net/sunrpc/clnt.c

   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  *  NB: BSD uses a more intelligent approach to guessing when a request
  17  *  or reply has been lost by keeping the RTO estimate for each procedure.
  18  *  We currently make do with a constant timeout value.
  19  *
  20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  22  */
  23
  24 #include <asm/system.h>
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/kallsyms.h>
  29 #include <linux/mm.h>
  30 #include <linux/namei.h>
  31 #include <linux/mount.h>
  32 #include <linux/slab.h>
  33 #include <linux/utsname.h>
  34 #include <linux/workqueue.h>
  35 #include <linux/in6.h>
  36
  37 #include <linux/sunrpc/clnt.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41
  42 #include "sunrpc.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 static LIST_HEAD(all_clients);
  56 static DEFINE_SPINLOCK(rpc_client_lock);
  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_decode(struct rpc_task *task);
  66 static void     call_bind(struct rpc_task *task);
  67 static void     call_bind_status(struct rpc_task *task);
  68 static void     call_transmit(struct rpc_task *task);
  69 #if defined(CONFIG_NFS_V4_1)
  70 static void     call_bc_transmit(struct rpc_task *task);
  71 #endif /* CONFIG_NFS_V4_1 */
  72 static void     call_status(struct rpc_task *task);
  73 static void     call_transmit_status(struct rpc_task *task);
  74 static void     call_refresh(struct rpc_task *task);
  75 static void     call_refreshresult(struct rpc_task *task);
  76 static void     call_timeout(struct rpc_task *task);
  77 static void     call_connect(struct rpc_task *task);
  78 static void     call_connect_status(struct rpc_task *task);
  79
  80 static __be32   *rpc_encode_header(struct rpc_task *task);
  81 static __be32   *rpc_verify_header(struct rpc_task *task);
  82 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
  83
  84 static void rpc_register_client(struct rpc_clnt *clnt)
  85 {
  86         spin_lock(&rpc_client_lock);
  87         list_add(&clnt->cl_clients, &all_clients);
  88         spin_unlock(&rpc_client_lock);
  89 }
  90
  91 static void rpc_unregister_client(struct rpc_clnt *clnt)
  92 {
  93         spin_lock(&rpc_client_lock);
  94         list_del(&clnt->cl_clients);
  95         spin_unlock(&rpc_client_lock);
  96 }
  97
  98 static int
  99 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
 100 {
 101         static uint32_t clntid;
 102         struct nameidata nd;
 103         struct path path;
 104         char name[15];
 105         struct qstr q = {
 106                 .name = name,
 107         };
 108         int error;
 109
 110         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
 111         clnt->cl_path.dentry = ERR_PTR(-ENOENT);
 112         if (dir_name == NULL)
 113                 return 0;
 114
 115         path.mnt = rpc_get_mount();
 116         if (IS_ERR(path.mnt))
 117                 return PTR_ERR(path.mnt);
 118         error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
 119         if (error)
 120                 goto err;
 121
 122         for (;;) {
 123                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 124                 name[sizeof(name) - 1] = '\0';
 125                 q.hash = full_name_hash(q.name, q.len);
 126                 path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
 127                 if (!IS_ERR(path.dentry))
 128                         break;
 129                 error = PTR_ERR(path.dentry);
 130                 if (error != -EEXIST) {
 131                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 132                                         " %s/%s, error %d\n",
 133                                         dir_name, name, error);
 134                         goto err_path_put;
 135                 }
 136         }
 137         path_put(&nd.path);
 138         clnt->cl_path = path;
 139         return 0;
 140 err_path_put:
 141         path_put(&nd.path);
 142 err:
 143         rpc_put_mount();
 144         return error;
 145 }
 146
 147 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 148 {
 149         struct rpc_program      *program = args->program;
 150         struct rpc_version      *version;
 151         struct rpc_clnt         *clnt = NULL;
 152         struct rpc_auth         *auth;
 153         int err;
 154         size_t len;
 155
 156         /* sanity check the name before trying to print it */
 157         err = -EINVAL;
 158         len = strlen(args->servername);
 159         if (len > RPC_MAXNETNAMELEN)
 160                 goto out_no_rpciod;
 161         len++;
 162
 163         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 164                         program->name, args->servername, xprt);
 165
 166         err = rpciod_up();
 167         if (err)
 168                 goto out_no_rpciod;
 169         err = -EINVAL;
 170         if (!xprt)
 171                 goto out_no_xprt;
 172
 173         if (args->version >= program->nrvers)
 174                 goto out_err;
 175         version = program->version[args->version];
 176         if (version == NULL)
 177                 goto out_err;
 178
 179         err = -ENOMEM;
 180         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 181         if (!clnt)
 182                 goto out_err;
 183         clnt->cl_parent = clnt;
 184
 185         clnt->cl_server = clnt->cl_inline_name;
 186         if (len > sizeof(clnt->cl_inline_name)) {
 187                 char *buf = kmalloc(len, GFP_KERNEL);
 188                 if (buf != NULL)
 189                         clnt->cl_server = buf;
 190                 else
 191                         len = sizeof(clnt->cl_inline_name);
 192         }
 193         strlcpy(clnt->cl_server, args->servername, len);
 194
 195         clnt->cl_xprt     = xprt;
 196         clnt->cl_procinfo = version->procs;
 197         clnt->cl_maxproc  = version->nrprocs;
 198         clnt->cl_protname = program->name;
 199         clnt->cl_prog     = args->prognumber ? : program->number;
 200         clnt->cl_vers     = version->number;
 201         clnt->cl_stats    = program->stats;
 202         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 203         err = -ENOMEM;
 204         if (clnt->cl_metrics == NULL)
 205                 goto out_no_stats;
 206         clnt->cl_program  = program;
 207         INIT_LIST_HEAD(&clnt->cl_tasks);
 208         spin_lock_init(&clnt->cl_lock);
 209
 210         if (!xprt_bound(clnt->cl_xprt))
 211                 clnt->cl_autobind = 1;
 212
 213         clnt->cl_timeout = xprt->timeout;
 214         if (args->timeout != NULL) {
 215                 memcpy(&clnt->cl_timeout_default, args->timeout,
 216                                 sizeof(clnt->cl_timeout_default));
 217                 clnt->cl_timeout = &clnt->cl_timeout_default;
 218         }
 219
 220         clnt->cl_rtt = &clnt->cl_rtt_default;
 221         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 222         clnt->cl_principal = NULL;
 223         if (args->client_name) {
 224                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
 225                 if (!clnt->cl_principal)
 226                         goto out_no_principal;
 227         }
 228
 229         kref_init(&clnt->cl_kref);
 230
 231         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
 232         if (err < 0)
 233                 goto out_no_path;
 234
 235         auth = rpcauth_create(args->authflavor, clnt);
 236         if (IS_ERR(auth)) {
 237                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 238                                 args->authflavor);
 239                 err = PTR_ERR(auth);
 240                 goto out_no_auth;
 241         }
 242
 243         /* save the nodename */
 244         clnt->cl_nodelen = strlen(init_utsname()->nodename);
 245         if (clnt->cl_nodelen > UNX_MAXNODENAME)
 246                 clnt->cl_nodelen = UNX_MAXNODENAME;
 247         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
 248         rpc_register_client(clnt);
 249         return clnt;
 250
 251 out_no_auth:
 252         if (!IS_ERR(clnt->cl_path.dentry)) {
 253                 rpc_remove_client_dir(clnt->cl_path.dentry);
 254                 rpc_put_mount();
 255         }
 256 out_no_path:
 257         kfree(clnt->cl_principal);
 258 out_no_principal:
 259         rpc_free_iostats(clnt->cl_metrics);
 260 out_no_stats:
 261         if (clnt->cl_server != clnt->cl_inline_name)
 262                 kfree(clnt->cl_server);
 263         kfree(clnt);
 264 out_err:
 265         xprt_put(xprt);
 266 out_no_xprt:
 267         rpciod_down();
 268 out_no_rpciod:
 269         return ERR_PTR(err);
 270 }
 271
 272 /*
 273  * rpc_create - create an RPC client and transport with one call
 274  * @args: rpc_clnt create argument structure
 275  *
 276  * Creates and initializes an RPC transport and an RPC client.
