Linux 4.11-rc6
[linux/fpc-iii.git] / net / sunrpc / clnt.c
blob52da3ce54bb53c8434f0acc276c0003e385486e7
1 /*
2 * linux/net/sunrpc/clnt.c
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.
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.
16 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
17 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
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>
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>
42 #include "sunrpc.h"
43 #include "netns.h"
45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
46 # define RPCDBG_FACILITY RPCDBG_CALL
47 #endif
49 #define dprint_status(t) \
50 dprintk("RPC: %5u %s (status %d)\n", t->tk_pid, \
51 __func__, t->tk_status)
54 * All RPC clients are linked into this list
57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
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);
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);
83 static void rpc_register_client(struct rpc_clnt *clnt)
85 struct net *net = rpc_net_ns(clnt);
86 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
88 spin_lock(&sn->rpc_client_lock);
89 list_add(&clnt->cl_clients, &sn->all_clients);
90 spin_unlock(&sn->rpc_client_lock);
93 static void rpc_unregister_client(struct rpc_clnt *clnt)
95 struct net *net = rpc_net_ns(clnt);
96 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
98 spin_lock(&sn->rpc_client_lock);
99 list_del(&clnt->cl_clients);
100 spin_unlock(&sn->rpc_client_lock);
103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
105 rpc_remove_client_dir(clnt);
108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
110 struct net *net = rpc_net_ns(clnt);
111 struct super_block *pipefs_sb;
113 pipefs_sb = rpc_get_sb_net(net);
114 if (pipefs_sb) {
115 __rpc_clnt_remove_pipedir(clnt);
116 rpc_put_sb_net(net);
120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
121 struct rpc_clnt *clnt)
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;
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;
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;
146 dput(dir);
147 return dentry;
150 static int
151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
153 struct dentry *dentry;
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);
160 return 0;
163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
165 if (clnt->cl_program->pipe_dir_name == NULL)
166 return 1;
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;
180 return 0;
183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
184 struct super_block *sb)
186 struct dentry *dentry;
188 switch (event) {
189 case RPC_PIPEFS_MOUNT:
190 dentry = rpc_setup_pipedir_sb(sb, clnt);
191 if (!dentry)
192 return -ENOENT;
193 if (IS_ERR(dentry))
194 return PTR_ERR(dentry);
195 break;
196 case RPC_PIPEFS_UMOUNT:
197 __rpc_clnt_remove_pipedir(clnt);
198 break;
199 default:
200 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
201 return -ENOTSUPP;
203 return 0;
206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
207 struct super_block *sb)
209 int error = 0;
211 for (;; clnt = clnt->cl_parent) {
212 if (!rpc_clnt_skip_event(clnt, event))
213 error = __rpc_clnt_handle_event(clnt, event, sb);
214 if (error || clnt == clnt->cl_parent)
215 break;
217 return error;
220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
222 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
223 struct rpc_clnt *clnt;
225 spin_lock(&sn->rpc_client_lock);
226 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
227 if (rpc_clnt_skip_event(clnt, event))
228 continue;
229 spin_unlock(&sn->rpc_client_lock);
230 return clnt;
232 spin_unlock(&sn->rpc_client_lock);
233 return NULL;
236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
237 void *ptr)
239 struct super_block *sb = ptr;
240 struct rpc_clnt *clnt;
241 int error = 0;
243 while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
244 error = __rpc_pipefs_event(clnt, event, sb);
245 if (error)
246 break;
248 return error;
251 static struct notifier_block rpc_clients_block = {
252 .notifier_call = rpc_pipefs_event,
253 .priority = SUNRPC_PIPEFS_RPC_PRIO,
256 int rpc_clients_notifier_register(void)
258 return rpc_pipefs_notifier_register(&rpc_clients_block);
261 void rpc_clients_notifier_unregister(void)
263 return rpc_pipefs_notifier_unregister(&rpc_clients_block);
266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
267 struct rpc_xprt *xprt,
268 const struct rpc_timeout *timeout)
270 struct rpc_xprt *old;
272 spin_lock(&clnt->cl_lock);
273 old = rcu_dereference_protected(clnt->cl_xprt,
274 lockdep_is_held(&clnt->cl_lock));
276 if (!xprt_bound(xprt))
277 clnt->cl_autobind = 1;
279 clnt->cl_timeout = timeout;
280 rcu_assign_pointer(clnt->cl_xprt, xprt);
281 spin_unlock(&clnt->cl_lock);
283 return old;
286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
288 clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
289 nodename, sizeof(clnt->cl_nodename));
292 static int rpc_client_register(struct rpc_clnt *clnt,
293 rpc_authflavor_t pseudoflavor,
294 const char *client_name)
296 struct rpc_auth_create_args auth_args = {
297 .pseudoflavor = pseudoflavor,
298 .target_name = client_name,
300 struct rpc_auth *auth;
301 struct net *net = rpc_net_ns(clnt);
302 struct super_block *pipefs_sb;
303 int err;
305 rpc_clnt_debugfs_register(clnt);
307 pipefs_sb = rpc_get_sb_net(net);
308 if (pipefs_sb) {
309 err = rpc_setup_pipedir(pipefs_sb, clnt);
310 if (err)
311 goto out;
314 rpc_register_client(clnt);
315 if (pipefs_sb)
316 rpc_put_sb_net(net);
318 auth = rpcauth_create(&auth_args, clnt);
319 if (IS_ERR(auth)) {
320 dprintk("RPC: Couldn't create auth handle (flavor %u)\n",
321 pseudoflavor);
322 err = PTR_ERR(auth);
323 goto err_auth;
325 return 0;
326 err_auth:
327 pipefs_sb = rpc_get_sb_net(net);
328 rpc_unregister_client(clnt);
329 __rpc_clnt_remove_pipedir(clnt);
330 out:
331 if (pipefs_sb)
332 rpc_put_sb_net(net);
333 rpc_clnt_debugfs_unregister(clnt);
334 return err;
337 static DEFINE_IDA(rpc_clids);
339 void rpc_cleanup_clids(void)
341 ida_destroy(&rpc_clids);
344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
346 int clid;
348 clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
349 if (clid < 0)
350 return clid;
351 clnt->cl_clid = clid;
352 return 0;
355 static void rpc_free_clid(struct rpc_clnt *clnt)
357 ida_simple_remove(&rpc_clids, clnt->cl_clid);
360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
361 struct rpc_xprt_switch *xps,
362 struct rpc_xprt *xprt,
363 struct rpc_clnt *parent)
365 const struct rpc_program *program = args->program;
366 const struct rpc_version *version;
367 struct rpc_clnt *clnt = NULL;
368 const struct rpc_timeout *timeout;
369 const char *nodename = args->nodename;
370 int err;
372 /* sanity check the name before trying to print it */
373 dprintk("RPC: creating %s client for %s (xprt %p)\n",
374 program->name, args->servername, xprt);
376 err = rpciod_up();
377 if (err)
378 goto out_no_rpciod;
380 err = -EINVAL;
381 if (args->version >= program->nrvers)
382 goto out_err;
383 version = program->version[args->version];
384 if (version == NULL)
385 goto out_err;
387 err = -ENOMEM;
388 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
389 if (!clnt)
390 goto out_err;
391 clnt->cl_parent = parent ? : clnt;
393 err = rpc_alloc_clid(clnt);
394 if (err)
395 goto out_no_clid;
397 clnt->cl_procinfo = version->procs;
398 clnt->cl_maxproc = version->nrprocs;
399 clnt->cl_prog = args->prognumber ? : program->number;
400 clnt->cl_vers = version->number;
401 clnt->cl_stats = program->stats;
402 clnt->cl_metrics = rpc_alloc_iostats(clnt);
403 rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
404 err = -ENOMEM;
405 if (clnt->cl_metrics == NULL)
406 goto out_no_stats;
407 clnt->cl_program = program;
408 INIT_LIST_HEAD(&clnt->cl_tasks);
409 spin_lock_init(&clnt->cl_lock);
411 timeout = xprt->timeout;
412 if (args->timeout != NULL) {
413 memcpy(&clnt->cl_timeout_default, args->timeout,
414 sizeof(clnt->cl_timeout_default));
415 timeout = &clnt->cl_timeout_default;
418 rpc_clnt_set_transport(clnt, xprt, timeout);
419 xprt_iter_init(&clnt->cl_xpi, xps);
420 xprt_switch_put(xps);
422 clnt->cl_rtt = &clnt->cl_rtt_default;
423 rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
425 atomic_set(&clnt->cl_count, 1);
427 if (nodename == NULL)
428 nodename = utsname()->nodename;
429 /* save the nodename */
430 rpc_clnt_set_nodename(clnt, nodename);
432 err = rpc_client_register(clnt, args->authflavor, args->client_name);
433 if (err)
434 goto out_no_path;
435 if (parent)
436 atomic_inc(&parent->cl_count);
437 return clnt;
439 out_no_path:
440 rpc_free_iostats(clnt->cl_metrics);
441 out_no_stats:
442 rpc_free_clid(clnt);
443 out_no_clid:
444 kfree(clnt);
445 out_err:
446 rpciod_down();
447 out_no_rpciod:
448 xprt_switch_put(xps);
449 xprt_put(xprt);
450 return ERR_PTR(err);
453 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
454 struct rpc_xprt *xprt)
456 struct rpc_clnt *clnt = NULL;
457 struct rpc_xprt_switch *xps;
459 if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
460 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
461 xps = args->bc_xprt->xpt_bc_xps;
462 xprt_switch_get(xps);
463 } else {
464 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
465 if (xps == NULL) {
466 xprt_put(xprt);
467 return ERR_PTR(-ENOMEM);
469 if (xprt->bc_xprt) {
470 xprt_switch_get(xps);
471 xprt->bc_xprt->xpt_bc_xps = xps;
474 clnt = rpc_new_client(args, xps, xprt, NULL);
475 if (IS_ERR(clnt))
476 return clnt;
478 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
479 int err = rpc_ping(clnt);
480 if (err != 0) {
481 rpc_shutdown_client(clnt);
482 return ERR_PTR(err);
486 clnt->cl_softrtry = 1;
487 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
488 clnt->cl_softrtry = 0;
490 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
491 clnt->cl_autobind = 1;
492 if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
493 clnt->cl_noretranstimeo = 1;
494 if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
495 clnt->cl_discrtry = 1;
496 if (!(args->flags & RPC_CLNT_CREATE_QUIET))
497 clnt->cl_chatty = 1;
499 return clnt;
503 * rpc_create - create an RPC client and transport with one call
504 * @args: rpc_clnt create argument structure
506 * Creates and initializes an RPC transport and an RPC client.
