41707450059273c55129312c0e18e20c42586a5a
[linux-3.10.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 #include <asm/system.h>
21
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/kallsyms.h>
25 #include <linux/mm.h>
26 #include <linux/namei.h>
27 #include <linux/mount.h>
28 #include <linux/slab.h>
29 #include <linux/utsname.h>
30 #include <linux/workqueue.h>
31 #include <linux/in.h>
32 #include <linux/in6.h>
33 #include <linux/un.h>
34
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/rpc_pipe_fs.h>
37 #include <linux/sunrpc/metrics.h>
38 #include <linux/sunrpc/bc_xprt.h>
39
40 #include "sunrpc.h"
41 #include "netns.h"
42
43 #ifdef RPC_DEBUG
44 # define RPCDBG_FACILITY        RPCDBG_CALL
45 #endif
46
47 #define dprint_status(t)                                        \
48         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
49                         __func__, t->tk_status)
50
51 /*
52  * All RPC clients are linked into this list
53  */
54
55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
56
57
58 static void     call_start(struct rpc_task *task);
59 static void     call_reserve(struct rpc_task *task);
60 static void     call_reserveresult(struct rpc_task *task);
61 static void     call_allocate(struct rpc_task *task);
62 static void     call_decode(struct rpc_task *task);
63 static void     call_bind(struct rpc_task *task);
64 static void     call_bind_status(struct rpc_task *task);
65 static void     call_transmit(struct rpc_task *task);
66 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
67 static void     call_bc_transmit(struct rpc_task *task);
68 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
69 static void     call_status(struct rpc_task *task);
70 static void     call_transmit_status(struct rpc_task *task);
71 static void     call_refresh(struct rpc_task *task);
72 static void     call_refreshresult(struct rpc_task *task);
73 static void     call_timeout(struct rpc_task *task);
74 static void     call_connect(struct rpc_task *task);
75 static void     call_connect_status(struct rpc_task *task);
76
77 static __be32   *rpc_encode_header(struct rpc_task *task);
78 static __be32   *rpc_verify_header(struct rpc_task *task);
79 static int      rpc_ping(struct rpc_clnt *clnt);
80
81 static void rpc_register_client(struct rpc_clnt *clnt)
82 {
83         struct sunrpc_net *sn = net_generic(clnt->cl_xprt->xprt_net, sunrpc_net_id);
84
85         spin_lock(&sn->rpc_client_lock);
86         list_add(&clnt->cl_clients, &sn->all_clients);
87         spin_unlock(&sn->rpc_client_lock);
88 }
89
90 static void rpc_unregister_client(struct rpc_clnt *clnt)
91 {
92         struct sunrpc_net *sn = net_generic(clnt->cl_xprt->xprt_net, sunrpc_net_id);
93
94         spin_lock(&sn->rpc_client_lock);
95         list_del(&clnt->cl_clients);
96         spin_unlock(&sn->rpc_client_lock);
97 }
98
99 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
100 {
101         if (clnt->cl_path.dentry) {
102                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
103                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
104                 rpc_remove_client_dir(clnt->cl_path.dentry);
105         }
106         clnt->cl_path.dentry = NULL;
107 }
108
109 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
110 {
111         struct super_block *pipefs_sb;
112         int put_mnt = 0;
113
114         pipefs_sb = rpc_get_sb_net(clnt->cl_xprt->xprt_net);
115         if (pipefs_sb) {
116                 if (clnt->cl_path.dentry)
117                         put_mnt = 1;
118                 __rpc_clnt_remove_pipedir(clnt);
119                 rpc_put_sb_net(clnt->cl_xprt->xprt_net);
120         }
121         if (put_mnt)
122                 rpc_put_mount();
123 }
124
125 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
126                                     struct rpc_clnt *clnt, char *dir_name)
127 {
128         static uint32_t clntid;
129         char name[15];
130         struct qstr q = {
131                 .name = name,
132         };
133         struct dentry *dir, *dentry;
134         int error;
135
136         dir = rpc_d_lookup_sb(sb, dir_name);
137         if (dir == NULL)
138                 return dir;
139         for (;;) {
140                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
141                 name[sizeof(name) - 1] = '\0';
142                 q.hash = full_name_hash(q.name, q.len);
143                 dentry = rpc_create_client_dir(dir, &q, clnt);
144                 if (!IS_ERR(dentry))
145                         break;
146                 error = PTR_ERR(dentry);
147                 if (error != -EEXIST) {
148                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
149                                         " %s/%s, error %d\n",
150                                         dir_name, name, error);
151                         break;
152                 }
153         }
154         dput(dir);
155         return dentry;
156 }
157
158 static int
159 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
160 {
161         struct super_block *pipefs_sb;
162         struct path path;
163
164         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
165         clnt->cl_path.dentry = NULL;
166         if (dir_name == NULL)
167                 return 0;
168
169         path.mnt = rpc_get_mount();
170         if (IS_ERR(path.mnt))
171                 return PTR_ERR(path.mnt);
172         pipefs_sb = rpc_get_sb_net(clnt->cl_xprt->xprt_net);
173         if (!pipefs_sb) {
174                 rpc_put_mount();
175                 return -ENOENT;
176         }
177         path.dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
178         rpc_put_sb_net(clnt->cl_xprt->xprt_net);
179         if (IS_ERR(path.dentry)) {
180                 rpc_put_mount();
181                 return PTR_ERR(path.dentry);
182         }
183         clnt->cl_path = path;
184         return 0;
185 }
186
187 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
188                                 struct super_block *sb)
189 {
190         struct dentry *dentry;
191         int err = 0;
192
193         switch (event) {
194         case RPC_PIPEFS_MOUNT:
195                 if (clnt->cl_program->pipe_dir_name == NULL)
196                         break;
197                 dentry = rpc_setup_pipedir_sb(sb, clnt,
198                                               clnt->cl_program->pipe_dir_name);
199                 BUG_ON(dentry == NULL);
200                 if (IS_ERR(dentry))
201                         return PTR_ERR(dentry);
202                 clnt->cl_path.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 notifier_block *nb, unsigned long event,
220                             void *ptr)
221 {
222         struct super_block *sb = ptr;
223         struct rpc_clnt *clnt;
224         int error = 0;
225         struct sunrpc_net *sn = net_generic(sb->s_fs_info, sunrpc_net_id);
226
227         spin_lock(&sn->rpc_client_lock);
228         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
229                 error = __rpc_pipefs_event(clnt, event, sb);
230                 if (error)
231                         break;
232         }
233         spin_unlock(&sn->rpc_client_lock);
234         return error;
235 }
236
237 static struct notifier_block rpc_clients_block = {
238         .notifier_call  = rpc_pipefs_event,
239 };
240
241 int rpc_clients_notifier_register(void)
242 {
243         return rpc_pipefs_notifier_register(&rpc_clients_block);
244 }
245
246 void rpc_clients_notifier_unregister(void)
247 {
248         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
249 }
250
251 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
252 {
253         struct rpc_program      *program = args->program;
254         struct rpc_version      *version;
255         struct rpc_clnt         *clnt = NULL;
256         struct rpc_auth         *auth;
257         int err;
258         size_t len;
259
260         /* sanity check the name before trying to print it */
261         err = -EINVAL;
262         len = strlen(args->servername);
263         if (len > RPC_MAXNETNAMELEN)
264                 goto out_no_rpciod;
265         len++;
266
267         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
268                         program->name, args->servername, xprt);
269
270         err = rpciod_up();
271         if (err)
272                 goto out_no_rpciod;
273         err = -EINVAL;
274         if (!xprt)
275                 goto out_no_xprt;
276
277         if (args->version >= program->nrvers)
278                 goto out_err;
279         version = program->version[args->version];
280         if (version == NULL)
281                 goto out_err;
282
283         err = -ENOMEM;
284         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
285         if (!clnt)
286                 goto out_err;
287         clnt->cl_parent = clnt;
288
289         clnt->cl_server = clnt->cl_inline_name;
