SUNRPC: Clean up rpc_run_task
[safe/jmp/linux-2.6] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  NB: BSD uses a more intelligent approach to guessing when a request
17  *  or reply has been lost by keeping the RTO estimate for each procedure.
18  *  We currently make do with a constant timeout value.
19  *
20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
22  */
23
24 #include <asm/system.h>
25
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/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 #ifdef RPC_DEBUG
40 # define RPCDBG_FACILITY        RPCDBG_CALL
41 #endif
42
43 #define dprint_status(t)                                        \
44         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
45                         __FUNCTION__, t->tk_status)
46
47 /*
48  * All RPC clients are linked into this list
49  */
50 static LIST_HEAD(all_clients);
51 static DEFINE_SPINLOCK(rpc_client_lock);
52
53 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
54
55
56 static void     call_start(struct rpc_task *task);
57 static void     call_reserve(struct rpc_task *task);
58 static void     call_reserveresult(struct rpc_task *task);
59 static void     call_allocate(struct rpc_task *task);
60 static void     call_encode(struct rpc_task *task);
61 static void     call_decode(struct rpc_task *task);
62 static void     call_bind(struct rpc_task *task);
63 static void     call_bind_status(struct rpc_task *task);
64 static void     call_transmit(struct rpc_task *task);
65 static void     call_status(struct rpc_task *task);
66 static void     call_transmit_status(struct rpc_task *task);
67 static void     call_refresh(struct rpc_task *task);
68 static void     call_refreshresult(struct rpc_task *task);
69 static void     call_timeout(struct rpc_task *task);
70 static void     call_connect(struct rpc_task *task);
71 static void     call_connect_status(struct rpc_task *task);
72 static __be32 * call_header(struct rpc_task *task);
73 static __be32 * call_verify(struct rpc_task *task);
74
75 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
76
77 static void rpc_register_client(struct rpc_clnt *clnt)
78 {
79         spin_lock(&rpc_client_lock);
80         list_add(&clnt->cl_clients, &all_clients);
81         spin_unlock(&rpc_client_lock);
82 }
83
84 static void rpc_unregister_client(struct rpc_clnt *clnt)
85 {
86         spin_lock(&rpc_client_lock);
87         list_del(&clnt->cl_clients);
88         spin_unlock(&rpc_client_lock);
89 }
90
91 static int
92 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
93 {
94         static uint32_t clntid;
95         int error;
96
97         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
98         clnt->cl_dentry = ERR_PTR(-ENOENT);
99         if (dir_name == NULL)
100                 return 0;
101
102         clnt->cl_vfsmnt = rpc_get_mount();
103         if (IS_ERR(clnt->cl_vfsmnt))
104                 return PTR_ERR(clnt->cl_vfsmnt);
105
106         for (;;) {
107                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
108                                 "%s/clnt%x", dir_name,
109                                 (unsigned int)clntid++);
110                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
111                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
112                 if (!IS_ERR(clnt->cl_dentry))
113                         return 0;
114                 error = PTR_ERR(clnt->cl_dentry);
115                 if (error != -EEXIST) {
116                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
117                                         clnt->cl_pathname, error);
118                         rpc_put_mount();
119                         return error;
120                 }
121         }
122 }
123
124 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
125 {
126         struct rpc_version      *version;
127         struct rpc_clnt         *clnt = NULL;
128         struct rpc_auth         *auth;
129         int err;
130         size_t len;
131
132         /* sanity check the name before trying to print it */
133         err = -EINVAL;
134         len = strlen(servname);
135         if (len > RPC_MAXNETNAMELEN)
136                 goto out_no_rpciod;
137         len++;
138
139         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
140                         program->name, servname, xprt);
141
142         err = rpciod_up();
143         if (err)
144                 goto out_no_rpciod;
145         err = -EINVAL;
146         if (!xprt)
147                 goto out_no_xprt;
148         if (vers >= program->nrvers || !(version = program->version[vers]))
149                 goto out_err;
150
151         err = -ENOMEM;
152         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
153         if (!clnt)
154                 goto out_err;
155         clnt->cl_parent = clnt;
156
157         clnt->cl_server = clnt->cl_inline_name;
158         if (len > sizeof(clnt->cl_inline_name)) {
159                 char *buf = kmalloc(len, GFP_KERNEL);
160                 if (buf != 0)
161                         clnt->cl_server = buf;
162                 else
163                         len = sizeof(clnt->cl_inline_name);
164         }
165         strlcpy(clnt->cl_server, servname, len);
166
167         clnt->cl_xprt     = xprt;
168         clnt->cl_procinfo = version->procs;
169         clnt->cl_maxproc  = version->nrprocs;
170         clnt->cl_protname = program->name;
171         clnt->cl_prog     = program->number;
172         clnt->cl_vers     = version->number;
173         clnt->cl_stats    = program->stats;
174         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
175         err = -ENOMEM;
176         if (clnt->cl_metrics == NULL)
177                 goto out_no_stats;
178         clnt->cl_program  = program;
179         INIT_LIST_HEAD(&clnt->cl_tasks);
180         spin_lock_init(&clnt->cl_lock);
181
182         if (!xprt_bound(clnt->cl_xprt))
183                 clnt->cl_autobind = 1;
184
185         clnt->cl_rtt = &clnt->cl_rtt_default;
186         rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
187
188         kref_init(&clnt->cl_kref);
189
190         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
191         if (err < 0)
192                 goto out_no_path;
193
194         auth = rpcauth_create(flavor, clnt);
195         if (IS_ERR(auth)) {
196                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
197                                 flavor);
198                 err = PTR_ERR(auth);
199                 goto out_no_auth;
200         }
201
202         /* save the nodename */
203         clnt->cl_nodelen = strlen(utsname()->nodename);
204         if (clnt->cl_nodelen > UNX_MAXNODENAME)
205                 clnt->cl_nodelen = UNX_MAXNODENAME;
206         memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
207         rpc_register_client(clnt);
208         return clnt;
209
210 out_no_auth:
211         if (!IS_ERR(clnt->cl_dentry)) {
212                 rpc_rmdir(clnt->cl_dentry);
213                 rpc_put_mount();
214         }
215 out_no_path:
216         rpc_free_iostats(clnt->cl_metrics);
217 out_no_stats:
218         if (clnt->cl_server != clnt->cl_inline_name)
219                 kfree(clnt->cl_server);
220         kfree(clnt);
221 out_err:
222         xprt_put(xprt);
223 out_no_xprt:
224         rpciod_down();
225 out_no_rpciod:
226         return ERR_PTR(err);
227 }
228
229 /*
230  * rpc_create - create an RPC client and transport with one call
231  * @args: rpc_clnt create argument structure
232  *
233  * Creates and initializes an RPC transport and an RPC client.
