SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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;
 560
 561         task = rpc_new_task(task_setup_data);
 562         if (IS_ERR(task))
 563                 goto out;
 564
 565         atomic_inc(&task->tk_count);
 566         rpc_execute(task);
 567 out:
 568         return task;
 569 }
 570 EXPORT_SYMBOL_GPL(rpc_run_task);
 571
 572 /**
 573  * rpc_call_sync - Perform a synchronous RPC call
 574  * @clnt: pointer to RPC client
 575  * @msg: RPC call parameters
 576  * @flags: RPC call flags
 577  */
 578 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 579 {
 580         struct rpc_task *task;
 581         struct rpc_task_setup task_setup_data = {
 582                 .rpc_client = clnt,
 583                 .rpc_message = msg,
 584                 .callback_ops = &rpc_default_ops,
 585                 .flags = flags,
 586         };
 587         int status;
 588
 589         BUG_ON(flags & RPC_TASK_ASYNC);
 590
 591         task = rpc_run_task(&task_setup_data);
 592         if (IS_ERR(task))
 593                 return PTR_ERR(task);
 594         status = task->tk_status;
 595         rpc_put_task(task);
 596         return status;
 597 }
 598 EXPORT_SYMBOL_GPL(rpc_call_sync);
 599
 600 /**
 601  * rpc_call_async - Perform an asynchronous RPC call
 602  * @clnt: pointer to RPC client
 603  * @msg: RPC call parameters
 604  * @flags: RPC call flags
 605  * @tk_ops: RPC call ops
 606  * @data: user call data
 607  */
 608 int
 609 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 610                const struct rpc_call_ops *tk_ops, void *data)
 611 {
 612         struct rpc_task *task;
 613         struct rpc_task_setup task_setup_data = {
 614                 .rpc_client = clnt,
 615                 .rpc_message = msg,
 616                 .callback_ops = tk_ops,
 617                 .callback_data = data,
 618                 .flags = flags|RPC_TASK_ASYNC,
 619         };
 620
 621         task = rpc_run_task(&task_setup_data);
 622         if (IS_ERR(task))
 623                 return PTR_ERR(task);
 624         rpc_put_task(task);
 625         return 0;
 626 }
 627 EXPORT_SYMBOL_GPL(rpc_call_async);
 628
 629 #if defined(CONFIG_NFS_V4_1)
 630 /**
 631  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 632  * rpc_execute against it
 633  * @req: RPC request
 634  * @tk_ops: RPC call ops
 635  */
 636 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 637                                 const struct rpc_call_ops *tk_ops)
 638 {
 639         struct rpc_task *task;
 640         struct xdr_buf *xbufp = &req->rq_snd_buf;
 641         struct rpc_task_setup task_setup_data = {
 642                 .callback_ops = tk_ops,
 643         };
 644
 645         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 646         /*
 647          * Create an rpc_task to send the data
 648          */
 649         task = rpc_new_task(&task_setup_data);
 650         if (IS_ERR(task)) {
 651                 xprt_free_bc_request(req);
 652                 goto out;
 653         }
 654         task->tk_rqstp = req;
 655
 656         /*
 657          * Set up the xdr_buf length.
 658          * This also indicates that the buffer is XDR encoded already.
 659          */
 660         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 661                         xbufp->tail[0].iov_len;
 662
 663         task->tk_action = call_bc_transmit;
 664         atomic_inc(&task->tk_count);
 665         BUG_ON(atomic_read(&task->tk_count) != 2);
 666         rpc_execute(task);
 667
 668 out:
 669         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 670         return task;
 671 }
 672 #endif /* CONFIG_NFS_V4_1 */
 673
 674 void
 675 rpc_call_start(struct rpc_task *task)
 676 {
 677         task->tk_action = call_start;
 678 }
 679 EXPORT_SYMBOL_GPL(rpc_call_start);
 680
 681 /**
 682  * rpc_peeraddr - extract remote peer address from clnt's xprt
 683  * @clnt: RPC client structure
 684  * @buf: target buffer
 685  * @bufsize: length of target buffer
 686  *
 687  * Returns the number of bytes that are actually in the stored address.
 688  */
 689 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 690 {
 691         size_t bytes;
 692         struct rpc_xprt *xprt = clnt->cl_xprt;
 693
 694         bytes = sizeof(xprt->addr);
 695         if (bytes > bufsize)
 696                 bytes = bufsize;
 697         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 698         return xprt->addrlen;
 699 }
 700 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 701
 702 /**
 703  * rpc_peeraddr2str - return remote peer address in printable format
 704  * @clnt: RPC client structure
 705  * @format: address format
 706  *
 707  */
 708 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 709                              enum rpc_display_format_t format)
 710 {
 711         struct rpc_xprt *xprt = clnt->cl_xprt;
 712
 713         if (xprt->address_strings[format] != NULL)
 714                 return xprt->address_strings[format];
 715         else
 716                 return "unprintable";
 717 }
 718 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 719
 720 void
 721 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 722 {
 723         struct rpc_xprt *xprt = clnt->cl_xprt;
 724         if (xprt->ops->set_buffer_size)
 725                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 726 }
 727 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 728
 729 /*
 730  * Return size of largest payload RPC client can support, in bytes
 731  *
 732  * For stream transports, this is one RPC record fragment (see RFC
 733  * 1831), as we don't support multi-record requests yet.  For datagram
 734  * transports, this is the size of an IP packet minus the IP, UDP, and
 735  * RPC header sizes.
