~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sunrpc/clnt.c

Version: ~ [ linux-5.17-rc1 ] ~ [ linux-5.16.2 ] ~ [ linux-5.15.16 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.93 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.173 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.225 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.262 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.297 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.299 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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_encode(struct rpc_task *task);
 65 static void     call_decode(struct rpc_task *task);
 66 static void     call_bind(struct rpc_task *task);
 67 static void     call_bind_status(struct rpc_task *task);
 68 static void     call_transmit(struct rpc_task *task);
 69 static void     call_status(struct rpc_task *task);
 70 static void     call_transmit_status(struct rpc_task *task);
 71 static void     call_refresh(struct rpc_task *task);
 72 static void     call_refreshresult(struct rpc_task *task);
 73 static void     call_connect(struct rpc_task *task);
 74 static void     call_connect_status(struct rpc_task *task);
 75 
 76 static int      rpc_encode_header(struct rpc_task *task,
 77                                   struct xdr_stream *xdr);
 78 static int      rpc_decode_header(struct rpc_task *task,
 79                                   struct xdr_stream *xdr);
 80 static int      rpc_ping(struct rpc_clnt *clnt);
 81 static void     rpc_check_timeout(struct rpc_task *task);
 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 
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;
202         }
203         return 0;
204 }
205 
206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
207                                 struct super_block *sb)
208 {
209         int error = 0;
210 
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;
216         }
217         return error;
218 }
219 
220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
221 {
222         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
223         struct rpc_clnt *clnt;
224 
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;
231         }
232         spin_unlock(&sn->rpc_client_lock);
233         return NULL;
234 }
235 
236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
237                             void *ptr)
238 {
239         struct super_block *sb = ptr;
240         struct rpc_clnt *clnt;
241         int error = 0;
242 
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;
247         }
248         return error;
249 }
250 
251 static struct notifier_block rpc_clients_block = {
252         .notifier_call  = rpc_pipefs_event,
253         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
254 };
255 
256 int rpc_clients_notifier_register(void)
257 {
258         return rpc_pipefs_notifier_register(&rpc_clients_block);
259 }
260 
261 void rpc_clients_notifier_unregister(void)
262 {
263         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
264 }
265 
266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
267                 struct rpc_xprt *xprt,
268                 const struct rpc_timeout *timeout)
269 {
270         struct rpc_xprt *old;
271 
272         spin_lock(&clnt->cl_lock);
273         old = rcu_dereference_protected(clnt->cl_xprt,
274                         lockdep_is_held(&clnt->cl_lock));
275 
276         if (!xprt_bound(xprt))
277                 clnt->cl_autobind = 1;
278 
279         clnt->cl_timeout = timeout;
280         rcu_assign_pointer(clnt->cl_xprt, xprt);
281         spin_unlock(&clnt->cl_lock);
282 
283         return old;
284 }
285 
286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
287 {
288         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
289                         nodename, sizeof(clnt->cl_nodename));
290 }
291 
292 static int rpc_client_register(struct rpc_clnt *clnt,
293                                rpc_authflavor_t pseudoflavor,
294                                const char *client_name)
295 {
296         struct rpc_auth_create_args auth_args = {
297                 .pseudoflavor = pseudoflavor,
298                 .target_name = client_name,
299         };
300         struct rpc_auth *auth;
301         struct net *net = rpc_net_ns(clnt);
302         struct super_block *pipefs_sb;
303         int err;
304 
305         rpc_clnt_debugfs_register(clnt);
306 
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;
312         }
313 
314         rpc_register_client(clnt);
315         if (pipefs_sb)
316                 rpc_put_sb_net(net);
317 
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;
324         }
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;
335 }
336 
337 static DEFINE_IDA(rpc_clids);
338 
339 void rpc_cleanup_clids(void)
340 {
341         ida_destroy(&rpc_clids);
342 }
343 
344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
345 {
346         int clid;
347 
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;
353 }
354 
355 static void rpc_free_clid(struct rpc_clnt *clnt)
356 {
357         ida_simple_remove(&rpc_clids, clnt->cl_clid);
358 }
359 
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)
364 {
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;
371 
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);
375 
376         err = rpciod_up();
377         if (err)
378                 goto out_no_rpciod;
379 
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;
386 
387         err = -ENOMEM;
388         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
389         if (!clnt)
390                 goto out_err;
391         clnt->cl_parent = parent ? : clnt;
392 
393         err = rpc_alloc_clid(clnt);
394         if (err)
395                 goto out_no_clid;
396 
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);
410 
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;
416         }
417 
418         rpc_clnt_set_transport(clnt, xprt, timeout);
419         xprt_iter_init(&clnt->cl_xpi, xps);
420         xprt_switch_put(xps);
421 
422         clnt->cl_rtt = &clnt->cl_rtt_default;
423         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
424 
425         atomic_set(&clnt->cl_count, 1);
426 
427         if (nodename == NULL)
428                 nodename = utsname()->nodename;
429         /* save the nodename */
430         rpc_clnt_set_nodename(clnt, nodename);
431 
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;
438 
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);
451 }
452 
453 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
454                                         struct rpc_xprt *xprt)
455 {
456         struct rpc_clnt *clnt = NULL;
457         struct rpc_xprt_switch *xps;
458 
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);
468                 }
469                 if (xprt->bc_xprt) {
470                         xprt_switch_get(xps);
471                         xprt->bc_xprt->xpt_bc_xps = xps;
472                 }
473         }
474         clnt = rpc_new_client(args, xps, xprt, NULL);
475         if (IS_ERR(clnt))
476                 return clnt;
477 
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);
483                 }
484         }
485 
486         clnt->cl_softrtry = 1;
487         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
488                 clnt->cl_softrtry = 0;
489 
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;
498 
499         return clnt;
500 }
501 
502 /**
503  * rpc_create - create an RPC client and transport with one call
504  * @args: rpc_clnt create argument structure
505  *
506  * Creates and initializes an RPC transport and an RPC client.
507  *
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.
511  */
512 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
513 {
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,
523         };
524         char servername[48];
525 
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);
532                 }
533         }
534 
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;
539         /*
540          * If the caller chooses not to specify a hostname, whip
541          * up a string representation of the passed-in address.
542          */
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;
550 
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);
569                 }
570                 xprtargs.servername = servername;
571         }
572 
573         xprt = xprt_create_transport(&xprtargs);
574         if (IS_ERR(xprt))
575                 return (struct rpc_clnt *)xprt;
576 
577         /*
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.
582          */
583         xprt->resvport = 1;
584         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
585                 xprt->resvport = 0;
586 
587         return rpc_create_xprt(args, xprt);
588 }
589 EXPORT_SYMBOL_GPL(rpc_create);
590 
591 /*
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.
595  */
596 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
597                                            struct rpc_clnt *clnt)
598 {
599         struct rpc_xprt_switch *xps;
600         struct rpc_xprt *xprt;
601         struct rpc_clnt *new;
602         int err;
603 
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;
613         }
614         args->servername = xprt->servername;
615         args->nodename = clnt->cl_nodename;
616 
617         new = rpc_new_client(args, xps, xprt, clnt);
618         if (IS_ERR(new)) {
619                 err = PTR_ERR(new);
620                 goto out_err;
621         }
622 
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         new->cl_principal = clnt->cl_principal;
630         return new;
631 
632 out_err:
633         dprintk("RPC:       %s: returned error %d\n", __func__, err);
634         return ERR_PTR(err);
635 }
636 
637 /**
638  * rpc_clone_client - Clone an RPC client structure
639  *
640  * @clnt: RPC client whose parameters are copied
641  *
642  * Returns a fresh RPC client or an ERR_PTR.
643  */
644 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
645 {
646         struct rpc_create_args args = {
647                 .program        = clnt->cl_program,
648                 .prognumber     = clnt->cl_prog,
649                 .version        = clnt->cl_vers,
650                 .authflavor     = clnt->cl_auth->au_flavor,
651         };
652         return __rpc_clone_client(&args, clnt);
653 }
654 EXPORT_SYMBOL_GPL(rpc_clone_client);
655 
656 /**
657  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
658  *
659  * @clnt: RPC client whose parameters are copied
660  * @flavor: security flavor for new client
661  *
662  * Returns a fresh RPC client or an ERR_PTR.
663  */
664 struct rpc_clnt *
665 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
666 {
667         struct rpc_create_args args = {
668                 .program        = clnt->cl_program,
669                 .prognumber     = clnt->cl_prog,
670                 .version        = clnt->cl_vers,
671                 .authflavor     = flavor,
672         };
673         return __rpc_clone_client(&args, clnt);
674 }
675 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
676 
677 /**
678  * rpc_switch_client_transport: switch the RPC transport on the fly
679  * @clnt: pointer to a struct rpc_clnt
680  * @args: pointer to the new transport arguments
681  * @timeout: pointer to the new timeout parameters
682  *
683  * This function allows the caller to switch the RPC transport for the
684  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
685  * server, for instance.  It assumes that the caller has ensured that
686  * there are no active RPC tasks by using some form of locking.
687  *
688  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
689  * negative errno is returned, and "clnt" continues to use the old
690  * xprt.
