Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  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
42 #ifdef RPC_DEBUG
43 # define RPCDBG_FACILITY        RPCDBG_CALL
44 #endif
45
46 #define dprint_status(t)                                        \
47         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
48                         __func__, t->tk_status)
49
50 /*
51  * All RPC clients are linked into this list
52  */
53 static LIST_HEAD(all_clients);
54 static DEFINE_SPINLOCK(rpc_client_lock);
55
56 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
57
58
59 static void     call_start(struct rpc_task *task);
60 static void     call_reserve(struct rpc_task *task);
61 static void     call_reserveresult(struct rpc_task *task);
62 static void     call_allocate(struct rpc_task *task);
63 static void     call_decode(struct rpc_task *task);
64 static void     call_bind(struct rpc_task *task);
65 static void     call_bind_status(struct rpc_task *task);
66 static void     call_transmit(struct rpc_task *task);
67 #if defined(CONFIG_NFS_V4_1)
68 static void     call_bc_transmit(struct rpc_task *task);
69 #endif /* CONFIG_NFS_V4_1 */
70 static void     call_status(struct rpc_task *task);
71 static void     call_transmit_status(struct rpc_task *task);
72 static void     call_refresh(struct rpc_task *task);
73 static void     call_refreshresult(struct rpc_task *task);
74 static void     call_timeout(struct rpc_task *task);
75 static void     call_connect(struct rpc_task *task);
76 static void     call_connect_status(struct rpc_task *task);
77
78 static __be32   *rpc_encode_header(struct rpc_task *task);
79 static __be32   *rpc_verify_header(struct rpc_task *task);
80 static int      rpc_ping(struct rpc_clnt *clnt);
81
82 static void rpc_register_client(struct rpc_clnt *clnt)
83 {
84         spin_lock(&rpc_client_lock);
85         list_add(&clnt->cl_clients, &all_clients);
86         spin_unlock(&rpc_client_lock);
87 }
88
89 static void rpc_unregister_client(struct rpc_clnt *clnt)
90 {
91         spin_lock(&rpc_client_lock);
92         list_del(&clnt->cl_clients);
93         spin_unlock(&rpc_client_lock);
94 }
95
96 static int
97 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
98 {
99         static uint32_t clntid;
100         struct nameidata nd;
101         struct path path;
102         char name[15];
103         struct qstr q = {
104                 .name = name,
105         };
106         int error;
107
108         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
109         clnt->cl_path.dentry = ERR_PTR(-ENOENT);
110         if (dir_name == NULL)
111                 return 0;
112
113         path.mnt = rpc_get_mount();
114         if (IS_ERR(path.mnt))
115                 return PTR_ERR(path.mnt);
116         error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
117         if (error)
118                 goto err;
119
120         for (;;) {
121                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
122                 name[sizeof(name) - 1] = '\0';
123                 q.hash = full_name_hash(q.name, q.len);
124                 path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
125                 if (!IS_ERR(path.dentry))
126                         break;
127                 error = PTR_ERR(path.dentry);
128                 if (error != -EEXIST) {
129                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
130                                         " %s/%s, error %d\n",
131                                         dir_name, name, error);
132                         goto err_path_put;
133                 }
134         }
135         path_put(&nd.path);
136         clnt->cl_path = path;
137         return 0;
138 err_path_put:
139         path_put(&nd.path);
140 err:
141         rpc_put_mount();
142         return error;
143 }
144
145 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
146 {
147         struct rpc_program      *program = args->program;
148         struct rpc_version      *version;
149         struct rpc_clnt         *clnt = NULL;
150         struct rpc_auth         *auth;
151         int err;
152         size_t len;
153
154         /* sanity check the name before trying to print it */
155         err = -EINVAL;
156         len = strlen(args->servername);
157         if (len > RPC_MAXNETNAMELEN)
158                 goto out_no_rpciod;
159         len++;
160
161         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
162                         program->name, args->servername, xprt);
163
164         err = rpciod_up();
165         if (err)
166                 goto out_no_rpciod;
167         err = -EINVAL;
168         if (!xprt)
169                 goto out_no_xprt;
170
171         if (args->version >= program->nrvers)
172                 goto out_err;
173         version = program->version[args->version];
174         if (version == NULL)
175                 goto out_err;
176
177         err = -ENOMEM;
178         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
179         if (!clnt)
180                 goto out_err;
181         clnt->cl_parent = clnt;
182
183         clnt->cl_server = clnt->cl_inline_name;
184         if (len > sizeof(clnt->cl_inline_name)) {
185                 char *buf = kmalloc(len, GFP_KERNEL);
186                 if (buf != NULL)
187                         clnt->cl_server = buf;
188                 else
189                         len = sizeof(clnt->cl_inline_name);
190         }
191         strlcpy(clnt->cl_server, args->servername, len);
192
193         clnt->cl_xprt     = xprt;
194         clnt->cl_procinfo = version->procs;
195         clnt->cl_maxproc  = version->nrprocs;
196         clnt->cl_protname = program->name;
197         clnt->cl_prog     = args->prognumber ? : program->number;
198         clnt->cl_vers     = version->number;
199         clnt->cl_stats    = program->stats;
200         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
201         err = -ENOMEM;
202         if (clnt->cl_metrics == NULL)
203                 goto out_no_stats;
204         clnt->cl_program  = program;
205         INIT_LIST_HEAD(&clnt->cl_tasks);
206         spin_lock_init(&clnt->cl_lock);
207
208         if (!xprt_bound(clnt->cl_xprt))
209                 clnt->cl_autobind = 1;
210
211         clnt->cl_timeout = xprt->timeout;
212         if (args->timeout != NULL) {
213                 memcpy(&clnt->cl_timeout_default, args->timeout,
214                                 sizeof(clnt->cl_timeout_default));
215                 clnt->cl_timeout = &clnt->cl_timeout_default;
216         }
217
218         clnt->cl_rtt = &clnt->cl_rtt_default;
219         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
220         clnt->cl_principal = NULL;
221         if (args->client_name) {
222                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
223                 if (!clnt->cl_principal)
224                         goto out_no_principal;
225         }
226
227         atomic_set(&clnt->cl_count, 1);
228
229         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
230         if (err < 0)
231                 goto out_no_path;
232
233         auth = rpcauth_create(args->authflavor, clnt);
234         if (IS_ERR(auth)) {
235                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
236                                 args->authflavor);
237                 err = PTR_ERR(auth);
238                 goto out_no_auth;
239         }
240
241         /* save the nodename */
242         clnt->cl_nodelen = strlen(init_utsname()->nodename);
243         if (clnt->cl_nodelen > UNX_MAXNODENAME)
244                 clnt->cl_nodelen = UNX_MAXNODENAME;
245         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
246         rpc_register_client(clnt);
247         return clnt;
248
249 out_no_auth:
250         if (!IS_ERR(clnt->cl_path.dentry)) {
251                 rpc_remove_client_dir(clnt->cl_path.dentry);
252                 rpc_put_mount();
253         }
254 out_no_path:
255         kfree(clnt->cl_principal);
256 out_no_principal:
257         rpc_free_iostats(clnt->cl_metrics);
258 out_no_stats:
259         if (clnt->cl_server != clnt->cl_inline_name)
260                 kfree(clnt->cl_server);
261         kfree(clnt);
262 out_err:
263         xprt_put(xprt);
264 out_no_xprt:
265         rpciod_down();
266 out_no_rpciod:
267         return ERR_PTR(err);
268 }
269
270 /*
271  * rpc_create - create an RPC client and transport with one call
272  * @args: rpc_clnt create argument structure
273  *
274  * Creates and initializes an RPC transport and an RPC client.