234  *
235  * It can ping the server in order to determine if it is up, and to see if
236  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
237  * this behavior so asynchronous tasks can also use rpc_create.
238  */
239 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
240 {
241         struct rpc_xprt *xprt;
242         struct rpc_clnt *clnt;
243         struct xprt_create xprtargs = {
244                 .ident = args->protocol,
245                 .srcaddr = args->saddress,
246                 .dstaddr = args->address,
247                 .addrlen = args->addrsize,
248                 .timeout = args->timeout
249         };
250         char servername[20];
251
252         xprt = xprt_create_transport(&xprtargs);
253         if (IS_ERR(xprt))
254                 return (struct rpc_clnt *)xprt;
255
256         /*
257          * If the caller chooses not to specify a hostname, whip
258          * up a string representation of the passed-in address.
259          */
260         if (args->servername == NULL) {
261                 struct sockaddr_in *addr =
262                                         (struct sockaddr_in *) args->address;
263                 snprintf(servername, sizeof(servername), NIPQUAD_FMT,
264                         NIPQUAD(addr->sin_addr.s_addr));
265                 args->servername = servername;
266         }
267
268         /*
269          * By default, kernel RPC client connects from a reserved port.
270          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
271          * but it is always enabled for rpciod, which handles the connect
272          * operation.
273          */
274         xprt->resvport = 1;
275         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
276                 xprt->resvport = 0;
277
278         clnt = rpc_new_client(xprt, args->servername, args->program,
279                                 args->version, args->authflavor);
280         if (IS_ERR(clnt))
281                 return clnt;
282
283         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
284                 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
285                 if (err != 0) {
286                         rpc_shutdown_client(clnt);
287                         return ERR_PTR(err);
288                 }
289         }
290
291         clnt->cl_softrtry = 1;
292         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
293                 clnt->cl_softrtry = 0;
294
295         if (args->flags & RPC_CLNT_CREATE_INTR)
296                 clnt->cl_intr = 1;
297         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
298                 clnt->cl_autobind = 1;
299         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
300                 clnt->cl_discrtry = 1;
301
302         return clnt;
303 }
304 EXPORT_SYMBOL_GPL(rpc_create);
305
306 /*
307  * This function clones the RPC client structure. It allows us to share the
308  * same transport while varying parameters such as the authentication
309  * flavour.
310  */
311 struct rpc_clnt *
312 rpc_clone_client(struct rpc_clnt *clnt)
313 {
314         struct rpc_clnt *new;
315         int err = -ENOMEM;
316
317         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
318         if (!new)
319                 goto out_no_clnt;
320         new->cl_parent = clnt;
321         /* Turn off autobind on clones */
322         new->cl_autobind = 0;
323         INIT_LIST_HEAD(&new->cl_tasks);
324         spin_lock_init(&new->cl_lock);
325         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
326         new->cl_metrics = rpc_alloc_iostats(clnt);
327         if (new->cl_metrics == NULL)
328                 goto out_no_stats;
329         kref_init(&new->cl_kref);
330         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
331         if (err != 0)
332                 goto out_no_path;
333         if (new->cl_auth)
334                 atomic_inc(&new->cl_auth->au_count);
335         xprt_get(clnt->cl_xprt);
336         kref_get(&clnt->cl_kref);
337         rpc_register_client(new);
338         rpciod_up();
339         return new;
340 out_no_path:
341         rpc_free_iostats(new->cl_metrics);
342 out_no_stats:
343         kfree(new);
344 out_no_clnt:
345         dprintk("RPC:       %s: returned error %d\n", __FUNCTION__, err);
346         return ERR_PTR(err);
347 }
348 EXPORT_SYMBOL_GPL(rpc_clone_client);
349
350 /*
351  * Properly shut down an RPC client, terminating all outstanding
352  * requests.
353  */
354 void rpc_shutdown_client(struct rpc_clnt *clnt)
355 {
356         dprintk("RPC:       shutting down %s client for %s\n",
357                         clnt->cl_protname, clnt->cl_server);
358
359         while (!list_empty(&clnt->cl_tasks)) {
360                 rpc_killall_tasks(clnt);
361                 wait_event_timeout(destroy_wait,
362                         list_empty(&clnt->cl_tasks), 1*HZ);
363         }
364
365         rpc_release_client(clnt);
366 }
367 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
368
369 /*
370  * Free an RPC client
371  */
372 static void
373 rpc_free_client(struct kref *kref)
374 {
375         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
376
377         dprintk("RPC:       destroying %s client for %s\n",
378                         clnt->cl_protname, clnt->cl_server);
379         if (!IS_ERR(clnt->cl_dentry)) {
380                 rpc_rmdir(clnt->cl_dentry);
381                 rpc_put_mount();
382         }
383         if (clnt->cl_parent != clnt) {
384                 rpc_release_client(clnt->cl_parent);
385                 goto out_free;
386         }
387         if (clnt->cl_server != clnt->cl_inline_name)
388                 kfree(clnt->cl_server);
389 out_free:
390         rpc_unregister_client(clnt);
391         rpc_free_iostats(clnt->cl_metrics);
392         clnt->cl_metrics = NULL;
393         xprt_put(clnt->cl_xprt);
394         rpciod_down();
395         kfree(clnt);
396 }
397
398 /*
399  * Free an RPC client
400  */
401 static void
402 rpc_free_auth(struct kref *kref)
403 {
404         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
405
406         if (clnt->cl_auth == NULL) {
407                 rpc_free_client(kref);
408                 return;
409         }
410
411         /*
412          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
413          *       release remaining GSS contexts. This mechanism ensures
414          *       that it can do so safely.
