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  * 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 kref *kref)
 469 {
 470         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 471
 472         dprintk("RPC:       destroying %s client for %s\n",
 473                         clnt->cl_protname, clnt->cl_server);
 474         if (!IS_ERR(clnt->cl_path.dentry)) {
 475                 rpc_remove_client_dir(clnt->cl_path.dentry);
 476                 rpc_put_mount();
 477         }
 478         if (clnt->cl_parent != clnt) {
 479                 rpc_release_client(clnt->cl_parent);
 480                 goto out_free;
 481         }
 482         if (clnt->cl_server != clnt->cl_inline_name)
 483                 kfree(clnt->cl_server);
 484 out_free:
 485         rpc_unregister_client(clnt);
 486         rpc_free_iostats(clnt->cl_metrics);
 487         kfree(clnt->cl_principal);
 488         clnt->cl_metrics = NULL;
 489         xprt_put(clnt->cl_xprt);
 490         rpciod_down();
 491         kfree(clnt);
 492 }
 493
 494 /*
 495  * Free an RPC client
 496  */
 497 static void
 498 rpc_free_auth(struct kref *kref)
 499 {
 500         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
 501
 502         if (clnt->cl_auth == NULL) {
 503                 rpc_free_client(kref);
 504                 return;
 505         }
 506
 507         /*
 508          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 509          *       release remaining GSS contexts. This mechanism ensures
 510          *       that it can do so safely.
 511          */
 512         kref_init(kref);
 513         rpcauth_release(clnt->cl_auth);
 514         clnt->cl_auth = NULL;
 515         kref_put(kref, rpc_free_client);
 516 }
 517
 518 /*
 519  * Release reference to the RPC client
 520  */
 521 void
 522 rpc_release_client(struct rpc_clnt *clnt)
 523 {
 524         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 525
 526         if (list_empty(&clnt->cl_tasks))
 527                 wake_up(&destroy_wait);
 528         kref_put(&clnt->cl_kref, rpc_free_auth);
 529 }
 530
 531 /**
 532  * rpc_bind_new_program - bind a new RPC program to an existing client
 533  * @old: old rpc_client
 534  * @program: rpc program to set
 535  * @vers: rpc program version
 536  *
 537  * Clones the rpc client and sets up a new RPC program. This is mainly
 538  * of use for enabling different RPC programs to share the same transport.
 539  * The Sun NFSv2/v3 ACL protocol can do this.
 540  */
 541 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 542                                       struct rpc_program *program,
 543                                       u32 vers)
 544 {
 545         struct rpc_clnt *clnt;
 546         struct rpc_version *version;
 547         int err;
 548
 549         BUG_ON(vers >= program->nrvers || !program->version[vers]);
 550         version = program->version[vers];
 551         clnt = rpc_clone_client(old);
 552         if (IS_ERR(clnt))
 553                 goto out;
 554         clnt->cl_procinfo = version->procs;
 555         clnt->cl_maxproc  = version->nrprocs;
 556         clnt->cl_protname = program->name;
 557         clnt->cl_prog     = program->number;
 558         clnt->cl_vers     = version->number;
 559         clnt->cl_stats    = program->stats;
 560         err = rpc_ping(clnt);
 561         if (err != 0) {
 562                 rpc_shutdown_client(clnt);
 563                 clnt = ERR_PTR(err);
 564         }
 565 out:
 566         return clnt;
 567 }
 568 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 569
 570 void rpc_task_release_client(struct rpc_task *task)
 571 {
 572         struct rpc_clnt *clnt = task->tk_client;
 573
 574         if (clnt != NULL) {
 575                 /* Remove from client task list */
 576                 spin_lock(&clnt->cl_lock);
 577                 list_del(&task->tk_task);
 578                 spin_unlock(&clnt->cl_lock);
 579                 task->tk_client = NULL;
 580
 581                 rpc_release_client(clnt);
 582         }
 583 }
 584
 585 static
 586 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 587 {
 588         if (clnt != NULL) {
 589                 rpc_task_release_client(task);
 590                 task->tk_client = clnt;
 591                 kref_get(&clnt->cl_kref);
 592                 if (clnt->cl_softrtry)
 593                         task->tk_flags |= RPC_TASK_SOFT;
 594                 /* Add to the client's list of all tasks */
 595                 spin_lock(&clnt->cl_lock);
 596                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 597                 spin_unlock(&clnt->cl_lock);
 598         }
 599 }
 600
 601 static void
 602 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 603 {
 604         if (msg != NULL) {
 605                 task->tk_msg.rpc_proc = msg->rpc_proc;
 606                 task->tk_msg.rpc_argp = msg->rpc_argp;
 607                 task->tk_msg.rpc_resp = msg->rpc_resp;
 608                 /* Bind the user cred */
 609                 rpcauth_bindcred(task, msg->rpc_cred, task->tk_flags);
 610         }
 611 }
 612
 613 /*
 614  * Default callback for async RPC calls
 615  */
 616 static void
 617 rpc_default_callback(struct rpc_task *task, void *data)
 618 {
 619 }
 620
 621 static const struct rpc_call_ops rpc_default_ops = {
 622         .rpc_call_done = rpc_default_callback,
 623 };
 624
 625 /**
 626  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
 627  * @task_setup_data: pointer to task initialisation data
 628  */
 629 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 630 {
 631         struct rpc_task *task;
 632
 633         task = rpc_new_task(task_setup_data);
 634         if (IS_ERR(task))
 635                 goto out;
 636
 637         rpc_task_set_client(task, task_setup_data->rpc_client);
 638         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
