Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes...
[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 #include <linux/in6.h>
34
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/rpc_pipe_fs.h>
37 #include <linux/sunrpc/metrics.h>
38
39
40 #ifdef RPC_DEBUG
41 # define RPCDBG_FACILITY        RPCDBG_CALL
42 #endif
43
44 #define dprint_status(t)                                        \
45         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
46                         __func__, t->tk_status)
47
48 /*
49  * All RPC clients are linked into this list
50  */
51 static LIST_HEAD(all_clients);
52 static DEFINE_SPINLOCK(rpc_client_lock);
53
54 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
55
56
57 static void     call_start(struct rpc_task *task);
58 static void     call_reserve(struct rpc_task *task);
59 static void     call_reserveresult(struct rpc_task *task);
60 static void     call_allocate(struct rpc_task *task);
61 static void     call_encode(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 static __be32 * call_header(struct rpc_task *task);
74 static __be32 * call_verify(struct rpc_task *task);
75
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     = 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(utsname()->nodename);
217         if (clnt->cl_nodelen > UNX_MAXNODENAME)
218                 clnt->cl_nodelen = UNX_MAXNODENAME;
219         memcpy(clnt->cl_nodename, 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
328         return clnt;
329 }
330 EXPORT_SYMBOL_GPL(rpc_create);
331
332 /*
333  * This function clones the RPC client structure. It allows us to share the
334  * same transport while varying parameters such as the authentication
335  * flavour.
336  */
337 struct rpc_clnt *
338 rpc_clone_client(struct rpc_clnt *clnt)
339 {
340         struct rpc_clnt *new;
341         int err = -ENOMEM;
342
343         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
344         if (!new)
345                 goto out_no_clnt;
346         new->cl_parent = clnt;
347         /* Turn off autobind on clones */
348         new->cl_autobind = 0;
349         INIT_LIST_HEAD(&new->cl_tasks);
350         spin_lock_init(&new->cl_lock);
351         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
352         new->cl_metrics = rpc_alloc_iostats(clnt);
353         if (new->cl_metrics == NULL)
354                 goto out_no_stats;
355         kref_init(&new->cl_kref);
356         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
357         if (err != 0)
358                 goto out_no_path;
359         if (new->cl_auth)
360                 atomic_inc(&new->cl_auth->au_count);
361         xprt_get(clnt->cl_xprt);
362         kref_get(&clnt->cl_kref);
363         rpc_register_client(new);
364         rpciod_up();
365         return new;
366 out_no_path:
367         rpc_free_iostats(new->cl_metrics);
368 out_no_stats:
369         kfree(new);
370 out_no_clnt:
371         dprintk("RPC:       %s: returned error %d\n", __func__, err);
372         return ERR_PTR(err);
373 }
374 EXPORT_SYMBOL_GPL(rpc_clone_client);
375
376 /*
377  * Properly shut down an RPC client, terminating all outstanding
378  * requests.
379  */
380 void rpc_shutdown_client(struct rpc_clnt *clnt)
381 {
382         dprintk("RPC:       shutting down %s client for %s\n",
383                         clnt->cl_protname, clnt->cl_server);
384
385         while (!list_empty(&clnt->cl_tasks)) {
386                 rpc_killall_tasks(clnt);
387                 wait_event_timeout(destroy_wait,
388                         list_empty(&clnt->cl_tasks), 1*HZ);
389         }
390
391         rpc_release_client(clnt);
392 }
393 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
394
395 /*
396  * Free an RPC client
397  */
398 static void
399 rpc_free_client(struct kref *kref)
400 {
401         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
402
403         dprintk("RPC:       destroying %s client for %s\n",
404                         clnt->cl_protname, clnt->cl_server);
405         if (!IS_ERR(clnt->cl_dentry)) {
406                 rpc_rmdir(clnt->cl_dentry);
407                 rpc_put_mount();
408         }
409         if (clnt->cl_parent != clnt) {
410                 rpc_release_client(clnt->cl_parent);
411                 goto out_free;
412         }
413         if (clnt->cl_server != clnt->cl_inline_name)
414                 kfree(clnt->cl_server);
415 out_free:
416         rpc_unregister_client(clnt);
417         rpc_free_iostats(clnt->cl_metrics);
418         clnt->cl_metrics = NULL;
419         xprt_put(clnt->cl_xprt);
420         rpciod_down();
421         kfree(clnt);
422 }
423
424 /*
425  * Free an RPC client
426  */
427 static void
428 rpc_free_auth(struct kref *kref)
429 {
430         struct rpc_clnt *clnt = container_of(kref, struct rpc_clnt, cl_kref);
431
432         if (clnt->cl_auth == NULL) {
433                 rpc_free_client(kref);
434                 return;
435         }
436
437         /*
438          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
439          *       release remaining GSS contexts. This mechanism ensures
440          *       that it can do so safely.