508 * It can ping the server in order to determine if it is up, and to see if
509 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
510 * this behavior so asynchronous tasks can also use rpc_create.
512 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
514 struct rpc_xprt *xprt;
515 struct xprt_create xprtargs = {
516 .net = args->net,
517 .ident = args->protocol,
518 .srcaddr = args->saddress,
519 .dstaddr = args->address,
520 .addrlen = args->addrsize,
521 .servername = args->servername,
522 .bc_xprt = args->bc_xprt,
524 char servername[48];
526 if (args->bc_xprt) {
527 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
528 xprt = args->bc_xprt->xpt_bc_xprt;
529 if (xprt) {
530 xprt_get(xprt);
531 return rpc_create_xprt(args, xprt);
535 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
536 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
537 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
538 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
540 * If the caller chooses not to specify a hostname, whip
541 * up a string representation of the passed-in address.
543 if (xprtargs.servername == NULL) {
544 struct sockaddr_un *sun =
545 (struct sockaddr_un *)args->address;
546 struct sockaddr_in *sin =
547 (struct sockaddr_in *)args->address;
548 struct sockaddr_in6 *sin6 =
549 (struct sockaddr_in6 *)args->address;
551 servername[0] = '\0';
552 switch (args->address->sa_family) {
553 case AF_LOCAL:
554 snprintf(servername, sizeof(servername), "%s",
555 sun->sun_path);
556 break;
557 case AF_INET:
558 snprintf(servername, sizeof(servername), "%pI4",
559 &sin->sin_addr.s_addr);
560 break;
561 case AF_INET6:
562 snprintf(servername, sizeof(servername), "%pI6",
563 &sin6->sin6_addr);
564 break;
565 default:
566 /* caller wants default server name, but
567 * address family isn't recognized. */
568 return ERR_PTR(-EINVAL);
570 xprtargs.servername = servername;
573 xprt = xprt_create_transport(&xprtargs);
574 if (IS_ERR(xprt))
575 return (struct rpc_clnt *)xprt;
578 * By default, kernel RPC client connects from a reserved port.
579 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
580 * but it is always enabled for rpciod, which handles the connect
581 * operation.
583 xprt->resvport = 1;
584 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
585 xprt->resvport = 0;
587 return rpc_create_xprt(args, xprt);
589 EXPORT_SYMBOL_GPL(rpc_create);
592 * This function clones the RPC client structure. It allows us to share the
593 * same transport while varying parameters such as the authentication
594 * flavour.
596 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
597 struct rpc_clnt *clnt)
599 struct rpc_xprt_switch *xps;
600 struct rpc_xprt *xprt;
601 struct rpc_clnt *new;
602 int err;
604 err = -ENOMEM;
605 rcu_read_lock();
606 xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
607 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
608 rcu_read_unlock();
609 if (xprt == NULL || xps == NULL) {
610 xprt_put(xprt);
611 xprt_switch_put(xps);
612 goto out_err;
614 args->servername = xprt->servername;
615 args->nodename = clnt->cl_nodename;
617 new = rpc_new_client(args, xps, xprt, clnt);
618 if (IS_ERR(new)) {
619 err = PTR_ERR(new);
620 goto out_err;
623 /* Turn off autobind on clones */
624 new->cl_autobind = 0;
625 new->cl_softrtry = clnt->cl_softrtry;
626 new->cl_noretranstimeo = clnt->cl_noretranstimeo;
627 new->cl_discrtry = clnt->cl_discrtry;
628 new->cl_chatty = clnt->cl_chatty;
629 return new;
631 out_err:
632 dprintk("RPC: %s: returned error %d\n", __func__, err);
633 return ERR_PTR(err);
637 * rpc_clone_client - Clone an RPC client structure
639 * @clnt: RPC client whose parameters are copied
641 * Returns a fresh RPC client or an ERR_PTR.
643 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
645 struct rpc_create_args args = {
646 .program = clnt->cl_program,
647 .prognumber = clnt->cl_prog,
648 .version = clnt->cl_vers,
649 .authflavor = clnt->cl_auth->au_flavor,
651 return __rpc_clone_client(&args, clnt);
653 EXPORT_SYMBOL_GPL(rpc_clone_client);
656 * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
658 * @clnt: RPC client whose parameters are copied
659 * @flavor: security flavor for new client
661 * Returns a fresh RPC client or an ERR_PTR.
663 struct rpc_clnt *
664 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
666 struct rpc_create_args args = {
667 .program = clnt->cl_program,
668 .prognumber = clnt->cl_prog,
669 .version = clnt->cl_vers,
670 .authflavor = flavor,
672 return __rpc_clone_client(&args, clnt);
674 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
677 * rpc_switch_client_transport: switch the RPC transport on the fly
678 * @clnt: pointer to a struct rpc_clnt
679 * @args: pointer to the new transport arguments
680 * @timeout: pointer to the new timeout parameters
682 * This function allows the caller to switch the RPC transport for the
683 * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
684 * server, for instance. It assumes that the caller has ensured that
685 * there are no active RPC tasks by using some form of locking.
687 * Returns zero if "clnt" is now using the new xprt. Otherwise a
688 * negative errno is returned, and "clnt" continues to use the old
689 * xprt.
691 int rpc_switch_client_transport(struct rpc_clnt *clnt,
692 struct xprt_create *args,
693 const struct rpc_timeout *timeout)
695 const struct rpc_timeout *old_timeo;
696 rpc_authflavor_t pseudoflavor;
697 struct rpc_xprt_switch *xps, *oldxps;
698 struct rpc_xprt *xprt, *old;
699 struct rpc_clnt *parent;
700 int err;
702 xprt = xprt_create_transport(args);
703 if (IS_ERR(xprt)) {
704 dprintk("RPC: failed to create new xprt for clnt %p\n",
705 clnt);
706 return PTR_ERR(xprt);
709 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
710 if (xps == NULL) {
711 xprt_put(xprt);
712 return -ENOMEM;
715 pseudoflavor = clnt->cl_auth->au_flavor;
717 old_timeo = clnt->cl_timeout;
718 old = rpc_clnt_set_transport(clnt, xprt, timeout);
719 oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
721 rpc_unregister_client(clnt);
722 __rpc_clnt_remove_pipedir(clnt);
723 rpc_clnt_debugfs_unregister(clnt);
726 * A new transport was created. "clnt" therefore
727 * becomes the root of a new cl_parent tree. clnt's
728 * children, if it has any, still point to the old xprt.
730 parent = clnt->cl_parent;
731 clnt->cl_parent = clnt;
734 * The old rpc_auth cache cannot be re-used. GSS
735 * contexts in particular are between a single
736 * client and server.
738 err = rpc_client_register(clnt, pseudoflavor, NULL);
739 if (err)
740 goto out_revert;
742 synchronize_rcu();
743 if (parent != clnt)
744 rpc_release_client(parent);
745 xprt_switch_put(oldxps);
746 xprt_put(old);
747 dprintk("RPC: replaced xprt for clnt %p\n", clnt);
748 return 0;
750 out_revert:
751 xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
752 rpc_clnt_set_transport(clnt, old, old_timeo);
753 clnt->cl_parent = parent;
754 rpc_client_register(clnt, pseudoflavor, NULL);
755 xprt_switch_put(xps);
756 xprt_put(xprt);
757 dprintk("RPC: failed to switch xprt for clnt %p\n", clnt);
758 return err;
760 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
762 static
763 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
765 struct rpc_xprt_switch *xps;
767 rcu_read_lock();
768 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
769 rcu_read_unlock();
770 if (xps == NULL)
771 return -EAGAIN;
772 xprt_iter_init_listall(xpi, xps);
773 xprt_switch_put(xps);
774 return 0;
778 * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
779 * @clnt: pointer to client
780 * @fn: function to apply
781 * @data: void pointer to function data
783 * Iterates through the list of RPC transports currently attached to the
784 * client and applies the function fn(clnt, xprt, data).
786 * On error, the iteration stops, and the function returns the error value.
788 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
789 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
790 void *data)
792 struct rpc_xprt_iter xpi;
793 int ret;
795 ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
796 if (ret)
797 return ret;
798 for (;;) {
799 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
801 if (!xprt)
802 break;
803 ret = fn(clnt, xprt, data);
804 xprt_put(xprt);
805 if (ret < 0)
806 break;
808 xprt_iter_destroy(&xpi);
809 return ret;
811 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
814 * Kill all tasks for the given client.
815 * XXX: kill their descendants as well?
817 void rpc_killall_tasks(struct rpc_clnt *clnt)
819 struct rpc_task *rovr;
822 if (list_empty(&clnt->cl_tasks))
823 return;
824 dprintk("RPC: killing all tasks for client %p\n", clnt);
826 * Spin lock all_tasks to prevent changes...
828 spin_lock(&clnt->cl_lock);
829 list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
830 if (!RPC_IS_ACTIVATED(rovr))
831 continue;
832 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
833 rovr->tk_flags |= RPC_TASK_KILLED;
834 rpc_exit(rovr, -EIO);
835 if (RPC_IS_QUEUED(rovr))
836 rpc_wake_up_queued_task(rovr->tk_waitqueue,
837 rovr);
840 spin_unlock(&clnt->cl_lock);
842 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
845 * Properly shut down an RPC client, terminating all outstanding
846 * requests.
848 void rpc_shutdown_client(struct rpc_clnt *clnt)
850 might_sleep();
852 dprintk_rcu("RPC: shutting down %s client for %s\n",
853 clnt->cl_program->name,
854 rcu_dereference(clnt->cl_xprt)->servername);
856 while (!list_empty(&clnt->cl_tasks)) {
857 rpc_killall_tasks(clnt);
858 wait_event_timeout(destroy_wait,
859 list_empty(&clnt->cl_tasks), 1*HZ);
862 rpc_release_client(clnt);
864 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
867 * Free an RPC client
869 static struct rpc_clnt *
870 rpc_free_client(struct rpc_clnt *clnt)
872 struct rpc_clnt *parent = NULL;
874 dprintk_rcu("RPC: destroying %s client for %s\n",
875 clnt->cl_program->name,
876 rcu_dereference(clnt->cl_xprt)->servername);
877 if (clnt->cl_parent != clnt)
878 parent = clnt->cl_parent;
879 rpc_clnt_debugfs_unregister(clnt);
880 rpc_clnt_remove_pipedir(clnt);
881 rpc_unregister_client(clnt);
882 rpc_free_iostats(clnt->cl_metrics);
883 clnt->cl_metrics = NULL;
884 xprt_put(rcu_dereference_raw(clnt->cl_xprt));
885 xprt_iter_destroy(&clnt->cl_xpi);
886 rpciod_down();
887 rpc_free_clid(clnt);
888 kfree(clnt);
889 return parent;
893 * Free an RPC client
895 static struct rpc_clnt *
896 rpc_free_auth(struct rpc_clnt *clnt)
898 if (clnt->cl_auth == NULL)
899 return rpc_free_client(clnt);
902 * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
903 * release remaining GSS contexts. This mechanism ensures
904 * that it can do so safely.
906 atomic_inc(&clnt->cl_count);
907 rpcauth_release(clnt->cl_auth);
908 clnt->cl_auth = NULL;
909 if (atomic_dec_and_test(&clnt->cl_count))
910 return rpc_free_client(clnt);
911 return NULL;
915 * Release reference to the RPC client
917 void
918 rpc_release_client(struct rpc_clnt *clnt)
920 dprintk("RPC: rpc_release_client(%p)\n", clnt);
922 do {
923 if (list_empty(&clnt->cl_tasks))
924 wake_up(&destroy_wait);
925 if (!atomic_dec_and_test(&clnt->cl_count))
926 break;
927 clnt = rpc_free_auth(clnt);
928 } while (clnt != NULL);
930 EXPORT_SYMBOL_GPL(rpc_release_client);
933 * rpc_bind_new_program - bind a new RPC program to an existing client
934 * @old: old rpc_client
935 * @program: rpc program to set
936 * @vers: rpc program version
938 * Clones the rpc client and sets up a new RPC program. This is mainly
939 * of use for enabling different RPC programs to share the same transport.
940 * The Sun NFSv2/v3 ACL protocol can do this.
942 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
943 const struct rpc_program *program,
944 u32 vers)
946 struct rpc_create_args args = {
947 .program = program,
948 .prognumber = program->number,
949 .version = vers,
950 .authflavor = old->cl_auth->au_flavor,
952 struct rpc_clnt *clnt;
953 int err;
955 clnt = __rpc_clone_client(&args, old);
956 if (IS_ERR(clnt))
957 goto out;
958 err = rpc_ping(clnt);
959 if (err != 0) {
960 rpc_shutdown_client(clnt);
961 clnt = ERR_PTR(err);
963 out:
964 return clnt;
966 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
968 void rpc_task_release_client(struct rpc_task *task)
970 struct rpc_clnt *clnt = task->tk_client;
971 struct rpc_xprt *xprt = task->tk_xprt;
973 if (clnt != NULL) {
974 /* Remove from client task list */
975 spin_lock(&clnt->cl_lock);
976 list_del(&task->tk_task);
977 spin_unlock(&clnt->cl_lock);
978 task->tk_client = NULL;
980 rpc_release_client(clnt);
983 if (xprt != NULL) {
984 task->tk_xprt = NULL;
986 xprt_put(xprt);
990 static
991 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
994 if (clnt != NULL) {
995 if (task->tk_xprt == NULL)
996 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
997 task->tk_client = clnt;
998 atomic_inc(&clnt->cl_count);
999 if (clnt->cl_softrtry)
1000 task->tk_flags |= RPC_TASK_SOFT;
1001 if (clnt->cl_noretranstimeo)
1002 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1003 if (atomic_read(&clnt->cl_swapper))
1004 task->tk_flags |= RPC_TASK_SWAPPER;
1005 /* Add to the client's list of all tasks */
1006 spin_lock(&clnt->cl_lock);
1007 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1008 spin_unlock(&clnt->cl_lock);
1012 static void
1013 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1015 if (msg != NULL) {
1016 task->tk_msg.rpc_proc = msg->rpc_proc;
1017 task->tk_msg.rpc_argp = msg->rpc_argp;
1018 task->tk_msg.rpc_resp = msg->rpc_resp;
1019 if (msg->rpc_cred != NULL)
1020 task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1025 * Default callback for async RPC calls
1027 static void
1028 rpc_default_callback(struct rpc_task *task, void *data)
1032 static const struct rpc_call_ops rpc_default_ops = {
1033 .rpc_call_done = rpc_default_callback,
1037 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1038 * @task_setup_data: pointer to task initialisation data
1040 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1042 struct rpc_task *task;
1044 task = rpc_new_task(task_setup_data);
1045 if (IS_ERR(task))
1046 goto out;
1048 rpc_task_set_client(task, task_setup_data->rpc_client);
1049 rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1051 if (task->tk_action == NULL)
1052 rpc_call_start(task);
1054 atomic_inc(&task->tk_count);
1055 rpc_execute(task);
1056 out:
1057 return task;
1059 EXPORT_SYMBOL_GPL(rpc_run_task);
1062 * rpc_call_sync - Perform a synchronous RPC call
1063 * @clnt: pointer to RPC client
1064 * @msg: RPC call parameters
1065 * @flags: RPC call flags
1067 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1069 struct rpc_task *task;
1070 struct rpc_task_setup task_setup_data = {
1071 .rpc_client = clnt,
1072 .rpc_message = msg,
1073 .callback_ops = &rpc_default_ops,
1074 .flags = flags,
1076 int status;
1078 WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1079 if (flags & RPC_TASK_ASYNC) {
1080 rpc_release_calldata(task_setup_data.callback_ops,
1081 task_setup_data.callback_data);
1082 return -EINVAL;
1085 task = rpc_run_task(&task_setup_data);
1086 if (IS_ERR(task))
1087 return PTR_ERR(task);
1088 status = task->tk_status;
1089 rpc_put_task(task);
1090 return status;
1092 EXPORT_SYMBOL_GPL(rpc_call_sync);
1095 * rpc_call_async - Perform an asynchronous RPC call
1096 * @clnt: pointer to RPC client
1097 * @msg: RPC call parameters
1098 * @flags: RPC call flags
1099 * @tk_ops: RPC call ops
1100 * @data: user call data
1103 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1104 const struct rpc_call_ops *tk_ops, void *data)
1106 struct rpc_task *task;
1107 struct rpc_task_setup task_setup_data = {
1108 .rpc_client = clnt,
1109 .rpc_message = msg,
1110 .callback_ops = tk_ops,
1111 .callback_data = data,
1112 .flags = flags|RPC_TASK_ASYNC,
1115 task = rpc_run_task(&task_setup_data);
1116 if (IS_ERR(task))
1117 return PTR_ERR(task);
1118 rpc_put_task(task);
1119 return 0;
1121 EXPORT_SYMBOL_GPL(rpc_call_async);
1123 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1125 * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1126 * rpc_execute against it
1127 * @req: RPC request
1129 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1131 struct rpc_task *task;
1132 struct xdr_buf *xbufp = &req->rq_snd_buf;
1133 struct rpc_task_setup task_setup_data = {
1134 .callback_ops = &rpc_default_ops,
1135 .flags = RPC_TASK_SOFTCONN,
1138 dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1140 * Create an rpc_task to send the data
1142 task = rpc_new_task(&task_setup_data);
1143 if (IS_ERR(task)) {
1144 xprt_free_bc_request(req);
1145 goto out;
1147 task->tk_rqstp = req;
1150 * Set up the xdr_buf length.
1151 * This also indicates that the buffer is XDR encoded already.