691  */
692 int rpc_switch_client_transport(struct rpc_clnt *clnt,
693                 struct xprt_create *args,
694                 const struct rpc_timeout *timeout)
695 {
696         const struct rpc_timeout *old_timeo;
697         rpc_authflavor_t pseudoflavor;
698         struct rpc_xprt_switch *xps, *oldxps;
699         struct rpc_xprt *xprt, *old;
700         struct rpc_clnt *parent;
701         int err;
702 
703         xprt = xprt_create_transport(args);
704         if (IS_ERR(xprt)) {
705                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
706                         clnt);
707                 return PTR_ERR(xprt);
708         }
709 
710         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
711         if (xps == NULL) {
712                 xprt_put(xprt);
713                 return -ENOMEM;
714         }
715 
716         pseudoflavor = clnt->cl_auth->au_flavor;
717 
718         old_timeo = clnt->cl_timeout;
719         old = rpc_clnt_set_transport(clnt, xprt, timeout);
720         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
721 
722         rpc_unregister_client(clnt);
723         __rpc_clnt_remove_pipedir(clnt);
724         rpc_clnt_debugfs_unregister(clnt);
725 
726         /*
727          * A new transport was created.  "clnt" therefore
728          * becomes the root of a new cl_parent tree.  clnt's
729          * children, if it has any, still point to the old xprt.
730          */
731         parent = clnt->cl_parent;
732         clnt->cl_parent = clnt;
733 
734         /*
735          * The old rpc_auth cache cannot be re-used.  GSS
736          * contexts in particular are between a single
737          * client and server.
738          */
739         err = rpc_client_register(clnt, pseudoflavor, NULL);
740         if (err)
741                 goto out_revert;
742 
743         synchronize_rcu();
744         if (parent != clnt)
745                 rpc_release_client(parent);
746         xprt_switch_put(oldxps);
747         xprt_put(old);
748         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
749         return 0;
750 
751 out_revert:
752         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
753         rpc_clnt_set_transport(clnt, old, old_timeo);
754         clnt->cl_parent = parent;
755         rpc_client_register(clnt, pseudoflavor, NULL);
756         xprt_switch_put(xps);
757         xprt_put(xprt);
758         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
759         return err;
760 }
761 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
762 
763 static
764 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
765 {
766         struct rpc_xprt_switch *xps;
767 
768         rcu_read_lock();
769         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
770         rcu_read_unlock();
771         if (xps == NULL)
772                 return -EAGAIN;
773         xprt_iter_init_listall(xpi, xps);
774         xprt_switch_put(xps);
775         return 0;
776 }
777 
778 /**
779  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
780  * @clnt: pointer to client
781  * @fn: function to apply
782  * @data: void pointer to function data
783  *
784  * Iterates through the list of RPC transports currently attached to the
785  * client and applies the function fn(clnt, xprt, data).
786  *
787  * On error, the iteration stops, and the function returns the error value.
788  */
789 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
790                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
791                 void *data)
792 {
793         struct rpc_xprt_iter xpi;
794         int ret;
795 
796         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
797         if (ret)
798                 return ret;
799         for (;;) {
800                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
801 
802                 if (!xprt)
803                         break;
804                 ret = fn(clnt, xprt, data);
805                 xprt_put(xprt);
806                 if (ret < 0)
807                         break;
808         }
809         xprt_iter_destroy(&xpi);
810         return ret;
811 }
812 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
813 
814 /*
815  * Kill all tasks for the given client.
816  * XXX: kill their descendants as well?
817  */
818 void rpc_killall_tasks(struct rpc_clnt *clnt)
819 {
820         struct rpc_task *rovr;
821 
822 
823         if (list_empty(&clnt->cl_tasks))
824                 return;
825         dprintk("RPC:       killing all tasks for client %p\n", clnt);
826         /*
827          * Spin lock all_tasks to prevent changes...
828          */
829         spin_lock(&clnt->cl_lock);
830         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
831                 if (!RPC_IS_ACTIVATED(rovr))
832                         continue;
833                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
834                         rovr->tk_flags |= RPC_TASK_KILLED;
835                         rpc_exit(rovr, -EIO);
836                 }
837         }
838         spin_unlock(&clnt->cl_lock);
839 }
840 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
841 
842 /*
843  * Properly shut down an RPC client, terminating all outstanding
844  * requests.
845  */
846 void rpc_shutdown_client(struct rpc_clnt *clnt)
847 {
848         might_sleep();
849 
850         dprintk_rcu("RPC:       shutting down %s client for %s\n",
851                         clnt->cl_program->name,
852                         rcu_dereference(clnt->cl_xprt)->servername);
853 
854         while (!list_empty(&clnt->cl_tasks)) {
855                 rpc_killall_tasks(clnt);
856                 wait_event_timeout(destroy_wait,
857                         list_empty(&clnt->cl_tasks), 1*HZ);
858         }
859 
860         rpc_release_client(clnt);
861 }
862 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
863 
864 /*
865  * Free an RPC client
866  */
867 static struct rpc_clnt *
868 rpc_free_client(struct rpc_clnt *clnt)
869 {
870         struct rpc_clnt *parent = NULL;
871 
872         dprintk_rcu("RPC:       destroying %s client for %s\n",
873                         clnt->cl_program->name,
874                         rcu_dereference(clnt->cl_xprt)->servername);
875         if (clnt->cl_parent != clnt)
876                 parent = clnt->cl_parent;
877         rpc_clnt_debugfs_unregister(clnt);
878         rpc_clnt_remove_pipedir(clnt);
879         rpc_unregister_client(clnt);
880         rpc_free_iostats(clnt->cl_metrics);
881         clnt->cl_metrics = NULL;
882         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
883         xprt_iter_destroy(&clnt->cl_xpi);
884         rpciod_down();
885         rpc_free_clid(clnt);
886         kfree(clnt);
887         return parent;
888 }
889 
890 /*
891  * Free an RPC client
892  */
893 static struct rpc_clnt *
894 rpc_free_auth(struct rpc_clnt *clnt)
895 {
896         if (clnt->cl_auth == NULL)
897                 return rpc_free_client(clnt);
898 
899         /*
900          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
901          *       release remaining GSS contexts. This mechanism ensures
902          *       that it can do so safely.
903          */
904         atomic_inc(&clnt->cl_count);
905         rpcauth_release(clnt->cl_auth);
906         clnt->cl_auth = NULL;
907         if (atomic_dec_and_test(&clnt->cl_count))
908                 return rpc_free_client(clnt);
909         return NULL;
910 }
911 
912 /*
913  * Release reference to the RPC client
914  */
915 void
916 rpc_release_client(struct rpc_clnt *clnt)
917 {
918         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
919 
920         do {
921                 if (list_empty(&clnt->cl_tasks))
922                         wake_up(&destroy_wait);
923                 if (!atomic_dec_and_test(&clnt->cl_count))
924                         break;
925                 clnt = rpc_free_auth(clnt);
926         } while (clnt != NULL);
927 }
928 EXPORT_SYMBOL_GPL(rpc_release_client);
929 
930 /**
931  * rpc_bind_new_program - bind a new RPC program to an existing client
932  * @old: old rpc_client
933  * @program: rpc program to set
934  * @vers: rpc program version
935  *
936  * Clones the rpc client and sets up a new RPC program. This is mainly
937  * of use for enabling different RPC programs to share the same transport.
938  * The Sun NFSv2/v3 ACL protocol can do this.
