Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linux
[~shefty/rdma-dev.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  NB: BSD uses a more intelligent approach to guessing when a request
17  *  or reply has been lost by keeping the RTO estimate for each procedure.
18  *  We currently make do with a constant timeout value.
19  *
20  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
21  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
22  */
23
24 #include <asm/system.h>
25
26 #include <linux/module.h>
27 #include <linux/types.h>
28 #include <linux/kallsyms.h>
29 #include <linux/mm.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/slab.h>
33 #include <linux/utsname.h>
34 #include <linux/workqueue.h>
35 #include <linux/in6.h>
36
37 #include <linux/sunrpc/clnt.h>
38 #include <linux/sunrpc/rpc_pipe_fs.h>
39 #include <linux/sunrpc/metrics.h>
40 #include <linux/sunrpc/bc_xprt.h>
41
42 #include "sunrpc.h"
43
44 #ifdef RPC_DEBUG
45 # define RPCDBG_FACILITY        RPCDBG_CALL
46 #endif
47
48 #define dprint_status(t)                                        \
49         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
50                         __func__, t->tk_status)
51
52 /*
53  * All RPC clients are linked into this list
54  */
55 static LIST_HEAD(all_clients);
56 static DEFINE_SPINLOCK(rpc_client_lock);
57
58 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
59
60
61 static void     call_start(struct rpc_task *task);
62 static void     call_reserve(struct rpc_task *task);
63 static void     call_reserveresult(struct rpc_task *task);
64 static void     call_allocate(struct rpc_task *task);
65 static void     call_decode(struct rpc_task *task);
66 static void     call_bind(struct rpc_task *task);
67 static void     call_bind_status(struct rpc_task *task);
68 static void     call_transmit(struct rpc_task *task);
69 #if defined(CONFIG_NFS_V4_1)
70 static void     call_bc_transmit(struct rpc_task *task);
71 #endif /* CONFIG_NFS_V4_1 */
72 static void     call_status(struct rpc_task *task);
73 static void     call_transmit_status(struct rpc_task *task);
74 static void     call_refresh(struct rpc_task *task);
75 static void     call_refreshresult(struct rpc_task *task);
76 static void     call_timeout(struct rpc_task *task);
77 static void     call_connect(struct rpc_task *task);
78 static void     call_connect_status(struct rpc_task *task);
79
80 static __be32   *rpc_encode_header(struct rpc_task *task);
81 static __be32   *rpc_verify_header(struct rpc_task *task);
82 static int      rpc_ping(struct rpc_clnt *clnt);
83
84 static void rpc_register_client(struct rpc_clnt *clnt)
85 {
86         spin_lock(&rpc_client_lock);
87         list_add(&clnt->cl_clients, &all_clients);
88         spin_unlock(&rpc_client_lock);
89 }
90
91 static void rpc_unregister_client(struct rpc_clnt *clnt)
92 {
93         spin_lock(&rpc_client_lock);
94         list_del(&clnt->cl_clients);
95         spin_unlock(&rpc_client_lock);
96 }
97
98 static int
99 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
100 {
101         static uint32_t clntid;
102         struct nameidata nd;
103         struct path path;
104         char name[15];
105         struct qstr q = {
106                 .name = name,
107         };
108         int error;
109
110         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
111         clnt->cl_path.dentry = ERR_PTR(-ENOENT);
112         if (dir_name == NULL)
113                 return 0;
114
115         path.mnt = rpc_get_mount();
116         if (IS_ERR(path.mnt))
117                 return PTR_ERR(path.mnt);
118         error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &nd);
119         if (error)
120                 goto err;
121
122         for (;;) {
123                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
124                 name[sizeof(name) - 1] = '\0';
125                 q.hash = full_name_hash(q.name, q.len);
126                 path.dentry = rpc_create_client_dir(nd.path.dentry, &q, clnt);
127                 if (!IS_ERR(path.dentry))
128                         break;
129                 error = PTR_ERR(path.dentry);
130                 if (error != -EEXIST) {
131                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
132                                         " %s/%s, error %d\n",
133                                         dir_name, name, error);
134                         goto err_path_put;
135                 }
136         }
137         path_put(&nd.path);
138         clnt->cl_path = path;
139         return 0;
140 err_path_put:
141         path_put(&nd.path);
142 err:
143         rpc_put_mount();
144         return error;
145 }
146
147 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
148 {
149         struct rpc_program      *program = args->program;
150         struct rpc_version      *version;
151         struct rpc_clnt         *clnt = NULL;
152         struct rpc_auth         *auth;
153         int err;
154         size_t len;
155
156         /* sanity check the name before trying to print it */
157         err = -EINVAL;
158         len = strlen(args->servername);
159         if (len > RPC_MAXNETNAMELEN)
160                 goto out_no_rpciod;
161         len++;
162
163         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
164                         program->name, args->servername, xprt);
165
166         err = rpciod_up();
167         if (err)
168                 goto out_no_rpciod;
169         err = -EINVAL;
170         if (!xprt)
171                 goto out_no_xprt;
172
173         if (args->version >= program->nrvers)
174                 goto out_err;
175         version = program->version[args->version];
176         if (version == NULL)
177                 goto out_err;
178
179         err = -ENOMEM;
180         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
181         if (!clnt)
182                 goto out_err;
183         clnt->cl_parent = clnt;
184
185         clnt->cl_server = clnt->cl_inline_name;
186         if (len > sizeof(clnt->cl_inline_name)) {
187                 char *buf = kmalloc(len, GFP_KERNEL);
188                 if (buf != NULL)
189                         clnt->cl_server = buf;
190                 else
191                         len = sizeof(clnt->cl_inline_name);
192         }
193         strlcpy(clnt->cl_server, args->servername, len);
194
195         clnt->cl_xprt     = xprt;
196         clnt->cl_procinfo = version->procs;
197         clnt->cl_maxproc  = version->nrprocs;
198         clnt->cl_protname = program->name;
199         clnt->cl_prog     = args->prognumber ? : program->number;
200         clnt->cl_vers     = version->number;
201         clnt->cl_stats    = program->stats;
202         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
203         err = -ENOMEM;
204         if (clnt->cl_metrics == NULL)
205                 goto out_no_stats;
206         clnt->cl_program  = program;
207         INIT_LIST_HEAD(&clnt->cl_tasks);
208         spin_lock_init(&clnt->cl_lock);
209
210         if (!xprt_bound(clnt->cl_xprt))
211                 clnt->cl_autobind = 1;
212
213         clnt->cl_timeout = xprt->timeout;
214         if (args->timeout != NULL) {
215                 memcpy(&clnt->cl_timeout_default, args->timeout,
216                                 sizeof(clnt->cl_timeout_default));
217                 clnt->cl_timeout = &clnt->cl_timeout_default;
218         }
219
220         clnt->cl_rtt = &clnt->cl_rtt_default;
221         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
222         clnt->cl_principal = NULL;
223         if (args->client_name) {
224                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
225                 if (!clnt->cl_principal)
226                         goto out_no_principal;
227         }
228
229         atomic_set(&clnt->cl_count, 1);
230
231         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
232         if (err < 0)
233                 goto out_no_path;
234
235         auth = rpcauth_create(args->authflavor, clnt);
236         if (IS_ERR(auth)) {
237                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
238                                 args->authflavor);
239                 err = PTR_ERR(auth);
240                 goto out_no_auth;
241         }
242
243         /* save the nodename */
244         clnt->cl_nodelen = strlen(init_utsname()->nodename);
245         if (clnt->cl_nodelen > UNX_MAXNODENAME)
246                 clnt->cl_nodelen = UNX_MAXNODENAME;
247         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
248         rpc_register_client(clnt);
249         return clnt;
250
251 out_no_auth:
252         if (!IS_ERR(clnt->cl_path.dentry)) {
253                 rpc_remove_client_dir(clnt->cl_path.dentry);
254                 rpc_put_mount();
255         }
256 out_no_path:
257         kfree(clnt->cl_principal);
258 out_no_principal:
259         rpc_free_iostats(clnt->cl_metrics);
260 out_no_stats:
261         if (clnt->cl_server != clnt->cl_inline_name)
262                 kfree(clnt->cl_server);
263         kfree(clnt);
264 out_err:
265         xprt_put(xprt);
266 out_no_xprt:
267         rpciod_down();
268 out_no_rpciod:
269         return ERR_PTR(err);
270 }
271
272 /*
273  * rpc_create - create an RPC client and transport with one call
274  * @args: rpc_clnt create argument structure
275  *
276  * Creates and initializes an RPC transport and an RPC client.
