->tk_msg.rpc_argp = msg->rpc_argp;
 750                task->tk_msg.rpc_resp = msg->rpc_resp;
 751                if (msg->rpc_cred != NULL)
 752                        task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 753        }
 754}
 755
 756/*
 757 * Default callback for async RPC calls
 758 */
 759static void
 760rpc_default_callback(struct rpc_task *task, void *data)
 761{
 762}
 763
 764static const struct rpc_call_ops rpc_default_ops = {
 765        .rpc_call_done = rpc_default_callback,
 766};
 767
 768/**
 769 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 770 * @task_setup_data: pointer to task initialisation data
 771 */
 772struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 773{
 774        struct rpc_task *task;
 775
 776        task = rpc_new_task(task_setup_data);
 777        if (IS_ERR(task))
 778                goto out;
 779
 780        rpc_task_set_client(task, task_setup_data->rpc_client);
 781        rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 782
 783        if (task->tk_action == NULL)
 784                rpc_call_start(task);
 785
 786        atomic_inc(&task->tk_count);
 787        rpc_execute(task);
 788out:
 789        return task;
 790}
 791EXPORT_SYMBOL_GPL(rpc_run_task);
 792
 793/**
 794 * rpc_call_sync - Perform a synchronous RPC call
 795 * @clnt: pointer to RPC client
 796 * @msg: RPC call parameters
 797 * @flags: RPC call flags
 798 */
 799int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 800{
 801        struct rpc_task *task;
 802        struct rpc_task_setup task_setup_data = {
 803                .rpc_client = clnt,
 804                .rpc_message = msg,
 805                .callback_ops = &rpc_default_ops,
 806                .flags = flags,
 807        };
 808        int status;
 809
 810        BUG_ON(flags & RPC_TASK_ASYNC);
 811
 812        task = rpc_run_task(&task_setup_data);
 813        if (IS_ERR(task))
 814                return PTR_ERR(task);
 815        status = task->tk_status;
 816        rpc_put_task(task);
 817        return status;
 818}
 819EXPORT_SYMBOL_GPL(rpc_call_sync);
 820
 821/**
 822 * rpc_call_async - Perform an asynchronous RPC call
 823 * @clnt: pointer to RPC client
 824 * @msg: RPC call parameters
 825 * @flags: RPC call flags
 826 * @tk_ops: RPC call ops
 827 * @data: user call data
 828 */
 829int
 830rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 831               const struct rpc_call_ops *tk_ops, void *data)
 832{
 833        struct rpc_task *task;
 834        struct rpc_task_setup task_setup_data = {
 835                .rpc_client = clnt,
 836                .rpc_message = msg,
 837                .callback_ops = tk_ops,
 838                .callback_data = data,
 839                .flags = flags|RPC_TASK_ASYNC,
 840        };
 841
 842        task = rpc_run_task(&task_setup_data);
 843        if (IS_ERR(task))
 844                return PTR_ERR(task);
 845        rpc_put_task(task);
 846        return 0;
 847}
 848EXPORT_SYMBOL_GPL(rpc_call_async);
 849
 850#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 851/**
 852 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 853 * rpc_execute against it
 854 * @req: RPC request
 855 * @tk_ops: RPC call ops
 856 */
 857struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 858                                const struct rpc_call_ops *tk_ops)
 859{
 860        struct rpc_task *task;
 861        struct xdr_buf *xbufp = &req->rq_snd_buf;
 862        struct rpc_task_setup task_setup_data = {
 863                .callback_ops = tk_ops,
 864        };
 865
 866        dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 867        /*
 868         * Create an rpc_task to send the data
 869         */
 870        task = rpc_new_task(&task_setup_data);
 871        if (IS_ERR(task)) {
 872                xprt_free_bc_request(req);
 873                goto out;
 874        }
 875        task->tk_rqstp = req;
 876
 877        /*
 878         * Set up the xdr_buf length.
 879         * This also indicates that the buffer is XDR encoded already.
 880         */
 881        xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 882                        xbufp->tail[0].iov_len;
 883
 884        task->tk_action = call_bc_transmit;
 885        atomic_inc(&task->tk_count);
 886        BUG_ON(atomic_read(&task->tk_count) != 2);
 887        rpc_execute(task);
 888
 889out:
 890        dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 891        return task;
 892}
 893#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 894
 895void
 896rpc_call_start(struct rpc_task *task)
 897{
 898        task->tk_action = call_start;
 899}
 900EXPORT_SYMBOL_GPL(rpc_call_start);
 901
 902/**
 903 * rpc_peeraddr - extract remote peer address from clnt's xprt
 904 * @clnt: RPC client structure
 905 * @buf: target buffer
 906 * @bufsize: length of target buffer
 907 *
 908 * Returns the number of bytes that are actually in the stored address.
 909 */
 910size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 911{
 912        size_t bytes;
 913        struct rpc_xprt *xprt;
 914
 915        rcu_read_lock();
 916        xprt = rcu_dereference(clnt->cl_xprt);
 917
 918        bytes = xprt->addrlen;
 919        if (bytes > bufsize)
 920                bytes = bufsize;
 921        memcpy(buf, &xprt->addr, bytes);
 922        rcu_read_unlock();
 923
 924        return bytes;
 925}
 926EXPORT_SYMBOL_GPL(rpc_peeraddr);
 927
 928/**
 929 * rpc_peeraddr2str - return remote peer address in printable format
 930 * @clnt: RPC client structure
 931 * @format: address format
 932 *
 933 * NB: the lifetime of the memory referenced by the returned pointer is
 934 * the same as the rpc_xprt itself.  As long as the caller uses this
 935 * pointer, it must hold the RCU read lock.
