4895c341e46d03b2ad31b23c229e58876dce1c68
[linux-2.6.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  NB: BSD uses a more intelligent approach to guessing when a request
17  *  or reply has been lost by keeping the RTO estimate for each procedure.
18  *  We currently make do with a constant timeout value.
19  *
20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
22  */
23
24 #include <asm/system.h>
25
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/kallsyms.h>
29 #include <linux/mm.h>
30 #include <linux/slab.h>
31 #include <linux/smp_lock.h>
32 #include <linux/utsname.h>
33 #include <linux/workqueue.h>
34 #include <linux/in6.h>
35
36 #include <linux/sunrpc/clnt.h>
37 #include <linux/sunrpc/rpc_pipe_fs.h>
38 #include <linux/sunrpc/metrics.h>
39
40
41 #ifdef RPC_DEBUG
42 # define RPCDBG_FACILITY        RPCDBG_CALL
43 #endif
44
45 #define dprint_status(t)                                        \
46         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
47                         __func__, t->tk_status)
48
49 /*
50  * All RPC clients are linked into this list
51  */
52 static LIST_HEAD(all_clients);
53 static DEFINE_SPINLOCK(rpc_client_lock);
54
55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
56
57
58 static void     call_start(struct rpc_task *task);
59 static void     call_reserve(struct rpc_task *task);
60 static void     call_reserveresult(struct rpc_task *task);
61 static void     call_allocate(struct rpc_task *task);
62 static void     call_decode(struct rpc_task *task);
63 static void     call_bind(struct rpc_task *task);
64 static void     call_bind_status(struct rpc_task *task);
65 static void     call_transmit(struct rpc_task *task);
66 static void     call_status(struct rpc_task *task);
67 static void     call_transmit_status(struct rpc_task *task);
68 static void     call_refresh(struct rpc_task *task);
69 static void     call_refreshresult(struct rpc_task *task);
70 static void     call_timeout(struct rpc_task *task);
71 static void     call_connect(struct rpc_task *task);
72 static void     call_connect_status(struct rpc_task *task);
73
74 static __be32   *rpc_encode_header(struct rpc_task *task);
75 static __be32   *rpc_verify_header(struct rpc_task *task);
76 static int      rpc_ping(struct rpc_clnt *clnt, int flags);
77
78 static void rpc_register_client(struct rpc_clnt *clnt)
79 {
80         spin_lock(&rpc_client_lock);
81         list_add(&clnt->cl_clients, &all_clients);
82         spin_unlock(&rpc_client_lock);
83 }
84
85 static void rpc_unregister_client(struct rpc_clnt *clnt)
86 {
87         spin_lock(&rpc_client_lock);
88         list_del(&clnt->cl_clients);
89         spin_unlock(&rpc_client_lock);
90 }
91
92 static int
93 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
94 {
95         static uint32_t clntid;
96         int error;
97
98         clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
99         clnt->cl_dentry = ERR_PTR(-ENOENT);
100         if (dir_name == NULL)
101                 return 0;
102
103         clnt->cl_vfsmnt = rpc_get_mount();
104         if (IS_ERR(clnt->cl_vfsmnt))
105                 return PTR_ERR(clnt->cl_vfsmnt);
106
107         for (;;) {
108                 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
109                                 "%s/clnt%x", dir_name,
110                                 (unsigned int)clntid++);
111                 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
112                 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
113                 if (!IS_ERR(clnt->cl_dentry))
114                         return 0;
115                 error = PTR_ERR(clnt->cl_dentry);
116                 if (error != -EEXIST) {
117                         printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
118                                         clnt->cl_pathname, error);
119                         rpc_put_mount();
120                         return error;
121                 }
122         }
123 }
124
125 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
126 {
127         struct rpc_program      *program = args->program;
128         struct rpc_version      *version;
129         struct rpc_clnt         *clnt = NULL;
130         struct rpc_auth         *auth;
131         int err;
132         size_t len;
133
134         /* sanity check the name before trying to print it */
135         err = -EINVAL;
136         len = strlen(args->servername);
137         if (len > RPC_MAXNETNAMELEN)
138                 goto out_no_rpciod;
139         len++;
140
141         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
142                         program->name, args->servername, xprt);
143
144         err = rpciod_up();
145         if (err)
146                 goto out_no_rpciod;
147         err = -EINVAL;
148         if (!xprt)
149                 goto out_no_xprt;
150
151         if (args->version >= program->nrvers)
152                 goto out_err;
153         version = program->version[args->version];
154         if (version == NULL)
155                 goto out_err;
156
157         err = -ENOMEM;
158         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
159         if (!clnt)
160                 goto out_err;
161         clnt->cl_parent = clnt;
162
163         clnt->cl_server = clnt->cl_inline_name;
164         if (len > sizeof(clnt->cl_inline_name)) {
165                 char *buf = kmalloc(len, GFP_KERNEL);
166                 if (buf != NULL)
167                         clnt->cl_server = buf;
168                 else
169                         len = sizeof(clnt->cl_inline_name);
170         }
171         strlcpy(clnt->cl_server, args->servername, len);
172
173         clnt->cl_xprt     = xprt;
174         clnt->cl_procinfo = version->procs;
175         clnt->cl_maxproc  = version->nrprocs;
176         clnt->cl_protname = program->name;
177         clnt->cl_prog     = args->prognumber ? : program->number;
178         clnt->cl_vers     = version->number;
179         clnt->cl_stats    = program->stats;
180         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
181         err = -ENOMEM;
182         if (clnt->cl_metrics == NULL)
183                 goto out_no_stats;
184         clnt->cl_program  = program;
185         INIT_LIST_HEAD(&clnt->cl_tasks);
186         spin_lock_init(&clnt->cl_lock);
187
188         if (!xprt_bound(clnt->cl_xprt))
189                 clnt->cl_autobind = 1;
190
191         clnt->cl_timeout = xprt->timeout;
192         if (args->timeout != NULL) {
193                 memcpy(&clnt->cl_timeout_default, args->timeout,
194                                 sizeof(clnt->cl_timeout_default));
195                 clnt->cl_timeout = &clnt->cl_timeout_default;
196         }
197
198         clnt->cl_rtt = &clnt->cl_rtt_default;
199         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
200
201         kref_init(&clnt->cl_kref);
202
203         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
204         if (err < 0)
205                 goto out_no_path;
206
207         auth = rpcauth_create(args->authflavor, clnt);
208         if (IS_ERR(auth)) {
209                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
210                                 args->authflavor);
211                 err = PTR_ERR(auth);
212                 goto out_no_auth;
213         }
214
215         /* save the nodename */
216         clnt->cl_nodelen = strlen(init_utsname()->nodename);
217         if (clnt->cl_nodelen > UNX_MAXNODENAME)
218                 clnt->cl_nodelen = UNX_MAXNODENAME;
219         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
220         rpc_register_client(clnt);
221         return clnt;
222
223 out_no_auth:
224         if (!IS_ERR(clnt->cl_dentry)) {
225                 rpc_rmdir(clnt->cl_dentry);
226                 rpc_put_mount();
227         }
228 out_no_path:
229         rpc_free_iostats(clnt->cl_metrics);
230 out_no_stats:
231         if (clnt->cl_server != clnt->cl_inline_name)
232                 kfree(clnt->cl_server);
233         kfree(clnt);
234 out_err:
235         xprt_put(xprt);
236 out_no_xprt:
237         rpciod_down();
238 out_no_rpciod:
239         return ERR_PTR(err);
240 }
241
242 /*
243  * rpc_create - create an RPC client and transport with one call
244  * @args: rpc_clnt create argument structure
245  *
246  * Creates and initializes an RPC transport and an RPC client.
247  *
248  * It can ping the server in order to determine if it is up, and to see if
249  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
250  * this behavior so asynchronous tasks can also use rpc_create.
251  */
252 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
253 {
254         struct rpc_xprt *xprt;
255         struct rpc_clnt *clnt;
256         struct xprt_create xprtargs = {
257                 .ident = args->protocol,
258                 .srcaddr = args->saddress,
259                 .dstaddr = args->address,
260                 .addrlen = args->addrsize,
261         };
262         char servername[48];
263
264         /*
265          * If the caller chooses not to specify a hostname, whip
266          * up a string representation of the passed-in address.
267          */
268         if (args->servername == NULL) {
269                 servername[0] = '\0';
270                 switch (args->address->sa_family) {
271                 case AF_INET: {
272                         struct sockaddr_in *sin =
273                                         (struct sockaddr_in *)args->address;
274                         snprintf(servername, sizeof(servername), NIPQUAD_FMT,
275                                  NIPQUAD(sin->sin_addr.s_addr));
276                         break;
277                 }
278                 case AF_INET6: {
279                         struct sockaddr_in6 *sin =
280                                         (struct sockaddr_in6 *)args->address;
281                         snprintf(servername, sizeof(servername), NIP6_FMT,
282                                  NIP6(sin->sin6_addr));
283                         break;
284                 }
285                 default:
286                         /* caller wants default server name, but
287                          * address family isn't recognized. */
288                         return ERR_PTR(-EINVAL);
289                 }
290                 args->servername = servername;
291         }
292
293         xprt = xprt_create_transport(&xprtargs);
294         if (IS_ERR(xprt))
295                 return (struct rpc_clnt *)xprt;
296
297         /*
298          * By default, kernel RPC client connects from a reserved port.
299          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
300          * but it is always enabled for rpciod, which handles the connect
301          * operation.
302          */
303         xprt->resvport = 1;
304         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
305                 xprt->resvport = 0;
306
307         clnt = rpc_new_client(args, xprt);
308         if (IS_ERR(clnt))
309                 return clnt;
310
311         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
312                 int err = rpc_ping(clnt, RPC_TASK_SOFT);
313                 if (err != 0) {
314                         rpc_shutdown_client(clnt);
315                         return ERR_PTR(err);
316                 }
317         }
318
319         clnt->cl_softrtry = 1;
320         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
321                 clnt->cl_softrtry = 0;
322
323         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
324                 clnt->cl_autobind = 1;
325         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
326                 clnt->cl_discrtry = 1;
327         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
328                 clnt->cl_chatty = 1;
329
330         return clnt;
331 }
332 EXPORT_SYMBOL_GPL(rpc_create);
333
334 /*
335  * This function clones the RPC client structure. It allows us to share the
336  * same transport while varying parameters such as the authentication
337  * flavour.
338  */
339 struct rpc_clnt *
340 rpc_clone_client(struct rpc_clnt *clnt)
341 {
342         struct rpc_clnt *new;
343         int err = -ENOMEM;
344
345         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
346         if (!new)
347                 goto out_no_clnt;
348         new->cl_parent = clnt;
349         /* Turn off autobind on clones */
350         new->cl_autobind = 0;
351         INIT_LIST_HEAD(&new->cl_tasks);
352         spin_lock_init(&new->cl_lock);
353         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
354         new->cl_metrics = rpc_alloc_iostats(clnt);
355         if (new->cl_metrics == NULL)
356                 goto out_no_stats;
357         kref_init(&new->cl_kref);
358         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
359         if (err != 0)
360                 goto out_no_path;
361         if (new->cl_auth)
362                 atomic_inc(&new->cl_auth->au_count);
363         xprt_get(clnt->cl_xprt);
364         kref_get(&clnt->cl_kref);
365         rpc_register_client(new);
366         rpciod_up();
367         return new;
368 out_no_path:
369         rpc_free_iostats(new->cl_metrics);
370 out_no_stats:
371         kfree(new);
372 out_no_clnt:
373         dprintk("RPC:       %s: returned error %d\n", __func__, err);
374         return ERR_PTR(err);
375 }
376 EXPORT_SYMBOL_GPL(rpc_clone_client);
377
378 /*
379  * Properly shut down an RPC client, terminating all outstanding
380  * requests.
381  */
382 void rpc_shutdown_client(struct rpc_clnt *clnt)
383 {
384         dprintk("RPC:       shutting down %s client for %s\n",
385                         clnt->cl_protname, clnt->cl_server);
386
387         while (!list_empty(&clnt->cl_tasks)) {
388                 rpc_killall_tasks(clnt);
389                 wait_event_timeout(destroy_wait,
390                         list_empty(&clnt->cl_tasks), 1*HZ);
391         }
392
393         rpc_release_client(clnt);
394 }
395 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
396
397 /*
398  * Free an RPC client
399  */
400 static void
401 rpc_free_client(struct kref *kref)
402 {
403         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
404
405         dprintk("RPC:       destroying %s client for %s\n",
406                         clnt->cl_protname, clnt->cl_server);
407         if (!IS_ERR(clnt->cl_dentry)) {
408                 rpc_rmdir(clnt->cl_dentry);
409                 rpc_put_mount();
410         }
411         if (clnt->cl_parent != clnt) {
412                 rpc_release_client(clnt->cl_parent);
413                 goto out_free;
414         }
415         if (clnt->cl_server != clnt->cl_inline_name)
416                 kfree(clnt->cl_server);
417 out_free:
418         rpc_unregister_client(clnt);
419         rpc_free_iostats(clnt->cl_metrics);
420         clnt->cl_metrics = NULL;
421         xprt_put(clnt->cl_xprt);
422         rpciod_down();
423         kfree(clnt);
424 }
425
426 /*
427  * Free an RPC client
428  */
429 static void
430 rpc_free_auth(struct kref *kref)
431 {
432         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
433
434         if (clnt->cl_auth == NULL) {
435                 rpc_free_client(kref);
436                 return;
437         }
438
439         /*
440          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
441          *       release remaining GSS contexts. This mechanism ensures
442          *       that it can do so safely.
443          */
444         kref_init(kref);
445         rpcauth_release(clnt->cl_auth);
446         clnt->cl_auth = NULL;
447         kref_put(kref, rpc_free_client);
448 }
449
450 /*
451  * Release reference to the RPC client
452  */
453 void
454 rpc_release_client(struct rpc_clnt *clnt)
455 {
456         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
457
458         if (list_empty(&clnt->cl_tasks))
459                 wake_up(&destroy_wait);
460         kref_put(&clnt->cl_kref, rpc_free_auth);
461 }
462
463 /**
464  * rpc_bind_new_program - bind a new RPC program to an existing client
465  * @old: old rpc_client
466  * @program: rpc program to set
467  * @vers: rpc program version
468  *
469  * Clones the rpc client and sets up a new RPC program. This is mainly
470  * of use for enabling different RPC programs to share the same transport.
471  * The Sun NFSv2/v3 ACL protocol can do this.
472  */
473 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
474                                       struct rpc_program *program,
475                                       u32 vers)
476 {
477         struct rpc_clnt *clnt;
478         struct rpc_version *version;
479         int err;
480
481         BUG_ON(vers >= program->nrvers || !program->version[vers]);
482         version = program->version[vers];
483         clnt = rpc_clone_client(old);
484         if (IS_ERR(clnt))
485                 goto out;
486         clnt->cl_procinfo = version->procs;
487         clnt->cl_maxproc  = version->nrprocs;
488         clnt->cl_protname = program->name;
489         clnt->cl_prog     = program->number;
490         clnt->cl_vers     = version->number;
491         clnt->cl_stats    = program->stats;
492         err = rpc_ping(clnt, RPC_TASK_SOFT);
493         if (err != 0) {
494                 rpc_shutdown_client(clnt);
495                 clnt = ERR_PTR(err);
496         }
497 out:
498         return clnt;
499 }
500 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
501
502 /*
503  * Default callback for async RPC calls
504  */
505 static void
506 rpc_default_callback(struct rpc_task *task, void *data)
507 {
508 }
509
510 static const struct rpc_call_ops rpc_default_ops = {
511         .rpc_call_done = rpc_default_callback,
512 };
513
514 /**
515  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
516  * @task_setup_data: pointer to task initialisation data
517  */
518 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
519 {
520         struct rpc_task *task, *ret;
521
522         task = rpc_new_task(task_setup_data);
523         if (task == NULL) {
524                 rpc_release_calldata(task_setup_data->callback_ops,
525                                 task_setup_data->callback_data);
526                 ret = ERR_PTR(-ENOMEM);
527                 goto out;
528         }
529
530         if (task->tk_status != 0) {
531                 ret = ERR_PTR(task->tk_status);
532                 rpc_put_task(task);
533                 goto out;
534         }
535         atomic_inc(&task->tk_count);
536         rpc_execute(task);
537         ret = task;
538 out:
539         return ret;
540 }
541 EXPORT_SYMBOL_GPL(rpc_run_task);
542
543 /**
544  * rpc_call_sync - Perform a synchronous RPC call
545  * @clnt: pointer to RPC client
546  * @msg: RPC call parameters
547  * @flags: RPC call flags
548  */
549 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
550 {
551         struct rpc_task *task;
552         struct rpc_task_setup task_setup_data = {
553                 .rpc_client = clnt,
554                 .rpc_message = msg,
555                 .callback_ops = &rpc_default_ops,
556                 .flags = flags,
557         };
558         int status;
559
560         BUG_ON(flags & RPC_TASK_ASYNC);
561
562         task = rpc_run_task(&task_setup_data);
563         if (IS_ERR(task))
564                 return PTR_ERR(task);
565         status = task->tk_status;
566         rpc_put_task(task);
567         return status;
568 }
569 EXPORT_SYMBOL_GPL(rpc_call_sync);
570
571 /**
572  * rpc_call_async - Perform an asynchronous RPC call
573  * @clnt: pointer to RPC client
574  * @msg: RPC call parameters
575  * @flags: RPC call flags
576  * @tk_ops: RPC call ops
577  * @data: user call data
578  */
579 int
580 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
581                const struct rpc_call_ops *tk_ops, void *data)
582 {
583         struct rpc_task *task;
584         struct rpc_task_setup task_setup_data = {
585                 .rpc_client = clnt,
586                 .rpc_message = msg,
587                 .callback_ops = tk_ops,
588                 .callback_data = data,
589                 .flags = flags|RPC_TASK_ASYNC,
590         };
591
592         task = rpc_run_task(&task_setup_data);
593         if (IS_ERR(task))
594                 return PTR_ERR(task);
595         rpc_put_task(task);
596         return 0;
597 }
598 EXPORT_SYMBOL_GPL(rpc_call_async);
599
600 void
601 rpc_call_start(struct rpc_task *task)
602 {
603         task->tk_action = call_start;
604 }
605 EXPORT_SYMBOL_GPL(rpc_call_start);
606
607 /**
608  * rpc_peeraddr - extract remote peer address from clnt's xprt
609  * @clnt: RPC client structure
610  * @buf: target buffer
611  * @bufsize: length of target buffer
612  *
613  * Returns the number of bytes that are actually in the stored address.
614  */
615 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
616 {
617         size_t bytes;
618         struct rpc_xprt *xprt = clnt->cl_xprt;
619
620         bytes = sizeof(xprt->addr);
621         if (bytes > bufsize)
622                 bytes = bufsize;
623         memcpy(buf, &clnt->cl_xprt->addr, bytes);
624         return xprt->addrlen;
625 }
626 EXPORT_SYMBOL_GPL(rpc_peeraddr);
627
628 /**
629  * rpc_peeraddr2str - return remote peer address in printable format
630  * @clnt: RPC client structure
631  * @format: address format
632  *
633  */
634 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
635                              enum rpc_display_format_t format)
636 {
637         struct rpc_xprt *xprt = clnt->cl_xprt;
638
639         if (xprt->address_strings[format] != NULL)
640                 return xprt->address_strings[format];
641         else
642                 return "unprintable";
643 }
644 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
645
646 void
647 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
648 {
649         struct rpc_xprt *xprt = clnt->cl_xprt;
650         if (xprt->ops->set_buffer_size)
651                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
652 }
653 EXPORT_SYMBOL_GPL(rpc_setbufsize);
654
655 /*
656  * Return size of largest payload RPC client can support, in bytes
657  *
658  * For stream transports, this is one RPC record fragment (see RFC
659  * 1831), as we don't support multi-record requests yet.  For datagram
660  * transports, this is the size of an IP packet minus the IP, UDP, and
661  * RPC header sizes.
662  */
663 size_t rpc_max_payload(struct rpc_clnt *clnt)
664 {
665         return clnt->cl_xprt->max_payload;
666 }
667 EXPORT_SYMBOL_GPL(rpc_max_payload);
668
669 /**
670  * rpc_force_rebind - force transport to check that remote port is unchanged
671  * @clnt: client to rebind
672  *
673  */
674 void rpc_force_rebind(struct rpc_clnt *clnt)
675 {
676         if (clnt->cl_autobind)
677                 xprt_clear_bound(clnt->cl_xprt);
678 }
679 EXPORT_SYMBOL_GPL(rpc_force_rebind);
680
681 /*
682  * Restart an (async) RPC call. Usually called from within the
683  * exit handler.
684  */
685 void
686 rpc_restart_call(struct rpc_task *task)
687 {
688         if (RPC_ASSASSINATED(task))
689                 return;
690
691         task->tk_action = call_start;
692 }
693 EXPORT_SYMBOL_GPL(rpc_restart_call);
694
695 #ifdef RPC_DEBUG
696 static const char *rpc_proc_name(const struct rpc_task *task)
697 {
698         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
699
700         if (proc) {
701                 if (proc->p_name)
702                         return proc->p_name;
703                 else
704                         return "NULL";
705         } else
706                 return "no proc";
707 }
708 #endif
709
710 /*
711  * 0.  Initial state
712  *
713  *     Other FSM states can be visited zero or more times, but
714  *     this state is visited exactly once for each RPC.
715  */
716 static void
717 call_start(struct rpc_task *task)
718 {
719         struct rpc_clnt *clnt = task->tk_client;
720
721         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
722                         clnt->cl_protname, clnt->cl_vers,
723                         rpc_proc_name(task),
724                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
725
726         /* Increment call count */
727         task->tk_msg.rpc_proc->p_count++;
728         clnt->cl_stats->rpccnt++;
729         task->tk_action = call_reserve;
730 }
731
732 /*
733  * 1.   Reserve an RPC call slot
734  */
735 static void
736 call_reserve(struct rpc_task *task)
737 {
738         dprint_status(task);
739
740         if (!rpcauth_uptodatecred(task)) {
741                 task->tk_action = call_refresh;
742                 return;
743         }
744
745         task->tk_status  = 0;
746         task->tk_action  = call_reserveresult;
747         xprt_reserve(task);
748 }
749
750 /*
751  * 1b.  Grok the result of xprt_reserve()
752  */
753 static void
754 call_reserveresult(struct rpc_task *task)
755 {
756         int status = task->tk_status;
757
758         dprint_status(task);
759
760         /*
761          * After a call to xprt_reserve(), we must have either
762          * a request slot or else an error status.
763          */
764         task->tk_status = 0;
765         if (status >= 0) {
766                 if (task->tk_rqstp) {
767                         task->tk_action = call_allocate;
768                         return;
769                 }
770
771                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
772                                 __func__, status);
773                 rpc_exit(task, -EIO);
774                 return;
775         }
776
777         /*
778          * Even though there was an error, we may have acquired
779          * a request slot somehow.  Make sure not to leak it.
780          */
781         if (task->tk_rqstp) {
782                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
783                                 __func__, status);
784                 xprt_release(task);
785         }
786
787         switch (status) {
788         case -EAGAIN:   /* woken up; retry */
789                 task->tk_action = call_reserve;
790                 return;
791         case -EIO:      /* probably a shutdown */
792                 break;
793         default:
794                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
795                                 __func__, status);
796                 break;
797         }
798         rpc_exit(task, status);
799 }
800
801 /*
802  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
803  *      (Note: buffer memory is freed in xprt_release).
804  */
805 static void
806 call_allocate(struct rpc_task *task)
807 {
808         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
809         struct rpc_rqst *req = task->tk_rqstp;
810         struct rpc_xprt *xprt = task->tk_xprt;
811         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
812
813         dprint_status(task);
814
815         task->tk_status = 0;
816         task->tk_action = call_bind;
817
818         if (req->rq_buffer)
819                 return;
820
821         if (proc->p_proc != 0) {
822                 BUG_ON(proc->p_arglen == 0);
823                 if (proc->p_decode != NULL)
824                         BUG_ON(proc->p_replen == 0);
825         }
826
827         /*
828          * Calculate the size (in quads) of the RPC call
829          * and reply headers, and convert both values
830          * to byte sizes.
831          */
832         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
833         req->rq_callsize <<= 2;
834         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
835         req->rq_rcvsize <<= 2;
836
837         req->rq_buffer = xprt->ops->buf_alloc(task,
838                                         req->rq_callsize + req->rq_rcvsize);
839         if (req->rq_buffer != NULL)
840                 return;
841
842         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
843
844         if (RPC_IS_ASYNC(task) || !signalled()) {
845                 task->tk_action = call_allocate;
846                 rpc_delay(task, HZ>>4);
847                 return;
848         }
849
850         rpc_exit(task, -ERESTARTSYS);
851 }
852
853 static inline int
854 rpc_task_need_encode(struct rpc_task *task)
855 {
856         return task->tk_rqstp->rq_snd_buf.len == 0;
857 }
858
859 static inline void
860 rpc_task_force_reencode(struct rpc_task *task)
861 {
862         task->tk_rqstp->rq_snd_buf.len = 0;
863 }
864
865 static inline void
866 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
867 {
868         buf->head[0].iov_base = start;
869         buf->head[0].iov_len = len;
870         buf->tail[0].iov_len = 0;
871         buf->page_len = 0;
872         buf->flags = 0;
873         buf->len = 0;
874         buf->buflen = len;
875 }
876
877 /*
878  * 3.   Encode arguments of an RPC call
879  */
880 static void
881 rpc_xdr_encode(struct rpc_task *task)
882 {
883         struct rpc_rqst *req = task->tk_rqstp;
884         kxdrproc_t      encode;
885         __be32          *p;
886
887         dprint_status(task);
888
889         rpc_xdr_buf_init(&req->rq_snd_buf,
890                          req->rq_buffer,
891                          req->rq_callsize);
892         rpc_xdr_buf_init(&req->rq_rcv_buf,
893                          (char *)req->rq_buffer + req->rq_callsize,
894                          req->rq_rcvsize);
895
896         p = rpc_encode_header(task);
897         if (p == NULL) {
898                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
899                 rpc_exit(task, -EIO);
900                 return;
901         }
902
903         encode = task->tk_msg.rpc_proc->p_encode;
904         if (encode == NULL)
905                 return;
906
907         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
908                         task->tk_msg.rpc_argp);
909 }
910
911 /*
912  * 4.   Get the server port number if not yet set
913  */
914 static void
915 call_bind(struct rpc_task *task)
916 {
917         struct rpc_xprt *xprt = task->tk_xprt;
918
919         dprint_status(task);
920
921         task->tk_action = call_connect;
922         if (!xprt_bound(xprt)) {
923                 task->tk_action = call_bind_status;
924                 task->tk_timeout = xprt->bind_timeout;
925                 xprt->ops->rpcbind(task);
926         }
927 }
928
929 /*
930  * 4a.  Sort out bind result
931  */
932 static void
933 call_bind_status(struct rpc_task *task)
934 {
935         int status = -EIO;
936
937         if (task->tk_status >= 0) {
938                 dprint_status(task);
939                 task->tk_status = 0;
940                 task->tk_action = call_connect;
941                 return;
942         }
943
944         switch (task->tk_status) {
945         case -ENOMEM:
946                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
947                 rpc_delay(task, HZ >> 2);
948                 goto retry_timeout;
949         case -EACCES:
950                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
951                                 "unavailable\n", task->tk_pid);
952                 /* fail immediately if this is an RPC ping */
953                 if (task->tk_msg.rpc_proc->p_proc == 0) {
954                         status = -EOPNOTSUPP;
955                         break;
956                 }
957                 rpc_delay(task, 3*HZ);
958                 goto retry_timeout;
959         case -ETIMEDOUT:
960                 dprintk("RPC: %5u rpcbind request timed out\n",
961                                 task->tk_pid);
962                 goto retry_timeout;
963         case -EPFNOSUPPORT:
964                 /* server doesn't support any rpcbind version we know of */
965                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
966                                 task->tk_pid);
967                 break;
968         case -EPROTONOSUPPORT:
969                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
970                                 task->tk_pid);
971                 task->tk_status = 0;
972                 task->tk_action = call_bind;
973                 return;
974         default:
975                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
976                                 task->tk_pid, -task->tk_status);
977         }
978
979         rpc_exit(task, status);
980         return;
981
982 retry_timeout:
983         task->tk_action = call_timeout;
984 }
985
986 /*
987  * 4b.  Connect to the RPC server
988  */
989 static void
990 call_connect(struct rpc_task *task)
991 {
992         struct rpc_xprt *xprt = task->tk_xprt;
993
994         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
995                         task->tk_pid, xprt,
996                         (xprt_connected(xprt) ? "is" : "is not"));
997
998         task->tk_action = call_transmit;
999         if (!xprt_connected(xprt)) {
1000                 task->tk_action = call_connect_status;
1001                 if (task->tk_status < 0)
1002                         return;
1003                 xprt_connect(task);
1004         }
1005 }
1006
1007 /*
1008  * 4c.  Sort out connect result
1009  */
1010 static void
1011 call_connect_status(struct rpc_task *task)
1012 {
1013         struct rpc_clnt *clnt = task->tk_client;
1014         int status = task->tk_status;
1015
1016         dprint_status(task);
1017
1018         task->tk_status = 0;
1019         if (status >= 0) {
1020                 clnt->cl_stats->netreconn++;
1021                 task->tk_action = call_transmit;
1022                 return;
1023         }
1024
1025         /* Something failed: remote service port may have changed */
1026         rpc_force_rebind(clnt);
1027
1028         switch (status) {
1029         case -ENOTCONN:
1030         case -EAGAIN:
1031                 task->tk_action = call_bind;
1032                 if (!RPC_IS_SOFT(task))
1033                         return;
1034                 /* if soft mounted, test if we've timed out */
1035         case -ETIMEDOUT:
1036                 task->tk_action = call_timeout;
1037                 return;
1038         }
1039         rpc_exit(task, -EIO);
1040 }
1041
1042 /*
1043  * 5.   Transmit the RPC request, and wait for reply
1044  */
1045 static void
1046 call_transmit(struct rpc_task *task)
1047 {
1048         dprint_status(task);
1049
1050         task->tk_action = call_status;
1051         if (task->tk_status < 0)
1052                 return;
1053         task->tk_status = xprt_prepare_transmit(task);
1054         if (task->tk_status != 0)
1055                 return;
1056         task->tk_action = call_transmit_status;
1057         /* Encode here so that rpcsec_gss can use correct sequence number. */
1058         if (rpc_task_need_encode(task)) {
1059                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1060                 rpc_xdr_encode(task);
1061                 /* Did the encode result in an error condition? */
1062                 if (task->tk_status != 0) {
1063                         /* Was the error nonfatal? */
1064                         if (task->tk_status == -EAGAIN)
1065                                 rpc_delay(task, HZ >> 4);
1066                         else
1067                                 rpc_exit(task, task->tk_status);
1068                         return;
1069                 }
1070         }
1071         xprt_transmit(task);
1072         if (task->tk_status < 0)
1073                 return;
1074         /*
1075          * On success, ensure that we call xprt_end_transmit() before sleeping
1076          * in order to allow access to the socket to other RPC requests.
1077          */
1078         call_transmit_status(task);
1079         if (task->tk_msg.rpc_proc->p_decode != NULL)
1080                 return;
1081         task->tk_action = rpc_exit_task;
1082         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1083 }
1084
1085 /*
1086  * 5a.  Handle cleanup after a transmission
1087  */
1088 static void
1089 call_transmit_status(struct rpc_task *task)
1090 {
1091         task->tk_action = call_status;
1092         /*
1093          * Special case: if we've been waiting on the socket's write_space()
1094          * callback, then don't call xprt_end_transmit().
1095          */
1096         if (task->tk_status == -EAGAIN)
1097                 return;
1098         xprt_end_transmit(task);
1099         rpc_task_force_reencode(task);
1100 }
1101
1102 /*
1103  * 6.   Sort out the RPC call status
1104  */
1105 static void
1106 call_status(struct rpc_task *task)
1107 {
1108         struct rpc_clnt *clnt = task->tk_client;
1109         struct rpc_rqst *req = task->tk_rqstp;
1110         int             status;
1111
1112         if (req->rq_received > 0 && !req->rq_bytes_sent)
1113                 task->tk_status = req->rq_received;
1114
1115         dprint_status(task);
1116
1117         status = task->tk_status;
1118         if (status >= 0) {
1119                 task->tk_action = call_decode;
1120                 return;
1121         }
1122
1123         task->tk_status = 0;
1124         switch(status) {
1125         case -EHOSTDOWN:
1126         case -EHOSTUNREACH:
1127         case -ENETUNREACH:
1128                 /*
1129                  * Delay any retries for 3 seconds, then handle as if it
1130                  * were a timeout.
1131                  */
1132                 rpc_delay(task, 3*HZ);
1133         case -ETIMEDOUT:
1134                 task->tk_action = call_timeout;
1135                 if (task->tk_client->cl_discrtry)
1136                         xprt_conditional_disconnect(task->tk_xprt,
1137                                         req->rq_connect_cookie);
1138                 break;
1139         case -ECONNREFUSED:
1140         case -ENOTCONN:
1141                 rpc_force_rebind(clnt);
1142                 task->tk_action = call_bind;
1143                 break;
1144         case -EAGAIN:
1145                 task->tk_action = call_transmit;
1146                 break;
1147         case -EIO:
1148                 /* shutdown or soft timeout */
1149                 rpc_exit(task, status);
1150                 break;
1151         default:
1152                 if (clnt->cl_chatty)
1153                         printk("%s: RPC call returned error %d\n",
1154                                clnt->cl_protname, -status);
1155                 rpc_exit(task, status);
1156         }
1157 }
1158
1159 /*
1160  * 6a.  Handle RPC timeout
1161  *      We do not release the request slot, so we keep using the
1162  *      same XID for all retransmits.
1163  */
1164 static void
1165 call_timeout(struct rpc_task *task)
1166 {
1167         struct rpc_clnt *clnt = task->tk_client;
1168
1169         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1170                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1171                 goto retry;
1172         }
1173
1174         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1175         task->tk_timeouts++;
1176
1177         if (RPC_IS_SOFT(task)) {
1178                 if (clnt->cl_chatty)
1179                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1180                                 clnt->cl_protname, clnt->cl_server);
1181                 rpc_exit(task, -EIO);
1182                 return;
1183         }
1184
1185         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1186                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1187                 if (clnt->cl_chatty)
1188                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1189                         clnt->cl_protname, clnt->cl_server);
1190         }
1191         rpc_force_rebind(clnt);
1192         /*
1193          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1194          * event? RFC2203 requires the server to drop all such requests.
1195          */
1196         rpcauth_invalcred(task);
1197
1198 retry:
1199         clnt->cl_stats->rpcretrans++;
1200         task->tk_action = call_bind;
1201         task->tk_status = 0;
1202 }
1203
1204 /*
1205  * 7.   Decode the RPC reply
1206  */
1207 static void
1208 call_decode(struct rpc_task *task)
1209 {
1210         struct rpc_clnt *clnt = task->tk_client;
1211         struct rpc_rqst *req = task->tk_rqstp;
1212         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1213         __be32          *p;
1214
1215         dprintk("RPC: %5u call_decode (status %d)\n",
1216                         task->tk_pid, task->tk_status);
1217
1218         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1219                 if (clnt->cl_chatty)
1220                         printk(KERN_NOTICE "%s: server %s OK\n",
1221                                 clnt->cl_protname, clnt->cl_server);
1222                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1223         }
1224
1225         /*
1226          * Ensure that we see all writes made by xprt_complete_rqst()
1227          * before it changed req->rq_received.
1228          */
1229         smp_rmb();
1230         req->rq_rcv_buf.len = req->rq_private_buf.len;
1231
1232         /* Check that the softirq receive buffer is valid */
1233         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1234                                 sizeof(req->rq_rcv_buf)) != 0);
1235
1236         if (req->rq_rcv_buf.len < 12) {
1237                 if (!RPC_IS_SOFT(task)) {
1238                         task->tk_action = call_bind;
1239                         clnt->cl_stats->rpcretrans++;
1240                         goto out_retry;
1241                 }
1242                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1243                                 clnt->cl_protname, task->tk_status);
1244                 task->tk_action = call_timeout;
1245                 goto out_retry;
1246         }
1247
1248         p = rpc_verify_header(task);
1249         if (IS_ERR(p)) {
1250                 if (p == ERR_PTR(-EAGAIN))
1251                         goto out_retry;
1252                 return;
1253         }
1254
1255         task->tk_action = rpc_exit_task;
1256
1257         if (decode) {
1258                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1259                                                       task->tk_msg.rpc_resp);
1260         }
1261         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1262                         task->tk_status);
1263         return;
1264 out_retry:
1265         task->tk_status = 0;
1266         /* Note: rpc_verify_header() may have freed the RPC slot */
1267         if (task->tk_rqstp == req) {
1268                 req->rq_received = req->rq_rcv_buf.len = 0;
1269                 if (task->tk_client->cl_discrtry)
1270                         xprt_conditional_disconnect(task->tk_xprt,
1271                                         req->rq_connect_cookie);
1272         }
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 static __be32 *
1314 rpc_encode_header(struct rpc_task *task)
1315 {
1316         struct rpc_clnt *clnt = task->tk_client;
1317         struct rpc_rqst *req = task->tk_rqstp;
1318         __be32          *p = req->rq_svec[0].iov_base;
1319
1320         /* FIXME: check buffer size? */
1321
1322         p = xprt_skip_transport_header(task->tk_xprt, p);
1323         *p++ = req->rq_xid;             /* XID */
1324         *p++ = htonl(RPC_CALL);         /* CALL */
1325         *p++ = htonl(RPC_VERSION);      /* RPC version */
1326         *p++ = htonl(clnt->cl_prog);    /* program number */
1327         *p++ = htonl(clnt->cl_vers);    /* program version */
1328         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1329         p = rpcauth_marshcred(task, p);
1330         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1331         return p;
1332 }
1333
1334 static __be32 *
1335 rpc_verify_header(struct rpc_task *task)
1336 {
1337         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1338         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1339         __be32  *p = iov->iov_base;
1340         u32 n;
1341         int error = -EACCES;
1342
1343         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1344                 /* RFC-1014 says that the representation of XDR data must be a
1345                  * multiple of four bytes
1346                  * - if it isn't pointer subtraction in the NFS client may give
1347                  *   undefined results
1348                  */
1349                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1350                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1351                        task->tk_rqstp->rq_rcv_buf.len);
1352                 goto out_eio;
1353         }
1354         if ((len -= 3) < 0)
1355                 goto out_overflow;
1356         p += 1; /* skip XID */
1357
1358         if ((n = ntohl(*p++)) != RPC_REPLY) {
1359                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1360                                 task->tk_pid, __func__, n);
1361                 goto out_garbage;
1362         }
1363         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1364                 if (--len < 0)
1365                         goto out_overflow;
1366                 switch ((n = ntohl(*p++))) {
1367                         case RPC_AUTH_ERROR:
1368                                 break;
1369                         case RPC_MISMATCH:
1370                                 dprintk("RPC: %5u %s: RPC call version "
1371                                                 "mismatch!\n",
1372                                                 task->tk_pid, __func__);
1373                                 error = -EPROTONOSUPPORT;
1374                                 goto out_err;
1375                         default:
1376                                 dprintk("RPC: %5u %s: RPC call rejected, "
1377                                                 "unknown error: %x\n",
1378                                                 task->tk_pid, __func__, n);
1379                                 goto out_eio;
1380                 }
1381                 if (--len < 0)
1382                         goto out_overflow;
1383                 switch ((n = ntohl(*p++))) {
1384                 case RPC_AUTH_REJECTEDCRED:
1385                 case RPC_AUTH_REJECTEDVERF:
1386                 case RPCSEC_GSS_CREDPROBLEM:
1387                 case RPCSEC_GSS_CTXPROBLEM:
1388                         if (!task->tk_cred_retry)
1389                                 break;
1390                         task->tk_cred_retry--;
1391                         dprintk("RPC: %5u %s: retry stale creds\n",
1392                                         task->tk_pid, __func__);
1393                         rpcauth_invalcred(task);
1394                         /* Ensure we obtain a new XID! */
1395                         xprt_release(task);
1396                         task->tk_action = call_refresh;
1397                         goto out_retry;
1398                 case RPC_AUTH_BADCRED:
1399                 case RPC_AUTH_BADVERF:
1400                         /* possibly garbled cred/verf? */
1401                         if (!task->tk_garb_retry)
1402                                 break;
1403                         task->tk_garb_retry--;
1404                         dprintk("RPC: %5u %s: retry garbled creds\n",
1405                                         task->tk_pid, __func__);
1406                         task->tk_action = call_bind;
1407                         goto out_retry;
1408                 case RPC_AUTH_TOOWEAK:
1409                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1410                                "authentication.\n", task->tk_client->cl_server);
1411                         break;
1412                 default:
1413                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1414                                         task->tk_pid, __func__, n);
1415                         error = -EIO;
1416                 }
1417                 dprintk("RPC: %5u %s: call rejected %d\n",
1418                                 task->tk_pid, __func__, n);
1419                 goto out_err;
1420         }
1421         if (!(p = rpcauth_checkverf(task, p))) {
1422                 dprintk("RPC: %5u %s: auth check failed\n",
1423                                 task->tk_pid, __func__);
1424                 goto out_garbage;               /* bad verifier, retry */
1425         }
1426         len = p - (__be32 *)iov->iov_base - 1;
1427         if (len < 0)
1428                 goto out_overflow;
1429         switch ((n = ntohl(*p++))) {
1430         case RPC_SUCCESS:
1431                 return p;
1432         case RPC_PROG_UNAVAIL:
1433                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1434                                 task->tk_pid, __func__,
1435                                 (unsigned int)task->tk_client->cl_prog,
1436                                 task->tk_client->cl_server);
1437                 error = -EPFNOSUPPORT;
1438                 goto out_err;
1439         case RPC_PROG_MISMATCH:
1440                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1441                                 "server %s\n", task->tk_pid, __func__,
1442                                 (unsigned int)task->tk_client->cl_prog,
1443                                 (unsigned int)task->tk_client->cl_vers,
1444                                 task->tk_client->cl_server);
1445                 error = -EPROTONOSUPPORT;
1446                 goto out_err;
1447         case RPC_PROC_UNAVAIL:
1448                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1449                                 "version %u on server %s\n",
1450                                 task->tk_pid, __func__,
1451                                 rpc_proc_name(task),
1452                                 task->tk_client->cl_prog,
1453                                 task->tk_client->cl_vers,
1454                                 task->tk_client->cl_server);
1455                 error = -EOPNOTSUPP;
1456                 goto out_err;
1457         case RPC_GARBAGE_ARGS:
1458                 dprintk("RPC: %5u %s: server saw garbage\n",
1459                                 task->tk_pid, __func__);
1460                 break;                  /* retry */
1461         default:
1462                 dprintk("RPC: %5u %s: server accept status: %x\n",
1463                                 task->tk_pid, __func__, n);
1464                 /* Also retry */
1465         }
1466
1467 out_garbage:
1468         task->tk_client->cl_stats->rpcgarbage++;
1469         if (task->tk_garb_retry) {
1470                 task->tk_garb_retry--;
1471                 dprintk("RPC: %5u %s: retrying\n",
1472                                 task->tk_pid, __func__);
1473                 task->tk_action = call_bind;
1474 out_retry:
1475                 return ERR_PTR(-EAGAIN);
1476         }
1477 out_eio:
1478         error = -EIO;
1479 out_err:
1480         rpc_exit(task, error);
1481         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1482                         __func__, error);
1483         return ERR_PTR(error);
1484 out_overflow:
1485         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1486                         __func__);
1487         goto out_garbage;
1488 }
1489
1490 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1491 {
1492         return 0;
1493 }
1494
1495 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1496 {
1497         return 0;
1498 }
1499
1500 static struct rpc_procinfo rpcproc_null = {
1501         .p_encode = rpcproc_encode_null,
1502         .p_decode = rpcproc_decode_null,
1503 };
1504
1505 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1506 {
1507         struct rpc_message msg = {
1508                 .rpc_proc = &rpcproc_null,
1509         };
1510         int err;
1511         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1512         err = rpc_call_sync(clnt, &msg, flags);
1513         put_rpccred(msg.rpc_cred);
1514         return err;
1515 }
1516
1517 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1518 {
1519         struct rpc_message msg = {
1520                 .rpc_proc = &rpcproc_null,
1521                 .rpc_cred = cred,
1522         };
1523         struct rpc_task_setup task_setup_data = {
1524                 .rpc_client = clnt,
1525                 .rpc_message = &msg,
1526                 .callback_ops = &rpc_default_ops,
1527                 .flags = flags,
1528         };
1529         return rpc_run_task(&task_setup_data);
1530 }
1531 EXPORT_SYMBOL_GPL(rpc_call_null);
1532
1533 #ifdef RPC_DEBUG
1534 static void rpc_show_header(void)
1535 {
1536         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1537                 "-timeout ---ops--\n");
1538 }
1539
1540 static void rpc_show_task(const struct rpc_clnt *clnt,
1541                           const struct rpc_task *task)
1542 {
1543         const char *rpc_waitq = "none";
1544         char *p, action[KSYM_SYMBOL_LEN];
1545
1546         if (RPC_IS_QUEUED(task))
1547                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1548
1549         /* map tk_action pointer to a function name; then trim off
1550          * the "+0x0 [sunrpc]" */
1551         sprint_symbol(action, (unsigned long)task->tk_action);
1552         p = strchr(action, '+');
1553         if (p)
1554                 *p = '\0';
1555
1556         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1557                 task->tk_pid, task->tk_flags, task->tk_status,
1558                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1559                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1560                 action, rpc_waitq);
1561 }
1562
1563 void rpc_show_tasks(void)
1564 {
1565         struct rpc_clnt *clnt;
1566         struct rpc_task *task;
1567         int header = 0;
1568
1569         spin_lock(&rpc_client_lock);
1570         list_for_each_entry(clnt, &all_clients, cl_clients) {
1571                 spin_lock(&clnt->cl_lock);
1572                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1573                         if (!header) {
1574                                 rpc_show_header();
1575                                 header++;
1576                         }
1577                         rpc_show_task(clnt, task);
1578                 }
1579                 spin_unlock(&clnt->cl_lock);
1580         }
1581         spin_unlock(&rpc_client_lock);
1582 }
1583 #endif