277  *
278  * It can ping the server in order to determine if it is up, and to see if
279  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
280  * this behavior so asynchronous tasks can also use rpc_create.
281  */
282 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
283 {
284         struct rpc_xprt *xprt;
285         struct rpc_clnt *clnt;
286         struct xprt_create xprtargs = {
287                 .net = args->net,
288                 .ident = args->protocol,
289                 .srcaddr = args->saddress,
290                 .dstaddr = args->address,
291                 .addrlen = args->addrsize,
292                 .bc_xprt = args->bc_xprt,
293         };
294         char servername[48];
295
296         /*
297          * If the caller chooses not to specify a hostname, whip
298          * up a string representation of the passed-in address.
299          */
300         if (args->servername == NULL) {
301                 servername[0] = '\0';
302                 switch (args->address->sa_family) {
303                 case AF_INET: {
304                         struct sockaddr_in *sin =
305                                         (struct sockaddr_in *)args->address;
306                         snprintf(servername, sizeof(servername), "%pI4",
307                                  &sin->sin_addr.s_addr);
308                         break;
309                 }
310                 case AF_INET6: {
311                         struct sockaddr_in6 *sin =
312                                         (struct sockaddr_in6 *)args->address;
313                         snprintf(servername, sizeof(servername), "%pI6",
314                                  &sin->sin6_addr);
315                         break;
316                 }
317                 default:
318                         /* caller wants default server name, but
319                          * address family isn't recognized. */
320                         return ERR_PTR(-EINVAL);
321                 }
322                 args->servername = servername;
323         }
324
325         xprt = xprt_create_transport(&xprtargs);
326         if (IS_ERR(xprt))
327                 return (struct rpc_clnt *)xprt;
328
329         /*
330          * By default, kernel RPC client connects from a reserved port.
331          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
332          * but it is always enabled for rpciod, which handles the connect
333          * operation.
334          */
335         xprt->resvport = 1;
336         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
337                 xprt->resvport = 0;
338
339         clnt = rpc_new_client(args, xprt);
340         if (IS_ERR(clnt))
341                 return clnt;
342
343         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
344                 int err = rpc_ping(clnt);
345                 if (err != 0) {
346                         rpc_shutdown_client(clnt);
347                         return ERR_PTR(err);
348                 }
349         }
350
351         clnt->cl_softrtry = 1;
352         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
353                 clnt->cl_softrtry = 0;
354
355         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
356                 clnt->cl_autobind = 1;
357         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
358                 clnt->cl_discrtry = 1;
359         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
360                 clnt->cl_chatty = 1;
361
362         return clnt;
363 }
364 EXPORT_SYMBOL_GPL(rpc_create);
365
366 /*
367  * This function clones the RPC client structure. It allows us to share the
368  * same transport while varying parameters such as the authentication
369  * flavour.
370  */
371 struct rpc_clnt *
372 rpc_clone_client(struct rpc_clnt *clnt)
373 {
374         struct rpc_clnt *new;
375         int err = -ENOMEM;
376
377         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
378         if (!new)
379                 goto out_no_clnt;
380         new->cl_parent = clnt;
381         /* Turn off autobind on clones */
382         new->cl_autobind = 0;
383         INIT_LIST_HEAD(&new->cl_tasks);
384         spin_lock_init(&new->cl_lock);
385         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
386         new->cl_metrics = rpc_alloc_iostats(clnt);
387         if (new->cl_metrics == NULL)
388                 goto out_no_stats;
389         if (clnt->cl_principal) {
390                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
391                 if (new->cl_principal == NULL)
392                         goto out_no_principal;
393         }
394         atomic_set(&new->cl_count, 1);
395         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
396         if (err != 0)
397                 goto out_no_path;
398         if (new->cl_auth)
399                 atomic_inc(&new->cl_auth->au_count);
400         xprt_get(clnt->cl_xprt);
401         atomic_inc(&clnt->cl_count);
402         rpc_register_client(new);
403         rpciod_up();
404         return new;
405 out_no_path:
406         kfree(new->cl_principal);
407 out_no_principal:
408         rpc_free_iostats(new->cl_metrics);
409 out_no_stats:
410         kfree(new);
411 out_no_clnt:
412         dprintk("RPC:       %s: returned error %d\n", __func__, err);
413         return ERR_PTR(err);
414 }
415 EXPORT_SYMBOL_GPL(rpc_clone_client);
416
417 /*
418  * Kill all tasks for the given client.
419  * XXX: kill their descendants as well?
420  */
421 void rpc_killall_tasks(struct rpc_clnt *clnt)
422 {
423         struct rpc_task *rovr;
424
425
426         if (list_empty(&clnt->cl_tasks))
427                 return;
428         dprintk("RPC:       killing all tasks for client %p\n", clnt);
429         /*
430          * Spin lock all_tasks to prevent changes...
431          */
432         spin_lock(&clnt->cl_lock);
433         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
434                 if (!RPC_IS_ACTIVATED(rovr))
435                         continue;
436                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
437                         rovr->tk_flags |= RPC_TASK_KILLED;
438                         rpc_exit(rovr, -EIO);
439                         rpc_wake_up_queued_task(rovr->tk_waitqueue, rovr);
440                 }
441         }
442         spin_unlock(&clnt->cl_lock);
443 }
444 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
445
446 /*
447  * Properly shut down an RPC client, terminating all outstanding
448  * requests.