939  */
940 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
941                                       const struct rpc_program *program,
942                                       u32 vers)
943 {
944         struct rpc_create_args args = {
945                 .program        = program,
946                 .prognumber     = program->number,
947                 .version        = vers,
948                 .authflavor     = old->cl_auth->au_flavor,
949         };
950         struct rpc_clnt *clnt;
951         int err;
952 
953         clnt = __rpc_clone_client(&args, old);
954         if (IS_ERR(clnt))
955                 goto out;
956         err = rpc_ping(clnt);
957         if (err != 0) {
958                 rpc_shutdown_client(clnt);
959                 clnt = ERR_PTR(err);
960         }
961 out:
962         return clnt;
963 }
964 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
965 
966 void rpc_task_release_transport(struct rpc_task *task)
967 {
968         struct rpc_xprt *xprt = task->tk_xprt;
969 
970         if (xprt) {
971                 task->tk_xprt = NULL;
972                 xprt_put(xprt);
973         }
974 }
975 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
976 
977 void rpc_task_release_client(struct rpc_task *task)
978 {
979         struct rpc_clnt *clnt = task->tk_client;
980 
981         if (clnt != NULL) {
982                 /* Remove from client task list */
983                 spin_lock(&clnt->cl_lock);
984                 list_del(&task->tk_task);
985                 spin_unlock(&clnt->cl_lock);
986                 task->tk_client = NULL;
987 
988                 rpc_release_client(clnt);
989         }
990         rpc_task_release_transport(task);
991 }
992 
993 static
994 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
995 {
996         if (!task->tk_xprt)
997                 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
998 }
999 
1000 static
1001 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1002 {
1003 
1004         if (clnt != NULL) {
1005                 rpc_task_set_transport(task, clnt);
1006                 task->tk_client = clnt;
1007                 atomic_inc(&clnt->cl_count);
1008                 if (clnt->cl_softrtry)
1009                         task->tk_flags |= RPC_TASK_SOFT;
1010                 if (clnt->cl_noretranstimeo)
1011                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1012                 if (atomic_read(&clnt->cl_swapper))
1013                         task->tk_flags |= RPC_TASK_SWAPPER;
1014                 /* Add to the client's list of all tasks */
1015                 spin_lock(&clnt->cl_lock);
1016                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1017                 spin_unlock(&clnt->cl_lock);
1018         }
1019 }
1020 
1021 static void
1022 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1023 {
1024         if (msg != NULL) {
1025                 task->tk_msg.rpc_proc = msg->rpc_proc;
1026                 task->tk_msg.rpc_argp = msg->rpc_argp;
1027                 task->tk_msg.rpc_resp = msg->rpc_resp;
1028                 if (msg->rpc_cred != NULL)
1029                         task->tk_msg.rpc_cred = get_cred(msg->rpc_cred);
1030         }
1031 }
1032 
1033 /*
1034  * Default callback for async RPC calls
1035  */
1036 static void
1037 rpc_default_callback(struct rpc_task *task, void *data)
1038 {
1039 }
1040 
1041 static const struct rpc_call_ops rpc_default_ops = {
1042         .rpc_call_done = rpc_default_callback,
1043 };
1044 
1045 /**
1046  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1047  * @task_setup_data: pointer to task initialisation data
1048  */
1049 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1050 {
1051         struct rpc_task *task;
1052 
1053         task = rpc_new_task(task_setup_data);
1054 
1055         rpc_task_set_client(task, task_setup_data->rpc_client);
1056         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1057 
1058         if (task->tk_action == NULL)
1059                 rpc_call_start(task);
1060 
1061         atomic_inc(&task->tk_count);
1062         rpc_execute(task);
1063         return task;
1064 }
1065 EXPORT_SYMBOL_GPL(rpc_run_task);
1066 
1067 /**
1068  * rpc_call_sync - Perform a synchronous RPC call
1069  * @clnt: pointer to RPC client
1070  * @msg: RPC call parameters
1071  * @flags: RPC call flags
1072  */
1073 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1074 {
1075         struct rpc_task *task;
1076         struct rpc_task_setup task_setup_data = {
1077                 .rpc_client = clnt,
1078                 .rpc_message = msg,
1079                 .callback_ops = &rpc_default_ops,
1080                 .flags = flags,
1081         };
1082         int status;
1083 
1084         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1085         if (flags & RPC_TASK_ASYNC) {
1086                 rpc_release_calldata(task_setup_data.callback_ops,
1087                         task_setup_data.callback_data);
1088                 return -EINVAL;
1089         }
1090 
1091         task = rpc_run_task(&task_setup_data);
1092         if (IS_ERR(task))
1093                 return PTR_ERR(task);
1094         status = task->tk_status;
1095         rpc_put_task(task);
1096         return status;
1097 }
1098 EXPORT_SYMBOL_GPL(rpc_call_sync);
1099 
1100 /**
1101  * rpc_call_async - Perform an asynchronous RPC call
1102  * @clnt: pointer to RPC client
1103  * @msg: RPC call parameters
1104  * @flags: RPC call flags
1105  * @tk_ops: RPC call ops
1106  * @data: user call data
1107  */
1108 int
1109 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1110                const struct rpc_call_ops *tk_ops, void *data)
1111 {
1112         struct rpc_task *task;
1113         struct rpc_task_setup task_setup_data = {
1114                 .rpc_client = clnt,
1115                 .rpc_message = msg,
1116                 .callback_ops = tk_ops,
1117                 .callback_data = data,
1118                 .flags = flags|RPC_TASK_ASYNC,
1119         };
1120 
1121         task = rpc_run_task(&task_setup_data);
1122         if (IS_ERR(task))
1123                 return PTR_ERR(task);
1124         rpc_put_task(task);
1125         return 0;
1126 }
1127 EXPORT_SYMBOL_GPL(rpc_call_async);
1128 
1129 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1130 static void call_bc_encode(struct rpc_task *task);
1131 
1132 /**
1133  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1134  * rpc_execute against it
1135  * @req: RPC request
1136  */
1137 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1138 {
1139         struct rpc_task *task;
1140         struct rpc_task_setup task_setup_data = {
1141                 .callback_ops = &rpc_default_ops,
1142                 .flags = RPC_TASK_SOFTCONN |
1143                         RPC_TASK_NO_RETRANS_TIMEOUT,
1144         };
1145 
1146         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1147         /*
1148          * Create an rpc_task to send the data
1149          */
1150         task = rpc_new_task(&task_setup_data);
1151         xprt_init_bc_request(req, task);
1152 
1153         task->tk_action = call_bc_encode;
1154         atomic_inc(&task->tk_count);
1155         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1156         rpc_execute(task);
1157 
1158         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1159         return task;
1160 }
1161 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1162 
1163 /**
1164  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1165  * @req: RPC request to prepare
1166  * @pages: vector of struct page pointers
1167  * @base: offset in first page where receive should start, in bytes
1168  * @len: expected size of the upper layer data payload, in bytes
1169  * @hdrsize: expected size of upper layer reply header, in XDR words
1170  *
1171  */
1172 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1173                              unsigned int base, unsigned int len,
1174                              unsigned int hdrsize)
1175 {
1176         /* Subtract one to force an extra word of buffer space for the
1177          * payload's XDR pad to fall into the rcv_buf's tail iovec.
1178          */
1179         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
1180 
1181         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1182         trace_rpc_reply_pages(req);
1183 }
1184 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1185 
1186 void
1187 rpc_call_start(struct rpc_task *task)
1188 {
1189         task->tk_action = call_start;
1190 }
1191 EXPORT_SYMBOL_GPL(rpc_call_start);
1192 
1193 /**
1194  * rpc_peeraddr - extract remote peer address from clnt's xprt
1195  * @clnt: RPC client structure
1196  * @buf: target buffer
1197  * @bufsize: length of target buffer
1198  *
1199  * Returns the number of bytes that are actually in the stored address.
1200  */
1201 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1202 {
1203         size_t bytes;
1204         struct rpc_xprt *xprt;
1205 
1206         rcu_read_lock();
1207         xprt = rcu_dereference(clnt->cl_xprt);
1208 
1209         bytes = xprt->addrlen;
1210         if (bytes > bufsize)
1211                 bytes = bufsize;
1212         memcpy(buf, &xprt->addr, bytes);
1213         rcu_read_unlock();
1214 
1215         return bytes;
1216 }
1217 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1218 
1219 /**
1220  * rpc_peeraddr2str - return remote peer address in printable format
1221  * @clnt: RPC client structure
1222  * @format: address format
1223  *
1224  * NB: the lifetime of the memory referenced by the returned pointer is
1225  * the same as the rpc_xprt itself.  As long as the caller uses this
1226  * pointer, it must hold the RCU read lock.
1227  */
1228 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1229                              enum rpc_display_format_t format)
1230 {
1231         struct rpc_xprt *xprt;
1232 
1233         xprt = rcu_dereference(clnt->cl_xprt);
1234 
1235         if (xprt->address_strings[format] != NULL)
1236                 return xprt->address_strings[format];
1237         else
1238                 return "unprintable";
1239 }
1240 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1241 
1242 static const struct sockaddr_in rpc_inaddr_loopback = {
1243         .sin_family             = AF_INET,
1244         .sin_addr.s_addr        = htonl(INADDR_ANY),
1245 };
1246 
1247 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1248         .sin6_family            = AF_INET6,
1249         .sin6_addr              = IN6ADDR_ANY_INIT,
1250 };
1251 
1252 /*
1253  * Try a getsockname() on a connected datagram socket.  Using a
1254  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1255  * This conserves the ephemeral port number space.
1256  *
1257  * Returns zero and fills in "buf" if successful; otherwise, a
1258  * negative errno is returned.
1259  */
1260 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1261                         struct sockaddr *buf)
1262 {
1263         struct socket *sock;
1264         int err;
1265 
1266         err = __sock_create(net, sap->sa_family,
1267                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1268         if (err < 0) {
1269                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1270                 goto out;
1271         }
1272 
1273         switch (sap->sa_family) {
1274         case AF_INET:
1275                 err = kernel_bind(sock,
1276                                 (struct sockaddr *)&rpc_inaddr_loopback,
1277                                 sizeof(rpc_inaddr_loopback));
1278                 break;
1279         case AF_INET6:
1280                 err = kernel_bind(sock,
1281                                 (struct sockaddr *)&rpc_in6addr_loopback,
1282                                 sizeof(rpc_in6addr_loopback));
1283                 break;
1284         default:
1285                 err = -EAFNOSUPPORT;
1286                 goto out;
1287         }
1288         if (err < 0) {
1289                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1290                 goto out_release;
1291         }
1292 
1293         err = kernel_connect(sock, sap, salen, 0);
1294         if (err < 0) {
1295                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1296                 goto out_release;
1297         }
1298 
1299         err = kernel_getsockname(sock, buf);
1300         if (err < 0) {
1301                 dprintk("RPC:       getsockname failed (%d)\n", err);
1302                 goto out_release;
1303         }
1304 
1305         err = 0;
1306         if (buf->sa_family == AF_INET6) {
1307                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1308                 sin6->sin6_scope_id = 0;
1309         }
1310         dprintk("RPC:       %s succeeded\n", __func__);
1311 
1312 out_release:
1313         sock_release(sock);
1314 out:
1315         return err;
1316 }
1317 
1318 /*
1319  * Scraping a connected socket failed, so we don't have a useable
1320  * local address.  Fallback: generate an address that will prevent
1321  * the server from calling us back.
1322  *
1323  * Returns zero and fills in "buf" if successful; otherwise, a
1324  * negative errno is returned.
1325  */
1326 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1327 {
1328         switch (family) {
1329         case AF_INET:
1330                 if (buflen < sizeof(rpc_inaddr_loopback))
1331                         return -EINVAL;
1332                 memcpy(buf, &rpc_inaddr_loopback,
1333                                 sizeof(rpc_inaddr_loopback));
1334                 break;
1335         case AF_INET6:
1336                 if (buflen < sizeof(rpc_in6addr_loopback))
1337                         return -EINVAL;
1338                 memcpy(buf, &rpc_in6addr_loopback,
1339                                 sizeof(rpc_in6addr_loopback));
1340                 break;
1341         default:
1342                 dprintk("RPC:       %s: address family not supported\n",
1343                         __func__);
1344                 return -EAFNOSUPPORT;
1345         }
1346         dprintk("RPC:       %s: succeeded\n", __func__);
1347         return 0;
1348 }
1349 
1350 /**
1351  * rpc_localaddr - discover local endpoint address for an RPC client
1352  * @clnt: RPC client structure
1353  * @buf: target buffer
1354  * @buflen: size of target buffer, in bytes
1355  *
1356  * Returns zero and fills in "buf" and "buflen" if successful;
1357  * otherwise, a negative errno is returned.
