]> git.openfabrics.org - ~shefty/rdma-dev.git/blob - net/sunrpc/clnt.c
Merge branch 'master' into devel and apply fixup from Stephen Rothwell:
[~shefty/rdma-dev.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
18  */
19
20 #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_SUNRPC_BACKCHANNEL)
68 static void     call_bc_transmit(struct rpc_task *task);
69 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
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 path path, dir;
101         char name[15];
102         struct qstr q = {
103                 .name = name,
104         };
105         int error;
106
107         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
108         clnt->cl_path.dentry = ERR_PTR(-ENOENT);
109         if (dir_name == NULL)
110                 return 0;
111
112         path.mnt = rpc_get_mount();
113         if (IS_ERR(path.mnt))
114                 return PTR_ERR(path.mnt);
115         error = vfs_path_lookup(path.mnt->mnt_root, path.mnt, dir_name, 0, &dir);
116         if (error)
117                 goto err;
118
119         for (;;) {
120                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
121                 name[sizeof(name) - 1] = '\0';
122                 q.hash = full_name_hash(q.name, q.len);
123                 path.dentry = rpc_create_client_dir(dir.dentry, &q, clnt);
124                 if (!IS_ERR(path.dentry))
125                         break;
126                 error = PTR_ERR(path.dentry);
127                 if (error != -EEXIST) {
128                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
129                                         " %s/%s, error %d\n",
130                                         dir_name, name, error);
131                         goto err_path_put;
132                 }
133         }
134         path_put(&dir);
135         clnt->cl_path = path;
136         return 0;
137 err_path_put:
138         path_put(&dir);
139 err:
140         rpc_put_mount();
141         return error;
142 }
143
144 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
145 {
146         struct rpc_program      *program = args->program;
147         struct rpc_version      *version;
148         struct rpc_clnt         *clnt = NULL;
149         struct rpc_auth         *auth;
150         int err;
151         size_t len;
152
153         /* sanity check the name before trying to print it */
154         err = -EINVAL;
155         len = strlen(args->servername);
156         if (len > RPC_MAXNETNAMELEN)
157                 goto out_no_rpciod;
158         len++;
159
160         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
161                         program->name, args->servername, xprt);
162
163         err = rpciod_up();
164         if (err)
165                 goto out_no_rpciod;
166         err = -EINVAL;
167         if (!xprt)
168                 goto out_no_xprt;
169
170         if (args->version >= program->nrvers)
171                 goto out_err;
172         version = program->version[args->version];
173         if (version == NULL)
174                 goto out_err;
175
176         err = -ENOMEM;
177         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
178         if (!clnt)
179                 goto out_err;
180         clnt->cl_parent = clnt;
181
182         clnt->cl_server = clnt->cl_inline_name;
183         if (len > sizeof(clnt->cl_inline_name)) {
184                 char *buf = kmalloc(len, GFP_KERNEL);
185                 if (buf != NULL)
186                         clnt->cl_server = buf;
187                 else
188                         len = sizeof(clnt->cl_inline_name);
189         }
190         strlcpy(clnt->cl_server, args->servername, len);
191
192         clnt->cl_xprt     = xprt;
193         clnt->cl_procinfo = version->procs;
194         clnt->cl_maxproc  = version->nrprocs;
195         clnt->cl_protname = program->name;
196         clnt->cl_prog     = args->prognumber ? : program->number;
197         clnt->cl_vers     = version->number;
198         clnt->cl_stats    = program->stats;
199         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
200         err = -ENOMEM;
201         if (clnt->cl_metrics == NULL)
202                 goto out_no_stats;
203         clnt->cl_program  = program;
204         INIT_LIST_HEAD(&clnt->cl_tasks);
205         spin_lock_init(&clnt->cl_lock);
206
207         if (!xprt_bound(clnt->cl_xprt))
208                 clnt->cl_autobind = 1;
209
210         clnt->cl_timeout = xprt->timeout;
211         if (args->timeout != NULL) {
212                 memcpy(&clnt->cl_timeout_default, args->timeout,
213                                 sizeof(clnt->cl_timeout_default));
214                 clnt->cl_timeout = &clnt->cl_timeout_default;
215         }
216
217         clnt->cl_rtt = &clnt->cl_rtt_default;
218         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
219         clnt->cl_principal = NULL;
220         if (args->client_name) {
221                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
222                 if (!clnt->cl_principal)
223                         goto out_no_principal;
224         }
225
226         atomic_set(&clnt->cl_count, 1);
227
228         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
229         if (err < 0)
230                 goto out_no_path;
231
232         auth = rpcauth_create(args->authflavor, clnt);
233         if (IS_ERR(auth)) {
234                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
235                                 args->authflavor);
236                 err = PTR_ERR(auth);
237                 goto out_no_auth;
238         }
239
240         /* save the nodename */
241         clnt->cl_nodelen = strlen(init_utsname()->nodename);
242         if (clnt->cl_nodelen > UNX_MAXNODENAME)
243                 clnt->cl_nodelen = UNX_MAXNODENAME;
244         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
245         rpc_register_client(clnt);
246         return clnt;
247
248 out_no_auth:
249         if (!IS_ERR(clnt->cl_path.dentry)) {
250                 rpc_remove_client_dir(clnt->cl_path.dentry);
251                 rpc_put_mount();
252         }
253 out_no_path:
254         kfree(clnt->cl_principal);
255 out_no_principal:
256         rpc_free_iostats(clnt->cl_metrics);
257 out_no_stats:
258         if (clnt->cl_server != clnt->cl_inline_name)
259                 kfree(clnt->cl_server);
260         kfree(clnt);
261 out_err:
262         xprt_put(xprt);
263 out_no_xprt:
264         rpciod_down();
265 out_no_rpciod:
266         return ERR_PTR(err);
267 }
268
269 /*
270  * rpc_create - create an RPC client and transport with one call
271  * @args: rpc_clnt create argument structure
272  *
273  * Creates and initializes an RPC transport and an RPC client.
274  *
275  * It can ping the server in order to determine if it is up, and to see if
276  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
277  * this behavior so asynchronous tasks can also use rpc_create.
278  */
279 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
280 {
281         struct rpc_xprt *xprt;
282         struct rpc_clnt *clnt;
283         struct xprt_create xprtargs = {
284                 .net = args->net,
285                 .ident = args->protocol,
286                 .srcaddr = args->saddress,
287                 .dstaddr = args->address,
288                 .addrlen = args->addrsize,
289                 .bc_xprt = args->bc_xprt,
290         };
291         char servername[48];
292
293         /*
294          * If the caller chooses not to specify a hostname, whip
295          * up a string representation of the passed-in address.