415          */
416         kref_init(kref);
417         rpcauth_release(clnt->cl_auth);
418         clnt->cl_auth = NULL;
419         kref_put(kref, rpc_free_client);
420 }
421
422 /*
423  * Release reference to the RPC client
424  */
425 void
426 rpc_release_client(struct rpc_clnt *clnt)
427 {
428         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
429
430         if (list_empty(&clnt->cl_tasks))
431                 wake_up(&destroy_wait);
432         kref_put(&clnt->cl_kref, rpc_free_auth);
433 }
434
435 /**
436  * rpc_bind_new_program - bind a new RPC program to an existing client
437  * @old - old rpc_client
438  * @program - rpc program to set
439  * @vers - rpc program version
440  *
441  * Clones the rpc client and sets up a new RPC program. This is mainly
442  * of use for enabling different RPC programs to share the same transport.
443  * The Sun NFSv2/v3 ACL protocol can do this.
444  */
445 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
446                                       struct rpc_program *program,
447                                       u32 vers)
448 {
449         struct rpc_clnt *clnt;
450         struct rpc_version *version;
451         int err;
452
453         BUG_ON(vers >= program->nrvers || !program->version[vers]);
454         version = program->version[vers];
455         clnt = rpc_clone_client(old);
456         if (IS_ERR(clnt))
457                 goto out;
458         clnt->cl_procinfo = version->procs;
459         clnt->cl_maxproc  = version->nrprocs;
460         clnt->cl_protname = program->name;
461         clnt->cl_prog     = program->number;
462         clnt->cl_vers     = version->number;
463         clnt->cl_stats    = program->stats;
464         err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
465         if (err != 0) {
466                 rpc_shutdown_client(clnt);
467                 clnt = ERR_PTR(err);
468         }
469 out:
470         return clnt;
471 }
472 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
473
474 /*
475  * Default callback for async RPC calls
476  */
477 static void
478 rpc_default_callback(struct rpc_task *task, void *data)
479 {
480 }
481
482 static const struct rpc_call_ops rpc_default_ops = {
483         .rpc_call_done = rpc_default_callback,
484 };
485
486 /*
487  *      Export the signal mask handling for synchronous code that
488  *      sleeps on RPC calls
489  */
490 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
491
492 static void rpc_save_sigmask(sigset_t *oldset, int intr)
493 {
494         unsigned long   sigallow = sigmask(SIGKILL);
495         sigset_t sigmask;
496
497         /* Block all signals except those listed in sigallow */
498         if (intr)
499                 sigallow |= RPC_INTR_SIGNALS;
500         siginitsetinv(&sigmask, sigallow);
501         sigprocmask(SIG_BLOCK, &sigmask, oldset);
502 }
503
504 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
505 {
506         rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
507 }
508
509 static inline void rpc_restore_sigmask(sigset_t *oldset)
510 {
511         sigprocmask(SIG_SETMASK, oldset, NULL);
512 }
513
514 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
515 {
516         rpc_save_sigmask(oldset, clnt->cl_intr);
517 }
518 EXPORT_SYMBOL_GPL(rpc_clnt_sigmask);
519
520 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
521 {
522         rpc_restore_sigmask(oldset);
523 }
524 EXPORT_SYMBOL_GPL(rpc_clnt_sigunmask);
525
526 /**
527  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
528  * @task_setup_data: pointer to task initialisation data
529  */
530 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
531 {
532         struct rpc_task *task, *ret;
533         sigset_t oldset;
534
535         task = rpc_new_task(task_setup_data);
536         if (task == NULL) {
537                 rpc_release_calldata(task_setup_data->callback_ops,
538                                 task_setup_data->callback_data);
539                 return ERR_PTR(-ENOMEM);
540         }
541
542         /* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
543         rpc_task_sigmask(task, &oldset);
544         if (task_setup_data->rpc_message != NULL) {
545                 rpc_call_setup(task, task_setup_data->rpc_message, 0);
546                 if (task->tk_status != 0) {
547                         ret = ERR_PTR(task->tk_status);
548                         rpc_put_task(task);
549                         goto out;
550                 }
551         }
552         atomic_inc(&task->tk_count);
553         rpc_execute(task);
554         ret = task;
555 out:
556         rpc_restore_sigmask(&oldset);
557         return ret;
558 }
559 EXPORT_SYMBOL_GPL(rpc_run_task);
560
561 /**
562  * rpc_call_sync - Perform a synchronous RPC call
563  * @clnt: pointer to RPC client
564  * @msg: RPC call parameters
565  * @flags: RPC call flags
566  */
567 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
568 {
569         struct rpc_task *task;
570         struct rpc_task_setup task_setup_data = {
571                 .rpc_client = clnt,
572                 .rpc_message = msg,
573                 .callback_ops = &rpc_default_ops,
574                 .flags = flags,
575         };
576         int status;
577
578         BUG_ON(flags & RPC_TASK_ASYNC);
579
580         task = rpc_run_task(&task_setup_data);
581         if (IS_ERR(task))
582                 return PTR_ERR(task);
583         status = task->tk_status;
584         rpc_put_task(task);
585         return status;
586 }
587 EXPORT_SYMBOL_GPL(rpc_call_sync);
588
589 /**
590  * rpc_call_async - Perform an asynchronous RPC call
591  * @clnt: pointer to RPC client
592  * @msg: RPC call parameters
593  * @flags: RPC call flags
594  * @ops: RPC call ops
595  * @data: user call data
596  */
597 int
598 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
599                const struct rpc_call_ops *tk_ops, void *data)
600 {
601         struct rpc_task *task;
602         struct rpc_task_setup task_setup_data = {
603                 .rpc_client = clnt,
604                 .rpc_message = msg,
605                 .callback_ops = tk_ops,
606                 .callback_data = data,
607                 .flags = flags|RPC_TASK_ASYNC,
608         };
609
610         task = rpc_run_task(&task_setup_data);
611         if (IS_ERR(task))
612                 return PTR_ERR(task);
613         rpc_put_task(task);
614         return 0;
615 }
616 EXPORT_SYMBOL_GPL(rpc_call_async);
617
618 void
619 rpc_call_setup(struct rpc_task *task, const struct rpc_message *msg, int flags)
620 {
621         task->tk_msg   = *msg;
622         task->tk_flags |= flags;
623         /* Bind the user cred */
624         if (task->tk_msg.rpc_cred != NULL)
625                 rpcauth_holdcred(task);
626         else
627                 rpcauth_bindcred(task);
628
629         if (task->tk_status == 0)
630                 task->tk_action = call_start;
631         else
632                 task->tk_action = rpc_exit_task;
633 }
634 EXPORT_SYMBOL_GPL(rpc_call_setup);
635
636 /**
637  * rpc_peeraddr - extract remote peer address from clnt's xprt
638  * @clnt: RPC client structure
639  * @buf: target buffer
640  * @size: length of target buffer
641  *
642  * Returns the number of bytes that are actually in the stored address.