290         if (len > sizeof(clnt->cl_inline_name)) {
291                 char *buf = kmalloc(len, GFP_KERNEL);
292                 if (buf != NULL)
293                         clnt->cl_server = buf;
294                 else
295                         len = sizeof(clnt->cl_inline_name);
296         }
297         strlcpy(clnt->cl_server, args->servername, len);
298
299         clnt->cl_xprt     = xprt;
300         clnt->cl_procinfo = version->procs;
301         clnt->cl_maxproc  = version->nrprocs;
302         clnt->cl_protname = program->name;
303         clnt->cl_prog     = args->prognumber ? : program->number;
304         clnt->cl_vers     = version->number;
305         clnt->cl_stats    = program->stats;
306         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
307         err = -ENOMEM;
308         if (clnt->cl_metrics == NULL)
309                 goto out_no_stats;
310         clnt->cl_program  = program;
311         INIT_LIST_HEAD(&clnt->cl_tasks);
312         spin_lock_init(&clnt->cl_lock);
313
314         if (!xprt_bound(clnt->cl_xprt))
315                 clnt->cl_autobind = 1;
316
317         clnt->cl_timeout = xprt->timeout;
318         if (args->timeout != NULL) {
319                 memcpy(&clnt->cl_timeout_default, args->timeout,
320                                 sizeof(clnt->cl_timeout_default));
321                 clnt->cl_timeout = &clnt->cl_timeout_default;
322         }
323
324         clnt->cl_rtt = &clnt->cl_rtt_default;
325         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
326         clnt->cl_principal = NULL;
327         if (args->client_name) {
328                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
329                 if (!clnt->cl_principal)
330                         goto out_no_principal;
331         }
332
333         atomic_set(&clnt->cl_count, 1);
334
335         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
336         if (err < 0)
337                 goto out_no_path;
338
339         auth = rpcauth_create(args->authflavor, clnt);
340         if (IS_ERR(auth)) {
341                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
342                                 args->authflavor);
343                 err = PTR_ERR(auth);
344                 goto out_no_auth;
345         }
346
347         /* save the nodename */
348         clnt->cl_nodelen = strlen(init_utsname()->nodename);
349         if (clnt->cl_nodelen > UNX_MAXNODENAME)
350                 clnt->cl_nodelen = UNX_MAXNODENAME;
351         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
352         rpc_register_client(clnt);
353         return clnt;
354
355 out_no_auth:
356         rpc_clnt_remove_pipedir(clnt);
357 out_no_path:
358         kfree(clnt->cl_principal);
359 out_no_principal:
360         rpc_free_iostats(clnt->cl_metrics);
361 out_no_stats:
362         if (clnt->cl_server != clnt->cl_inline_name)
363                 kfree(clnt->cl_server);
364         kfree(clnt);
365 out_err:
366         xprt_put(xprt);
367 out_no_xprt:
368         rpciod_down();
369 out_no_rpciod:
370         return ERR_PTR(err);
371 }
372
373 /*
374  * rpc_create - create an RPC client and transport with one call
375  * @args: rpc_clnt create argument structure
376  *
377  * Creates and initializes an RPC transport and an RPC client.
378  *
379  * It can ping the server in order to determine if it is up, and to see if
380  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
381  * this behavior so asynchronous tasks can also use rpc_create.
382  */
383 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
384 {
385         struct rpc_xprt *xprt;
386         struct rpc_clnt *clnt;
387         struct xprt_create xprtargs = {
388                 .net = args->net,
389                 .ident = args->protocol,
390                 .srcaddr = args->saddress,
391                 .dstaddr = args->address,
392                 .addrlen = args->addrsize,
393                 .bc_xprt = args->bc_xprt,
394         };
395         char servername[48];
396
397         /*
398          * If the caller chooses not to specify a hostname, whip
399          * up a string representation of the passed-in address.
400          */
401         if (args->servername == NULL) {
402                 struct sockaddr_un *sun =
403                                 (struct sockaddr_un *)args->address;
404                 struct sockaddr_in *sin =
405                                 (struct sockaddr_in *)args->address;
406                 struct sockaddr_in6 *sin6 =
407                                 (struct sockaddr_in6 *)args->address;
408
409                 servername[0] = '\0';
410                 switch (args->address->sa_family) {
411                 case AF_LOCAL:
412                         snprintf(servername, sizeof(servername), "%s",
413                                  sun->sun_path);
414                         break;
415                 case AF_INET:
416                         snprintf(servername, sizeof(servername), "%pI4",
417                                  &sin->sin_addr.s_addr);
418                         break;
419                 case AF_INET6:
420                         snprintf(servername, sizeof(servername), "%pI6",
421                                  &sin6->sin6_addr);
422                         break;
423                 default:
424                         /* caller wants default server name, but
425                          * address family isn't recognized. */
426                         return ERR_PTR(-EINVAL);
427                 }
428                 args->servername = servername;
429         }
430
431         xprt = xprt_create_transport(&xprtargs);
432         if (IS_ERR(xprt))
433                 return (struct rpc_clnt *)xprt;
434
435         /*
436          * By default, kernel RPC client connects from a reserved port.
437          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
438          * but it is always enabled for rpciod, which handles the connect
439          * operation.
440          */
441         xprt->resvport = 1;
442         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
443                 xprt->resvport = 0;
444
445         clnt = rpc_new_client(args, xprt);
446         if (IS_ERR(clnt))
447                 return clnt;
448
449         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
450                 int err = rpc_ping(clnt);
451                 if (err != 0) {
452                         rpc_shutdown_client(clnt);
453                         return ERR_PTR(err);
454                 }
455         }
456
457         clnt->cl_softrtry = 1;
458         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
459                 clnt->cl_softrtry = 0;
460
461         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
462                 clnt->cl_autobind = 1;
463         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
464                 clnt->cl_discrtry = 1;
465         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
466                 clnt->cl_chatty = 1;
467
468         return clnt;
469 }
470 EXPORT_SYMBOL_GPL(rpc_create);
471
472 /*
473  * This function clones the RPC client structure. It allows us to share the
474  * same transport while varying parameters such as the authentication
475  * flavour.
476  */
477 struct rpc_clnt *
478 rpc_clone_client(struct rpc_clnt *clnt)
479 {
480         struct rpc_clnt *new;
481         int err = -ENOMEM;
482
483         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
484         if (!new)
485                 goto out_no_clnt;
486         new->cl_parent = clnt;
487         /* Turn off autobind on clones */
488         new->cl_autobind = 0;
489         INIT_LIST_HEAD(&new->cl_tasks);
490         spin_lock_init(&new->cl_lock);
491         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
492         new->cl_metrics = rpc_alloc_iostats(clnt);
493         if (new->cl_metrics == NULL)
494                 goto out_no_stats;
495         if (clnt->cl_principal) {
496                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
497                 if (new->cl_principal == NULL)
498                         goto out_no_principal;
499         }
500         atomic_set(&new->cl_count, 1);
501         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
502         if (err != 0)
503                 goto out_no_path;
504         if (new->cl_auth)
505                 atomic_inc(&new->cl_auth->au_count);
506         xprt_get(clnt->cl_xprt);
507         atomic_inc(&clnt->cl_count);
508         rpc_register_client(new);
509         rpciod_up();
510         return new;
511 out_no_path:
512         kfree(new->cl_principal);
513 out_no_principal:
514         rpc_free_iostats(new->cl_metrics);
515 out_no_stats:
516         kfree(new);
517 out_no_clnt:
518         dprintk("RPC:       %s: returned error %d\n", __func__, err);
519         return ERR_PTR(err);
520 }
521 EXPORT_SYMBOL_GPL(rpc_clone_client);
522
523 /*
524  * Kill all tasks for the given client.
