SUNRPC: remove RPC pipefs mount point manipulations from RPC clients code
[linux-3.10.git] / net / sunrpc / clnt.c
1 /*
2  *  linux/net/sunrpc/clnt.c
3  *
4  *  This file contains the high-level RPC interface.
5  *  It is modeled as a finite state machine to support both synchronous
6  *  and asynchronous requests.
7  *
8  *  -   RPC header generation and argument serialization.
9  *  -   Credential refresh.
10  *  -   TCP connect handling.
11  *  -   Retry of operation when it is suspected the operation failed because
12  *      of uid squashing on the server, or when the credentials were stale
13  *      and need to be refreshed, or when a packet was damaged in transit.
14  *      This may be have to be moved to the VFS layer.
15  *
16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
18  */
19
20 #include <asm/system.h>
21
22 #include <linux/module.h>
23 #include <linux/types.h>
24 #include <linux/kallsyms.h>
25 #include <linux/mm.h>
26 #include <linux/namei.h>
27 #include <linux/mount.h>
28 #include <linux/slab.h>
29 #include <linux/utsname.h>
30 #include <linux/workqueue.h>
31 #include <linux/in.h>
32 #include <linux/in6.h>
33 #include <linux/un.h>
34
35 #include <linux/sunrpc/clnt.h>
36 #include <linux/sunrpc/rpc_pipe_fs.h>
37 #include <linux/sunrpc/metrics.h>
38 #include <linux/sunrpc/bc_xprt.h>
39
40 #include "sunrpc.h"
41 #include "netns.h"
42
43 #ifdef RPC_DEBUG
44 # define RPCDBG_FACILITY        RPCDBG_CALL
45 #endif
46
47 #define dprint_status(t)                                        \
48         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
49                         __func__, t->tk_status)
50
51 /*
52  * All RPC clients are linked into this list
53  */
54
55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
56
57
58 static void     call_start(struct rpc_task *task);
59 static void     call_reserve(struct rpc_task *task);
60 static void     call_reserveresult(struct rpc_task *task);
61 static void     call_allocate(struct rpc_task *task);
62 static void     call_decode(struct rpc_task *task);
63 static void     call_bind(struct rpc_task *task);
64 static void     call_bind_status(struct rpc_task *task);
65 static void     call_transmit(struct rpc_task *task);
66 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
67 static void     call_bc_transmit(struct rpc_task *task);
68 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
69 static void     call_status(struct rpc_task *task);
70 static void     call_transmit_status(struct rpc_task *task);
71 static void     call_refresh(struct rpc_task *task);
72 static void     call_refreshresult(struct rpc_task *task);
73 static void     call_timeout(struct rpc_task *task);
74 static void     call_connect(struct rpc_task *task);
75 static void     call_connect_status(struct rpc_task *task);
76
77 static __be32   *rpc_encode_header(struct rpc_task *task);
78 static __be32   *rpc_verify_header(struct rpc_task *task);
79 static int      rpc_ping(struct rpc_clnt *clnt);
80
81 static void rpc_register_client(struct rpc_clnt *clnt)
82 {
83         struct sunrpc_net *sn = net_generic(clnt->cl_xprt->xprt_net, sunrpc_net_id);
84
85         spin_lock(&sn->rpc_client_lock);
86         list_add(&clnt->cl_clients, &sn->all_clients);
87         spin_unlock(&sn->rpc_client_lock);
88 }
89
90 static void rpc_unregister_client(struct rpc_clnt *clnt)
91 {
92         struct sunrpc_net *sn = net_generic(clnt->cl_xprt->xprt_net, sunrpc_net_id);
93
94         spin_lock(&sn->rpc_client_lock);
95         list_del(&clnt->cl_clients);
96         spin_unlock(&sn->rpc_client_lock);
97 }
98
99 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
100 {
101         if (clnt->cl_path.dentry) {
102                 if (clnt->cl_auth && clnt->cl_auth->au_ops->pipes_destroy)
103                         clnt->cl_auth->au_ops->pipes_destroy(clnt->cl_auth);
104                 rpc_remove_client_dir(clnt->cl_path.dentry);
105         }
106         clnt->cl_path.dentry = NULL;
107 }
108
109 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
110 {
111         struct super_block *pipefs_sb;
112
113         pipefs_sb = rpc_get_sb_net(clnt->cl_xprt->xprt_net);
114         if (pipefs_sb) {
115                 __rpc_clnt_remove_pipedir(clnt);
116                 rpc_put_sb_net(clnt->cl_xprt->xprt_net);
117         }
118 }
119
120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
121                                     struct rpc_clnt *clnt, char *dir_name)
122 {
123         static uint32_t clntid;
124         char name[15];
125         struct qstr q = {
126                 .name = name,
127         };
128         struct dentry *dir, *dentry;
129         int error;
130
131         dir = rpc_d_lookup_sb(sb, dir_name);
132         if (dir == NULL)
133                 return dir;
134         for (;;) {
135                 q.len = snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
136                 name[sizeof(name) - 1] = '\0';
137                 q.hash = full_name_hash(q.name, q.len);
138                 dentry = rpc_create_client_dir(dir, &q, clnt);
139                 if (!IS_ERR(dentry))
140                         break;
141                 error = PTR_ERR(dentry);
142                 if (error != -EEXIST) {
143                         printk(KERN_INFO "RPC: Couldn't create pipefs entry"
144                                         " %s/%s, error %d\n",
145                                         dir_name, name, error);
146                         break;
147                 }
148         }
149         dput(dir);
150         return dentry;
151 }
152
153 static int
154 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
155 {
156         struct super_block *pipefs_sb;
157         struct path path;
158
159         clnt->cl_path.mnt = ERR_PTR(-ENOENT);
160         clnt->cl_path.dentry = NULL;
161         if (dir_name == NULL)
162                 return 0;
163         pipefs_sb = rpc_get_sb_net(clnt->cl_xprt->xprt_net);
164         if (!pipefs_sb)
165                 return 0;
166         path.dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
167         rpc_put_sb_net(clnt->cl_xprt->xprt_net);
168         if (IS_ERR(path.dentry))
169                 return PTR_ERR(path.dentry);
170         clnt->cl_path = path;
171         return 0;
172 }
173
174 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
175                                 struct super_block *sb)
176 {
177         struct dentry *dentry;
178         int err = 0;
179
180         switch (event) {
181         case RPC_PIPEFS_MOUNT:
182                 if (clnt->cl_program->pipe_dir_name == NULL)
183                         break;
184                 dentry = rpc_setup_pipedir_sb(sb, clnt,
185                                               clnt->cl_program->pipe_dir_name);
186                 BUG_ON(dentry == NULL);
187                 if (IS_ERR(dentry))
188                         return PTR_ERR(dentry);
189                 clnt->cl_path.dentry = dentry;
190                 if (clnt->cl_auth->au_ops->pipes_create) {
191                         err = clnt->cl_auth->au_ops->pipes_create(clnt->cl_auth);
192                         if (err)
193                                 __rpc_clnt_remove_pipedir(clnt);
194                 }
195                 break;
196         case RPC_PIPEFS_UMOUNT:
197                 __rpc_clnt_remove_pipedir(clnt);
198                 break;
199         default:
200                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
201                 return -ENOTSUPP;
202         }
203         return err;
204 }
205
206 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
207                             void *ptr)
208 {
209         struct super_block *sb = ptr;
210         struct rpc_clnt *clnt;
211         int error = 0;
212         struct sunrpc_net *sn = net_generic(sb->s_fs_info, sunrpc_net_id);
213
214         spin_lock(&sn->rpc_client_lock);
215         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
216                 error = __rpc_pipefs_event(clnt, event, sb);
217                 if (error)
218                         break;
219         }
220         spin_unlock(&sn->rpc_client_lock);
221         return error;
222 }
223
224 static struct notifier_block rpc_clients_block = {
225         .notifier_call  = rpc_pipefs_event,
226 };
227
228 int rpc_clients_notifier_register(void)
229 {
230         return rpc_pipefs_notifier_register(&rpc_clients_block);
231 }
232
233 void rpc_clients_notifier_unregister(void)
234 {
235         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
236 }
237
238 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