643  */
644 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
645 {
646         size_t bytes;
647         struct rpc_xprt *xprt = clnt->cl_xprt;
648
649         bytes = sizeof(xprt->addr);
650         if (bytes > bufsize)
651                 bytes = bufsize;
652         memcpy(buf, &clnt->cl_xprt->addr, bytes);
653         return xprt->addrlen;
654 }
655 EXPORT_SYMBOL_GPL(rpc_peeraddr);
656
657 /**
658  * rpc_peeraddr2str - return remote peer address in printable format
659  * @clnt: RPC client structure
660  * @format: address format
661  *
662  */
663 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
664 {
665         struct rpc_xprt *xprt = clnt->cl_xprt;
666
667         if (xprt->address_strings[format] != NULL)
668                 return xprt->address_strings[format];
669         else
670                 return "unprintable";
671 }
672 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
673
674 void
675 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
676 {
677         struct rpc_xprt *xprt = clnt->cl_xprt;
678         if (xprt->ops->set_buffer_size)
679                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
680 }
681 EXPORT_SYMBOL_GPL(rpc_setbufsize);
682
683 /*
684  * Return size of largest payload RPC client can support, in bytes
685  *
686  * For stream transports, this is one RPC record fragment (see RFC
687  * 1831), as we don't support multi-record requests yet.  For datagram
688  * transports, this is the size of an IP packet minus the IP, UDP, and
689  * RPC header sizes.
690  */
691 size_t rpc_max_payload(struct rpc_clnt *clnt)
692 {
693         return clnt->cl_xprt->max_payload;
694 }
695 EXPORT_SYMBOL_GPL(rpc_max_payload);
696
697 /**
698  * rpc_force_rebind - force transport to check that remote port is unchanged
699  * @clnt: client to rebind
700  *
701  */
702 void rpc_force_rebind(struct rpc_clnt *clnt)
703 {
704         if (clnt->cl_autobind)
705                 xprt_clear_bound(clnt->cl_xprt);
706 }
707 EXPORT_SYMBOL_GPL(rpc_force_rebind);
708
709 /*
710  * Restart an (async) RPC call. Usually called from within the
711  * exit handler.
712  */
713 void
714 rpc_restart_call(struct rpc_task *task)
715 {
716         if (RPC_ASSASSINATED(task))
717                 return;
718
719         task->tk_action = call_start;
720 }
721 EXPORT_SYMBOL_GPL(rpc_restart_call);
722
723 /*
724  * 0.  Initial state
725  *
726  *     Other FSM states can be visited zero or more times, but
727  *     this state is visited exactly once for each RPC.
728  */
729 static void
730 call_start(struct rpc_task *task)
731 {
732         struct rpc_clnt *clnt = task->tk_client;
733
734         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
735                         clnt->cl_protname, clnt->cl_vers,
736                         task->tk_msg.rpc_proc->p_proc,
737                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
738
739         /* Increment call count */
740         task->tk_msg.rpc_proc->p_count++;
741         clnt->cl_stats->rpccnt++;
742         task->tk_action = call_reserve;
743 }
744
745 /*
746  * 1.   Reserve an RPC call slot
747  */
748 static void
749 call_reserve(struct rpc_task *task)
750 {
751         dprint_status(task);
752
753         if (!rpcauth_uptodatecred(task)) {
754                 task->tk_action = call_refresh;
755                 return;
756         }
757
758         task->tk_status  = 0;
759         task->tk_action  = call_reserveresult;
760         xprt_reserve(task);
761 }
762
763 /*
764  * 1b.  Grok the result of xprt_reserve()
765  */
766 static void
767 call_reserveresult(struct rpc_task *task)
768 {
769         int status = task->tk_status;
770
771         dprint_status(task);
772
773         /*
774          * After a call to xprt_reserve(), we must have either
775          * a request slot or else an error status.
776          */
777         task->tk_status = 0;
778         if (status >= 0) {
779                 if (task->tk_rqstp) {
780                         task->tk_action = call_allocate;
781                         return;
782                 }
783
784                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
785                                 __FUNCTION__, status);
786                 rpc_exit(task, -EIO);
787                 return;
788         }
789
790         /*
791          * Even though there was an error, we may have acquired
792          * a request slot somehow.  Make sure not to leak it.
793          */
794         if (task->tk_rqstp) {
795                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
796                                 __FUNCTION__, status);
797                 xprt_release(task);
798         }
799
800         switch (status) {
801         case -EAGAIN:   /* woken up; retry */
802                 task->tk_action = call_reserve;
803                 return;
804         case -EIO:      /* probably a shutdown */
805                 break;
806         default:
807                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
808                                 __FUNCTION__, status);
809                 break;
810         }
811         rpc_exit(task, status);
812 }
813
814 /*
815  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
816  *      (Note: buffer memory is freed in xprt_release).