525  * XXX: kill their descendants as well?
526  */
527 void rpc_killall_tasks(struct rpc_clnt *clnt)
528 {
529         struct rpc_task *rovr;
530
531
532         if (list_empty(&clnt->cl_tasks))
533                 return;
534         dprintk("RPC:       killing all tasks for client %p\n", clnt);
535         /*
536          * Spin lock all_tasks to prevent changes...
537          */
538         spin_lock(&clnt->cl_lock);
539         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
540                 if (!RPC_IS_ACTIVATED(rovr))
541                         continue;
542                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
543                         rovr->tk_flags |= RPC_TASK_KILLED;
544                         rpc_exit(rovr, -EIO);
545                         if (RPC_IS_QUEUED(rovr))
546                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
547                                                         rovr);
548                 }
549         }
550         spin_unlock(&clnt->cl_lock);
551 }
552 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
553
554 /*
555  * Properly shut down an RPC client, terminating all outstanding
556  * requests.
557  */
558 void rpc_shutdown_client(struct rpc_clnt *clnt)
559 {
560         dprintk("RPC:       shutting down %s client for %s\n",
561                         clnt->cl_protname, clnt->cl_server);
562
563         while (!list_empty(&clnt->cl_tasks)) {
564                 rpc_killall_tasks(clnt);
565                 wait_event_timeout(destroy_wait,
566                         list_empty(&clnt->cl_tasks), 1*HZ);
567         }
568
569         rpc_release_client(clnt);
570 }
571 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
572
573 /*
574  * Free an RPC client
575  */
576 static void
577 rpc_free_client(struct rpc_clnt *clnt)
578 {
579         dprintk("RPC:       destroying %s client for %s\n",
580                         clnt->cl_protname, clnt->cl_server);
581         rpc_clnt_remove_pipedir(clnt);
582         if (clnt->cl_parent != clnt) {
583                 rpc_release_client(clnt->cl_parent);
584                 goto out_free;
585         }
586         if (clnt->cl_server != clnt->cl_inline_name)
587                 kfree(clnt->cl_server);
588 out_free:
589         rpc_unregister_client(clnt);
590         rpc_free_iostats(clnt->cl_metrics);
591         kfree(clnt->cl_principal);
592         clnt->cl_metrics = NULL;
593         xprt_put(clnt->cl_xprt);
594         rpciod_down();
595         kfree(clnt);
596 }
597
598 /*
599  * Free an RPC client
600  */
601 static void
602 rpc_free_auth(struct rpc_clnt *clnt)
603 {
604         if (clnt->cl_auth == NULL) {
605                 rpc_free_client(clnt);
606                 return;
607         }
608
609         /*
610          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
611          *       release remaining GSS contexts. This mechanism ensures
612          *       that it can do so safely.
613          */
614         atomic_inc(&clnt->cl_count);
615         rpcauth_release(clnt->cl_auth);
616         clnt->cl_auth = NULL;
617         if (atomic_dec_and_test(&clnt->cl_count))
618                 rpc_free_client(clnt);
619 }
620
621 /*
622  * Release reference to the RPC client
623  */
624 void
625 rpc_release_client(struct rpc_clnt *clnt)
626 {
627         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
628
629         if (list_empty(&clnt->cl_tasks))
630                 wake_up(&destroy_wait);
631         if (atomic_dec_and_test(&clnt->cl_count))
632                 rpc_free_auth(clnt);
633 }
634
635 /**
636  * rpc_bind_new_program - bind a new RPC program to an existing client
637  * @old: old rpc_client
638  * @program: rpc program to set
639  * @vers: rpc program version
640  *
641  * Clones the rpc client and sets up a new RPC program. This is mainly
642  * of use for enabling different RPC programs to share the same transport.
643  * The Sun NFSv2/v3 ACL protocol can do this.
644  */
645 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
646                                       struct rpc_program *program,
647                                       u32 vers)
648 {
649         struct rpc_clnt *clnt;
650         struct rpc_version *version;
651         int err;
652
653         BUG_ON(vers >= program->nrvers || !program->version[vers]);
654         version = program->version[vers];
655         clnt = rpc_clone_client(old);
656         if (IS_ERR(clnt))
657                 goto out;
658         clnt->cl_procinfo = version->procs;
659         clnt->cl_maxproc  = version->nrprocs;
660         clnt->cl_protname = program->name;
661         clnt->cl_prog     = program->number;
662         clnt->cl_vers     = version->number;
663         clnt->cl_stats    = program->stats;
664         err = rpc_ping(clnt);
665         if (err != 0) {
666                 rpc_shutdown_client(clnt);
667                 clnt = ERR_PTR(err);
668         }
669 out:
670         return clnt;
671 }
672 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
673
674 void rpc_task_release_client(struct rpc_task *task)
675 {
676         struct rpc_clnt *clnt = task->tk_client;
677
678         if (clnt != NULL) {
679                 /* Remove from client task list */
680                 spin_lock(&clnt->cl_lock);
681                 list_del(&task->tk_task);
682                 spin_unlock(&clnt->cl_lock);
683                 task->tk_client = NULL;
684
685                 rpc_release_client(clnt);
686         }
687 }
688
689 static
690 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
691 {
692         if (clnt != NULL) {
693                 rpc_task_release_client(task);
694                 task->tk_client = clnt;
695                 atomic_inc(&clnt->cl_count);
696                 if (clnt->cl_softrtry)
697                         task->tk_flags |= RPC_TASK_SOFT;
698                 /* Add to the client's list of all tasks */
699                 spin_lock(&clnt->cl_lock);
700                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
701                 spin_unlock(&clnt->cl_lock);
702         }
703 }
704
705 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
706 {
707         rpc_task_release_client(task);
708         rpc_task_set_client(task, clnt);
709 }
710 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
711
712
713 static void
714 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
715 {
716         if (msg != NULL) {
717                 task->tk_msg.rpc_proc = msg->rpc_proc;
718                 task->tk_msg.rpc_argp = msg->rpc_argp;
719                 task->tk_msg.rpc_resp = msg->rpc_resp;
720                 if (msg->rpc_cred != NULL)
721                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
722         }
723 }
724
725 /*
726  * Default callback for async RPC calls
727  */
728 static void
729 rpc_default_callback(struct rpc_task *task, void *data)
730 {
731 }
732
733 static const struct rpc_call_ops rpc_default_ops = {
734         .rpc_call_done = rpc_default_callback,
735 };
736
737 /**
738  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
739  * @task_setup_data: pointer to task initialisation data
740  */
741 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
742 {
743         struct rpc_task *task;
744
745         task = rpc_new_task(task_setup_data);
746         if (IS_ERR(task))
747                 goto out;
748
749         rpc_task_set_client(task, task_setup_data->rpc_client);
750         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
751
752         if (task->tk_action == NULL)
753                 rpc_call_start(task);
754
755         atomic_inc(&task->tk_count);
756         rpc_execute(task);
757 out:
758         return task;
759 }
760 EXPORT_SYMBOL_GPL(rpc_run_task);
761
762 /**
763  * rpc_call_sync - Perform a synchronous RPC call
764  * @clnt: pointer to RPC client
765  * @msg: RPC call parameters
766  * @flags: RPC call flags
767  */
768 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
769 {
770         struct rpc_task *task;
771         struct rpc_task_setup task_setup_data = {