 639
 640         if (task->tk_status != 0) {
 641                 int ret = task->tk_status;
 642                 rpc_put_task(task);
 643                 return ERR_PTR(ret);
 644         }
 645
 646         if (task->tk_action == NULL)
 647                 rpc_call_start(task);
 648
 649         atomic_inc(&task->tk_count);
 650         rpc_execute(task);
 651 out:
 652         return task;
 653 }
 654 EXPORT_SYMBOL_GPL(rpc_run_task);
 655
 656 /**
 657  * rpc_call_sync - Perform a synchronous RPC call
 658  * @clnt: pointer to RPC client
 659  * @msg: RPC call parameters
 660  * @flags: RPC call flags
 661  */
 662 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
 663 {
 664         struct rpc_task *task;
 665         struct rpc_task_setup task_setup_data = {
 666                 .rpc_client = clnt,
 667                 .rpc_message = msg,
 668                 .callback_ops = &rpc_default_ops,
 669                 .flags = flags,
 670         };
 671         int status;
 672
 673         BUG_ON(flags & RPC_TASK_ASYNC);
 674
 675         task = rpc_run_task(&task_setup_data);
 676         if (IS_ERR(task))
 677                 return PTR_ERR(task);
 678         status = task->tk_status;
 679         rpc_put_task(task);
 680         return status;
 681 }
 682 EXPORT_SYMBOL_GPL(rpc_call_sync);
 683
 684 /**
 685  * rpc_call_async - Perform an asynchronous RPC call
 686  * @clnt: pointer to RPC client
 687  * @msg: RPC call parameters
 688  * @flags: RPC call flags
 689  * @tk_ops: RPC call ops
 690  * @data: user call data
 691  */
 692 int
 693 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
 694                const struct rpc_call_ops *tk_ops, void *data)
 695 {
 696         struct rpc_task *task;
 697         struct rpc_task_setup task_setup_data = {
 698                 .rpc_client = clnt,
 699                 .rpc_message = msg,
 700                 .callback_ops = tk_ops,
 701                 .callback_data = data,
 702                 .flags = flags|RPC_TASK_ASYNC,
 703         };
 704
 705         task = rpc_run_task(&task_setup_data);
 706         if (IS_ERR(task))
 707                 return PTR_ERR(task);
 708         rpc_put_task(task);
 709         return 0;
 710 }
 711 EXPORT_SYMBOL_GPL(rpc_call_async);
 712
 713 #if defined(CONFIG_NFS_V4_1)
 714 /**
 715  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
 716  * rpc_execute against it
 717  * @req: RPC request
 718  * @tk_ops: RPC call ops
 719  */
 720 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
 721                                 const struct rpc_call_ops *tk_ops)
 722 {
 723         struct rpc_task *task;
 724         struct xdr_buf *xbufp = &req->rq_snd_buf;
 725         struct rpc_task_setup task_setup_data = {
 726                 .callback_ops = tk_ops,
 727         };
 728
 729         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
 730         /*
 731          * Create an rpc_task to send the data
 732          */
 733         task = rpc_new_task(&task_setup_data);
 734         if (IS_ERR(task)) {
 735                 xprt_free_bc_request(req);
 736                 goto out;
 737         }
 738         task->tk_rqstp = req;
 739
 740         /*
 741          * Set up the xdr_buf length.
 742          * This also indicates that the buffer is XDR encoded already.
 743          */
 744         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
 745                         xbufp->tail[0].iov_len;
 746
 747         task->tk_action = call_bc_transmit;
 748         atomic_inc(&task->tk_count);
 749         BUG_ON(atomic_read(&task->tk_count) != 2);
 750         rpc_execute(task);
 751
 752 out:
 753         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 754         return task;
 755 }
 756 #endif /* CONFIG_NFS_V4_1 */
 757
 758 void
 759 rpc_call_start(struct rpc_task *task)
 760 {
 761         task->tk_action = call_start;
 762 }
 763 EXPORT_SYMBOL_GPL(rpc_call_start);
 764
 765 /**
 766  * rpc_peeraddr - extract remote peer address from clnt's xprt
 767  * @clnt: RPC client structure
 768  * @buf: target buffer
 769  * @bufsize: length of target buffer
 770  *
 771  * Returns the number of bytes that are actually in the stored address.
 772  */
 773 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
 774 {
 775         size_t bytes;
 776         struct rpc_xprt *xprt = clnt->cl_xprt;
 777
 778         bytes = sizeof(xprt->addr);
 779         if (bytes > bufsize)
 780                 bytes = bufsize;
 781         memcpy(buf, &clnt->cl_xprt->addr, bytes);
 782         return xprt->addrlen;
 783 }
 784 EXPORT_SYMBOL_GPL(rpc_peeraddr);
 785
 786 /**
 787  * rpc_peeraddr2str - return remote peer address in printable format
 788  * @clnt: RPC client structure
 789  * @format: address format
 790  *
 791  */
 792 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
 793                              enum rpc_display_format_t format)
 794 {
 795         struct rpc_xprt *xprt = clnt->cl_xprt;
 796
 797         if (xprt->address_strings[format] != NULL)
 798                 return xprt->address_strings[format];
 799         else
 800                 return "unprintable";
 801 }
 802 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
 803
 804 void
 805 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
 806 {
 807         struct rpc_xprt *xprt = clnt->cl_xprt;
 808         if (xprt->ops->set_buffer_size)
 809                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
 810 }
 811 EXPORT_SYMBOL_GPL(rpc_setbufsize);
 812
 813 /*
 814  * Return size of largest payload RPC client can support, in bytes
 815  *
 816  * For stream transports, this is one RPC record fragment (see RFC
 817  * 1831), as we don't support multi-record requests yet.  For datagram
 818  * transports, this is the size of an IP packet minus the IP, UDP, and
 819  * RPC header sizes.