441          */
442         kref_init(kref);
443         rpcauth_release(clnt->cl_auth);
444         clnt->cl_auth = NULL;
445         kref_put(kref, rpc_free_client);
446 }
447
448 /*
449  * Release reference to the RPC client
450  */
451 void
452 rpc_release_client(struct rpc_clnt *clnt)
453 {
454         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
455
456         if (list_empty(&clnt->cl_tasks))
457                 wake_up(&destroy_wait);
458         kref_put(&clnt->cl_kref, rpc_free_auth);
459 }
460
461 /**
462  * rpc_bind_new_program - bind a new RPC program to an existing client
463  * @old: old rpc_client
464  * @program: rpc program to set
465  * @vers: rpc program version
466  *
467  * Clones the rpc client and sets up a new RPC program. This is mainly
468  * of use for enabling different RPC programs to share the same transport.
469  * The Sun NFSv2/v3 ACL protocol can do this.
470  */
471 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
472                                       struct rpc_program *program,
473                                       u32 vers)
474 {
475         struct rpc_clnt *clnt;
476         struct rpc_version *version;
477         int err;
478
479         BUG_ON(vers >= program->nrvers || !program->version[vers]);
480         version = program->version[vers];
481         clnt = rpc_clone_client(old);
482         if (IS_ERR(clnt))
483                 goto out;
484         clnt->cl_procinfo = version->procs;
485         clnt->cl_maxproc  = version->nrprocs;
486         clnt->cl_protname = program->name;
487         clnt->cl_prog     = program->number;
488         clnt->cl_vers     = version->number;
489         clnt->cl_stats    = program->stats;
490         err = rpc_ping(clnt, RPC_TASK_SOFT);
491         if (err != 0) {
492                 rpc_shutdown_client(clnt);
493                 clnt = ERR_PTR(err);
494         }
495 out:
496         return clnt;
497 }
498 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
499
500 /*
501  * Default callback for async RPC calls
502  */
503 static void
504 rpc_default_callback(struct rpc_task *task, void *data)
505 {
506 }
507
508 static const struct rpc_call_ops rpc_default_ops = {
509         .rpc_call_done = rpc_default_callback,
510 };
511
512 /**
513  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
514  * @task_setup_data: pointer to task initialisation data
515  */
516 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
517 {
518         struct rpc_task *task, *ret;
519
520         task = rpc_new_task(task_setup_data);
521         if (task == NULL) {
522                 rpc_release_calldata(task_setup_data->callback_ops,
523                                 task_setup_data->callback_data);
524                 ret = ERR_PTR(-ENOMEM);
525                 goto out;
526         }
527
528         if (task->tk_status != 0) {
529                 ret = ERR_PTR(task->tk_status);
530                 rpc_put_task(task);
531                 goto out;
532         }
533         atomic_inc(&task->tk_count);
534         rpc_execute(task);
535         ret = task;
536 out:
537         return ret;
538 }
539 EXPORT_SYMBOL_GPL(rpc_run_task);
540
541 /**
542  * rpc_call_sync - Perform a synchronous RPC call
543  * @clnt: pointer to RPC client
544  * @msg: RPC call parameters
545  * @flags: RPC call flags
546  */
547 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
548 {
549         struct rpc_task *task;
550         struct rpc_task_setup task_setup_data = {
551                 .rpc_client = clnt,
552                 .rpc_message = msg,
553                 .callback_ops = &rpc_default_ops,
554                 .flags = flags,
555         };
556         int status;
557
558         BUG_ON(flags & RPC_TASK_ASYNC);
559
560         task = rpc_run_task(&task_setup_data);
561         if (IS_ERR(task))
562                 return PTR_ERR(task);
563         status = task->tk_status;
564         rpc_put_task(task);
565         return status;
566 }
567 EXPORT_SYMBOL_GPL(rpc_call_sync);
568
569 /**
570  * rpc_call_async - Perform an asynchronous RPC call
571  * @clnt: pointer to RPC client
572  * @msg: RPC call parameters
573  * @flags: RPC call flags
574  * @tk_ops: RPC call ops
575  * @data: user call data
576  */
577 int
578 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
579                const struct rpc_call_ops *tk_ops, void *data)
580 {
581         struct rpc_task *task;
582         struct rpc_task_setup task_setup_data = {
583                 .rpc_client = clnt,
584                 .rpc_message = msg,
585                 .callback_ops = tk_ops,
586                 .callback_data = data,
587                 .flags = flags|RPC_TASK_ASYNC,
588         };
589
590         task = rpc_run_task(&task_setup_data);
591         if (IS_ERR(task))
592                 return PTR_ERR(task);
593         rpc_put_task(task);
594         return 0;
595 }
596 EXPORT_SYMBOL_GPL(rpc_call_async);
597
598 void
599 rpc_call_start(struct rpc_task *task)
600 {
601         task->tk_action = call_start;
602 }
603 EXPORT_SYMBOL_GPL(rpc_call_start);
604
605 /**
606  * rpc_peeraddr - extract remote peer address from clnt's xprt
607  * @clnt: RPC client structure
608  * @buf: target buffer
609  * @bufsize: length of target buffer
610  *
611  * Returns the number of bytes that are actually in the stored address.