772                 .rpc_client = clnt,
773                 .rpc_message = msg,
774                 .callback_ops = &rpc_default_ops,
775                 .flags = flags,
776         };
777         int status;
778
779         BUG_ON(flags & RPC_TASK_ASYNC);
780
781         task = rpc_run_task(&task_setup_data);
782         if (IS_ERR(task))
783                 return PTR_ERR(task);
784         status = task->tk_status;
785         rpc_put_task(task);
786         return status;
787 }
788 EXPORT_SYMBOL_GPL(rpc_call_sync);
789
790 /**
791  * rpc_call_async - Perform an asynchronous RPC call
792  * @clnt: pointer to RPC client
793  * @msg: RPC call parameters
794  * @flags: RPC call flags
795  * @tk_ops: RPC call ops
796  * @data: user call data
797  */
798 int
799 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
800                const struct rpc_call_ops *tk_ops, void *data)
801 {
802         struct rpc_task *task;
803         struct rpc_task_setup task_setup_data = {
804                 .rpc_client = clnt,
805                 .rpc_message = msg,
806                 .callback_ops = tk_ops,
807                 .callback_data = data,
808                 .flags = flags|RPC_TASK_ASYNC,
809         };
810
811         task = rpc_run_task(&task_setup_data);
812         if (IS_ERR(task))
813                 return PTR_ERR(task);
814         rpc_put_task(task);
815         return 0;
816 }
817 EXPORT_SYMBOL_GPL(rpc_call_async);
818
819 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
820 /**
821  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
822  * rpc_execute against it
823  * @req: RPC request
824  * @tk_ops: RPC call ops
825  */
826 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
827                                 const struct rpc_call_ops *tk_ops)
828 {
829         struct rpc_task *task;
830         struct xdr_buf *xbufp = &req->rq_snd_buf;
831         struct rpc_task_setup task_setup_data = {
832                 .callback_ops = tk_ops,
833         };
834
835         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
836         /*
837          * Create an rpc_task to send the data
838          */
839         task = rpc_new_task(&task_setup_data);
840         if (IS_ERR(task)) {
841                 xprt_free_bc_request(req);
842                 goto out;
843         }
844         task->tk_rqstp = req;
845
846         /*
847          * Set up the xdr_buf length.
848          * This also indicates that the buffer is XDR encoded already.
849          */
850         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
851                         xbufp->tail[0].iov_len;
852
853         task->tk_action = call_bc_transmit;
854         atomic_inc(&task->tk_count);
855         BUG_ON(atomic_read(&task->tk_count) != 2);
856         rpc_execute(task);
857
858 out:
859         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
860         return task;
861 }
862 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
863
864 void
865 rpc_call_start(struct rpc_task *task)
866 {
867         task->tk_action = call_start;
868 }
869 EXPORT_SYMBOL_GPL(rpc_call_start);
870
871 /**
872  * rpc_peeraddr - extract remote peer address from clnt's xprt
873  * @clnt: RPC client structure
874  * @buf: target buffer
875  * @bufsize: length of target buffer
876  *
877  * Returns the number of bytes that are actually in the stored address.
878  */
879 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
880 {
881         size_t bytes;
882         struct rpc_xprt *xprt = clnt->cl_xprt;
883
884         bytes = sizeof(xprt->addr);
885         if (bytes > bufsize)
886                 bytes = bufsize;
887         memcpy(buf, &clnt->cl_xprt->addr, bytes);
888         return xprt->addrlen;
889 }
890 EXPORT_SYMBOL_GPL(rpc_peeraddr);
891
892 /**
893  * rpc_peeraddr2str - return remote peer address in printable format
894  * @clnt: RPC client structure
895  * @format: address format
896  *
897  */
898 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
899                              enum rpc_display_format_t format)
900 {
901         struct rpc_xprt *xprt = clnt->cl_xprt;
902
903         if (xprt->address_strings[format] != NULL)
904                 return xprt->address_strings[format];
905         else
906                 return "unprintable";
907 }
908 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
909
910 void
911 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
912 {
913         struct rpc_xprt *xprt = clnt->cl_xprt;
914         if (xprt->ops->set_buffer_size)
915                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
916 }
917 EXPORT_SYMBOL_GPL(rpc_setbufsize);
918
919 /*
920  * Return size of largest payload RPC client can support, in bytes
921  *
922  * For stream transports, this is one RPC record fragment (see RFC
923  * 1831), as we don't support multi-record requests yet.  For datagram
924  * transports, this is the size of an IP packet minus the IP, UDP, and
925  * RPC header sizes.
926  */
927 size_t rpc_max_payload(struct rpc_clnt *clnt)
928 {
929         return clnt->cl_xprt->max_payload;
930 }
931 EXPORT_SYMBOL_GPL(rpc_max_payload);
932
933 /**
934  * rpc_force_rebind - force transport to check that remote port is unchanged
935  * @clnt: client to rebind
936  *
937  */
938 void rpc_force_rebind(struct rpc_clnt *clnt)
939 {
940         if (clnt->cl_autobind)
941                 xprt_clear_bound(clnt->cl_xprt);
942 }
943 EXPORT_SYMBOL_GPL(rpc_force_rebind);
944
945 /*
946  * Restart an (async) RPC call from the call_prepare state.
947  * Usually called from within the exit handler.
948  */
949 int
950 rpc_restart_call_prepare(struct rpc_task *task)
951 {
952         if (RPC_ASSASSINATED(task))
953                 return 0;
954         task->tk_action = call_start;
955         if (task->tk_ops->rpc_call_prepare != NULL)
956                 task->tk_action = rpc_prepare_task;
957         return 1;
958 }
959 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
960
961 /*
962  * Restart an (async) RPC call. Usually called from within the
963  * exit handler.
964  */
965 int
966 rpc_restart_call(struct rpc_task *task)
967 {
968         if (RPC_ASSASSINATED(task))
969                 return 0;
970         task->tk_action = call_start;
971         return 1;
972 }
973 EXPORT_SYMBOL_GPL(rpc_restart_call);
974
975 #ifdef RPC_DEBUG
976 static const char *rpc_proc_name(const struct rpc_task *task)
977 {
978         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
979
980         if (proc) {
981                 if (proc->p_name)
982                         return proc->p_name;
983                 else
984                         return "NULL";
985         } else
986                 return "no proc";
987 }
988 #endif
989
990 /*
991  * 0.  Initial state
992  *
993  *     Other FSM states can be visited zero or more times, but
994  *     this state is visited exactly once for each RPC.
995  */
996 static void
997 call_start(struct rpc_task *task)
998 {
999         struct rpc_clnt *clnt = task->tk_client;
1000
1001         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1002                         clnt->cl_protname, clnt->cl_vers,
1003                         rpc_proc_name(task),
1004                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1005
1006         /* Increment call count */
1007         task->tk_msg.rpc_proc->p_count++;
1008         clnt->cl_stats->rpccnt++;
1009         task->tk_action = call_reserve;
1010 }
1011
1012 /*
1013  * 1.   Reserve an RPC call slot
1014  */
1015 static void
1016 call_reserve(struct rpc_task *task)
1017 {
1018         dprint_status(task);
1019
1020         task->tk_status  = 0;
1021         task->tk_action  = call_reserveresult;
1022         xprt_reserve(task);
1023 }
1024
1025 /*
1026  * 1b.  Grok the result of xprt_reserve()
1027  */
1028 static void
1029 call_reserveresult(struct rpc_task *task)
1030 {
1031         int status = task->tk_status;
1032
1033         dprint_status(task);
1034
1035         /*
1036          * After a call to xprt_reserve(), we must have either
1037          * a request slot or else an error status.