 936 */
 937const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 938                             enum rpc_display_format_t format)
 939{
 940        struct rpc_xprt *xprt;
 941
 942        xprt = rcu_dereference(clnt->cl_xprt);
 943
 944        if (xprt->address_strings[format] != NULL)
 945                return xprt->address_strings[format];
 946        else
 947                return "unprintable";
 948}
 949EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 950
 951static const struct sockaddr_in rpc_inaddr_loopback = {
 952        .sin_family             = AF_INET,
 953        .sin_addr.s_addr        = htonl(INADDR_ANY),
 954};
 955
 956static const struct sockaddr_in6 rpc_in6addr_loopback = {
 957        .sin6_family            = AF_INET6,
 958        .sin6_addr              = IN6ADDR_ANY_INIT,
 959};
 960
 961/*
 962 * Try a getsockname() on a connected datagram socket.  Using a
 963 * connected datagram socket prevents leaving a socket in TIME_WAIT.
 964 * This conserves the ephemeral port number space.
 965 *
 966 * Returns zero and fills in "buf" if successful; otherwise, a
 967 * negative errno is returned.
 968 */
 969static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
 970                        struct sockaddr *buf, int buflen)
 971{
 972        struct socket *sock;
 973        int err;
 974
 975        err = __sock_create(net, sap->sa_family,
 976                                SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
 977        if (err < 0) {
 978                dprintk("RPC:       can't create UDP socket (%d)\n", err);
 979                goto out;
 980        }
 981
 982        switch (sap->sa_family) {
 983        case AF_INET:
 984                err = kernel_bind(sock,
 985                                (struct sockaddr *)&rpc_inaddr_loopback,
 986                                sizeof(rpc_inaddr_loopback));
 987                break;
 988        case AF_INET6:
 989                err = kernel_bind(sock,
 990                                (struct sockaddr *)&rpc_in6addr_loopback,
 991                                sizeof(rpc_in6addr_loopback));
 992                break;
 993        default:
 994                err = -EAFNOSUPPORT;
 995                goto out;
 996        }
 997        if (err < 0) {
 998                dprintk("RPC:       can't bind UDP socket (%d)\n", err);
 999                goto out_release;
1000        }
1001
1002        err = kernel_connect(sock, sap, salen, 0);
1003        if (err < 0) {
1004                dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1005                goto out_release;
1006        }
1007
1008        err = kernel_getsockname(sock, buf, &buflen);
1009        if (err < 0) {
1010                dprintk("RPC:       getsockname failed (%d)\n", err);
1011                goto out_release;
1012        }
1013
1014        err = 0;
1015        if (buf->sa_family == AF_INET6) {
1016                struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1017                sin6->sin6_scope_id = 0;
1018        }
1019        dprintk("RPC:       %s succeeded\n", __func__);
1020
1021out_release:
1022        sock_release(sock);
1023out:
1024        return err;
1025}
1026
1027/*
1028 * Scraping a connected socket failed, so we don't have a useable
1029 * local address.  Fallback: generate an address that will prevent
1030 * the server from calling us back.
1031 *
1032 * Returns zero and fills in "buf" if successful; otherwise, a
1033 * negative errno is returned.
1034 */
1035static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1036{
1037        switch (family) {
1038        case AF_INET:
1039                if (buflen < sizeof(rpc_inaddr_loopback))
1040                        return -EINVAL;
1041                memcpy(buf, &rpc_inaddr_loopback,
1042                                sizeof(rpc_inaddr_loopback));
1043                break;
1044        case AF_INET6:
1045                if (buflen < sizeof(rpc_in6addr_loopback))
1046                        return -EINVAL;
1047                memcpy(buf, &rpc_in6addr_loopback,
1048                                sizeof(rpc_in6addr_loopback));
1049        default:
1050                dprintk("RPC:       %s: address family not supported\n",
1051                        __func__);
1052                return -EAFNOSUPPORT;
1053        }
1054        dprintk("RPC:       %s: succeeded\n", __func__);
1055        return 0;
1056}
1057
1058/**
1059 * rpc_localaddr - discover local endpoint address for an RPC client
1060 * @clnt: RPC client structure
1061 * @buf: target buffer
1062 * @buflen: size of target buffer, in bytes
1063 *
1064 * Returns zero and fills in "buf" and "buflen" if successful;
1065 * otherwise, a negative errno is returned.
1066 *
1067 * This works even if the underlying transport is not currently connected,
1068 * or if the upper layer never previously provided a source address.
1069 *
1070 * The result of this function call is transient: multiple calls in
1071 * succession may give different results, depending on how local
1072 * networking configuration changes over time.
1073 */
1074int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1075{
1076        struct sockaddr_storage address;
1077        struct sockaddr *sap = (struct sockaddr *)&address;
1078        struct rpc_xprt *xprt;
1079        struct net *net;
1080        size_t salen;
1081        int err;
1082
1083        rcu_read_lock();
1084        xprt = rcu_dereference(clnt->cl_xprt);
1085        salen = xprt->addrlen;
1086        memcpy(sap, &xprt->addr, salen);
1087        net = get_net(xprt->xprt_net);
1088        rcu_read_unlock();
1089
1090        rpc_set_port(sap, 0);
1091        err = rpc_sockname(net, sap, salen, buf, buflen);
1092        put_net(net);
1093        if (err != 0)
1094                /* Couldn't discover local address, return ANYADDR */
1095                return rpc_anyaddr(sap->sa_family, buf, buflen);
1096        return 0;
1097}
1098EXPORT_SYMBOL_GPL(rpc_localaddr);
1099
1100void
1101rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1102{
1103        struct rpc_xprt *xprt;
1104
1105        rcu_read_lock();
1106        xprt = rcu_dereference(clnt->cl_xprt);
1107        if (xprt->ops->set_buffer_size)
1108                xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1109        rcu_read_unlock();
1110}
1111EXPORT_SYMBOL_GPL(rpc_setbufsize);
1112
1113/**
1114 * rpc_protocol - Get transport protocol number for an RPC client
1115 * @clnt: RPC client to query
1116 *
1117 */
1118int rpc_protocol(struct rpc_clnt *clnt)
1119{
1120        int protocol;
1121
1122        rcu_read_lock();
1123        protocol = rcu_dereference(clnt->cl_xprt)->prot;
1124        rcu_read_unlock();
1125        return protocol;
1126}
1127EXPORT_SYMBOL_GPL(rpc_protocol);
1128
1129/**
1130 * rpc_net_ns - Get the network namespace for this RPC client
1131 * @clnt: RPC client to query
1132 *
1133 */
1134struct net *rpc_net_ns(struct rpc_clnt *clnt)
1135{
1136        struct net *ret;
1137
1138        rcu_read_lock();
1139        ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1140        rcu_read_unlock();
1141        return ret;
1142}
1143EXPORT_SYMBOL_GPL(rpc_net_ns);
1144
1145/**
1146 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1147 * @clnt: RPC client to query
1148 *
1149 * For stream transports, this is one RPC record fragment (see RFC
1150 * 1831), as we don't support multi-record requests yet.  For datagram
1151 * transports, this is the size of an IP packet minus the IP, UDP, and
1152 * RPC header sizes.
