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SUNRPC: Make rpc_clnt store the multipath iterators
[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_switch *xps,
358 struct rpc_xprt *xprt,
359 struct rpc_clnt *parent)
360 {
361 const struct rpc_program *program = args->program;
362 const struct rpc_version *version;
363 struct rpc_clnt *clnt = NULL;
364 const struct rpc_timeout *timeout;
365 const char *nodename = args->nodename;
366 int err;
367
368 /* sanity check the name before trying to print it */
369 dprintk("RPC: creating %s client for %s (xprt %p)\n",
370 program->name, args->servername, xprt);
371
372 err = rpciod_up();
373 if (err)
374 goto out_no_rpciod;
375
376 err = -EINVAL;
377 if (args->version >= program->nrvers)
378 goto out_err;
379 version = program->version[args->version];
380 if (version == NULL)
381 goto out_err;
382
383 err = -ENOMEM;
384 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
385 if (!clnt)
386 goto out_err;
387 clnt->cl_parent = parent ? : clnt;
388
389 err = rpc_alloc_clid(clnt);
390 if (err)
391 goto out_no_clid;
392
393 clnt->cl_procinfo = version->procs;
394 clnt->cl_maxproc = version->nrprocs;
395 clnt->cl_prog = args->prognumber ? : program->number;
396 clnt->cl_vers = version->number;
397 clnt->cl_stats = program->stats;
398 clnt->cl_metrics = rpc_alloc_iostats(clnt);
399 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
400 err = -ENOMEM;
401 if (clnt->cl_metrics == NULL)
402 goto out_no_stats;
403 clnt->cl_program = program;
404 INIT_LIST_HEAD(&clnt->cl_tasks);
405 spin_lock_init(&clnt->cl_lock);
406
407 timeout = xprt->timeout;
408 if (args->timeout != NULL) {
409 memcpy(&clnt->cl_timeout_default, args->timeout,
410 sizeof(clnt->cl_timeout_default));
411 timeout = &clnt->cl_timeout_default;
412 }
413
414 rpc_clnt_set_transport(clnt, xprt, timeout);
415 xprt_iter_init(&clnt->cl_xpi, xps);
416 xprt_switch_put(xps);
417
418 clnt->cl_rtt = &clnt->cl_rtt_default;
419 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
420
421 atomic_set(&clnt->cl_count, 1);
422
423 if (nodename == NULL)
424 nodename = utsname()->nodename;
425 /* save the nodename */
426 rpc_clnt_set_nodename(clnt, nodename);
427
428 err = rpc_client_register(clnt, args->authflavor, args->client_name);
429 if (err)
430 goto out_no_path;
431 if (parent)
432 atomic_inc(&parent->cl_count);
433 return clnt;
434
435 out_no_path:
436 rpc_free_iostats(clnt->cl_metrics);
437 out_no_stats:
438 rpc_free_clid(clnt);
439 out_no_clid:
440 kfree(clnt);
441 out_err:
442 rpciod_down();
443 out_no_rpciod:
444 xprt_switch_put(xps);
445 xprt_put(xprt);
446 return ERR_PTR(err);
447 }
448
449 struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
450 struct rpc_xprt *xprt)
451 {
452 struct rpc_clnt *clnt = NULL;
453 struct rpc_xprt_switch *xps;
454
455 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
456 if (xps == NULL)
457 return ERR_PTR(-ENOMEM);
458
459 clnt = rpc_new_client(args, xps, xprt, NULL);
460 if (IS_ERR(clnt))
461 return clnt;
462
463 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
464 int err = rpc_ping(clnt);
465 if (err != 0) {
466 rpc_shutdown_client(clnt);
467 return ERR_PTR(err);
468 }
469 }
470
471 clnt->cl_softrtry = 1;
472 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
473 clnt->cl_softrtry = 0;
474
475 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
476 clnt->cl_autobind = 1;
477 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
478 clnt->cl_noretranstimeo = 1;
479 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
480 clnt->cl_discrtry = 1;
481 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
482 clnt->cl_chatty = 1;
483
484 return clnt;
485 }
486 EXPORT_SYMBOL_GPL(rpc_create_xprt);
487
488 /**
489 * rpc_create - create an RPC client and transport with one call
490 * @args: rpc_clnt create argument structure
491 *
492 * Creates and initializes an RPC transport and an RPC client.
493 *
494 * It can ping the server in order to determine if it is up, and to see if
495 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
496 * this behavior so asynchronous tasks can also use rpc_create.
497 */
498 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
499 {
500 struct rpc_xprt *xprt;
501 struct xprt_create xprtargs = {
502 .net = args->net,
503 .ident = args->protocol,
504 .srcaddr = args->saddress,
505 .dstaddr = args->address,
506 .addrlen = args->addrsize,
507 .servername = args->servername,
508 .bc_xprt = args->bc_xprt,
509 };
510 char servername[48];
511
512 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
513 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
514 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
515 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
516 /*
517 * If the caller chooses not to specify a hostname, whip
518 * up a string representation of the passed-in address.
519 */
520 if (xprtargs.servername == NULL) {
521 struct sockaddr_un *sun =
522 (struct sockaddr_un *)args->address;
523 struct sockaddr_in *sin =
524 (struct sockaddr_in *)args->address;
525 struct sockaddr_in6 *sin6 =
526 (struct sockaddr_in6 *)args->address;
527
528 servername[0] = '\0';
529 switch (args->address->sa_family) {
530 case AF_LOCAL:
531 snprintf(servername, sizeof(servername), "%s",
532 sun->sun_path);
533 break;
534 case AF_INET:
535 snprintf(servername, sizeof(servername), "%pI4",
536 &sin->sin_addr.s_addr);
537 break;
538 case AF_INET6:
539 snprintf(servername, sizeof(servername), "%pI6",
540 &sin6->sin6_addr);
541 break;
542 default:
543 /* caller wants default server name, but
544 * address family isn't recognized. */
545 return ERR_PTR(-EINVAL);
546 }
547 xprtargs.servername = servername;
548 }
549
550 xprt = xprt_create_transport(&xprtargs);
551 if (IS_ERR(xprt))
552 return (struct rpc_clnt *)xprt;
553
554 /*
555 * By default, kernel RPC client connects from a reserved port.
556 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
557 * but it is always enabled for rpciod, which handles the connect
558 * operation.
559 */
560 xprt->resvport = 1;
561 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
562 xprt->resvport = 0;
563
564 return rpc_create_xprt(args, xprt);
565 }
566 EXPORT_SYMBOL_GPL(rpc_create);
567
568 /*
569 * This function clones the RPC client structure. It allows us to share the
570 * same transport while varying parameters such as the authentication
571 * flavour.
572 */
573 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
574 struct rpc_clnt *clnt)
575 {
576 struct rpc_xprt_switch *xps;
577 struct rpc_xprt *xprt;
578 struct rpc_clnt *new;
579 int err;
580
581 err = -ENOMEM;
582 rcu_read_lock();
583 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
584 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
585 rcu_read_unlock();
586 if (xprt == NULL || xps == NULL) {
587 xprt_put(xprt);
588 xprt_switch_put(xps);
589 goto out_err;
590 }
591 args->servername = xprt->servername;
592 args->nodename = clnt->cl_nodename;
593
594 new = rpc_new_client(args, xps, xprt, clnt);
595 if (IS_ERR(new)) {
596 err = PTR_ERR(new);
597 goto out_err;
598 }
599
600 /* Turn off autobind on clones */
601 new->cl_autobind = 0;
602 new->cl_softrtry = clnt->cl_softrtry;
603 new->cl_noretranstimeo = clnt->cl_noretranstimeo;
604 new->cl_discrtry = clnt->cl_discrtry;
605 new->cl_chatty = clnt->cl_chatty;
606 return new;
607
608 out_err:
609 dprintk("RPC: %s: returned error %d\n", __func__, err);
610 return ERR_PTR(err);
611 }
612
613 /**
614 * rpc_clone_client - Clone an RPC client structure
615 *
616 * @clnt: RPC client whose parameters are copied
617 *
618 * Returns a fresh RPC client or an ERR_PTR.
