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         atomic_set(&clnt->cl_count, 1);
 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         atomic_set(&new->cl_count, 1);
 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         atomic_inc(&clnt->cl_count);
 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  * Kill all tasks for the given client.
 418  * XXX: kill their descendants as well?
 419  */
 420 void rpc_killall_tasks(struct rpc_clnt *clnt)
 421 {
 422         struct rpc_task *rovr;
 423
 424
 425         if (list_empty(&clnt->cl_tasks))
 426                 return;
 427         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 428         /*
 429          * Spin lock all_tasks to prevent changes...
 430          */
 431         spin_lock(&clnt->cl_lock);
 432         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 433                 if (!RPC_IS_ACTIVATED(rovr))
 434                         continue;
 435                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 436                         rovr->tk_flags |= RPC_TASK_KILLED;
 437                         rpc_exit(rovr, -EIO);
 438                         rpc_wake_up_queued_task(rovr->tk_waitqueue, rovr);
 439                 }
 440         }
 441         spin_unlock(&clnt->cl_lock);
 442 }
 443 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 444
 445 /*
 446  * Properly shut down an RPC client, terminating all outstanding
 447  * requests.
 448  */
 449 void rpc_shutdown_client(struct rpc_clnt *clnt)
 450 {
 451         dprintk("RPC:       shutting down %s client for %s\n",
 452                         clnt->cl_protname, clnt->cl_server);
 453
 454         while (!list_empty(&clnt->cl_tasks)) {
 455                 rpc_killall_tasks(clnt);
 456                 wait_event_timeout(destroy_wait,
 457                         list_empty(&clnt->cl_tasks), 1*HZ);
 458         }
 459
 460         rpc_release_client(clnt);
 461 }
 462 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 463
 464 /*
 465  * Free an RPC client
 466  */
 467 static void
 468 rpc_free_client(struct rpc_clnt *clnt)
 469 {
 470         dprintk("RPC:       destroying %s client for %s\n",
 471                         clnt->cl_protname, clnt->cl_server);
 472         if (!IS_ERR(clnt->cl_path.dentry)) {
 473                 rpc_remove_client_dir(clnt->cl_path.dentry);
 474                 rpc_put_mount();
 475         }
 476         if (clnt->cl_parent != clnt) {
 477                 rpc_release_client(clnt->cl_parent);
 478                 goto out_free;
 479         }
 480         if (clnt->cl_server != clnt->cl_inline_name)
 481                 kfree(clnt->cl_server);
 482 out_free:
 483         rpc_unregister_client(clnt);
 484         rpc_free_iostats(clnt->cl_metrics);
 485         kfree(clnt->cl_principal);
 486         clnt->cl_metrics = NULL;
 487         xprt_put(clnt->cl_xprt);
 488         rpciod_down();
 489         kfree(clnt);
 490 }
 491
 492 /*
 493  * Free an RPC client
 494  */
 495 static void
 496 rpc_free_auth(struct rpc_clnt *clnt)
 497 {
 498         if (clnt->cl_auth == NULL) {
 499                 rpc_free_client(clnt);
 500                 return;
 501         }
 502
 503         /*
 504          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 505          *       release remaining GSS contexts. This mechanism ensures
 506          *       that it can do so safely.
 507          */
 508         atomic_inc(&clnt->cl_count);
 509         rpcauth_release(clnt->cl_auth);
 510         clnt->cl_auth = NULL;
 511         if (atomic_dec_and_test(&clnt->cl_count))
 512                 rpc_free_client(clnt);
 513 }
 514
 515 /*
 516  * Release reference to the RPC client
 517  */
 518 void
 519 rpc_release_client(struct rpc_clnt *clnt)
 520 {
 521         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 522
 523         if (list_empty(&clnt->cl_tasks))
 524                 wake_up(&destroy_wait);
 525         if (atomic_dec_and_test(&clnt->cl_count))
 526                 rpc_free_auth(clnt);
 527 }
 528
 529 /**
 530  * rpc_bind_new_program - bind a new RPC program to an existing client
 531  * @old: old rpc_client
 532  * @program: rpc program to set
 533  * @vers: rpc program version
 534  *
 535  * Clones the rpc client and sets up a new RPC program. This is mainly
 536  * of use for enabling different RPC programs to share the same transport.
 537  * The Sun NFSv2/v3 ACL protocol can do this.