 736  */
 737 size_t rpc_max_payload(struct rpc_clnt *clnt)
 738 {
 739         return clnt->cl_xprt->max_payload;
 740 }
 741 EXPORT_SYMBOL_GPL(rpc_max_payload);
 742
 743 /**
 744  * rpc_force_rebind - force transport to check that remote port is unchanged
 745  * @clnt: client to rebind
 746  *
 747  */
 748 void rpc_force_rebind(struct rpc_clnt *clnt)
 749 {
 750         if (clnt->cl_autobind)
 751                 xprt_clear_bound(clnt->cl_xprt);
 752 }
 753 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 754
 755 /*
 756  * Restart an (async) RPC call from the call_prepare state.
 757  * Usually called from within the exit handler.
 758  */
 759 void
 760 rpc_restart_call_prepare(struct rpc_task *task)
 761 {
 762         if (RPC_ASSASSINATED(task))
 763                 return;
 764         task->tk_action = rpc_prepare_task;
 765 }
 766 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 767
 768 /*
 769  * Restart an (async) RPC call. Usually called from within the
 770  * exit handler.
 771  */
 772 void
 773 rpc_restart_call(struct rpc_task *task)
 774 {
 775         if (RPC_ASSASSINATED(task))
 776                 return;
 777
 778         task->tk_action = call_start;
 779 }
 780 EXPORT_SYMBOL_GPL(rpc_restart_call);
 781
 782 #ifdef RPC_DEBUG
 783 static const char *rpc_proc_name(const struct rpc_task *task)
 784 {
 785         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 786
 787         if (proc) {
 788                 if (proc->p_name)
 789                         return proc->p_name;
 790                 else
 791                         return "NULL";
 792         } else
 793                 return "no proc";
 794 }
 795 #endif
 796
 797 /*
 798  * 0.  Initial state
 799  *
 800  *     Other FSM states can be visited zero or more times, but
 801  *     this state is visited exactly once for each RPC.
 802  */
 803 static void
 804 call_start(struct rpc_task *task)
 805 {
 806         struct rpc_clnt *clnt = task->tk_client;
 807
 808         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 809                         clnt->cl_protname, clnt->cl_vers,
 810                         rpc_proc_name(task),
 811                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 812
 813         /* Increment call count */
 814         task->tk_msg.rpc_proc->p_count++;
 815         clnt->cl_stats->rpccnt++;
 816         task->tk_action = call_reserve;
 817 }
 818
 819 /*
 820  * 1.   Reserve an RPC call slot
 821  */
 822 static void
 823 call_reserve(struct rpc_task *task)
 824 {
 825         dprint_status(task);
 826
 827         if (!rpcauth_uptodatecred(task)) {
 828                 task->tk_action = call_refresh;
 829                 return;
 830         }
 831
 832         task->tk_status  = 0;
 833         task->tk_action  = call_reserveresult;
 834         xprt_reserve(task);
 835 }
 836
 837 /*
 838  * 1b.  Grok the result of xprt_reserve()
 839  */
 840 static void
 841 call_reserveresult(struct rpc_task *task)
 842 {
 843         int status = task->tk_status;
 844
 845         dprint_status(task);
 846
 847         /*
 848          * After a call to xprt_reserve(), we must have either
 849          * a request slot or else an error status.
 850          */
 851         task->tk_status = 0;
 852         if (status >= 0) {
 853                 if (task->tk_rqstp) {
 854                         task->tk_action = call_allocate;
 855                         return;
 856                 }
 857
 858                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 859                                 __func__, status);
 860                 rpc_exit(task, -EIO);
 861                 return;
 862         }
 863
 864         /*
 865          * Even though there was an error, we may have acquired
 866          * a request slot somehow.  Make sure not to leak it.
 867          */
 868         if (task->tk_rqstp) {
 869                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 870                                 __func__, status);
 871                 xprt_release(task);
 872         }
 873
 874         switch (status) {
 875         case -EAGAIN:   /* woken up; retry */
 876                 task->tk_action = call_reserve;
 877                 return;
 878         case -EIO:      /* probably a shutdown */
 879                 break;
 880         default:
 881                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 882                                 __func__, status);
 883                 break;
 884         }
 885         rpc_exit(task, status);
 886 }
 887
 888 /*
 889  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 890  *      (Note: buffer memory is freed in xprt_release).
 891  */
 892 static void
 893 call_allocate(struct rpc_task *task)
 894 {
 895         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 896         struct rpc_rqst *req = task->tk_rqstp;
 897         struct rpc_xprt *xprt = task->tk_xprt;
 898         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 899
 900         dprint_status(task);
 901
 902         task->tk_status = 0;
 903         task->tk_action = call_bind;
 904
 905         if (req->rq_buffer)
 906                 return;
 907
 908         if (proc->p_proc != 0) {
 909                 BUG_ON(proc->p_arglen == 0);
 910                 if (proc->p_decode != NULL)
 911                         BUG_ON(proc->p_replen == 0);
 912         }
 913
 914         /*
 915          * Calculate the size (in quads) of the RPC call
 916          * and reply headers, and convert both values
 917          * to byte sizes.
 918          */
 919         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
 920         req->rq_callsize <<= 2;
 921         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
 922         req->rq_rcvsize <<= 2;
 923
 924         req->rq_buffer = xprt->ops->buf_alloc(task,
 925                                         req->rq_callsize + req->rq_rcvsize);
 926         if (req->rq_buffer != NULL)
 927                 return;
 928
 929         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
 930
 931         if (RPC_IS_ASYNC(task) || !signalled()) {
 932                 task->tk_action = call_allocate;
 933                 rpc_delay(task, HZ>>4);
 934                 return;
 935         }
 936
 937         rpc_exit(task, -ERESTARTSYS);
 938 }
 939
 940 static inline int
 941 rpc_task_need_encode(struct rpc_task *task)
 942 {
 943         return task->tk_rqstp->rq_snd_buf.len == 0;
 944 }
 945
 946 static inline void
 947 rpc_task_force_reencode(struct rpc_task *task)
 948 {
 949         task->tk_rqstp->rq_snd_buf.len = 0;
 950         task->tk_rqstp->rq_bytes_sent = 0;
 951 }
 952
 953 static inline void
 954 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
 955 {
 956         buf->head[0].iov_base = start;
 957         buf->head[0].iov_len = len;
 958         buf->tail[0].iov_len = 0;
 959         buf->page_len = 0;
 960         buf->flags = 0;
 961         buf->len = 0;
 962         buf->buflen = len;
 963 }
 964
 965 /*
 966  * 3.   Encode arguments of an RPC call
 967  */
 968 static void
 969 rpc_xdr_encode(struct rpc_task *task)
 970 {
 971         struct rpc_rqst *req = task->tk_rqstp;
 972         kxdrproc_t      encode;
 973         __be32          *p;
 974
 975         dprint_status(task);
 976
 977         rpc_xdr_buf_init(&req->rq_snd_buf,
 978                          req->rq_buffer,
 979                          req->rq_callsize);
 980         rpc_xdr_buf_init(&req->rq_rcv_buf,
 981                          (char *)req->rq_buffer + req->rq_callsize,
 982                          req->rq_rcvsize);
 983
 984         p = rpc_encode_header(task);
 985         if (p == NULL) {
 986                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
 987                 rpc_exit(task, -EIO);
 988                 return;
 989         }
 990
 991         encode = task->tk_msg.rpc_proc->p_encode;
 992         if (encode == NULL)
 993                 return;
 994
 995         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
 996                         task->tk_msg.rpc_argp);
 997 }
 998
 999 /*
1000  * 4.   Get the server port number if not yet set
1001  */
1002 static void
1003 call_bind(struct rpc_task *task)
1004 {
1005         struct rpc_xprt *xprt = task->tk_xprt;
1006
1007         dprint_status(task);
1008
1009         task->tk_action = call_connect;
1010         if (!xprt_bound(xprt)) {
1011                 task->tk_action = call_bind_status;
1012                 task->tk_timeout = xprt->bind_timeout;
1013                 xprt->ops->rpcbind(task);
1014         }
1015 }
1016
1017 /*
1018  * 4a.  Sort out bind result
1019  */
1020 static void
1021 call_bind_status(struct rpc_task *task)
1022 {
1023         int status = -EIO;
1024
1025         if (task->tk_status >= 0) {
1026                 dprint_status(task);
1027                 task->tk_status = 0;
1028                 task->tk_action = call_connect;
1029                 return;
1030         }
1031
1032         switch (task->tk_status) {
1033         case -ENOMEM:
1034                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1035                 rpc_delay(task, HZ >> 2);
1036                 goto retry_timeout;
1037         case -EACCES:
1038                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1039                                 "unavailable\n", task->tk_pid);
1040                 /* fail immediately if this is an RPC ping */
1041                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1042                         status = -EOPNOTSUPP;
1043                         break;
1044                 }
1045                 rpc_delay(task, 3*HZ);
1046                 goto retry_timeout;
1047         case -ETIMEDOUT:
1048                 dprintk("RPC: %5u rpcbind request timed out\n",
1049                                 task->tk_pid);
1050                 goto retry_timeout;
1051         case -EPFNOSUPPORT:
1052                 /* server doesn't support any rpcbind version we know of */
1053                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1054                                 task->tk_pid);
1055                 break;