1153 */
1154size_t rpc_max_payload(struct rpc_clnt *clnt)
1155{
1156        size_t ret;
1157
1158        rcu_read_lock();
1159        ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1160        rcu_read_unlock();
1161        return ret;
1162}
1163EXPORT_SYMBOL_GPL(rpc_max_payload);
1164
1165/**
1166 * rpc_force_rebind - force transport to check that remote port is unchanged
1167 * @clnt: client to rebind
1168 *
1169 */
1170void rpc_force_rebind(struct rpc_clnt *clnt)
1171{
1172        if (clnt->cl_autobind) {
1173                rcu_read_lock();
1174                xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1175                rcu_read_unlock();
1176        }
1177}
1178EXPORT_SYMBOL_GPL(rpc_force_rebind);
1179
1180/*
1181 * Restart an (async) RPC call from the call_prepare state.
1182 * Usually called from within the exit handler.
1183 */
1184int
1185rpc_restart_call_prepare(struct rpc_task *task)
1186{
1187        if (RPC_ASSASSINATED(task))
1188                return 0;
1189        task->tk_action = call_start;
1190        if (task->tk_ops->rpc_call_prepare != NULL)
1191                task->tk_action = rpc_prepare_task;
1192        return 1;
1193}
1194EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1195
1196/*
1197 * Restart an (async) RPC call. Usually called from within the
1198 * exit handler.
1199 */
1200int
1201rpc_restart_call(struct rpc_task *task)
1202{
1203        if (RPC_ASSASSINATED(task))
1204                return 0;
1205        task->tk_action = call_start;
1206        return 1;
1207}
1208EXPORT_SYMBOL_GPL(rpc_restart_call);
1209
1210#ifdef RPC_DEBUG
1211static const char *rpc_proc_name(const struct rpc_task *task)
1212{
1213        const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1214
1215        if (proc) {
1216                if (proc->p_name)
1217                        return proc->p_name;
1218                else
1219                        return "NULL";
1220        } else
1221                return "no proc";
1222}
1223#endif
1224
1225/*
1226 * 0.  Initial state
1227 *
1228 *     Other FSM states can be visited zero or more times, but
1229 *     this state is visited exactly once for each RPC.
1230 */
1231static void
1232call_start(struct rpc_task *task)
1233{
1234        struct rpc_clnt *clnt = task->tk_client;
1235
1236        dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1237                        clnt->cl_protname, clnt->cl_vers,
1238                        rpc_proc_name(task),
1239                        (RPC_IS_ASYNC(task) ? "async" : "sync"));
1240
1241        /* Increment call count */
1242        task->tk_msg.rpc_proc->p_count++;
1243        clnt->cl_stats->rpccnt++;
1244        task->tk_action = call_reserve;
1245}
1246
1247/*
1248 * 1.   Reserve an RPC call slot
1249 */
1250static void
1251call_reserve(struct rpc_task *task)
1252{
1253        dprint_status(task);
1254
1255        task->tk_status  = 0;
1256        task->tk_action  = call_reserveresult;
1257        xprt_reserve(task);
1258}
1259
1260/*
1261 * 1b.  Grok the result of xprt_reserve()
1262 */
1263static void
1264call_reserveresult(struct rpc_task *task)
1265{
1266        int status = task->tk_status;
1267
1268        dprint_status(task);
1269
1270        /*
1271         * After a call to xprt_reserve(), we must have either
1272         * a request slot or else an error status.
1273         */
1274        task->tk_status = 0;
1275        if (status >= 0) {
1276                if (task->tk_rqstp) {
1277                        task->tk_action = call_refresh;
1278                        return;
1279                }
1280
1281                printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1282                                __func__, status);
1283                rpc_exit(task, -EIO);
1284                return;
1285        }
1286
1287        /*
1288         * Even though there was an error, we may have acquired
1289         * a request slot somehow.  Make sure not to leak it.
