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ubifs: make ubifs_[get|set]xattr atomic
[deliverable/linux.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
21 #include <linux/module.h>
22 #include <linux/types.h>
23 #include <linux/kallsyms.h>
24 #include <linux/mm.h>
25 #include <linux/namei.h>
26 #include <linux/mount.h>
27 #include <linux/slab.h>
28 #include <linux/rcupdate.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/addr.h>
37 #include <linux/sunrpc/rpc_pipe_fs.h>
38 #include <linux/sunrpc/metrics.h>
39 #include <linux/sunrpc/bc_xprt.h>
40 #include <trace/events/sunrpc.h>
41
42 #include "sunrpc.h"
43 #include "netns.h"
44
45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
46 # define RPCDBG_FACILITY RPCDBG_CALL
47 #endif
48
49 #define dprint_status(t) \
50 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \
51 __func__, t->tk_status)
52
53 /*
54 * All RPC clients are linked into this list
55 */
56
57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
58
59
60 static void call_start(struct rpc_task *task);
61 static void call_reserve(struct rpc_task *task);
62 static void call_reserveresult(struct rpc_task *task);
63 static void call_allocate(struct rpc_task *task);
64 static void call_decode(struct rpc_task *task);
65 static void call_bind(struct rpc_task *task);
66 static void call_bind_status(struct rpc_task *task);
67 static void call_transmit(struct rpc_task *task);
68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
69 static void call_bc_transmit(struct rpc_task *task);
70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
71 static void call_status(struct rpc_task *task);
72 static void call_transmit_status(struct rpc_task *task);
73 static void call_refresh(struct rpc_task *task);
74 static void call_refreshresult(struct rpc_task *task);
75 static void call_timeout(struct rpc_task *task);
76 static void call_connect(struct rpc_task *task);
77 static void call_connect_status(struct rpc_task *task);
78
79 static __be32 *rpc_encode_header(struct rpc_task *task);
80 static __be32 *rpc_verify_header(struct rpc_task *task);
81 static int rpc_ping(struct rpc_clnt *clnt);
82
83 static void rpc_register_client(struct rpc_clnt *clnt)
84 {
85 struct net *net = rpc_net_ns(clnt);
86 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
87
88 spin_lock(&sn->rpc_client_lock);
89 list_add(&clnt->cl_clients, &sn->all_clients);
90 spin_unlock(&sn->rpc_client_lock);
91 }
92
93 static void rpc_unregister_client(struct rpc_clnt *clnt)
94 {
95 struct net *net = rpc_net_ns(clnt);
96 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
97
98 spin_lock(&sn->rpc_client_lock);
99 list_del(&clnt->cl_clients);
100 spin_unlock(&sn->rpc_client_lock);
101 }
102
103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
104 {
105 rpc_remove_client_dir(clnt);
106 }
107
108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
109 {
110 struct net *net = rpc_net_ns(clnt);
111 struct super_block *pipefs_sb;
112
113 pipefs_sb = rpc_get_sb_net(net);
114 if (pipefs_sb) {
115 __rpc_clnt_remove_pipedir(clnt);
116 rpc_put_sb_net(net);
117 }
118 }
119
120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
121 struct rpc_clnt *clnt)
122 {
123 static uint32_t clntid;
124 const char *dir_name = clnt->cl_program->pipe_dir_name;
125 char name[15];
126 struct dentry *dir, *dentry;
127
128 dir = rpc_d_lookup_sb(sb, dir_name);
129 if (dir == NULL) {
130 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
131 return dir;
132 }
133 for (;;) {
134 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
135 name[sizeof(name) - 1] = '\0';
136 dentry = rpc_create_client_dir(dir, name, clnt);
137 if (!IS_ERR(dentry))
138 break;
139 if (dentry == ERR_PTR(-EEXIST))
140 continue;
141 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
142 " %s/%s, error %ld\n",
143 dir_name, name, PTR_ERR(dentry));
144 break;
145 }
146 dput(dir);
147 return dentry;
148 }
149
150 static int
151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
152 {
153 struct dentry *dentry;
154
155 if (clnt->cl_program->pipe_dir_name != NULL) {
156 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
157 if (IS_ERR(dentry))
158 return PTR_ERR(dentry);
159 }
160 return 0;
161 }
162
163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
164 {
165 if (clnt->cl_program->pipe_dir_name == NULL)
166 return 1;
167
168 switch (event) {
169 case RPC_PIPEFS_MOUNT:
170 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
171 return 1;
172 if (atomic_read(&clnt->cl_count) == 0)
173 return 1;
174 break;
175 case RPC_PIPEFS_UMOUNT:
176 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
177 return 1;
178 break;
179 }
180 return 0;
181 }
182
183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
184 struct super_block *sb)
185 {
186 struct dentry *dentry;
187 int err = 0;
188
189 switch (event) {
190 case RPC_PIPEFS_MOUNT:
191 dentry = rpc_setup_pipedir_sb(sb, clnt);
192 if (!dentry)
193 return -ENOENT;
194 if (IS_ERR(dentry))
195 return PTR_ERR(dentry);
196 break;
197 case RPC_PIPEFS_UMOUNT:
198 __rpc_clnt_remove_pipedir(clnt);
199 break;
200 default:
201 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
202 return -ENOTSUPP;
203 }
204 return err;
205 }
206
207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
208 struct super_block *sb)
209 {
210 int error = 0;
211
212 for (;; clnt = clnt->cl_parent) {
213 if (!rpc_clnt_skip_event(clnt, event))
214 error = __rpc_clnt_handle_event(clnt, event, sb);
215 if (error || clnt == clnt->cl_parent)
216 break;
217 }
218 return error;
219 }
220
221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
222 {
223 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
224 struct rpc_clnt *clnt;
225
226 spin_lock(&sn->rpc_client_lock);
227 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
228 if (rpc_clnt_skip_event(clnt, event))
229 continue;
230 spin_unlock(&sn->rpc_client_lock);
231 return clnt;
232 }
233 spin_unlock(&sn->rpc_client_lock);
234 return NULL;
235 }
236
237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
238 void *ptr)
239 {
240 struct super_block *sb = ptr;
241 struct rpc_clnt *clnt;
242 int error = 0;
243
244 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
245 error = __rpc_pipefs_event(clnt, event, sb);
246 if (error)
247 break;
248 }
249 return error;
250 }
251
252 static struct notifier_block rpc_clients_block = {
253 .notifier_call = rpc_pipefs_event,
254 .priority = SUNRPC_PIPEFS_RPC_PRIO,
255 };
256
257 int rpc_clients_notifier_register(void)
258 {
259 return rpc_pipefs_notifier_register(&rpc_clients_block);
260 }
261
262 void rpc_clients_notifier_unregister(void)
263 {
264 return rpc_pipefs_notifier_unregister(&rpc_clients_block);
265 }
266
267 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
268 struct rpc_xprt *xprt,
269 const struct rpc_timeout *timeout)
270 {
271 struct rpc_xprt *old;
272
273 spin_lock(&clnt->cl_lock);
274 old = rcu_dereference_protected(clnt->cl_xprt,
275 lockdep_is_held(&clnt->cl_lock));
276
277 if (!xprt_bound(xprt))
278 clnt->cl_autobind = 1;
279
280 clnt->cl_timeout = timeout;
281 rcu_assign_pointer(clnt->cl_xprt, xprt);
282 spin_unlock(&clnt->cl_lock);
283
284 return old;
285 }
286
287 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
288 {
289 clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
290 nodename, sizeof(clnt->cl_nodename));
291 }
292
293 static int rpc_client_register(struct rpc_clnt *clnt,
294 rpc_authflavor_t pseudoflavor,
295 const char *client_name)
296 {
297 struct rpc_auth_create_args auth_args = {
298 .pseudoflavor = pseudoflavor,
299 .target_name = client_name,
300 };
301 struct rpc_auth *auth;
302 struct net *net = rpc_net_ns(clnt);
303 struct super_block *pipefs_sb;
304 int err;
305
306 rpc_clnt_debugfs_register(clnt);
307
308 pipefs_sb = rpc_get_sb_net(net);
309 if (pipefs_sb) {
310 err = rpc_setup_pipedir(pipefs_sb, clnt);
311 if (err)
312 goto out;
313 }
314
315 rpc_register_client(clnt);
316 if (pipefs_sb)
317 rpc_put_sb_net(net);
318
319 auth = rpcauth_create(&auth_args, clnt);
320 if (IS_ERR(auth)) {
321 dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
322 pseudoflavor);
323 err = PTR_ERR(auth);
324 goto err_auth;
325 }
326 return 0;
327 err_auth:
328 pipefs_sb = rpc_get_sb_net(net);
329 rpc_unregister_client(clnt);
330 __rpc_clnt_remove_pipedir(clnt);
331 out:
332 if (pipefs_sb)
333 rpc_put_sb_net(net);
334 rpc_clnt_debugfs_unregister(clnt);
335 return err;
336 }
337
338 static DEFINE_IDA(rpc_clids);
339
340 static int rpc_alloc_clid(struct rpc_clnt *clnt)
341 {
342 int clid;
343
344 clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
345 if (clid < 0)
346 return clid;
347 clnt->cl_clid = clid;
348 return 0;
349 }
350
351 static void rpc_free_clid(struct rpc_clnt *clnt)
352 {
353 ida_simple_remove(&rpc_clids, clnt->cl_clid);
354 }
355
356 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
357 struct rpc_xprt *xprt,
358 struct rpc_clnt *parent)
359 {
360 const struct rpc_program *program = args->program;
361 const struct rpc_version *version;
362 struct rpc_clnt *clnt = NULL;
363 const struct rpc_timeout *timeout;
364 const char *nodename = args->nodename;
365 int err;
366
367 /* sanity check the name before trying to print it */
368 dprintk("RPC: creating %s client for %s (xprt %p)\n",
369 program->name, args->servername, xprt);
370
371 err = rpciod_up();
372 if (err)
373 goto out_no_rpciod;
374
375 err = -EINVAL;
376 if (args->version >= program->nrvers)
377 goto out_err;
378 version = program->version[args->version];
379 if (version == NULL)
380 goto out_err;
381
382 err = -ENOMEM;
383 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
384 if (!clnt)
385 goto out_err;
386 clnt->cl_parent = parent ? : clnt;
387
388 err = rpc_alloc_clid(clnt);
389 if (err)
390 goto out_no_clid;
391
392 clnt->cl_procinfo = version->procs;
393 clnt->cl_maxproc = version->nrprocs;
394 clnt->cl_prog = args->prognumber ? : program->number;
395 clnt->cl_vers = version->number;
396 clnt->cl_stats = program->stats;
397 clnt->cl_metrics = rpc_alloc_iostats(clnt);
398 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
399 err = -ENOMEM;
400 if (clnt->cl_metrics == NULL)
401 goto out_no_stats;
402 clnt->cl_program = program;
403 INIT_LIST_HEAD(&clnt->cl_tasks);
404 spin_lock_init(&clnt->cl_lock);
405
406 timeout = xprt->timeout;
407 if (args->timeout != NULL) {
408 memcpy(&clnt->cl_timeout_default, args->timeout,
409 sizeof(clnt->cl_timeout_default));
410 timeout = &clnt->cl_timeout_default;
411 }
412
413 rpc_clnt_set_transport(clnt, xprt, timeout);
414
415 clnt->cl_rtt = &clnt->cl_rtt_default;
416 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
417
418 atomic_set(&clnt->cl_count, 1);
419
420 if (nodename == NULL)
421 nodename = utsname()->nodename;
422 /* save the nodename */
423 rpc_clnt_set_nodename(clnt, nodename);
424
425 err = rpc_client_register(clnt, args->authflavor, args->client_name);
426 if (err)
427 goto out_no_path;
428 if (parent)
429 atomic_inc(&parent->cl_count);
430 return clnt;
431
432 out_no_path:
433 rpc_free_iostats(clnt->cl_metrics);
434 out_no_stats:
435 rpc_free_clid(clnt);
436 out_no_clid:
437 kfree(clnt);
438 out_err:
439 rpciod_down();
440 out_no_rpciod:
441 xprt_put(xprt);
442 return ERR_PTR(err);
443 }
444
445 struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
446 struct rpc_xprt *xprt)
447 {
448 struct rpc_clnt *clnt = NULL;
449
450 clnt = rpc_new_client(args, xprt, NULL);
451 if (IS_ERR(clnt))
452 return clnt;
453
454 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
455 int err = rpc_ping(clnt);
456 if (err != 0) {
457 rpc_shutdown_client(clnt);
458 return ERR_PTR(err);
459 }
460 }
461
462 clnt->cl_softrtry = 1;
463 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
464 clnt->cl_softrtry = 0;
465
466 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
467 clnt->cl_autobind = 1;
468 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
469 clnt->cl_noretranstimeo = 1;
470 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
471 clnt->cl_discrtry = 1;
472 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
473 clnt->cl_chatty = 1;
474
475 return clnt;
476 }
477 EXPORT_SYMBOL_GPL(rpc_create_xprt);
478
479 /**
480 * rpc_create - create an RPC client and transport with one call
481 * @args: rpc_clnt create argument structure
482 *
483 * Creates and initializes an RPC transport and an RPC client.
484 *
485 * It can ping the server in order to determine if it is up, and to see if
486 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
487 * this behavior so asynchronous tasks can also use rpc_create.
488 */
489 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
490 {
491 struct rpc_xprt *xprt;
492 struct xprt_create xprtargs = {
493 .net = args->net,
494 .ident = args->protocol,
495 .srcaddr = args->saddress,
496 .dstaddr = args->address,
497 .addrlen = args->addrsize,
498 .servername = args->servername,
499 .bc_xprt = args->bc_xprt,
500 };
501 char servername[48];
502
503 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
504 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
505 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
506 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
507 /*
508 * If the caller chooses not to specify a hostname, whip
509 * up a string representation of the passed-in address.
510 */
511 if (xprtargs.servername == NULL) {
512 struct sockaddr_un *sun =
513 (struct sockaddr_un *)args->address;
514 struct sockaddr_in *sin =
515 (struct sockaddr_in *)args->address;
516 struct sockaddr_in6 *sin6 =
517 (struct sockaddr_in6 *)args->address;
518
519 servername[0] = '\0';
520 switch (args->address->sa_family) {
521 case AF_LOCAL:
522 snprintf(servername, sizeof(servername), "%s",
523 sun->sun_path);
524 break;
525 case AF_INET:
526 snprintf(servername, sizeof(servername), "%pI4",
527 &sin->sin_addr.s_addr);
528 break;
529 case AF_INET6:
530 snprintf(servername, sizeof(servername), "%pI6",
531 &sin6->sin6_addr);
532 break;
533 default:
534 /* caller wants default server name, but
535 * address family isn't recognized. */
536 return ERR_PTR(-EINVAL);
537 }
538 xprtargs.servername = servername;
539 }
540
541 xprt = xprt_create_transport(&xprtargs);
542 if (IS_ERR(xprt))
543 return (struct rpc_clnt *)xprt;
544
545 /*
546 * By default, kernel RPC client connects from a reserved port.
547 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
548 * but it is always enabled for rpciod, which handles the connect
549 * operation.
550 */
551 xprt->resvport = 1;
552 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
553 xprt->resvport = 0;
554
555 return rpc_create_xprt(args, xprt);
556 }
557 EXPORT_SYMBOL_GPL(rpc_create);
558
559 /*
560 * This function clones the RPC client structure. It allows us to share the
561 * same transport while varying parameters such as the authentication
562 * flavour.
563 */
564 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
565 struct rpc_clnt *clnt)
566 {
567 struct rpc_xprt *xprt;
568 struct rpc_clnt *new;
569 int err;
570
571 err = -ENOMEM;
572 rcu_read_lock();
573 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
574 rcu_read_unlock();
575 if (xprt == NULL)
576 goto out_err;
577 args->servername = xprt->servername;
578 args->nodename = clnt->cl_nodename;
579
580 new = rpc_new_client(args, xprt, clnt);
581 if (IS_ERR(new)) {
582 err = PTR_ERR(new);
583 goto out_err;
584 }
585
586 /* Turn off autobind on clones */
587 new->cl_autobind = 0;
588 new->cl_softrtry = clnt->cl_softrtry;
589 new->cl_noretranstimeo = clnt->cl_noretranstimeo;
590 new->cl_discrtry = clnt->cl_discrtry;
591 new->cl_chatty = clnt->cl_chatty;
592 return new;
593
594 out_err:
595 dprintk("RPC: %s: returned error %d\n", __func__, err);
596 return ERR_PTR(err);
597 }
598
599 /**
600 * rpc_clone_client - Clone an RPC client structure
601 *
602 * @clnt: RPC client whose parameters are copied
603 *
604 * Returns a fresh RPC client or an ERR_PTR.
605 */
606 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
607 {
608 struct rpc_create_args args = {
609 .program = clnt->cl_program,
610 .prognumber = clnt->cl_prog,
611 .version = clnt->cl_vers,
612 .authflavor = clnt->cl_auth->au_flavor,
613 };
614 return __rpc_clone_client(&args, clnt);
615 }
616 EXPORT_SYMBOL_GPL(rpc_clone_client);
617
618 /**
619 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
620 *
621 * @clnt: RPC client whose parameters are copied
622 * @flavor: security flavor for new client
623 *
624 * Returns a fresh RPC client or an ERR_PTR.
625 */
626 struct rpc_clnt *
627 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
628 {
629 struct rpc_create_args args = {
630 .program = clnt->cl_program,
631 .prognumber = clnt->cl_prog,
632 .version = clnt->cl_vers,
633 .authflavor = flavor,
634 };
635 return __rpc_clone_client(&args, clnt);
636 }
637 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
638
639 /**
640 * rpc_switch_client_transport: switch the RPC transport on the fly
641 * @clnt: pointer to a struct rpc_clnt
642 * @args: pointer to the new transport arguments
643 * @timeout: pointer to the new timeout parameters
644 *
645 * This function allows the caller to switch the RPC transport for the
646 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
647 * server, for instance. It assumes that the caller has ensured that
648 * there are no active RPC tasks by using some form of locking.
649 *
650 * Returns zero if "clnt" is now using the new xprt. Otherwise a
651 * negative errno is returned, and "clnt" continues to use the old
652 * xprt.
653 */
654 int rpc_switch_client_transport(struct rpc_clnt *clnt,
655 struct xprt_create *args,
656 const struct rpc_timeout *timeout)
657 {
658 const struct rpc_timeout *old_timeo;
659 rpc_authflavor_t pseudoflavor;
660 struct rpc_xprt *xprt, *old;
661 struct rpc_clnt *parent;
662 int err;
663
664 xprt = xprt_create_transport(args);
665 if (IS_ERR(xprt)) {
666 dprintk("RPC: failed to create new xprt for clnt %p\n",
667 clnt);
668 return PTR_ERR(xprt);
669 }
670
671 pseudoflavor = clnt->cl_auth->au_flavor;
672
673 old_timeo = clnt->cl_timeout;
674 old = rpc_clnt_set_transport(clnt, xprt, timeout);
675
676 rpc_unregister_client(clnt);
677 __rpc_clnt_remove_pipedir(clnt);
678 rpc_clnt_debugfs_unregister(clnt);
679
680 /*
681 * A new transport was created. "clnt" therefore
682 * becomes the root of a new cl_parent tree. clnt's
683 * children, if it has any, still point to the old xprt.
684 */
685 parent = clnt->cl_parent;
686 clnt->cl_parent = clnt;
687
688 /*
689 * The old rpc_auth cache cannot be re-used. GSS
690 * contexts in particular are between a single
691 * client and server.
692 */
693 err = rpc_client_register(clnt, pseudoflavor, NULL);
694 if (err)
695 goto out_revert;
696
697 synchronize_rcu();
698 if (parent != clnt)
699 rpc_release_client(parent);
700 xprt_put(old);
701 dprintk("RPC: replaced xprt for clnt %p\n", clnt);
702 return 0;
703
704 out_revert:
705 rpc_clnt_set_transport(clnt, old, old_timeo);
706 clnt->cl_parent = parent;
707 rpc_client_register(clnt, pseudoflavor, NULL);
708 xprt_put(xprt);
709 dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
710 return err;
711 }
712 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
713
714 /*
715 * Kill all tasks for the given client.
716 * XXX: kill their descendants as well?
717 */
718 void rpc_killall_tasks(struct rpc_clnt *clnt)
719 {
720 struct rpc_task *rovr;
721
722
723 if (list_empty(&clnt->cl_tasks))
724 return;
725 dprintk("RPC: killing all tasks for client %p\n", clnt);
726 /*
727 * Spin lock all_tasks to prevent changes...
728 */
729 spin_lock(&clnt->cl_lock);
730 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
731 if (!RPC_IS_ACTIVATED(rovr))
732 continue;
733 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
734 rovr->tk_flags |= RPC_TASK_KILLED;
735 rpc_exit(rovr, -EIO);
736 if (RPC_IS_QUEUED(rovr))
737 rpc_wake_up_queued_task(rovr->tk_waitqueue,
738 rovr);
739 }
740 }
741 spin_unlock(&clnt->cl_lock);
742 }
743 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
744
745 /*
746 * Properly shut down an RPC client, terminating all outstanding
747 * requests.
748 */
749 void rpc_shutdown_client(struct rpc_clnt *clnt)
750 {
751 might_sleep();
752
753 dprintk_rcu("RPC: shutting down %s client for %s\n",
754 clnt->cl_program->name,
755 rcu_dereference(clnt->cl_xprt)->servername);
756
757 while (!list_empty(&clnt->cl_tasks)) {
758 rpc_killall_tasks(clnt);
759 wait_event_timeout(destroy_wait,
760 list_empty(&clnt->cl_tasks), 1*HZ);
761 }
762
763 rpc_release_client(clnt);
764 }
765 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
766
767 /*
768 * Free an RPC client
769 */
770 static struct rpc_clnt *
771 rpc_free_client(struct rpc_clnt *clnt)
772 {
773 struct rpc_clnt *parent = NULL;
774
775 dprintk_rcu("RPC: destroying %s client for %s\n",
776 clnt->cl_program->name,
777 rcu_dereference(clnt->cl_xprt)->servername);
778 if (clnt->cl_parent != clnt)
779 parent = clnt->cl_parent;
780 rpc_clnt_debugfs_unregister(clnt);
781 rpc_clnt_remove_pipedir(clnt);
782 rpc_unregister_client(clnt);
783 rpc_free_iostats(clnt->cl_metrics);
784 clnt->cl_metrics = NULL;
785 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
786 rpciod_down();
787 rpc_free_clid(clnt);
788 kfree(clnt);
789 return parent;
790 }
791
792 /*
793 * Free an RPC client
794 */
795 static struct rpc_clnt *
796 rpc_free_auth(struct rpc_clnt *clnt)
797 {
798 if (clnt->cl_auth == NULL)
799 return rpc_free_client(clnt);
800
801 /*
802 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
803 * release remaining GSS contexts. This mechanism ensures
804 * that it can do so safely.
805 */
806 atomic_inc(&clnt->cl_count);
807 rpcauth_release(clnt->cl_auth);
808 clnt->cl_auth = NULL;
809 if (atomic_dec_and_test(&clnt->cl_count))
810 return rpc_free_client(clnt);
811 return NULL;
812 }
813
814 /*
815 * Release reference to the RPC client
816 */
817 void
818 rpc_release_client(struct rpc_clnt *clnt)
819 {
820 dprintk("RPC: rpc_release_client(%p)\n", clnt);
821
822 do {
823 if (list_empty(&clnt->cl_tasks))
824 wake_up(&destroy_wait);
825 if (!atomic_dec_and_test(&clnt->cl_count))
826 break;
827 clnt = rpc_free_auth(clnt);
828 } while (clnt != NULL);
829 }
830 EXPORT_SYMBOL_GPL(rpc_release_client);
831
832 /**
833 * rpc_bind_new_program - bind a new RPC program to an existing client
834 * @old: old rpc_client
835 * @program: rpc program to set
836 * @vers: rpc program version
837 *
838 * Clones the rpc client and sets up a new RPC program. This is mainly
839 * of use for enabling different RPC programs to share the same transport.
840 * The Sun NFSv2/v3 ACL protocol can do this.
841 */
842 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
843 const struct rpc_program *program,
844 u32 vers)
845 {
846 struct rpc_create_args args = {
847 .program = program,
848 .prognumber = program->number,
849 .version = vers,
850 .authflavor = old->cl_auth->au_flavor,
851 };
852 struct rpc_clnt *clnt;
853 int err;
854
855 clnt = __rpc_clone_client(&args, old);
856 if (IS_ERR(clnt))
857 goto out;
858 err = rpc_ping(clnt);
859 if (err != 0) {
860 rpc_shutdown_client(clnt);
861 clnt = ERR_PTR(err);
862 }
863 out:
864 return clnt;
865 }
866 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
867
868 void rpc_task_release_client(struct rpc_task *task)
869 {
870 struct rpc_clnt *clnt = task->tk_client;
871
872 if (clnt != NULL) {
873 /* Remove from client task list */
874 spin_lock(&clnt->cl_lock);
875 list_del(&task->tk_task);
876 spin_unlock(&clnt->cl_lock);
877 task->tk_client = NULL;
878
879 rpc_release_client(clnt);
880 }
881 }
882
883 static
884 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
885 {
886 if (clnt != NULL) {
887 rpc_task_release_client(task);
888 task->tk_client = clnt;
889 atomic_inc(&clnt->cl_count);
890 if (clnt->cl_softrtry)
891 task->tk_flags |= RPC_TASK_SOFT;
892 if (clnt->cl_noretranstimeo)
893 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
894 if (atomic_read(&clnt->cl_swapper))
895 task->tk_flags |= RPC_TASK_SWAPPER;
896 /* Add to the client's list of all tasks */
897 spin_lock(&clnt->cl_lock);
898 list_add_tail(&task->tk_task, &clnt->cl_tasks);
899 spin_unlock(&clnt->cl_lock);
900 }
901 }
902
903 void rpc_task_reset_client(struct rpc_task *task, struct rpc_clnt *clnt)
904 {
905 rpc_task_release_client(task);
906 rpc_task_set_client(task, clnt);
907 }
908 EXPORT_SYMBOL_GPL(rpc_task_reset_client);
909
910
911 static void
912 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
913 {
914 if (msg != NULL) {
915 task->tk_msg.rpc_proc = msg->rpc_proc;
916 task->tk_msg.rpc_argp = msg->rpc_argp;
917 task->tk_msg.rpc_resp = msg->rpc_resp;
918 if (msg->rpc_cred != NULL)
919 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
920 }
921 }
922
923 /*
924 * Default callback for async RPC calls
925 */
926 static void
927 rpc_default_callback(struct rpc_task *task, void *data)
928 {
929 }
930
931 static const struct rpc_call_ops rpc_default_ops = {
932 .rpc_call_done = rpc_default_callback,
933 };
934
935 /**
936 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
937 * @task_setup_data: pointer to task initialisation data
938 */
939 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
940 {
941 struct rpc_task *task;
942
943 task = rpc_new_task(task_setup_data);
944 if (IS_ERR(task))
945 goto out;
946
947 rpc_task_set_client(task, task_setup_data->rpc_client);
948 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
949
950 if (task->tk_action == NULL)
951 rpc_call_start(task);
952
953 atomic_inc(&task->tk_count);
954 rpc_execute(task);
955 out:
956 return task;
957 }
958 EXPORT_SYMBOL_GPL(rpc_run_task);
959
960 /**
961 * rpc_call_sync - Perform a synchronous RPC call
962 * @clnt: pointer to RPC client
963 * @msg: RPC call parameters
964 * @flags: RPC call flags
965 */
966 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
967 {
968 struct rpc_task *task;
969 struct rpc_task_setup task_setup_data = {
970 .rpc_client = clnt,
971 .rpc_message = msg,
972 .callback_ops = &rpc_default_ops,
973 .flags = flags,
974 };
975 int status;
976
977 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
978 if (flags & RPC_TASK_ASYNC) {
979 rpc_release_calldata(task_setup_data.callback_ops,
980 task_setup_data.callback_data);
981 return -EINVAL;
982 }
983
984 task = rpc_run_task(&task_setup_data);
985 if (IS_ERR(task))
986 return PTR_ERR(task);
987 status = task->tk_status;
988 rpc_put_task(task);
989 return status;
990 }
991 EXPORT_SYMBOL_GPL(rpc_call_sync);
992
993 /**
994 * rpc_call_async - Perform an asynchronous RPC call
995 * @clnt: pointer to RPC client
996 * @msg: RPC call parameters
997 * @flags: RPC call flags
998 * @tk_ops: RPC call ops
999 * @data: user call data
1000 */
1001 int
1002 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1003 const struct rpc_call_ops *tk_ops, void *data)
1004 {
1005 struct rpc_task *task;
1006 struct rpc_task_setup task_setup_data = {
1007 .rpc_client = clnt,
1008 .rpc_message = msg,
1009 .callback_ops = tk_ops,
1010 .callback_data = data,
1011 .flags = flags|RPC_TASK_ASYNC,
1012 };
1013
1014 task = rpc_run_task(&task_setup_data);
1015 if (IS_ERR(task))
1016 return PTR_ERR(task);
1017 rpc_put_task(task);
1018 return 0;
1019 }
1020 EXPORT_SYMBOL_GPL(rpc_call_async);
1021
1022 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1023 /**
1024 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1025 * rpc_execute against it
1026 * @req: RPC request
1027 */
1028 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1029 {
1030 struct rpc_task *task;
1031 struct xdr_buf *xbufp = &req->rq_snd_buf;
1032 struct rpc_task_setup task_setup_data = {
1033 .callback_ops = &rpc_default_ops,
1034 .flags = RPC_TASK_SOFTCONN,
1035 };
1036
1037 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1038 /*
1039 * Create an rpc_task to send the data
1040 */
1041 task = rpc_new_task(&task_setup_data);
1042 if (IS_ERR(task)) {
1043 xprt_free_bc_request(req);
1044 goto out;
1045 }
1046 task->tk_rqstp = req;
1047
1048 /*
1049 * Set up the xdr_buf length.
1050 * This also indicates that the buffer is XDR encoded already.
1051 */
1052 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1053 xbufp->tail[0].iov_len;
1054
1055 task->tk_action = call_bc_transmit;
1056 atomic_inc(&task->tk_count);
1057 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1058 rpc_execute(task);
1059
1060 out:
1061 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1062 return task;
1063 }
1064 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1065
1066 void
1067 rpc_call_start(struct rpc_task *task)
1068 {
1069 task->tk_action = call_start;
1070 }
1071 EXPORT_SYMBOL_GPL(rpc_call_start);
1072
1073 /**
1074 * rpc_peeraddr - extract remote peer address from clnt's xprt
1075 * @clnt: RPC client structure
1076 * @buf: target buffer
1077 * @bufsize: length of target buffer
1078 *
1079 * Returns the number of bytes that are actually in the stored address.
1080 */
1081 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1082 {
1083 size_t bytes;
1084 struct rpc_xprt *xprt;
1085
1086 rcu_read_lock();
1087 xprt = rcu_dereference(clnt->cl_xprt);
1088
1089 bytes = xprt->addrlen;
1090 if (bytes > bufsize)
1091 bytes = bufsize;
1092 memcpy(buf, &xprt->addr, bytes);
1093 rcu_read_unlock();
1094
1095 return bytes;
1096 }
1097 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1098
1099 /**
1100 * rpc_peeraddr2str - return remote peer address in printable format
1101 * @clnt: RPC client structure
1102 * @format: address format
1103 *
1104 * NB: the lifetime of the memory referenced by the returned pointer is
1105 * the same as the rpc_xprt itself. As long as the caller uses this
1106 * pointer, it must hold the RCU read lock.
1107 */
1108 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1109 enum rpc_display_format_t format)
1110 {
1111 struct rpc_xprt *xprt;
1112
1113 xprt = rcu_dereference(clnt->cl_xprt);
1114
1115 if (xprt->address_strings[format] != NULL)
1116 return xprt->address_strings[format];
1117 else
1118 return "unprintable";
1119 }
1120 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1121
1122 static const struct sockaddr_in rpc_inaddr_loopback = {
1123 .sin_family = AF_INET,
1124 .sin_addr.s_addr = htonl(INADDR_ANY),
1125 };
1126
1127 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1128 .sin6_family = AF_INET6,
1129 .sin6_addr = IN6ADDR_ANY_INIT,
1130 };
1131
1132 /*
1133 * Try a getsockname() on a connected datagram socket. Using a
1134 * connected datagram socket prevents leaving a socket in TIME_WAIT.
1135 * This conserves the ephemeral port number space.
1136 *
1137 * Returns zero and fills in "buf" if successful; otherwise, a
1138 * negative errno is returned.
1139 */
1140 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1141 struct sockaddr *buf, int buflen)
1142 {
1143 struct socket *sock;
1144 int err;
1145
1146 err = __sock_create(net, sap->sa_family,
1147 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1148 if (err < 0) {
1149 dprintk("RPC: can't create UDP socket (%d)\n", err);
1150 goto out;
1151 }
1152
1153 switch (sap->sa_family) {
1154 case AF_INET:
1155 err = kernel_bind(sock,
1156 (struct sockaddr *)&rpc_inaddr_loopback,
1157 sizeof(rpc_inaddr_loopback));
1158 break;
1159 case AF_INET6:
1160 err = kernel_bind(sock,
1161 (struct sockaddr *)&rpc_in6addr_loopback,
1162 sizeof(rpc_in6addr_loopback));
1163 break;
1164 default:
1165 err = -EAFNOSUPPORT;
1166 goto out;
1167 }
1168 if (err < 0) {
1169 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1170 goto out_release;
1171 }
1172
1173 err = kernel_connect(sock, sap, salen, 0);
1174 if (err < 0) {
1175 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1176 goto out_release;
1177 }
1178
1179 err = kernel_getsockname(sock, buf, &buflen);
1180 if (err < 0) {
1181 dprintk("RPC: getsockname failed (%d)\n", err);
1182 goto out_release;
1183 }
1184
1185 err = 0;
1186 if (buf->sa_family == AF_INET6) {
1187 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1188 sin6->sin6_scope_id = 0;
1189 }
1190 dprintk("RPC: %s succeeded\n", __func__);
1191
1192 out_release:
1193 sock_release(sock);
1194 out:
1195 return err;
1196 }
1197
1198 /*
1199 * Scraping a connected socket failed, so we don't have a useable
1200 * local address. Fallback: generate an address that will prevent
1201 * the server from calling us back.
1202 *
1203 * Returns zero and fills in "buf" if successful; otherwise, a
1204 * negative errno is returned.
1205 */
1206 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1207 {
1208 switch (family) {
1209 case AF_INET:
1210 if (buflen < sizeof(rpc_inaddr_loopback))
1211 return -EINVAL;
1212 memcpy(buf, &rpc_inaddr_loopback,
1213 sizeof(rpc_inaddr_loopback));
1214 break;
1215 case AF_INET6:
1216 if (buflen < sizeof(rpc_in6addr_loopback))
1217 return -EINVAL;
1218 memcpy(buf, &rpc_in6addr_loopback,
1219 sizeof(rpc_in6addr_loopback));
1220 default:
1221 dprintk("RPC: %s: address family not supported\n",
1222 __func__);
1223 return -EAFNOSUPPORT;
1224 }
1225 dprintk("RPC: %s: succeeded\n", __func__);
1226 return 0;
1227 }
1228
1229 /**
1230 * rpc_localaddr - discover local endpoint address for an RPC client
1231 * @clnt: RPC client structure
1232 * @buf: target buffer
1233 * @buflen: size of target buffer, in bytes
1234 *
1235 * Returns zero and fills in "buf" and "buflen" if successful;
1236 * otherwise, a negative errno is returned.
1237 *
1238 * This works even if the underlying transport is not currently connected,
1239 * or if the upper layer never previously provided a source address.
1240 *
1241 * The result of this function call is transient: multiple calls in
1242 * succession may give different results, depending on how local
1243 * networking configuration changes over time.
1244 */
1245 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1246 {
1247 struct sockaddr_storage address;
1248 struct sockaddr *sap = (struct sockaddr *)&address;
1249 struct rpc_xprt *xprt;
1250 struct net *net;
1251 size_t salen;
1252 int err;
1253
1254 rcu_read_lock();
1255 xprt = rcu_dereference(clnt->cl_xprt);
1256 salen = xprt->addrlen;
1257 memcpy(sap, &xprt->addr, salen);
1258 net = get_net(xprt->xprt_net);
1259 rcu_read_unlock();
1260
1261 rpc_set_port(sap, 0);
1262 err = rpc_sockname(net, sap, salen, buf, buflen);
1263 put_net(net);
1264 if (err != 0)
1265 /* Couldn't discover local address, return ANYADDR */
1266 return rpc_anyaddr(sap->sa_family, buf, buflen);
1267 return 0;
1268 }
1269 EXPORT_SYMBOL_GPL(rpc_localaddr);
1270
1271 void
1272 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1273 {
1274 struct rpc_xprt *xprt;
1275
1276 rcu_read_lock();
1277 xprt = rcu_dereference(clnt->cl_xprt);
1278 if (xprt->ops->set_buffer_size)
1279 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1280 rcu_read_unlock();
1281 }
1282 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1283
1284 /**
1285 * rpc_protocol - Get transport protocol number for an RPC client
1286 * @clnt: RPC client to query
1287 *
1288 */
1289 int rpc_protocol(struct rpc_clnt *clnt)
1290 {
1291 int protocol;
1292
1293 rcu_read_lock();
1294 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1295 rcu_read_unlock();
1296 return protocol;
1297 }
1298 EXPORT_SYMBOL_GPL(rpc_protocol);
1299
1300 /**
1301 * rpc_net_ns - Get the network namespace for this RPC client
1302 * @clnt: RPC client to query
1303 *
1304 */
1305 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1306 {
1307 struct net *ret;
1308
1309 rcu_read_lock();
1310 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1311 rcu_read_unlock();
1312 return ret;
1313 }
1314 EXPORT_SYMBOL_GPL(rpc_net_ns);
1315
1316 /**
1317 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1318 * @clnt: RPC client to query
1319 *
1320 * For stream transports, this is one RPC record fragment (see RFC
1321 * 1831), as we don't support multi-record requests yet. For datagram
1322 * transports, this is the size of an IP packet minus the IP, UDP, and
1323 * RPC header sizes.
1324 */
1325 size_t rpc_max_payload(struct rpc_clnt *clnt)
1326 {
1327 size_t ret;
1328
1329 rcu_read_lock();
1330 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1331 rcu_read_unlock();
1332 return ret;
1333 }
1334 EXPORT_SYMBOL_GPL(rpc_max_payload);
1335
1336 /**
1337 * rpc_get_timeout - Get timeout for transport in units of HZ
1338 * @clnt: RPC client to query
1339 */
1340 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1341 {
1342 unsigned long ret;
1343
1344 rcu_read_lock();
1345 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1346 rcu_read_unlock();
1347 return ret;
1348 }
1349 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1350
1351 /**
1352 * rpc_force_rebind - force transport to check that remote port is unchanged
1353 * @clnt: client to rebind
1354 *
1355 */
1356 void rpc_force_rebind(struct rpc_clnt *clnt)
1357 {
1358 if (clnt->cl_autobind) {
1359 rcu_read_lock();
1360 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1361 rcu_read_unlock();
1362 }
1363 }
1364 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1365
1366 /*
1367 * Restart an (async) RPC call from the call_prepare state.
1368 * Usually called from within the exit handler.
1369 */
1370 int
1371 rpc_restart_call_prepare(struct rpc_task *task)
1372 {
1373 if (RPC_ASSASSINATED(task))
1374 return 0;
1375 task->tk_action = call_start;
1376 task->tk_status = 0;
1377 if (task->tk_ops->rpc_call_prepare != NULL)
1378 task->tk_action = rpc_prepare_task;
1379 return 1;
1380 }
1381 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1382
1383 /*
1384 * Restart an (async) RPC call. Usually called from within the
1385 * exit handler.
1386 */
1387 int
1388 rpc_restart_call(struct rpc_task *task)
1389 {
1390 if (RPC_ASSASSINATED(task))
1391 return 0;
1392 task->tk_action = call_start;
1393 task->tk_status = 0;
1394 return 1;
1395 }
1396 EXPORT_SYMBOL_GPL(rpc_restart_call);
1397
1398 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1399 const char
1400 *rpc_proc_name(const struct rpc_task *task)
1401 {
1402 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1403
1404 if (proc) {
1405 if (proc->p_name)
1406 return proc->p_name;
1407 else
1408 return "NULL";
1409 } else
1410 return "no proc";
1411 }
1412 #endif
1413
1414 /*
1415 * 0. Initial state
1416 *
1417 * Other FSM states can be visited zero or more times, but
1418 * this state is visited exactly once for each RPC.
1419 */
1420 static void
1421 call_start(struct rpc_task *task)
1422 {
1423 struct rpc_clnt *clnt = task->tk_client;
1424
1425 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1426 clnt->cl_program->name, clnt->cl_vers,
1427 rpc_proc_name(task),
1428 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1429
1430 /* Increment call count */
1431 task->tk_msg.rpc_proc->p_count++;
1432 clnt->cl_stats->rpccnt++;
1433 task->tk_action = call_reserve;
1434 }
1435
1436 /*
1437 * 1. Reserve an RPC call slot
1438 */
1439 static void
1440 call_reserve(struct rpc_task *task)
1441 {
1442 dprint_status(task);
1443
1444 task->tk_status = 0;
1445 task->tk_action = call_reserveresult;
1446 xprt_reserve(task);
1447 }
1448
1449 static void call_retry_reserve(struct rpc_task *task);
1450
1451 /*
1452 * 1b. Grok the result of xprt_reserve()
1453 */
1454 static void
1455 call_reserveresult(struct rpc_task *task)
1456 {
1457 int status = task->tk_status;
1458
1459 dprint_status(task);
1460
1461 /*
1462 * After a call to xprt_reserve(), we must have either
1463 * a request slot or else an error status.
1464 */
1465 task->tk_status = 0;
1466 if (status >= 0) {
1467 if (task->tk_rqstp) {
1468 task->tk_action = call_refresh;
1469 return;
1470 }
1471
1472 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1473 __func__, status);
1474 rpc_exit(task, -EIO);
1475 return;
1476 }
1477
1478 /*
1479 * Even though there was an error, we may have acquired
1480 * a request slot somehow. Make sure not to leak it.
1481 */
1482 if (task->tk_rqstp) {
1483 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1484 __func__, status);
1485 xprt_release(task);
1486 }
1487
1488 switch (status) {
1489 case -ENOMEM:
1490 rpc_delay(task, HZ >> 2);
1491 case -EAGAIN: /* woken up; retry */
1492 task->tk_action = call_retry_reserve;
1493 return;
1494 case -EIO: /* probably a shutdown */
1495 break;
1496 default:
1497 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1498 __func__, status);
1499 break;
1500 }
1501 rpc_exit(task, status);
1502 }
1503
1504 /*
1505 * 1c. Retry reserving an RPC call slot
1506 */
1507 static void
1508 call_retry_reserve(struct rpc_task *task)
1509 {
1510 dprint_status(task);
1511
1512 task->tk_status = 0;
1513 task->tk_action = call_reserveresult;
1514 xprt_retry_reserve(task);
1515 }
1516
1517 /*
1518 * 2. Bind and/or refresh the credentials
1519 */
1520 static void
1521 call_refresh(struct rpc_task *task)
1522 {
1523 dprint_status(task);
1524
1525 task->tk_action = call_refreshresult;
1526 task->tk_status = 0;
1527 task->tk_client->cl_stats->rpcauthrefresh++;
1528 rpcauth_refreshcred(task);
1529 }
1530
1531 /*
1532 * 2a. Process the results of a credential refresh
1533 */
1534 static void
1535 call_refreshresult(struct rpc_task *task)
1536 {
1537 int status = task->tk_status;
1538
1539 dprint_status(task);
1540
1541 task->tk_status = 0;
1542 task->tk_action = call_refresh;
1543 switch (status) {
1544 case 0:
1545 if (rpcauth_uptodatecred(task)) {
1546 task->tk_action = call_allocate;
1547 return;
1548 }
1549 /* Use rate-limiting and a max number of retries if refresh
1550 * had status 0 but failed to update the cred.
1551 */
1552 case -ETIMEDOUT:
1553 rpc_delay(task, 3*HZ);
1554 case -EAGAIN:
1555 status = -EACCES;
1556 case -EKEYEXPIRED:
1557 if (!task->tk_cred_retry)
1558 break;
1559 task->tk_cred_retry--;
1560 dprintk("RPC: %5u %s: retry refresh creds\n",
1561 task->tk_pid, __func__);
1562 return;
1563 }
1564 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1565 task->tk_pid, __func__, status);
1566 rpc_exit(task, status);
1567 }
1568
1569 /*
1570 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1571 * (Note: buffer memory is freed in xprt_release).
1572 */
1573 static void
1574 call_allocate(struct rpc_task *task)
1575 {
1576 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1577 struct rpc_rqst *req = task->tk_rqstp;
1578 struct rpc_xprt *xprt = req->rq_xprt;
1579 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1580
1581 dprint_status(task);
1582
1583 task->tk_status = 0;
1584 task->tk_action = call_bind;
1585
1586 if (req->rq_buffer)
1587 return;
1588
1589 if (proc->p_proc != 0) {
1590 BUG_ON(proc->p_arglen == 0);
1591 if (proc->p_decode != NULL)
1592 BUG_ON(proc->p_replen == 0);
1593 }
1594
1595 /*
1596 * Calculate the size (in quads) of the RPC call
1597 * and reply headers, and convert both values
1598 * to byte sizes.
1599 */
1600 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1601 req->rq_callsize <<= 2;
1602 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1603 req->rq_rcvsize <<= 2;
1604
1605 req->rq_buffer = xprt->ops->buf_alloc(task,
1606 req->rq_callsize + req->rq_rcvsize);
1607 if (req->rq_buffer != NULL)
1608 return;
1609 xprt_inject_disconnect(xprt);
1610
1611 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1612
1613 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1614 task->tk_action = call_allocate;
1615 rpc_delay(task, HZ>>4);
1616 return;
1617 }
1618
1619 rpc_exit(task, -ERESTARTSYS);
1620 }
1621
1622 static inline int
1623 rpc_task_need_encode(struct rpc_task *task)
1624 {
1625 return task->tk_rqstp->rq_snd_buf.len == 0;
1626 }
1627
1628 static inline void
1629 rpc_task_force_reencode(struct rpc_task *task)
1630 {
1631 task->tk_rqstp->rq_snd_buf.len = 0;
1632 task->tk_rqstp->rq_bytes_sent = 0;
1633 }
1634
1635 static inline void
1636 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1637 {
1638 buf->head[0].iov_base = start;
1639 buf->head[0].iov_len = len;
1640 buf->tail[0].iov_len = 0;
1641 buf->page_len = 0;
1642 buf->flags = 0;
1643 buf->len = 0;
1644 buf->buflen = len;
1645 }
1646
1647 /*
1648 * 3. Encode arguments of an RPC call
1649 */
1650 static void
1651 rpc_xdr_encode(struct rpc_task *task)
1652 {
1653 struct rpc_rqst *req = task->tk_rqstp;
1654 kxdreproc_t encode;
1655 __be32 *p;
1656
1657 dprint_status(task);
1658
1659 rpc_xdr_buf_init(&req->rq_snd_buf,
1660 req->rq_buffer,
1661 req->rq_callsize);
1662 rpc_xdr_buf_init(&req->rq_rcv_buf,
1663 (char *)req->rq_buffer + req->rq_callsize,
1664 req->rq_rcvsize);
1665
1666 p = rpc_encode_header(task);
1667 if (p == NULL) {
1668 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1669 rpc_exit(task, -EIO);
1670 return;
1671 }
1672
1673 encode = task->tk_msg.rpc_proc->p_encode;
1674 if (encode == NULL)
1675 return;
1676
1677 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1678 task->tk_msg.rpc_argp);
1679 }
1680
1681 /*
1682 * 4. Get the server port number if not yet set
1683 */
1684 static void
1685 call_bind(struct rpc_task *task)
1686 {
1687 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1688
1689 dprint_status(task);
1690
1691 task->tk_action = call_connect;
1692 if (!xprt_bound(xprt)) {
1693 task->tk_action = call_bind_status;
1694 task->tk_timeout = xprt->bind_timeout;
1695 xprt->ops->rpcbind(task);
1696 }
1697 }
1698
1699 /*
1700 * 4a. Sort out bind result
1701 */
1702 static void
1703 call_bind_status(struct rpc_task *task)
1704 {
1705 int status = -EIO;
1706
1707 if (task->tk_status >= 0) {
1708 dprint_status(task);
1709 task->tk_status = 0;
1710 task->tk_action = call_connect;
1711 return;
1712 }
1713
1714 trace_rpc_bind_status(task);
1715 switch (task->tk_status) {
1716 case -ENOMEM:
1717 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1718 rpc_delay(task, HZ >> 2);
1719 goto retry_timeout;
1720 case -EACCES:
1721 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1722 "unavailable\n", task->tk_pid);
1723 /* fail immediately if this is an RPC ping */
1724 if (task->tk_msg.rpc_proc->p_proc == 0) {
1725 status = -EOPNOTSUPP;
1726 break;
1727 }
1728 if (task->tk_rebind_retry == 0)
1729 break;
1730 task->tk_rebind_retry--;
1731 rpc_delay(task, 3*HZ);
1732 goto retry_timeout;
1733 case -ETIMEDOUT:
1734 dprintk("RPC: %5u rpcbind request timed out\n",
1735 task->tk_pid);
1736 goto retry_timeout;
1737 case -EPFNOSUPPORT:
1738 /* server doesn't support any rpcbind version we know of */
1739 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1740 task->tk_pid);
1741 break;
1742 case -EPROTONOSUPPORT:
1743 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1744 task->tk_pid);
1745 goto retry_timeout;
1746 case -ECONNREFUSED: /* connection problems */
1747 case -ECONNRESET:
1748 case -ECONNABORTED:
1749 case -ENOTCONN:
1750 case -EHOSTDOWN:
1751 case -EHOSTUNREACH:
1752 case -ENETUNREACH:
1753 case -ENOBUFS:
1754 case -EPIPE:
1755 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1756 task->tk_pid, task->tk_status);
1757 if (!RPC_IS_SOFTCONN(task)) {
1758 rpc_delay(task, 5*HZ);
1759 goto retry_timeout;
1760 }
1761 status = task->tk_status;
1762 break;
1763 default:
1764 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1765 task->tk_pid, -task->tk_status);
1766 }
1767
1768 rpc_exit(task, status);
1769 return;
1770
1771 retry_timeout:
1772 task->tk_status = 0;
1773 task->tk_action = call_timeout;
1774 }
1775
1776 /*
1777 * 4b. Connect to the RPC server
1778 */
1779 static void
1780 call_connect(struct rpc_task *task)
1781 {
1782 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1783
1784 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1785 task->tk_pid, xprt,
1786 (xprt_connected(xprt) ? "is" : "is not"));
1787
1788 task->tk_action = call_transmit;
1789 if (!xprt_connected(xprt)) {
1790 task->tk_action = call_connect_status;
1791 if (task->tk_status < 0)
1792 return;
1793 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1794 rpc_exit(task, -ENOTCONN);
1795 return;
1796 }
1797 xprt_connect(task);
1798 }
1799 }
1800
1801 /*
1802 * 4c. Sort out connect result
1803 */
1804 static void
1805 call_connect_status(struct rpc_task *task)
1806 {
1807 struct rpc_clnt *clnt = task->tk_client;
1808 int status = task->tk_status;
1809
1810 dprint_status(task);
1811
1812 trace_rpc_connect_status(task, status);
1813 task->tk_status = 0;
1814 switch (status) {
1815 case -ECONNREFUSED:
1816 case -ECONNRESET:
1817 case -ECONNABORTED:
1818 case -ENETUNREACH:
1819 case -EHOSTUNREACH:
1820 case -EADDRINUSE:
1821 case -ENOBUFS:
1822 case -EPIPE:
1823 if (RPC_IS_SOFTCONN(task))
1824 break;
1825 /* retry with existing socket, after a delay */
1826 rpc_delay(task, 3*HZ);
1827 case -EAGAIN:
1828 /* Check for timeouts before looping back to call_bind */
1829 case -ETIMEDOUT:
1830 task->tk_action = call_timeout;
1831 return;
1832 case 0:
1833 clnt->cl_stats->netreconn++;
1834 task->tk_action = call_transmit;
1835 return;
1836 }
1837 rpc_exit(task, status);
1838 }
1839
1840 /*
1841 * 5. Transmit the RPC request, and wait for reply
1842 */
1843 static void
1844 call_transmit(struct rpc_task *task)
1845 {
1846 int is_retrans = RPC_WAS_SENT(task);
1847
1848 dprint_status(task);
1849
1850 task->tk_action = call_status;
1851 if (task->tk_status < 0)
1852 return;
1853 if (!xprt_prepare_transmit(task))
1854 return;
1855 task->tk_action = call_transmit_status;
1856 /* Encode here so that rpcsec_gss can use correct sequence number. */
1857 if (rpc_task_need_encode(task)) {
1858 rpc_xdr_encode(task);
1859 /* Did the encode result in an error condition? */
1860 if (task->tk_status != 0) {
1861 /* Was the error nonfatal? */
1862 if (task->tk_status == -EAGAIN)
1863 rpc_delay(task, HZ >> 4);
1864 else
1865 rpc_exit(task, task->tk_status);
1866 return;
1867 }
1868 }
1869 xprt_transmit(task);
1870 if (task->tk_status < 0)
1871 return;
1872 if (is_retrans)
1873 task->tk_client->cl_stats->rpcretrans++;
1874 /*
1875 * On success, ensure that we call xprt_end_transmit() before sleeping
1876 * in order to allow access to the socket to other RPC requests.
1877 */
1878 call_transmit_status(task);
1879 if (rpc_reply_expected(task))
1880 return;
1881 task->tk_action = rpc_exit_task;
1882 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1883 }
1884
1885 /*
1886 * 5a. Handle cleanup after a transmission
1887 */
1888 static void
1889 call_transmit_status(struct rpc_task *task)
1890 {
1891 task->tk_action = call_status;
1892
1893 /*
1894 * Common case: success. Force the compiler to put this
1895 * test first.
1896 */
1897 if (task->tk_status == 0) {
1898 xprt_end_transmit(task);
1899 rpc_task_force_reencode(task);
1900 return;
1901 }
1902
1903 switch (task->tk_status) {
1904 case -EAGAIN:
1905 case -ENOBUFS:
1906 break;
1907 default:
1908 dprint_status(task);
1909 xprt_end_transmit(task);
1910 rpc_task_force_reencode(task);
1911 break;
1912 /*
1913 * Special cases: if we've been waiting on the
1914 * socket's write_space() callback, or if the
1915 * socket just returned a connection error,
1916 * then hold onto the transport lock.
1917 */
1918 case -ECONNREFUSED:
1919 case -EHOSTDOWN:
1920 case -EHOSTUNREACH:
1921 case -ENETUNREACH:
1922 case -EPERM:
1923 if (RPC_IS_SOFTCONN(task)) {
1924 xprt_end_transmit(task);
1925 rpc_exit(task, task->tk_status);
1926 break;
1927 }
1928 case -ECONNRESET:
1929 case -ECONNABORTED:
1930 case -EADDRINUSE:
1931 case -ENOTCONN:
1932 case -EPIPE:
1933 rpc_task_force_reencode(task);
1934 }
1935 }
1936
1937 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1938 /*
1939 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
1940 * addition, disconnect on connectivity errors.
1941 */
1942 static void
1943 call_bc_transmit(struct rpc_task *task)
1944 {
1945 struct rpc_rqst *req = task->tk_rqstp;
1946
1947 if (!xprt_prepare_transmit(task))
1948 goto out_retry;
1949
1950 if (task->tk_status < 0) {
1951 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1952 "error: %d\n", task->tk_status);
1953 goto out_done;
1954 }
1955 if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
1956 req->rq_bytes_sent = 0;
1957
1958 xprt_transmit(task);
1959
1960 if (task->tk_status == -EAGAIN)
1961 goto out_nospace;
1962
1963 xprt_end_transmit(task);
1964 dprint_status(task);
1965 switch (task->tk_status) {
1966 case 0:
1967 /* Success */
1968 case -EHOSTDOWN:
1969 case -EHOSTUNREACH:
1970 case -ENETUNREACH:
1971 case -ECONNRESET:
1972 case -ECONNREFUSED:
1973 case -EADDRINUSE:
1974 case -ENOTCONN:
1975 case -EPIPE:
1976 break;
1977 case -ETIMEDOUT:
1978 /*
1979 * Problem reaching the server. Disconnect and let the
1980 * forechannel reestablish the connection. The server will
1981 * have to retransmit the backchannel request and we'll
1982 * reprocess it. Since these ops are idempotent, there's no
1983 * need to cache our reply at this time.
1984 */
1985 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1986 "error: %d\n", task->tk_status);
1987 xprt_conditional_disconnect(req->rq_xprt,
1988 req->rq_connect_cookie);
1989 break;
1990 default:
1991 /*
1992 * We were unable to reply and will have to drop the
1993 * request. The server should reconnect and retransmit.
1994 */
1995 WARN_ON_ONCE(task->tk_status == -EAGAIN);
1996 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1997 "error: %d\n", task->tk_status);
1998 break;
1999 }
2000 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2001 out_done:
2002 task->tk_action = rpc_exit_task;
2003 return;
2004 out_nospace:
2005 req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2006 out_retry:
2007 task->tk_status = 0;
2008 }
2009 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2010
2011 /*
2012 * 6. Sort out the RPC call status
2013 */
2014 static void
2015 call_status(struct rpc_task *task)
2016 {
2017 struct rpc_clnt *clnt = task->tk_client;
2018 struct rpc_rqst *req = task->tk_rqstp;
2019 int status;
2020
2021 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2022 task->tk_status = req->rq_reply_bytes_recvd;
2023
2024 dprint_status(task);
2025
2026 status = task->tk_status;
2027 if (status >= 0) {
2028 task->tk_action = call_decode;
2029 return;
2030 }
2031
2032 trace_rpc_call_status(task);
2033 task->tk_status = 0;
2034 switch(status) {
2035 case -EHOSTDOWN:
2036 case -EHOSTUNREACH:
2037 case -ENETUNREACH:
2038 case -EPERM:
2039 if (RPC_IS_SOFTCONN(task)) {
2040 rpc_exit(task, status);
2041 break;
2042 }
2043 /*
2044 * Delay any retries for 3 seconds, then handle as if it
2045 * were a timeout.
2046 */
2047 rpc_delay(task, 3*HZ);
2048 case -ETIMEDOUT:
2049 task->tk_action = call_timeout;
2050 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2051 && task->tk_client->cl_discrtry)
2052 xprt_conditional_disconnect(req->rq_xprt,
2053 req->rq_connect_cookie);
2054 break;
2055 case -ECONNREFUSED:
2056 case -ECONNRESET:
2057 case -ECONNABORTED:
2058 rpc_force_rebind(clnt);
2059 case -EADDRINUSE:
2060 rpc_delay(task, 3*HZ);
2061 case -EPIPE:
2062 case -ENOTCONN:
2063 task->tk_action = call_bind;
2064 break;
2065 case -ENOBUFS:
2066 rpc_delay(task, HZ>>2);
2067 case -EAGAIN:
2068 task->tk_action = call_transmit;
2069 break;
2070 case -EIO:
2071 /* shutdown or soft timeout */
2072 rpc_exit(task, status);
2073 break;
2074 default:
2075 if (clnt->cl_chatty)
2076 printk("%s: RPC call returned error %d\n",
2077 clnt->cl_program->name, -status);
2078 rpc_exit(task, status);
2079 }
2080 }
2081
2082 /*
2083 * 6a. Handle RPC timeout
2084 * We do not release the request slot, so we keep using the
2085 * same XID for all retransmits.
2086 */
2087 static void
2088 call_timeout(struct rpc_task *task)
2089 {
2090 struct rpc_clnt *clnt = task->tk_client;
2091
2092 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2093 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2094 goto retry;
2095 }
2096
2097 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2098 task->tk_timeouts++;
2099
2100 if (RPC_IS_SOFTCONN(task)) {
2101 rpc_exit(task, -ETIMEDOUT);
2102 return;
2103 }
2104 if (RPC_IS_SOFT(task)) {
2105 if (clnt->cl_chatty) {
2106 rcu_read_lock();
2107 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2108 clnt->cl_program->name,
2109 rcu_dereference(clnt->cl_xprt)->servername);
2110 rcu_read_unlock();
2111 }
2112 if (task->tk_flags & RPC_TASK_TIMEOUT)
2113 rpc_exit(task, -ETIMEDOUT);
2114 else
2115 rpc_exit(task, -EIO);
2116 return;
2117 }
2118
2119 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2120 task->tk_flags |= RPC_CALL_MAJORSEEN;
2121 if (clnt->cl_chatty) {
2122 rcu_read_lock();
2123 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2124 clnt->cl_program->name,
2125 rcu_dereference(clnt->cl_xprt)->servername);
2126 rcu_read_unlock();
2127 }
2128 }
2129 rpc_force_rebind(clnt);
2130 /*
2131 * Did our request time out due to an RPCSEC_GSS out-of-sequence
2132 * event? RFC2203 requires the server to drop all such requests.
2133 */
2134 rpcauth_invalcred(task);
2135
2136 retry:
2137 task->tk_action = call_bind;
2138 task->tk_status = 0;
2139 }
2140
2141 /*
2142 * 7. Decode the RPC reply
2143 */
2144 static void
2145 call_decode(struct rpc_task *task)
2146 {
2147 struct rpc_clnt *clnt = task->tk_client;
2148 struct rpc_rqst *req = task->tk_rqstp;
2149 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
2150 __be32 *p;
2151
2152 dprint_status(task);
2153
2154 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2155 if (clnt->cl_chatty) {
2156 rcu_read_lock();
2157 printk(KERN_NOTICE "%s: server %s OK\n",
2158 clnt->cl_program->name,
2159 rcu_dereference(clnt->cl_xprt)->servername);
2160 rcu_read_unlock();
2161 }
2162 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2163 }
2164
2165 /*
2166 * Ensure that we see all writes made by xprt_complete_rqst()
2167 * before it changed req->rq_reply_bytes_recvd.