 820  */
 821 size_t rpc_max_payload(struct rpc_clnt *clnt)
 822 {
 823         return clnt->cl_xprt->max_payload;
 824 }
 825 EXPORT_SYMBOL_GPL(rpc_max_payload);
 826
 827 /**
 828  * rpc_force_rebind - force transport to check that remote port is unchanged
 829  * @clnt: client to rebind
 830  *
 831  */
 832 void rpc_force_rebind(struct rpc_clnt *clnt)
 833 {
 834         if (clnt->cl_autobind)
 835                 xprt_clear_bound(clnt->cl_xprt);
 836 }
 837 EXPORT_SYMBOL_GPL(rpc_force_rebind);
 838
 839 /*
 840  * Restart an (async) RPC call from the call_prepare state.
 841  * Usually called from within the exit handler.
 842  */
 843 int
 844 rpc_restart_call_prepare(struct rpc_task *task)
 845 {
 846         if (RPC_ASSASSINATED(task))
 847                 return 0;
 848         task->tk_action = rpc_prepare_task;
 849         return 1;
 850 }
 851 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
 852
 853 /*
 854  * Restart an (async) RPC call. Usually called from within the
 855  * exit handler.
 856  */
 857 int
 858 rpc_restart_call(struct rpc_task *task)
 859 {
 860         if (RPC_ASSASSINATED(task))
 861                 return 0;
 862         task->tk_action = call_start;
 863         return 1;
 864 }
 865 EXPORT_SYMBOL_GPL(rpc_restart_call);
 866
 867 #ifdef RPC_DEBUG
 868 static const char *rpc_proc_name(const struct rpc_task *task)
 869 {
 870         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 871
 872         if (proc) {
 873                 if (proc->p_name)
 874                         return proc->p_name;
 875                 else
 876                         return "NULL";
 877         } else
 878                 return "no proc";
 879 }
 880 #endif
 881
 882 /*
 883  * 0.  Initial state
 884  *
 885  *     Other FSM states can be visited zero or more times, but
 886  *     this state is visited exactly once for each RPC.
 887  */
 888 static void
 889 call_start(struct rpc_task *task)
 890 {
 891         struct rpc_clnt *clnt = task->tk_client;
 892
 893         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
 894                         clnt->cl_protname, clnt->cl_vers,
 895                         rpc_proc_name(task),
 896                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
 897
 898         /* Increment call count */
 899         task->tk_msg.rpc_proc->p_count++;
 900         clnt->cl_stats->rpccnt++;
 901         task->tk_action = call_reserve;
 902 }
 903
 904 /*
 905  * 1.   Reserve an RPC call slot
 906  */
 907 static void
 908 call_reserve(struct rpc_task *task)
 909 {
 910         dprint_status(task);
 911
 912         if (!rpcauth_uptodatecred(task)) {
 913                 task->tk_action = call_refresh;
 914                 return;
 915         }
 916
 917         task->tk_status  = 0;
 918         task->tk_action  = call_reserveresult;
 919         xprt_reserve(task);
 920 }
 921
 922 /*
 923  * 1b.  Grok the result of xprt_reserve()
 924  */
 925 static void
 926 call_reserveresult(struct rpc_task *task)
 927 {
 928         int status = task->tk_status;
 929
 930         dprint_status(task);
 931
 932         /*
 933          * After a call to xprt_reserve(), we must have either
 934          * a request slot or else an error status.
 935          */
 936         task->tk_status = 0;
 937         if (status >= 0) {
 938                 if (task->tk_rqstp) {
 939                         task->tk_action = call_allocate;
 940                         return;
 941                 }
 942
 943                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
 944                                 __func__, status);
 945                 rpc_exit(task, -EIO);
 946                 return;
 947         }
 948
 949         /*
 950          * Even though there was an error, we may have acquired
 951          * a request slot somehow.  Make sure not to leak it.
 952          */
 953         if (task->tk_rqstp) {
 954                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
 955                                 __func__, status);
 956                 xprt_release(task);
 957         }
 958
 959         switch (status) {
 960         case -EAGAIN:   /* woken up; retry */
 961                 task->tk_action = call_reserve;
 962                 return;
 963         case -EIO:      /* probably a shutdown */
 964                 break;
 965         default:
 966                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
 967                                 __func__, status);
 968                 break;
 969         }
 970         rpc_exit(task, status);
 971 }
 972
 973 /*
 974  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
 975  *      (Note: buffer memory is freed in xprt_release).
 976  */
 977 static void
 978 call_allocate(struct rpc_task *task)
 979 {
 980         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
 981         struct rpc_rqst *req = task->tk_rqstp;
 982         struct rpc_xprt *xprt = task->tk_xprt;
 983         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
 984
 985         dprint_status(task);
 986
 987         task->tk_status = 0;
 988         task->tk_action = call_bind;
 989
 990         if (req->rq_buffer)
 991                 return;
 992
 993         if (proc->p_proc != 0) {
 994                 BUG_ON(proc->p_arglen == 0);
 995                 if (proc->p_decode != NULL)
 996                         BUG_ON(proc->p_replen == 0);
 997         }
 998
 999         /*
1000          * Calculate the size (in quads) of the RPC call
1001          * and reply headers, and convert both values
1002          * to byte sizes.