1290         */
1291        if (task->tk_rqstp) {
1292                printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1293                                __func__, status);
1294                xprt_release(task);
1295        }
1296
1297        switch (status) {
1298        case -ENOMEM:
1299                rpc_delay(task, HZ >> 2);
1300        case -EAGAIN:   /* woken up; retry */
1301                task->tk_action = call_reserve;
1302                return;
1303        case -EIO:      /* probably a shutdown */
1304                break;
1305        default:
1306                printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1307                                __func__, status);
1308                break;
1309        }
1310        rpc_exit(task, status);
1311}
1312
1313/*
1314 * 2.   Bind and/or refresh the credentials
1315 */
1316static void
1317call_refresh(struct rpc_task *task)
1318{
1319        dprint_status(task);
1320
1321        task->tk_action = call_refreshresult;
1322        task->tk_status = 0;
1323        task->tk_client->cl_stats->rpcauthrefresh++;
1324        rpcauth_refreshcred(task);
1325}
1326
1327/*
1328 * 2a.  Process the results of a credential refresh
1329 */
1330static void
1331call_refreshresult(struct rpc_task *task)
1332{
1333        int status = task->tk_status;
1334
1335        dprint_status(task);
1336
1337        task->tk_status = 0;
1338        task->tk_action = call_refresh;
1339        switch (status) {
1340        case 0:
1341                if (rpcauth_uptodatecred(task))
1342                        task->tk_action = call_allocate;
1343                return;
1344        case -ETIMEDOUT:
1345                rpc_delay(task, 3*HZ);
1346        case -EAGAIN:
1347                status = -EACCES;
1348                if (!task->tk_cred_retry)
1349                        break;
1350                task->tk_cred_retry--;
1351                dprintk("RPC: %5u %s: retry refresh creds\n",
1352                                task->tk_pid, __func__);
1353                return;
1354        }
1355        dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1356                                task->tk_pid, __func__, status);
1357        rpc_exit(task, status);
1358}
1359
1360/*
1361 * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1362 *      (Note: buffer memory is freed in xprt_release).
1363 */
1364static void
1365call_allocate(struct rpc_task *task)
1366{
1367        unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1368        struct rpc_rqst *req = task->tk_rqstp;
1369        struct rpc_xprt *xprt = task->tk_xprt;
1370        struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1371
1372        dprint_status(task);
1373
1374        task->tk_status = 0;
1375        task->tk_action = call_bind;
1376
1377        if (req->rq_buffer)
1378                return;
1379
1380        if (proc->p_proc != 0) {
1381                BUG_ON(proc->p_arglen == 0);
1382                if (proc->p_decode != NULL)
1383                        BUG_ON(proc->p_replen == 0);
1384        }
1385
1386        /*
1387         * Calculate the size (in quads) of the RPC call
1388         * and reply headers, and convert both values
1389         * to byte sizes.
1390         */
1391        req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1392        req->rq_callsize <<= 2;
1393        req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1394        req->rq_rcvsize <<= 2;
1395
1396        req->rq_buffer = xprt->ops->buf_alloc(task,
1397                                        req->rq_callsize + req->rq_rcvsize);
1398        if (req->rq_buffer != NULL)
1399                return;
1400
1401        dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1402
1403        if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1404                task->tk_action = call_allocate;
1405                rpc_delay(task, HZ>>4);
1406                return;
1407        }
1408
1409        rpc_exit(task, -ERESTARTSYS);
1410}
1411
1412static inline int
1413rpc_task_need_encode(struct rpc_task *task)
1414{
1415        return task->tk_rqstp->rq_snd_buf.len == 0;
1416}
1417
1418static inline void
1419rpc_task_force_reencode(struct rpc_task *task)
1420{
1421        task->tk_rqstp->rq_snd_buf.len = 0;
1422        task->tk_rqstp->rq_bytes_sent = 0;
1423}
1424
1425static inline void
1426rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1427{
1428        buf->head[0].iov_base = start;
1429        buf->head[0].iov_len = len;
1430        buf->tail[0].iov_len = 0;
1431        buf->page_len = 0;
1432        buf->flags = 0;
1433        buf->len = 0;
1434        buf->buflen = len;
1435}
1436
1437/*
1438 * 3.   Encode arguments of an RPC call
1439 */
1440static void
1441rpc_xdr_encode(struct rpc_task *task)
1442{
1443        struct rpc_rqst *req = task->tk_rqstp;
1444        kxdreproc_t     encode;
1445        __be32          *p;
1446
1447        dprint_status(task);
1448
1449        rpc_xdr_buf_init(&req->rq_snd_buf,
1450                         req->rq_buffer,
1451                         req->rq_callsize);
1452        rpc_xdr_buf_init(&req->rq_rcv_buf,
1453                         (char *)req->rq_buffer + req->rq_callsize,
1454                         req->rq_rcvsize);
1455
1456        p = rpc_encode_header(task);
1457        if (p == NULL) {
1458                printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1459                rpc_exit(task, -EIO);
1460                return;
1461        }
1462
1463        encode = task->tk_msg.rpc_proc->p_encode;
1464        if (encode == NULL)
1465                return;
1466
1467        task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1468                        task->tk_msg.rpc_argp);
1469}
1470
1471/*
1472 * 4.   Get the server port number if not yet set
1473 */
1474static void
1475call_bind(struct rpc_task *task)
1476{
1477        struct rpc_xprt *xprt = task->tk_xprt;
1478
1479        dprint_status(task);
1480
1481        task->tk_action = call_connect;
1482        if (!xprt_bound(xprt)) {
1483                task->tk_action = call_bind_status;
1484                task->tk_timeout = xprt->bind_timeout;
1485                xprt->ops->rpcbind(task);
1486        }
1487}
1488
1489/*
1490 * 4a.  Sort out bind result
1491 */
1492static void
1493call_bind_status(struct rpc_task *task)
1494{
1495        int status = -EIO;
1496
1497        if (task->tk_status >= 0) {
1498                dprint_status(task);
1499                task->tk_status = 0;
1500                task->tk_action = call_connect;
1501                return;
1502        }
1503
1504        trace_rpc_bind_status(task);
1505        switch (task->tk_status) {
1506        case -ENOMEM:
1507                dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1508                rpc_delay(task, HZ >> 2);
1509                goto retry_timeout;
1510        case -EACCES:
1511                dprintk("RPC: %5u remote rpcbind: RPC program/version "
1512                                "unavailable\n", task->tk_pid);