449  */
450 void rpc_shutdown_client(struct rpc_clnt *clnt)
451 {
452         dprintk("RPC:       shutting down %s client for %s\n",
453                         clnt->cl_protname, clnt->cl_server);
454
455         while (!list_empty(&clnt->cl_tasks)) {
456                 rpc_killall_tasks(clnt);
457                 wait_event_timeout(destroy_wait,
458                         list_empty(&clnt->cl_tasks), 1*HZ);
459         }
460
461         rpc_release_client(clnt);
462 }
463 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
464
465 /*
466  * Free an RPC client
467  */
468 static void
469 rpc_free_client(struct rpc_clnt *clnt)
470 {
471         dprintk("RPC:       destroying %s client for %s\n",
472                         clnt->cl_protname, clnt->cl_server);
473         if (!IS_ERR(clnt->cl_path.dentry)) {
474                 rpc_remove_client_dir(clnt->cl_path.dentry);
475                 rpc_put_mount();
476         }
477         if (clnt->cl_parent != clnt) {
478                 rpc_release_client(clnt->cl_parent);
479                 goto out_free;
480         }
481         if (clnt->cl_server != clnt->cl_inline_name)
482                 kfree(clnt->cl_server);
483 out_free:
484         rpc_unregister_client(clnt);
485         rpc_free_iostats(clnt->cl_metrics);
486         kfree(clnt->cl_principal);
487         clnt->cl_metrics = NULL;
488         xprt_put(clnt->cl_xprt);
489         rpciod_down();
490         kfree(clnt);
491 }
492
493 /*
494  * Free an RPC client
495  */
496 static void
497 rpc_free_auth(struct rpc_clnt *clnt)
498 {
499         if (clnt->cl_auth == NULL) {
500                 rpc_free_client(clnt);
501                 return;
502         }
503
504         /*
505          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
506          *       release remaining GSS contexts. This mechanism ensures
507          *       that it can do so safely.
508          */
509         atomic_inc(&clnt->cl_count);
510         rpcauth_release(clnt->cl_auth);
511         clnt->cl_auth = NULL;
512         if (atomic_dec_and_test(&clnt->cl_count))
513                 rpc_free_client(clnt);
514 }
515
516 /*
517  * Release reference to the RPC client
518  */
519 void
520 rpc_release_client(struct rpc_clnt *clnt)
521 {
522         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
523
524         if (list_empty(&clnt->cl_tasks))
525                 wake_up(&destroy_wait);
526         if (atomic_dec_and_test(&clnt->cl_count))
527                 rpc_free_auth(clnt);
528 }
529
530 /**
531  * rpc_bind_new_program - bind a new RPC program to an existing client
532  * @old: old rpc_client
533  * @program: rpc program to set
534  * @vers: rpc program version
535  *
536  * Clones the rpc client and sets up a new RPC program. This is mainly
537  * of use for enabling different RPC programs to share the same transport.
538  * The Sun NFSv2/v3 ACL protocol can do this.
539  */
540 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
541                                       struct rpc_program *program,
542                                       u32 vers)
543 {
544         struct rpc_clnt *clnt;
545         struct rpc_version *version;
546         int err;
547
548         BUG_ON(vers >= program->nrvers || !program->version[vers]);
549         version = program->version[vers];
550         clnt = rpc_clone_client(old);
551         if (IS_ERR(clnt))
552                 goto out;
553         clnt->cl_procinfo = version->procs;
554         clnt->cl_maxproc  = version->nrprocs;
555         clnt->cl_protname = program->name;
556         clnt->cl_prog     = program->number;
557         clnt->cl_vers     = version->number;
558         clnt->cl_stats    = program->stats;
559         err = rpc_ping(clnt);
560         if (err != 0) {
561                 rpc_shutdown_client(clnt);
562                 clnt = ERR_PTR(err);
563         }
564 out:
565         return clnt;
566 }
567 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
568
569 void rpc_task_release_client(struct rpc_task *task)
570 {
571         struct rpc_clnt *clnt = task->tk_client;
572
573         if (clnt != NULL) {
574                 /* Remove from client task list */
575                 spin_lock(&clnt->cl_lock);
576                 list_del(&task->tk_task);
577                 spin_unlock(&clnt->cl_lock);
578                 task->tk_client = NULL;
579
580                 rpc_release_client(clnt);
581         }
582 }
583
584 static
585 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
586 {
587         if (clnt != NULL) {
588                 rpc_task_release_client(task);
589                 task->tk_client = clnt;
590                 atomic_inc(&clnt->cl_count);
591                 if (clnt->cl_softrtry)
592                         task->tk_flags |= RPC_TASK_SOFT;
593                 /* Add to the client's list of all tasks */
594                 spin_lock(&clnt->cl_lock);
595                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
596                 spin_unlock(&clnt->cl_lock);
597         }
598 }
599
600 static void
601 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
602 {
603         if (msg != NULL) {
604                 task->tk_msg.rpc_proc = msg->rpc_proc;
605                 task->tk_msg.rpc_argp = msg->rpc_argp;
606                 task->tk_msg.rpc_resp = msg->rpc_resp;
607                 if (msg->rpc_cred != NULL)
608                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
609         }
610 }
611
612 /*
613  * Default callback for async RPC calls
614  */
615 static void
616 rpc_default_callback(struct rpc_task *task, void *data)
617 {
618 }
619
620 static const struct rpc_call_ops rpc_default_ops = {
621         .rpc_call_done = rpc_default_callback,
622 };
623
624 /**
625  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
626  * @task_setup_data: pointer to task initialisation data
627  */
628 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
629 {
630         struct rpc_task *task;
631
632         task = rpc_new_task(task_setup_data);
633         if (IS_ERR(task))
634                 goto out;
635
636         rpc_task_set_client(task, task_setup_data->rpc_client);
637         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
638
639         if (task->tk_status != 0) {
640                 int ret = task->tk_status;
641                 rpc_put_task(task);
642                 return ERR_PTR(ret);
643         }
644
645         if (task->tk_action == NULL)
646                 rpc_call_start(task);
647
648         atomic_inc(&task->tk_count);
649         rpc_execute(task);
650 out:
651         return task;
652 }
653 EXPORT_SYMBOL_GPL(rpc_run_task);
654
655 /**
656  * rpc_call_sync - Perform a synchronous RPC call
657  * @clnt: pointer to RPC client
658  * @msg: RPC call parameters
659  * @flags: RPC call flags
660  */
661 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
662 {
663         struct rpc_task *task;
664         struct rpc_task_setup task_setup_data = {
665                 .rpc_client = clnt,
666                 .rpc_message = msg,
667                 .callback_ops = &rpc_default_ops,
668                 .flags = flags,
669         };
670         int status;
671
672         BUG_ON(flags & RPC_TASK_ASYNC);
673
674         task = rpc_run_task(&task_setup_data);
675         if (IS_ERR(task))
676                 return PTR_ERR(task);
677         status = task->tk_status;
678         rpc_put_task(task);
679         return status;
680 }
681 EXPORT_SYMBOL_GPL(rpc_call_sync);
682
683 /**
684  * rpc_call_async - Perform an asynchronous RPC call
685  * @clnt: pointer to RPC client
686  * @msg: RPC call parameters
687  * @flags: RPC call flags
688  * @tk_ops: RPC call ops
689  * @data: user call data
690  */
691 int
692 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
693                const struct rpc_call_ops *tk_ops, void *data)
694 {
695         struct rpc_task *task;
696         struct rpc_task_setup task_setup_data = {
697                 .rpc_client = clnt,
698                 .rpc_message = msg,
699                 .callback_ops = tk_ops,
700                 .callback_data = data,
701                 .flags = flags|RPC_TASK_ASYNC,
702         };
703
704         task = rpc_run_task(&task_setup_data);
705         if (IS_ERR(task))
706                 return PTR_ERR(task);
707         rpc_put_task(task);
708         return 0;
709 }
710 EXPORT_SYMBOL_GPL(rpc_call_async);
711
712 #if defined(CONFIG_NFS_V4_1)
713 /**
714  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
715  * rpc_execute against it
716  * @req: RPC request
717  * @tk_ops: RPC call ops
718  */
719 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
720                                 const struct rpc_call_ops *tk_ops)
721 {
722         struct rpc_task *task;
723         struct xdr_buf *xbufp = &req->rq_snd_buf;
724         struct rpc_task_setup task_setup_data = {
725                 .callback_ops = tk_ops,
726         };
727
728         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
729         /*
730          * Create an rpc_task to send the data
731          */
732         task = rpc_new_task(&task_setup_data);
733         if (IS_ERR(task)) {
734                 xprt_free_bc_request(req);
735                 goto out;
736         }
737         task->tk_rqstp = req;
738
739         /*
740          * Set up the xdr_buf length.