275  *
276  * It can ping the server in order to determine if it is up, and to see if
277  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
278  * this behavior so asynchronous tasks can also use rpc_create.
279  */
280 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
281 {
282         struct rpc_xprt *xprt;
283         struct rpc_clnt *clnt;
284         struct xprt_create xprtargs = {
285                 .net = args->net,
286                 .ident = args->protocol,
287                 .srcaddr = args->saddress,
288                 .dstaddr = args->address,
289                 .addrlen = args->addrsize,
290                 .bc_xprt = args->bc_xprt,
291         };
292         char servername[48];
293
294         /*
295          * If the caller chooses not to specify a hostname, whip
296          * up a string representation of the passed-in address.
297          */
298         if (args->servername == NULL) {
299                 struct sockaddr_un *sun =
300                                 (struct sockaddr_un *)args->address;
301                 struct sockaddr_in *sin =
302                                 (struct sockaddr_in *)args->address;
303                 struct sockaddr_in6 *sin6 =
304                                 (struct sockaddr_in6 *)args->address;
305
306                 servername[0] = '\0';
307                 switch (args->address->sa_family) {
308                 case AF_LOCAL:
309                         snprintf(servername, sizeof(servername), "%s",
310                                  sun->sun_path);
311                         break;
312                 case AF_INET:
313                         snprintf(servername, sizeof(servername), "%pI4",
314                                  &sin->sin_addr.s_addr);
315                         break;
316                 case AF_INET6:
317                         snprintf(servername, sizeof(servername), "%pI6",
318                                  &sin6->sin6_addr);
319                         break;
320                 default:
321                         /* caller wants default server name, but
322                          * address family isn't recognized. */
323                         return ERR_PTR(-EINVAL);
324                 }
325                 args->servername = servername;
326         }
327
328         xprt = xprt_create_transport(&xprtargs);
329         if (IS_ERR(xprt))
330                 return (struct rpc_clnt *)xprt;
331
332         /*
333          * By default, kernel RPC client connects from a reserved port.
334          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
335          * but it is always enabled for rpciod, which handles the connect
336          * operation.
337          */
338         xprt->resvport = 1;
339         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
340                 xprt->resvport = 0;
341
342         clnt = rpc_new_client(args, xprt);
343         if (IS_ERR(clnt))
344                 return clnt;
345
346         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
347                 int err = rpc_ping(clnt);
348                 if (err != 0) {
349                         rpc_shutdown_client(clnt);
350                         return ERR_PTR(err);
351                 }
352         }
353
354         clnt->cl_softrtry = 1;
355         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
356                 clnt->cl_softrtry = 0;
357
358         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
359                 clnt->cl_autobind = 1;
360         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
361                 clnt->cl_discrtry = 1;
362         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
363                 clnt->cl_chatty = 1;
364
365         return clnt;
366 }
367 EXPORT_SYMBOL_GPL(rpc_create);
368
369 /*
370  * This function clones the RPC client structure. It allows us to share the
371  * same transport while varying parameters such as the authentication
372  * flavour.
373  */
374 struct rpc_clnt *
375 rpc_clone_client(struct rpc_clnt *clnt)
376 {
377         struct rpc_clnt *new;
378         int err = -ENOMEM;
379
380         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
381         if (!new)
382                 goto out_no_clnt;
383         new->cl_parent = clnt;
384         /* Turn off autobind on clones */
385         new->cl_autobind = 0;
386         INIT_LIST_HEAD(&new->cl_tasks);
387         spin_lock_init(&new->cl_lock);
388         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
389         new->cl_metrics = rpc_alloc_iostats(clnt);
390         if (new->cl_metrics == NULL)
391                 goto out_no_stats;
392         if (clnt->cl_principal) {
393                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
394                 if (new->cl_principal == NULL)
395                         goto out_no_principal;
396         }
397         atomic_set(&new->cl_count, 1);
398         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
399         if (err != 0)
400                 goto out_no_path;
401         if (new->cl_auth)
402                 atomic_inc(&new->cl_auth->au_count);
403         xprt_get(clnt->cl_xprt);
404         atomic_inc(&clnt->cl_count);
405         rpc_register_client(new);
406         rpciod_up();
407         return new;
408 out_no_path:
409         kfree(new->cl_principal);
410 out_no_principal:
411         rpc_free_iostats(new->cl_metrics);
412 out_no_stats:
413         kfree(new);
414 out_no_clnt:
415         dprintk("RPC:       %s: returned error %d\n", __func__, err);
416         return ERR_PTR(err);
417 }
418 EXPORT_SYMBOL_GPL(rpc_clone_client);
419
420 /*
421  * Kill all tasks for the given client.
422  * XXX: kill their descendants as well?
423  */
424 void rpc_killall_tasks(struct rpc_clnt *clnt)
425 {
426         struct rpc_task *rovr;
427
428
429         if (list_empty(&clnt->cl_tasks))
430                 return;
431         dprintk("RPC:       killing all tasks for client %p\n", clnt);
432         /*
433          * Spin lock all_tasks to prevent changes...
434          */
435         spin_lock(&clnt->cl_lock);
436         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
437                 if (!RPC_IS_ACTIVATED(rovr))
438                         continue;
439                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
440                         rovr->tk_flags |= RPC_TASK_KILLED;
441                         rpc_exit(rovr, -EIO);
442                         if (RPC_IS_QUEUED(rovr))
443                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
444                                                         rovr);
445                 }
446         }
447         spin_unlock(&clnt->cl_lock);
448 }
449 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
450
451 /*
452  * Properly shut down an RPC client, terminating all outstanding
453  * requests.
454  */
455 void rpc_shutdown_client(struct rpc_clnt *clnt)
456 {
457         dprintk("RPC:       shutting down %s client for %s\n",
458                         clnt->cl_protname, clnt->cl_server);
459
460         while (!list_empty(&clnt->cl_tasks)) {
461                 rpc_killall_tasks(clnt);
462                 wait_event_timeout(destroy_wait,
463                         list_empty(&clnt->cl_tasks), 1*HZ);
464         }
465
466         rpc_release_client(clnt);
467 }
468 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
469
470 /*
471  * Free an RPC client
472  */
473 static void
474 rpc_free_client(struct rpc_clnt *clnt)
475 {
476         dprintk("RPC:       destroying %s client for %s\n",
477                         clnt->cl_protname, clnt->cl_server);
478         if (!IS_ERR(clnt->cl_path.dentry)) {
479                 rpc_remove_client_dir(clnt->cl_path.dentry);
480                 rpc_put_mount();
481         }
482         if (clnt->cl_parent != clnt) {
483                 rpc_release_client(clnt->cl_parent);
484                 goto out_free;
485         }
486         if (clnt->cl_server != clnt->cl_inline_name)
487                 kfree(clnt->cl_server);
488 out_free:
489         rpc_unregister_client(clnt);
490         rpc_free_iostats(clnt->cl_metrics);
491         kfree(clnt->cl_principal);
492         clnt->cl_metrics = NULL;
493         xprt_put(clnt->cl_xprt);
494         rpciod_down();
495         kfree(clnt);
496 }
497
498 /*
499  * Free an RPC client
500  */
501 static void
502 rpc_free_auth(struct rpc_clnt *clnt)
503 {
504         if (clnt->cl_auth == NULL) {
505                 rpc_free_client(clnt);
506                 return;
507         }
508
509         /*
510          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
511          *       release remaining GSS contexts. This mechanism ensures
512          *       that it can do so safely.