619 */
620 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
621 {
622 struct rpc_create_args args = {
623 .program = clnt->cl_program,
624 .prognumber = clnt->cl_prog,
625 .version = clnt->cl_vers,
626 .authflavor = clnt->cl_auth->au_flavor,
627 };
628 return __rpc_clone_client(&args, clnt);
629 }
630 EXPORT_SYMBOL_GPL(rpc_clone_client);
631
632 /**
633 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
634 *
635 * @clnt: RPC client whose parameters are copied
636 * @flavor: security flavor for new client
637 *
638 * Returns a fresh RPC client or an ERR_PTR.
639 */
640 struct rpc_clnt *
641 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
642 {
643 struct rpc_create_args args = {
644 .program = clnt->cl_program,
645 .prognumber = clnt->cl_prog,
646 .version = clnt->cl_vers,
647 .authflavor = flavor,
648 };
649 return __rpc_clone_client(&args, clnt);
650 }
651 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
652
653 /**
654 * rpc_switch_client_transport: switch the RPC transport on the fly
655 * @clnt: pointer to a struct rpc_clnt
656 * @args: pointer to the new transport arguments
657 * @timeout: pointer to the new timeout parameters
658 *
659 * This function allows the caller to switch the RPC transport for the
660 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
661 * server, for instance. It assumes that the caller has ensured that
662 * there are no active RPC tasks by using some form of locking.
663 *
664 * Returns zero if "clnt" is now using the new xprt. Otherwise a
665 * negative errno is returned, and "clnt" continues to use the old
666 * xprt.
667 */
668 int rpc_switch_client_transport(struct rpc_clnt *clnt,
669 struct xprt_create *args,
670 const struct rpc_timeout *timeout)
671 {
672 const struct rpc_timeout *old_timeo;
673 rpc_authflavor_t pseudoflavor;
674 struct rpc_xprt_switch *xps, *oldxps;
675 struct rpc_xprt *xprt, *old;
676 struct rpc_clnt *parent;
677 int err;
678
679 xprt = xprt_create_transport(args);
680 if (IS_ERR(xprt)) {
681 dprintk("RPC: failed to create new xprt for clnt %p\n",
682 clnt);
683 return PTR_ERR(xprt);
684 }
685
686 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
687 if (xps == NULL) {
688 xprt_put(xprt);
689 return -ENOMEM;
690 }
691
692 pseudoflavor = clnt->cl_auth->au_flavor;
693
694 old_timeo = clnt->cl_timeout;
695 old = rpc_clnt_set_transport(clnt, xprt, timeout);
696 oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
697
698 rpc_unregister_client(clnt);
699 __rpc_clnt_remove_pipedir(clnt);
700 rpc_clnt_debugfs_unregister(clnt);
701
702 /*
703 * A new transport was created. "clnt" therefore
704 * becomes the root of a new cl_parent tree. clnt's
705 * children, if it has any, still point to the old xprt.
706 */
707 parent = clnt->cl_parent;
708 clnt->cl_parent = clnt;
709
710 /*
711 * The old rpc_auth cache cannot be re-used. GSS
712 * contexts in particular are between a single
713 * client and server.
714 */
715 err = rpc_client_register(clnt, pseudoflavor, NULL);
716 if (err)
717 goto out_revert;
718
719 synchronize_rcu();
720 if (parent != clnt)
721 rpc_release_client(parent);
722 xprt_switch_put(oldxps);
723 xprt_put(old);
724 dprintk("RPC: replaced xprt for clnt %p\n", clnt);
725 return 0;
726
727 out_revert:
728 xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
729 rpc_clnt_set_transport(clnt, old, old_timeo);
730 clnt->cl_parent = parent;
731 rpc_client_register(clnt, pseudoflavor, NULL);
732 xprt_switch_put(xps);
733 xprt_put(xprt);
734 dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
735 return err;
736 }
737 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
738
739 /*
740 * Kill all tasks for the given client.
741 * XXX: kill their descendants as well?
742 */
743 void rpc_killall_tasks(struct rpc_clnt *clnt)
744 {
745 struct rpc_task *rovr;
746
747
748 if (list_empty(&clnt->cl_tasks))
749 return;
750 dprintk("RPC: killing all tasks for client %p\n", clnt);
751 /*
752 * Spin lock all_tasks to prevent changes...
753 */
754 spin_lock(&clnt->cl_lock);
755 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
756 if (!RPC_IS_ACTIVATED(rovr))
757 continue;
758 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
759 rovr->tk_flags |= RPC_TASK_KILLED;
760 rpc_exit(rovr, -EIO);
761 if (RPC_IS_QUEUED(rovr))
762 rpc_wake_up_queued_task(rovr->tk_waitqueue,
763 rovr);
764 }
765 }
766 spin_unlock(&clnt->cl_lock);
767 }
768 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
769
770 /*
771 * Properly shut down an RPC client, terminating all outstanding
772 * requests.
773 */
774 void rpc_shutdown_client(struct rpc_clnt *clnt)
775 {
776 might_sleep();
777
778 dprintk_rcu("RPC: shutting down %s client for %s\n",
779 clnt->cl_program->name,
780 rcu_dereference(clnt->cl_xprt)->servername);
781
782 while (!list_empty(&clnt->cl_tasks)) {
783 rpc_killall_tasks(clnt);
784 wait_event_timeout(destroy_wait,
785 list_empty(&clnt->cl_tasks), 1*HZ);
786 }
787
788 rpc_release_client(clnt);
789 }
790 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
791
792 /*
793 * Free an RPC client
794 */
795 static struct rpc_clnt *
796 rpc_free_client(struct rpc_clnt *clnt)
797 {
798 struct rpc_clnt *parent = NULL;
799
800 dprintk_rcu("RPC: destroying %s client for %s\n",
801 clnt->cl_program->name,
802 rcu_dereference(clnt->cl_xprt)->servername);
803 if (clnt->cl_parent != clnt)
804 parent = clnt->cl_parent;
805 rpc_clnt_debugfs_unregister(clnt);
806 rpc_clnt_remove_pipedir(clnt);
807 rpc_unregister_client(clnt);
808 rpc_free_iostats(clnt->cl_metrics);
809 clnt->cl_metrics = NULL;
810 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
811 xprt_iter_destroy(&clnt->cl_xpi);
812 rpciod_down();
813 rpc_free_clid(clnt);
814 kfree(clnt);
815 return parent;
816 }
817
818 /*
819 * Free an RPC client
820 */
821 static struct rpc_clnt *
822 rpc_free_auth(struct rpc_clnt *clnt)
823 {
824 if (clnt->cl_auth == NULL)
825 return rpc_free_client(clnt);
826
827 /*
828 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
829 * release remaining GSS contexts. This mechanism ensures
830 * that it can do so safely.
831 */
832 atomic_inc(&clnt->cl_count);
833 rpcauth_release(clnt->cl_auth);
834 clnt->cl_auth = NULL;
835 if (atomic_dec_and_test(&clnt->cl_count))
836 return rpc_free_client(clnt);
837 return NULL;
838 }
839
840 /*
841 * Release reference to the RPC client
842 */
843 void
844 rpc_release_client(struct rpc_clnt *clnt)
845 {
846 dprintk("RPC: rpc_release_client(%p)\n", clnt);
847
848 do {
849 if (list_empty(&clnt->cl_tasks))
850 wake_up(&destroy_wait);
851 if (!atomic_dec_and_test(&clnt->cl_count))
852 break;
853 clnt = rpc_free_auth(clnt);
854 } while (clnt != NULL);
855 }
856 EXPORT_SYMBOL_GPL(rpc_release_client);
857
858 /**
859 * rpc_bind_new_program - bind a new RPC program to an existing client
860 * @old: old rpc_client
861 * @program: rpc program to set
862 * @vers: rpc program version
863 *
864 * Clones the rpc client and sets up a new RPC program. This is mainly
865 * of use for enabling different RPC programs to share the same transport.
866 * The Sun NFSv2/v3 ACL protocol can do this.