239 {
240         struct rpc_program      *program = args->program;
241         struct rpc_version      *version;
242         struct rpc_clnt         *clnt = NULL;
243         struct rpc_auth         *auth;
244         int err;
245         size_t len;
246
247         /* sanity check the name before trying to print it */
248         err = -EINVAL;
249         len = strlen(args->servername);
250         if (len > RPC_MAXNETNAMELEN)
251                 goto out_no_rpciod;
252         len++;
253
254         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
255                         program->name, args->servername, xprt);
256
257         err = rpciod_up();
258         if (err)
259                 goto out_no_rpciod;
260         err = -EINVAL;
261         if (!xprt)
262                 goto out_no_xprt;
263
264         if (args->version >= program->nrvers)
265                 goto out_err;
266         version = program->version[args->version];
267         if (version == NULL)
268                 goto out_err;
269
270         err = -ENOMEM;
271         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
272         if (!clnt)
273                 goto out_err;
274         clnt->cl_parent = clnt;
275
276         clnt->cl_server = clnt->cl_inline_name;
277         if (len > sizeof(clnt->cl_inline_name)) {
278                 char *buf = kmalloc(len, GFP_KERNEL);
279                 if (buf != NULL)
280                         clnt->cl_server = buf;
281                 else
282                         len = sizeof(clnt->cl_inline_name);
283         }
284         strlcpy(clnt->cl_server, args->servername, len);
285
286         clnt->cl_xprt     = xprt;
287         clnt->cl_procinfo = version->procs;
288         clnt->cl_maxproc  = version->nrprocs;
289         clnt->cl_protname = program->name;
290         clnt->cl_prog     = args->prognumber ? : program->number;
291         clnt->cl_vers     = version->number;
292         clnt->cl_stats    = program->stats;
293         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
294         err = -ENOMEM;
295         if (clnt->cl_metrics == NULL)
296                 goto out_no_stats;
297         clnt->cl_program  = program;
298         INIT_LIST_HEAD(&clnt->cl_tasks);
299         spin_lock_init(&clnt->cl_lock);
300
301         if (!xprt_bound(clnt->cl_xprt))
302                 clnt->cl_autobind = 1;
303
304         clnt->cl_timeout = xprt->timeout;
305         if (args->timeout != NULL) {
306                 memcpy(&clnt->cl_timeout_default, args->timeout,
307                                 sizeof(clnt->cl_timeout_default));
308                 clnt->cl_timeout = &clnt->cl_timeout_default;
309         }
310
311         clnt->cl_rtt = &clnt->cl_rtt_default;
312         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
313         clnt->cl_principal = NULL;
314         if (args->client_name) {
315                 clnt->cl_principal = kstrdup(args->client_name, GFP_KERNEL);
316                 if (!clnt->cl_principal)
317                         goto out_no_principal;
318         }
319
320         atomic_set(&clnt->cl_count, 1);
321
322         err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
323         if (err < 0)
324                 goto out_no_path;
325
326         auth = rpcauth_create(args->authflavor, clnt);
327         if (IS_ERR(auth)) {
328                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
329                                 args->authflavor);
330                 err = PTR_ERR(auth);
331                 goto out_no_auth;
332         }
333
334         /* save the nodename */
335         clnt->cl_nodelen = strlen(init_utsname()->nodename);
336         if (clnt->cl_nodelen > UNX_MAXNODENAME)
337                 clnt->cl_nodelen = UNX_MAXNODENAME;
338         memcpy(clnt->cl_nodename, init_utsname()->nodename, clnt->cl_nodelen);
339         rpc_register_client(clnt);
340         return clnt;
341
342 out_no_auth:
343         rpc_clnt_remove_pipedir(clnt);
344 out_no_path:
345         kfree(clnt->cl_principal);
346 out_no_principal:
347         rpc_free_iostats(clnt->cl_metrics);
348 out_no_stats:
349         if (clnt->cl_server != clnt->cl_inline_name)
350                 kfree(clnt->cl_server);
351         kfree(clnt);
352 out_err:
353         xprt_put(xprt);
354 out_no_xprt:
355         rpciod_down();
356 out_no_rpciod:
357         return ERR_PTR(err);
358 }
359
360 /*
361  * rpc_create - create an RPC client and transport with one call
362  * @args: rpc_clnt create argument structure
363  *
364  * Creates and initializes an RPC transport and an RPC client.
365  *
366  * It can ping the server in order to determine if it is up, and to see if
367  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
368  * this behavior so asynchronous tasks can also use rpc_create.
369  */
370 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
371 {
372         struct rpc_xprt *xprt;
373         struct rpc_clnt *clnt;
374         struct xprt_create xprtargs = {
375                 .net = args->net,
376                 .ident = args->protocol,
377                 .srcaddr = args->saddress,
378                 .dstaddr = args->address,
379                 .addrlen = args->addrsize,
380                 .bc_xprt = args->bc_xprt,
381         };
382         char servername[48];
383
384         /*
385          * If the caller chooses not to specify a hostname, whip
386          * up a string representation of the passed-in address.
387          */
388         if (args->servername == NULL) {
389                 struct sockaddr_un *sun =
390                                 (struct sockaddr_un *)args->address;
391                 struct sockaddr_in *sin =
392                                 (struct sockaddr_in *)args->address;
393                 struct sockaddr_in6 *sin6 =
394                                 (struct sockaddr_in6 *)args->address;
395
396                 servername[0] = '\0';
397                 switch (args->address->sa_family) {
398                 case AF_LOCAL:
399                         snprintf(servername, sizeof(servername), "%s",
400                                  sun->sun_path);
401                         break;
402                 case AF_INET:
403                         snprintf(servername, sizeof(servername), "%pI4",
404                                  &sin->sin_addr.s_addr);
405                         break;
406                 case AF_INET6:
407                         snprintf(servername, sizeof(servername), "%pI6",
408                                  &sin6->sin6_addr);
409                         break;
410                 default:
411                         /* caller wants default server name, but
412                          * address family isn't recognized. */
413                         return ERR_PTR(-EINVAL);
414                 }
415                 args->servername = servername;
416         }
417
418         xprt = xprt_create_transport(&xprtargs);
419         if (IS_ERR(xprt))
420                 return (struct rpc_clnt *)xprt;
421
422         /*
423          * By default, kernel RPC client connects from a reserved port.
424          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
425          * but it is always enabled for rpciod, which handles the connect
426          * operation.
427          */
428         xprt->resvport = 1;
429         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
430                 xprt->resvport = 0;
431
432         clnt = rpc_new_client(args, xprt);
433         if (IS_ERR(clnt))
434                 return clnt;
435
436         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
437                 int err = rpc_ping(clnt);
438                 if (err != 0) {
439                         rpc_shutdown_client(clnt);
440                         return ERR_PTR(err);
441                 }
442         }
443
444         clnt->cl_softrtry = 1;
445         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
446                 clnt->cl_softrtry = 0;
447
448         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
449                 clnt->cl_autobind = 1;
450         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
451                 clnt->cl_discrtry = 1;
452         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
453                 clnt->cl_chatty = 1;
454
455         return clnt;
456 }
457 EXPORT_SYMBOL_GPL(rpc_create);
458
459 /*
460  * This function clones the RPC client structure. It allows us to share the
461  * same transport while varying parameters such as the authentication
462  * flavour.