1153 xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1154 xbufp->tail[0].iov_len;
1156 task->tk_action = call_bc_transmit;
1157 atomic_inc(&task->tk_count);
1158 WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1159 rpc_execute(task);
1161 out:
1162 dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1163 return task;
1165 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1167 void
1168 rpc_call_start(struct rpc_task *task)
1170 task->tk_action = call_start;
1172 EXPORT_SYMBOL_GPL(rpc_call_start);
1175 * rpc_peeraddr - extract remote peer address from clnt's xprt
1176 * @clnt: RPC client structure
1177 * @buf: target buffer
1178 * @bufsize: length of target buffer
1180 * Returns the number of bytes that are actually in the stored address.
1182 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1184 size_t bytes;
1185 struct rpc_xprt *xprt;
1187 rcu_read_lock();
1188 xprt = rcu_dereference(clnt->cl_xprt);
1190 bytes = xprt->addrlen;
1191 if (bytes > bufsize)
1192 bytes = bufsize;
1193 memcpy(buf, &xprt->addr, bytes);
1194 rcu_read_unlock();
1196 return bytes;
1198 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1201 * rpc_peeraddr2str - return remote peer address in printable format
1202 * @clnt: RPC client structure
1203 * @format: address format
1205 * NB: the lifetime of the memory referenced by the returned pointer is
1206 * the same as the rpc_xprt itself. As long as the caller uses this
1207 * pointer, it must hold the RCU read lock.
1209 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1210 enum rpc_display_format_t format)
1212 struct rpc_xprt *xprt;
1214 xprt = rcu_dereference(clnt->cl_xprt);
1216 if (xprt->address_strings[format] != NULL)
1217 return xprt->address_strings[format];
1218 else
1219 return "unprintable";
1221 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1223 static const struct sockaddr_in rpc_inaddr_loopback = {
1224 .sin_family = AF_INET,
1225 .sin_addr.s_addr = htonl(INADDR_ANY),
1228 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1229 .sin6_family = AF_INET6,
1230 .sin6_addr = IN6ADDR_ANY_INIT,
1234 * Try a getsockname() on a connected datagram socket. Using a
1235 * connected datagram socket prevents leaving a socket in TIME_WAIT.
1236 * This conserves the ephemeral port number space.
1238 * Returns zero and fills in "buf" if successful; otherwise, a
1239 * negative errno is returned.
1241 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1242 struct sockaddr *buf, int buflen)
1244 struct socket *sock;
1245 int err;
1247 err = __sock_create(net, sap->sa_family,
1248 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1249 if (err < 0) {
1250 dprintk("RPC: can't create UDP socket (%d)\n", err);
1251 goto out;
1254 switch (sap->sa_family) {
1255 case AF_INET:
1256 err = kernel_bind(sock,
1257 (struct sockaddr *)&rpc_inaddr_loopback,
1258 sizeof(rpc_inaddr_loopback));
1259 break;
1260 case AF_INET6:
1261 err = kernel_bind(sock,
1262 (struct sockaddr *)&rpc_in6addr_loopback,
1263 sizeof(rpc_in6addr_loopback));
1264 break;
1265 default:
1266 err = -EAFNOSUPPORT;
1267 goto out;
1269 if (err < 0) {
1270 dprintk("RPC: can't bind UDP socket (%d)\n", err);
1271 goto out_release;
1274 err = kernel_connect(sock, sap, salen, 0);
1275 if (err < 0) {
1276 dprintk("RPC: can't connect UDP socket (%d)\n", err);
1277 goto out_release;
1280 err = kernel_getsockname(sock, buf, &buflen);
1281 if (err < 0) {
1282 dprintk("RPC: getsockname failed (%d)\n", err);
1283 goto out_release;
1286 err = 0;
1287 if (buf->sa_family == AF_INET6) {
1288 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1289 sin6->sin6_scope_id = 0;
1291 dprintk("RPC: %s succeeded\n", __func__);
1293 out_release:
1294 sock_release(sock);
1295 out:
1296 return err;
1300 * Scraping a connected socket failed, so we don't have a useable
1301 * local address. Fallback: generate an address that will prevent
1302 * the server from calling us back.
1304 * Returns zero and fills in "buf" if successful; otherwise, a
1305 * negative errno is returned.
1307 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1309 switch (family) {
1310 case AF_INET:
1311 if (buflen < sizeof(rpc_inaddr_loopback))
1312 return -EINVAL;
1313 memcpy(buf, &rpc_inaddr_loopback,
1314 sizeof(rpc_inaddr_loopback));
1315 break;
1316 case AF_INET6:
1317 if (buflen < sizeof(rpc_in6addr_loopback))
1318 return -EINVAL;
1319 memcpy(buf, &rpc_in6addr_loopback,
1320 sizeof(rpc_in6addr_loopback));
1321 break;
1322 default:
1323 dprintk("RPC: %s: address family not supported\n",
1324 __func__);
1325 return -EAFNOSUPPORT;
1327 dprintk("RPC: %s: succeeded\n", __func__);
1328 return 0;
1332 * rpc_localaddr - discover local endpoint address for an RPC client
1333 * @clnt: RPC client structure
1334 * @buf: target buffer
1335 * @buflen: size of target buffer, in bytes
1337 * Returns zero and fills in "buf" and "buflen" if successful;
1338 * otherwise, a negative errno is returned.
1340 * This works even if the underlying transport is not currently connected,
1341 * or if the upper layer never previously provided a source address.
1343 * The result of this function call is transient: multiple calls in
1344 * succession may give different results, depending on how local
1345 * networking configuration changes over time.
1347 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1349 struct sockaddr_storage address;
1350 struct sockaddr *sap = (struct sockaddr *)&address;
1351 struct rpc_xprt *xprt;
1352 struct net *net;
1353 size_t salen;
1354 int err;
1356 rcu_read_lock();
1357 xprt = rcu_dereference(clnt->cl_xprt);
1358 salen = xprt->addrlen;
1359 memcpy(sap, &xprt->addr, salen);
1360 net = get_net(xprt->xprt_net);
1361 rcu_read_unlock();
1363 rpc_set_port(sap, 0);
1364 err = rpc_sockname(net, sap, salen, buf, buflen);
1365 put_net(net);
1366 if (err != 0)
1367 /* Couldn't discover local address, return ANYADDR */
1368 return rpc_anyaddr(sap->sa_family, buf, buflen);
1369 return 0;
1371 EXPORT_SYMBOL_GPL(rpc_localaddr);
1373 void
1374 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1376 struct rpc_xprt *xprt;
1378 rcu_read_lock();
1379 xprt = rcu_dereference(clnt->cl_xprt);
1380 if (xprt->ops->set_buffer_size)
1381 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1382 rcu_read_unlock();
1384 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1387 * rpc_protocol - Get transport protocol number for an RPC client
1388 * @clnt: RPC client to query
1391 int rpc_protocol(struct rpc_clnt *clnt)
1393 int protocol;
1395 rcu_read_lock();
1396 protocol = rcu_dereference(clnt->cl_xprt)->prot;
1397 rcu_read_unlock();
1398 return protocol;
1400 EXPORT_SYMBOL_GPL(rpc_protocol);
1403 * rpc_net_ns - Get the network namespace for this RPC client
1404 * @clnt: RPC client to query
1407 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1409 struct net *ret;
1411 rcu_read_lock();
1412 ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1413 rcu_read_unlock();
1414 return ret;
1416 EXPORT_SYMBOL_GPL(rpc_net_ns);
1419 * rpc_max_payload - Get maximum payload size for a transport, in bytes
1420 * @clnt: RPC client to query
1422 * For stream transports, this is one RPC record fragment (see RFC
1423 * 1831), as we don't support multi-record requests yet. For datagram
1424 * transports, this is the size of an IP packet minus the IP, UDP, and
1425 * RPC header sizes.
1427 size_t rpc_max_payload(struct rpc_clnt *clnt)
1429 size_t ret;
1431 rcu_read_lock();
1432 ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1433 rcu_read_unlock();
1434 return ret;
1436 EXPORT_SYMBOL_GPL(rpc_max_payload);
1439 * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1440 * @clnt: RPC client to query
1442 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1444 struct rpc_xprt *xprt;
1445 size_t ret;
1447 rcu_read_lock();
1448 xprt = rcu_dereference(clnt->cl_xprt);
1449 ret = xprt->ops->bc_maxpayload(xprt);
1450 rcu_read_unlock();
1451 return ret;
1453 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1456 * rpc_force_rebind - force transport to check that remote port is unchanged
1457 * @clnt: client to rebind
1460 void rpc_force_rebind(struct rpc_clnt *clnt)
1462 if (clnt->cl_autobind) {
1463 rcu_read_lock();
1464 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1465 rcu_read_unlock();
1468 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1471 * Restart an (async) RPC call from the call_prepare state.
1472 * Usually called from within the exit handler.
1475 rpc_restart_call_prepare(struct rpc_task *task)
1477 if (RPC_ASSASSINATED(task))
1478 return 0;
1479 task->tk_action = call_start;
1480 task->tk_status = 0;
1481 if (task->tk_ops->rpc_call_prepare != NULL)
1482 task->tk_action = rpc_prepare_task;
1483 return 1;
1485 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1488 * Restart an (async) RPC call. Usually called from within the
1489 * exit handler.