867 */
868 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
869 const struct rpc_program *program,
870 u32 vers)
871 {
872 struct rpc_create_args args = {
873 .program = program,
874 .prognumber = program->number,
875 .version = vers,
876 .authflavor = old->cl_auth->au_flavor,
877 };
878 struct rpc_clnt *clnt;
879 int err;
880
881 clnt = __rpc_clone_client(&args, old);
882 if (IS_ERR(clnt))
883 goto out;
884 err = rpc_ping(clnt);
885 if (err != 0) {
886 rpc_shutdown_client(clnt);
887 clnt = ERR_PTR(err);
888 }
889 out:
890 return clnt;
891 }
892 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
893
894 void rpc_task_release_client(struct rpc_task *task)
895 {
896 struct rpc_clnt *clnt = task->tk_client;
897
898 if (clnt != NULL) {
899 /* Remove from client task list */
900 spin_lock(&clnt->cl_lock);
901 list_del(&task->tk_task);
902 spin_unlock(&clnt->cl_lock);
903 task->tk_client = NULL;
904
905 rpc_release_client(clnt);
906 }
907 }
908
909 static
910 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
911 {
912 if (clnt != NULL) {
913 rpc_task_release_client(task);
914 task->tk_client = clnt;
915 atomic_inc(&clnt->cl_count);
916 if (clnt->cl_softrtry)
917 task->tk_flags |= RPC_TASK_SOFT;
918 if (clnt->cl_noretranstimeo)
919 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
920 if (atomic_read(&clnt->cl_swapper))
921 task->tk_flags |= RPC_TASK_SWAPPER;
922 /* Add to the client's list of all tasks */
923 spin_lock(&clnt->cl_lock);
924 list_add_tail(&task->tk_task, &clnt->cl_tasks);
925 spin_unlock(&clnt->cl_lock);
926 }
927 }
928
929 static void
930 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
931 {
932 if (msg != NULL) {
933 task->tk_msg.rpc_proc = msg->rpc_proc;
934 task->tk_msg.rpc_argp = msg->rpc_argp;
935 task->tk_msg.rpc_resp = msg->rpc_resp;
936 if (msg->rpc_cred != NULL)
937 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
938 }
939 }
940
941 /*
942 * Default callback for async RPC calls
943 */
944 static void
945 rpc_default_callback(struct rpc_task *task, void *data)
946 {
947 }
948
949 static const struct rpc_call_ops rpc_default_ops = {
950 .rpc_call_done = rpc_default_callback,
951 };
952
953 /**
954 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
955 * @task_setup_data: pointer to task initialisation data
956 */
957 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
958 {
959 struct rpc_task *task;
960
961 task = rpc_new_task(task_setup_data);
962 if (IS_ERR(task))
963 goto out;
964
965 rpc_task_set_client(task, task_setup_data->rpc_client);
966 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
967
968 if (task->tk_action == NULL)
969 rpc_call_start(task);
970
971 atomic_inc(&task->tk_count);
972 rpc_execute(task);
973 out:
974 return task;
975 }
976 EXPORT_SYMBOL_GPL(rpc_run_task);
977
978 /**
979 * rpc_call_sync - Perform a synchronous RPC call
980 * @clnt: pointer to RPC client
981 * @msg: RPC call parameters
982 * @flags: RPC call flags
983 */
984 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
985 {
986 struct rpc_task *task;
987 struct rpc_task_setup task_setup_data = {
988 .rpc_client = clnt,
989 .rpc_message = msg,
990 .callback_ops = &rpc_default_ops,
991 .flags = flags,
992 };
993 int status;
994
995 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
996 if (flags & RPC_TASK_ASYNC) {
997 rpc_release_calldata(task_setup_data.callback_ops,
998 task_setup_data.callback_data);
999 return -EINVAL;
1000 }
1001
1002 task = rpc_run_task(&task_setup_data);
1003 if (IS_ERR(task))
1004 return PTR_ERR(task);
1005 status = task->tk_status;
1006 rpc_put_task(task);
1007 return status;
1008 }
1009 EXPORT_SYMBOL_GPL(rpc_call_sync);
1010
1011 /**
1012 * rpc_call_async - Perform an asynchronous RPC call
1013 * @clnt: pointer to RPC client
1014 * @msg: RPC call parameters
1015 * @flags: RPC call flags
1016 * @tk_ops: RPC call ops
1017 * @data: user call data
1018 */
1019 int
1020 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1021 const struct rpc_call_ops *tk_ops, void *data)
1022 {
1023 struct rpc_task *task;
1024 struct rpc_task_setup task_setup_data = {
1025 .rpc_client = clnt,
1026 .rpc_message = msg,
1027 .callback_ops = tk_ops,
1028 .callback_data = data,
1029 .flags = flags|RPC_TASK_ASYNC,
1030 };
1031
1032 task = rpc_run_task(&task_setup_data);
1033 if (IS_ERR(task))
1034 return PTR_ERR(task);
1035 rpc_put_task(task);
1036 return 0;
1037 }
1038 EXPORT_SYMBOL_GPL(rpc_call_async);
1039
1040 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1041 /**
1042 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1043 * rpc_execute against it
1044 * @req: RPC request
1045 */
1046 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1047 {
1048 struct rpc_task *task;
1049 struct xdr_buf *xbufp = &req->rq_snd_buf;
1050 struct rpc_task_setup task_setup_data = {
1051 .callback_ops = &rpc_default_ops,
1052 .flags = RPC_TASK_SOFTCONN,
1053 };
1054
1055 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1056 /*
1057 * Create an rpc_task to send the data
1058 */
1059 task = rpc_new_task(&task_setup_data);
1060 if (IS_ERR(task)) {
1061 xprt_free_bc_request(req);
1062 goto out;
1063 }
1064 task->tk_rqstp = req;
1065
1066 /*
1067 * Set up the xdr_buf length.
1068 * This also indicates that the buffer is XDR encoded already.
1069 */
1070 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1071 xbufp->tail[0].iov_len;
1072
1073 task->tk_action = call_bc_transmit;
1074 atomic_inc(&task->tk_count);
1075 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1076 rpc_execute(task);
1077
1078 out:
1079 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1080 return task;
1081 }
1082 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1083
1084 void
1085 rpc_call_start(struct rpc_task *task)
1086 {
1087 task->tk_action = call_start;
1088 }
1089 EXPORT_SYMBOL_GPL(rpc_call_start);
1090
1091 /**
1092 * rpc_peeraddr - extract remote peer address from clnt's xprt
1093 * @clnt: RPC client structure
1094 * @buf: target buffer
1095 * @bufsize: length of target buffer
1096 *
1097 * Returns the number of bytes that are actually in the stored address.
1098 */
1099 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1100 {
1101 size_t bytes;
1102 struct rpc_xprt *xprt;
1103
1104 rcu_read_lock();
1105 xprt = rcu_dereference(clnt->cl_xprt);
1106
1107 bytes = xprt->addrlen;
1108 if (bytes > bufsize)
1109 bytes = bufsize;
1110 memcpy(buf, &xprt->addr, bytes);
1111 rcu_read_unlock();
1112
1113 return bytes;
1114 }
1115 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1116
1117 /**
1118 * rpc_peeraddr2str - return remote peer address in printable format
1119 * @clnt: RPC client structure
1120 * @format: address format
1121 *
1122 * NB: the lifetime of the memory referenced by the returned pointer is
1123 * the same as the rpc_xprt itself. As long as the caller uses this
1124 * pointer, it must hold the RCU read lock.
1125 */
1126 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1127 enum rpc_display_format_t format)
1128 {
1129 struct rpc_xprt *xprt;
1130
1131 xprt = rcu_dereference(clnt->cl_xprt);
1132
1133 if (xprt->address_strings[format] != NULL)
1134 return xprt->address_strings[format];
1135 else
1136 return "unprintable";
1137 }
1138 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1139
1140 static const struct sockaddr_in rpc_inaddr_loopback = {
1141 .sin_family = AF_INET,
1142 .sin_addr.s_addr = htonl(INADDR_ANY),
1143 };
1144
1145 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1146 .sin6_family = AF_INET6,
1147 .sin6_addr = IN6ADDR_ANY_INIT,
1148 };
1149
1150 /*
1151 * Try a getsockname() on a connected datagram socket. Using a
1152 * connected datagram socket prevents leaving a socket in TIME_WAIT.
1153 * This conserves the ephemeral port number space.
1154 *
1155 * Returns zero and fills in "buf" if successful; otherwise, a
1156 * negative errno is returned.