463  */
464 struct rpc_clnt *
465 rpc_clone_client(struct rpc_clnt *clnt)
466 {
467         struct rpc_clnt *new;
468         int err = -ENOMEM;
469
470         new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
471         if (!new)
472                 goto out_no_clnt;
473         new->cl_parent = clnt;
474         /* Turn off autobind on clones */
475         new->cl_autobind = 0;
476         INIT_LIST_HEAD(&new->cl_tasks);
477         spin_lock_init(&new->cl_lock);
478         rpc_init_rtt(&new->cl_rtt_default, clnt->cl_timeout->to_initval);
479         new->cl_metrics = rpc_alloc_iostats(clnt);
480         if (new->cl_metrics == NULL)
481                 goto out_no_stats;
482         if (clnt->cl_principal) {
483                 new->cl_principal = kstrdup(clnt->cl_principal, GFP_KERNEL);
484                 if (new->cl_principal == NULL)
485                         goto out_no_principal;
486         }
487         atomic_set(&new->cl_count, 1);
488         err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
489         if (err != 0)
490                 goto out_no_path;
491         if (new->cl_auth)
492                 atomic_inc(&new->cl_auth->au_count);
493         xprt_get(clnt->cl_xprt);
494         atomic_inc(&clnt->cl_count);
495         rpc_register_client(new);
496         rpciod_up();
497         return new;
498 out_no_path:
499         kfree(new->cl_principal);
500 out_no_principal:
501         rpc_free_iostats(new->cl_metrics);
502 out_no_stats:
503         kfree(new);
504 out_no_clnt:
505         dprintk("RPC:       %s: returned error %d\n", __func__, err);
506         return ERR_PTR(err);
507 }
508 EXPORT_SYMBOL_GPL(rpc_clone_client);
509
510 /*
511  * Kill all tasks for the given client.
512  * XXX: kill their descendants as well?
513  */
514 void rpc_killall_tasks(struct rpc_clnt *clnt)
515 {
516         struct rpc_task *rovr;
517
518
519         if (list_empty(&clnt->cl_tasks))
520                 return;
521         dprintk("RPC:       killing all tasks for client %p\n", clnt);
522         /*
523          * Spin lock all_tasks to prevent changes...
524          */
525         spin_lock(&clnt->cl_lock);
526         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
527                 if (!RPC_IS_ACTIVATED(rovr))
528                         continue;
529                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
530                         rovr->tk_flags |= RPC_TASK_KILLED;
531                         rpc_exit(rovr, -EIO);
532                         if (RPC_IS_QUEUED(rovr))
533                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
534                                                         rovr);
535                 }
536         }
537         spin_unlock(&clnt->cl_lock);
538 }
539 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
540
541 /*
542  * Properly shut down an RPC client, terminating all outstanding
543  * requests.
544  */
545 void rpc_shutdown_client(struct rpc_clnt *clnt)
546 {
547         dprintk("RPC:       shutting down %s client for %s\n",
548                         clnt->cl_protname, clnt->cl_server);
549
550         while (!list_empty(&clnt->cl_tasks)) {
551                 rpc_killall_tasks(clnt);
552                 wait_event_timeout(destroy_wait,
553                         list_empty(&clnt->cl_tasks), 1*HZ);
554         }
555
556         rpc_release_client(clnt);
557 }
558 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
559
560 /*
561  * Free an RPC client
562  */
563 static void
564 rpc_free_client(struct rpc_clnt *clnt)
565 {
566         dprintk("RPC:       destroying %s client for %s\n",
567                         clnt->cl_protname, clnt->cl_server);
568         if (clnt->cl_parent != clnt) {
569                 rpc_release_client(clnt->cl_parent);
570                 goto out_free;
571         }
572         if (clnt->cl_server != clnt->cl_inline_name)
573                 kfree(clnt->cl_server);
574 out_free:
575         rpc_unregister_client(clnt);
576         rpc_clnt_remove_pipedir(clnt);
577         rpc_free_iostats(clnt->cl_metrics);
578         kfree(clnt->cl_principal);
579         clnt->cl_metrics = NULL;
580         xprt_put(clnt->cl_xprt);
581         rpciod_down();
582         kfree(clnt);
583 }
584
585 /*
586  * Free an RPC client
587  */
588 static void
589 rpc_free_auth(struct rpc_clnt *clnt)
590 {
591         if (clnt->cl_auth == NULL) {
592                 rpc_free_client(clnt);
593                 return;
594         }
595
596         /*
597          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
598          *       release remaining GSS contexts. This mechanism ensures
599          *       that it can do so safely.
600          */
601         atomic_inc(&clnt->cl_count);
602         rpcauth_release(clnt->cl_auth);
603         clnt->cl_auth = NULL;
604         if (atomic_dec_and_test(&clnt->cl_count))
605                 rpc_free_client(clnt);
606 }
607
608 /*
609  * Release reference to the RPC client
610  */
611 void
612 rpc_release_client(struct rpc_clnt *clnt)
613 {
614         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
615
616         if (list_empty(&clnt->cl_tasks))
617                 wake_up(&destroy_wait);
618         if (atomic_dec_and_test(&clnt->cl_count))
619                 rpc_free_auth(clnt);
620 }
621
622 /**
623  * rpc_bind_new_program - bind a new RPC program to an existing client
624  * @old: old rpc_client
625  * @program: rpc program to set
626  * @vers: rpc program version
627  *
628  * Clones the rpc client and sets up a new RPC program. This is mainly
629  * of use for enabling different RPC programs to share the same transport.
630  * The Sun NFSv2/v3 ACL protocol can do this.
631  */
632 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
633                                       struct rpc_program *program,
634                                       u32 vers)
635 {
636         struct rpc_clnt *clnt;
637         struct rpc_version *version;
638         int err;
639
640         BUG_ON(vers >= program->nrvers || !program->version[vers]);
641         version = program->version[vers];
642         clnt = rpc_clone_client(old);
643         if (IS_ERR(clnt))
644                 goto out;
645         clnt->cl_procinfo = version->procs;
646         clnt->cl_maxproc  = version->nrprocs;
647         clnt->cl_protname = program->name;
648         clnt->cl_prog     = program->number;
649         clnt->cl_vers     = version->number;
650         clnt->cl_stats    = program->stats;
651         err = rpc_ping(clnt);
652         if (err != 0) {
653                 rpc_shutdown_client(clnt);
654                 clnt = ERR_PTR(err);
655         }
656 out:
657         return clnt;
658 }
659 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
660
661 void rpc_task_release_client(struct rpc_task *task)
662 {
663         struct rpc_clnt *clnt = task->tk_client;
664
665         if (clnt != NULL) {
666                 /* Remove from client task list */
667                 spin_lock(&clnt->cl_lock);
668                 list_del(&task->tk_task);
669                 spin_unlock(&clnt->cl_lock);
670                 task->tk_client = NULL;
671
672                 rpc_release_client(clnt);
673         }
674 }
675
676 static
677 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
678 {
679         if (clnt != NULL) {
680                 rpc_task_release_client(task);
681                 task->tk_client = clnt;
682                 atomic_inc(&clnt->cl_count);
683                 if (clnt->cl_softrtry)
684                         task->tk_flags |= RPC_TASK_SOFT;
685                 /* Add to the client's list of all tasks */
686                 spin_lock(&clnt->cl_lock);
687                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
688                 spin_unlock(&clnt->cl_lock);
689         }
690 }
691
692 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
693 {
694         rpc_task_release_client(task);
695         rpc_task_set_client(task, clnt);
696 }
697 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
698
699
700 static void
701 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
702 {
703         if (msg != NULL) {
704                 task->tk_msg.rpc_proc = msg->rpc_proc;
705                 task->tk_msg.rpc_argp = msg->rpc_argp;
706                 task->tk_msg.rpc_resp = msg->rpc_resp;