741          * This also indicates that the buffer is XDR encoded already.
742          */
743         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
744                         xbufp->tail[0].iov_len;
745
746         task->tk_action = call_bc_transmit;
747         atomic_inc(&task->tk_count);
748         BUG_ON(atomic_read(&task->tk_count) != 2);
749         rpc_execute(task);
750
751 out:
752         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
753         return task;
754 }
755 #endif /* CONFIG_NFS_V4_1 */
756
757 void
758 rpc_call_start(struct rpc_task *task)
759 {
760         task->tk_action = call_start;
761 }
762 EXPORT_SYMBOL_GPL(rpc_call_start);
763
764 /**
765  * rpc_peeraddr - extract remote peer address from clnt's xprt
766  * @clnt: RPC client structure
767  * @buf: target buffer
768  * @bufsize: length of target buffer
769  *
770  * Returns the number of bytes that are actually in the stored address.
771  */
772 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
773 {
774         size_t bytes;
775         struct rpc_xprt *xprt = clnt->cl_xprt;
776
777         bytes = sizeof(xprt->addr);
778         if (bytes > bufsize)
779                 bytes = bufsize;
780         memcpy(buf, &clnt->cl_xprt->addr, bytes);
781         return xprt->addrlen;
782 }
783 EXPORT_SYMBOL_GPL(rpc_peeraddr);
784
785 /**
786  * rpc_peeraddr2str - return remote peer address in printable format
787  * @clnt: RPC client structure
788  * @format: address format
789  *
790  */
791 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
792                              enum rpc_display_format_t format)
793 {
794         struct rpc_xprt *xprt = clnt->cl_xprt;
795
796         if (xprt->address_strings[format] != NULL)
797                 return xprt->address_strings[format];
798         else
799                 return "unprintable";
800 }
801 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
802
803 void
804 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
805 {
806         struct rpc_xprt *xprt = clnt->cl_xprt;
807         if (xprt->ops->set_buffer_size)
808                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
809 }
810 EXPORT_SYMBOL_GPL(rpc_setbufsize);
811
812 /*
813  * Return size of largest payload RPC client can support, in bytes
814  *
815  * For stream transports, this is one RPC record fragment (see RFC
816  * 1831), as we don't support multi-record requests yet.  For datagram
817  * transports, this is the size of an IP packet minus the IP, UDP, and
818  * RPC header sizes.
819  */
820 size_t rpc_max_payload(struct rpc_clnt *clnt)
821 {
822         return clnt->cl_xprt->max_payload;
823 }
824 EXPORT_SYMBOL_GPL(rpc_max_payload);
825
826 /**
827  * rpc_force_rebind - force transport to check that remote port is unchanged
828  * @clnt: client to rebind
829  *
830  */
831 void rpc_force_rebind(struct rpc_clnt *clnt)
832 {
833         if (clnt->cl_autobind)
834                 xprt_clear_bound(clnt->cl_xprt);
835 }
836 EXPORT_SYMBOL_GPL(rpc_force_rebind);
837
838 /*
839  * Restart an (async) RPC call from the call_prepare state.
840  * Usually called from within the exit handler.
841  */
842 int
843 rpc_restart_call_prepare(struct rpc_task *task)
844 {
845         if (RPC_ASSASSINATED(task))
846                 return 0;
847         task->tk_action = rpc_prepare_task;
848         return 1;
849 }
850 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
851
852 /*
853  * Restart an (async) RPC call. Usually called from within the
854  * exit handler.
855  */
856 int
857 rpc_restart_call(struct rpc_task *task)
858 {
859         if (RPC_ASSASSINATED(task))
860                 return 0;
861         task->tk_action = call_start;
862         return 1;
863 }
864 EXPORT_SYMBOL_GPL(rpc_restart_call);
865
866 #ifdef RPC_DEBUG
867 static const char *rpc_proc_name(const struct rpc_task *task)
868 {
869         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
870
871         if (proc) {
872                 if (proc->p_name)
873                         return proc->p_name;
874                 else
875                         return "NULL";
876         } else
877                 return "no proc";
878 }
879 #endif
880
881 /*
882  * 0.  Initial state
883  *
884  *     Other FSM states can be visited zero or more times, but
885  *     this state is visited exactly once for each RPC.
886  */
887 static void
888 call_start(struct rpc_task *task)
889 {
890         struct rpc_clnt *clnt = task->tk_client;
891
892         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
893                         clnt->cl_protname, clnt->cl_vers,
894                         rpc_proc_name(task),
895                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
896
897         /* Increment call count */
898         task->tk_msg.rpc_proc->p_count++;
899         clnt->cl_stats->rpccnt++;
900         task->tk_action = call_reserve;
901 }
902
903 /*
904  * 1.   Reserve an RPC call slot
905  */
906 static void
907 call_reserve(struct rpc_task *task)
908 {
909         dprint_status(task);
910
911         task->tk_status  = 0;
912         task->tk_action  = call_reserveresult;
913         xprt_reserve(task);
914 }
915
916 /*
917  * 1b.  Grok the result of xprt_reserve()
918  */
919 static void
920 call_reserveresult(struct rpc_task *task)
921 {
922         int status = task->tk_status;
923
924         dprint_status(task);
925
926         /*
927          * After a call to xprt_reserve(), we must have either
928          * a request slot or else an error status.
929          */
930         task->tk_status = 0;
931         if (status >= 0) {
932                 if (task->tk_rqstp) {
933                         task->tk_action = call_refresh;
934                         return;
935                 }
936
937                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
938                                 __func__, status);
939                 rpc_exit(task, -EIO);
940                 return;
941         }
942
943         /*
944          * Even though there was an error, we may have acquired
945          * a request slot somehow.  Make sure not to leak it.