1056         case -EPROTONOSUPPORT:
1057                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1058                                 task->tk_pid);
1059                 task->tk_status = 0;
1060                 task->tk_action = call_bind;
1061                 return;
1062         case -ECONNREFUSED:             /* connection problems */
1063         case -ECONNRESET:
1064         case -ENOTCONN:
1065         case -EHOSTDOWN:
1066         case -EHOSTUNREACH:
1067         case -ENETUNREACH:
1068         case -EPIPE:
1069                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1070                                 task->tk_pid, task->tk_status);
1071                 if (!RPC_IS_SOFTCONN(task)) {
1072                         rpc_delay(task, 5*HZ);
1073                         goto retry_timeout;
1074                 }
1075                 status = task->tk_status;
1076                 break;
1077         default:
1078                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1079                                 task->tk_pid, -task->tk_status);
1080         }
1081
1082         rpc_exit(task, status);
1083         return;
1084
1085 retry_timeout:
1086         task->tk_action = call_timeout;
1087 }
1088
1089 /*
1090  * 4b.  Connect to the RPC server
1091  */
1092 static void
1093 call_connect(struct rpc_task *task)
1094 {
1095         struct rpc_xprt *xprt = task->tk_xprt;
1096
1097         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1098                         task->tk_pid, xprt,
1099                         (xprt_connected(xprt) ? "is" : "is not"));
1100
1101         task->tk_action = call_transmit;
1102         if (!xprt_connected(xprt)) {
1103                 task->tk_action = call_connect_status;
1104                 if (task->tk_status < 0)
1105                         return;
1106                 xprt_connect(task);
1107         }
1108 }
1109
1110 /*
1111  * 4c.  Sort out connect result
1112  */
1113 static void
1114 call_connect_status(struct rpc_task *task)
1115 {
1116         struct rpc_clnt *clnt = task->tk_client;
1117         int status = task->tk_status;
1118
1119         dprint_status(task);
1120
1121         task->tk_status = 0;
1122         if (status >= 0 || status == -EAGAIN) {
1123                 clnt->cl_stats->netreconn++;
1124                 task->tk_action = call_transmit;
1125                 return;
1126         }
1127
1128         switch (status) {
1129                 /* if soft mounted, test if we've timed out */
1130         case -ETIMEDOUT:
1131                 task->tk_action = call_timeout;
1132                 break;
1133         default:
1134                 rpc_exit(task, -EIO);
1135         }
1136 }
1137
1138 /*
1139  * 5.   Transmit the RPC request, and wait for reply
1140  */
1141 static void
1142 call_transmit(struct rpc_task *task)
1143 {
1144         dprint_status(task);
1145
1146         task->tk_action = call_status;
1147         if (task->tk_status < 0)
1148                 return;
1149         task->tk_status = xprt_prepare_transmit(task);
1150         if (task->tk_status != 0)
1151                 return;
1152         task->tk_action = call_transmit_status;
1153         /* Encode here so that rpcsec_gss can use correct sequence number. */
1154         if (rpc_task_need_encode(task)) {
1155                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1156                 rpc_xdr_encode(task);
1157                 /* Did the encode result in an error condition? */
1158                 if (task->tk_status != 0) {
1159                         /* Was the error nonfatal? */
1160                         if (task->tk_status == -EAGAIN)
1161                                 rpc_delay(task, HZ >> 4);
1162                         else
1163                                 rpc_exit(task, task->tk_status);
1164                         return;
1165                 }
1166         }
1167         xprt_transmit(task);
1168         if (task->tk_status < 0)
1169                 return;
1170         /*
1171          * On success, ensure that we call xprt_end_transmit() before sleeping
1172          * in order to allow access to the socket to other RPC requests.
1173          */
1174         call_transmit_status(task);
1175         if (rpc_reply_expected(task))
1176                 return;
1177         task->tk_action = rpc_exit_task;
1178         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1179 }
1180
1181 /*
1182  * 5a.  Handle cleanup after a transmission
1183  */
1184 static void
1185 call_transmit_status(struct rpc_task *task)
1186 {
1187         task->tk_action = call_status;
1188
1189         /*
1190          * Common case: success.  Force the compiler to put this
1191          * test first.
1192          */
1193         if (task->tk_status == 0) {
1194                 xprt_end_transmit(task);
1195                 rpc_task_force_reencode(task);
1196                 return;
1197         }
1198
1199         switch (task->tk_status) {
1200         case -EAGAIN:
1201                 break;
1202         default:
1203                 dprint_status(task);
1204                 xprt_end_transmit(task);
1205                 rpc_task_force_reencode(task);
1206                 break;
1207                 /*
1208                  * Special cases: if we've been waiting on the
1209                  * socket's write_space() callback, or if the
1210                  * socket just returned a connection error,
1211                  * then hold onto the transport lock.
1212                  */
1213         case -ECONNREFUSED:
1214         case -EHOSTDOWN:
1215         case -EHOSTUNREACH:
1216         case -ENETUNREACH:
1217                 if (RPC_IS_SOFTCONN(task)) {
1218                         xprt_end_transmit(task);
1219                         rpc_exit(task, task->tk_status);
1220                         break;
1221                 }
1222         case -ECONNRESET:
1223         case -ENOTCONN:
1224         case -EPIPE:
1225                 rpc_task_force_reencode(task);
1226         }
1227 }
1228
1229 #if defined(CONFIG_NFS_V4_1)
1230 /*
1231  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1232  * addition, disconnect on connectivity errors.
1233  */
1234 static void
1235 call_bc_transmit(struct rpc_task *task)
1236 {
1237         struct rpc_rqst *req = task->tk_rqstp;
1238
1239         BUG_ON(task->tk_status != 0);
1240         task->tk_status = xprt_prepare_transmit(task);
1241         if (task->tk_status == -EAGAIN) {
1242                 /*
1243                  * Could not reserve the transport. Try again after the
1244                  * transport is released.
1245                  */
1246                 task->tk_status = 0;
1247                 task->tk_action = call_bc_transmit;
1248                 return;
1249         }
1250
1251         task->tk_action = rpc_exit_task;
1252         if (task->tk_status < 0) {
1253                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1254                         "error: %d\n", task->tk_status);
1255                 return;
1256         }
1257
1258         xprt_transmit(task);
1259         xprt_end_transmit(task);
1260         dprint_status(task);
1261         switch (task->tk_status) {
1262         case 0:
1263                 /* Success */
1264                 break;
1265         case -EHOSTDOWN:
1266         case -EHOSTUNREACH:
1267         case -ENETUNREACH:
1268         case -ETIMEDOUT:
1269                 /*
1270                  * Problem reaching the server.  Disconnect and let the
1271                  * forechannel reestablish the connection.  The server will
1272                  * have to retransmit the backchannel request and we'll
1273                  * reprocess it.  Since these ops are idempotent, there's no
1274                  * need to cache our reply at this time.
1275                  */
1276                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1277                         "error: %d\n", task->tk_status);
1278                 xprt_conditional_disconnect(task->tk_xprt,
1279                         req->rq_connect_cookie);
1280                 break;
1281         default:
1282                 /*
1283                  * We were unable to reply and will have to drop the
1284                  * request.  The server should reconnect and retransmit.
1285                  */
1286                 BUG_ON(task->tk_status == -EAGAIN);
1287                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1288                         "error: %d\n", task->tk_status);
1289                 break;
1290         }
1291         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1292 }
1293 #endif /* CONFIG_NFS_V4_1 */
1294
1295 /*
1296  * 6.   Sort out the RPC call status
1297  */
1298 static void
1299 call_status(struct rpc_task *task)
1300 {
1301         struct rpc_clnt *clnt = task->tk_client;
1302         struct rpc_rqst *req = task->tk_rqstp;
1303         int             status;
1304
1305         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1306                 task->tk_status = req->rq_reply_bytes_recvd;
1307
1308         dprint_status(task);
1309
1310         status = task->tk_status;
1311         if (status >= 0) {
1312                 task->tk_action = call_decode;
1313                 return;
1314         }
1315
1316         task->tk_status = 0;
1317         switch(status) {
1318         case -EHOSTDOWN:
1319         case -EHOSTUNREACH:
1320         case -ENETUNREACH:
1321                 /*
1322                  * Delay any retries for 3 seconds, then handle as if it
1323                  * were a timeout.
1324                  */
1325                 rpc_delay(task, 3*HZ);
1326         case -ETIMEDOUT:
1327                 task->tk_action = call_timeout;
1328                 if (task->tk_client->cl_discrtry)
1329                         xprt_conditional_disconnect(task->tk_xprt,
1330                                         req->rq_connect_cookie);
1331                 break;
1332         case -ECONNRESET:
1333         case -ECONNREFUSED:
1334                 rpc_force_rebind(clnt);
1335                 rpc_delay(task, 3*HZ);
1336         case -EPIPE:
1337         case -ENOTCONN:
1338                 task->tk_action = call_bind;
1339                 break;
1340         case -EAGAIN:
1341                 task->tk_action = call_transmit;
1342                 break;
1343         case -EIO:
1344                 /* shutdown or soft timeout */
1345                 rpc_exit(task, status);
1346                 break;
1347         default:
1348                 if (clnt->cl_chatty)
1349                         printk("%s: RPC call returned error %d\n",
1350                                clnt->cl_protname, -status);
1351                 rpc_exit(task, status);
1352         }
1353 }
1354
1355 /*
1356  * 6a.  Handle RPC timeout
1357  *      We do not release the request slot, so we keep using the
1358  *      same XID for all retransmits.
1359  */
1360 static void
1361 call_timeout(struct rpc_task *task)
1362 {
1363         struct rpc_clnt *clnt = task->tk_client;
1364
1365         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1366                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1367                 goto retry;
1368         }
1369
1370         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1371         task->tk_timeouts++;
1372
1373         if (RPC_IS_SOFTCONN(task)) {
1374                 rpc_exit(task, -ETIMEDOUT);
1375                 return;
1376         }
1377         if (RPC_IS_SOFT(task)) {
1378                 if (clnt->cl_chatty)
1379                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1380                                 clnt->cl_protname, clnt->cl_server);
1381                 rpc_exit(task, -EIO);
1382                 return;
1383         }
1384
1385         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1386                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1387                 if (clnt->cl_chatty)
1388                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1389                         clnt->cl_protname, clnt->cl_server);
1390         }
1391         rpc_force_rebind(clnt);
1392         /*
1393          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1394          * event? RFC2203 requires the server to drop all such requests.
1395          */
1396         rpcauth_invalcred(task);
1397
1398 retry:
1399         clnt->cl_stats->rpcretrans++;
1400         task->tk_action = call_bind;
1401         task->tk_status = 0;
1402 }
1403
1404 /*
1405  * 7.   Decode the RPC reply
1406  */
1407 static void
1408 call_decode(struct rpc_task *task)
1409 {
1410         struct rpc_clnt *clnt = task->tk_client;
1411         struct rpc_rqst *req = task->tk_rqstp;
1412         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1413         __be32          *p;
1414
1415         dprintk("RPC: %5u call_decode (status %d)\n",
1416                         task->tk_pid, task->tk_status);
1417
1418         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1419                 if (clnt->cl_chatty)
1420                         printk(KERN_NOTICE "%s: server %s OK\n",
1421                                 clnt->cl_protname, clnt->cl_server);
1422                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1423         }
1424
1425         /*
1426          * Ensure that we see all writes made by xprt_complete_rqst()
1427          * before it changed req->rq_reply_bytes_recvd.
1428          */
1429         smp_rmb();
1430         req->rq_rcv_buf.len = req->rq_private_buf.len;
1431
1432         /* Check that the softirq receive buffer is valid */
1433         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1434                                 sizeof(req->rq_rcv_buf)) != 0);
1435
1436         if (req->rq_rcv_buf.len < 12) {
1437                 if (!RPC_IS_SOFT(task)) {
1438                         task->tk_action = call_bind;
1439                         clnt->cl_stats->rpcretrans++;
1440                         goto out_retry;
1441                 }
1442                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1443                                 clnt->cl_protname, task->tk_status);
1444                 task->tk_action = call_timeout;
1445                 goto out_retry;
1446         }
1447
1448         p = rpc_verify_header(task);
1449         if (IS_ERR(p)) {
1450                 if (p == ERR_PTR(-EAGAIN))
1451                         goto out_retry;
1452                 return;
1453         }
1454
1455         task->tk_action = rpc_exit_task;
1456
1457         if (decode) {
1458                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1459                                                       task->tk_msg.rpc_resp);
1460         }
1461         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1462                         task->tk_status);
1463         return;
1464 out_retry:
1465         task->tk_status = 0;
1466         /* Note: rpc_verify_header() may have freed the RPC slot */
1467         if (task->tk_rqstp == req) {
1468                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1469                 if (task->tk_client->cl_discrtry)
1470                         xprt_conditional_disconnect(task->tk_xprt,
1471                                         req->rq_connect_cookie);
1472         }
1473 }
1474
1475 /*
1476  * 8.   Refresh the credentials if rejected by the server
1477  */
1478 static void
1479 call_refresh(struct rpc_task *task)
1480 {
1481         dprint_status(task);
1482
1483         task->tk_action = call_refreshresult;
1484         task->tk_status = 0;
1485         task->tk_client->cl_stats->rpcauthrefresh++;
1486         rpcauth_refreshcred(task);
1487 }
1488
1489 /*
1490  * 8a.  Process the results of a credential refresh
1491  */
1492 static void
1493 call_refreshresult(struct rpc_task *task)
1494 {
1495         int status = task->tk_status;
1496
1497         dprint_status(task);
1498
1499         task->tk_status = 0;
1500         task->tk_action = call_reserve;
1501         if (status >= 0 && rpcauth_uptodatecred(task))
1502                 return;
1503         if (status == -EACCES) {
1504                 rpc_exit(task, -EACCES);
1505                 return;
1506         }
1507         task->tk_action = call_refresh;
1508         if (status != -ETIMEDOUT)
1509                 rpc_delay(task, 3*HZ);
1510 }
1511
1512 static __be32 *
1513 rpc_encode_header(struct rpc_task *task)
1514 {
1515         struct rpc_clnt *clnt = task->tk_client;
1516         struct rpc_rqst *req = task->tk_rqstp;