513          */
514         atomic_inc(&clnt->cl_count);
515         rpcauth_release(clnt->cl_auth);
516         clnt->cl_auth = NULL;
517         if (atomic_dec_and_test(&clnt->cl_count))
518                 rpc_free_client(clnt);
519 }
520
521 /*
522  * Release reference to the RPC client
523  */
524 void
525 rpc_release_client(struct rpc_clnt *clnt)
526 {
527         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
528
529         if (list_empty(&clnt->cl_tasks))
530                 wake_up(&destroy_wait);
531         if (atomic_dec_and_test(&clnt->cl_count))
532                 rpc_free_auth(clnt);
533 }
534
535 /**
536  * rpc_bind_new_program - bind a new RPC program to an existing client
537  * @old: old rpc_client
538  * @program: rpc program to set
539  * @vers: rpc program version
540  *
541  * Clones the rpc client and sets up a new RPC program. This is mainly
542  * of use for enabling different RPC programs to share the same transport.
543  * The Sun NFSv2/v3 ACL protocol can do this.
544  */
545 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
546                                       struct rpc_program *program,
547                                       u32 vers)
548 {
549         struct rpc_clnt *clnt;
550         struct rpc_version *version;
551         int err;
552
553         BUG_ON(vers >= program->nrvers || !program->version[vers]);
554         version = program->version[vers];
555         clnt = rpc_clone_client(old);
556         if (IS_ERR(clnt))
557                 goto out;
558         clnt->cl_procinfo = version->procs;
559         clnt->cl_maxproc  = version->nrprocs;
560         clnt->cl_protname = program->name;
561         clnt->cl_prog     = program->number;
562         clnt->cl_vers     = version->number;
563         clnt->cl_stats    = program->stats;
564         err = rpc_ping(clnt);
565         if (err != 0) {
566                 rpc_shutdown_client(clnt);
567                 clnt = ERR_PTR(err);
568         }
569 out:
570         return clnt;
571 }
572 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
573
574 void rpc_task_release_client(struct rpc_task *task)
575 {
576         struct rpc_clnt *clnt = task->tk_client;
577
578         if (clnt != NULL) {
579                 /* Remove from client task list */
580                 spin_lock(&clnt->cl_lock);
581                 list_del(&task->tk_task);
582                 spin_unlock(&clnt->cl_lock);
583                 task->tk_client = NULL;
584
585                 rpc_release_client(clnt);
586         }
587 }
588
589 static
590 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
591 {
592         if (clnt != NULL) {
593                 rpc_task_release_client(task);
594                 task->tk_client = clnt;
595                 atomic_inc(&clnt->cl_count);
596                 if (clnt->cl_softrtry)
597                         task->tk_flags |= RPC_TASK_SOFT;
598                 /* Add to the client's list of all tasks */
599                 spin_lock(&clnt->cl_lock);
600                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
601                 spin_unlock(&clnt->cl_lock);
602         }
603 }
604
605 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
606 {
607         rpc_task_release_client(task);
608         rpc_task_set_client(task, clnt);
609 }
610 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
611
612
613 static void
614 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
615 {
616         if (msg != NULL) {
617                 task->tk_msg.rpc_proc = msg->rpc_proc;
618                 task->tk_msg.rpc_argp = msg->rpc_argp;
619                 task->tk_msg.rpc_resp = msg->rpc_resp;
620                 if (msg->rpc_cred != NULL)
621                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
622         }
623 }
624
625 /*
626  * Default callback for async RPC calls
627  */
628 static void
629 rpc_default_callback(struct rpc_task *task, void *data)
630 {
631 }
632
633 static const struct rpc_call_ops rpc_default_ops = {
634         .rpc_call_done = rpc_default_callback,
635 };
636
637 /**
638  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
639  * @task_setup_data: pointer to task initialisation data
640  */
641 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
642 {
643         struct rpc_task *task;
644
645         task = rpc_new_task(task_setup_data);
646         if (IS_ERR(task))
647                 goto out;
648
649         rpc_task_set_client(task, task_setup_data->rpc_client);
650         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
651
652         if (task->tk_action == NULL)
653                 rpc_call_start(task);
654
655         atomic_inc(&task->tk_count);
656         rpc_execute(task);
657 out:
658         return task;
659 }
660 EXPORT_SYMBOL_GPL(rpc_run_task);
661
662 /**
663  * rpc_call_sync - Perform a synchronous RPC call
664  * @clnt: pointer to RPC client
665  * @msg: RPC call parameters
666  * @flags: RPC call flags
667  */
668 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
669 {
670         struct rpc_task *task;
671         struct rpc_task_setup task_setup_data = {
672                 .rpc_client = clnt,
673                 .rpc_message = msg,
674                 .callback_ops = &rpc_default_ops,
675                 .flags = flags,
676         };
677         int status;
678
679         BUG_ON(flags & RPC_TASK_ASYNC);
680
681         task = rpc_run_task(&task_setup_data);
682         if (IS_ERR(task))
683                 return PTR_ERR(task);
684         status = task->tk_status;
685         rpc_put_task(task);
686         return status;
687 }
688 EXPORT_SYMBOL_GPL(rpc_call_sync);
689
690 /**
691  * rpc_call_async - Perform an asynchronous RPC call
692  * @clnt: pointer to RPC client
693  * @msg: RPC call parameters
694  * @flags: RPC call flags
695  * @tk_ops: RPC call ops
696  * @data: user call data
697  */
698 int
699 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
700                const struct rpc_call_ops *tk_ops, void *data)
701 {
702         struct rpc_task *task;
703         struct rpc_task_setup task_setup_data = {
704                 .rpc_client = clnt,
705                 .rpc_message = msg,
706                 .callback_ops = tk_ops,
707                 .callback_data = data,
708                 .flags = flags|RPC_TASK_ASYNC,
709         };
710
711         task = rpc_run_task(&task_setup_data);
712         if (IS_ERR(task))
713                 return PTR_ERR(task);
714         rpc_put_task(task);
715         return 0;
716 }
717 EXPORT_SYMBOL_GPL(rpc_call_async);
718
719 #if defined(CONFIG_NFS_V4_1)
720 /**
721  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
722  * rpc_execute against it
723  * @req: RPC request
724  * @tk_ops: RPC call ops
725  */
726 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
727                                 const struct rpc_call_ops *tk_ops)
728 {
729         struct rpc_task *task;
730         struct xdr_buf *xbufp = &req->rq_snd_buf;
731         struct rpc_task_setup task_setup_data = {
732                 .callback_ops = tk_ops,
733         };
734
735         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
736         /*
737          * Create an rpc_task to send the data
738          */
739         task = rpc_new_task(&task_setup_data);
740         if (IS_ERR(task)) {
741                 xprt_free_bc_request(req);
742                 goto out;
743         }
744         task->tk_rqstp = req;
745
746         /*
747          * Set up the xdr_buf length.