612  */
613 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
614 {
615         size_t bytes;
616         struct rpc_xprt *xprt = clnt->cl_xprt;
617
618         bytes = sizeof(xprt->addr);
619         if (bytes > bufsize)
620                 bytes = bufsize;
621         memcpy(buf, &clnt->cl_xprt->addr, bytes);
622         return xprt->addrlen;
623 }
624 EXPORT_SYMBOL_GPL(rpc_peeraddr);
625
626 /**
627  * rpc_peeraddr2str - return remote peer address in printable format
628  * @clnt: RPC client structure
629  * @format: address format
630  *
631  */
632 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
633                              enum rpc_display_format_t format)
634 {
635         struct rpc_xprt *xprt = clnt->cl_xprt;
636
637         if (xprt->address_strings[format] != NULL)
638                 return xprt->address_strings[format];
639         else
640                 return "unprintable";
641 }
642 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
643
644 void
645 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
646 {
647         struct rpc_xprt *xprt = clnt->cl_xprt;
648         if (xprt->ops->set_buffer_size)
649                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
650 }
651 EXPORT_SYMBOL_GPL(rpc_setbufsize);
652
653 /*
654  * Return size of largest payload RPC client can support, in bytes
655  *
656  * For stream transports, this is one RPC record fragment (see RFC
657  * 1831), as we don't support multi-record requests yet.  For datagram
658  * transports, this is the size of an IP packet minus the IP, UDP, and
659  * RPC header sizes.
660  */
661 size_t rpc_max_payload(struct rpc_clnt *clnt)
662 {
663         return clnt->cl_xprt->max_payload;
664 }
665 EXPORT_SYMBOL_GPL(rpc_max_payload);
666
667 /**
668  * rpc_force_rebind - force transport to check that remote port is unchanged
669  * @clnt: client to rebind
670  *
671  */
672 void rpc_force_rebind(struct rpc_clnt *clnt)
673 {
674         if (clnt->cl_autobind)
675                 xprt_clear_bound(clnt->cl_xprt);
676 }
677 EXPORT_SYMBOL_GPL(rpc_force_rebind);
678
679 /*
680  * Restart an (async) RPC call. Usually called from within the
681  * exit handler.
682  */
683 void
684 rpc_restart_call(struct rpc_task *task)
685 {
686         if (RPC_ASSASSINATED(task))
687                 return;
688
689         task->tk_action = call_start;
690 }
691 EXPORT_SYMBOL_GPL(rpc_restart_call);
692
693 /*
694  * 0.  Initial state
695  *
696  *     Other FSM states can be visited zero or more times, but
697  *     this state is visited exactly once for each RPC.
698  */
699 static void
700 call_start(struct rpc_task *task)
701 {
702         struct rpc_clnt *clnt = task->tk_client;
703
704         dprintk("RPC: %5u call_start %s%d proc %d (%s)\n", task->tk_pid,
705                         clnt->cl_protname, clnt->cl_vers,
706                         task->tk_msg.rpc_proc->p_proc,
707                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
708
709         /* Increment call count */
710         task->tk_msg.rpc_proc->p_count++;
711         clnt->cl_stats->rpccnt++;
712         task->tk_action = call_reserve;
713 }
714
715 /*
716  * 1.   Reserve an RPC call slot
717  */
718 static void
719 call_reserve(struct rpc_task *task)
720 {
721         dprint_status(task);
722
723         if (!rpcauth_uptodatecred(task)) {
724                 task->tk_action = call_refresh;
725                 return;
726         }
727
728         task->tk_status  = 0;
729         task->tk_action  = call_reserveresult;
730         xprt_reserve(task);
731 }
732
733 /*
734  * 1b.  Grok the result of xprt_reserve()
735  */
736 static void
737 call_reserveresult(struct rpc_task *task)
738 {
739         int status = task->tk_status;
740
741         dprint_status(task);
742
743         /*
744          * After a call to xprt_reserve(), we must have either
745          * a request slot or else an error status.
746          */
747         task->tk_status = 0;
748         if (status >= 0) {
749                 if (task->tk_rqstp) {
750                         task->tk_action = call_allocate;
751                         return;
752                 }
753
754                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
755                                 __func__, status);
756                 rpc_exit(task, -EIO);
757                 return;
758         }
759
760         /*
761          * Even though there was an error, we may have acquired
762          * a request slot somehow.  Make sure not to leak it.
763          */
764         if (task->tk_rqstp) {
765                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
766                                 __func__, status);
767                 xprt_release(task);
768         }
769
770         switch (status) {
771         case -EAGAIN:   /* woken up; retry */
772                 task->tk_action = call_reserve;
773                 return;
774         case -EIO:      /* probably a shutdown */
775                 break;
776         default:
777                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
778                                 __func__, status);
779                 break;
780         }
781         rpc_exit(task, status);
782 }
783
784 /*
785  * 2.   Allocate the buffer. For details, see sched.c:rpc_malloc.
786  *      (Note: buffer memory is freed in xprt_release).
787  */
788 static void
789 call_allocate(struct rpc_task *task)
790 {
791         unsigned int slack = task->tk_msg.rpc_cred->cr_auth->au_cslack;
792         struct rpc_rqst *req = task->tk_rqstp;
793         struct rpc_xprt *xprt = task->tk_xprt;
794         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
795
796         dprint_status(task);
797
798         task->tk_status = 0;
799         task->tk_action = call_bind;
800
801         if (req->rq_buffer)
802                 return;
803
804         if (proc->p_proc != 0) {
805                 BUG_ON(proc->p_arglen == 0);
806                 if (proc->p_decode != NULL)
807                         BUG_ON(proc->p_replen == 0);
808         }
809
810         /*
811          * Calculate the size (in quads) of the RPC call
812          * and reply headers, and convert both values
813          * to byte sizes.
814          */
815         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
816         req->rq_callsize <<= 2;
817         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
818         req->rq_rcvsize <<= 2;
819
820         req->rq_buffer = xprt->ops->buf_alloc(task,
821                                         req->rq_callsize + req->rq_rcvsize);
822         if (req->rq_buffer != NULL)
823                 return;
824
825         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
826
827         if (RPC_IS_ASYNC(task) || !signalled()) {
828                 task->tk_action = call_allocate;
829                 rpc_delay(task, HZ>>4);
830                 return;
831         }
832
833         rpc_exit(task, -ERESTARTSYS);
834 }
835
836 static inline int
837 rpc_task_need_encode(struct rpc_task *task)
838 {
839         return task->tk_rqstp->rq_snd_buf.len == 0;
840 }
841
842 static inline void
843 rpc_task_force_reencode(struct rpc_task *task)
844 {
845         task->tk_rqstp->rq_snd_buf.len = 0;
846 }
847
848 static inline void
849 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
850 {
851         buf->head[0].iov_base = start;
852         buf->head[0].iov_len = len;
853         buf->tail[0].iov_len = 0;
854         buf->page_len = 0;
855         buf->flags = 0;
856         buf->len = 0;
857         buf->buflen = len;
858 }
859
860 /*
861  * 3.   Encode arguments of an RPC call
862  */
863 static void
864 call_encode(struct rpc_task *task)
865 {
866         struct rpc_rqst *req = task->tk_rqstp;
867         kxdrproc_t      encode;
868         __be32          *p;
869
870         dprint_status(task);
871
872         rpc_xdr_buf_init(&req->rq_snd_buf,
873                          req->rq_buffer,
874                          req->rq_callsize);
875         rpc_xdr_buf_init(&req->rq_rcv_buf,
876                          (char *)req->rq_buffer + req->rq_callsize,
877                          req->rq_rcvsize);
878
879         /* Encode header and provided arguments */
880         encode = task->tk_msg.rpc_proc->p_encode;
881         if (!(p = call_header(task))) {
882                 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
883                 rpc_exit(task, -EIO);
884                 return;
885         }
886         if (encode == NULL)
887                 return;
888
889         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
890                         task->tk_msg.rpc_argp);
891         if (task->tk_status == -ENOMEM) {
892                 /* XXX: Is this sane? */
893                 rpc_delay(task, 3*HZ);
894                 task->tk_status = -EAGAIN;
895         }
896 }
897
898 /*
899  * 4.   Get the server port number if not yet set
900  */
901 static void
902 call_bind(struct rpc_task *task)
903 {
904         struct rpc_xprt *xprt = task->tk_xprt;
905
906         dprint_status(task);
907
908         task->tk_action = call_connect;
909         if (!xprt_bound(xprt)) {
910                 task->tk_action = call_bind_status;
911                 task->tk_timeout = xprt->bind_timeout;
912                 xprt->ops->rpcbind(task);
913         }
914 }
915
916 /*
917  * 4a.  Sort out bind result
918  */
919 static void
920 call_bind_status(struct rpc_task *task)
921 {
922         int status = -EIO;
923
924         if (task->tk_status >= 0) {
925                 dprint_status(task);
926                 task->tk_status = 0;
927                 task->tk_action = call_connect;
928                 return;
929         }
930
931         switch (task->tk_status) {
932         case -EAGAIN:
933                 dprintk("RPC: %5u rpcbind waiting for another request "
934                                 "to finish\n", task->tk_pid);
935                 /* avoid busy-waiting here -- could be a network outage. */
936                 rpc_delay(task, 5*HZ);
937                 goto retry_timeout;
938         case -EACCES:
939                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
940                                 "unavailable\n", task->tk_pid);
941                 /* fail immediately if this is an RPC ping */
942                 if (task->tk_msg.rpc_proc->p_proc == 0) {
943                         status = -EOPNOTSUPP;
944                         break;
945                 }
946                 rpc_delay(task, 3*HZ);
947                 goto retry_timeout;
948         case -ETIMEDOUT:
949                 dprintk("RPC: %5u rpcbind request timed out\n",
950                                 task->tk_pid);
951                 goto retry_timeout;
952         case -EPFNOSUPPORT:
953                 /* server doesn't support any rpcbind version we know of */
954                 dprintk("RPC: %5u remote rpcbind service unavailable\n",
955                                 task->tk_pid);
956                 break;
957         case -EPROTONOSUPPORT:
958                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
959                                 task->tk_pid);
960                 task->tk_status = 0;
961                 task->tk_action = call_bind;
962                 return;
963         default:
964                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
965                                 task->tk_pid, -task->tk_status);
966         }
967
968         rpc_exit(task, status);
969         return;
970
971 retry_timeout:
972         task->tk_action = call_timeout;
973 }
974
975 /*
976  * 4b.  Connect to the RPC server
977  */
978 static void
979 call_connect(struct rpc_task *task)
980 {
981         struct rpc_xprt *xprt = task->tk_xprt;
982
983         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
984                         task->tk_pid, xprt,
985                         (xprt_connected(xprt) ? "is" : "is not"));
986
987         task->tk_action = call_transmit;
988         if (!xprt_connected(xprt)) {
989                 task->tk_action = call_connect_status;
990                 if (task->tk_status < 0)
991                         return;
992                 xprt_connect(task);
993         }
994 }
995
996 /*
997  * 4c.  Sort out connect result
998  */
999 static void
1000 call_connect_status(struct rpc_task *task)
1001 {
1002         struct rpc_clnt *clnt = task->tk_client;
1003         int status = task->tk_status;
1004
1005         dprint_status(task);
1006
1007         task->tk_status = 0;
1008         if (status >= 0) {
1009                 clnt->cl_stats->netreconn++;
1010                 task->tk_action = call_transmit;
1011                 return;
1012         }
1013
1014         /* Something failed: remote service port may have changed */
1015         rpc_force_rebind(clnt);
1016
1017         switch (status) {
1018         case -ENOTCONN:
1019         case -EAGAIN:
1020                 task->tk_action = call_bind;
1021                 if (!RPC_IS_SOFT(task))
1022                         return;
1023                 /* if soft mounted, test if we've timed out */
1024         case -ETIMEDOUT:
1025                 task->tk_action = call_timeout;
1026                 return;
1027         }
1028         rpc_exit(task, -EIO);
1029 }
1030
1031 /*
1032  * 5.   Transmit the RPC request, and wait for reply
1033  */
1034 static void
1035 call_transmit(struct rpc_task *task)
1036 {
1037         dprint_status(task);
1038
1039         task->tk_action = call_status;
1040         if (task->tk_status < 0)
1041                 return;
1042         task->tk_status = xprt_prepare_transmit(task);
1043         if (task->tk_status != 0)
1044                 return;
1045         task->tk_action = call_transmit_status;
1046         /* Encode here so that rpcsec_gss can use correct sequence number. */
1047         if (rpc_task_need_encode(task)) {
1048                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1049                 call_encode(task);
1050                 /* Did the encode result in an error condition? */
1051                 if (task->tk_status != 0)
1052                         return;
1053         }
1054         xprt_transmit(task);
1055         if (task->tk_status < 0)
1056                 return;
1057         /*
1058          * On success, ensure that we call xprt_end_transmit() before sleeping
1059          * in order to allow access to the socket to other RPC requests.
1060          */
1061         call_transmit_status(task);
1062         if (task->tk_msg.rpc_proc->p_decode != NULL)
1063                 return;
1064         task->tk_action = rpc_exit_task;
1065         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1066 }
1067
1068 /*
1069  * 5a.  Handle cleanup after a transmission
1070  */
1071 static void
1072 call_transmit_status(struct rpc_task *task)
1073 {
1074         task->tk_action = call_status;
1075         /*
1076          * Special case: if we've been waiting on the socket's write_space()
1077          * callback, then don't call xprt_end_transmit().
1078          */
1079         if (task->tk_status == -EAGAIN)
1080                 return;
1081         xprt_end_transmit(task);
1082         rpc_task_force_reencode(task);
1083 }
1084
1085 /*
1086  * 6.   Sort out the RPC call status
1087  */
1088 static void
1089 call_status(struct rpc_task *task)
1090 {
1091         struct rpc_clnt *clnt = task->tk_client;
1092         struct rpc_rqst *req = task->tk_rqstp;
1093         int             status;
1094
1095         if (req->rq_received > 0 && !req->rq_bytes_sent)
1096                 task->tk_status = req->rq_received;
1097
1098         dprint_status(task);
1099
1100         status = task->tk_status;
1101         if (status >= 0) {
1102                 task->tk_action = call_decode;
1103                 return;
1104         }
1105
1106         task->tk_status = 0;
1107         switch(status) {
1108         case -EHOSTDOWN:
1109         case -EHOSTUNREACH:
1110         case -ENETUNREACH:
1111                 /*
1112                  * Delay any retries for 3 seconds, then handle as if it
1113                  * were a timeout.
1114                  */
1115                 rpc_delay(task, 3*HZ);
1116         case -ETIMEDOUT:
1117                 task->tk_action = call_timeout;
1118                 if (task->tk_client->cl_discrtry)
1119                         xprt_conditional_disconnect(task->tk_xprt,
1120                                         req->rq_connect_cookie);
1121                 break;
1122         case -ECONNREFUSED:
1123         case -ENOTCONN:
1124                 rpc_force_rebind(clnt);
1125                 task->tk_action = call_bind;
1126                 break;
1127         case -EAGAIN:
1128                 task->tk_action = call_transmit;
1129                 break;
1130         case -EIO:
1131                 /* shutdown or soft timeout */
1132                 rpc_exit(task, status);
1133                 break;
1134         default:
1135                 printk("%s: RPC call returned error %d\n",
1136                                clnt->cl_protname, -status);
1137                 rpc_exit(task, status);
1138         }
1139 }
1140
1141 /*
1142  * 6a.  Handle RPC timeout
1143  *      We do not release the request slot, so we keep using the
1144  *      same XID for all retransmits.
1145  */
1146 static void
1147 call_timeout(struct rpc_task *task)
1148 {
1149         struct rpc_clnt *clnt = task->tk_client;
1150
1151         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1152                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1153                 goto retry;
1154         }
1155
1156         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1157         task->tk_timeouts++;
1158
1159         if (RPC_IS_SOFT(task)) {
1160                 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1161                                 clnt->cl_protname, clnt->cl_server);
1162                 rpc_exit(task, -EIO);
1163                 return;
1164         }
1165
1166         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1167                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1168                 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1169                         clnt->cl_protname, clnt->cl_server);
1170         }
1171         rpc_force_rebind(clnt);
1172         /*
1173          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1174          * event? RFC2203 requires the server to drop all such requests.
1175          */
1176         rpcauth_invalcred(task);
1177
1178 retry:
1179         clnt->cl_stats->rpcretrans++;
1180         task->tk_action = call_bind;
1181         task->tk_status = 0;
1182 }
1183
1184 /*
1185  * 7.   Decode the RPC reply
1186  */
1187 static void
1188 call_decode(struct rpc_task *task)
1189 {
1190         struct rpc_clnt *clnt = task->tk_client;
1191         struct rpc_rqst *req = task->tk_rqstp;
1192         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1193         __be32          *p;
1194
1195         dprintk("RPC: %5u call_decode (status %d)\n",
1196                         task->tk_pid, task->tk_status);
1197
1198         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1199                 printk(KERN_NOTICE "%s: server %s OK\n",
1200                         clnt->cl_protname, clnt->cl_server);
1201                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1202         }
1203
1204         /*
1205          * Ensure that we see all writes made by xprt_complete_rqst()
1206          * before it changed req->rq_received.
1207          */
1208         smp_rmb();
1209         req->rq_rcv_buf.len = req->rq_private_buf.len;
1210
1211         /* Check that the softirq receive buffer is valid */
1212         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1213                                 sizeof(req->rq_rcv_buf)) != 0);
1214
1215         if (req->rq_rcv_buf.len < 12) {
1216                 if (!RPC_IS_SOFT(task)) {
1217                         task->tk_action = call_bind;
1218                         clnt->cl_stats->rpcretrans++;
1219                         goto out_retry;
1220                 }
1221                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1222                                 clnt->cl_protname, task->tk_status);
1223                 task->tk_action = call_timeout;
1224                 goto out_retry;
1225         }
1226
1227         /* Verify the RPC header */
1228         p = call_verify(task);
1229         if (IS_ERR(p)) {
1230                 if (p == ERR_PTR(-EAGAIN))
1231                         goto out_retry;
1232                 return;
1233         }
1234
1235         task->tk_action = rpc_exit_task;
1236
1237         if (decode) {
1238                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1239                                                       task->tk_msg.rpc_resp);
1240         }
1241         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1242                         task->tk_status);
1243         return;
1244 out_retry:
1245         task->tk_status = 0;
1246         /* Note: call_verify() may have freed the RPC slot */
1247         if (task->tk_rqstp == req) {
1248                 req->rq_received = req->rq_rcv_buf.len = 0;
1249                 if (task->tk_client->cl_discrtry)
1250                         xprt_conditional_disconnect(task->tk_xprt,
1251                                         req->rq_connect_cookie);
1252         }
1253 }
1254
1255 /*
1256  * 8.   Refresh the credentials if rejected by the server
1257  */
1258 static void
1259 call_refresh(struct rpc_task *task)
1260 {
1261         dprint_status(task);
1262
1263         task->tk_action = call_refreshresult;
1264         task->tk_status = 0;
1265         task->tk_client->cl_stats->rpcauthrefresh++;
1266         rpcauth_refreshcred(task);
1267 }
1268
1269 /*
1270  * 8a.  Process the results of a credential refresh
1271  */
1272 static void
1273 call_refreshresult(struct rpc_task *task)
1274 {
1275         int status = task->tk_status;
1276
1277         dprint_status(task);
1278
1279         task->tk_status = 0;