1517         __be32          *p = req->rq_svec[0].iov_base;
1518
1519         /* FIXME: check buffer size? */
1520
1521         p = xprt_skip_transport_header(task->tk_xprt, p);
1522         *p++ = req->rq_xid;             /* XID */
1523         *p++ = htonl(RPC_CALL);         /* CALL */
1524         *p++ = htonl(RPC_VERSION);      /* RPC version */
1525         *p++ = htonl(clnt->cl_prog);    /* program number */
1526         *p++ = htonl(clnt->cl_vers);    /* program version */
1527         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1528         p = rpcauth_marshcred(task, p);
1529         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1530         return p;
1531 }
1532
1533 static __be32 *
1534 rpc_verify_header(struct rpc_task *task)
1535 {
1536         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1537         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1538         __be32  *p = iov->iov_base;
1539         u32 n;
1540         int error = -EACCES;
1541
1542         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1543                 /* RFC-1014 says that the representation of XDR data must be a
1544                  * multiple of four bytes
1545                  * - if it isn't pointer subtraction in the NFS client may give
1546                  *   undefined results
1547                  */
1548                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1549                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1550                        task->tk_rqstp->rq_rcv_buf.len);
1551                 goto out_eio;
1552         }
1553         if ((len -= 3) < 0)
1554                 goto out_overflow;
1555
1556         p += 1; /* skip XID */
1557         if ((n = ntohl(*p++)) != RPC_REPLY) {
1558                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1559                         task->tk_pid, __func__, n);
1560                 goto out_garbage;
1561         }
1562
1563         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1564                 if (--len < 0)
1565                         goto out_overflow;
1566                 switch ((n = ntohl(*p++))) {
1567                         case RPC_AUTH_ERROR:
1568                                 break;
1569                         case RPC_MISMATCH:
1570                                 dprintk("RPC: %5u %s: RPC call version "
1571                                                 "mismatch!\n",
1572                                                 task->tk_pid, __func__);
1573                                 error = -EPROTONOSUPPORT;
1574                                 goto out_err;
1575                         default:
1576                                 dprintk("RPC: %5u %s: RPC call rejected, "
1577                                                 "unknown error: %x\n",
1578                                                 task->tk_pid, __func__, n);
1579                                 goto out_eio;
1580                 }
1581                 if (--len < 0)
1582                         goto out_overflow;
1583                 switch ((n = ntohl(*p++))) {
1584                 case RPC_AUTH_REJECTEDCRED:
1585                 case RPC_AUTH_REJECTEDVERF:
1586                 case RPCSEC_GSS_CREDPROBLEM:
1587                 case RPCSEC_GSS_CTXPROBLEM:
1588                         if (!task->tk_cred_retry)
1589                                 break;
1590                         task->tk_cred_retry--;
1591                         dprintk("RPC: %5u %s: retry stale creds\n",
1592                                         task->tk_pid, __func__);
1593                         rpcauth_invalcred(task);
1594                         /* Ensure we obtain a new XID! */
1595                         xprt_release(task);
1596                         task->tk_action = call_refresh;
1597                         goto out_retry;
1598                 case RPC_AUTH_BADCRED:
1599                 case RPC_AUTH_BADVERF:
1600                         /* possibly garbled cred/verf? */
1601                         if (!task->tk_garb_retry)
1602                                 break;
1603                         task->tk_garb_retry--;
1604                         dprintk("RPC: %5u %s: retry garbled creds\n",
1605                                         task->tk_pid, __func__);
1606                         task->tk_action = call_bind;
1607                         goto out_retry;
1608                 case RPC_AUTH_TOOWEAK:
1609                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1610                                "authentication.\n", task->tk_client->cl_server);
1611                         break;
1612                 default:
1613                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1614                                         task->tk_pid, __func__, n);
1615                         error = -EIO;
1616                 }
1617                 dprintk("RPC: %5u %s: call rejected %d\n",
1618                                 task->tk_pid, __func__, n);
1619                 goto out_err;
1620         }
1621         if (!(p = rpcauth_checkverf(task, p))) {
1622                 dprintk("RPC: %5u %s: auth check failed\n",
1623                                 task->tk_pid, __func__);
1624                 goto out_garbage;               /* bad verifier, retry */
1625         }
1626         len = p - (__be32 *)iov->iov_base - 1;
1627         if (len < 0)
1628                 goto out_overflow;
1629         switch ((n = ntohl(*p++))) {
1630         case RPC_SUCCESS:
1631                 return p;
1632         case RPC_PROG_UNAVAIL:
1633                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1634                                 task->tk_pid, __func__,