 277  *
 278  * It can ping the server in order to determine if it is up, and to see if
 279  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 280  * this behavior so asynchronous tasks can also use rpc_create.
 281  */
 282 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 283 {
 284         struct rpc_xprt *xprt;
 285         struct rpc_clnt *clnt;
 286         struct xprt_create xprtargs = {
 287                 .ident = args->protocol,
 288                 .srcaddr = args->saddress,
 289                 .dstaddr = args->address,
 290                 .addrlen = args->addrsize,
 291         };
 292         char servername[48];
 293
 294         /*
 295          * If the caller chooses not to specify a hostname, whip
 296          * up a string representation of the passed-in address.
 297          */
 298         if (args->servername == NULL) {
 299                 servername[0] = '\0';
 300                 switch (args->address->sa_family) {
 301                 case AF_INET: {
 302                         struct sockaddr_in *sin =
 303                                         (struct sockaddr_in *)args->address;
 304                         snprintf(servername, sizeof(servername), "%pI4",
 305                                  &sin->sin_addr.s_addr);
 306                         break;
 307                 }
 308                 case AF_INET6: {
 309                         struct sockaddr_in6 *sin =
 310                                         (struct sockaddr_in6 *)args->address;
 311                         snprintf(servername, sizeof(servername), "%pI6",
 312                                  &sin->sin6_addr);
 313                         break;
 314                 }
 315                 default:
 316                         /* caller wants default server name, but
 317                          * address family isn't recognized. */
 318                         return ERR_PTR(-EINVAL);
 319                 }
 320                 args->servername = servername;
 321         }
 322
 323         xprt = xprt_create_transport(&xprtargs);
 324         if (IS_ERR(xprt))
 325                 return (struct rpc_clnt *)xprt;
 326
 327         /*
 328          * By default, kernel RPC client connects from a reserved port.
 329          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 330          * but it is always enabled for rpciod, which handles the connect
 331          * operation.
 332          */
 333         xprt->resvport = 1;
 334         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 335                 xprt->resvport = 0;
 336
 337         clnt = rpc_new_client(args, xprt);
 338         if (IS_ERR(clnt))
 339                 return clnt;
 340
 341         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 342                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
 343                 if (err != 0) {
 344                         rpc_shutdown_client(clnt);
 345                         return ERR_PTR(err);
 346                 }
 347         }
 348
 349         clnt->cl_softrtry = 1;
 350         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 351                 clnt->cl_softrtry = 0;
 352
 353         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 354                 clnt->cl_autobind = 1;
 355         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 356                 clnt->cl_discrtry = 1;
 357         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 358                 clnt->cl_chatty = 1;
 359
 360         return clnt;
 361 }
 362 EXPORT_SYMBOL_GPL(rpc_create);
 363
 364 /*
 365  * This function clones the RPC client structure. It allows us to share the
 366  * same transport while varying parameters such as the authentication
 367  * flavour.
 368  */
 369 struct rpc_clnt *
 370 rpc_clone_client(struct rpc_clnt *clnt)
 371 {
 372         struct rpc_clnt *new;
 373         int err = -ENOMEM;
 374
 375         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 376         if (!new)
 377                 goto out_no_clnt;
 378         new->cl_parent = clnt;
 379         /* Turn off autobind on clones */
 380         new->cl_autobind = 0;
 381         INIT_LIST_HEAD(&new->cl_tasks);
 382         spin_lock_init(&new->cl_lock);
 383         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 384         new->cl_metrics = rpc_alloc_iostats(clnt);
 385         if (new->cl_metrics == NULL)
 386                 goto out_no_stats;
 387         if (clnt->cl_principal) {
 388                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
 389                 if (new->cl_principal == NULL)
 390                         goto out_no_principal;
 391         }
 392         kref_init(&new->cl_kref);
 393         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 394         if (err != 0)
 395                 goto out_no_path;
 396         if (new->cl_auth)
 397                 atomic_inc(&new->cl_auth->au_count);
 398         xprt_get(clnt->cl_xprt);
 399         kref_get(&clnt->cl_kref);
 400         rpc_register_client(new);
 401         rpciod_up();
 402         return new;
 403 out_no_path:
 404         kfree(new->cl_principal);
 405 out_no_principal:
 406         rpc_free_iostats(new->cl_metrics);
 407 out_no_stats:
 408         kfree(new);
 409 out_no_clnt:
 410         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 411         return ERR_PTR(err);
 412 }
 413 EXPORT_SYMBOL_GPL(rpc_clone_client);
 414
 415 /*
 416  * Properly shut down an RPC client, terminating all outstanding
 417  * requests.