1038          */
1039         task->tk_status = 0;
1040         if (status >= 0) {
1041                 if (task->tk_rqstp) {
1042                         task->tk_action = call_refresh;
1043                         return;
1044                 }
1045
1046                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1047                                 __func__, status);
1048                 rpc_exit(task, -EIO);
1049                 return;
1050         }
1051
1052         /*
1053          * Even though there was an error, we may have acquired
1054          * a request slot somehow.  Make sure not to leak it.
1055          */
1056         if (task->tk_rqstp) {
1057                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1058                                 __func__, status);
1059                 xprt_release(task);
1060         }
1061
1062         switch (status) {
1063         case -EAGAIN:   /* woken up; retry */
1064                 task->tk_action = call_reserve;
1065                 return;
1066         case -EIO:      /* probably a shutdown */
1067                 break;
1068         default:
1069                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1070                                 __func__, status);
1071                 break;
1072         }
1073         rpc_exit(task, status);
1074 }
1075
1076 /*
1077  * 2.   Bind and/or refresh the credentials
1078  */
1079 static void
1080 call_refresh(struct rpc_task *task)
1081 {
1082         dprint_status(task);
1083
1084         task->tk_action = call_refreshresult;
1085         task->tk_status = 0;
1086         task->tk_client->cl_stats->rpcauthrefresh++;
1087         rpcauth_refreshcred(task);
1088 }
1089
1090 /*
1091  * 2a.  Process the results of a credential refresh
1092  */
1093 static void
1094 call_refreshresult(struct rpc_task *task)
1095 {
1096         int status = task->tk_status;
1097
1098         dprint_status(task);
1099
1100         task->tk_status = 0;
1101         task->tk_action = call_refresh;
1102         switch (status) {
1103         case 0:
1104                 if (rpcauth_uptodatecred(task))
1105                         task->tk_action = call_allocate;
1106                 return;
1107         case -ETIMEDOUT:
1108                 rpc_delay(task, 3*HZ);
1109         case -EAGAIN:
1110                 status = -EACCES;
1111                 if (!task->tk_cred_retry)
1112                         break;
1113                 task->tk_cred_retry--;
1114                 dprintk("RPC: %5u %s: retry refresh creds\n",
1115                                 task->tk_pid, __func__);
1116                 return;
1117         }
1118         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1119                                 task->tk_pid, __func__, status);
1120         rpc_exit(task, status);
1121 }
1122
1123 /*
1124  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1125  *      (Note: buffer memory is freed in xprt_release).
1126  */
1127 static void
1128 call_allocate(struct rpc_task *task)
1129 {
1130         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1131         struct rpc_rqst *req = task->tk_rqstp;
1132         struct rpc_xprt *xprt = task->tk_xprt;
1133         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1134
1135         dprint_status(task);
1136
1137         task->tk_status = 0;
1138         task->tk_action = call_bind;
1139
1140         if (req->rq_buffer)
1141                 return;
1142
1143         if (proc->p_proc != 0) {
1144                 BUG_ON(proc->p_arglen == 0);
1145                 if (proc->p_decode != NULL)
1146                         BUG_ON(proc->p_replen == 0);
1147         }
1148
1149         /*
1150          * Calculate the size (in quads) of the RPC call
1151          * and reply headers, and convert both values
1152          * to byte sizes.
1153          */
1154         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1155         req->rq_callsize <<= 2;
1156         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1157         req->rq_rcvsize <<= 2;
1158
1159         req->rq_buffer = xprt->ops->buf_alloc(task,
1160                                         req->rq_callsize + req->rq_rcvsize);
1161         if (req->rq_buffer != NULL)
1162                 return;
1163
1164         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1165
1166         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1167                 task->tk_action = call_allocate;
1168                 rpc_delay(task, HZ>>4);
1169                 return;
1170         }
1171
1172         rpc_exit(task, -ERESTARTSYS);
1173 }
1174
1175 static inline int
1176 rpc_task_need_encode(struct rpc_task *task)
1177 {
1178         return task->tk_rqstp->rq_snd_buf.len == 0;
1179 }
1180
1181 static inline void
1182 rpc_task_force_reencode(struct rpc_task *task)
1183 {
1184         task->tk_rqstp->rq_snd_buf.len = 0;
1185         task->tk_rqstp->rq_bytes_sent = 0;
1186 }
1187
1188 static inline void
1189 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1190 {
1191         buf->head[0].iov_base = start;
1192         buf->head[0].iov_len = len;
1193         buf->tail[0].iov_len = 0;
1194         buf->page_len = 0;
1195         buf->flags = 0;
1196         buf->len = 0;
1197         buf->buflen = len;
1198 }
1199
1200 /*
1201  * 3.   Encode arguments of an RPC call
1202  */
1203 static void
1204 rpc_xdr_encode(struct rpc_task *task)
1205 {
1206         struct rpc_rqst *req = task->tk_rqstp;
1207         kxdreproc_t     encode;
1208         __be32          *p;
1209
1210         dprint_status(task);
1211
1212         rpc_xdr_buf_init(&req->rq_snd_buf,
1213                          req->rq_buffer,
1214                          req->rq_callsize);
1215         rpc_xdr_buf_init(&req->rq_rcv_buf,
1216                          (char *)req->rq_buffer + req->rq_callsize,
1217                          req->rq_rcvsize);
1218
1219         p = rpc_encode_header(task);
1220         if (p == NULL) {
1221                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1222                 rpc_exit(task, -EIO);
1223                 return;
1224         }
1225
1226         encode = task->tk_msg.rpc_proc->p_encode;
1227         if (encode == NULL)
1228                 return;
1229
1230         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1231                         task->tk_msg.rpc_argp);
1232 }
1233
1234 /*
1235  * 4.   Get the server port number if not yet set
1236  */
1237 static void
1238 call_bind(struct rpc_task *task)
1239 {
1240         struct rpc_xprt *xprt = task->tk_xprt;
1241
1242         dprint_status(task);
1243
1244         task->tk_action = call_connect;
1245         if (!xprt_bound(xprt)) {
1246                 task->tk_action = call_bind_status;
1247                 task->tk_timeout = xprt->bind_timeout;
1248                 xprt->ops->rpcbind(task);
1249         }
1250 }
1251
1252 /*
1253  * 4a.  Sort out bind result
1254  */
1255 static void
1256 call_bind_status(struct rpc_task *task)
1257 {
1258         int status = -EIO;
1259
1260         if (task->tk_status >= 0) {
1261                 dprint_status(task);
1262                 task->tk_status = 0;
1263                 task->tk_action = call_connect;
1264                 return;
1265         }
1266
1267         switch (task->tk_status) {
1268         case -ENOMEM:
1269                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1270                 rpc_delay(task, HZ >> 2);
1271                 goto retry_timeout;
1272         case -EACCES:
1273                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1274                                 "unavailable\n", task->tk_pid);
1275                 /* fail immediately if this is an RPC ping */
1276                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1277                         status = -EOPNOTSUPP;
1278                         break;
1279                 }
1280                 if (task->tk_rebind_retry == 0)
1281                         break;
1282                 task->tk_rebind_retry--;
1283                 rpc_delay(task, 3*HZ);
1284                 goto retry_timeout;
1285         case -ETIMEDOUT:
1286                 dprintk("RPC: %5u rpcbind request timed out\n",
1287                                 task->tk_pid);
1288                 goto retry_timeout;
1289         case -EPFNOSUPPORT:
1290                 /* server doesn't support any rpcbind version we know of */