817  */
818 static void
819 call_allocate(struct rpc_task *task)
820 {
821         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
822         struct rpc_rqst *req = task->tk_rqstp;
823         struct rpc_xprt *xprt = task->tk_xprt;
824         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
825
826         dprint_status(task);
827
828         task->tk_status = 0;
829         task->tk_action = call_bind;
830
831         if (req->rq_buffer)
832                 return;
833
834         if (proc->p_proc != 0) {
835                 BUG_ON(proc->p_arglen == 0);
836                 if (proc->p_decode != NULL)
837                         BUG_ON(proc->p_replen == 0);
838         }
839
840         /*
841          * Calculate the size (in quads) of the RPC call
842          * and reply headers, and convert both values
843          * to byte sizes.
844          */
845         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
846         req->rq_callsize <<= 2;
847         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
848         req->rq_rcvsize <<= 2;
849
850         req->rq_buffer = xprt->ops->buf_alloc(task,
851                                         req->rq_callsize + req->rq_rcvsize);
852         if (req->rq_buffer != NULL)
853                 return;
854
855         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
856
857         if (RPC_IS_ASYNC(task) || !signalled()) {
858                 task->tk_action = call_allocate;
859                 rpc_delay(task, HZ>>4);
860                 return;
861         }
862
863         rpc_exit(task, -ERESTARTSYS);
864 }
865
866 static inline int
867 rpc_task_need_encode(struct rpc_task *task)
868 {
869         return task->tk_rqstp->rq_snd_buf.len == 0;
870 }
871
872 static inline void
873 rpc_task_force_reencode(struct rpc_task *task)
874 {
875         task->tk_rqstp->rq_snd_buf.len = 0;
876 }
877
878 static inline void
879 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
880 {
881         buf->head[0].iov_base = start;
882         buf->head[0].iov_len = len;
883         buf->tail[0].iov_len = 0;
884         buf->page_len = 0;
885         buf->flags = 0;
886         buf->len = 0;
887         buf->buflen = len;
888 }
889
890 /*
891  * 3.   Encode arguments of an RPC call
892  */
893 static void
894 call_encode(struct rpc_task *task)
895 {
896         struct rpc_rqst *req = task->tk_rqstp;
897         kxdrproc_t      encode;
898         __be32          *p;
899
900         dprint_status(task);
901
902         rpc_xdr_buf_init(&req->rq_snd_buf,
903                          req->rq_buffer,
904                          req->rq_callsize);
905         rpc_xdr_buf_init(&req->rq_rcv_buf,
906                          (char *)req->rq_buffer + req->rq_callsize,
907                          req->rq_rcvsize);
908
909         /* Encode header and provided arguments */
910         encode = task->tk_msg.rpc_proc->p_encode;
911         if (!(p = call_header(task))) {
912                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
913                 rpc_exit(task, -EIO);
914                 return;
915         }
916         if (encode == NULL)
917                 return;
918
919         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
920                         task->tk_msg.rpc_argp);
921         if (task->tk_status == -ENOMEM) {
922                 /* XXX: Is this sane? */
923                 rpc_delay(task, 3*HZ);
924                 task->tk_status = -EAGAIN;
925         }
926 }
927
928 /*
929  * 4.   Get the server port number if not yet set
930  */
931 static void
932 call_bind(struct rpc_task *task)
933 {
934         struct rpc_xprt *xprt = task->tk_xprt;
935
936         dprint_status(task);
937
938         task->tk_action = call_connect;
939         if (!xprt_bound(xprt)) {
940                 task->tk_action = call_bind_status;
941                 task->tk_timeout = xprt->bind_timeout;
942                 xprt->ops->rpcbind(task);
943         }
944 }
945
946 /*
947  * 4a.  Sort out bind result
948  */
949 static void
950 call_bind_status(struct rpc_task *task)
951 {
952         int status = -EIO;
953
954         if (task->tk_status >= 0) {
955                 dprint_status(task);
956                 task->tk_status = 0;
957                 task->tk_action = call_connect;
958                 return;
959         }
960
961         switch (task->tk_status) {
962         case -EAGAIN:
963                 dprintk("RPC: %5u rpcbind waiting for another request "
964                                 "to finish\n", task->tk_pid);
965                 /* avoid busy-waiting here -- could be a network outage. */
966                 rpc_delay(task, 5*HZ);
967                 goto retry_timeout;
968         case -EACCES:
969                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
970                                 "unavailable\n", task->tk_pid);
971                 /* fail immediately if this is an RPC ping */
972                 if (task->tk_msg.rpc_proc->p_proc == 0) {
973                         status = -EOPNOTSUPP;
974                         break;
975                 }
976                 rpc_delay(task, 3*HZ);
977                 goto retry_timeout;
978         case -ETIMEDOUT:
979                 dprintk("RPC: %5u rpcbind request timed out\n",
980                                 task->tk_pid);
981                 goto retry_timeout;
982         case -EPFNOSUPPORT:
983                 /* server doesn't support any rpcbind version we know of */
984                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
985                                 task->tk_pid);
986                 break;
987         case -EPROTONOSUPPORT:
988                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
989                                 task->tk_pid);
990                 task->tk_status = 0;
991                 task->tk_action = call_bind;
992                 return;
993         default:
994                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
995                                 task->tk_pid, -task->tk_status);
996         }
997
998         rpc_exit(task, status);
999         return;
1000
1001 retry_timeout:
1002         task->tk_action = call_timeout;
1003 }
1004
1005 /*
1006  * 4b.  Connect to the RPC server
1007  */
1008 static void
1009 call_connect(struct rpc_task *task)
1010 {
1011         struct rpc_xprt *xprt = task->tk_xprt;
1012
1013         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1014                         task->tk_pid, xprt,
1015                         (xprt_connected(xprt) ? "is" : "is not"));
1016
1017         task->tk_action = call_transmit;
1018         if (!xprt_connected(xprt)) {
1019                 task->tk_action = call_connect_status;
1020                 if (task->tk_status < 0)
1021                         return;
1022                 xprt_connect(task);
1023         }
1024 }
1025
1026 /*
1027  * 4c.  Sort out connect result
1028  */
1029 static void
1030 call_connect_status(struct rpc_task *task)
1031 {
1032         struct rpc_clnt *clnt = task->tk_client;
1033         int status = task->tk_status;
1034
1035         dprint_status(task);
1036
1037         task->tk_status = 0;
1038         if (status >= 0) {
1039                 clnt->cl_stats->netreconn++;
1040                 task->tk_action = call_transmit;
1041                 return;
1042         }
1043
1044         /* Something failed: remote service port may have changed */
1045         rpc_force_rebind(clnt);
1046
1047         switch (status) {
1048         case -ENOTCONN:
1049         case -EAGAIN:
1050                 task->tk_action = call_bind;
1051                 if (!RPC_IS_SOFT(task))
1052                         return;
1053                 /* if soft mounted, test if we've timed out */
1054         case -ETIMEDOUT:
1055                 task->tk_action = call_timeout;
1056                 return;
1057         }
1058         rpc_exit(task, -EIO);
1059 }
1060
1061 /*
1062  * 5.   Transmit the RPC request, and wait for reply
1063  */
1064 static void
1065 call_transmit(struct rpc_task *task)
1066 {
1067         dprint_status(task);
1068
1069         task->tk_action = call_status;
1070         if (task->tk_status < 0)
1071                 return;
1072         task->tk_status = xprt_prepare_transmit(task);
1073         if (task->tk_status != 0)
1074                 return;
1075         task->tk_action = call_transmit_status;
1076         /* Encode here so that rpcsec_gss can use correct sequence number. */
1077         if (rpc_task_need_encode(task)) {
1078                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1079                 call_encode(task);
1080                 /* Did the encode result in an error condition? */
1081                 if (task->tk_status != 0)
1082                         return;
1083         }
1084         xprt_transmit(task);
1085         if (task->tk_status < 0)
1086                 return;
1087         /*
1088          * On success, ensure that we call xprt_end_transmit() before sleeping
1089          * in order to allow access to the socket to other RPC requests.