1513                /* fail immediately if this is an RPC ping */
1514                if (task->tk_msg.rpc_proc->p_proc == 0) {
1515                        status = -EOPNOTSUPP;
1516                        break;
1517                }
1518                if (task->tk_rebind_retry == 0)
1519                        break;
1520                task->tk_rebind_retry--;
1521                rpc_delay(task, 3*HZ);
1522                goto retry_timeout;
1523        case -ETIMEDOUT:
1524                dprintk("RPC: %5u rpcbind request timed out\n",
1525                                task->tk_pid);
1526                goto retry_timeout;
1527        case -EPFNOSUPPORT:
1528                /* server doesn't support any rpcbind version we know of */
1529                dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1530                                task->tk_pid);
1531                break;
1532        case -EPROTONOSUPPORT:
1533                dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1534                                task->tk_pid);
1535                task->tk_status = 0;
1536                task->tk_action = call_bind;
1537                return;
1538        case -ECONNREFUSED:             /* connection problems */
1539        case -ECONNRESET:
1540        case -ENOTCONN:
1541        case -EHOSTDOWN:
1542        case -EHOSTUNREACH:
1543        case -ENETUNREACH:
1544        case -EPIPE:
1545                dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1546                                task->tk_pid, task->tk_status);
1547                if (!RPC_IS_SOFTCONN(task)) {
1548                        rpc_delay(task, 5*HZ);
1549                        goto retry_timeout;
1550                }
1551                status = task->tk_status;
1552                break;
1553        default:
1554                dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1555                                task->tk_pid, -task->tk_status);
1556        }
1557
1558        rpc_exit(task, status);
1559        return;
1560
1561retry_timeout:
1562        task->tk_action = call_timeout;
1563}
1564
1565/*
1566 * 4b.  Connect to the RPC server
1567 */
1568static void
1569call_connect(struct rpc_task *task)
1570{
1571        struct rpc_xprt *xprt = task->tk_xprt;
1572
1573        dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1574                        task->tk_pid, xprt,
1575                        (xprt_connected(xprt) ? "is" : "is not"));
1576
1577        task->tk_action = call_transmit;
1578        if (!xprt_connected(xprt)) {
1579                task->tk_action = call_connect_status;
1580                if (task->tk_status < 0)
1581                        return;
1582                xprt_connect(task);
1583        }
1584}
1585
1586/*
1587 * 4c.  Sort out connect result
1588 */
1589static void
1590call_connect_status(struct rpc_task *task)
1591{
1592        struct rpc_clnt *clnt = task->tk_client;
1593        int status = task->tk_status;
1594
1595        dprint_status(task);
1596
1597        task->tk_status = 0;
1598        if (status >= 0 || status == -EAGAIN) {
1599                clnt->cl_stats->netreconn++;
1600                task->tk_action = call_transmit;
1601                return;
1602        }
1603
1604        trace_rpc_connect_status(task, status);
1605        switch (status) {
1606                /* if soft mounted, test if we've timed out */
1607        case -ETIMEDOUT:
1608                task->tk_action = call_timeout;
1609                break;
1610        default:
1611                rpc_exit(task, -EIO);
1612        }
1613}
1614
1615/*
1616 * 5.   Transmit the RPC request, and wait for reply
1617 */
1618static void
1619call_transmit(struct rpc_task *task)
1620{
1621        dprint_status(task);
1622
1623        task->tk_action = call_status;
1624        if (task->tk_status < 0)
1625                return;
1626        task->tk_status = xprt_prepare_transmit(task);
1627        if (task->tk_status != 0)
1628                return;
1629        task->tk_action = call_transmit_status;
1630        /* Encode here so that rpcsec_gss can use correct sequence number. */
1631        if (rpc_task_need_encode(task)) {
1632                BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1633                rpc_xdr_encode(task);
1634                /* Did the encode result in an error condition? */
1635                if (task->tk_status != 0) {
1636                        /* Was the error nonfatal? */
1637                        if (task->tk_status == -EAGAIN)
1638                                rpc_delay(task, HZ >> 4);
1639                        else
1640                                rpc_exit(task, task->tk_status);
1641                        return;
1642                }
1643        }
1644        xprt_transmit(task);
1645        if (task->tk_status < 0)
1646                return;
1647        /*
1648         * On success, ensure that we call xprt_end_transmit() before sleeping
1649         * in order to allow access to the socket to other RPC requests.
1650         */
1651        call_transmit_status(task);
1652        if (rpc_reply_expected(task))
1653                return;
1654        task->tk_action = rpc_exit_task;
1655        rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1656}
1657
1658/*
1659 * 5a.  Handle cleanup after a transmission
1660 */
1661static void
1662call_transmit_status(struct rpc_task *task)
1663{
1664        task->tk_action = call_status;
1665
1666        /*
1667         * Common case: success.  Force the compiler to put this
1668         * test first.
1669         */
1670        if (task->tk_status == 0) {
1671                xprt_end_transmit(task);
1672                rpc_task_force_reencode(task);
1673                return;
1674        }
1675
1676        switch (task->tk_status) {
1677        case -EAGAIN:
1678                break;
1679        default:
1680                dprint_status(task);
1681                xprt_end_transmit(task);
1682                rpc_task_force_reencode(task);
1683                break;
1684                /*
1685                 * Special cases: if we've been waiting on the
1686                 * socket's write_space() callback, or if the
1687                 * socket just returned a connection error,
1688                 * then hold onto the transport lock.
1689                 */
1690        case -ECONNREFUSED:
1691        case -EHOSTDOWN:
1692        case -EHOSTUNREACH:
1693        case -ENETUNREACH:
1694                if (RPC_IS_SOFTCONN(task)) {
1695                        xprt_end_transmit(task);
1696                        rpc_exit(task, task->tk_status);
1697                        break;
1698                }
1699        case -ECONNRESET:
1700        case -ENOTCONN:
1701        case -EPIPE:
1702                rpc_task_force_reencode(task);
1703        }
1704}
1705
1706#if defined(CONFIG_SUNRPC_BACKCHANNEL)
1707/*
1708 * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1709 * addition, disconnect on connectivity errors.