748          * This also indicates that the buffer is XDR encoded already.
749          */
750         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
751                         xbufp->tail[0].iov_len;
752
753         task->tk_action = call_bc_transmit;
754         atomic_inc(&task->tk_count);
755         BUG_ON(atomic_read(&task->tk_count) != 2);
756         rpc_execute(task);
757
758 out:
759         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
760         return task;
761 }
762 #endif /* CONFIG_NFS_V4_1 */
763
764 void
765 rpc_call_start(struct rpc_task *task)
766 {
767         task->tk_action = call_start;
768 }
769 EXPORT_SYMBOL_GPL(rpc_call_start);
770
771 /**
772  * rpc_peeraddr - extract remote peer address from clnt's xprt
773  * @clnt: RPC client structure
774  * @buf: target buffer
775  * @bufsize: length of target buffer
776  *
777  * Returns the number of bytes that are actually in the stored address.
778  */
779 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
780 {
781         size_t bytes;
782         struct rpc_xprt *xprt = clnt->cl_xprt;
783
784         bytes = sizeof(xprt->addr);
785         if (bytes > bufsize)
786                 bytes = bufsize;
787         memcpy(buf, &clnt->cl_xprt->addr, bytes);
788         return xprt->addrlen;
789 }
790 EXPORT_SYMBOL_GPL(rpc_peeraddr);
791
792 /**
793  * rpc_peeraddr2str - return remote peer address in printable format
794  * @clnt: RPC client structure
795  * @format: address format
796  *
797  */
798 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
799                              enum rpc_display_format_t format)
800 {
801         struct rpc_xprt *xprt = clnt->cl_xprt;
802
803         if (xprt->address_strings[format] != NULL)
804                 return xprt->address_strings[format];
805         else
806                 return "unprintable";
807 }
808 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
809
810 void
811 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
812 {
813         struct rpc_xprt *xprt = clnt->cl_xprt;
814         if (xprt->ops->set_buffer_size)
815                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
816 }
817 EXPORT_SYMBOL_GPL(rpc_setbufsize);
818
819 /*
820  * Return size of largest payload RPC client can support, in bytes
821  *
822  * For stream transports, this is one RPC record fragment (see RFC
823  * 1831), as we don't support multi-record requests yet.  For datagram
824  * transports, this is the size of an IP packet minus the IP, UDP, and
825  * RPC header sizes.
826  */
827 size_t rpc_max_payload(struct rpc_clnt *clnt)
828 {
829         return clnt->cl_xprt->max_payload;
830 }
831 EXPORT_SYMBOL_GPL(rpc_max_payload);
832
833 /**
834  * rpc_force_rebind - force transport to check that remote port is unchanged
835  * @clnt: client to rebind
836  *
837  */
838 void rpc_force_rebind(struct rpc_clnt *clnt)
839 {
840         if (clnt->cl_autobind)
841                 xprt_clear_bound(clnt->cl_xprt);
842 }
843 EXPORT_SYMBOL_GPL(rpc_force_rebind);
844
845 /*
846  * Restart an (async) RPC call from the call_prepare state.
847  * Usually called from within the exit handler.
848  */
849 int
850 rpc_restart_call_prepare(struct rpc_task *task)
851 {
852         if (RPC_ASSASSINATED(task))
853                 return 0;
854         task->tk_action = rpc_prepare_task;
855         return 1;
856 }
857 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
858
859 /*
860  * Restart an (async) RPC call. Usually called from within the
861  * exit handler.
862  */
863 int
864 rpc_restart_call(struct rpc_task *task)
865 {
866         if (RPC_ASSASSINATED(task))
867                 return 0;
868         task->tk_action = call_start;
869         return 1;
870 }
871 EXPORT_SYMBOL_GPL(rpc_restart_call);
872
873 #ifdef RPC_DEBUG
874 static const char *rpc_proc_name(const struct rpc_task *task)
875 {
876         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
877
878         if (proc) {
879                 if (proc->p_name)
880                         return proc->p_name;
881                 else
882                         return "NULL";
883         } else
884                 return "no proc";
885 }
886 #endif
887
888 /*
889  * 0.  Initial state
890  *
891  *     Other FSM states can be visited zero or more times, but
892  *     this state is visited exactly once for each RPC.
893  */
894 static void
895 call_start(struct rpc_task *task)
896 {
897         struct rpc_clnt *clnt = task->tk_client;
898
899         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
900                         clnt->cl_protname, clnt->cl_vers,
901                         rpc_proc_name(task),
902                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
903
904         /* Increment call count */
905         task->tk_msg.rpc_proc->p_count++;
906         clnt->cl_stats->rpccnt++;
907         task->tk_action = call_reserve;
908 }
909
910 /*
911  * 1.   Reserve an RPC call slot
912  */
913 static void
914 call_reserve(struct rpc_task *task)
915 {
916         dprint_status(task);
917
918         task->tk_status  = 0;
919         task->tk_action  = call_reserveresult;
920         xprt_reserve(task);
921 }
922
923 /*
924  * 1b.  Grok the result of xprt_reserve()
925  */
926 static void
927 call_reserveresult(struct rpc_task *task)
928 {
929         int status = task->tk_status;
930
931         dprint_status(task);
932
933         /*
934          * After a call to xprt_reserve(), we must have either
935          * a request slot or else an error status.
936          */
937         task->tk_status = 0;
938         if (status >= 0) {
939                 if (task->tk_rqstp) {
940                         task->tk_action = call_refresh;
941                         return;
942                 }
943
944                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
945                                 __func__, status);
946                 rpc_exit(task, -EIO);
947                 return;
948         }
949
950         /*
951          * Even though there was an error, we may have acquired
952          * a request slot somehow.  Make sure not to leak it.