1358  *
1359  * This works even if the underlying transport is not currently connected,
1360  * or if the upper layer never previously provided a source address.
1361  *
1362  * The result of this function call is transient: multiple calls in
1363  * succession may give different results, depending on how local
1364  * networking configuration changes over time.
1365  */
1366 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1367 {
1368         struct sockaddr_storage address;
1369         struct sockaddr *sap = (struct sockaddr *)&address;
1370         struct rpc_xprt *xprt;
1371         struct net *net;
1372         size_t salen;
1373         int err;
1374 
1375         rcu_read_lock();
1376         xprt = rcu_dereference(clnt->cl_xprt);
1377         salen = xprt->addrlen;
1378         memcpy(sap, &xprt->addr, salen);
1379         net = get_net(xprt->xprt_net);
1380         rcu_read_unlock();
1381 
1382         rpc_set_port(sap, 0);
1383         err = rpc_sockname(net, sap, salen, buf);
1384         put_net(net);
1385         if (err != 0)
1386                 /* Couldn't discover local address, return ANYADDR */
1387                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1388         return 0;
1389 }
1390 EXPORT_SYMBOL_GPL(rpc_localaddr);
1391 
1392 void
1393 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1394 {
1395         struct rpc_xprt *xprt;
1396 
1397         rcu_read_lock();
1398         xprt = rcu_dereference(clnt->cl_xprt);
1399         if (xprt->ops->set_buffer_size)
1400                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1401         rcu_read_unlock();
1402 }
1403 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1404 
1405 /**
1406  * rpc_net_ns - Get the network namespace for this RPC client
1407  * @clnt: RPC client to query
1408  *
1409  */
1410 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1411 {
1412         struct net *ret;
1413 
1414         rcu_read_lock();
1415         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1416         rcu_read_unlock();
1417         return ret;
1418 }
1419 EXPORT_SYMBOL_GPL(rpc_net_ns);
1420 
1421 /**
1422  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1423  * @clnt: RPC client to query
1424  *
1425  * For stream transports, this is one RPC record fragment (see RFC
1426  * 1831), as we don't support multi-record requests yet.  For datagram
1427  * transports, this is the size of an IP packet minus the IP, UDP, and
1428  * RPC header sizes.
1429  */
1430 size_t rpc_max_payload(struct rpc_clnt *clnt)
1431 {
1432         size_t ret;
1433 
1434         rcu_read_lock();
1435         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1436         rcu_read_unlock();
1437         return ret;
1438 }
1439 EXPORT_SYMBOL_GPL(rpc_max_payload);
1440 
1441 /**
1442  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1443  * @clnt: RPC client to query
1444  */
1445 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1446 {
1447         struct rpc_xprt *xprt;
1448         size_t ret;
1449 
1450         rcu_read_lock();
1451         xprt = rcu_dereference(clnt->cl_xprt);
1452         ret = xprt->ops->bc_maxpayload(xprt);
1453         rcu_read_unlock();
1454         return ret;
1455 }
1456 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1457 
1458 /**
1459  * rpc_force_rebind - force transport to check that remote port is unchanged
1460  * @clnt: client to rebind
1461  *
1462  */
1463 void rpc_force_rebind(struct rpc_clnt *clnt)
1464 {
1465         if (clnt->cl_autobind) {
1466                 rcu_read_lock();
1467                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1468                 rcu_read_unlock();
1469         }
1470 }
1471 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1472 
1473 /*
1474  * Restart an (async) RPC call from the call_prepare state.
1475  * Usually called from within the exit handler.
1476  */
1477 int
1478 rpc_restart_call_prepare(struct rpc_task *task)
1479 {
1480         if (RPC_ASSASSINATED(task))
1481                 return 0;
1482         task->tk_action = call_start;
1483         task->tk_status = 0;
1484         if (task->tk_ops->rpc_call_prepare != NULL)
1485                 task->tk_action = rpc_prepare_task;
1486         return 1;
1487 }
1488 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1489 
1490 /*
1491  * Restart an (async) RPC call. Usually called from within the
1492  * exit handler.
1493  */
1494 int
1495 rpc_restart_call(struct rpc_task *task)
1496 {
1497         if (RPC_ASSASSINATED(task))
1498                 return 0;
1499         task->tk_action = call_start;
1500         task->tk_status = 0;
1501         return 1;
1502 }
1503 EXPORT_SYMBOL_GPL(rpc_restart_call);
1504 
1505 const char
1506 *rpc_proc_name(const struct rpc_task *task)
1507 {
1508         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1509 
1510         if (proc) {
1511                 if (proc->p_name)
1512                         return proc->p_name;
1513                 else
1514                         return "NULL";
1515         } else
1516                 return "no proc";
1517 }
1518 
1519 /*
1520  * 0.  Initial state
1521  *
1522  *     Other FSM states can be visited zero or more times, but
1523  *     this state is visited exactly once for each RPC.
1524  */
1525 static void
1526 call_start(struct rpc_task *task)
1527 {
1528         struct rpc_clnt *clnt = task->tk_client;
1529         int idx = task->tk_msg.rpc_proc->p_statidx;
1530 
1531         trace_rpc_request(task);
1532         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1533                         clnt->cl_program->name, clnt->cl_vers,
1534                         rpc_proc_name(task),
1535                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1536 
1537         /* Increment call count (version might not be valid for ping) */
1538         if (clnt->cl_program->version[clnt->cl_vers])
1539                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1540         clnt->cl_stats->rpccnt++;
1541         task->tk_action = call_reserve;
1542         rpc_task_set_transport(task, clnt);
1543 }
1544 
1545 /*
1546  * 1.   Reserve an RPC call slot
1547  */
1548 static void
1549 call_reserve(struct rpc_task *task)
1550 {
1551         dprint_status(task);
1552 
1553         task->tk_status  = 0;
1554         task->tk_action  = call_reserveresult;
1555         xprt_reserve(task);
1556 }
1557 
1558 static void call_retry_reserve(struct rpc_task *task);
1559 
1560 /*
1561  * 1b.  Grok the result of xprt_reserve()
1562  */
1563 static void
1564 call_reserveresult(struct rpc_task *task)
1565 {
1566         int status = task->tk_status;
1567 
1568         dprint_status(task);
1569 
1570         /*
1571          * After a call to xprt_reserve(), we must have either
1572          * a request slot or else an error status.
1573          */
1574         task->tk_status = 0;
1575         if (status >= 0) {
1576                 if (task->tk_rqstp) {
1577                         task->tk_action = call_refresh;
1578                         return;
1579                 }
1580 
1581                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1582                                 __func__, status);
1583                 rpc_exit(task, -EIO);
1584                 return;
1585         }
1586 
1587         /*
1588          * Even though there was an error, we may have acquired
1589          * a request slot somehow.  Make sure not to leak it.
1590          */
1591         if (task->tk_rqstp) {
1592                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1593                                 __func__, status);
1594                 xprt_release(task);
1595         }
1596 
1597         switch (status) {
1598         case -ENOMEM:
1599                 rpc_delay(task, HZ >> 2);
1600                 /* fall through */
1601         case -EAGAIN:   /* woken up; retry */
1602                 task->tk_action = call_retry_reserve;
1603                 return;
1604         case -EIO:      /* probably a shutdown */
1605                 break;
1606         default:
1607                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1608                                 __func__, status);
1609                 break;
1610         }
1611         rpc_exit(task, status);
1612 }
1613 
1614 /*
1615  * 1c.  Retry reserving an RPC call slot
1616  */
1617 static void
1618 call_retry_reserve(struct rpc_task *task)
1619 {
1620         dprint_status(task);
1621 
1622         task->tk_status  = 0;
1623         task->tk_action  = call_reserveresult;
1624         xprt_retry_reserve(task);
1625 }
1626 
1627 /*
1628  * 2.   Bind and/or refresh the credentials
1629  */
1630 static void
1631 call_refresh(struct rpc_task *task)
1632 {
1633         dprint_status(task);
1634 
1635         task->tk_action = call_refreshresult;
1636         task->tk_status = 0;
1637         task->tk_client->cl_stats->rpcauthrefresh++;
1638         rpcauth_refreshcred(task);
1639 }
1640 
1641 /*
1642  * 2a.  Process the results of a credential refresh
1643  */
1644 static void
1645 call_refreshresult(struct rpc_task *task)
1646 {
1647         int status = task->tk_status;
1648 
1649         dprint_status(task);
1650 
1651         task->tk_status = 0;
1652         task->tk_action = call_refresh;
1653         switch (status) {
1654         case 0:
1655                 if (rpcauth_uptodatecred(task)) {
1656                         task->tk_action = call_allocate;
1657                         return;
1658                 }
1659                 /* Use rate-limiting and a max number of retries if refresh
1660                  * had status 0 but failed to update the cred.
1661                  */
1662                 /* fall through */
1663         case -ETIMEDOUT:
1664                 rpc_delay(task, 3*HZ);
1665                 /* fall through */
1666         case -EAGAIN:
1667                 status = -EACCES;
1668                 /* fall through */
1669         case -EKEYEXPIRED:
1670                 if (!task->tk_cred_retry)
1671                         break;
1672                 task->tk_cred_retry--;
1673                 dprintk("RPC: %5u %s: retry refresh creds\n",
1674                                 task->tk_pid, __func__);
1675                 return;
1676         }
1677         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1678                                 task->tk_pid, __func__, status);
1679         rpc_exit(task, status);
1680 }
1681 
1682 /*
1683  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1684  *      (Note: buffer memory is freed in xprt_release).