1492 rpc_restart_call(struct rpc_task *task)
1494 if (RPC_ASSASSINATED(task))
1495 return 0;
1496 task->tk_action = call_start;
1497 task->tk_status = 0;
1498 return 1;
1500 EXPORT_SYMBOL_GPL(rpc_restart_call);
1502 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1503 const char
1504 *rpc_proc_name(const struct rpc_task *task)
1506 const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1508 if (proc) {
1509 if (proc->p_name)
1510 return proc->p_name;
1511 else
1512 return "NULL";
1513 } else
1514 return "no proc";
1516 #endif
1519 * 0. Initial state
1521 * Other FSM states can be visited zero or more times, but
1522 * this state is visited exactly once for each RPC.
1524 static void
1525 call_start(struct rpc_task *task)
1527 struct rpc_clnt *clnt = task->tk_client;
1529 dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1530 clnt->cl_program->name, clnt->cl_vers,
1531 rpc_proc_name(task),
1532 (RPC_IS_ASYNC(task) ? "async" : "sync"));
1534 /* Increment call count */
1535 task->tk_msg.rpc_proc->p_count++;
1536 clnt->cl_stats->rpccnt++;
1537 task->tk_action = call_reserve;
1541 * 1. Reserve an RPC call slot
1543 static void
1544 call_reserve(struct rpc_task *task)
1546 dprint_status(task);
1548 task->tk_status = 0;
1549 task->tk_action = call_reserveresult;
1550 xprt_reserve(task);
1553 static void call_retry_reserve(struct rpc_task *task);
1556 * 1b. Grok the result of xprt_reserve()
1558 static void
1559 call_reserveresult(struct rpc_task *task)
1561 int status = task->tk_status;
1563 dprint_status(task);
1566 * After a call to xprt_reserve(), we must have either
1567 * a request slot or else an error status.
1569 task->tk_status = 0;
1570 if (status >= 0) {
1571 if (task->tk_rqstp) {
1572 task->tk_action = call_refresh;
1573 return;
1576 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1577 __func__, status);
1578 rpc_exit(task, -EIO);
1579 return;
1583 * Even though there was an error, we may have acquired
1584 * a request slot somehow. Make sure not to leak it.
1586 if (task->tk_rqstp) {
1587 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1588 __func__, status);
1589 xprt_release(task);
1592 switch (status) {
1593 case -ENOMEM:
1594 rpc_delay(task, HZ >> 2);
1595 case -EAGAIN: /* woken up; retry */
1596 task->tk_action = call_retry_reserve;
1597 return;
1598 case -EIO: /* probably a shutdown */
1599 break;
1600 default:
1601 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1602 __func__, status);
1603 break;
1605 rpc_exit(task, status);
1609 * 1c. Retry reserving an RPC call slot
1611 static void
1612 call_retry_reserve(struct rpc_task *task)
1614 dprint_status(task);
1616 task->tk_status = 0;
1617 task->tk_action = call_reserveresult;
1618 xprt_retry_reserve(task);
1622 * 2. Bind and/or refresh the credentials
1624 static void
1625 call_refresh(struct rpc_task *task)
1627 dprint_status(task);
1629 task->tk_action = call_refreshresult;
1630 task->tk_status = 0;
1631 task->tk_client->cl_stats->rpcauthrefresh++;
1632 rpcauth_refreshcred(task);
1636 * 2a. Process the results of a credential refresh
1638 static void
1639 call_refreshresult(struct rpc_task *task)
1641 int status = task->tk_status;
1643 dprint_status(task);
1645 task->tk_status = 0;
1646 task->tk_action = call_refresh;
1647 switch (status) {
1648 case 0:
1649 if (rpcauth_uptodatecred(task)) {
1650 task->tk_action = call_allocate;
1651 return;
1653 /* Use rate-limiting and a max number of retries if refresh
1654 * had status 0 but failed to update the cred.
1656 case -ETIMEDOUT:
1657 rpc_delay(task, 3*HZ);
1658 case -EAGAIN:
1659 status = -EACCES;
1660 case -EKEYEXPIRED:
1661 if (!task->tk_cred_retry)
1662 break;
1663 task->tk_cred_retry--;
1664 dprintk("RPC: %5u %s: retry refresh creds\n",
1665 task->tk_pid, __func__);
1666 return;
1668 dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1669 task->tk_pid, __func__, status);
1670 rpc_exit(task, status);
1674 * 2b. Allocate the buffer. For details, see sched.c:rpc_malloc.
1675 * (Note: buffer memory is freed in xprt_release).
1677 static void
1678 call_allocate(struct rpc_task *task)
1680 unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1681 struct rpc_rqst *req = task->tk_rqstp;
1682 struct rpc_xprt *xprt = req->rq_xprt;
1683 struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1684 int status;
1686 dprint_status(task);
1688 task->tk_status = 0;
1689 task->tk_action = call_bind;
1691 if (req->rq_buffer)
1692 return;
1694 if (proc->p_proc != 0) {
1695 BUG_ON(proc->p_arglen == 0);
1696 if (proc->p_decode != NULL)
1697 BUG_ON(proc->p_replen == 0);
1701 * Calculate the size (in quads) of the RPC call
1702 * and reply headers, and convert both values
1703 * to byte sizes.
1705 req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1706 req->rq_callsize <<= 2;
1707 req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1708 req->rq_rcvsize <<= 2;
1710 status = xprt->ops->buf_alloc(task);
1711 xprt_inject_disconnect(xprt);
1712 if (status == 0)
1713 return;
1714 if (status != -ENOMEM) {
1715 rpc_exit(task, status);
1716 return;
1719 dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1721 if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1722 task->tk_action = call_allocate;
1723 rpc_delay(task, HZ>>4);
1724 return;
1727 rpc_exit(task, -ERESTARTSYS);
1730 static inline int
1731 rpc_task_need_encode(struct rpc_task *task)
1733 return task->tk_rqstp->rq_snd_buf.len == 0;
1736 static inline void
1737 rpc_task_force_reencode(struct rpc_task *task)
1739 task->tk_rqstp->rq_snd_buf.len = 0;
1740 task->tk_rqstp->rq_bytes_sent = 0;
1744 * 3. Encode arguments of an RPC call
1746 static void
1747 rpc_xdr_encode(struct rpc_task *task)
1749 struct rpc_rqst *req = task->tk_rqstp;
1750 kxdreproc_t encode;
1751 __be32 *p;
1753 dprint_status(task);
1755 xdr_buf_init(&req->rq_snd_buf,
1756 req->rq_buffer,
1757 req->rq_callsize);
1758 xdr_buf_init(&req->rq_rcv_buf,
1759 req->rq_rbuffer,
1760 req->rq_rcvsize);
1762 p = rpc_encode_header(task);
1763 if (p == NULL) {
1764 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1765 rpc_exit(task, -EIO);
1766 return;
1769 encode = task->tk_msg.rpc_proc->p_encode;
1770 if (encode == NULL)
1771 return;
1773 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1774 task->tk_msg.rpc_argp);
1778 * 4. Get the server port number if not yet set
1780 static void
1781 call_bind(struct rpc_task *task)
1783 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1785 dprint_status(task);
1787 task->tk_action = call_connect;
1788 if (!xprt_bound(xprt)) {
1789 task->tk_action = call_bind_status;
1790 task->tk_timeout = xprt->bind_timeout;
1791 xprt->ops->rpcbind(task);
1796 * 4a. Sort out bind result
1798 static void
1799 call_bind_status(struct rpc_task *task)
1801 int status = -EIO;
1803 if (task->tk_status >= 0) {
1804 dprint_status(task);
1805 task->tk_status = 0;
1806 task->tk_action = call_connect;
1807 return;
1810 trace_rpc_bind_status(task);
1811 switch (task->tk_status) {
1812 case -ENOMEM:
1813 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1814 rpc_delay(task, HZ >> 2);
1815 goto retry_timeout;
1816 case -EACCES:
1817 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1818 "unavailable\n", task->tk_pid);
1819 /* fail immediately if this is an RPC ping */
1820 if (task->tk_msg.rpc_proc->p_proc == 0) {
1821 status = -EOPNOTSUPP;
1822 break;
1824 if (task->tk_rebind_retry == 0)
1825 break;
1826 task->tk_rebind_retry--;
1827 rpc_delay(task, 3*HZ);
1828 goto retry_timeout;
1829 case -ETIMEDOUT:
1830 dprintk("RPC: %5u rpcbind request timed out\n",
1831 task->tk_pid);
1832 goto retry_timeout;
1833 case -EPFNOSUPPORT:
1834 /* server doesn't support any rpcbind version we know of */
1835 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1836 task->tk_pid);
1837 break;
1838 case -EPROTONOSUPPORT:
1839 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1840 task->tk_pid);
1841 goto retry_timeout;
1842 case -ECONNREFUSED: /* connection problems */
1843 case -ECONNRESET:
1844 case -ECONNABORTED:
1845 case -ENOTCONN:
1846 case -EHOSTDOWN:
1847 case -EHOSTUNREACH:
1848 case -ENETUNREACH:
1849 case -ENOBUFS:
1850 case -EPIPE:
1851 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1852 task->tk_pid, task->tk_status);
1853 if (!RPC_IS_SOFTCONN(task)) {
1854 rpc_delay(task, 5*HZ);
1855 goto retry_timeout;
1857 status = task->tk_status;
1858 break;
1859 default:
1860 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1861 task->tk_pid, -task->tk_status);
1864 rpc_exit(task, status);
1865 return;
1867 retry_timeout:
1868 task->tk_status = 0;
1869 task->tk_action = call_timeout;
1873 * 4b. Connect to the RPC server
1875 static void
1876 call_connect(struct rpc_task *task)
