Merge tag 'nfs-for-3.9-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[~shefty/rdma-dev.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  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
18  */
19
20
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kallsyms.h>
24 #include <linux/mm.h>
25 #include <linux/namei.h>
26 #include <linux/mount.h>
27 #include <linux/slab.h>
28 #include <linux/utsname.h>
29 #include <linux/workqueue.h>
30 #include <linux/in.h>
31 #include <linux/in6.h>
32 #include <linux/un.h>
33 #include <linux/rcupdate.h>
34
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/addr.h>
37 #include <linux/sunrpc/rpc_pipe_fs.h>
38 #include <linux/sunrpc/metrics.h>
39 #include <linux/sunrpc/bc_xprt.h>
40 #include <trace/events/sunrpc.h>
41
42 #include "sunrpc.h"
43 #include "netns.h"
44
45 #ifdef RPC_DEBUG
46 # define RPCDBG_FACILITY        RPCDBG_CALL
47 #endif
48
49 #define dprint_status(t)                                        \
50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
51                         __func__, t->tk_status)
52
53 /*
54  * All RPC clients are linked into this list
55  */
56
57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
58
59
60 static void     call_start(struct rpc_task *task);
61 static void     call_reserve(struct rpc_task *task);
62 static void     call_reserveresult(struct rpc_task *task);
63 static void     call_allocate(struct rpc_task *task);
64 static void     call_decode(struct rpc_task *task);
65 static void     call_bind(struct rpc_task *task);
66 static void     call_bind_status(struct rpc_task *task);
67 static void     call_transmit(struct rpc_task *task);
68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
69 static void     call_bc_transmit(struct rpc_task *task);
70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
71 static void     call_status(struct rpc_task *task);
72 static void     call_transmit_status(struct rpc_task *task);
73 static void     call_refresh(struct rpc_task *task);
74 static void     call_refreshresult(struct rpc_task *task);
75 static void     call_timeout(struct rpc_task *task);
76 static void     call_connect(struct rpc_task *task);
77 static void     call_connect_status(struct rpc_task *task);
78
79 static __be32   *rpc_encode_header(struct rpc_task *task);
80 static __be32   *rpc_verify_header(struct rpc_task *task);
81 static int      rpc_ping(struct rpc_clnt *clnt);
82
83 static void rpc_register_client(struct rpc_clnt *clnt)
84 {
85         struct net *net = rpc_net_ns(clnt);
86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
87
88         spin_lock(&sn->rpc_client_lock);
89         list_add(&clnt->cl_clients, &sn->all_clients);
90         spin_unlock(&sn->rpc_client_lock);
91 }
92
93 static void rpc_unregister_client(struct rpc_clnt *clnt)
94 {
95         struct net *net = rpc_net_ns(clnt);
96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
97
98         spin_lock(&sn->rpc_client_lock);
99         list_del(&clnt->cl_clients);
100         spin_unlock(&sn->rpc_client_lock);
101 }
102
103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 {
105         if (clnt->cl_dentry) {
106                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
107                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
108                 rpc_remove_client_dir(clnt->cl_dentry);
109         }
110         clnt->cl_dentry = NULL;
111 }
112
113 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
114 {
115         struct net *net = rpc_net_ns(clnt);
116         struct super_block *pipefs_sb;
117
118         pipefs_sb = rpc_get_sb_net(net);
119         if (pipefs_sb) {
120                 __rpc_clnt_remove_pipedir(clnt);
121                 rpc_put_sb_net(net);
122         }
123 }
124
125 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
126                                     struct rpc_clnt *clnt,
127                                     const char *dir_name)
128 {
129         static uint32_t clntid;
130         char name[15];
131         struct qstr q = { .name = name };
132         struct dentry *dir, *dentry;
133         int error;
134
135         dir = rpc_d_lookup_sb(sb, dir_name);
136         if (dir == NULL) {
137                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
138                 return dir;
139         }
140         for (;;) {
141                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
142                 name[sizeof(name) - 1] = '\0';
143                 q.hash = full_name_hash(q.name, q.len);
144                 dentry = rpc_create_client_dir(dir, &q, clnt);
145                 if (!IS_ERR(dentry))
146                         break;
147                 error = PTR_ERR(dentry);
148                 if (error != -EEXIST) {
149                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
150                                         " %s/%s, error %d\n",
151                                         dir_name, name, error);
152                         break;
153                 }
154         }
155         dput(dir);
156         return dentry;
157 }
158
159 static int
160 rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
161 {
162         struct net *net = rpc_net_ns(clnt);
163         struct super_block *pipefs_sb;
164         struct dentry *dentry;
165
166         clnt->cl_dentry = NULL;
167         if (dir_name == NULL)
168                 return 0;
169         pipefs_sb = rpc_get_sb_net(net);
170         if (!pipefs_sb)
171                 return 0;
172         dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
173         rpc_put_sb_net(net);
174         if (IS_ERR(dentry))
175                 return PTR_ERR(dentry);
176         clnt->cl_dentry = dentry;
177         return 0;
178 }
179
180 static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
181 {
182         if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
183             ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
184                 return 1;
185         return 0;
186 }
187
188 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
189                                    struct super_block *sb)
190 {
191         struct dentry *dentry;
192         int err = 0;
193
194         switch (event) {
195         case RPC_PIPEFS_MOUNT:
196                 dentry = rpc_setup_pipedir_sb(sb, clnt,
197                                               clnt->cl_program->pipe_dir_name);
198                 if (!dentry)
199                         return -ENOENT;
200                 if (IS_ERR(dentry))
201                         return PTR_ERR(dentry);
202                 clnt->cl_dentry = dentry;
203                 if (clnt->cl_auth->au_ops->pipes_create) {
204                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
205                         if (err)
206                                 __rpc_clnt_remove_pipedir(clnt);
207                 }
208                 break;
209         case RPC_PIPEFS_UMOUNT:
210                 __rpc_clnt_remove_pipedir(clnt);
211                 break;
212         default:
213                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
214                 return -ENOTSUPP;
215         }
216         return err;
217 }
218
219 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
220                                 struct super_block *sb)
221 {
222         int error = 0;
223
224         for (;; clnt = clnt->cl_parent) {
225                 if (!rpc_clnt_skip_event(clnt, event))
226                         error = __rpc_clnt_handle_event(clnt, event, sb);
227                 if (error || clnt == clnt->cl_parent)
228                         break;
229         }
230         return error;
231 }
232
233 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
234 {
235         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
236         struct rpc_clnt *clnt;
237
238         spin_lock(&sn->rpc_client_lock);
239         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
240                 if (clnt->cl_program->pipe_dir_name == NULL)
241                         continue;
242                 if (rpc_clnt_skip_event(clnt, event))
243                         continue;
244                 if (atomic_inc_not_zero(&clnt->cl_count) == 0)
245                         continue;
246                 spin_unlock(&sn->rpc_client_lock);
247                 return clnt;
248         }
249         spin_unlock(&sn->rpc_client_lock);
250         return NULL;
251 }
252
253 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
254                             void *ptr)
255 {
256         struct super_block *sb = ptr;
257         struct rpc_clnt *clnt;
258         int error = 0;
259
260         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
261                 error = __rpc_pipefs_event(clnt, event, sb);
262                 rpc_release_client(clnt);
263                 if (error)
264                         break;
265         }
266         return error;
267 }
268
269 static struct notifier_block rpc_clients_block = {
270         .notifier_call  = rpc_pipefs_event,
271         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
272 };
273
274 int rpc_clients_notifier_register(void)
275 {
276         return rpc_pipefs_notifier_register(&rpc_clients_block);
277 }
278
279 void rpc_clients_notifier_unregister(void)
280 {
281         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
282 }
283
284 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
285 {
286         clnt->cl_nodelen = strlen(nodename);
287         if (clnt->cl_nodelen > UNX_MAXNODENAME)
288                 clnt->cl_nodelen = UNX_MAXNODENAME;
289         memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
290 }
291
292 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
293 {
294         const struct rpc_program *program = args->program;
295         const struct rpc_version *version;
296         struct rpc_clnt         *clnt = NULL;
297         struct rpc_auth         *auth;
298         int err;
299
300         /* sanity check the name before trying to print it */
301         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
302                         program->name, args->servername, xprt);
303
304         err = rpciod_up();
305         if (err)
306                 goto out_no_rpciod;