1710 */
1711static void
1712call_bc_transmit(struct rpc_task *task)
1713{
1714        struct rpc_rqst *req = task->tk_rqstp;
1715
1716        BUG_ON(task->tk_status != 0);
1717        task->tk_status = xprt_prepare_transmit(task);
1718        if (task->tk_status == -EAGAIN) {
1719                /*
1720                 * Could not reserve the transport. Try again after the
1721                 * transport is released.
1722                 */
1723                task->tk_status = 0;
1724                task->tk_action = call_bc_transmit;
1725                return;
1726        }
1727
1728        task->tk_action = rpc_exit_task;
1729        if (task->tk_status < 0) {
1730                printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1731                        "error: %d\n", task->tk_status);
1732                return;
1733        }
1734
1735        xprt_transmit(task);
1736        xprt_end_transmit(task);
1737        dprint_status(task);
1738        switch (task->tk_status) {
1739        case 0:
1740                /* Success */
1741                break;
1742        case -EHOSTDOWN:
1743        case -EHOSTUNREACH:
1744        case -ENETUNREACH:
1745        case -ETIMEDOUT:
1746                /*
1747                 * Problem reaching the server.  Disconnect and let the
1748                 * forechannel reestablish the connection.  The server will
1749                 * have to retransmit the backchannel request and we'll
1750                 * reprocess it.  Since these ops are idempotent, there's no
1751                 * need to cache our reply at this time.
1752                 */
1753                printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1754                        "error: %d\n", task->tk_status);
1755                xprt_conditional_disconnect(task->tk_xprt,
1756                        req->rq_connect_cookie);
1757                break;
1758        default:
1759                /*
1760                 * We were unable to reply and will have to drop the
1761                 * request.  The server should reconnect and retransmit.
1762                 */
1763                BUG_ON(task->tk_status == -EAGAIN);
1764                printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1765                        "error: %d\n", task->tk_status);
1766                break;
1767        }
1768        rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1769}
1770#endif /* CONFIG_SUNRPC_BACKCHANNEL */
1771
1772/*
1773 * 6.   Sort out the RPC call status
1774 */
1775static void
1776call_status(struct rpc_task *task)
1777{
1778        struct rpc_clnt *clnt = task->tk_client;
1779        struct rpc_rqst *req = task->tk_rqstp;
1780        int             status;
1781
1782        if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1783                task->tk_status = req->rq_reply_bytes_recvd;
1784
1785        dprint_status(task);
1786
1787        status = task->tk_status;
1788        if (status >= 0) {
1789                task->tk_action = call_decode;
1790                return;
1791        }
1792
1793        trace_rpc_call_status(task);
1794        task->tk_status = 0;
1795        switch(status) {
1796        case -EHOSTDOWN:
1797        case -EHOSTUNREACH:
1798        case -ENETUNREACH:
1799                /*
1800                 * Delay any retries for 3 seconds, then handle as if it
1801                 * were a timeout.
1802                 */
1803                rpc_delay(task, 3*HZ);
1804        case -ETIMEDOUT:
1805                task->tk_action = call_timeout;
1806                if (task->tk_client->cl_discrtry)
1807                        xprt_conditional_disconnect(task->tk_xprt,
1808                                        req->rq_connect_cookie);
1809                break;
1810        case -ECONNRESET:
1811        case -ECONNREFUSED:
1812                rpc_force_rebind(clnt);
1813                rpc_delay(task, 3*HZ);
1814        case -EPIPE:
1815        case -ENOTCONN:
1816                task->tk_action = call_bind;
1817                break;
1818        case -EAGAIN:
1819                task->tk_action = call_transmit;
1820                break;
1821        case -EIO:
1822                /* shutdown or soft timeout */
1823                rpc_exit(task, status);
1824                break;
1825        default:
1826                if (clnt->cl_chatty)
1827                        printk("%s: RPC call returned error %d\n",
1828                               clnt->cl_protname, -status);
1829                rpc_exit(task, status);
1830        }
1831}
1832
1833/*
1834 * 6a.  Handle RPC timeout
1835 *      We do not release the request slot, so we keep using the
1836 *      same XID for all retransmits.
1837 */
1838static void
1839call_timeout(struct rpc_task *task)
1840{
1841        struct rpc_clnt *clnt = task->tk_client;
1842
1843        if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1844                dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1845                goto retry;
1846        }
1847
1848        dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1849        task->tk_timeouts++;
1850
1851        if (RPC_IS_SOFTCONN(task)) {
1852                rpc_exit(task, -ETIMEDOUT);
1853                return;
1854        }
1855        if (RPC_IS_SOFT(task)) {
1856                if (clnt->cl_chatty) {
1857                        rcu_read_lock();
1858                        printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1859                                clnt->cl_protname,
1860                                rcu_dereference(clnt->cl_xprt)->servername);
1861                        rcu_read_unlock();
1862                }
1863                if (task->tk_flags & RPC_TASK_TIMEOUT)
1864                        rpc_exit(task, -ETIMEDOUT);
1865                else
1866                        rpc_exit(task, -EIO);
1867                return;
1868        }
1869
1870        if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1871                task->tk_flags |= RPC_CALL_MAJORSEEN;
1872                if (clnt->cl_chatty) {
1873                        rcu_read_lock();
1874                        printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1875                        clnt->cl_protname,
1876                        rcu_dereference(clnt->cl_xprt)->servername);
1877                        rcu_read_unlock();
1878                }
1879        }
1880        rpc_force_rebind(clnt);
1881        /*
1882         * Did our request time out due to an RPCSEC_GSS out-of-sequence
1883         * event? RFC2203 requires the server to drop all such requests.