1280         task->tk_action = call_reserve;
1281         if (status >= 0 && rpcauth_uptodatecred(task))
1282                 return;
1283         if (status == -EACCES) {
1284                 rpc_exit(task, -EACCES);
1285                 return;
1286         }
1287         task->tk_action = call_refresh;
1288         if (status != -ETIMEDOUT)
1289                 rpc_delay(task, 3*HZ);
1290         return;
1291 }
1292
1293 /*
1294  * Call header serialization
1295  */
1296 static __be32 *
1297 call_header(struct rpc_task *task)
1298 {
1299         struct rpc_clnt *clnt = task->tk_client;
1300         struct rpc_rqst *req = task->tk_rqstp;
1301         __be32          *p = req->rq_svec[0].iov_base;
1302
1303         /* FIXME: check buffer size? */
1304
1305         p = xprt_skip_transport_header(task->tk_xprt, p);
1306         *p++ = req->rq_xid;             /* XID */
1307         *p++ = htonl(RPC_CALL);         /* CALL */
1308         *p++ = htonl(RPC_VERSION);      /* RPC version */
1309         *p++ = htonl(clnt->cl_prog);    /* program number */
1310         *p++ = htonl(clnt->cl_vers);    /* program version */
1311         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1312         p = rpcauth_marshcred(task, p);
1313         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1314         return p;
1315 }
1316
1317 /*
1318  * Reply header verification
1319  */
1320 static __be32 *
1321 call_verify(struct rpc_task *task)
1322 {
1323         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1324         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1325         __be32  *p = iov->iov_base;
1326         u32 n;
1327         int error = -EACCES;
1328
1329         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1330                 /* RFC-1014 says that the representation of XDR data must be a
1331                  * multiple of four bytes
1332                  * - if it isn't pointer subtraction in the NFS client may give
1333                  *   undefined results
1334                  */
1335                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1336                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1337                        task->tk_rqstp->rq_rcv_buf.len);
1338                 goto out_eio;
1339         }
1340         if ((len -= 3) < 0)
1341                 goto out_overflow;
1342         p += 1; /* skip XID */
1343
1344         if ((n = ntohl(*p++)) != RPC_REPLY) {
1345                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1346                                 task->tk_pid, __func__, n);
1347                 goto out_garbage;
1348         }
1349         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1350                 if (--len < 0)
1351                         goto out_overflow;
1352                 switch ((n = ntohl(*p++))) {
1353                         case RPC_AUTH_ERROR:
1354                                 break;
1355                         case RPC_MISMATCH:
1356                                 dprintk("RPC: %5u %s: RPC call version "
1357                                                 "mismatch!\n",
1358                                                 task->tk_pid, __func__);
1359                                 error = -EPROTONOSUPPORT;
1360                                 goto out_err;
1361                         default:
1362                                 dprintk("RPC: %5u %s: RPC call rejected, "
1363                                                 "unknown error: %x\n",
1364                                                 task->tk_pid, __func__, n);
1365                                 goto out_eio;
1366                 }
1367                 if (--len < 0)
1368                         goto out_overflow;
1369                 switch ((n = ntohl(*p++))) {
1370                 case RPC_AUTH_REJECTEDCRED:
1371                 case RPC_AUTH_REJECTEDVERF:
1372                 case RPCSEC_GSS_CREDPROBLEM:
1373                 case RPCSEC_GSS_CTXPROBLEM:
1374                         if (!task->tk_cred_retry)
1375                                 break;
1376                         task->tk_cred_retry--;
1377                         dprintk("RPC: %5u %s: retry stale creds\n",
1378                                         task->tk_pid, __func__);
1379                         rpcauth_invalcred(task);
1380                         /* Ensure we obtain a new XID! */
1381                         xprt_release(task);
1382                         task->tk_action = call_refresh;
1383                         goto out_retry;
1384                 case RPC_AUTH_BADCRED:
1385                 case RPC_AUTH_BADVERF:
1386                         /* possibly garbled cred/verf? */
1387                         if (!task->tk_garb_retry)
1388                                 break;
1389                         task->tk_garb_retry--;
1390                         dprintk("RPC: %5u %s: retry garbled creds\n",
1391                                         task->tk_pid, __func__);
1392                         task->tk_action = call_bind;
1393                         goto out_retry;
1394                 case RPC_AUTH_TOOWEAK:
1395                         printk(KERN_NOTICE "call_verify: server %s requires stronger "
1396                                "authentication.\n", task->tk_client->cl_server);
1397                         break;
1398                 default:
1399                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1400                                         task->tk_pid, __func__, n);
1401                         error = -EIO;
1402                 }
1403                 dprintk("RPC: %5u %s: call rejected %d\n",
1404                                 task->tk_pid, __func__, n);
1405                 goto out_err;
1406         }
1407         if (!(p = rpcauth_checkverf(task, p))) {
1408                 dprintk("RPC: %5u %s: auth check failed\n",
1409                                 task->tk_pid, __func__);
1410                 goto out_garbage;               /* bad verifier, retry */