1291                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1292                                 task->tk_pid);
1293                 break;
1294         case -EPROTONOSUPPORT:
1295                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1296                                 task->tk_pid);
1297                 task->tk_status = 0;
1298                 task->tk_action = call_bind;
1299                 return;
1300         case -ECONNREFUSED:             /* connection problems */
1301         case -ECONNRESET:
1302         case -ENOTCONN:
1303         case -EHOSTDOWN:
1304         case -EHOSTUNREACH:
1305         case -ENETUNREACH:
1306         case -EPIPE:
1307                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1308                                 task->tk_pid, task->tk_status);
1309                 if (!RPC_IS_SOFTCONN(task)) {
1310                         rpc_delay(task, 5*HZ);
1311                         goto retry_timeout;
1312                 }
1313                 status = task->tk_status;
1314                 break;
1315         default:
1316                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1317                                 task->tk_pid, -task->tk_status);
1318         }
1319
1320         rpc_exit(task, status);
1321         return;
1322
1323 retry_timeout:
1324         task->tk_action = call_timeout;
1325 }
1326
1327 /*
1328  * 4b.  Connect to the RPC server
1329  */
1330 static void
1331 call_connect(struct rpc_task *task)
1332 {
1333         struct rpc_xprt *xprt = task->tk_xprt;
1334
1335         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1336                         task->tk_pid, xprt,
1337                         (xprt_connected(xprt) ? "is" : "is not"));
1338
1339         task->tk_action = call_transmit;
1340         if (!xprt_connected(xprt)) {
1341                 task->tk_action = call_connect_status;
1342                 if (task->tk_status < 0)
1343                         return;
1344                 xprt_connect(task);
1345         }
1346 }
1347
1348 /*
1349  * 4c.  Sort out connect result
1350  */
1351 static void
1352 call_connect_status(struct rpc_task *task)
1353 {
1354         struct rpc_clnt *clnt = task->tk_client;
1355         int status = task->tk_status;
1356
1357         dprint_status(task);
1358
1359         task->tk_status = 0;
1360         if (status >= 0 || status == -EAGAIN) {
1361                 clnt->cl_stats->netreconn++;
1362                 task->tk_action = call_transmit;
1363                 return;
1364         }
1365
1366         switch (status) {
1367                 /* if soft mounted, test if we've timed out */
1368         case -ETIMEDOUT:
1369                 task->tk_action = call_timeout;
1370                 break;
1371         default:
1372                 rpc_exit(task, -EIO);
1373         }
1374 }
1375
1376 /*
1377  * 5.   Transmit the RPC request, and wait for reply
1378  */
1379 static void
1380 call_transmit(struct rpc_task *task)
1381 {
1382         dprint_status(task);
1383
1384         task->tk_action = call_status;
1385         if (task->tk_status < 0)
1386                 return;
1387         task->tk_status = xprt_prepare_transmit(task);
1388         if (task->tk_status != 0)
1389                 return;
1390         task->tk_action = call_transmit_status;
1391         /* Encode here so that rpcsec_gss can use correct sequence number. */
1392         if (rpc_task_need_encode(task)) {
1393                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1394                 rpc_xdr_encode(task);
1395                 /* Did the encode result in an error condition? */
1396                 if (task->tk_status != 0) {
1397                         /* Was the error nonfatal? */
1398                         if (task->tk_status == -EAGAIN)
1399                                 rpc_delay(task, HZ >> 4);
1400                         else
1401                                 rpc_exit(task, task->tk_status);
1402                         return;
1403                 }
1404         }
1405         xprt_transmit(task);
1406         if (task->tk_status < 0)
1407                 return;
1408         /*
1409          * On success, ensure that we call xprt_end_transmit() before sleeping
1410          * in order to allow access to the socket to other RPC requests.
1411          */
1412         call_transmit_status(task);
1413         if (rpc_reply_expected(task))
1414                 return;
1415         task->tk_action = rpc_exit_task;
1416         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1417 }
1418
1419 /*
1420  * 5a.  Handle cleanup after a transmission
1421  */
1422 static void
1423 call_transmit_status(struct rpc_task *task)
1424 {
1425         task->tk_action = call_status;
1426
1427         /*
1428          * Common case: success.  Force the compiler to put this
1429          * test first.
1430          */
1431         if (task->tk_status == 0) {
1432                 xprt_end_transmit(task);
1433                 rpc_task_force_reencode(task);
1434                 return;
1435         }
1436
1437         switch (task->tk_status) {
1438         case -EAGAIN:
1439                 break;
1440         default:
1441                 dprint_status(task);
1442                 xprt_end_transmit(task);
1443                 rpc_task_force_reencode(task);
1444                 break;
1445                 /*
1446                  * Special cases: if we've been waiting on the
1447                  * socket's write_space() callback, or if the
1448                  * socket just returned a connection error,
1449                  * then hold onto the transport lock.
1450                  */
1451         case -ECONNREFUSED:
1452         case -EHOSTDOWN:
1453         case -EHOSTUNREACH:
1454         case -ENETUNREACH:
1455                 if (RPC_IS_SOFTCONN(task)) {
1456                         xprt_end_transmit(task);
1457                         rpc_exit(task, task->tk_status);
1458                         break;
1459                 }
1460         case -ECONNRESET:
1461         case -ENOTCONN:
1462         case -EPIPE:
1463                 rpc_task_force_reencode(task);
1464         }
1465 }
1466
1467 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1468 /*
1469  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1470  * addition, disconnect on connectivity errors.
1471  */
1472 static void
1473 call_bc_transmit(struct rpc_task *task)
1474 {
1475         struct rpc_rqst *req = task->tk_rqstp;
1476
1477         BUG_ON(task->tk_status != 0);
1478         task->tk_status = xprt_prepare_transmit(task);
1479         if (task->tk_status == -EAGAIN) {
1480                 /*
1481                  * Could not reserve the transport. Try again after the
1482                  * transport is released.
1483                  */
1484                 task->tk_status = 0;
1485                 task->tk_action = call_bc_transmit;
1486                 return;
1487         }
1488
1489         task->tk_action = rpc_exit_task;
1490         if (task->tk_status < 0) {
1491                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1492                         "error: %d\n", task->tk_status);
1493                 return;
1494         }
1495
1496         xprt_transmit(task);
1497         xprt_end_transmit(task);
1498         dprint_status(task);
1499         switch (task->tk_status) {
1500         case 0:
1501                 /* Success */
1502                 break;
1503         case -EHOSTDOWN:
1504         case -EHOSTUNREACH:
1505         case -ENETUNREACH:
1506         case -ETIMEDOUT:
1507                 /*
1508                  * Problem reaching the server.  Disconnect and let the
1509                  * forechannel reestablish the connection.  The server will
1510                  * have to retransmit the backchannel request and we'll
1511                  * reprocess it.  Since these ops are idempotent, there's no
1512                  * need to cache our reply at this time.
1513                  */
1514                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1515                         "error: %d\n", task->tk_status);
1516                 xprt_conditional_disconnect(task->tk_xprt,
1517                         req->rq_connect_cookie);
1518                 break;
1519         default:
1520                 /*
1521                  * We were unable to reply and will have to drop the
1522                  * request.  The server should reconnect and retransmit.
