TTY: synclink_cs, use dynamic tty devices
[linux-2.6.git] / net / sunrpc / clnt.c
blobfa48c60aef2305430956ef9735b20f6a0f62c073
1 /*
2 * linux/net/sunrpc/clnt.c
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.
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.
16 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
17 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kallsyms.h>
24 #include <linux/mm.h>
25 #include <linux/namei.h>
26 #include <linux/mount.h>
27 #include <linux/slab.h>
28 #include <linux/utsname.h>
29 #include <linux/workqueue.h>
30 #include <linux/in.h>
31 #include <linux/in6.h>
32 #include <linux/un.h>
33 #include <linux/rcupdate.h>
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/rpc_pipe_fs.h>
37 #include <linux/sunrpc/metrics.h>
38 #include <linux/sunrpc/bc_xprt.h>
39 #include <trace/events/sunrpc.h>
41 #include "sunrpc.h"
42 #include "netns.h"
44 #ifdef RPC_DEBUG
45 # define RPCDBG_FACILITY RPCDBG_CALL
46 #endif
48 #define dprint_status(t) \
49 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \
50 __func__, t->tk_status)
53 * All RPC clients are linked into this list
56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
59 static void call_start(struct rpc_task *task);
60 static void call_reserve(struct rpc_task *task);
61 static void call_reserveresult(struct rpc_task *task);
62 static void call_allocate(struct rpc_task *task);
63 static void call_decode(struct rpc_task *task);
64 static void call_bind(struct rpc_task *task);
65 static void call_bind_status(struct rpc_task *task);
66 static void call_transmit(struct rpc_task *task);
67 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
68 static void call_bc_transmit(struct rpc_task *task);
69 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
70 static void call_status(struct rpc_task *task);
71 static void call_transmit_status(struct rpc_task *task);
72 static void call_refresh(struct rpc_task *task);
73 static void call_refreshresult(struct rpc_task *task);
74 static void call_timeout(struct rpc_task *task);
75 static void call_connect(struct rpc_task *task);
76 static void call_connect_status(struct rpc_task *task);
78 static __be32 *rpc_encode_header(struct rpc_task *task);
79 static __be32 *rpc_verify_header(struct rpc_task *task);
80 static int rpc_ping(struct rpc_clnt *clnt);
82 static void rpc_register_client(struct rpc_clnt *clnt)
84 struct net *net = rpc_net_ns(clnt);
85 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
87 spin_lock(&sn->rpc_client_lock);
88 list_add(&clnt->cl_clients, &sn->all_clients);
89 spin_unlock(&sn->rpc_client_lock);
92 static void rpc_unregister_client(struct rpc_clnt *clnt)
94 struct net *net = rpc_net_ns(clnt);
95 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
97 spin_lock(&sn->rpc_client_lock);
98 list_del(&clnt->cl_clients);
99 spin_unlock(&sn->rpc_client_lock);
102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 if (clnt->cl_dentry) {
105 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
106 clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
107 rpc_remove_client_dir(clnt->cl_dentry);
109 clnt->cl_dentry = NULL;
112 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
114 struct net *net = rpc_net_ns(clnt);
115 struct super_block *pipefs_sb;
117 pipefs_sb = rpc_get_sb_net(net);
118 if (pipefs_sb) {
119 __rpc_clnt_remove_pipedir(clnt);
120 rpc_put_sb_net(net);
124 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
125 struct rpc_clnt *clnt,
126 const char *dir_name)
128 static uint32_t clntid;
129 char name[15];
130 struct qstr q = { .name = name };
131 struct dentry *dir, *dentry;
132 int error;
134 dir = rpc_d_lookup_sb(sb, dir_name);
135 if (dir == NULL)
136 return dir;
137 for (;;) {
138 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
139 name[sizeof(name) - 1] = '\0';
140 q.hash = full_name_hash(q.name, q.len);
141 dentry = rpc_create_client_dir(dir, &q, clnt);
142 if (!IS_ERR(dentry))
143 break;
144 error = PTR_ERR(dentry);
145 if (error != -EEXIST) {
146 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
147 " %s/%s, error %d\n",
148 dir_name, name, error);
149 break;
152 dput(dir);
153 return dentry;
156 static int
157 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
159 struct net *net = rpc_net_ns(clnt);
160 struct super_block *pipefs_sb;
161 struct dentry *dentry;
163 clnt->cl_dentry = NULL;
164 if (dir_name == NULL)
165 return 0;
166 pipefs_sb = rpc_get_sb_net(net);
167 if (!pipefs_sb)
168 return 0;
169 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
170 rpc_put_sb_net(net);
171 if (IS_ERR(dentry))
172 return PTR_ERR(dentry);
173 clnt->cl_dentry = dentry;
174 return 0;
177 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
179 if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
180 ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
181 return 1;
182 return 0;
185 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
186 struct super_block *sb)
188 struct dentry *dentry;
189 int err = 0;
191 switch (event) {
192 case RPC_PIPEFS_MOUNT:
193 dentry = rpc_setup_pipedir_sb(sb, clnt,
194 clnt->cl_program->pipe_dir_name);
195 BUG_ON(dentry == NULL);
196 if (IS_ERR(dentry))
197 return PTR_ERR(dentry);
198 clnt->cl_dentry = dentry;
199 if (clnt->cl_auth->au_ops->pipes_create) {
200 err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
201 if (err)
202 __rpc_clnt_remove_pipedir(clnt);
204 break;
205 case RPC_PIPEFS_UMOUNT:
206 __rpc_clnt_remove_pipedir(clnt);
207 break;
208 default:
209 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
210 return -ENOTSUPP;
212 return err;
215 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
216 struct super_block *sb)
218 int error = 0;
220 for (;; clnt = clnt->cl_parent) {
221 if (!rpc_clnt_skip_event(clnt, event))
222 error = __rpc_clnt_handle_event(clnt, event, sb);
223 if (error || clnt == clnt->cl_parent)
224 break;
226 return error;
229 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
231 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
232 struct rpc_clnt *clnt;
234 spin_lock(&sn->rpc_client_lock);
235 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
236 if (clnt->cl_program->pipe_dir_name == NULL)
237 break;
238 if (rpc_clnt_skip_event(clnt, event))
239 continue;
240 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
241 continue;
242 spin_unlock(&sn->rpc_client_lock);
243 return clnt;
245 spin_unlock(&sn->rpc_client_lock);
246 return NULL;
249 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
250 void *ptr)
252 struct super_block *sb = ptr;
253 struct rpc_clnt *clnt;
254 int error = 0;
256 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
257 error = __rpc_pipefs_event(clnt, event, sb);
258 rpc_release_client(clnt);
259 if (error)
260 break;
262 return error;
265 static struct notifier_block rpc_clients_block = {
266 .notifier_call = rpc_pipefs_event,
267 .priority = SUNRPC_PIPEFS_RPC_PRIO,
270 int rpc_clients_notifier_register(void)
272 return rpc_pipefs_notifier_register(&rpc_clients_block);
275 void rpc_clients_notifier_unregister(void)
277 return rpc_pipefs_notifier_unregister(&rpc_clients_block);
280 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
282 clnt->cl_nodelen = strlen(nodename);
283 if (clnt->cl_nodelen > UNX_MAXNODENAME)
284 clnt->cl_nodelen = UNX_MAXNODENAME;
285 memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
288 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
290 const struct rpc_program *program = args->program;
291 const struct rpc_version *version;
292 struct rpc_clnt *clnt = NULL;
293 struct rpc_auth *auth;
294 int err;
296 /* sanity check the name before trying to print it */
297 dprintk("RPC: creating %s client for %s (xprt %p)\n",
298 program->name, args->servername, xprt);
300 err = rpciod_up();
301 if (err)
302 goto out_no_rpciod;
303 err = -EINVAL;
304 if (!xprt)
305 goto out_no_xprt;
307 if (args->version >= program->nrvers)
308 goto out_err;
309 version = program->version[args->version];
310 if (version == NULL)
311 goto out_err;
313 err = -ENOMEM;
314 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
315 if (!clnt)
316 goto out_err;
317 clnt->cl_parent = clnt;
319 rcu_assign_pointer(clnt->cl_xprt, xprt);
320 clnt->cl_procinfo = version->procs;
321 clnt->cl_maxproc = version->nrprocs;
322 clnt->cl_protname = program->name;
323 clnt->cl_prog = args->prognumber ? : program->number;
324 clnt->cl_vers = version->number;
325 clnt->cl_stats = program->stats;
326 clnt->cl_metrics = rpc_alloc_iostats(clnt);
327 err = -ENOMEM;
328 if (clnt->cl_metrics == NULL)
329 goto out_no_stats;
330 clnt->cl_program = program;
331 INIT_LIST_HEAD(&clnt->cl_tasks);
332 spin_lock_init(&clnt->cl_lock);
334 if (!xprt_bound(xprt))
335 clnt->cl_autobind = 1;
337 clnt->cl_timeout = xprt->timeout;
338 if (args->timeout != NULL) {
339 memcpy(&clnt->cl_timeout_default, args->timeout,
340 sizeof(clnt->cl_timeout_default));
341 clnt->cl_timeout = &clnt->cl_timeout_default;
344 clnt->cl_rtt = &clnt->cl_rtt_default;
345 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
346 clnt->cl_principal = NULL;
347 if (args->client_name) {
348 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
349 if (!clnt->cl_principal)
350 goto out_no_principal;
353 atomic_set(&clnt->cl_count, 1);
355 err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
356 if (err < 0)
357 goto out_no_path;
359 auth = rpcauth_create(args->authflavor, clnt);
360 if (IS_ERR(auth)) {
361 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
362 args->authflavor);
363 err = PTR_ERR(auth);
364 goto out_no_auth;
367 /* save the nodename */
368 rpc_clnt_set_nodename(clnt, utsname()->nodename);
369 rpc_register_client(clnt);
370 return clnt;
372 out_no_auth:
373 rpc_clnt_remove_pipedir(clnt);
374 out_no_path:
375 kfree(clnt->cl_principal);
376 out_no_principal:
377 rpc_free_iostats(clnt->cl_metrics);
378 out_no_stats:
379 kfree(clnt);
380 out_err:
381 xprt_put(xprt);
382 out_no_xprt:
383 rpciod_down();
384 out_no_rpciod:
385 return ERR_PTR(err);
389 * rpc_create - create an RPC client and transport with one call
390 * @args: rpc_clnt create argument structure
392 * Creates and initializes an RPC transport and an RPC client.
394 * It can ping the server in order to determine if it is up, and to see if
395 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
396 * this behavior so asynchronous tasks can also use rpc_create.
398 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
400 struct rpc_xprt *xprt;
401 struct rpc_clnt *clnt;
402 struct xprt_create xprtargs = {
403 .net = args->net,
404 .ident = args->protocol,
405 .srcaddr = args->saddress,
406 .dstaddr = args->address,
407 .addrlen = args->addrsize,
408 .servername = args->servername,
409 .bc_xprt = args->bc_xprt,
411 char servername[48];
414 * If the caller chooses not to specify a hostname, whip
415 * up a string representation of the passed-in address.
417 if (xprtargs.servername == NULL) {
418 struct sockaddr_un *sun =
419 (struct sockaddr_un *)args->address;
420 struct sockaddr_in *sin =
421 (struct sockaddr_in *)args->address;
422 struct sockaddr_in6 *sin6 =
423 (struct sockaddr_in6 *)args->address;
425 servername[0] = '\0';
426 switch (args->address->sa_family) {
427 case AF_LOCAL:
428 snprintf(servername, sizeof(servername), "%s",
429 sun->sun_path);
430 break;
431 case AF_INET:
432 snprintf(servername, sizeof(servername), "%pI4",
433 &sin->sin_addr.s_addr);
434 break;
435 case AF_INET6:
436 snprintf(servername, sizeof(servername), "%pI6",
437 &sin6->sin6_addr);
438 break;
439 default:
440 /* caller wants default server name, but
441 * address family isn't recognized. */
442 return ERR_PTR(-EINVAL);
444 xprtargs.servername = servername;
447 xprt = xprt_create_transport(&xprtargs);
448 if (IS_ERR(xprt))
449 return (struct rpc_clnt *)xprt;
452 * By default, kernel RPC client connects from a reserved port.
453 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
454 * but it is always enabled for rpciod, which handles the connect
455 * operation.
457 xprt->resvport = 1;
458 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
459 xprt->resvport = 0;
461 clnt = rpc_new_client(args, xprt);
462 if (IS_ERR(clnt))
463 return clnt;
465 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
466 int err = rpc_ping(clnt);
467 if (err != 0) {
468 rpc_shutdown_client(clnt);
469 return ERR_PTR(err);
473 clnt->cl_softrtry = 1;
474 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
475 clnt->cl_softrtry = 0;
477 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
478 clnt->cl_autobind = 1;
479 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
480 clnt->cl_discrtry = 1;
481 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
482 clnt->cl_chatty = 1;
484 return clnt;
486 EXPORT_SYMBOL_GPL(rpc_create);
489 * This function clones the RPC client structure. It allows us to share the
490 * same transport while varying parameters such as the authentication
491 * flavour.
493 struct rpc_clnt *
494 rpc_clone_client(struct rpc_clnt *clnt)
496 struct rpc_clnt *new;
497 struct rpc_xprt *xprt;
498 int err = -ENOMEM;
500 new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
501 if (!new)
502 goto out_no_clnt;
503 new->cl_parent = clnt;
504 /* Turn off autobind on clones */
505 new->cl_autobind = 0;
506 INIT_LIST_HEAD(&new->cl_tasks);
507 spin_lock_init(&new->cl_lock);
508 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
509 new->cl_metrics = rpc_alloc_iostats(clnt);
510 if (new->cl_metrics == NULL)
511 goto out_no_stats;
512 if (clnt->cl_principal) {
513 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
514 if (new->cl_principal == NULL)
515 goto out_no_principal;
517 rcu_read_lock();
518 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
519 rcu_read_unlock();
520 if (xprt == NULL)
521 goto out_no_transport;
522 rcu_assign_pointer(new->cl_xprt, xprt);
523 atomic_set(&new->cl_count, 1);
524 err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
525 if (err != 0)
526 goto out_no_path;
527 rpc_clnt_set_nodename(new, utsname()->nodename);
528 if (new->cl_auth)
529 atomic_inc(&new->cl_auth->au_count);
530 atomic_inc(&clnt->cl_count);
531 rpc_register_client(new);
532 rpciod_up();
533 return new;
534 out_no_path:
535 xprt_put(xprt);
536 out_no_transport:
537 kfree(new->cl_principal);
538 out_no_principal:
539 rpc_free_iostats(new->cl_metrics);
540 out_no_stats:
541 kfree(new);
542 out_no_clnt:
543 dprintk("RPC: %s: returned error %d\n", __func__, err);
544 return ERR_PTR(err);
546 EXPORT_SYMBOL_GPL(rpc_clone_client);
549 * Kill all tasks for the given client.
550 * XXX: kill their descendants as well?
552 void rpc_killall_tasks(struct rpc_clnt *clnt)
554 struct rpc_task *rovr;
557 if (list_empty(&clnt->cl_tasks))
558 return;
559 dprintk("RPC: killing all tasks for client %p\n", clnt);
561 * Spin lock all_tasks to prevent changes...
563 spin_lock(&clnt->cl_lock);
564 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
565 if (!RPC_IS_ACTIVATED(rovr))
566 continue;
567 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
568 rovr->tk_flags |= RPC_TASK_KILLED;
569 rpc_exit(rovr, -EIO);
570 if (RPC_IS_QUEUED(rovr))
571 rpc_wake_up_queued_task(rovr->tk_waitqueue,
572 rovr);
575 spin_unlock(&clnt->cl_lock);
577 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
580 * Properly shut down an RPC client, terminating all outstanding
581 * requests.
583 void rpc_shutdown_client(struct rpc_clnt *clnt)
585 dprintk_rcu("RPC: shutting down %s client for %s\n",
586 clnt->cl_protname,
587 rcu_dereference(clnt->cl_xprt)->servername);
589 while (!list_empty(&clnt->cl_tasks)) {
590 rpc_killall_tasks(clnt);
591 wait_event_timeout(destroy_wait,
592 list_empty(&clnt->cl_tasks), 1*HZ);
595 rpc_release_client(clnt);
597 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
600 * Free an RPC client
602 static void
603 rpc_free_client(struct rpc_clnt *clnt)
605 dprintk_rcu("RPC: destroying %s client for %s\n",
606 clnt->cl_protname,
607 rcu_dereference(clnt->cl_xprt)->servername);
608 if (clnt->cl_parent != clnt)
609 rpc_release_client(clnt->cl_parent);
610 rpc_unregister_client(clnt);
611 rpc_clnt_remove_pipedir(clnt);
612 rpc_free_iostats(clnt->cl_metrics);
613 kfree(clnt->cl_principal);
614 clnt->cl_metrics = NULL;
615 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
616 rpciod_down();
617 kfree(clnt);
621 * Free an RPC client
623 static void
624 rpc_free_auth(struct rpc_clnt *clnt)
626 if (clnt->cl_auth == NULL) {
627 rpc_free_client(clnt);
628 return;
632 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
633 * release remaining GSS contexts. This mechanism ensures
634 * that it can do so safely.
636 atomic_inc(&clnt->cl_count);
637 rpcauth_release(clnt->cl_auth);
638 clnt->cl_auth = NULL;
639 if (atomic_dec_and_test(&clnt->cl_count))
640 rpc_free_client(clnt);
644 * Release reference to the RPC client
646 void
647 rpc_release_client(struct rpc_clnt *clnt)
649 dprintk("RPC: rpc_release_client(%p)\n", clnt);
651 if (list_empty(&clnt->cl_tasks))
652 wake_up(&destroy_wait);
653 if (atomic_dec_and_test(&clnt->cl_count))
654 rpc_free_auth(clnt);
658 * rpc_bind_new_program - bind a new RPC program to an existing client
659 * @old: old rpc_client
660 * @program: rpc program to set
661 * @vers: rpc program version
663 * Clones the rpc client and sets up a new RPC program. This is mainly
664 * of use for enabling different RPC programs to share the same transport.
665 * The Sun NFSv2/v3 ACL protocol can do this.
667 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
668 const struct rpc_program *program,
669 u32 vers)
671 struct rpc_clnt *clnt;
672 const struct rpc_version *version;
673 int err;
675 BUG_ON(vers >= program->nrvers || !program->version[vers]);
676 version = program->version[vers];
677 clnt = rpc_clone_client(old);
678 if (IS_ERR(clnt))
679 goto out;
680 clnt->cl_procinfo = version->procs;
681 clnt->cl_maxproc = version->nrprocs;
682 clnt->cl_protname = program->name;
683 clnt->cl_prog = program->number;
684 clnt->cl_vers = version->number;
685 clnt->cl_stats = program->stats;
686 err = rpc_ping(clnt);
687 if (err != 0) {
688 rpc_shutdown_client(clnt);
689 clnt = ERR_PTR(err);
691 out:
692 return clnt;
694 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
696 void rpc_task_release_client(struct rpc_task *task)
698 struct rpc_clnt *clnt = task->tk_client;
700 if (clnt != NULL) {
701 /* Remove from client task list */
702 spin_lock(&clnt->cl_lock);
703 list_del(&task->tk_task);
704 spin_unlock(&clnt->cl_lock);
705 task->tk_client = NULL;
707 rpc_release_client(clnt);
711 static
712 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
714 if (clnt != NULL) {
715 rpc_task_release_client(task);
716 task->tk_client = clnt;
717 atomic_inc(&clnt->cl_count);
718 if (clnt->cl_softrtry)
719 task->tk_flags |= RPC_TASK_SOFT;
720 if (sk_memalloc_socks()) {
721 struct rpc_xprt *xprt;
723 rcu_read_lock();
724 xprt = rcu_dereference(clnt->cl_xprt);
725 if (xprt->swapper)
726 task->tk_flags |= RPC_TASK_SWAPPER;
727 rcu_read_unlock();
729 /* Add to the client's list of all tasks */
730 spin_lock(&clnt->cl_lock);
731 list_add_tail(&task->tk_task, &clnt->cl_tasks);
732 spin_unlock(&clnt->cl_lock);
736 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
738 rpc_task_release_client(task);
739 rpc_task_set_client(task, clnt);
741 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
744 static void
745 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
747 if (msg != NULL) {
748 task->tk_msg.rpc_proc = msg->rpc_proc;
749 task->tk_msg.rpc_argp = msg->rpc_argp;
750 task->tk_msg.rpc_resp = msg->rpc_resp;
751 if (msg->rpc_cred != NULL)
752 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
757 * Default callback for async RPC calls
759 static void
760 rpc_default_callback(struct rpc_task *task, void *data)
764 static const struct rpc_call_ops rpc_default_ops = {
765 .rpc_call_done = rpc_default_callback,
769 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
770 * @task_setup_data: pointer to task initialisation data
772 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
774 struct rpc_task *task;
776 task = rpc_new_task(task_setup_data);
777 if (IS_ERR(task))
778 goto out;
780 rpc_task_set_client(task, task_setup_data->rpc_client);
781 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
783 if (task->tk_action == NULL)
784 rpc_call_start(task);
786 atomic_inc(&task->tk_count);
787 rpc_execute(task);
788 out:
789 return task;
791 EXPORT_SYMBOL_GPL(rpc_run_task);
794 * rpc_call_sync - Perform a synchronous RPC call
795 * @clnt: pointer to RPC client
796 * @msg: RPC call parameters
797 * @flags: RPC call flags
799 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
801 struct rpc_task *task;
802 struct rpc_task_setup task_setup_data = {
803 .rpc_client = clnt,
804 .rpc_message = msg,
805 .callback_ops = &rpc_default_ops,
806 .flags = flags,
808 int status;
810 BUG_ON(flags & RPC_TASK_ASYNC);
812 task = rpc_run_task(&task_setup_data);
813 if (IS_ERR(task))
814 return PTR_ERR(task);
815 status = task->tk_status;
816 rpc_put_task(task);
817 return status;
819 EXPORT_SYMBOL_GPL(rpc_call_sync);
822 * rpc_call_async - Perform an asynchronous RPC call
823 * @clnt: pointer to RPC client
824 * @msg: RPC call parameters
825 * @flags: RPC call flags
826 * @tk_ops: RPC call ops
827 * @data: user call data
830 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
831 const struct rpc_call_ops *tk_ops, void *data)
833 struct rpc_task *task;
834 struct rpc_task_setup task_setup_data = {
835 .rpc_client = clnt,
836 .rpc_message = msg,
837 .callback_ops = tk_ops,
838 .callback_data = data,
839 .flags = flags|RPC_TASK_ASYNC,
842 task = rpc_run_task(&task_setup_data);
843 if (IS_ERR(task))
844 return PTR_ERR(task);
845 rpc_put_task(task);
846 return 0;
848 EXPORT_SYMBOL_GPL(rpc_call_async);
850 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
852 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
853 * rpc_execute against it
854 * @req: RPC request
855 * @tk_ops: RPC call ops
857 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
858 const struct rpc_call_ops *tk_ops)
860 struct rpc_task *task;
861 struct xdr_buf *xbufp = &req->rq_snd_buf;
862 struct rpc_task_setup task_setup_data = {
863 .callback_ops = tk_ops,
866 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
868 * Create an rpc_task to send the data
870 task = rpc_new_task(&task_setup_data);
871 if (IS_ERR(task)) {
872 xprt_free_bc_request(req);
873 goto out;
875 task->tk_rqstp = req;
878 * Set up the xdr_buf length.
879 * This also indicates that the buffer is XDR encoded already.
881 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
882 xbufp->tail[0].iov_len;
884 task->tk_action = call_bc_transmit;
885 atomic_inc(&task->tk_count);
886 BUG_ON(atomic_read(&task->tk_count) != 2);
887 rpc_execute(task);
889 out:
890 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
891 return task;
893 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
895 void
896 rpc_call_start(struct rpc_task *task)
898 task->tk_action = call_start;
900 EXPORT_SYMBOL_GPL(rpc_call_start);
903 * rpc_peeraddr - extract remote peer address from clnt's xprt
904 * @clnt: RPC client structure
905 * @buf: target buffer
906 * @bufsize: length of target buffer
908 * Returns the number of bytes that are actually in the stored address.
910 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
912 size_t bytes;
913 struct rpc_xprt *xprt;
915 rcu_read_lock();
916 xprt = rcu_dereference(clnt->cl_xprt);
918 bytes = xprt->addrlen;
919 if (bytes > bufsize)
920 bytes = bufsize;
921 memcpy(buf, &xprt->addr, bytes);
922 rcu_read_unlock();
924 return bytes;
926 EXPORT_SYMBOL_GPL(rpc_peeraddr);
929 * rpc_peeraddr2str - return remote peer address in printable format
930 * @clnt: RPC client structure
931 * @format: address format
933 * NB: the lifetime of the memory referenced by the returned pointer is
934 * the same as the rpc_xprt itself. As long as the caller uses this
935 * pointer, it must hold the RCU read lock.
937 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
938 enum rpc_display_format_t format)
940 struct rpc_xprt *xprt;
942 xprt = rcu_dereference(clnt->cl_xprt);
944 if (xprt->address_strings[format] != NULL)
945 return xprt->address_strings[format];
946 else
947 return "unprintable";
949 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
951 static const struct sockaddr_in rpc_inaddr_loopback = {
952 .sin_family = AF_INET,
953 .sin_addr.s_addr = htonl(INADDR_ANY),
956 static const struct sockaddr_in6 rpc_in6addr_loopback = {
957 .sin6_family = AF_INET6,
958 .sin6_addr = IN6ADDR_ANY_INIT,
962 * Try a getsockname() on a connected datagram socket. Using a
963 * connected datagram socket prevents leaving a socket in TIME_WAIT.
964 * This conserves the ephemeral port number space.
966 * Returns zero and fills in "buf" if successful; otherwise, a
967 * negative errno is returned.
969 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
970 struct sockaddr *buf, int buflen)
972 struct socket *sock;
973 int err;
975 err = __sock_create(net, sap->sa_family,
976 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
977 if (err < 0) {
978 dprintk("RPC: can't create UDP socket (%d)\n", err);
979 goto out;
982 switch (sap->sa_family) {
983 case AF_INET:
984 err = kernel_bind(sock,
985 (struct sockaddr *)&rpc_inaddr_loopback,
986 sizeof(rpc_inaddr_loopback));
987 break;
988 case AF_INET6:
989 err = kernel_bind(sock,
990 (struct sockaddr *)&rpc_in6addr_loopback,
991 sizeof(rpc_in6addr_loopback));
992 break;
993 default:
994 err = -EAFNOSUPPORT;
995 goto out;
997 if (err < 0) {
998 dprintk("RPC: can't bind UDP socket (%d)\n", err);
999 goto out_release;
1002 err = kernel_connect(sock, sap, salen, 0);
1003 if (err < 0) {
1004 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1005 goto out_release;
1008 err = kernel_getsockname(sock, buf, &buflen);
1009 if (err < 0) {
1010 dprintk("RPC: getsockname failed (%d)\n", err);
1011 goto out_release;
1014 err = 0;
1015 if (buf->sa_family == AF_INET6) {
1016 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1017 sin6->sin6_scope_id = 0;
1019 dprintk("RPC: %s succeeded\n", __func__);
1021 out_release:
1022 sock_release(sock);
1023 out:
1024 return err;
1028 * Scraping a connected socket failed, so we don't have a useable
1029 * local address. Fallback: generate an address that will prevent
1030 * the server from calling us back.
1032 * Returns zero and fills in "buf" if successful; otherwise, a
1033 * negative errno is returned.
1035 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1037 switch (family) {
1038 case AF_INET:
1039 if (buflen < sizeof(rpc_inaddr_loopback))
1040 return -EINVAL;
1041 memcpy(buf, &rpc_inaddr_loopback,
1042 sizeof(rpc_inaddr_loopback));
1043 break;
1044 case AF_INET6:
1045 if (buflen < sizeof(rpc_in6addr_loopback))
1046 return -EINVAL;
1047 memcpy(buf, &rpc_in6addr_loopback,
1048 sizeof(rpc_in6addr_loopback));
1049 default:
1050 dprintk("RPC: %s: address family not supported\n",
1051 __func__);
1052 return -EAFNOSUPPORT;
1054 dprintk("RPC: %s: succeeded\n", __func__);
1055 return 0;
1059 * rpc_localaddr - discover local endpoint address for an RPC client
1060 * @clnt: RPC client structure
1061 * @buf: target buffer
1062 * @buflen: size of target buffer, in bytes
1064 * Returns zero and fills in "buf" and "buflen" if successful;
1065 * otherwise, a negative errno is returned.
1067 * This works even if the underlying transport is not currently connected,
1068 * or if the upper layer never previously provided a source address.
1070 * The result of this function call is transient: multiple calls in
1071 * succession may give different results, depending on how local
1072 * networking configuration changes over time.
1074 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1076 struct sockaddr_storage address;
1077 struct sockaddr *sap = (struct sockaddr *)&address;
1078 struct rpc_xprt *xprt;
1079 struct net *net;
1080 size_t salen;
1081 int err;
1083 rcu_read_lock();
1084 xprt = rcu_dereference(clnt->cl_xprt);
1085 salen = xprt->addrlen;
1086 memcpy(sap, &xprt->addr, salen);
1087 net = get_net(xprt->xprt_net);
1088 rcu_read_unlock();
1090 rpc_set_port(sap, 0);
1091 err = rpc_sockname(net, sap, salen, buf, buflen);
1092 put_net(net);
1093 if (err != 0)
1094 /* Couldn't discover local address, return ANYADDR */
1095 return rpc_anyaddr(sap->sa_family, buf, buflen);
1096 return 0;
1098 EXPORT_SYMBOL_GPL(rpc_localaddr);
1100 void
1101 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1103 struct rpc_xprt *xprt;
1105 rcu_read_lock();
1106 xprt = rcu_dereference(clnt->cl_xprt);
1107 if (xprt->ops->set_buffer_size)
1108 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1109 rcu_read_unlock();
1111 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1114 * rpc_protocol - Get transport protocol number for an RPC client
1115 * @clnt: RPC client to query
1118 int rpc_protocol(struct rpc_clnt *clnt)
1120 int protocol;
1122 rcu_read_lock();
1123 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1124 rcu_read_unlock();
1125 return protocol;
1127 EXPORT_SYMBOL_GPL(rpc_protocol);
1130 * rpc_net_ns - Get the network namespace for this RPC client
1131 * @clnt: RPC client to query
1134 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1136 struct net *ret;
1138 rcu_read_lock();
1139 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1140 rcu_read_unlock();
1141 return ret;
1143 EXPORT_SYMBOL_GPL(rpc_net_ns);
1146 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1147 * @clnt: RPC client to query
1149 * For stream transports, this is one RPC record fragment (see RFC
1150 * 1831), as we don't support multi-record requests yet. For datagram
1151 * transports, this is the size of an IP packet minus the IP, UDP, and
1152 * RPC header sizes.
1154 size_t rpc_max_payload(struct rpc_clnt *clnt)
1156 size_t ret;
1158 rcu_read_lock();
1159 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1160 rcu_read_unlock();
1161 return ret;
1163 EXPORT_SYMBOL_GPL(rpc_max_payload);
1166 * rpc_force_rebind - force transport to check that remote port is unchanged
1167 * @clnt: client to rebind
1170 void rpc_force_rebind(struct rpc_clnt *clnt)
1172 if (clnt->cl_autobind) {
1173 rcu_read_lock();
1174 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1175 rcu_read_unlock();
1178 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1181 * Restart an (async) RPC call from the call_prepare state.
1182 * Usually called from within the exit handler.
1185 rpc_restart_call_prepare(struct rpc_task *task)
1187 if (RPC_ASSASSINATED(task))
1188 return 0;
1189 task->tk_action = call_start;
1190 if (task->tk_ops->rpc_call_prepare != NULL)
1191 task->tk_action = rpc_prepare_task;
1192 return 1;
1194 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1197 * Restart an (async) RPC call. Usually called from within the
1198 * exit handler.
1201 rpc_restart_call(struct rpc_task *task)
1203 if (RPC_ASSASSINATED(task))
1204 return 0;
1205 task->tk_action = call_start;
1206 return 1;
1208 EXPORT_SYMBOL_GPL(rpc_restart_call);
1210 #ifdef RPC_DEBUG
1211 static const char *rpc_proc_name(const struct rpc_task *task)
1213 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1215 if (proc) {
1216 if (proc->p_name)
1217 return proc->p_name;
1218 else
1219 return "NULL";
1220 } else
1221 return "no proc";
1223 #endif
1226 * 0. Initial state
1228 * Other FSM states can be visited zero or more times, but
1229 * this state is visited exactly once for each RPC.
1231 static void
1232 call_start(struct rpc_task *task)
1234 struct rpc_clnt *clnt = task->tk_client;
1236 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1237 clnt->cl_protname, clnt->cl_vers,
1238 rpc_proc_name(task),
1239 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1241 /* Increment call count */
1242 task->tk_msg.rpc_proc->p_count++;
1243 clnt->cl_stats->rpccnt++;
1244 task->tk_action = call_reserve;
1248 * 1. Reserve an RPC call slot
1250 static void
1251 call_reserve(struct rpc_task *task)
1253 dprint_status(task);
1255 task->tk_status = 0;
1256 task->tk_action = call_reserveresult;
1257 xprt_reserve(task);
1261 * 1b. Grok the result of xprt_reserve()
1263 static void
1264 call_reserveresult(struct rpc_task *task)
1266 int status = task->tk_status;
1268 dprint_status(task);
1271 * After a call to xprt_reserve(), we must have either
1272 * a request slot or else an error status.
1274 task->tk_status = 0;
1275 if (status >= 0) {
1276 if (task->tk_rqstp) {
1277 task->tk_action = call_refresh;
1278 return;
1281 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1282 __func__, status);
1283 rpc_exit(task, -EIO);
1284 return;
1288 * Even though there was an error, we may have acquired
1289 * a request slot somehow. Make sure not to leak it.
1291 if (task->tk_rqstp) {
1292 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1293 __func__, status);
1294 xprt_release(task);
1297 switch (status) {
1298 case -ENOMEM:
1299 rpc_delay(task, HZ >> 2);
1300 case -EAGAIN: /* woken up; retry */
1301 task->tk_action = call_reserve;
1302 return;
1303 case -EIO: /* probably a shutdown */
1304 break;
1305 default:
1306 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1307 __func__, status);
1308 break;
1310 rpc_exit(task, status);
1314 * 2. Bind and/or refresh the credentials
1316 static void
1317 call_refresh(struct rpc_task *task)
1319 dprint_status(task);
1321 task->tk_action = call_refreshresult;
1322 task->tk_status = 0;
1323 task->tk_client->cl_stats->rpcauthrefresh++;
1324 rpcauth_refreshcred(task);
1328 * 2a. Process the results of a credential refresh
1330 static void
1331 call_refreshresult(struct rpc_task *task)
1333 int status = task->tk_status;
1335 dprint_status(task);
1337 task->tk_status = 0;
1338 task->tk_action = call_refresh;
1339 switch (status) {
1340 case 0:
1341 if (rpcauth_uptodatecred(task))
1342 task->tk_action = call_allocate;
1343 return;
1344 case -ETIMEDOUT:
1345 rpc_delay(task, 3*HZ);
1346 case -EAGAIN:
1347 status = -EACCES;
1348 if (!task->tk_cred_retry)
1349 break;
1350 task->tk_cred_retry--;
1351 dprintk("RPC: %5u %s: retry refresh creds\n",
1352 task->tk_pid, __func__);
1353 return;
1355 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1356 task->tk_pid, __func__, status);
1357 rpc_exit(task, status);
1361 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1362 * (Note: buffer memory is freed in xprt_release).
1364 static void
1365 call_allocate(struct rpc_task *task)
1367 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1368 struct rpc_rqst *req = task->tk_rqstp;
1369 struct rpc_xprt *xprt = task->tk_xprt;
1370 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1372 dprint_status(task);
1374 task->tk_status = 0;
1375 task->tk_action = call_bind;
1377 if (req->rq_buffer)
1378 return;
1380 if (proc->p_proc != 0) {
1381 BUG_ON(proc->p_arglen == 0);
1382 if (proc->p_decode != NULL)
1383 BUG_ON(proc->p_replen == 0);
1387 * Calculate the size (in quads) of the RPC call
1388 * and reply headers, and convert both values
1389 * to byte sizes.
1391 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1392 req->rq_callsize <<= 2;
1393 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1394 req->rq_rcvsize <<= 2;
1396 req->rq_buffer = xprt->ops->buf_alloc(task,
1397 req->rq_callsize + req->rq_rcvsize);
1398 if (req->rq_buffer != NULL)
1399 return;
1401 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1403 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1404 task->tk_action = call_allocate;
1405 rpc_delay(task, HZ>>4);
1406 return;
1409 rpc_exit(task, -ERESTARTSYS);
1412 static inline int
1413 rpc_task_need_encode(struct rpc_task *task)
1415 return task->tk_rqstp->rq_snd_buf.len == 0;
1418 static inline void
1419 rpc_task_force_reencode(struct rpc_task *task)
1421 task->tk_rqstp->rq_snd_buf.len = 0;
1422 task->tk_rqstp->rq_bytes_sent = 0;
1425 static inline void
1426 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1428 buf->head[0].iov_base = start;
1429 buf->head[0].iov_len = len;
1430 buf->tail[0].iov_len = 0;
1431 buf->page_len = 0;
1432 buf->flags = 0;
1433 buf->len = 0;
1434 buf->buflen = len;
1438 * 3. Encode arguments of an RPC call
1440 static void
1441 rpc_xdr_encode(struct rpc_task *task)
1443 struct rpc_rqst *req = task->tk_rqstp;
1444 kxdreproc_t encode;
1445 __be32 *p;
1447 dprint_status(task);
1449 rpc_xdr_buf_init(&req->rq_snd_buf,
1450 req->rq_buffer,
1451 req->rq_callsize);
1452 rpc_xdr_buf_init(&req->rq_rcv_buf,
1453 (char *)req->rq_buffer + req->rq_callsize,
1454 req->rq_rcvsize);
1456 p = rpc_encode_header(task);
1457 if (p == NULL) {
1458 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1459 rpc_exit(task, -EIO);
1460 return;
1463 encode = task->tk_msg.rpc_proc->p_encode;
1464 if (encode == NULL)
1465 return;
1467 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1468 task->tk_msg.rpc_argp);
1472 * 4. Get the server port number if not yet set
1474 static void
1475 call_bind(struct rpc_task *task)
1477 struct rpc_xprt *xprt = task->tk_xprt;
1479 dprint_status(task);
1481 task->tk_action = call_connect;
1482 if (!xprt_bound(xprt)) {
1483 task->tk_action = call_bind_status;
1484 task->tk_timeout = xprt->bind_timeout;
1485 xprt->ops->rpcbind(task);
1490 * 4a. Sort out bind result
1492 static void
1493 call_bind_status(struct rpc_task *task)
1495 int status = -EIO;
1497 if (task->tk_status >= 0) {
1498 dprint_status(task);
1499 task->tk_status = 0;
1500 task->tk_action = call_connect;
1501 return;
1504 trace_rpc_bind_status(task);
1505 switch (task->tk_status) {
1506 case -ENOMEM:
1507 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1508 rpc_delay(task, HZ >> 2);
1509 goto retry_timeout;
1510 case -EACCES:
1511 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1512 "unavailable\n", task->tk_pid);
1513 /* fail immediately if this is an RPC ping */
1514 if (task->tk_msg.rpc_proc->p_proc == 0) {
1515 status = -EOPNOTSUPP;
1516 break;
1518 if (task->tk_rebind_retry == 0)
1519 break;
1520 task->tk_rebind_retry--;
1521 rpc_delay(task, 3*HZ);
1522 goto retry_timeout;
1523 case -ETIMEDOUT:
1524 dprintk("RPC: %5u rpcbind request timed out\n",
1525 task->tk_pid);
1526 goto retry_timeout;
1527 case -EPFNOSUPPORT:
1528 /* server doesn't support any rpcbind version we know of */
1529 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1530 task->tk_pid);
1531 break;
1532 case -EPROTONOSUPPORT:
1533 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1534 task->tk_pid);
1535 task->tk_status = 0;
1536 task->tk_action = call_bind;
1537 return;
1538 case -ECONNREFUSED: /* connection problems */
1539 case -ECONNRESET:
1540 case -ENOTCONN:
1541 case -EHOSTDOWN:
1542 case -EHOSTUNREACH:
1543 case -ENETUNREACH:
1544 case -EPIPE:
1545 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1546 task->tk_pid, task->tk_status);
1547 if (!RPC_IS_SOFTCONN(task)) {
1548 rpc_delay(task, 5*HZ);
1549 goto retry_timeout;
1551 status = task->tk_status;
1552 break;
1553 default:
1554 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1555 task->tk_pid, -task->tk_status);
1558 rpc_exit(task, status);
1559 return;
1561 retry_timeout:
1562 task->tk_action = call_timeout;
1566 * 4b. Connect to the RPC server
1568 static void
1569 call_connect(struct rpc_task *task)
1571 struct rpc_xprt *xprt = task->tk_xprt;
1573 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1574 task->tk_pid, xprt,
1575 (xprt_connected(xprt) ? "is" : "is not"));
1577 task->tk_action = call_transmit;
1578 if (!xprt_connected(xprt)) {
1579 task->tk_action = call_connect_status;
1580 if (task->tk_status < 0)
1581 return;
1582 xprt_connect(task);
1587 * 4c. Sort out connect result
1589 static void
1590 call_connect_status(struct rpc_task *task)
1592 struct rpc_clnt *clnt = task->tk_client;
1593 int status = task->tk_status;
1595 dprint_status(task);
1597 task->tk_status = 0;
1598 if (status >= 0 || status == -EAGAIN) {
1599 clnt->cl_stats->netreconn++;
1600 task->tk_action = call_transmit;
1601 return;
1604 trace_rpc_connect_status(task, status);
1605 switch (status) {
1606 /* if soft mounted, test if we've timed out */
1607 case -ETIMEDOUT:
1608 task->tk_action = call_timeout;
1609 break;
1610 default:
1611 rpc_exit(task, -EIO);
1616 * 5. Transmit the RPC request, and wait for reply
1618 static void
1619 call_transmit(struct rpc_task *task)
1621 dprint_status(task);
1623 task->tk_action = call_status;
1624 if (task->tk_status < 0)
1625 return;
1626 task->tk_status = xprt_prepare_transmit(task);
1627 if (task->tk_status != 0)
1628 return;
1629 task->tk_action = call_transmit_status;
1630 /* Encode here so that rpcsec_gss can use correct sequence number. */
1631 if (rpc_task_need_encode(task)) {
1632 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1633 rpc_xdr_encode(task);
1634 /* Did the encode result in an error condition? */
1635 if (task->tk_status != 0) {
1636 /* Was the error nonfatal? */
1637 if (task->tk_status == -EAGAIN)
1638 rpc_delay(task, HZ >> 4);
1639 else
1640 rpc_exit(task, task->tk_status);
1641 return;
1644 xprt_transmit(task);
1645 if (task->tk_status < 0)
1646 return;
1648 * On success, ensure that we call xprt_end_transmit() before sleeping
1649 * in order to allow access to the socket to other RPC requests.
1651 call_transmit_status(task);
1652 if (rpc_reply_expected(task))
1653 return;
1654 task->tk_action = rpc_exit_task;
1655 rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1659 * 5a. Handle cleanup after a transmission
1661 static void
1662 call_transmit_status(struct rpc_task *task)
1664 task->tk_action = call_status;
1667 * Common case: success. Force the compiler to put this
1668 * test first.
1670 if (task->tk_status == 0) {
1671 xprt_end_transmit(task);
1672 rpc_task_force_reencode(task);
1673 return;
1676 switch (task->tk_status) {
1677 case -EAGAIN:
1678 break;
1679 default:
1680 dprint_status(task);
1681 xprt_end_transmit(task);
1682 rpc_task_force_reencode(task);
1683 break;
1685 * Special cases: if we've been waiting on the
1686 * socket's write_space() callback, or if the
1687 * socket just returned a connection error,
1688 * then hold onto the transport lock.
1690 case -ECONNREFUSED:
1691 case -EHOSTDOWN:
1692 case -EHOSTUNREACH:
1693 case -ENETUNREACH:
1694 if (RPC_IS_SOFTCONN(task)) {
1695 xprt_end_transmit(task);
1696 rpc_exit(task, task->tk_status);
1697 break;
1699 case -ECONNRESET:
1700 case -ENOTCONN:
1701 case -EPIPE:
1702 rpc_task_force_reencode(task);
1706 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1708 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
1709 * addition, disconnect on connectivity errors.
1711 static void
1712 call_bc_transmit(struct rpc_task *task)
1714 struct rpc_rqst *req = task->tk_rqstp;
1716 BUG_ON(task->tk_status != 0);
1717 task->tk_status = xprt_prepare_transmit(task);
1718 if (task->tk_status == -EAGAIN) {
1720 * Could not reserve the transport. Try again after the
1721 * transport is released.
1723 task->tk_status = 0;
1724 task->tk_action = call_bc_transmit;
1725 return;
1728 task->tk_action = rpc_exit_task;
1729 if (task->tk_status < 0) {
1730 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1731 "error: %d\n", task->tk_status);
1732 return;
1735 xprt_transmit(task);
1736 xprt_end_transmit(task);
1737 dprint_status(task);
1738 switch (task->tk_status) {
1739 case 0:
1740 /* Success */
1741 break;
1742 case -EHOSTDOWN:
1743 case -EHOSTUNREACH:
1744 case -ENETUNREACH:
1745 case -ETIMEDOUT:
1747 * Problem reaching the server. Disconnect and let the
1748 * forechannel reestablish the connection. The server will
1749 * have to retransmit the backchannel request and we'll
1750 * reprocess it. Since these ops are idempotent, there's no
1751 * need to cache our reply at this time.
1753 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1754 "error: %d\n", task->tk_status);
1755 xprt_conditional_disconnect(task->tk_xprt,
1756 req->rq_connect_cookie);
1757 break;
1758 default:
1760 * We were unable to reply and will have to drop the
1761 * request. The server should reconnect and retransmit.
1763 BUG_ON(task->tk_status == -EAGAIN);
1764 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1765 "error: %d\n", task->tk_status);
1766 break;
1768 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1770 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1773 * 6. Sort out the RPC call status
1775 static void
1776 call_status(struct rpc_task *task)
1778 struct rpc_clnt *clnt = task->tk_client;
1779 struct rpc_rqst *req = task->tk_rqstp;
1780 int status;
1782 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1783 task->tk_status = req->rq_reply_bytes_recvd;
1785 dprint_status(task);
1787 status = task->tk_status;
1788 if (status >= 0) {
1789 task->tk_action = call_decode;
1790 return;
1793 trace_rpc_call_status(task);
1794 task->tk_status = 0;
1795 switch(status) {
1796 case -EHOSTDOWN:
1797 case -EHOSTUNREACH:
1798 case -ENETUNREACH:
1800 * Delay any retries for 3 seconds, then handle as if it
1801 * were a timeout.
1803 rpc_delay(task, 3*HZ);
1804 case -ETIMEDOUT:
1805 task->tk_action = call_timeout;
1806 if (task->tk_client->cl_discrtry)
1807 xprt_conditional_disconnect(task->tk_xprt,
1808 req->rq_connect_cookie);
1809 break;
1810 case -ECONNRESET:
1811 case -ECONNREFUSED:
1812 rpc_force_rebind(clnt);
1813 rpc_delay(task, 3*HZ);
1814 case -EPIPE:
1815 case -ENOTCONN:
1816 task->tk_action = call_bind;
1817 break;
1818 case -EAGAIN:
1819 task->tk_action = call_transmit;
1820 break;
1821 case -EIO:
1822 /* shutdown or soft timeout */
1823 rpc_exit(task, status);
1824 break;
1825 default:
1826 if (clnt->cl_chatty)
1827 printk("%s: RPC call returned error %d\n",
1828 clnt->cl_protname, -status);
1829 rpc_exit(task, status);
1834 * 6a. Handle RPC timeout
1835 * We do not release the request slot, so we keep using the
1836 * same XID for all retransmits.
1838 static void
1839 call_timeout(struct rpc_task *task)
1841 struct rpc_clnt *clnt = task->tk_client;
1843 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1844 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1845 goto retry;
1848 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1849 task->tk_timeouts++;
1851 if (RPC_IS_SOFTCONN(task)) {
1852 rpc_exit(task, -ETIMEDOUT);
1853 return;
1855 if (RPC_IS_SOFT(task)) {
1856 if (clnt->cl_chatty) {
1857 rcu_read_lock();
1858 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1859 clnt->cl_protname,
1860 rcu_dereference(clnt->cl_xprt)->servername);
1861 rcu_read_unlock();
1863 if (task->tk_flags & RPC_TASK_TIMEOUT)
1864 rpc_exit(task, -ETIMEDOUT);
1865 else
1866 rpc_exit(task, -EIO);
1867 return;
1870 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1871 task->tk_flags |= RPC_CALL_MAJORSEEN;
1872 if (clnt->cl_chatty) {
1873 rcu_read_lock();
1874 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1875 clnt->cl_protname,
1876 rcu_dereference(clnt->cl_xprt)->servername);
1877 rcu_read_unlock();
1880 rpc_force_rebind(clnt);
1882 * Did our request time out due to an RPCSEC_GSS out-of-sequence
1883 * event? RFC2203 requires the server to drop all such requests.
1885 rpcauth_invalcred(task);
1887 retry:
1888 clnt->cl_stats->rpcretrans++;
1889 task->tk_action = call_bind;
1890 task->tk_status = 0;
1894 * 7. Decode the RPC reply
1896 static void
1897 call_decode(struct rpc_task *task)
1899 struct rpc_clnt *clnt = task->tk_client;
1900 struct rpc_rqst *req = task->tk_rqstp;
1901 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
1902 __be32 *p;
1904 dprint_status(task);
1906 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1907 if (clnt->cl_chatty) {
1908 rcu_read_lock();
1909 printk(KERN_NOTICE "%s: server %s OK\n",
1910 clnt->cl_protname,
1911 rcu_dereference(clnt->cl_xprt)->servername);
1912 rcu_read_unlock();
1914 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1918 * Ensure that we see all writes made by xprt_complete_rqst()
1919 * before it changed req->rq_reply_bytes_recvd.
1921 smp_rmb();
1922 req->rq_rcv_buf.len = req->rq_private_buf.len;
1924 /* Check that the softirq receive buffer is valid */
1925 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1926 sizeof(req->rq_rcv_buf)) != 0);
1928 if (req->rq_rcv_buf.len < 12) {
1929 if (!RPC_IS_SOFT(task)) {
1930 task->tk_action = call_bind;
1931 clnt->cl_stats->rpcretrans++;
1932 goto out_retry;
1934 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
1935 clnt->cl_protname, task->tk_status);
1936 task->tk_action = call_timeout;
1937 goto out_retry;
1940 p = rpc_verify_header(task);
1941 if (IS_ERR(p)) {
1942 if (p == ERR_PTR(-EAGAIN))
1943 goto out_retry;
1944 return;
1947 task->tk_action = rpc_exit_task;
1949 if (decode) {
1950 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1951 task->tk_msg.rpc_resp);
1953 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1954 task->tk_status);
1955 return;
1956 out_retry:
1957 task->tk_status = 0;
1958 /* Note: rpc_verify_header() may have freed the RPC slot */
1959 if (task->tk_rqstp == req) {
1960 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1961 if (task->tk_client->cl_discrtry)
1962 xprt_conditional_disconnect(task->tk_xprt,
1963 req->rq_connect_cookie);
1967 static __be32 *
1968 rpc_encode_header(struct rpc_task *task)
1970 struct rpc_clnt *clnt = task->tk_client;
1971 struct rpc_rqst *req = task->tk_rqstp;
1972 __be32 *p = req->rq_svec[0].iov_base;
1974 /* FIXME: check buffer size? */
1976 p = xprt_skip_transport_header(task->tk_xprt, p);
1977 *p++ = req->rq_xid; /* XID */
1978 *p++ = htonl(RPC_CALL); /* CALL */
1979 *p++ = htonl(RPC_VERSION); /* RPC version */
1980 *p++ = htonl(clnt->cl_prog); /* program number */
1981 *p++ = htonl(clnt->cl_vers); /* program version */
1982 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
1983 p = rpcauth_marshcred(task, p);
1984 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1985 return p;
1988 static __be32 *
1989 rpc_verify_header(struct rpc_task *task)
1991 struct rpc_clnt *clnt = task->tk_client;
1992 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1993 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1994 __be32 *p = iov->iov_base;
1995 u32 n;
1996 int error = -EACCES;
1998 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1999 /* RFC-1014 says that the representation of XDR data must be a
2000 * multiple of four bytes
2001 * - if it isn't pointer subtraction in the NFS client may give
2002 * undefined results
2004 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2005 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2006 task->tk_rqstp->rq_rcv_buf.len);
2007 goto out_eio;
2009 if ((len -= 3) < 0)
2010 goto out_overflow;
2012 p += 1; /* skip XID */
2013 if ((n = ntohl(*p++)) != RPC_REPLY) {
2014 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2015 task->tk_pid, __func__, n);
2016 goto out_garbage;
2019 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2020 if (--len < 0)
2021 goto out_overflow;
2022 switch ((n = ntohl(*p++))) {
2023 case RPC_AUTH_ERROR:
2024 break;
2025 case RPC_MISMATCH:
2026 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2027 task->tk_pid, __func__);
2028 error = -EPROTONOSUPPORT;
2029 goto out_err;
2030 default:
2031 dprintk("RPC: %5u %s: RPC call rejected, "
2032 "unknown error: %x\n",
2033 task->tk_pid, __func__, n);
2034 goto out_eio;
2036 if (--len < 0)
2037 goto out_overflow;
2038 switch ((n = ntohl(*p++))) {
2039 case RPC_AUTH_REJECTEDCRED:
2040 case RPC_AUTH_REJECTEDVERF:
2041 case RPCSEC_GSS_CREDPROBLEM:
2042 case RPCSEC_GSS_CTXPROBLEM:
2043 if (!task->tk_cred_retry)
2044 break;
2045 task->tk_cred_retry--;
2046 dprintk("RPC: %5u %s: retry stale creds\n",
2047 task->tk_pid, __func__);
2048 rpcauth_invalcred(task);
2049 /* Ensure we obtain a new XID! */
2050 xprt_release(task);
2051 task->tk_action = call_reserve;
2052 goto out_retry;
2053 case RPC_AUTH_BADCRED:
2054 case RPC_AUTH_BADVERF:
2055 /* possibly garbled cred/verf? */
2056 if (!task->tk_garb_retry)
2057 break;
2058 task->tk_garb_retry--;
2059 dprintk("RPC: %5u %s: retry garbled creds\n",
2060 task->tk_pid, __func__);
2061 task->tk_action = call_bind;
2062 goto out_retry;
2063 case RPC_AUTH_TOOWEAK:
2064 rcu_read_lock();
2065 printk(KERN_NOTICE "RPC: server %s requires stronger "
2066 "authentication.\n",
2067 rcu_dereference(clnt->cl_xprt)->servername);
2068 rcu_read_unlock();
2069 break;
2070 default:
2071 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2072 task->tk_pid, __func__, n);
2073 error = -EIO;
2075 dprintk("RPC: %5u %s: call rejected %d\n",
2076 task->tk_pid, __func__, n);
2077 goto out_err;
2079 if (!(p = rpcauth_checkverf(task, p))) {
2080 dprintk("RPC: %5u %s: auth check failed\n",
2081 task->tk_pid, __func__);
2082 goto out_garbage; /* bad verifier, retry */
2084 len = p - (__be32 *)iov->iov_base - 1;
2085 if (len < 0)
2086 goto out_overflow;
2087 switch ((n = ntohl(*p++))) {
2088 case RPC_SUCCESS:
2089 return p;
2090 case RPC_PROG_UNAVAIL:
2091 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2092 "by server %s\n", task->tk_pid, __func__,
2093 (unsigned int)clnt->cl_prog,
2094 rcu_dereference(clnt->cl_xprt)->servername);
2095 error = -EPFNOSUPPORT;
2096 goto out_err;
2097 case RPC_PROG_MISMATCH:
2098 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2099 "by server %s\n", task->tk_pid, __func__,
2100 (unsigned int)clnt->cl_prog,
2101 (unsigned int)clnt->cl_vers,
2102 rcu_dereference(clnt->cl_xprt)->servername);
2103 error = -EPROTONOSUPPORT;
2104 goto out_err;
2105 case RPC_PROC_UNAVAIL:
2106 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2107 "version %u on server %s\n",
2108 task->tk_pid, __func__,
2109 rpc_proc_name(task),
2110 clnt->cl_prog, clnt->cl_vers,
2111 rcu_dereference(clnt->cl_xprt)->servername);
2112 error = -EOPNOTSUPP;
2113 goto out_err;
2114 case RPC_GARBAGE_ARGS:
2115 dprintk("RPC: %5u %s: server saw garbage\n",
2116 task->tk_pid, __func__);
2117 break; /* retry */
2118 default:
2119 dprintk("RPC: %5u %s: server accept status: %x\n",
2120 task->tk_pid, __func__, n);
2121 /* Also retry */
2124 out_garbage:
2125 clnt->cl_stats->rpcgarbage++;
2126 if (task->tk_garb_retry) {
2127 task->tk_garb_retry--;
2128 dprintk("RPC: %5u %s: retrying\n",
2129 task->tk_pid, __func__);
2130 task->tk_action = call_bind;
2131 out_retry:
2132 return ERR_PTR(-EAGAIN);
2134 out_eio:
2135 error = -EIO;
2136 out_err:
2137 rpc_exit(task, error);
2138 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2139 __func__, error);
2140 return ERR_PTR(error);
2141 out_overflow:
2142 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2143 __func__);
2144 goto out_garbage;
2147 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2151 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2153 return 0;
2156 static struct rpc_procinfo rpcproc_null = {
2157 .p_encode = rpcproc_encode_null,
2158 .p_decode = rpcproc_decode_null,
2161 static int rpc_ping(struct rpc_clnt *clnt)
2163 struct rpc_message msg = {
2164 .rpc_proc = &rpcproc_null,
2166 int err;
2167 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2168 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2169 put_rpccred(msg.rpc_cred);
2170 return err;
2173 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2175 struct rpc_message msg = {
2176 .rpc_proc = &rpcproc_null,
2177 .rpc_cred = cred,
2179 struct rpc_task_setup task_setup_data = {
2180 .rpc_client = clnt,
2181 .rpc_message = &msg,
2182 .callback_ops = &rpc_default_ops,
2183 .flags = flags,
2185 return rpc_run_task(&task_setup_data);
2187 EXPORT_SYMBOL_GPL(rpc_call_null);
2189 #ifdef RPC_DEBUG
2190 static void rpc_show_header(void)
2192 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2193 "-timeout ---ops--\n");
2196 static void rpc_show_task(const struct rpc_clnt *clnt,
2197 const struct rpc_task *task)
2199 const char *rpc_waitq = "none";
2201 if (RPC_IS_QUEUED(task))
2202 rpc_waitq = rpc_qname(task->tk_waitqueue);
2204 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2205 task->tk_pid, task->tk_flags, task->tk_status,
2206 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2207 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2208 task->tk_action, rpc_waitq);
2211 void rpc_show_tasks(struct net *net)
2213 struct rpc_clnt *clnt;
2214 struct rpc_task *task;
2215 int header = 0;
2216 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2218 spin_lock(&sn->rpc_client_lock);
2219 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2220 spin_lock(&clnt->cl_lock);
2221 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2222 if (!header) {
2223 rpc_show_header();
2224 header++;
2226 rpc_show_task(clnt, task);
2228 spin_unlock(&clnt->cl_lock);
2230 spin_unlock(&sn->rpc_client_lock);
2232 #endif