net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/rcupdate.h>
  29 #include <linux/utsname.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/in.h>
  32 #include <linux/in6.h>
  33 #include <linux/un.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #include <trace/events/sunrpc.h>
  41
  42 #include "sunrpc.h"
  43 #include "netns.h"
  44
  45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  46 # define RPCDBG_FACILITY        RPCDBG_CALL
  47 #endif
  48
  49 #define dprint_status(t)                                        \
  50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  51                         __func__, t->tk_status)
  52
  53 /*
  54  * All RPC clients are linked into this list
  55  */
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         struct net *net = rpc_net_ns(clnt);
  86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  87
  88         spin_lock(&sn->rpc_client_lock);
  89         list_add(&clnt->cl_clients, &sn->all_clients);
  90         spin_unlock(&sn->rpc_client_lock);
  91 }
  92
  93 static void rpc_unregister_client(struct rpc_clnt *clnt)
  94 {
  95         struct net *net = rpc_net_ns(clnt);
  96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  97
  98         spin_lock(&sn->rpc_client_lock);
  99         list_del(&clnt->cl_clients);
 100         spin_unlock(&sn->rpc_client_lock);
 101 }
 102
 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 104 {
 105         rpc_remove_client_dir(clnt);
 106 }
 107
 108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 109 {
 110         struct net *net = rpc_net_ns(clnt);
 111         struct super_block *pipefs_sb;
 112
 113         pipefs_sb = rpc_get_sb_net(net);
 114         if (pipefs_sb) {
 115                 __rpc_clnt_remove_pipedir(clnt);
 116                 rpc_put_sb_net(net);
 117         }
 118 }
 119
 120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 121                                     struct rpc_clnt *clnt)
 122 {
 123         static uint32_t clntid;
 124         const char *dir_name = clnt->cl_program->pipe_dir_name;
 125         char name[15];
 126         struct dentry *dir, *dentry;
 127
 128         dir = rpc_d_lookup_sb(sb, dir_name);
 129         if (dir == NULL) {
 130                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 131                 return dir;
 132         }
 133         for (;;) {
 134                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 135                 name[sizeof(name) - 1] = '\0';
 136                 dentry = rpc_create_client_dir(dir, name, clnt);
 137                 if (!IS_ERR(dentry))
 138                         break;
 139                 if (dentry == ERR_PTR(-EEXIST))
 140                         continue;
 141                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 142                                 " %s/%s, error %ld\n",
 143                                 dir_name, name, PTR_ERR(dentry));
 144                 break;
 145         }
 146         dput(dir);
 147         return dentry;
 148 }
 149
 150 static int
 151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 152 {
 153         struct dentry *dentry;
 154
 155         if (clnt->cl_program->pipe_dir_name != NULL) {
 156                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 157                 if (IS_ERR(dentry))
 158                         return PTR_ERR(dentry);
 159         }
 160         return 0;
 161 }
 162
 163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 164 {
 165         if (clnt->cl_program->pipe_dir_name == NULL)
 166                 return 1;
 167
 168         switch (event) {
 169         case RPC_PIPEFS_MOUNT:
 170                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 171                         return 1;
 172                 if (atomic_read(&clnt->cl_count) == 0)
 173                         return 1;
 174                 break;
 175         case RPC_PIPEFS_UMOUNT:
 176                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 177                         return 1;
 178                 break;
 179         }
 180         return 0;
 181 }
 182
 183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 184                                    struct super_block *sb)
 185 {
 186         struct dentry *dentry;
 187         int err = 0;
 188
 189         switch (event) {
 190         case RPC_PIPEFS_MOUNT:
 191                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 192                 if (!dentry)
 193                         return -ENOENT;
 194                 if (IS_ERR(dentry))
 195                         return PTR_ERR(dentry);
 196                 break;
 197         case RPC_PIPEFS_UMOUNT:
 198                 __rpc_clnt_remove_pipedir(clnt);
 199                 break;
 200         default:
 201                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 202                 return -ENOTSUPP;
 203         }
 204         return err;
 205 }
 206
 207 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 208                                 struct super_block *sb)
 209 {
 210         int error = 0;
 211
 212         for (;; clnt = clnt->cl_parent) {
 213                 if (!rpc_clnt_skip_event(clnt, event))
 214                         error = __rpc_clnt_handle_event(clnt, event, sb);
 215                 if (error || clnt == clnt->cl_parent)
 216                         break;
 217         }
 218         return error;
 219 }
 220
 221 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 222 {
 223         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 224         struct rpc_clnt *clnt;
 225
 226         spin_lock(&sn->rpc_client_lock);
 227         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 228                 if (rpc_clnt_skip_event(clnt, event))
 229                         continue;
 230                 spin_unlock(&sn->rpc_client_lock);
 231                 return clnt;
 232         }
 233         spin_unlock(&sn->rpc_client_lock);
 234         return NULL;
 235 }
 236
 237 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 238                             void *ptr)
 239 {
 240         struct super_block *sb = ptr;
 241         struct rpc_clnt *clnt;
 242         int error = 0;
 243
 244         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 245                 error = __rpc_pipefs_event(clnt, event, sb);
 246                 if (error)
 247                         break;
 248         }
 249         return error;
 250 }
 251
 252 static struct notifier_block rpc_clients_block = {
 253         .notifier_call  = rpc_pipefs_event,
 254         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 255 };
 256
 257 int rpc_clients_notifier_register(void)
 258 {
 259         return rpc_pipefs_notifier_register(&rpc_clients_block);
 260 }
 261
 262 void rpc_clients_notifier_unregister(void)
 263 {
 264         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 265 }
 266
 267 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 268                 struct rpc_xprt *xprt,
 269                 const struct rpc_timeout *timeout)
 270 {
 271         struct rpc_xprt *old;
 272
 273         spin_lock(&clnt->cl_lock);
 274         old = rcu_dereference_protected(clnt->cl_xprt,
 275                         lockdep_is_held(&clnt->cl_lock));
 276
 277         if (!xprt_bound(xprt))
 278                 clnt->cl_autobind = 1;
 279
 280         clnt->cl_timeout = timeout;
 281         rcu_assign_pointer(clnt->cl_xprt, xprt);
 282         spin_unlock(&clnt->cl_lock);
 283
 284         return old;
 285 }
 286
 287 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 288 {
 289         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 290                         nodename, sizeof(clnt->cl_nodename));
 291 }
 292
 293 static int rpc_client_register(struct rpc_clnt *clnt,
 294                                rpc_authflavor_t pseudoflavor,
 295                                const char *client_name)
 296 {
 297         struct rpc_auth_create_args auth_args = {
 298                 .pseudoflavor = pseudoflavor,
 299                 .target_name = client_name,
 300         };
 301         struct rpc_auth *auth;
 302         struct net *net = rpc_net_ns(clnt);
 303         struct super_block *pipefs_sb;
 304         int err;
 305
 306         rpc_clnt_debugfs_register(clnt);
 307
 308         pipefs_sb = rpc_get_sb_net(net);
 309         if (pipefs_sb) {
 310                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 311                 if (err)
 312                         goto out;
 313         }
 314
 315         rpc_register_client(clnt);
 316         if (pipefs_sb)
 317                 rpc_put_sb_net(net);
 318
 319         auth = rpcauth_create(&auth_args, clnt);
 320         if (IS_ERR(auth)) {
 321                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 322                                 pseudoflavor);
 323                 err = PTR_ERR(auth);
 324                 goto err_auth;
 325         }
 326         return 0;
 327 err_auth:
 328         pipefs_sb = rpc_get_sb_net(net);
 329         rpc_unregister_client(clnt);
 330         __rpc_clnt_remove_pipedir(clnt);
 331 out:
 332         if (pipefs_sb)
 333                 rpc_put_sb_net(net);
 334         rpc_clnt_debugfs_unregister(clnt);
 335         return err;
 336 }
 337
 338 static DEFINE_IDA(rpc_clids);
 339
 340 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 341 {
 342         int clid;
 343
 344         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 345         if (clid < 0)
 346                 return clid;
 347         clnt->cl_clid = clid;
 348         return 0;
 349 }
 350
 351 static void rpc_free_clid(struct rpc_clnt *clnt)
 352 {
 353         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 354 }
 355
 356 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 357                 struct rpc_xprt_switch *xps,
 358                 struct rpc_xprt *xprt,
 359                 struct rpc_clnt *parent)
 360 {
 361         const struct rpc_program *program = args->program;
 362         const struct rpc_version *version;
 363         struct rpc_clnt *clnt = NULL;
 364         const struct rpc_timeout *timeout;
 365         const char *nodename = args->nodename;
 366         int err;
 367
 368         /* sanity check the name before trying to print it */
 369         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 370                         program->name, args->servername, xprt);
 371
 372         err = rpciod_up();
 373         if (err)
 374                 goto out_no_rpciod;
 375
 376         err = -EINVAL;
 377         if (args->version >= program->nrvers)
 378                 goto out_err;
 379         version = program->version[args->version];
 380         if (version == NULL)
 381                 goto out_err;
 382
 383         err = -ENOMEM;
 384         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 385         if (!clnt)
 386                 goto out_err;
 387         clnt->cl_parent = parent ? : clnt;
 388
 389         err = rpc_alloc_clid(clnt);
 390         if (err)
 391                 goto out_no_clid;
 392
 393         clnt->cl_procinfo = version->procs;
 394         clnt->cl_maxproc  = version->nrprocs;
 395         clnt->cl_prog     = args->prognumber ? : program->number;
 396         clnt->cl_vers     = version->number;
 397         clnt->cl_stats    = program->stats;
 398         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 399         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 400         err = -ENOMEM;
 401         if (clnt->cl_metrics == NULL)
 402                 goto out_no_stats;
 403         clnt->cl_program  = program;
 404         INIT_LIST_HEAD(&clnt->cl_tasks);
 405         spin_lock_init(&clnt->cl_lock);
 406
 407         timeout = xprt->timeout;
 408         if (args->timeout != NULL) {
 409                 memcpy(&clnt->cl_timeout_default, args->timeout,
 410                                 sizeof(clnt->cl_timeout_default));
 411                 timeout = &clnt->cl_timeout_default;
 412         }
 413
 414         rpc_clnt_set_transport(clnt, xprt, timeout);
 415         xprt_iter_init(&clnt->cl_xpi, xps);
 416         xprt_switch_put(xps);
 417
 418         clnt->cl_rtt = &clnt->cl_rtt_default;
 419         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 420
 421         atomic_set(&clnt->cl_count, 1);
 422
 423         if (nodename == NULL)
 424                 nodename = utsname()->nodename;
 425         /* save the nodename */
 426         rpc_clnt_set_nodename(clnt, nodename);
 427
 428         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 429         if (err)
 430                 goto out_no_path;
 431         if (parent)
 432                 atomic_inc(&parent->cl_count);
 433         return clnt;
 434
 435 out_no_path:
 436         rpc_free_iostats(clnt->cl_metrics);
 437 out_no_stats:
 438         rpc_free_clid(clnt);
 439 out_no_clid:
 440         kfree(clnt);
 441 out_err:
 442         rpciod_down();
 443 out_no_rpciod:
 444         xprt_switch_put(xps);
 445         xprt_put(xprt);
 446         return ERR_PTR(err);
 447 }
 448
 449 struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 450                                         struct rpc_xprt *xprt)
 451 {
 452         struct rpc_clnt *clnt = NULL;
 453         struct rpc_xprt_switch *xps;
 454
 455         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 456         if (xps == NULL)
 457                 return ERR_PTR(-ENOMEM);
 458
 459         clnt = rpc_new_client(args, xps, xprt, NULL);
 460         if (IS_ERR(clnt))
 461                 return clnt;
 462
 463         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 464                 int err = rpc_ping(clnt);
 465                 if (err != 0) {
 466                         rpc_shutdown_client(clnt);
 467                         return ERR_PTR(err);
 468                 }
 469         }
 470
 471         clnt->cl_softrtry = 1;
 472         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 473                 clnt->cl_softrtry = 0;
 474
 475         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 476                 clnt->cl_autobind = 1;
 477         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 478                 clnt->cl_noretranstimeo = 1;
 479         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 480                 clnt->cl_discrtry = 1;
 481         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 482                 clnt->cl_chatty = 1;
 483
 484         return clnt;
 485 }
 486 EXPORT_SYMBOL_GPL(rpc_create_xprt);
 487
 488 /**
 489  * rpc_create - create an RPC client and transport with one call
 490  * @args: rpc_clnt create argument structure
 491  *
 492  * Creates and initializes an RPC transport and an RPC client.