296          */
297         if (args->servername == NULL) {
298                 struct sockaddr_un *sun =
299                                 (struct sockaddr_un *)args->address;
300                 struct sockaddr_in *sin =
301                                 (struct sockaddr_in *)args->address;
302                 struct sockaddr_in6 *sin6 =
303                                 (struct sockaddr_in6 *)args->address;
304
305                 servername[0] = '\0';
306                 switch (args->address->sa_family) {
307                 case AF_LOCAL:
308                         snprintf(servername, sizeof(servername), "%s",
309                                  sun->sun_path);
310                         break;
311                 case AF_INET:
312                         snprintf(servername, sizeof(servername), "%pI4",
313                                  &sin->sin_addr.s_addr);
314                         break;
315                 case AF_INET6:
316                         snprintf(servername, sizeof(servername), "%pI6",
317                                  &sin6->sin6_addr);
318                         break;
319                 default:
320                         /* caller wants default server name, but
321                          * address family isn't recognized. */
322                         return ERR_PTR(-EINVAL);
323                 }
324                 args->servername = servername;
325         }
326
327         xprt = xprt_create_transport(&xprtargs);
328         if (IS_ERR(xprt))
329                 return (struct rpc_clnt *)xprt;
330
331         /*
332          * By default, kernel RPC client connects from a reserved port.
333          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
334          * but it is always enabled for rpciod, which handles the connect
335          * operation.
336          */
337         xprt->resvport = 1;
338         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
339                 xprt->resvport = 0;
340
341         clnt = rpc_new_client(args, xprt);
342         if (IS_ERR(clnt))
343                 return clnt;
344
345         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
346                 int err = rpc_ping(clnt);
347                 if (err != 0) {
348                         rpc_shutdown_client(clnt);
349                         return ERR_PTR(err);
350                 }
351         }
352
353         clnt->cl_softrtry = 1;
354         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
355                 clnt->cl_softrtry = 0;
356
357         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
358                 clnt->cl_autobind = 1;
359         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
360                 clnt->cl_discrtry = 1;
361         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
362                 clnt->cl_chatty = 1;
363
364         return clnt;
365 }
366 EXPORT_SYMBOL_GPL(rpc_create);
367
368 /*
369  * This function clones the RPC client structure. It allows us to share the
370  * same transport while varying parameters such as the authentication
371  * flavour.
372  */
373 struct rpc_clnt *
374 rpc_clone_client(struct rpc_clnt *clnt)
375 {
376         struct rpc_clnt *new;
377         int err = -ENOMEM;
378
379         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
380         if (!new)
381                 goto out_no_clnt;
382         new->cl_parent = clnt;
383         /* Turn off autobind on clones */
384         new->cl_autobind = 0;
385         INIT_LIST_HEAD(&new->cl_tasks);
386         spin_lock_init(&new->cl_lock);
387         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
388         new->cl_metrics = rpc_alloc_iostats(clnt);
389         if (new->cl_metrics == NULL)
390                 goto out_no_stats;
391         if (clnt->cl_principal) {
392                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
393                 if (new->cl_principal == NULL)
394                         goto out_no_principal;
395         }
396         atomic_set(&new->cl_count, 1);
397         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
398         if (err != 0)
399                 goto out_no_path;
400         if (new->cl_auth)
401                 atomic_inc(&new->cl_auth->au_count);
402         xprt_get(clnt->cl_xprt);
403         atomic_inc(&clnt->cl_count);
404         rpc_register_client(new);
405         rpciod_up();
406         return new;
407 out_no_path:
408         kfree(new->cl_principal);
409 out_no_principal:
410         rpc_free_iostats(new->cl_metrics);
411 out_no_stats:
412         kfree(new);
413 out_no_clnt:
414         dprintk("RPC:       %s: returned error %d\n", __func__, err);
415         return ERR_PTR(err);
416 }
417 EXPORT_SYMBOL_GPL(rpc_clone_client);
418
419 /*
420  * Kill all tasks for the given client.
421  * XXX: kill their descendants as well?
422  */
423 void rpc_killall_tasks(struct rpc_clnt *clnt)
424 {
425         struct rpc_task *rovr;
426
427
428         if (list_empty(&clnt->cl_tasks))
429                 return;
430         dprintk("RPC:       killing all tasks for client %p\n", clnt);
431         /*
432          * Spin lock all_tasks to prevent changes...
433          */
434         spin_lock(&clnt->cl_lock);
435         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
436                 if (!RPC_IS_ACTIVATED(rovr))
437                         continue;
438                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
439                         rovr->tk_flags |= RPC_TASK_KILLED;
440                         rpc_exit(rovr, -EIO);
441                         if (RPC_IS_QUEUED(rovr))
442                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
443                                                         rovr);
444                 }
445         }
446         spin_unlock(&clnt->cl_lock);
447 }
448 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
449
450 /*
451  * Properly shut down an RPC client, terminating all outstanding
452  * requests.
453  */
454 void rpc_shutdown_client(struct rpc_clnt *clnt)
455 {
456         dprintk("RPC:       shutting down %s client for %s\n",
457                         clnt->cl_protname, clnt->cl_server);
458
459         while (!list_empty(&clnt->cl_tasks)) {
460                 rpc_killall_tasks(clnt);
461                 wait_event_timeout(destroy_wait,
462                         list_empty(&clnt->cl_tasks), 1*HZ);
463         }
464
465         rpc_release_client(clnt);
466 }
467 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
468
469 /*
470  * Free an RPC client
471  */
472 static void
473 rpc_free_client(struct rpc_clnt *clnt)
474 {
475         dprintk("RPC:       destroying %s client for %s\n",
476                         clnt->cl_protname, clnt->cl_server);
477         if (!IS_ERR(clnt->cl_path.dentry)) {
478                 rpc_remove_client_dir(clnt->cl_path.dentry);
479                 rpc_put_mount();
480         }
481         if (clnt->cl_parent != clnt) {
482                 rpc_release_client(clnt->cl_parent);
483                 goto out_free;
484         }
485         if (clnt->cl_server != clnt->cl_inline_name)
486                 kfree(clnt->cl_server);
487 out_free:
488         rpc_unregister_client(clnt);
489         rpc_free_iostats(clnt->cl_metrics);
490         kfree(clnt->cl_principal);
491         clnt->cl_metrics = NULL;
492         xprt_put(clnt->cl_xprt);
493         rpciod_down();
494         kfree(clnt);
495 }
496
497 /*
498  * Free an RPC client
499  */
500 static void
501 rpc_free_auth(struct rpc_clnt *clnt)
502 {
503         if (clnt->cl_auth == NULL) {
504                 rpc_free_client(clnt);
505                 return;
506         }
507
508         /*
509          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
510          *       release remaining GSS contexts. This mechanism ensures
511          *       that it can do so safely.