1157 */
1158 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1159 struct sockaddr *buf, int buflen)
1160 {
1161 struct socket *sock;
1162 int err;
1163
1164 err = __sock_create(net, sap->sa_family,
1165 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1166 if (err < 0) {
1167 dprintk("RPC: can't create UDP socket (%d)\n", err);
1168 goto out;
1169 }
1170
1171 switch (sap->sa_family) {
1172 case AF_INET:
1173 err = kernel_bind(sock,
1174 (struct sockaddr *)&rpc_inaddr_loopback,
1175 sizeof(rpc_inaddr_loopback));
1176 break;
1177 case AF_INET6:
1178 err = kernel_bind(sock,
1179 (struct sockaddr *)&rpc_in6addr_loopback,
1180 sizeof(rpc_in6addr_loopback));
1181 break;
1182 default:
1183 err = -EAFNOSUPPORT;
1184 goto out;
1185 }
1186 if (err < 0) {
1187 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1188 goto out_release;
1189 }
1190
1191 err = kernel_connect(sock, sap, salen, 0);
1192 if (err < 0) {
1193 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1194 goto out_release;
1195 }
1196
1197 err = kernel_getsockname(sock, buf, &buflen);
1198 if (err < 0) {
1199 dprintk("RPC: getsockname failed (%d)\n", err);
1200 goto out_release;
1201 }
1202
1203 err = 0;
1204 if (buf->sa_family == AF_INET6) {
1205 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1206 sin6->sin6_scope_id = 0;
1207 }
1208 dprintk("RPC: %s succeeded\n", __func__);
1209
1210 out_release:
1211 sock_release(sock);
1212 out:
1213 return err;
1214 }
1215
1216 /*
1217 * Scraping a connected socket failed, so we don't have a useable
1218 * local address. Fallback: generate an address that will prevent
1219 * the server from calling us back.
1220 *
1221 * Returns zero and fills in "buf" if successful; otherwise, a
1222 * negative errno is returned.
1223 */
1224 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1225 {
1226 switch (family) {
1227 case AF_INET:
1228 if (buflen < sizeof(rpc_inaddr_loopback))
1229 return -EINVAL;
1230 memcpy(buf, &rpc_inaddr_loopback,
1231 sizeof(rpc_inaddr_loopback));
1232 break;
1233 case AF_INET6:
1234 if (buflen < sizeof(rpc_in6addr_loopback))
1235 return -EINVAL;
1236 memcpy(buf, &rpc_in6addr_loopback,
1237 sizeof(rpc_in6addr_loopback));
1238 break;
1239 default:
1240 dprintk("RPC: %s: address family not supported\n",
1241 __func__);
1242 return -EAFNOSUPPORT;
1243 }
1244 dprintk("RPC: %s: succeeded\n", __func__);
1245 return 0;
1246 }
1247
1248 /**
1249 * rpc_localaddr - discover local endpoint address for an RPC client
1250 * @clnt: RPC client structure
1251 * @buf: target buffer
1252 * @buflen: size of target buffer, in bytes
1253 *
1254 * Returns zero and fills in "buf" and "buflen" if successful;
1255 * otherwise, a negative errno is returned.
1256 *
1257 * This works even if the underlying transport is not currently connected,
1258 * or if the upper layer never previously provided a source address.
1259 *
1260 * The result of this function call is transient: multiple calls in
1261 * succession may give different results, depending on how local
1262 * networking configuration changes over time.
1263 */
1264 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1265 {
1266 struct sockaddr_storage address;
1267 struct sockaddr *sap = (struct sockaddr *)&address;
1268 struct rpc_xprt *xprt;
1269 struct net *net;
1270 size_t salen;
1271 int err;
1272
1273 rcu_read_lock();
1274 xprt = rcu_dereference(clnt->cl_xprt);
1275 salen = xprt->addrlen;
1276 memcpy(sap, &xprt->addr, salen);
1277 net = get_net(xprt->xprt_net);
1278 rcu_read_unlock();
1279
1280 rpc_set_port(sap, 0);
1281 err = rpc_sockname(net, sap, salen, buf, buflen);
1282 put_net(net);
1283 if (err != 0)
1284 /* Couldn't discover local address, return ANYADDR */
1285 return rpc_anyaddr(sap->sa_family, buf, buflen);
1286 return 0;
1287 }
1288 EXPORT_SYMBOL_GPL(rpc_localaddr);
1289
1290 void
1291 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1292 {
1293 struct rpc_xprt *xprt;
1294
1295 rcu_read_lock();
1296 xprt = rcu_dereference(clnt->cl_xprt);
1297 if (xprt->ops->set_buffer_size)
1298 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1299 rcu_read_unlock();
1300 }
1301 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1302
1303 /**
1304 * rpc_protocol - Get transport protocol number for an RPC client
1305 * @clnt: RPC client to query
1306 *
1307 */
1308 int rpc_protocol(struct rpc_clnt *clnt)
1309 {
1310 int protocol;
1311
1312 rcu_read_lock();
1313 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1314 rcu_read_unlock();
1315 return protocol;
1316 }
1317 EXPORT_SYMBOL_GPL(rpc_protocol);
1318
1319 /**
1320 * rpc_net_ns - Get the network namespace for this RPC client
1321 * @clnt: RPC client to query
1322 *
1323 */
1324 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1325 {
1326 struct net *ret;
1327
1328 rcu_read_lock();
1329 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1330 rcu_read_unlock();
1331 return ret;
1332 }
1333 EXPORT_SYMBOL_GPL(rpc_net_ns);
1334
1335 /**
1336 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1337 * @clnt: RPC client to query
1338 *
1339 * For stream transports, this is one RPC record fragment (see RFC
1340 * 1831), as we don't support multi-record requests yet. For datagram
1341 * transports, this is the size of an IP packet minus the IP, UDP, and
1342 * RPC header sizes.
1343 */
1344 size_t rpc_max_payload(struct rpc_clnt *clnt)
1345 {
1346 size_t ret;
1347
1348 rcu_read_lock();
1349 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1350 rcu_read_unlock();
1351 return ret;
1352 }
1353 EXPORT_SYMBOL_GPL(rpc_max_payload);
1354
1355 /**
1356 * rpc_get_timeout - Get timeout for transport in units of HZ
1357 * @clnt: RPC client to query
1358 */
1359 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1360 {
1361 unsigned long ret;
1362
1363 rcu_read_lock();
1364 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1365 rcu_read_unlock();
1366 return ret;
1367 }
1368 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1369
1370 /**
1371 * rpc_force_rebind - force transport to check that remote port is unchanged
1372 * @clnt: client to rebind
1373 *
1374 */
1375 void rpc_force_rebind(struct rpc_clnt *clnt)
1376 {
1377 if (clnt->cl_autobind) {
1378 rcu_read_lock();
1379 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1380 rcu_read_unlock();
1381 }
1382 }
1383 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1384
1385 /*
1386 * Restart an (async) RPC call from the call_prepare state.
1387 * Usually called from within the exit handler.
1388 */
1389 int
1390 rpc_restart_call_prepare(struct rpc_task *task)
1391 {
1392 if (RPC_ASSASSINATED(task))
1393 return 0;
1394 task->tk_action = call_start;
1395 task->tk_status = 0;
1396 if (task->tk_ops->rpc_call_prepare != NULL)
1397 task->tk_action = rpc_prepare_task;
1398 return 1;
1399 }
1400 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1401
1402 /*
1403 * Restart an (async) RPC call. Usually called from within the
1404 * exit handler.
1405 */
1406 int
1407 rpc_restart_call(struct rpc_task *task)
1408 {
1409 if (RPC_ASSASSINATED(task))
1410 return 0;
1411 task->tk_action = call_start;
1412 task->tk_status = 0;
1413 return 1;
1414 }
1415 EXPORT_SYMBOL_GPL(rpc_restart_call);
1416
1417 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1418 const char
1419 *rpc_proc_name(const struct rpc_task *task)
1420 {
1421 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1422
1423 if (proc) {
1424 if (proc->p_name)
1425 return proc->p_name;
1426 else
1427 return "NULL";
1428 } else
1429 return "no proc";
1430 }
1431 #endif
1432
1433 /*
1434 * 0. Initial state
1435 *
1436 * Other FSM states can be visited zero or more times, but
1437 * this state is visited exactly once for each RPC.
1438 */
1439 static void
1440 call_start(struct rpc_task *task)
1441 {
1442 struct rpc_clnt *clnt = task->tk_client;
1443
1444 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1445 clnt->cl_program->name, clnt->cl_vers,
1446 rpc_proc_name(task),
1447 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1448
1449 /* Increment call count */
1450 task->tk_msg.rpc_proc->p_count++;
1451 clnt->cl_stats->rpccnt++;
1452 task->tk_action = call_reserve;
1453 }
1454
1455 /*
1456 * 1. Reserve an RPC call slot
1457 */
1458 static void
1459 call_reserve(struct rpc_task *task)
1460 {
1461 dprint_status(task);
1462
1463 task->tk_status = 0;
1464 task->tk_action = call_reserveresult;
1465 xprt_reserve(task);
1466 }
1467
1468 static void call_retry_reserve(struct rpc_task *task);
1469
1470 /*
1471 * 1b. Grok the result of xprt_reserve()
1472 */
1473 static void
1474 call_reserveresult(struct rpc_task *task)
1475 {
1476 int status = task->tk_status;
1477
1478 dprint_status(task);
1479
1480 /*
1481 * After a call to xprt_reserve(), we must have either
1482 * a request slot or else an error status.
1483 */
1484 task->tk_status = 0;
1485 if (status >= 0) {
1486 if (task->tk_rqstp) {
1487 task->tk_action = call_refresh;
1488 return;
1489 }
1490
1491 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1492 __func__, status);
1493 rpc_exit(task, -EIO);
1494 return;
1495 }
1496
1497 /*
1498 * Even though there was an error, we may have acquired
1499 * a request slot somehow. Make sure not to leak it.
1500 */
1501 if (task->tk_rqstp) {
1502 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1503 __func__, status);
1504 xprt_release(task);
1505 }
1506
1507 switch (status) {
1508 case -ENOMEM:
1509 rpc_delay(task, HZ >> 2);
1510 case -EAGAIN: /* woken up; retry */
1511 task->tk_action = call_retry_reserve;
1512 return;
1513 case -EIO: /* probably a shutdown */
1514 break;
1515 default:
1516 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1517 __func__, status);
1518 break;
1519 }
1520 rpc_exit(task, status);
1521 }
1522
1523 /*
1524 * 1c. Retry reserving an RPC call slot
1525 */
1526 static void
1527 call_retry_reserve(struct rpc_task *task)
1528 {
1529 dprint_status(task);
1530
1531 task->tk_status = 0;
1532 task->tk_action = call_reserveresult;
1533 xprt_retry_reserve(task);
1534 }
1535
1536 /*
1537 * 2. Bind and/or refresh the credentials
1538 */
1539 static void
1540 call_refresh(struct rpc_task *task)
1541 {
1542 dprint_status(task);
1543
1544 task->tk_action = call_refreshresult;
1545 task->tk_status = 0;
1546 task->tk_client->cl_stats->rpcauthrefresh++;
1547 rpcauth_refreshcred(task);
1548 }
1549
1550 /*
1551 * 2a. Process the results of a credential refresh
1552 */
1553 static void
1554 call_refreshresult(struct rpc_task *task)
1555 {
1556 int status = task->tk_status;
1557
1558 dprint_status(task);
1559
1560 task->tk_status = 0;
1561 task->tk_action = call_refresh;
1562 switch (status) {
1563 case 0:
1564 if (rpcauth_uptodatecred(task)) {
1565 task->tk_action = call_allocate;
1566 return;
1567 }
1568 /* Use rate-limiting and a max number of retries if refresh
1569 * had status 0 but failed to update the cred.
1570 */
1571 case -ETIMEDOUT:
1572 rpc_delay(task, 3*HZ);
1573 case -EAGAIN:
1574 status = -EACCES;
1575 case -EKEYEXPIRED:
1576 if (!task->tk_cred_retry)
1577 break;
1578 task->tk_cred_retry--;
1579 dprintk("RPC: %5u %s: retry refresh creds\n",
1580 task->tk_pid, __func__);
1581 return;
1582 }
1583 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1584 task->tk_pid, __func__, status);
1585 rpc_exit(task, status);
1586 }
1587
1588 /*
1589 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1590 * (Note: buffer memory is freed in xprt_release).
1591 */
1592 static void
1593 call_allocate(struct rpc_task *task)
1594 {
1595 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1596 struct rpc_rqst *req = task->tk_rqstp;
1597 struct rpc_xprt *xprt = req->rq_xprt;
1598 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1599
1600 dprint_status(task);
1601
1602 task->tk_status = 0;
1603 task->tk_action = call_bind;
1604
1605 if (req->rq_buffer)
1606 return;
1607
1608 if (proc->p_proc != 0) {
1609 BUG_ON(proc->p_arglen == 0);
1610 if (proc->p_decode != NULL)
1611 BUG_ON(proc->p_replen == 0);
1612 }
1613
1614 /*
1615 * Calculate the size (in quads) of the RPC call
1616 * and reply headers, and convert both values
1617 * to byte sizes.
1618 */
1619 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1620 req->rq_callsize <<= 2;
1621 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1622 req->rq_rcvsize <<= 2;
1623
1624 req->rq_buffer = xprt->ops->buf_alloc(task,
1625 req->rq_callsize + req->rq_rcvsize);
1626 if (req->rq_buffer != NULL)
1627 return;
1628 xprt_inject_disconnect(xprt);
1629
1630 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1631
1632 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1633 task->tk_action = call_allocate;
1634 rpc_delay(task, HZ>>4);
1635 return;
1636 }
1637
1638 rpc_exit(task, -ERESTARTSYS);
1639 }
1640
1641 static inline int
1642 rpc_task_need_encode(struct rpc_task *task)
1643 {
1644 return task->tk_rqstp->rq_snd_buf.len == 0;
1645 }
1646
1647 static inline void
1648 rpc_task_force_reencode(struct rpc_task *task)
1649 {
1650 task->tk_rqstp->rq_snd_buf.len = 0;
1651 task->tk_rqstp->rq_bytes_sent = 0;
1652 }
1653
1654 static inline void
1655 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1656 {
1657 buf->head[0].iov_base = start;
1658 buf->head[0].iov_len = len;
1659 buf->tail[0].iov_len = 0;
1660 buf->page_len = 0;
1661 buf->flags = 0;
1662 buf->len = 0;
1663 buf->buflen = len;
1664 }
1665
1666 /*
1667 * 3. Encode arguments of an RPC call
1668 */
1669 static void
1670 rpc_xdr_encode(struct rpc_task *task)
1671 {
1672 struct rpc_rqst *req = task->tk_rqstp;
1673 kxdreproc_t encode;
1674 __be32 *p;
1675
1676 dprint_status(task);
1677
1678 rpc_xdr_buf_init(&req->rq_snd_buf,
1679 req->rq_buffer,
1680 req->rq_callsize);
1681 rpc_xdr_buf_init(&req->rq_rcv_buf,
1682 (char *)req->rq_buffer + req->rq_callsize,
1683 req->rq_rcvsize);
1684
1685 p = rpc_encode_header(task);
1686 if (p == NULL) {
1687 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1688 rpc_exit(task, -EIO);
1689 return;
1690 }
1691
1692 encode = task->tk_msg.rpc_proc->p_encode;
1693 if (encode == NULL)
1694 return;
1695
1696 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1697 task->tk_msg.rpc_argp);
1698 }
1699
1700 /*
1701 * 4. Get the server port number if not yet set
1702 */
1703 static void
1704 call_bind(struct rpc_task *task)
1705 {
1706 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1707
1708 dprint_status(task);
1709
1710 task->tk_action = call_connect;
1711 if (!xprt_bound(xprt)) {
1712 task->tk_action = call_bind_status;
1713 task->tk_timeout = xprt->bind_timeout;
1714 xprt->ops->rpcbind(task);
1715 }
1716 }
1717
1718 /*
1719 * 4a. Sort out bind result
1720 */
1721 static void
1722 call_bind_status(struct rpc_task *task)
1723 {
1724 int status = -EIO;
1725
1726 if (task->tk_status >= 0) {
1727 dprint_status(task);
1728 task->tk_status = 0;
1729 task->tk_action = call_connect;
1730 return;
1731 }
1732
1733 trace_rpc_bind_status(task);
1734 switch (task->tk_status) {
1735 case -ENOMEM:
1736 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1737 rpc_delay(task, HZ >> 2);
1738 goto retry_timeout;
1739 case -EACCES:
1740 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1741 "unavailable\n", task->tk_pid);
1742 /* fail immediately if this is an RPC ping */
1743 if (task->tk_msg.rpc_proc->p_proc == 0) {
1744 status = -EOPNOTSUPP;
1745 break;
1746 }
1747 if (task->tk_rebind_retry == 0)
1748 break;
1749 task->tk_rebind_retry--;
1750 rpc_delay(task, 3*HZ);
1751 goto retry_timeout;
1752 case -ETIMEDOUT:
1753 dprintk("RPC: %5u rpcbind request timed out\n",
1754 task->tk_pid);
1755 goto retry_timeout;