946          */
947         if (task->tk_rqstp) {
948                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
949                                 __func__, status);
950                 xprt_release(task);
951         }
952
953         switch (status) {
954         case -EAGAIN:   /* woken up; retry */
955                 task->tk_action = call_reserve;
956                 return;
957         case -EIO:      /* probably a shutdown */
958                 break;
959         default:
960                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
961                                 __func__, status);
962                 break;
963         }
964         rpc_exit(task, status);
965 }
966
967 /*
968  * 2.   Bind and/or refresh the credentials
969  */
970 static void
971 call_refresh(struct rpc_task *task)
972 {
973         dprint_status(task);
974
975         task->tk_action = call_refreshresult;
976         task->tk_status = 0;
977         task->tk_client->cl_stats->rpcauthrefresh++;
978         rpcauth_refreshcred(task);
979 }
980
981 /*
982  * 2a.  Process the results of a credential refresh
983  */
984 static void
985 call_refreshresult(struct rpc_task *task)
986 {
987         int status = task->tk_status;
988
989         dprint_status(task);
990
991         task->tk_status = 0;
992         task->tk_action = call_allocate;
993         if (status >= 0 && rpcauth_uptodatecred(task))
994                 return;
995         switch (status) {
996         case -EACCES:
997                 rpc_exit(task, -EACCES);
998                 return;
999         case -ENOMEM:
1000                 rpc_exit(task, -ENOMEM);
1001                 return;
1002         case -ETIMEDOUT:
1003                 rpc_delay(task, 3*HZ);
1004         }
1005         task->tk_action = call_refresh;
1006 }
1007
1008 /*
1009  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1010  *      (Note: buffer memory is freed in xprt_release).
1011  */
1012 static void
1013 call_allocate(struct rpc_task *task)
1014 {
1015         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1016         struct rpc_rqst *req = task->tk_rqstp;
1017         struct rpc_xprt *xprt = task->tk_xprt;
1018         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1019
1020         dprint_status(task);
1021
1022         task->tk_status = 0;
1023         task->tk_action = call_bind;
1024
1025         if (req->rq_buffer)
1026                 return;
1027
1028         if (proc->p_proc != 0) {
1029                 BUG_ON(proc->p_arglen == 0);
1030                 if (proc->p_decode != NULL)
1031                         BUG_ON(proc->p_replen == 0);
1032         }
1033
1034         /*
1035          * Calculate the size (in quads) of the RPC call
1036          * and reply headers, and convert both values
1037          * to byte sizes.
1038          */
1039         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1040         req->rq_callsize <<= 2;
1041         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1042         req->rq_rcvsize <<= 2;
1043
1044         req->rq_buffer = xprt->ops->buf_alloc(task,
1045                                         req->rq_callsize + req->rq_rcvsize);
1046         if (req->rq_buffer != NULL)
1047                 return;
1048
1049         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1050
1051         if (RPC_IS_ASYNC(task) || !signalled()) {
1052                 task->tk_action = call_allocate;
1053                 rpc_delay(task, HZ>>4);
1054                 return;
1055         }
1056
1057         rpc_exit(task, -ERESTARTSYS);
1058 }
1059
1060 static inline int
1061 rpc_task_need_encode(struct rpc_task *task)
1062 {
1063         return task->tk_rqstp->rq_snd_buf.len == 0;
1064 }
1065
1066 static inline void
1067 rpc_task_force_reencode(struct rpc_task *task)
1068 {
1069         task->tk_rqstp->rq_snd_buf.len = 0;
1070         task->tk_rqstp->rq_bytes_sent = 0;
1071 }
1072
1073 static inline void
1074 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1075 {
1076         buf->head[0].iov_base = start;
1077         buf->head[0].iov_len = len;
1078         buf->tail[0].iov_len = 0;
1079         buf->page_len = 0;
1080         buf->flags = 0;
1081         buf->len = 0;
1082         buf->buflen = len;
1083 }
1084
1085 /*
1086  * 3.   Encode arguments of an RPC call
1087  */
1088 static void
1089 rpc_xdr_encode(struct rpc_task *task)
1090 {
1091         struct rpc_rqst *req = task->tk_rqstp;
1092         kxdrproc_t      encode;
1093         __be32          *p;
1094
1095         dprint_status(task);
1096
1097         rpc_xdr_buf_init(&req->rq_snd_buf,
1098                          req->rq_buffer,
1099                          req->rq_callsize);
1100         rpc_xdr_buf_init(&req->rq_rcv_buf,
1101                          (char *)req->rq_buffer + req->rq_callsize,
1102                          req->rq_rcvsize);
1103
1104         p = rpc_encode_header(task);
1105         if (p == NULL) {
1106                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1107                 rpc_exit(task, -EIO);
1108                 return;
1109         }
1110
1111         encode = task->tk_msg.rpc_proc->p_encode;
1112         if (encode == NULL)
1113                 return;
1114
1115         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1116                         task->tk_msg.rpc_argp);
1117 }
1118
1119 /*
1120  * 4.   Get the server port number if not yet set
1121  */
1122 static void
1123 call_bind(struct rpc_task *task)
1124 {
1125         struct rpc_xprt *xprt = task->tk_xprt;
1126
1127         dprint_status(task);
1128
1129         task->tk_action = call_connect;
1130         if (!xprt_bound(xprt)) {
1131                 task->tk_action = call_bind_status;
1132                 task->tk_timeout = xprt->bind_timeout;
1133                 xprt->ops->rpcbind(task);
1134         }
1135 }
1136
1137 /*
1138  * 4a.  Sort out bind result
1139  */
1140 static void
1141 call_bind_status(struct rpc_task *task)
1142 {
1143         int status = -EIO;
1144
1145         if (task->tk_status >= 0) {
1146                 dprint_status(task);
1147                 task->tk_status = 0;
1148                 task->tk_action = call_connect;
1149                 return;
1150         }
1151
1152         switch (task->tk_status) {
1153         case -ENOMEM:
1154                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1155                 rpc_delay(task, HZ >> 2);
1156                 goto retry_timeout;
1157         case -EACCES:
1158                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1159                                 "unavailable\n", task->tk_pid);
1160                 /* fail immediately if this is an RPC ping */
1161                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1162                         status = -EOPNOTSUPP;
1163                         break;
1164                 }
1165                 rpc_delay(task, 3*HZ);
1166                 goto retry_timeout;
1167         case -ETIMEDOUT:
1168                 dprintk("RPC: %5u rpcbind request timed out\n",
1169                                 task->tk_pid);
1170                 goto retry_timeout;
1171         case -EPFNOSUPPORT:
1172                 /* server doesn't support any rpcbind version we know of */
1173                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1174                                 task->tk_pid);
1175                 break;
1176         case -EPROTONOSUPPORT:
1177                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1178                                 task->tk_pid);
1179                 task->tk_status = 0;
1180                 task->tk_action = call_bind;
1181                 return;
1182         case -ECONNREFUSED:             /* connection problems */
1183         case -ECONNRESET:
1184         case -ENOTCONN:
1185         case -EHOSTDOWN:
1186         case -EHOSTUNREACH:
1187         case -ENETUNREACH:
1188         case -EPIPE:
1189                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1190                                 task->tk_pid, task->tk_status);
1191                 if (!RPC_IS_SOFTCONN(task)) {
1192                         rpc_delay(task, 5*HZ);
1193                         goto retry_timeout;
1194                 }
1195                 status = task->tk_status;
1196                 break;
1197         default:
1198                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1199                                 task->tk_pid, -task->tk_status);
