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Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[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 static 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 if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
456 WARN_ON(args->protocol != XPRT_TRANSPORT_BC_TCP);
457 xps = args->bc_xprt->xpt_bc_xps;
458 xprt_switch_get(xps);
459 } else {
460 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
461 if (xps == NULL) {
462 xprt_put(xprt);
463 return ERR_PTR(-ENOMEM);
464 }
465 if (xprt->bc_xprt) {
466 xprt_switch_get(xps);
467 xprt->bc_xprt->xpt_bc_xps = xps;
468 }
469 }
470 clnt = rpc_new_client(args, xps, xprt, NULL);
471 if (IS_ERR(clnt))
472 return clnt;
473
474 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
475 int err = rpc_ping(clnt);
476 if (err != 0) {
477 rpc_shutdown_client(clnt);
478 return ERR_PTR(err);
479 }
480 }
481
482 clnt->cl_softrtry = 1;
483 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
484 clnt->cl_softrtry = 0;
485
486 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
487 clnt->cl_autobind = 1;
488 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
489 clnt->cl_noretranstimeo = 1;
490 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
491 clnt->cl_discrtry = 1;
492 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
493 clnt->cl_chatty = 1;
494
495 return clnt;
496 }
497
498 /**
499 * rpc_create - create an RPC client and transport with one call
500 * @args: rpc_clnt create argument structure
501 *
502 * Creates and initializes an RPC transport and an RPC client.
503 *
504 * It can ping the server in order to determine if it is up, and to see if
505 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
506 * this behavior so asynchronous tasks can also use rpc_create.
507 */
508 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
509 {
510 struct rpc_xprt *xprt;
511 struct xprt_create xprtargs = {
512 .net = args->net,
513 .ident = args->protocol,
514 .srcaddr = args->saddress,
515 .dstaddr = args->address,
516 .addrlen = args->addrsize,
517 .servername = args->servername,
518 .bc_xprt = args->bc_xprt,
519 };
520 char servername[48];
521
522 if (args->bc_xprt) {
523 WARN_ON(args->protocol != XPRT_TRANSPORT_BC_TCP);
524 xprt = args->bc_xprt->xpt_bc_xprt;
525 if (xprt) {
526 xprt_get(xprt);
527 return rpc_create_xprt(args, xprt);
528 }
529 }
530
531 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
532 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
533 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
534 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
535 /*
536 * If the caller chooses not to specify a hostname, whip
537 * up a string representation of the passed-in address.
538 */
539 if (xprtargs.servername == NULL) {
540 struct sockaddr_un *sun =
541 (struct sockaddr_un *)args->address;
542 struct sockaddr_in *sin =
543 (struct sockaddr_in *)args->address;
544 struct sockaddr_in6 *sin6 =
545 (struct sockaddr_in6 *)args->address;
546
547 servername[0] = '\0';
548 switch (args->address->sa_family) {
549 case AF_LOCAL:
550 snprintf(servername, sizeof(servername), "%s",
551 sun->sun_path);
552 break;
553 case AF_INET:
554 snprintf(servername, sizeof(servername), "%pI4",
555 &sin->sin_addr.s_addr);
556 break;
557 case AF_INET6:
558 snprintf(servername, sizeof(servername), "%pI6",
559 &sin6->sin6_addr);
560 break;
561 default:
562 /* caller wants default server name, but
563 * address family isn't recognized. */
564 return ERR_PTR(-EINVAL);
565 }
566 xprtargs.servername = servername;
567 }
568
569 xprt = xprt_create_transport(&xprtargs);
570 if (IS_ERR(xprt))
571 return (struct rpc_clnt *)xprt;
572
573 /*
574 * By default, kernel RPC client connects from a reserved port.
575 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
576 * but it is always enabled for rpciod, which handles the connect
577 * operation.
578 */
579 xprt->resvport = 1;
580 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
581 xprt->resvport = 0;
582
583 return rpc_create_xprt(args, xprt);
584 }
585 EXPORT_SYMBOL_GPL(rpc_create);
586
587 /*
588 * This function clones the RPC client structure. It allows us to share the
589 * same transport while varying parameters such as the authentication
590 * flavour.
591 */
592 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
593 struct rpc_clnt *clnt)
594 {
595 struct rpc_xprt_switch *xps;
596 struct rpc_xprt *xprt;
597 struct rpc_clnt *new;
598 int err;
599
600 err = -ENOMEM;
601 rcu_read_lock();
602 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
603 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
604 rcu_read_unlock();
605 if (xprt == NULL || xps == NULL) {
606 xprt_put(xprt);
607 xprt_switch_put(xps);
608 goto out_err;
609 }
610 args->servername = xprt->servername;
611 args->nodename = clnt->cl_nodename;
612
613 new = rpc_new_client(args, xps, xprt, clnt);
614 if (IS_ERR(new)) {
615 err = PTR_ERR(new);
616 goto out_err;
617 }
618
619 /* Turn off autobind on clones */
620 new->cl_autobind = 0;
621 new->cl_softrtry = clnt->cl_softrtry;
622 new->cl_noretranstimeo = clnt->cl_noretranstimeo;
623 new->cl_discrtry = clnt->cl_discrtry;
624 new->cl_chatty = clnt->cl_chatty;
625 return new;
626
627 out_err:
628 dprintk("RPC: %s: returned error %d\n", __func__, err);
629 return ERR_PTR(err);
630 }
631
632 /**
633 * rpc_clone_client - Clone an RPC client structure
634 *
635 * @clnt: RPC client whose parameters are copied
636 *
637 * Returns a fresh RPC client or an ERR_PTR.
638 */
639 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
640 {
641 struct rpc_create_args args = {
642 .program = clnt->cl_program,
643 .prognumber = clnt->cl_prog,
644 .version = clnt->cl_vers,
645 .authflavor = clnt->cl_auth->au_flavor,
646 };
647 return __rpc_clone_client(&args, clnt);
648 }
649 EXPORT_SYMBOL_GPL(rpc_clone_client);
650
651 /**
652 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
653 *
654 * @clnt: RPC client whose parameters are copied
655 * @flavor: security flavor for new client
656 *
657 * Returns a fresh RPC client or an ERR_PTR.
658 */
659 struct rpc_clnt *
660 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
661 {
662 struct rpc_create_args args = {
663 .program = clnt->cl_program,
664 .prognumber = clnt->cl_prog,
665 .version = clnt->cl_vers,
666 .authflavor = flavor,
667 };
668 return __rpc_clone_client(&args, clnt);
669 }
670 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
671
672 /**
673 * rpc_switch_client_transport: switch the RPC transport on the fly
674 * @clnt: pointer to a struct rpc_clnt
675 * @args: pointer to the new transport arguments
676 * @timeout: pointer to the new timeout parameters
677 *
678 * This function allows the caller to switch the RPC transport for the
679 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
680 * server, for instance. It assumes that the caller has ensured that
681 * there are no active RPC tasks by using some form of locking.
682 *
683 * Returns zero if "clnt" is now using the new xprt. Otherwise a
684 * negative errno is returned, and "clnt" continues to use the old
685 * xprt.
686 */
687 int rpc_switch_client_transport(struct rpc_clnt *clnt,
688 struct xprt_create *args,
689 const struct rpc_timeout *timeout)
690 {
691 const struct rpc_timeout *old_timeo;
692 rpc_authflavor_t pseudoflavor;
693 struct rpc_xprt_switch *xps, *oldxps;
694 struct rpc_xprt *xprt, *old;
695 struct rpc_clnt *parent;
696 int err;
697
698 xprt = xprt_create_transport(args);
699 if (IS_ERR(xprt)) {
700 dprintk("RPC: failed to create new xprt for clnt %p\n",
701 clnt);
702 return PTR_ERR(xprt);
703 }
704
705 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
706 if (xps == NULL) {
707 xprt_put(xprt);
708 return -ENOMEM;
709 }
710
711 pseudoflavor = clnt->cl_auth->au_flavor;
712
713 old_timeo = clnt->cl_timeout;
714 old = rpc_clnt_set_transport(clnt, xprt, timeout);
715 oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
716
717 rpc_unregister_client(clnt);
718 __rpc_clnt_remove_pipedir(clnt);
719 rpc_clnt_debugfs_unregister(clnt);
720
721 /*
722 * A new transport was created. "clnt" therefore
723 * becomes the root of a new cl_parent tree. clnt's
724 * children, if it has any, still point to the old xprt.
725 */
726 parent = clnt->cl_parent;
727 clnt->cl_parent = clnt;
728
729 /*
730 * The old rpc_auth cache cannot be re-used. GSS
731 * contexts in particular are between a single
732 * client and server.