 493  *
 494  * It can ping the server in order to determine if it is up, and to see if
 495  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 496  * this behavior so asynchronous tasks can also use rpc_create.
 497  */
 498 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 499 {
 500         struct rpc_xprt *xprt;
 501         struct xprt_create xprtargs = {
 502                 .net = args->net,
 503                 .ident = args->protocol,
 504                 .srcaddr = args->saddress,
 505                 .dstaddr = args->address,
 506                 .addrlen = args->addrsize,
 507                 .servername = args->servername,
 508                 .bc_xprt = args->bc_xprt,
 509         };
 510         char servername[48];
 511
 512         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 513                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 514         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 515                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 516         /*
 517          * If the caller chooses not to specify a hostname, whip
 518          * up a string representation of the passed-in address.
 519          */
 520         if (xprtargs.servername == NULL) {
 521                 struct sockaddr_un *sun =
 522                                 (struct sockaddr_un *)args->address;
 523                 struct sockaddr_in *sin =
 524                                 (struct sockaddr_in *)args->address;
 525                 struct sockaddr_in6 *sin6 =
 526                                 (struct sockaddr_in6 *)args->address;
 527
 528                 servername[0] = '\0';
 529                 switch (args->address->sa_family) {
 530                 case AF_LOCAL:
 531                         snprintf(servername, sizeof(servername), "%s",
 532                                  sun->sun_path);
 533                         break;
 534                 case AF_INET:
 535                         snprintf(servername, sizeof(servername), "%pI4",
 536                                  &sin->sin_addr.s_addr);
 537                         break;
 538                 case AF_INET6:
 539                         snprintf(servername, sizeof(servername), "%pI6",
 540                                  &sin6->sin6_addr);
 541                         break;
 542                 default:
 543                         /* caller wants default server name, but
 544                          * address family isn't recognized. */
 545                         return ERR_PTR(-EINVAL);
 546                 }
 547                 xprtargs.servername = servername;
 548         }
 549
 550         xprt = xprt_create_transport(&xprtargs);
 551         if (IS_ERR(xprt))
 552                 return (struct rpc_clnt *)xprt;
 553
 554         /*
 555          * By default, kernel RPC client connects from a reserved port.
 556          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 557          * but it is always enabled for rpciod, which handles the connect
 558          * operation.
 559          */
 560         xprt->resvport = 1;
 561         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 562                 xprt->resvport = 0;
 563
 564         return rpc_create_xprt(args, xprt);
 565 }
 566 EXPORT_SYMBOL_GPL(rpc_create);
 567
 568 /*
 569  * This function clones the RPC client structure. It allows us to share the
 570  * same transport while varying parameters such as the authentication
 571  * flavour.
 572  */
 573 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 574                                            struct rpc_clnt *clnt)
 575 {
 576         struct rpc_xprt_switch *xps;
 577         struct rpc_xprt *xprt;
 578         struct rpc_clnt *new;
 579         int err;
 580
 581         err = -ENOMEM;
 582         rcu_read_lock();
 583         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 584         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 585         rcu_read_unlock();
 586         if (xprt == NULL || xps == NULL) {
 587                 xprt_put(xprt);
 588                 xprt_switch_put(xps);
 589                 goto out_err;
 590         }
 591         args->servername = xprt->servername;
 592         args->nodename = clnt->cl_nodename;
 593
 594         new = rpc_new_client(args, xps, xprt, clnt);
 595         if (IS_ERR(new)) {
 596                 err = PTR_ERR(new);
 597                 goto out_err;
 598         }
 599
 600         /* Turn off autobind on clones */
 601         new->cl_autobind = 0;
 602         new->cl_softrtry = clnt->cl_softrtry;
 603         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 604         new->cl_discrtry = clnt->cl_discrtry;
 605         new->cl_chatty = clnt->cl_chatty;
 606         return new;
 607
 608 out_err:
 609         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 610         return ERR_PTR(err);
 611 }
 612
 613 /**
 614  * rpc_clone_client - Clone an RPC client structure
 615  *
 616  * @clnt: RPC client whose parameters are copied
 617  *
 618  * Returns a fresh RPC client or an ERR_PTR.
 619  */
 620 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 621 {
 622         struct rpc_create_args args = {
 623                 .program        = clnt->cl_program,
 624                 .prognumber     = clnt->cl_prog,
 625                 .version        = clnt->cl_vers,
 626                 .authflavor     = clnt->cl_auth->au_flavor,
 627         };
 628         return __rpc_clone_client(&args, clnt);
 629 }
 630 EXPORT_SYMBOL_GPL(rpc_clone_client);
 631
 632 /**
 633  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 634  *
 635  * @clnt: RPC client whose parameters are copied
 636  * @flavor: security flavor for new client
 637  *
 638  * Returns a fresh RPC client or an ERR_PTR.
 639  */
 640 struct rpc_clnt *
 641 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 642 {
 643         struct rpc_create_args args = {
 644                 .program        = clnt->cl_program,
 645                 .prognumber     = clnt->cl_prog,
 646                 .version        = clnt->cl_vers,
 647                 .authflavor     = flavor,
 648         };
 649         return __rpc_clone_client(&args, clnt);
 650 }
 651 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 652
 653 /**
 654  * rpc_switch_client_transport: switch the RPC transport on the fly
 655  * @clnt: pointer to a struct rpc_clnt
 656  * @args: pointer to the new transport arguments
 657  * @timeout: pointer to the new timeout parameters
 658  *
 659  * This function allows the caller to switch the RPC transport for the
 660  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 661  * server, for instance.  It assumes that the caller has ensured that
 662  * there are no active RPC tasks by using some form of locking.
 663  *
 664  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 665  * negative errno is returned, and "clnt" continues to use the old
 666  * xprt.
 667  */
 668 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 669                 struct xprt_create *args,
 670                 const struct rpc_timeout *timeout)
 671 {
 672         const struct rpc_timeout *old_timeo;
 673         rpc_authflavor_t pseudoflavor;
 674         struct rpc_xprt_switch *xps, *oldxps;
 675         struct rpc_xprt *xprt, *old;
 676         struct rpc_clnt *parent;
 677         int err;
 678
 679         xprt = xprt_create_transport(args);
 680         if (IS_ERR(xprt)) {
 681                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 682                         clnt);
 683                 return PTR_ERR(xprt);
 684         }
 685
 686         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 687         if (xps == NULL) {
 688                 xprt_put(xprt);
 689                 return -ENOMEM;
 690         }
 691
 692         pseudoflavor = clnt->cl_auth->au_flavor;
 693
 694         old_timeo = clnt->cl_timeout;
 695         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 696         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 697
 698         rpc_unregister_client(clnt);
 699         __rpc_clnt_remove_pipedir(clnt);
 700         rpc_clnt_debugfs_unregister(clnt);
 701
 702         /*
 703          * A new transport was created.  "clnt" therefore
 704          * becomes the root of a new cl_parent tree.  clnt's
 705          * children, if it has any, still point to the old xprt.
 706          */
 707         parent = clnt->cl_parent;
 708         clnt->cl_parent = clnt;
 709
 710         /*
 711          * The old rpc_auth cache cannot be re-used.  GSS
 712          * contexts in particular are between a single
 713          * client and server.