 538  */
 539 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 540                                       struct rpc_program *program,
 541                                       u32 vers)
 542 {
 543         struct rpc_clnt *clnt;
 544         struct rpc_version *version;
 545         int err;
 546
 547         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 548         version = program->version[vers];
 549         clnt = rpc_clone_client(old);
 550         if (IS_ERR(clnt))
 551                 goto out;
 552         clnt->cl_procinfo = version->procs;
 553         clnt->cl_maxproc  = version->nrprocs;
 554         clnt->cl_protname = program->name;
 555         clnt->cl_prog     = program->number;
 556         clnt->cl_vers     = version->number;
 557         clnt->cl_stats    = program->stats;
 558         err = rpc_ping(clnt);
 559         if (err != 0) {
 560                 rpc_shutdown_client(clnt);
 561                 clnt = ERR_PTR(err);
 562         }
 563 out:
 564         return clnt;
 565 }
 566 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 567
 568 void rpc_task_release_client(struct rpc_task *task)
 569 {
 570         struct rpc_clnt *clnt = task->tk_client;
 571
 572         if (clnt != NULL) {
 573                 /* Remove from client task list */
 574                 spin_lock(&clnt->cl_lock);
 575                 list_del(&task->tk_task);
 576                 spin_unlock(&clnt->cl_lock);
 577                 task->tk_client = NULL;
 578
 579                 rpc_release_client(clnt);
 580         }
 581 }
 582
 583 static
 584 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 585 {
 586         if (clnt != NULL) {
 587                 rpc_task_release_client(task);
 588                 task->tk_client = clnt;
 589                 atomic_inc(&clnt->cl_count);
 590                 if (clnt->cl_softrtry)
 591                         task->tk_flags |= RPC_TASK_SOFT;
 592                 /* Add to the client's list of all tasks */
 593                 spin_lock(&clnt->cl_lock);
 594                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 595                 spin_unlock(&clnt->cl_lock);
 596         }
 597 }
 598
 599 static void
 600 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 601 {
 602         if (msg != NULL) {
 603                 task->tk_msg.rpc_proc = msg->rpc_proc;
 604                 task->tk_msg.rpc_argp = msg->rpc_argp;
 605                 task->tk_msg.rpc_resp = msg->rpc_resp;
 606                 if (msg->rpc_cred != NULL)
 607                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 608         }
 609 }
 610
 611 /*
 612  * Default callback for async RPC calls
 613  */
 614 static void
 615 rpc_default_callback(struct rpc_task *task, void *data)
 616 {
 617 }
 618
 619 static const struct rpc_call_ops rpc_default_ops = {
 620         .rpc_call_done = rpc_default_callback,
 621 };
 622
 623 /**
 624  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 625  * @task_setup_data: pointer to task initialisation data
 626  */
 627 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 628 {
 629         struct rpc_task *task;
 630
 631         task = rpc_new_task(task_setup_data);
 632         if (IS_ERR(task))
 633                 goto out;
 634
 635         rpc_task_set_client(task, task_setup_data->rpc_client);
 636         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 637
 638         if (task->tk_status != 0) {
 639                 int ret = task->tk_status;
 640                 rpc_put_task(task);
 641                 return ERR_PTR(ret);
 642         }
 643
 644         if (task->tk_action == NULL)
 645                 rpc_call_start(task);
 646
 647         atomic_inc(&task->tk_count);
 648         rpc_execute(task);
 649 out:
 650         return task;
 651 }
 652 EXPORT_SYMBOL_GPL(rpc_run_task);
 653
 654 /**
 655  * rpc_call_sync - Perform a synchronous RPC call
 656  * @clnt: pointer to RPC client
 657  * @msg: RPC call parameters
 658  * @flags: RPC call flags
 659  */
 660 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 661 {
 662         struct rpc_task *task;
 663         struct rpc_task_setup task_setup_data = {
 664                 .rpc_client = clnt,
 665                 .rpc_message = msg,
 666                 .callback_ops = &rpc_default_ops,
 667                 .flags = flags,
 668         };
 669         int status;
 670
 671         BUG_ON(flags & RPC_TASK_ASYNC);
 672
 673         task = rpc_run_task(&task_setup_data);
 674         if (IS_ERR(task))
 675                 return PTR_ERR(task);
 676         status = task->tk_status;
 677         rpc_put_task(task);
 678         return status;
 679 }
 680 EXPORT_SYMBOL_GPL(rpc_call_sync);
 681
 682 /**
 683  * rpc_call_async - Perform an asynchronous RPC call
 684  * @clnt: pointer to RPC client
 685  * @msg: RPC call parameters
 686  * @flags: RPC call flags
 687  * @tk_ops: RPC call ops
 688  * @data: user call data
 689  */
 690 int
 691 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 692                const struct rpc_call_ops *tk_ops, void *data)
 693 {
 694         struct rpc_task *task;
 695         struct rpc_task_setup task_setup_data = {
 696                 .rpc_client = clnt,
 697                 .rpc_message = msg,
 698                 .callback_ops = tk_ops,
 699                 .callback_data = data,
 700                 .flags = flags|RPC_TASK_ASYNC,
 701         };
 702
 703         task = rpc_run_task(&task_setup_data);
 704         if (IS_ERR(task))
 705                 return PTR_ERR(task);
 706         rpc_put_task(task);
 707         return 0;
 708 }
 709 EXPORT_SYMBOL_GPL(rpc_call_async);
 710
 711 #if defined(CONFIG_NFS_V4_1)
 712 /**
 713  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 714  * rpc_execute against it
 715  * @req: RPC request
 716  * @tk_ops: RPC call ops
 717  */
 718 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 719                                 const struct rpc_call_ops *tk_ops)
 720 {
 721         struct rpc_task *task;
 722         struct xdr_buf *xbufp = &req->rq_snd_buf;
 723         struct rpc_task_setup task_setup_data = {
 724                 .callback_ops = tk_ops,
 725         };
 726
 727         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 728         /*
 729          * Create an rpc_task to send the data
 730          */
 731         task = rpc_new_task(&task_setup_data);
 732         if (IS_ERR(task)) {
 733                 xprt_free_bc_request(req);
 734                 goto out;
 735         }
 736         task->tk_rqstp = req;
 737
 738         /*
 739          * Set up the xdr_buf length.
 740          * This also indicates that the buffer is XDR encoded already.
 741          */
 742         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 743                         xbufp->tail[0].iov_len;
 744
 745         task->tk_action = call_bc_transmit;
 746         atomic_inc(&task->tk_count);
 747         BUG_ON(atomic_read(&task->tk_count) != 2);
 748         rpc_execute(task);
 749
 750 out:
 751         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 752         return task;
 753 }
 754 #endif /* CONFIG_NFS_V4_1 */
 755
 756 void
 757 rpc_call_start(struct rpc_task *task)
 758 {
 759         task->tk_action = call_start;
 760 }
 761 EXPORT_SYMBOL_GPL(rpc_call_start);
 762
 763 /**
 764  * rpc_peeraddr - extract remote peer address from clnt's xprt
 765  * @clnt: RPC client structure
 766  * @buf: target buffer
 767  * @bufsize: length of target buffer
 768  *
 769  * Returns the number of bytes that are actually in the stored address.