1884         */
1885        rpcauth_invalcred(task);
1886
1887retry:
1888        clnt->cl_stats->rpcretrans++;
1889        task->tk_action = call_bind;
1890        task->tk_status = 0;
1891}
1892
1893/*
1894 * 7.   Decode the RPC reply
1895 */
1896static void
1897call_decode(struct rpc_task *task)
1898{
1899        struct rpc_clnt *clnt = task->tk_client;
1900        struct rpc_rqst *req = task->tk_rqstp;
1901        kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1902        __be32          *p;
1903
1904        dprint_status(task);
1905
1906        if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1907                if (clnt->cl_chatty) {
1908                        rcu_read_lock();
1909                        printk(KERN_NOTICE "%s: server %s OK\n",
1910                                clnt->cl_protname,
1911                                rcu_dereference(clnt->cl_xprt)->servername);
1912                        rcu_read_unlock();
1913                }
1914                task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1915        }
1916
1917        /*
1918         * Ensure that we see all writes made by xprt_complete_rqst()
1919         * before it changed req->rq_reply_bytes_recvd.
1920         */
1921        smp_rmb();
1922        req->rq_rcv_buf.len = req->rq_private_buf.len;
1923
1924        /* Check that the softirq receive buffer is valid */
1925        WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1926                                sizeof(req->rq_rcv_buf)) != 0);
1927
1928        if (req->rq_rcv_buf.len < 12) {
1929                if (!RPC_IS_SOFT(task)) {
1930                        task->tk_action = call_bind;
1931                        clnt->cl_stats->rpcretrans++;
1932                        goto out_retry;
1933                }
1934                dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1935                                clnt->cl_protname, task->tk_status);
1936                task->tk_action = call_timeout;
1937                goto out_retry;
1938        }
1939
1940        p = rpc_verify_header(task);
1941        if (IS_ERR(p)) {
1942                if (p == ERR_PTR(-EAGAIN))
1943                        goto out_retry;
1944                return;
1945        }
1946
1947        task->tk_action = rpc_exit_task;
1948
1949        if (decode) {
1950                task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1951                                                      task->tk_msg.rpc_resp);
1952        }
1953        dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1954                        task->tk_status);
1955        return;
1956out_retry:
1957        task->tk_status = 0;
1958        /* Note: rpc_verify_header() may have freed the RPC slot */
1959        if (task->tk_rqstp == req) {
1960                req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1961                if (task->tk_client->cl_discrtry)
1962                        xprt_conditional_disconnect(task->tk_xprt,
1963                                        req->rq_connect_cookie);
1964        }
1965}
1966
1967static __be32 *
1968rpc_encode_header(struct rpc_task *task)
1969{
1970        struct rpc_clnt *clnt = task->tk_client;
1971        struct rpc_rqst *req = task->tk_rqstp;
1972        __be32          *p = req->rq_svec[0].iov_base;
1973
1974        /* FIXME: check buffer size? */
1975
1976        p = xprt_skip_transport_header(task->tk_xprt, p);
1977        *p++ = req->rq_xid;             /* XID */
1978        *p++ = htonl(RPC_CALL);         /* CALL */
1979        *p++ = htonl(RPC_VERSION);      /* RPC version */
1980        *p++ = htonl(clnt->cl_prog);    /* program number */
1981        *p++ = htonl(clnt->cl_vers);    /* program version */
1982        *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1983        p = rpcauth_marshcred(task, p);
1984        req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1985        return p;
1986}
1987
1988static __be32 *
1989rpc_verify_header(struct rpc_task *task)
1990{
1991        struct rpc_clnt *clnt = task->tk_client;
1992        struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1993        int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1994        __be32  *p = iov->iov_base;
1995        u32 n;
1996        int error = -EACCES;
1997
1998        if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1999                /* RFC-1014 says that the representation of XDR data must be a
2000                 * multiple of four bytes
2001                 * - if it isn't pointer subtraction in the NFS client may give
2002                 *   undefined results
2003                 */
2004                dprintk("RPC: %5u %s: XDR representation not a multiple of"
2005                       " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2006                       task->tk_rqstp->rq_rcv_buf.len);
2007                goto out_eio;
2008        }
2009        if ((len -= 3) < 0)
2010                goto out_overflow;
2011
2012        p += 1; /* skip XID */
2013        if ((n = ntohl(*p++)) != RPC_REPLY) {
2014                dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2015                        task->tk_pid, __func__, n);
2016                goto out_garbage;
2017        }
2018
2019        if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2020                if (--len < 0)
2021                        goto out_overflow;
2022                switch ((n = ntohl(*p++))) {
2023                case RPC_AUTH_ERROR:
2024                        break;
2025                case RPC_MISMATCH:
2026                        dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2027                                task->tk_pid, __func__);
2028                        error = -EPROTONOSUPPORT;
2029                        goto out_err;
2030                default:
2031                        dprintk("RPC: %5u %s: RPC call rejected, "
2032                                "unknown error: %x\n",
2033                                task->tk_pid, __func__, n);
2034                        goto out_eio;
2035                }
2036                if (--len < 0)
2037                        goto out_overflow;
2038                switch ((n = ntohl(*p++))) {
2039                case RPC_AUTH_REJECTEDCRED:
2040                case RPC_AUTH_REJECTEDVERF:
2041                case RPCSEC_GSS_CREDPROBLEM:
2042                case RPCSEC_GSS_CTXPROBLEM:
2043                        if (!task->tk_cred_retry)
2044                                break;
2045                        task->tk_cred_retry--;
2046                        dprintk("RPC: %5u %s: retry stale creds\n",
2047                                        task->tk_pid, __func__);
2048                        rpcauth_invalcred(task);
2049                        /* Ensure we obtain a new XID! */
2050                        xprt_release(task);
2051                        task->tk_action = call_reserve;
2052                        goto out_retry;
2053                case RPC_AUTH_BADCRED:
2054                case RPC_AUTH_BADVERF:
2055                        /* possibly garbled cred/verf? */
2056                        if (!task->tk_garb_retry)