1090          */
1091         call_transmit_status(task);
1092         if (task->tk_msg.rpc_proc->p_decode != NULL)
1093                 return;
1094         task->tk_action = rpc_exit_task;
1095         rpc_wake_up_task(task);
1096 }
1097
1098 /*
1099  * 5a.  Handle cleanup after a transmission
1100  */
1101 static void
1102 call_transmit_status(struct rpc_task *task)
1103 {
1104         task->tk_action = call_status;
1105         /*
1106          * Special case: if we've been waiting on the socket's write_space()
1107          * callback, then don't call xprt_end_transmit().
1108          */
1109         if (task->tk_status == -EAGAIN)
1110                 return;
1111         xprt_end_transmit(task);
1112         rpc_task_force_reencode(task);
1113 }
1114
1115 /*
1116  * 6.   Sort out the RPC call status
1117  */
1118 static void
1119 call_status(struct rpc_task *task)
1120 {
1121         struct rpc_clnt *clnt = task->tk_client;
1122         struct rpc_rqst *req = task->tk_rqstp;
1123         int             status;
1124
1125         if (req->rq_received > 0 && !req->rq_bytes_sent)
1126                 task->tk_status = req->rq_received;
1127
1128         dprint_status(task);
1129
1130         status = task->tk_status;
1131         if (status >= 0) {
1132                 task->tk_action = call_decode;
1133                 return;
1134         }
1135
1136         task->tk_status = 0;
1137         switch(status) {
1138         case -EHOSTDOWN:
1139         case -EHOSTUNREACH:
1140         case -ENETUNREACH:
1141                 /*
1142                  * Delay any retries for 3 seconds, then handle as if it
1143                  * were a timeout.
1144                  */
1145                 rpc_delay(task, 3*HZ);
1146         case -ETIMEDOUT:
1147                 task->tk_action = call_timeout;
1148                 if (task->tk_client->cl_discrtry)
1149                         xprt_force_disconnect(task->tk_xprt);
1150                 break;
1151         case -ECONNREFUSED:
1152         case -ENOTCONN:
1153                 rpc_force_rebind(clnt);
1154                 task->tk_action = call_bind;
1155                 break;
1156         case -EAGAIN:
1157                 task->tk_action = call_transmit;
1158                 break;
1159         case -EIO:
1160                 /* shutdown or soft timeout */
1161                 rpc_exit(task, status);
1162                 break;
1163         default:
1164                 printk("%s: RPC call returned error %d\n",
1165                                clnt->cl_protname, -status);
1166                 rpc_exit(task, status);
1167         }
1168 }
1169
1170 /*
1171  * 6a.  Handle RPC timeout
1172  *      We do not release the request slot, so we keep using the
1173  *      same XID for all retransmits.
1174  */
1175 static void
1176 call_timeout(struct rpc_task *task)
1177 {
1178         struct rpc_clnt *clnt = task->tk_client;
1179
1180         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1181                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1182                 goto retry;
1183         }
1184
1185         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1186         task->tk_timeouts++;
1187
1188         if (RPC_IS_SOFT(task)) {
1189                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1190                                 clnt->cl_protname, clnt->cl_server);
1191                 rpc_exit(task, -EIO);
1192                 return;
1193         }
1194
1195         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1196                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1197                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1198                         clnt->cl_protname, clnt->cl_server);
1199         }
1200         rpc_force_rebind(clnt);
1201
1202 retry:
1203         clnt->cl_stats->rpcretrans++;
1204         task->tk_action = call_bind;
1205         task->tk_status = 0;
1206 }
1207
1208 /*
1209  * 7.   Decode the RPC reply
1210  */
1211 static void
1212 call_decode(struct rpc_task *task)
1213 {
1214         struct rpc_clnt *clnt = task->tk_client;
1215         struct rpc_rqst *req = task->tk_rqstp;
1216         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1217         __be32          *p;
1218
1219         dprintk("RPC: %5u call_decode (status %d)\n",
1220                         task->tk_pid, task->tk_status);
1221
1222         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1223                 printk(KERN_NOTICE "%s: server %s OK\n",
1224                         clnt->cl_protname, clnt->cl_server);
1225                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1226         }
1227
1228         if (task->tk_status < 12) {
1229                 if (!RPC_IS_SOFT(task)) {
1230                         task->tk_action = call_bind;
1231                         clnt->cl_stats->rpcretrans++;
1232                         goto out_retry;
1233                 }
1234                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1235                                 clnt->cl_protname, task->tk_status);
1236                 task->tk_action = call_timeout;
1237                 goto out_retry;
1238         }
1239
1240         /*
1241          * Ensure that we see all writes made by xprt_complete_rqst()
1242          * before it changed req->rq_received.