307         err = -EINVAL;
308         if (!xprt)
309                 goto out_no_xprt;
310
311         if (args->version >= program->nrvers)
312                 goto out_err;
313         version = program->version[args->version];
314         if (version == NULL)
315                 goto out_err;
316
317         err = -ENOMEM;
318         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
319         if (!clnt)
320                 goto out_err;
321         clnt->cl_parent = clnt;
322
323         rcu_assign_pointer(clnt->cl_xprt, xprt);
324         clnt->cl_procinfo = version->procs;
325         clnt->cl_maxproc  = version->nrprocs;
326         clnt->cl_protname = program->name;
327         clnt->cl_prog     = args->prognumber ? : program->number;
328         clnt->cl_vers     = version->number;
329         clnt->cl_stats    = program->stats;
330         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
331         err = -ENOMEM;
332         if (clnt->cl_metrics == NULL)
333                 goto out_no_stats;
334         clnt->cl_program  = program;
335         INIT_LIST_HEAD(&clnt->cl_tasks);
336         spin_lock_init(&clnt->cl_lock);
337
338         if (!xprt_bound(xprt))
339                 clnt->cl_autobind = 1;
340
341         clnt->cl_timeout = xprt->timeout;
342         if (args->timeout != NULL) {
343                 memcpy(&clnt->cl_timeout_default, args->timeout,
344                                 sizeof(clnt->cl_timeout_default));
345                 clnt->cl_timeout = &clnt->cl_timeout_default;
346         }
347
348         clnt->cl_rtt = &clnt->cl_rtt_default;
349         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
350         clnt->cl_principal = NULL;
351         if (args->client_name) {
352                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
353                 if (!clnt->cl_principal)
354                         goto out_no_principal;
355         }
356
357         atomic_set(&clnt->cl_count, 1);
358
359         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
360         if (err < 0)
361                 goto out_no_path;
362
363         auth = rpcauth_create(args->authflavor, clnt);
364         if (IS_ERR(auth)) {
365                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
366                                 args->authflavor);
367                 err = PTR_ERR(auth);
368                 goto out_no_auth;
369         }
370
371         /* save the nodename */
372         rpc_clnt_set_nodename(clnt, utsname()->nodename);
373         rpc_register_client(clnt);
374         return clnt;
375
376 out_no_auth:
377         rpc_clnt_remove_pipedir(clnt);
378 out_no_path:
379         kfree(clnt->cl_principal);
380 out_no_principal:
381         rpc_free_iostats(clnt->cl_metrics);
382 out_no_stats:
383         kfree(clnt);
384 out_err:
385         xprt_put(xprt);
386 out_no_xprt:
387         rpciod_down();
388 out_no_rpciod:
389         return ERR_PTR(err);
390 }
391
392 /**
393  * rpc_create - create an RPC client and transport with one call
394  * @args: rpc_clnt create argument structure
395  *
396  * Creates and initializes an RPC transport and an RPC client.
397  *
398  * It can ping the server in order to determine if it is up, and to see if
399  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
400  * this behavior so asynchronous tasks can also use rpc_create.
401  */
402 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
403 {
404         struct rpc_xprt *xprt;
405         struct rpc_clnt *clnt;
406         struct xprt_create xprtargs = {
407                 .net = args->net,
408                 .ident = args->protocol,
409                 .srcaddr = args->saddress,
410                 .dstaddr = args->address,
411                 .addrlen = args->addrsize,
412                 .servername = args->servername,
413                 .bc_xprt = args->bc_xprt,
414         };
415         char servername[48];
416
417         /*
418          * If the caller chooses not to specify a hostname, whip
419          * up a string representation of the passed-in address.
420          */
421         if (xprtargs.servername == NULL) {
422                 struct sockaddr_un *sun =
423                                 (struct sockaddr_un *)args->address;
424                 struct sockaddr_in *sin =
425                                 (struct sockaddr_in *)args->address;
426                 struct sockaddr_in6 *sin6 =
427                                 (struct sockaddr_in6 *)args->address;
428
429                 servername[0] = '\0';
430                 switch (args->address->sa_family) {
431                 case AF_LOCAL:
432                         snprintf(servername, sizeof(servername), "%s",
433                                  sun->sun_path);
434                         break;
435                 case AF_INET:
436                         snprintf(servername, sizeof(servername), "%pI4",
437                                  &sin->sin_addr.s_addr);
438                         break;
439                 case AF_INET6:
440                         snprintf(servername, sizeof(servername), "%pI6",
441                                  &sin6->sin6_addr);
442                         break;
443                 default:
444                         /* caller wants default server name, but
445                          * address family isn't recognized. */
446                         return ERR_PTR(-EINVAL);
447                 }
448                 xprtargs.servername = servername;
449         }
450
451         xprt = xprt_create_transport(&xprtargs);
452         if (IS_ERR(xprt))
453                 return (struct rpc_clnt *)xprt;
454
455         /*
456          * By default, kernel RPC client connects from a reserved port.
457          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
458          * but it is always enabled for rpciod, which handles the connect
459          * operation.
460          */
461         xprt->resvport = 1;
462         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
463                 xprt->resvport = 0;
464
465         clnt = rpc_new_client(args, xprt);
466         if (IS_ERR(clnt))
467                 return clnt;
468
469         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
470                 int err = rpc_ping(clnt);
471                 if (err != 0) {
472                         rpc_shutdown_client(clnt);
473                         return ERR_PTR(err);
474                 }
475         }
476
477         clnt->cl_softrtry = 1;
478         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
479                 clnt->cl_softrtry = 0;
480
481         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
482                 clnt->cl_autobind = 1;
483         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
484                 clnt->cl_discrtry = 1;
485         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
486                 clnt->cl_chatty = 1;
487
488         return clnt;
489 }
490 EXPORT_SYMBOL_GPL(rpc_create);
491
492 /*
493  * This function clones the RPC client structure. It allows us to share the
494  * same transport while varying parameters such as the authentication
495  * flavour.
496  */
497 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
498                                            struct rpc_clnt *clnt)
499 {
500         struct rpc_xprt *xprt;
501         struct rpc_clnt *new;
502         int err;
503
504         err = -ENOMEM;
505         rcu_read_lock();
506         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
507         rcu_read_unlock();
508         if (xprt == NULL)
509                 goto out_err;
510         args->servername = xprt->servername;
511
512         new = rpc_new_client(args, xprt);
513         if (IS_ERR(new)) {
514                 err = PTR_ERR(new);
515                 goto out_put;
516         }
517
518         atomic_inc(&clnt->cl_count);
519         new->cl_parent = clnt;
520
521         /* Turn off autobind on clones */
522         new->cl_autobind = 0;
523         new->cl_softrtry = clnt->cl_softrtry;
524         new->cl_discrtry = clnt->cl_discrtry;
525         new->cl_chatty = clnt->cl_chatty;
526         return new;
527
528 out_put:
529         xprt_put(xprt);
530 out_err:
531         dprintk("RPC:       %s: returned error %d\n", __func__, err);
532         return ERR_PTR(err);
533 }
534
535 /**
536  * rpc_clone_client - Clone an RPC client structure
537  *
538  * @clnt: RPC client whose parameters are copied
539  *
540  * Returns a fresh RPC client or an ERR_PTR.
541  */
542 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
543 {
544         struct rpc_create_args args = {
545                 .program        = clnt->cl_program,
546                 .prognumber     = clnt->cl_prog,
547                 .version        = clnt->cl_vers,
548                 .authflavor     = clnt->cl_auth->au_flavor,
549                 .client_name    = clnt->cl_principal,
550         };
551         return __rpc_clone_client(&args, clnt);
552 }
553 EXPORT_SYMBOL_GPL(rpc_clone_client);
554
555 /**
556  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
557  *
558  * @clnt: RPC client whose parameters are copied
559  * @flavor: security flavor for new client
560  *
561  * Returns a fresh RPC client or an ERR_PTR.
562  */
563 struct rpc_clnt *
564 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
565 {
566         struct rpc_create_args args = {
567                 .program        = clnt->cl_program,
568                 .prognumber     = clnt->cl_prog,
569                 .version        = clnt->cl_vers,
570                 .authflavor     = flavor,
571                 .client_name    = clnt->cl_principal,
572         };
573         return __rpc_clone_client(&args, clnt);
574 }
575 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
576
577 /*
578  * Kill all tasks for the given client.
579  * XXX: kill their descendants as well?
580  */
581 void rpc_killall_tasks(struct rpc_clnt *clnt)
582 {
583         struct rpc_task *rovr;
584
585
586         if (list_empty(&clnt->cl_tasks))
587                 return;
588         dprintk("RPC:       killing all tasks for client %p\n", clnt);
589         /*
590          * Spin lock all_tasks to prevent changes...