953          */
954         if (task->tk_rqstp) {
955                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
956                                 __func__, status);
957                 xprt_release(task);
958         }
959
960         switch (status) {
961         case -EAGAIN:   /* woken up; retry */
962                 task->tk_action = call_reserve;
963                 return;
964         case -EIO:      /* probably a shutdown */
965                 break;
966         default:
967                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
968                                 __func__, status);
969                 break;
970         }
971         rpc_exit(task, status);
972 }
973
974 /*
975  * 2.   Bind and/or refresh the credentials
976  */
977 static void
978 call_refresh(struct rpc_task *task)
979 {
980         dprint_status(task);
981
982         task->tk_action = call_refreshresult;
983         task->tk_status = 0;
984         task->tk_client->cl_stats->rpcauthrefresh++;
985         rpcauth_refreshcred(task);
986 }
987
988 /*
989  * 2a.  Process the results of a credential refresh
990  */
991 static void
992 call_refreshresult(struct rpc_task *task)
993 {
994         int status = task->tk_status;
995
996         dprint_status(task);
997
998         task->tk_status = 0;
999         task->tk_action = call_refresh;
1000         switch (status) {
1001         case 0:
1002                 if (rpcauth_uptodatecred(task))
1003                         task->tk_action = call_allocate;
1004                 return;
1005         case -ETIMEDOUT:
1006                 rpc_delay(task, 3*HZ);
1007         case -EAGAIN:
1008                 status = -EACCES;
1009                 if (!task->tk_cred_retry)
1010                         break;
1011                 task->tk_cred_retry--;
1012                 dprintk("RPC: %5u %s: retry refresh creds\n",
1013                                 task->tk_pid, __func__);
1014                 return;
1015         }
1016         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1017                                 task->tk_pid, __func__, status);
1018         rpc_exit(task, status);
1019 }
1020
1021 /*
1022  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1023  *      (Note: buffer memory is freed in xprt_release).
1024  */
1025 static void
1026 call_allocate(struct rpc_task *task)
1027 {
1028         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1029         struct rpc_rqst *req = task->tk_rqstp;
1030         struct rpc_xprt *xprt = task->tk_xprt;
1031         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1032
1033         dprint_status(task);
1034
1035         task->tk_status = 0;
1036         task->tk_action = call_bind;
1037
1038         if (req->rq_buffer)
1039                 return;
1040
1041         if (proc->p_proc != 0) {
1042                 BUG_ON(proc->p_arglen == 0);
1043                 if (proc->p_decode != NULL)
1044                         BUG_ON(proc->p_replen == 0);
1045         }
1046
1047         /*
1048          * Calculate the size (in quads) of the RPC call
1049          * and reply headers, and convert both values
1050          * to byte sizes.
1051          */
1052         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1053         req->rq_callsize <<= 2;
1054         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1055         req->rq_rcvsize <<= 2;
1056
1057         req->rq_buffer = xprt->ops->buf_alloc(task,
1058                                         req->rq_callsize + req->rq_rcvsize);
1059         if (req->rq_buffer != NULL)
1060                 return;
1061
1062         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1063
1064         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1065                 task->tk_action = call_allocate;
1066                 rpc_delay(task, HZ>>4);
1067                 return;
1068         }
1069
1070         rpc_exit(task, -ERESTARTSYS);
1071 }
1072
1073 static inline int
1074 rpc_task_need_encode(struct rpc_task *task)
1075 {
1076         return task->tk_rqstp->rq_snd_buf.len == 0;
1077 }
1078
1079 static inline void
1080 rpc_task_force_reencode(struct rpc_task *task)
1081 {
1082         task->tk_rqstp->rq_snd_buf.len = 0;
1083         task->tk_rqstp->rq_bytes_sent = 0;
1084 }
1085
1086 static inline void
1087 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1088 {
1089         buf->head[0].iov_base = start;
1090         buf->head[0].iov_len = len;
1091         buf->tail[0].iov_len = 0;
1092         buf->page_len = 0;
1093         buf->flags = 0;
1094         buf->len = 0;
1095         buf->buflen = len;
1096 }
1097
1098 /*
1099  * 3.   Encode arguments of an RPC call
1100  */
1101 static void
1102 rpc_xdr_encode(struct rpc_task *task)
1103 {
1104         struct rpc_rqst *req = task->tk_rqstp;
1105         kxdreproc_t     encode;
1106         __be32          *p;
1107
1108         dprint_status(task);
1109
1110         rpc_xdr_buf_init(&req->rq_snd_buf,
1111                          req->rq_buffer,
1112                          req->rq_callsize);
1113         rpc_xdr_buf_init(&req->rq_rcv_buf,
1114                          (char *)req->rq_buffer + req->rq_callsize,
1115                          req->rq_rcvsize);
1116
1117         p = rpc_encode_header(task);
1118         if (p == NULL) {
1119                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1120                 rpc_exit(task, -EIO);
1121                 return;
1122         }
1123
1124         encode = task->tk_msg.rpc_proc->p_encode;
1125         if (encode == NULL)
1126                 return;
1127
1128         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1129                         task->tk_msg.rpc_argp);
1130 }
1131
1132 /*
1133  * 4.   Get the server port number if not yet set
1134  */
1135 static void
1136 call_bind(struct rpc_task *task)
1137 {
1138         struct rpc_xprt *xprt = task->tk_xprt;
1139
1140         dprint_status(task);
1141
1142         task->tk_action = call_connect;
1143         if (!xprt_bound(xprt)) {
1144                 task->tk_action = call_bind_status;
1145                 task->tk_timeout = xprt->bind_timeout;
1146                 xprt->ops->rpcbind(task);
1147         }
1148 }
1149
1150 /*
1151  * 4a.  Sort out bind result
1152  */
1153 static void
1154 call_bind_status(struct rpc_task *task)
1155 {
1156         int status = -EIO;
1157
1158         if (task->tk_status >= 0) {
1159                 dprint_status(task);
1160                 task->tk_status = 0;
1161                 task->tk_action = call_connect;
1162                 return;
1163         }
1164
1165         switch (task->tk_status) {
1166         case -ENOMEM:
1167                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1168                 rpc_delay(task, HZ >> 2);
1169                 goto retry_timeout;
1170         case -EACCES:
1171                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1172                                 "unavailable\n", task->tk_pid);
1173                 /* fail immediately if this is an RPC ping */
1174                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1175                         status = -EOPNOTSUPP;
1176                         break;
1177                 }
1178                 if (task->tk_rebind_retry == 0)
1179                         break;
1180                 task->tk_rebind_retry--;
1181                 rpc_delay(task, 3*HZ);
1182                 goto retry_timeout;
1183         case -ETIMEDOUT:
1184                 dprintk("RPC: %5u rpcbind request timed out\n",
1185                                 task->tk_pid);
1186                 goto retry_timeout;
1187         case -EPFNOSUPPORT:
1188                 /* server doesn't support any rpcbind version we know of */
1189                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1190                                 task->tk_pid);
1191                 break;
1192         case -EPROTONOSUPPORT:
1193                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1194                                 task->tk_pid);
1195                 task->tk_status = 0;
1196                 task->tk_action = call_bind;
1197                 return;
1198         case -ECONNREFUSED:             /* connection problems */
1199         case -ECONNRESET:
1200         case -ENOTCONN:
1201         case -EHOSTDOWN:
1202         case -EHOSTUNREACH:
1203         case -ENETUNREACH:
1204         case -EPIPE:
1205                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1206                                 task->tk_pid, task->tk_status);
1207                 if (!RPC_IS_SOFTCONN(task)) {
1208                         rpc_delay(task, 5*HZ);
1209                         goto retry_timeout;
1210                 }