512          */
513         atomic_inc(&clnt->cl_count);
514         rpcauth_release(clnt->cl_auth);
515         clnt->cl_auth = NULL;
516         if (atomic_dec_and_test(&clnt->cl_count))
517                 rpc_free_client(clnt);
518 }
519
520 /*
521  * Release reference to the RPC client
522  */
523 void
524 rpc_release_client(struct rpc_clnt *clnt)
525 {
526         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
527
528         if (list_empty(&clnt->cl_tasks))
529                 wake_up(&destroy_wait);
530         if (atomic_dec_and_test(&clnt->cl_count))
531                 rpc_free_auth(clnt);
532 }
533
534 /**
535  * rpc_bind_new_program - bind a new RPC program to an existing client
536  * @old: old rpc_client
537  * @program: rpc program to set
538  * @vers: rpc program version
539  *
540  * Clones the rpc client and sets up a new RPC program. This is mainly
541  * of use for enabling different RPC programs to share the same transport.
542  * The Sun NFSv2/v3 ACL protocol can do this.
543  */
544 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
545                                       struct rpc_program *program,
546                                       u32 vers)
547 {
548         struct rpc_clnt *clnt;
549         struct rpc_version *version;
550         int err;
551
552         BUG_ON(vers >= program->nrvers || !program->version[vers]);
553         version = program->version[vers];
554         clnt = rpc_clone_client(old);
555         if (IS_ERR(clnt))
556                 goto out;
557         clnt->cl_procinfo = version->procs;
558         clnt->cl_maxproc  = version->nrprocs;
559         clnt->cl_protname = program->name;
560         clnt->cl_prog     = program->number;
561         clnt->cl_vers     = version->number;
562         clnt->cl_stats    = program->stats;
563         err = rpc_ping(clnt);
564         if (err != 0) {
565                 rpc_shutdown_client(clnt);
566                 clnt = ERR_PTR(err);
567         }
568 out:
569         return clnt;
570 }
571 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
572
573 void rpc_task_release_client(struct rpc_task *task)
574 {
575         struct rpc_clnt *clnt = task->tk_client;
576
577         if (clnt != NULL) {
578                 /* Remove from client task list */
579                 spin_lock(&clnt->cl_lock);
580                 list_del(&task->tk_task);
581                 spin_unlock(&clnt->cl_lock);
582                 task->tk_client = NULL;
583
584                 rpc_release_client(clnt);
585         }
586 }
587
588 static
589 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
590 {
591         if (clnt != NULL) {
592                 rpc_task_release_client(task);
593                 task->tk_client = clnt;
594                 atomic_inc(&clnt->cl_count);
595                 if (clnt->cl_softrtry)
596                         task->tk_flags |= RPC_TASK_SOFT;
597                 /* Add to the client's list of all tasks */
598                 spin_lock(&clnt->cl_lock);
599                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
600                 spin_unlock(&clnt->cl_lock);
601         }
602 }
603
604 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
605 {
606         rpc_task_release_client(task);
607         rpc_task_set_client(task, clnt);
608 }
609 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
610
611
612 static void
613 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
614 {
615         if (msg != NULL) {
616                 task->tk_msg.rpc_proc = msg->rpc_proc;
617                 task->tk_msg.rpc_argp = msg->rpc_argp;
618                 task->tk_msg.rpc_resp = msg->rpc_resp;
619                 if (msg->rpc_cred != NULL)
620                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
621         }
622 }
623
624 /*
625  * Default callback for async RPC calls
626  */
627 static void
628 rpc_default_callback(struct rpc_task *task, void *data)
629 {
630 }
631
632 static const struct rpc_call_ops rpc_default_ops = {
633         .rpc_call_done = rpc_default_callback,
634 };
635
636 /**
637  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
638  * @task_setup_data: pointer to task initialisation data
639  */
640 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
641 {
642         struct rpc_task *task;
643
644         task = rpc_new_task(task_setup_data);
645         if (IS_ERR(task))
646                 goto out;
647
648         rpc_task_set_client(task, task_setup_data->rpc_client);
649         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
650
651         if (task->tk_action == NULL)
652                 rpc_call_start(task);
653
654         atomic_inc(&task->tk_count);
655         rpc_execute(task);
656 out:
657         return task;
658 }
659 EXPORT_SYMBOL_GPL(rpc_run_task);
660
661 /**
662  * rpc_call_sync - Perform a synchronous RPC call
663  * @clnt: pointer to RPC client
664  * @msg: RPC call parameters
665  * @flags: RPC call flags
666  */
667 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
668 {
669         struct rpc_task *task;
670         struct rpc_task_setup task_setup_data = {
671                 .rpc_client = clnt,
672                 .rpc_message = msg,
673                 .callback_ops = &rpc_default_ops,
674                 .flags = flags,
675         };
676         int status;
677
678         BUG_ON(flags & RPC_TASK_ASYNC);
679
680         task = rpc_run_task(&task_setup_data);
681         if (IS_ERR(task))
682                 return PTR_ERR(task);
683         status = task->tk_status;
684         rpc_put_task(task);
685         return status;
686 }
687 EXPORT_SYMBOL_GPL(rpc_call_sync);
688
689 /**
690  * rpc_call_async - Perform an asynchronous RPC call
691  * @clnt: pointer to RPC client
692  * @msg: RPC call parameters
693  * @flags: RPC call flags
694  * @tk_ops: RPC call ops
695  * @data: user call data
696  */
697 int
698 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
699                const struct rpc_call_ops *tk_ops, void *data)
700 {
701         struct rpc_task *task;
702         struct rpc_task_setup task_setup_data = {
703                 .rpc_client = clnt,
704                 .rpc_message = msg,
705                 .callback_ops = tk_ops,
706                 .callback_data = data,
707                 .flags = flags|RPC_TASK_ASYNC,
708         };
709
710         task = rpc_run_task(&task_setup_data);
711         if (IS_ERR(task))
712                 return PTR_ERR(task);
713         rpc_put_task(task);
714         return 0;
715 }
716 EXPORT_SYMBOL_GPL(rpc_call_async);
717
718 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
719 /**
720  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
721  * rpc_execute against it
722  * @req: RPC request
723  * @tk_ops: RPC call ops
724  */
725 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
726                                 const struct rpc_call_ops *tk_ops)
727 {
728         struct rpc_task *task;
729         struct xdr_buf *xbufp = &req->rq_snd_buf;
730         struct rpc_task_setup task_setup_data = {
731                 .callback_ops = tk_ops,
732         };
733
734         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
735         /*
736          * Create an rpc_task to send the data
737          */
738         task = rpc_new_task(&task_setup_data);
739         if (IS_ERR(task)) {
740                 xprt_free_bc_request(req);
741                 goto out;
742         }
743         task->tk_rqstp = req;
744
745         /*
746          * Set up the xdr_buf length.
747          * This also indicates that the buffer is XDR encoded already.
