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);
  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                 .bc_xprt = args->bc_xprt,
 292         };
 293         char servername[48];
 294
 295         /*
 296          * If the caller chooses not to specify a hostname, whip
 297          * up a string representation of the passed-in address.
 298          */
 299         if (args->servername == NULL) {
 300                 servername[0] = '\0';
 301                 switch (args->address->sa_family) {
 302                 case AF_INET: {
 303                         struct sockaddr_in *sin =
 304                                         (struct sockaddr_in *)args->address;
 305                         snprintf(servername, sizeof(servername), "%pI4",
 306                                  &sin->sin_addr.s_addr);
 307                         break;
 308                 }
 309                 case AF_INET6: {
 310                         struct sockaddr_in6 *sin =
 311                                         (struct sockaddr_in6 *)args->address;
 312                         snprintf(servername, sizeof(servername), "%pI6",
 313                                  &sin->sin6_addr);
 314                         break;
 315                 }
 316                 default:
 317                         /* caller wants default server name, but
 318                          * address family isn't recognized. */
 319                         return ERR_PTR(-EINVAL);
 320                 }
 321                 args->servername = servername;
 322         }
 323
 324         xprt = xprt_create_transport(&xprtargs);
 325         if (IS_ERR(xprt))
 326                 return (struct rpc_clnt *)xprt;
 327
 328         /*
 329          * By default, kernel RPC client connects from a reserved port.
 330          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 331          * but it is always enabled for rpciod, which handles the connect
 332          * operation.
 333          */
 334         xprt->resvport = 1;
 335         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 336                 xprt->resvport = 0;
 337
 338         clnt = rpc_new_client(args, xprt);
 339         if (IS_ERR(clnt))
 340                 return clnt;
 341
 342         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 343                 int err = rpc_ping(clnt);
 344                 if (err != 0) {
 345                         rpc_shutdown_client(clnt);
 346                         return ERR_PTR(err);
 347                 }
 348         }
 349
 350         clnt->cl_softrtry = 1;
 351         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 352                 clnt->cl_softrtry = 0;
 353
 354         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 355                 clnt->cl_autobind = 1;
 356         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 357                 clnt->cl_discrtry = 1;
 358         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 359                 clnt->cl_chatty = 1;
 360
 361         return clnt;
 362 }
 363 EXPORT_SYMBOL_GPL(rpc_create);
 364
 365 /*
 366  * This function clones the RPC client structure. It allows us to share the
 367  * same transport while varying parameters such as the authentication
 368  * flavour.
 369  */
 370 struct rpc_clnt *
 371 rpc_clone_client(struct rpc_clnt *clnt)
 372 {
 373         struct rpc_clnt *new;
 374         int err = -ENOMEM;
 375
 376         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
 377         if (!new)
 378                 goto out_no_clnt;
 379         new->cl_parent = clnt;
 380         /* Turn off autobind on clones */
 381         new->cl_autobind = 0;
 382         INIT_LIST_HEAD(&new->cl_tasks);
 383         spin_lock_init(&new->cl_lock);
 384         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
 385         new->cl_metrics = rpc_alloc_iostats(clnt);
 386         if (new->cl_metrics == NULL)
 387                 goto out_no_stats;
 388         if (clnt->cl_principal) {
 389                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
 390                 if (new->cl_principal == NULL)
 391                         goto out_no_principal;
 392         }
 393         kref_init(&new->cl_kref);
 394         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
 395         if (err != 0)
 396                 goto out_no_path;
 397         if (new->cl_auth)
 398                 atomic_inc(&new->cl_auth->au_count);
 399         xprt_get(clnt->cl_xprt);
 400         kref_get(&clnt->cl_kref);
 401         rpc_register_client(new);
 402         rpciod_up();
 403         return new;
 404 out_no_path:
 405         kfree(new->cl_principal);
 406 out_no_principal:
 407         rpc_free_iostats(new->cl_metrics);
 408 out_no_stats:
 409         kfree(new);
 410 out_no_clnt:
 411         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 412         return ERR_PTR(err);
 413 }
 414 EXPORT_SYMBOL_GPL(rpc_clone_client);
 415
 416 /*
 417  * Properly shut down an RPC client, terminating all outstanding
 418  * requests.
 419  */
 420 void rpc_shutdown_client(struct rpc_clnt *clnt)
 421 {
 422         dprintk("RPC:       shutting down %s client for %s\n",
 423                         clnt->cl_protname, clnt->cl_server);
 424
 425         while (!list_empty(&clnt->cl_tasks)) {
 426                 rpc_killall_tasks(clnt);
 427                 wait_event_timeout(destroy_wait,
 428                         list_empty(&clnt->cl_tasks), 1*HZ);
 429         }
 430
 431         rpc_release_client(clnt);
 432 }
 433 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 434
 435 /*
 436  * Free an RPC client
 437  */
 438 static void
 439 rpc_free_client(struct kref *kref)
 440 {
 441         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 442
 443         dprintk("RPC:       destroying %s client for %s\n",
 444                         clnt->cl_protname, clnt->cl_server);
 445         if (!IS_ERR(clnt->cl_path.dentry)) {
 446                 rpc_remove_client_dir(clnt->cl_path.dentry);
 447                 rpc_put_mount();
 448         }
 449         if (clnt->cl_parent != clnt) {
 450                 rpc_release_client(clnt->cl_parent);
 451                 goto out_free;
 452         }
 453         if (clnt->cl_server != clnt->cl_inline_name)
 454                 kfree(clnt->cl_server);
 455 out_free:
 456         rpc_unregister_client(clnt);
 457         rpc_free_iostats(clnt->cl_metrics);
 458         kfree(clnt->cl_principal);
 459         clnt->cl_metrics = NULL;
 460         xprt_put(clnt->cl_xprt);
 461         rpciod_down();
 462         kfree(clnt);
 463 }
 464
 465 /*
 466  * Free an RPC client
 467  */
 468 static void
 469 rpc_free_auth(struct kref *kref)
 470 {
 471         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 472
 473         if (clnt->cl_auth == NULL) {
 474                 rpc_free_client(kref);
 475                 return;
 476         }
 477
 478         /*
 479          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 480          *       release remaining GSS contexts. This mechanism ensures
 481          *       that it can do so safely.
 482          */
 483         kref_init(kref);
 484         rpcauth_release(clnt->cl_auth);
 485         clnt->cl_auth = NULL;
 486         kref_put(kref, rpc_free_client);
 487 }
 488
 489 /*
 490  * Release reference to the RPC client
 491  */
 492 void
 493 rpc_release_client(struct rpc_clnt *clnt)
 494 {
 495         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 496
 497         if (list_empty(&clnt->cl_tasks))
 498                 wake_up(&destroy_wait);
 499         kref_put(&clnt->cl_kref, rpc_free_auth);
 500 }
 501
 502 /**
 503  * rpc_bind_new_program - bind a new RPC program to an existing client
 504  * @old: old rpc_client
 505  * @program: rpc program to set
 506  * @vers: rpc program version
 507  *
 508  * Clones the rpc client and sets up a new RPC program. This is mainly
 509  * of use for enabling different RPC programs to share the same transport.
 510  * The Sun NFSv2/v3 ACL protocol can do this.
 511  */
 512 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 513                                       struct rpc_program *program,
 514                                       u32 vers)
 515 {
 516         struct rpc_clnt *clnt;
 517         struct rpc_version *version;
 518         int err;
 519
 520         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 521         version = program->version[vers];
 522         clnt = rpc_clone_client(old);
 523         if (IS_ERR(clnt))
 524                 goto out;
 525         clnt->cl_procinfo = version->procs;
 526         clnt->cl_maxproc  = version->nrprocs;
 527         clnt->cl_protname = program->name;
 528         clnt->cl_prog     = program->number;
 529         clnt->cl_vers     = version->number;
 530         clnt->cl_stats    = program->stats;
 531         err = rpc_ping(clnt);
 532         if (err != 0) {
 533                 rpc_shutdown_client(clnt);
 534                 clnt = ERR_PTR(err);
 535         }
 536 out:
 537         return clnt;
 538 }
 539 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 540
 541 /*
 542  * Default callback for async RPC calls
 543  */
 544 static void
 545 rpc_default_callback(struct rpc_task *task, void *data)
 546 {
 547 }
 548
 549 static const struct rpc_call_ops rpc_default_ops = {
 550         .rpc_call_done = rpc_default_callback,
 551 };
 552
 553 /**
 554  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 555  * @task_setup_data: pointer to task initialisation data
 556  */
 557 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 558 {
 559         struct rpc_task *task, *ret;
 560
 561         task = rpc_new_task(task_setup_data);
 562         if (task == NULL) {
 563                 rpc_release_calldata(task_setup_data->callback_ops,
 564                                 task_setup_data->callback_data);
 565                 ret = ERR_PTR(-ENOMEM);
 566                 goto out;
 567         }
 568
 569         if (task->tk_status != 0) {
 570                 ret = ERR_PTR(task->tk_status);
 571                 rpc_put_task(task);
 572                 goto out;
 573         }
 574         atomic_inc(&task->tk_count);
 575         rpc_execute(task);
 576         ret = task;
 577 out:
 578         return ret;
 579 }
 580 EXPORT_SYMBOL_GPL(rpc_run_task);
 581
 582 /**
 583  * rpc_call_sync - Perform a synchronous RPC call
 584  * @clnt: pointer to RPC client
 585  * @msg: RPC call parameters
 586  * @flags: RPC call flags
 587  */
 588 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 589 {
 590         struct rpc_task *task;
 591         struct rpc_task_setup task_setup_data = {
 592                 .rpc_client = clnt,
 593                 .rpc_message = msg,
 594                 .callback_ops = &rpc_default_ops,
 595                 .flags = flags,
 596         };
 597         int status;
 598
 599         BUG_ON(flags & RPC_TASK_ASYNC);
 600
 601         task = rpc_run_task(&task_setup_data);
 602         if (IS_ERR(task))
 603                 return PTR_ERR(task);
 604         status = task->tk_status;
 605         rpc_put_task(task);
 606         return status;
 607 }
 608 EXPORT_SYMBOL_GPL(rpc_call_sync);
 609
 610 /**
 611  * rpc_call_async - Perform an asynchronous RPC call
 612  * @clnt: pointer to RPC client
 613  * @msg: RPC call parameters
 614  * @flags: RPC call flags
 615  * @tk_ops: RPC call ops
 616  * @data: user call data
 617  */
 618 int
 619 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 620                const struct rpc_call_ops *tk_ops, void *data)
 621 {
 622         struct rpc_task *task;
 623         struct rpc_task_setup task_setup_data = {
 624                 .rpc_client = clnt,
 625                 .rpc_message = msg,
 626                 .callback_ops = tk_ops,
 627                 .callback_data = data,
 628                 .flags = flags|RPC_TASK_ASYNC,
 629         };
 630
 631         task = rpc_run_task(&task_setup_data);
 632         if (IS_ERR(task))
 633                 return PTR_ERR(task);
 634         rpc_put_task(task);
 635         return 0;
 636 }
 637 EXPORT_SYMBOL_GPL(rpc_call_async);
 638
 639 #if defined(CONFIG_NFS_V4_1)
 640 /**
 641  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 642  * rpc_execute against it
 643  * @req: RPC request
 644  * @tk_ops: RPC call ops
 645  */
 646 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 647                                 const struct rpc_call_ops *tk_ops)
 648 {
 649         struct rpc_task *task;
 650         struct xdr_buf *xbufp = &req->rq_snd_buf;
 651         struct rpc_task_setup task_setup_data = {
 652                 .callback_ops = tk_ops,
 653         };
 654
 655         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 656         /*
 657          * Create an rpc_task to send the data
 658          */
 659         task = rpc_new_task(&task_setup_data);
 660         if (!task) {
 661                 xprt_free_bc_request(req);
 662                 task = ERR_PTR(-ENOMEM);
 663                 goto out;
 664         }
 665         task->tk_rqstp = req;
 666
 667         /*
 668          * Set up the xdr_buf length.
 669          * This also indicates that the buffer is XDR encoded already.
 670          */
 671         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 672                         xbufp->tail[0].iov_len;
 673
 674         task->tk_action = call_bc_transmit;
 675         atomic_inc(&task->tk_count);
 676         BUG_ON(atomic_read(&task->tk_count) != 2);
 677         rpc_execute(task);
 678
 679 out:
 680         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 681         return task;
 682 }
 683 #endif /* CONFIG_NFS_V4_1 */
 684
 685 void
 686 rpc_call_start(struct rpc_task *task)
 687 {
 688         task->tk_action = call_start;
 689 }
 690 EXPORT_SYMBOL_GPL(rpc_call_start);
 691
 692 /**
 693  * rpc_peeraddr - extract remote peer address from clnt's xprt
 694  * @clnt: RPC client structure
 695  * @buf: target buffer
 696  * @bufsize: length of target buffer
 697  *
 698  * Returns the number of bytes that are actually in the stored address.
 699  */
 700 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 701 {
 702         size_t bytes;
 703         struct rpc_xprt *xprt = clnt->cl_xprt;
 704
 705         bytes = sizeof(xprt->addr);
 706         if (bytes > bufsize)
 707                 bytes = bufsize;
 708         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 709         return xprt->addrlen;
 710 }
 711 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 712
 713 /**
 714  * rpc_peeraddr2str - return remote peer address in printable format
 715  * @clnt: RPC client structure
 716  * @format: address format
 717  *
 718  */
 719 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 720                              enum rpc_display_format_t format)
 721 {
 722         struct rpc_xprt *xprt = clnt->cl_xprt;
 723
 724         if (xprt->address_strings[format] != NULL)
 725                 return xprt->address_strings[format];
 726         else
 727                 return "unprintable";
 728 }
 729 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 730
 731 void
 732 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 733 {
 734         struct rpc_xprt *xprt = clnt->cl_xprt;
 735         if (xprt->ops->set_buffer_size)
 736                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 737 }
 738 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 739
 740 /*
 741  * Return size of largest payload RPC client can support, in bytes
 742  *
 743  * For stream transports, this is one RPC record fragment (see RFC
 744  * 1831), as we don't support multi-record requests yet.  For datagram
 745  * transports, this is the size of an IP packet minus the IP, UDP, and
 746  * RPC header sizes.
 747  */
 748 size_t rpc_max_payload(struct rpc_clnt *clnt)
 749 {
 750         return clnt->cl_xprt->max_payload;
 751 }
 752 EXPORT_SYMBOL_GPL(rpc_max_payload);
 753
 754 /**
 755  * rpc_force_rebind - force transport to check that remote port is unchanged
 756  * @clnt: client to rebind
 757  *
 758  */
 759 void rpc_force_rebind(struct rpc_clnt *clnt)
 760 {
 761         if (clnt->cl_autobind)
 762                 xprt_clear_bound(clnt->cl_xprt);
 763 }
 764 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 765
 766 /*
 767  * Restart an (async) RPC call from the call_prepare state.
 768  * Usually called from within the exit handler.
 769  */
 770 void
 771 rpc_restart_call_prepare(struct rpc_task *task)
 772 {
 773         if (RPC_ASSASSINATED(task))
 774                 return;
 775         task->tk_action = rpc_prepare_task;
 776 }
 777 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 778
 779 /*
 780  * Restart an (async) RPC call. Usually called from within the
 781  * exit handler.
 782  */
 783 void
 784 rpc_restart_call(struct rpc_task *task)
 785 {
 786         if (RPC_ASSASSINATED(task))
 787                 return;
 788
 789         task->tk_action = call_start;
 790 }
 791 EXPORT_SYMBOL_GPL(rpc_restart_call);
 792
 793 #ifdef RPC_DEBUG
 794 static const char *rpc_proc_name(const struct rpc_task *task)
 795 {
 796         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 797
 798         if (proc) {
 799                 if (proc->p_name)
 800                         return proc->p_name;
 801                 else
 802                         return "NULL";
 803         } else
 804                 return "no proc";
 805 }
 806 #endif
 807
 808 /*
 809  * 0.  Initial state
 810  *
 811  *     Other FSM states can be visited zero or more times, but
 812  *     this state is visited exactly once for each RPC.
 813  */
 814 static void
 815 call_start(struct rpc_task *task)
 816 {
 817         struct rpc_clnt *clnt = task->tk_client;
 818
 819         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 820                         clnt->cl_protname, clnt->cl_vers,
 821                         rpc_proc_name(task),
 822                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 823
 824         /* Increment call count */
 825         task->tk_msg.rpc_proc->p_count++;
 826         clnt->cl_stats->rpccnt++;
 827         task->tk_action = call_reserve;
 828 }
 829
 830 /*
 831  * 1.   Reserve an RPC call slot
 832  */
 833 static void
 834 call_reserve(struct rpc_task *task)
 835 {
 836         dprint_status(task);
 837
 838         if (!rpcauth_uptodatecred(task)) {
 839                 task->tk_action = call_refresh;
 840                 return;
 841         }
 842
 843         task->tk_status  = 0;
 844         task->tk_action  = call_reserveresult;
 845         xprt_reserve(task);
 846 }
 847
 848 /*
 849  * 1b.  Grok the result of xprt_reserve()
 850  */
 851 static void
 852 call_reserveresult(struct rpc_task *task)
 853 {
 854         int status = task->tk_status;
 855
 856         dprint_status(task);
 857
 858         /*
 859          * After a call to xprt_reserve(), we must have either
 860          * a request slot or else an error status.
 861          */
 862         task->tk_status = 0;
 863         if (status >= 0) {
 864                 if (task->tk_rqstp) {
 865                         task->tk_action = call_allocate;
 866                         return;
 867                 }
 868
 869                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 870                                 __func__, status);
 871                 rpc_exit(task, -EIO);
 872                 return;
 873         }
 874
 875         /*
 876          * Even though there was an error, we may have acquired
 877          * a request slot somehow.  Make sure not to leak it.
 878          */
 879         if (task->tk_rqstp) {
 880                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 881                                 __func__, status);
 882                 xprt_release(task);
 883         }
 884
 885         switch (status) {
 886         case -EAGAIN:   /* woken up; retry */
 887                 task->tk_action = call_reserve;
 888                 return;
 889         case -EIO:      /* probably a shutdown */
 890                 break;
 891         default:
 892                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 893                                 __func__, status);
 894                 break;
 895         }
 896         rpc_exit(task, status);
 897 }
 898
 899 /*
 900  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 901  *      (Note: buffer memory is freed in xprt_release).
 902  */
 903 static void
 904 call_allocate(struct rpc_task *task)
 905 {
 906         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 907         struct rpc_rqst *req = task->tk_rqstp;
 908         struct rpc_xprt *xprt = task->tk_xprt;
 909         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 910
 911         dprint_status(task);
 912
 913         task->tk_status = 0;
 914         task->tk_action = call_bind;
 915
 916         if (req->rq_buffer)
 917                 return;
 918
 919         if (proc->p_proc != 0) {
 920                 BUG_ON(proc->p_arglen == 0);
 921                 if (proc->p_decode != NULL)
 922                         BUG_ON(proc->p_replen == 0);
 923         }
 924
 925         /*
 926          * Calculate the size (in quads) of the RPC call
 927          * and reply headers, and convert both values
 928          * to byte sizes.
 929          */
 930         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 931         req->rq_callsize <<= 2;
 932         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 933         req->rq_rcvsize <<= 2;
 934
 935         req->rq_buffer = xprt->ops->buf_alloc(task,
 936                                         req->rq_callsize + req->rq_rcvsize);
 937         if (req->rq_buffer != NULL)
 938                 return;
 939
 940         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 941
 942         if (RPC_IS_ASYNC(task) || !signalled()) {
 943                 task->tk_action = call_allocate;
 944                 rpc_delay(task, HZ>>4);
 945                 return;
 946         }
 947
 948         rpc_exit(task, -ERESTARTSYS);
 949 }
 950
 951 static inline int
 952 rpc_task_need_encode(struct rpc_task *task)
 953 {
 954         return task->tk_rqstp->rq_snd_buf.len == 0;
 955 }
 956
 957 static inline void
 958 rpc_task_force_reencode(struct rpc_task *task)
 959 {
 960         task->tk_rqstp->rq_snd_buf.len = 0;
 961         task->tk_rqstp->rq_bytes_sent = 0;
 962 }
 963
 964 static inline void
 965 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 966 {
 967         buf->head[0].iov_base = start;
 968         buf->head[0].iov_len = len;
 969         buf->tail[0].iov_len = 0;
 970         buf->page_len = 0;
 971         buf->flags = 0;
 972         buf->len = 0;
 973         buf->buflen = len;
 974 }
 975
 976 /*
 977  * 3.   Encode arguments of an RPC call
 978  */
 979 static void
 980 rpc_xdr_encode(struct rpc_task *task)
 981 {
 982         struct rpc_rqst *req = task->tk_rqstp;
 983         kxdrproc_t      encode;
 984         __be32          *p;
 985
 986         dprint_status(task);
 987
 988         rpc_xdr_buf_init(&req->rq_snd_buf,
 989                          req->rq_buffer,
 990                          req->rq_callsize);
 991         rpc_xdr_buf_init(&req->rq_rcv_buf,
 992                          (char *)req->rq_buffer + req->rq_callsize,
 993                          req->rq_rcvsize);
 994
 995         p = rpc_encode_header(task);
 996         if (p == NULL) {
 997                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 998                 rpc_exit(task, -EIO);
 999                 return;
1000         }
1001
1002         encode = task->tk_msg.rpc_proc->p_encode;
1003         if (encode == NULL)
1004                 return;
1005
1006         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1007                         task->tk_msg.rpc_argp);
1008 }
1009
1010 /*
1011  * 4.   Get the server port number if not yet set
1012  */
1013 static void
1014 call_bind(struct rpc_task *task)
1015 {
1016         struct rpc_xprt *xprt = task->tk_xprt;
1017
1018         dprint_status(task);
1019
1020         task->tk_action = call_connect;
1021         if (!xprt_bound(xprt)) {
1022                 task->tk_action = call_bind_status;
1023                 task->tk_timeout = xprt->bind_timeout;
1024                 xprt->ops->rpcbind(task);
1025         }
1026 }
1027
1028 /*
1029  * 4a.  Sort out bind result
1030  */
1031 static void
1032 call_bind_status(struct rpc_task *task)
1033 {
1034         int status = -EIO;
1035
1036         if (task->tk_status >= 0) {
1037                 dprint_status(task);
1038                 task->tk_status = 0;
1039                 task->tk_action = call_connect;
1040                 return;
1041         }
1042
1043         switch (task->tk_status) {
1044         case -ENOMEM:
1045                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1046                 rpc_delay(task, HZ >> 2);
1047                 goto retry_timeout;
1048         case -EACCES:
1049                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1050                                 "unavailable\n", task->tk_pid);
1051                 /* fail immediately if this is an RPC ping */
1052                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1053                         status = -EOPNOTSUPP;
1054                         break;
1055                 }
1056                 rpc_delay(task, 3*HZ);
1057                 goto retry_timeout;
1058         case -ETIMEDOUT:
1059                 dprintk("RPC: %5u rpcbind request timed out\n",
1060                                 task->tk_pid);
1061                 goto retry_timeout;
1062         case -EPFNOSUPPORT:
1063                 /* server doesn't support any rpcbind version we know of */
1064                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1065                                 task->tk_pid);
1066                 break;
1067         case -EPROTONOSUPPORT:
1068                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1069                                 task->tk_pid);
1070                 task->tk_status = 0;
1071                 task->tk_action = call_bind;
1072                 return;
1073         case -ECONNREFUSED:             /* connection problems */
1074         case -ECONNRESET:
1075         case -ENOTCONN:
1076         case -EHOSTDOWN:
1077         case -EHOSTUNREACH:
1078         case -ENETUNREACH:
1079         case -EPIPE:
1080                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1081                                 task->tk_pid, task->tk_status);
1082                 if (!RPC_IS_SOFTCONN(task)) {
1083                         rpc_delay(task, 5*HZ);
1084                         goto retry_timeout;
1085                 }
1086                 status = task->tk_status;
1087                 break;
1088         default:
1089                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1090                                 task->tk_pid, -task->tk_status);
1091         }
1092
1093         rpc_exit(task, status);
1094         return;
1095
1096 retry_timeout:
1097         task->tk_action = call_timeout;
1098 }
1099
1100 /*
1101  * 4b.  Connect to the RPC server
1102  */
1103 static void
1104 call_connect(struct rpc_task *task)
1105 {
1106         struct rpc_xprt *xprt = task->tk_xprt;
1107
1108         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1109                         task->tk_pid, xprt,
1110                         (xprt_connected(xprt) ? "is" : "is not"));
1111
1112         task->tk_action = call_transmit;
1113         if (!xprt_connected(xprt)) {
1114                 task->tk_action = call_connect_status;
1115                 if (task->tk_status < 0)
1116                         return;
1117                 xprt_connect(task);
1118         }
1119 }
1120
1121 /*
1122  * 4c.  Sort out connect result
1123  */
1124 static void
1125 call_connect_status(struct rpc_task *task)
1126 {
1127         struct rpc_clnt *clnt = task->tk_client;
1128         int status = task->tk_status;
1129
1130         dprint_status(task);
1131
1132         task->tk_status = 0;
1133         if (status >= 0 || status == -EAGAIN) {
1134                 clnt->cl_stats->netreconn++;
1135                 task->tk_action = call_transmit;
1136                 return;
1137         }
1138
1139         switch (status) {
1140                 /* if soft mounted, test if we've timed out */
1141         case -ETIMEDOUT:
1142                 task->tk_action = call_timeout;
1143                 break;
1144         default:
1145                 rpc_exit(task, -EIO);
1146         }
1147 }
1148
1149 /*
1150  * 5.   Transmit the RPC request, and wait for reply
1151  */
1152 static void
1153 call_transmit(struct rpc_task *task)
1154 {
1155         dprint_status(task);
1156
1157         task->tk_action = call_status;
1158         if (task->tk_status < 0)
1159                 return;
1160         task->tk_status = xprt_prepare_transmit(task);
1161         if (task->tk_status != 0)
1162                 return;
1163         task->tk_action = call_transmit_status;
1164         /* Encode here so that rpcsec_gss can use correct sequence number. */
1165         if (rpc_task_need_encode(task)) {
1166                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1167                 rpc_xdr_encode(task);
1168                 /* Did the encode result in an error condition? */
1169                 if (task->tk_status != 0) {
1170                         /* Was the error nonfatal? */
1171                         if (task->tk_status == -EAGAIN)
1172                                 rpc_delay(task, HZ >> 4);
1173                         else
1174                                 rpc_exit(task, task->tk_status);
1175                         return;
1176                 }
1177         }
1178         xprt_transmit(task);
1179         if (task->tk_status < 0)
1180                 return;
1181         /*
1182          * On success, ensure that we call xprt_end_transmit() before sleeping
1183          * in order to allow access to the socket to other RPC requests.
1184          */
1185         call_transmit_status(task);
1186         if (rpc_reply_expected(task))
1187                 return;
1188         task->tk_action = rpc_exit_task;
1189         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1190 }
1191
1192 /*
1193  * 5a.  Handle cleanup after a transmission
1194  */
1195 static void
1196 call_transmit_status(struct rpc_task *task)
1197 {
1198         task->tk_action = call_status;
1199
1200         /*
1201          * Common case: success.  Force the compiler to put this
1202          * test first.
1203          */
1204         if (task->tk_status == 0) {
1205                 xprt_end_transmit(task);
1206                 rpc_task_force_reencode(task);
1207                 return;
1208         }
1209
1210         switch (task->tk_status) {
1211         case -EAGAIN:
1212                 break;
1213         default:
1214                 dprint_status(task);
1215                 xprt_end_transmit(task);
1216                 rpc_task_force_reencode(task);
1217                 break;
1218                 /*
1219                  * Special cases: if we've been waiting on the
1220                  * socket's write_space() callback, or if the
1221                  * socket just returned a connection error,
1222                  * then hold onto the transport lock.
1223                  */
1224         case -ECONNREFUSED:
1225         case -EHOSTDOWN:
1226         case -EHOSTUNREACH:
1227         case -ENETUNREACH:
1228                 if (RPC_IS_SOFTCONN(task)) {
1229                         xprt_end_transmit(task);
1230                         rpc_exit(task, task->tk_status);
1231                         break;
1232                 }
1233         case -ECONNRESET:
1234         case -ENOTCONN:
1235         case -EPIPE:
1236                 rpc_task_force_reencode(task);
1237         }
1238 }
1239
1240 #if defined(CONFIG_NFS_V4_1)
1241 /*
1242  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1243  * addition, disconnect on connectivity errors.
1244  */
1245 static void
1246 call_bc_transmit(struct rpc_task *task)
1247 {
1248         struct rpc_rqst *req = task->tk_rqstp;
1249
1250         BUG_ON(task->tk_status != 0);
1251         task->tk_status = xprt_prepare_transmit(task);
1252         if (task->tk_status == -EAGAIN) {
1253                 /*
1254                  * Could not reserve the transport. Try again after the
1255                  * transport is released.
1256                  */
1257                 task->tk_status = 0;
1258                 task->tk_action = call_bc_transmit;
1259                 return;
1260         }
1261
1262         task->tk_action = rpc_exit_task;
1263         if (task->tk_status < 0) {
1264                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1265                         "error: %d\n", task->tk_status);
1266                 return;
1267         }
1268
1269         xprt_transmit(task);
1270         xprt_end_transmit(task);
1271         dprint_status(task);
1272         switch (task->tk_status) {
1273         case 0:
1274                 /* Success */
1275                 break;
1276         case -EHOSTDOWN:
1277         case -EHOSTUNREACH:
1278         case -ENETUNREACH:
1279         case -ETIMEDOUT:
1280                 /*
1281                  * Problem reaching the server.  Disconnect and let the
1282                  * forechannel reestablish the connection.  The server will
1283                  * have to retransmit the backchannel request and we'll
1284                  * reprocess it.  Since these ops are idempotent, there's no
1285                  * need to cache our reply at this time.
1286                  */
1287                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1288                         "error: %d\n", task->tk_status);
1289                 xprt_conditional_disconnect(task->tk_xprt,
1290                         req->rq_connect_cookie);
1291                 break;
1292         default:
1293                 /*
1294                  * We were unable to reply and will have to drop the
1295                  * request.  The server should reconnect and retransmit.
1296                  */
1297                 BUG_ON(task->tk_status == -EAGAIN);
1298                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1299                         "error: %d\n", task->tk_status);
1300                 break;
1301         }
1302         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1303 }
1304 #endif /* CONFIG_NFS_V4_1 */
1305
1306 /*
1307  * 6.   Sort out the RPC call status
1308  */
1309 static void
1310 call_status(struct rpc_task *task)
1311 {
1312         struct rpc_clnt *clnt = task->tk_client;
1313         struct rpc_rqst *req = task->tk_rqstp;
1314         int             status;
1315
1316         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1317                 task->tk_status = req->rq_reply_bytes_recvd;
1318
1319         dprint_status(task);
1320
1321         status = task->tk_status;
1322         if (status >= 0) {
1323                 task->tk_action = call_decode;
1324                 return;
1325         }
1326
1327         task->tk_status = 0;
1328         switch(status) {
1329         case -EHOSTDOWN:
1330         case -EHOSTUNREACH:
1331         case -ENETUNREACH:
1332                 /*
1333                  * Delay any retries for 3 seconds, then handle as if it
1334                  * were a timeout.
1335                  */
1336                 rpc_delay(task, 3*HZ);
1337         case -ETIMEDOUT:
1338                 task->tk_action = call_timeout;
1339                 if (task->tk_client->cl_discrtry)
1340                         xprt_conditional_disconnect(task->tk_xprt,
1341                                         req->rq_connect_cookie);
1342                 break;
1343         case -ECONNRESET:
1344         case -ECONNREFUSED:
1345                 rpc_force_rebind(clnt);
1346                 rpc_delay(task, 3*HZ);
1347         case -EPIPE:
1348         case -ENOTCONN:
1349                 task->tk_action = call_bind;
1350                 break;
1351         case -EAGAIN:
1352                 task->tk_action = call_transmit;
1353                 break;
1354         case -EIO:
1355                 /* shutdown or soft timeout */
1356                 rpc_exit(task, status);
1357                 break;
1358         default:
1359                 if (clnt->cl_chatty)
1360                         printk("%s: RPC call returned error %d\n",
1361                                clnt->cl_protname, -status);
1362                 rpc_exit(task, status);
1363         }
1364 }
1365
1366 /*
1367  * 6a.  Handle RPC timeout
1368  *      We do not release the request slot, so we keep using the
1369  *      same XID for all retransmits.
1370  */
1371 static void
1372 call_timeout(struct rpc_task *task)
1373 {
1374         struct rpc_clnt *clnt = task->tk_client;
1375
1376         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1377                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1378                 goto retry;
1379         }
1380
1381         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1382         task->tk_timeouts++;
1383
1384         if (RPC_IS_SOFTCONN(task)) {
1385                 rpc_exit(task, -ETIMEDOUT);
1386                 return;
1387         }
1388         if (RPC_IS_SOFT(task)) {
1389                 if (clnt->cl_chatty)
1390                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1391                                 clnt->cl_protname, clnt->cl_server);
1392                 rpc_exit(task, -EIO);
1393                 return;
1394         }
1395
1396         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1397                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1398                 if (clnt->cl_chatty)
1399                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1400                         clnt->cl_protname, clnt->cl_server);
1401         }
1402         rpc_force_rebind(clnt);
1403         /*
1404          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1405          * event? RFC2203 requires the server to drop all such requests.
1406          */
1407         rpcauth_invalcred(task);
1408
1409 retry:
1410         clnt->cl_stats->rpcretrans++;
1411         task->tk_action = call_bind;
1412         task->tk_status = 0;
1413 }
1414
1415 /*
1416  * 7.   Decode the RPC reply
1417  */
1418 static void
1419 call_decode(struct rpc_task *task)
1420 {
1421         struct rpc_clnt *clnt = task->tk_client;
1422         struct rpc_rqst *req = task->tk_rqstp;
1423         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1424         __be32          *p;
1425
1426         dprintk("RPC: %5u call_decode (status %d)\n",
1427                         task->tk_pid, task->tk_status);
1428
1429         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1430                 if (clnt->cl_chatty)
1431                         printk(KERN_NOTICE "%s: server %s OK\n",
1432                                 clnt->cl_protname, clnt->cl_server);
1433                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1434         }
1435
1436         /*
1437          * Ensure that we see all writes made by xprt_complete_rqst()
1438          * before it changed req->rq_reply_bytes_recvd.
1439          */
1440         smp_rmb();
1441         req->rq_rcv_buf.len = req->rq_private_buf.len;
1442
1443         /* Check that the softirq receive buffer is valid */
1444         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1445                                 sizeof(req->rq_rcv_buf)) != 0);
1446
1447         if (req->rq_rcv_buf.len < 12) {
1448                 if (!RPC_IS_SOFT(task)) {
1449                         task->tk_action = call_bind;
1450                         clnt->cl_stats->rpcretrans++;
1451                         goto out_retry;
1452                 }
1453                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1454                                 clnt->cl_protname, task->tk_status);
1455                 task->tk_action = call_timeout;
1456                 goto out_retry;
1457         }
1458
1459         p = rpc_verify_header(task);
1460         if (IS_ERR(p)) {
1461                 if (p == ERR_PTR(-EAGAIN))
1462                         goto out_retry;
1463                 return;
1464         }
1465
1466         task->tk_action = rpc_exit_task;
1467
1468         if (decode) {
1469                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1470                                                       task->tk_msg.rpc_resp);
1471         }
1472         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1473                         task->tk_status);
1474         return;
1475 out_retry:
1476         task->tk_status = 0;
1477         /* Note: rpc_verify_header() may have freed the RPC slot */
1478         if (task->tk_rqstp == req) {
1479                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1480                 if (task->tk_client->cl_discrtry)
1481                         xprt_conditional_disconnect(task->tk_xprt,
1482                                         req->rq_connect_cookie);
1483         }
1484 }
1485
1486 /*
1487  * 8.   Refresh the credentials if rejected by the server
1488  */
1489 static void
1490 call_refresh(struct rpc_task *task)
1491 {
1492         dprint_status(task);
1493
1494         task->tk_action = call_refreshresult;
1495         task->tk_status = 0;
1496         task->tk_client->cl_stats->rpcauthrefresh++;
1497         rpcauth_refreshcred(task);
1498 }
1499
1500 /*
1501  * 8a.  Process the results of a credential refresh
1502  */
1503 static void
1504 call_refreshresult(struct rpc_task *task)
1505 {
1506         int status = task->tk_status;
1507
1508         dprint_status(task);
1509
1510         task->tk_status = 0;
1511         task->tk_action = call_reserve;
1512         if (status >= 0 && rpcauth_uptodatecred(task))
1513                 return;
1514         if (status == -EACCES) {
1515                 rpc_exit(task, -EACCES);
1516                 return;
1517         }
1518         task->tk_action = call_refresh;
1519         if (status != -ETIMEDOUT)
1520                 rpc_delay(task, 3*HZ);
1521         return;
1522 }
1523
1524 static __be32 *
1525 rpc_encode_header(struct rpc_task *task)
1526 {
1527         struct rpc_clnt *clnt = task->tk_client;
1528         struct rpc_rqst *req = task->tk_rqstp;
1529         __be32          *p = req->rq_svec[0].iov_base;
1530
1531         /* FIXME: check buffer size? */
1532
1533         p = xprt_skip_transport_header(task->tk_xprt, p);
1534         *p++ = req->rq_xid;             /* XID */
1535         *p++ = htonl(RPC_CALL);         /* CALL */
1536         *p++ = htonl(RPC_VERSION);      /* RPC version */
1537         *p++ = htonl(clnt->cl_prog);    /* program number */
1538         *p++ = htonl(clnt->cl_vers);    /* program version */
1539         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1540         p = rpcauth_marshcred(task, p);
1541         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1542         return p;
1543 }
1544
1545 static __be32 *
1546 rpc_verify_header(struct rpc_task *task)
1547 {
1548         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1549         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1550         __be32  *p = iov->iov_base;
1551         u32 n;
1552         int error = -EACCES;
1553
1554         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1555                 /* RFC-1014 says that the representation of XDR data must be a
1556                  * multiple of four bytes
1557                  * - if it isn't pointer subtraction in the NFS client may give
1558                  *   undefined results
1559                  */
1560                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1561                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1562                        task->tk_rqstp->rq_rcv_buf.len);
1563                 goto out_eio;
1564         }
1565         if ((len -= 3) < 0)
1566                 goto out_overflow;
1567
1568         p += 1; /* skip XID */
1569         if ((n = ntohl(*p++)) != RPC_REPLY) {
1570                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1571                         task->tk_pid, __func__, n);
1572                 goto out_garbage;
1573         }
1574
1575         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1576                 if (--len < 0)
1577                         goto out_overflow;
1578                 switch ((n = ntohl(*p++))) {
1579                         case RPC_AUTH_ERROR:
1580                                 break;
1581                         case RPC_MISMATCH:
1582                                 dprintk("RPC: %5u %s: RPC call version "
1583                                                 "mismatch!\n",
1584                                                 task->tk_pid, __func__);
1585                                 error = -EPROTONOSUPPORT;
1586                                 goto out_err;
1587                         default:
1588                                 dprintk("RPC: %5u %s: RPC call rejected, "
1589                                                 "unknown error: %x\n",
1590                                                 task->tk_pid, __func__, n);
1591                                 goto out_eio;
1592                 }
1593                 if (--len < 0)
1594                         goto out_overflow;
1595                 switch ((n = ntohl(*p++))) {
1596                 case RPC_AUTH_REJECTEDCRED:
1597                 case RPC_AUTH_REJECTEDVERF:
1598                 case RPCSEC_GSS_CREDPROBLEM:
1599                 case RPCSEC_GSS_CTXPROBLEM:
1600                         if (!task->tk_cred_retry)
1601                                 break;
1602                         task->tk_cred_retry--;
1603                         dprintk("RPC: %5u %s: retry stale creds\n",
1604                                         task->tk_pid, __func__);
1605                         rpcauth_invalcred(task);
1606                         /* Ensure we obtain a new XID! */
1607                         xprt_release(task);
1608                         task->tk_action = call_refresh;
1609                         goto out_retry;
1610                 case RPC_AUTH_BADCRED:
1611                 case RPC_AUTH_BADVERF:
1612                         /* possibly garbled cred/verf? */
1613                         if (!task->tk_garb_retry)
1614                                 break;
1615                         task->tk_garb_retry--;
1616                         dprintk("RPC: %5u %s: retry garbled creds\n",
1617                                         task->tk_pid, __func__);
1618                         task->tk_action = call_bind;
1619                         goto out_retry;
1620                 case RPC_AUTH_TOOWEAK:
1621                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1622                                "authentication.\n", task->tk_client->cl_server);
1623                         break;
1624                 default:
1625                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1626                                         task->tk_pid, __func__, n);
1627                         error = -EIO;
1628                 }
1629                 dprintk("RPC: %5u %s: call rejected %d\n",
1630                                 task->tk_pid, __func__, n);
1631                 goto out_err;
1632         }
1633         if (!(p = rpcauth_checkverf(task, p))) {
1634                 dprintk("RPC: %5u %s: auth check failed\n",
1635                                 task->tk_pid, __func__);
1636                 goto out_garbage;               /* bad verifier, retry */
1637         }
1638         len = p - (__be32 *)iov->iov_base - 1;
1639         if (len < 0)
1640                 goto out_overflow;
1641         switch ((n = ntohl(*p++))) {
1642         case RPC_SUCCESS:
1643                 return p;
1644         case RPC_PROG_UNAVAIL:
1645                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1646                                 task->tk_pid, __func__,
1647                                 (unsigned int)task->tk_client->cl_prog,
1648                                 task->tk_client->cl_server);
1649                 error = -EPFNOSUPPORT;
1650                 goto out_err;
1651         case RPC_PROG_MISMATCH:
1652                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1653                                 "server %s\n", task->tk_pid, __func__,
1654                                 (unsigned int)task->tk_client->cl_prog,
1655                                 (unsigned int)task->tk_client->cl_vers,
1656                                 task->tk_client->cl_server);
1657                 error = -EPROTONOSUPPORT;
1658                 goto out_err;
1659         case RPC_PROC_UNAVAIL:
1660                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1661                                 "version %u on server %s\n",
1662                                 task->tk_pid, __func__,
1663                                 rpc_proc_name(task),
1664                                 task->tk_client->cl_prog,
1665                                 task->tk_client->cl_vers,
1666                                 task->tk_client->cl_server);
1667                 error = -EOPNOTSUPP;
1668                 goto out_err;
1669         case RPC_GARBAGE_ARGS:
1670                 dprintk("RPC: %5u %s: server saw garbage\n",
1671                                 task->tk_pid, __func__);
1672                 break;                  /* retry */
1673         default:
1674                 dprintk("RPC: %5u %s: server accept status: %x\n",
1675                                 task->tk_pid, __func__, n);
1676                 /* Also retry */
1677         }
1678
1679 out_garbage:
1680         task->tk_client->cl_stats->rpcgarbage++;
1681         if (task->tk_garb_retry) {
1682                 task->tk_garb_retry--;
1683                 dprintk("RPC: %5u %s: retrying\n",
1684                                 task->tk_pid, __func__);
1685                 task->tk_action = call_bind;
1686 out_retry:
1687                 return ERR_PTR(-EAGAIN);
1688         }
1689 out_eio:
1690         error = -EIO;
1691 out_err:
1692         rpc_exit(task, error);
1693         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1694                         __func__, error);
1695         return ERR_PTR(error);
1696 out_overflow:
1697         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1698                         __func__);
1699         goto out_garbage;
1700 }
1701
1702 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1703 {
1704         return 0;
1705 }
1706
1707 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1708 {
1709         return 0;
1710 }
1711
1712 static struct rpc_procinfo rpcproc_null = {
1713         .p_encode = rpcproc_encode_null,
1714         .p_decode = rpcproc_decode_null,
1715 };
1716
1717 static int rpc_ping(struct rpc_clnt *clnt)
1718 {
1719         struct rpc_message msg = {
1720                 .rpc_proc = &rpcproc_null,
1721         };
1722         int err;
1723         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1724         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1725         put_rpccred(msg.rpc_cred);
1726         return err;
1727 }
1728
1729 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1730 {
1731         struct rpc_message msg = {
1732                 .rpc_proc = &rpcproc_null,
1733                 .rpc_cred = cred,
1734         };
1735         struct rpc_task_setup task_setup_data = {
1736                 .rpc_client = clnt,
1737                 .rpc_message = &msg,
1738                 .callback_ops = &rpc_default_ops,
1739                 .flags = flags,
1740         };
1741         return rpc_run_task(&task_setup_data);
1742 }
1743 EXPORT_SYMBOL_GPL(rpc_call_null);
1744
1745 #ifdef RPC_DEBUG
1746 static void rpc_show_header(void)
1747 {
1748         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1749                 "-timeout ---ops--\n");
1750 }
1751
1752 static void rpc_show_task(const struct rpc_clnt *clnt,
1753                           const struct rpc_task *task)
1754 {
1755         const char *rpc_waitq = "none";
1756         char *p, action[KSYM_SYMBOL_LEN];
1757
1758         if (RPC_IS_QUEUED(task))
1759                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1760
1761         /* map tk_action pointer to a function name; then trim off
1762          * the "+0x0 [sunrpc]" */
1763         sprint_symbol(action, (unsigned long)task->tk_action);
1764         p = strchr(action, '+');
1765         if (p)
1766                 *p = '\0';
1767
1768         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1769                 task->tk_pid, task->tk_flags, task->tk_status,
1770                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1771                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1772                 action, rpc_waitq);
1773 }
1774
1775 void rpc_show_tasks(void)
1776 {
1777         struct rpc_clnt *clnt;
1778         struct rpc_task *task;
1779         int header = 0;
1780
1781         spin_lock(&rpc_client_lock);
1782         list_for_each_entry(clnt, &all_clients, cl_clients) {
1783                 spin_lock(&clnt->cl_lock);
1784                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1785                         if (!header) {
1786                                 rpc_show_header();
1787                                 header++;
1788                         }
1789                         rpc_show_task(clnt, task);
1790                 }
1791                 spin_unlock(&clnt->cl_lock);
1792         }
1793         spin_unlock(&rpc_client_lock);
1794 }
1795 #endif