1211                 status = task->tk_status;
1212                 break;
1213         default:
1214                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1215                                 task->tk_pid, -task->tk_status);
1216         }
1217
1218         rpc_exit(task, status);
1219         return;
1220
1221 retry_timeout:
1222         task->tk_action = call_timeout;
1223 }
1224
1225 /*
1226  * 4b.  Connect to the RPC server
1227  */
1228 static void
1229 call_connect(struct rpc_task *task)
1230 {
1231         struct rpc_xprt *xprt = task->tk_xprt;
1232
1233         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1234                         task->tk_pid, xprt,
1235                         (xprt_connected(xprt) ? "is" : "is not"));
1236
1237         task->tk_action = call_transmit;
1238         if (!xprt_connected(xprt)) {
1239                 task->tk_action = call_connect_status;
1240                 if (task->tk_status < 0)
1241                         return;
1242                 xprt_connect(task);
1243         }
1244 }
1245
1246 /*
1247  * 4c.  Sort out connect result
1248  */
1249 static void
1250 call_connect_status(struct rpc_task *task)
1251 {
1252         struct rpc_clnt *clnt = task->tk_client;
1253         int status = task->tk_status;
1254
1255         dprint_status(task);
1256
1257         task->tk_status = 0;
1258         if (status >= 0 || status == -EAGAIN) {
1259                 clnt->cl_stats->netreconn++;
1260                 task->tk_action = call_transmit;
1261                 return;
1262         }
1263
1264         switch (status) {
1265                 /* if soft mounted, test if we've timed out */
1266         case -ETIMEDOUT:
1267                 task->tk_action = call_timeout;
1268                 break;
1269         default:
1270                 rpc_exit(task, -EIO);
1271         }
1272 }
1273
1274 /*
1275  * 5.   Transmit the RPC request, and wait for reply
1276  */
1277 static void
1278 call_transmit(struct rpc_task *task)
1279 {
1280         dprint_status(task);
1281
1282         task->tk_action = call_status;
1283         if (task->tk_status < 0)
1284                 return;
1285         task->tk_status = xprt_prepare_transmit(task);
1286         if (task->tk_status != 0)
1287                 return;
1288         task->tk_action = call_transmit_status;
1289         /* Encode here so that rpcsec_gss can use correct sequence number. */
1290         if (rpc_task_need_encode(task)) {
1291                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1292                 rpc_xdr_encode(task);
1293                 /* Did the encode result in an error condition? */
1294                 if (task->tk_status != 0) {
1295                         /* Was the error nonfatal? */
1296                         if (task->tk_status == -EAGAIN)
1297                                 rpc_delay(task, HZ >> 4);
1298                         else
1299                                 rpc_exit(task, task->tk_status);
1300                         return;
1301                 }
1302         }
1303         xprt_transmit(task);
1304         if (task->tk_status < 0)
1305                 return;
1306         /*
1307          * On success, ensure that we call xprt_end_transmit() before sleeping
1308          * in order to allow access to the socket to other RPC requests.
1309          */
1310         call_transmit_status(task);
1311         if (rpc_reply_expected(task))
1312                 return;
1313         task->tk_action = rpc_exit_task;
1314         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1315 }
1316
1317 /*
1318  * 5a.  Handle cleanup after a transmission
1319  */
1320 static void
1321 call_transmit_status(struct rpc_task *task)
1322 {
1323         task->tk_action = call_status;
1324
1325         /*
1326          * Common case: success.  Force the compiler to put this
1327          * test first.
1328          */
1329         if (task->tk_status == 0) {
1330                 xprt_end_transmit(task);
1331                 rpc_task_force_reencode(task);
1332                 return;
1333         }
1334
1335         switch (task->tk_status) {
1336         case -EAGAIN:
1337                 break;
1338         default:
1339                 dprint_status(task);
1340                 xprt_end_transmit(task);
1341                 rpc_task_force_reencode(task);
1342                 break;
1343                 /*
1344                  * Special cases: if we've been waiting on the
1345                  * socket's write_space() callback, or if the
1346                  * socket just returned a connection error,
1347                  * then hold onto the transport lock.
1348                  */
1349         case -ECONNREFUSED:
1350         case -EHOSTDOWN:
1351         case -EHOSTUNREACH:
1352         case -ENETUNREACH:
1353                 if (RPC_IS_SOFTCONN(task)) {
1354                         xprt_end_transmit(task);
1355                         rpc_exit(task, task->tk_status);
1356                         break;
1357                 }
1358         case -ECONNRESET:
1359         case -ENOTCONN:
1360         case -EPIPE:
1361                 rpc_task_force_reencode(task);
1362         }
1363 }
1364
1365 #if defined(CONFIG_NFS_V4_1)
1366 /*
1367  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1368  * addition, disconnect on connectivity errors.
1369  */
1370 static void
1371 call_bc_transmit(struct rpc_task *task)
1372 {
1373         struct rpc_rqst *req = task->tk_rqstp;
1374
1375         BUG_ON(task->tk_status != 0);
1376         task->tk_status = xprt_prepare_transmit(task);
1377         if (task->tk_status == -EAGAIN) {
1378                 /*
1379                  * Could not reserve the transport. Try again after the
1380                  * transport is released.
1381                  */
1382                 task->tk_status = 0;
1383                 task->tk_action = call_bc_transmit;
1384                 return;
1385         }
1386
1387         task->tk_action = rpc_exit_task;
1388         if (task->tk_status < 0) {
1389                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1390                         "error: %d\n", task->tk_status);
1391                 return;
1392         }
1393
1394         xprt_transmit(task);
1395         xprt_end_transmit(task);
1396         dprint_status(task);
1397         switch (task->tk_status) {
1398         case 0:
1399                 /* Success */
1400                 break;
1401         case -EHOSTDOWN:
1402         case -EHOSTUNREACH:
1403         case -ENETUNREACH:
1404         case -ETIMEDOUT:
1405                 /*
1406                  * Problem reaching the server.  Disconnect and let the
1407                  * forechannel reestablish the connection.  The server will
1408                  * have to retransmit the backchannel request and we'll
1409                  * reprocess it.  Since these ops are idempotent, there's no
1410                  * need to cache our reply at this time.
1411                  */
1412                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1413                         "error: %d\n", task->tk_status);
1414                 xprt_conditional_disconnect(task->tk_xprt,
1415                         req->rq_connect_cookie);
1416                 break;
1417         default:
1418                 /*
1419                  * We were unable to reply and will have to drop the
1420                  * request.  The server should reconnect and retransmit.
1421                  */
1422                 BUG_ON(task->tk_status == -EAGAIN);
1423                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1424                         "error: %d\n", task->tk_status);
1425                 break;
1426         }
1427         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1428 }
1429 #endif /* CONFIG_NFS_V4_1 */
1430
1431 /*
1432  * 6.   Sort out the RPC call status
1433  */
1434 static void
1435 call_status(struct rpc_task *task)
1436 {
1437         struct rpc_clnt *clnt = task->tk_client;
1438         struct rpc_rqst *req = task->tk_rqstp;
1439         int             status;
1440
1441         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1442                 task->tk_status = req->rq_reply_bytes_recvd;
1443
1444         dprint_status(task);
1445
1446         status = task->tk_status;
1447         if (status >= 0) {
1448                 task->tk_action = call_decode;
1449                 return;
1450         }
1451
1452         task->tk_status = 0;
1453         switch(status) {
1454         case -EHOSTDOWN:
1455         case -EHOSTUNREACH:
1456         case -ENETUNREACH:
1457                 /*
1458                  * Delay any retries for 3 seconds, then handle as if it
1459                  * were a timeout.