748          */
749         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
750                         xbufp->tail[0].iov_len;
751
752         task->tk_action = call_bc_transmit;
753         atomic_inc(&task->tk_count);
754         BUG_ON(atomic_read(&task->tk_count) != 2);
755         rpc_execute(task);
756
757 out:
758         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
759         return task;
760 }
761 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
762
763 void
764 rpc_call_start(struct rpc_task *task)
765 {
766         task->tk_action = call_start;
767 }
768 EXPORT_SYMBOL_GPL(rpc_call_start);
769
770 /**
771  * rpc_peeraddr - extract remote peer address from clnt's xprt
772  * @clnt: RPC client structure
773  * @buf: target buffer
774  * @bufsize: length of target buffer
775  *
776  * Returns the number of bytes that are actually in the stored address.
777  */
778 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
779 {
780         size_t bytes;
781         struct rpc_xprt *xprt = clnt->cl_xprt;
782
783         bytes = sizeof(xprt->addr);
784         if (bytes > bufsize)
785                 bytes = bufsize;
786         memcpy(buf, &clnt->cl_xprt->addr, bytes);
787         return xprt->addrlen;
788 }
789 EXPORT_SYMBOL_GPL(rpc_peeraddr);
790
791 /**
792  * rpc_peeraddr2str - return remote peer address in printable format
793  * @clnt: RPC client structure
794  * @format: address format
795  *
796  */
797 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
798                              enum rpc_display_format_t format)
799 {
800         struct rpc_xprt *xprt = clnt->cl_xprt;
801
802         if (xprt->address_strings[format] != NULL)
803                 return xprt->address_strings[format];
804         else
805                 return "unprintable";
806 }
807 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
808
809 void
810 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
811 {
812         struct rpc_xprt *xprt = clnt->cl_xprt;
813         if (xprt->ops->set_buffer_size)
814                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
815 }
816 EXPORT_SYMBOL_GPL(rpc_setbufsize);
817
818 /*
819  * Return size of largest payload RPC client can support, in bytes
820  *
821  * For stream transports, this is one RPC record fragment (see RFC
822  * 1831), as we don't support multi-record requests yet.  For datagram
823  * transports, this is the size of an IP packet minus the IP, UDP, and
824  * RPC header sizes.
825  */
826 size_t rpc_max_payload(struct rpc_clnt *clnt)
827 {
828         return clnt->cl_xprt->max_payload;
829 }
830 EXPORT_SYMBOL_GPL(rpc_max_payload);
831
832 /**
833  * rpc_force_rebind - force transport to check that remote port is unchanged
834  * @clnt: client to rebind
835  *
836  */
837 void rpc_force_rebind(struct rpc_clnt *clnt)
838 {
839         if (clnt->cl_autobind)
840                 xprt_clear_bound(clnt->cl_xprt);
841 }
842 EXPORT_SYMBOL_GPL(rpc_force_rebind);
843
844 /*
845  * Restart an (async) RPC call from the call_prepare state.
846  * Usually called from within the exit handler.
847  */
848 int
849 rpc_restart_call_prepare(struct rpc_task *task)
850 {
851         if (RPC_ASSASSINATED(task))
852                 return 0;
853         task->tk_action = rpc_prepare_task;
854         return 1;
855 }
856 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
857
858 /*
859  * Restart an (async) RPC call. Usually called from within the
860  * exit handler.
861  */
862 int
863 rpc_restart_call(struct rpc_task *task)
864 {
865         if (RPC_ASSASSINATED(task))
866                 return 0;
867         task->tk_action = call_start;
868         return 1;
869 }
870 EXPORT_SYMBOL_GPL(rpc_restart_call);
871
872 #ifdef RPC_DEBUG
873 static const char *rpc_proc_name(const struct rpc_task *task)
874 {
875         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
876
877         if (proc) {
878                 if (proc->p_name)
879                         return proc->p_name;
880                 else
881                         return "NULL";
882         } else
883                 return "no proc";
884 }
885 #endif
886
887 /*
888  * 0.  Initial state
889  *
890  *     Other FSM states can be visited zero or more times, but
891  *     this state is visited exactly once for each RPC.
892  */
893 static void
894 call_start(struct rpc_task *task)
895 {
896         struct rpc_clnt *clnt = task->tk_client;
897
898         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
899                         clnt->cl_protname, clnt->cl_vers,
900                         rpc_proc_name(task),
901                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
902
903         /* Increment call count */
904         task->tk_msg.rpc_proc->p_count++;
905         clnt->cl_stats->rpccnt++;
906         task->tk_action = call_reserve;
907 }
908
909 /*
910  * 1.   Reserve an RPC call slot
911  */
912 static void
913 call_reserve(struct rpc_task *task)
914 {
915         dprint_status(task);
916
917         task->tk_status  = 0;
918         task->tk_action  = call_reserveresult;
919         xprt_reserve(task);
920 }
921
922 /*
923  * 1b.  Grok the result of xprt_reserve()
924  */
925 static void
926 call_reserveresult(struct rpc_task *task)
927 {
928         int status = task->tk_status;
929
930         dprint_status(task);
931
932         /*
933          * After a call to xprt_reserve(), we must have either
934          * a request slot or else an error status.
935          */
936         task->tk_status = 0;
937         if (status >= 0) {
938                 if (task->tk_rqstp) {
939                         task->tk_action = call_refresh;
940                         return;
941                 }
942
943                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
944                                 __func__, status);
945                 rpc_exit(task, -EIO);
946                 return;
947         }
948
949         /*
950          * Even though there was an error, we may have acquired
951          * a request slot somehow.  Make sure not to leak it.
952          */
953         if (task->tk_rqstp) {
954                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
955                                 __func__, status);
956                 xprt_release(task);
957         }
958
959         switch (status) {
960         case -EAGAIN:   /* woken up; retry */
961                 task->tk_action = call_reserve;
962                 return;
963         case -EIO:      /* probably a shutdown */
964                 break;
965         default:
966                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
967                                 __func__, status);
968                 break;
969         }
970         rpc_exit(task, status);
971 }
972
973 /*
974  * 2.   Bind and/or refresh the credentials
975  */
976 static void
977 call_refresh(struct rpc_task *task)
978 {
979         dprint_status(task);
980
981         task->tk_action = call_refreshresult;
982         task->tk_status = 0;
983         task->tk_client->cl_stats->rpcauthrefresh++;
984         rpcauth_refreshcred(task);
985 }
986
987 /*
988  * 2a.  Process the results of a credential refresh
989  */
990 static void
991 call_refreshresult(struct rpc_task *task)
992 {
993         int status = task->tk_status;
994
995         dprint_status(task);
996
997         task->tk_status = 0;
998         task->tk_action = call_refresh;
999         switch (status) {
1000         case 0:
1001                 if (rpcauth_uptodatecred(task))
1002                         task->tk_action = call_allocate;
1003                 return;
1004         case -ETIMEDOUT:
1005                 rpc_delay(task, 3*HZ);
1006         case -EAGAIN:
1007                 status = -EACCES;
1008                 if (!task->tk_cred_retry)
1009                         break;
1010                 task->tk_cred_retry--;
1011                 dprintk("RPC: %5u %s: retry refresh creds\n",
1012                                 task->tk_pid, __func__);
1013                 return;
1014         }
1015         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1016                                 task->tk_pid, __func__, status);
1017         rpc_exit(task, status);
1018 }
1019
1020 /*
1021  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1022  *      (Note: buffer memory is freed in xprt_release).