1411         }
1412         len = p - (__be32 *)iov->iov_base - 1;
1413         if (len < 0)
1414                 goto out_overflow;
1415         switch ((n = ntohl(*p++))) {
1416         case RPC_SUCCESS:
1417                 return p;
1418         case RPC_PROG_UNAVAIL:
1419                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1420                                 task->tk_pid, __func__,
1421                                 (unsigned int)task->tk_client->cl_prog,
1422                                 task->tk_client->cl_server);
1423                 error = -EPFNOSUPPORT;
1424                 goto out_err;
1425         case RPC_PROG_MISMATCH:
1426                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1427                                 "server %s\n", task->tk_pid, __func__,
1428                                 (unsigned int)task->tk_client->cl_prog,
1429                                 (unsigned int)task->tk_client->cl_vers,
1430                                 task->tk_client->cl_server);
1431                 error = -EPROTONOSUPPORT;
1432                 goto out_err;
1433         case RPC_PROC_UNAVAIL:
1434                 dprintk("RPC: %5u %s: proc %p unsupported by program %u, "
1435                                 "version %u on server %s\n",
1436                                 task->tk_pid, __func__,
1437                                 task->tk_msg.rpc_proc,
1438                                 task->tk_client->cl_prog,
1439                                 task->tk_client->cl_vers,
1440                                 task->tk_client->cl_server);
1441                 error = -EOPNOTSUPP;
1442                 goto out_err;
1443         case RPC_GARBAGE_ARGS:
1444                 dprintk("RPC: %5u %s: server saw garbage\n",
1445                                 task->tk_pid, __func__);
1446                 break;                  /* retry */
1447         default:
1448                 dprintk("RPC: %5u %s: server accept status: %x\n",
1449                                 task->tk_pid, __func__, n);
1450                 /* Also retry */
1451         }
1452
1453 out_garbage:
1454         task->tk_client->cl_stats->rpcgarbage++;
1455         if (task->tk_garb_retry) {
1456                 task->tk_garb_retry--;
1457                 dprintk("RPC: %5u %s: retrying\n",
1458                                 task->tk_pid, __func__);
1459                 task->tk_action = call_bind;
1460 out_retry:
1461                 return ERR_PTR(-EAGAIN);
1462         }
1463 out_eio:
1464         error = -EIO;
1465 out_err:
1466         rpc_exit(task, error);
1467         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1468                         __func__, error);
1469         return ERR_PTR(error);
1470 out_overflow:
1471         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1472                         __func__);
1473         goto out_garbage;
1474 }
1475
1476 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1477 {
1478         return 0;
1479 }
1480
1481 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1482 {
1483         return 0;
1484 }
1485
1486 static struct rpc_procinfo rpcproc_null = {
1487         .p_encode = rpcproc_encode_null,
1488         .p_decode = rpcproc_decode_null,
1489 };
1490
1491 static int rpc_ping(struct rpc_clnt *clnt, int flags)
1492 {
1493         struct rpc_message msg = {
1494                 .rpc_proc = &rpcproc_null,
1495         };
1496         int err;
1497         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1498         err = rpc_call_sync(clnt, &msg, flags);
1499         put_rpccred(msg.rpc_cred);
1500         return err;
1501 }
1502
1503 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1504 {
1505         struct rpc_message msg = {
1506                 .rpc_proc = &rpcproc_null,
1507                 .rpc_cred = cred,
1508         };
1509         struct rpc_task_setup task_setup_data = {
1510                 .rpc_client = clnt,
1511                 .rpc_message = &msg,
1512                 .callback_ops = &rpc_default_ops,
1513                 .flags = flags,
1514         };
1515         return rpc_run_task(&task_setup_data);
1516 }
1517 EXPORT_SYMBOL_GPL(rpc_call_null);
1518
1519 #ifdef RPC_DEBUG
1520 void rpc_show_tasks(void)
1521 {
1522         struct rpc_clnt *clnt;
1523         struct rpc_task *t;
1524
1525         spin_lock(&rpc_client_lock);
1526         if (list_empty(&all_clients))
1527                 goto out;
1528         printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1529                 "-rpcwait -action- ---ops--\n");
1530         list_for_each_entry(clnt, &all_clients, cl_clients) {
1531                 if (list_empty(&clnt->cl_tasks))
1532                         continue;
1533                 spin_lock(&clnt->cl_lock);
1534                 list_for_each_entry(t, &clnt->cl_tasks, tk_task) {
1535                         const char *rpc_waitq = "none";
1536                         int proc;
1537
1538                         if (t->tk_msg.rpc_proc)
1539                                 proc = t->tk_msg.rpc_proc->p_proc;
1540                         else
1541                                 proc = -1;
1542
1543                         if (RPC_IS_QUEUED(t))
1544                                 rpc_waitq = rpc_qname(t->tk_waitqueue);
1545
1546                         printk("%5u %04d %04x %6d %8p %6d %8p %8ld %8s %8p %8p\n",
1547                                 t->tk_pid, proc,
1548                                 t->tk_flags, t->tk_status,
1549                                 t->tk_client,
1550                                 (t->tk_client ? t->tk_client->cl_prog : 0),
1551                                 t->tk_rqstp, t->tk_timeout,
1552                                 rpc_waitq,
1553                                 t->tk_action, t->tk_ops);
1554                 }
1555                 spin_unlock(&clnt->cl_lock);
1556         }
1557 out:
1558         spin_unlock(&rpc_client_lock);
1559 }
1560 #endif