1200         }
1201
1202         rpc_exit(task, status);
1203         return;
1204
1205 retry_timeout:
1206         task->tk_action = call_timeout;
1207 }
1208
1209 /*
1210  * 4b.  Connect to the RPC server
1211  */
1212 static void
1213 call_connect(struct rpc_task *task)
1214 {
1215         struct rpc_xprt *xprt = task->tk_xprt;
1216
1217         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1218                         task->tk_pid, xprt,
1219                         (xprt_connected(xprt) ? "is" : "is not"));
1220
1221         task->tk_action = call_transmit;
1222         if (!xprt_connected(xprt)) {
1223                 task->tk_action = call_connect_status;
1224                 if (task->tk_status < 0)
1225                         return;
1226                 xprt_connect(task);
1227         }
1228 }
1229
1230 /*
1231  * 4c.  Sort out connect result
1232  */
1233 static void
1234 call_connect_status(struct rpc_task *task)
1235 {
1236         struct rpc_clnt *clnt = task->tk_client;
1237         int status = task->tk_status;
1238
1239         dprint_status(task);
1240
1241         task->tk_status = 0;
1242         if (status >= 0 || status == -EAGAIN) {
1243                 clnt->cl_stats->netreconn++;
1244                 task->tk_action = call_transmit;
1245                 return;
1246         }
1247
1248         switch (status) {
1249                 /* if soft mounted, test if we've timed out */
1250         case -ETIMEDOUT:
1251                 task->tk_action = call_timeout;
1252                 break;
1253         default:
1254                 rpc_exit(task, -EIO);
1255         }
1256 }
1257
1258 /*
1259  * 5.   Transmit the RPC request, and wait for reply
1260  */
1261 static void
1262 call_transmit(struct rpc_task *task)
1263 {
1264         dprint_status(task);
1265
1266         task->tk_action = call_status;
1267         if (task->tk_status < 0)
1268                 return;
1269         task->tk_status = xprt_prepare_transmit(task);
1270         if (task->tk_status != 0)
1271                 return;
1272         task->tk_action = call_transmit_status;
1273         /* Encode here so that rpcsec_gss can use correct sequence number. */
1274         if (rpc_task_need_encode(task)) {
1275                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1276                 rpc_xdr_encode(task);
1277                 /* Did the encode result in an error condition? */
1278                 if (task->tk_status != 0) {
1279                         /* Was the error nonfatal? */
1280                         if (task->tk_status == -EAGAIN)
1281                                 rpc_delay(task, HZ >> 4);
1282                         else
1283                                 rpc_exit(task, task->tk_status);
1284                         return;
1285                 }
1286         }
1287         xprt_transmit(task);
1288         if (task->tk_status < 0)
1289                 return;
1290         /*
1291          * On success, ensure that we call xprt_end_transmit() before sleeping
1292          * in order to allow access to the socket to other RPC requests.
1293          */
1294         call_transmit_status(task);
1295         if (rpc_reply_expected(task))
1296                 return;
1297         task->tk_action = rpc_exit_task;
1298         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1299 }
1300
1301 /*
1302  * 5a.  Handle cleanup after a transmission
1303  */
1304 static void
1305 call_transmit_status(struct rpc_task *task)
1306 {
1307         task->tk_action = call_status;
1308
1309         /*
1310          * Common case: success.  Force the compiler to put this
1311          * test first.
1312          */
1313         if (task->tk_status == 0) {
1314                 xprt_end_transmit(task);
1315                 rpc_task_force_reencode(task);
1316                 return;
1317         }
1318
1319         switch (task->tk_status) {
1320         case -EAGAIN:
1321                 break;
1322         default:
1323                 dprint_status(task);
1324                 xprt_end_transmit(task);
1325                 rpc_task_force_reencode(task);
1326                 break;
1327                 /*
1328                  * Special cases: if we've been waiting on the
1329                  * socket's write_space() callback, or if the
1330                  * socket just returned a connection error,
1331                  * then hold onto the transport lock.
1332                  */
1333         case -ECONNREFUSED:
1334         case -EHOSTDOWN:
1335         case -EHOSTUNREACH:
1336         case -ENETUNREACH:
1337                 if (RPC_IS_SOFTCONN(task)) {
1338                         xprt_end_transmit(task);
1339                         rpc_exit(task, task->tk_status);
1340                         break;
1341                 }
1342         case -ECONNRESET:
1343         case -ENOTCONN:
1344         case -EPIPE:
1345                 rpc_task_force_reencode(task);
1346         }
1347 }
1348
1349 #if defined(CONFIG_NFS_V4_1)
1350 /*
1351  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1352  * addition, disconnect on connectivity errors.
1353  */
1354 static void
1355 call_bc_transmit(struct rpc_task *task)
1356 {
1357         struct rpc_rqst *req = task->tk_rqstp;
1358
1359         BUG_ON(task->tk_status != 0);
1360         task->tk_status = xprt_prepare_transmit(task);
1361         if (task->tk_status == -EAGAIN) {
1362                 /*
1363                  * Could not reserve the transport. Try again after the
1364                  * transport is released.
1365                  */
1366                 task->tk_status = 0;
1367                 task->tk_action = call_bc_transmit;
1368                 return;
1369         }
1370
1371         task->tk_action = rpc_exit_task;
1372         if (task->tk_status < 0) {
1373                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1374                         "error: %d\n", task->tk_status);
1375                 return;
1376         }
1377
1378         xprt_transmit(task);
1379         xprt_end_transmit(task);
1380         dprint_status(task);
1381         switch (task->tk_status) {
1382         case 0:
1383                 /* Success */
1384                 break;
1385         case -EHOSTDOWN:
1386         case -EHOSTUNREACH:
1387         case -ENETUNREACH:
1388         case -ETIMEDOUT:
1389                 /*
1390                  * Problem reaching the server.  Disconnect and let the
1391                  * forechannel reestablish the connection.  The server will
1392                  * have to retransmit the backchannel request and we'll
1393                  * reprocess it.  Since these ops are idempotent, there's no
1394                  * need to cache our reply at this time.
1395                  */
1396                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1397                         "error: %d\n", task->tk_status);
1398                 xprt_conditional_disconnect(task->tk_xprt,
1399                         req->rq_connect_cookie);
1400                 break;
1401         default:
1402                 /*
1403                  * We were unable to reply and will have to drop the
1404                  * request.  The server should reconnect and retransmit.
1405                  */
1406                 BUG_ON(task->tk_status == -EAGAIN);
1407                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1408                         "error: %d\n", task->tk_status);
1409                 break;
1410         }
1411         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1412 }
1413 #endif /* CONFIG_NFS_V4_1 */
1414
1415 /*
1416  * 6.   Sort out the RPC call status
1417  */
1418 static void
1419 call_status(struct rpc_task *task)
1420 {
1421         struct rpc_clnt *clnt = task->tk_client;
1422         struct rpc_rqst *req = task->tk_rqstp;
1423         int             status;
1424
1425         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1426                 task->tk_status = req->rq_reply_bytes_recvd;
1427
1428         dprint_status(task);
1429
1430         status = task->tk_status;
1431         if (status >= 0) {
1432                 task->tk_action = call_decode;
1433                 return;
1434         }
1435
1436         task->tk_status = 0;
1437         switch(status) {
1438         case -EHOSTDOWN:
1439         case -EHOSTUNREACH:
1440         case -ENETUNREACH:
1441                 /*
1442                  * Delay any retries for 3 seconds, then handle as if it
1443                  * were a timeout.
1444                  */
1445                 rpc_delay(task, 3*HZ);
1446         case -ETIMEDOUT:
1447                 task->tk_action = call_timeout;
1448                 if (task->tk_client->cl_discrtry)
1449                         xprt_conditional_disconnect(task->tk_xprt,
1450                                         req->rq_connect_cookie);
1451                 break;
1452         case -ECONNRESET:
1453         case -ECONNREFUSED:
1454                 rpc_force_rebind(clnt);
1455                 rpc_delay(task, 3*HZ);
1456         case -EPIPE:
1457         case -ENOTCONN:
1458                 task->tk_action = call_bind;
1459                 break;
1460         case -EAGAIN:
1461                 task->tk_action = call_transmit;
1462                 break;
1463         case -EIO:
1464                 /* shutdown or soft timeout */
1465                 rpc_exit(task, status);
1466                 break;
1467         default:
1468                 if (clnt->cl_chatty)
1469                         printk("%s: RPC call returned error %d\n",
1470                                clnt->cl_protname, -status);
1471                 rpc_exit(task, status);
1472         }
1473 }
1474
1475 /*
1476  * 6a.  Handle RPC timeout
1477  *      We do not release the request slot, so we keep using the
1478  *      same XID for all retransmits.
1479  */
1480 static void
1481 call_timeout(struct rpc_task *task)
1482 {
1483         struct rpc_clnt *clnt = task->tk_client;
1484
1485         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1486                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1487                 goto retry;
1488         }
1489
1490         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1491         task->tk_timeouts++;
1492
1493         if (RPC_IS_SOFTCONN(task)) {
1494                 rpc_exit(task, -ETIMEDOUT);
1495                 return;
1496         }
1497         if (RPC_IS_SOFT(task)) {
1498                 if (clnt->cl_chatty)
1499                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1500                                 clnt->cl_protname, clnt->cl_server);
1501                 rpc_exit(task, -EIO);
1502                 return;
1503         }
1504
1505         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1506                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1507                 if (clnt->cl_chatty)
1508                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1509                         clnt->cl_protname, clnt->cl_server);
1510         }
1511         rpc_force_rebind(clnt);
1512         /*
1513          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1514          * event? RFC2203 requires the server to drop all such requests.
1515          */
1516         rpcauth_invalcred(task);
1517
1518 retry:
1519         clnt->cl_stats->rpcretrans++;
1520         task->tk_action = call_bind;
1521         task->tk_status = 0;
1522 }
1523
1524 /*
1525  * 7.   Decode the RPC reply
1526  */
1527 static void
1528 call_decode(struct rpc_task *task)
1529 {
1530         struct rpc_clnt *clnt = task->tk_client;
1531         struct rpc_rqst *req = task->tk_rqstp;
1532         kxdrproc_t      decode = task->tk_msg.rpc_proc->p_decode;
1533         __be32          *p;
1534
1535         dprintk("RPC: %5u call_decode (status %d)\n",
1536                         task->tk_pid, task->tk_status);
1537
1538         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1539                 if (clnt->cl_chatty)
1540                         printk(KERN_NOTICE "%s: server %s OK\n",
1541                                 clnt->cl_protname, clnt->cl_server);
1542                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1543         }
1544
1545         /*
1546          * Ensure that we see all writes made by xprt_complete_rqst()
1547          * before it changed req->rq_reply_bytes_recvd.
1548          */
1549         smp_rmb();
1550         req->rq_rcv_buf.len = req->rq_private_buf.len;
1551
1552         /* Check that the softirq receive buffer is valid */
1553         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1554                                 sizeof(req->rq_rcv_buf)) != 0);
1555
1556         if (req->rq_rcv_buf.len < 12) {
1557                 if (!RPC_IS_SOFT(task)) {
1558                         task->tk_action = call_bind;
1559                         clnt->cl_stats->rpcretrans++;
1560                         goto out_retry;
1561                 }
1562                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1563                                 clnt->cl_protname, task->tk_status);
1564                 task->tk_action = call_timeout;
1565                 goto out_retry;
1566         }
1567
1568         p = rpc_verify_header(task);
1569         if (IS_ERR(p)) {
1570                 if (p == ERR_PTR(-EAGAIN))
1571                         goto out_retry;
1572                 return;
1573         }
1574
1575         task->tk_action = rpc_exit_task;
1576
1577         if (decode) {
1578                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1579                                                       task->tk_msg.rpc_resp);
1580         }
1581         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1582                         task->tk_status);
1583         return;
1584 out_retry:
1585         task->tk_status = 0;
1586         /* Note: rpc_verify_header() may have freed the RPC slot */
1587         if (task->tk_rqstp == req) {
1588                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1589                 if (task->tk_client->cl_discrtry)
1590                         xprt_conditional_disconnect(task->tk_xprt,
1591                                         req->rq_connect_cookie);
1592         }
1593 }
1594
1595 static __be32 *
1596 rpc_encode_header(struct rpc_task *task)
1597 {
1598         struct rpc_clnt *clnt = task->tk_client;
1599         struct rpc_rqst *req = task->tk_rqstp;
1600         __be32          *p = req->rq_svec[0].iov_base;
1601
1602         /* FIXME: check buffer size? */
1603
1604         p = xprt_skip_transport_header(task->tk_xprt, p);
1605         *p++ = req->rq_xid;             /* XID */
1606         *p++ = htonl(RPC_CALL);         /* CALL */
1607         *p++ = htonl(RPC_VERSION);      /* RPC version */
1608         *p++ = htonl(clnt->cl_prog);    /* program number */
1609         *p++ = htonl(clnt->cl_vers);    /* program version */
1610         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1611         p = rpcauth_marshcred(task, p);
1612         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1613         return p;
1614 }
1615
1616 static __be32 *
1617 rpc_verify_header(struct rpc_task *task)
1618 {
1619         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1620         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1621         __be32  *p = iov->iov_base;
1622         u32 n;
1623         int error = -EACCES;
1624
1625         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1626                 /* RFC-1014 says that the representation of XDR data must be a
1627                  * multiple of four bytes
1628                  * - if it isn't pointer subtraction in the NFS client may give
1629                  *   undefined results
1630                  */
1631                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1632                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1633                        task->tk_rqstp->rq_rcv_buf.len);
1634                 goto out_eio;
1635         }
1636         if ((len -= 3) < 0)
1637                 goto out_overflow;
1638
1639         p += 1; /* skip XID */
1640         if ((n = ntohl(*p++)) != RPC_REPLY) {
1641                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1642                         task->tk_pid, __func__, n);
1643                 goto out_garbage;
1644         }
1645
1646         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1647                 if (--len < 0)
1648                         goto out_overflow;
1649                 switch ((n = ntohl(*p++))) {
1650                         case RPC_AUTH_ERROR:
1651                                 break;
1652                         case RPC_MISMATCH:
1653                                 dprintk("RPC: %5u %s: RPC call version "
1654                                                 "mismatch!\n",
1655                                                 task->tk_pid, __func__);
1656                                 error = -EPROTONOSUPPORT;
1657                                 goto out_err;
1658                         default:
1659                                 dprintk("RPC: %5u %s: RPC call rejected, "