1023  */
1024 static void
1025 call_allocate(struct rpc_task *task)
1026 {
1027         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1028         struct rpc_rqst *req = task->tk_rqstp;
1029         struct rpc_xprt *xprt = task->tk_xprt;
1030         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1031
1032         dprint_status(task);
1033
1034         task->tk_status = 0;
1035         task->tk_action = call_bind;
1036
1037         if (req->rq_buffer)
1038                 return;
1039
1040         if (proc->p_proc != 0) {
1041                 BUG_ON(proc->p_arglen == 0);
1042                 if (proc->p_decode != NULL)
1043                         BUG_ON(proc->p_replen == 0);
1044         }
1045
1046         /*
1047          * Calculate the size (in quads) of the RPC call
1048          * and reply headers, and convert both values
1049          * to byte sizes.
1050          */
1051         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1052         req->rq_callsize <<= 2;
1053         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1054         req->rq_rcvsize <<= 2;
1055
1056         req->rq_buffer = xprt->ops->buf_alloc(task,
1057                                         req->rq_callsize + req->rq_rcvsize);
1058         if (req->rq_buffer != NULL)
1059                 return;
1060
1061         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1062
1063         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1064                 task->tk_action = call_allocate;
1065                 rpc_delay(task, HZ>>4);
1066                 return;
1067         }
1068
1069         rpc_exit(task, -ERESTARTSYS);
1070 }
1071
1072 static inline int
1073 rpc_task_need_encode(struct rpc_task *task)
1074 {
1075         return task->tk_rqstp->rq_snd_buf.len == 0;
1076 }
1077
1078 static inline void
1079 rpc_task_force_reencode(struct rpc_task *task)
1080 {
1081         task->tk_rqstp->rq_snd_buf.len = 0;
1082         task->tk_rqstp->rq_bytes_sent = 0;
1083 }
1084
1085 static inline void
1086 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1087 {
1088         buf->head[0].iov_base = start;
1089         buf->head[0].iov_len = len;
1090         buf->tail[0].iov_len = 0;
1091         buf->page_len = 0;
1092         buf->flags = 0;
1093         buf->len = 0;
1094         buf->buflen = len;
1095 }
1096
1097 /*
1098  * 3.   Encode arguments of an RPC call
1099  */
1100 static void
1101 rpc_xdr_encode(struct rpc_task *task)
1102 {
1103         struct rpc_rqst *req = task->tk_rqstp;
1104         kxdreproc_t     encode;
1105         __be32          *p;
1106
1107         dprint_status(task);
1108
1109         rpc_xdr_buf_init(&req->rq_snd_buf,
1110                          req->rq_buffer,
1111                          req->rq_callsize);
1112         rpc_xdr_buf_init(&req->rq_rcv_buf,
1113                          (char *)req->rq_buffer + req->rq_callsize,
1114                          req->rq_rcvsize);
1115
1116         p = rpc_encode_header(task);
1117         if (p == NULL) {
1118                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1119                 rpc_exit(task, -EIO);
1120                 return;
1121         }
1122
1123         encode = task->tk_msg.rpc_proc->p_encode;
1124         if (encode == NULL)
1125                 return;
1126
1127         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1128                         task->tk_msg.rpc_argp);
1129 }
1130
1131 /*
1132  * 4.   Get the server port number if not yet set
1133  */
1134 static void
1135 call_bind(struct rpc_task *task)
1136 {
1137         struct rpc_xprt *xprt = task->tk_xprt;
1138
1139         dprint_status(task);
1140
1141         task->tk_action = call_connect;
1142         if (!xprt_bound(xprt)) {
1143                 task->tk_action = call_bind_status;
1144                 task->tk_timeout = xprt->bind_timeout;
1145                 xprt->ops->rpcbind(task);
1146         }
1147 }
1148
1149 /*
1150  * 4a.  Sort out bind result
1151  */
1152 static void
1153 call_bind_status(struct rpc_task *task)
1154 {
1155         int status = -EIO;
1156
1157         if (task->tk_status >= 0) {
1158                 dprint_status(task);
1159                 task->tk_status = 0;
1160                 task->tk_action = call_connect;
1161                 return;
1162         }
1163
1164         switch (task->tk_status) {
1165         case -ENOMEM:
1166                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1167                 rpc_delay(task, HZ >> 2);
1168                 goto retry_timeout;
1169         case -EACCES:
1170                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1171                                 "unavailable\n", task->tk_pid);
1172                 /* fail immediately if this is an RPC ping */
1173                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1174                         status = -EOPNOTSUPP;
1175                         break;
1176                 }
1177                 if (task->tk_rebind_retry == 0)
1178                         break;
1179                 task->tk_rebind_retry--;
1180                 rpc_delay(task, 3*HZ);
1181                 goto retry_timeout;
1182         case -ETIMEDOUT:
1183                 dprintk("RPC: %5u rpcbind request timed out\n",
1184                                 task->tk_pid);
1185                 goto retry_timeout;
1186         case -EPFNOSUPPORT:
1187                 /* server doesn't support any rpcbind version we know of */
1188                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1189                                 task->tk_pid);
1190                 break;
1191         case -EPROTONOSUPPORT:
1192                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1193                                 task->tk_pid);
1194                 task->tk_status = 0;
1195                 task->tk_action = call_bind;
1196                 return;
1197         case -ECONNREFUSED:             /* connection problems */
1198         case -ECONNRESET:
1199         case -ENOTCONN:
1200         case -EHOSTDOWN:
1201         case -EHOSTUNREACH:
1202         case -ENETUNREACH:
1203         case -EPIPE:
1204                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1205                                 task->tk_pid, task->tk_status);
1206                 if (!RPC_IS_SOFTCONN(task)) {
1207                         rpc_delay(task, 5*HZ);
1208                         goto retry_timeout;
1209                 }
1210                 status = task->tk_status;
1211                 break;
1212         default:
1213                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1214                                 task->tk_pid, -task->tk_status);
1215         }
1216
1217         rpc_exit(task, status);
1218         return;
1219
1220 retry_timeout:
1221         task->tk_action = call_timeout;
1222 }
1223
1224 /*
1225  * 4b.  Connect to the RPC server
1226  */
1227 static void
1228 call_connect(struct rpc_task *task)
1229 {
1230         struct rpc_xprt *xprt = task->tk_xprt;
1231
1232         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1233                         task->tk_pid, xprt,
1234                         (xprt_connected(xprt) ? "is" : "is not"));
1235
1236         task->tk_action = call_transmit;
1237         if (!xprt_connected(xprt)) {
1238                 task->tk_action = call_connect_status;
1239                 if (task->tk_status < 0)
1240                         return;
1241                 xprt_connect(task);
1242         }
1243 }
1244
1245 /*
1246  * 4c.  Sort out connect result
1247  */
1248 static void
1249 call_connect_status(struct rpc_task *task)
1250 {
1251         struct rpc_clnt *clnt = task->tk_client;
1252         int status = task->tk_status;
1253
1254         dprint_status(task);
1255
1256         task->tk_status = 0;
1257         if (status >= 0 || status == -EAGAIN) {
1258                 clnt->cl_stats->netreconn++;
1259                 task->tk_action = call_transmit;
1260                 return;
1261         }
1262
1263         switch (status) {
1264                 /* if soft mounted, test if we've timed out */
1265         case -ETIMEDOUT:
1266                 task->tk_action = call_timeout;
1267                 break;
1268         default:
1269                 rpc_exit(task, -EIO);
1270         }
1271 }
1272
1273 /*
1274  * 5.   Transmit the RPC request, and wait for reply
1275  */
1276 static void
1277 call_transmit(struct rpc_task *task)
1278 {
1279         dprint_status(task);
1280
1281         task->tk_action = call_status;
1282         if (task->tk_status < 0)
1283                 return;
1284         task->tk_status = xprt_prepare_transmit(task);
1285         if (task->tk_status != 0)
1286                 return;
1287         task->tk_action = call_transmit_status;
1288         /* Encode here so that rpcsec_gss can use correct sequence number. */
1289         if (rpc_task_need_encode(task)) {
1290                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1291                 rpc_xdr_encode(task);
1292                 /* Did the encode result in an error condition? */
1293                 if (task->tk_status != 0) {
1294                         /* Was the error nonfatal? */
1295                         if (task->tk_status == -EAGAIN)
1296                                 rpc_delay(task, HZ >> 4);
1297                         else
1298                                 rpc_exit(task, task->tk_status);
1299                         return;
1300                 }
1301         }
1302         xprt_transmit(task);
1303         if (task->tk_status < 0)
1304                 return;
1305         /*
1306          * On success, ensure that we call xprt_end_transmit() before sleeping
1307          * in order to allow access to the socket to other RPC requests.
1308          */
1309         call_transmit_status(task);
1310         if (rpc_reply_expected(task))
1311                 return;
1312         task->tk_action = rpc_exit_task;
1313         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1314 }
1315
1316 /*
1317  * 5a.  Handle cleanup after a transmission
1318  */
1319 static void
1320 call_transmit_status(struct rpc_task *task)
1321 {
1322         task->tk_action = call_status;
1323
1324         /*
1325          * Common case: success.  Force the compiler to put this
1326          * test first.
1327          */
1328         if (task->tk_status == 0) {
1329                 xprt_end_transmit(task);
1330                 rpc_task_force_reencode(task);
1331                 return;
1332         }
1333
1334         switch (task->tk_status) {
1335         case -EAGAIN:
1336                 break;
1337         default:
1338                 dprint_status(task);
1339                 xprt_end_transmit(task);
1340                 rpc_task_force_reencode(task);
1341                 break;
1342                 /*
1343                  * Special cases: if we've been waiting on the
1344                  * socket's write_space() callback, or if the
1345                  * socket just returned a connection error,
1346                  * then hold onto the transport lock.
1347                  */
1348         case -ECONNREFUSED:
1349         case -EHOSTDOWN:
1350         case -EHOSTUNREACH:
1351         case -ENETUNREACH:
1352                 if (RPC_IS_SOFTCONN(task)) {
1353                         xprt_end_transmit(task);
1354                         rpc_exit(task, task->tk_status);
1355                         break;
1356                 }
1357         case -ECONNRESET:
1358         case -ENOTCONN:
1359         case -EPIPE:
1360                 rpc_task_force_reencode(task);
1361         }
1362 }
1363
1364 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1365 /*
1366  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1367  * addition, disconnect on connectivity errors.
1368  */
1369 static void
1370 call_bc_transmit(struct rpc_task *task)
1371 {
1372         struct rpc_rqst *req = task->tk_rqstp;
1373
1374         BUG_ON(task->tk_status != 0);
1375         task->tk_status = xprt_prepare_transmit(task);
1376         if (task->tk_status == -EAGAIN) {
1377                 /*
1378                  * Could not reserve the transport. Try again after the
1379                  * transport is released.
1380                  */
1381                 task->tk_status = 0;
1382                 task->tk_action = call_bc_transmit;
1383                 return;
1384         }
1385
1386         task->tk_action = rpc_exit_task;
1387         if (task->tk_status < 0) {
1388                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1389                         "error: %d\n", task->tk_status);
1390                 return;
1391         }
1392
1393         xprt_transmit(task);
1394         xprt_end_transmit(task);
1395         dprint_status(task);
1396         switch (task->tk_status) {
1397         case 0:
1398                 /* Success */
1399                 break;
1400         case -EHOSTDOWN:
1401         case -EHOSTUNREACH:
1402         case -ENETUNREACH:
1403         case -ETIMEDOUT:
1404                 /*
1405                  * Problem reaching the server.  Disconnect and let the
1406                  * forechannel reestablish the connection.  The server will
1407                  * have to retransmit the backchannel request and we'll
1408                  * reprocess it.  Since these ops are idempotent, there's no
1409                  * need to cache our reply at this time.
1410                  */
1411                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1412                         "error: %d\n", task->tk_status);
1413                 xprt_conditional_disconnect(task->tk_xprt,
1414                         req->rq_connect_cookie);
1415                 break;
1416         default:
1417                 /*
1418                  * We were unable to reply and will have to drop the
1419                  * request.  The server should reconnect and retransmit.
1420                  */
1421                 BUG_ON(task->tk_status == -EAGAIN);
1422                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1423                         "error: %d\n", task->tk_status);
1424                 break;
1425         }
1426         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1427 }
1428 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1429
1430 /*
1431  * 6.   Sort out the RPC call status
1432  */
1433 static void
1434 call_status(struct rpc_task *task)
1435 {
1436         struct rpc_clnt *clnt = task->tk_client;
1437         struct rpc_rqst *req = task->tk_rqstp;
1438         int             status;
1439
1440         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1441                 task->tk_status = req->rq_reply_bytes_recvd;
1442
1443         dprint_status(task);
1444
1445         status = task->tk_status;
1446         if (status >= 0) {
1447                 task->tk_action = call_decode;
1448                 return;
1449         }
1450
1451         task->tk_status = 0;
1452         switch(status) {
1453         case -EHOSTDOWN:
1454         case -EHOSTUNREACH:
1455         case -ENETUNREACH:
1456                 /*
1457                  * Delay any retries for 3 seconds, then handle as if it
1458                  * were a timeout.
1459                  */
1460                 rpc_delay(task, 3*HZ);
1461         case -ETIMEDOUT:
1462                 task->tk_action = call_timeout;
1463                 if (task->tk_client->cl_discrtry)
1464                         xprt_conditional_disconnect(task->tk_xprt,
1465                                         req->rq_connect_cookie);
1466                 break;
1467         case -ECONNRESET:
1468         case -ECONNREFUSED:
1469                 rpc_force_rebind(clnt);
1470                 rpc_delay(task, 3*HZ);
1471         case -EPIPE:
1472         case -ENOTCONN:
1473                 task->tk_action = call_bind;
1474                 break;
1475         case -EAGAIN:
1476                 task->tk_action = call_transmit;
1477                 break;
1478         case -EIO:
1479                 /* shutdown or soft timeout */
1480                 rpc_exit(task, status);
1481                 break;
1482         default:
1483                 if (clnt->cl_chatty)
1484                         printk("%s: RPC call returned error %d\n",
1485                                clnt->cl_protname, -status);
1486                 rpc_exit(task, status);
1487         }
1488 }
1489
1490 /*
1491  * 6a.  Handle RPC timeout
1492  *      We do not release the request slot, so we keep using the
1493  *      same XID for all retransmits.
1494  */
1495 static void
1496 call_timeout(struct rpc_task *task)
1497 {
1498         struct rpc_clnt *clnt = task->tk_client;
1499
1500         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1501                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1502                 goto retry;
1503         }
1504
1505         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1506         task->tk_timeouts++;
1507
1508         if (RPC_IS_SOFTCONN(task)) {
1509                 rpc_exit(task, -ETIMEDOUT);
1510                 return;
1511         }
1512         if (RPC_IS_SOFT(task)) {
1513                 if (clnt->cl_chatty)
1514                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1515                                 clnt->cl_protname, clnt->cl_server);
1516                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1517                         rpc_exit(task, -ETIMEDOUT);
1518                 else
1519                         rpc_exit(task, -EIO);
1520                 return;
1521         }
1522
1523         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1524                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1525                 if (clnt->cl_chatty)
1526                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1527                         clnt->cl_protname, clnt->cl_server);
1528         }
1529         rpc_force_rebind(clnt);
1530         /*
1531          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1532          * event? RFC2203 requires the server to drop all such requests.
1533          */
1534         rpcauth_invalcred(task);
1535
1536 retry:
1537         clnt->cl_stats->rpcretrans++;
1538         task->tk_action = call_bind;
1539         task->tk_status = 0;
1540 }
1541
1542 /*
1543  * 7.   Decode the RPC reply
1544  */
1545 static void
1546 call_decode(struct rpc_task *task)
1547 {
1548         struct rpc_clnt *clnt = task->tk_client;
1549         struct rpc_rqst *req = task->tk_rqstp;
1550         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1551         __be32          *p;
1552
1553         dprint_status(task);
1554
1555         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1556                 if (clnt->cl_chatty)
1557                         printk(KERN_NOTICE "%s: server %s OK\n",
1558                                 clnt->cl_protname, clnt->cl_server);
1559                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1560         }
1561
1562         /*
1563          * Ensure that we see all writes made by xprt_complete_rqst()
1564          * before it changed req->rq_reply_bytes_recvd.
1565          */
1566         smp_rmb();
1567         req->rq_rcv_buf.len = req->rq_private_buf.len;
1568
1569         /* Check that the softirq receive buffer is valid */
1570         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1571                                 sizeof(req->rq_rcv_buf)) != 0);
1572
1573         if (req->rq_rcv_buf.len < 12) {
1574                 if (!RPC_IS_SOFT(task)) {
1575                         task->tk_action = call_bind;
1576                         clnt->cl_stats->rpcretrans++;
1577                         goto out_retry;
1578                 }
1579                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1580                                 clnt->cl_protname, task->tk_status);
1581                 task->tk_action = call_timeout;
1582                 goto out_retry;
1583         }
1584
1585         p = rpc_verify_header(task);
1586         if (IS_ERR(p)) {
1587                 if (p == ERR_PTR(-EAGAIN))
1588                         goto out_retry;
1589                 return;
1590         }
1591
1592         task->tk_action = rpc_exit_task;
1593
1594         if (decode) {
1595                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1596                                                       task->tk_msg.rpc_resp);
1597         }
1598         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1599                         task->tk_status);
1600         return;
1601 out_retry:
1602         task->tk_status = 0;
1603         /* Note: rpc_verify_header() may have freed the RPC slot */
1604         if (task->tk_rqstp == req) {
1605                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1606                 if (task->tk_client->cl_discrtry)
1607                         xprt_conditional_disconnect(task->tk_xprt,
1608                                         req->rq_connect_cookie);
1609         }
1610 }
1611
1612 static __be32 *
1613 rpc_encode_header(struct rpc_task *task)
1614 {
1615         struct rpc_clnt *clnt = task->tk_client;
1616         struct rpc_rqst *req = task->tk_rqstp;
1617         __be32          *p = req->rq_svec[0].iov_base;
1618
1619         /* FIXME: check buffer size? */
1620
1621         p = xprt_skip_transport_header(task->tk_xprt, p);
1622         *p++ = req->rq_xid;             /* XID */
1623         *p++ = htonl(RPC_CALL);         /* CALL */
1624         *p++ = htonl(RPC_VERSION);      /* RPC version */
1625         *p++ = htonl(clnt->cl_prog);    /* program number */
1626         *p++ = htonl(clnt->cl_vers);    /* program version */
1627         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1628         p = rpcauth_marshcred(task, p);
1629         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1630         return p;
1631 }
1632
1633 static __be32 *
1634 rpc_verify_header(struct rpc_task *task)
1635 {
1636         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1637         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1638         __be32  *p = iov->iov_base;
1639         u32 n;
1640         int error = -EACCES;
1641
1642         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1643                 /* RFC-1014 says that the representation of XDR data must be a
1644                  * multiple of four bytes
1645                  * - if it isn't pointer subtraction in the NFS client may give
1646                  *   undefined results
1647                  */
1648                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1649                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1650                        task->tk_rqstp->rq_rcv_buf.len);
1651                 goto out_eio;
1652         }
1653         if ((len -= 3) < 0)
1654                 goto out_overflow;
1655
1656         p += 1; /* skip XID */
1657         if ((n = ntohl(*p++)) != RPC_REPLY) {
1658                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1659                         task->tk_pid, __func__, n);
1660                 goto out_garbage;
1661         }
1662
1663         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1664                 if (--len < 0)
1665                         goto out_overflow;
1666                 switch ((n = ntohl(*p++))) {
1667                 case RPC_AUTH_ERROR:
1668                         break;
1669                 case RPC_MISMATCH:
1670                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
1671                                 task->tk_pid, __func__);
1672                         error = -EPROTONOSUPPORT;
1673                         goto out_err;
1674                 default:
1675                         dprintk("RPC: %5u %s: RPC call rejected, "
1676                                 "unknown error: %x\n",
1677                                 task->tk_pid, __func__, n);
1678                         goto out_eio;
1679                 }
1680                 if (--len < 0)
1681                         goto out_overflow;
1682                 switch ((n = ntohl(*p++))) {
1683                 case RPC_AUTH_REJECTEDCRED:
1684                 case RPC_AUTH_REJECTEDVERF:
1685                 case RPCSEC_GSS_CREDPROBLEM:
1686                 case RPCSEC_GSS_CTXPROBLEM:
1687                         if (!task->tk_cred_retry)
1688                                 break;
1689                         task->tk_cred_retry--;
1690                         dprintk("RPC: %5u %s: retry stale creds\n",
1691                                         task->tk_pid, __func__);
1692                         rpcauth_invalcred(task);
1693                         /* Ensure we obtain a new XID! */
1694                         xprt_release(task);
1695                         task->tk_action = call_reserve;
1696                         goto out_retry;
1697                 case RPC_AUTH_BADCRED:
1698                 case RPC_AUTH_BADVERF:
1699                         /* possibly garbled cred/verf? */
1700                         if (!task->tk_garb_retry)
1701                                 break;
1702                         task->tk_garb_retry--;
1703                         dprintk("RPC: %5u %s: retry garbled creds\n",
1704                                         task->tk_pid, __func__);
1705                         task->tk_action = call_bind;
1706                         goto out_retry;
1707                 case RPC_AUTH_TOOWEAK:
1708                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1709                                "authentication.\n", task->tk_client->cl_server);
1710                         break;
1711                 default:
1712                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1713                                         task->tk_pid, __func__, n);
1714                         error = -EIO;
1715                 }
1716                 dprintk("RPC: %5u %s: call rejected %d\n",
1717                                 task->tk_pid, __func__, n);
1718                 goto out_err;
1719         }
1720         if (!(p = rpcauth_checkverf(task, p))) {
1721                 dprintk("RPC: %5u %s: auth check failed\n",
1722                                 task->tk_pid, __func__);
1723                 goto out_garbage;               /* bad verifier, retry */
1724         }
1725         len = p - (__be32 *)iov->iov_base - 1;
1726         if (len < 0)
1727                 goto out_overflow;
1728         switch ((n = ntohl(*p++))) {
1729         case RPC_SUCCESS:
1730                 return p;
1731         case RPC_PROG_UNAVAIL:
1732                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1733                                 task->tk_pid, __func__,
1734                                 (unsigned int)task->tk_client->cl_prog,
1735                                 task->tk_client->cl_server);
1736                 error = -EPFNOSUPPORT;
1737                 goto out_err;
1738         case RPC_PROG_MISMATCH:
1739                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1740                                 "server %s\n", task->tk_pid, __func__,
1741                                 (unsigned int)task->tk_client->cl_prog,
1742                                 (unsigned int)task->tk_client->cl_vers,
1743                                 task->tk_client->cl_server);
1744                 error = -EPROTONOSUPPORT;
1745                 goto out_err;
1746         case RPC_PROC_UNAVAIL:
1747                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1748                                 "version %u on server %s\n",
1749                                 task->tk_pid, __func__,
1750                                 rpc_proc_name(task),
1751                                 task->tk_client->cl_prog,
1752                                 task->tk_client->cl_vers,
1753                                 task->tk_client->cl_server);
1754                 error = -EOPNOTSUPP;
1755                 goto out_err;
1756         case RPC_GARBAGE_ARGS:
1757                 dprintk("RPC: %5u %s: server saw garbage\n",
1758                                 task->tk_pid, __func__);
1759                 break;                  /* retry */
1760         default:
1761                 dprintk("RPC: %5u %s: server accept status: %x\n",
1762                                 task->tk_pid, __func__, n);
1763                 /* Also retry */
1764         }
1765
1766 out_garbage:
1767         task->tk_client->cl_stats->rpcgarbage++;
1768         if (task->tk_garb_retry) {
1769                 task->tk_garb_retry--;
1770                 dprintk("RPC: %5u %s: retrying\n",
1771                                 task->tk_pid, __func__);
1772                 task->tk_action = call_bind;
1773 out_retry:
1774                 return ERR_PTR(-EAGAIN);
1775         }
1776 out_eio:
1777         error = -EIO;
1778 out_err:
1779         rpc_exit(task, error);
1780         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1781                         __func__, error);
1782         return ERR_PTR(error);
1783 out_overflow:
1784         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1785                         __func__);
1786         goto out_garbage;
1787 }
1788
1789 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1790 {
1791 }
1792
1793 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1794 {
1795         return 0;
1796 }
1797
1798 static struct rpc_procinfo rpcproc_null = {
1799         .p_encode = rpcproc_encode_null,
1800         .p_decode = rpcproc_decode_null,
1801 };
1802
1803 static int rpc_ping(struct rpc_clnt *clnt)
1804 {
1805         struct rpc_message msg = {
1806                 .rpc_proc = &rpcproc_null,
1807         };
1808         int err;
1809         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1810         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1811         put_rpccred(msg.rpc_cred);
1812         return err;
1813 }
1814
1815 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1816 {
1817         struct rpc_message msg = {
1818                 .rpc_proc = &rpcproc_null,
1819                 .rpc_cred = cred,
1820         };
1821         struct rpc_task_setup task_setup_data = {
1822                 .rpc_client = clnt,
1823                 .rpc_message = &msg,
1824                 .callback_ops = &rpc_default_ops,
1825                 .flags = flags,
1826         };
1827         return rpc_run_task(&task_setup_data);
1828 }
1829 EXPORT_SYMBOL_GPL(rpc_call_null);
1830
1831 #ifdef RPC_DEBUG
1832 static void rpc_show_header(void)
1833 {
1834         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1835                 "-timeout ---ops--\n");
1836 }
1837
1838 static void rpc_show_task(const struct rpc_clnt *clnt,
1839                           const struct rpc_task *task)
1840 {
1841         const char *rpc_waitq = "none";
1842
1843         if (RPC_IS_QUEUED(task))
1844                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1845
1846         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
1847                 task->tk_pid, task->tk_flags, task->tk_status,
1848                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1849                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1850                 task->tk_action, rpc_waitq);
1851 }
1852
1853 void rpc_show_tasks(void)
1854 {
1855         struct rpc_clnt *clnt;
1856         struct rpc_task *task;
1857         int header = 0;
1858
1859         spin_lock(&rpc_client_lock);
1860         list_for_each_entry(clnt, &all_clients, cl_clients) {
1861                 spin_lock(&clnt->cl_lock);
1862                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1863                         if (!header) {
1864                                 rpc_show_header();
1865                                 header++;
1866                         }
1867                         rpc_show_task(clnt, task);
1868                 }
1869                 spin_unlock(&clnt->cl_lock);
1870         }
1871         spin_unlock(&rpc_client_lock);
1872 }
1873 #endif