 418  */
 419 void rpc_shutdown_client(struct rpc_clnt *clnt)
 420 {
 421         dprintk("RPC:       shutting down %s client for %s\n",
 422                         clnt->cl_protname, clnt->cl_server);
 423
 424         while (!list_empty(&clnt->cl_tasks)) {
 425                 rpc_killall_tasks(clnt);
 426                 wait_event_timeout(destroy_wait,
 427                         list_empty(&clnt->cl_tasks), 1*HZ);
 428         }
 429
 430         rpc_release_client(clnt);
 431 }
 432 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 433
 434 /*
 435  * Free an RPC client
 436  */
 437 static void
 438 rpc_free_client(struct kref *kref)
 439 {
 440         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 441
 442         dprintk("RPC:       destroying %s client for %s\n",
 443                         clnt->cl_protname, clnt->cl_server);
 444         if (!IS_ERR(clnt->cl_path.dentry)) {
 445                 rpc_remove_client_dir(clnt->cl_path.dentry);
 446                 rpc_put_mount();
 447         }
 448         if (clnt->cl_parent != clnt) {
 449                 rpc_release_client(clnt->cl_parent);
 450                 goto out_free;
 451         }
 452         if (clnt->cl_server != clnt->cl_inline_name)
 453                 kfree(clnt->cl_server);
 454 out_free:
 455         rpc_unregister_client(clnt);
 456         rpc_free_iostats(clnt->cl_metrics);
 457         kfree(clnt->cl_principal);
 458         clnt->cl_metrics = NULL;
 459         xprt_put(clnt->cl_xprt);
 460         rpciod_down();
 461         kfree(clnt);
 462 }
 463
 464 /*
 465  * Free an RPC client
 466  */
 467 static void
 468 rpc_free_auth(struct kref *kref)
 469 {
 470         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 471
 472         if (clnt->cl_auth == NULL) {
 473                 rpc_free_client(kref);
 474                 return;
 475         }
 476
 477         /*
 478          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 479          *       release remaining GSS contexts. This mechanism ensures
 480          *       that it can do so safely.
 481          */
 482         kref_init(kref);
 483         rpcauth_release(clnt->cl_auth);
 484         clnt->cl_auth = NULL;
 485         kref_put(kref, rpc_free_client);
 486 }
 487
 488 /*
 489  * Release reference to the RPC client
 490  */
 491 void
 492 rpc_release_client(struct rpc_clnt *clnt)
 493 {
 494         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 495
 496         if (list_empty(&clnt->cl_tasks))
 497                 wake_up(&destroy_wait);
 498         kref_put(&clnt->cl_kref, rpc_free_auth);
 499 }
 500
 501 /**
 502  * rpc_bind_new_program - bind a new RPC program to an existing client
 503  * @old: old rpc_client
 504  * @program: rpc program to set
 505  * @vers: rpc program version
 506  *
 507  * Clones the rpc client and sets up a new RPC program. This is mainly
 508  * of use for enabling different RPC programs to share the same transport.
 509  * The Sun NFSv2/v3 ACL protocol can do this.
 510  */
 511 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 512                                       struct rpc_program *program,
 513                                       u32 vers)
 514 {
 515         struct rpc_clnt *clnt;
 516         struct rpc_version *version;
 517         int err;
 518
 519         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 520         version = program->version[vers];
 521         clnt = rpc_clone_client(old);
 522         if (IS_ERR(clnt))
 523                 goto out;
 524         clnt->cl_procinfo = version->procs;
 525         clnt->cl_maxproc  = version->nrprocs;
 526         clnt->cl_protname = program->name;
 527         clnt->cl_prog     = program->number;
 528         clnt->cl_vers     = version->number;
 529         clnt->cl_stats    = program->stats;
 530         err = rpc_ping(clnt, RPC_TASK_SOFT);
 531         if (err != 0) {
 532                 rpc_shutdown_client(clnt);
 533                 clnt = ERR_PTR(err);
 534         }
 535 out:
 536         return clnt;
 537 }
 538 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 539
 540 /*
 541  * Default callback for async RPC calls
 542  */
 543 static void
 544 rpc_default_callback(struct rpc_task *task, void *data)
 545 {
 546 }
 547
 548 static const struct rpc_call_ops rpc_default_ops = {
 549         .rpc_call_done = rpc_default_callback,
 550 };
 551
 552 /**
 553  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 554  * @task_setup_data: pointer to task initialisation data
 555  */
 556 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 557 {
 558         struct rpc_task *task, *ret;
 559
 560         task = rpc_new_task(task_setup_data);
 561         if (task == NULL) {
 562                 rpc_release_calldata(task_setup_data->callback_ops,
 563                                 task_setup_data->callback_data);
 564                 ret = ERR_PTR(-ENOMEM);
 565                 goto out;
 566         }
 567
 568         if (task->tk_status != 0) {
 569                 ret = ERR_PTR(task->tk_status);
 570                 rpc_put_task(task);
 571                 goto out;
 572         }
 573         atomic_inc(&task->tk_count);
 574         rpc_execute(task);
 575         ret = task;
 576 out:
 577         return ret;
 578 }
 579 EXPORT_SYMBOL_GPL(rpc_run_task);
 580
 581 /**
 582  * rpc_call_sync - Perform a synchronous RPC call
 583  * @clnt: pointer to RPC client
 584  * @msg: RPC call parameters
 585  * @flags: RPC call flags
 586  */
 587 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 588 {
 589         struct rpc_task *task;
 590         struct rpc_task_setup task_setup_data = {
 591                 .rpc_client = clnt,
 592                 .rpc_message = msg,
 593                 .callback_ops = &rpc_default_ops,
 594                 .flags = flags,
 595         };
 596         int status;
 597
 598         BUG_ON(flags & RPC_TASK_ASYNC);
 599
 600         task = rpc_run_task(&task_setup_data);
 601         if (IS_ERR(task))
 602                 return PTR_ERR(task);
 603         status = task->tk_status;
 604         rpc_put_task(task);
 605         return status;
 606 }
 607 EXPORT_SYMBOL_GPL(rpc_call_sync);
 608
 609 /**
 610  * rpc_call_async - Perform an asynchronous RPC call
 611  * @clnt: pointer to RPC client
 612  * @msg: RPC call parameters
 613  * @flags: RPC call flags
 614  * @tk_ops: RPC call ops
 615  * @data: user call data
 616  */
 617 int
 618 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 619                const struct rpc_call_ops *tk_ops, void *data)
 620 {
 621         struct rpc_task *task;
 622         struct rpc_task_setup task_setup_data = {
 623                 .rpc_client = clnt,
 624                 .rpc_message = msg,
 625                 .callback_ops = tk_ops,
 626                 .callback_data = data,
 627                 .flags = flags|RPC_TASK_ASYNC,
 628         };
 629
 630         task = rpc_run_task(&task_setup_data);
 631         if (IS_ERR(task))
 632                 return PTR_ERR(task);
 633         rpc_put_task(task);
 634         return 0;
 635 }
 636 EXPORT_SYMBOL_GPL(rpc_call_async);
 637
 638 #if defined(CONFIG_NFS_V4_1)
 639 /**
 640  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 641  * rpc_execute against it
 642  * @ops: RPC call ops
 643  */
 644 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 645                                         const struct rpc_call_ops *tk_ops)
 646 {
 647         struct rpc_task *task;
 648         struct xdr_buf *xbufp = &req->rq_snd_buf;
 649         struct rpc_task_setup task_setup_data = {
 650                 .callback_ops = tk_ops,
 651         };
 652
 653         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 654         /*
 655          * Create an rpc_task to send the data
 656          */
 657         task = rpc_new_task(&task_setup_data);
 658         if (!task) {
 659                 xprt_free_bc_request(req);
 660                 goto out;
 661         }
 662         task->tk_rqstp = req;
 663
 664         /*
 665          * Set up the xdr_buf length.
