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/mm.h> 29 #include <linux/slab.h> 30 #include <linux/smp_lock.h> 31 #include <linux/utsname.h> 32 #include <linux/workqueue.h> 33 34 #include <linux/sunrpc/clnt.h> 35 #include <linux/sunrpc/rpc_pipe_fs.h> 36 #include <linux/sunrpc/metrics.h> 37 38 39 #define RPC_SLACK_SPACE (1024) /* total overkill */ 40 41 #ifdef RPC_DEBUG 42 # define RPCDBG_FACILITY RPCDBG_CALL 43 #endif 44 45 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait); 46 47 48 static void call_start(struct rpc_task *task); 49 static void call_reserve(struct rpc_task *task); 50 static void call_reserveresult(struct rpc_task *task); 51 static void call_allocate(struct rpc_task *task); 52 static void call_encode(struct rpc_task *task); 53 static void call_decode(struct rpc_task *task); 54 static void call_bind(struct rpc_task *task); 55 static void call_bind_status(struct rpc_task *task); 56 static void call_transmit(struct rpc_task *task); 57 static void call_status(struct rpc_task *task); 58 static void call_transmit_status(struct rpc_task *task); 59 static void call_refresh(struct rpc_task *task); 60 static void call_refreshresult(struct rpc_task *task); 61 static void call_timeout(struct rpc_task *task); 62 static void call_connect(struct rpc_task *task); 63 static void call_connect_status(struct rpc_task *task); 64 static __be32 * call_header(struct rpc_task *task); 65 static __be32 * call_verify(struct rpc_task *task); 66 67 68 static int 69 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name) 70 { 71 static uint32_t clntid; 72 int error; 73 74 clnt->cl_vfsmnt = ERR_PTR(-ENOENT); 75 clnt->cl_dentry = ERR_PTR(-ENOENT); 76 if (dir_name == NULL) 77 return 0; 78 79 clnt->cl_vfsmnt = rpc_get_mount(); 80 if (IS_ERR(clnt->cl_vfsmnt)) 81 return PTR_ERR(clnt->cl_vfsmnt); 82 83 for (;;) { 84 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname), 85 "%s/clnt%x", dir_name, 86 (unsigned int)clntid++); 87 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0'; 88 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt); 89 if (!IS_ERR(clnt->cl_dentry)) 90 return 0; 91 error = PTR_ERR(clnt->cl_dentry); 92 if (error != -EEXIST) { 93 printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n", 94 clnt->cl_pathname, error); 95 rpc_put_mount(); 96 return error; 97 } 98 } 99 } 100 101 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor) 102 { 103 struct rpc_version *version; 104 struct rpc_clnt *clnt = NULL; 105 struct rpc_auth *auth; 106 int err; 107 int len; 108 109 dprintk("RPC: creating %s client for %s (xprt %p)\n", 110 program->name, servname, xprt); 111 112 err = -EINVAL; 113 if (!xprt) 114 goto out_no_xprt; 115 if (vers >= program->nrvers || !(version = program->version[vers])) 116 goto out_err; 117 118 err = -ENOMEM; 119 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL); 120 if (!clnt) 121 goto out_err; 122 atomic_set(&clnt->cl_users, 0); 123 atomic_set(&clnt->cl_count, 1); 124 clnt->cl_parent = clnt; 125 126 clnt->cl_server = clnt->cl_inline_name; 127 len = strlen(servname) + 1; 128 if (len > sizeof(clnt->cl_inline_name)) { 129 char *buf = kmalloc(len, GFP_KERNEL); 130 if (buf != 0) 131 clnt->cl_server = buf; 132 else 133 len = sizeof(clnt->cl_inline_name); 134 } 135 strlcpy(clnt->cl_server, servname, len); 136 137 clnt->cl_xprt = xprt; 138 clnt->cl_procinfo = version->procs; 139 clnt->cl_maxproc = version->nrprocs; 140 clnt->cl_protname = program->name; 141 clnt->cl_prog = program->number; 142 clnt->cl_vers = version->number; 143 clnt->cl_stats = program->stats; 144 clnt->cl_metrics = rpc_alloc_iostats(clnt); 145 err = -ENOMEM; 146 if (clnt->cl_metrics == NULL) 147 goto out_no_stats; 148 clnt->cl_program = program; 149 150 if (!xprt_bound(clnt->cl_xprt)) 151 clnt->cl_autobind = 1; 152 153 clnt->cl_rtt = &clnt->cl_rtt_default; 154 rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval); 155 156 err = rpc_setup_pipedir(clnt, program->pipe_dir_name); 157 if (err < 0) 158 goto out_no_path; 159 160 auth = rpcauth_create(flavor, clnt); 161 if (IS_ERR(auth)) { 162 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n", 163 flavor); 164 err = PTR_ERR(auth); 165 goto out_no_auth; 166 } 167 168 /* save the nodename */ 169 clnt->cl_nodelen = strlen(utsname()->nodename); 170 if (clnt->cl_nodelen > UNX_MAXNODENAME) 171 clnt->cl_nodelen = UNX_MAXNODENAME; 172 memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen); 173 return clnt; 174 175 out_no_auth: 176 if (!IS_ERR(clnt->cl_dentry)) { 177 rpc_rmdir(clnt->cl_dentry); 178 rpc_put_mount(); 179 } 180 out_no_path: 181 rpc_free_iostats(clnt->cl_metrics); 182 out_no_stats: 183 if (clnt->cl_server != clnt->cl_inline_name) 184 kfree(clnt->cl_server); 185 kfree(clnt); 186 out_err: 187 xprt_put(xprt); 188 out_no_xprt: 189 return ERR_PTR(err); 190 } 191 192 /* 193 * rpc_create - create an RPC client and transport with one call 194 * @args: rpc_clnt create argument structure 195 * 196 * Creates and initializes an RPC transport and an RPC client. 197 * 198 * It can ping the server in order to determine if it is up, and to see if 199 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables 200 * this behavior so asynchronous tasks can also use rpc_create. 201 */ 202 struct rpc_clnt *rpc_create(struct rpc_create_args *args) 203 { 204 struct rpc_xprt *xprt; 205 struct rpc_clnt *clnt; 206 207 xprt = xprt_create_transport(args->protocol, args->address, 208 args->addrsize, args->timeout); 209 if (IS_ERR(xprt)) 210 return (struct rpc_clnt *)xprt; 211 212 /* 213 * By default, kernel RPC client connects from a reserved port. 214 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters, 215 * but it is always enabled for rpciod, which handles the connect 216 * operation. 217 */ 218 xprt->resvport = 1; 219 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT) 220 xprt->resvport = 0; 221 222 dprintk("RPC: creating %s client for %s (xprt %p)\n", 223 args->program->name, args->servername, xprt); 224 225 clnt = rpc_new_client(xprt, args->servername, args->program, 226 args->version, args->authflavor); 227 if (IS_ERR(clnt)) 228 return clnt; 229 230 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) { 231 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 232 if (err != 0) { 233 rpc_shutdown_client(clnt); 234 return ERR_PTR(err); 235 } 236 } 237 238 clnt->cl_softrtry = 1; 239 if (args->flags & RPC_CLNT_CREATE_HARDRTRY) 240 clnt->cl_softrtry = 0; 241 242 if (args->flags & RPC_CLNT_CREATE_INTR) 243 clnt->cl_intr = 1; 244 if (args->flags & RPC_CLNT_CREATE_AUTOBIND) 245 clnt->cl_autobind = 1; 246 if (args->flags & RPC_CLNT_CREATE_ONESHOT) 247 clnt->cl_oneshot = 1; 248 249 return clnt; 250 } 251 EXPORT_SYMBOL_GPL(rpc_create); 252 253 /* 254 * This function clones the RPC client structure. It allows us to share the 255 * same transport while varying parameters such as the authentication 256 * flavour. 257 */ 258 struct rpc_clnt * 259 rpc_clone_client(struct rpc_clnt *clnt) 260 { 261 struct rpc_clnt *new; 262 int err = -ENOMEM; 263 264 new = kmemdup(clnt, sizeof(*new), GFP_KERNEL); 265 if (!new) 266 goto out_no_clnt; 267 atomic_set(&new->cl_count, 1); 268 atomic_set(&new->cl_users, 0); 269 new->cl_metrics = rpc_alloc_iostats(clnt); 270 if (new->cl_metrics == NULL) 271 goto out_no_stats; 272 err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name); 273 if (err != 0) 274 goto out_no_path; 275 new->cl_parent = clnt; 276 atomic_inc(&clnt->cl_count); 277 new->cl_xprt = xprt_get(clnt->cl_xprt); 278 /* Turn off autobind on clones */ 279 new->cl_autobind = 0; 280 new->cl_oneshot = 0; 281 new->cl_dead = 0; 282 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval); 283 if (new->cl_auth) 284 atomic_inc(&new->cl_auth->au_count); 285 return new; 286 out_no_path: 287 rpc_free_iostats(new->cl_metrics); 288 out_no_stats: 289 kfree(new); 290 out_no_clnt: 291 dprintk("RPC: %s returned error %d\n", __FUNCTION__, err); 292 return ERR_PTR(err); 293 } 294 295 /* 296 * Properly shut down an RPC client, terminating all outstanding 297 * requests. Note that we must be certain that cl_oneshot and 298 * cl_dead are cleared, or else the client would be destroyed 299 * when the last task releases it. 300 */ 301 int 302 rpc_shutdown_client(struct rpc_clnt *clnt) 303 { 304 dprintk("RPC: shutting down %s client for %s, tasks=%d\n", 305 clnt->cl_protname, clnt->cl_server, 306 atomic_read(&clnt->cl_users)); 307 308 while (atomic_read(&clnt->cl_users) > 0) { 309 /* Don't let rpc_release_client destroy us */ 310 clnt->cl_oneshot = 0; 311 clnt->cl_dead = 0; 312 rpc_killall_tasks(clnt); 313 wait_event_timeout(destroy_wait, 314 !atomic_read(&clnt->cl_users), 1*HZ); 315 } 316 317 if (atomic_read(&clnt->cl_users) < 0) { 318 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n", 319 clnt, atomic_read(&clnt->cl_users)); 320 #ifdef RPC_DEBUG 321 rpc_show_tasks(); 322 #endif 323 BUG(); 324 } 325 326 return rpc_destroy_client(clnt); 327 } 328 329 /* 330 * Delete an RPC client 331 */ 332 int 333 rpc_destroy_client(struct rpc_clnt *clnt) 334 { 335 if (!atomic_dec_and_test(&clnt->cl_count)) 336 return 1; 337 BUG_ON(atomic_read(&clnt->cl_users) != 0); 338 339 dprintk("RPC: destroying %s client for %s\n", 340 clnt->cl_protname, clnt->cl_server); 341 if (clnt->cl_auth) { 342 rpcauth_destroy(clnt->cl_auth); 343 clnt->cl_auth = NULL; 344 } 345 if (!IS_ERR(clnt->cl_dentry)) { 346 rpc_rmdir(clnt->cl_dentry); 347 rpc_put_mount(); 348 } 349 if (clnt->cl_parent != clnt) { 350 rpc_destroy_client(clnt->cl_parent); 351 goto out_free; 352 } 353 if (clnt->cl_server != clnt->cl_inline_name) 354 kfree(clnt->cl_server); 355 out_free: 356 rpc_free_iostats(clnt->cl_metrics); 357 clnt->cl_metrics = NULL; 358 xprt_put(clnt->cl_xprt); 359 kfree(clnt); 360 return 0; 361 } 362 363 /* 364 * Release an RPC client 365 */ 366 void 367 rpc_release_client(struct rpc_clnt *clnt) 368 { 369 dprintk("RPC: rpc_release_client(%p, %d)\n", 370 clnt, atomic_read(&clnt->cl_users)); 371 372 if (!atomic_dec_and_test(&clnt->cl_users)) 373 return; 374 wake_up(&destroy_wait); 375 if (clnt->cl_oneshot || clnt->cl_dead) 376 rpc_destroy_client(clnt); 377 } 378 379 /** 380 * rpc_bind_new_program - bind a new RPC program to an existing client 381 * @old - old rpc_client 382 * @program - rpc program to set 383 * @vers - rpc program version 384 * 385 * Clones the rpc client and sets up a new RPC program. This is mainly 386 * of use for enabling different RPC programs to share the same transport. 387 * The Sun NFSv2/v3 ACL protocol can do this. 388 */ 389 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old, 390 struct rpc_program *program, 391 int vers) 392 { 393 struct rpc_clnt *clnt; 394 struct rpc_version *version; 395 int err; 396 397 BUG_ON(vers >= program->nrvers || !program->version[vers]); 398 version = program->version[vers]; 399 clnt = rpc_clone_client(old); 400 if (IS_ERR(clnt)) 401 goto out; 402 clnt->cl_procinfo = version->procs; 403 clnt->cl_maxproc = version->nrprocs; 404 clnt->cl_protname = program->name; 405 clnt->cl_prog = program->number; 406 clnt->cl_vers = version->number; 407 clnt->cl_stats = program->stats; 408 err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR); 409 if (err != 0) { 410 rpc_shutdown_client(clnt); 411 clnt = ERR_PTR(err); 412 } 413 out: 414 return clnt; 415 } 416 417 /* 418 * Default callback for async RPC calls 419 */ 420 static void 421 rpc_default_callback(struct rpc_task *task, void *data) 422 { 423 } 424 425 static const struct rpc_call_ops rpc_default_ops = { 426 .rpc_call_done = rpc_default_callback, 427 }; 428 429 /* 430 * Export the signal mask handling for synchronous code that 431 * sleeps on RPC calls 432 */ 433 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM)) 434 435 static void rpc_save_sigmask(sigset_t *oldset, int intr) 436 { 437 unsigned long sigallow = sigmask(SIGKILL); 438 sigset_t sigmask; 439 440 /* Block all signals except those listed in sigallow */ 441 if (intr) 442 sigallow |= RPC_INTR_SIGNALS; 443 siginitsetinv(&sigmask, sigallow); 444 sigprocmask(SIG_BLOCK, &sigmask, oldset); 445 } 446 447 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset) 448 { 449 rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task)); 450 } 451 452 static inline void rpc_restore_sigmask(sigset_t *oldset) 453 { 454 sigprocmask(SIG_SETMASK, oldset, NULL); 455 } 456 457 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset) 458 { 459 rpc_save_sigmask(oldset, clnt->cl_intr); 460 } 461 462 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset) 463 { 464 rpc_restore_sigmask(oldset); 465 } 466 467 /* 468 * New rpc_call implementation 469 */ 470 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags) 471 { 472 struct rpc_task *task; 473 sigset_t oldset; 474 int status; 475 476 /* If this client is slain all further I/O fails */ 477 if (clnt->cl_dead) 478 return -EIO; 479 480 BUG_ON(flags & RPC_TASK_ASYNC); 481 482 task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL); 483 if (task == NULL) 484 return -ENOMEM; 485 486 /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */ 487 rpc_task_sigmask(task, &oldset); 488 489 rpc_call_setup(task, msg, 0); 490 491 /* Set up the call info struct and execute the task */ 492 status = task->tk_status; 493 if (status != 0) 494 goto out; 495 atomic_inc(&task->tk_count); 496 status = rpc_execute(task); 497 if (status == 0) 498 status = task->tk_status; 499 out: 500 rpc_put_task(task); 501 rpc_restore_sigmask(&oldset); 502 return status; 503 } 504 505 /* 506 * New rpc_call implementation 507 */ 508 int 509 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags, 510 const struct rpc_call_ops *tk_ops, void *data) 511 { 512 struct rpc_task *task; 513 sigset_t oldset; 514 int status; 515 516 /* If this client is slain all further I/O fails */ 517 status = -EIO; 518 if (clnt->cl_dead) 519 goto out_release; 520 521 flags |= RPC_TASK_ASYNC; 522 523 /* Create/initialize a new RPC task */ 524 status = -ENOMEM; 525 if (!(task = rpc_new_task(clnt, flags, tk_ops, data))) 526 goto out_release; 527 528 /* Mask signals on GSS_AUTH upcalls */ 529 rpc_task_sigmask(task, &oldset); 530 531 rpc_call_setup(task, msg, 0); 532 533 /* Set up the call info struct and execute the task */ 534 status = task->tk_status; 535 if (status == 0) 536 rpc_execute(task); 537 else 538 rpc_put_task(task); 539 540 rpc_restore_sigmask(&oldset); 541 return status; 542 out_release: 543 rpc_release_calldata(tk_ops, data); 544 return status; 545 } 546 547 548 void 549 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags) 550 { 551 task->tk_msg = *msg; 552 task->tk_flags |= flags; 553 /* Bind the user cred */ 554 if (task->tk_msg.rpc_cred != NULL) 555 rpcauth_holdcred(task); 556 else 557 rpcauth_bindcred(task); 558 559 if (task->tk_status == 0) 560 task->tk_action = call_start; 561 else 562 task->tk_action = rpc_exit_task; 563 } 564 565 /** 566 * rpc_peeraddr - extract remote peer address from clnt's xprt 567 * @clnt: RPC client structure 568 * @buf: target buffer 569 * @size: length of target buffer 570 * 571 * Returns the number of bytes that are actually in the stored address. 572 */ 573 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize) 574 { 575 size_t bytes; 576 struct rpc_xprt *xprt = clnt->cl_xprt; 577 578 bytes = sizeof(xprt->addr); 579 if (bytes > bufsize) 580 bytes = bufsize; 581 memcpy(buf, &clnt->cl_xprt->addr, bytes); 582 return xprt->addrlen; 583 } 584 EXPORT_SYMBOL_GPL(rpc_peeraddr); 585 586 /** 587 * rpc_peeraddr2str - return remote peer address in printable format 588 * @clnt: RPC client structure 589 * @format: address format 590 * 591 */ 592 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format) 593 { 594 struct rpc_xprt *xprt = clnt->cl_xprt; 595 596 if (xprt->address_strings[format] != NULL) 597 return xprt->address_strings[format]; 598 else 599 return "unprintable"; 600 } 601 EXPORT_SYMBOL_GPL(rpc_peeraddr2str); 602 603 void 604 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize) 605 { 606 struct rpc_xprt *xprt = clnt->cl_xprt; 607 if (xprt->ops->set_buffer_size) 608 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize); 609 } 610 611 /* 612 * Return size of largest payload RPC client can support, in bytes 613 * 614 * For stream transports, this is one RPC record fragment (see RFC 615 * 1831), as we don't support multi-record requests yet. For datagram 616 * transports, this is the size of an IP packet minus the IP, UDP, and 617 * RPC header sizes. 618 */ 619 size_t rpc_max_payload(struct rpc_clnt *clnt) 620 { 621 return clnt->cl_xprt->max_payload; 622 } 623 EXPORT_SYMBOL_GPL(rpc_max_payload); 624 625 /** 626 * rpc_force_rebind - force transport to check that remote port is unchanged 627 * @clnt: client to rebind 628 * 629 */ 630 void rpc_force_rebind(struct rpc_clnt *clnt) 631 { 632 if (clnt->cl_autobind) 633 xprt_clear_bound(clnt->cl_xprt); 634 } 635 EXPORT_SYMBOL_GPL(rpc_force_rebind); 636 637 /* 638 * Restart an (async) RPC call. Usually called from within the 639 * exit handler. 640 */ 641 void 642 rpc_restart_call(struct rpc_task *task) 643 { 644 if (RPC_ASSASSINATED(task)) 645 return; 646 647 task->tk_action = call_start; 648 } 649 650 /* 651 * 0. Initial state 652 * 653 * Other FSM states can be visited zero or more times, but 654 * this state is visited exactly once for each RPC. 655 */ 656 static void 657 call_start(struct rpc_task *task) 658 { 659 struct rpc_clnt *clnt = task->tk_client; 660 661 dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid, 662 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc, 663 (RPC_IS_ASYNC(task) ? "async" : "sync")); 664 665 /* Increment call count */ 666 task->tk_msg.rpc_proc->p_count++; 667 clnt->cl_stats->rpccnt++; 668 task->tk_action = call_reserve; 669 } 670 671 /* 672 * 1. Reserve an RPC call slot 673 */ 674 static void 675 call_reserve(struct rpc_task *task) 676 { 677 dprintk("RPC: %4d call_reserve\n", task->tk_pid); 678 679 if (!rpcauth_uptodatecred(task)) { 680 task->tk_action = call_refresh; 681 return; 682 } 683 684 task->tk_status = 0; 685 task->tk_action = call_reserveresult; 686 xprt_reserve(task); 687 } 688 689 /* 690 * 1b. Grok the result of xprt_reserve() 691 */ 692 static void 693 call_reserveresult(struct rpc_task *task) 694 { 695 int status = task->tk_status; 696 697 dprintk("RPC: %4d call_reserveresult (status %d)\n", 698 task->tk_pid, task->tk_status); 699 700 /* 701 * After a call to xprt_reserve(), we must have either 702 * a request slot or else an error status. 703 */ 704 task->tk_status = 0; 705 if (status >= 0) { 706 if (task->tk_rqstp) { 707 task->tk_action = call_allocate; 708 return; 709 } 710 711 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n", 712 __FUNCTION__, status); 713 rpc_exit(task, -EIO); 714 return; 715 } 716 717 /* 718 * Even though there was an error, we may have acquired 719 * a request slot somehow. Make sure not to leak it. 720 */ 721 if (task->tk_rqstp) { 722 printk(KERN_ERR "%s: status=%d, request allocated anyway\n", 723 __FUNCTION__, status); 724 xprt_release(task); 725 } 726 727 switch (status) { 728 case -EAGAIN: /* woken up; retry */ 729 task->tk_action = call_reserve; 730 return; 731 case -EIO: /* probably a shutdown */ 732 break; 733 default: 734 printk(KERN_ERR "%s: unrecognized error %d, exiting\n", 735 __FUNCTION__, status); 736 break; 737 } 738 rpc_exit(task, status); 739 } 740 741 /* 742 * 2. Allocate the buffer. For details, see sched.c:rpc_malloc. 743 * (Note: buffer memory is freed in xprt_release). 744 */ 745 static void 746 call_allocate(struct rpc_task *task) 747 { 748 struct rpc_rqst *req = task->tk_rqstp; 749 struct rpc_xprt *xprt = task->tk_xprt; 750 unsigned int bufsiz; 751 752 dprintk("RPC: %4d call_allocate (status %d)\n", 753 task->tk_pid, task->tk_status); 754 task->tk_action = call_bind; 755 if (req->rq_buffer) 756 return; 757 758 /* FIXME: compute buffer requirements more exactly using 759 * auth->au_wslack */ 760 bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE; 761 762 if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL) 763 return; 764 printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task); 765 766 if (RPC_IS_ASYNC(task) || !signalled()) { 767 xprt_release(task); 768 task->tk_action = call_reserve; 769 rpc_delay(task, HZ>>4); 770 return; 771 } 772 773 rpc_exit(task, -ERESTARTSYS); 774 } 775 776 static inline int 777 rpc_task_need_encode(struct rpc_task *task) 778 { 779 return task->tk_rqstp->rq_snd_buf.len == 0; 780 } 781 782 static inline void 783 rpc_task_force_reencode(struct rpc_task *task) 784 { 785 task->tk_rqstp->rq_snd_buf.len = 0; 786 } 787 788 /* 789 * 3. Encode arguments of an RPC call 790 */ 791 static void 792 call_encode(struct rpc_task *task) 793 { 794 struct rpc_rqst *req = task->tk_rqstp; 795 struct xdr_buf *sndbuf = &req->rq_snd_buf; 796 struct xdr_buf *rcvbuf = &req->rq_rcv_buf; 797 unsigned int bufsiz; 798 kxdrproc_t encode; 799 __be32 *p; 800 801 dprintk("RPC: %4d call_encode (status %d)\n", 802 task->tk_pid, task->tk_status); 803 804 /* Default buffer setup */ 805 bufsiz = req->rq_bufsize >> 1; 806 sndbuf->head[0].iov_base = (void *)req->rq_buffer; 807 sndbuf->head[0].iov_len = bufsiz; 808 sndbuf->tail[0].iov_len = 0; 809 sndbuf->page_len = 0; 810 sndbuf->len = 0; 811 sndbuf->buflen = bufsiz; 812 rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz); 813 rcvbuf->head[0].iov_len = bufsiz; 814 rcvbuf->tail[0].iov_len = 0; 815 rcvbuf->page_len = 0; 816 rcvbuf->len = 0; 817 rcvbuf->buflen = bufsiz; 818 819 /* Encode header and provided arguments */ 820 encode = task->tk_msg.rpc_proc->p_encode; 821 if (!(p = call_header(task))) { 822 printk(KERN_INFO "RPC: call_header failed, exit EIO\n"); 823 rpc_exit(task, -EIO); 824 return; 825 } 826 if (encode == NULL) 827 return; 828 829 lock_kernel(); 830 task->tk_status = rpcauth_wrap_req(task, encode, req, p, 831 task->tk_msg.rpc_argp); 832 unlock_kernel(); 833 if (task->tk_status == -ENOMEM) { 834 /* XXX: Is this sane? */ 835 rpc_delay(task, 3*HZ); 836 task->tk_status = -EAGAIN; 837 } 838 } 839 840 /* 841 * 4. Get the server port number if not yet set 842 */ 843 static void 844 call_bind(struct rpc_task *task) 845 { 846 struct rpc_xprt *xprt = task->tk_xprt; 847 848 dprintk("RPC: %4d call_bind (status %d)\n", 849 task->tk_pid, task->tk_status); 850 851 task->tk_action = call_connect; 852 if (!xprt_bound(xprt)) { 853 task->tk_action = call_bind_status; 854 task->tk_timeout = xprt->bind_timeout; 855 xprt->ops->rpcbind(task); 856 } 857 } 858 859 /* 860 * 4a. Sort out bind result 861 */ 862 static void 863 call_bind_status(struct rpc_task *task) 864 { 865 int status = -EACCES; 866 867 if (task->tk_status >= 0) { 868 dprintk("RPC: %4d call_bind_status (status %d)\n", 869 task->tk_pid, task->tk_status); 870 task->tk_status = 0; 871 task->tk_action = call_connect; 872 return; 873 } 874 875 switch (task->tk_status) { 876 case -EACCES: 877 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n", 878 task->tk_pid); 879 rpc_delay(task, 3*HZ); 880 goto retry_timeout; 881 case -ETIMEDOUT: 882 dprintk("RPC: %4d rpcbind request timed out\n", 883 task->tk_pid); 884 goto retry_timeout; 885 case -EPFNOSUPPORT: 886 dprintk("RPC: %4d remote rpcbind service unavailable\n", 887 task->tk_pid); 888 break; 889 case -EPROTONOSUPPORT: 890 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n", 891 task->tk_pid); 892 break; 893 default: 894 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n", 895 task->tk_pid, -task->tk_status); 896 status = -EIO; 897 } 898 899 rpc_exit(task, status); 900 return; 901 902 retry_timeout: 903 task->tk_action = call_timeout; 904 } 905 906 /* 907 * 4b. Connect to the RPC server 908 */ 909 static void 910 call_connect(struct rpc_task *task) 911 { 912 struct rpc_xprt *xprt = task->tk_xprt; 913 914 dprintk("RPC: %4d call_connect xprt %p %s connected\n", 915 task->tk_pid, xprt, 916 (xprt_connected(xprt) ? "is" : "is not")); 917 918 task->tk_action = call_transmit; 919 if (!xprt_connected(xprt)) { 920 task->tk_action = call_connect_status; 921 if (task->tk_status < 0) 922 return; 923 xprt_connect(task); 924 } 925 } 926 927 /* 928 * 4c. Sort out connect result 929 */ 930 static void 931 call_connect_status(struct rpc_task *task) 932 { 933 struct rpc_clnt *clnt = task->tk_client; 934 int status = task->tk_status; 935 936 dprintk("RPC: %5u call_connect_status (status %d)\n", 937 task->tk_pid, task->tk_status); 938 939 task->tk_status = 0; 940 if (status >= 0) { 941 clnt->cl_stats->netreconn++; 942 task->tk_action = call_transmit; 943 return; 944 } 945 946 /* Something failed: remote service port may have changed */ 947 rpc_force_rebind(clnt); 948 949 switch (status) { 950 case -ENOTCONN: 951 case -EAGAIN: 952 task->tk_action = call_bind; 953 if (!RPC_IS_SOFT(task)) 954 return; 955 /* if soft mounted, test if we've timed out */ 956 case -ETIMEDOUT: 957 task->tk_action = call_timeout; 958 return; 959 } 960 rpc_exit(task, -EIO); 961 } 962 963 /* 964 * 5. Transmit the RPC request, and wait for reply 965 */ 966 static void 967 call_transmit(struct rpc_task *task) 968 { 969 dprintk("RPC: %4d call_transmit (status %d)\n", 970 task->tk_pid, task->tk_status); 971 972 task->tk_action = call_status; 973 if (task->tk_status < 0) 974 return; 975 task->tk_status = xprt_prepare_transmit(task); 976 if (task->tk_status != 0) 977 return; 978 task->tk_action = call_transmit_status; 979 /* Encode here so that rpcsec_gss can use correct sequence number. */ 980 if (rpc_task_need_encode(task)) { 981 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0); 982 call_encode(task); 983 /* Did the encode result in an error condition? */ 984 if (task->tk_status != 0) 985 return; 986 } 987 xprt_transmit(task); 988 if (task->tk_status < 0) 989 return; 990 /* 991 * On success, ensure that we call xprt_end_transmit() before sleeping 992 * in order to allow access to the socket to other RPC requests. 993 */ 994 call_transmit_status(task); 995 if (task->tk_msg.rpc_proc->p_decode != NULL) 996 return; 997 task->tk_action = rpc_exit_task; 998 rpc_wake_up_task(task); 999 } 1000 1001 /* 1002 * 5a. Handle cleanup after a transmission 1003 */ 1004 static void 1005 call_transmit_status(struct rpc_task *task) 1006 { 1007 task->tk_action = call_status; 1008 /* 1009 * Special case: if we've been waiting on the socket's write_space() 1010 * callback, then don't call xprt_end_transmit(). 1011 */ 1012 if (task->tk_status == -EAGAIN) 1013 return; 1014 xprt_end_transmit(task); 1015 rpc_task_force_reencode(task); 1016 } 1017 1018 /* 1019 * 6. Sort out the RPC call status 1020 */ 1021 static void 1022 call_status(struct rpc_task *task) 1023 { 1024 struct rpc_clnt *clnt = task->tk_client; 1025 struct rpc_rqst *req = task->tk_rqstp; 1026 int status; 1027 1028 if (req->rq_received > 0 && !req->rq_bytes_sent) 1029 task->tk_status = req->rq_received; 1030 1031 dprintk("RPC: %4d call_status (status %d)\n", 1032 task->tk_pid, task->tk_status); 1033 1034 status = task->tk_status; 1035 if (status >= 0) { 1036 task->tk_action = call_decode; 1037 return; 1038 } 1039 1040 task->tk_status = 0; 1041 switch(status) { 1042 case -EHOSTDOWN: 1043 case -EHOSTUNREACH: 1044 case -ENETUNREACH: 1045 /* 1046 * Delay any retries for 3 seconds, then handle as if it 1047 * were a timeout. 1048 */ 1049 rpc_delay(task, 3*HZ); 1050 case -ETIMEDOUT: 1051 task->tk_action = call_timeout; 1052 break; 1053 case -ECONNREFUSED: 1054 case -ENOTCONN: 1055 rpc_force_rebind(clnt); 1056 task->tk_action = call_bind; 1057 break; 1058 case -EAGAIN: 1059 task->tk_action = call_transmit; 1060 break; 1061 case -EIO: 1062 /* shutdown or soft timeout */ 1063 rpc_exit(task, status); 1064 break; 1065 default: 1066 printk("%s: RPC call returned error %d\n", 1067 clnt->cl_protname, -status); 1068 rpc_exit(task, status); 1069 } 1070 } 1071 1072 /* 1073 * 6a. Handle RPC timeout 1074 * We do not release the request slot, so we keep using the 1075 * same XID for all retransmits. 