707                 if (msg->rpc_cred != NULL)
708                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
709         }
710 }
711
712 /*
713  * Default callback for async RPC calls
714  */
715 static void
716 rpc_default_callback(struct rpc_task *task, void *data)
717 {
718 }
719
720 static const struct rpc_call_ops rpc_default_ops = {
721         .rpc_call_done = rpc_default_callback,
722 };
723
724 /**
725  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
726  * @task_setup_data: pointer to task initialisation data
727  */
728 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
729 {
730         struct rpc_task *task;
731
732         task = rpc_new_task(task_setup_data);
733         if (IS_ERR(task))
734                 goto out;
735
736         rpc_task_set_client(task, task_setup_data->rpc_client);
737         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
738
739         if (task->tk_action == NULL)
740                 rpc_call_start(task);
741
742         atomic_inc(&task->tk_count);
743         rpc_execute(task);
744 out:
745         return task;
746 }
747 EXPORT_SYMBOL_GPL(rpc_run_task);
748
749 /**
750  * rpc_call_sync - Perform a synchronous RPC call
751  * @clnt: pointer to RPC client
752  * @msg: RPC call parameters
753  * @flags: RPC call flags
754  */
755 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
756 {
757         struct rpc_task *task;
758         struct rpc_task_setup task_setup_data = {
759                 .rpc_client = clnt,
760                 .rpc_message = msg,
761                 .callback_ops = &rpc_default_ops,
762                 .flags = flags,
763         };
764         int status;
765
766         BUG_ON(flags & RPC_TASK_ASYNC);
767
768         task = rpc_run_task(&task_setup_data);
769         if (IS_ERR(task))
770                 return PTR_ERR(task);
771         status = task->tk_status;
772         rpc_put_task(task);
773         return status;
774 }
775 EXPORT_SYMBOL_GPL(rpc_call_sync);
776
777 /**
778  * rpc_call_async - Perform an asynchronous RPC call
779  * @clnt: pointer to RPC client
780  * @msg: RPC call parameters
781  * @flags: RPC call flags
782  * @tk_ops: RPC call ops
783  * @data: user call data
784  */
785 int
786 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
787                const struct rpc_call_ops *tk_ops, void *data)
788 {
789         struct rpc_task *task;
790         struct rpc_task_setup task_setup_data = {
791                 .rpc_client = clnt,
792                 .rpc_message = msg,
793                 .callback_ops = tk_ops,
794                 .callback_data = data,
795                 .flags = flags|RPC_TASK_ASYNC,
796         };
797
798         task = rpc_run_task(&task_setup_data);
799         if (IS_ERR(task))
800                 return PTR_ERR(task);
801         rpc_put_task(task);
802         return 0;
803 }
804 EXPORT_SYMBOL_GPL(rpc_call_async);
805
806 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
807 /**
808  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
809  * rpc_execute against it
810  * @req: RPC request
811  * @tk_ops: RPC call ops
812  */
813 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
814                                 const struct rpc_call_ops *tk_ops)
815 {
816         struct rpc_task *task;
817         struct xdr_buf *xbufp = &req->rq_snd_buf;
818         struct rpc_task_setup task_setup_data = {
819                 .callback_ops = tk_ops,
820         };
821
822         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
823         /*
824          * Create an rpc_task to send the data
825          */
826         task = rpc_new_task(&task_setup_data);
827         if (IS_ERR(task)) {
828                 xprt_free_bc_request(req);
829                 goto out;
830         }
831         task->tk_rqstp = req;
832
833         /*
834          * Set up the xdr_buf length.
835          * This also indicates that the buffer is XDR encoded already.
836          */
837         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
838                         xbufp->tail[0].iov_len;
839
840         task->tk_action = call_bc_transmit;
841         atomic_inc(&task->tk_count);
842         BUG_ON(atomic_read(&task->tk_count) != 2);
843         rpc_execute(task);
844
845 out:
846         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
847         return task;
848 }
849 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
850
851 void
852 rpc_call_start(struct rpc_task *task)
853 {
854         task->tk_action = call_start;
855 }
856 EXPORT_SYMBOL_GPL(rpc_call_start);
857
858 /**
859  * rpc_peeraddr - extract remote peer address from clnt's xprt
860  * @clnt: RPC client structure
861  * @buf: target buffer
862  * @bufsize: length of target buffer
863  *
864  * Returns the number of bytes that are actually in the stored address.
865  */
866 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
867 {
868         size_t bytes;
869         struct rpc_xprt *xprt = clnt->cl_xprt;
870
871         bytes = sizeof(xprt->addr);
872         if (bytes > bufsize)
873                 bytes = bufsize;
874         memcpy(buf, &clnt->cl_xprt->addr, bytes);
875         return xprt->addrlen;
876 }
877 EXPORT_SYMBOL_GPL(rpc_peeraddr);
878
879 /**
880  * rpc_peeraddr2str - return remote peer address in printable format
881  * @clnt: RPC client structure
882  * @format: address format
883  *
884  */
885 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
886                              enum rpc_display_format_t format)
887 {
888         struct rpc_xprt *xprt = clnt->cl_xprt;
889
890         if (xprt->address_strings[format] != NULL)
891                 return xprt->address_strings[format];
892         else
893                 return "unprintable";
894 }
895 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
896
897 void
898 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
899 {
900         struct rpc_xprt *xprt = clnt->cl_xprt;
901         if (xprt->ops->set_buffer_size)
902                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
903 }
904 EXPORT_SYMBOL_GPL(rpc_setbufsize);
905
906 /*
907  * Return size of largest payload RPC client can support, in bytes
908  *
909  * For stream transports, this is one RPC record fragment (see RFC
910  * 1831), as we don't support multi-record requests yet.  For datagram
911  * transports, this is the size of an IP packet minus the IP, UDP, and
912  * RPC header sizes.
913  */
914 size_t rpc_max_payload(struct rpc_clnt *clnt)
915 {
916         return clnt->cl_xprt->max_payload;
917 }
918 EXPORT_SYMBOL_GPL(rpc_max_payload);
919
920 /**
921  * rpc_force_rebind - force transport to check that remote port is unchanged
922  * @clnt: client to rebind
923  *
924  */
925 void rpc_force_rebind(struct rpc_clnt *clnt)
926 {
927         if (clnt->cl_autobind)
928                 xprt_clear_bound(clnt->cl_xprt);
929 }
930 EXPORT_SYMBOL_GPL(rpc_force_rebind);
931
932 /*
933  * Restart an (async) RPC call from the call_prepare state.
934  * Usually called from within the exit handler.
935  */
936 int
937 rpc_restart_call_prepare(struct rpc_task *task)
938 {
939         if (RPC_ASSASSINATED(task))
940                 return 0;
941         task->tk_action = call_start;
942         if (task->tk_ops->rpc_call_prepare != NULL)
943                 task->tk_action = rpc_prepare_task;
944         return 1;
945 }
946 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
947
948 /*
949  * Restart an (async) RPC call. Usually called from within the
950  * exit handler.
951  */
952 int
953 rpc_restart_call(struct rpc_task *task)
954 {
955         if (RPC_ASSASSINATED(task))
956                 return 0;
957         task->tk_action = call_start;
958         return 1;
959 }
960 EXPORT_SYMBOL_GPL(rpc_restart_call);
961
962 #ifdef RPC_DEBUG
963 static const char *rpc_proc_name(const struct rpc_task *task)
964 {
965         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
966
967         if (proc) {
968                 if (proc->p_name)
969                         return proc->p_name;
970                 else
971                         return "NULL";
972         } else
973                 return "no proc";
974 }
975 #endif
976
977 /*
978  * 0.  Initial state
979  *
980  *     Other FSM states can be visited zero or more times, but
981  *     this state is visited exactly once for each RPC.