2057                                break;
2058                        task->tk_garb_retry--;
2059                        dprintk("RPC: %5u %s: retry garbled creds\n",
2060                                        task->tk_pid, __func__);
2061                        task->tk_action = call_bind;
2062                        goto out_retry;
2063                case RPC_AUTH_TOOWEAK:
2064                        rcu_read_lock();
2065                        printk(KERN_NOTICE "RPC: server %s requires stronger "
2066                               "authentication.\n",
2067                               rcu_dereference(clnt->cl_xprt)->servername);
2068                        rcu_read_unlock();
2069                        break;
2070                default:
2071                        dprintk("RPC: %5u %s: unknown auth error: %x\n",
2072                                        task->tk_pid, __func__, n);
2073                        error = -EIO;
2074                }
2075                dprintk("RPC: %5u %s: call rejected %d\n",
2076                                task->tk_pid, __func__, n);
2077                goto out_err;
2078        }
2079        if (!(p = rpcauth_checkverf(task, p))) {
2080                dprintk("RPC: %5u %s: auth check failed\n",
2081                                task->tk_pid, __func__);
2082                goto out_garbage;               /* bad verifier, retry */
2083        }
2084        len = p - (__be32 *)iov->iov_base - 1;
2085        if (len < 0)
2086                goto out_overflow;
2087        switch ((n = ntohl(*p++))) {
2088        case RPC_SUCCESS:
2089                return p;
2090        case RPC_PROG_UNAVAIL:
2091                dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2092                                "by server %s\n", task->tk_pid, __func__,
2093                                (unsigned int)clnt->cl_prog,
2094                                rcu_dereference(clnt->cl_xprt)->servername);
2095                error = -EPFNOSUPPORT;
2096                goto out_err;
2097        case RPC_PROG_MISMATCH:
2098                dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2099                                "by server %s\n", task->tk_pid, __func__,
2100                                (unsigned int)clnt->cl_prog,
2101                                (unsigned int)clnt->cl_vers,
2102                                rcu_dereference(clnt->cl_xprt)->servername);
2103                error = -EPROTONOSUPPORT;
2104                goto out_err;
2105        case RPC_PROC_UNAVAIL:
2106                dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2107                                "version %u on server %s\n",
2108                                task->tk_pid, __func__,
2109                                rpc_proc_name(task),
2110                                clnt->cl_prog, clnt->cl_vers,
2111                                rcu_dereference(clnt->cl_xprt)->servername);
2112                error = -EOPNOTSUPP;
2113                goto out_err;
2114        case RPC_GARBAGE_ARGS:
2115                dprintk("RPC: %5u %s: server saw garbage\n",
2116                                task->tk_pid, __func__);
2117                break;                  /* retry */
2118        default:
2119                dprintk("RPC: %5u %s: server accept status: %x\n",
2120                                task->tk_pid, __func__, n);
2121                /* Also retry */
2122        }
2123
2124out_garbage:
2125        clnt->cl_stats->rpcgarbage++;
2126        if (task->tk_garb_retry) {
2127                task->tk_garb_retry--;
2128                dprintk("RPC: %5u %s: retrying\n",
2129                                task->tk_pid, __func__);
2130                task->tk_action = call_bind;
2131out_retry:
2132                return ERR_PTR(-EAGAIN);
2133        }
2134out_eio:
2135        error = -EIO;
2136out_err:
2137        rpc_exit(task, error);
2138        dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2139                        __func__, error);
2140        return ERR_PTR(error);
2141out_overflow:
2142        dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2143                        __func__);
2144        goto out_garbage;
2145}
2146
2147static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2148{
2149}
2150
2151static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2152{
2153        return 0;
2154}
2155
2156static struct rpc_procinfo rpcproc_null = {
2157        .p_encode = rpcproc_encode_null,
2158        .p_decode = rpcproc_decode_null,
2159};
2160
2161static int rpc_ping(struct rpc_clnt *clnt)
2162{
2163        struct rpc_message msg = {
2164                .rpc_proc = &rpcproc_null,
2165        };
2166        int err;
2167        msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2168        err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2169        put_rpccred(msg.rpc_cred);
2170        return err;
2171}
2172
2173struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2174{
2175        struct rpc_message msg = {
2176                .rpc_proc = &rpcproc_null,
2177                .rpc_cred = cred,
2178        };
2179        struct rpc_task_setup task_setup_data = {
2180                .rpc_client = clnt,
2181                .rpc_message = &msg,
2182                .callback_ops = &rpc_default_ops,
2183                .flags = flags,
2184        };
2185        return rpc_run_task(&task_setup_data);
2186}
2187EXPORT_SYMBOL_GPL(rpc_call_null);
2188
2189#ifdef RPC_DEBUG
2190static void rpc_show_header(void)
2191{
2192        printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2193                "-timeout ---ops--\n");
2194}
2195
2196static void rpc_show_task(const struct rpc_clnt *clnt,
2197                          const struct rpc_task *task)
2198{
2199        const char *rpc_waitq = "none";
2200
2201        if (RPC_IS_QUEUED(task))
2202                rpc_waitq = rpc_qname(task->tk_waitqueue);
2203
2204        printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2205                task->tk_pid, task->tk_flags, task->tk_status,
2206                clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2207                clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2208                task->tk_action, rpc_waitq);
2209}
2210
2211void rpc_show_tasks(struct net *net)
2212{
2213        struct rpc_clnt *clnt;
2214        struct rpc_task *task;
2215        int header = 0;
2216        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2217
2218        spin_lock(&sn->rpc_client_lock);
2219        list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2220                spin_lock(&clnt->cl_lock);
2221                list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2222                        if (!header) {
2223                                rpc_show_header();
2224                                header++;
2225                        }
2226                        rpc_show_task(clnt, task);
2227                }
2228                spin_unlock(&clnt->cl_lock);
2229        }
2230        spin_unlock(&sn->rpc_client_lock);
2231}
2232#endif
2233
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