 666          * This also indicates that the buffer is XDR encoded already.
 667          */
 668         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 669                         xbufp->tail[0].iov_len;
 670
 671         task->tk_action = call_bc_transmit;
 672         atomic_inc(&task->tk_count);
 673         BUG_ON(atomic_read(&task->tk_count) != 2);
 674         rpc_execute(task);
 675
 676 out:
 677         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 678         return task;
 679 }
 680 #endif /* CONFIG_NFS_V4_1 */
 681
 682 void
 683 rpc_call_start(struct rpc_task *task)
 684 {
 685         task->tk_action = call_start;
 686 }
 687 EXPORT_SYMBOL_GPL(rpc_call_start);
 688
 689 /**
 690  * rpc_peeraddr - extract remote peer address from clnt's xprt
 691  * @clnt: RPC client structure
 692  * @buf: target buffer
 693  * @bufsize: length of target buffer
 694  *
 695  * Returns the number of bytes that are actually in the stored address.
 696  */
 697 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 698 {
 699         size_t bytes;
 700         struct rpc_xprt *xprt = clnt->cl_xprt;
 701
 702         bytes = sizeof(xprt->addr);
 703         if (bytes > bufsize)
 704                 bytes = bufsize;
 705         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 706         return xprt->addrlen;
 707 }
 708 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 709
 710 /**
 711  * rpc_peeraddr2str - return remote peer address in printable format
 712  * @clnt: RPC client structure
 713  * @format: address format
 714  *
 715  */
 716 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 717                              enum rpc_display_format_t format)
 718 {
 719         struct rpc_xprt *xprt = clnt->cl_xprt;
 720
 721         if (xprt->address_strings[format] != NULL)
 722                 return xprt->address_strings[format];
 723         else
 724                 return "unprintable";
 725 }
 726 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 727
 728 void
 729 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 730 {
 731         struct rpc_xprt *xprt = clnt->cl_xprt;
 732         if (xprt->ops->set_buffer_size)
 733                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 734 }
 735 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 736
 737 /*
 738  * Return size of largest payload RPC client can support, in bytes
 739  *
 740  * For stream transports, this is one RPC record fragment (see RFC
 741  * 1831), as we don't support multi-record requests yet.  For datagram
 742  * transports, this is the size of an IP packet minus the IP, UDP, and
 743  * RPC header sizes.
 744  */
 745 size_t rpc_max_payload(struct rpc_clnt *clnt)
 746 {
 747         return clnt->cl_xprt->max_payload;
 748 }
 749 EXPORT_SYMBOL_GPL(rpc_max_payload);
 750
 751 /**
 752  * rpc_force_rebind - force transport to check that remote port is unchanged
 753  * @clnt: client to rebind
 754  *
 755  */
 756 void rpc_force_rebind(struct rpc_clnt *clnt)
 757 {
 758         if (clnt->cl_autobind)
 759                 xprt_clear_bound(clnt->cl_xprt);
 760 }
 761 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 762
 763 /*
 764  * Restart an (async) RPC call from the call_prepare state.
 765  * Usually called from within the exit handler.
 766  */
 767 void
 768 rpc_restart_call_prepare(struct rpc_task *task)
 769 {
 770         if (RPC_ASSASSINATED(task))
 771                 return;
 772         task->tk_action = rpc_prepare_task;
 773 }
 774 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 775
 776 /*
 777  * Restart an (async) RPC call. Usually called from within the
 778  * exit handler.
 779  */
 780 void
 781 rpc_restart_call(struct rpc_task *task)
 782 {
 783         if (RPC_ASSASSINATED(task))
 784                 return;
 785
 786         task->tk_action = call_start;
 787 }
 788 EXPORT_SYMBOL_GPL(rpc_restart_call);
 789
 790 #ifdef RPC_DEBUG
 791 static const char *rpc_proc_name(const struct rpc_task *task)
 792 {
 793         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 794
 795         if (proc) {
 796                 if (proc->p_name)
 797                         return proc->p_name;
 798                 else
 799                         return "NULL";
 800         } else
 801                 return "no proc";
 802 }
 803 #endif
 804
 805 /*
 806  * 0.  Initial state
 807  *
 808  *     Other FSM states can be visited zero or more times, but
 809  *     this state is visited exactly once for each RPC.
 810  */
 811 static void
 812 call_start(struct rpc_task *task)
 813 {
 814         struct rpc_clnt *clnt = task->tk_client;
 815
 816         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 817                         clnt->cl_protname, clnt->cl_vers,
 818                         rpc_proc_name(task),
 819                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 820
 821         /* Increment call count */
 822         task->tk_msg.rpc_proc->p_count++;
 823         clnt->cl_stats->rpccnt++;
 824         task->tk_action = call_reserve;
 825 }
 826
 827 /*
 828  * 1.   Reserve an RPC call slot
 829  */
 830 static void
 831 call_reserve(struct rpc_task *task)
 832 {
 833         dprint_status(task);
 834
 835         if (!rpcauth_uptodatecred(task)) {
 836                 task->tk_action = call_refresh;
 837                 return;
 838         }
 839
 840         task->tk_status  = 0;
 841         task->tk_action  = call_reserveresult;
 842         xprt_reserve(task);
 843 }
 844
 845 /*
 846  * 1b.  Grok the result of xprt_reserve()
 847  */
 848 static void
 849 call_reserveresult(struct rpc_task *task)
 850 {
 851         int status = task->tk_status;
 852
 853         dprint_status(task);
 854
 855         /*
 856          * After a call to xprt_reserve(), we must have either
 857          * a request slot or else an error status.
 858          */
 859         task->tk_status = 0;
 860         if (status >= 0) {
 861                 if (task->tk_rqstp) {
 862                         task->tk_action = call_allocate;
 863                         return;
 864                 }
 865
 866                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 867                                 __func__, status);
 868                 rpc_exit(task, -EIO);
 869                 return;
 870         }
 871
 872         /*
 873          * Even though there was an error, we may have acquired
 874          * a request slot somehow.  Make sure not to leak it.
 875          */
 876         if (task->tk_rqstp) {
 877                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 878                                 __func__, status);
 879                 xprt_release(task);
 880         }
 881
 882         switch (status) {
 883         case -EAGAIN:   /* woken up; retry */
 884                 task->tk_action = call_reserve;
 885                 return;
 886         case -EIO:      /* probably a shutdown */
 887                 break;
 888         default:
 889                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 890                                 __func__, status);
 891                 break;
 892         }
 893         rpc_exit(task, status);
 894 }
 895
 896 /*
 897  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 898  *      (Note: buffer memory is freed in xprt_release).