1878 struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1880 dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1881 task->tk_pid, xprt,
1882 (xprt_connected(xprt) ? "is" : "is not"));
1884 task->tk_action = call_transmit;
1885 if (!xprt_connected(xprt)) {
1886 task->tk_action = call_connect_status;
1887 if (task->tk_status < 0)
1888 return;
1889 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1890 rpc_exit(task, -ENOTCONN);
1891 return;
1893 xprt_connect(task);
1898 * 4c. Sort out connect result
1900 static void
1901 call_connect_status(struct rpc_task *task)
1903 struct rpc_clnt *clnt = task->tk_client;
1904 int status = task->tk_status;
1906 dprint_status(task);
1908 trace_rpc_connect_status(task, status);
1909 task->tk_status = 0;
1910 switch (status) {
1911 case -ECONNREFUSED:
1912 case -ECONNRESET:
1913 case -ECONNABORTED:
1914 case -ENETUNREACH:
1915 case -EHOSTUNREACH:
1916 case -EADDRINUSE:
1917 case -ENOBUFS:
1918 case -EPIPE:
1919 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1920 task->tk_rqstp->rq_connect_cookie);
1921 if (RPC_IS_SOFTCONN(task))
1922 break;
1923 /* retry with existing socket, after a delay */
1924 rpc_delay(task, 3*HZ);
1925 case -EAGAIN:
1926 /* Check for timeouts before looping back to call_bind */
1927 case -ETIMEDOUT:
1928 task->tk_action = call_timeout;
1929 return;
1930 case 0:
1931 clnt->cl_stats->netreconn++;
1932 task->tk_action = call_transmit;
1933 return;
1935 rpc_exit(task, status);
1939 * 5. Transmit the RPC request, and wait for reply
1941 static void
1942 call_transmit(struct rpc_task *task)
1944 int is_retrans = RPC_WAS_SENT(task);
1946 dprint_status(task);
1948 task->tk_action = call_status;
1949 if (task->tk_status < 0)
1950 return;
1951 if (!xprt_prepare_transmit(task))
1952 return;
1953 task->tk_action = call_transmit_status;
1954 /* Encode here so that rpcsec_gss can use correct sequence number. */
1955 if (rpc_task_need_encode(task)) {
1956 rpc_xdr_encode(task);
1957 /* Did the encode result in an error condition? */
1958 if (task->tk_status != 0) {
1959 /* Was the error nonfatal? */
1960 if (task->tk_status == -EAGAIN)
1961 rpc_delay(task, HZ >> 4);
1962 else
1963 rpc_exit(task, task->tk_status);
1964 return;
1967 xprt_transmit(task);
1968 if (task->tk_status < 0)
1969 return;
1970 if (is_retrans)
1971 task->tk_client->cl_stats->rpcretrans++;
1973 * On success, ensure that we call xprt_end_transmit() before sleeping
1974 * in order to allow access to the socket to other RPC requests.
1976 call_transmit_status(task);
1977 if (rpc_reply_expected(task))
1978 return;
1979 task->tk_action = rpc_exit_task;
1980 rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1984 * 5a. Handle cleanup after a transmission
1986 static void
1987 call_transmit_status(struct rpc_task *task)
1989 task->tk_action = call_status;
1992 * Common case: success. Force the compiler to put this
1993 * test first.
1995 if (task->tk_status == 0) {
1996 xprt_end_transmit(task);
1997 rpc_task_force_reencode(task);
1998 return;
2001 switch (task->tk_status) {
2002 case -EAGAIN:
2003 case -ENOBUFS:
2004 break;
2005 default:
2006 dprint_status(task);
2007 xprt_end_transmit(task);
2008 rpc_task_force_reencode(task);
2009 break;
2011 * Special cases: if we've been waiting on the
2012 * socket's write_space() callback, or if the
2013 * socket just returned a connection error,
2014 * then hold onto the transport lock.
2016 case -ECONNREFUSED:
2017 case -EHOSTDOWN:
2018 case -EHOSTUNREACH:
2019 case -ENETUNREACH:
2020 case -EPERM:
2021 if (RPC_IS_SOFTCONN(task)) {
2022 xprt_end_transmit(task);
2023 rpc_exit(task, task->tk_status);
2024 break;
2026 case -ECONNRESET:
2027 case -ECONNABORTED:
2028 case -EADDRINUSE:
2029 case -ENOTCONN:
2030 case -EPIPE:
2031 rpc_task_force_reencode(task);
2035 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2037 * 5b. Send the backchannel RPC reply. On error, drop the reply. In
2038 * addition, disconnect on connectivity errors.
2040 static void
2041 call_bc_transmit(struct rpc_task *task)
2043 struct rpc_rqst *req = task->tk_rqstp;
2045 if (!xprt_prepare_transmit(task))
2046 goto out_retry;
2048 if (task->tk_status < 0) {
2049 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2050 "error: %d\n", task->tk_status);
2051 goto out_done;
2053 if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2054 req->rq_bytes_sent = 0;
2056 xprt_transmit(task);
2058 if (task->tk_status == -EAGAIN)
2059 goto out_nospace;
2061 xprt_end_transmit(task);
2062 dprint_status(task);
2063 switch (task->tk_status) {
2064 case 0:
2065 /* Success */
2066 case -EHOSTDOWN:
2067 case -EHOSTUNREACH:
2068 case -ENETUNREACH:
2069 case -ECONNRESET:
2070 case -ECONNREFUSED:
2071 case -EADDRINUSE:
2072 case -ENOTCONN:
2073 case -EPIPE:
2074 break;
2075 case -ETIMEDOUT:
2077 * Problem reaching the server. Disconnect and let the
2078 * forechannel reestablish the connection. The server will
2079 * have to retransmit the backchannel request and we'll
2080 * reprocess it. Since these ops are idempotent, there's no
2081 * need to cache our reply at this time.
2083 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2084 "error: %d\n", task->tk_status);
2085 xprt_conditional_disconnect(req->rq_xprt,
2086 req->rq_connect_cookie);
2087 break;
2088 default:
2090 * We were unable to reply and will have to drop the
2091 * request. The server should reconnect and retransmit.
2093 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2094 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2095 "error: %d\n", task->tk_status);
2096 break;
2098 rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2099 out_done:
2100 task->tk_action = rpc_exit_task;
2101 return;
2102 out_nospace:
2103 req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2104 out_retry:
2105 task->tk_status = 0;
2107 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2110 * 6. Sort out the RPC call status
2112 static void
2113 call_status(struct rpc_task *task)
2115 struct rpc_clnt *clnt = task->tk_client;
2116 struct rpc_rqst *req = task->tk_rqstp;
2117 int status;
2119 if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2120 task->tk_status = req->rq_reply_bytes_recvd;
2122 dprint_status(task);
2124 status = task->tk_status;
2125 if (status >= 0) {
2126 task->tk_action = call_decode;
2127 return;
2130 trace_rpc_call_status(task);
2131 task->tk_status = 0;
2132 switch(status) {
2133 case -EHOSTDOWN:
2134 case -EHOSTUNREACH:
2135 case -ENETUNREACH:
2136 case -EPERM:
2137 if (RPC_IS_SOFTCONN(task)) {
2138 rpc_exit(task, status);
2139 break;
2142 * Delay any retries for 3 seconds, then handle as if it
2143 * were a timeout.
2145 rpc_delay(task, 3*HZ);
2146 case -ETIMEDOUT:
2147 task->tk_action = call_timeout;
2148 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2149 && task->tk_client->cl_discrtry)
2150 xprt_conditional_disconnect(req->rq_xprt,
2151 req->rq_connect_cookie);
2152 break;
2153 case -ECONNREFUSED:
2154 case -ECONNRESET:
2155 case -ECONNABORTED:
2156 rpc_force_rebind(clnt);
2157 case -EADDRINUSE:
2158 rpc_delay(task, 3*HZ);
2159 case -EPIPE:
2160 case -ENOTCONN:
2161 task->tk_action = call_bind;
2162 break;
2163 case -ENOBUFS:
2164 rpc_delay(task, HZ>>2);
2165 case -EAGAIN:
2166 task->tk_action = call_transmit;
2167 break;
2168 case -EIO:
2169 /* shutdown or soft timeout */
2170 rpc_exit(task, status);
2171 break;
2172 default:
2173 if (clnt->cl_chatty)
2174 printk("%s: RPC call returned error %d\n",
2175 clnt->cl_program->name, -status);
2176 rpc_exit(task, status);
2181 * 6a. Handle RPC timeout
2182 * We do not release the request slot, so we keep using the
2183 * same XID for all retransmits.
2185 static void
2186 call_timeout(struct rpc_task *task)
2188 struct rpc_clnt *clnt = task->tk_client;
2190 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2191 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2192 goto retry;
2195 dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2196 task->tk_timeouts++;
2198 if (RPC_IS_SOFTCONN(task)) {
2199 rpc_exit(task, -ETIMEDOUT);
2200 return;
2202 if (RPC_IS_SOFT(task)) {
2203 if (clnt->cl_chatty) {
2204 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2205 clnt->cl_program->name,
2206 task->tk_xprt->servername);
2208 if (task->tk_flags & RPC_TASK_TIMEOUT)
2209 rpc_exit(task, -ETIMEDOUT);
2210 else
2211 rpc_exit(task, -EIO);
2212 return;
2215 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2216 task->tk_flags |= RPC_CALL_MAJORSEEN;
2217 if (clnt->cl_chatty) {
2218 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2219 clnt->cl_program->name,
2220 task->tk_xprt->servername);
2223 rpc_force_rebind(clnt);
2225 * Did our request time out due to an RPCSEC_GSS out-of-sequence
2226 * event? RFC2203 requires the server to drop all such requests.