982  */
983 static void
984 call_start(struct rpc_task *task)
985 {
986         struct rpc_clnt *clnt = task->tk_client;
987
988         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
989                         clnt->cl_protname, clnt->cl_vers,
990                         rpc_proc_name(task),
991                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
992
993         /* Increment call count */
994         task->tk_msg.rpc_proc->p_count++;
995         clnt->cl_stats->rpccnt++;
996         task->tk_action = call_reserve;
997 }
998
999 /*
1000  * 1.   Reserve an RPC call slot
1001  */
1002 static void
1003 call_reserve(struct rpc_task *task)
1004 {
1005         dprint_status(task);
1006
1007         task->tk_status  = 0;
1008         task->tk_action  = call_reserveresult;
1009         xprt_reserve(task);
1010 }
1011
1012 /*
1013  * 1b.  Grok the result of xprt_reserve()
1014  */
1015 static void
1016 call_reserveresult(struct rpc_task *task)
1017 {
1018         int status = task->tk_status;
1019
1020         dprint_status(task);
1021
1022         /*
1023          * After a call to xprt_reserve(), we must have either
1024          * a request slot or else an error status.
1025          */
1026         task->tk_status = 0;
1027         if (status >= 0) {
1028                 if (task->tk_rqstp) {
1029                         task->tk_action = call_refresh;
1030                         return;
1031                 }
1032
1033                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1034                                 __func__, status);
1035                 rpc_exit(task, -EIO);
1036                 return;
1037         }
1038
1039         /*
1040          * Even though there was an error, we may have acquired
1041          * a request slot somehow.  Make sure not to leak it.
1042          */
1043         if (task->tk_rqstp) {
1044                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1045                                 __func__, status);
1046                 xprt_release(task);
1047         }
1048
1049         switch (status) {
1050         case -EAGAIN:   /* woken up; retry */
1051                 task->tk_action = call_reserve;
1052                 return;
1053         case -EIO:      /* probably a shutdown */
1054                 break;
1055         default:
1056                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1057                                 __func__, status);
1058                 break;
1059         }
1060         rpc_exit(task, status);
1061 }
1062
1063 /*
1064  * 2.   Bind and/or refresh the credentials
1065  */
1066 static void
1067 call_refresh(struct rpc_task *task)
1068 {
1069         dprint_status(task);
1070
1071         task->tk_action = call_refreshresult;
1072         task->tk_status = 0;
1073         task->tk_client->cl_stats->rpcauthrefresh++;
1074         rpcauth_refreshcred(task);
1075 }
1076
1077 /*
1078  * 2a.  Process the results of a credential refresh
1079  */
1080 static void
1081 call_refreshresult(struct rpc_task *task)
1082 {
1083         int status = task->tk_status;
1084
1085         dprint_status(task);
1086
1087         task->tk_status = 0;
1088         task->tk_action = call_refresh;
1089         switch (status) {
1090         case 0:
1091                 if (rpcauth_uptodatecred(task))
1092                         task->tk_action = call_allocate;
1093                 return;
1094         case -ETIMEDOUT:
1095                 rpc_delay(task, 3*HZ);
1096         case -EAGAIN:
1097                 status = -EACCES;
1098                 if (!task->tk_cred_retry)
1099                         break;
1100                 task->tk_cred_retry--;
1101                 dprintk("RPC: %5u %s: retry refresh creds\n",
1102                                 task->tk_pid, __func__);
1103                 return;
1104         }
1105         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1106                                 task->tk_pid, __func__, status);
1107         rpc_exit(task, status);
1108 }
1109
1110 /*
1111  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1112  *      (Note: buffer memory is freed in xprt_release).
1113  */
1114 static void
1115 call_allocate(struct rpc_task *task)
1116 {
1117         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1118         struct rpc_rqst *req = task->tk_rqstp;
1119         struct rpc_xprt *xprt = task->tk_xprt;
1120         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1121
1122         dprint_status(task);
1123
1124         task->tk_status = 0;
1125         task->tk_action = call_bind;
1126
1127         if (req->rq_buffer)
1128                 return;
1129
1130         if (proc->p_proc != 0) {
1131                 BUG_ON(proc->p_arglen == 0);
1132                 if (proc->p_decode != NULL)
1133                         BUG_ON(proc->p_replen == 0);
1134         }
1135
1136         /*
1137          * Calculate the size (in quads) of the RPC call
1138          * and reply headers, and convert both values
1139          * to byte sizes.
1140          */
1141         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1142         req->rq_callsize <<= 2;
1143         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1144         req->rq_rcvsize <<= 2;
1145
1146         req->rq_buffer = xprt->ops->buf_alloc(task,
1147                                         req->rq_callsize + req->rq_rcvsize);
1148         if (req->rq_buffer != NULL)
1149                 return;
1150
1151         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1152
1153         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1154                 task->tk_action = call_allocate;
1155                 rpc_delay(task, HZ>>4);
1156                 return;
1157         }
1158
1159         rpc_exit(task, -ERESTARTSYS);
1160 }
1161
1162 static inline int
1163 rpc_task_need_encode(struct rpc_task *task)
1164 {
1165         return task->tk_rqstp->rq_snd_buf.len == 0;
1166 }
1167
1168 static inline void
1169 rpc_task_force_reencode(struct rpc_task *task)
1170 {
1171         task->tk_rqstp->rq_snd_buf.len = 0;
1172         task->tk_rqstp->rq_bytes_sent = 0;
1173 }
1174
1175 static inline void
1176 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1177 {
1178         buf->head[0].iov_base = start;
1179         buf->head[0].iov_len = len;
1180         buf->tail[0].iov_len = 0;
1181         buf->page_len = 0;
1182         buf->flags = 0;
1183         buf->len = 0;
1184         buf->buflen = len;
1185 }
1186
1187 /*
1188  * 3.   Encode arguments of an RPC call
1189  */
1190 static void
1191 rpc_xdr_encode(struct rpc_task *task)
1192 {
1193         struct rpc_rqst *req = task->tk_rqstp;
1194         kxdreproc_t     encode;
1195         __be32          *p;
1196
1197         dprint_status(task);
1198
1199         rpc_xdr_buf_init(&req->rq_snd_buf,
1200                          req->rq_buffer,
1201                          req->rq_callsize);
1202         rpc_xdr_buf_init(&req->rq_rcv_buf,
1203                          (char *)req->rq_buffer + req->rq_callsize,
1204                          req->rq_rcvsize);
1205
1206         p = rpc_encode_header(task);
1207         if (p == NULL) {
1208                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1209                 rpc_exit(task, -EIO);
1210                 return;
1211         }
1212
1213         encode = task->tk_msg.rpc_proc->p_encode;
1214         if (encode == NULL)
1215                 return;
1216
1217         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1218                         task->tk_msg.rpc_argp);
1219 }
1220
1221 /*
1222  * 4.   Get the server port number if not yet set
1223  */
1224 static void
1225 call_bind(struct rpc_task *task)
1226 {
1227         struct rpc_xprt *xprt = task->tk_xprt;
1228
1229         dprint_status(task);
1230
1231         task->tk_action = call_connect;
1232         if (!xprt_bound(xprt)) {
1233                 task->tk_action = call_bind_status;
1234                 task->tk_timeout = xprt->bind_timeout;
1235                 xprt->ops->rpcbind(task);
1236         }
1237 }
1238
1239 /*
1240  * 4a.  Sort out bind result
1241  */
1242 static void
1243 call_bind_status(struct rpc_task *task)
1244 {
1245         int status = -EIO;
1246
1247         if (task->tk_status >= 0) {
1248                 dprint_status(task);
1249                 task->tk_status = 0;
1250                 task->tk_action = call_connect;
1251                 return;
1252         }
1253
1254         switch (task->tk_status) {
1255         case -ENOMEM:
1256                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1257                 rpc_delay(task, HZ >> 2);
1258                 goto retry_timeout;
1259         case -EACCES:
1260                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1261                                 "unavailable\n", task->tk_pid);
1262                 /* fail immediately if this is an RPC ping */
1263                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1264                         status = -EOPNOTSUPP;
1265                         break;
1266                 }
1267                 if (task->tk_rebind_retry == 0)
1268                         break;
1269                 task->tk_rebind_retry--;
1270                 rpc_delay(task, 3*HZ);
1271                 goto retry_timeout;
1272         case -ETIMEDOUT:
1273                 dprintk("RPC: %5u rpcbind request timed out\n",
1274                                 task->tk_pid);
1275                 goto retry_timeout;
1276         case -EPFNOSUPPORT:
1277                 /* server doesn't support any rpcbind version we know of */
1278                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1279                                 task->tk_pid);
1280                 break;
1281         case -EPROTONOSUPPORT:
1282                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1283                                 task->tk_pid);
1284                 task->tk_status = 0;
1285                 task->tk_action = call_bind;
1286                 return;
1287         case -ECONNREFUSED:             /* connection problems */
1288         case -ECONNRESET:
1289         case -ENOTCONN:
1290         case -EHOSTDOWN:
1291         case -EHOSTUNREACH:
1292         case -ENETUNREACH:
1293         case -EPIPE:
1294                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1295                                 task->tk_pid, task->tk_status);
1296                 if (!RPC_IS_SOFTCONN(task)) {
1297                         rpc_delay(task, 5*HZ);
1298                         goto retry_timeout;
1299                 }
1300                 status = task->tk_status;
1301                 break;
1302         default:
1303                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1304                                 task->tk_pid, -task->tk_status);
1305         }
1306
1307         rpc_exit(task, status);
1308         return;
1309
1310 retry_timeout:
1311         task->tk_action = call_timeout;
1312 }
1313
1314 /*
1315  * 4b.  Connect to the RPC server
1316  */
1317 static void
1318 call_connect(struct rpc_task *task)
1319 {
1320         struct rpc_xprt *xprt = task->tk_xprt;
1321
1322         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1323                         task->tk_pid, xprt,
1324                         (xprt_connected(xprt) ? "is" : "is not"));
1325
1326         task->tk_action = call_transmit;
1327         if (!xprt_connected(xprt)) {
1328                 task->tk_action = call_connect_status;
1329                 if (task->tk_status < 0)
1330                         return;
1331                 xprt_connect(task);
1332         }
1333 }
1334
1335 /*
1336  * 4c.  Sort out connect result
1337  */
1338 static void
1339 call_connect_status(struct rpc_task *task)
1340 {
1341         struct rpc_clnt *clnt = task->tk_client;
1342         int status = task->tk_status;
1343
1344         dprint_status(task);
1345
1346         task->tk_status = 0;
1347         if (status >= 0 || status == -EAGAIN) {
1348                 clnt->cl_stats->netreconn++;
1349                 task->tk_action = call_transmit;
1350                 return;
1351         }
1352
1353         switch (status) {
1354                 /* if soft mounted, test if we've timed out */
1355         case -ETIMEDOUT:
1356                 task->tk_action = call_timeout;
1357                 break;
1358         default:
1359                 rpc_exit(task, -EIO);
1360         }
1361 }
1362
1363 /*
1364  * 5.   Transmit the RPC request, and wait for reply
1365  */
1366 static void
1367 call_transmit(struct rpc_task *task)
1368 {
1369         dprint_status(task);
1370
1371         task->tk_action = call_status;
1372         if (task->tk_status < 0)
1373                 return;
1374         task->tk_status = xprt_prepare_transmit(task);
1375         if (task->tk_status != 0)
1376                 return;
1377         task->tk_action = call_transmit_status;
1378         /* Encode here so that rpcsec_gss can use correct sequence number. */
1379         if (rpc_task_need_encode(task)) {
1380                 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
1381                 rpc_xdr_encode(task);
1382                 /* Did the encode result in an error condition? */
1383                 if (task->tk_status != 0) {
1384                         /* Was the error nonfatal? */
1385                         if (task->tk_status == -EAGAIN)
1386                                 rpc_delay(task, HZ >> 4);
1387                         else
1388                                 rpc_exit(task, task->tk_status);
1389                         return;
1390                 }
1391         }
1392         xprt_transmit(task);
1393         if (task->tk_status < 0)
1394                 return;
1395         /*
1396          * On success, ensure that we call xprt_end_transmit() before sleeping
1397          * in order to allow access to the socket to other RPC requests.
1398          */
1399         call_transmit_status(task);
1400         if (rpc_reply_expected(task))
1401                 return;
1402         task->tk_action = rpc_exit_task;
1403         rpc_wake_up_queued_task(&task->tk_xprt->pending, task);
1404 }
1405
1406 /*
1407  * 5a.  Handle cleanup after a transmission
1408  */
1409 static void
1410 call_transmit_status(struct rpc_task *task)
1411 {
1412         task->tk_action = call_status;
1413
1414         /*
1415          * Common case: success.  Force the compiler to put this
1416          * test first.
1417          */
1418         if (task->tk_status == 0) {
1419                 xprt_end_transmit(task);
1420                 rpc_task_force_reencode(task);
1421                 return;
1422         }
1423
1424         switch (task->tk_status) {
1425         case -EAGAIN:
1426                 break;
1427         default:
1428                 dprint_status(task);
1429                 xprt_end_transmit(task);
1430                 rpc_task_force_reencode(task);
1431                 break;
1432                 /*
1433                  * Special cases: if we've been waiting on the
1434                  * socket's write_space() callback, or if the
1435                  * socket just returned a connection error,
1436                  * then hold onto the transport lock.
1437                  */
1438         case -ECONNREFUSED:
1439         case -EHOSTDOWN:
1440         case -EHOSTUNREACH:
1441         case -ENETUNREACH:
1442                 if (RPC_IS_SOFTCONN(task)) {
1443                         xprt_end_transmit(task);
1444                         rpc_exit(task, task->tk_status);
1445                         break;
1446                 }
1447         case -ECONNRESET:
1448         case -ENOTCONN:
1449         case -EPIPE:
1450                 rpc_task_force_reencode(task);
1451         }
1452 }
1453
1454 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1455 /*
1456  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
1457  * addition, disconnect on connectivity errors.
1458  */
1459 static void
1460 call_bc_transmit(struct rpc_task *task)
1461 {
1462         struct rpc_rqst *req = task->tk_rqstp;
1463
1464         BUG_ON(task->tk_status != 0);
1465         task->tk_status = xprt_prepare_transmit(task);
1466         if (task->tk_status == -EAGAIN) {
1467                 /*
1468                  * Could not reserve the transport. Try again after the
1469                  * transport is released.
1470                  */
1471                 task->tk_status = 0;
1472                 task->tk_action = call_bc_transmit;
1473                 return;
1474         }
1475
1476         task->tk_action = rpc_exit_task;
1477         if (task->tk_status < 0) {
1478                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1479                         "error: %d\n", task->tk_status);
1480                 return;
1481         }
1482
1483         xprt_transmit(task);
1484         xprt_end_transmit(task);
1485         dprint_status(task);
1486         switch (task->tk_status) {
1487         case 0:
1488                 /* Success */
1489                 break;
1490         case -EHOSTDOWN:
1491         case -EHOSTUNREACH:
1492         case -ENETUNREACH:
1493         case -ETIMEDOUT:
1494                 /*
1495                  * Problem reaching the server.  Disconnect and let the
1496                  * forechannel reestablish the connection.  The server will
1497                  * have to retransmit the backchannel request and we'll
1498                  * reprocess it.  Since these ops are idempotent, there's no
1499                  * need to cache our reply at this time.
1500                  */
1501                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1502                         "error: %d\n", task->tk_status);
1503                 xprt_conditional_disconnect(task->tk_xprt,
1504                         req->rq_connect_cookie);
1505                 break;
1506         default:
1507                 /*
1508                  * We were unable to reply and will have to drop the
1509                  * request.  The server should reconnect and retransmit.
1510                  */
1511                 BUG_ON(task->tk_status == -EAGAIN);
1512                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1513                         "error: %d\n", task->tk_status);
1514                 break;
1515         }
1516         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
1517 }
1518 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1519
1520 /*
1521  * 6.   Sort out the RPC call status
1522  */
1523 static void
1524 call_status(struct rpc_task *task)
1525 {
1526         struct rpc_clnt *clnt = task->tk_client;
1527         struct rpc_rqst *req = task->tk_rqstp;
1528         int             status;
1529
1530         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
1531                 task->tk_status = req->rq_reply_bytes_recvd;
1532
1533         dprint_status(task);
1534
1535         status = task->tk_status;
1536         if (status >= 0) {
1537                 task->tk_action = call_decode;
1538                 return;
1539         }
1540
1541         task->tk_status = 0;
1542         switch(status) {
1543         case -EHOSTDOWN:
1544         case -EHOSTUNREACH:
1545         case -ENETUNREACH:
1546                 /*
1547                  * Delay any retries for 3 seconds, then handle as if it
1548                  * were a timeout.
1549                  */
1550                 rpc_delay(task, 3*HZ);
1551         case -ETIMEDOUT:
1552                 task->tk_action = call_timeout;
1553                 if (task->tk_client->cl_discrtry)
1554                         xprt_conditional_disconnect(task->tk_xprt,
1555                                         req->rq_connect_cookie);
1556                 break;
1557         case -ECONNRESET:
1558         case -ECONNREFUSED:
1559                 rpc_force_rebind(clnt);
1560                 rpc_delay(task, 3*HZ);
1561         case -EPIPE:
1562         case -ENOTCONN:
1563                 task->tk_action = call_bind;
1564                 break;
1565         case -EAGAIN:
1566                 task->tk_action = call_transmit;
1567                 break;
1568         case -EIO:
1569                 /* shutdown or soft timeout */
1570                 rpc_exit(task, status);
1571                 break;
1572         default:
1573                 if (clnt->cl_chatty)
1574                         printk("%s: RPC call returned error %d\n",
1575                                clnt->cl_protname, -status);
1576                 rpc_exit(task, status);
1577         }
1578 }
1579
1580 /*
1581  * 6a.  Handle RPC timeout
1582  *      We do not release the request slot, so we keep using the
1583  *      same XID for all retransmits.
1584  */
1585 static void
1586 call_timeout(struct rpc_task *task)
1587 {
1588         struct rpc_clnt *clnt = task->tk_client;
1589
1590         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1591                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
1592                 goto retry;
1593         }
1594
1595         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
1596         task->tk_timeouts++;
1597
1598         if (RPC_IS_SOFTCONN(task)) {
1599                 rpc_exit(task, -ETIMEDOUT);
1600                 return;
1601         }
1602         if (RPC_IS_SOFT(task)) {
1603                 if (clnt->cl_chatty)
1604                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1605                                 clnt->cl_protname, clnt->cl_server);
1606                 if (task->tk_flags & RPC_TASK_TIMEOUT)
1607                         rpc_exit(task, -ETIMEDOUT);
1608                 else
1609                         rpc_exit(task, -EIO);
1610                 return;
1611         }
1612
1613         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1614                 task->tk_flags |= RPC_CALL_MAJORSEEN;
1615                 if (clnt->cl_chatty)
1616                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1617                         clnt->cl_protname, clnt->cl_server);
1618         }
1619         rpc_force_rebind(clnt);
1620         /*
1621          * Did our request time out due to an RPCSEC_GSS out-of-sequence
1622          * event? RFC2203 requires the server to drop all such requests.
1623          */
1624         rpcauth_invalcred(task);
1625
1626 retry:
1627         clnt->cl_stats->rpcretrans++;
1628         task->tk_action = call_bind;
1629         task->tk_status = 0;
1630 }
1631
1632 /*
1633  * 7.   Decode the RPC reply
1634  */
1635 static void
1636 call_decode(struct rpc_task *task)
1637 {
1638         struct rpc_clnt *clnt = task->tk_client;
1639         struct rpc_rqst *req = task->tk_rqstp;
1640         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
1641         __be32          *p;
1642
1643         dprint_status(task);
1644
1645         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1646                 if (clnt->cl_chatty)
1647                         printk(KERN_NOTICE "%s: server %s OK\n",
1648                                 clnt->cl_protname, clnt->cl_server);
1649                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1650         }
1651
1652         /*
1653          * Ensure that we see all writes made by xprt_complete_rqst()
1654          * before it changed req->rq_reply_bytes_recvd.
1655          */
1656         smp_rmb();
1657         req->rq_rcv_buf.len = req->rq_private_buf.len;
1658
1659         /* Check that the softirq receive buffer is valid */
1660         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1661                                 sizeof(req->rq_rcv_buf)) != 0);
1662
1663         if (req->rq_rcv_buf.len < 12) {
1664                 if (!RPC_IS_SOFT(task)) {
1665                         task->tk_action = call_bind;
1666                         clnt->cl_stats->rpcretrans++;
1667                         goto out_retry;
1668                 }
1669                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
1670                                 clnt->cl_protname, task->tk_status);
1671                 task->tk_action = call_timeout;
1672                 goto out_retry;
1673         }
1674
1675         p = rpc_verify_header(task);
1676         if (IS_ERR(p)) {
1677                 if (p == ERR_PTR(-EAGAIN))
1678                         goto out_retry;
1679                 return;
1680         }
1681
1682         task->tk_action = rpc_exit_task;
1683
1684         if (decode) {
1685                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1686                                                       task->tk_msg.rpc_resp);
1687         }
1688         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
1689                         task->tk_status);
1690         return;
1691 out_retry:
1692         task->tk_status = 0;
1693         /* Note: rpc_verify_header() may have freed the RPC slot */
1694         if (task->tk_rqstp == req) {
1695                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
1696                 if (task->tk_client->cl_discrtry)
1697                         xprt_conditional_disconnect(task->tk_xprt,
1698                                         req->rq_connect_cookie);
1699         }
1700 }
1701
1702 static __be32 *
1703 rpc_encode_header(struct rpc_task *task)
1704 {
1705         struct rpc_clnt *clnt = task->tk_client;
1706         struct rpc_rqst *req = task->tk_rqstp;
1707         __be32          *p = req->rq_svec[0].iov_base;
1708
1709         /* FIXME: check buffer size? */
1710
1711         p = xprt_skip_transport_header(task->tk_xprt, p);
1712         *p++ = req->rq_xid;             /* XID */
1713         *p++ = htonl(RPC_CALL);         /* CALL */
1714         *p++ = htonl(RPC_VERSION);      /* RPC version */
1715         *p++ = htonl(clnt->cl_prog);    /* program number */
1716         *p++ = htonl(clnt->cl_vers);    /* program version */
1717         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
1718         p = rpcauth_marshcred(task, p);
1719         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1720         return p;
1721 }
1722
1723 static __be32 *
1724 rpc_verify_header(struct rpc_task *task)
1725 {
1726         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1727         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1728         __be32  *p = iov->iov_base;
1729         u32 n;
1730         int error = -EACCES;
1731
1732         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1733                 /* RFC-1014 says that the representation of XDR data must be a
1734                  * multiple of four bytes
1735                  * - if it isn't pointer subtraction in the NFS client may give
1736                  *   undefined results
1737                  */
1738                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
1739                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
1740                        task->tk_rqstp->rq_rcv_buf.len);
1741                 goto out_eio;
1742         }
1743         if ((len -= 3) < 0)
1744                 goto out_overflow;
1745
1746         p += 1; /* skip XID */
1747         if ((n = ntohl(*p++)) != RPC_REPLY) {
1748                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
1749                         task->tk_pid, __func__, n);
1750                 goto out_garbage;
1751         }
1752
1753         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1754                 if (--len < 0)
1755                         goto out_overflow;
1756                 switch ((n = ntohl(*p++))) {
1757                 case RPC_AUTH_ERROR:
1758                         break;
1759                 case RPC_MISMATCH:
1760                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
1761                                 task->tk_pid, __func__);
1762                         error = -EPROTONOSUPPORT;
1763                         goto out_err;
1764                 default:
1765                         dprintk("RPC: %5u %s: RPC call rejected, "
1766                                 "unknown error: %x\n",
1767                                 task->tk_pid, __func__, n);
1768                         goto out_eio;
1769                 }
1770                 if (--len < 0)
1771                         goto out_overflow;
1772                 switch ((n = ntohl(*p++))) {
1773                 case RPC_AUTH_REJECTEDCRED:
1774                 case RPC_AUTH_REJECTEDVERF:
1775                 case RPCSEC_GSS_CREDPROBLEM:
1776                 case RPCSEC_GSS_CTXPROBLEM:
1777                         if (!task->tk_cred_retry)
1778                                 break;
1779                         task->tk_cred_retry--;
1780                         dprintk("RPC: %5u %s: retry stale creds\n",
1781                                         task->tk_pid, __func__);
1782                         rpcauth_invalcred(task);
1783                         /* Ensure we obtain a new XID! */
1784                         xprt_release(task);
1785                         task->tk_action = call_reserve;
1786                         goto out_retry;
1787                 case RPC_AUTH_BADCRED:
1788                 case RPC_AUTH_BADVERF:
1789                         /* possibly garbled cred/verf? */
1790                         if (!task->tk_garb_retry)
1791                                 break;
1792                         task->tk_garb_retry--;
1793                         dprintk("RPC: %5u %s: retry garbled creds\n",
1794                                         task->tk_pid, __func__);
1795                         task->tk_action = call_bind;
1796                         goto out_retry;
1797                 case RPC_AUTH_TOOWEAK:
1798                         printk(KERN_NOTICE "RPC: server %s requires stronger "
1799                                "authentication.\n", task->tk_client->cl_server);
1800                         break;
1801                 default:
1802                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
1803                                         task->tk_pid, __func__, n);
1804                         error = -EIO;
1805                 }
1806                 dprintk("RPC: %5u %s: call rejected %d\n",
1807                                 task->tk_pid, __func__, n);
1808                 goto out_err;
1809         }
1810         if (!(p = rpcauth_checkverf(task, p))) {
1811                 dprintk("RPC: %5u %s: auth check failed\n",
1812                                 task->tk_pid, __func__);
1813                 goto out_garbage;               /* bad verifier, retry */
1814         }
1815         len = p - (__be32 *)iov->iov_base - 1;
1816         if (len < 0)
1817                 goto out_overflow;
1818         switch ((n = ntohl(*p++))) {
1819         case RPC_SUCCESS:
1820                 return p;
1821         case RPC_PROG_UNAVAIL:
1822                 dprintk("RPC: %5u %s: program %u is unsupported by server %s\n",
1823                                 task->tk_pid, __func__,
1824                                 (unsigned int)task->tk_client->cl_prog,
1825                                 task->tk_client->cl_server);
1826                 error = -EPFNOSUPPORT;
1827                 goto out_err;
1828         case RPC_PROG_MISMATCH:
1829                 dprintk("RPC: %5u %s: program %u, version %u unsupported by "
1830                                 "server %s\n", task->tk_pid, __func__,
1831                                 (unsigned int)task->tk_client->cl_prog,
1832                                 (unsigned int)task->tk_client->cl_vers,
1833                                 task->tk_client->cl_server);
1834                 error = -EPROTONOSUPPORT;
1835                 goto out_err;
1836         case RPC_PROC_UNAVAIL:
1837                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
1838                                 "version %u on server %s\n",
1839                                 task->tk_pid, __func__,
1840                                 rpc_proc_name(task),
1841                                 task->tk_client->cl_prog,
1842                                 task->tk_client->cl_vers,
1843                                 task->tk_client->cl_server);
1844                 error = -EOPNOTSUPP;
1845                 goto out_err;
1846         case RPC_GARBAGE_ARGS:
1847                 dprintk("RPC: %5u %s: server saw garbage\n",
1848                                 task->tk_pid, __func__);
1849                 break;                  /* retry */
1850         default:
1851                 dprintk("RPC: %5u %s: server accept status: %x\n",
1852                                 task->tk_pid, __func__, n);
1853                 /* Also retry */
1854         }
1855
1856 out_garbage:
1857         task->tk_client->cl_stats->rpcgarbage++;
1858         if (task->tk_garb_retry) {
1859                 task->tk_garb_retry--;
1860                 dprintk("RPC: %5u %s: retrying\n",
1861                                 task->tk_pid, __func__);
1862                 task->tk_action = call_bind;
1863 out_retry:
1864                 return ERR_PTR(-EAGAIN);
1865         }
1866 out_eio:
1867         error = -EIO;
1868 out_err:
1869         rpc_exit(task, error);
1870         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
1871                         __func__, error);
1872         return ERR_PTR(error);
1873 out_overflow:
1874         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
1875                         __func__);
1876         goto out_garbage;
1877 }
1878
1879 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1880 {
1881 }
1882
1883 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
1884 {
1885         return 0;
1886 }
1887
1888 static struct rpc_procinfo rpcproc_null = {
1889         .p_encode = rpcproc_encode_null,
1890         .p_decode = rpcproc_decode_null,
1891 };
1892
1893 static int rpc_ping(struct rpc_clnt *clnt)
1894 {
1895         struct rpc_message msg = {
1896                 .rpc_proc = &rpcproc_null,
1897         };
1898         int err;
1899         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1900         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
1901         put_rpccred(msg.rpc_cred);
1902         return err;
1903 }
1904
1905 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
1906 {
1907         struct rpc_message msg = {
1908                 .rpc_proc = &rpcproc_null,
1909                 .rpc_cred = cred,
1910         };
1911         struct rpc_task_setup task_setup_data = {
1912                 .rpc_client = clnt,
1913                 .rpc_message = &msg,
1914                 .callback_ops = &rpc_default_ops,
1915                 .flags = flags,
1916         };
1917         return rpc_run_task(&task_setup_data);
1918 }
1919 EXPORT_SYMBOL_GPL(rpc_call_null);
1920
1921 #ifdef RPC_DEBUG
1922 static void rpc_show_header(void)
1923 {
1924         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
1925                 "-timeout ---ops--\n");
1926 }
1927
1928 static void rpc_show_task(const struct rpc_clnt *clnt,
1929                           const struct rpc_task *task)
1930 {
1931         const char *rpc_waitq = "none";
1932
1933         if (RPC_IS_QUEUED(task))
1934                 rpc_waitq = rpc_qname(task->tk_waitqueue);
1935
1936         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
1937                 task->tk_pid, task->tk_flags, task->tk_status,
1938                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
1939                 clnt->cl_protname, clnt->cl_vers, rpc_proc_name(task),
1940                 task->tk_action, rpc_waitq);
1941 }
1942
1943 void rpc_show_tasks(struct net *net)
1944 {
1945         struct rpc_clnt *clnt;
1946         struct rpc_task *task;
1947         int header = 0;
1948         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
1949
1950         spin_lock(&sn->rpc_client_lock);
1951         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
1952                 spin_lock(&clnt->cl_lock);
1953                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
1954                         if (!header) {
1955                                 rpc_show_header();
1956                                 header++;
1957                         }
1958                         rpc_show_task(clnt, task);
1959                 }
1960                 spin_unlock(&clnt->cl_lock);
1961         }
1962         spin_unlock(&sn->rpc_client_lock);
1963 }
1964 #endif