1660                                                 "unknown error: %x\n",
1661                                                 task->tk_pid, __func__, n);
1662                                 goto out_eio;
1663                 }
1664                 if (--len < 0)
1665                         goto out_overflow;
1666                 switch ((n = ntohl(*p++))) {
1667                 case RPC_AUTH_REJECTEDCRED:
1668                 case RPC_AUTH_REJECTEDVERF:
1669                 case RPCSEC_GSS_CREDPROBLEM:
1670                 case RPCSEC_GSS_CTXPROBLEM:
1671                         if (!task->tk_cred_retry)
1672                                 break;
1673                         task->tk_cred_retry--;
1674                         dprintk("RPC: %5u %s: retry stale creds\n",
1675                                         task->tk_pid, __func__);
1676                         rpcauth_invalcred(task);
1677                         /* Ensure we obtain a new XID! */
1678                         xprt_release(task);
1679                         task->tk_action = call_reserve;
1680                         goto out_retry;
1681                 case RPC_AUTH_BADCRED:
1682                 case RPC_AUTH_BADVERF:
1683                         /* possibly garbled cred/verf? */
1684                         if (!task->tk_garb_retry)
1685                                 break;
1686                         task->tk_garb_retry--;
1687                         dprintk("RPC: %5u %s: retry garbled creds\n",
1688                                         task->tk_pid, __func__);
1689                         task->tk_action = call_bind;
1690                         goto out_retry;
1691                 case RPC_AUTH_TOOWEAK:
1692                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1693                                "authentication.\n", task->tk_client->cl_server);
1694                         break;
1695                 default:
1696                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1697                                         task->tk_pid, __func__, n);
1698                         error = -EIO;
1699                 }
1700                 dprintk("RPC: %5u %s: call rejected %d\n",
1701                                 task->tk_pid, __func__, n);
1702                 goto out_err;
1703         }
1704         if (!(p = rpcauth_checkverf(task, p))) {
1705                 dprintk("RPC: %5u %s: auth check failed\n",
1706                                 task->tk_pid, __func__);
1707                 goto out_garbage;               /* bad verifier, retry */
1708         }
1709         len = p - (__be32 *)iov->iov_base - 1;
1710         if (len < 0)
1711                 goto out_overflow;
1712         switch ((n = ntohl(*p++))) {
1713         case RPC_SUCCESS:
1714                 return p;
1715         case RPC_PROG_UNAVAIL:
1716                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1717                                 task->tk_pid, __func__,
1718                                 (unsigned int)task->tk_client->cl_prog,
1719                                 task->tk_client->cl_server);
1720                 error = -EPFNOSUPPORT;
1721                 goto out_err;
1722         case RPC_PROG_MISMATCH:
1723                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1724                                 "server %s\n", task->tk_pid, __func__,
1725                                 (unsigned int)task->tk_client->cl_prog,
1726                                 (unsigned int)task->tk_client->cl_vers,
1727                                 task->tk_client->cl_server);
1728                 error = -EPROTONOSUPPORT;
1729                 goto out_err;
1730         case RPC_PROC_UNAVAIL:
1731                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1732                                 "version %u on server %s\n",
1733                                 task->tk_pid, __func__,
1734                                 rpc_proc_name(task),
1735                                 task->tk_client->cl_prog,
1736                                 task->tk_client->cl_vers,
1737                                 task->tk_client->cl_server);
1738                 error = -EOPNOTSUPP;
1739                 goto out_err;
1740         case RPC_GARBAGE_ARGS:
1741                 dprintk("RPC: %5u %s: server saw garbage\n",
1742                                 task->tk_pid, __func__);
1743                 break;                  /* retry */
1744         default:
1745                 dprintk("RPC: %5u %s: server accept status: %x\n",
1746                                 task->tk_pid, __func__, n);
1747                 /* Also retry */
1748         }
1749
1750 out_garbage:
1751         task->tk_client->cl_stats->rpcgarbage++;
1752         if (task->tk_garb_retry) {
1753                 task->tk_garb_retry--;
1754                 dprintk("RPC: %5u %s: retrying\n",
1755                                 task->tk_pid, __func__);
1756                 task->tk_action = call_bind;
1757 out_retry:
1758                 return ERR_PTR(-EAGAIN);
1759         }
1760 out_eio:
1761         error = -EIO;
1762 out_err:
1763         rpc_exit(task, error);
1764         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1765                         __func__, error);
1766         return ERR_PTR(error);
1767 out_overflow:
1768         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1769                         __func__);
1770         goto out_garbage;
1771 }
1772
1773 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1774 {
1775         return 0;
1776 }
1777
1778 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1779 {
1780         return 0;
1781 }
1782
1783 static struct rpc_procinfo rpcproc_null = {
1784         .p_encode = rpcproc_encode_null,
1785         .p_decode = rpcproc_decode_null,
1786 };
1787
1788 static int rpc_ping(struct rpc_clnt *clnt)
1789 {
1790         struct rpc_message msg = {
1791                 .rpc_proc = &rpcproc_null,
1792         };
1793         int err;
1794         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1795         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1796         put_rpccred(msg.rpc_cred);
1797         return err;
1798 }
1799
1800 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1801 {
1802         struct rpc_message msg = {
1803                 .rpc_proc = &rpcproc_null,
1804                 .rpc_cred = cred,
1805         };
1806         struct rpc_task_setup task_setup_data = {
1807                 .rpc_client = clnt,
1808                 .rpc_message = &msg,
1809                 .callback_ops = &rpc_default_ops,
1810                 .flags = flags,
1811         };
1812         return rpc_run_task(&task_setup_data);
1813 }
1814 EXPORT_SYMBOL_GPL(rpc_call_null);
1815
1816 #ifdef RPC_DEBUG
1817 static void rpc_show_header(void)
1818 {
1819         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1820                 "-timeout ---ops--\n");
1821 }
1822
1823 static void rpc_show_task(const struct rpc_clnt *clnt,
1824                           const struct rpc_task *task)
1825 {
1826         const char *rpc_waitq = "none";
1827         char *p, action[KSYM_SYMBOL_LEN];
1828
1829         if (RPC_IS_QUEUED(task))
1830                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1831
1832         /* map tk_action pointer to a function name; then trim off
1833          * the "+0x0 [sunrpc]" */
1834         sprint_symbol(action, (unsigned long)task->tk_action);
1835         p = strchr(action, '+');
1836         if (p)
1837                 *p = '\0';
1838
1839         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%s q:%s\n",
1840                 task->tk_pid, task->tk_flags, task->tk_status,
1841                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1842                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1843                 action, rpc_waitq);
1844 }
1845
1846 void rpc_show_tasks(void)
1847 {
1848         struct rpc_clnt *clnt;
1849         struct rpc_task *task;
1850         int header = 0;
1851
1852         spin_lock(&rpc_client_lock);
1853         list_for_each_entry(clnt, &all_clients, cl_clients) {
1854                 spin_lock(&clnt->cl_lock);
1855                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1856                         if (!header) {
1857                                 rpc_show_header();
1858                                 header++;
1859                         }
1860                         rpc_show_task(clnt, task);
1861                 }
1862                 spin_unlock(&clnt->cl_lock);
1863         }
1864         spin_unlock(&rpc_client_lock);
1865 }
1866 #endif