 714          */
 715         err = rpc_client_register(clnt, pseudoflavor, NULL);
 716         if (err)
 717                 goto out_revert;
 718
 719         synchronize_rcu();
 720         if (parent != clnt)
 721                 rpc_release_client(parent);
 722         xprt_switch_put(oldxps);
 723         xprt_put(old);
 724         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 725         return 0;
 726
 727 out_revert:
 728         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 729         rpc_clnt_set_transport(clnt, old, old_timeo);
 730         clnt->cl_parent = parent;
 731         rpc_client_register(clnt, pseudoflavor, NULL);
 732         xprt_switch_put(xps);
 733         xprt_put(xprt);
 734         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 735         return err;
 736 }
 737 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 738
 739 static
 740 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 741 {
 742         struct rpc_xprt_switch *xps;
 743
 744         rcu_read_lock();
 745         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 746         rcu_read_unlock();
 747         if (xps == NULL)
 748                 return -EAGAIN;
 749         xprt_iter_init_listall(xpi, xps);
 750         xprt_switch_put(xps);
 751         return 0;
 752 }
 753
 754 /**
 755  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 756  * @clnt: pointer to client
 757  * @fn: function to apply
 758  * @data: void pointer to function data
 759  *
 760  * Iterates through the list of RPC transports currently attached to the
 761  * client and applies the function fn(clnt, xprt, data).
 762  *
 763  * On error, the iteration stops, and the function returns the error value.
 764  */
 765 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 766                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 767                 void *data)
 768 {
 769         struct rpc_xprt_iter xpi;
 770         int ret;
 771
 772         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 773         if (ret)
 774                 return ret;
 775         for (;;) {
 776                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 777
 778                 if (!xprt)
 779                         break;
 780                 ret = fn(clnt, xprt, data);
 781                 xprt_put(xprt);
 782                 if (ret < 0)
 783                         break;
 784         }
 785         xprt_iter_destroy(&xpi);
 786         return ret;
 787 }
 788 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 789
 790 /*
 791  * Kill all tasks for the given client.
 792  * XXX: kill their descendants as well?
 793  */
 794 void rpc_killall_tasks(struct rpc_clnt *clnt)
 795 {
 796         struct rpc_task *rovr;
 797
 798
 799         if (list_empty(&clnt->cl_tasks))
 800                 return;
 801         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 802         /*
 803          * Spin lock all_tasks to prevent changes...
 804          */
 805         spin_lock(&clnt->cl_lock);
 806         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 807                 if (!RPC_IS_ACTIVATED(rovr))
 808                         continue;
 809                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 810                         rovr->tk_flags |= RPC_TASK_KILLED;
 811                         rpc_exit(rovr, -EIO);
 812                         if (RPC_IS_QUEUED(rovr))
 813                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 814                                                         rovr);
 815                 }
 816         }
 817         spin_unlock(&clnt->cl_lock);
 818 }
 819 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 820
 821 /*
 822  * Properly shut down an RPC client, terminating all outstanding
 823  * requests.
 824  */
 825 void rpc_shutdown_client(struct rpc_clnt *clnt)
 826 {
 827         might_sleep();
 828
 829         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 830                         clnt->cl_program->name,
 831                         rcu_dereference(clnt->cl_xprt)->servername);
 832
 833         while (!list_empty(&clnt->cl_tasks)) {
 834                 rpc_killall_tasks(clnt);
 835                 wait_event_timeout(destroy_wait,
 836                         list_empty(&clnt->cl_tasks), 1*HZ);
 837         }
 838
 839         rpc_release_client(clnt);
 840 }
 841 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 842
 843 /*
 844  * Free an RPC client
 845  */
 846 static struct rpc_clnt *
 847 rpc_free_client(struct rpc_clnt *clnt)
 848 {
 849         struct rpc_clnt *parent = NULL;
 850
 851         dprintk_rcu("RPC:       destroying %s client for %s\n",
 852                         clnt->cl_program->name,
 853                         rcu_dereference(clnt->cl_xprt)->servername);
 854         if (clnt->cl_parent != clnt)
 855                 parent = clnt->cl_parent;
 856         rpc_clnt_debugfs_unregister(clnt);
 857         rpc_clnt_remove_pipedir(clnt);
 858         rpc_unregister_client(clnt);
 859         rpc_free_iostats(clnt->cl_metrics);
 860         clnt->cl_metrics = NULL;
 861         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 862         xprt_iter_destroy(&clnt->cl_xpi);
 863         rpciod_down();
 864         rpc_free_clid(clnt);
 865         kfree(clnt);
 866         return parent;
 867 }
 868
 869 /*
 870  * Free an RPC client
 871  */
 872 static struct rpc_clnt *
 873 rpc_free_auth(struct rpc_clnt *clnt)
 874 {
 875         if (clnt->cl_auth == NULL)
 876                 return rpc_free_client(clnt);
 877
 878         /*
 879          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 880          *       release remaining GSS contexts. This mechanism ensures
 881          *       that it can do so safely.
 882          */
 883         atomic_inc(&clnt->cl_count);
 884         rpcauth_release(clnt->cl_auth);
 885         clnt->cl_auth = NULL;
 886         if (atomic_dec_and_test(&clnt->cl_count))
 887                 return rpc_free_client(clnt);
 888         return NULL;
 889 }
 890
 891 /*
 892  * Release reference to the RPC client
 893  */
 894 void
 895 rpc_release_client(struct rpc_clnt *clnt)
 896 {
 897         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 898
 899         do {
 900                 if (list_empty(&clnt->cl_tasks))
 901                         wake_up(&destroy_wait);
 902                 if (!atomic_dec_and_test(&clnt->cl_count))
 903                         break;
 904                 clnt = rpc_free_auth(clnt);
 905         } while (clnt != NULL);
 906 }
 907 EXPORT_SYMBOL_GPL(rpc_release_client);
 908
 909 /**
 910  * rpc_bind_new_program - bind a new RPC program to an existing client
 911  * @old: old rpc_client
 912  * @program: rpc program to set
 913  * @vers: rpc program version
 914  *
 915  * Clones the rpc client and sets up a new RPC program. This is mainly
 916  * of use for enabling different RPC programs to share the same transport.
 917  * The Sun NFSv2/v3 ACL protocol can do this.
 918  */
 919 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 920                                       const struct rpc_program *program,
 921                                       u32 vers)
 922 {
 923         struct rpc_create_args args = {
 924                 .program        = program,
 925                 .prognumber     = program->number,
 926                 .version        = vers,
 927                 .authflavor     = old->cl_auth->au_flavor,
 928         };
 929         struct rpc_clnt *clnt;
 930         int err;
 931
 932         clnt = __rpc_clone_client(&args, old);
 933         if (IS_ERR(clnt))
 934                 goto out;
 935         err = rpc_ping(clnt);
 936         if (err != 0) {
 937                 rpc_shutdown_client(clnt);
 938                 clnt = ERR_PTR(err);
 939         }
 940 out:
 941         return clnt;
 942 }
 943 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 944
 945 void rpc_task_release_client(struct rpc_task *task)
 946 {
 947         struct rpc_clnt *clnt = task->tk_client;
 948         struct rpc_xprt *xprt = task->tk_xprt;
 949
 950         if (clnt != NULL) {
 951                 /* Remove from client task list */
 952                 spin_lock(&clnt->cl_lock);
 953                 list_del(&task->tk_task);
 954                 spin_unlock(&clnt->cl_lock);
 955                 task->tk_client = NULL;
 956
 957                 rpc_release_client(clnt);
 958         }
 959
 960         if (xprt != NULL) {
 961                 task->tk_xprt = NULL;
 962
 963                 xprt_put(xprt);
 964         }
 965 }
 966
 967 static
 968 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 969 {
 970
 971         if (clnt != NULL) {
 972                 rpc_task_release_client(task);
 973                 if (task->tk_xprt == NULL)
 974                         task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
 975                 task->tk_client = clnt;
 976                 atomic_inc(&clnt->cl_count);
 977                 if (clnt->cl_softrtry)
 978                         task->tk_flags |= RPC_TASK_SOFT;
 979                 if (clnt->cl_noretranstimeo)
 980                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
 981                 if (atomic_read(&clnt->cl_swapper))
 982                         task->tk_flags |= RPC_TASK_SWAPPER;
 983                 /* Add to the client's list of all tasks */
 984                 spin_lock(&clnt->cl_lock);
 985                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
 986                 spin_unlock(&clnt->cl_lock);
 987         }
 988 }
 989
 990 static void
 991 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
 992 {
 993         if (msg != NULL) {
 994                 task->tk_msg.rpc_proc = msg->rpc_proc;
 995                 task->tk_msg.rpc_argp = msg->rpc_argp;
 996                 task->tk_msg.rpc_resp = msg->rpc_resp;
 997                 if (msg->rpc_cred != NULL)
 998                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
 999         }
1000 }
1001
1002 /*
1003  * Default callback for async RPC calls
1004  */
1005 static void
1006 rpc_default_callback(struct rpc_task *task, void *data)
1007 {
1008 }
1009
1010 static const struct rpc_call_ops rpc_default_ops = {
1011         .rpc_call_done = rpc_default_callback,
1012 };
1013
1014 /**
1015  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1016  * @task_setup_data: pointer to task initialisation data
1017  */
1018 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1019 {
1020         struct rpc_task *task;
1021
1022         task = rpc_new_task(task_setup_data);
1023         if (IS_ERR(task))
1024                 goto out;
1025
1026         rpc_task_set_client(task, task_setup_data->rpc_client);
1027         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1028
1029         if (task->tk_action == NULL)
1030                 rpc_call_start(task);
1031
1032         atomic_inc(&task->tk_count);
1033         rpc_execute(task);
1034 out:
1035         return task;
1036 }
1037 EXPORT_SYMBOL_GPL(rpc_run_task);
1038
1039 /**
1040  * rpc_call_sync - Perform a synchronous RPC call
1041  * @clnt: pointer to RPC client
1042  * @msg: RPC call parameters
1043  * @flags: RPC call flags
1044  */
1045 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1046 {
1047         struct rpc_task *task;
1048         struct rpc_task_setup task_setup_data = {
1049                 .rpc_client = clnt,
1050                 .rpc_message = msg,
1051                 .callback_ops = &rpc_default_ops,
1052                 .flags = flags,
1053         };
1054         int status;
1055
1056         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1057         if (flags & RPC_TASK_ASYNC) {
1058                 rpc_release_calldata(task_setup_data.callback_ops,
1059                         task_setup_data.callback_data);
1060                 return -EINVAL;
1061         }
1062
1063         task = rpc_run_task(&task_setup_data);
1064         if (IS_ERR(task))
1065                 return PTR_ERR(task);
1066         status = task->tk_status;
1067         rpc_put_task(task);
1068         return status;
1069 }
1070 EXPORT_SYMBOL_GPL(rpc_call_sync);
1071
1072 /**
1073  * rpc_call_async - Perform an asynchronous RPC call
1074  * @clnt: pointer to RPC client
1075  * @msg: RPC call parameters
1076  * @flags: RPC call flags
1077  * @tk_ops: RPC call ops
1078  * @data: user call data
1079  */
1080 int
1081 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1082                const struct rpc_call_ops *tk_ops, void *data)
1083 {
1084         struct rpc_task *task;
1085         struct rpc_task_setup task_setup_data = {
1086                 .rpc_client = clnt,
1087                 .rpc_message = msg,
1088                 .callback_ops = tk_ops,
1089                 .callback_data = data,
1090                 .flags = flags|RPC_TASK_ASYNC,
1091         };
1092
1093         task = rpc_run_task(&task_setup_data);
1094         if (IS_ERR(task))
1095                 return PTR_ERR(task);
1096         rpc_put_task(task);
1097         return 0;
1098 }
1099 EXPORT_SYMBOL_GPL(rpc_call_async);
1100
1101 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1102 /**
1103  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1104  * rpc_execute against it
1105  * @req: RPC request
1106  */
1107 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1108 {
1109         struct rpc_task *task;
1110         struct xdr_buf *xbufp = &req->rq_snd_buf;
1111         struct rpc_task_setup task_setup_data = {
1112                 .callback_ops = &rpc_default_ops,
1113                 .flags = RPC_TASK_SOFTCONN,
1114         };
1115
1116         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1117         /*
1118          * Create an rpc_task to send the data
1119          */
1120         task = rpc_new_task(&task_setup_data);
1121         if (IS_ERR(task)) {
1122                 xprt_free_bc_request(req);
1123                 goto out;
1124         }
1125         task->tk_rqstp = req;
1126
1127         /*
1128          * Set up the xdr_buf length.