 899  */
 900 static void
 901 call_allocate(struct rpc_task *task)
 902 {
 903         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 904         struct rpc_rqst *req = task->tk_rqstp;
 905         struct rpc_xprt *xprt = task->tk_xprt;
 906         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 907
 908         dprint_status(task);
 909
 910         task->tk_status = 0;
 911         task->tk_action = call_bind;
 912
 913         if (req->rq_buffer)
 914                 return;
 915
 916         if (proc->p_proc != 0) {
 917                 BUG_ON(proc->p_arglen == 0);
 918                 if (proc->p_decode != NULL)
 919                         BUG_ON(proc->p_replen == 0);
 920         }
 921
 922         /*
 923          * Calculate the size (in quads) of the RPC call
 924          * and reply headers, and convert both values
 925          * to byte sizes.
 926          */
 927         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 928         req->rq_callsize <<= 2;
 929         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 930         req->rq_rcvsize <<= 2;
 931
 932         req->rq_buffer = xprt->ops->buf_alloc(task,
 933                                         req->rq_callsize + req->rq_rcvsize);
 934         if (req->rq_buffer != NULL)
 935                 return;
 936
 937         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 938
 939         if (RPC_IS_ASYNC(task) || !signalled()) {
 940                 task->tk_action = call_allocate;
 941                 rpc_delay(task, HZ>>4);
 942                 return;
 943         }
 944
 945         rpc_exit(task, -ERESTARTSYS);
 946 }
 947
 948 static inline int
 949 rpc_task_need_encode(struct rpc_task *task)
 950 {
 951         return task->tk_rqstp->rq_snd_buf.len == 0;
 952 }
 953
 954 static inline void
 955 rpc_task_force_reencode(struct rpc_task *task)
 956 {
 957         task->tk_rqstp->rq_snd_buf.len = 0;
 958 }
 959
 960 static inline void
 961 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 962 {
 963         buf->head[0].iov_base = start;
 964         buf->head[0].iov_len = len;
 965         buf->tail[0].iov_len = 0;
 966         buf->page_len = 0;
 967         buf->flags = 0;
 968         buf->len = 0;
 969         buf->buflen = len;
 970 }
 971
 972 /*
 973  * 3.   Encode arguments of an RPC call
 974  */
 975 static void
 976 rpc_xdr_encode(struct rpc_task *task)
 977 {
 978         struct rpc_rqst *req = task->tk_rqstp;
 979         kxdrproc_t      encode;
 980         __be32          *p;
 981
 982         dprint_status(task);
 983
 984         rpc_xdr_buf_init(&req->rq_snd_buf,
 985                          req->rq_buffer,
 986                          req->rq_callsize);
 987         rpc_xdr_buf_init(&req->rq_rcv_buf,
 988                          (char *)req->rq_buffer + req->rq_callsize,
 989                          req->rq_rcvsize);
 990
 991         p = rpc_encode_header(task);
 992         if (p == NULL) {
 993                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 994                 rpc_exit(task, -EIO);
 995                 return;
 996         }
 997
 998         encode = task->tk_msg.rpc_proc->p_encode;
 999         if (encode == NULL)
1000                 return;
1001
1002         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1003                         task->tk_msg.rpc_argp);
1004 }
1005
1006 /*
1007  * 4.   Get the server port number if not yet set
1008  */
1009 static void
1010 call_bind(struct rpc_task *task)
1011 {
1012         struct rpc_xprt *xprt = task->tk_xprt;
1013
1014         dprint_status(task);
1015
1016         task->tk_action = call_connect;
1017         if (!xprt_bound(xprt)) {
1018                 task->tk_action = call_bind_status;
1019                 task->tk_timeout = xprt->bind_timeout;
1020                 xprt->ops->rpcbind(task);
1021         }
1022 }
1023
1024 /*
1025  * 4a.  Sort out bind result
1026  */
1027 static void
1028 call_bind_status(struct rpc_task *task)
1029 {
1030         int status = -EIO;
1031
1032         if (task->tk_status >= 0) {
1033                 dprint_status(task);
1034                 task->tk_status = 0;
1035                 task->tk_action = call_connect;
1036                 return;
1037         }
1038
1039         switch (task->tk_status) {
1040         case -ENOMEM:
1041                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1042                 rpc_delay(task, HZ >> 2);
1043                 goto retry_timeout;
1044         case -EACCES:
1045                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1046                                 "unavailable\n", task->tk_pid);
1047                 /* fail immediately if this is an RPC ping */
1048                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1049                         status = -EOPNOTSUPP;
1050                         break;
1051                 }
1052                 rpc_delay(task, 3*HZ);
1053                 goto retry_timeout;
1054         case -ETIMEDOUT:
1055                 dprintk("RPC: %5u rpcbind request timed out\n",
1056                                 task->tk_pid);
1057                 goto retry_timeout;
1058         case -EPFNOSUPPORT:
1059                 /* server doesn't support any rpcbind version we know of */
1060                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
1061                                 task->tk_pid);
1062                 break;
1063         case -EPROTONOSUPPORT:
1064                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1065                                 task->tk_pid);
1066                 task->tk_status = 0;
1067                 task->tk_action = call_bind;
1068                 return;
1069         default:
1070                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1071                                 task->tk_pid, -task->tk_status);
1072         }
1073
1074         rpc_exit(task, status);
1075         return;
1076
1077 retry_timeout:
1078         task->tk_action = call_timeout;
1079 }
1080
1081 /*
1082  * 4b.  Connect to the RPC server
1083  */
1084 static void
1085 call_connect(struct rpc_task *task)
1086 {
1087         struct rpc_xprt *xprt = task->tk_xprt;
1088
1089         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1090                         task->tk_pid, xprt,
1091                         (xprt_connected(xprt) ? "is" : "is not"));
1092
1093         task->tk_action = call_transmit;
1094         if (!xprt_connected(xprt)) {
1095                 task->tk_action = call_connect_status;
1096                 if (task->tk_status < 0)
1097                         return;
1098                 xprt_connect(task);
1099         }
1100 }
1101
1102 /*
1103  * 4c.  Sort out connect result
1104  */
1105 static void
1106 call_connect_status(struct rpc_task *task)
1107 {
1108         struct rpc_clnt *clnt = task->tk_client;
1109         int status = task->tk_status;
1110
1111         dprint_status(task);
1112
1113         task->tk_status = 0;
1114         if (status >= 0 || status == -EAGAIN) {
1115                 clnt->cl_stats->netreconn++;
1116                 task->tk_action = call_transmit;
1117                 return;
1118         }
1119
1120         switch (status) {
1121                 /* if soft mounted, test if we've timed out */
1122         case -ETIMEDOUT:
1123                 task->tk_action = call_timeout;
1124                 break;
1125         default:
1126                 rpc_exit(task, -EIO);
1127         }
1128 }
1129
1130 /*
1131  * 5.   Transmit the RPC request, and wait for reply
1132  */
1133 static void
1134 call_transmit(struct rpc_task *task)
1135 {
1136         dprint_status(task);
1137
1138         task->tk_action = call_status;
1139         if (task->tk_status < 0)
1140                 return;
1141         task->tk_status = xprt_prepare_transmit(task);
1142         if (task->tk_status != 0)
1143                 return;
1144         task->tk_action = call_transmit_status;
1145         /* Encode here so that rpcsec_gss can use correct sequence number. */
1146         if (rpc_task_need_encode(task)) {
1147                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1148                 rpc_xdr_encode(task);
1149                 /* Did the encode result in an error condition? */
1150                 if (task->tk_status != 0) {
1151                         /* Was the error nonfatal? */
1152                         if (task->tk_status == -EAGAIN)
1153                                 rpc_delay(task, HZ >> 4);
1154                         else
1155                                 rpc_exit(task, task->tk_status);
1156                         return;
1157                 }
1158         }
1159         xprt_transmit(task);
1160         if (task->tk_status < 0)
1161                 return;
1162         /*
1163          * On success, ensure that we call xprt_end_transmit() before sleeping
1164          * in order to allow access to the socket to other RPC requests.
1165          */
1166         call_transmit_status(task);
1167         if (rpc_reply_expected(task))
1168                 return;
1169         task->tk_action = rpc_exit_task;
1170         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1171 }
1172
1173 /*
1174  * 5a.  Handle cleanup after a transmission
1175  */
1176 static void
1177 call_transmit_status(struct rpc_task *task)
1178 {
1179         task->tk_action = call_status;
1180         switch (task->tk_status) {
1181         case -EAGAIN:
1182                 break;
1183         default:
1184                 xprt_end_transmit(task);
1185                 /*
1186                  * Special cases: if we've been waiting on the
1187                  * socket's write_space() callback, or if the
1188                  * socket just returned a connection error,
1189                  * then hold onto the transport lock.
1190                  */
1191         case -ECONNREFUSED:
1192         case -ECONNRESET:
1193         case -ENOTCONN:
1194         case -EHOSTDOWN:
1195         case -EHOSTUNREACH:
1196         case -ENETUNREACH:
1197         case -EPIPE:
1198                 rpc_task_force_reencode(task);
1199         }
1200 }
1201
1202 #if defined(CONFIG_NFS_V4_1)
1203 /*
1204  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1205  * addition, disconnect on connectivity errors.
1206  */
1207 static void
1208 call_bc_transmit(struct rpc_task *task)
1209 {
1210         struct rpc_rqst *req = task->tk_rqstp;
1211
1212         BUG_ON(task->tk_status != 0);
1213         task->tk_status = xprt_prepare_transmit(task);
1214         if (task->tk_status == -EAGAIN) {
1215                 /*
1216                  * Could not reserve the transport. Try again after the
1217                  * transport is released.
1218                  */
1219                 task->tk_status = 0;
1220                 task->tk_action = call_bc_transmit;
1221                 return;
1222         }
1223
1224         task->tk_action = rpc_exit_task;
1225         if (task->tk_status < 0) {
1226                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1227                         "error: %d\n", task->tk_status);
1228                 return;
1229         }
1230
1231         xprt_transmit(task);
1232         xprt_end_transmit(task);
1233         dprint_status(task);
1234         switch (task->tk_status) {
1235         case 0:
1236                 /* Success */
1237                 break;
1238         case -EHOSTDOWN:
1239         case -EHOSTUNREACH:
1240         case -ENETUNREACH:
1241         case -ETIMEDOUT:
1242                 /*
1243                  * Problem reaching the server.  Disconnect and let the
1244                  * forechannel reestablish the connection.  The server will
1245                  * have to retransmit the backchannel request and we'll
1246                  * reprocess it.  Since these ops are idempotent, there's no
1247                  * need to cache our reply at this time.
1248                  */
1249                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1250                         "error: %d\n", task->tk_status);
1251                 xprt_conditional_disconnect(task->tk_xprt,
1252                         req->rq_connect_cookie);
1253                 break;
1254         default:
1255                 /*
1256                  * We were unable to reply and will have to drop the
1257                  * request.  The server should reconnect and retransmit.
1258                  */
1259                 BUG_ON(task->tk_status == -EAGAIN);
1260                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1261                         "error: %d\n", task->tk_status);
1262                 break;
1263         }
1264         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1265 }
1266 #endif /* CONFIG_NFS_V4_1 */
1267
1268 /*
1269  * 6.   Sort out the RPC call status
1270  */
1271 static void
1272 call_status(struct rpc_task *task)
1273 {
1274         struct rpc_clnt *clnt = task->tk_client;
1275         struct rpc_rqst *req = task->tk_rqstp;
1276         int             status;
1277
1278         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1279                 task->tk_status = req->rq_reply_bytes_recvd;
1280
1281         dprint_status(task);
1282
1283         status = task->tk_status;
1284         if (status >= 0) {
1285                 task->tk_action = call_decode;
1286                 return;
1287         }
1288
1289         task->tk_status = 0;
1290         switch(status) {
1291         case -EHOSTDOWN:
1292         case -EHOSTUNREACH:
1293         case -ENETUNREACH:
1294                 /*
1295                  * Delay any retries for 3 seconds, then handle as if it
1296                  * were a timeout.
1297                  */
1298                 rpc_delay(task, 3*HZ);
1299         case -ETIMEDOUT:
1300                 task->tk_action = call_timeout;
1301                 if (task->tk_client->cl_discrtry)
1302                         xprt_conditional_disconnect(task->tk_xprt,
1303                                         req->rq_connect_cookie);
1304                 break;
1305         case -ECONNRESET:
1306         case -ECONNREFUSED:
1307                 rpc_force_rebind(clnt);
1308                 rpc_delay(task, 3*HZ);
1309         case -EPIPE:
1310         case -ENOTCONN:
1311                 task->tk_action = call_bind;
1312                 break;
1313         case -EAGAIN:
1314                 task->tk_action = call_transmit;
1315                 break;
1316         case -EIO:
1317                 /* shutdown or soft timeout */
1318                 rpc_exit(task, status);
1319                 break;
1320         default:
1321                 if (clnt->cl_chatty)
1322                         printk("%s: RPC call returned error %d\n",
1323                                clnt->cl_protname, -status);
1324                 rpc_exit(task, status);
1325         }
1326 }
1327
1328 /*
1329  * 6a.  Handle RPC timeout
1330  *      We do not release the request slot, so we keep using the
1331  *      same XID for all retransmits.
1332  */
1333 static void
1334 call_timeout(struct rpc_task *task)
1335 {
1336         struct rpc_clnt *clnt = task->tk_client;
1337
1338         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1339                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1340                 goto retry;
1341         }
1342
1343         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1344         task->tk_timeouts++;
1345
1346         if (RPC_IS_SOFT(task)) {
1347                 if (clnt->cl_chatty)
1348                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1349                                 clnt->cl_protname, clnt->cl_server);
1350                 rpc_exit(task, -EIO);
1351                 return;
1352         }
1353
1354         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1355                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1356                 if (clnt->cl_chatty)
1357                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1358                         clnt->cl_protname, clnt->cl_server);
1359         }
1360         rpc_force_rebind(clnt);
1361         /*
1362          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1363          * event? RFC2203 requires the server to drop all such requests.
1364          */
1365         rpcauth_invalcred(task);
1366
1367 retry:
1368         clnt->cl_stats->rpcretrans++;
1369         task->tk_action = call_bind;
1370         task->tk_status = 0;
1371 }
1372
1373 /*
1374  * 7.   Decode the RPC reply
1375  */
1376 static void
1377 call_decode(struct rpc_task *task)
1378 {
1379         struct rpc_clnt *clnt = task->tk_client;
1380         struct rpc_rqst *req = task->tk_rqstp;
1381         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1382         __be32          *p;
1383
1384         dprintk("RPC: %5u call_decode (status %d)\n",
1385                         task->tk_pid, task->tk_status);
1386
1387         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1388                 if (clnt->cl_chatty)
1389                         printk(KERN_NOTICE "%s: server %s OK\n",
1390                                 clnt->cl_protname, clnt->cl_server);
1391                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1392         }
1393
1394         /*
1395          * Ensure that we see all writes made by xprt_complete_rqst()
1396          * before it changed req->rq_reply_bytes_recvd.
1397          */
1398         smp_rmb();
1399         req->rq_rcv_buf.len = req->rq_private_buf.len;
1400
1401         /* Check that the softirq receive buffer is valid */
1402         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1403                                 sizeof(req->rq_rcv_buf)) != 0);
1404
1405         if (req->rq_rcv_buf.len < 12) {
1406                 if (!RPC_IS_SOFT(task)) {
1407                         task->tk_action = call_bind;
1408                         clnt->cl_stats->rpcretrans++;
1409                         goto out_retry;
1410                 }
1411                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1412                                 clnt->cl_protname, task->tk_status);
1413                 task->tk_action = call_timeout;
1414                 goto out_retry;
1415         }
1416
1417         p = rpc_verify_header(task);
1418         if (IS_ERR(p)) {
1419                 if (p == ERR_PTR(-EAGAIN))
1420                         goto out_retry;
1421                 return;
1422         }
1423
1424         task->tk_action = rpc_exit_task;
1425
1426         if (decode) {
1427                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1428                                                       task->tk_msg.rpc_resp);
1429         }
1430         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1431                         task->tk_status);
1432         return;
1433 out_retry:
1434         task->tk_status = 0;
1435         /* Note: rpc_verify_header() may have freed the RPC slot */
1436         if (task->tk_rqstp == req) {
1437                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1438                 if (task->tk_client->cl_discrtry)
1439                         xprt_conditional_disconnect(task->tk_xprt,
1440                                         req->rq_connect_cookie);
1441         }
1442 }
1443
1444 /*
1445  * 8.   Refresh the credentials if rejected by the server
1446  */
1447 static void
1448 call_refresh(struct rpc_task *task)
1449 {
1450         dprint_status(task);
1451
1452         task->tk_action = call_refreshresult;
1453         task->tk_status = 0;
1454         task->tk_client->cl_stats->rpcauthrefresh++;
1455         rpcauth_refreshcred(task);
1456 }
1457
1458 /*
1459  * 8a.  Process the results of a credential refresh
1460  */
1461 static void
1462 call_refreshresult(struct rpc_task *task)
1463 {
1464         int status = task->tk_status;
1465
1466         dprint_status(task);
1467
1468         task->tk_status = 0;
1469         task->tk_action = call_reserve;
1470         if (status >= 0 && rpcauth_uptodatecred(task))
1471                 return;
1472         if (status == -EACCES) {
1473                 rpc_exit(task, -EACCES);
1474                 return;
1475         }
1476         task->tk_action = call_refresh;
1477         if (status != -ETIMEDOUT)
1478                 rpc_delay(task, 3*HZ);
1479         return;
1480 }
1481
1482 static __be32 *
1483 rpc_encode_header(struct rpc_task *task)
1484 {
1485         struct rpc_clnt *clnt = task->tk_client;
1486         struct rpc_rqst *req = task->tk_rqstp;
1487         __be32          *p = req->rq_svec[0].iov_base;
1488
1489         /* FIXME: check buffer size? */
1490
1491         p = xprt_skip_transport_header(task->tk_xprt, p);
1492         *p++ = req->rq_xid;             /* XID */
1493         *p++ = htonl(RPC_CALL);         /* CALL */
1494         *p++ = htonl(RPC_VERSION);      /* RPC version */
1495         *p++ = htonl(clnt->cl_prog);    /* program number */
1496         *p++ = htonl(clnt->cl_vers);    /* program version */
1497         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1498         p = rpcauth_marshcred(task, p);
1499         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1500         return p;
1501 }
1502
1503 static __be32 *
1504 rpc_verify_header(struct rpc_task *task)
1505 {
1506         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1507         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1508         __be32  *p = iov->iov_base;
1509         u32 n;
1510         int error = -EACCES;
1511
1512         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1513                 /* RFC-1014 says that the representation of XDR data must be a
1514                  * multiple of four bytes
1515                  * - if it isn't pointer subtraction in the NFS client may give
1516                  *   undefined results
1517                  */
1518                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1519                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1520                        task->tk_rqstp->rq_rcv_buf.len);
1521                 goto out_eio;
1522         }
1523         if ((len -= 3) < 0)
1524                 goto out_overflow;
1525
1526         p += 1; /* skip XID */
1527         if ((n = ntohl(*p++)) != RPC_REPLY) {
1528                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1529                         task->tk_pid, __func__, n);
1530                 goto out_garbage;
1531         }
1532
1533         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1534                 if (--len < 0)
1535                         goto out_overflow;
1536                 switch ((n = ntohl(*p++))) {
1537                         case RPC_AUTH_ERROR:
1538                                 break;
1539                         case RPC_MISMATCH:
1540                                 dprintk("RPC: %5u %s: RPC call version "
1541                                                 "mismatch!\n",
1542                                                 task->tk_pid, __func__);
1543                                 error = -EPROTONOSUPPORT;
1544                                 goto out_err;
1545                         default:
1546                                 dprintk("RPC: %5u %s: RPC call rejected, "
1547                                                 "unknown error: %x\n",
1548                                                 task->tk_pid, __func__, n);
1549                                 goto out_eio;
1550                 }
1551                 if (--len < 0)
1552                         goto out_overflow;
1553                 switch ((n = ntohl(*p++))) {
1554                 case RPC_AUTH_REJECTEDCRED:
1555                 case RPC_AUTH_REJECTEDVERF:
1556                 case RPCSEC_GSS_CREDPROBLEM:
1557                 case RPCSEC_GSS_CTXPROBLEM:
1558                         if (!task->tk_cred_retry)
1559                                 break;
1560                         task->tk_cred_retry--;
1561                         dprintk("RPC: %5u %s: retry stale creds\n",
1562                                         task->tk_pid, __func__);
1563                         rpcauth_invalcred(task);
1564                         /* Ensure we obtain a new XID! */
1565                         xprt_release(task);
1566                         task->tk_action = call_refresh;
1567                         goto out_retry;
1568                 case RPC_AUTH_BADCRED:
1569                 case RPC_AUTH_BADVERF:
1570                         /* possibly garbled cred/verf? */
1571                         if (!task->tk_garb_retry)
1572                                 break;
1573                         task->tk_garb_retry--;
1574                         dprintk("RPC: %5u %s: retry garbled creds\n",
1575                                         task->tk_pid, __func__);
1576                         task->tk_action = call_bind;
1577                         goto out_retry;
1578                 case RPC_AUTH_TOOWEAK:
1579                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1580                                "authentication.\n", task->tk_client->cl_server);
1581                         break;
1582                 default:
1583                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1584                                         task->tk_pid, __func__, n);
1585                         error = -EIO;
1586                 }
1587                 dprintk("RPC: %5u %s: call rejected %d\n",
1588                                 task->tk_pid, __func__, n);
1589                 goto out_err;
1590         }
1591         if (!(p = rpcauth_checkverf(task, p))) {
1592                 dprintk("RPC: %5u %s: auth check failed\n",
1593                                 task->tk_pid, __func__);
1594                 goto out_garbage;               /* bad verifier, retry */
1595         }
1596         len = p - (__be32 *)iov->iov_base - 1;
1597         if (len < 0)
1598                 goto out_overflow;
1599         switch ((n = ntohl(*p++))) {
1600         case RPC_SUCCESS:
1601                 return p;
1602         case RPC_PROG_UNAVAIL:
1603                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1604                                 task->tk_pid, __func__,
1605                                 (unsigned int)task->tk_client->cl_prog,
1606                                 task->tk_client->cl_server);
1607                 error = -EPFNOSUPPORT;
1608                 goto out_err;
1609         case RPC_PROG_MISMATCH:
1610                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1611                                 "server %s\n", task->tk_pid, __func__,
1612                                 (unsigned int)task->tk_client->cl_prog,
1613                                 (unsigned int)task->tk_client->cl_vers,
1614                                 task->tk_client->cl_server);
1615                 error = -EPROTONOSUPPORT;
1616                 goto out_err;
1617         case RPC_PROC_UNAVAIL:
1618                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1619                                 "version %u on server %s\n",
1620                                 task->tk_pid, __func__,
1621                                 rpc_proc_name(task),
1622                                 task->tk_client->cl_prog,
1623                                 task->tk_client->cl_vers,
1624                                 task->tk_client->cl_server);
1625                 error = -EOPNOTSUPP;
1626                 goto out_err;
1627         case RPC_GARBAGE_ARGS:
1628                 dprintk("RPC: %5u %s: server saw garbage\n",
1629                                 task->tk_pid, __func__);
1630                 break;                  /* retry */
1631         default:
1632                 dprintk("RPC: %5u %s: server accept status: %x\n",
1633                                 task->tk_pid, __func__, n);
1634                 /* Also retry */
1635         }
1636
1637 out_garbage:
1638         task->tk_client->cl_stats->rpcgarbage++;
1639         if (task->tk_garb_retry) {
1640                 task->tk_garb_retry--;
1641                 dprintk("RPC: %5u %s: retrying\n",
1642                                 task->tk_pid, __func__);
1643                 task->tk_action = call_bind;
1644 out_retry:
1645                 return ERR_PTR(-EAGAIN);
1646         }
1647 out_eio:
1648         error = -EIO;
1649 out_err:
1650         rpc_exit(task, error);
1651         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1652                         __func__, error);
1653         return ERR_PTR(error);
1654 out_overflow:
1655         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1656                         __func__);
1657         goto out_garbage;
1658 }
1659
1660 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1661 {
1662         return 0;
1663 }
1664
1665 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1666 {
1667         return 0;
1668 }
1669
1670 static struct rpc_procinfo rpcproc_null = {
1671         .p_encode = rpcproc_encode_null,
1672         .p_decode = rpcproc_decode_null,
1673 };
1674
1675 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1676 {
1677         struct rpc_message msg = {
1678                 .rpc_proc = &rpcproc_null,
1679         };
1680         int err;
1681         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1682         err = rpc_call_sync(clnt, &msg, flags);
1683         put_rpccred(msg.rpc_cred);
1684         return err;
1685 }
1686
1687 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1688 {
1689         struct rpc_message msg = {
1690                 .rpc_proc = &rpcproc_null,
1691                 .rpc_cred = cred,
1692         };
1693         struct rpc_task_setup task_setup_data = {
1694                 .rpc_client = clnt,
1695                 .rpc_message = &msg,
1696                 .callback_ops = &rpc_default_ops,
1697                 .flags = flags,
1698         };
1699         return rpc_run_task(&task_setup_data);
1700 }
1701 EXPORT_SYMBOL_GPL(rpc_call_null);
1702
1703 #ifdef RPC_DEBUG
1704 static void rpc_show_header(void)
1705 {
1706         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1707                 "-timeout ---ops--\n");
1708 }
1709
1710 static void rpc_show_task(const struct rpc_clnt *clnt,
1711                           const struct rpc_task *task)
1712 {
1713         const char *rpc_waitq = "none";
1714         char *p, action[KSYM_SYMBOL_LEN];
1715
1716         if (RPC_IS_QUEUED(task))
1717                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1718
1719         /* map tk_action pointer to a function name; then trim off
1720          * the "+0x0 [sunrpc]" */
1721         sprint_symbol(action, (unsigned long)task->tk_action);
1722         p = strchr(action, '+');
1723         if (p)
1724                 *p = '\0';
1725
1726         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1727                 task->tk_pid, task->tk_flags, task->tk_status,
1728                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1729                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1730                 action, rpc_waitq);
1731 }
1732
1733 void rpc_show_tasks(void)
1734 {
1735         struct rpc_clnt *clnt;
1736         struct rpc_task *task;
1737         int header = 0;
1738
1739         spin_lock(&rpc_client_lock);
1740         list_for_each_entry(clnt, &all_clients, cl_clients) {
1741                 spin_lock(&clnt->cl_lock);
1742                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1743                         if (!header) {
1744                                 rpc_show_header();
1745                                 header++;
1746                         }
1747                         rpc_show_task(clnt, task);
1748                 }
1749                 spin_unlock(&clnt->cl_lock);
1750         }
1751         spin_unlock(&rpc_client_lock);
1752 }
1753 #endif