2228 rpcauth_invalcred(task);
2230 retry:
2231 task->tk_action = call_bind;
2232 task->tk_status = 0;
2236 * 7. Decode the RPC reply
2238 static void
2239 call_decode(struct rpc_task *task)
2241 struct rpc_clnt *clnt = task->tk_client;
2242 struct rpc_rqst *req = task->tk_rqstp;
2243 kxdrdproc_t decode = task->tk_msg.rpc_proc->p_decode;
2244 __be32 *p;
2246 dprint_status(task);
2248 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2249 if (clnt->cl_chatty) {
2250 printk(KERN_NOTICE "%s: server %s OK\n",
2251 clnt->cl_program->name,
2252 task->tk_xprt->servername);
2254 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2258 * Ensure that we see all writes made by xprt_complete_rqst()
2259 * before it changed req->rq_reply_bytes_recvd.
2261 smp_rmb();
2262 req->rq_rcv_buf.len = req->rq_private_buf.len;
2264 /* Check that the softirq receive buffer is valid */
2265 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2266 sizeof(req->rq_rcv_buf)) != 0);
2268 if (req->rq_rcv_buf.len < 12) {
2269 if (!RPC_IS_SOFT(task)) {
2270 task->tk_action = call_bind;
2271 goto out_retry;
2273 dprintk("RPC: %s: too small RPC reply size (%d bytes)\n",
2274 clnt->cl_program->name, task->tk_status);
2275 task->tk_action = call_timeout;
2276 goto out_retry;
2279 p = rpc_verify_header(task);
2280 if (IS_ERR(p)) {
2281 if (p == ERR_PTR(-EAGAIN))
2282 goto out_retry;
2283 return;
2286 task->tk_action = rpc_exit_task;
2288 if (decode) {
2289 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2290 task->tk_msg.rpc_resp);
2292 dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2293 task->tk_status);
2294 return;
2295 out_retry:
2296 task->tk_status = 0;
2297 /* Note: rpc_verify_header() may have freed the RPC slot */
2298 if (task->tk_rqstp == req) {
2299 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2300 if (task->tk_client->cl_discrtry)
2301 xprt_conditional_disconnect(req->rq_xprt,
2302 req->rq_connect_cookie);
2306 static __be32 *
2307 rpc_encode_header(struct rpc_task *task)
2309 struct rpc_clnt *clnt = task->tk_client;
2310 struct rpc_rqst *req = task->tk_rqstp;
2311 __be32 *p = req->rq_svec[0].iov_base;
2313 /* FIXME: check buffer size? */
2315 p = xprt_skip_transport_header(req->rq_xprt, p);
2316 *p++ = req->rq_xid; /* XID */
2317 *p++ = htonl(RPC_CALL); /* CALL */
2318 *p++ = htonl(RPC_VERSION); /* RPC version */
2319 *p++ = htonl(clnt->cl_prog); /* program number */
2320 *p++ = htonl(clnt->cl_vers); /* program version */
2321 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
2322 p = rpcauth_marshcred(task, p);
2323 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2324 return p;
2327 static __be32 *
2328 rpc_verify_header(struct rpc_task *task)
2330 struct rpc_clnt *clnt = task->tk_client;
2331 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2332 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2333 __be32 *p = iov->iov_base;
2334 u32 n;
2335 int error = -EACCES;
2337 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2338 /* RFC-1014 says that the representation of XDR data must be a
2339 * multiple of four bytes
2340 * - if it isn't pointer subtraction in the NFS client may give
2341 * undefined results
2343 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2344 " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2345 task->tk_rqstp->rq_rcv_buf.len);
2346 error = -EIO;
2347 goto out_err;
2349 if ((len -= 3) < 0)
2350 goto out_overflow;
2352 p += 1; /* skip XID */
2353 if ((n = ntohl(*p++)) != RPC_REPLY) {
2354 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2355 task->tk_pid, __func__, n);
2356 error = -EIO;
2357 goto out_garbage;
2360 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2361 if (--len < 0)
2362 goto out_overflow;
2363 switch ((n = ntohl(*p++))) {
2364 case RPC_AUTH_ERROR:
2365 break;
2366 case RPC_MISMATCH:
2367 dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2368 task->tk_pid, __func__);
2369 error = -EPROTONOSUPPORT;
2370 goto out_err;
2371 default:
2372 dprintk("RPC: %5u %s: RPC call rejected, "
2373 "unknown error: %x\n",
2374 task->tk_pid, __func__, n);
2375 error = -EIO;
2376 goto out_err;
2378 if (--len < 0)
2379 goto out_overflow;
2380 switch ((n = ntohl(*p++))) {
2381 case RPC_AUTH_REJECTEDCRED:
2382 case RPC_AUTH_REJECTEDVERF:
2383 case RPCSEC_GSS_CREDPROBLEM:
2384 case RPCSEC_GSS_CTXPROBLEM:
2385 if (!task->tk_cred_retry)
2386 break;
2387 task->tk_cred_retry--;
2388 dprintk("RPC: %5u %s: retry stale creds\n",
2389 task->tk_pid, __func__);
2390 rpcauth_invalcred(task);
2391 /* Ensure we obtain a new XID! */
2392 xprt_release(task);
2393 task->tk_action = call_reserve;
2394 goto out_retry;
2395 case RPC_AUTH_BADCRED:
2396 case RPC_AUTH_BADVERF:
2397 /* possibly garbled cred/verf? */
2398 if (!task->tk_garb_retry)
2399 break;
2400 task->tk_garb_retry--;
2401 dprintk("RPC: %5u %s: retry garbled creds\n",
2402 task->tk_pid, __func__);
2403 task->tk_action = call_bind;
2404 goto out_retry;
2405 case RPC_AUTH_TOOWEAK:
2406 printk(KERN_NOTICE "RPC: server %s requires stronger "
2407 "authentication.\n",
2408 task->tk_xprt->servername);
2409 break;
2410 default:
2411 dprintk("RPC: %5u %s: unknown auth error: %x\n",
2412 task->tk_pid, __func__, n);
2413 error = -EIO;
2415 dprintk("RPC: %5u %s: call rejected %d\n",
2416 task->tk_pid, __func__, n);
2417 goto out_err;
2419 p = rpcauth_checkverf(task, p);
2420 if (IS_ERR(p)) {
2421 error = PTR_ERR(p);
2422 dprintk("RPC: %5u %s: auth check failed with %d\n",
2423 task->tk_pid, __func__, error);
2424 goto out_garbage; /* bad verifier, retry */
2426 len = p - (__be32 *)iov->iov_base - 1;
2427 if (len < 0)
2428 goto out_overflow;
2429 switch ((n = ntohl(*p++))) {
2430 case RPC_SUCCESS:
2431 return p;
2432 case RPC_PROG_UNAVAIL:
2433 dprintk("RPC: %5u %s: program %u is unsupported "
2434 "by server %s\n", task->tk_pid, __func__,
2435 (unsigned int)clnt->cl_prog,
2436 task->tk_xprt->servername);
2437 error = -EPFNOSUPPORT;
2438 goto out_err;
2439 case RPC_PROG_MISMATCH:
2440 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2441 "by server %s\n", task->tk_pid, __func__,
2442 (unsigned int)clnt->cl_prog,
2443 (unsigned int)clnt->cl_vers,
2444 task->tk_xprt->servername);
2445 error = -EPROTONOSUPPORT;
2446 goto out_err;
2447 case RPC_PROC_UNAVAIL:
2448 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2449 "version %u on server %s\n",
2450 task->tk_pid, __func__,
2451 rpc_proc_name(task),
2452 clnt->cl_prog, clnt->cl_vers,
2453 task->tk_xprt->servername);
2454 error = -EOPNOTSUPP;
2455 goto out_err;
2456 case RPC_GARBAGE_ARGS:
2457 dprintk("RPC: %5u %s: server saw garbage\n",
2458 task->tk_pid, __func__);
2459 break; /* retry */
2460 default:
2461 dprintk("RPC: %5u %s: server accept status: %x\n",
2462 task->tk_pid, __func__, n);
2463 /* Also retry */
2466 out_garbage:
2467 clnt->cl_stats->rpcgarbage++;
2468 if (task->tk_garb_retry) {
2469 task->tk_garb_retry--;
2470 dprintk("RPC: %5u %s: retrying\n",
2471 task->tk_pid, __func__);
2472 task->tk_action = call_bind;
2473 out_retry:
2474 return ERR_PTR(-EAGAIN);
2476 out_err:
2477 rpc_exit(task, error);
2478 dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2479 __func__, error);
2480 return ERR_PTR(error);
2481 out_overflow:
2482 dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2483 __func__);
2484 goto out_garbage;
2487 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2491 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2493 return 0;
2496 static struct rpc_procinfo rpcproc_null = {
2497 .p_encode = rpcproc_encode_null,
2498 .p_decode = rpcproc_decode_null,
2501 static int rpc_ping(struct rpc_clnt *clnt)
2503 struct rpc_message msg = {
2504 .rpc_proc = &rpcproc_null,
2506 int err;
2507 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2508 err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2509 put_rpccred(msg.rpc_cred);
2510 return err;
2513 static
2514 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2515 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2516 const struct rpc_call_ops *ops, void *data)
2518 struct rpc_message msg = {
2519 .rpc_proc = &rpcproc_null,
2520 .rpc_cred = cred,
2522 struct rpc_task_setup task_setup_data = {
2523 .rpc_client = clnt,
2524 .rpc_xprt = xprt,
2525 .rpc_message = &msg,
2526 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2527 .callback_data = data,
2528 .flags = flags,
2531 return rpc_run_task(&task_setup_data);
2534 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2536 return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2538 EXPORT_SYMBOL_GPL(rpc_call_null);
2540 struct rpc_cb_add_xprt_calldata {
2541 struct rpc_xprt_switch *xps;
2542 struct rpc_xprt *xprt;
2545 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2547 struct rpc_cb_add_xprt_calldata *data = calldata;
2549 if (task->tk_status == 0)
2550 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2553 static void rpc_cb_add_xprt_release(void *calldata)
2555 struct rpc_cb_add_xprt_calldata *data = calldata;
2557 xprt_put(data->xprt);
2558 xprt_switch_put(data->xps);
2559 kfree(data);
2562 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2563 .rpc_call_done = rpc_cb_add_xprt_done,
2564 .rpc_release = rpc_cb_add_xprt_release,
2568 * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2569 * @clnt: pointer to struct rpc_clnt
2570 * @xps: pointer to struct rpc_xprt_switch,
2571 * @xprt: pointer struct rpc_xprt
2572 * @dummy: unused
2574 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2575 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2576 void *dummy)
2578 struct rpc_cb_add_xprt_calldata *data;
2579 struct rpc_cred *cred;
2580 struct rpc_task *task;
2582 data = kmalloc(sizeof(*data), GFP_NOFS);
2583 if (!data)
2584 return -ENOMEM;
2585 data->xps = xprt_switch_get(xps);
2586 data->xprt = xprt_get(xprt);
2588 cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2589 task = rpc_call_null_helper(clnt, xprt, cred,
2590 RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2591 &rpc_cb_add_xprt_call_ops, data);
2592 put_rpccred(cred);
2593 if (IS_ERR(task))
2594 return PTR_ERR(task);
2595 rpc_put_task(task);
2596 return 1;
2598 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2601 * rpc_clnt_setup_test_and_add_xprt()
2603 * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2604 * 1) caller of the test function must dereference the rpc_xprt_switch
2605 * and the rpc_xprt.