1243          */
1244         smp_rmb();
1245         req->rq_rcv_buf.len = req->rq_private_buf.len;
1246
1247         /* Check that the softirq receive buffer is valid */
1248         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1249                                 sizeof(req->rq_rcv_buf)) != 0);
1250
1251         /* Verify the RPC header */
1252         p = call_verify(task);
1253         if (IS_ERR(p)) {
1254                 if (p == ERR_PTR(-EAGAIN))
1255                         goto out_retry;
1256                 return;
1257         }
1258
1259         task->tk_action = rpc_exit_task;
1260
1261         if (decode) {
1262                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1263                                                       task->tk_msg.rpc_resp);
1264         }
1265         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1266                         task->tk_status);
1267         return;
1268 out_retry:
1269         req->rq_received = req->rq_private_buf.len = 0;
1270         task->tk_status = 0;
1271         if (task->tk_client->cl_discrtry)
1272                 xprt_force_disconnect(task->tk_xprt);
1273 }
1274
1275 /*
1276  * 8.   Refresh the credentials if rejected by the server
1277  */
1278 static void
1279 call_refresh(struct rpc_task *task)
1280 {
1281         dprint_status(task);
1282
1283         task->tk_action = call_refreshresult;
1284         task->tk_status = 0;
1285         task->tk_client->cl_stats->rpcauthrefresh++;
1286         rpcauth_refreshcred(task);
1287 }
1288
1289 /*
1290  * 8a.  Process the results of a credential refresh
1291  */
1292 static void
1293 call_refreshresult(struct rpc_task *task)
1294 {
1295         int status = task->tk_status;
1296
1297         dprint_status(task);
1298
1299         task->tk_status = 0;
1300         task->tk_action = call_reserve;
1301         if (status >= 0 && rpcauth_uptodatecred(task))
1302                 return;
1303         if (status == -EACCES) {
1304                 rpc_exit(task, -EACCES);
1305                 return;
1306         }
1307         task->tk_action = call_refresh;
1308         if (status != -ETIMEDOUT)
1309                 rpc_delay(task, 3*HZ);
1310         return;
1311 }
1312
1313 /*
1314  * Call header serialization
1315  */
1316 static __be32 *
1317 call_header(struct rpc_task *task)
1318 {
1319         struct rpc_clnt *clnt = task->tk_client;
1320         struct rpc_rqst *req = task->tk_rqstp;
1321         __be32          *p = req->rq_svec[0].iov_base;
1322
1323         /* FIXME: check buffer size? */
1324
1325         p = xprt_skip_transport_header(task->tk_xprt, p);
1326         *p++ = req->rq_xid;             /* XID */
1327         *p++ = htonl(RPC_CALL);         /* CALL */
1328         *p++ = htonl(RPC_VERSION);      /* RPC version */
1329         *p++ = htonl(clnt->cl_prog);    /* program number */
1330         *p++ = htonl(clnt->cl_vers);    /* program version */
1331         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1332         p = rpcauth_marshcred(task, p);
1333         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1334         return p;
1335 }
1336
1337 /*
1338  * Reply header verification
1339  */
1340 static __be32 *
1341 call_verify(struct rpc_task *task)
1342 {
1343         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1344         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1345         __be32  *p = iov->iov_base;
1346         u32 n;
1347         int error = -EACCES;
1348
1349         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1350                 /* RFC-1014 says that the representation of XDR data must be a
1351                  * multiple of four bytes
1352                  * - if it isn't pointer subtraction in the NFS client may give
1353                  *   undefined results
1354                  */
1355                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1356                        " 4 bytes: 0x%x\n", task->tk_pid, __FUNCTION__,
1357                        task->tk_rqstp->rq_rcv_buf.len);
1358                 goto out_eio;
1359         }
1360         if ((len -= 3) < 0)
1361                 goto out_overflow;
1362         p += 1; /* skip XID */
1363
1364         if ((n = ntohl(*p++)) != RPC_REPLY) {
1365                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1366                                 task->tk_pid, __FUNCTION__, n);
1367                 goto out_garbage;
1368         }
1369         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1370                 if (--len < 0)
1371                         goto out_overflow;
1372                 switch ((n = ntohl(*p++))) {
1373                         case RPC_AUTH_ERROR:
1374                                 break;
1375                         case RPC_MISMATCH:
1376                                 dprintk("RPC: %5u %s: RPC call version "
1377                                                 "mismatch!\n",
1378                                                 task->tk_pid, __FUNCTION__);
1379                                 error = -EPROTONOSUPPORT;
1380                                 goto out_err;
1381                         default:
1382                                 dprintk("RPC: %5u %s: RPC call rejected, "
1383                                                 "unknown error: %x\n",
1384                                                 task->tk_pid, __FUNCTION__, n);
1385                                 goto out_eio;
1386                 }
1387                 if (--len < 0)
1388                         goto out_overflow;
1389                 switch ((n = ntohl(*p++))) {
1390                 case RPC_AUTH_REJECTEDCRED:
1391                 case RPC_AUTH_REJECTEDVERF:
1392                 case RPCSEC_GSS_CREDPROBLEM:
1393                 case RPCSEC_GSS_CTXPROBLEM:
1394                         if (!task->tk_cred_retry)
1395                                 break;
1396                         task->tk_cred_retry--;
1397                         dprintk("RPC: %5u %s: retry stale creds\n",
1398                                         task->tk_pid, __FUNCTION__);
1399                         rpcauth_invalcred(task);
1400                         /* Ensure we obtain a new XID! */
1401                         xprt_release(task);
1402                         task->tk_action = call_refresh;
1403                         goto out_retry;
1404                 case RPC_AUTH_BADCRED:
1405                 case RPC_AUTH_BADVERF:
1406                         /* possibly garbled cred/verf? */
1407                         if (!task->tk_garb_retry)
1408                                 break;
1409                         task->tk_garb_retry--;
1410                         dprintk("RPC: %5u %s: retry garbled creds\n",
1411                                         task->tk_pid, __FUNCTION__);
1412                         task->tk_action = call_bind;
1413                         goto out_retry;
1414                 case RPC_AUTH_TOOWEAK:
1415                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1416                                "authentication.\n", task->tk_client->cl_server);
1417                         break;
1418                 default:
1419                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1420                                         task->tk_pid, __FUNCTION__, n);
1421                         error = -EIO;
1422                 }
1423                 dprintk("RPC: %5u %s: call rejected %d\n",
1424                                 task->tk_pid, __FUNCTION__, n);
1425                 goto out_err;
1426         }
1427         if (!(p = rpcauth_checkverf(task, p))) {
1428                 dprintk("RPC: %5u %s: auth check failed\n",
1429                                 task->tk_pid, __FUNCTION__);
1430                 goto out_garbage;               /* bad verifier, retry */
1431         }
1432         len = p - (__be32 *)iov->iov_base - 1;
1433         if (len < 0)
1434                 goto out_overflow;
1435         switch ((n = ntohl(*p++))) {
1436         case RPC_SUCCESS:
1437                 return p;
1438         case RPC_PROG_UNAVAIL:
1439                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1440                                 task->tk_pid, __FUNCTION__,
1441                                 (unsigned int)task->tk_client->cl_prog,
1442                                 task->tk_client->cl_server);
1443                 error = -EPFNOSUPPORT;
1444                 goto out_err;
1445         case RPC_PROG_MISMATCH:
1446                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1447                                 "server %s\n", task->tk_pid, __FUNCTION__,
1448                                 (unsigned int)task->tk_client->cl_prog,
1449                                 (unsigned int)task->tk_client->cl_vers,
1450                                 task->tk_client->cl_server);
1451                 error = -EPROTONOSUPPORT;
1452                 goto out_err;
1453         case RPC_PROC_UNAVAIL:
1454                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1455                                 "version %u on server %s\n",
1456                                 task->tk_pid, __FUNCTION__,
1457                                 task->tk_msg.rpc_proc,
1458                                 task->tk_client->cl_prog,
1459                                 task->tk_client->cl_vers,
1460                                 task->tk_client->cl_server);
1461                 error = -EOPNOTSUPP;
1462                 goto out_err;
1463         case RPC_GARBAGE_ARGS:
1464                 dprintk("RPC: %5u %s: server saw garbage\n",
1465                                 task->tk_pid, __FUNCTION__);
1466                 break;                  /* retry */
1467         default:
1468                 dprintk("RPC: %5u %s: server accept status: %x\n",
1469                                 task->tk_pid, __FUNCTION__, n);
1470                 /* Also retry */
1471         }
1472
1473 out_garbage:
1474         task->tk_client->cl_stats->rpcgarbage++;
1475         if (task->tk_garb_retry) {
1476                 task->tk_garb_retry--;
1477                 dprintk("RPC: %5u %s: retrying\n",
1478                                 task->tk_pid, __FUNCTION__);
1479                 task->tk_action = call_bind;
1480 out_retry:
1481                 return ERR_PTR(-EAGAIN);
1482         }
1483 out_eio:
1484         error = -EIO;
1485 out_err:
1486         rpc_exit(task, error);
1487         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1488                         __FUNCTION__, error);
1489         return ERR_PTR(error);
1490 out_overflow:
1491         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1492                         __FUNCTION__);
1493         goto out_garbage;
1494 }
1495
1496 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1497 {
1498         return 0;
1499 }
1500
1501 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1502 {
1503         return 0;
1504 }
1505
1506 static struct rpc_procinfo rpcproc_null = {
1507         .p_encode = rpcproc_encode_null,
1508         .p_decode = rpcproc_decode_null,
1509 };
1510
1511 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1512 {
1513         struct rpc_message msg = {
1514                 .rpc_proc = &rpcproc_null,
1515         };
1516         int err;
1517         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1518         err = rpc_call_sync(clnt, &msg, flags);
1519         put_rpccred(msg.rpc_cred);
1520         return err;
1521 }
1522
1523 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1524 {
1525         struct rpc_message msg = {
1526                 .rpc_proc = &rpcproc_null,
1527                 .rpc_cred = cred,
1528         };
1529         struct rpc_task_setup task_setup_data = {
1530                 .rpc_client = clnt,
1531                 .rpc_message = &msg,
1532                 .callback_ops = &rpc_default_ops,
1533                 .flags = flags,
1534         };
1535         return rpc_run_task(&task_setup_data);
1536 }
1537 EXPORT_SYMBOL_GPL(rpc_call_null);
1538
1539 #ifdef RPC_DEBUG
1540 void rpc_show_tasks(void)
1541 {
1542         struct rpc_clnt *clnt;
1543         struct rpc_task *t;
1544
1545         spin_lock(&rpc_client_lock);
1546         if (list_empty(&all_clients))
1547                 goto out;
1548         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1549                 "-rpcwait -action- ---ops--\n");
1550         list_for_each_entry(clnt, &all_clients, cl_clients) {
1551                 if (list_empty(&clnt->cl_tasks))
1552                         continue;
1553                 spin_lock(&clnt->cl_lock);
1554                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1555                         const char *rpc_waitq = "none";
1556                         int proc;
1557
1558                         if (t->tk_msg.rpc_proc)
1559                                 proc = t->tk_msg.rpc_proc->p_proc;
1560                         else
1561                                 proc = -1;
1562
1563                         if (RPC_IS_QUEUED(t))
1564                                 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1565
1566                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1567                                 t->tk_pid, proc,
1568                                 t->tk_flags, t->tk_status,
1569                                 t->tk_client,
1570                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1571                                 t->tk_rqstp, t->tk_timeout,
1572                                 rpc_waitq,
1573                                 t->tk_action, t->tk_ops);
1574                 }
1575                 spin_unlock(&clnt->cl_lock);
1576         }
1577 out:
1578         spin_unlock(&rpc_client_lock);
1579 }
1580 #endif