1685  */
1686 static void
1687 call_allocate(struct rpc_task *task)
1688 {
1689         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1690         struct rpc_rqst *req = task->tk_rqstp;
1691         struct rpc_xprt *xprt = req->rq_xprt;
1692         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1693         int status;
1694 
1695         dprint_status(task);
1696 
1697         task->tk_status = 0;
1698         task->tk_action = call_encode;
1699 
1700         if (req->rq_buffer)
1701                 return;
1702 
1703         if (proc->p_proc != 0) {
1704                 BUG_ON(proc->p_arglen == 0);
1705                 if (proc->p_decode != NULL)
1706                         BUG_ON(proc->p_replen == 0);
1707         }
1708 
1709         /*
1710          * Calculate the size (in quads) of the RPC call
1711          * and reply headers, and convert both values
1712          * to byte sizes.
1713          */
1714         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1715                            proc->p_arglen;
1716         req->rq_callsize <<= 2;
1717         /*
1718          * Note: the reply buffer must at minimum allocate enough space
1719          * for the 'struct accepted_reply' from RFC5531.
1720          */
1721         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1722                         max_t(size_t, proc->p_replen, 2);
1723         req->rq_rcvsize <<= 2;
1724 
1725         status = xprt->ops->buf_alloc(task);
1726         xprt_inject_disconnect(xprt);
1727         if (status == 0)
1728                 return;
1729         if (status != -ENOMEM) {
1730                 rpc_exit(task, status);
1731                 return;
1732         }
1733 
1734         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1735 
1736         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1737                 task->tk_action = call_allocate;
1738                 rpc_delay(task, HZ>>4);
1739                 return;
1740         }
1741 
1742         rpc_exit(task, -ERESTARTSYS);
1743 }
1744 
1745 static int
1746 rpc_task_need_encode(struct rpc_task *task)
1747 {
1748         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1749                 (!(task->tk_flags & RPC_TASK_SENT) ||
1750                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1751                  xprt_request_need_retransmit(task));
1752 }
1753 
1754 static void
1755 rpc_xdr_encode(struct rpc_task *task)
1756 {
1757         struct rpc_rqst *req = task->tk_rqstp;
1758         struct xdr_stream xdr;
1759 
1760         xdr_buf_init(&req->rq_snd_buf,
1761                      req->rq_buffer,
1762                      req->rq_callsize);
1763         xdr_buf_init(&req->rq_rcv_buf,
1764                      req->rq_rbuffer,
1765                      req->rq_rcvsize);
1766 
1767         req->rq_snd_buf.head[0].iov_len = 0;
1768         xdr_init_encode(&xdr, &req->rq_snd_buf,
1769                         req->rq_snd_buf.head[0].iov_base, req);
1770         xdr_free_bvec(&req->rq_snd_buf);
1771         if (rpc_encode_header(task, &xdr))
1772                 return;
1773 
1774         task->tk_status = rpcauth_wrap_req(task, &xdr);
1775 }
1776 
1777 /*
1778  * 3.   Encode arguments of an RPC call
1779  */
1780 static void
1781 call_encode(struct rpc_task *task)
1782 {
1783         if (!rpc_task_need_encode(task))
1784                 goto out;
1785         dprint_status(task);
1786         /* Encode here so that rpcsec_gss can use correct sequence number. */
1787         rpc_xdr_encode(task);
1788         /* Did the encode result in an error condition? */
1789         if (task->tk_status != 0) {
1790                 /* Was the error nonfatal? */
1791                 switch (task->tk_status) {
1792                 case -EAGAIN:
1793                 case -ENOMEM:
1794                         rpc_delay(task, HZ >> 4);
1795                         break;
1796                 case -EKEYEXPIRED:
1797                         task->tk_action = call_refresh;
1798                         break;
1799                 default:
1800                         rpc_exit(task, task->tk_status);
1801                 }
1802                 return;
1803         }
1804 
1805         /* Add task to reply queue before transmission to avoid races */
1806         if (rpc_reply_expected(task))
1807                 xprt_request_enqueue_receive(task);
1808         xprt_request_enqueue_transmit(task);
1809 out:
1810         task->tk_action = call_transmit;
1811         /* Check that the connection is OK */
1812         if (!xprt_bound(task->tk_xprt))
1813                 task->tk_action = call_bind;
1814         else if (!xprt_connected(task->tk_xprt))
1815                 task->tk_action = call_connect;
1816 }
1817 
1818 /*
1819  * Helpers to check if the task was already transmitted, and
1820  * to take action when that is the case.
1821  */
1822 static bool
1823 rpc_task_transmitted(struct rpc_task *task)
1824 {
1825         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1826 }
1827 
1828 static void
1829 rpc_task_handle_transmitted(struct rpc_task *task)
1830 {
1831         xprt_end_transmit(task);
1832         task->tk_action = call_transmit_status;
1833 }
1834 
1835 /*
1836  * 4.   Get the server port number if not yet set
1837  */
1838 static void
1839 call_bind(struct rpc_task *task)
1840 {
1841         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1842 
1843         if (rpc_task_transmitted(task)) {
1844                 rpc_task_handle_transmitted(task);
1845                 return;
1846         }
1847 
1848         if (xprt_bound(xprt)) {
1849                 task->tk_action = call_connect;
1850                 return;
1851         }
1852 
1853         dprint_status(task);
1854 
1855         task->tk_action = call_bind_status;
1856         if (!xprt_prepare_transmit(task))
1857                 return;
1858 
1859         task->tk_timeout = xprt->bind_timeout;
1860         xprt->ops->rpcbind(task);
1861 }
1862 
1863 /*
1864  * 4a.  Sort out bind result
1865  */
1866 static void
1867 call_bind_status(struct rpc_task *task)
1868 {
1869         int status = -EIO;
1870 
1871         if (rpc_task_transmitted(task)) {
1872                 rpc_task_handle_transmitted(task);
1873                 return;
1874         }
1875 
1876         if (task->tk_status >= 0) {
1877                 dprint_status(task);
1878                 task->tk_status = 0;
1879                 task->tk_action = call_connect;
1880                 return;
1881         }
1882 
1883         trace_rpc_bind_status(task);
1884         switch (task->tk_status) {
1885         case -ENOMEM:
1886                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1887                 rpc_delay(task, HZ >> 2);
1888                 goto retry_timeout;
1889         case -EACCES:
1890                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1891                                 "unavailable\n", task->tk_pid);
1892                 /* fail immediately if this is an RPC ping */
1893                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1894                         status = -EOPNOTSUPP;
1895                         break;
1896                 }
1897                 if (task->tk_rebind_retry == 0)
1898                         break;
1899                 task->tk_rebind_retry--;
1900                 rpc_delay(task, 3*HZ);
1901                 goto retry_timeout;
1902         case -EAGAIN:
1903                 goto retry_timeout;
1904         case -ETIMEDOUT:
1905                 dprintk("RPC: %5u rpcbind request timed out\n",
1906                                 task->tk_pid);
1907                 goto retry_timeout;
1908         case -EPFNOSUPPORT:
1909                 /* server doesn't support any rpcbind version we know of */
1910                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1911                                 task->tk_pid);
1912                 break;
1913         case -EPROTONOSUPPORT:
1914                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1915                                 task->tk_pid);
1916                 goto retry_timeout;
1917         case -ECONNREFUSED:             /* connection problems */
1918         case -ECONNRESET:
1919         case -ECONNABORTED:
1920         case -ENOTCONN:
1921         case -EHOSTDOWN:
1922         case -ENETDOWN:
1923         case -EHOSTUNREACH:
1924         case -ENETUNREACH:
1925         case -ENOBUFS:
1926         case -EPIPE:
1927                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1928                                 task->tk_pid, task->tk_status);
1929                 if (!RPC_IS_SOFTCONN(task)) {
1930                         rpc_delay(task, 5*HZ);
1931                         goto retry_timeout;
1932                 }
1933                 status = task->tk_status;
1934                 break;
1935         default:
1936                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1937                                 task->tk_pid, -task->tk_status);
1938         }
1939 
1940         rpc_exit(task, status);
1941         return;
1942 
1943 retry_timeout:
1944         task->tk_status = 0;
1945         task->tk_action = call_bind;
1946         rpc_check_timeout(task);
1947 }
1948 
1949 /*
1950  * 4b.  Connect to the RPC server
1951  */
1952 static void
1953 call_connect(struct rpc_task *task)
1954 {
1955         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1956 
1957         if (rpc_task_transmitted(task)) {
1958                 rpc_task_handle_transmitted(task);
1959                 return;
1960         }
1961 
1962         if (xprt_connected(xprt)) {
1963                 task->tk_action = call_transmit;
1964                 return;
1965         }
1966 
1967         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1968                         task->tk_pid, xprt,
1969                         (xprt_connected(xprt) ? "is" : "is not"));
1970 
1971         task->tk_action = call_connect_status;
1972         if (task->tk_status < 0)
1973                 return;
1974         if (task->tk_flags & RPC_TASK_NOCONNECT) {
1975                 rpc_exit(task, -ENOTCONN);
1976                 return;
1977         }
1978         if (!xprt_prepare_transmit(task))
1979                 return;
1980         xprt_connect(task);
1981 }
1982 
1983 /*
1984  * 4c.  Sort out connect result
1985  */
1986 static void
1987 call_connect_status(struct rpc_task *task)
1988 {
1989         struct rpc_clnt *clnt = task->tk_client;
1990         int status = task->tk_status;
1991 
1992         if (rpc_task_transmitted(task)) {
1993                 rpc_task_handle_transmitted(task);
1994                 return;
1995         }
1996 
1997         dprint_status(task);
1998 
1999         trace_rpc_connect_status(task);
2000         task->tk_status = 0;
2001         switch (status) {
2002         case -ECONNREFUSED:
2003                 /* A positive refusal suggests a rebind is needed. */
2004                 if (RPC_IS_SOFTCONN(task))
2005                         break;
2006                 if (clnt->cl_autobind) {
2007                         rpc_force_rebind(clnt);
2008                         goto out_retry;
2009                 }
2010                 /* fall through */
2011         case -ECONNRESET:
2012         case -ECONNABORTED:
2013         case -ENETDOWN:
2014         case -ENETUNREACH:
2015         case -EHOSTUNREACH:
2016         case -EADDRINUSE:
2017         case -ENOBUFS:
2018         case -EPIPE:
2019                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2020                                             task->tk_rqstp->rq_connect_cookie);
2021                 if (RPC_IS_SOFTCONN(task))
2022                         break;
2023                 /* retry with existing socket, after a delay */
2024                 rpc_delay(task, 3*HZ);
2025                 /* fall through */
2026         case -ENOTCONN:
2027         case -EAGAIN:
2028         case -ETIMEDOUT:
2029                 goto out_retry;
2030         case 0:
2031                 clnt->cl_stats->netreconn++;
2032                 task->tk_action = call_transmit;
2033                 return;
2034         }
2035         rpc_exit(task, status);
2036         return;
2037 out_retry:
2038         /* Check for timeouts before looping back to call_bind */
2039         task->tk_action = call_bind;
2040         rpc_check_timeout(task);
2041 }
2042 
2043 /*
2044  * 5.   Transmit the RPC request, and wait for reply
2045  */
2046 static void
2047 call_transmit(struct rpc_task *task)
2048 {
2049         if (rpc_task_transmitted(task)) {
2050                 rpc_task_handle_transmitted(task);
2051                 return;
2052         }
2053 
2054         dprint_status(task);
2055 
2056         task->tk_action = call_transmit_status;
2057         if (!xprt_prepare_transmit(task))
2058                 return;
2059         task->tk_status = 0;
2060         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2061                 if (!xprt_connected(task->tk_xprt)) {
2062                         task->tk_status = -ENOTCONN;
2063                         return;
2064                 }
2065                 xprt_transmit(task);
2066         }
2067         xprt_end_transmit(task);
2068 }
2069 
2070 /*
2071  * 5a.  Handle cleanup after a transmission
2072  */
2073 static void
2074 call_transmit_status(struct rpc_task *task)
2075 {
2076         task->tk_action = call_status;
2077 
2078         /*
2079          * Common case: success.  Force the compiler to put this
2080          * test first.