1756 case -EPFNOSUPPORT:
1757 /* server doesn't support any rpcbind version we know of */
1758 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1759 task->tk_pid);
1760 break;
1761 case -EPROTONOSUPPORT:
1762 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1763 task->tk_pid);
1764 goto retry_timeout;
1765 case -ECONNREFUSED: /* connection problems */
1766 case -ECONNRESET:
1767 case -ECONNABORTED:
1768 case -ENOTCONN:
1769 case -EHOSTDOWN:
1770 case -EHOSTUNREACH:
1771 case -ENETUNREACH:
1772 case -ENOBUFS:
1773 case -EPIPE:
1774 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1775 task->tk_pid, task->tk_status);
1776 if (!RPC_IS_SOFTCONN(task)) {
1777 rpc_delay(task, 5*HZ);
1778 goto retry_timeout;
1779 }
1780 status = task->tk_status;
1781 break;
1782 default:
1783 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1784 task->tk_pid, -task->tk_status);
1785 }
1786
1787 rpc_exit(task, status);
1788 return;
1789
1790 retry_timeout:
1791 task->tk_status = 0;
1792 task->tk_action = call_timeout;
1793 }
1794
1795 /*
1796 * 4b. Connect to the RPC server
1797 */
1798 static void
1799 call_connect(struct rpc_task *task)
1800 {
1801 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1802
1803 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1804 task->tk_pid, xprt,
1805 (xprt_connected(xprt) ? "is" : "is not"));
1806
1807 task->tk_action = call_transmit;
1808 if (!xprt_connected(xprt)) {
1809 task->tk_action = call_connect_status;
1810 if (task->tk_status < 0)
1811 return;
1812 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1813 rpc_exit(task, -ENOTCONN);
1814 return;
1815 }
1816 xprt_connect(task);
1817 }
1818 }
1819
1820 /*
1821 * 4c. Sort out connect result
1822 */
1823 static void
1824 call_connect_status(struct rpc_task *task)
1825 {
1826 struct rpc_clnt *clnt = task->tk_client;
1827 int status = task->tk_status;
1828
1829 dprint_status(task);
1830
1831 trace_rpc_connect_status(task, status);
1832 task->tk_status = 0;
1833 switch (status) {
1834 case -ECONNREFUSED:
1835 case -ECONNRESET:
1836 case -ECONNABORTED:
1837 case -ENETUNREACH:
1838 case -EHOSTUNREACH:
1839 case -EADDRINUSE:
1840 case -ENOBUFS:
1841 case -EPIPE:
1842 if (RPC_IS_SOFTCONN(task))
1843 break;
1844 /* retry with existing socket, after a delay */
1845 rpc_delay(task, 3*HZ);
1846 case -EAGAIN:
1847 /* Check for timeouts before looping back to call_bind */
1848 case -ETIMEDOUT:
1849 task->tk_action = call_timeout;
1850 return;
1851 case 0:
1852 clnt->cl_stats->netreconn++;
1853 task->tk_action = call_transmit;
1854 return;
1855 }
1856 rpc_exit(task, status);
1857 }
1858
1859 /*
1860 * 5. Transmit the RPC request, and wait for reply
1861 */
1862 static void
1863 call_transmit(struct rpc_task *task)
1864 {
1865 int is_retrans = RPC_WAS_SENT(task);
1866
1867 dprint_status(task);
1868
1869 task->tk_action = call_status;
1870 if (task->tk_status < 0)
1871 return;
1872 if (!xprt_prepare_transmit(task))
1873 return;
1874 task->tk_action = call_transmit_status;
1875 /* Encode here so that rpcsec_gss can use correct sequence number. */
1876 if (rpc_task_need_encode(task)) {
1877 rpc_xdr_encode(task);
1878 /* Did the encode result in an error condition? */
1879 if (task->tk_status != 0) {
1880 /* Was the error nonfatal? */
1881 if (task->tk_status == -EAGAIN)
1882 rpc_delay(task, HZ >> 4);
1883 else
1884 rpc_exit(task, task->tk_status);
1885 return;
1886 }
1887 }
1888 xprt_transmit(task);
1889 if (task->tk_status < 0)
1890 return;
1891 if (is_retrans)
1892 task->tk_client->cl_stats->rpcretrans++;
1893 /*
1894 * On success, ensure that we call xprt_end_transmit() before sleeping
1895 * in order to allow access to the socket to other RPC requests.
1896 */
1897 call_transmit_status(task);
1898 if (rpc_reply_expected(task))
1899 return;
1900 task->tk_action = rpc_exit_task;
1901 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1902 }
1903
1904 /*
1905 * 5a. Handle cleanup after a transmission
1906 */
1907 static void
1908 call_transmit_status(struct rpc_task *task)
1909 {
1910 task->tk_action = call_status;
1911
1912 /*
1913 * Common case: success. Force the compiler to put this
1914 * test first.
1915 */
1916 if (task->tk_status == 0) {
1917 xprt_end_transmit(task);
1918 rpc_task_force_reencode(task);
1919 return;
1920 }
1921
1922 switch (task->tk_status) {
1923 case -EAGAIN:
1924 case -ENOBUFS:
1925 break;
1926 default:
1927 dprint_status(task);
1928 xprt_end_transmit(task);
1929 rpc_task_force_reencode(task);
1930 break;
1931 /*
1932 * Special cases: if we've been waiting on the
1933 * socket's write_space() callback, or if the
1934 * socket just returned a connection error,
1935 * then hold onto the transport lock.
1936 */
1937 case -ECONNREFUSED:
1938 case -EHOSTDOWN:
1939 case -EHOSTUNREACH:
1940 case -ENETUNREACH:
1941 case -EPERM:
1942 if (RPC_IS_SOFTCONN(task)) {
1943 xprt_end_transmit(task);
1944 rpc_exit(task, task->tk_status);
1945 break;
1946 }
1947 case -ECONNRESET:
1948 case -ECONNABORTED:
1949 case -EADDRINUSE:
1950 case -ENOTCONN:
1951 case -EPIPE:
1952 rpc_task_force_reencode(task);
1953 }
1954 }
1955
1956 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1957 /*
1958 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
1959 * addition, disconnect on connectivity errors.
1960 */
1961 static void
1962 call_bc_transmit(struct rpc_task *task)
1963 {
1964 struct rpc_rqst *req = task->tk_rqstp;
1965
1966 if (!xprt_prepare_transmit(task))
1967 goto out_retry;
1968
1969 if (task->tk_status < 0) {
1970 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
1971 "error: %d\n", task->tk_status);
1972 goto out_done;
1973 }
1974 if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
1975 req->rq_bytes_sent = 0;
1976
1977 xprt_transmit(task);
1978
1979 if (task->tk_status == -EAGAIN)
1980 goto out_nospace;
1981
1982 xprt_end_transmit(task);
1983 dprint_status(task);
1984 switch (task->tk_status) {
1985 case 0:
1986 /* Success */
1987 case -EHOSTDOWN:
1988 case -EHOSTUNREACH:
1989 case -ENETUNREACH:
1990 case -ECONNRESET:
1991 case -ECONNREFUSED:
1992 case -EADDRINUSE:
1993 case -ENOTCONN:
1994 case -EPIPE:
1995 break;
1996 case -ETIMEDOUT:
1997 /*
1998 * Problem reaching the server. Disconnect and let the
1999 * forechannel reestablish the connection. The server will
2000 * have to retransmit the backchannel request and we'll
2001 * reprocess it. Since these ops are idempotent, there's no
2002 * need to cache our reply at this time.
2003 */
2004 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2005 "error: %d\n", task->tk_status);
2006 xprt_conditional_disconnect(req->rq_xprt,
2007 req->rq_connect_cookie);
2008 break;
2009 default:
2010 /*
2011 * We were unable to reply and will have to drop the
2012 * request. The server should reconnect and retransmit.
2013 */
2014 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2015 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2016 "error: %d\n", task->tk_status);
2017 break;
2018 }
2019 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2020 out_done:
2021 task->tk_action = rpc_exit_task;
2022 return;
2023 out_nospace:
2024 req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2025 out_retry:
2026 task->tk_status = 0;
2027 }
2028 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2029
2030 /*
2031 * 6. Sort out the RPC call status
2032 */
2033 static void
2034 call_status(struct rpc_task *task)
2035 {
2036 struct rpc_clnt *clnt = task->tk_client;
2037 struct rpc_rqst *req = task->tk_rqstp;
2038 int status;
2039
2040 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2041 task->tk_status = req->rq_reply_bytes_recvd;
2042
2043 dprint_status(task);
2044
2045 status = task->tk_status;
2046 if (status >= 0) {
2047 task->tk_action = call_decode;
2048 return;
2049 }
2050
2051 trace_rpc_call_status(task);
2052 task->tk_status = 0;
2053 switch(status) {
2054 case -EHOSTDOWN:
2055 case -EHOSTUNREACH:
2056 case -ENETUNREACH:
2057 case -EPERM:
2058 if (RPC_IS_SOFTCONN(task)) {
2059 rpc_exit(task, status);
2060 break;
2061 }
2062 /*
2063 * Delay any retries for 3 seconds, then handle as if it
2064 * were a timeout.
2065 */
2066 rpc_delay(task, 3*HZ);
2067 case -ETIMEDOUT:
2068 task->tk_action = call_timeout;
2069 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2070 && task->tk_client->cl_discrtry)
2071 xprt_conditional_disconnect(req->rq_xprt,
2072 req->rq_connect_cookie);
2073 break;
2074 case -ECONNREFUSED:
2075 case -ECONNRESET:
2076 case -ECONNABORTED:
2077 rpc_force_rebind(clnt);
2078 case -EADDRINUSE:
2079 rpc_delay(task, 3*HZ);
2080 case -EPIPE:
2081 case -ENOTCONN:
2082 task->tk_action = call_bind;
2083 break;
2084 case -ENOBUFS:
2085 rpc_delay(task, HZ>>2);
2086 case -EAGAIN:
2087 task->tk_action = call_transmit;
2088 break;
2089 case -EIO:
2090 /* shutdown or soft timeout */
2091 rpc_exit(task, status);
2092 break;
2093 default:
2094 if (clnt->cl_chatty)
2095 printk("%s: RPC call returned error %d\n",
2096 clnt->cl_program->name, -status);
2097 rpc_exit(task, status);
2098 }
2099 }
2100
2101 /*
2102 * 6a. Handle RPC timeout
2103 * We do not release the request slot, so we keep using the
2104 * same XID for all retransmits.
2105 */
2106 static void
2107 call_timeout(struct rpc_task *task)
2108 {
2109 struct rpc_clnt *clnt = task->tk_client;
2110
2111 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2112 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2113 goto retry;
2114 }
2115
2116 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2117 task->tk_timeouts++;
2118
2119 if (RPC_IS_SOFTCONN(task)) {
2120 rpc_exit(task, -ETIMEDOUT);
2121 return;
2122 }
2123 if (RPC_IS_SOFT(task)) {
2124 if (clnt->cl_chatty) {
2125 rcu_read_lock();
2126 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2127 clnt->cl_program->name,
2128 rcu_dereference(clnt->cl_xprt)->servername);
2129 rcu_read_unlock();
2130 }
2131 if (task->tk_flags & RPC_TASK_TIMEOUT)
2132 rpc_exit(task, -ETIMEDOUT);
2133 else
2134 rpc_exit(task, -EIO);
2135 return;
2136 }
2137
2138 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2139 task->tk_flags |= RPC_CALL_MAJORSEEN;
2140 if (clnt->cl_chatty) {
2141 rcu_read_lock();
2142 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2143 clnt->cl_program->name,
2144 rcu_dereference(clnt->cl_xprt)->servername);
2145 rcu_read_unlock();
2146 }
2147 }
2148 rpc_force_rebind(clnt);
2149 /*
2150 * Did our request time out due to an RPCSEC_GSS out-of-sequence
2151 * event? RFC2203 requires the server to drop all such requests.
2152 */
2153 rpcauth_invalcred(task);
2154
2155 retry:
2156 task->tk_action = call_bind;
2157 task->tk_status = 0;
2158 }
2159
2160 /*
2161 * 7. Decode the RPC reply
2162 */
2163 static void
2164 call_decode(struct rpc_task *task)
2165 {
2166 struct rpc_clnt *clnt = task->tk_client;
2167 struct rpc_rqst *req = task->tk_rqstp;
2168 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
2169 __be32 *p;
2170
2171 dprint_status(task);
2172
2173 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2174 if (clnt->cl_chatty) {
2175 rcu_read_lock();
2176 printk(KERN_NOTICE "%s: server %s OK\n",
2177 clnt->cl_program->name,
2178 rcu_dereference(clnt->cl_xprt)->servername);
2179 rcu_read_unlock();
2180 }
2181 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2182 }
2183
2184 /*
2185 * Ensure that we see all writes made by xprt_complete_rqst()
2186 * before it changed req->rq_reply_bytes_recvd.
2187 */
2188 smp_rmb();
2189 req->rq_rcv_buf.len = req->rq_private_buf.len;
2190
2191 /* Check that the softirq receive buffer is valid */
2192 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2193 sizeof(req->rq_rcv_buf)) != 0);
2194
2195 if (req->rq_rcv_buf.len < 12) {
2196 if (!RPC_IS_SOFT(task)) {
2197 task->tk_action = call_bind;
2198 goto out_retry;
2199 }
2200 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
2201 clnt->cl_program->name, task->tk_status);
2202 task->tk_action = call_timeout;
2203 goto out_retry;
2204 }
2205
2206 p = rpc_verify_header(task);
2207 if (IS_ERR(p)) {
2208 if (p == ERR_PTR(-EAGAIN))
2209 goto out_retry;
2210 return;
2211 }
2212
2213 task->tk_action = rpc_exit_task;
2214
2215 if (decode) {
2216 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2217 task->tk_msg.rpc_resp);
2218 }
2219 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2220 task->tk_status);
2221 return;
2222 out_retry:
2223 task->tk_status = 0;
2224 /* Note: rpc_verify_header() may have freed the RPC slot */
2225 if (task->tk_rqstp == req) {
2226 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2227 if (task->tk_client->cl_discrtry)
2228 xprt_conditional_disconnect(req->rq_xprt,
2229 req->rq_connect_cookie);
2230 }
2231 }
2232
2233 static __be32 *
2234 rpc_encode_header(struct rpc_task *task)
2235 {
2236 struct rpc_clnt *clnt = task->tk_client;
2237 struct rpc_rqst *req = task->tk_rqstp;
2238 __be32 *p = req->rq_svec[0].iov_base;
2239
2240 /* FIXME: check buffer size? */
2241
2242 p = xprt_skip_transport_header(req->rq_xprt, p);
2243 *p++ = req->rq_xid; /* XID */
2244 *p++ = htonl(RPC_CALL); /* CALL */
2245 *p++ = htonl(RPC_VERSION); /* RPC version */
2246 *p++ = htonl(clnt->cl_prog); /* program number */
2247 *p++ = htonl(clnt->cl_vers); /* program version */
2248 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
2249 p = rpcauth_marshcred(task, p);
2250 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2251 return p;
2252 }
2253
2254 static __be32 *
2255 rpc_verify_header(struct rpc_task *task)
2256 {
2257 struct rpc_clnt *clnt = task->tk_client;
2258 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2259 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2260 __be32 *p = iov->iov_base;
2261 u32 n;
2262 int error = -EACCES;
2263
2264 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2265 /* RFC-1014 says that the representation of XDR data must be a
2266 * multiple of four bytes
2267 * - if it isn't pointer subtraction in the NFS client may give
2268 * undefined results
2269 */
2270 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2271 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2272 task->tk_rqstp->rq_rcv_buf.len);
2273 error = -EIO;
2274 goto out_err;
2275 }
2276 if ((len -= 3) < 0)
2277 goto out_overflow;
2278
2279 p += 1; /* skip XID */
2280 if ((n = ntohl(*p++)) != RPC_REPLY) {
2281 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2282 task->tk_pid, __func__, n);
2283 error = -EIO;
2284 goto out_garbage;
2285 }
2286
2287 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2288 if (--len < 0)
2289 goto out_overflow;
2290 switch ((n = ntohl(*p++))) {
2291 case RPC_AUTH_ERROR:
2292 break;
2293 case RPC_MISMATCH:
2294 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2295 task->tk_pid, __func__);
2296 error = -EPROTONOSUPPORT;
2297 goto out_err;
2298 default:
2299 dprintk("RPC: %5u %s: RPC call rejected, "
2300 "unknown error: %x\n",
2301 task->tk_pid, __func__, n);
2302 error = -EIO;
2303 goto out_err;
2304 }
2305 if (--len < 0)
2306 goto out_overflow;
2307 switch ((n = ntohl(*p++))) {
2308 case RPC_AUTH_REJECTEDCRED:
2309 case RPC_AUTH_REJECTEDVERF:
2310 case RPCSEC_GSS_CREDPROBLEM:
2311 case RPCSEC_GSS_CTXPROBLEM:
2312 if (!task->tk_cred_retry)
2313 break;
2314 task->tk_cred_retry--;
2315 dprintk("RPC: %5u %s: retry stale creds\n",
2316 task->tk_pid, __func__);
2317 rpcauth_invalcred(task);
2318 /* Ensure we obtain a new XID! */
2319 xprt_release(task);
2320 task->tk_action = call_reserve;
2321 goto out_retry;
2322 case RPC_AUTH_BADCRED:
2323 case RPC_AUTH_BADVERF:
2324 /* possibly garbled cred/verf? */
2325 if (!task->tk_garb_retry)
2326 break;
2327 task->tk_garb_retry--;
2328 dprintk("RPC: %5u %s: retry garbled creds\n",
2329 task->tk_pid, __func__);
2330 task->tk_action = call_bind;
2331 goto out_retry;
2332 case RPC_AUTH_TOOWEAK:
2333 rcu_read_lock();
2334 printk(KERN_NOTICE "RPC: server %s requires stronger "
2335 "authentication.\n",
2336 rcu_dereference(clnt->cl_xprt)->servername);
2337 rcu_read_unlock();
2338 break;
2339 default:
2340 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2341 task->tk_pid, __func__, n);
2342 error = -EIO;
2343 }
2344 dprintk("RPC: %5u %s: call rejected %d\n",
2345 task->tk_pid, __func__, n);
2346 goto out_err;
2347 }
2348 p = rpcauth_checkverf(task, p);
2349 if (IS_ERR(p)) {
2350 error = PTR_ERR(p);
2351 dprintk("RPC: %5u %s: auth check failed with %d\n",
2352 task->tk_pid, __func__, error);
2353 goto out_garbage; /* bad verifier, retry */
2354 }
2355 len = p - (__be32 *)iov->iov_base - 1;
2356 if (len < 0)
2357 goto out_overflow;
2358 switch ((n = ntohl(*p++))) {
2359 case RPC_SUCCESS:
2360 return p;
2361 case RPC_PROG_UNAVAIL:
2362 dprintk_rcu("RPC: %5u %s: program %u is unsupported "
2363 "by server %s\n", task->tk_pid, __func__,
2364 (unsigned int)clnt->cl_prog,
2365 rcu_dereference(clnt->cl_xprt)->servername);
2366 error = -EPFNOSUPPORT;
2367 goto out_err;
2368 case RPC_PROG_MISMATCH:
2369 dprintk_rcu("RPC: %5u %s: program %u, version %u unsupported "
2370 "by server %s\n", task->tk_pid, __func__,
2371 (unsigned int)clnt->cl_prog,
2372 (unsigned int)clnt->cl_vers,
2373 rcu_dereference(clnt->cl_xprt)->servername);
2374 error = -EPROTONOSUPPORT;
2375 goto out_err;
2376 case RPC_PROC_UNAVAIL:
2377 dprintk_rcu("RPC: %5u %s: proc %s unsupported by program %u, "
2378 "version %u on server %s\n",
2379 task->tk_pid, __func__,
2380 rpc_proc_name(task),
2381 clnt->cl_prog, clnt->cl_vers,
2382 rcu_dereference(clnt->cl_xprt)->servername);
2383 error = -EOPNOTSUPP;
2384 goto out_err;
2385 case RPC_GARBAGE_ARGS:
2386 dprintk("RPC: %5u %s: server saw garbage\n",
2387 task->tk_pid, __func__);
2388 break; /* retry */
2389 default:
2390 dprintk("RPC: %5u %s: server accept status: %x\n",
2391 task->tk_pid, __func__, n);
2392 /* Also retry */
2393 }
2394
2395 out_garbage:
2396 clnt->cl_stats->rpcgarbage++;
2397 if (task->tk_garb_retry) {
2398 task->tk_garb_retry--;
2399 dprintk("RPC: %5u %s: retrying\n",
2400 task->tk_pid, __func__);
2401 task->tk_action = call_bind;
2402 out_retry:
2403 return ERR_PTR(-EAGAIN);
2404 }
2405 out_err:
2406 rpc_exit(task, error);
2407 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2408 __func__, error);
2409 return ERR_PTR(error);
2410 out_overflow:
2411 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2412 __func__);
2413 goto out_garbage;
2414 }
2415
2416 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2417 {
2418 }
2419
2420 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2421 {
2422 return 0;
2423 }
2424
2425 static struct rpc_procinfo rpcproc_null = {
2426 .p_encode = rpcproc_encode_null,
2427 .p_decode = rpcproc_decode_null,
2428 };
2429
2430 static int rpc_ping(struct rpc_clnt *clnt)
2431 {
2432 struct rpc_message msg = {
2433 .rpc_proc = &rpcproc_null,
2434 };
2435 int err;
2436 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2437 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2438 put_rpccred(msg.rpc_cred);
2439 return err;
2440 }
2441
2442 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2443 {
2444 struct rpc_message msg = {
2445 .rpc_proc = &rpcproc_null,
2446 .rpc_cred = cred,
2447 };
2448 struct rpc_task_setup task_setup_data = {
2449 .rpc_client = clnt,
2450 .rpc_message = &msg,
2451 .callback_ops = &rpc_default_ops,
2452 .flags = flags,
2453 };
2454 return rpc_run_task(&task_setup_data);
2455 }
2456 EXPORT_SYMBOL_GPL(rpc_call_null);
2457
2458 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2459 static void rpc_show_header(void)
2460 {
2461 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2462 "-timeout ---ops--\n");
2463 }
2464
2465 static void rpc_show_task(const struct rpc_clnt *clnt,
2466 const struct rpc_task *task)
2467 {
2468 const char *rpc_waitq = "none";
2469
2470 if (RPC_IS_QUEUED(task))
2471 rpc_waitq = rpc_qname(task->tk_waitqueue);
2472
2473 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2474 task->tk_pid, task->tk_flags, task->tk_status,
2475 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2476 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2477 task->tk_action, rpc_waitq);
2478 }
2479
2480 void rpc_show_tasks(struct net *net)
2481 {
2482 struct rpc_clnt *clnt;
2483 struct rpc_task *task;
2484 int header = 0;
2485 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2486
2487 spin_lock(&sn->rpc_client_lock);
2488 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2489 spin_lock(&clnt->cl_lock);
2490 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2491 if (!header) {
2492 rpc_show_header();
2493 header++;
2494 }
2495 rpc_show_task(clnt, task);
2496 }
2497 spin_unlock(&clnt->cl_lock);
2498 }
2499 spin_unlock(&sn->rpc_client_lock);
2500 }
2501 #endif
2502
2503 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2504 int
2505 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2506 {
2507 int ret = 0;
2508 struct rpc_xprt *xprt;
2509
2510 if (atomic_inc_return(&clnt->cl_swapper) == 1) {
2511 retry:
2512 rcu_read_lock();
2513 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
2514 rcu_read_unlock();
2515 if (!xprt) {
2516 /*
2517 * If we didn't get a reference, then we likely are
2518 * racing with a migration event. Wait for a grace
2519 * period and try again.
2520 */
2521 synchronize_rcu();
2522 goto retry;
2523 }
2524
2525 ret = xprt_enable_swap(xprt);
2526 xprt_put(xprt);
2527 }
2528 return ret;
2529 }
2530 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2531
2532 void
2533 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2534 {
2535 struct rpc_xprt *xprt;
2536
2537 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0) {
2538 retry:
2539 rcu_read_lock();
2540 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
2541 rcu_read_unlock();
2542 if (!xprt) {
2543 /*
2544 * If we didn't get a reference, then we likely are
2545 * racing with a migration event. Wait for a grace
2546 * period and try again.
2547 */
2548 synchronize_rcu();
2549 goto retry;
2550 }
2551
2552 xprt_disable_swap(xprt);
2553 xprt_put(xprt);
2554 }
2555 }
2556 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2557 #endif /* CONFIG_SUNRPC_SWAP */
Linux kernel - Deliverables
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