 770  */
 771 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 772 {
 773         size_t bytes;
 774         struct rpc_xprt *xprt = clnt->cl_xprt;
 775
 776         bytes = sizeof(xprt->addr);
 777         if (bytes > bufsize)
 778                 bytes = bufsize;
 779         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 780         return xprt->addrlen;
 781 }
 782 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 783
 784 /**
 785  * rpc_peeraddr2str - return remote peer address in printable format
 786  * @clnt: RPC client structure
 787  * @format: address format
 788  *
 789  */
 790 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 791                              enum rpc_display_format_t format)
 792 {
 793         struct rpc_xprt *xprt = clnt->cl_xprt;
 794
 795         if (xprt->address_strings[format] != NULL)
 796                 return xprt->address_strings[format];
 797         else
 798                 return "unprintable";
 799 }
 800 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 801
 802 void
 803 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 804 {
 805         struct rpc_xprt *xprt = clnt->cl_xprt;
 806         if (xprt->ops->set_buffer_size)
 807                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 808 }
 809 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 810
 811 /*
 812  * Return size of largest payload RPC client can support, in bytes
 813  *
 814  * For stream transports, this is one RPC record fragment (see RFC
 815  * 1831), as we don't support multi-record requests yet.  For datagram
 816  * transports, this is the size of an IP packet minus the IP, UDP, and
 817  * RPC header sizes.
 818  */
 819 size_t rpc_max_payload(struct rpc_clnt *clnt)
 820 {
 821         return clnt->cl_xprt->max_payload;
 822 }
 823 EXPORT_SYMBOL_GPL(rpc_max_payload);
 824
 825 /**
 826  * rpc_force_rebind - force transport to check that remote port is unchanged
 827  * @clnt: client to rebind
 828  *
 829  */
 830 void rpc_force_rebind(struct rpc_clnt *clnt)
 831 {
 832         if (clnt->cl_autobind)
 833                 xprt_clear_bound(clnt->cl_xprt);
 834 }
 835 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 836
 837 /*
 838  * Restart an (async) RPC call from the call_prepare state.
 839  * Usually called from within the exit handler.
 840  */
 841 int
 842 rpc_restart_call_prepare(struct rpc_task *task)
 843 {
 844         if (RPC_ASSASSINATED(task))
 845                 return 0;
 846         task->tk_action = rpc_prepare_task;
 847         return 1;
 848 }
 849 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 850
 851 /*
 852  * Restart an (async) RPC call. Usually called from within the
 853  * exit handler.
 854  */
 855 int
 856 rpc_restart_call(struct rpc_task *task)
 857 {
 858         if (RPC_ASSASSINATED(task))
 859                 return 0;
 860         task->tk_action = call_start;
 861         return 1;
 862 }
 863 EXPORT_SYMBOL_GPL(rpc_restart_call);
 864
 865 #ifdef RPC_DEBUG
 866 static const char *rpc_proc_name(const struct rpc_task *task)
 867 {
 868         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 869
 870         if (proc) {
 871                 if (proc->p_name)
 872                         return proc->p_name;
 873                 else
 874                         return "NULL";
 875         } else
 876                 return "no proc";
 877 }
 878 #endif
 879
 880 /*
 881  * 0.  Initial state
 882  *
 883  *     Other FSM states can be visited zero or more times, but
 884  *     this state is visited exactly once for each RPC.
 885  */
 886 static void
 887 call_start(struct rpc_task *task)
 888 {
 889         struct rpc_clnt *clnt = task->tk_client;
 890
 891         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 892                         clnt->cl_protname, clnt->cl_vers,
 893                         rpc_proc_name(task),
 894                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 895
 896         /* Increment call count */
 897         task->tk_msg.rpc_proc->p_count++;
 898         clnt->cl_stats->rpccnt++;
 899         task->tk_action = call_reserve;
 900 }
 901
 902 /*
 903  * 1.   Reserve an RPC call slot
 904  */
 905 static void
 906 call_reserve(struct rpc_task *task)
 907 {
 908         dprint_status(task);
 909
 910         task->tk_status  = 0;
 911         task->tk_action  = call_reserveresult;
 912         xprt_reserve(task);
 913 }
 914
 915 /*
 916  * 1b.  Grok the result of xprt_reserve()
 917  */
 918 static void
 919 call_reserveresult(struct rpc_task *task)
 920 {
 921         int status = task->tk_status;
 922
 923         dprint_status(task);
 924
 925         /*
 926          * After a call to xprt_reserve(), we must have either
 927          * a request slot or else an error status.
 928          */
 929         task->tk_status = 0;
 930         if (status >= 0) {
 931                 if (task->tk_rqstp) {
 932                         task->tk_action = call_refresh;
 933                         return;
 934                 }
 935
 936                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 937                                 __func__, status);
 938                 rpc_exit(task, -EIO);
 939                 return;
 940         }
 941
 942         /*
 943          * Even though there was an error, we may have acquired
 944          * a request slot somehow.  Make sure not to leak it.