2168 */
2169 smp_rmb();
2170 req->rq_rcv_buf.len = req->rq_private_buf.len;
2171
2172 /* Check that the softirq receive buffer is valid */
2173 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2174 sizeof(req->rq_rcv_buf)) != 0);
2175
2176 if (req->rq_rcv_buf.len < 12) {
2177 if (!RPC_IS_SOFT(task)) {
2178 task->tk_action = call_bind;
2179 goto out_retry;
2180 }
2181 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
2182 clnt->cl_program->name, task->tk_status);
2183 task->tk_action = call_timeout;
2184 goto out_retry;
2185 }
2186
2187 p = rpc_verify_header(task);
2188 if (IS_ERR(p)) {
2189 if (p == ERR_PTR(-EAGAIN))
2190 goto out_retry;
2191 return;
2192 }
2193
2194 task->tk_action = rpc_exit_task;
2195
2196 if (decode) {
2197 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2198 task->tk_msg.rpc_resp);
2199 }
2200 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2201 task->tk_status);
2202 return;
2203 out_retry:
2204 task->tk_status = 0;
2205 /* Note: rpc_verify_header() may have freed the RPC slot */
2206 if (task->tk_rqstp == req) {
2207 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2208 if (task->tk_client->cl_discrtry)
2209 xprt_conditional_disconnect(req->rq_xprt,
2210 req->rq_connect_cookie);
2211 }
2212 }
2213
2214 static __be32 *
2215 rpc_encode_header(struct rpc_task *task)
2216 {
2217 struct rpc_clnt *clnt = task->tk_client;
2218 struct rpc_rqst *req = task->tk_rqstp;
2219 __be32 *p = req->rq_svec[0].iov_base;
2220
2221 /* FIXME: check buffer size? */
2222
2223 p = xprt_skip_transport_header(req->rq_xprt, p);
2224 *p++ = req->rq_xid; /* XID */
2225 *p++ = htonl(RPC_CALL); /* CALL */
2226 *p++ = htonl(RPC_VERSION); /* RPC version */
2227 *p++ = htonl(clnt->cl_prog); /* program number */
2228 *p++ = htonl(clnt->cl_vers); /* program version */
2229 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
2230 p = rpcauth_marshcred(task, p);
2231 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2232 return p;
2233 }
2234
2235 static __be32 *
2236 rpc_verify_header(struct rpc_task *task)
2237 {
2238 struct rpc_clnt *clnt = task->tk_client;
2239 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2240 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2241 __be32 *p = iov->iov_base;
2242 u32 n;
2243 int error = -EACCES;
2244
2245 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2246 /* RFC-1014 says that the representation of XDR data must be a
2247 * multiple of four bytes
2248 * - if it isn't pointer subtraction in the NFS client may give
2249 * undefined results
2250 */
2251 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2252 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2253 task->tk_rqstp->rq_rcv_buf.len);
2254 error = -EIO;
2255 goto out_err;
2256 }
2257 if ((len -= 3) < 0)
2258 goto out_overflow;
2259
2260 p += 1; /* skip XID */
2261 if ((n = ntohl(*p++)) != RPC_REPLY) {
2262 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2263 task->tk_pid, __func__, n);
2264 error = -EIO;
2265 goto out_garbage;
2266 }
2267
2268 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2269 if (--len < 0)
2270 goto out_overflow;
2271 switch ((n = ntohl(*p++))) {
2272 case RPC_AUTH_ERROR:
2273 break;
2274 case RPC_MISMATCH:
2275 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2276 task->tk_pid, __func__);
2277 error = -EPROTONOSUPPORT;
2278 goto out_err;
2279 default:
2280 dprintk("RPC: %5u %s: RPC call rejected, "
2281 "unknown error: %x\n",
2282 task->tk_pid, __func__, n);
2283 error = -EIO;
2284 goto out_err;
2285 }
2286 if (--len < 0)
2287 goto out_overflow;
2288 switch ((n = ntohl(*p++))) {
2289 case RPC_AUTH_REJECTEDCRED:
2290 case RPC_AUTH_REJECTEDVERF:
2291 case RPCSEC_GSS_CREDPROBLEM:
2292 case RPCSEC_GSS_CTXPROBLEM:
2293 if (!task->tk_cred_retry)
2294 break;
2295 task->tk_cred_retry--;
2296 dprintk("RPC: %5u %s: retry stale creds\n",
2297 task->tk_pid, __func__);
2298 rpcauth_invalcred(task);
2299 /* Ensure we obtain a new XID! */
2300 xprt_release(task);
2301 task->tk_action = call_reserve;
2302 goto out_retry;
2303 case RPC_AUTH_BADCRED:
2304 case RPC_AUTH_BADVERF:
2305 /* possibly garbled cred/verf? */
2306 if (!task->tk_garb_retry)
2307 break;
2308 task->tk_garb_retry--;
2309 dprintk("RPC: %5u %s: retry garbled creds\n",
2310 task->tk_pid, __func__);
2311 task->tk_action = call_bind;
2312 goto out_retry;
2313 case RPC_AUTH_TOOWEAK:
2314 rcu_read_lock();
2315 printk(KERN_NOTICE "RPC: server %s requires stronger "
2316 "authentication.\n",
2317 rcu_dereference(clnt->cl_xprt)->servername);
2318 rcu_read_unlock();
2319 break;
2320 default:
2321 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2322 task->tk_pid, __func__, n);
2323 error = -EIO;
2324 }
2325 dprintk("RPC: %5u %s: call rejected %d\n",
2326 task->tk_pid, __func__, n);
2327 goto out_err;
2328 }
2329 p = rpcauth_checkverf(task, p);
2330 if (IS_ERR(p)) {
2331 error = PTR_ERR(p);
2332 dprintk("RPC: %5u %s: auth check failed with %d\n",
2333 task->tk_pid, __func__, error);
2334 goto out_garbage; /* bad verifier, retry */
2335 }
2336 len = p - (__be32 *)iov->iov_base - 1;
2337 if (len < 0)
2338 goto out_overflow;
2339 switch ((n = ntohl(*p++))) {
2340 case RPC_SUCCESS:
2341 return p;
2342 case RPC_PROG_UNAVAIL:
2343 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2344 "by server %s\n", task->tk_pid, __func__,
2345 (unsigned int)clnt->cl_prog,
2346 rcu_dereference(clnt->cl_xprt)->servername);
2347 error = -EPFNOSUPPORT;
2348 goto out_err;
2349 case RPC_PROG_MISMATCH:
2350 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2351 "by server %s\n", task->tk_pid, __func__,
2352 (unsigned int)clnt->cl_prog,
2353 (unsigned int)clnt->cl_vers,
2354 rcu_dereference(clnt->cl_xprt)->servername);
2355 error = -EPROTONOSUPPORT;
2356 goto out_err;
2357 case RPC_PROC_UNAVAIL:
2358 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2359 "version %u on server %s\n",
2360 task->tk_pid, __func__,
2361 rpc_proc_name(task),
2362 clnt->cl_prog, clnt->cl_vers,
2363 rcu_dereference(clnt->cl_xprt)->servername);
2364 error = -EOPNOTSUPP;
2365 goto out_err;
2366 case RPC_GARBAGE_ARGS:
2367 dprintk("RPC: %5u %s: server saw garbage\n",
2368 task->tk_pid, __func__);
2369 break; /* retry */
2370 default:
2371 dprintk("RPC: %5u %s: server accept status: %x\n",
2372 task->tk_pid, __func__, n);
2373 /* Also retry */
2374 }
2375
2376 out_garbage:
2377 clnt->cl_stats->rpcgarbage++;
2378 if (task->tk_garb_retry) {
2379 task->tk_garb_retry--;
2380 dprintk("RPC: %5u %s: retrying\n",
2381 task->tk_pid, __func__);
2382 task->tk_action = call_bind;
2383 out_retry:
2384 return ERR_PTR(-EAGAIN);
2385 }
2386 out_err:
2387 rpc_exit(task, error);
2388 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2389 __func__, error);
2390 return ERR_PTR(error);
2391 out_overflow:
2392 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2393 __func__);
2394 goto out_garbage;
2395 }
2396
2397 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2398 {
2399 }
2400
2401 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2402 {
2403 return 0;
2404 }
2405
2406 static struct rpc_procinfo rpcproc_null = {
2407 .p_encode = rpcproc_encode_null,
2408 .p_decode = rpcproc_decode_null,
2409 };
2410
2411 static int rpc_ping(struct rpc_clnt *clnt)
2412 {
2413 struct rpc_message msg = {
2414 .rpc_proc = &rpcproc_null,
2415 };
2416 int err;
2417 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2418 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2419 put_rpccred(msg.rpc_cred);
2420 return err;
2421 }
2422
2423 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2424 {
2425 struct rpc_message msg = {
2426 .rpc_proc = &rpcproc_null,
2427 .rpc_cred = cred,
2428 };
2429 struct rpc_task_setup task_setup_data = {
2430 .rpc_client = clnt,
2431 .rpc_message = &msg,
2432 .callback_ops = &rpc_default_ops,
2433 .flags = flags,
2434 };
2435 return rpc_run_task(&task_setup_data);
2436 }
2437 EXPORT_SYMBOL_GPL(rpc_call_null);
2438
2439 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2440 static void rpc_show_header(void)
2441 {
2442 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2443 "-timeout ---ops--\n");
2444 }
2445
2446 static void rpc_show_task(const struct rpc_clnt *clnt,
2447 const struct rpc_task *task)
2448 {
2449 const char *rpc_waitq = "none";
2450
2451 if (RPC_IS_QUEUED(task))
2452 rpc_waitq = rpc_qname(task->tk_waitqueue);
2453
2454 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2455 task->tk_pid, task->tk_flags, task->tk_status,
2456 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2457 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2458 task->tk_action, rpc_waitq);
2459 }
2460
2461 void rpc_show_tasks(struct net *net)
2462 {
2463 struct rpc_clnt *clnt;
2464 struct rpc_task *task;
2465 int header = 0;
2466 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2467
2468 spin_lock(&sn->rpc_client_lock);
2469 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2470 spin_lock(&clnt->cl_lock);
2471 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2472 if (!header) {
2473 rpc_show_header();
2474 header++;
2475 }
2476 rpc_show_task(clnt, task);
2477 }
2478 spin_unlock(&clnt->cl_lock);
2479 }
2480 spin_unlock(&sn->rpc_client_lock);
2481 }
2482 #endif
2483
2484 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2485 int
2486 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2487 {
2488 int ret = 0;
2489 struct rpc_xprt *xprt;
2490
2491 if (atomic_inc_return(&clnt->cl_swapper) == 1) {
2492 retry:
2493 rcu_read_lock();
2494 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
2495 rcu_read_unlock();
2496 if (!xprt) {
2497 /*
2498 * If we didn't get a reference, then we likely are
2499 * racing with a migration event. Wait for a grace
2500 * period and try again.
2501 */
2502 synchronize_rcu();
2503 goto retry;
2504 }
2505
2506 ret = xprt_enable_swap(xprt);
2507 xprt_put(xprt);
2508 }
2509 return ret;
2510 }
2511 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2512
2513 void
2514 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2515 {
2516 struct rpc_xprt *xprt;
2517
2518 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) {
2519 retry:
2520 rcu_read_lock();
2521 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
2522 rcu_read_unlock();
2523 if (!xprt) {
2524 /*
2525 * If we didn't get a reference, then we likely are
2526 * racing with a migration event. Wait for a grace
2527 * period and try again.
2528 */
2529 synchronize_rcu();
2530 goto retry;
2531 }
2532
2533 xprt_disable_swap(xprt);
2534 xprt_put(xprt);
2535 }
2536 }
2537 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2538 #endif /* CONFIG_SUNRPC_SWAP */
Linux kernel - Deliverables
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