1460                  */
1461                 rpc_delay(task, 3*HZ);
1462         case -ETIMEDOUT:
1463                 task->tk_action = call_timeout;
1464                 if (task->tk_client->cl_discrtry)
1465                         xprt_conditional_disconnect(task->tk_xprt,
1466                                         req->rq_connect_cookie);
1467                 break;
1468         case -ECONNRESET:
1469         case -ECONNREFUSED:
1470                 rpc_force_rebind(clnt);
1471                 rpc_delay(task, 3*HZ);
1472         case -EPIPE:
1473         case -ENOTCONN:
1474                 task->tk_action = call_bind;
1475                 break;
1476         case -EAGAIN:
1477                 task->tk_action = call_transmit;
1478                 break;
1479         case -EIO:
1480                 /* shutdown or soft timeout */
1481                 rpc_exit(task, status);
1482                 break;
1483         default:
1484                 if (clnt->cl_chatty)
1485                         printk("%s: RPC call returned error %d\n",
1486                                clnt->cl_protname, -status);
1487                 rpc_exit(task, status);
1488         }
1489 }
1490
1491 /*
1492  * 6a.  Handle RPC timeout
1493  *      We do not release the request slot, so we keep using the
1494  *      same XID for all retransmits.
1495  */
1496 static void
1497 call_timeout(struct rpc_task *task)
1498 {
1499         struct rpc_clnt *clnt = task->tk_client;
1500
1501         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1502                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1503                 goto retry;
1504         }
1505
1506         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1507         task->tk_timeouts++;
1508
1509         if (RPC_IS_SOFTCONN(task)) {
1510                 rpc_exit(task, -ETIMEDOUT);
1511                 return;
1512         }
1513         if (RPC_IS_SOFT(task)) {
1514                 if (clnt->cl_chatty)
1515                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1516                                 clnt->cl_protname, clnt->cl_server);
1517                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1518                         rpc_exit(task, -ETIMEDOUT);
1519                 else
1520                         rpc_exit(task, -EIO);
1521                 return;
1522         }
1523
1524         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1525                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1526                 if (clnt->cl_chatty)
1527                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1528                         clnt->cl_protname, clnt->cl_server);
1529         }
1530         rpc_force_rebind(clnt);
1531         /*
1532          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1533          * event? RFC2203 requires the server to drop all such requests.
1534          */
1535         rpcauth_invalcred(task);
1536
1537 retry:
1538         clnt->cl_stats->rpcretrans++;
1539         task->tk_action = call_bind;
1540         task->tk_status = 0;
1541 }
1542
1543 /*
1544  * 7.   Decode the RPC reply
1545  */
1546 static void
1547 call_decode(struct rpc_task *task)
1548 {
1549         struct rpc_clnt *clnt = task->tk_client;
1550         struct rpc_rqst *req = task->tk_rqstp;
1551         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1552         __be32          *p;
1553
1554         dprintk("RPC: %5u call_decode (status %d)\n",
1555                         task->tk_pid, task->tk_status);
1556
1557         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1558                 if (clnt->cl_chatty)
1559                         printk(KERN_NOTICE "%s: server %s OK\n",
1560                                 clnt->cl_protname, clnt->cl_server);
1561                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1562         }
1563
1564         /*
1565          * Ensure that we see all writes made by xprt_complete_rqst()
1566          * before it changed req->rq_reply_bytes_recvd.
1567          */
1568         smp_rmb();
1569         req->rq_rcv_buf.len = req->rq_private_buf.len;
1570
1571         /* Check that the softirq receive buffer is valid */
1572         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1573                                 sizeof(req->rq_rcv_buf)) != 0);
1574
1575         if (req->rq_rcv_buf.len < 12) {
1576                 if (!RPC_IS_SOFT(task)) {
1577                         task->tk_action = call_bind;
1578                         clnt->cl_stats->rpcretrans++;
1579                         goto out_retry;
1580                 }
1581                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1582                                 clnt->cl_protname, task->tk_status);
1583                 task->tk_action = call_timeout;
1584                 goto out_retry;
1585         }
1586
1587         p = rpc_verify_header(task);
1588         if (IS_ERR(p)) {
1589                 if (p == ERR_PTR(-EAGAIN))
1590                         goto out_retry;
1591                 return;
1592         }
1593
1594         task->tk_action = rpc_exit_task;
1595
1596         if (decode) {
1597                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1598                                                       task->tk_msg.rpc_resp);
1599         }
1600         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1601                         task->tk_status);
1602         return;
1603 out_retry:
1604         task->tk_status = 0;
1605         /* Note: rpc_verify_header() may have freed the RPC slot */
1606         if (task->tk_rqstp == req) {
1607                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1608                 if (task->tk_client->cl_discrtry)
1609                         xprt_conditional_disconnect(task->tk_xprt,
1610                                         req->rq_connect_cookie);
1611         }
1612 }
1613
1614 static __be32 *
1615 rpc_encode_header(struct rpc_task *task)
1616 {
1617         struct rpc_clnt *clnt = task->tk_client;
1618         struct rpc_rqst *req = task->tk_rqstp;
1619         __be32          *p = req->rq_svec[0].iov_base;
1620
1621         /* FIXME: check buffer size? */
1622
1623         p = xprt_skip_transport_header(task->tk_xprt, p);
1624         *p++ = req->rq_xid;             /* XID */
1625         *p++ = htonl(RPC_CALL);         /* CALL */
1626         *p++ = htonl(RPC_VERSION);      /* RPC version */
1627         *p++ = htonl(clnt->cl_prog);    /* program number */
1628         *p++ = htonl(clnt->cl_vers);    /* program version */
1629         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1630         p = rpcauth_marshcred(task, p);
1631         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1632         return p;
1633 }
1634
1635 static __be32 *
1636 rpc_verify_header(struct rpc_task *task)
1637 {
1638         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1639         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1640         __be32  *p = iov->iov_base;
1641         u32 n;
1642         int error = -EACCES;
1643
1644         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1645                 /* RFC-1014 says that the representation of XDR data must be a
1646                  * multiple of four bytes
1647                  * - if it isn't pointer subtraction in the NFS client may give
1648                  *   undefined results
1649                  */
1650                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1651                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1652                        task->tk_rqstp->rq_rcv_buf.len);
1653                 goto out_eio;
1654         }
1655         if ((len -= 3) < 0)
1656                 goto out_overflow;
1657
1658         p += 1; /* skip XID */
1659         if ((n = ntohl(*p++)) != RPC_REPLY) {
1660                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1661                         task->tk_pid, __func__, n);
1662                 goto out_garbage;
1663         }
1664
1665         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1666                 if (--len < 0)
1667                         goto out_overflow;
1668                 switch ((n = ntohl(*p++))) {
1669                 case RPC_AUTH_ERROR:
1670                         break;
1671                 case RPC_MISMATCH:
1672                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
1673                                 task->tk_pid, __func__);