1129          * This also indicates that the buffer is XDR encoded already.
1130          */
1131         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1132                         xbufp->tail[0].iov_len;
1133
1134         task->tk_action = call_bc_transmit;
1135         atomic_inc(&task->tk_count);
1136         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1137         rpc_execute(task);
1138
1139 out:
1140         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1141         return task;
1142 }
1143 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1144
1145 void
1146 rpc_call_start(struct rpc_task *task)
1147 {
1148         task->tk_action = call_start;
1149 }
1150 EXPORT_SYMBOL_GPL(rpc_call_start);
1151
1152 /**
1153  * rpc_peeraddr - extract remote peer address from clnt's xprt
1154  * @clnt: RPC client structure
1155  * @buf: target buffer
1156  * @bufsize: length of target buffer
1157  *
1158  * Returns the number of bytes that are actually in the stored address.
1159  */
1160 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1161 {
1162         size_t bytes;
1163         struct rpc_xprt *xprt;
1164
1165         rcu_read_lock();
1166         xprt = rcu_dereference(clnt->cl_xprt);
1167
1168         bytes = xprt->addrlen;
1169         if (bytes > bufsize)
1170                 bytes = bufsize;
1171         memcpy(buf, &xprt->addr, bytes);
1172         rcu_read_unlock();
1173
1174         return bytes;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1177
1178 /**
1179  * rpc_peeraddr2str - return remote peer address in printable format
1180  * @clnt: RPC client structure
1181  * @format: address format
1182  *
1183  * NB: the lifetime of the memory referenced by the returned pointer is
1184  * the same as the rpc_xprt itself.  As long as the caller uses this
1185  * pointer, it must hold the RCU read lock.
1186  */
1187 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1188                              enum rpc_display_format_t format)
1189 {
1190         struct rpc_xprt *xprt;
1191
1192         xprt = rcu_dereference(clnt->cl_xprt);
1193
1194         if (xprt->address_strings[format] != NULL)
1195                 return xprt->address_strings[format];
1196         else
1197                 return "unprintable";
1198 }
1199 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1200
1201 static const struct sockaddr_in rpc_inaddr_loopback = {
1202         .sin_family             = AF_INET,
1203         .sin_addr.s_addr        = htonl(INADDR_ANY),
1204 };
1205
1206 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1207         .sin6_family            = AF_INET6,
1208         .sin6_addr              = IN6ADDR_ANY_INIT,
1209 };
1210
1211 /*
1212  * Try a getsockname() on a connected datagram socket.  Using a
1213  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1214  * This conserves the ephemeral port number space.
1215  *
1216  * Returns zero and fills in "buf" if successful; otherwise, a
1217  * negative errno is returned.
1218  */
1219 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1220                         struct sockaddr *buf, int buflen)
1221 {
1222         struct socket *sock;
1223         int err;
1224
1225         err = __sock_create(net, sap->sa_family,
1226                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1227         if (err < 0) {
1228                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1229                 goto out;
1230         }
1231
1232         switch (sap->sa_family) {
1233         case AF_INET:
1234                 err = kernel_bind(sock,
1235                                 (struct sockaddr *)&rpc_inaddr_loopback,
1236                                 sizeof(rpc_inaddr_loopback));
1237                 break;
1238         case AF_INET6:
1239                 err = kernel_bind(sock,
1240                                 (struct sockaddr *)&rpc_in6addr_loopback,
1241                                 sizeof(rpc_in6addr_loopback));
1242                 break;
1243         default:
1244                 err = -EAFNOSUPPORT;
1245                 goto out;
1246         }
1247         if (err < 0) {
1248                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1249                 goto out_release;
1250         }
1251
1252         err = kernel_connect(sock, sap, salen, 0);
1253         if (err < 0) {
1254                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1255                 goto out_release;
1256         }
1257
1258         err = kernel_getsockname(sock, buf, &buflen);
1259         if (err < 0) {
1260                 dprintk("RPC:       getsockname failed (%d)\n", err);
1261                 goto out_release;
1262         }
1263
1264         err = 0;
1265         if (buf->sa_family == AF_INET6) {
1266                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1267                 sin6->sin6_scope_id = 0;
1268         }
1269         dprintk("RPC:       %s succeeded\n", __func__);
1270
1271 out_release:
1272         sock_release(sock);
1273 out:
1274         return err;
1275 }
1276
1277 /*
1278  * Scraping a connected socket failed, so we don't have a useable
1279  * local address.  Fallback: generate an address that will prevent
1280  * the server from calling us back.
1281  *
1282  * Returns zero and fills in "buf" if successful; otherwise, a
1283  * negative errno is returned.
1284  */
1285 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1286 {
1287         switch (family) {
1288         case AF_INET:
1289                 if (buflen < sizeof(rpc_inaddr_loopback))
1290                         return -EINVAL;
1291                 memcpy(buf, &rpc_inaddr_loopback,
1292                                 sizeof(rpc_inaddr_loopback));
1293                 break;
1294         case AF_INET6:
1295                 if (buflen < sizeof(rpc_in6addr_loopback))
1296                         return -EINVAL;
1297                 memcpy(buf, &rpc_in6addr_loopback,
1298                                 sizeof(rpc_in6addr_loopback));
1299                 break;
1300         default:
1301                 dprintk("RPC:       %s: address family not supported\n",
1302                         __func__);
1303                 return -EAFNOSUPPORT;
1304         }
1305         dprintk("RPC:       %s: succeeded\n", __func__);
1306         return 0;
1307 }
1308
1309 /**
1310  * rpc_localaddr - discover local endpoint address for an RPC client
1311  * @clnt: RPC client structure
1312  * @buf: target buffer
1313  * @buflen: size of target buffer, in bytes
1314  *
1315  * Returns zero and fills in "buf" and "buflen" if successful;
1316  * otherwise, a negative errno is returned.
1317  *
1318  * This works even if the underlying transport is not currently connected,
1319  * or if the upper layer never previously provided a source address.
1320  *
1321  * The result of this function call is transient: multiple calls in
1322  * succession may give different results, depending on how local
1323  * networking configuration changes over time.
1324  */
1325 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1326 {
1327         struct sockaddr_storage address;
1328         struct sockaddr *sap = (struct sockaddr *)&address;
1329         struct rpc_xprt *xprt;
1330         struct net *net;
1331         size_t salen;
1332         int err;
1333
1334         rcu_read_lock();
1335         xprt = rcu_dereference(clnt->cl_xprt);
1336         salen = xprt->addrlen;
1337         memcpy(sap, &xprt->addr, salen);
1338         net = get_net(xprt->xprt_net);
1339         rcu_read_unlock();
1340
1341         rpc_set_port(sap, 0);
1342         err = rpc_sockname(net, sap, salen, buf, buflen);
1343         put_net(net);
1344         if (err != 0)
1345                 /* Couldn't discover local address, return ANYADDR */
1346                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1347         return 0;
1348 }
1349 EXPORT_SYMBOL_GPL(rpc_localaddr);
1350
1351 void
1352 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1353 {
1354         struct rpc_xprt *xprt;
1355
1356         rcu_read_lock();
1357         xprt = rcu_dereference(clnt->cl_xprt);
1358         if (xprt->ops->set_buffer_size)
1359                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1360         rcu_read_unlock();
1361 }
1362 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1363
1364 /**
1365  * rpc_protocol - Get transport protocol number for an RPC client
1366  * @clnt: RPC client to query
1367  *
1368  */
1369 int rpc_protocol(struct rpc_clnt *clnt)
1370 {
1371         int protocol;
1372
1373         rcu_read_lock();
1374         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1375         rcu_read_unlock();
1376         return protocol;
1377 }
1378 EXPORT_SYMBOL_GPL(rpc_protocol);
1379
1380 /**
1381  * rpc_net_ns - Get the network namespace for this RPC client
1382  * @clnt: RPC client to query
1383  *
1384  */
1385 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1386 {
1387         struct net *ret;
1388
1389         rcu_read_lock();
1390         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1391         rcu_read_unlock();
1392         return ret;
1393 }
1394 EXPORT_SYMBOL_GPL(rpc_net_ns);
1395
1396 /**
1397  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1398  * @clnt: RPC client to query
1399  *
1400  * For stream transports, this is one RPC record fragment (see RFC
1401  * 1831), as we don't support multi-record requests yet.  For datagram
1402  * transports, this is the size of an IP packet minus the IP, UDP, and
1403  * RPC header sizes.
1404  */
1405 size_t rpc_max_payload(struct rpc_clnt *clnt)
1406 {
1407         size_t ret;
1408
1409         rcu_read_lock();
1410         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1411         rcu_read_unlock();
1412         return ret;
1413 }
1414 EXPORT_SYMBOL_GPL(rpc_max_payload);
1415
1416 /**
1417  * rpc_get_timeout - Get timeout for transport in units of HZ
1418  * @clnt: RPC client to query
1419  */
1420 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1421 {
1422         unsigned long ret;
1423
1424         rcu_read_lock();
1425         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1426         rcu_read_unlock();
1427         return ret;
1428 }
1429 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1430
1431 /**
1432  * rpc_force_rebind - force transport to check that remote port is unchanged
1433  * @clnt: client to rebind
1434  *
1435  */
1436 void rpc_force_rebind(struct rpc_clnt *clnt)
1437 {
1438         if (clnt->cl_autobind) {
1439                 rcu_read_lock();
1440                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1441                 rcu_read_unlock();
1442         }
1443 }
1444 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1445
1446 /*
1447  * Restart an (async) RPC call from the call_prepare state.
1448  * Usually called from within the exit handler.
1449  */
1450 int
1451 rpc_restart_call_prepare(struct rpc_task *task)
1452 {
1453         if (RPC_ASSASSINATED(task))
1454                 return 0;
1455         task->tk_action = call_start;
1456         task->tk_status = 0;
1457         if (task->tk_ops->rpc_call_prepare != NULL)
1458                 task->tk_action = rpc_prepare_task;
1459         return 1;
1460 }
1461 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1462
1463 /*
1464  * Restart an (async) RPC call. Usually called from within the
1465  * exit handler.
1466  */
1467 int
1468 rpc_restart_call(struct rpc_task *task)
1469 {
1470         if (RPC_ASSASSINATED(task))
1471                 return 0;
1472         task->tk_action = call_start;
1473         task->tk_status = 0;
1474         return 1;
1475 }
1476 EXPORT_SYMBOL_GPL(rpc_restart_call);
1477
1478 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1479 const char
1480 *rpc_proc_name(const struct rpc_task *task)
1481 {
1482         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1483
1484         if (proc) {
1485                 if (proc->p_name)
1486                         return proc->p_name;
1487                 else
1488                         return "NULL";
1489         } else
1490                 return "no proc";
1491 }
1492 #endif
1493
1494 /*
1495  * 0.  Initial state
1496  *
1497  *     Other FSM states can be visited zero or more times, but
1498  *     this state is visited exactly once for each RPC.
1499  */
1500 static void
1501 call_start(struct rpc_task *task)
1502 {
1503         struct rpc_clnt *clnt = task->tk_client;
1504
1505         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1506                         clnt->cl_program->name, clnt->cl_vers,
1507                         rpc_proc_name(task),
1508                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1509
1510         /* Increment call count */
1511         task->tk_msg.rpc_proc->p_count++;
1512         clnt->cl_stats->rpccnt++;
1513         task->tk_action = call_reserve;
1514 }
1515
1516 /*
1517  * 1.   Reserve an RPC call slot
1518  */
1519 static void
1520 call_reserve(struct rpc_task *task)
1521 {
1522         dprint_status(task);
1523
1524         task->tk_status  = 0;
1525         task->tk_action  = call_reserveresult;
1526         xprt_reserve(task);
1527 }
1528
1529 static void call_retry_reserve(struct rpc_task *task);
1530
1531 /*
1532  * 1b.  Grok the result of xprt_reserve()
1533  */
1534 static void
1535 call_reserveresult(struct rpc_task *task)
1536 {
1537         int status = task->tk_status;
1538
1539         dprint_status(task);
1540
1541         /*
1542          * After a call to xprt_reserve(), we must have either
1543          * a request slot or else an error status.
1544          */
1545         task->tk_status = 0;
1546         if (status >= 0) {
1547                 if (task->tk_rqstp) {
1548                         task->tk_action = call_refresh;
1549                         return;
1550                 }
1551
1552                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1553                                 __func__, status);
1554                 rpc_exit(task, -EIO);
1555                 return;
1556         }
1557
1558         /*
1559          * Even though there was an error, we may have acquired
1560          * a request slot somehow.  Make sure not to leak it.
1561          */
1562         if (task->tk_rqstp) {
1563                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1564                                 __func__, status);
1565                 xprt_release(task);
1566         }
1567
1568         switch (status) {
1569         case -ENOMEM:
1570                 rpc_delay(task, HZ >> 2);
1571         case -EAGAIN:   /* woken up; retry */
1572                 task->tk_action = call_retry_reserve;
1573                 return;
1574         case -EIO:      /* probably a shutdown */
1575                 break;
1576         default:
1577                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1578                                 __func__, status);
1579                 break;
1580         }
1581         rpc_exit(task, status);
1582 }
1583
1584 /*
1585  * 1c.  Retry reserving an RPC call slot
1586  */
1587 static void
1588 call_retry_reserve(struct rpc_task *task)
1589 {
1590         dprint_status(task);
1591
1592         task->tk_status  = 0;
1593         task->tk_action  = call_reserveresult;
1594         xprt_retry_reserve(task);
1595 }
1596
1597 /*
1598  * 2.   Bind and/or refresh the credentials
1599  */
1600 static void
1601 call_refresh(struct rpc_task *task)
1602 {
1603         dprint_status(task);
1604
1605         task->tk_action = call_refreshresult;
1606         task->tk_status = 0;
1607         task->tk_client->cl_stats->rpcauthrefresh++;
1608         rpcauth_refreshcred(task);
1609 }
1610
1611 /*
1612  * 2a.  Process the results of a credential refresh
1613  */
1614 static void
1615 call_refreshresult(struct rpc_task *task)
1616 {
1617         int status = task->tk_status;
1618
1619         dprint_status(task);
1620
1621         task->tk_status = 0;
1622         task->tk_action = call_refresh;
1623         switch (status) {
1624         case 0:
1625                 if (rpcauth_uptodatecred(task)) {
1626                         task->tk_action = call_allocate;
1627                         return;
1628                 }
1629                 /* Use rate-limiting and a max number of retries if refresh
1630                  * had status 0 but failed to update the cred.
1631                  */
1632         case -ETIMEDOUT:
1633                 rpc_delay(task, 3*HZ);
1634         case -EAGAIN:
1635                 status = -EACCES;
1636         case -EKEYEXPIRED:
1637                 if (!task->tk_cred_retry)
1638                         break;
1639                 task->tk_cred_retry--;
1640                 dprintk("RPC: %5u %s: retry refresh creds\n",
1641                                 task->tk_pid, __func__);
1642                 return;
1643         }
1644         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1645                                 task->tk_pid, __func__, status);
1646         rpc_exit(task, status);
1647 }
1648
1649 /*
1650  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1651  *      (Note: buffer memory is freed in xprt_release).
1652  */
1653 static void
1654 call_allocate(struct rpc_task *task)
1655 {
1656         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1657         struct rpc_rqst *req = task->tk_rqstp;
1658         struct rpc_xprt *xprt = req->rq_xprt;
1659         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1660
1661         dprint_status(task);
1662
1663         task->tk_status = 0;
1664         task->tk_action = call_bind;
1665
1666         if (req->rq_buffer)
1667                 return;
1668
1669         if (proc->p_proc != 0) {
1670                 BUG_ON(proc->p_arglen == 0);
1671                 if (proc->p_decode != NULL)
1672                         BUG_ON(proc->p_replen == 0);
1673         }
1674
1675         /*
1676          * Calculate the size (in quads) of the RPC call
1677          * and reply headers, and convert both values
1678          * to byte sizes.
1679          */
1680         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1681         req->rq_callsize <<= 2;
1682         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1683         req->rq_rcvsize <<= 2;
1684
1685         req->rq_buffer = xprt->ops->buf_alloc(task,
1686                                         req->rq_callsize + req->rq_rcvsize);
1687         if (req->rq_buffer != NULL)
1688                 return;
1689         xprt_inject_disconnect(xprt);
1690
1691         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1692
1693         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1694                 task->tk_action = call_allocate;
1695                 rpc_delay(task, HZ>>4);
1696                 return;
1697         }
1698
1699         rpc_exit(task, -ERESTARTSYS);
1700 }
1701
1702 static inline int
1703 rpc_task_need_encode(struct rpc_task *task)
1704 {
1705         return task->tk_rqstp->rq_snd_buf.len == 0;
1706 }
1707
1708 static inline void
1709 rpc_task_force_reencode(struct rpc_task *task)
1710 {
1711         task->tk_rqstp->rq_snd_buf.len = 0;
1712         task->tk_rqstp->rq_bytes_sent = 0;
1713 }
1714
1715 static inline void
1716 rpc_xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
1717 {
1718         buf->head[0].iov_base = start;
1719         buf->head[0].iov_len = len;
1720         buf->tail[0].iov_len = 0;
1721         buf->page_len = 0;
1722         buf->flags = 0;
1723         buf->len = 0;
1724         buf->buflen = len;
1725 }
1726
1727 /*
1728  * 3.   Encode arguments of an RPC call
1729  */
1730 static void
1731 rpc_xdr_encode(struct rpc_task *task)
1732 {
1733         struct rpc_rqst *req = task->tk_rqstp;
1734         kxdreproc_t     encode;
1735         __be32          *p;
1736
1737         dprint_status(task);
1738
1739         rpc_xdr_buf_init(&req->rq_snd_buf,
1740                          req->rq_buffer,
1741                          req->rq_callsize);
1742         rpc_xdr_buf_init(&req->rq_rcv_buf,
1743                          (char *)req->rq_buffer + req->rq_callsize,
1744                          req->rq_rcvsize);
1745
1746         p = rpc_encode_header(task);
1747         if (p == NULL) {
1748                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1749                 rpc_exit(task, -EIO);
1750                 return;
1751         }
1752
1753         encode = task->tk_msg.rpc_proc->p_encode;
1754         if (encode == NULL)
1755                 return;
1756
1757         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1758                         task->tk_msg.rpc_argp);
1759 }
1760
1761 /*
1762  * 4.   Get the server port number if not yet set
1763  */
1764 static void
1765 call_bind(struct rpc_task *task)
1766 {
1767         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1768
1769         dprint_status(task);
1770
1771         task->tk_action = call_connect;
1772         if (!xprt_bound(xprt)) {
1773                 task->tk_action = call_bind_status;
1774                 task->tk_timeout = xprt->bind_timeout;
1775                 xprt->ops->rpcbind(task);
1776         }
1777 }
1778
1779 /*
1780  * 4a.  Sort out bind result
1781  */
1782 static void
1783 call_bind_status(struct rpc_task *task)
1784 {
1785         int status = -EIO;
1786
1787         if (task->tk_status >= 0) {
1788                 dprint_status(task);
1789                 task->tk_status = 0;
1790                 task->tk_action = call_connect;
1791                 return;
1792         }
1793
1794         trace_rpc_bind_status(task);
1795         switch (task->tk_status) {
1796         case -ENOMEM:
1797                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1798                 rpc_delay(task, HZ >> 2);
1799                 goto retry_timeout;
1800         case -EACCES:
1801                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1802                                 "unavailable\n", task->tk_pid);
1803                 /* fail immediately if this is an RPC ping */
1804                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1805                         status = -EOPNOTSUPP;
1806                         break;
1807                 }
1808                 if (task->tk_rebind_retry == 0)
1809                         break;
1810                 task->tk_rebind_retry--;
1811                 rpc_delay(task, 3*HZ);
1812                 goto retry_timeout;
1813         case -ETIMEDOUT:
1814                 dprintk("RPC: %5u rpcbind request timed out\n",
1815                                 task->tk_pid);
1816                 goto retry_timeout;
1817         case -EPFNOSUPPORT:
1818                 /* server doesn't support any rpcbind version we know of */
1819                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1820                                 task->tk_pid);
1821                 break;
1822         case -EPROTONOSUPPORT:
1823                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1824                                 task->tk_pid);
1825                 goto retry_timeout;
1826         case -ECONNREFUSED:             /* connection problems */
1827         case -ECONNRESET:
1828         case -ECONNABORTED:
1829         case -ENOTCONN:
1830         case -EHOSTDOWN:
1831         case -EHOSTUNREACH:
1832         case -ENETUNREACH:
1833         case -ENOBUFS:
1834         case -EPIPE:
1835                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1836                                 task->tk_pid, task->tk_status);
1837                 if (!RPC_IS_SOFTCONN(task)) {
1838                         rpc_delay(task, 5*HZ);
1839                         goto retry_timeout;
1840                 }
1841                 status = task->tk_status;
1842                 break;
1843         default:
1844                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1845                                 task->tk_pid, -task->tk_status);
1846         }
1847
1848         rpc_exit(task, status);
1849         return;
1850
1851 retry_timeout:
1852         task->tk_status = 0;
1853         task->tk_action = call_timeout;
1854 }
1855
1856 /*
1857  * 4b.  Connect to the RPC server
1858  */
1859 static void
1860 call_connect(struct rpc_task *task)
1861 {
1862         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1863
1864         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1865                         task->tk_pid, xprt,
1866                         (xprt_connected(xprt) ? "is" : "is not"));
1867
1868         task->tk_action = call_transmit;
1869         if (!xprt_connected(xprt)) {
1870                 task->tk_action = call_connect_status;
1871                 if (task->tk_status < 0)
1872                         return;
1873                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1874                         rpc_exit(task, -ENOTCONN);
1875                         return;
1876                 }
1877                 xprt_connect(task);
1878         }
1879 }
1880
1881 /*
1882  * 4c.  Sort out connect result
1883  */
1884 static void
1885 call_connect_status(struct rpc_task *task)
1886 {
1887         struct rpc_clnt *clnt = task->tk_client;
1888         int status = task->tk_status;
1889
1890         dprint_status(task);
1891
1892         trace_rpc_connect_status(task, status);
1893         task->tk_status = 0;
1894         switch (status) {
1895         case -ECONNREFUSED:
1896         case -ECONNRESET:
1897         case -ECONNABORTED:
1898         case -ENETUNREACH:
1899         case -EHOSTUNREACH:
1900         case -EADDRINUSE:
1901         case -ENOBUFS:
1902         case -EPIPE:
1903                 if (RPC_IS_SOFTCONN(task))
1904                         break;
1905                 /* retry with existing socket, after a delay */
1906                 rpc_delay(task, 3*HZ);
1907         case -EAGAIN:
1908                 /* Check for timeouts before looping back to call_bind */
1909         case -ETIMEDOUT:
1910                 task->tk_action = call_timeout;
1911                 return;
1912         case 0:
1913                 clnt->cl_stats->netreconn++;
1914                 task->tk_action = call_transmit;
1915                 return;
1916         }
1917         rpc_exit(task, status);
1918 }
1919
1920 /*
1921  * 5.   Transmit the RPC request, and wait for reply
1922  */
1923 static void
1924 call_transmit(struct rpc_task *task)
1925 {
1926         int is_retrans = RPC_WAS_SENT(task);
1927
1928         dprint_status(task);
1929
1930         task->tk_action = call_status;
1931         if (task->tk_status < 0)
1932                 return;
1933         if (!xprt_prepare_transmit(task))
1934                 return;
1935         task->tk_action = call_transmit_status;
1936         /* Encode here so that rpcsec_gss can use correct sequence number. */
1937         if (rpc_task_need_encode(task)) {
1938                 rpc_xdr_encode(task);
1939                 /* Did the encode result in an error condition? */
1940                 if (task->tk_status != 0) {
1941                         /* Was the error nonfatal? */
1942                         if (task->tk_status == -EAGAIN)
1943                                 rpc_delay(task, HZ >> 4);
1944                         else
1945                                 rpc_exit(task, task->tk_status);
1946                         return;
1947                 }
1948         }
1949         xprt_transmit(task);
1950         if (task->tk_status < 0)
1951                 return;
1952         if (is_retrans)
1953                 task->tk_client->cl_stats->rpcretrans++;
1954         /*
1955          * On success, ensure that we call xprt_end_transmit() before sleeping
1956          * in order to allow access to the socket to other RPC requests.
1957          */
1958         call_transmit_status(task);
1959         if (rpc_reply_expected(task))
1960                 return;
1961         task->tk_action = rpc_exit_task;
1962         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1963 }
1964
1965 /*
1966  * 5a.  Handle cleanup after a transmission
1967  */
1968 static void
1969 call_transmit_status(struct rpc_task *task)
1970 {
1971         task->tk_action = call_status;
1972
1973         /*
1974          * Common case: success.  Force the compiler to put this
1975          * test first.
1976          */
1977         if (task->tk_status == 0) {
1978                 xprt_end_transmit(task);
1979                 rpc_task_force_reencode(task);
1980                 return;
1981         }
1982
1983         switch (task->tk_status) {
1984         case -EAGAIN:
1985         case -ENOBUFS:
1986                 break;
1987         default:
1988                 dprint_status(task);
1989                 xprt_end_transmit(task);
1990                 rpc_task_force_reencode(task);
1991                 break;
1992                 /*
1993                  * Special cases: if we've been waiting on the
1994                  * socket's write_space() callback, or if the
1995                  * socket just returned a connection error,
1996                  * then hold onto the transport lock.
1997                  */
1998         case -ECONNREFUSED:
1999         case -EHOSTDOWN:
2000         case -EHOSTUNREACH:
2001         case -ENETUNREACH:
2002         case -EPERM:
2003                 if (RPC_IS_SOFTCONN(task)) {
2004                         xprt_end_transmit(task);
2005                         rpc_exit(task, task->tk_status);
2006                         break;
2007                 }
2008         case -ECONNRESET:
2009         case -ECONNABORTED:
2010         case -EADDRINUSE:
2011         case -ENOTCONN:
2012         case -EPIPE:
2013                 rpc_task_force_reencode(task);
2014         }
2015 }
2016
2017 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2018 /*
2019  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2020  * addition, disconnect on connectivity errors.
2021  */
2022 static void
2023 call_bc_transmit(struct rpc_task *task)
2024 {
2025         struct rpc_rqst *req = task->tk_rqstp;
2026
2027         if (!xprt_prepare_transmit(task))
2028                 goto out_retry;
2029
2030         if (task->tk_status < 0) {
2031                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2032                         "error: %d\n", task->tk_status);
2033                 goto out_done;
2034         }
2035         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2036                 req->rq_bytes_sent = 0;
2037
2038         xprt_transmit(task);
2039
2040         if (task->tk_status == -EAGAIN)
2041                 goto out_nospace;
2042
2043         xprt_end_transmit(task);
2044         dprint_status(task);
2045         switch (task->tk_status) {
2046         case 0:
2047                 /* Success */
2048         case -EHOSTDOWN:
2049         case -EHOSTUNREACH:
2050         case -ENETUNREACH:
2051         case -ECONNRESET:
2052         case -ECONNREFUSED:
2053         case -EADDRINUSE:
2054         case -ENOTCONN:
2055         case -EPIPE:
2056                 break;
2057         case -ETIMEDOUT:
2058                 /*
2059                  * Problem reaching the server.  Disconnect and let the
2060                  * forechannel reestablish the connection.  The server will
2061                  * have to retransmit the backchannel request and we'll
2062                  * reprocess it.  Since these ops are idempotent, there's no
2063                  * need to cache our reply at this time.
2064                  */
2065                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2066                         "error: %d\n", task->tk_status);
2067                 xprt_conditional_disconnect(req->rq_xprt,
2068                         req->rq_connect_cookie);
2069                 break;
2070         default:
2071                 /*
2072                  * We were unable to reply and will have to drop the
2073                  * request.  The server should reconnect and retransmit.
2074                  */
2075                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2076                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2077                         "error: %d\n", task->tk_status);
2078                 break;
2079         }
2080         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2081 out_done:
2082         task->tk_action = rpc_exit_task;
2083         return;
2084 out_nospace:
2085         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2086 out_retry:
2087         task->tk_status = 0;
2088 }
2089 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2090
2091 /*
2092  * 6.   Sort out the RPC call status
2093  */
2094 static void
2095 call_status(struct rpc_task *task)
2096 {
2097         struct rpc_clnt *clnt = task->tk_client;
2098         struct rpc_rqst *req = task->tk_rqstp;
2099         int             status;
2100
2101         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2102                 task->tk_status = req->rq_reply_bytes_recvd;
2103
2104         dprint_status(task);
2105
2106         status = task->tk_status;
2107         if (status >= 0) {
2108                 task->tk_action = call_decode;
2109                 return;
2110         }
2111
2112         trace_rpc_call_status(task);
2113         task->tk_status = 0;
2114         switch(status) {
2115         case -EHOSTDOWN:
2116         case -EHOSTUNREACH:
2117         case -ENETUNREACH:
2118         case -EPERM:
2119                 if (RPC_IS_SOFTCONN(task)) {
2120                         rpc_exit(task, status);
2121                         break;
2122                 }
2123                 /*
2124                  * Delay any retries for 3 seconds, then handle as if it
2125                  * were a timeout.
2126                  */
2127                 rpc_delay(task, 3*HZ);
2128         case -ETIMEDOUT:
2129                 task->tk_action = call_timeout;
2130                 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2131                     && task->tk_client->cl_discrtry)
2132                         xprt_conditional_disconnect(req->rq_xprt,
2133                                         req->rq_connect_cookie);
2134                 break;
2135         case -ECONNREFUSED:
2136         case -ECONNRESET:
2137         case -ECONNABORTED:
2138                 rpc_force_rebind(clnt);
2139         case -EADDRINUSE:
2140                 rpc_delay(task, 3*HZ);
2141         case -EPIPE:
2142         case -ENOTCONN:
2143                 task->tk_action = call_bind;
2144                 break;
2145         case -ENOBUFS:
2146                 rpc_delay(task, HZ>>2);
2147         case -EAGAIN:
2148                 task->tk_action = call_transmit;
2149                 break;
2150         case -EIO:
2151                 /* shutdown or soft timeout */
2152                 rpc_exit(task, status);
2153                 break;
2154         default:
2155                 if (clnt->cl_chatty)
2156                         printk("%s: RPC call returned error %d\n",
2157                                clnt->cl_program->name, -status);
2158                 rpc_exit(task, status);
2159         }
2160 }
2161
2162 /*
2163  * 6a.  Handle RPC timeout
2164  *      We do not release the request slot, so we keep using the
2165  *      same XID for all retransmits.
2166  */
2167 static void
2168 call_timeout(struct rpc_task *task)
2169 {
2170         struct rpc_clnt *clnt = task->tk_client;
2171
2172         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2173                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2174                 goto retry;
2175         }
2176
2177         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2178         task->tk_timeouts++;
2179
2180         if (RPC_IS_SOFTCONN(task)) {
2181                 rpc_exit(task, -ETIMEDOUT);
2182                 return;
2183         }
2184         if (RPC_IS_SOFT(task)) {
2185                 if (clnt->cl_chatty) {
2186                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2187                                 clnt->cl_program->name,
2188                                 task->tk_xprt->servername);
2189                 }
2190                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2191                         rpc_exit(task, -ETIMEDOUT);
2192                 else
2193                         rpc_exit(task, -EIO);
2194                 return;
2195         }
2196
2197         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2198                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2199                 if (clnt->cl_chatty) {
2200                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2201                         clnt->cl_program->name,
2202                         task->tk_xprt->servername);
2203                 }
2204         }
2205         rpc_force_rebind(clnt);
2206         /*
2207          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2208          * event? RFC2203 requires the server to drop all such requests.
2209          */
2210         rpcauth_invalcred(task);
2211
2212 retry:
2213         task->tk_action = call_bind;
2214         task->tk_status = 0;
2215 }
2216
2217 /*
2218  * 7.   Decode the RPC reply
2219  */
2220 static void
2221 call_decode(struct rpc_task *task)
2222 {
2223         struct rpc_clnt *clnt = task->tk_client;
2224         struct rpc_rqst *req = task->tk_rqstp;
2225         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2226         __be32          *p;
2227
2228         dprint_status(task);
2229
2230         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2231                 if (clnt->cl_chatty) {
2232                         printk(KERN_NOTICE "%s: server %s OK\n",
2233                                 clnt->cl_program->name,
2234                                 task->tk_xprt->servername);
2235                 }
2236                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2237         }
2238
2239         /*
2240          * Ensure that we see all writes made by xprt_complete_rqst()
2241          * before it changed req->rq_reply_bytes_recvd.
2242          */
2243         smp_rmb();
2244         req->rq_rcv_buf.len = req->rq_private_buf.len;
2245
2246         /* Check that the softirq receive buffer is valid */
2247         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2248                                 sizeof(req->rq_rcv_buf)) != 0);
2249
2250         if (req->rq_rcv_buf.len < 12) {
2251                 if (!RPC_IS_SOFT(task)) {
2252                         task->tk_action = call_bind;
2253                         goto out_retry;
2254                 }
2255                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2256                                 clnt->cl_program->name, task->tk_status);
2257                 task->tk_action = call_timeout;
2258                 goto out_retry;
2259         }
2260
2261         p = rpc_verify_header(task);
2262         if (IS_ERR(p)) {
2263                 if (p == ERR_PTR(-EAGAIN))
2264                         goto out_retry;
2265                 return;
2266         }
2267
2268         task->tk_action = rpc_exit_task;
2269
2270         if (decode) {
2271                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2272                                                       task->tk_msg.rpc_resp);
2273         }
2274         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2275                         task->tk_status);
2276         return;
2277 out_retry:
2278         task->tk_status = 0;
2279         /* Note: rpc_verify_header() may have freed the RPC slot */
2280         if (task->tk_rqstp == req) {
2281                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2282                 if (task->tk_client->cl_discrtry)
2283                         xprt_conditional_disconnect(req->rq_xprt,
2284                                         req->rq_connect_cookie);
2285         }
2286 }
2287
2288 static __be32 *
2289 rpc_encode_header(struct rpc_task *task)
2290 {
2291         struct rpc_clnt *clnt = task->tk_client;
2292         struct rpc_rqst *req = task->tk_rqstp;
2293         __be32          *p = req->rq_svec[0].iov_base;
2294
2295         /* FIXME: check buffer size? */
2296
2297         p = xprt_skip_transport_header(req->rq_xprt, p);
2298         *p++ = req->rq_xid;             /* XID */
2299         *p++ = htonl(RPC_CALL);         /* CALL */
2300         *p++ = htonl(RPC_VERSION);      /* RPC version */
2301         *p++ = htonl(clnt->cl_prog);    /* program number */
2302         *p++ = htonl(clnt->cl_vers);    /* program version */
2303         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2304         p = rpcauth_marshcred(task, p);
2305         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2306         return p;
2307 }
2308
2309 static __be32 *
2310 rpc_verify_header(struct rpc_task *task)
2311 {
2312         struct rpc_clnt *clnt = task->tk_client;
2313         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2314         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2315         __be32  *p = iov->iov_base;
2316         u32 n;
2317         int error = -EACCES;
2318
2319         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2320                 /* RFC-1014 says that the representation of XDR data must be a
2321                  * multiple of four bytes
2322                  * - if it isn't pointer subtraction in the NFS client may give
2323                  *   undefined results
2324                  */
2325                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2326                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2327                        task->tk_rqstp->rq_rcv_buf.len);
2328                 error = -EIO;
2329                 goto out_err;
2330         }
2331         if ((len -= 3) < 0)
2332                 goto out_overflow;
2333
2334         p += 1; /* skip XID */
2335         if ((n = ntohl(*p++)) != RPC_REPLY) {
2336                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2337                         task->tk_pid, __func__, n);
2338                 error = -EIO;
2339                 goto out_garbage;
2340         }
2341
2342         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2343                 if (--len < 0)
2344                         goto out_overflow;
2345                 switch ((n = ntohl(*p++))) {
2346                 case RPC_AUTH_ERROR:
2347                         break;
2348                 case RPC_MISMATCH:
2349                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2350                                 task->tk_pid, __func__);
2351                         error = -EPROTONOSUPPORT;
2352                         goto out_err;
2353                 default:
2354                         dprintk("RPC: %5u %s: RPC call rejected, "
2355                                 "unknown error: %x\n",
2356                                 task->tk_pid, __func__, n);
2357                         error = -EIO;
2358                         goto out_err;
2359                 }
2360                 if (--len < 0)
2361                         goto out_overflow;
2362                 switch ((n = ntohl(*p++))) {
2363                 case RPC_AUTH_REJECTEDCRED:
2364                 case RPC_AUTH_REJECTEDVERF:
2365                 case RPCSEC_GSS_CREDPROBLEM:
2366                 case RPCSEC_GSS_CTXPROBLEM:
2367                         if (!task->tk_cred_retry)
2368                                 break;
2369                         task->tk_cred_retry--;
2370                         dprintk("RPC: %5u %s: retry stale creds\n",
2371                                         task->tk_pid, __func__);
2372                         rpcauth_invalcred(task);
2373                         /* Ensure we obtain a new XID! */
2374                         xprt_release(task);
2375                         task->tk_action = call_reserve;
2376                         goto out_retry;
2377                 case RPC_AUTH_BADCRED:
2378                 case RPC_AUTH_BADVERF:
2379                         /* possibly garbled cred/verf? */
2380                         if (!task->tk_garb_retry)
2381                                 break;
2382                         task->tk_garb_retry--;
2383                         dprintk("RPC: %5u %s: retry garbled creds\n",
2384                                         task->tk_pid, __func__);
2385                         task->tk_action = call_bind;
2386                         goto out_retry;