1003          */
1004         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1005         req->rq_callsize <<= 2;
1006         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1007         req->rq_rcvsize <<= 2;
1008
1009         req->rq_buffer = xprt->ops->buf_alloc(task,
1010                                         req->rq_callsize + req->rq_rcvsize);
1011         if (req->rq_buffer != NULL)
1012                 return;
1013
1014         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1015
1016         if (RPC_IS_ASYNC(task) || !signalled()) {
1017                 task->tk_action = call_allocate;
1018                 rpc_delay(task, HZ>>4);
1019                 return;
1020         }
1021
1022         rpc_exit(task, -ERESTARTSYS);
1023 }
1024
1025 static inline int
1026 rpc_task_need_encode(struct rpc_task *task)
1027 {
1028         return task->tk_rqstp->rq_snd_buf.len == 0;
1029 }
1030
1031 static inline void
1032 rpc_task_force_reencode(struct rpc_task *task)
1033 {
1034         task->tk_rqstp->rq_snd_buf.len = 0;
1035         task->tk_rqstp->rq_bytes_sent = 0;
1036 }
1037
1038 static inline void
1039 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1040 {
1041         buf->head[0].iov_base = start;
1042         buf->head[0].iov_len = len;
1043         buf->tail[0].iov_len = 0;
1044         buf->page_len = 0;
1045         buf->flags = 0;
1046         buf->len = 0;
1047         buf->buflen = len;
1048 }
1049
1050 /*
1051  * 3.   Encode arguments of an RPC call
1052  */
1053 static void
1054 rpc_xdr_encode(struct rpc_task *task)
1055 {
1056         struct rpc_rqst *req = task->tk_rqstp;
1057         kxdrproc_t      encode;
1058         __be32          *p;
1059
1060         dprint_status(task);
1061
1062         rpc_xdr_buf_init(&req->rq_snd_buf,
1063                          req->rq_buffer,
1064                          req->rq_callsize);
1065         rpc_xdr_buf_init(&req->rq_rcv_buf,
1066                          (char *)req->rq_buffer + req->rq_callsize,
1067                          req->rq_rcvsize);
1068
1069         p = rpc_encode_header(task);
1070         if (p == NULL) {
1071                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1072                 rpc_exit(task, -EIO);
1073                 return;
1074         }
1075
1076         encode = task->tk_msg.rpc_proc->p_encode;
1077         if (encode == NULL)
1078                 return;
1079
1080         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1081                         task->tk_msg.rpc_argp);
1082 }
1083
1084 /*
1085  * 4.   Get the server port number if not yet set
1086  */
1087 static void
1088 call_bind(struct rpc_task *task)
1089 {
1090         struct rpc_xprt *xprt = task->tk_xprt;
1091
1092         dprint_status(task);
1093
1094         task->tk_action = call_connect;
1095         if (!xprt_bound(xprt)) {
1096                 task->tk_action = call_bind_status;
1097                 task->tk_timeout = xprt->bind_timeout;
1098                 xprt->ops->rpcbind(task);
1099         }
1100 }
1101
1102 /*
1103  * 4a.  Sort out bind result
1104  */
1105 static void
1106 call_bind_status(struct rpc_task *task)
1107 {
1108         int status = -EIO;
1109
1110         if (task->tk_status >= 0) {
1111                 dprint_status(task);
1112                 task->tk_status = 0;
1113                 task->tk_action = call_connect;
1114                 return;
1115         }
1116
1117         switch (task->tk_status) {
1118         case -ENOMEM:
1119                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1120                 rpc_delay(task, HZ >> 2);
1121                 goto retry_timeout;
1122         case -EACCES:
1123                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1124                                 "unavailable\n", task->tk_pid);
1125                 /* fail immediately if this is an RPC ping */
1126                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1127                         status = -EOPNOTSUPP;
1128                         break;
1129                 }
1130                 rpc_delay(task, 3*HZ);
1131                 goto retry_timeout;
1132         case -ETIMEDOUT:
1133                 dprintk("RPC: %5u rpcbind request timed out\n",
1134                                 task->tk_pid);
1135                 goto retry_timeout;
1136         case -EPFNOSUPPORT:
1137                 /* server doesn't support any rpcbind version we know of */
1138                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1139                                 task->tk_pid);
1140                 break;
1141         case -EPROTONOSUPPORT:
1142                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1143                                 task->tk_pid);
1144                 task->tk_status = 0;
1145                 task->tk_action = call_bind;
1146                 return;
1147         case -ECONNREFUSED:             /* connection problems */
1148         case -ECONNRESET:
1149         case -ENOTCONN:
1150         case -EHOSTDOWN:
1151         case -EHOSTUNREACH:
1152         case -ENETUNREACH:
1153         case -EPIPE:
1154                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1155                                 task->tk_pid, task->tk_status);
1156                 if (!RPC_IS_SOFTCONN(task)) {
1157                         rpc_delay(task, 5*HZ);
1158                         goto retry_timeout;
1159                 }
1160                 status = task->tk_status;
1161                 break;
1162         default:
1163                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1164                                 task->tk_pid, -task->tk_status);
1165         }
1166
1167         rpc_exit(task, status);
1168         return;
1169
1170 retry_timeout:
1171         task->tk_action = call_timeout;
1172 }
1173
1174 /*
1175  * 4b.  Connect to the RPC server
1176  */
1177 static void
1178 call_connect(struct rpc_task *task)
1179 {
1180         struct rpc_xprt *xprt = task->tk_xprt;
1181
1182         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1183                         task->tk_pid, xprt,
1184                         (xprt_connected(xprt) ? "is" : "is not"));
1185
1186         task->tk_action = call_transmit;
1187         if (!xprt_connected(xprt)) {
1188                 task->tk_action = call_connect_status;
1189                 if (task->tk_status < 0)
1190                         return;
1191                 xprt_connect(task);
1192         }
1193 }
1194
1195 /*
1196  * 4c.  Sort out connect result
1197  */
1198 static void
1199 call_connect_status(struct rpc_task *task)
1200 {
1201         struct rpc_clnt *clnt = task->tk_client;
1202         int status = task->tk_status;
1203
1204         dprint_status(task);
1205
1206         task->tk_status = 0;
1207         if (status >= 0 || status == -EAGAIN) {
1208                 clnt->cl_stats->netreconn++;
1209                 task->tk_action = call_transmit;
1210                 return;
1211         }
1212
1213         switch (status) {
1214                 /* if soft mounted, test if we've timed out */
1215         case -ETIMEDOUT:
1216                 task->tk_action = call_timeout;
1217                 break;
1218         default:
1219                 rpc_exit(task, -EIO);
1220         }
1221 }
1222
1223 /*
1224  * 5.   Transmit the RPC request, and wait for reply
1225  */
1226 static void
1227 call_transmit(struct rpc_task *task)
1228 {
1229         dprint_status(task);
1230
1231         task->tk_action = call_status;
1232         if (task->tk_status < 0)
1233                 return;
1234         task->tk_status = xprt_prepare_transmit(task);
1235         if (task->tk_status != 0)
1236                 return;
1237         task->tk_action = call_transmit_status;
1238         /* Encode here so that rpcsec_gss can use correct sequence number. */
1239         if (rpc_task_need_encode(task)) {
1240                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1241                 rpc_xdr_encode(task);
1242                 /* Did the encode result in an error condition? */
1243                 if (task->tk_status != 0) {
1244                         /* Was the error nonfatal? */
1245                         if (task->tk_status == -EAGAIN)
1246                                 rpc_delay(task, HZ >> 4);
1247                         else
1248                                 rpc_exit(task, task->tk_status);
1249                         return;
1250                 }
1251         }
1252         xprt_transmit(task);
1253         if (task->tk_status < 0)
1254                 return;
1255         /*
1256          * On success, ensure that we call xprt_end_transmit() before sleeping
1257          * in order to allow access to the socket to other RPC requests.
1258          */
1259         call_transmit_status(task);
1260         if (rpc_reply_expected(task))
1261                 return;
1262         task->tk_action = rpc_exit_task;
1263         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1264 }
1265
1266 /*
1267  * 5a.  Handle cleanup after a transmission
1268  */
1269 static void
1270 call_transmit_status(struct rpc_task *task)
1271 {
1272         task->tk_action = call_status;
1273
1274         /*
1275          * Common case: success.  Force the compiler to put this
1276          * test first.
1277          */
1278         if (task->tk_status == 0) {
1279                 xprt_end_transmit(task);
1280                 rpc_task_force_reencode(task);
1281                 return;
1282         }
1283
1284         switch (task->tk_status) {
1285         case -EAGAIN:
1286                 break;
1287         default:
1288                 dprint_status(task);
1289                 xprt_end_transmit(task);
1290                 rpc_task_force_reencode(task);
1291                 break;
1292                 /*
1293                  * Special cases: if we've been waiting on the
1294                  * socket's write_space() callback, or if the
1295                  * socket just returned a connection error,
1296                  * then hold onto the transport lock.
1297                  */
1298         case -ECONNREFUSED:
1299         case -EHOSTDOWN:
1300         case -EHOSTUNREACH:
1301         case -ENETUNREACH:
1302                 if (RPC_IS_SOFTCONN(task)) {
1303                         xprt_end_transmit(task);
1304                         rpc_exit(task, task->tk_status);
1305                         break;
1306                 }
1307         case -ECONNRESET:
1308         case -ENOTCONN:
1309         case -EPIPE:
1310                 rpc_task_force_reencode(task);
1311         }
1312 }
1313
1314 #if defined(CONFIG_NFS_V4_1)
1315 /*
1316  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1317  * addition, disconnect on connectivity errors.
1318  */
1319 static void
1320 call_bc_transmit(struct rpc_task *task)
1321 {
1322         struct rpc_rqst *req = task->tk_rqstp;
1323
1324         BUG_ON(task->tk_status != 0);
1325         task->tk_status = xprt_prepare_transmit(task);
1326         if (task->tk_status == -EAGAIN) {
1327                 /*
1328                  * Could not reserve the transport. Try again after the
1329                  * transport is released.
1330                  */
1331                 task->tk_status = 0;
1332                 task->tk_action = call_bc_transmit;
1333                 return;
1334         }
1335
1336         task->tk_action = rpc_exit_task;
1337         if (task->tk_status < 0) {
1338                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1339                         "error: %d\n", task->tk_status);
1340                 return;
1341         }
1342
1343         xprt_transmit(task);
1344         xprt_end_transmit(task);
1345         dprint_status(task);
1346         switch (task->tk_status) {
1347         case 0:
1348                 /* Success */
1349                 break;
1350         case -EHOSTDOWN:
1351         case -EHOSTUNREACH:
1352         case -ENETUNREACH:
1353         case -ETIMEDOUT:
1354                 /*
1355                  * Problem reaching the server.  Disconnect and let the
1356                  * forechannel reestablish the connection.  The server will
1357                  * have to retransmit the backchannel request and we'll
1358                  * reprocess it.  Since these ops are idempotent, there's no
1359                  * need to cache our reply at this time.
1360                  */
1361                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1362                         "error: %d\n", task->tk_status);
1363                 xprt_conditional_disconnect(task->tk_xprt,
1364                         req->rq_connect_cookie);
1365                 break;
1366         default:
1367                 /*
1368                  * We were unable to reply and will have to drop the
1369                  * request.  The server should reconnect and retransmit.
1370                  */
1371                 BUG_ON(task->tk_status == -EAGAIN);
1372                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1373                         "error: %d\n", task->tk_status);
1374                 break;
1375         }
1376         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1377 }
1378 #endif /* CONFIG_NFS_V4_1 */
1379
1380 /*
1381  * 6.   Sort out the RPC call status
1382  */
1383 static void
1384 call_status(struct rpc_task *task)
1385 {
1386         struct rpc_clnt *clnt = task->tk_client;
1387         struct rpc_rqst *req = task->tk_rqstp;
1388         int             status;
1389
1390         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1391                 task->tk_status = req->rq_reply_bytes_recvd;
1392
1393         dprint_status(task);
1394
1395         status = task->tk_status;
1396         if (status >= 0) {
1397                 task->tk_action = call_decode;
1398                 return;
1399         }
1400
1401         task->tk_status = 0;
1402         switch(status) {
1403         case -EHOSTDOWN:
1404         case -EHOSTUNREACH:
1405         case -ENETUNREACH:
1406                 /*
1407                  * Delay any retries for 3 seconds, then handle as if it
1408                  * were a timeout.
1409                  */
1410                 rpc_delay(task, 3*HZ);
1411         case -ETIMEDOUT:
1412                 task->tk_action = call_timeout;
1413                 if (task->tk_client->cl_discrtry)
1414                         xprt_conditional_disconnect(task->tk_xprt,
1415                                         req->rq_connect_cookie);
1416                 break;
1417         case -ECONNRESET:
1418         case -ECONNREFUSED:
1419                 rpc_force_rebind(clnt);
1420                 rpc_delay(task, 3*HZ);
1421         case -EPIPE:
1422         case -ENOTCONN:
1423                 task->tk_action = call_bind;
1424                 break;
1425         case -EAGAIN:
1426                 task->tk_action = call_transmit;
1427                 break;
1428         case -EIO:
1429                 /* shutdown or soft timeout */
1430                 rpc_exit(task, status);
1431                 break;
1432         default:
1433                 if (clnt->cl_chatty)
1434                         printk("%s: RPC call returned error %d\n",
1435                                clnt->cl_protname, -status);
1436                 rpc_exit(task, status);
1437         }
1438 }
1439
1440 /*
1441  * 6a.  Handle RPC timeout
1442  *      We do not release the request slot, so we keep using the
1443  *      same XID for all retransmits.
1444  */
1445 static void
1446 call_timeout(struct rpc_task *task)
1447 {
1448         struct rpc_clnt *clnt = task->tk_client;
1449
1450         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1451                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1452                 goto retry;
1453         }
1454
1455         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1456         task->tk_timeouts++;
1457
1458         if (RPC_IS_SOFTCONN(task)) {
1459                 rpc_exit(task, -ETIMEDOUT);
1460                 return;
1461         }
1462         if (RPC_IS_SOFT(task)) {
1463                 if (clnt->cl_chatty)
1464                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1465                                 clnt->cl_protname, clnt->cl_server);
1466                 rpc_exit(task, -EIO);
1467                 return;
1468         }
1469
1470         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1471                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1472                 if (clnt->cl_chatty)
1473                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1474                         clnt->cl_protname, clnt->cl_server);
1475         }
1476         rpc_force_rebind(clnt);
1477         /*
1478          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1479          * event? RFC2203 requires the server to drop all such requests.
1480          */
1481         rpcauth_invalcred(task);
1482
1483 retry:
1484         clnt->cl_stats->rpcretrans++;
1485         task->tk_action = call_bind;
1486         task->tk_status = 0;
1487 }
1488
1489 /*
1490  * 7.   Decode the RPC reply
1491  */
1492 static void
1493 call_decode(struct rpc_task *task)
1494 {
1495         struct rpc_clnt *clnt = task->tk_client;
1496         struct rpc_rqst *req = task->tk_rqstp;
1497         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1498         __be32          *p;
1499
1500         dprintk("RPC: %5u call_decode (status %d)\n",
1501                         task->tk_pid, task->tk_status);
1502
1503         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1504                 if (clnt->cl_chatty)
1505                         printk(KERN_NOTICE "%s: server %s OK\n",
1506                                 clnt->cl_protname, clnt->cl_server);
1507                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1508         }
1509
1510         /*
1511          * Ensure that we see all writes made by xprt_complete_rqst()
1512          * before it changed req->rq_reply_bytes_recvd.
1513          */
1514         smp_rmb();
1515         req->rq_rcv_buf.len = req->rq_private_buf.len;
1516
1517         /* Check that the softirq receive buffer is valid */
1518         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1519                                 sizeof(req->rq_rcv_buf)) != 0);
1520
1521         if (req->rq_rcv_buf.len < 12) {
1522                 if (!RPC_IS_SOFT(task)) {
1523                         task->tk_action = call_bind;
1524                         clnt->cl_stats->rpcretrans++;
1525                         goto out_retry;
1526                 }
1527                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1528                                 clnt->cl_protname, task->tk_status);
1529                 task->tk_action = call_timeout;
1530                 goto out_retry;
1531         }
1532
1533         p = rpc_verify_header(task);
1534         if (IS_ERR(p)) {
1535                 if (p == ERR_PTR(-EAGAIN))
1536                         goto out_retry;
1537                 return;
1538         }
1539
1540         task->tk_action = rpc_exit_task;
1541
1542         if (decode) {
1543                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1544                                                       task->tk_msg.rpc_resp);
1545         }
1546         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1547                         task->tk_status);
1548         return;
1549 out_retry:
1550         task->tk_status = 0;
1551         /* Note: rpc_verify_header() may have freed the RPC slot */
1552         if (task->tk_rqstp == req) {
1553                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1554                 if (task->tk_client->cl_discrtry)
1555                         xprt_conditional_disconnect(task->tk_xprt,
1556                                         req->rq_connect_cookie);
1557         }
1558 }
1559
1560 /*
1561  * 8.   Refresh the credentials if rejected by the server
1562  */
1563 static void
1564 call_refresh(struct rpc_task *task)
1565 {
1566         dprint_status(task);
1567
1568         task->tk_action = call_refreshresult;
1569         task->tk_status = 0;
1570         task->tk_client->cl_stats->rpcauthrefresh++;
1571         rpcauth_refreshcred(task);
1572 }
1573
1574 /*
1575  * 8a.  Process the results of a credential refresh
1576  */
1577 static void
1578 call_refreshresult(struct rpc_task *task)
1579 {
1580         int status = task->tk_status;
1581
1582         dprint_status(task);
1583
1584         task->tk_status = 0;
1585         task->tk_action = call_reserve;
1586         if (status >= 0 && rpcauth_uptodatecred(task))
1587                 return;
1588         if (status == -EACCES) {
1589                 rpc_exit(task, -EACCES);
1590                 return;
1591         }
1592         task->tk_action = call_refresh;
1593         if (status != -ETIMEDOUT)
1594                 rpc_delay(task, 3*HZ);
1595 }
1596
1597 static __be32 *
1598 rpc_encode_header(struct rpc_task *task)
1599 {
1600         struct rpc_clnt *clnt = task->tk_client;
1601         struct rpc_rqst *req = task->tk_rqstp;
1602         __be32          *p = req->rq_svec[0].iov_base;
1603
1604         /* FIXME: check buffer size? */
1605
1606         p = xprt_skip_transport_header(task->tk_xprt, p);
1607         *p++ = req->rq_xid;             /* XID */
1608         *p++ = htonl(RPC_CALL);         /* CALL */
1609         *p++ = htonl(RPC_VERSION);      /* RPC version */
1610         *p++ = htonl(clnt->cl_prog);    /* program number */
1611         *p++ = htonl(clnt->cl_vers);    /* program version */
1612         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1613         p = rpcauth_marshcred(task, p);
1614         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1615         return p;
1616 }
1617
1618 static __be32 *
1619 rpc_verify_header(struct rpc_task *task)
1620 {
1621         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1622         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1623         __be32  *p = iov->iov_base;
1624         u32 n;
1625         int error = -EACCES;
1626
1627         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1628                 /* RFC-1014 says that the representation of XDR data must be a
1629                  * multiple of four bytes
1630                  * - if it isn't pointer subtraction in the NFS client may give
1631                  *   undefined results
1632                  */
1633                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1634                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1635                        task->tk_rqstp->rq_rcv_buf.len);
1636                 goto out_eio;
1637         }
1638         if ((len -= 3) < 0)
1639                 goto out_overflow;
1640
1641         p += 1; /* skip XID */
1642         if ((n = ntohl(*p++)) != RPC_REPLY) {
1643                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1644                         task->tk_pid, __func__, n);
1645                 goto out_garbage;
1646         }
1647
1648         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1649                 if (--len < 0)
1650                         goto out_overflow;
1651                 switch ((n = ntohl(*p++))) {
1652                         case RPC_AUTH_ERROR:
1653                                 break;
1654                         case RPC_MISMATCH:
1655                                 dprintk("RPC: %5u %s: RPC call version "
1656                                                 "mismatch!\n",
1657                                                 task->tk_pid, __func__);
1658                                 error = -EPROTONOSUPPORT;
1659                                 goto out_err;
1660                         default:
1661                                 dprintk("RPC: %5u %s: RPC call rejected, "
1662                                                 "unknown error: %x\n",
1663                                                 task->tk_pid, __func__, n);
1664                                 goto out_eio;
1665                 }
1666                 if (--len < 0)
1667                         goto out_overflow;
1668                 switch ((n = ntohl(*p++))) {
1669                 case RPC_AUTH_REJECTEDCRED:
1670                 case RPC_AUTH_REJECTEDVERF:
1671                 case RPCSEC_GSS_CREDPROBLEM:
1672                 case RPCSEC_GSS_CTXPROBLEM:
1673                         if (!task->tk_cred_retry)
1674                                 break;
1675                         task->tk_cred_retry--;
1676                         dprintk("RPC: %5u %s: retry stale creds\n",
1677                                         task->tk_pid, __func__);
1678                         rpcauth_invalcred(task);
1679                         /* Ensure we obtain a new XID! */
1680                         xprt_release(task);
1681                         task->tk_action = call_refresh;
1682                         goto out_retry;
1683                 case RPC_AUTH_BADCRED:
1684                 case RPC_AUTH_BADVERF:
1685                         /* possibly garbled cred/verf? */
1686                         if (!task->tk_garb_retry)
1687                                 break;
1688                         task->tk_garb_retry--;