1076 */ 1077 static void 1078 call_timeout(struct rpc_task *task) 1079 { 1080 struct rpc_clnt *clnt = task->tk_client; 1081 1082 if (xprt_adjust_timeout(task->tk_rqstp) == 0) { 1083 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid); 1084 goto retry; 1085 } 1086 1087 dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid); 1088 task->tk_timeouts++; 1089 1090 if (RPC_IS_SOFT(task)) { 1091 printk(KERN_NOTICE "%s: server %s not responding, timed out\n", 1092 clnt->cl_protname, clnt->cl_server); 1093 rpc_exit(task, -EIO); 1094 return; 1095 } 1096 1097 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) { 1098 task->tk_flags |= RPC_CALL_MAJORSEEN; 1099 printk(KERN_NOTICE "%s: server %s not responding, still trying\n", 1100 clnt->cl_protname, clnt->cl_server); 1101 } 1102 rpc_force_rebind(clnt); 1103 1104 retry: 1105 clnt->cl_stats->rpcretrans++; 1106 task->tk_action = call_bind; 1107 task->tk_status = 0; 1108 } 1109 1110 /* 1111 * 7. Decode the RPC reply 1112 */ 1113 static void 1114 call_decode(struct rpc_task *task) 1115 { 1116 struct rpc_clnt *clnt = task->tk_client; 1117 struct rpc_rqst *req = task->tk_rqstp; 1118 kxdrproc_t decode = task->tk_msg.rpc_proc->p_decode; 1119 __be32 *p; 1120 1121 dprintk("RPC: %4d call_decode (status %d)\n", 1122 task->tk_pid, task->tk_status); 1123 1124 if (task->tk_flags & RPC_CALL_MAJORSEEN) { 1125 printk(KERN_NOTICE "%s: server %s OK\n", 1126 clnt->cl_protname, clnt->cl_server); 1127 task->tk_flags &= ~RPC_CALL_MAJORSEEN; 1128 } 1129 1130 if (task->tk_status < 12) { 1131 if (!RPC_IS_SOFT(task)) { 1132 task->tk_action = call_bind; 1133 clnt->cl_stats->rpcretrans++; 1134 goto out_retry; 1135 } 1136 dprintk("%s: too small RPC reply size (%d bytes)\n", 1137 clnt->cl_protname, task->tk_status); 1138 task->tk_action = call_timeout; 1139 goto out_retry; 1140 } 1141 1142 /* 1143 * Ensure that we see all writes made by xprt_complete_rqst() 1144 * before it changed req->rq_received. 1145 */ 1146 smp_rmb(); 1147 req->rq_rcv_buf.len = req->rq_private_buf.len; 1148 1149 /* Check that the softirq receive buffer is valid */ 1150 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf, 1151 sizeof(req->rq_rcv_buf)) != 0); 1152 1153 /* Verify the RPC header */ 1154 p = call_verify(task); 1155 if (IS_ERR(p)) { 1156 if (p == ERR_PTR(-EAGAIN)) 1157 goto out_retry; 1158 return; 1159 } 1160 1161 task->tk_action = rpc_exit_task; 1162 1163 if (decode) { 1164 lock_kernel(); 1165 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p, 1166 task->tk_msg.rpc_resp); 1167 unlock_kernel(); 1168 } 1169 dprintk("RPC: %4d call_decode result %d\n", task->tk_pid, 1170 task->tk_status); 1171 return; 1172 out_retry: 1173 req->rq_received = req->rq_private_buf.len = 0; 1174 task->tk_status = 0; 1175 } 1176 1177 /* 1178 * 8. Refresh the credentials if rejected by the server 1179 */ 1180 static void 1181 call_refresh(struct rpc_task *task) 1182 { 1183 dprintk("RPC: %4d call_refresh\n", task->tk_pid); 1184 1185 xprt_release(task); /* Must do to obtain new XID */ 1186 task->tk_action = call_refreshresult; 1187 task->tk_status = 0; 1188 task->tk_client->cl_stats->rpcauthrefresh++; 1189 rpcauth_refreshcred(task); 1190 } 1191 1192 /* 1193 * 8a. Process the results of a credential refresh 1194 */ 1195 static void 1196 call_refreshresult(struct rpc_task *task) 1197 { 1198 int status = task->tk_status; 1199 dprintk("RPC: %4d call_refreshresult (status %d)\n", 1200 task->tk_pid, task->tk_status); 1201 1202 task->tk_status = 0; 1203 task->tk_action = call_reserve; 1204 if (status >= 0 && rpcauth_uptodatecred(task)) 1205 return; 1206 if (status == -EACCES) { 1207 rpc_exit(task, -EACCES); 1208 return; 1209 } 1210 task->tk_action = call_refresh; 1211 if (status != -ETIMEDOUT) 1212 rpc_delay(task, 3*HZ); 1213 return; 1214 } 1215 1216 /* 1217 * Call header serialization 1218 */ 1219 static __be32 * 1220 call_header(struct rpc_task *task) 1221 { 1222 struct rpc_clnt *clnt = task->tk_client; 1223 struct rpc_rqst *req = task->tk_rqstp; 1224 __be32 *p = req->rq_svec[0].iov_base; 1225 1226 /* FIXME: check buffer size? */ 1227 1228 p = xprt_skip_transport_header(task->tk_xprt, p); 1229 *p++ = req->rq_xid; /* XID */ 1230 *p++ = htonl(RPC_CALL); /* CALL */ 1231 *p++ = htonl(RPC_VERSION); /* RPC version */ 1232 *p++ = htonl(clnt->cl_prog); /* program number */ 1233 *p++ = htonl(clnt->cl_vers); /* program version */ 1234 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */ 1235 p = rpcauth_marshcred(task, p); 1236 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p); 1237 return p; 1238 } 1239 1240 /* 1241 * Reply header verification 1242 */ 1243 static __be32 * 1244 call_verify(struct rpc_task *task) 1245 { 1246 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0]; 1247 int len = task->tk_rqstp->rq_rcv_buf.len >> 2; 1248 __be32 *p = iov->iov_base; 1249 u32 n; 1250 int error = -EACCES; 1251 1252 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) { 1253 /* RFC-1014 says that the representation of XDR data must be a 1254 * multiple of four bytes 1255 * - if it isn't pointer subtraction in the NFS client may give 1256 * undefined results 1257 */ 1258 printk(KERN_WARNING 1259 "call_verify: XDR representation not a multiple of" 1260 " 4 bytes: 0x%x\n", task->tk_rqstp->rq_rcv_buf.len); 1261 goto out_eio; 1262 } 1263 if ((len -= 3) < 0) 1264 goto out_overflow; 1265 p += 1; /* skip XID */ 1266 1267 if ((n = ntohl(*p++)) != RPC_REPLY) { 1268 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n); 1269 goto out_garbage; 1270 } 1271 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { 1272 if (--len < 0) 1273 goto out_overflow; 1274 switch ((n = ntohl(*p++))) { 1275 case RPC_AUTH_ERROR: 1276 break; 1277 case RPC_MISMATCH: 1278 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__); 1279 error = -EPROTONOSUPPORT; 1280 goto out_err; 1281 default: 1282 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n); 1283 goto out_eio; 1284 } 1285 if (--len < 0) 1286 goto out_overflow; 1287 switch ((n = ntohl(*p++))) { 1288 case RPC_AUTH_REJECTEDCRED: 1289 case RPC_AUTH_REJECTEDVERF: 1290 case RPCSEC_GSS_CREDPROBLEM: 1291 case RPCSEC_GSS_CTXPROBLEM: 1292 if (!task->tk_cred_retry) 1293 break; 1294 task->tk_cred_retry--; 1295 dprintk("RPC: %4d call_verify: retry stale creds\n", 1296 task->tk_pid); 1297 rpcauth_invalcred(task); 1298 task->tk_action = call_refresh; 1299 goto out_retry; 1300 case RPC_AUTH_BADCRED: 1301 case RPC_AUTH_BADVERF: 1302 /* possibly garbled cred/verf? */ 1303 if (!task->tk_garb_retry) 1304 break; 1305 task->tk_garb_retry--; 1306 dprintk("RPC: %4d call_verify: retry garbled creds\n", 1307 task->tk_pid); 1308 task->tk_action = call_bind; 1309 goto out_retry; 1310 case RPC_AUTH_TOOWEAK: 1311 printk(KERN_NOTICE "call_verify: server %s requires stronger " 1312 "authentication.\n", task->tk_client->cl_server); 1313 break; 1314 default: 1315 printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n); 1316 error = -EIO; 1317 } 1318 dprintk("RPC: %4d call_verify: call rejected %d\n", 1319 task->tk_pid, n); 1320 goto out_err; 1321 } 1322 if (!(p = rpcauth_checkverf(task, p))) { 1323 printk(KERN_WARNING "call_verify: auth check failed\n"); 1324 goto out_garbage; /* bad verifier, retry */ 1325 } 1326 len = p - (__be32 *)iov->iov_base - 1; 1327 if (len < 0) 1328 goto out_overflow; 1329 switch ((n = ntohl(*p++))) { 1330 case RPC_SUCCESS: 1331 return p; 1332 case RPC_PROG_UNAVAIL: 1333 dprintk("RPC: call_verify: program %u is unsupported by server %s\n", 1334 (unsigned int)task->tk_client->cl_prog, 1335 task->tk_client->cl_server); 1336 error = -EPFNOSUPPORT; 1337 goto out_err; 1338 case RPC_PROG_MISMATCH: 1339 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n", 1340 (unsigned int)task->tk_client->cl_prog, 1341 (unsigned int)task->tk_client->cl_vers, 1342 task->tk_client->cl_server); 1343 error = -EPROTONOSUPPORT; 1344 goto out_err; 1345 case RPC_PROC_UNAVAIL: 1346 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n", 1347 task->tk_msg.rpc_proc, 1348 task->tk_client->cl_prog, 1349 task->tk_client->cl_vers, 1350 task->tk_client->cl_server); 1351 error = -EOPNOTSUPP; 1352 goto out_err; 1353 case RPC_GARBAGE_ARGS: 1354 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__); 1355 break; /* retry */ 1356 default: 1357 printk(KERN_WARNING "call_verify: server accept status: %x\n", n); 1358 /* Also retry */ 1359 } 1360 1361 out_garbage: 1362 task->tk_client->cl_stats->rpcgarbage++; 1363 if (task->tk_garb_retry) { 1364 task->tk_garb_retry--; 1365 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid); 1366 task->tk_action = call_bind; 1367 out_retry: 1368 return ERR_PTR(-EAGAIN); 1369 } 1370 printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__); 1371 out_eio: 1372 error = -EIO; 1373 out_err: 1374 rpc_exit(task, error); 1375 return ERR_PTR(error); 1376 out_overflow: 1377 printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__); 1378 goto out_garbage; 1379 } 1380 1381 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj) 1382 { 1383 return 0; 1384 } 1385 1386 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj) 1387 { 1388 return 0; 1389 } 1390 1391 static struct rpc_procinfo rpcproc_null = { 1392 .p_encode = rpcproc_encode_null, 1393 .p_decode = rpcproc_decode_null, 1394 }; 1395 1396 int rpc_ping(struct rpc_clnt *clnt, int flags) 1397 { 1398 struct rpc_message msg = { 1399 .rpc_proc = &rpcproc_null, 1400 }; 1401 int err; 1402 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0); 1403 err = rpc_call_sync(clnt, &msg, flags); 1404 put_rpccred(msg.rpc_cred); 1405 return err; 1406 } 1407