2606 * 2) test function must call rpc_xprt_switch_add_xprt, usually in
2607 * the rpc_call_done routine.
2609 * Upon success (return of 1), the test function adds the new
2610 * transport to the rpc_clnt xprt switch
2612 * @clnt: struct rpc_clnt to get the new transport
2613 * @xps: the rpc_xprt_switch to hold the new transport
2614 * @xprt: the rpc_xprt to test
2615 * @data: a struct rpc_add_xprt_test pointer that holds the test function
2616 * and test function call data
2618 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2619 struct rpc_xprt_switch *xps,
2620 struct rpc_xprt *xprt,
2621 void *data)
2623 struct rpc_cred *cred;
2624 struct rpc_task *task;
2625 struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2626 int status = -EADDRINUSE;
2628 xprt = xprt_get(xprt);
2629 xprt_switch_get(xps);
2631 if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2632 goto out_err;
2634 /* Test the connection */
2635 cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2636 task = rpc_call_null_helper(clnt, xprt, cred,
2637 RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2638 NULL, NULL);
2639 put_rpccred(cred);
2640 if (IS_ERR(task)) {
2641 status = PTR_ERR(task);
2642 goto out_err;
2644 status = task->tk_status;
2645 rpc_put_task(task);
2647 if (status < 0)
2648 goto out_err;
2650 /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2651 xtest->add_xprt_test(clnt, xprt, xtest->data);
2653 /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2654 return 1;
2655 out_err:
2656 xprt_put(xprt);
2657 xprt_switch_put(xps);
2658 pr_info("RPC: rpc_clnt_test_xprt failed: %d addr %s not added\n",
2659 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2660 return status;
2662 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2665 * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2666 * @clnt: pointer to struct rpc_clnt
2667 * @xprtargs: pointer to struct xprt_create
2668 * @setup: callback to test and/or set up the connection
2669 * @data: pointer to setup function data
2671 * Creates a new transport using the parameters set in args and
2672 * adds it to clnt.
2673 * If ping is set, then test that connectivity succeeds before
2674 * adding the new transport.
2677 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2678 struct xprt_create *xprtargs,
2679 int (*setup)(struct rpc_clnt *,
2680 struct rpc_xprt_switch *,
2681 struct rpc_xprt *,
2682 void *),
2683 void *data)
2685 struct rpc_xprt_switch *xps;
2686 struct rpc_xprt *xprt;
2687 unsigned long connect_timeout;
2688 unsigned long reconnect_timeout;
2689 unsigned char resvport;
2690 int ret = 0;
2692 rcu_read_lock();
2693 xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2694 xprt = xprt_iter_xprt(&clnt->cl_xpi);
2695 if (xps == NULL || xprt == NULL) {
2696 rcu_read_unlock();
2697 return -EAGAIN;
2699 resvport = xprt->resvport;
2700 connect_timeout = xprt->connect_timeout;
2701 reconnect_timeout = xprt->max_reconnect_timeout;
2702 rcu_read_unlock();
2704 xprt = xprt_create_transport(xprtargs);
2705 if (IS_ERR(xprt)) {
2706 ret = PTR_ERR(xprt);
2707 goto out_put_switch;
2709 xprt->resvport = resvport;
2710 if (xprt->ops->set_connect_timeout != NULL)
2711 xprt->ops->set_connect_timeout(xprt,
2712 connect_timeout,
2713 reconnect_timeout);
2715 rpc_xprt_switch_set_roundrobin(xps);
2716 if (setup) {
2717 ret = setup(clnt, xps, xprt, data);
2718 if (ret != 0)
2719 goto out_put_xprt;
2721 rpc_xprt_switch_add_xprt(xps, xprt);
2722 out_put_xprt:
2723 xprt_put(xprt);
2724 out_put_switch:
2725 xprt_switch_put(xps);
2726 return ret;
2728 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2730 struct connect_timeout_data {
2731 unsigned long connect_timeout;
2732 unsigned long reconnect_timeout;
2735 static int
2736 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2737 struct rpc_xprt *xprt,
2738 void *data)
2740 struct connect_timeout_data *timeo = data;
2742 if (xprt->ops->set_connect_timeout)
2743 xprt->ops->set_connect_timeout(xprt,
2744 timeo->connect_timeout,
2745 timeo->reconnect_timeout);
2746 return 0;
2749 void
2750 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2751 unsigned long connect_timeout,
2752 unsigned long reconnect_timeout)
2754 struct connect_timeout_data timeout = {
2755 .connect_timeout = connect_timeout,
2756 .reconnect_timeout = reconnect_timeout,
2758 rpc_clnt_iterate_for_each_xprt(clnt,
2759 rpc_xprt_set_connect_timeout,
2760 &timeout);
2762 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2764 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2766 rcu_read_lock();
2767 xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2768 rcu_read_unlock();
2770 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2772 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2774 rcu_read_lock();
2775 rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2776 xprt);
2777 rcu_read_unlock();
2779 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2781 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2782 const struct sockaddr *sap)
2784 struct rpc_xprt_switch *xps;
2785 bool ret;
2787 rcu_read_lock();
2788 xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2789 ret = rpc_xprt_switch_has_addr(xps, sap);
2790 rcu_read_unlock();
2791 return ret;
2793 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2795 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2796 static void rpc_show_header(void)
2798 printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2799 "-timeout ---ops--\n");
2802 static void rpc_show_task(const struct rpc_clnt *clnt,
2803 const struct rpc_task *task)
2805 const char *rpc_waitq = "none";
2807 if (RPC_IS_QUEUED(task))
2808 rpc_waitq = rpc_qname(task->tk_waitqueue);
2810 printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2811 task->tk_pid, task->tk_flags, task->tk_status,
2812 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2813 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2814 task->tk_action, rpc_waitq);
2817 void rpc_show_tasks(struct net *net)
2819 struct rpc_clnt *clnt;
2820 struct rpc_task *task;
2821 int header = 0;
2822 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2824 spin_lock(&sn->rpc_client_lock);
2825 list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2826 spin_lock(&clnt->cl_lock);
2827 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2828 if (!header) {
2829 rpc_show_header();
2830 header++;
2832 rpc_show_task(clnt, task);
2834 spin_unlock(&clnt->cl_lock);
2836 spin_unlock(&sn->rpc_client_lock);
2838 #endif
2840 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2841 static int
2842 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2843 struct rpc_xprt *xprt,
2844 void *dummy)
2846 return xprt_enable_swap(xprt);
2850 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2852 if (atomic_inc_return(&clnt->cl_swapper) == 1)
2853 return rpc_clnt_iterate_for_each_xprt(clnt,
2854 rpc_clnt_swap_activate_callback, NULL);
2855 return 0;
2857 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2859 static int
2860 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2861 struct rpc_xprt *xprt,
2862 void *dummy)
2864 xprt_disable_swap(xprt);
2865 return 0;
2868 void
2869 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2871 if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2872 rpc_clnt_iterate_for_each_xprt(clnt,
2873 rpc_clnt_swap_deactivate_callback, NULL);
2875 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2876 #endif /* CONFIG_SUNRPC_SWAP */