733 */
734 err = rpc_client_register(clnt, pseudoflavor, NULL);
735 if (err)
736 goto out_revert;
737
738 synchronize_rcu();
739 if (parent != clnt)
740 rpc_release_client(parent);
741 xprt_switch_put(oldxps);
742 xprt_put(old);
743 dprintk("RPC: replaced xprt for clnt %p\n", clnt);
744 return 0;
745
746 out_revert:
747 xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
748 rpc_clnt_set_transport(clnt, old, old_timeo);
749 clnt->cl_parent = parent;
750 rpc_client_register(clnt, pseudoflavor, NULL);
751 xprt_switch_put(xps);
752 xprt_put(xprt);
753 dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
754 return err;
755 }
756 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
757
758 static
759 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
760 {
761 struct rpc_xprt_switch *xps;
762
763 rcu_read_lock();
764 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
765 rcu_read_unlock();
766 if (xps == NULL)
767 return -EAGAIN;
768 xprt_iter_init_listall(xpi, xps);
769 xprt_switch_put(xps);
770 return 0;
771 }
772
773 /**
774 * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
775 * @clnt: pointer to client
776 * @fn: function to apply
777 * @data: void pointer to function data
778 *
779 * Iterates through the list of RPC transports currently attached to the
780 * client and applies the function fn(clnt, xprt, data).
781 *
782 * On error, the iteration stops, and the function returns the error value.
783 */
784 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
785 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
786 void *data)
787 {
788 struct rpc_xprt_iter xpi;
789 int ret;
790
791 ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
792 if (ret)
793 return ret;
794 for (;;) {
795 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
796
797 if (!xprt)
798 break;
799 ret = fn(clnt, xprt, data);
800 xprt_put(xprt);
801 if (ret < 0)
802 break;
803 }
804 xprt_iter_destroy(&xpi);
805 return ret;
806 }
807 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
808
809 /*
810 * Kill all tasks for the given client.
811 * XXX: kill their descendants as well?
812 */
813 void rpc_killall_tasks(struct rpc_clnt *clnt)
814 {
815 struct rpc_task *rovr;
816
817
818 if (list_empty(&clnt->cl_tasks))
819 return;
820 dprintk("RPC: killing all tasks for client %p\n", clnt);
821 /*
822 * Spin lock all_tasks to prevent changes...
823 */
824 spin_lock(&clnt->cl_lock);
825 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
826 if (!RPC_IS_ACTIVATED(rovr))
827 continue;
828 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
829 rovr->tk_flags |= RPC_TASK_KILLED;
830 rpc_exit(rovr, -EIO);
831 if (RPC_IS_QUEUED(rovr))
832 rpc_wake_up_queued_task(rovr->tk_waitqueue,
833 rovr);
834 }
835 }
836 spin_unlock(&clnt->cl_lock);
837 }
838 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
839
840 /*
841 * Properly shut down an RPC client, terminating all outstanding
842 * requests.
843 */
844 void rpc_shutdown_client(struct rpc_clnt *clnt)
845 {
846 might_sleep();
847
848 dprintk_rcu("RPC: shutting down %s client for %s\n",
849 clnt->cl_program->name,
850 rcu_dereference(clnt->cl_xprt)->servername);
851
852 while (!list_empty(&clnt->cl_tasks)) {
853 rpc_killall_tasks(clnt);
854 wait_event_timeout(destroy_wait,
855 list_empty(&clnt->cl_tasks), 1*HZ);
856 }
857
858 rpc_release_client(clnt);
859 }
860 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
861
862 /*
863 * Free an RPC client
864 */
865 static struct rpc_clnt *
866 rpc_free_client(struct rpc_clnt *clnt)
867 {
868 struct rpc_clnt *parent = NULL;
869
870 dprintk_rcu("RPC: destroying %s client for %s\n",
871 clnt->cl_program->name,
872 rcu_dereference(clnt->cl_xprt)->servername);
873 if (clnt->cl_parent != clnt)
874 parent = clnt->cl_parent;
875 rpc_clnt_debugfs_unregister(clnt);
876 rpc_clnt_remove_pipedir(clnt);
877 rpc_unregister_client(clnt);
878 rpc_free_iostats(clnt->cl_metrics);
879 clnt->cl_metrics = NULL;
880 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
881 xprt_iter_destroy(&clnt->cl_xpi);
882 rpciod_down();
883 rpc_free_clid(clnt);
884 kfree(clnt);
885 return parent;
886 }
887
888 /*
889 * Free an RPC client
890 */
891 static struct rpc_clnt *
892 rpc_free_auth(struct rpc_clnt *clnt)
893 {
894 if (clnt->cl_auth == NULL)
895 return rpc_free_client(clnt);
896
897 /*
898 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
899 * release remaining GSS contexts. This mechanism ensures
900 * that it can do so safely.
901 */
902 atomic_inc(&clnt->cl_count);
903 rpcauth_release(clnt->cl_auth);
904 clnt->cl_auth = NULL;
905 if (atomic_dec_and_test(&clnt->cl_count))
906 return rpc_free_client(clnt);
907 return NULL;
908 }
909
910 /*
911 * Release reference to the RPC client
912 */
913 void
914 rpc_release_client(struct rpc_clnt *clnt)
915 {
916 dprintk("RPC: rpc_release_client(%p)\n", clnt);
917
918 do {
919 if (list_empty(&clnt->cl_tasks))
920 wake_up(&destroy_wait);
921 if (!atomic_dec_and_test(&clnt->cl_count))
922 break;
923 clnt = rpc_free_auth(clnt);
924 } while (clnt != NULL);
925 }
926 EXPORT_SYMBOL_GPL(rpc_release_client);
927
928 /**
929 * rpc_bind_new_program - bind a new RPC program to an existing client
930 * @old: old rpc_client
931 * @program: rpc program to set
932 * @vers: rpc program version
933 *
934 * Clones the rpc client and sets up a new RPC program. This is mainly
935 * of use for enabling different RPC programs to share the same transport.
936 * The Sun NFSv2/v3 ACL protocol can do this.
937 */
938 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
939 const struct rpc_program *program,
940 u32 vers)
941 {
942 struct rpc_create_args args = {
943 .program = program,
944 .prognumber = program->number,
945 .version = vers,
946 .authflavor = old->cl_auth->au_flavor,
947 };
948 struct rpc_clnt *clnt;
949 int err;
950
951 clnt = __rpc_clone_client(&args, old);
952 if (IS_ERR(clnt))
953 goto out;
954 err = rpc_ping(clnt);
955 if (err != 0) {
956 rpc_shutdown_client(clnt);
957 clnt = ERR_PTR(err);
958 }
959 out:
960 return clnt;
961 }
962 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
963
964 void rpc_task_release_client(struct rpc_task *task)
965 {
966 struct rpc_clnt *clnt = task->tk_client;
967 struct rpc_xprt *xprt = task->tk_xprt;
968
969 if (clnt != NULL) {
970 /* Remove from client task list */
971 spin_lock(&clnt->cl_lock);
972 list_del(&task->tk_task);
973 spin_unlock(&clnt->cl_lock);
974 task->tk_client = NULL;
975
976 rpc_release_client(clnt);
977 }
978
979 if (xprt != NULL) {
980 task->tk_xprt = NULL;
981
982 xprt_put(xprt);
983 }
984 }
985
986 static
987 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
988 {
989
990 if (clnt != NULL) {
991 rpc_task_release_client(task);
992 if (task->tk_xprt == NULL)
993 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
994 task->tk_client = clnt;
995 atomic_inc(&clnt->cl_count);
996 if (clnt->cl_softrtry)
997 task->tk_flags |= RPC_TASK_SOFT;
998 if (clnt->cl_noretranstimeo)
999 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1000 if (atomic_read(&clnt->cl_swapper))
1001 task->tk_flags |= RPC_TASK_SWAPPER;
1002 /* Add to the client's list of all tasks */
1003 spin_lock(&clnt->cl_lock);
1004 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1005 spin_unlock(&clnt->cl_lock);
1006 }
1007 }
1008
1009 static void
1010 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1011 {
1012 if (msg != NULL) {
1013 task->tk_msg.rpc_proc = msg->rpc_proc;
1014 task->tk_msg.rpc_argp = msg->rpc_argp;
1015 task->tk_msg.rpc_resp = msg->rpc_resp;
1016 if (msg->rpc_cred != NULL)
1017 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1018 }
1019 }
1020
1021 /*
1022 * Default callback for async RPC calls
1023 */
1024 static void
1025 rpc_default_callback(struct rpc_task *task, void *data)
1026 {
1027 }
1028
1029 static const struct rpc_call_ops rpc_default_ops = {
1030 .rpc_call_done = rpc_default_callback,
1031 };
1032
1033 /**
1034 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1035 * @task_setup_data: pointer to task initialisation data
1036 */
1037 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1038 {
1039 struct rpc_task *task;
1040
1041 task = rpc_new_task(task_setup_data);
1042 if (IS_ERR(task))
1043 goto out;
1044
1045 rpc_task_set_client(task, task_setup_data->rpc_client);
1046 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1047
1048 if (task->tk_action == NULL)
1049 rpc_call_start(task);
1050
1051 atomic_inc(&task->tk_count);
1052 rpc_execute(task);
1053 out:
1054 return task;
1055 }
1056 EXPORT_SYMBOL_GPL(rpc_run_task);
1057
1058 /**
1059 * rpc_call_sync - Perform a synchronous RPC call
1060 * @clnt: pointer to RPC client
1061 * @msg: RPC call parameters
1062 * @flags: RPC call flags
1063 */
1064 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1065 {
1066 struct rpc_task *task;
1067 struct rpc_task_setup task_setup_data = {
1068 .rpc_client = clnt,
1069 .rpc_message = msg,
1070 .callback_ops = &rpc_default_ops,
1071 .flags = flags,
1072 };
1073 int status;
1074
1075 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1076 if (flags & RPC_TASK_ASYNC) {
1077 rpc_release_calldata(task_setup_data.callback_ops,
1078 task_setup_data.callback_data);
1079 return -EINVAL;
1080 }
1081
1082 task = rpc_run_task(&task_setup_data);
1083 if (IS_ERR(task))
1084 return PTR_ERR(task);
1085 status = task->tk_status;
1086 rpc_put_task(task);
1087 return status;
1088 }
1089 EXPORT_SYMBOL_GPL(rpc_call_sync);
1090
1091 /**
1092 * rpc_call_async - Perform an asynchronous RPC call
1093 * @clnt: pointer to RPC client
1094 * @msg: RPC call parameters
1095 * @flags: RPC call flags
1096 * @tk_ops: RPC call ops
1097 * @data: user call data
1098 */
1099 int
1100 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1101 const struct rpc_call_ops *tk_ops, void *data)
1102 {
1103 struct rpc_task *task;
1104 struct rpc_task_setup task_setup_data = {
1105 .rpc_client = clnt,
1106 .rpc_message = msg,
1107 .callback_ops = tk_ops,
1108 .callback_data = data,
1109 .flags = flags|RPC_TASK_ASYNC,
1110 };
1111
1112 task = rpc_run_task(&task_setup_data);
1113 if (IS_ERR(task))
1114 return PTR_ERR(task);
1115 rpc_put_task(task);
1116 return 0;
1117 }
1118 EXPORT_SYMBOL_GPL(rpc_call_async);
1119
1120 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1121 /**
1122 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1123 * rpc_execute against it
1124 * @req: RPC request
1125 */
1126 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1127 {
1128 struct rpc_task *task;
1129 struct xdr_buf *xbufp = &req->rq_snd_buf;
1130 struct rpc_task_setup task_setup_data = {
1131 .callback_ops = &rpc_default_ops,
1132 .flags = RPC_TASK_SOFTCONN,
1133 };
1134
1135 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1136 /*
1137 * Create an rpc_task to send the data
1138 */
1139 task = rpc_new_task(&task_setup_data);
1140 if (IS_ERR(task)) {
1141 xprt_free_bc_request(req);
1142 goto out;
1143 }
1144 task->tk_rqstp = req;
1145
1146 /*
1147 * Set up the xdr_buf length.
1148 * This also indicates that the buffer is XDR encoded already.
1149 */
1150 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1151 xbufp->tail[0].iov_len;
1152
1153 task->tk_action = call_bc_transmit;
1154 atomic_inc(&task->tk_count);
1155 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1156 rpc_execute(task);
1157
1158 out:
1159 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1160 return task;
1161 }
1162 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1163
1164 void
1165 rpc_call_start(struct rpc_task *task)
1166 {
1167 task->tk_action = call_start;
1168 }
1169 EXPORT_SYMBOL_GPL(rpc_call_start);
1170
1171 /**
1172 * rpc_peeraddr - extract remote peer address from clnt's xprt
1173 * @clnt: RPC client structure
1174 * @buf: target buffer
1175 * @bufsize: length of target buffer
1176 *
1177 * Returns the number of bytes that are actually in the stored address.
1178 */
1179 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1180 {
1181 size_t bytes;
1182 struct rpc_xprt *xprt;
1183
1184 rcu_read_lock();
1185 xprt = rcu_dereference(clnt->cl_xprt);
1186
1187 bytes = xprt->addrlen;
1188 if (bytes > bufsize)
1189 bytes = bufsize;
1190 memcpy(buf, &xprt->addr, bytes);
1191 rcu_read_unlock();
1192
1193 return bytes;
1194 }
1195 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1196
1197 /**
1198 * rpc_peeraddr2str - return remote peer address in printable format
1199 * @clnt: RPC client structure
1200 * @format: address format
1201 *
1202 * NB: the lifetime of the memory referenced by the returned pointer is
1203 * the same as the rpc_xprt itself. As long as the caller uses this
1204 * pointer, it must hold the RCU read lock.
1205 */
1206 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1207 enum rpc_display_format_t format)
1208 {
1209 struct rpc_xprt *xprt;
1210
1211 xprt = rcu_dereference(clnt->cl_xprt);
1212
1213 if (xprt->address_strings[format] != NULL)
1214 return xprt->address_strings[format];
1215 else
1216 return "unprintable";
1217 }
1218 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1219
1220 static const struct sockaddr_in rpc_inaddr_loopback = {
1221 .sin_family = AF_INET,
1222 .sin_addr.s_addr = htonl(INADDR_ANY),
1223 };
1224
1225 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1226 .sin6_family = AF_INET6,
1227 .sin6_addr = IN6ADDR_ANY_INIT,
1228 };
1229
1230 /*
1231 * Try a getsockname() on a connected datagram socket. Using a
1232 * connected datagram socket prevents leaving a socket in TIME_WAIT.
1233 * This conserves the ephemeral port number space.
1234 *
1235 * Returns zero and fills in "buf" if successful; otherwise, a
1236 * negative errno is returned.
1237 */
1238 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1239 struct sockaddr *buf, int buflen)
1240 {
1241 struct socket *sock;
1242 int err;
1243
1244 err = __sock_create(net, sap->sa_family,
1245 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1246 if (err < 0) {
1247 dprintk("RPC: can't create UDP socket (%d)\n", err);
1248 goto out;
1249 }
1250
1251 switch (sap->sa_family) {
1252 case AF_INET:
1253 err = kernel_bind(sock,
1254 (struct sockaddr *)&rpc_inaddr_loopback,
1255 sizeof(rpc_inaddr_loopback));
1256 break;
1257 case AF_INET6:
1258 err = kernel_bind(sock,
1259 (struct sockaddr *)&rpc_in6addr_loopback,
1260 sizeof(rpc_in6addr_loopback));
1261 break;
1262 default:
1263 err = -EAFNOSUPPORT;
1264 goto out;
1265 }
1266 if (err < 0) {
1267 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1268 goto out_release;
1269 }
1270
1271 err = kernel_connect(sock, sap, salen, 0);
1272 if (err < 0) {
1273 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1274 goto out_release;
1275 }
1276
1277 err = kernel_getsockname(sock, buf, &buflen);
1278 if (err < 0) {
1279 dprintk("RPC: getsockname failed (%d)\n", err);
1280 goto out_release;
1281 }
1282
1283 err = 0;
1284 if (buf->sa_family == AF_INET6) {
1285 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1286 sin6->sin6_scope_id = 0;
1287 }
1288 dprintk("RPC: %s succeeded\n", __func__);
1289
1290 out_release:
1291 sock_release(sock);
1292 out:
1293 return err;
1294 }
1295
1296 /*
1297 * Scraping a connected socket failed, so we don't have a useable
1298 * local address. Fallback: generate an address that will prevent
1299 * the server from calling us back.
1300 *
1301 * Returns zero and fills in "buf" if successful; otherwise, a
1302 * negative errno is returned.
1303 */
1304 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1305 {
1306 switch (family) {
1307 case AF_INET:
1308 if (buflen < sizeof(rpc_inaddr_loopback))
1309 return -EINVAL;
1310 memcpy(buf, &rpc_inaddr_loopback,
1311 sizeof(rpc_inaddr_loopback));
1312 break;
1313 case AF_INET6:
1314 if (buflen < sizeof(rpc_in6addr_loopback))
1315 return -EINVAL;
1316 memcpy(buf, &rpc_in6addr_loopback,
1317 sizeof(rpc_in6addr_loopback));
1318 break;
1319 default:
1320 dprintk("RPC: %s: address family not supported\n",
1321 __func__);
1322 return -EAFNOSUPPORT;
1323 }
1324 dprintk("RPC: %s: succeeded\n", __func__);
1325 return 0;
1326 }
1327
1328 /**
1329 * rpc_localaddr - discover local endpoint address for an RPC client
1330 * @clnt: RPC client structure
1331 * @buf: target buffer
1332 * @buflen: size of target buffer, in bytes
1333 *
1334 * Returns zero and fills in "buf" and "buflen" if successful;
1335 * otherwise, a negative errno is returned.
1336 *
1337 * This works even if the underlying transport is not currently connected,
1338 * or if the upper layer never previously provided a source address.
1339 *
1340 * The result of this function call is transient: multiple calls in
1341 * succession may give different results, depending on how local
1342 * networking configuration changes over time.
1343 */
1344 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1345 {
1346 struct sockaddr_storage address;
1347 struct sockaddr *sap = (struct sockaddr *)&address;
1348 struct rpc_xprt *xprt;
1349 struct net *net;
1350 size_t salen;
1351 int err;
1352
1353 rcu_read_lock();
1354 xprt = rcu_dereference(clnt->cl_xprt);
1355 salen = xprt->addrlen;
1356 memcpy(sap, &xprt->addr, salen);
1357 net = get_net(xprt->xprt_net);
1358 rcu_read_unlock();
1359
1360 rpc_set_port(sap, 0);
1361 err = rpc_sockname(net, sap, salen, buf, buflen);
1362 put_net(net);
1363 if (err != 0)
1364 /* Couldn't discover local address, return ANYADDR */
1365 return rpc_anyaddr(sap->sa_family, buf, buflen);
1366 return 0;
1367 }
1368 EXPORT_SYMBOL_GPL(rpc_localaddr);
1369
1370 void
1371 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1372 {
1373 struct rpc_xprt *xprt;
1374
1375 rcu_read_lock();
1376 xprt = rcu_dereference(clnt->cl_xprt);
1377 if (xprt->ops->set_buffer_size)
1378 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1379 rcu_read_unlock();
1380 }
1381 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1382
1383 /**
1384 * rpc_protocol - Get transport protocol number for an RPC client
1385 * @clnt: RPC client to query
1386 *
1387 */
1388 int rpc_protocol(struct rpc_clnt *clnt)
1389 {
1390 int protocol;
1391
1392 rcu_read_lock();
1393 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1394 rcu_read_unlock();
1395 return protocol;
1396 }
1397 EXPORT_SYMBOL_GPL(rpc_protocol);
1398
1399 /**
1400 * rpc_net_ns - Get the network namespace for this RPC client
1401 * @clnt: RPC client to query
1402 *
1403 */
1404 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1405 {
1406 struct net *ret;
1407
1408 rcu_read_lock();
1409 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1410 rcu_read_unlock();
1411 return ret;
1412 }
1413 EXPORT_SYMBOL_GPL(rpc_net_ns);
1414
1415 /**
1416 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1417 * @clnt: RPC client to query
1418 *
1419 * For stream transports, this is one RPC record fragment (see RFC
1420 * 1831), as we don't support multi-record requests yet. For datagram
1421 * transports, this is the size of an IP packet minus the IP, UDP, and
1422 * RPC header sizes.
1423 */
1424 size_t rpc_max_payload(struct rpc_clnt *clnt)
1425 {
1426 size_t ret;
1427
1428 rcu_read_lock();
1429 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1430 rcu_read_unlock();
1431 return ret;
1432 }
1433 EXPORT_SYMBOL_GPL(rpc_max_payload);
1434
1435 /**
1436 * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1437 * @clnt: RPC client to query
1438 */
1439 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1440 {
1441 struct rpc_xprt *xprt;
1442 size_t ret;
1443
1444 rcu_read_lock();
1445 xprt = rcu_dereference(clnt->cl_xprt);
1446 ret = xprt->ops->bc_maxpayload(xprt);
1447 rcu_read_unlock();
1448 return ret;
1449 }
1450 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1451
1452 /**
1453 * rpc_get_timeout - Get timeout for transport in units of HZ
1454 * @clnt: RPC client to query
1455 */
1456 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1457 {
1458 unsigned long ret;
1459
1460 rcu_read_lock();
1461 ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1462 rcu_read_unlock();
1463 return ret;
1464 }
1465 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1466
1467 /**
1468 * rpc_force_rebind - force transport to check that remote port is unchanged
1469 * @clnt: client to rebind
1470 *
1471 */
1472 void rpc_force_rebind(struct rpc_clnt *clnt)
1473 {
1474 if (clnt->cl_autobind) {
1475 rcu_read_lock();
1476 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1477 rcu_read_unlock();
1478 }
1479 }
1480 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1481
1482 /*
1483 * Restart an (async) RPC call from the call_prepare state.
1484 * Usually called from within the exit handler.
1485 */
1486 int
1487 rpc_restart_call_prepare(struct rpc_task *task)
1488 {
1489 if (RPC_ASSASSINATED(task))
1490 return 0;
1491 task->tk_action = call_start;
1492 task->tk_status = 0;
1493 if (task->tk_ops->rpc_call_prepare != NULL)
1494 task->tk_action = rpc_prepare_task;
1495 return 1;
1496 }
1497 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1498
1499 /*
1500 * Restart an (async) RPC call. Usually called from within the
1501 * exit handler.
1502 */
1503 int
1504 rpc_restart_call(struct rpc_task *task)
1505 {
1506 if (RPC_ASSASSINATED(task))
1507 return 0;
1508 task->tk_action = call_start;
1509 task->tk_status = 0;
1510 return 1;
1511 }
1512 EXPORT_SYMBOL_GPL(rpc_restart_call);
1513
1514 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1515 const char
1516 *rpc_proc_name(const struct rpc_task *task)
1517 {
1518 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1519
1520 if (proc) {
1521 if (proc->p_name)
1522 return proc->p_name;
1523 else
1524 return "NULL";
1525 } else
1526 return "no proc";
1527 }
1528 #endif
1529
1530 /*
1531 * 0. Initial state
1532 *
1533 * Other FSM states can be visited zero or more times, but
1534 * this state is visited exactly once for each RPC.
1535 */
1536 static void
1537 call_start(struct rpc_task *task)
1538 {
1539 struct rpc_clnt *clnt = task->tk_client;
1540
1541 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1542 clnt->cl_program->name, clnt->cl_vers,
1543 rpc_proc_name(task),
1544 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1545
1546 /* Increment call count */
1547 task->tk_msg.rpc_proc->p_count++;
1548 clnt->cl_stats->rpccnt++;
1549 task->tk_action = call_reserve;
1550 }
1551
1552 /*
1553 * 1. Reserve an RPC call slot
1554 */
1555 static void
1556 call_reserve(struct rpc_task *task)
1557 {
1558 dprint_status(task);
1559
1560 task->tk_status = 0;
1561 task->tk_action = call_reserveresult;
1562 xprt_reserve(task);
1563 }
1564
1565 static void call_retry_reserve(struct rpc_task *task);
1566
1567 /*
1568 * 1b. Grok the result of xprt_reserve()
1569 */
1570 static void
1571 call_reserveresult(struct rpc_task *task)
1572 {
1573 int status = task->tk_status;
1574
1575 dprint_status(task);
1576
1577 /*
1578 * After a call to xprt_reserve(), we must have either
1579 * a request slot or else an error status.
1580 */
1581 task->tk_status = 0;
1582 if (status >= 0) {
1583 if (task->tk_rqstp) {
1584 task->tk_action = call_refresh;
1585 return;
1586 }
1587
1588 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1589 __func__, status);
1590 rpc_exit(task, -EIO);
1591 return;
1592 }
1593
1594 /*
1595 * Even though there was an error, we may have acquired
1596 * a request slot somehow. Make sure not to leak it.
1597 */
1598 if (task->tk_rqstp) {
1599 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1600 __func__, status);
1601 xprt_release(task);
1602 }
1603
1604 switch (status) {
1605 case -ENOMEM:
1606 rpc_delay(task, HZ >> 2);
1607 case -EAGAIN: /* woken up; retry */
1608 task->tk_action = call_retry_reserve;
1609 return;
1610 case -EIO: /* probably a shutdown */
1611 break;
1612 default:
1613 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1614 __func__, status);
1615 break;
1616 }
1617 rpc_exit(task, status);
1618 }
1619
1620 /*
1621 * 1c. Retry reserving an RPC call slot
1622 */
1623 static void
1624 call_retry_reserve(struct rpc_task *task)
1625 {
1626 dprint_status(task);
1627
1628 task->tk_status = 0;
1629 task->tk_action = call_reserveresult;
1630 xprt_retry_reserve(task);
1631 }
1632
1633 /*
1634 * 2. Bind and/or refresh the credentials
1635 */
1636 static void
1637 call_refresh(struct rpc_task *task)
1638 {
1639 dprint_status(task);
1640
1641 task->tk_action = call_refreshresult;
1642 task->tk_status = 0;
1643 task->tk_client->cl_stats->rpcauthrefresh++;
1644 rpcauth_refreshcred(task);
1645 }
1646
1647 /*
1648 * 2a. Process the results of a credential refresh
1649 */
1650 static void
1651 call_refreshresult(struct rpc_task *task)
1652 {
1653 int status = task->tk_status;
1654
1655 dprint_status(task);
1656
1657 task->tk_status = 0;
1658 task->tk_action = call_refresh;
1659 switch (status) {
1660 case 0:
1661 if (rpcauth_uptodatecred(task)) {
1662 task->tk_action = call_allocate;
1663 return;
1664 }
1665 /* Use rate-limiting and a max number of retries if refresh
1666 * had status 0 but failed to update the cred.
1667 */
1668 case -ETIMEDOUT:
1669 rpc_delay(task, 3*HZ);
1670 case -EAGAIN:
1671 status = -EACCES;
1672 case -EKEYEXPIRED:
1673 if (!task->tk_cred_retry)
1674 break;
1675 task->tk_cred_retry--;
1676 dprintk("RPC: %5u %s: retry refresh creds\n",
1677 task->tk_pid, __func__);
1678 return;
1679 }
1680 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1681 task->tk_pid, __func__, status);
1682 rpc_exit(task, status);
1683 }
1684
1685 /*
1686 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1687 * (Note: buffer memory is freed in xprt_release).
1688 */
1689 static void
1690 call_allocate(struct rpc_task *task)
1691 {
1692 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1693 struct rpc_rqst *req = task->tk_rqstp;
1694 struct rpc_xprt *xprt = req->rq_xprt;
1695 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1696
1697 dprint_status(task);
1698
1699 task->tk_status = 0;
1700 task->tk_action = call_bind;
1701
1702 if (req->rq_buffer)
1703 return;
1704
1705 if (proc->p_proc != 0) {
1706 BUG_ON(proc->p_arglen == 0);
1707 if (proc->p_decode != NULL)
1708 BUG_ON(proc->p_replen == 0);
1709 }
1710
1711 /*
1712 * Calculate the size (in quads) of the RPC call
1713 * and reply headers, and convert both values
1714 * to byte sizes.
1715 */
1716 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1717 req->rq_callsize <<= 2;
1718 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1719 req->rq_rcvsize <<= 2;
1720
1721 req->rq_buffer = xprt->ops->buf_alloc(task,
1722 req->rq_callsize + req->rq_rcvsize);
1723 if (req->rq_buffer != NULL)
1724 return;
1725 xprt_inject_disconnect(xprt);
1726
1727 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1728
1729 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1730 task->tk_action = call_allocate;
1731 rpc_delay(task, HZ>>4);
1732 return;
1733 }
1734
1735 rpc_exit(task, -ERESTARTSYS);
1736 }
1737
1738 static inline int
1739 rpc_task_need_encode(struct rpc_task *task)
1740 {
1741 return task->tk_rqstp->rq_snd_buf.len == 0;
1742 }
1743
1744 static inline void
1745 rpc_task_force_reencode(struct rpc_task *task)
1746 {
1747 task->tk_rqstp->rq_snd_buf.len = 0;
1748 task->tk_rqstp->rq_bytes_sent = 0;
1749 }
1750
1751 static inline void
1752 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1753 {
1754 buf->head[0].iov_base = start;
1755 buf->head[0].iov_len = len;
1756 buf->tail[0].iov_len = 0;
1757 buf->page_len = 0;
1758 buf->flags = 0;
1759 buf->len = 0;
1760 buf->buflen = len;
1761 }
1762
1763 /*
1764 * 3. Encode arguments of an RPC call
1765 */
1766 static void
1767 rpc_xdr_encode(struct rpc_task *task)
1768 {
1769 struct rpc_rqst *req = task->tk_rqstp;
1770 kxdreproc_t encode;
1771 __be32 *p;
1772
1773 dprint_status(task);
1774
1775 rpc_xdr_buf_init(&req->rq_snd_buf,
1776 req->rq_buffer,
1777 req->rq_callsize);
1778 rpc_xdr_buf_init(&req->rq_rcv_buf,
1779 (char *)req->rq_buffer + req->rq_callsize,
1780 req->rq_rcvsize);
1781
1782 p = rpc_encode_header(task);
1783 if (p == NULL) {
1784 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1785 rpc_exit(task, -EIO);
1786 return;
1787 }
1788
1789 encode = task->tk_msg.rpc_proc->p_encode;
1790 if (encode == NULL)
1791 return;
1792
1793 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1794 task->tk_msg.rpc_argp);
1795 }
1796
1797 /*
1798 * 4. Get the server port number if not yet set
1799 */
1800 static void
1801 call_bind(struct rpc_task *task)
1802 {
1803 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1804
1805 dprint_status(task);
1806
1807 task->tk_action = call_connect;
1808 if (!xprt_bound(xprt)) {
1809 task->tk_action = call_bind_status;
1810 task->tk_timeout = xprt->bind_timeout;
1811 xprt->ops->rpcbind(task);
1812 }
1813 }
1814
1815 /*
1816 * 4a. Sort out bind result
1817 */
1818 static void
1819 call_bind_status(struct rpc_task *task)
1820 {
1821 int status = -EIO;
1822
1823 if (task->tk_status >= 0) {
1824 dprint_status(task);
1825 task->tk_status = 0;
1826 task->tk_action = call_connect;
1827 return;
1828 }
1829
1830 trace_rpc_bind_status(task);
1831 switch (task->tk_status) {
1832 case -ENOMEM:
1833 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1834 rpc_delay(task, HZ >> 2);
1835 goto retry_timeout;
1836 case -EACCES:
1837 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1838 "unavailable\n", task->tk_pid);
1839 /* fail immediately if this is an RPC ping */
1840 if (task->tk_msg.rpc_proc->p_proc == 0) {
1841 status = -EOPNOTSUPP;
1842 break;
1843 }
1844 if (task->tk_rebind_retry == 0)
1845 break;
1846 task->tk_rebind_retry--;
1847 rpc_delay(task, 3*HZ);
1848 goto retry_timeout;
1849 case -ETIMEDOUT:
1850 dprintk("RPC: %5u rpcbind request timed out\n",
1851 task->tk_pid);
1852 goto retry_timeout;
1853 case -EPFNOSUPPORT:
1854 /* server doesn't support any rpcbind version we know of */
1855 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1856 task->tk_pid);
1857 break;
1858 case -EPROTONOSUPPORT:
1859 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1860 task->tk_pid);
1861 goto retry_timeout;
1862 case -ECONNREFUSED: /* connection problems */
1863 case -ECONNRESET:
1864 case -ECONNABORTED:
1865 case -ENOTCONN:
1866 case -EHOSTDOWN:
1867 case -EHOSTUNREACH:
1868 case -ENETUNREACH:
1869 case -ENOBUFS:
1870 case -EPIPE:
1871 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1872 task->tk_pid, task->tk_status);
1873 if (!RPC_IS_SOFTCONN(task)) {
1874 rpc_delay(task, 5*HZ);
1875 goto retry_timeout;
1876 }
1877 status = task->tk_status;
1878 break;
1879 default:
1880 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1881 task->tk_pid, -task->tk_status);
1882 }
1883
1884 rpc_exit(task, status);
1885 return;
1886
1887 retry_timeout:
1888 task->tk_status = 0;
1889 task->tk_action = call_timeout;
1890 }
1891
1892 /*
1893 * 4b. Connect to the RPC server
1894 */
1895 static void
1896 call_connect(struct rpc_task *task)
1897 {
1898 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1899
1900 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1901 task->tk_pid, xprt,
1902 (xprt_connected(xprt) ? "is" : "is not"));
1903
1904 task->tk_action = call_transmit;
1905 if (!xprt_connected(xprt)) {
1906 task->tk_action = call_connect_status;
1907 if (task->tk_status < 0)
1908 return;
1909 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1910 rpc_exit(task, -ENOTCONN);
1911 return;
1912 }
1913 xprt_connect(task);
1914 }
1915 }
1916
1917 /*
1918 * 4c. Sort out connect result
1919 */
1920 static void
1921 call_connect_status(struct rpc_task *task)
1922 {
1923 struct rpc_clnt *clnt = task->tk_client;
1924 int status = task->tk_status;
1925
1926 dprint_status(task);
1927
1928 trace_rpc_connect_status(task, status);
1929 task->tk_status = 0;
1930 switch (status) {
1931 case -ECONNREFUSED:
1932 case -ECONNRESET:
1933 case -ECONNABORTED:
1934 case -ENETUNREACH:
1935 case -EHOSTUNREACH:
1936 case -EADDRINUSE:
1937 case -ENOBUFS:
1938 case -EPIPE:
1939 if (RPC_IS_SOFTCONN(task))
1940 break;
1941 /* retry with existing socket, after a delay */
1942 rpc_delay(task, 3*HZ);
1943 case -EAGAIN:
1944 /* Check for timeouts before looping back to call_bind */
1945 case -ETIMEDOUT:
1946 task->tk_action = call_timeout;
1947 return;
1948 case 0:
1949 clnt->cl_stats->netreconn++;
1950 task->tk_action = call_transmit;
1951 return;
1952 }
1953 rpc_exit(task, status);
1954 }
1955
1956 /*
1957 * 5. Transmit the RPC request, and wait for reply
1958 */
1959 static void
1960 call_transmit(struct rpc_task *task)
1961 {
1962 int is_retrans = RPC_WAS_SENT(task);
1963
1964 dprint_status(task);
1965
1966 task->tk_action = call_status;
1967 if (task->tk_status < 0)
1968 return;
1969 if (!xprt_prepare_transmit(task))
1970 return;
1971 task->tk_action = call_transmit_status;
1972 /* Encode here so that rpcsec_gss can use correct sequence number. */
1973 if (rpc_task_need_encode(task)) {
1974 rpc_xdr_encode(task);
1975 /* Did the encode result in an error condition? */
1976 if (task->tk_status != 0) {
1977 /* Was the error nonfatal? */
1978 if (task->tk_status == -EAGAIN)
1979 rpc_delay(task, HZ >> 4);
1980 else
1981 rpc_exit(task, task->tk_status);
1982 return;
1983 }
1984 }
1985 xprt_transmit(task);
1986 if (task->tk_status < 0)
1987 return;
1988 if (is_retrans)
1989 task->tk_client->cl_stats->rpcretrans++;
1990 /*
1991 * On success, ensure that we call xprt_end_transmit() before sleeping
1992 * in order to allow access to the socket to other RPC requests.
1993 */
1994 call_transmit_status(task);
1995 if (rpc_reply_expected(task))
1996 return;
1997 task->tk_action = rpc_exit_task;
1998 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1999 }
2000
2001 /*
2002 * 5a. Handle cleanup after a transmission
2003 */
2004 static void
2005 call_transmit_status(struct rpc_task *task)
2006 {
2007 task->tk_action = call_status;
2008
2009 /*
2010 * Common case: success. Force the compiler to put this
2011 * test first.
2012 */
2013 if (task->tk_status == 0) {
2014 xprt_end_transmit(task);
2015 rpc_task_force_reencode(task);
2016 return;
2017 }
2018
2019 switch (task->tk_status) {
2020 case -EAGAIN:
2021 case -ENOBUFS:
2022 break;
2023 default:
2024 dprint_status(task);
2025 xprt_end_transmit(task);
2026 rpc_task_force_reencode(task);
2027 break;
2028 /*
2029 * Special cases: if we've been waiting on the
2030 * socket's write_space() callback, or if the
2031 * socket just returned a connection error,
2032 * then hold onto the transport lock.
2033 */
2034 case -ECONNREFUSED:
2035 case -EHOSTDOWN:
2036 case -EHOSTUNREACH:
2037 case -ENETUNREACH:
2038 case -EPERM:
2039 if (RPC_IS_SOFTCONN(task)) {
2040 xprt_end_transmit(task);
2041 rpc_exit(task, task->tk_status);
2042 break;
2043 }
2044 case -ECONNRESET:
2045 case -ECONNABORTED:
2046 case -EADDRINUSE:
2047 case -ENOTCONN:
2048 case -EPIPE:
2049 rpc_task_force_reencode(task);
2050 }
2051 }
2052
2053 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2054 /*
2055 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
2056 * addition, disconnect on connectivity errors.
2057 */
2058 static void
2059 call_bc_transmit(struct rpc_task *task)
2060 {
2061 struct rpc_rqst *req = task->tk_rqstp;
2062
2063 if (!xprt_prepare_transmit(task))
2064 goto out_retry;
2065
2066 if (task->tk_status < 0) {
2067 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2068 "error: %d\n", task->tk_status);
2069 goto out_done;
2070 }
2071 if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2072 req->rq_bytes_sent = 0;
2073
2074 xprt_transmit(task);
2075
2076 if (task->tk_status == -EAGAIN)
2077 goto out_nospace;
2078
2079 xprt_end_transmit(task);
2080 dprint_status(task);
2081 switch (task->tk_status) {
2082 case 0:
2083 /* Success */
2084 case -EHOSTDOWN:
2085 case -EHOSTUNREACH:
2086 case -ENETUNREACH:
2087 case -ECONNRESET:
2088 case -ECONNREFUSED:
2089 case -EADDRINUSE:
2090 case -ENOTCONN:
2091 case -EPIPE:
2092 break;
2093 case -ETIMEDOUT:
2094 /*
2095 * Problem reaching the server. Disconnect and let the
2096 * forechannel reestablish the connection. The server will
2097 * have to retransmit the backchannel request and we'll
2098 * reprocess it. Since these ops are idempotent, there's no
2099 * need to cache our reply at this time.
2100 */
2101 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2102 "error: %d\n", task->tk_status);
2103 xprt_conditional_disconnect(req->rq_xprt,
2104 req->rq_connect_cookie);
2105 break;
2106 default:
2107 /*
2108 * We were unable to reply and will have to drop the
2109 * request. The server should reconnect and retransmit.
2110 */
2111 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2112 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2113 "error: %d\n", task->tk_status);
2114 break;
2115 }
2116 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2117 out_done:
2118 task->tk_action = rpc_exit_task;
2119 return;
2120 out_nospace:
2121 req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2122 out_retry:
2123 task->tk_status = 0;
2124 }
2125 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2126
2127 /*
2128 * 6. Sort out the RPC call status
2129 */
2130 static void
2131 call_status(struct rpc_task *task)
2132 {
2133 struct rpc_clnt *clnt = task->tk_client;
2134 struct rpc_rqst *req = task->tk_rqstp;
2135 int status;
2136
2137 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2138 task->tk_status = req->rq_reply_bytes_recvd;
2139
2140 dprint_status(task);
2141
2142 status = task->tk_status;
2143 if (status >= 0) {
2144 task->tk_action = call_decode;
2145 return;
2146 }
2147
2148 trace_rpc_call_status(task);
2149 task->tk_status = 0;
2150 switch(status) {
2151 case -EHOSTDOWN:
2152 case -EHOSTUNREACH:
2153 case -ENETUNREACH:
2154 case -EPERM:
2155 if (RPC_IS_SOFTCONN(task)) {
2156 rpc_exit(task, status);
2157 break;
2158 }
2159 /*
2160 * Delay any retries for 3 seconds, then handle as if it
2161 * were a timeout.
2162 */
2163 rpc_delay(task, 3*HZ);
2164 case -ETIMEDOUT:
2165 task->tk_action = call_timeout;
2166 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2167 && task->tk_client->cl_discrtry)
2168 xprt_conditional_disconnect(req->rq_xprt,
2169 req->rq_connect_cookie);
2170 break;
2171 case -ECONNREFUSED:
2172 case -ECONNRESET:
2173 case -ECONNABORTED:
2174 rpc_force_rebind(clnt);
2175 case -EADDRINUSE:
2176 rpc_delay(task, 3*HZ);
2177 case -EPIPE:
2178 case -ENOTCONN:
2179 task->tk_action = call_bind;
2180 break;
2181 case -ENOBUFS:
2182 rpc_delay(task, HZ>>2);
2183 case -EAGAIN:
2184 task->tk_action = call_transmit;
2185 break;
2186 case -EIO:
2187 /* shutdown or soft timeout */
2188 rpc_exit(task, status);
2189 break;
2190 default:
2191 if (clnt->cl_chatty)
2192 printk("%s: RPC call returned error %d\n",
2193 clnt->cl_program->name, -status);
2194 rpc_exit(task, status);
2195 }
2196 }
2197
2198 /*
2199 * 6a. Handle RPC timeout
2200 * We do not release the request slot, so we keep using the
2201 * same XID for all retransmits.
2202 */
2203 static void
2204 call_timeout(struct rpc_task *task)
2205 {
2206 struct rpc_clnt *clnt = task->tk_client;
2207
2208 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2209 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2210 goto retry;
2211 }
2212
2213 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2214 task->tk_timeouts++;
2215
2216 if (RPC_IS_SOFTCONN(task)) {
2217 rpc_exit(task, -ETIMEDOUT);
2218 return;
2219 }
2220 if (RPC_IS_SOFT(task)) {
2221 if (clnt->cl_chatty) {
2222 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2223 clnt->cl_program->name,
2224 task->tk_xprt->servername);
2225 }
2226 if (task->tk_flags & RPC_TASK_TIMEOUT)
2227 rpc_exit(task, -ETIMEDOUT);
2228 else
2229 rpc_exit(task, -EIO);
2230 return;
2231 }
2232
2233 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2234 task->tk_flags |= RPC_CALL_MAJORSEEN;
2235 if (clnt->cl_chatty) {
2236 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2237 clnt->cl_program->name,
2238 task->tk_xprt->servername);
2239 }
2240 }
2241 rpc_force_rebind(clnt);
2242 /*
2243 * Did our request time out due to an RPCSEC_GSS out-of-sequence
2244 * event? RFC2203 requires the server to drop all such requests.
2245 */
2246 rpcauth_invalcred(task);
2247
2248 retry:
2249 task->tk_action = call_bind;
2250 task->tk_status = 0;
2251 }
2252
2253 /*
2254 * 7. Decode the RPC reply
2255 */
2256 static void
2257 call_decode(struct rpc_task *task)
2258 {
2259 struct rpc_clnt *clnt = task->tk_client;
2260 struct rpc_rqst *req = task->tk_rqstp;
2261 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
2262 __be32 *p;
2263
2264 dprint_status(task);
2265
2266 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2267 if (clnt->cl_chatty) {
2268 printk(KERN_NOTICE "%s: server %s OK\n",
2269 clnt->cl_program->name,
2270 task->tk_xprt->servername);
2271 }
2272 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2273 }
2274
2275 /*
2276 * Ensure that we see all writes made by xprt_complete_rqst()
2277 * before it changed req->rq_reply_bytes_recvd.
2278 */
2279 smp_rmb();
2280 req->rq_rcv_buf.len = req->rq_private_buf.len;
2281
2282 /* Check that the softirq receive buffer is valid */
2283 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2284 sizeof(req->rq_rcv_buf)) != 0);
2285
2286 if (req->rq_rcv_buf.len < 12) {
2287 if (!RPC_IS_SOFT(task)) {
2288 task->tk_action = call_bind;
2289 goto out_retry;
2290 }
2291 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
2292 clnt->cl_program->name, task->tk_status);
2293 task->tk_action = call_timeout;
2294 goto out_retry;
2295 }
2296
2297 p = rpc_verify_header(task);
2298 if (IS_ERR(p)) {
2299 if (p == ERR_PTR(-EAGAIN))
2300 goto out_retry;
2301 return;
2302 }
2303
2304 task->tk_action = rpc_exit_task;
2305
2306 if (decode) {
2307 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2308 task->tk_msg.rpc_resp);
2309 }
2310 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2311 task->tk_status);
2312 return;
2313 out_retry:
2314 task->tk_status = 0;
2315 /* Note: rpc_verify_header() may have freed the RPC slot */
2316 if (task->tk_rqstp == req) {
2317 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2318 if (task->tk_client->cl_discrtry)
2319 xprt_conditional_disconnect(req->rq_xprt,
2320 req->rq_connect_cookie);
2321 }
2322 }
2323
2324 static __be32 *
2325 rpc_encode_header(struct rpc_task *task)
2326 {
2327 struct rpc_clnt *clnt = task->tk_client;
2328 struct rpc_rqst *req = task->tk_rqstp;
2329 __be32 *p = req->rq_svec[0].iov_base;
2330
2331 /* FIXME: check buffer size? */
2332
2333 p = xprt_skip_transport_header(req->rq_xprt, p);
2334 *p++ = req->rq_xid; /* XID */
2335 *p++ = htonl(RPC_CALL); /* CALL */
2336 *p++ = htonl(RPC_VERSION); /* RPC version */
2337 *p++ = htonl(clnt->cl_prog); /* program number */
2338 *p++ = htonl(clnt->cl_vers); /* program version */
2339 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
2340 p = rpcauth_marshcred(task, p);
2341 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2342 return p;
2343 }
2344
2345 static __be32 *
2346 rpc_verify_header(struct rpc_task *task)
2347 {
2348 struct rpc_clnt *clnt = task->tk_client;
2349 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2350 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2351 __be32 *p = iov->iov_base;
2352 u32 n;
2353 int error = -EACCES;
2354
2355 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2356 /* RFC-1014 says that the representation of XDR data must be a
2357 * multiple of four bytes
2358 * - if it isn't pointer subtraction in the NFS client may give
2359 * undefined results
2360 */
2361 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2362 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2363 task->tk_rqstp->rq_rcv_buf.len);
2364 error = -EIO;
2365 goto out_err;
2366 }
2367 if ((len -= 3) < 0)
2368 goto out_overflow;
2369
2370 p += 1; /* skip XID */
2371 if ((n = ntohl(*p++)) != RPC_REPLY) {
2372 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2373 task->tk_pid, __func__, n);
2374 error = -EIO;
2375 goto out_garbage;
2376 }
2377
2378 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2379 if (--len < 0)
2380 goto out_overflow;
2381 switch ((n = ntohl(*p++))) {
2382 case RPC_AUTH_ERROR:
2383 break;
2384 case RPC_MISMATCH:
2385 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2386 task->tk_pid, __func__);
2387 error = -EPROTONOSUPPORT;
2388 goto out_err;
2389 default:
2390 dprintk("RPC: %5u %s: RPC call rejected, "
2391 "unknown error: %x\n",
2392 task->tk_pid, __func__, n);
2393 error = -EIO;
2394 goto out_err;
2395 }
2396 if (--len < 0)
2397 goto out_overflow;
2398 switch ((n = ntohl(*p++))) {
2399 case RPC_AUTH_REJECTEDCRED:
2400 case RPC_AUTH_REJECTEDVERF:
2401 case RPCSEC_GSS_CREDPROBLEM:
2402 case RPCSEC_GSS_CTXPROBLEM:
2403 if (!task->tk_cred_retry)
2404 break;
2405 task->tk_cred_retry--;
2406 dprintk("RPC: %5u %s: retry stale creds\n",
2407 task->tk_pid, __func__);
2408 rpcauth_invalcred(task);
2409 /* Ensure we obtain a new XID! */
2410 xprt_release(task);
2411 task->tk_action = call_reserve;
2412 goto out_retry;
2413 case RPC_AUTH_BADCRED:
2414 case RPC_AUTH_BADVERF:
2415 /* possibly garbled cred/verf? */
2416 if (!task->tk_garb_retry)
2417 break;
2418 task->tk_garb_retry--;
2419 dprintk("RPC: %5u %s: retry garbled creds\n",
2420 task->tk_pid, __func__);
2421 task->tk_action = call_bind;
2422 goto out_retry;
2423 case RPC_AUTH_TOOWEAK:
2424 printk(KERN_NOTICE "RPC: server %s requires stronger "
2425 "authentication.\n",
2426 task->tk_xprt->servername);
2427 break;
2428 default:
2429 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2430 task->tk_pid, __func__, n);
2431 error = -EIO;
2432 }
2433 dprintk("RPC: %5u %s: call rejected %d\n",
2434 task->tk_pid, __func__, n);
2435 goto out_err;
2436 }
2437 p = rpcauth_checkverf(task, p);
2438 if (IS_ERR(p)) {
2439 error = PTR_ERR(p);
2440 dprintk("RPC: %5u %s: auth check failed with %d\n",
2441 task->tk_pid, __func__, error);
2442 goto out_garbage; /* bad verifier, retry */
2443 }
2444 len = p - (__be32 *)iov->iov_base - 1;
2445 if (len < 0)
2446 goto out_overflow;
2447 switch ((n = ntohl(*p++))) {
2448 case RPC_SUCCESS:
2449 return p;
2450 case RPC_PROG_UNAVAIL:
2451 dprintk("RPC: %5u %s: program %u is unsupported "
2452 "by server %s\n", task->tk_pid, __func__,
2453 (unsigned int)clnt->cl_prog,
2454 task->tk_xprt->servername);
2455 error = -EPFNOSUPPORT;
2456 goto out_err;
2457 case RPC_PROG_MISMATCH:
2458 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2459 "by server %s\n", task->tk_pid, __func__,
2460 (unsigned int)clnt->cl_prog,
2461 (unsigned int)clnt->cl_vers,
2462 task->tk_xprt->servername);
2463 error = -EPROTONOSUPPORT;
2464 goto out_err;
2465 case RPC_PROC_UNAVAIL:
2466 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2467 "version %u on server %s\n",
2468 task->tk_pid, __func__,
2469 rpc_proc_name(task),
2470 clnt->cl_prog, clnt->cl_vers,
2471 task->tk_xprt->servername);
2472 error = -EOPNOTSUPP;
2473 goto out_err;
2474 case RPC_GARBAGE_ARGS:
2475 dprintk("RPC: %5u %s: server saw garbage\n",
2476 task->tk_pid, __func__);
2477 break; /* retry */
2478 default:
2479 dprintk("RPC: %5u %s: server accept status: %x\n",
2480 task->tk_pid, __func__, n);
2481 /* Also retry */
2482 }
2483
2484 out_garbage:
2485 clnt->cl_stats->rpcgarbage++;
2486 if (task->tk_garb_retry) {
2487 task->tk_garb_retry--;
2488 dprintk("RPC: %5u %s: retrying\n",
2489 task->tk_pid, __func__);
2490 task->tk_action = call_bind;
2491 out_retry:
2492 return ERR_PTR(-EAGAIN);
2493 }
2494 out_err:
2495 rpc_exit(task, error);
2496 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2497 __func__, error);
2498 return ERR_PTR(error);
2499 out_overflow:
2500 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2501 __func__);
2502 goto out_garbage;
2503 }
2504
2505 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2506 {
2507 }
2508
2509 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2510 {