1635                                 (unsigned int)task->tk_client->cl_prog,
1636                                 task->tk_client->cl_server);
1637                 error = -EPFNOSUPPORT;
1638                 goto out_err;
1639         case RPC_PROG_MISMATCH:
1640                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1641                                 "server %s\n", task->tk_pid, __func__,
1642                                 (unsigned int)task->tk_client->cl_prog,
1643                                 (unsigned int)task->tk_client->cl_vers,
1644                                 task->tk_client->cl_server);
1645                 error = -EPROTONOSUPPORT;
1646                 goto out_err;
1647         case RPC_PROC_UNAVAIL:
1648                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1649                                 "version %u on server %s\n",
1650                                 task->tk_pid, __func__,
1651                                 rpc_proc_name(task),
1652                                 task->tk_client->cl_prog,
1653                                 task->tk_client->cl_vers,
1654                                 task->tk_client->cl_server);
1655                 error = -EOPNOTSUPP;
1656                 goto out_err;
1657         case RPC_GARBAGE_ARGS:
1658                 dprintk("RPC: %5u %s: server saw garbage\n",
1659                                 task->tk_pid, __func__);
1660                 break;                  /* retry */
1661         default:
1662                 dprintk("RPC: %5u %s: server accept status: %x\n",
1663                                 task->tk_pid, __func__, n);
1664                 /* Also retry */
1665         }
1666
1667 out_garbage:
1668         task->tk_client->cl_stats->rpcgarbage++;
1669         if (task->tk_garb_retry) {
1670                 task->tk_garb_retry--;
1671                 dprintk("RPC: %5u %s: retrying\n",
1672                                 task->tk_pid, __func__);
1673                 task->tk_action = call_bind;
1674 out_retry:
1675                 return ERR_PTR(-EAGAIN);
1676         }
1677 out_eio:
1678         error = -EIO;
1679 out_err:
1680         rpc_exit(task, error);
1681         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1682                         __func__, error);
1683         return ERR_PTR(error);
1684 out_overflow:
1685         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1686                         __func__);
1687         goto out_garbage;
1688 }
1689
1690 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1691 {
1692         return 0;
1693 }
1694
1695 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1696 {
1697         return 0;
1698 }
1699
1700 static struct rpc_procinfo rpcproc_null = {
1701         .p_encode = rpcproc_encode_null,
1702         .p_decode = rpcproc_decode_null,
1703 };
1704
1705 static int rpc_ping(struct rpc_clnt *clnt)
1706 {
1707         struct rpc_message msg = {
1708                 .rpc_proc = &rpcproc_null,
1709         };
1710         int err;
1711         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1712         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1713         put_rpccred(msg.rpc_cred);
1714         return err;
1715 }
1716
1717 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1718 {
1719         struct rpc_message msg = {
1720                 .rpc_proc = &rpcproc_null,
1721                 .rpc_cred = cred,
1722         };
1723         struct rpc_task_setup task_setup_data = {
1724                 .rpc_client = clnt,
1725                 .rpc_message = &msg,
1726                 .callback_ops = &rpc_default_ops,
1727                 .flags = flags,
1728         };
1729         return rpc_run_task(&task_setup_data);
1730 }
1731 EXPORT_SYMBOL_GPL(rpc_call_null);
1732
1733 #ifdef RPC_DEBUG
1734 static void rpc_show_header(void)
1735 {
1736         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1737                 "-timeout ---ops--\n");
1738 }
1739
1740 static void rpc_show_task(const struct rpc_clnt *clnt,
1741                           const struct rpc_task *task)
1742 {
1743         const char *rpc_waitq = "none";
1744         char *p, action[KSYM_SYMBOL_LEN];
1745
1746         if (RPC_IS_QUEUED(task))
1747                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1748
1749         /* map tk_action pointer to a function name; then trim off
1750          * the "+0x0 [sunrpc]" */
1751         sprint_symbol(action, (unsigned long)task->tk_action);
1752         p = strchr(action, '+');
1753         if (p)
1754                 *p = '\0';
1755
1756         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1757                 task->tk_pid, task->tk_flags, task->tk_status,
1758                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1759                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1760                 action, rpc_waitq);
1761 }
1762
1763 void rpc_show_tasks(void)
1764 {
1765         struct rpc_clnt *clnt;
1766         struct rpc_task *task;
1767         int header = 0;
1768
1769         spin_lock(&rpc_client_lock);
1770         list_for_each_entry(clnt, &all_clients, cl_clients) {
1771                 spin_lock(&clnt->cl_lock);
1772                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1773                         if (!header) {
1774                                 rpc_show_header();
1775                                 header++;
1776                         }
1777                         rpc_show_task(clnt, task);
1778                 }
1779                 spin_unlock(&clnt->cl_lock);
1780         }
1781         spin_unlock(&rpc_client_lock);
1782 }
1783 #endif