1689                         dprintk("RPC: %5u %s: retry garbled creds\n",
1690                                         task->tk_pid, __func__);
1691                         task->tk_action = call_bind;
1692                         goto out_retry;
1693                 case RPC_AUTH_TOOWEAK:
1694                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1695                                "authentication.\n", task->tk_client->cl_server);
1696                         break;
1697                 default:
1698                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1699                                         task->tk_pid, __func__, n);
1700                         error = -EIO;
1701                 }
1702                 dprintk("RPC: %5u %s: call rejected %d\n",
1703                                 task->tk_pid, __func__, n);
1704                 goto out_err;
1705         }
1706         if (!(p = rpcauth_checkverf(task, p))) {
1707                 dprintk("RPC: %5u %s: auth check failed\n",
1708                                 task->tk_pid, __func__);
1709                 goto out_garbage;               /* bad verifier, retry */
1710         }
1711         len = p - (__be32 *)iov->iov_base - 1;
1712         if (len < 0)
1713                 goto out_overflow;
1714         switch ((n = ntohl(*p++))) {
1715         case RPC_SUCCESS:
1716                 return p;
1717         case RPC_PROG_UNAVAIL:
1718                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1719                                 task->tk_pid, __func__,
1720                                 (unsigned int)task->tk_client->cl_prog,
1721                                 task->tk_client->cl_server);
1722                 error = -EPFNOSUPPORT;
1723                 goto out_err;
1724         case RPC_PROG_MISMATCH:
1725                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1726                                 "server %s\n", task->tk_pid, __func__,
1727                                 (unsigned int)task->tk_client->cl_prog,
1728                                 (unsigned int)task->tk_client->cl_vers,
1729                                 task->tk_client->cl_server);
1730                 error = -EPROTONOSUPPORT;
1731                 goto out_err;
1732         case RPC_PROC_UNAVAIL:
1733                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1734                                 "version %u on server %s\n",
1735                                 task->tk_pid, __func__,
1736                                 rpc_proc_name(task),
1737                                 task->tk_client->cl_prog,
1738                                 task->tk_client->cl_vers,
1739                                 task->tk_client->cl_server);
1740                 error = -EOPNOTSUPP;
1741                 goto out_err;
1742         case RPC_GARBAGE_ARGS:
1743                 dprintk("RPC: %5u %s: server saw garbage\n",
1744                                 task->tk_pid, __func__);
1745                 break;                  /* retry */
1746         default:
1747                 dprintk("RPC: %5u %s: server accept status: %x\n",
1748                                 task->tk_pid, __func__, n);
1749                 /* Also retry */
1750         }
1751
1752 out_garbage:
1753         task->tk_client->cl_stats->rpcgarbage++;
1754         if (task->tk_garb_retry) {
1755                 task->tk_garb_retry--;
1756                 dprintk("RPC: %5u %s: retrying\n",
1757                                 task->tk_pid, __func__);
1758                 task->tk_action = call_bind;
1759 out_retry:
1760                 return ERR_PTR(-EAGAIN);
1761         }
1762 out_eio:
1763         error = -EIO;
1764 out_err:
1765         rpc_exit(task, error);
1766         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1767                         __func__, error);
1768         return ERR_PTR(error);
1769 out_overflow:
1770         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1771                         __func__);
1772         goto out_garbage;
1773 }
1774
1775 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1776 {
1777         return 0;
1778 }
1779
1780 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1781 {
1782         return 0;
1783 }
1784
1785 static struct rpc_procinfo rpcproc_null = {
1786         .p_encode = rpcproc_encode_null,
1787         .p_decode = rpcproc_decode_null,
1788 };
1789
1790 static int rpc_ping(struct rpc_clnt *clnt)
1791 {
1792         struct rpc_message msg = {
1793                 .rpc_proc = &rpcproc_null,
1794         };
1795         int err;
1796         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1797         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1798         put_rpccred(msg.rpc_cred);
1799         return err;
1800 }
1801
1802 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1803 {
1804         struct rpc_message msg = {
1805                 .rpc_proc = &rpcproc_null,
1806                 .rpc_cred = cred,
1807         };
1808         struct rpc_task_setup task_setup_data = {
1809                 .rpc_client = clnt,
1810                 .rpc_message = &msg,
1811                 .callback_ops = &rpc_default_ops,
1812                 .flags = flags,
1813         };
1814         return rpc_run_task(&task_setup_data);
1815 }
1816 EXPORT_SYMBOL_GPL(rpc_call_null);
1817
1818 #ifdef RPC_DEBUG
1819 static void rpc_show_header(void)
1820 {
1821         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1822                 "-timeout ---ops--\n");
1823 }
1824
1825 static void rpc_show_task(const struct rpc_clnt *clnt,
1826                           const struct rpc_task *task)
1827 {
1828         const char *rpc_waitq = "none";
1829         char *p, action[KSYM_SYMBOL_LEN];
1830
1831         if (RPC_IS_QUEUED(task))
1832                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1833
1834         /* map tk_action pointer to a function name; then trim off
1835          * the "+0x0 [sunrpc]" */
1836         sprint_symbol(action, (unsigned long)task->tk_action);
1837         p = strchr(action, '+');
1838         if (p)
1839                 *p = '\0';
1840
1841         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1842                 task->tk_pid, task->tk_flags, task->tk_status,
1843                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1844                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1845                 action, rpc_waitq);
1846 }
1847
1848 void rpc_show_tasks(void)
1849 {
1850         struct rpc_clnt *clnt;
1851         struct rpc_task *task;
1852         int header = 0;
1853
1854         spin_lock(&rpc_client_lock);
1855         list_for_each_entry(clnt, &all_clients, cl_clients) {
1856                 spin_lock(&clnt->cl_lock);
1857                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1858                         if (!header) {
1859                                 rpc_show_header();
1860                                 header++;
1861                         }
1862                         rpc_show_task(clnt, task);
1863                 }
1864                 spin_unlock(&clnt->cl_lock);
1865         }
1866         spin_unlock(&rpc_client_lock);
1867 }
1868 #endif