1523                  */
1524                 BUG_ON(task->tk_status == -EAGAIN);
1525                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1526                         "error: %d\n", task->tk_status);
1527                 break;
1528         }
1529         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1530 }
1531 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1532
1533 /*
1534  * 6.   Sort out the RPC call status
1535  */
1536 static void
1537 call_status(struct rpc_task *task)
1538 {
1539         struct rpc_clnt *clnt = task->tk_client;
1540         struct rpc_rqst *req = task->tk_rqstp;
1541         int             status;
1542
1543         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1544                 task->tk_status = req->rq_reply_bytes_recvd;
1545
1546         dprint_status(task);
1547
1548         status = task->tk_status;
1549         if (status >= 0) {
1550                 task->tk_action = call_decode;
1551                 return;
1552         }
1553
1554         task->tk_status = 0;
1555         switch(status) {
1556         case -EHOSTDOWN:
1557         case -EHOSTUNREACH:
1558         case -ENETUNREACH:
1559                 /*
1560                  * Delay any retries for 3 seconds, then handle as if it
1561                  * were a timeout.
1562                  */
1563                 rpc_delay(task, 3*HZ);
1564         case -ETIMEDOUT:
1565                 task->tk_action = call_timeout;
1566                 if (task->tk_client->cl_discrtry)
1567                         xprt_conditional_disconnect(task->tk_xprt,
1568                                         req->rq_connect_cookie);
1569                 break;
1570         case -ECONNRESET:
1571         case -ECONNREFUSED:
1572                 rpc_force_rebind(clnt);
1573                 rpc_delay(task, 3*HZ);
1574         case -EPIPE:
1575         case -ENOTCONN:
1576                 task->tk_action = call_bind;
1577                 break;
1578         case -EAGAIN:
1579                 task->tk_action = call_transmit;
1580                 break;
1581         case -EIO:
1582                 /* shutdown or soft timeout */
1583                 rpc_exit(task, status);
1584                 break;
1585         default:
1586                 if (clnt->cl_chatty)
1587                         printk("%s: RPC call returned error %d\n",
1588                                clnt->cl_protname, -status);
1589                 rpc_exit(task, status);
1590         }
1591 }
1592
1593 /*
1594  * 6a.  Handle RPC timeout
1595  *      We do not release the request slot, so we keep using the
1596  *      same XID for all retransmits.
1597  */
1598 static void
1599 call_timeout(struct rpc_task *task)
1600 {
1601         struct rpc_clnt *clnt = task->tk_client;
1602
1603         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1604                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1605                 goto retry;
1606         }
1607
1608         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1609         task->tk_timeouts++;
1610
1611         if (RPC_IS_SOFTCONN(task)) {
1612                 rpc_exit(task, -ETIMEDOUT);
1613                 return;
1614         }
1615         if (RPC_IS_SOFT(task)) {
1616                 if (clnt->cl_chatty)
1617                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1618                                 clnt->cl_protname, clnt->cl_server);
1619                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1620                         rpc_exit(task, -ETIMEDOUT);
1621                 else
1622                         rpc_exit(task, -EIO);
1623                 return;
1624         }
1625
1626         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1627                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1628                 if (clnt->cl_chatty)
1629                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1630                         clnt->cl_protname, clnt->cl_server);
1631         }
1632         rpc_force_rebind(clnt);
1633         /*
1634          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1635          * event? RFC2203 requires the server to drop all such requests.
1636          */
1637         rpcauth_invalcred(task);
1638
1639 retry:
1640         clnt->cl_stats->rpcretrans++;
1641         task->tk_action = call_bind;
1642         task->tk_status = 0;
1643 }
1644
1645 /*
1646  * 7.   Decode the RPC reply
1647  */
1648 static void
1649 call_decode(struct rpc_task *task)
1650 {
1651         struct rpc_clnt *clnt = task->tk_client;
1652         struct rpc_rqst *req = task->tk_rqstp;
1653         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1654         __be32          *p;
1655
1656         dprint_status(task);
1657
1658         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1659                 if (clnt->cl_chatty)
1660                         printk(KERN_NOTICE "%s: server %s OK\n",
1661                                 clnt->cl_protname, clnt->cl_server);
1662                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1663         }
1664
1665         /*
1666          * Ensure that we see all writes made by xprt_complete_rqst()
1667          * before it changed req->rq_reply_bytes_recvd.
1668          */
1669         smp_rmb();
1670         req->rq_rcv_buf.len = req->rq_private_buf.len;
1671
1672         /* Check that the softirq receive buffer is valid */
1673         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1674                                 sizeof(req->rq_rcv_buf)) != 0);
1675
1676         if (req->rq_rcv_buf.len < 12) {
1677                 if (!RPC_IS_SOFT(task)) {
1678                         task->tk_action = call_bind;
1679                         clnt->cl_stats->rpcretrans++;
1680                         goto out_retry;
1681                 }
1682                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1683                                 clnt->cl_protname, task->tk_status);
1684                 task->tk_action = call_timeout;
1685                 goto out_retry;
1686         }
1687
1688         p = rpc_verify_header(task);
1689         if (IS_ERR(p)) {
1690                 if (p == ERR_PTR(-EAGAIN))
1691                         goto out_retry;
1692                 return;
1693         }
1694
1695         task->tk_action = rpc_exit_task;
1696
1697         if (decode) {
1698                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1699                                                       task->tk_msg.rpc_resp);
1700         }
1701         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1702                         task->tk_status);
1703         return;
1704 out_retry:
1705         task->tk_status = 0;
1706         /* Note: rpc_verify_header() may have freed the RPC slot */
1707         if (task->tk_rqstp == req) {
1708                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1709                 if (task->tk_client->cl_discrtry)
1710                         xprt_conditional_disconnect(task->tk_xprt,
1711                                         req->rq_connect_cookie);
1712         }
1713 }
1714
1715 static __be32 *
1716 rpc_encode_header(struct rpc_task *task)
1717 {
1718         struct rpc_clnt *clnt = task->tk_client;
1719         struct rpc_rqst *req = task->tk_rqstp;
1720         __be32          *p = req->rq_svec[0].iov_base;
1721
1722         /* FIXME: check buffer size? */
1723
1724         p = xprt_skip_transport_header(task->tk_xprt, p);
1725         *p++ = req->rq_xid;             /* XID */
1726         *p++ = htonl(RPC_CALL);         /* CALL */
1727         *p++ = htonl(RPC_VERSION);      /* RPC version */
1728         *p++ = htonl(clnt->cl_prog);    /* program number */
1729         *p++ = htonl(clnt->cl_vers);    /* program version */
1730         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1731         p = rpcauth_marshcred(task, p);
1732         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1733         return p;
1734 }
1735
1736 static __be32 *
1737 rpc_verify_header(struct rpc_task *task)
1738 {
1739         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1740         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1741         __be32  *p = iov->iov_base;
1742         u32 n;
1743         int error = -EACCES;
1744
1745         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1746                 /* RFC-1014 says that the representation of XDR data must be a
1747                  * multiple of four bytes
1748                  * - if it isn't pointer subtraction in the NFS client may give
1749                  *   undefined results
1750                  */
1751                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1752                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1753                        task->tk_rqstp->rq_rcv_buf.len);
1754                 goto out_eio;
1755         }
1756         if ((len -= 3) < 0)
1757                 goto out_overflow;
1758
1759         p += 1; /* skip XID */
1760         if ((n = ntohl(*p++)) != RPC_REPLY) {