 945          */
 946         if (task->tk_rqstp) {
 947                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 948                                 __func__, status);
 949                 xprt_release(task);
 950         }
 951
 952         switch (status) {
 953         case -EAGAIN:   /* woken up; retry */
 954                 task->tk_action = call_reserve;
 955                 return;
 956         case -EIO:      /* probably a shutdown */
 957                 break;
 958         default:
 959                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 960                                 __func__, status);
 961                 break;
 962         }
 963         rpc_exit(task, status);
 964 }
 965
 966 /*
 967  * 2.   Bind and/or refresh the credentials
 968  */
 969 static void
 970 call_refresh(struct rpc_task *task)
 971 {
 972         dprint_status(task);
 973
 974         task->tk_action = call_refreshresult;
 975         task->tk_status = 0;
 976         task->tk_client->cl_stats->rpcauthrefresh++;
 977         rpcauth_refreshcred(task);
 978 }
 979
 980 /*
 981  * 2a.  Process the results of a credential refresh
 982  */
 983 static void
 984 call_refreshresult(struct rpc_task *task)
 985 {
 986         int status = task->tk_status;
 987
 988         dprint_status(task);
 989
 990         task->tk_status = 0;
 991         task->tk_action = call_allocate;
 992         if (status >= 0 && rpcauth_uptodatecred(task))
 993                 return;
 994         switch (status) {
 995         case -EACCES:
 996                 rpc_exit(task, -EACCES);
 997                 return;
 998         case -ENOMEM:
 999                 rpc_exit(task, -ENOMEM);
1000                 return;
1001         case -ETIMEDOUT:
1002                 rpc_delay(task, 3*HZ);
1003         }
1004         task->tk_action = call_refresh;
1005 }
1006
1007 /*
1008  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1009  *      (Note: buffer memory is freed in xprt_release).
1010  */
1011 static void
1012 call_allocate(struct rpc_task *task)
1013 {
1014         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1015         struct rpc_rqst *req = task->tk_rqstp;
1016         struct rpc_xprt *xprt = task->tk_xprt;
1017         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1018
1019         dprint_status(task);
1020
1021         task->tk_status = 0;
1022         task->tk_action = call_bind;
1023
1024         if (req->rq_buffer)
1025                 return;
1026
1027         if (proc->p_proc != 0) {
1028                 BUG_ON(proc->p_arglen == 0);
1029                 if (proc->p_decode != NULL)
1030                         BUG_ON(proc->p_replen == 0);
1031         }
1032
1033         /*
1034          * Calculate the size (in quads) of the RPC call
1035          * and reply headers, and convert both values
1036          * to byte sizes.
1037          */
1038         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1039         req->rq_callsize <<= 2;
1040         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1041         req->rq_rcvsize <<= 2;
1042
1043         req->rq_buffer = xprt->ops->buf_alloc(task,
1044                                         req->rq_callsize + req->rq_rcvsize);
1045         if (req->rq_buffer != NULL)
1046                 return;
1047
1048         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1049
1050         if (RPC_IS_ASYNC(task) || !signalled()) {
1051                 task->tk_action = call_allocate;
1052                 rpc_delay(task, HZ>>4);
1053                 return;
1054         }
1055
1056         rpc_exit(task, -ERESTARTSYS);
1057 }
1058
1059 static inline int
1060 rpc_task_need_encode(struct rpc_task *task)
1061 {
1062         return task->tk_rqstp->rq_snd_buf.len == 0;
1063 }
1064
1065 static inline void
1066 rpc_task_force_reencode(struct rpc_task *task)
1067 {
1068         task->tk_rqstp->rq_snd_buf.len = 0;
1069         task->tk_rqstp->rq_bytes_sent = 0;
1070 }
1071
1072 static inline void
1073 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1074 {
1075         buf->head[0].iov_base = start;
1076         buf->head[0].iov_len = len;
1077         buf->tail[0].iov_len = 0;
1078         buf->page_len = 0;
1079         buf->flags = 0;
1080         buf->len = 0;
1081         buf->buflen = len;
1082 }
1083
1084 /*
1085  * 3.   Encode arguments of an RPC call
1086  */
1087 static void
1088 rpc_xdr_encode(struct rpc_task *task)
1089 {
1090         struct rpc_rqst *req = task->tk_rqstp;
1091         kxdrproc_t      encode;
1092         __be32          *p;
1093
1094         dprint_status(task);
1095
1096         rpc_xdr_buf_init(&req->rq_snd_buf,
1097                          req->rq_buffer,
1098                          req->rq_callsize);
1099         rpc_xdr_buf_init(&req->rq_rcv_buf,
1100                          (char *)req->rq_buffer + req->rq_callsize,
1101                          req->rq_rcvsize);
1102
1103         p = rpc_encode_header(task);
1104         if (p == NULL) {
1105                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1106                 rpc_exit(task, -EIO);
1107                 return;
1108         }
1109
1110         encode = task->tk_msg.rpc_proc->p_encode;
1111         if (encode == NULL)
1112                 return;
1113
1114         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1115                         task->tk_msg.rpc_argp);
1116 }
1117
1118 /*
1119  * 4.   Get the server port number if not yet set
1120  */
1121 static void
1122 call_bind(struct rpc_task *task)
1123 {
1124         struct rpc_xprt *xprt = task->tk_xprt;
1125
1126         dprint_status(task);
1127
1128         task->tk_action = call_connect;
1129         if (!xprt_bound(xprt)) {
1130                 task->tk_action = call_bind_status;
1131                 task->tk_timeout = xprt->bind_timeout;
1132                 xprt->ops->rpcbind(task);
1133         }
1134 }
1135
1136 /*
1137  * 4a.  Sort out bind result
1138  */
1139 static void
1140 call_bind_status(struct rpc_task *task)
1141 {
1142         int status = -EIO;
1143
1144         if (task->tk_status >= 0) {
1145                 dprint_status(task);
1146                 task->tk_status = 0;
1147                 task->tk_action = call_connect;
1148                 return;
1149         }
1150
1151         switch (task->tk_status) {
1152         case -ENOMEM:
1153                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1154                 rpc_delay(task, HZ >> 2);
1155                 goto retry_timeout;
1156         case -EACCES:
1157                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1158                                 "unavailable\n", task->tk_pid);
1159                 /* fail immediately if this is an RPC ping */
1160                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1161                         status = -EOPNOTSUPP;