1674                         error = -EPROTONOSUPPORT;
1675                         goto out_err;
1676                 default:
1677                         dprintk("RPC: %5u %s: RPC call rejected, "
1678                                 "unknown error: %x\n",
1679                                 task->tk_pid, __func__, n);
1680                         goto out_eio;
1681                 }
1682                 if (--len < 0)
1683                         goto out_overflow;
1684                 switch ((n = ntohl(*p++))) {
1685                 case RPC_AUTH_REJECTEDCRED:
1686                 case RPC_AUTH_REJECTEDVERF:
1687                 case RPCSEC_GSS_CREDPROBLEM:
1688                 case RPCSEC_GSS_CTXPROBLEM:
1689                         if (!task->tk_cred_retry)
1690                                 break;
1691                         task->tk_cred_retry--;
1692                         dprintk("RPC: %5u %s: retry stale creds\n",
1693                                         task->tk_pid, __func__);
1694                         rpcauth_invalcred(task);
1695                         /* Ensure we obtain a new XID! */
1696                         xprt_release(task);
1697                         task->tk_action = call_reserve;
1698                         goto out_retry;
1699                 case RPC_AUTH_BADCRED:
1700                 case RPC_AUTH_BADVERF:
1701                         /* possibly garbled cred/verf? */
1702                         if (!task->tk_garb_retry)
1703                                 break;
1704                         task->tk_garb_retry--;
1705                         dprintk("RPC: %5u %s: retry garbled creds\n",
1706                                         task->tk_pid, __func__);
1707                         task->tk_action = call_bind;
1708                         goto out_retry;
1709                 case RPC_AUTH_TOOWEAK:
1710                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1711                                "authentication.\n", task->tk_client->cl_server);
1712                         break;
1713                 default:
1714                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1715                                         task->tk_pid, __func__, n);
1716                         error = -EIO;
1717                 }
1718                 dprintk("RPC: %5u %s: call rejected %d\n",
1719                                 task->tk_pid, __func__, n);
1720                 goto out_err;
1721         }
1722         if (!(p = rpcauth_checkverf(task, p))) {
1723                 dprintk("RPC: %5u %s: auth check failed\n",
1724                                 task->tk_pid, __func__);
1725                 goto out_garbage;               /* bad verifier, retry */
1726         }
1727         len = p - (__be32 *)iov->iov_base - 1;
1728         if (len < 0)
1729                 goto out_overflow;
1730         switch ((n = ntohl(*p++))) {
1731         case RPC_SUCCESS:
1732                 return p;
1733         case RPC_PROG_UNAVAIL:
1734                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1735                                 task->tk_pid, __func__,
1736                                 (unsigned int)task->tk_client->cl_prog,
1737                                 task->tk_client->cl_server);
1738                 error = -EPFNOSUPPORT;
1739                 goto out_err;
1740         case RPC_PROG_MISMATCH:
1741                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1742                                 "server %s\n", task->tk_pid, __func__,
1743                                 (unsigned int)task->tk_client->cl_prog,
1744                                 (unsigned int)task->tk_client->cl_vers,
1745                                 task->tk_client->cl_server);
1746                 error = -EPROTONOSUPPORT;
1747                 goto out_err;
1748         case RPC_PROC_UNAVAIL:
1749                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1750                                 "version %u on server %s\n",
1751                                 task->tk_pid, __func__,
1752                                 rpc_proc_name(task),
1753                                 task->tk_client->cl_prog,
1754                                 task->tk_client->cl_vers,
1755                                 task->tk_client->cl_server);
1756                 error = -EOPNOTSUPP;
1757                 goto out_err;
1758         case RPC_GARBAGE_ARGS:
1759                 dprintk("RPC: %5u %s: server saw garbage\n",
1760                                 task->tk_pid, __func__);
1761                 break;                  /* retry */
1762         default:
1763                 dprintk("RPC: %5u %s: server accept status: %x\n",
1764                                 task->tk_pid, __func__, n);
1765                 /* Also retry */
1766         }
1767
1768 out_garbage:
1769         task->tk_client->cl_stats->rpcgarbage++;
1770         if (task->tk_garb_retry) {
1771                 task->tk_garb_retry--;
1772                 dprintk("RPC: %5u %s: retrying\n",
1773                                 task->tk_pid, __func__);
1774                 task->tk_action = call_bind;
1775 out_retry:
1776                 return ERR_PTR(-EAGAIN);
1777         }
1778 out_eio:
1779         error = -EIO;
1780 out_err:
1781         rpc_exit(task, error);
1782         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1783                         __func__, error);
1784         return ERR_PTR(error);
1785 out_overflow:
1786         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1787                         __func__);
1788         goto out_garbage;
1789 }
1790
1791 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1792 {
1793 }
1794
1795 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1796 {
1797         return 0;
1798 }
1799
1800 static struct rpc_procinfo rpcproc_null = {
1801         .p_encode = rpcproc_encode_null,
1802         .p_decode = rpcproc_decode_null,
1803 };
1804
1805 static int rpc_ping(struct rpc_clnt *clnt)
1806 {
1807         struct rpc_message msg = {
1808                 .rpc_proc = &rpcproc_null,
1809         };
1810         int err;
1811         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1812         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1813         put_rpccred(msg.rpc_cred);
1814         return err;
1815 }
1816
1817 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1818 {
1819         struct rpc_message msg = {
1820                 .rpc_proc = &rpcproc_null,
1821                 .rpc_cred = cred,
1822         };
1823         struct rpc_task_setup task_setup_data = {
1824                 .rpc_client = clnt,
1825                 .rpc_message = &msg,
1826                 .callback_ops = &rpc_default_ops,
1827                 .flags = flags,
1828         };
1829         return rpc_run_task(&task_setup_data);
1830 }
1831 EXPORT_SYMBOL_GPL(rpc_call_null);
1832
1833 #ifdef RPC_DEBUG
1834 static void rpc_show_header(void)
1835 {
1836         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1837                 "-timeout ---ops--\n");
1838 }
1839
1840 static void rpc_show_task(const struct rpc_clnt *clnt,
1841                           const struct rpc_task *task)
1842 {
1843         const char *rpc_waitq = "none";
1844
1845         if (RPC_IS_QUEUED(task))
1846                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1847
1848         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
1849                 task->tk_pid, task->tk_flags, task->tk_status,
1850                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1851                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1852                 task->tk_action, rpc_waitq);
1853 }
1854
1855 void rpc_show_tasks(void)
1856 {
1857         struct rpc_clnt *clnt;
1858         struct rpc_task *task;
1859         int header = 0;
1860
1861         spin_lock(&rpc_client_lock);
1862         list_for_each_entry(clnt, &all_clients, cl_clients) {
1863                 spin_lock(&clnt->cl_lock);
1864                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1865                         if (!header) {
1866                                 rpc_show_header();
1867                                 header++;
1868                         }
1869                         rpc_show_task(clnt, task);
1870                 }
1871                 spin_unlock(&clnt->cl_lock);
1872         }
1873         spin_unlock(&rpc_client_lock);
1874 }
1875 #endif