2081          */
2082         if (rpc_task_transmitted(task)) {
2083                 task->tk_status = 0;
2084                 xprt_request_wait_receive(task);
2085                 return;
2086         }
2087 
2088         switch (task->tk_status) {
2089         default:
2090                 dprint_status(task);
2091                 break;
2092         case -EBADMSG:
2093                 task->tk_status = 0;
2094                 task->tk_action = call_encode;
2095                 break;
2096                 /*
2097                  * Special cases: if we've been waiting on the
2098                  * socket's write_space() callback, or if the
2099                  * socket just returned a connection error,
2100                  * then hold onto the transport lock.
2101                  */
2102         case -ENOBUFS:
2103                 rpc_delay(task, HZ>>2);
2104                 /* fall through */
2105         case -EBADSLT:
2106         case -EAGAIN:
2107                 task->tk_action = call_transmit;
2108                 task->tk_status = 0;
2109                 break;
2110         case -ECONNREFUSED:
2111         case -EHOSTDOWN:
2112         case -ENETDOWN:
2113         case -EHOSTUNREACH:
2114         case -ENETUNREACH:
2115         case -EPERM:
2116                 if (RPC_IS_SOFTCONN(task)) {
2117                         if (!task->tk_msg.rpc_proc->p_proc)
2118                                 trace_xprt_ping(task->tk_xprt,
2119                                                 task->tk_status);
2120                         rpc_exit(task, task->tk_status);
2121                         return;
2122                 }
2123                 /* fall through */
2124         case -ECONNRESET:
2125         case -ECONNABORTED:
2126         case -EADDRINUSE:
2127         case -ENOTCONN:
2128         case -EPIPE:
2129                 task->tk_action = call_bind;
2130                 task->tk_status = 0;
2131                 break;
2132         }
2133         rpc_check_timeout(task);
2134 }
2135 
2136 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2137 static void call_bc_transmit(struct rpc_task *task);
2138 static void call_bc_transmit_status(struct rpc_task *task);
2139 
2140 static void
2141 call_bc_encode(struct rpc_task *task)
2142 {
2143         xprt_request_enqueue_transmit(task);
2144         task->tk_action = call_bc_transmit;
2145 }
2146 
2147 /*
2148  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2149  * addition, disconnect on connectivity errors.
2150  */
2151 static void
2152 call_bc_transmit(struct rpc_task *task)
2153 {
2154         task->tk_action = call_bc_transmit_status;
2155         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2156                 if (!xprt_prepare_transmit(task))
2157                         return;
2158                 task->tk_status = 0;
2159                 xprt_transmit(task);
2160         }
2161         xprt_end_transmit(task);
2162 }
2163 
2164 static void
2165 call_bc_transmit_status(struct rpc_task *task)
2166 {
2167         struct rpc_rqst *req = task->tk_rqstp;
2168 
2169         if (rpc_task_transmitted(task))
2170                 task->tk_status = 0;
2171 
2172         dprint_status(task);
2173 
2174         switch (task->tk_status) {
2175         case 0:
2176                 /* Success */
2177         case -ENETDOWN:
2178         case -EHOSTDOWN:
2179         case -EHOSTUNREACH:
2180         case -ENETUNREACH:
2181         case -ECONNRESET:
2182         case -ECONNREFUSED:
2183         case -EADDRINUSE:
2184         case -ENOTCONN:
2185         case -EPIPE:
2186                 break;
2187         case -ENOBUFS:
2188                 rpc_delay(task, HZ>>2);
2189                 /* fall through */
2190         case -EBADSLT:
2191         case -EAGAIN:
2192                 task->tk_status = 0;
2193                 task->tk_action = call_bc_transmit;
2194                 return;
2195         case -ETIMEDOUT:
2196                 /*
2197                  * Problem reaching the server.  Disconnect and let the
2198                  * forechannel reestablish the connection.  The server will
2199                  * have to retransmit the backchannel request and we'll
2200                  * reprocess it.  Since these ops are idempotent, there's no
2201                  * need to cache our reply at this time.
2202                  */
2203                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2204                         "error: %d\n", task->tk_status);
2205                 xprt_conditional_disconnect(req->rq_xprt,
2206                         req->rq_connect_cookie);
2207                 break;
2208         default:
2209                 /*
2210                  * We were unable to reply and will have to drop the
2211                  * request.  The server should reconnect and retransmit.
2212                  */
2213                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2214                         "error: %d\n", task->tk_status);
2215                 break;
2216         }
2217         task->tk_action = rpc_exit_task;
2218 }
2219 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2220 
2221 /*
2222  * 6.   Sort out the RPC call status
2223  */
2224 static void
2225 call_status(struct rpc_task *task)
2226 {
2227         struct rpc_clnt *clnt = task->tk_client;
2228         int             status;
2229 
2230         if (!task->tk_msg.rpc_proc->p_proc)
2231                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2232 
2233         dprint_status(task);
2234 
2235         status = task->tk_status;
2236         if (status >= 0) {
2237                 task->tk_action = call_decode;
2238                 return;
2239         }
2240 
2241         trace_rpc_call_status(task);
2242         task->tk_status = 0;
2243         switch(status) {
2244         case -EHOSTDOWN:
2245         case -ENETDOWN:
2246         case -EHOSTUNREACH:
2247         case -ENETUNREACH:
2248         case -EPERM:
2249                 if (RPC_IS_SOFTCONN(task))
2250                         goto out_exit;
2251                 /*
2252                  * Delay any retries for 3 seconds, then handle as if it
2253                  * were a timeout.
2254                  */
2255                 rpc_delay(task, 3*HZ);
2256                 /* fall through */
2257         case -ETIMEDOUT:
2258                 break;
2259         case -ECONNREFUSED:
2260         case -ECONNRESET:
2261         case -ECONNABORTED:
2262         case -ENOTCONN:
2263                 rpc_force_rebind(clnt);
2264                 /* fall through */
2265         case -EADDRINUSE:
2266                 rpc_delay(task, 3*HZ);
2267                 /* fall through */
2268         case -EPIPE:
2269         case -EAGAIN:
2270                 break;
2271         case -EIO:
2272                 /* shutdown or soft timeout */
2273                 goto out_exit;
2274         default:
2275                 if (clnt->cl_chatty)
2276                         printk("%s: RPC call returned error %d\n",
2277                                clnt->cl_program->name, -status);
2278                 goto out_exit;
2279         }
2280         task->tk_action = call_encode;
2281         rpc_check_timeout(task);
2282         return;
2283 out_exit:
2284         rpc_exit(task, status);
2285 }
2286 
2287 static bool
2288 rpc_check_connected(const struct rpc_rqst *req)
2289 {
2290         /* No allocated request or transport? return true */
2291         if (!req || !req->rq_xprt)
2292                 return true;
2293         return xprt_connected(req->rq_xprt);
2294 }
2295 
2296 static void
2297 rpc_check_timeout(struct rpc_task *task)
2298 {
2299         struct rpc_clnt *clnt = task->tk_client;
2300 
2301         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2302                 return;
2303 
2304         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2305         task->tk_timeouts++;
2306 
2307         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2308                 rpc_exit(task, -ETIMEDOUT);
2309                 return;
2310         }
2311 
2312         if (RPC_IS_SOFT(task)) {
2313                 if (clnt->cl_chatty) {
2314                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2315                                 clnt->cl_program->name,
2316                                 task->tk_xprt->servername);
2317                 }
2318                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2319                         rpc_exit(task, -ETIMEDOUT);
2320                 else
2321                         rpc_exit(task, -EIO);
2322                 return;
2323         }
2324 
2325         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2326                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2327                 if (clnt->cl_chatty) {
2328                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2329                         clnt->cl_program->name,
2330                         task->tk_xprt->servername);
2331                 }
2332         }
2333         rpc_force_rebind(clnt);
2334         /*
2335          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2336          * event? RFC2203 requires the server to drop all such requests.