2387                 case RPC_AUTH_TOOWEAK:
2388                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2389                                "authentication.\n",
2390                                task->tk_xprt->servername);
2391                         break;
2392                 default:
2393                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2394                                         task->tk_pid, __func__, n);
2395                         error = -EIO;
2396                 }
2397                 dprintk("RPC: %5u %s: call rejected %d\n",
2398                                 task->tk_pid, __func__, n);
2399                 goto out_err;
2400         }
2401         p = rpcauth_checkverf(task, p);
2402         if (IS_ERR(p)) {
2403                 error = PTR_ERR(p);
2404                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2405                                 task->tk_pid, __func__, error);
2406                 goto out_garbage;               /* bad verifier, retry */
2407         }
2408         len = p - (__be32 *)iov->iov_base - 1;
2409         if (len < 0)
2410                 goto out_overflow;
2411         switch ((n = ntohl(*p++))) {
2412         case RPC_SUCCESS:
2413                 return p;
2414         case RPC_PROG_UNAVAIL:
2415                 dprintk("RPC: %5u %s: program %u is unsupported "
2416                                 "by server %s\n", task->tk_pid, __func__,
2417                                 (unsigned int)clnt->cl_prog,
2418                                 task->tk_xprt->servername);
2419                 error = -EPFNOSUPPORT;
2420                 goto out_err;
2421         case RPC_PROG_MISMATCH:
2422                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2423                                 "by server %s\n", task->tk_pid, __func__,
2424                                 (unsigned int)clnt->cl_prog,
2425                                 (unsigned int)clnt->cl_vers,
2426                                 task->tk_xprt->servername);
2427                 error = -EPROTONOSUPPORT;
2428                 goto out_err;
2429         case RPC_PROC_UNAVAIL:
2430                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2431                                 "version %u on server %s\n",
2432                                 task->tk_pid, __func__,
2433                                 rpc_proc_name(task),
2434                                 clnt->cl_prog, clnt->cl_vers,
2435                                 task->tk_xprt->servername);
2436                 error = -EOPNOTSUPP;
2437                 goto out_err;
2438         case RPC_GARBAGE_ARGS:
2439                 dprintk("RPC: %5u %s: server saw garbage\n",
2440                                 task->tk_pid, __func__);
2441                 break;                  /* retry */
2442         default:
2443                 dprintk("RPC: %5u %s: server accept status: %x\n",
2444                                 task->tk_pid, __func__, n);
2445                 /* Also retry */
2446         }
2447
2448 out_garbage:
2449         clnt->cl_stats->rpcgarbage++;
2450         if (task->tk_garb_retry) {
2451                 task->tk_garb_retry--;
2452                 dprintk("RPC: %5u %s: retrying\n",
2453                                 task->tk_pid, __func__);
2454                 task->tk_action = call_bind;
2455 out_retry:
2456                 return ERR_PTR(-EAGAIN);
2457         }
2458 out_err:
2459         rpc_exit(task, error);
2460         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2461                         __func__, error);
2462         return ERR_PTR(error);
2463 out_overflow:
2464         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2465                         __func__);
2466         goto out_garbage;
2467 }
2468
2469 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2470 {
2471 }
2472
2473 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2474 {
2475         return 0;
2476 }
2477
2478 static struct rpc_procinfo rpcproc_null = {
2479         .p_encode = rpcproc_encode_null,
2480         .p_decode = rpcproc_decode_null,
2481 };
2482
2483 static int rpc_ping(struct rpc_clnt *clnt)
2484 {
2485         struct rpc_message msg = {
2486                 .rpc_proc = &rpcproc_null,
2487         };
2488         int err;
2489         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2490         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2491         put_rpccred(msg.rpc_cred);
2492         return err;
2493 }
2494
2495 static
2496 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2497                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2498                 const struct rpc_call_ops *ops, void *data)
2499 {
2500         struct rpc_message msg = {
2501                 .rpc_proc = &rpcproc_null,
2502                 .rpc_cred = cred,
2503         };
2504         struct rpc_task_setup task_setup_data = {
2505                 .rpc_client = clnt,
2506                 .rpc_xprt = xprt,
2507                 .rpc_message = &msg,
2508                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2509                 .callback_data = data,
2510                 .flags = flags,
2511         };
2512
2513         return rpc_run_task(&task_setup_data);
2514 }
2515
2516 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2517 {
2518         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2519 }
2520 EXPORT_SYMBOL_GPL(rpc_call_null);
2521
2522 struct rpc_cb_add_xprt_calldata {
2523         struct rpc_xprt_switch *xps;
2524         struct rpc_xprt *xprt;
2525 };
2526
2527 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2528 {
2529         struct rpc_cb_add_xprt_calldata *data = calldata;
2530
2531         if (task->tk_status == 0)
2532                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2533 }
2534
2535 static void rpc_cb_add_xprt_release(void *calldata)
2536 {
2537         struct rpc_cb_add_xprt_calldata *data = calldata;
2538
2539         xprt_put(data->xprt);
2540         xprt_switch_put(data->xps);
2541         kfree(data);
2542 }
2543
2544 const static struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2545         .rpc_call_done = rpc_cb_add_xprt_done,
2546         .rpc_release = rpc_cb_add_xprt_release,
2547 };
2548
2549 /**
2550  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2551  * @clnt: pointer to struct rpc_clnt
2552  * @xps: pointer to struct rpc_xprt_switch,
2553  * @xprt: pointer struct rpc_xprt
2554  * @dummy: unused
2555  */
2556 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2557                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2558                 void *dummy)
2559 {
2560         struct rpc_cb_add_xprt_calldata *data;
2561         struct rpc_cred *cred;
2562         struct rpc_task *task;
2563
2564         data = kmalloc(sizeof(*data), GFP_NOFS);
2565         if (!data)
2566                 return -ENOMEM;
2567         data->xps = xprt_switch_get(xps);
2568         data->xprt = xprt_get(xprt);
2569
2570         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2571         task = rpc_call_null_helper(clnt, xprt, cred,
2572                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2573                         &rpc_cb_add_xprt_call_ops, data);
2574         put_rpccred(cred);
2575         if (IS_ERR(task))
2576                 return PTR_ERR(task);
2577         rpc_put_task(task);
2578         return 1;
2579 }
2580 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2581
2582 /**
2583  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2584  * @clnt: pointer to struct rpc_clnt
2585  * @xprtargs: pointer to struct xprt_create
2586  * @setup: callback to test and/or set up the connection
2587  * @data: pointer to setup function data
2588  *
2589  * Creates a new transport using the parameters set in args and
2590  * adds it to clnt.
2591  * If ping is set, then test that connectivity succeeds before
2592  * adding the new transport.
2593  *
2594  */
2595 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2596                 struct xprt_create *xprtargs,
2597                 int (*setup)(struct rpc_clnt *,
2598                         struct rpc_xprt_switch *,
2599                         struct rpc_xprt *,
2600                         void *),
2601                 void *data)
2602 {
2603         struct rpc_xprt_switch *xps;
2604         struct rpc_xprt *xprt;
2605         unsigned char resvport;
2606         int ret = 0;
2607
2608         rcu_read_lock();
2609         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2610         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2611         if (xps == NULL || xprt == NULL) {
2612                 rcu_read_unlock();
2613                 return -EAGAIN;
2614         }
2615         resvport = xprt->resvport;
2616         rcu_read_unlock();
2617
2618         xprt = xprt_create_transport(xprtargs);
2619         if (IS_ERR(xprt)) {
2620                 ret = PTR_ERR(xprt);
2621                 goto out_put_switch;
2622         }
2623         xprt->resvport = resvport;
2624
2625         rpc_xprt_switch_set_roundrobin(xps);
2626         if (setup) {
2627                 ret = setup(clnt, xps, xprt, data);
2628                 if (ret != 0)
2629                         goto out_put_xprt;
2630         }
2631         rpc_xprt_switch_add_xprt(xps, xprt);
2632 out_put_xprt:
2633         xprt_put(xprt);
2634 out_put_switch:
2635         xprt_switch_put(xps);
2636         return ret;
2637 }
2638 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2639
2640 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2641 static void rpc_show_header(void)
2642 {
2643         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2644                 "-timeout ---ops--\n");
2645 }
2646
2647 static void rpc_show_task(const struct rpc_clnt *clnt,
2648                           const struct rpc_task *task)
2649 {
2650         const char *rpc_waitq = "none";
2651
2652         if (RPC_IS_QUEUED(task))
2653                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2654
2655         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2656                 task->tk_pid, task->tk_flags, task->tk_status,
2657                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2658                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2659                 task->tk_action, rpc_waitq);
2660 }
2661
2662 void rpc_show_tasks(struct net *net)
2663 {
2664         struct rpc_clnt *clnt;
2665         struct rpc_task *task;
2666         int header = 0;
2667         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2668
2669         spin_lock(&sn->rpc_client_lock);
2670         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2671                 spin_lock(&clnt->cl_lock);
2672                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2673                         if (!header) {
2674                                 rpc_show_header();
2675                                 header++;
2676                         }
2677                         rpc_show_task(clnt, task);
2678                 }
2679                 spin_unlock(&clnt->cl_lock);
2680         }
2681         spin_unlock(&sn->rpc_client_lock);
2682 }
2683 #endif
2684
2685 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2686 static int
2687 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2688                 struct rpc_xprt *xprt,
2689                 void *dummy)
2690 {
2691         return xprt_enable_swap(xprt);
2692 }
2693
2694 int
2695 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2696 {
2697         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2698                 return rpc_clnt_iterate_for_each_xprt(clnt,
2699                                 rpc_clnt_swap_activate_callback, NULL);
2700         return 0;
2701 }
2702 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2703
2704 static int
2705 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2706                 struct rpc_xprt *xprt,
2707                 void *dummy)
2708 {
2709         xprt_disable_swap(xprt);
2710         return 0;
2711 }
2712
2713 void
2714 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2715 {
2716         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2717                 rpc_clnt_iterate_for_each_xprt(clnt,
2718                                 rpc_clnt_swap_deactivate_callback, NULL);
2719 }
2720 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2721 #endif /* CONFIG_SUNRPC_SWAP */