1761                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1762                         task->tk_pid, __func__, n);
1763                 goto out_garbage;
1764         }
1765
1766         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1767                 if (--len < 0)
1768                         goto out_overflow;
1769                 switch ((n = ntohl(*p++))) {
1770                 case RPC_AUTH_ERROR:
1771                         break;
1772                 case RPC_MISMATCH:
1773                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
1774                                 task->tk_pid, __func__);
1775                         error = -EPROTONOSUPPORT;
1776                         goto out_err;
1777                 default:
1778                         dprintk("RPC: %5u %s: RPC call rejected, "
1779                                 "unknown error: %x\n",
1780                                 task->tk_pid, __func__, n);
1781                         goto out_eio;
1782                 }
1783                 if (--len < 0)
1784                         goto out_overflow;
1785                 switch ((n = ntohl(*p++))) {
1786                 case RPC_AUTH_REJECTEDCRED:
1787                 case RPC_AUTH_REJECTEDVERF:
1788                 case RPCSEC_GSS_CREDPROBLEM:
1789                 case RPCSEC_GSS_CTXPROBLEM:
1790                         if (!task->tk_cred_retry)
1791                                 break;
1792                         task->tk_cred_retry--;
1793                         dprintk("RPC: %5u %s: retry stale creds\n",
1794                                         task->tk_pid, __func__);
1795                         rpcauth_invalcred(task);
1796                         /* Ensure we obtain a new XID! */
1797                         xprt_release(task);
1798                         task->tk_action = call_reserve;
1799                         goto out_retry;
1800                 case RPC_AUTH_BADCRED:
1801                 case RPC_AUTH_BADVERF:
1802                         /* possibly garbled cred/verf? */
1803                         if (!task->tk_garb_retry)
1804                                 break;
1805                         task->tk_garb_retry--;
1806                         dprintk("RPC: %5u %s: retry garbled creds\n",
1807                                         task->tk_pid, __func__);
1808                         task->tk_action = call_bind;
1809                         goto out_retry;
1810                 case RPC_AUTH_TOOWEAK:
1811                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1812                                "authentication.\n", task->tk_client->cl_server);
1813                         break;
1814                 default:
1815                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1816                                         task->tk_pid, __func__, n);
1817                         error = -EIO;
1818                 }
1819                 dprintk("RPC: %5u %s: call rejected %d\n",
1820                                 task->tk_pid, __func__, n);
1821                 goto out_err;
1822         }
1823         if (!(p = rpcauth_checkverf(task, p))) {
1824                 dprintk("RPC: %5u %s: auth check failed\n",
1825                                 task->tk_pid, __func__);
1826                 goto out_garbage;               /* bad verifier, retry */
1827         }
1828         len = p - (__be32 *)iov->iov_base - 1;
1829         if (len < 0)
1830                 goto out_overflow;
1831         switch ((n = ntohl(*p++))) {
1832         case RPC_SUCCESS:
1833                 return p;
1834         case RPC_PROG_UNAVAIL:
1835                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1836                                 task->tk_pid, __func__,
1837                                 (unsigned int)task->tk_client->cl_prog,
1838                                 task->tk_client->cl_server);
1839                 error = -EPFNOSUPPORT;
1840                 goto out_err;
1841         case RPC_PROG_MISMATCH:
1842                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1843                                 "server %s\n", task->tk_pid, __func__,
1844                                 (unsigned int)task->tk_client->cl_prog,
1845                                 (unsigned int)task->tk_client->cl_vers,
1846                                 task->tk_client->cl_server);
1847                 error = -EPROTONOSUPPORT;
1848                 goto out_err;
1849         case RPC_PROC_UNAVAIL:
1850                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1851                                 "version %u on server %s\n",
1852                                 task->tk_pid, __func__,
1853                                 rpc_proc_name(task),
1854                                 task->tk_client->cl_prog,
1855                                 task->tk_client->cl_vers,
1856                                 task->tk_client->cl_server);
1857                 error = -EOPNOTSUPP;
1858                 goto out_err;
1859         case RPC_GARBAGE_ARGS:
1860                 dprintk("RPC: %5u %s: server saw garbage\n",
1861                                 task->tk_pid, __func__);
1862                 break;                  /* retry */
1863         default:
1864                 dprintk("RPC: %5u %s: server accept status: %x\n",
1865                                 task->tk_pid, __func__, n);
1866                 /* Also retry */
1867         }
1868
1869 out_garbage:
1870         task->tk_client->cl_stats->rpcgarbage++;
1871         if (task->tk_garb_retry) {
1872                 task->tk_garb_retry--;
1873                 dprintk("RPC: %5u %s: retrying\n",
1874                                 task->tk_pid, __func__);
1875                 task->tk_action = call_bind;
1876 out_retry:
1877                 return ERR_PTR(-EAGAIN);
1878         }
1879 out_eio:
1880         error = -EIO;
1881 out_err:
1882         rpc_exit(task, error);
1883         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1884                         __func__, error);
1885         return ERR_PTR(error);
1886 out_overflow:
1887         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1888                         __func__);
1889         goto out_garbage;
1890 }
1891
1892 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1893 {
1894 }
1895
1896 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1897 {
1898         return 0;
1899 }
1900
1901 static struct rpc_procinfo rpcproc_null = {
1902         .p_encode = rpcproc_encode_null,
1903         .p_decode = rpcproc_decode_null,
1904 };
1905
1906 static int rpc_ping(struct rpc_clnt *clnt)
1907 {
1908         struct rpc_message msg = {
1909                 .rpc_proc = &rpcproc_null,
1910         };
1911         int err;
1912         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1913         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1914         put_rpccred(msg.rpc_cred);
1915         return err;
1916 }
1917
1918 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1919 {
1920         struct rpc_message msg = {
1921                 .rpc_proc = &rpcproc_null,
1922                 .rpc_cred = cred,
1923         };
1924         struct rpc_task_setup task_setup_data = {
1925                 .rpc_client = clnt,
1926                 .rpc_message = &msg,
1927                 .callback_ops = &rpc_default_ops,
1928                 .flags = flags,
1929         };
1930         return rpc_run_task(&task_setup_data);
1931 }
1932 EXPORT_SYMBOL_GPL(rpc_call_null);
1933
1934 #ifdef RPC_DEBUG
1935 static void rpc_show_header(void)
1936 {
1937         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1938                 "-timeout ---ops--\n");
1939 }
1940
1941 static void rpc_show_task(const struct rpc_clnt *clnt,
1942                           const struct rpc_task *task)
1943 {
1944         const char *rpc_waitq = "none";
1945
1946         if (RPC_IS_QUEUED(task))
1947                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1948
1949         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
1950                 task->tk_pid, task->tk_flags, task->tk_status,
1951                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1952                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1953                 task->tk_action, rpc_waitq);
1954 }
1955
1956 void rpc_show_tasks(struct net *net)
1957 {
1958         struct rpc_clnt *clnt;
1959         struct rpc_task *task;
1960         int header = 0;
1961         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1962
1963         spin_lock(&sn->rpc_client_lock);
1964         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
1965                 spin_lock(&clnt->cl_lock);
1966                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1967                         if (!header) {
1968                                 rpc_show_header();
1969                                 header++;
1970                         }
1971                         rpc_show_task(clnt, task);
1972                 }
1973                 spin_unlock(&clnt->cl_lock);
1974         }
1975         spin_unlock(&sn->rpc_client_lock);
1976 }
1977 #endif