2511 return 0;
2512 }
2513
2514 static struct rpc_procinfo rpcproc_null = {
2515 .p_encode = rpcproc_encode_null,
2516 .p_decode = rpcproc_decode_null,
2517 };
2518
2519 static int rpc_ping(struct rpc_clnt *clnt)
2520 {
2521 struct rpc_message msg = {
2522 .rpc_proc = &rpcproc_null,
2523 };
2524 int err;
2525 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2526 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2527 put_rpccred(msg.rpc_cred);
2528 return err;
2529 }
2530
2531 static
2532 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2533 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2534 const struct rpc_call_ops *ops, void *data)
2535 {
2536 struct rpc_message msg = {
2537 .rpc_proc = &rpcproc_null,
2538 .rpc_cred = cred,
2539 };
2540 struct rpc_task_setup task_setup_data = {
2541 .rpc_client = clnt,
2542 .rpc_xprt = xprt,
2543 .rpc_message = &msg,
2544 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2545 .callback_data = data,
2546 .flags = flags,
2547 };
2548
2549 return rpc_run_task(&task_setup_data);
2550 }
2551
2552 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2553 {
2554 return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2555 }
2556 EXPORT_SYMBOL_GPL(rpc_call_null);
2557
2558 struct rpc_cb_add_xprt_calldata {
2559 struct rpc_xprt_switch *xps;
2560 struct rpc_xprt *xprt;
2561 };
2562
2563 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2564 {
2565 struct rpc_cb_add_xprt_calldata *data = calldata;
2566
2567 if (task->tk_status == 0)
2568 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2569 }
2570
2571 static void rpc_cb_add_xprt_release(void *calldata)
2572 {
2573 struct rpc_cb_add_xprt_calldata *data = calldata;
2574
2575 xprt_put(data->xprt);
2576 xprt_switch_put(data->xps);
2577 kfree(data);
2578 }
2579
2580 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2581 .rpc_call_done = rpc_cb_add_xprt_done,
2582 .rpc_release = rpc_cb_add_xprt_release,
2583 };
2584
2585 /**
2586 * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2587 * @clnt: pointer to struct rpc_clnt
2588 * @xps: pointer to struct rpc_xprt_switch,
2589 * @xprt: pointer struct rpc_xprt
2590 * @dummy: unused
2591 */
2592 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2593 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2594 void *dummy)
2595 {
2596 struct rpc_cb_add_xprt_calldata *data;
2597 struct rpc_cred *cred;
2598 struct rpc_task *task;
2599
2600 data = kmalloc(sizeof(*data), GFP_NOFS);
2601 if (!data)
2602 return -ENOMEM;
2603 data->xps = xprt_switch_get(xps);
2604 data->xprt = xprt_get(xprt);
2605
2606 cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2607 task = rpc_call_null_helper(clnt, xprt, cred,
2608 RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2609 &rpc_cb_add_xprt_call_ops, data);
2610 put_rpccred(cred);
2611 if (IS_ERR(task))
2612 return PTR_ERR(task);
2613 rpc_put_task(task);
2614 return 1;
2615 }
2616 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2617
2618 /**
2619 * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2620 * @clnt: pointer to struct rpc_clnt
2621 * @xprtargs: pointer to struct xprt_create
2622 * @setup: callback to test and/or set up the connection
2623 * @data: pointer to setup function data
2624 *
2625 * Creates a new transport using the parameters set in args and
2626 * adds it to clnt.
2627 * If ping is set, then test that connectivity succeeds before
2628 * adding the new transport.
2629 *
2630 */
2631 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2632 struct xprt_create *xprtargs,
2633 int (*setup)(struct rpc_clnt *,
2634 struct rpc_xprt_switch *,
2635 struct rpc_xprt *,
2636 void *),
2637 void *data)
2638 {
2639 struct rpc_xprt_switch *xps;
2640 struct rpc_xprt *xprt;
2641 unsigned long reconnect_timeout;
2642 unsigned char resvport;
2643 int ret = 0;
2644
2645 rcu_read_lock();
2646 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2647 xprt = xprt_iter_xprt(&clnt->cl_xpi);
2648 if (xps == NULL || xprt == NULL) {
2649 rcu_read_unlock();
2650 return -EAGAIN;
2651 }
2652 resvport = xprt->resvport;
2653 reconnect_timeout = xprt->max_reconnect_timeout;
2654 rcu_read_unlock();
2655
2656 xprt = xprt_create_transport(xprtargs);
2657 if (IS_ERR(xprt)) {
2658 ret = PTR_ERR(xprt);
2659 goto out_put_switch;
2660 }
2661 xprt->resvport = resvport;
2662 xprt->max_reconnect_timeout = reconnect_timeout;
2663
2664 rpc_xprt_switch_set_roundrobin(xps);
2665 if (setup) {
2666 ret = setup(clnt, xps, xprt, data);
2667 if (ret != 0)
2668 goto out_put_xprt;
2669 }
2670 rpc_xprt_switch_add_xprt(xps, xprt);
2671 out_put_xprt:
2672 xprt_put(xprt);
2673 out_put_switch:
2674 xprt_switch_put(xps);
2675 return ret;
2676 }
2677 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2678
2679 static int
2680 rpc_xprt_cap_max_reconnect_timeout(struct rpc_clnt *clnt,
2681 struct rpc_xprt *xprt,
2682 void *data)
2683 {
2684 unsigned long timeout = *((unsigned long *)data);
2685
2686 if (timeout < xprt->max_reconnect_timeout)
2687 xprt->max_reconnect_timeout = timeout;
2688 return 0;
2689 }
2690
2691 void
2692 rpc_cap_max_reconnect_timeout(struct rpc_clnt *clnt, unsigned long timeo)
2693 {
2694 rpc_clnt_iterate_for_each_xprt(clnt,
2695 rpc_xprt_cap_max_reconnect_timeout,
2696 &timeo);
2697 }
2698 EXPORT_SYMBOL_GPL(rpc_cap_max_reconnect_timeout);
2699
2700 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2701 static void rpc_show_header(void)
2702 {
2703 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2704 "-timeout ---ops--\n");
2705 }
2706
2707 static void rpc_show_task(const struct rpc_clnt *clnt,
2708 const struct rpc_task *task)
2709 {
2710 const char *rpc_waitq = "none";
2711
2712 if (RPC_IS_QUEUED(task))
2713 rpc_waitq = rpc_qname(task->tk_waitqueue);
2714
2715 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2716 task->tk_pid, task->tk_flags, task->tk_status,
2717 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2718 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2719 task->tk_action, rpc_waitq);
2720 }
2721
2722 void rpc_show_tasks(struct net *net)
2723 {
2724 struct rpc_clnt *clnt;
2725 struct rpc_task *task;
2726 int header = 0;
2727 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2728
2729 spin_lock(&sn->rpc_client_lock);
2730 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2731 spin_lock(&clnt->cl_lock);
2732 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2733 if (!header) {
2734 rpc_show_header();
2735 header++;
2736 }
2737 rpc_show_task(clnt, task);
2738 }
2739 spin_unlock(&clnt->cl_lock);
2740 }
2741 spin_unlock(&sn->rpc_client_lock);
2742 }
2743 #endif
2744
2745 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2746 static int
2747 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2748 struct rpc_xprt *xprt,
2749 void *dummy)
2750 {
2751 return xprt_enable_swap(xprt);
2752 }
2753
2754 int
2755 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2756 {
2757 if (atomic_inc_return(&clnt->cl_swapper) == 1)
2758 return rpc_clnt_iterate_for_each_xprt(clnt,
2759 rpc_clnt_swap_activate_callback, NULL);
2760 return 0;
2761 }
2762 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2763
2764 static int
2765 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2766 struct rpc_xprt *xprt,
2767 void *dummy)
2768 {
2769 xprt_disable_swap(xprt);
2770 return 0;
2771 }
2772
2773 void
2774 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2775 {
2776 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2777 rpc_clnt_iterate_for_each_xprt(clnt,
2778 rpc_clnt_swap_deactivate_callback, NULL);
2779 }
2780 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2781 #endif /* CONFIG_SUNRPC_SWAP */
Linux kernel - Deliverables
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