1162                         break;
1163                 }
1164                 rpc_delay(task, 3*HZ);
1165                 goto retry_timeout;
1166         case -ETIMEDOUT:
1167                 dprintk("RPC: %5u rpcbind request timed out\n",
1168                                 task->tk_pid);
1169                 goto retry_timeout;
1170         case -EPFNOSUPPORT:
1171                 /* server doesn't support any rpcbind version we know of */
1172                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1173                                 task->tk_pid);
1174                 break;
1175         case -EPROTONOSUPPORT:
1176                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1177                                 task->tk_pid);
1178                 task->tk_status = 0;
1179                 task->tk_action = call_bind;
1180                 return;
1181         case -ECONNREFUSED:             /* connection problems */
1182         case -ECONNRESET:
1183         case -ENOTCONN:
1184         case -EHOSTDOWN:
1185         case -EHOSTUNREACH:
1186         case -ENETUNREACH:
1187         case -EPIPE:
1188                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1189                                 task->tk_pid, task->tk_status);
1190                 if (!RPC_IS_SOFTCONN(task)) {
1191                         rpc_delay(task, 5*HZ);
1192                         goto retry_timeout;
1193                 }
1194                 status = task->tk_status;
1195                 break;
1196         default:
1197                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1198                                 task->tk_pid, -task->tk_status);
1199         }
1200
1201         rpc_exit(task, status);
1202         return;
1203
1204 retry_timeout:
1205         task->tk_action = call_timeout;
1206 }
1207
1208 /*
1209  * 4b.  Connect to the RPC server
1210  */
1211 static void
1212 call_connect(struct rpc_task *task)
1213 {
1214         struct rpc_xprt *xprt = task->tk_xprt;
1215
1216         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1217                         task->tk_pid, xprt,
1218                         (xprt_connected(xprt) ? "is" : "is not"));
1219
1220         task->tk_action = call_transmit;
1221         if (!xprt_connected(xprt)) {
1222                 task->tk_action = call_connect_status;
1223                 if (task->tk_status < 0)
1224                         return;
1225                 xprt_connect(task);
1226         }
1227 }
1228
1229 /*
1230  * 4c.  Sort out connect result
1231  */
1232 static void
1233 call_connect_status(struct rpc_task *task)
1234 {
1235         struct rpc_clnt *clnt = task->tk_client;
1236         int status = task->tk_status;
1237
1238         dprint_status(task);
1239
1240         task->tk_status = 0;
1241         if (status >= 0 || status == -EAGAIN) {
1242                 clnt->cl_stats->netreconn++;
1243                 task->tk_action = call_transmit;
1244                 return;
1245         }
1246
1247         switch (status) {
1248                 /* if soft mounted, test if we've timed out */
1249         case -ETIMEDOUT:
1250                 task->tk_action = call_timeout;
1251                 break;
1252         default:
1253                 rpc_exit(task, -EIO);
1254         }
1255 }
1256
1257 /*
1258  * 5.   Transmit the RPC request, and wait for reply
1259  */
1260 static void
1261 call_transmit(struct rpc_task *task)
1262 {
1263         dprint_status(task);
1264
1265         task->tk_action = call_status;
1266         if (task->tk_status < 0)
1267                 return;
1268         task->tk_status = xprt_prepare_transmit(task);
1269         if (task->tk_status != 0)
1270                 return;
1271         task->tk_action = call_transmit_status;
1272         /* Encode here so that rpcsec_gss can use correct sequence number. */
1273         if (rpc_task_need_encode(task)) {
1274                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1275                 rpc_xdr_encode(task);
1276                 /* Did the encode result in an error condition? */
1277                 if (task->tk_status != 0) {
1278                         /* Was the error nonfatal? */
1279                         if (task->tk_status == -EAGAIN)
1280                                 rpc_delay(task, HZ >> 4);
1281                         else
1282                                 rpc_exit(task, task->tk_status);
1283                         return;
1284                 }
1285         }
1286         xprt_transmit(task);
1287         if (task->tk_status < 0)
1288                 return;
1289         /*
1290          * On success, ensure that we call xprt_end_transmit() before sleeping
1291          * in order to allow access to the socket to other RPC requests.
1292          */
1293         call_transmit_status(task);
1294         if (rpc_reply_expected(task))
1295                 return;
1296         task->tk_action = rpc_exit_task;
1297         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1298 }
1299
1300 /*
1301  * 5a.  Handle cleanup after a transmission
1302  */
1303 static void
1304 call_transmit_status(struct rpc_task *task)
1305 {
1306         task->tk_action = call_status;
1307
1308         /*
1309          * Common case: success.  Force the compiler to put this
1310          * test first.
1311          */
1312         if (task->tk_status == 0) {
1313                 xprt_end_transmit(task);
1314                 rpc_task_force_reencode(task);
1315                 return;
1316         }
1317
1318         switch (task->tk_status) {
1319         case -EAGAIN:
1320                 break;
1321         default:
1322                 dprint_status(task);
1323                 xprt_end_transmit(task);
1324                 rpc_task_force_reencode(task);
1325                 break;
1326                 /*
1327                  * Special cases: if we've been waiting on the
1328                  * socket's write_space() callback, or if the
1329                  * socket just returned a connection error,
1330                  * then hold onto the transport lock.
1331                  */
1332         case -ECONNREFUSED:
1333         case -EHOSTDOWN:
1334         case -EHOSTUNREACH:
1335         case -ENETUNREACH:
1336                 if (RPC_IS_SOFTCONN(task)) {
1337                         xprt_end_transmit(task);
1338                         rpc_exit(task, task->tk_status);
1339                         break;
1340                 }
1341         case -ECONNRESET:
1342         case -ENOTCONN:
1343         case -EPIPE:
1344                 rpc_task_force_reencode(task);
1345         }
1346 }
1347
1348 #if defined(CONFIG_NFS_V4_1)
1349 /*
1350  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1351  * addition, disconnect on connectivity errors.