2337          */
2338         rpcauth_invalcred(task);
2339 }
2340 
2341 /*
2342  * 7.   Decode the RPC reply
2343  */
2344 static void
2345 call_decode(struct rpc_task *task)
2346 {
2347         struct rpc_clnt *clnt = task->tk_client;
2348         struct rpc_rqst *req = task->tk_rqstp;
2349         struct xdr_stream xdr;
2350 
2351         dprint_status(task);
2352 
2353         if (!task->tk_msg.rpc_proc->p_decode) {
2354                 task->tk_action = rpc_exit_task;
2355                 return;
2356         }
2357 
2358         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2359                 if (clnt->cl_chatty) {
2360                         printk(KERN_NOTICE "%s: server %s OK\n",
2361                                 clnt->cl_program->name,
2362                                 task->tk_xprt->servername);
2363                 }
2364                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2365         }
2366 
2367         /*
2368          * Ensure that we see all writes made by xprt_complete_rqst()
2369          * before it changed req->rq_reply_bytes_recvd.
2370          */
2371         smp_rmb();
2372         req->rq_rcv_buf.len = req->rq_private_buf.len;
2373 
2374         /* Check that the softirq receive buffer is valid */
2375         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2376                                 sizeof(req->rq_rcv_buf)) != 0);
2377 
2378         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2379                         req->rq_rcv_buf.head[0].iov_base, req);
2380         switch (rpc_decode_header(task, &xdr)) {
2381         case 0:
2382                 task->tk_action = rpc_exit_task;
2383                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2384                 dprintk("RPC: %5u %s result %d\n",
2385                         task->tk_pid, __func__, task->tk_status);
2386                 return;
2387         case -EAGAIN:
2388                 task->tk_status = 0;
2389                 xdr_free_bvec(&req->rq_rcv_buf);
2390                 req->rq_reply_bytes_recvd = 0;
2391                 req->rq_rcv_buf.len = 0;
2392                 if (task->tk_client->cl_discrtry)
2393                         xprt_conditional_disconnect(req->rq_xprt,
2394                                                     req->rq_connect_cookie);
2395                 task->tk_action = call_encode;
2396                 rpc_check_timeout(task);
2397                 break;
2398         case -EKEYREJECTED:
2399                 task->tk_action = call_reserve;
2400                 rpc_check_timeout(task);
2401                 rpcauth_invalcred(task);
2402                 /* Ensure we obtain a new XID if we retry! */
2403                 xprt_release(task);
2404         }
2405 }
2406 
2407 static int
2408 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2409 {
2410         struct rpc_clnt *clnt = task->tk_client;
2411         struct rpc_rqst *req = task->tk_rqstp;
2412         __be32 *p;
2413         int error;
2414 
2415         error = -EMSGSIZE;
2416         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2417         if (!p)
2418                 goto out_fail;
2419         *p++ = req->rq_xid;
2420         *p++ = rpc_call;
2421         *p++ = cpu_to_be32(RPC_VERSION);
2422         *p++ = cpu_to_be32(clnt->cl_prog);
2423         *p++ = cpu_to_be32(clnt->cl_vers);
2424         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2425 
2426         error = rpcauth_marshcred(task, xdr);
2427         if (error < 0)
2428                 goto out_fail;
2429         return 0;
2430 out_fail:
2431         trace_rpc_bad_callhdr(task);
2432         rpc_exit(task, error);
2433         return error;
2434 }
2435 
2436 static noinline int
2437 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2438 {
2439         struct rpc_clnt *clnt = task->tk_client;
2440         int error;
2441         __be32 *p;
2442 
2443         /* RFC-1014 says that the representation of XDR data must be a
2444          * multiple of four bytes
2445          * - if it isn't pointer subtraction in the NFS client may give
2446          *   undefined results
2447          */
2448         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2449                 goto out_unparsable;
2450 
2451         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2452         if (!p)
2453                 goto out_unparsable;
2454         p++;    /* skip XID */
2455         if (*p++ != rpc_reply)
2456                 goto out_unparsable;
2457         if (*p++ != rpc_msg_accepted)
2458                 goto out_msg_denied;
2459 
2460         error = rpcauth_checkverf(task, xdr);
2461         if (error)
2462                 goto out_verifier;
2463 
2464         p = xdr_inline_decode(xdr, sizeof(*p));
2465         if (!p)
2466                 goto out_unparsable;
2467         switch (*p) {
2468         case rpc_success:
2469                 return 0;
2470         case rpc_prog_unavail:
2471                 trace_rpc__prog_unavail(task);
2472                 error = -EPFNOSUPPORT;
2473                 goto out_err;
2474         case rpc_prog_mismatch:
2475                 trace_rpc__prog_mismatch(task);
2476                 error = -EPROTONOSUPPORT;
2477                 goto out_err;
2478         case rpc_proc_unavail:
2479                 trace_rpc__proc_unavail(task);
2480                 error = -EOPNOTSUPP;
2481                 goto out_err;
2482         case rpc_garbage_args:
2483         case rpc_system_err:
2484                 trace_rpc__garbage_args(task);
2485                 error = -EIO;
2486                 break;
2487         default:
2488                 goto out_unparsable;
2489         }
2490 
2491 out_garbage:
2492         clnt->cl_stats->rpcgarbage++;
2493         if (task->tk_garb_retry) {
2494                 task->tk_garb_retry--;
2495                 task->tk_action = call_encode;
2496                 return -EAGAIN;
2497         }
2498 out_err:
2499         rpc_exit(task, error);
2500         return error;
2501 
2502 out_unparsable:
2503         trace_rpc__unparsable(task);
2504         error = -EIO;
2505         goto out_garbage;
2506 
2507 out_verifier:
2508         trace_rpc_bad_verifier(task);
2509         goto out_garbage;
2510 
2511 out_msg_denied:
2512         error = -EACCES;
2513         p = xdr_inline_decode(xdr, sizeof(*p));
2514         if (!p)
2515                 goto out_unparsable;
2516         switch (*p++) {
2517         case rpc_auth_error:
2518                 break;
2519         case rpc_mismatch:
2520                 trace_rpc__mismatch(task);
2521                 error = -EPROTONOSUPPORT;
2522                 goto out_err;
2523         default:
2524                 goto out_unparsable;
2525         }
2526 
2527         p = xdr_inline_decode(xdr, sizeof(*p));
2528         if (!p)
2529                 goto out_unparsable;
2530         switch (*p++) {
2531         case rpc_autherr_rejectedcred:
2532         case rpc_autherr_rejectedverf:
2533         case rpcsec_gsserr_credproblem:
2534         case rpcsec_gsserr_ctxproblem:
2535                 if (!task->tk_cred_retry)
2536                         break;
2537                 task->tk_cred_retry--;
2538                 trace_rpc__stale_creds(task);
2539                 return -EKEYREJECTED;
2540         case rpc_autherr_badcred:
2541         case rpc_autherr_badverf:
2542                 /* possibly garbled cred/verf? */
2543                 if (!task->tk_garb_retry)
2544                         break;
2545                 task->tk_garb_retry--;
2546                 trace_rpc__bad_creds(task);
2547                 task->tk_action = call_encode;
2548                 return -EAGAIN;
2549         case rpc_autherr_tooweak:
2550                 trace_rpc__auth_tooweak(task);
2551                 pr_warn("RPC: server %s requires stronger authentication.\n",
2552                         task->tk_xprt->servername);
2553                 break;
2554         default:
2555                 goto out_unparsable;
2556         }
2557         goto out_err;
2558 }
2559 
2560 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2561                 const void *obj)
2562 {
2563 }
2564 
2565 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2566                 void *obj)
2567 {
2568         return 0;
2569 }
2570 
2571 static const struct rpc_procinfo rpcproc_null = {
2572         .p_encode = rpcproc_encode_null,
2573         .p_decode = rpcproc_decode_null,
2574 };
2575 
2576 static int rpc_ping(struct rpc_clnt *clnt)
2577 {
2578         struct rpc_message msg = {
2579                 .rpc_proc = &rpcproc_null,
2580         };
2581         int err;
2582         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2583                             RPC_TASK_NULLCREDS);
2584         return err;
2585 }
2586 
2587 static
2588 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2589                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2590                 const struct rpc_call_ops *ops, void *data)
2591 {
2592         struct rpc_message msg = {
2593                 .rpc_proc = &rpcproc_null,
2594         };
2595         struct rpc_task_setup task_setup_data = {
2596                 .rpc_client = clnt,
2597                 .rpc_xprt = xprt,
2598                 .rpc_message = &msg,
2599                 .rpc_op_cred = cred,
2600                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2601                 .callback_data = data,
2602                 .flags = flags | RPC_TASK_NULLCREDS,
2603         };
2604 
2605         return rpc_run_task(&task_setup_data);
2606 }
2607 
2608 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2609 {
2610         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2611 }
2612 EXPORT_SYMBOL_GPL(rpc_call_null);
2613 
2614 struct rpc_cb_add_xprt_calldata {
2615         struct rpc_xprt_switch *xps;
2616         struct rpc_xprt *xprt;
2617 };
2618 
2619 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2620 {
2621         struct rpc_cb_add_xprt_calldata *data = calldata;
2622 
2623         if (task->tk_status == 0)
2624                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2625 }
2626 
2627 static void rpc_cb_add_xprt_release(void *calldata)
2628 {
2629         struct rpc_cb_add_xprt_calldata *data = calldata;
2630 
2631         xprt_put(data->xprt);
2632         xprt_switch_put(data->xps);
2633         kfree(data);
2634 }
2635 
2636 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2637         .rpc_call_done = rpc_cb_add_xprt_done,
2638         .rpc_release = rpc_cb_add_xprt_release,
2639 };
2640 
2641 /**
2642  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2643  * @clnt: pointer to struct rpc_clnt
2644  * @xps: pointer to struct rpc_xprt_switch,
2645  * @xprt: pointer struct rpc_xprt
2646  * @dummy: unused
2647  */
2648 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2649                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2650                 void *dummy)
2651 {
2652         struct rpc_cb_add_xprt_calldata *data;
2653         struct rpc_task *task;
2654 
2655         data = kmalloc(sizeof(*data), GFP_NOFS);
2656         if (!data)
2657                 return -ENOMEM;
2658         data->xps = xprt_switch_get(xps);
2659         data->xprt = xprt_get(xprt);
2660 
2661         task = rpc_call_null_helper(clnt, xprt, NULL,
2662                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
2663                         &rpc_cb_add_xprt_call_ops, data);
2664         if (IS_ERR(task))
2665                 return PTR_ERR(task);
2666         rpc_put_task(task);
2667         return 1;
2668 }
2669 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2670 
2671 /**
2672  * rpc_clnt_setup_test_and_add_xprt()
2673  *
2674  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2675  *   1) caller of the test function must dereference the rpc_xprt_switch
2676  *   and the rpc_xprt.