591          */
592         spin_lock(&clnt->cl_lock);
593         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
594                 if (!RPC_IS_ACTIVATED(rovr))
595                         continue;
596                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
597                         rovr->tk_flags |= RPC_TASK_KILLED;
598                         rpc_exit(rovr, -EIO);
599                         if (RPC_IS_QUEUED(rovr))
600                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
601                                                         rovr);
602                 }
603         }
604         spin_unlock(&clnt->cl_lock);
605 }
606 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
607
608 /*
609  * Properly shut down an RPC client, terminating all outstanding
610  * requests.
611  */
612 void rpc_shutdown_client(struct rpc_clnt *clnt)
613 {
614         might_sleep();
615
616         dprintk_rcu("RPC:       shutting down %s client for %s\n",
617                         clnt->cl_protname,
618                         rcu_dereference(clnt->cl_xprt)->servername);
619
620         while (!list_empty(&clnt->cl_tasks)) {
621                 rpc_killall_tasks(clnt);
622                 wait_event_timeout(destroy_wait,
623                         list_empty(&clnt->cl_tasks), 1*HZ);
624         }
625
626         rpc_release_client(clnt);
627 }
628 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
629
630 /*
631  * Free an RPC client
632  */
633 static void
634 rpc_free_client(struct rpc_clnt *clnt)
635 {
636         dprintk_rcu("RPC:       destroying %s client for %s\n",
637                         clnt->cl_protname,
638                         rcu_dereference(clnt->cl_xprt)->servername);
639         if (clnt->cl_parent != clnt)
640                 rpc_release_client(clnt->cl_parent);
641         rpc_unregister_client(clnt);
642         rpc_clnt_remove_pipedir(clnt);
643         rpc_free_iostats(clnt->cl_metrics);
644         kfree(clnt->cl_principal);
645         clnt->cl_metrics = NULL;
646         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
647         rpciod_down();
648         kfree(clnt);
649 }
650
651 /*
652  * Free an RPC client
653  */
654 static void
655 rpc_free_auth(struct rpc_clnt *clnt)
656 {
657         if (clnt->cl_auth == NULL) {
658                 rpc_free_client(clnt);
659                 return;
660         }
661
662         /*
663          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
664          *       release remaining GSS contexts. This mechanism ensures
665          *       that it can do so safely.
666          */
667         atomic_inc(&clnt->cl_count);
668         rpcauth_release(clnt->cl_auth);
669         clnt->cl_auth = NULL;
670         if (atomic_dec_and_test(&clnt->cl_count))
671                 rpc_free_client(clnt);
672 }
673
674 /*
675  * Release reference to the RPC client
676  */
677 void
678 rpc_release_client(struct rpc_clnt *clnt)
679 {
680         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
681
682         if (list_empty(&clnt->cl_tasks))
683                 wake_up(&destroy_wait);
684         if (atomic_dec_and_test(&clnt->cl_count))
685                 rpc_free_auth(clnt);
686 }
687
688 /**
689  * rpc_bind_new_program - bind a new RPC program to an existing client
690  * @old: old rpc_client
691  * @program: rpc program to set
692  * @vers: rpc program version
693  *
694  * Clones the rpc client and sets up a new RPC program. This is mainly
695  * of use for enabling different RPC programs to share the same transport.
696  * The Sun NFSv2/v3 ACL protocol can do this.
697  */
698 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
699                                       const struct rpc_program *program,
700                                       u32 vers)
701 {
702         struct rpc_create_args args = {
703                 .program        = program,
704                 .prognumber     = program->number,
705                 .version        = vers,
706                 .authflavor     = old->cl_auth->au_flavor,
707                 .client_name    = old->cl_principal,
708         };
709         struct rpc_clnt *clnt;
710         int err;
711
712         clnt = __rpc_clone_client(&args, old);
713         if (IS_ERR(clnt))
714                 goto out;
715         err = rpc_ping(clnt);
716         if (err != 0) {
717                 rpc_shutdown_client(clnt);
718                 clnt = ERR_PTR(err);
719         }
720 out:
721         return clnt;
722 }
723 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
724
725 void rpc_task_release_client(struct rpc_task *task)
726 {
727         struct rpc_clnt *clnt = task->tk_client;
728
729         if (clnt != NULL) {
730                 /* Remove from client task list */
731                 spin_lock(&clnt->cl_lock);
732                 list_del(&task->tk_task);
733                 spin_unlock(&clnt->cl_lock);
734                 task->tk_client = NULL;
735
736                 rpc_release_client(clnt);
737         }
738 }
739
740 static
741 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
742 {
743         if (clnt != NULL) {
744                 rpc_task_release_client(task);
745                 task->tk_client = clnt;
746                 atomic_inc(&clnt->cl_count);
747                 if (clnt->cl_softrtry)
748                         task->tk_flags |= RPC_TASK_SOFT;
749                 if (sk_memalloc_socks()) {
750                         struct rpc_xprt *xprt;
751
752                         rcu_read_lock();
753                         xprt = rcu_dereference(clnt->cl_xprt);
754                         if (xprt->swapper)
755                                 task->tk_flags |= RPC_TASK_SWAPPER;
756                         rcu_read_unlock();
757                 }
758                 /* Add to the client's list of all tasks */
759                 spin_lock(&clnt->cl_lock);
760                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
761                 spin_unlock(&clnt->cl_lock);
762         }
763 }
764
765 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
766 {
767         rpc_task_release_client(task);
768         rpc_task_set_client(task, clnt);
769 }
770 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
771
772
773 static void
774 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
775 {
776         if (msg != NULL) {
777                 task->tk_msg.rpc_proc = msg->rpc_proc;
778                 task->tk_msg.rpc_argp = msg->rpc_argp;
779                 task->tk_msg.rpc_resp = msg->rpc_resp;
780                 if (msg->rpc_cred != NULL)
781                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
782         }
783 }
784
785 /*
786  * Default callback for async RPC calls
787  */
788 static void
789 rpc_default_callback(struct rpc_task *task, void *data)
790 {
791 }
792
793 static const struct rpc_call_ops rpc_default_ops = {
794         .rpc_call_done = rpc_default_callback,
795 };
796
797 /**
798  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
799  * @task_setup_data: pointer to task initialisation data
800  */
801 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
802 {
803         struct rpc_task *task;
804
805         task = rpc_new_task(task_setup_data);
806         if (IS_ERR(task))
807                 goto out;
808
809         rpc_task_set_client(task, task_setup_data->rpc_client);
810         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
811
812         if (task->tk_action == NULL)
813                 rpc_call_start(task);
814
815         atomic_inc(&task->tk_count);
816         rpc_execute(task);
817 out:
818         return task;
819 }
820 EXPORT_SYMBOL_GPL(rpc_run_task);
821
822 /**
823  * rpc_call_sync - Perform a synchronous RPC call
824  * @clnt: pointer to RPC client
825  * @msg: RPC call parameters
826  * @flags: RPC call flags
827  */
828 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
829 {
830         struct rpc_task *task;
831         struct rpc_task_setup task_setup_data = {
832                 .rpc_client = clnt,
833                 .rpc_message = msg,
834                 .callback_ops = &rpc_default_ops,
835                 .flags = flags,
836         };
837         int status;
838
839         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
840         if (flags & RPC_TASK_ASYNC) {
841                 rpc_release_calldata(task_setup_data.callback_ops,
842                         task_setup_data.callback_data);
843                 return -EINVAL;
844         }
845
846         task = rpc_run_task(&task_setup_data);
847         if (IS_ERR(task))
848                 return PTR_ERR(task);
849         status = task->tk_status;
850         rpc_put_task(task);
851         return status;
852 }
853 EXPORT_SYMBOL_GPL(rpc_call_sync);
854
855 /**
856  * rpc_call_async - Perform an asynchronous RPC call
857  * @clnt: pointer to RPC client
858  * @msg: RPC call parameters
859  * @flags: RPC call flags
860  * @tk_ops: RPC call ops
861  * @data: user call data
862  */
863 int
864 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
865                const struct rpc_call_ops *tk_ops, void *data)
866 {
867         struct rpc_task *task;
868         struct rpc_task_setup task_setup_data = {
869                 .rpc_client = clnt,
870                 .rpc_message = msg,
871                 .callback_ops = tk_ops,
872                 .callback_data = data,
873                 .flags = flags|RPC_TASK_ASYNC,
874         };
875
876         task = rpc_run_task(&task_setup_data);
877         if (IS_ERR(task))
878                 return PTR_ERR(task);
879         rpc_put_task(task);
880         return 0;
881 }
882 EXPORT_SYMBOL_GPL(rpc_call_async);
883
884 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
885 /**
886  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
887  * rpc_execute against it
888  * @req: RPC request
889  * @tk_ops: RPC call ops
890  */
891 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
892                                 const struct rpc_call_ops *tk_ops)
893 {
894         struct rpc_task *task;
895         struct xdr_buf *xbufp = &req->rq_snd_buf;
896         struct rpc_task_setup task_setup_data = {
897                 .callback_ops = tk_ops,
898         };
899
900         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
901         /*
902          * Create an rpc_task to send the data
903          */
904         task = rpc_new_task(&task_setup_data);
905         if (IS_ERR(task)) {
906                 xprt_free_bc_request(req);
907                 goto out;
908         }
909         task->tk_rqstp = req;
910
911         /*
912          * Set up the xdr_buf length.
913          * This also indicates that the buffer is XDR encoded already.
914          */
915         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
916                         xbufp->tail[0].iov_len;
917
918         task->tk_action = call_bc_transmit;
919         atomic_inc(&task->tk_count);
920         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
921         rpc_execute(task);
922
923 out:
924         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
925         return task;
926 }
927 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
928
929 void
930 rpc_call_start(struct rpc_task *task)
931 {
932         task->tk_action = call_start;
933 }
934 EXPORT_SYMBOL_GPL(rpc_call_start);
935
936 /**
937  * rpc_peeraddr - extract remote peer address from clnt's xprt
938  * @clnt: RPC client structure
939  * @buf: target buffer
940  * @bufsize: length of target buffer
941  *
942  * Returns the number of bytes that are actually in the stored address.
943  */
944 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
945 {
946         size_t bytes;
947         struct rpc_xprt *xprt;
948
949         rcu_read_lock();
950         xprt = rcu_dereference(clnt->cl_xprt);
951
952         bytes = xprt->addrlen;
953         if (bytes > bufsize)
954                 bytes = bufsize;
955         memcpy(buf, &xprt->addr, bytes);
956         rcu_read_unlock();
957
958         return bytes;
959 }
960 EXPORT_SYMBOL_GPL(rpc_peeraddr);
961
962 /**
963  * rpc_peeraddr2str - return remote peer address in printable format
964  * @clnt: RPC client structure
965  * @format: address format
966  *
967  * NB: the lifetime of the memory referenced by the returned pointer is
968  * the same as the rpc_xprt itself.  As long as the caller uses this
969  * pointer, it must hold the RCU read lock.
970  */
971 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
972                              enum rpc_display_format_t format)
973 {
974         struct rpc_xprt *xprt;
975
976         xprt = rcu_dereference(clnt->cl_xprt);
977
978         if (xprt->address_strings[format] != NULL)
979                 return xprt->address_strings[format];
980         else
981                 return "unprintable";
982 }
983 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
984
985 static const struct sockaddr_in rpc_inaddr_loopback = {
986         .sin_family             = AF_INET,
987         .sin_addr.s_addr        = htonl(INADDR_ANY),
988 };
989
990 static const struct sockaddr_in6 rpc_in6addr_loopback = {
991         .sin6_family            = AF_INET6,
992         .sin6_addr              = IN6ADDR_ANY_INIT,
993 };
994
995 /*
996  * Try a getsockname() on a connected datagram socket.  Using a
997  * connected datagram socket prevents leaving a socket in TIME_WAIT.
998  * This conserves the ephemeral port number space.
999  *
1000  * Returns zero and fills in "buf" if successful; otherwise, a
1001  * negative errno is returned.
1002  */
1003 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1004                         struct sockaddr *buf, int buflen)
1005 {
1006         struct socket *sock;
1007         int err;
1008
1009         err = __sock_create(net, sap->sa_family,
1010                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1011         if (err < 0) {
1012                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1013                 goto out;
1014         }
1015
1016         switch (sap->sa_family) {
1017         case AF_INET:
1018                 err = kernel_bind(sock,
1019                                 (struct sockaddr *)&rpc_inaddr_loopback,
1020                                 sizeof(rpc_inaddr_loopback));
1021                 break;
1022         case AF_INET6:
1023                 err = kernel_bind(sock,
1024                                 (struct sockaddr *)&rpc_in6addr_loopback,
1025                                 sizeof(rpc_in6addr_loopback));
1026                 break;
1027         default:
1028                 err = -EAFNOSUPPORT;
1029                 goto out;
1030         }
1031         if (err < 0) {
1032                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1033                 goto out_release;
1034         }
1035
1036         err = kernel_connect(sock, sap, salen, 0);
1037         if (err < 0) {
1038                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1039                 goto out_release;
1040         }
1041
1042         err = kernel_getsockname(sock, buf, &buflen);
1043         if (err < 0) {
1044                 dprintk("RPC:       getsockname failed (%d)\n", err);
1045                 goto out_release;
1046         }
1047
1048         err = 0;
1049         if (buf->sa_family == AF_INET6) {
1050                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1051                 sin6->sin6_scope_id = 0;
1052         }
1053         dprintk("RPC:       %s succeeded\n", __func__);
1054
1055 out_release:
1056         sock_release(sock);
1057 out:
1058         return err;
1059 }
1060
1061 /*
1062  * Scraping a connected socket failed, so we don't have a useable
1063  * local address.  Fallback: generate an address that will prevent
1064  * the server from calling us back.
1065  *
1066  * Returns zero and fills in "buf" if successful; otherwise, a
1067  * negative errno is returned.
1068  */
1069 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1070 {
1071         switch (family) {
1072         case AF_INET:
1073                 if (buflen < sizeof(rpc_inaddr_loopback))
1074                         return -EINVAL;
1075                 memcpy(buf, &rpc_inaddr_loopback,
1076                                 sizeof(rpc_inaddr_loopback));
1077                 break;
1078         case AF_INET6:
1079                 if (buflen < sizeof(rpc_in6addr_loopback))
1080                         return -EINVAL;
1081                 memcpy(buf, &rpc_in6addr_loopback,
1082                                 sizeof(rpc_in6addr_loopback));
1083         default:
1084                 dprintk("RPC:       %s: address family not supported\n",
1085                         __func__);
1086                 return -EAFNOSUPPORT;
1087         }
1088         dprintk("RPC:       %s: succeeded\n", __func__);
1089         return 0;
1090 }
1091
1092 /**
1093  * rpc_localaddr - discover local endpoint address for an RPC client
1094  * @clnt: RPC client structure
1095  * @buf: target buffer
1096  * @buflen: size of target buffer, in bytes
1097  *
1098  * Returns zero and fills in "buf" and "buflen" if successful;
1099  * otherwise, a negative errno is returned.
1100  *
1101  * This works even if the underlying transport is not currently connected,
1102  * or if the upper layer never previously provided a source address.
1103  *
1104  * The result of this function call is transient: multiple calls in
1105  * succession may give different results, depending on how local
1106  * networking configuration changes over time.
1107  */
1108 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1109 {
1110         struct sockaddr_storage address;
1111         struct sockaddr *sap = (struct sockaddr *)&address;
1112         struct rpc_xprt *xprt;
1113         struct net *net;
1114         size_t salen;
1115         int err;
1116
1117         rcu_read_lock();
1118         xprt = rcu_dereference(clnt->cl_xprt);
1119         salen = xprt->addrlen;
1120         memcpy(sap, &xprt->addr, salen);
1121         net = get_net(xprt->xprt_net);
1122         rcu_read_unlock();
1123
1124         rpc_set_port(sap, 0);
1125         err = rpc_sockname(net, sap, salen, buf, buflen);
1126         put_net(net);
1127         if (err != 0)
1128                 /* Couldn't discover local address, return ANYADDR */
1129                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1130         return 0;
1131 }
1132 EXPORT_SYMBOL_GPL(rpc_localaddr);
1133
1134 void
1135 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1136 {
1137         struct rpc_xprt *xprt;
1138
1139         rcu_read_lock();
1140         xprt = rcu_dereference(clnt->cl_xprt);
1141         if (xprt->ops->set_buffer_size)
1142                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1143         rcu_read_unlock();
1144 }
1145 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1146
1147 /**
1148  * rpc_protocol - Get transport protocol number for an RPC client
1149  * @clnt: RPC client to query
1150  *
1151  */
1152 int rpc_protocol(struct rpc_clnt *clnt)
1153 {
1154         int protocol;
1155
1156         rcu_read_lock();
1157         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1158         rcu_read_unlock();
1159         return protocol;
1160 }
1161 EXPORT_SYMBOL_GPL(rpc_protocol);
1162
1163 /**
1164  * rpc_net_ns - Get the network namespace for this RPC client
1165  * @clnt: RPC client to query
1166  *
1167  */
1168 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1169 {
1170         struct net *ret;
1171
1172         rcu_read_lock();
1173         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1174         rcu_read_unlock();
1175         return ret;
1176 }
1177 EXPORT_SYMBOL_GPL(rpc_net_ns);
1178
1179 /**
1180  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1181  * @clnt: RPC client to query
1182  *
1183  * For stream transports, this is one RPC record fragment (see RFC
1184  * 1831), as we don't support multi-record requests yet.  For datagram
1185  * transports, this is the size of an IP packet minus the IP, UDP, and
1186  * RPC header sizes.
1187  */
1188 size_t rpc_max_payload(struct rpc_clnt *clnt)
1189 {
1190         size_t ret;
1191
1192         rcu_read_lock();
1193         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1194         rcu_read_unlock();
1195         return ret;
1196 }
1197 EXPORT_SYMBOL_GPL(rpc_max_payload);
1198
1199 /**
1200  * rpc_get_timeout - Get timeout for transport in units of HZ
1201  * @clnt: RPC client to query
1202  */
1203 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1204 {
1205         unsigned long ret;
1206
1207         rcu_read_lock();
1208         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1209         rcu_read_unlock();
1210         return ret;
1211 }
1212 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1213
1214 /**
1215  * rpc_force_rebind - force transport to check that remote port is unchanged
1216  * @clnt: client to rebind
1217  *
1218  */
1219 void rpc_force_rebind(struct rpc_clnt *clnt)
1220 {
1221         if (clnt->cl_autobind) {
1222                 rcu_read_lock();
1223                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1224                 rcu_read_unlock();
1225         }
1226 }
1227 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1228
1229 /*
1230  * Restart an (async) RPC call from the call_prepare state.
1231  * Usually called from within the exit handler.
1232  */
1233 int
1234 rpc_restart_call_prepare(struct rpc_task *task)
1235 {
1236         if (RPC_ASSASSINATED(task))
1237                 return 0;
1238         task->tk_action = call_start;
1239         if (task->tk_ops->rpc_call_prepare != NULL)
1240                 task->tk_action = rpc_prepare_task;
1241         return 1;
1242 }
1243 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1244
1245 /*
1246  * Restart an (async) RPC call. Usually called from within the
1247  * exit handler.
1248  */
1249 int
1250 rpc_restart_call(struct rpc_task *task)
1251 {
1252         if (RPC_ASSASSINATED(task))
1253                 return 0;
1254         task->tk_action = call_start;
1255         return 1;
1256 }
1257 EXPORT_SYMBOL_GPL(rpc_restart_call);
1258
1259 #ifdef RPC_DEBUG
1260 static const char *rpc_proc_name(const struct rpc_task *task)
1261 {
1262         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1263
1264         if (proc) {
1265                 if (proc->p_name)
1266                         return proc->p_name;
1267                 else
1268                         return "NULL";
1269         } else
1270                 return "no proc";
1271 }
1272 #endif
1273
1274 /*
1275  * 0.  Initial state
1276  *
1277  *     Other FSM states can be visited zero or more times, but
1278  *     this state is visited exactly once for each RPC.
1279  */
1280 static void
1281 call_start(struct rpc_task *task)
1282 {
1283         struct rpc_clnt *clnt = task->tk_client;
1284
1285         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1286                         clnt->cl_protname, clnt->cl_vers,
1287                         rpc_proc_name(task),
1288                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1289
1290         /* Increment call count */
1291         task->tk_msg.rpc_proc->p_count++;
1292         clnt->cl_stats->rpccnt++;
1293         task->tk_action = call_reserve;
1294 }
1295
1296 /*
1297  * 1.   Reserve an RPC call slot
1298  */
1299 static void
1300 call_reserve(struct rpc_task *task)
1301 {
1302         dprint_status(task);
1303
1304         task->tk_status  = 0;
1305         task->tk_action  = call_reserveresult;
1306         xprt_reserve(task);
1307 }
1308
1309 /*
1310  * 1b.  Grok the result of xprt_reserve()
1311  */
1312 static void
1313 call_reserveresult(struct rpc_task *task)
1314 {
1315         int status = task->tk_status;
1316
1317         dprint_status(task);
1318
1319         /*
1320          * After a call to xprt_reserve(), we must have either
1321          * a request slot or else an error status.
1322          */
1323         task->tk_status = 0;
1324         if (status >= 0) {
1325                 if (task->tk_rqstp) {
1326                         task->tk_action = call_refresh;
1327                         return;
1328                 }
1329
1330                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1331                                 __func__, status);
1332                 rpc_exit(task, -EIO);
1333                 return;
1334         }
1335
1336         /*
1337          * Even though there was an error, we may have acquired
1338          * a request slot somehow.  Make sure not to leak it.
1339          */
1340         if (task->tk_rqstp) {
1341                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1342                                 __func__, status);
1343                 xprt_release(task);
1344         }
1345
1346         switch (status) {
1347         case -ENOMEM:
1348                 rpc_delay(task, HZ >> 2);
1349         case -EAGAIN:   /* woken up; retry */
1350                 task->tk_action = call_reserve;
1351                 return;
1352         case -EIO:      /* probably a shutdown */
1353                 break;
1354         default:
1355                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1356                                 __func__, status);
1357                 break;
1358         }
1359         rpc_exit(task, status);
1360 }
1361
1362 /*
1363  * 2.   Bind and/or refresh the credentials
1364  */
1365 static void
1366 call_refresh(struct rpc_task *task)
1367 {
1368         dprint_status(task);
1369
1370         task->tk_action = call_refreshresult;
1371         task->tk_status = 0;
1372         task->tk_client->cl_stats->rpcauthrefresh++;
1373         rpcauth_refreshcred(task);
1374 }
1375
1376 /*
1377  * 2a.  Process the results of a credential refresh
1378  */
1379 static void
1380 call_refreshresult(struct rpc_task *task)
1381 {
1382         int status = task->tk_status;
1383
1384         dprint_status(task);
1385
1386         task->tk_status = 0;
1387         task->tk_action = call_refresh;
1388         switch (status) {
1389         case 0:
1390                 if (rpcauth_uptodatecred(task))
1391                         task->tk_action = call_allocate;
1392                 return;
1393         case -ETIMEDOUT:
1394                 rpc_delay(task, 3*HZ);
1395         case -EKEYEXPIRED:
1396         case -EAGAIN:
1397                 status = -EACCES;
1398                 if (!task->tk_cred_retry)
1399                         break;
1400                 task->tk_cred_retry--;
1401                 dprintk("RPC: %5u %s: retry refresh creds\n",
1402                                 task->tk_pid, __func__);
1403                 return;
1404         }
1405         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1406                                 task->tk_pid, __func__, status);
1407         rpc_exit(task, status);
1408 }
1409
1410 /*
1411  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1412  *      (Note: buffer memory is freed in xprt_release).
1413  */
1414 static void
1415 call_allocate(struct rpc_task *task)
1416 {
1417         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1418         struct rpc_rqst *req = task->tk_rqstp;
1419         struct rpc_xprt *xprt = req->rq_xprt;
1420         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1421
1422         dprint_status(task);
1423
1424         task->tk_status = 0;
1425         task->tk_action = call_bind;
1426
1427         if (req->rq_buffer)
1428                 return;
1429
1430         if (proc->p_proc != 0) {
1431                 BUG_ON(proc->p_arglen == 0);
1432                 if (proc->p_decode != NULL)
1433                         BUG_ON(proc->p_replen == 0);
1434         }
1435
1436         /*
1437          * Calculate the size (in quads) of the RPC call
1438          * and reply headers, and convert both values
1439          * to byte sizes.
1440          */
1441         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1442         req->rq_callsize <<= 2;
1443         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1444         req->rq_rcvsize <<= 2;
1445
1446         req->rq_buffer = xprt->ops->buf_alloc(task,
1447                                         req->rq_callsize + req->rq_rcvsize);
1448         if (req->rq_buffer != NULL)
1449                 return;
1450
1451         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1452
1453         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1454                 task->tk_action = call_allocate;
1455                 rpc_delay(task, HZ>>4);
1456                 return;
1457         }
1458
1459         rpc_exit(task, -ERESTARTSYS);
1460 }
1461
1462 static inline int
1463 rpc_task_need_encode(struct rpc_task *task)
1464 {
1465         return task->tk_rqstp->rq_snd_buf.len == 0;
1466 }
1467
1468 static inline void
1469 rpc_task_force_reencode(struct rpc_task *task)
1470 {
1471         task->tk_rqstp->rq_snd_buf.len = 0;
1472         task->tk_rqstp->rq_bytes_sent = 0;
1473 }
1474
1475 static inline void
1476 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1477 {
1478         buf->head[0].iov_base = start;
1479         buf->head[0].iov_len = len;
1480         buf->tail[0].iov_len = 0;
1481         buf->page_len = 0;
1482         buf->flags = 0;
1483         buf->len = 0;
1484         buf->buflen = len;
1485 }
1486
1487 /*
1488  * 3.   Encode arguments of an RPC call
1489  */
1490 static void
1491 rpc_xdr_encode(struct rpc_task *task)
1492 {
1493         struct rpc_rqst *req = task->tk_rqstp;
1494         kxdreproc_t     encode;
1495         __be32          *p;
1496
1497         dprint_status(task);
1498
1499         rpc_xdr_buf_init(&req->rq_snd_buf,
1500                          req->rq_buffer,
1501                          req->rq_callsize);
1502         rpc_xdr_buf_init(&req->rq_rcv_buf,
1503                          (char *)req->rq_buffer + req->rq_callsize,
1504                          req->rq_rcvsize);
1505
1506         p = rpc_encode_header(task);
1507         if (p == NULL) {
1508                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1509                 rpc_exit(task, -EIO);
1510                 return;
1511         }
1512
1513         encode = task->tk_msg.rpc_proc->p_encode;
1514         if (encode == NULL)
1515                 return;
1516
1517         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1518                         task->tk_msg.rpc_argp);
1519 }
1520
1521 /*
1522  * 4.   Get the server port number if not yet set
1523  */
1524 static void
1525 call_bind(struct rpc_task *task)
1526 {
1527         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1528
1529         dprint_status(task);
1530
1531         task->tk_action = call_connect;
1532         if (!xprt_bound(xprt)) {
1533                 task->tk_action = call_bind_status;
1534                 task->tk_timeout = xprt->bind_timeout;
1535                 xprt->ops->rpcbind(task);
1536         }
1537 }
1538
1539 /*
1540  * 4a.  Sort out bind result
1541  */
1542 static void
1543 call_bind_status(struct rpc_task *task)
1544 {
1545         int status = -EIO;
1546
1547         if (task->tk_status >= 0) {
1548                 dprint_status(task);
1549                 task->tk_status = 0;
1550                 task->tk_action = call_connect;
1551                 return;
1552         }
1553
1554         trace_rpc_bind_status(task);
1555         switch (task->tk_status) {
1556         case -ENOMEM:
1557                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1558                 rpc_delay(task, HZ >> 2);
1559                 goto retry_timeout;
1560         case -EACCES:
1561                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1562                                 "unavailable\n", task->tk_pid);
1563                 /* fail immediately if this is an RPC ping */
1564                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1565                         status = -EOPNOTSUPP;
1566                         break;
1567                 }
1568                 if (task->tk_rebind_retry == 0)
1569                         break;
1570                 task->tk_rebind_retry--;
1571                 rpc_delay(task, 3*HZ);
1572                 goto retry_timeout;
1573         case -ETIMEDOUT:
1574                 dprintk("RPC: %5u rpcbind request timed out\n",
1575                                 task->tk_pid);
1576                 goto retry_timeout;
1577         case -EPFNOSUPPORT:
1578                 /* server doesn't support any rpcbind version we know of */
1579                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1580                                 task->tk_pid);
1581                 break;
1582         case -EPROTONOSUPPORT:
1583                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1584                                 task->tk_pid);
1585                 task->tk_status = 0;
1586                 task->tk_action = call_bind;
1587                 return;
1588         case -ECONNREFUSED:             /* connection problems */
1589         case -ECONNRESET:
1590         case -ENOTCONN:
1591         case -EHOSTDOWN:
1592         case -EHOSTUNREACH:
1593         case -ENETUNREACH:
1594         case -EPIPE:
1595                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1596                                 task->tk_pid, task->tk_status);
1597                 if (!RPC_IS_SOFTCONN(task)) {
1598                         rpc_delay(task, 5*HZ);
1599                         goto retry_timeout;
1600                 }
1601                 status = task->tk_status;
1602                 break;
1603         default:
1604                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1605                                 task->tk_pid, -task->tk_status);
1606         }
1607
1608         rpc_exit(task, status);
1609         return;
1610
1611 retry_timeout:
1612         task->tk_action = call_timeout;
1613 }
1614
1615 /*
1616  * 4b.  Connect to the RPC server
1617  */
1618 static void
1619 call_connect(struct rpc_task *task)
1620 {
1621         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1622
1623         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1624                         task->tk_pid, xprt,
1625                         (xprt_connected(xprt) ? "is" : "is not"));
1626
1627         task->tk_action = call_transmit;
1628         if (!xprt_connected(xprt)) {
1629                 task->tk_action = call_connect_status;
1630                 if (task->tk_status < 0)
1631                         return;
1632                 xprt_connect(task);
1633         }
1634 }
1635
1636 /*
1637  * 4c.  Sort out connect result
1638  */
1639 static void
1640 call_connect_status(struct rpc_task *task)
1641 {
1642         struct rpc_clnt *clnt = task->tk_client;
1643         int status = task->tk_status;
1644
1645         dprint_status(task);
1646
1647         task->tk_status = 0;
1648         if (status >= 0 || status == -EAGAIN) {
1649                 clnt->cl_stats->netreconn++;
1650                 task->tk_action = call_transmit;
1651                 return;
1652         }
1653
1654         trace_rpc_connect_status(task, status);
1655         switch (status) {
1656                 /* if soft mounted, test if we've timed out */
1657         case -ETIMEDOUT:
1658                 task->tk_action = call_timeout;
1659                 break;
1660         default:
1661                 rpc_exit(task, -EIO);
1662         }
1663 }
1664
1665 /*
1666  * 5.   Transmit the RPC request, and wait for reply
1667  */
1668 static void
1669 call_transmit(struct rpc_task *task)
1670 {
1671         dprint_status(task);
1672
1673         task->tk_action = call_status;
1674         if (task->tk_status < 0)
1675                 return;
1676         task->tk_status = xprt_prepare_transmit(task);
1677         if (task->tk_status != 0)
1678                 return;
1679         task->tk_action = call_transmit_status;
1680         /* Encode here so that rpcsec_gss can use correct sequence number. */
1681         if (rpc_task_need_encode(task)) {
1682                 rpc_xdr_encode(task);
1683                 /* Did the encode result in an error condition? */
1684                 if (task->tk_status != 0) {
1685                         /* Was the error nonfatal? */
1686                         if (task->tk_status == -EAGAIN)
1687                                 rpc_delay(task, HZ >> 4);
1688                         else
1689                                 rpc_exit(task, task->tk_status);
1690                         return;
1691                 }
1692         }
1693         xprt_transmit(task);
1694         if (task->tk_status < 0)
1695                 return;
1696         /*
1697          * On success, ensure that we call xprt_end_transmit() before sleeping
1698          * in order to allow access to the socket to other RPC requests.
1699          */
1700         call_transmit_status(task);
1701         if (rpc_reply_expected(task))
1702                 return;
1703         task->tk_action = rpc_exit_task;
1704         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1705 }
1706
1707 /*
1708  * 5a.  Handle cleanup after a transmission
1709  */
1710 static void
1711 call_transmit_status(struct rpc_task *task)
1712 {
1713         task->tk_action = call_status;
1714
1715         /*
1716          * Common case: success.  Force the compiler to put this
1717          * test first.
1718          */
1719         if (task->tk_status == 0) {
1720                 xprt_end_transmit(task);
1721                 rpc_task_force_reencode(task);
1722                 return;
1723         }
1724
1725         switch (task->tk_status) {
1726         case -EAGAIN:
1727                 break;
1728         default:
1729                 dprint_status(task);
1730                 xprt_end_transmit(task);
1731                 rpc_task_force_reencode(task);
1732                 break;
1733                 /*
1734                  * Special cases: if we've been waiting on the
1735                  * socket's write_space() callback, or if the
1736                  * socket just returned a connection error,
1737                  * then hold onto the transport lock.
1738                  */
1739         case -ECONNREFUSED:
1740         case -EHOSTDOWN:
1741         case -EHOSTUNREACH:
1742         case -ENETUNREACH:
1743                 if (RPC_IS_SOFTCONN(task)) {
1744                         xprt_end_transmit(task);
1745                         rpc_exit(task, task->tk_status);
1746                         break;
1747                 }
1748         case -ECONNRESET:
1749         case -ENOTCONN:
1750         case -EPIPE:
1751                 rpc_task_force_reencode(task);
1752         }
1753 }
1754
1755 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1756 /*
1757  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1758  * addition, disconnect on connectivity errors.
1759  */
1760 static void
1761 call_bc_transmit(struct rpc_task *task)
1762 {
1763         struct rpc_rqst *req = task->tk_rqstp;
1764
1765         task->tk_status = xprt_prepare_transmit(task);
1766         if (task->tk_status == -EAGAIN) {
1767                 /*
1768                  * Could not reserve the transport. Try again after the
1769                  * transport is released.
1770                  */
1771                 task->tk_status = 0;
1772                 task->tk_action = call_bc_transmit;
1773                 return;
1774         }
1775
1776         task->tk_action = rpc_exit_task;
1777         if (task->tk_status < 0) {
1778                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1779                         "error: %d\n", task->tk_status);
1780                 return;
1781         }
1782
1783         xprt_transmit(task);
1784         xprt_end_transmit(task);
1785         dprint_status(task);
1786         switch (task->tk_status) {
1787         case 0:
1788                 /* Success */
1789                 break;
1790         case -EHOSTDOWN:
1791         case -EHOSTUNREACH:
1792         case -ENETUNREACH:
1793         case -ETIMEDOUT:
1794                 /*
1795                  * Problem reaching the server.  Disconnect and let the
1796                  * forechannel reestablish the connection.  The server will
1797                  * have to retransmit the backchannel request and we'll
1798                  * reprocess it.  Since these ops are idempotent, there's no
1799                  * need to cache our reply at this time.
1800                  */
1801                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1802                         "error: %d\n", task->tk_status);
1803                 xprt_conditional_disconnect(req->rq_xprt,
1804                         req->rq_connect_cookie);
1805                 break;
1806         default:
1807                 /*
1808                  * We were unable to reply and will have to drop the
1809                  * request.  The server should reconnect and retransmit.
1810                  */
1811                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1812                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1813                         "error: %d\n", task->tk_status);
1814                 break;
1815         }
1816         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1817 }
1818 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1819
1820 /*
1821  * 6.   Sort out the RPC call status
1822  */
1823 static void
1824 call_status(struct rpc_task *task)
1825 {
1826         struct rpc_clnt *clnt = task->tk_client;
1827         struct rpc_rqst *req = task->tk_rqstp;
1828         int             status;
1829
1830         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1831                 task->tk_status = req->rq_reply_bytes_recvd;
1832
1833         dprint_status(task);
1834
1835         status = task->tk_status;
1836         if (status >= 0) {
1837                 task->tk_action = call_decode;
1838                 return;
1839         }
1840
1841         trace_rpc_call_status(task);
1842         task->tk_status = 0;
1843         switch(status) {
1844         case -EHOSTDOWN:
1845         case -EHOSTUNREACH:
1846         case -ENETUNREACH:
1847                 /*
1848                  * Delay any retries for 3 seconds, then handle as if it
1849                  * were a timeout.
1850                  */
1851                 rpc_delay(task, 3*HZ);
1852         case -ETIMEDOUT:
1853                 task->tk_action = call_timeout;
1854                 if (task->tk_client->cl_discrtry)
1855                         xprt_conditional_disconnect(req->rq_xprt,
1856                                         req->rq_connect_cookie);
1857                 break;
1858         case -ECONNRESET:
1859         case -ECONNREFUSED:
1860                 rpc_force_rebind(clnt);
1861                 rpc_delay(task, 3*HZ);
1862         case -EPIPE:
1863         case -ENOTCONN:
1864                 task->tk_action = call_bind;
1865                 break;
1866         case -EAGAIN:
1867                 task->tk_action = call_transmit;
1868                 break;
1869         case -EIO:
1870                 /* shutdown or soft timeout */
1871                 rpc_exit(task, status);
1872                 break;
1873         default:
1874                 if (clnt->cl_chatty)
1875                         printk("%s: RPC call returned error %d\n",
1876                                clnt->cl_protname, -status);
1877                 rpc_exit(task, status);
1878         }
1879 }
1880
1881 /*
1882  * 6a.  Handle RPC timeout
1883  *      We do not release the request slot, so we keep using the
1884  *      same XID for all retransmits.
1885  */
1886 static void
1887 call_timeout(struct rpc_task *task)
1888 {
1889         struct rpc_clnt *clnt = task->tk_client;
1890
1891         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1892                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1893                 goto retry;
1894         }
1895
1896         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1897         task->tk_timeouts++;
1898
1899         if (RPC_IS_SOFTCONN(task)) {
1900                 rpc_exit(task, -ETIMEDOUT);
1901                 return;
1902         }
1903         if (RPC_IS_SOFT(task)) {
1904                 if (clnt->cl_chatty) {
1905                         rcu_read_lock();
1906                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1907                                 clnt->cl_protname,
1908                                 rcu_dereference(clnt->cl_xprt)->servername);
1909                         rcu_read_unlock();
1910                 }
1911                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1912                         rpc_exit(task, -ETIMEDOUT);
1913                 else
1914                         rpc_exit(task, -EIO);
1915                 return;
1916         }
1917
1918         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1919                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1920                 if (clnt->cl_chatty) {
1921                         rcu_read_lock();
1922                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1923                         clnt->cl_protname,
1924                         rcu_dereference(clnt->cl_xprt)->servername);
1925                         rcu_read_unlock();
1926                 }
1927         }
1928         rpc_force_rebind(clnt);
1929         /*
1930          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1931          * event? RFC2203 requires the server to drop all such requests.
1932          */
1933         rpcauth_invalcred(task);
1934
1935 retry:
1936         clnt->cl_stats->rpcretrans++;
1937         task->tk_action = call_bind;
1938         task->tk_status = 0;
1939 }
1940
1941 /*
1942  * 7.   Decode the RPC reply
1943  */
1944 static void
1945 call_decode(struct rpc_task *task)
1946 {
1947         struct rpc_clnt *clnt = task->tk_client;
1948         struct rpc_rqst *req = task->tk_rqstp;
1949         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1950         __be32          *p;
1951
1952         dprint_status(task);
1953
1954         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1955                 if (clnt->cl_chatty) {
1956                         rcu_read_lock();
1957                         printk(KERN_NOTICE "%s: server %s OK\n",
1958                                 clnt->cl_protname,
1959                                 rcu_dereference(clnt->cl_xprt)->servername);
1960                         rcu_read_unlock();
1961                 }
1962                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1963         }
1964
1965         /*
1966          * Ensure that we see all writes made by xprt_complete_rqst()
1967          * before it changed req->rq_reply_bytes_recvd.
1968          */
1969         smp_rmb();
1970         req->rq_rcv_buf.len = req->rq_private_buf.len;
1971
1972         /* Check that the softirq receive buffer is valid */
1973         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1974                                 sizeof(req->rq_rcv_buf)) != 0);
1975
1976         if (req->rq_rcv_buf.len < 12) {
1977                 if (!RPC_IS_SOFT(task)) {
1978                         task->tk_action = call_bind;
1979                         clnt->cl_stats->rpcretrans++;
1980                         goto out_retry;
1981                 }
1982                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1983                                 clnt->cl_protname, task->tk_status);
1984                 task->tk_action = call_timeout;
1985                 goto out_retry;
1986         }
1987
1988         p = rpc_verify_header(task);
1989         if (IS_ERR(p)) {
1990                 if (p == ERR_PTR(-EAGAIN))
1991                         goto out_retry;
1992                 return;
1993         }
1994
1995         task->tk_action = rpc_exit_task;
1996
1997         if (decode) {
1998                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1999                                                       task->tk_msg.rpc_resp);
2000         }
2001         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2002                         task->tk_status);
2003         return;
2004 out_retry:
2005         task->tk_status = 0;
2006         /* Note: rpc_verify_header() may have freed the RPC slot */
2007         if (task->tk_rqstp == req) {
2008                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2009                 if (task->tk_client->cl_discrtry)
2010                         xprt_conditional_disconnect(req->rq_xprt,
2011                                         req->rq_connect_cookie);
2012         }
2013 }
2014
2015 static __be32 *
2016 rpc_encode_header(struct rpc_task *task)
2017 {
2018         struct rpc_clnt *clnt = task->tk_client;
2019         struct rpc_rqst *req = task->tk_rqstp;
2020         __be32          *p = req->rq_svec[0].iov_base;
2021
2022         /* FIXME: check buffer size? */
2023
2024         p = xprt_skip_transport_header(req->rq_xprt, p);
2025         *p++ = req->rq_xid;             /* XID */
2026         *p++ = htonl(RPC_CALL);         /* CALL */
2027         *p++ = htonl(RPC_VERSION);      /* RPC version */
2028         *p++ = htonl(clnt->cl_prog);    /* program number */
2029         *p++ = htonl(clnt->cl_vers);    /* program version */
2030         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2031         p = rpcauth_marshcred(task, p);
2032         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2033         return p;
2034 }
2035
2036 static __be32 *
2037 rpc_verify_header(struct rpc_task *task)
2038 {
2039         struct rpc_clnt *clnt = task->tk_client;
2040         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2041         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2042         __be32  *p = iov->iov_base;
2043         u32 n;
2044         int error = -EACCES;
2045
2046         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2047                 /* RFC-1014 says that the representation of XDR data must be a
2048                  * multiple of four bytes
2049                  * - if it isn't pointer subtraction in the NFS client may give
2050                  *   undefined results
2051                  */
2052                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2053                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2054                        task->tk_rqstp->rq_rcv_buf.len);
2055                 goto out_eio;
2056         }
2057         if ((len -= 3) < 0)
2058                 goto out_overflow;
2059
2060         p += 1; /* skip XID */
2061         if ((n = ntohl(*p++)) != RPC_REPLY) {
2062                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2063                         task->tk_pid, __func__, n);
2064                 goto out_garbage;
2065         }
2066
2067         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2068                 if (--len < 0)
2069                         goto out_overflow;
2070                 switch ((n = ntohl(*p++))) {
2071                 case RPC_AUTH_ERROR:
2072                         break;
2073                 case RPC_MISMATCH:
2074                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2075                                 task->tk_pid, __func__);
2076                         error = -EPROTONOSUPPORT;
2077                         goto out_err;
2078                 default:
2079                         dprintk("RPC: %5u %s: RPC call rejected, "
2080                                 "unknown error: %x\n",
2081                                 task->tk_pid, __func__, n);
2082                         goto out_eio;
2083                 }
2084                 if (--len < 0)
2085                         goto out_overflow;
2086                 switch ((n = ntohl(*p++))) {
2087                 case RPC_AUTH_REJECTEDCRED:
2088                 case RPC_AUTH_REJECTEDVERF:
2089                 case RPCSEC_GSS_CREDPROBLEM:
2090                 case RPCSEC_GSS_CTXPROBLEM:
2091                         if (!task->tk_cred_retry)
2092                                 break;
2093                         task->tk_cred_retry--;
2094                         dprintk("RPC: %5u %s: retry stale creds\n",
2095                                         task->tk_pid, __func__);
2096                         rpcauth_invalcred(task);
2097                         /* Ensure we obtain a new XID! */
2098                         xprt_release(task);
2099                         task->tk_action = call_reserve;
2100                         goto out_retry;
2101                 case RPC_AUTH_BADCRED:
2102                 case RPC_AUTH_BADVERF:
2103                         /* possibly garbled cred/verf? */
2104                         if (!task->tk_garb_retry)
2105                                 break;
2106                         task->tk_garb_retry--;
2107                         dprintk("RPC: %5u %s: retry garbled creds\n",
2108                                         task->tk_pid, __func__);
2109                         task->tk_action = call_bind;
2110                         goto out_retry;
2111                 case RPC_AUTH_TOOWEAK:
2112                         rcu_read_lock();
2113                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2114                                "authentication.\n",
2115                                rcu_dereference(clnt->cl_xprt)->servername);
2116                         rcu_read_unlock();
2117                         break;
2118                 default:
2119                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2120                                         task->tk_pid, __func__, n);
2121                         error = -EIO;
2122                 }
2123                 dprintk("RPC: %5u %s: call rejected %d\n",
2124                                 task->tk_pid, __func__, n);
2125                 goto out_err;
2126         }
2127         if (!(p = rpcauth_checkverf(task, p))) {
2128                 dprintk("RPC: %5u %s: auth check failed\n",
2129                                 task->tk_pid, __func__);
2130                 goto out_garbage;               /* bad verifier, retry */
2131         }
2132         len = p - (__be32 *)iov->iov_base - 1;
2133         if (len < 0)
2134                 goto out_overflow;
2135         switch ((n = ntohl(*p++))) {
2136         case RPC_SUCCESS:
2137                 return p;
2138         case RPC_PROG_UNAVAIL:
2139                 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2140                                 "by server %s\n", task->tk_pid, __func__,
2141                                 (unsigned int)clnt->cl_prog,
2142                                 rcu_dereference(clnt->cl_xprt)->servername);
2143                 error = -EPFNOSUPPORT;
2144                 goto out_err;
2145         case RPC_PROG_MISMATCH:
2146                 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2147                                 "by server %s\n", task->tk_pid, __func__,
2148                                 (unsigned int)clnt->cl_prog,
2149                                 (unsigned int)clnt->cl_vers,
2150                                 rcu_dereference(clnt->cl_xprt)->servername);
2151                 error = -EPROTONOSUPPORT;
2152                 goto out_err;
2153         case RPC_PROC_UNAVAIL:
2154                 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2155                                 "version %u on server %s\n",
2156                                 task->tk_pid, __func__,
2157                                 rpc_proc_name(task),
2158                                 clnt->cl_prog, clnt->cl_vers,
2159                                 rcu_dereference(clnt->cl_xprt)->servername);
2160                 error = -EOPNOTSUPP;
2161                 goto out_err;
2162         case RPC_GARBAGE_ARGS:
2163                 dprintk("RPC: %5u %s: server saw garbage\n",
2164                                 task->tk_pid, __func__);
2165                 break;                  /* retry */
2166         default:
2167                 dprintk("RPC: %5u %s: server accept status: %x\n",
2168                                 task->tk_pid, __func__, n);
2169                 /* Also retry */
2170         }
2171
2172 out_garbage:
2173         clnt->cl_stats->rpcgarbage++;
2174         if (task->tk_garb_retry) {
2175                 task->tk_garb_retry--;
2176                 dprintk("RPC: %5u %s: retrying\n",
2177                                 task->tk_pid, __func__);
2178                 task->tk_action = call_bind;
2179 out_retry:
2180                 return ERR_PTR(-EAGAIN);
2181         }
2182 out_eio:
2183         error = -EIO;
2184 out_err:
2185         rpc_exit(task, error);
2186         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2187                         __func__, error);
2188         return ERR_PTR(error);
2189 out_overflow:
2190         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2191                         __func__);
2192         goto out_garbage;
2193 }
2194
2195 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2196 {
2197 }
2198
2199 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2200 {
2201         return 0;
2202 }
2203
2204 static struct rpc_procinfo rpcproc_null = {
2205         .p_encode = rpcproc_encode_null,
2206         .p_decode = rpcproc_decode_null,
2207 };
2208
2209 static int rpc_ping(struct rpc_clnt *clnt)
2210 {
2211         struct rpc_message msg = {
2212                 .rpc_proc = &rpcproc_null,
2213         };
2214         int err;
2215         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2216         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2217         put_rpccred(msg.rpc_cred);
2218         return err;
2219 }
2220
2221 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2222 {
2223         struct rpc_message msg = {
2224                 .rpc_proc = &rpcproc_null,
2225                 .rpc_cred = cred,
2226         };
2227         struct rpc_task_setup task_setup_data = {
2228                 .rpc_client = clnt,
2229                 .rpc_message = &msg,
2230                 .callback_ops = &rpc_default_ops,
2231                 .flags = flags,
2232         };
2233         return rpc_run_task(&task_setup_data);
2234 }
2235 EXPORT_SYMBOL_GPL(rpc_call_null);
2236
2237 #ifdef RPC_DEBUG
2238 static void rpc_show_header(void)
2239 {
2240         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2241                 "-timeout ---ops--\n");
2242 }
2243
2244 static void rpc_show_task(const struct rpc_clnt *clnt,
2245                           const struct rpc_task *task)
2246 {
2247         const char *rpc_waitq = "none";
2248
2249         if (RPC_IS_QUEUED(task))
2250                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2251
2252         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2253                 task->tk_pid, task->tk_flags, task->tk_status,
2254                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2255                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
2256                 task->tk_action, rpc_waitq);
2257 }
2258
2259 void rpc_show_tasks(struct net *net)
2260 {
2261         struct rpc_clnt *clnt;
2262         struct rpc_task *task;
2263         int header = 0;
2264         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2265
2266         spin_lock(&sn->rpc_client_lock);
2267         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2268                 spin_lock(&clnt->cl_lock);
2269                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2270                         if (!header) {
2271                                 rpc_show_header();
2272                                 header++;
2273                         }
2274                         rpc_show_task(clnt, task);
2275                 }
2276                 spin_unlock(&clnt->cl_lock);
2277         }
2278         spin_unlock(&sn->rpc_client_lock);
2279 }
2280 #endif