1352  */
1353 static void
1354 call_bc_transmit(struct rpc_task *task)
1355 {
1356         struct rpc_rqst *req = task->tk_rqstp;
1357
1358         BUG_ON(task->tk_status != 0);
1359         task->tk_status = xprt_prepare_transmit(task);
1360         if (task->tk_status == -EAGAIN) {
1361                 /*
1362                  * Could not reserve the transport. Try again after the
1363                  * transport is released.
1364                  */
1365                 task->tk_status = 0;
1366                 task->tk_action = call_bc_transmit;
1367                 return;
1368         }
1369
1370         task->tk_action = rpc_exit_task;
1371         if (task->tk_status < 0) {
1372                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1373                         "error: %d\n", task->tk_status);
1374                 return;
1375         }
1376
1377         xprt_transmit(task);
1378         xprt_end_transmit(task);
1379         dprint_status(task);
1380         switch (task->tk_status) {
1381         case 0:
1382                 /* Success */
1383                 break;
1384         case -EHOSTDOWN:
1385         case -EHOSTUNREACH:
1386         case -ENETUNREACH:
1387         case -ETIMEDOUT:
1388                 /*
1389                  * Problem reaching the server.  Disconnect and let the
1390                  * forechannel reestablish the connection.  The server will
1391                  * have to retransmit the backchannel request and we'll
1392                  * reprocess it.  Since these ops are idempotent, there's no
1393                  * need to cache our reply at this time.
1394                  */
1395                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1396                         "error: %d\n", task->tk_status);
1397                 xprt_conditional_disconnect(task->tk_xprt,
1398                         req->rq_connect_cookie);
1399                 break;
1400         default:
1401                 /*
1402                  * We were unable to reply and will have to drop the
1403                  * request.  The server should reconnect and retransmit.
1404                  */
1405                 BUG_ON(task->tk_status == -EAGAIN);
1406                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1407                         "error: %d\n", task->tk_status);
1408                 break;
1409         }
1410         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1411 }
1412 #endif /* CONFIG_NFS_V4_1 */
1413
1414 /*
1415  * 6.   Sort out the RPC call status
1416  */
1417 static void
1418 call_status(struct rpc_task *task)
1419 {
1420         struct rpc_clnt *clnt = task->tk_client;
1421         struct rpc_rqst *req = task->tk_rqstp;
1422         int             status;
1423
1424         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1425                 task->tk_status = req->rq_reply_bytes_recvd;
1426
1427         dprint_status(task);
1428
1429         status = task->tk_status;
1430         if (status >= 0) {
1431                 task->tk_action = call_decode;
1432                 return;
1433         }
1434
1435         task->tk_status = 0;
1436         switch(status) {
1437         case -EHOSTDOWN:
1438         case -EHOSTUNREACH:
1439         case -ENETUNREACH:
1440                 /*
1441                  * Delay any retries for 3 seconds, then handle as if it
1442                  * were a timeout.
1443                  */
1444                 rpc_delay(task, 3*HZ);
1445         case -ETIMEDOUT:
1446                 task->tk_action = call_timeout;
1447                 if (task->tk_client->cl_discrtry)
1448                         xprt_conditional_disconnect(task->tk_xprt,
1449                                         req->rq_connect_cookie);
1450                 break;
1451         case -ECONNRESET:
1452         case -ECONNREFUSED:
1453                 rpc_force_rebind(clnt);
1454                 rpc_delay(task, 3*HZ);
1455         case -EPIPE:
1456         case -ENOTCONN:
1457                 task->tk_action = call_bind;
1458                 break;
1459         case -EAGAIN:
1460                 task->tk_action = call_transmit;
1461                 break;
1462         case -EIO:
1463                 /* shutdown or soft timeout */
1464                 rpc_exit(task, status);
1465                 break;
1466         default:
1467                 if (clnt->cl_chatty)
1468                         printk("%s: RPC call returned error %d\n",
1469                                clnt->cl_protname, -status);
1470                 rpc_exit(task, status);
1471         }
1472 }
1473
1474 /*
1475  * 6a.  Handle RPC timeout
1476  *      We do not release the request slot, so we keep using the
1477  *      same XID for all retransmits.
1478  */
1479 static void
1480 call_timeout(struct rpc_task *task)
1481 {
1482         struct rpc_clnt *clnt = task->tk_client;
1483
1484         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1485                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1486                 goto retry;
1487         }
1488
1489         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1490         task->tk_timeouts++;
1491
1492         if (RPC_IS_SOFTCONN(task)) {
1493                 rpc_exit(task, -ETIMEDOUT);
1494                 return;
1495         }
1496         if (RPC_IS_SOFT(task)) {
1497                 if (clnt->cl_chatty)
1498                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1499                                 clnt->cl_protname, clnt->cl_server);
1500                 rpc_exit(task, -EIO);
1501                 return;
1502         }
1503
1504         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1505                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1506                 if (clnt->cl_chatty)
1507                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1508                         clnt->cl_protname, clnt->cl_server);
1509         }
1510         rpc_force_rebind(clnt);
1511         /*
1512          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1513          * event? RFC2203 requires the server to drop all such requests.
1514          */
1515         rpcauth_invalcred(task);
1516
1517 retry:
1518         clnt->cl_stats->rpcretrans++;
1519         task->tk_action = call_bind;
1520         task->tk_status = 0;
1521 }
1522
1523 /*
1524  * 7.   Decode the RPC reply
1525  */
1526 static void
1527 call_decode(struct rpc_task *task)
1528 {
1529         struct rpc_clnt *clnt = task->tk_client;
1530         struct rpc_rqst *req = task->tk_rqstp;
1531         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1532         __be32          *p;
1533
1534         dprintk("RPC: %5u call_decode (status %d)\n",
1535                         task->tk_pid, task->tk_status);
1536
1537         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1538                 if (clnt->cl_chatty)
1539                         printk(KERN_NOTICE "%s: server %s OK\n",
1540                                 clnt->cl_protname, clnt->cl_server);
1541                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1542         }
1543
1544         /*
1545          * Ensure that we see all writes made by xprt_complete_rqst()
1546          * before it changed req->rq_reply_bytes_recvd.
1547          */
1548         smp_rmb();
1549         req->rq_rcv_buf.len = req->rq_private_buf.len;
1550
1551         /* Check that the softirq receive buffer is valid */
1552         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1553                                 sizeof(req->rq_rcv_buf)) != 0);
1554
1555         if (req->rq_rcv_buf.len < 12) {
1556                 if (!RPC_IS_SOFT(task)) {
1557                         task->tk_action = call_bind;
1558                         clnt->cl_stats->rpcretrans++;
1559                         goto out_retry;
1560                 }
1561                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1562                                 clnt->cl_protname, task->tk_status);
1563                 task->tk_action = call_timeout;
1564                 goto out_retry;
1565         }
1566
1567         p = rpc_verify_header(task);
1568         if (IS_ERR(p)) {
1569                 if (p == ERR_PTR(-EAGAIN))
1570                         goto out_retry;
1571                 return;
1572         }
1573
1574         task->tk_action = rpc_exit_task;
1575
1576         if (decode) {
1577                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1578                                                       task->tk_msg.rpc_resp);
1579         }
1580         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1581                         task->tk_status);
1582         return;
1583 out_retry:
1584         task->tk_status = 0;
1585         /* Note: rpc_verify_header() may have freed the RPC slot */
1586         if (task->tk_rqstp == req) {
1587                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1588                 if (task->tk_client->cl_discrtry)
1589                         xprt_conditional_disconnect(task->tk_xprt,
1590                                         req->rq_connect_cookie);
1591         }
1592 }
1593
1594 static __be32 *
1595 rpc_encode_header(struct rpc_task *task)
1596 {
1597         struct rpc_clnt *clnt = task->tk_client;
1598         struct rpc_rqst *req = task->tk_rqstp;
1599         __be32          *p = req->rq_svec[0].iov_base;
1600
1601         /* FIXME: check buffer size? */
1602
1603         p = xprt_skip_transport_header(task->tk_xprt, p);
1604         *p++ = req->rq_xid;             /* XID */
1605         *p++ = htonl(RPC_CALL);         /* CALL */
1606         *p++ = htonl(RPC_VERSION);      /* RPC version */
1607         *p++ = htonl(clnt->cl_prog);    /* program number */
1608         *p++ = htonl(clnt->cl_vers);    /* program version */
1609         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1610         p = rpcauth_marshcred(task, p);
1611         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1612         return p;
1613 }
1614
1615 static __be32 *
1616 rpc_verify_header(struct rpc_task *task)
1617 {
1618         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1619         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1620         __be32  *p = iov->iov_base;
1621         u32 n;
1622         int error = -EACCES;
1623
1624         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1625                 /* RFC-1014 says that the representation of XDR data must be a
1626                  * multiple of four bytes
1627                  * - if it isn't pointer subtraction in the NFS client may give
1628                  *   undefined results
1629                  */
1630                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1631                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1632                        task->tk_rqstp->rq_rcv_buf.len);
1633                 goto out_eio;
1634         }
1635         if ((len -= 3) < 0)
1636                 goto out_overflow;
1637
1638         p += 1; /* skip XID */
1639         if ((n = ntohl(*p++)) != RPC_REPLY) {
1640                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1641                         task->tk_pid, __func__, n);
1642                 goto out_garbage;
1643         }
1644
1645         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1646                 if (--len < 0)
1647                         goto out_overflow;
1648                 switch ((n = ntohl(*p++))) {
1649                         case RPC_AUTH_ERROR:
1650                                 break;
1651                         case RPC_MISMATCH:
1652                                 dprintk("RPC: %5u %s: RPC call version "
1653                                                 "mismatch!\n",
1654                                                 task->tk_pid, __func__);
1655                                 error = -EPROTONOSUPPORT;
1656                                 goto out_err;
1657                         default:
1658                                 dprintk("RPC: %5u %s: RPC call rejected, "
1659                                                 "unknown error: %x\n",
1660                                                 task->tk_pid, __func__, n);
1661                                 goto out_eio;
1662                 }
1663                 if (--len < 0)
1664                         goto out_overflow;
1665                 switch ((n = ntohl(*p++))) {
1666                 case RPC_AUTH_REJECTEDCRED:
1667                 case RPC_AUTH_REJECTEDVERF:
1668                 case RPCSEC_GSS_CREDPROBLEM:
1669                 case RPCSEC_GSS_CTXPROBLEM:
1670                         if (!task->tk_cred_retry)
1671                                 break;
1672                         task->tk_cred_retry--;
1673                         dprintk("RPC: %5u %s: retry stale creds\n",
1674                                         task->tk_pid, __func__);
1675                         rpcauth_invalcred(task);
1676                         /* Ensure we obtain a new XID! */
1677                         xprt_release(task);
1678                         task->tk_action = call_reserve;
1679                         goto out_retry;
1680                 case RPC_AUTH_BADCRED:
1681                 case RPC_AUTH_BADVERF:
1682                         /* possibly garbled cred/verf? */
1683                         if (!task->tk_garb_retry)
1684                                 break;
1685                         task->tk_garb_retry--;
1686                         dprintk("RPC: %5u %s: retry garbled creds\n",
1687                                         task->tk_pid, __func__);
1688                         task->tk_action = call_bind;
1689                         goto out_retry;
1690                 case RPC_AUTH_TOOWEAK:
1691                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1692                                "authentication.\n", task->tk_client->cl_server);
1693                         break;
1694                 default:
1695                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1696                                         task->tk_pid, __func__, n);
1697                         error = -EIO;
1698                 }
1699                 dprintk("RPC: %5u %s: call rejected %d\n",
1700                                 task->tk_pid, __func__, n);
1701                 goto out_err;
1702         }
1703         if (!(p = rpcauth_checkverf(task, p))) {
1704                 dprintk("RPC: %5u %s: auth check failed\n",
1705                                 task->tk_pid, __func__);
1706                 goto out_garbage;               /* bad verifier, retry */
1707         }
1708         len = p - (__be32 *)iov->iov_base - 1;
1709         if (len < 0)
1710                 goto out_overflow;
1711         switch ((n = ntohl(*p++))) {
1712         case RPC_SUCCESS:
1713                 return p;
1714         case RPC_PROG_UNAVAIL:
1715                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1716                                 task->tk_pid, __func__,
1717                                 (unsigned int)task->tk_client->cl_prog,
1718                                 task->tk_client->cl_server);
1719                 error = -EPFNOSUPPORT;
1720                 goto out_err;
1721         case RPC_PROG_MISMATCH:
1722                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1723                                 "server %s\n", task->tk_pid, __func__,
1724                                 (unsigned int)task->tk_client->cl_prog,
1725                                 (unsigned int)task->tk_client->cl_vers,
1726                                 task->tk_client->cl_server);
1727                 error = -EPROTONOSUPPORT;
1728                 goto out_err;
1729         case RPC_PROC_UNAVAIL:
1730                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1731                                 "version %u on server %s\n",
1732                                 task->tk_pid, __func__,
1733                                 rpc_proc_name(task),
1734                                 task->tk_client->cl_prog,
1735                                 task->tk_client->cl_vers,
1736                                 task->tk_client->cl_server);
1737                 error = -EOPNOTSUPP;
1738                 goto out_err;
1739         case RPC_GARBAGE_ARGS:
1740                 dprintk("RPC: %5u %s: server saw garbage\n",
1741                                 task->tk_pid, __func__);
1742                 break;                  /* retry */
1743         default:
1744                 dprintk("RPC: %5u %s: server accept status: %x\n",
1745                                 task->tk_pid, __func__, n);
1746                 /* Also retry */
1747         }
1748
1749 out_garbage:
1750         task->tk_client->cl_stats->rpcgarbage++;
1751         if (task->tk_garb_retry) {
1752                 task->tk_garb_retry--;
1753                 dprintk("RPC: %5u %s: retrying\n",
1754                                 task->tk_pid, __func__);
1755                 task->tk_action = call_bind;
1756 out_retry:
1757                 return ERR_PTR(-EAGAIN);
1758         }
1759 out_eio:
1760         error = -EIO;
1761 out_err:
1762         rpc_exit(task, error);
1763         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1764                         __func__, error);
1765         return ERR_PTR(error);
1766 out_overflow:
1767         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1768                         __func__);
1769         goto out_garbage;
1770 }
1771
1772 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1773 {
1774         return 0;
1775 }
1776
1777 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1778 {
1779         return 0;
1780 }
1781
1782 static struct rpc_procinfo rpcproc_null = {
1783         .p_encode = rpcproc_encode_null,
1784         .p_decode = rpcproc_decode_null,
1785 };
1786
1787 static int rpc_ping(struct rpc_clnt *clnt)
1788 {
1789         struct rpc_message msg = {
1790                 .rpc_proc = &rpcproc_null,
1791         };
1792         int err;
1793         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1794         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1795         put_rpccred(msg.rpc_cred);
1796         return err;
1797 }
1798
1799 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1800 {
1801         struct rpc_message msg = {
1802                 .rpc_proc = &rpcproc_null,
1803                 .rpc_cred = cred,
1804         };
1805         struct rpc_task_setup task_setup_data = {
1806                 .rpc_client = clnt,
1807                 .rpc_message = &msg,
1808                 .callback_ops = &rpc_default_ops,
1809                 .flags = flags,
1810         };
1811         return rpc_run_task(&task_setup_data);
1812 }
1813 EXPORT_SYMBOL_GPL(rpc_call_null);
1814
1815 #ifdef RPC_DEBUG
1816 static void rpc_show_header(void)
1817 {
1818         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1819                 "-timeout ---ops--\n");
1820 }
1821
1822 static void rpc_show_task(const struct rpc_clnt *clnt,
1823                           const struct rpc_task *task)
1824 {
1825         const char *rpc_waitq = "none";
1826         char *p, action[KSYM_SYMBOL_LEN];
1827
1828         if (RPC_IS_QUEUED(task))
1829                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1830
1831         /* map tk_action pointer to a function name; then trim off
1832          * the "+0x0 [sunrpc]" */
1833         sprint_symbol(action, (unsigned long)task->tk_action);
1834         p = strchr(action, '+');
1835         if (p)
1836                 *p = '\0';
1837
1838         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1839                 task->tk_pid, task->tk_flags, task->tk_status,
1840                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1841                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1842                 action, rpc_waitq);
1843 }
1844
1845 void rpc_show_tasks(void)
1846 {
1847         struct rpc_clnt *clnt;
1848         struct rpc_task *task;
1849         int header = 0;
1850
1851         spin_lock(&rpc_client_lock);
1852         list_for_each_entry(clnt, &all_clients, cl_clients) {
1853                 spin_lock(&clnt->cl_lock);
1854                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1855                         if (!header) {
1856                                 rpc_show_header();
1857                                 header++;
1858                         }
1859                         rpc_show_task(clnt, task);
1860                 }
1861                 spin_unlock(&clnt->cl_lock);
1862         }
1863         spin_unlock(&rpc_client_lock);
1864 }
1865 #endif