2677  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2678  *   the rpc_call_done routine.
2679  *
2680  * Upon success (return of 1), the test function adds the new
2681  * transport to the rpc_clnt xprt switch
2682  *
2683  * @clnt: struct rpc_clnt to get the new transport
2684  * @xps:  the rpc_xprt_switch to hold the new transport
2685  * @xprt: the rpc_xprt to test
2686  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2687  *        and test function call data
2688  */
2689 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2690                                      struct rpc_xprt_switch *xps,
2691                                      struct rpc_xprt *xprt,
2692                                      void *data)
2693 {
2694         struct rpc_task *task;
2695         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2696         int status = -EADDRINUSE;
2697 
2698         xprt = xprt_get(xprt);
2699         xprt_switch_get(xps);
2700 
2701         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2702                 goto out_err;
2703 
2704         /* Test the connection */
2705         task = rpc_call_null_helper(clnt, xprt, NULL,
2706                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2707                                     NULL, NULL);
2708         if (IS_ERR(task)) {
2709                 status = PTR_ERR(task);
2710                 goto out_err;
2711         }
2712         status = task->tk_status;
2713         rpc_put_task(task);
2714 
2715         if (status < 0)
2716                 goto out_err;
2717 
2718         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2719         xtest->add_xprt_test(clnt, xprt, xtest->data);
2720 
2721         xprt_put(xprt);
2722         xprt_switch_put(xps);
2723 
2724         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2725         return 1;
2726 out_err:
2727         xprt_put(xprt);
2728         xprt_switch_put(xps);
2729         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2730                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2731         return status;
2732 }
2733 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2734 
2735 /**
2736  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2737  * @clnt: pointer to struct rpc_clnt
2738  * @xprtargs: pointer to struct xprt_create
2739  * @setup: callback to test and/or set up the connection
2740  * @data: pointer to setup function data
2741  *
2742  * Creates a new transport using the parameters set in args and
2743  * adds it to clnt.
2744  * If ping is set, then test that connectivity succeeds before
2745  * adding the new transport.
2746  *
2747  */
2748 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2749                 struct xprt_create *xprtargs,
2750                 int (*setup)(struct rpc_clnt *,
2751                         struct rpc_xprt_switch *,
2752                         struct rpc_xprt *,
2753                         void *),
2754                 void *data)
2755 {
2756         struct rpc_xprt_switch *xps;
2757         struct rpc_xprt *xprt;
2758         unsigned long connect_timeout;
2759         unsigned long reconnect_timeout;
2760         unsigned char resvport;
2761         int ret = 0;
2762 
2763         rcu_read_lock();
2764         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2765         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2766         if (xps == NULL || xprt == NULL) {
2767                 rcu_read_unlock();
2768                 return -EAGAIN;
2769         }
2770         resvport = xprt->resvport;
2771         connect_timeout = xprt->connect_timeout;
2772         reconnect_timeout = xprt->max_reconnect_timeout;
2773         rcu_read_unlock();
2774 
2775         xprt = xprt_create_transport(xprtargs);
2776         if (IS_ERR(xprt)) {
2777                 ret = PTR_ERR(xprt);
2778                 goto out_put_switch;
2779         }
2780         xprt->resvport = resvport;
2781         if (xprt->ops->set_connect_timeout != NULL)
2782                 xprt->ops->set_connect_timeout(xprt,
2783                                 connect_timeout,
2784                                 reconnect_timeout);
2785 
2786         rpc_xprt_switch_set_roundrobin(xps);
2787         if (setup) {
2788                 ret = setup(clnt, xps, xprt, data);
2789                 if (ret != 0)
2790                         goto out_put_xprt;
2791         }
2792         rpc_xprt_switch_add_xprt(xps, xprt);
2793 out_put_xprt:
2794         xprt_put(xprt);
2795 out_put_switch:
2796         xprt_switch_put(xps);
2797         return ret;
2798 }
2799 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2800 
2801 struct connect_timeout_data {
2802         unsigned long connect_timeout;
2803         unsigned long reconnect_timeout;
2804 };
2805 
2806 static int
2807 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2808                 struct rpc_xprt *xprt,
2809                 void *data)
2810 {
2811         struct connect_timeout_data *timeo = data;
2812 
2813         if (xprt->ops->set_connect_timeout)
2814                 xprt->ops->set_connect_timeout(xprt,
2815                                 timeo->connect_timeout,
2816                                 timeo->reconnect_timeout);
2817         return 0;
2818 }
2819 
2820 void
2821 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2822                 unsigned long connect_timeout,
2823                 unsigned long reconnect_timeout)
2824 {
2825         struct connect_timeout_data timeout = {
2826                 .connect_timeout = connect_timeout,
2827                 .reconnect_timeout = reconnect_timeout,
2828         };
2829         rpc_clnt_iterate_for_each_xprt(clnt,
2830                         rpc_xprt_set_connect_timeout,
2831                         &timeout);
2832 }
2833 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2834 
2835 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2836 {
2837         rcu_read_lock();
2838         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2839         rcu_read_unlock();
2840 }
2841 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2842 
2843 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2844 {
2845         rcu_read_lock();
2846         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2847                                  xprt);
2848         rcu_read_unlock();
2849 }
2850 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2851 
2852 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2853                                    const struct sockaddr *sap)
2854 {
2855         struct rpc_xprt_switch *xps;
2856         bool ret;
2857 
2858         rcu_read_lock();
2859         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2860         ret = rpc_xprt_switch_has_addr(xps, sap);
2861         rcu_read_unlock();
2862         return ret;
2863 }
2864 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2865 
2866 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2867 static void rpc_show_header(void)
2868 {
2869         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2870                 "-timeout ---ops--\n");
2871 }
2872 
2873 static void rpc_show_task(const struct rpc_clnt *clnt,
2874                           const struct rpc_task *task)
2875 {
2876         const char *rpc_waitq = "none";
2877 
2878         if (RPC_IS_QUEUED(task))
2879                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2880 
2881         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2882                 task->tk_pid, task->tk_flags, task->tk_status,
2883                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2884                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2885                 task->tk_action, rpc_waitq);
2886 }
2887 
2888 void rpc_show_tasks(struct net *net)
2889 {
2890         struct rpc_clnt *clnt;
2891         struct rpc_task *task;
2892         int header = 0;
2893         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2894 
2895         spin_lock(&sn->rpc_client_lock);
2896         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2897                 spin_lock(&clnt->cl_lock);
2898                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2899                         if (!header) {
2900                                 rpc_show_header();
2901                                 header++;
2902                         }
2903                         rpc_show_task(clnt, task);
2904                 }
2905                 spin_unlock(&clnt->cl_lock);
2906         }
2907         spin_unlock(&sn->rpc_client_lock);
2908 }
2909 #endif
2910 
2911 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2912 static int
2913 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2914                 struct rpc_xprt *xprt,
2915                 void *dummy)
2916 {
2917         return xprt_enable_swap(xprt);
2918 }
2919 
2920 int
2921 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2922 {
2923         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2924                 return rpc_clnt_iterate_for_each_xprt(clnt,
2925                                 rpc_clnt_swap_activate_callback, NULL);
2926         return 0;
2927 }
2928 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2929 
2930 static int
2931 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2932                 struct rpc_xprt *xprt,
2933                 void *dummy)
2934 {
2935         xprt_disable_swap(xprt);
2936         return 0;
2937 }
2938 
2939 void
2940 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2941 {
2942         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2943                 rpc_clnt_iterate_for_each_xprt(clnt,
2944                                 rpc_clnt_swap_deactivate_callback, NULL);
2945 }
2946 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2947 #endif /* CONFIG_SUNRPC_SWAP */
2948 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp