net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "sysfs.h"
  45 #include "netns.h"
  46
  47 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  48 # define RPCDBG_FACILITY        RPCDBG_CALL
  49 #endif
  50
  51 /*
  52  * All RPC clients are linked into this list
  53  */
  54
  55 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  56
  57
  58 static void     call_start(struct rpc_task *task);
  59 static void     call_reserve(struct rpc_task *task);
  60 static void     call_reserveresult(struct rpc_task *task);
  61 static void     call_allocate(struct rpc_task *task);
  62 static void     call_encode(struct rpc_task *task);
  63 static void     call_decode(struct rpc_task *task);
  64 static void     call_bind(struct rpc_task *task);
  65 static void     call_bind_status(struct rpc_task *task);
  66 static void     call_transmit(struct rpc_task *task);
  67 static void     call_status(struct rpc_task *task);
  68 static void     call_transmit_status(struct rpc_task *task);
  69 static void     call_refresh(struct rpc_task *task);
  70 static void     call_refreshresult(struct rpc_task *task);
  71 static void     call_connect(struct rpc_task *task);
  72 static void     call_connect_status(struct rpc_task *task);
  73
  74 static int      rpc_encode_header(struct rpc_task *task,
  75                                   struct xdr_stream *xdr);
  76 static int      rpc_decode_header(struct rpc_task *task,
  77                                   struct xdr_stream *xdr);
  78 static int      rpc_ping(struct rpc_clnt *clnt);
  79 static int      rpc_ping_noreply(struct rpc_clnt *clnt);
  80 static void     rpc_check_timeout(struct rpc_task *task);
  81
  82 static void rpc_register_client(struct rpc_clnt *clnt)
  83 {
  84         struct net *net = rpc_net_ns(clnt);
  85         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  86
  87         spin_lock(&sn->rpc_client_lock);
  88         list_add(&clnt->cl_clients, &sn->all_clients);
  89         spin_unlock(&sn->rpc_client_lock);
  90 }
  91
  92 static void rpc_unregister_client(struct rpc_clnt *clnt)
  93 {
  94         struct net *net = rpc_net_ns(clnt);
  95         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  96
  97         spin_lock(&sn->rpc_client_lock);
  98         list_del(&clnt->cl_clients);
  99         spin_unlock(&sn->rpc_client_lock);
 100 }
 101
 102 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 103 {
 104         rpc_remove_client_dir(clnt);
 105 }
 106
 107 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 108 {
 109         struct net *net = rpc_net_ns(clnt);
 110         struct super_block *pipefs_sb;
 111
 112         pipefs_sb = rpc_get_sb_net(net);
 113         if (pipefs_sb) {
 114                 if (pipefs_sb == clnt->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         clnt->pipefs_sb = pipefs_sb;
 156
 157         if (clnt->cl_program->pipe_dir_name != NULL) {
 158                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 159                 if (IS_ERR(dentry))
 160                         return PTR_ERR(dentry);
 161         }
 162         return 0;
 163 }
 164
 165 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 166 {
 167         if (clnt->cl_program->pipe_dir_name == NULL)
 168                 return 1;
 169
 170         switch (event) {
 171         case RPC_PIPEFS_MOUNT:
 172                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 173                         return 1;
 174                 if (refcount_read(&clnt->cl_count) == 0)
 175                         return 1;
 176                 break;
 177         case RPC_PIPEFS_UMOUNT:
 178                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 179                         return 1;
 180                 break;
 181         }
 182         return 0;
 183 }
 184
 185 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 186                                    struct super_block *sb)
 187 {
 188         struct dentry *dentry;
 189
 190         switch (event) {
 191         case RPC_PIPEFS_MOUNT:
 192                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 193                 if (!dentry)
 194                         return -ENOENT;
 195                 if (IS_ERR(dentry))
 196                         return PTR_ERR(dentry);
 197                 break;
 198         case RPC_PIPEFS_UMOUNT:
 199                 __rpc_clnt_remove_pipedir(clnt);
 200                 break;
 201         default:
 202                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 203                 return -ENOTSUPP;
 204         }
 205         return 0;
 206 }
 207
 208 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 209                                 struct super_block *sb)
 210 {
 211         int error = 0;
 212
 213         for (;; clnt = clnt->cl_parent) {
 214                 if (!rpc_clnt_skip_event(clnt, event))
 215                         error = __rpc_clnt_handle_event(clnt, event, sb);
 216                 if (error || clnt == clnt->cl_parent)
 217                         break;
 218         }
 219         return error;
 220 }
 221
 222 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 223 {
 224         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 225         struct rpc_clnt *clnt;
 226
 227         spin_lock(&sn->rpc_client_lock);
 228         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 229                 if (rpc_clnt_skip_event(clnt, event))
 230                         continue;
 231                 spin_unlock(&sn->rpc_client_lock);
 232                 return clnt;
 233         }
 234         spin_unlock(&sn->rpc_client_lock);
 235         return NULL;
 236 }
 237
 238 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 239                             void *ptr)
 240 {
 241         struct super_block *sb = ptr;
 242         struct rpc_clnt *clnt;
 243         int error = 0;
 244
 245         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 246                 error = __rpc_pipefs_event(clnt, event, sb);
 247                 if (error)
 248                         break;
 249         }
 250         return error;
 251 }
 252
 253 static struct notifier_block rpc_clients_block = {
 254         .notifier_call  = rpc_pipefs_event,
 255         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 256 };
 257
 258 int rpc_clients_notifier_register(void)
 259 {
 260         return rpc_pipefs_notifier_register(&rpc_clients_block);
 261 }
 262
 263 void rpc_clients_notifier_unregister(void)
 264 {
 265         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 266 }
 267
 268 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 269                 struct rpc_xprt *xprt,
 270                 const struct rpc_timeout *timeout)
 271 {
 272         struct rpc_xprt *old;
 273
 274         spin_lock(&clnt->cl_lock);
 275         old = rcu_dereference_protected(clnt->cl_xprt,
 276                         lockdep_is_held(&clnt->cl_lock));
 277
 278         if (!xprt_bound(xprt))
 279                 clnt->cl_autobind = 1;
 280
 281         clnt->cl_timeout = timeout;
 282         rcu_assign_pointer(clnt->cl_xprt, xprt);
 283         spin_unlock(&clnt->cl_lock);
 284
 285         return old;
 286 }
 287
 288 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 289 {
 290         ssize_t copied;
 291
 292         copied = strscpy(clnt->cl_nodename,
 293                          nodename, sizeof(clnt->cl_nodename));
 294
 295         clnt->cl_nodelen = copied < 0
 296                                 ? sizeof(clnt->cl_nodename) - 1
 297                                 : copied;
 298 }
 299
 300 static int rpc_client_register(struct rpc_clnt *clnt,
 301                                rpc_authflavor_t pseudoflavor,
 302                                const char *client_name)
 303 {
 304         struct rpc_auth_create_args auth_args = {
 305                 .pseudoflavor = pseudoflavor,
 306                 .target_name = client_name,
 307         };
 308         struct rpc_auth *auth;
 309         struct net *net = rpc_net_ns(clnt);
 310         struct super_block *pipefs_sb;
 311         int err;
 312
 313         rpc_clnt_debugfs_register(clnt);
 314
 315         pipefs_sb = rpc_get_sb_net(net);
 316         if (pipefs_sb) {
 317                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 318                 if (err)
 319                         goto out;
 320         }
 321
 322         rpc_register_client(clnt);
 323         if (pipefs_sb)
 324                 rpc_put_sb_net(net);
 325
 326         auth = rpcauth_create(&auth_args, clnt);
 327         if (IS_ERR(auth)) {
 328                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 329                                 pseudoflavor);
 330                 err = PTR_ERR(auth);
 331                 goto err_auth;
 332         }
 333         return 0;
 334 err_auth:
 335         pipefs_sb = rpc_get_sb_net(net);
 336         rpc_unregister_client(clnt);
 337         __rpc_clnt_remove_pipedir(clnt);
 338 out:
 339         if (pipefs_sb)
 340                 rpc_put_sb_net(net);
 341         rpc_sysfs_client_destroy(clnt);
 342         rpc_clnt_debugfs_unregister(clnt);
 343         return err;
 344 }
 345
 346 static DEFINE_IDA(rpc_clids);
 347
 348 void rpc_cleanup_clids(void)
 349 {
 350         ida_destroy(&rpc_clids);
 351 }
 352
 353 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 354 {
 355         int clid;
 356
 357         clid = ida_alloc(&rpc_clids, GFP_KERNEL);
 358         if (clid < 0)
 359                 return clid;
 360         clnt->cl_clid = clid;
 361         return 0;
 362 }
 363
 364 static void rpc_free_clid(struct rpc_clnt *clnt)
 365 {
 366         ida_free(&rpc_clids, clnt->cl_clid);
 367 }
 368
 369 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 370                 struct rpc_xprt_switch *xps,
 371                 struct rpc_xprt *xprt,
 372                 struct rpc_clnt *parent)
 373 {
 374         const struct rpc_program *program = args->program;
 375         const struct rpc_version *version;
 376         struct rpc_clnt *clnt = NULL;
 377         const struct rpc_timeout *timeout;
 378         const char *nodename = args->nodename;
 379         int err;
 380
 381         err = rpciod_up();
 382         if (err)
 383                 goto out_no_rpciod;
 384
 385         err = -EINVAL;
 386         if (args->version >= program->nrvers)
 387                 goto out_err;
 388         version = program->version[args->version];
 389         if (version == NULL)
 390                 goto out_err;
 391
 392         err = -ENOMEM;
 393         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 394         if (!clnt)
 395                 goto out_err;
 396         clnt->cl_parent = parent ? : clnt;
 397         clnt->cl_xprtsec = args->xprtsec;
 398
 399         err = rpc_alloc_clid(clnt);
 400         if (err)
 401                 goto out_no_clid;
 402
 403         clnt->cl_cred     = get_cred(args->cred);
 404         clnt->cl_procinfo = version->procs;
 405         clnt->cl_maxproc  = version->nrprocs;
 406         clnt->cl_prog     = args->prognumber ? : program->number;
 407         clnt->cl_vers     = version->number;
 408         clnt->cl_stats    = args->stats ? : program->stats;
 409         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 410         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 411         err = -ENOMEM;
 412         if (clnt->cl_metrics == NULL)
 413                 goto out_no_stats;
 414         clnt->cl_program  = program;
 415         INIT_LIST_HEAD(&clnt->cl_tasks);
 416         spin_lock_init(&clnt->cl_lock);
 417
 418         timeout = xprt->timeout;
 419         if (args->timeout != NULL) {
 420                 memcpy(&clnt->cl_timeout_default, args->timeout,
 421                                 sizeof(clnt->cl_timeout_default));
 422                 timeout = &clnt->cl_timeout_default;
 423         }
 424
 425         rpc_clnt_set_transport(clnt, xprt, timeout);
 426         xprt->main = true;
 427         xprt_iter_init(&clnt->cl_xpi, xps);
 428         xprt_switch_put(xps);
 429
 430         clnt->cl_rtt = &clnt->cl_rtt_default;
 431         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 432
 433         refcount_set(&clnt->cl_count, 1);
 434
 435         if (nodename == NULL)
 436                 nodename = utsname()->nodename;
 437         /* save the nodename */
 438         rpc_clnt_set_nodename(clnt, nodename);
 439
 440         rpc_sysfs_client_setup(clnt, xps, rpc_net_ns(clnt));
 441         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 442         if (err)
 443                 goto out_no_path;
 444         if (parent)
 445                 refcount_inc(&parent->cl_count);
 446
 447         trace_rpc_clnt_new(clnt, xprt, args);
 448         return clnt;
 449
 450 out_no_path:
 451         rpc_free_iostats(clnt->cl_metrics);
 452 out_no_stats:
 453         put_cred(clnt->cl_cred);
 454         rpc_free_clid(clnt);
 455 out_no_clid:
 456         kfree(clnt);
 457 out_err:
 458         rpciod_down();
 459 out_no_rpciod:
 460         xprt_switch_put(xps);
 461         xprt_put(xprt);
 462         trace_rpc_clnt_new_err(program->name, args->servername, err);
 463         return ERR_PTR(err);
 464 }
 465
 466 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 467                                         struct rpc_xprt *xprt)
 468 {
 469         struct rpc_clnt *clnt = NULL;
 470         struct rpc_xprt_switch *xps;
 471
 472         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 473                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 474                 xps = args->bc_xprt->xpt_bc_xps;
 475                 xprt_switch_get(xps);
 476         } else {
 477                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 478                 if (xps == NULL) {
 479                         xprt_put(xprt);
 480                         return ERR_PTR(-ENOMEM);
 481                 }
 482                 if (xprt->bc_xprt) {
 483                         xprt_switch_get(xps);
 484                         xprt->bc_xprt->xpt_bc_xps = xps;
 485                 }
 486         }
 487         clnt = rpc_new_client(args, xps, xprt, NULL);
 488         if (IS_ERR(clnt))
 489                 return clnt;
 490
 491         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 492                 int err = rpc_ping(clnt);
 493                 if (err != 0) {
 494                         rpc_shutdown_client(clnt);
 495                         return ERR_PTR(err);
 496                 }
 497         } else if (args->flags & RPC_CLNT_CREATE_CONNECTED) {
 498                 int err = rpc_ping_noreply(clnt);
 499                 if (err != 0) {
 500                         rpc_shutdown_client(clnt);
 501                         return ERR_PTR(err);
 502                 }
 503         }
 504
 505         clnt->cl_softrtry = 1;
 506         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 507                 clnt->cl_softrtry = 0;
 508                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 509                         clnt->cl_softerr = 1;
 510         }
 511
 512         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 513                 clnt->cl_autobind = 1;
 514         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 515                 clnt->cl_noretranstimeo = 1;
 516         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 517                 clnt->cl_discrtry = 1;
 518         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 519                 clnt->cl_chatty = 1;
 520
 521         return clnt;
 522 }
 523
 524 /**
 525  * rpc_create - create an RPC client and transport with one call
 526  * @args: rpc_clnt create argument structure
 527  *
 528  * Creates and initializes an RPC transport and an RPC client.
 529  *
 530  * It can ping the server in order to determine if it is up, and to see if
 531  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 532  * this behavior so asynchronous tasks can also use rpc_create.
 533  */
 534 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 535 {
 536         struct rpc_xprt *xprt;
 537         struct xprt_create xprtargs = {
 538                 .net = args->net,
 539                 .ident = args->protocol,
 540                 .srcaddr = args->saddress,
 541                 .dstaddr = args->address,
 542                 .addrlen = args->addrsize,
 543                 .servername = args->servername,
 544                 .bc_xprt = args->bc_xprt,
 545                 .xprtsec = args->xprtsec,
 546                 .connect_timeout = args->connect_timeout,
 547                 .reconnect_timeout = args->reconnect_timeout,
 548         };
 549         char servername[48];
 550         struct rpc_clnt *clnt;
 551         int i;
 552
 553         if (args->bc_xprt) {
 554                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 555                 xprt = args->bc_xprt->xpt_bc_xprt;
 556                 if (xprt) {
 557                         xprt_get(xprt);
 558                         return rpc_create_xprt(args, xprt);
 559                 }
 560         }
 561
 562         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 563                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 564         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 565                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 566         /*
 567          * If the caller chooses not to specify a hostname, whip
 568          * up a string representation of the passed-in address.
 569          */
 570         if (xprtargs.servername == NULL) {
 571                 struct sockaddr_un *sun =
 572                                 (struct sockaddr_un *)args->address;
 573                 struct sockaddr_in *sin =
 574                                 (struct sockaddr_in *)args->address;
 575                 struct sockaddr_in6 *sin6 =
 576                                 (struct sockaddr_in6 *)args->address;
 577
 578                 servername[0] = '\0';
 579                 switch (args->address->sa_family) {
 580                 case AF_LOCAL:
 581                         if (sun->sun_path[0])
 582                                 snprintf(servername, sizeof(servername), "%s",
 583                                          sun->sun_path);
 584                         else
 585                                 snprintf(servername, sizeof(servername), "@%s",
 586                                          sun->sun_path+1);
 587                         break;
 588                 case AF_INET:
 589                         snprintf(servername, sizeof(servername), "%pI4",
 590                                  &sin->sin_addr.s_addr);
 591                         break;
 592                 case AF_INET6:
 593                         snprintf(servername, sizeof(servername), "%pI6",
 594                                  &sin6->sin6_addr);
 595                         break;
 596                 default:
 597                         /* caller wants default server name, but
 598                          * address family isn't recognized. */
 599                         return ERR_PTR(-EINVAL);
 600                 }
 601                 xprtargs.servername = servername;
 602         }
 603
 604         xprt = xprt_create_transport(&xprtargs);
 605         if (IS_ERR(xprt))
 606                 return (struct rpc_clnt *)xprt;
 607
 608         /*
 609          * By default, kernel RPC client connects from a reserved port.
 610          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 611          * but it is always enabled for rpciod, which handles the connect
 612          * operation.
 613          */
 614         xprt->resvport = 1;
 615         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 616                 xprt->resvport = 0;
 617         xprt->reuseport = 0;
 618         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 619                 xprt->reuseport = 1;
 620
 621         clnt = rpc_create_xprt(args, xprt);
 622         if (IS_ERR(clnt) || args->nconnect <= 1)
 623                 return clnt;
 624
 625         for (i = 0; i < args->nconnect - 1; i++) {
 626                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 627                         break;
 628         }
 629         return clnt;
 630 }
 631 EXPORT_SYMBOL_GPL(rpc_create);
 632
 633 /*
 634  * This function clones the RPC client structure. It allows us to share the
 635  * same transport while varying parameters such as the authentication
 636  * flavour.
 637  */
 638 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 639                                            struct rpc_clnt *clnt)
 640 {
 641         struct rpc_xprt_switch *xps;
 642         struct rpc_xprt *xprt;
 643         struct rpc_clnt *new;
 644         int err;
 645
 646         err = -ENOMEM;
 647         rcu_read_lock();
 648         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 649         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 650         rcu_read_unlock();
 651         if (xprt == NULL || xps == NULL) {
 652                 xprt_put(xprt);
 653                 xprt_switch_put(xps);
 654                 goto out_err;
 655         }
 656         args->servername = xprt->servername;
 657         args->nodename = clnt->cl_nodename;
 658
 659         new = rpc_new_client(args, xps, xprt, clnt);
 660         if (IS_ERR(new))
 661                 return new;
 662
 663         /* Turn off autobind on clones */
 664         new->cl_autobind = 0;
 665         new->cl_softrtry = clnt->cl_softrtry;
 666         new->cl_softerr = clnt->cl_softerr;
 667         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 668         new->cl_discrtry = clnt->cl_discrtry;
 669         new->cl_chatty = clnt->cl_chatty;
 670         new->cl_principal = clnt->cl_principal;
 671         new->cl_max_connect = clnt->cl_max_connect;
 672         return new;
 673
 674 out_err:
 675         trace_rpc_clnt_clone_err(clnt, err);
 676         return ERR_PTR(err);
 677 }
 678
 679 /**
 680  * rpc_clone_client - Clone an RPC client structure
 681  *
 682  * @clnt: RPC client whose parameters are copied
 683  *
 684  * Returns a fresh RPC client or an ERR_PTR.
 685  */
 686 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 687 {
 688         struct rpc_create_args args = {
 689                 .program        = clnt->cl_program,
 690                 .prognumber     = clnt->cl_prog,
 691                 .version        = clnt->cl_vers,
 692                 .authflavor     = clnt->cl_auth->au_flavor,
 693                 .cred           = clnt->cl_cred,
 694                 .stats          = clnt->cl_stats,
 695         };
 696         return __rpc_clone_client(&args, clnt);
 697 }
 698 EXPORT_SYMBOL_GPL(rpc_clone_client);
 699
 700 /**
 701  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 702  *
 703  * @clnt: RPC client whose parameters are copied
 704  * @flavor: security flavor for new client
 705  *
 706  * Returns a fresh RPC client or an ERR_PTR.
 707  */
 708 struct rpc_clnt *
 709 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 710 {
 711         struct rpc_create_args args = {
 712                 .program        = clnt->cl_program,
 713                 .prognumber     = clnt->cl_prog,
 714                 .version        = clnt->cl_vers,
 715                 .authflavor     = flavor,
 716                 .cred           = clnt->cl_cred,
 717                 .stats          = clnt->cl_stats,
 718         };
 719         return __rpc_clone_client(&args, clnt);
 720 }
 721 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 722
 723 /**
 724  * rpc_switch_client_transport: switch the RPC transport on the fly
 725  * @clnt: pointer to a struct rpc_clnt
 726  * @args: pointer to the new transport arguments
 727  * @timeout: pointer to the new timeout parameters
 728  *
 729  * This function allows the caller to switch the RPC transport for the
 730  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 731  * server, for instance.  It assumes that the caller has ensured that
 732  * there are no active RPC tasks by using some form of locking.
 733  *
 734  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 735  * negative errno is returned, and "clnt" continues to use the old
 736  * xprt.
 737  */
 738 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 739                 struct xprt_create *args,
 740                 const struct rpc_timeout *timeout)
 741 {
 742         const struct rpc_timeout *old_timeo;
 743         rpc_authflavor_t pseudoflavor;
 744         struct rpc_xprt_switch *xps, *oldxps;
 745         struct rpc_xprt *xprt, *old;
 746         struct rpc_clnt *parent;
 747         int err;
 748
 749         args->xprtsec = clnt->cl_xprtsec;
 750         xprt = xprt_create_transport(args);
 751         if (IS_ERR(xprt))
 752                 return PTR_ERR(xprt);
 753
 754         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 755         if (xps == NULL) {
 756                 xprt_put(xprt);
 757                 return -ENOMEM;
 758         }
 759
 760         pseudoflavor = clnt->cl_auth->au_flavor;
 761
 762         old_timeo = clnt->cl_timeout;
 763         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 764         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 765
 766         rpc_unregister_client(clnt);
 767         __rpc_clnt_remove_pipedir(clnt);
 768         rpc_sysfs_client_destroy(clnt);
 769         rpc_clnt_debugfs_unregister(clnt);
 770
 771         /*
 772          * A new transport was created.  "clnt" therefore
 773          * becomes the root of a new cl_parent tree.  clnt's
 774          * children, if it has any, still point to the old xprt.
 775          */
 776         parent = clnt->cl_parent;
 777         clnt->cl_parent = clnt;
 778
 779         /*
 780          * The old rpc_auth cache cannot be re-used.  GSS
 781          * contexts in particular are between a single
 782          * client and server.
 783          */
 784         err = rpc_client_register(clnt, pseudoflavor, NULL);
 785         if (err)
 786                 goto out_revert;
 787
 788         synchronize_rcu();
 789         if (parent != clnt)
 790                 rpc_release_client(parent);
 791         xprt_switch_put(oldxps);
 792         xprt_put(old);
 793         trace_rpc_clnt_replace_xprt(clnt);
 794         return 0;
 795
 796 out_revert:
 797         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 798         rpc_clnt_set_transport(clnt, old, old_timeo);
 799         clnt->cl_parent = parent;
 800         rpc_client_register(clnt, pseudoflavor, NULL);
 801         xprt_switch_put(xps);
 802         xprt_put(xprt);
 803         trace_rpc_clnt_replace_xprt_err(clnt);
 804         return err;
 805 }
 806 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 807
 808 static struct rpc_xprt_switch *rpc_clnt_xprt_switch_get(struct rpc_clnt *clnt)
 809 {
 810         struct rpc_xprt_switch *xps;
 811
 812         rcu_read_lock();
 813         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 814         rcu_read_unlock();
 815
 816         return xps;
 817 }
 818
 819 static
 820 int _rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi,
 821                              void func(struct rpc_xprt_iter *xpi, struct rpc_xprt_switch *xps))
 822 {
 823         struct rpc_xprt_switch *xps;
 824
 825         xps = rpc_clnt_xprt_switch_get(clnt);
 826         if (xps == NULL)
 827                 return -EAGAIN;
 828         func(xpi, xps);
 829         xprt_switch_put(xps);
 830         return 0;
 831 }
 832
 833 static
 834 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 835 {
 836         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listall);
 837 }
 838
 839 static
 840 int rpc_clnt_xprt_iter_offline_init(struct rpc_clnt *clnt,
 841                                     struct rpc_xprt_iter *xpi)
 842 {
 843         return _rpc_clnt_xprt_iter_init(clnt, xpi, xprt_iter_init_listoffline);
 844 }
 845
 846 /**
 847  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 848  * @clnt: pointer to client
 849  * @fn: function to apply
 850  * @data: void pointer to function data
 851  *
 852  * Iterates through the list of RPC transports currently attached to the
 853  * client and applies the function fn(clnt, xprt, data).
 854  *
 855  * On error, the iteration stops, and the function returns the error value.
 856  */
 857 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 858                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 859                 void *data)
 860 {
 861         struct rpc_xprt_iter xpi;
 862         int ret;
 863
 864         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 865         if (ret)
 866                 return ret;
 867         for (;;) {
 868                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 869
 870                 if (!xprt)
 871                         break;
 872                 ret = fn(clnt, xprt, data);
 873                 xprt_put(xprt);
 874                 if (ret < 0)
 875                         break;
 876         }
 877         xprt_iter_destroy(&xpi);
 878         return ret;
 879 }
 880 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 881
 882 /*
 883  * Kill all tasks for the given client.
 884  * XXX: kill their descendants as well?
 885  */
 886 void rpc_killall_tasks(struct rpc_clnt *clnt)
 887 {
 888         struct rpc_task *rovr;
 889
 890
 891         if (list_empty(&clnt->cl_tasks))
 892                 return;
 893
 894         /*
 895          * Spin lock all_tasks to prevent changes...
 896          */
 897         trace_rpc_clnt_killall(clnt);
 898         spin_lock(&clnt->cl_lock);
 899         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 900                 rpc_signal_task(rovr);
 901         spin_unlock(&clnt->cl_lock);
 902 }
 903 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 904
 905 /**
 906  * rpc_cancel_tasks - try to cancel a set of RPC tasks
 907  * @clnt: Pointer to RPC client
 908  * @error: RPC task error value to set
 909  * @fnmatch: Pointer to selector function
 910  * @data: User data
 911  *
 912  * Uses @fnmatch to define a set of RPC tasks that are to be cancelled.
 913  * The argument @error must be a negative error value.
 914  */
 915 unsigned long rpc_cancel_tasks(struct rpc_clnt *clnt, int error,
 916                                bool (*fnmatch)(const struct rpc_task *,
 917                                                const void *),
 918                                const void *data)
 919 {
 920         struct rpc_task *task;
 921         unsigned long count = 0;
 922
 923         if (list_empty(&clnt->cl_tasks))
 924                 return 0;
 925         /*
 926          * Spin lock all_tasks to prevent changes...
 927          */
 928         spin_lock(&clnt->cl_lock);
 929         list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
 930                 if (!RPC_IS_ACTIVATED(task))
 931                         continue;
 932                 if (!fnmatch(task, data))
 933                         continue;
 934                 rpc_task_try_cancel(task, error);
 935                 count++;
 936         }
 937         spin_unlock(&clnt->cl_lock);
 938         return count;
 939 }
 940 EXPORT_SYMBOL_GPL(rpc_cancel_tasks);
 941
 942 static int rpc_clnt_disconnect_xprt(struct rpc_clnt *clnt,
 943                                     struct rpc_xprt *xprt, void *dummy)
 944 {
 945         if (xprt_connected(xprt))
 946                 xprt_force_disconnect(xprt);
 947         return 0;
 948 }
 949
 950 void rpc_clnt_disconnect(struct rpc_clnt *clnt)
 951 {
 952         rpc_clnt_iterate_for_each_xprt(clnt, rpc_clnt_disconnect_xprt, NULL);
 953 }
 954 EXPORT_SYMBOL_GPL(rpc_clnt_disconnect);
 955
 956 /*
 957  * Properly shut down an RPC client, terminating all outstanding
 958  * requests.
 959  */
 960 void rpc_shutdown_client(struct rpc_clnt *clnt)
 961 {
 962         might_sleep();
 963
 964         trace_rpc_clnt_shutdown(clnt);
 965
 966         while (!list_empty(&clnt->cl_tasks)) {
 967                 rpc_killall_tasks(clnt);
 968                 wait_event_timeout(destroy_wait,
 969                         list_empty(&clnt->cl_tasks), 1*HZ);
 970         }
 971
 972         rpc_release_client(clnt);
 973 }
 974 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 975
 976 /*
 977  * Free an RPC client
 978  */
 979 static void rpc_free_client_work(struct work_struct *work)
 980 {
 981         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 982
 983         trace_rpc_clnt_free(clnt);
 984
 985         /* These might block on processes that might allocate memory,
 986          * so they cannot be called in rpciod, so they are handled separately
 987          * here.
 988          */
 989         rpc_sysfs_client_destroy(clnt);
 990         rpc_clnt_debugfs_unregister(clnt);
 991         rpc_free_clid(clnt);
 992         rpc_clnt_remove_pipedir(clnt);
 993         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 994
 995         kfree(clnt);
 996         rpciod_down();
 997 }
 998 static struct rpc_clnt *
 999 rpc_free_client(struct rpc_clnt *clnt)
1000 {
1001         struct rpc_clnt *parent = NULL;
1002
1003         trace_rpc_clnt_release(clnt);
1004         if (clnt->cl_parent != clnt)
1005                 parent = clnt->cl_parent;
1006         rpc_unregister_client(clnt);
1007         rpc_free_iostats(clnt->cl_metrics);
1008         clnt->cl_metrics = NULL;
1009         xprt_iter_destroy(&clnt->cl_xpi);
1010         put_cred(clnt->cl_cred);
1011
1012         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
1013         schedule_work(&clnt->cl_work);
1014         return parent;
1015 }
1016
1017 /*
1018  * Free an RPC client
1019  */
1020 static struct rpc_clnt *
1021 rpc_free_auth(struct rpc_clnt *clnt)
1022 {
1023         /*
1024          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
1025          *       release remaining GSS contexts. This mechanism ensures
1026          *       that it can do so safely.
1027          */
1028         if (clnt->cl_auth != NULL) {
1029                 rpcauth_release(clnt->cl_auth);
1030                 clnt->cl_auth = NULL;
1031         }
1032         if (refcount_dec_and_test(&clnt->cl_count))
1033                 return rpc_free_client(clnt);
1034         return NULL;
1035 }
1036
1037 /*
1038  * Release reference to the RPC client
1039  */
1040 void
1041 rpc_release_client(struct rpc_clnt *clnt)
1042 {
1043         do {
1044                 if (list_empty(&clnt->cl_tasks))
1045                         wake_up(&destroy_wait);
1046                 if (refcount_dec_not_one(&clnt->cl_count))
1047                         break;
1048                 clnt = rpc_free_auth(clnt);
1049         } while (clnt != NULL);
1050 }
1051 EXPORT_SYMBOL_GPL(rpc_release_client);
1052
1053 /**
1054  * rpc_bind_new_program - bind a new RPC program to an existing client
1055  * @old: old rpc_client
1056  * @program: rpc program to set
1057  * @vers: rpc program version
1058  *
1059  * Clones the rpc client and sets up a new RPC program. This is mainly
1060  * of use for enabling different RPC programs to share the same transport.
1061  * The Sun NFSv2/v3 ACL protocol can do this.
1062  */
1063 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
1064                                       const struct rpc_program *program,
1065                                       u32 vers)
1066 {
1067         struct rpc_create_args args = {
1068                 .program        = program,
1069                 .prognumber     = program->number,
1070                 .version        = vers,
1071                 .authflavor     = old->cl_auth->au_flavor,
1072                 .cred           = old->cl_cred,
1073                 .stats          = old->cl_stats,
1074         };
1075         struct rpc_clnt *clnt;
1076         int err;
1077
1078         clnt = __rpc_clone_client(&args, old);
1079         if (IS_ERR(clnt))
1080                 goto out;
1081         err = rpc_ping(clnt);
1082         if (err != 0) {
1083                 rpc_shutdown_client(clnt);
1084                 clnt = ERR_PTR(err);
1085         }
1086 out:
1087         return clnt;
1088 }
1089 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
1090
1091 struct rpc_xprt *
1092 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1093 {
1094         struct rpc_xprt_switch *xps;
1095
1096         if (!xprt)
1097                 return NULL;
1098         rcu_read_lock();
1099         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1100         atomic_long_inc(&xps->xps_queuelen);
1101         rcu_read_unlock();
1102         atomic_long_inc(&xprt->queuelen);
1103
1104         return xprt;
1105 }
1106
1107 static void
1108 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1109 {
1110         struct rpc_xprt_switch *xps;
1111
1112         atomic_long_dec(&xprt->queuelen);
1113         rcu_read_lock();
1114         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1115         atomic_long_dec(&xps->xps_queuelen);
1116         rcu_read_unlock();
1117
1118         xprt_put(xprt);
1119 }
1120
1121 void rpc_task_release_transport(struct rpc_task *task)
1122 {
1123         struct rpc_xprt *xprt = task->tk_xprt;
1124
1125         if (xprt) {
1126                 task->tk_xprt = NULL;
1127                 if (task->tk_client)
1128                         rpc_task_release_xprt(task->tk_client, xprt);
1129                 else
1130                         xprt_put(xprt);
1131         }
1132 }
1133 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1134
1135 void rpc_task_release_client(struct rpc_task *task)
1136 {
1137         struct rpc_clnt *clnt = task->tk_client;
1138
1139         rpc_task_release_transport(task);
1140         if (clnt != NULL) {
1141                 /* Remove from client task list */
1142                 spin_lock(&clnt->cl_lock);
1143                 list_del(&task->tk_task);
1144                 spin_unlock(&clnt->cl_lock);
1145                 task->tk_client = NULL;
1146
1147                 rpc_release_client(clnt);
1148         }
1149 }
1150
1151 static struct rpc_xprt *
1152 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1153 {
1154         struct rpc_xprt *xprt;
1155
1156         rcu_read_lock();
1157         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1158         rcu_read_unlock();
1159         return rpc_task_get_xprt(clnt, xprt);
1160 }
1161
1162 static struct rpc_xprt *
1163 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1164 {
1165         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1166 }
1167
1168 static
1169 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1170 {
1171         if (task->tk_xprt) {
1172                 if (!(test_bit(XPRT_OFFLINE, &task->tk_xprt->state) &&
1173                       (task->tk_flags & RPC_TASK_MOVEABLE)))
1174                         return;
1175                 xprt_release(task);
1176                 xprt_put(task->tk_xprt);
1177         }
1178         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1179                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1180         else
1181                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1182 }
1183
1184 static
1185 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1186 {
1187         rpc_task_set_transport(task, clnt);
1188         task->tk_client = clnt;
1189         refcount_inc(&clnt->cl_count);
1190         if (clnt->cl_softrtry)
1191                 task->tk_flags |= RPC_TASK_SOFT;
1192         if (clnt->cl_softerr)
1193                 task->tk_flags |= RPC_TASK_TIMEOUT;
1194         if (clnt->cl_noretranstimeo)
1195                 task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1196         /* Add to the client's list of all tasks */
1197         spin_lock(&clnt->cl_lock);
1198         list_add_tail(&task->tk_task, &clnt->cl_tasks);
1199         spin_unlock(&clnt->cl_lock);
1200 }
1201
1202 static void
1203 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1204 {
1205         if (msg != NULL) {
1206                 task->tk_msg.rpc_proc = msg->rpc_proc;
1207                 task->tk_msg.rpc_argp = msg->rpc_argp;
1208                 task->tk_msg.rpc_resp = msg->rpc_resp;
1209                 task->tk_msg.rpc_cred = msg->rpc_cred;
1210                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1211                         get_cred(task->tk_msg.rpc_cred);
1212         }
1213 }
1214
1215 /*
1216  * Default callback for async RPC calls
1217  */
1218 static void
1219 rpc_default_callback(struct rpc_task *task, void *data)
1220 {
1221 }
1222
1223 static const struct rpc_call_ops rpc_default_ops = {
1224         .rpc_call_done = rpc_default_callback,
1225 };
1226
1227 /**
1228  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1229  * @task_setup_data: pointer to task initialisation data
1230  */
1231 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1232 {
1233         struct rpc_task *task;
1234
1235         task = rpc_new_task(task_setup_data);
1236         if (IS_ERR(task))
1237                 return task;
1238
1239         if (!RPC_IS_ASYNC(task))
1240                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1241
1242         rpc_task_set_client(task, task_setup_data->rpc_client);
1243         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1244
1245         if (task->tk_action == NULL)
1246                 rpc_call_start(task);
1247
1248         atomic_inc(&task->tk_count);
1249         rpc_execute(task);
1250         return task;
1251 }
1252 EXPORT_SYMBOL_GPL(rpc_run_task);
1253
1254 /**
1255  * rpc_call_sync - Perform a synchronous RPC call
1256  * @clnt: pointer to RPC client
1257  * @msg: RPC call parameters
1258  * @flags: RPC call flags
1259  */
1260 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1261 {
1262         struct rpc_task *task;
1263         struct rpc_task_setup task_setup_data = {
1264                 .rpc_client = clnt,
1265                 .rpc_message = msg,
1266                 .callback_ops = &rpc_default_ops,
1267                 .flags = flags,
1268         };
1269         int status;
1270
1271         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1272         if (flags & RPC_TASK_ASYNC) {
1273                 rpc_release_calldata(task_setup_data.callback_ops,
1274                         task_setup_data.callback_data);
1275                 return -EINVAL;
1276         }
1277
1278         task = rpc_run_task(&task_setup_data);
1279         if (IS_ERR(task))
1280                 return PTR_ERR(task);
1281         status = task->tk_status;
1282         rpc_put_task(task);
1283         return status;
1284 }
1285 EXPORT_SYMBOL_GPL(rpc_call_sync);
1286
1287 /**
1288  * rpc_call_async - Perform an asynchronous RPC call
1289  * @clnt: pointer to RPC client
1290  * @msg: RPC call parameters
1291  * @flags: RPC call flags
1292  * @tk_ops: RPC call ops
1293  * @data: user call data
1294  */
1295 int
1296 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1297                const struct rpc_call_ops *tk_ops, void *data)
1298 {
1299         struct rpc_task *task;
1300         struct rpc_task_setup task_setup_data = {
1301                 .rpc_client = clnt,
1302                 .rpc_message = msg,
1303                 .callback_ops = tk_ops,
1304                 .callback_data = data,
1305                 .flags = flags|RPC_TASK_ASYNC,
1306         };
1307
1308         task = rpc_run_task(&task_setup_data);
1309         if (IS_ERR(task))
1310                 return PTR_ERR(task);
1311         rpc_put_task(task);
1312         return 0;
1313 }
1314 EXPORT_SYMBOL_GPL(rpc_call_async);
1315
1316 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1317 static void call_bc_encode(struct rpc_task *task);
1318
1319 /**
1320  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1321  * rpc_execute against it
1322  * @req: RPC request
1323  * @timeout: timeout values to use for this task
1324  */
1325 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req,
1326                 struct rpc_timeout *timeout)
1327 {
1328         struct rpc_task *task;
1329         struct rpc_task_setup task_setup_data = {
1330                 .callback_ops = &rpc_default_ops,
1331                 .flags = RPC_TASK_SOFTCONN |
1332                         RPC_TASK_NO_RETRANS_TIMEOUT,
1333         };
1334
1335         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1336         /*
1337          * Create an rpc_task to send the data
1338          */
1339         task = rpc_new_task(&task_setup_data);
1340         if (IS_ERR(task)) {
1341                 xprt_free_bc_request(req);
1342                 return task;
1343         }
1344
1345         xprt_init_bc_request(req, task, timeout);
1346
1347         task->tk_action = call_bc_encode;
1348         atomic_inc(&task->tk_count);
1349         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1350         rpc_execute(task);
1351
1352         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1353         return task;
1354 }
1355 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1356
1357 /**
1358  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1359  * @req: RPC request to prepare
1360  * @pages: vector of struct page pointers
1361  * @base: offset in first page where receive should start, in bytes
1362  * @len: expected size of the upper layer data payload, in bytes
1363  * @hdrsize: expected size of upper layer reply header, in XDR words
1364  *
1365  */
1366 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1367                              unsigned int base, unsigned int len,
1368                              unsigned int hdrsize)
1369 {
1370         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1371
1372         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1373         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1374 }
1375 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1376
1377 void
1378 rpc_call_start(struct rpc_task *task)
1379 {
1380         task->tk_action = call_start;
1381 }
1382 EXPORT_SYMBOL_GPL(rpc_call_start);
1383
1384 /**
1385  * rpc_peeraddr - extract remote peer address from clnt's xprt
1386  * @clnt: RPC client structure
1387  * @buf: target buffer
1388  * @bufsize: length of target buffer
1389  *
1390  * Returns the number of bytes that are actually in the stored address.
1391  */
1392 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1393 {
1394         size_t bytes;
1395         struct rpc_xprt *xprt;
1396
1397         rcu_read_lock();
1398         xprt = rcu_dereference(clnt->cl_xprt);
1399
1400         bytes = xprt->addrlen;
1401         if (bytes > bufsize)
1402                 bytes = bufsize;
1403         memcpy(buf, &xprt->addr, bytes);
1404         rcu_read_unlock();
1405
1406         return bytes;
1407 }
1408 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1409
1410 /**
1411  * rpc_peeraddr2str - return remote peer address in printable format
1412  * @clnt: RPC client structure
1413  * @format: address format
1414  *
1415  * NB: the lifetime of the memory referenced by the returned pointer is
1416  * the same as the rpc_xprt itself.  As long as the caller uses this
1417  * pointer, it must hold the RCU read lock.
1418  */
1419 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1420                              enum rpc_display_format_t format)
1421 {
1422         struct rpc_xprt *xprt;
1423
1424         xprt = rcu_dereference(clnt->cl_xprt);
1425
1426         if (xprt->address_strings[format] != NULL)
1427                 return xprt->address_strings[format];
1428         else
1429                 return "unprintable";
1430 }
1431 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1432
1433 static const struct sockaddr_in rpc_inaddr_loopback = {
1434         .sin_family             = AF_INET,
1435         .sin_addr.s_addr        = htonl(INADDR_ANY),
1436 };
1437
1438 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1439         .sin6_family            = AF_INET6,
1440         .sin6_addr              = IN6ADDR_ANY_INIT,
1441 };
1442
1443 /*
1444  * Try a getsockname() on a connected datagram socket.  Using a
1445  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1446  * This conserves the ephemeral port number space.
1447  *
1448  * Returns zero and fills in "buf" if successful; otherwise, a
1449  * negative errno is returned.
1450  */
1451 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1452                         struct sockaddr *buf)
1453 {
1454         struct socket *sock;
1455         int err;
1456
1457         err = __sock_create(net, sap->sa_family,
1458                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1459         if (err < 0) {
1460                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1461                 goto out;
1462         }
1463
1464         switch (sap->sa_family) {
1465         case AF_INET:
1466                 err = kernel_bind(sock,
1467                                 (struct sockaddr *)&rpc_inaddr_loopback,
1468                                 sizeof(rpc_inaddr_loopback));
1469                 break;
1470         case AF_INET6:
1471                 err = kernel_bind(sock,
1472                                 (struct sockaddr *)&rpc_in6addr_loopback,
1473                                 sizeof(rpc_in6addr_loopback));
1474                 break;
1475         default:
1476                 err = -EAFNOSUPPORT;
1477                 goto out_release;
1478         }
1479         if (err < 0) {
1480                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1481                 goto out_release;
1482         }
1483
1484         err = kernel_connect(sock, sap, salen, 0);
1485         if (err < 0) {
1486                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1487                 goto out_release;
1488         }
1489
1490         err = kernel_getsockname(sock, buf);
1491         if (err < 0) {
1492                 dprintk("RPC:       getsockname failed (%d)\n", err);
1493                 goto out_release;
1494         }
1495
1496         err = 0;
1497         if (buf->sa_family == AF_INET6) {
1498                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1499                 sin6->sin6_scope_id = 0;
1500         }
1501         dprintk("RPC:       %s succeeded\n", __func__);
1502
1503 out_release:
1504         sock_release(sock);
1505 out:
1506         return err;
1507 }
1508
1509 /*
1510  * Scraping a connected socket failed, so we don't have a useable
1511  * local address.  Fallback: generate an address that will prevent
1512  * the server from calling us back.
1513  *
1514  * Returns zero and fills in "buf" if successful; otherwise, a
1515  * negative errno is returned.
1516  */
1517 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1518 {
1519         switch (family) {
1520         case AF_INET:
1521                 if (buflen < sizeof(rpc_inaddr_loopback))
1522                         return -EINVAL;
1523                 memcpy(buf, &rpc_inaddr_loopback,
1524                                 sizeof(rpc_inaddr_loopback));
1525                 break;
1526         case AF_INET6:
1527                 if (buflen < sizeof(rpc_in6addr_loopback))
1528                         return -EINVAL;
1529                 memcpy(buf, &rpc_in6addr_loopback,
1530                                 sizeof(rpc_in6addr_loopback));
1531                 break;
1532         default:
1533                 dprintk("RPC:       %s: address family not supported\n",
1534                         __func__);
1535                 return -EAFNOSUPPORT;
1536         }
1537         dprintk("RPC:       %s: succeeded\n", __func__);
1538         return 0;
1539 }
1540
1541 /**
1542  * rpc_localaddr - discover local endpoint address for an RPC client
1543  * @clnt: RPC client structure
1544  * @buf: target buffer
1545  * @buflen: size of target buffer, in bytes
1546  *
1547  * Returns zero and fills in "buf" and "buflen" if successful;
1548  * otherwise, a negative errno is returned.
1549  *
1550  * This works even if the underlying transport is not currently connected,
1551  * or if the upper layer never previously provided a source address.
1552  *
1553  * The result of this function call is transient: multiple calls in
1554  * succession may give different results, depending on how local
1555  * networking configuration changes over time.
1556  */
1557 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1558 {
1559         struct sockaddr_storage address;
1560         struct sockaddr *sap = (struct sockaddr *)&address;
1561         struct rpc_xprt *xprt;
1562         struct net *net;
1563         size_t salen;
1564         int err;
1565
1566         rcu_read_lock();
1567         xprt = rcu_dereference(clnt->cl_xprt);
1568         salen = xprt->addrlen;
1569         memcpy(sap, &xprt->addr, salen);
1570         net = get_net(xprt->xprt_net);
1571         rcu_read_unlock();
1572
1573         rpc_set_port(sap, 0);
1574         err = rpc_sockname(net, sap, salen, buf);
1575         put_net(net);
1576         if (err != 0)
1577                 /* Couldn't discover local address, return ANYADDR */
1578                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1579         return 0;
1580 }
1581 EXPORT_SYMBOL_GPL(rpc_localaddr);
1582
1583 void
1584 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1585 {
1586         struct rpc_xprt *xprt;
1587
1588         rcu_read_lock();
1589         xprt = rcu_dereference(clnt->cl_xprt);
1590         if (xprt->ops->set_buffer_size)
1591                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1592         rcu_read_unlock();
1593 }
1594 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1595
1596 /**
1597  * rpc_net_ns - Get the network namespace for this RPC client
1598  * @clnt: RPC client to query
1599  *
1600  */
1601 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1602 {
1603         struct net *ret;
1604
1605         rcu_read_lock();
1606         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1607         rcu_read_unlock();
1608         return ret;
1609 }
1610 EXPORT_SYMBOL_GPL(rpc_net_ns);
1611
1612 /**
1613  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1614  * @clnt: RPC client to query
1615  *
1616  * For stream transports, this is one RPC record fragment (see RFC
1617  * 1831), as we don't support multi-record requests yet.  For datagram
1618  * transports, this is the size of an IP packet minus the IP, UDP, and
1619  * RPC header sizes.
1620  */
1621 size_t rpc_max_payload(struct rpc_clnt *clnt)
1622 {
1623         size_t ret;
1624
1625         rcu_read_lock();
1626         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1627         rcu_read_unlock();
1628         return ret;
1629 }
1630 EXPORT_SYMBOL_GPL(rpc_max_payload);
1631
1632 /**
1633  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1634  * @clnt: RPC client to query
1635  */
1636 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1637 {
1638         struct rpc_xprt *xprt;
1639         size_t ret;
1640
1641         rcu_read_lock();
1642         xprt = rcu_dereference(clnt->cl_xprt);
1643         ret = xprt->ops->bc_maxpayload(xprt);
1644         rcu_read_unlock();
1645         return ret;
1646 }
1647 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1648
1649 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1650 {
1651         struct rpc_xprt *xprt;
1652         unsigned int ret;
1653
1654         rcu_read_lock();
1655         xprt = rcu_dereference(clnt->cl_xprt);
1656         ret = xprt->ops->bc_num_slots(xprt);
1657         rcu_read_unlock();
1658         return ret;
1659 }
1660 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1661
1662 /**
1663  * rpc_force_rebind - force transport to check that remote port is unchanged
1664  * @clnt: client to rebind
1665  *
1666  */
1667 void rpc_force_rebind(struct rpc_clnt *clnt)
1668 {
1669         if (clnt->cl_autobind) {
1670                 rcu_read_lock();
1671                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1672                 rcu_read_unlock();
1673         }
1674 }
1675 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1676
1677 static int
1678 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1679 {
1680         task->tk_status = 0;
1681         task->tk_rpc_status = 0;
1682         task->tk_action = action;
1683         return 1;
1684 }
1685
1686 /*
1687  * Restart an (async) RPC call. Usually called from within the
1688  * exit handler.
1689  */
1690 int
1691 rpc_restart_call(struct rpc_task *task)
1692 {
1693         return __rpc_restart_call(task, call_start);
1694 }
1695 EXPORT_SYMBOL_GPL(rpc_restart_call);
1696
1697 /*
1698  * Restart an (async) RPC call from the call_prepare state.
1699  * Usually called from within the exit handler.
1700  */
1701 int
1702 rpc_restart_call_prepare(struct rpc_task *task)
1703 {
1704         if (task->tk_ops->rpc_call_prepare != NULL)
1705                 return __rpc_restart_call(task, rpc_prepare_task);
1706         return rpc_restart_call(task);
1707 }
1708 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1709
1710 const char
1711 *rpc_proc_name(const struct rpc_task *task)
1712 {
1713         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1714
1715         if (proc) {
1716                 if (proc->p_name)
1717                         return proc->p_name;
1718                 else
1719                         return "NULL";
1720         } else
1721                 return "no proc";
1722 }
1723
1724 static void
1725 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1726 {
1727         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1728         rpc_task_set_rpc_status(task, rpc_status);
1729         rpc_exit(task, tk_status);
1730 }
1731
1732 static void
1733 rpc_call_rpcerror(struct rpc_task *task, int status)
1734 {
1735         __rpc_call_rpcerror(task, status, status);
1736 }
1737
1738 /*
1739  * 0.  Initial state
1740  *
1741  *     Other FSM states can be visited zero or more times, but
1742  *     this state is visited exactly once for each RPC.
1743  */
1744 static void
1745 call_start(struct rpc_task *task)
1746 {
1747         struct rpc_clnt *clnt = task->tk_client;
1748         int idx = task->tk_msg.rpc_proc->p_statidx;
1749
1750         trace_rpc_request(task);
1751
1752         if (task->tk_client->cl_shutdown) {
1753                 rpc_call_rpcerror(task, -EIO);
1754                 return;
1755         }
1756
1757         /* Increment call count (version might not be valid for ping) */
1758         if (clnt->cl_program->version[clnt->cl_vers])
1759                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1760         clnt->cl_stats->rpccnt++;
1761         task->tk_action = call_reserve;
1762         rpc_task_set_transport(task, clnt);
1763 }
1764
1765 /*
1766  * 1.   Reserve an RPC call slot
1767  */
1768 static void
1769 call_reserve(struct rpc_task *task)
1770 {
1771         task->tk_status  = 0;
1772         task->tk_action  = call_reserveresult;
1773         xprt_reserve(task);
1774 }
1775
1776 static void call_retry_reserve(struct rpc_task *task);
1777
1778 /*
1779  * 1b.  Grok the result of xprt_reserve()
1780  */
1781 static void
1782 call_reserveresult(struct rpc_task *task)
1783 {
1784         int status = task->tk_status;
1785
1786         /*
1787          * After a call to xprt_reserve(), we must have either
1788          * a request slot or else an error status.
1789          */
1790         task->tk_status = 0;
1791         if (status >= 0) {
1792                 if (task->tk_rqstp) {
1793                         task->tk_action = call_refresh;
1794                         return;
1795                 }
1796
1797                 rpc_call_rpcerror(task, -EIO);
1798                 return;
1799         }
1800
1801         switch (status) {
1802         case -ENOMEM:
1803                 rpc_delay(task, HZ >> 2);
1804                 fallthrough;
1805         case -EAGAIN:   /* woken up; retry */
1806                 task->tk_action = call_retry_reserve;
1807                 return;
1808         default:
1809                 rpc_call_rpcerror(task, status);
1810         }
1811 }
1812
1813 /*
1814  * 1c.  Retry reserving an RPC call slot
1815  */
1816 static void
1817 call_retry_reserve(struct rpc_task *task)
1818 {
1819         task->tk_status  = 0;
1820         task->tk_action  = call_reserveresult;
1821         xprt_retry_reserve(task);
1822 }
1823
1824 /*
1825  * 2.   Bind and/or refresh the credentials
1826  */
1827 static void
1828 call_refresh(struct rpc_task *task)
1829 {
1830         task->tk_action = call_refreshresult;
1831         task->tk_status = 0;
1832         task->tk_client->cl_stats->rpcauthrefresh++;
1833         rpcauth_refreshcred(task);
1834 }
1835
1836 /*
1837  * 2a.  Process the results of a credential refresh
1838  */
1839 static void
1840 call_refreshresult(struct rpc_task *task)
1841 {
1842         int status = task->tk_status;
1843
1844         task->tk_status = 0;
1845         task->tk_action = call_refresh;
1846         switch (status) {
1847         case 0:
1848                 if (rpcauth_uptodatecred(task)) {
1849                         task->tk_action = call_allocate;
1850                         return;
1851                 }
1852                 /* Use rate-limiting and a max number of retries if refresh
1853                  * had status 0 but failed to update the cred.
1854                  */
1855                 fallthrough;
1856         case -ETIMEDOUT:
1857                 rpc_delay(task, 3*HZ);
1858                 fallthrough;
1859         case -EAGAIN:
1860                 status = -EACCES;
1861                 fallthrough;
1862         case -EKEYEXPIRED:
1863                 if (!task->tk_cred_retry)
1864                         break;
1865                 task->tk_cred_retry--;
1866                 trace_rpc_retry_refresh_status(task);
1867                 return;
1868         case -ENOMEM:
1869                 rpc_delay(task, HZ >> 4);
1870                 return;
1871         }
1872         trace_rpc_refresh_status(task);
1873         rpc_call_rpcerror(task, status);
1874 }
1875
1876 /*
1877  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1878  *      (Note: buffer memory is freed in xprt_release).
1879  */
1880 static void
1881 call_allocate(struct rpc_task *task)
1882 {
1883         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1884         struct rpc_rqst *req = task->tk_rqstp;
1885         struct rpc_xprt *xprt = req->rq_xprt;
1886         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1887         int status;
1888
1889         task->tk_status = 0;
1890         task->tk_action = call_encode;
1891
1892         if (req->rq_buffer)
1893                 return;
1894
1895         if (proc->p_proc != 0) {
1896                 BUG_ON(proc->p_arglen == 0);
1897                 if (proc->p_decode != NULL)
1898                         BUG_ON(proc->p_replen == 0);
1899         }
1900
1901         /*
1902          * Calculate the size (in quads) of the RPC call
1903          * and reply headers, and convert both values
1904          * to byte sizes.
1905          */
1906         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1907                            proc->p_arglen;
1908         req->rq_callsize <<= 2;
1909         /*
1910          * Note: the reply buffer must at minimum allocate enough space
1911          * for the 'struct accepted_reply' from RFC5531.
1912          */
1913         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1914                         max_t(size_t, proc->p_replen, 2);
1915         req->rq_rcvsize <<= 2;
1916
1917         status = xprt->ops->buf_alloc(task);
1918         trace_rpc_buf_alloc(task, status);
1919         if (status == 0)
1920                 return;
1921         if (status != -ENOMEM) {
1922                 rpc_call_rpcerror(task, status);
1923                 return;
1924         }
1925
1926         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1927                 task->tk_action = call_allocate;
1928                 rpc_delay(task, HZ>>4);
1929                 return;
1930         }
1931
1932         rpc_call_rpcerror(task, -ERESTARTSYS);
1933 }
1934
1935 static int
1936 rpc_task_need_encode(struct rpc_task *task)
1937 {
1938         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1939                 (!(task->tk_flags & RPC_TASK_SENT) ||
1940                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1941                  xprt_request_need_retransmit(task));
1942 }
1943
1944 static void
1945 rpc_xdr_encode(struct rpc_task *task)
1946 {
1947         struct rpc_rqst *req = task->tk_rqstp;
1948         struct xdr_stream xdr;
1949
1950         xdr_buf_init(&req->rq_snd_buf,
1951                      req->rq_buffer,
1952                      req->rq_callsize);
1953         xdr_buf_init(&req->rq_rcv_buf,
1954                      req->rq_rbuffer,
1955                      req->rq_rcvsize);
1956
1957         req->rq_reply_bytes_recvd = 0;
1958         req->rq_snd_buf.head[0].iov_len = 0;
1959         xdr_init_encode(&xdr, &req->rq_snd_buf,
1960                         req->rq_snd_buf.head[0].iov_base, req);
1961         if (rpc_encode_header(task, &xdr))
1962                 return;
1963
1964         task->tk_status = rpcauth_wrap_req(task, &xdr);
1965 }
1966
1967 /*
1968  * 3.   Encode arguments of an RPC call
1969  */
1970 static void
1971 call_encode(struct rpc_task *task)
1972 {
1973         if (!rpc_task_need_encode(task))
1974                 goto out;
1975
1976         /* Dequeue task from the receive queue while we're encoding */
1977         xprt_request_dequeue_xprt(task);
1978         /* Encode here so that rpcsec_gss can use correct sequence number. */
1979         rpc_xdr_encode(task);
1980         /* Add task to reply queue before transmission to avoid races */
1981         if (task->tk_status == 0 && rpc_reply_expected(task))
1982                 task->tk_status = xprt_request_enqueue_receive(task);
1983         /* Did the encode result in an error condition? */
1984         if (task->tk_status != 0) {
1985                 /* Was the error nonfatal? */
1986                 switch (task->tk_status) {
1987                 case -EAGAIN:
1988                 case -ENOMEM:
1989                         rpc_delay(task, HZ >> 4);
1990                         break;
1991                 case -EKEYEXPIRED:
1992                         if (!task->tk_cred_retry) {
1993                                 rpc_call_rpcerror(task, task->tk_status);
1994                         } else {
1995                                 task->tk_action = call_refresh;
1996                                 task->tk_cred_retry--;
1997                                 trace_rpc_retry_refresh_status(task);
1998                         }
1999                         break;
2000                 default:
2001                         rpc_call_rpcerror(task, task->tk_status);
2002                 }
2003                 return;
2004         }
2005
2006         xprt_request_enqueue_transmit(task);
2007 out:
2008         task->tk_action = call_transmit;
2009         /* Check that the connection is OK */
2010         if (!xprt_bound(task->tk_xprt))
2011                 task->tk_action = call_bind;
2012         else if (!xprt_connected(task->tk_xprt))
2013                 task->tk_action = call_connect;
2014 }
2015
2016 /*
2017  * Helpers to check if the task was already transmitted, and
2018  * to take action when that is the case.
2019  */
2020 static bool
2021 rpc_task_transmitted(struct rpc_task *task)
2022 {
2023         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
2024 }
2025
2026 static void
2027 rpc_task_handle_transmitted(struct rpc_task *task)
2028 {
2029         xprt_end_transmit(task);
2030         task->tk_action = call_transmit_status;
2031 }
2032
2033 /*
2034  * 4.   Get the server port number if not yet set
2035  */
2036 static void
2037 call_bind(struct rpc_task *task)
2038 {
2039         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2040
2041         if (rpc_task_transmitted(task)) {
2042                 rpc_task_handle_transmitted(task);
2043                 return;
2044         }
2045
2046         if (xprt_bound(xprt)) {
2047                 task->tk_action = call_connect;
2048                 return;
2049         }
2050
2051         task->tk_action = call_bind_status;
2052         if (!xprt_prepare_transmit(task))
2053                 return;
2054
2055         xprt->ops->rpcbind(task);
2056 }
2057
2058 /*
2059  * 4a.  Sort out bind result
2060  */
2061 static void
2062 call_bind_status(struct rpc_task *task)
2063 {
2064         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2065         int status = -EIO;
2066
2067         if (rpc_task_transmitted(task)) {
2068                 rpc_task_handle_transmitted(task);
2069                 return;
2070         }
2071
2072         if (task->tk_status >= 0)
2073                 goto out_next;
2074         if (xprt_bound(xprt)) {
2075                 task->tk_status = 0;
2076                 goto out_next;
2077         }
2078
2079         switch (task->tk_status) {
2080         case -ENOMEM:
2081                 rpc_delay(task, HZ >> 2);
2082                 goto retry_timeout;
2083         case -EACCES:
2084                 trace_rpcb_prog_unavail_err(task);
2085                 /* fail immediately if this is an RPC ping */
2086                 if (task->tk_msg.rpc_proc->p_proc == 0) {
2087                         status = -EOPNOTSUPP;
2088                         break;
2089                 }
2090                 rpc_delay(task, 3*HZ);
2091                 goto retry_timeout;
2092         case -ENOBUFS:
2093                 rpc_delay(task, HZ >> 2);
2094                 goto retry_timeout;
2095         case -EAGAIN:
2096                 goto retry_timeout;
2097         case -ETIMEDOUT:
2098                 trace_rpcb_timeout_err(task);
2099                 goto retry_timeout;
2100         case -EPFNOSUPPORT:
2101                 /* server doesn't support any rpcbind version we know of */
2102                 trace_rpcb_bind_version_err(task);
2103                 break;
2104         case -EPROTONOSUPPORT:
2105                 trace_rpcb_bind_version_err(task);
2106                 goto retry_timeout;
2107         case -ECONNREFUSED:             /* connection problems */
2108         case -ECONNRESET:
2109         case -ECONNABORTED:
2110         case -ENOTCONN:
2111         case -EHOSTDOWN:
2112         case -ENETDOWN:
2113         case -EHOSTUNREACH:
2114         case -ENETUNREACH:
2115         case -EPIPE:
2116                 trace_rpcb_unreachable_err(task);
2117                 if (!RPC_IS_SOFTCONN(task)) {
2118                         rpc_delay(task, 5*HZ);
2119                         goto retry_timeout;
2120                 }
2121                 status = task->tk_status;
2122                 break;
2123         default:
2124                 trace_rpcb_unrecognized_err(task);
2125         }
2126
2127         rpc_call_rpcerror(task, status);
2128         return;
2129 out_next:
2130         task->tk_action = call_connect;
2131         return;
2132 retry_timeout:
2133         task->tk_status = 0;
2134         task->tk_action = call_bind;
2135         rpc_check_timeout(task);
2136 }
2137
2138 /*
2139  * 4b.  Connect to the RPC server
2140  */
2141 static void
2142 call_connect(struct rpc_task *task)
2143 {
2144         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2145
2146         if (rpc_task_transmitted(task)) {
2147                 rpc_task_handle_transmitted(task);
2148                 return;
2149         }
2150
2151         if (xprt_connected(xprt)) {
2152                 task->tk_action = call_transmit;
2153                 return;
2154         }
2155
2156         task->tk_action = call_connect_status;
2157         if (task->tk_status < 0)
2158                 return;
2159         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2160                 rpc_call_rpcerror(task, -ENOTCONN);
2161                 return;
2162         }
2163         if (!xprt_prepare_transmit(task))
2164                 return;
2165         xprt_connect(task);
2166 }
2167
2168 /*
2169  * 4c.  Sort out connect result
2170  */
2171 static void
2172 call_connect_status(struct rpc_task *task)
2173 {
2174         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2175         struct rpc_clnt *clnt = task->tk_client;
2176         int status = task->tk_status;
2177
2178         if (rpc_task_transmitted(task)) {
2179                 rpc_task_handle_transmitted(task);
2180                 return;
2181         }
2182
2183         trace_rpc_connect_status(task);
2184
2185         if (task->tk_status == 0) {
2186                 clnt->cl_stats->netreconn++;
2187                 goto out_next;
2188         }
2189         if (xprt_connected(xprt)) {
2190                 task->tk_status = 0;
2191                 goto out_next;
2192         }
2193
2194         task->tk_status = 0;
2195         switch (status) {
2196         case -ECONNREFUSED:
2197         case -ECONNRESET:
2198                 /* A positive refusal suggests a rebind is needed. */
2199                 if (RPC_IS_SOFTCONN(task))
2200                         break;
2201                 if (clnt->cl_autobind) {
2202                         rpc_force_rebind(clnt);
2203                         goto out_retry;
2204                 }
2205                 fallthrough;
2206         case -ECONNABORTED:
2207         case -ENETDOWN:
2208         case -ENETUNREACH:
2209         case -EHOSTUNREACH:
2210         case -EPIPE:
2211         case -EPROTO:
2212                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2213                                             task->tk_rqstp->rq_connect_cookie);
2214                 if (RPC_IS_SOFTCONN(task))
2215                         break;
2216                 /* retry with existing socket, after a delay */
2217                 rpc_delay(task, 3*HZ);
2218                 fallthrough;
2219         case -EADDRINUSE:
2220         case -ENOTCONN:
2221         case -EAGAIN:
2222         case -ETIMEDOUT:
2223                 if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
2224                     (task->tk_flags & RPC_TASK_MOVEABLE) &&
2225                     test_bit(XPRT_REMOVE, &xprt->state)) {
2226                         struct rpc_xprt *saved = task->tk_xprt;
2227                         struct rpc_xprt_switch *xps;
2228
2229                         xps = rpc_clnt_xprt_switch_get(clnt);
2230                         if (xps->xps_nxprts > 1) {
2231                                 long value;
2232
2233                                 xprt_release(task);
2234                                 value = atomic_long_dec_return(&xprt->queuelen);
2235                                 if (value == 0)
2236                                         rpc_xprt_switch_remove_xprt(xps, saved,
2237                                                                     true);
2238                                 xprt_put(saved);
2239                                 task->tk_xprt = NULL;
2240                                 task->tk_action = call_start;
2241                         }
2242                         xprt_switch_put(xps);
2243                         if (!task->tk_xprt)
2244                                 goto out;
2245                 }
2246                 goto out_retry;
2247         case -ENOBUFS:
2248                 rpc_delay(task, HZ >> 2);
2249                 goto out_retry;
2250         }
2251         rpc_call_rpcerror(task, status);
2252         return;
2253 out_next:
2254         task->tk_action = call_transmit;
2255         return;
2256 out_retry:
2257         /* Check for timeouts before looping back to call_bind */
2258         task->tk_action = call_bind;
2259 out:
2260         rpc_check_timeout(task);
2261 }
2262
2263 /*
2264  * 5.   Transmit the RPC request, and wait for reply
2265  */
2266 static void
2267 call_transmit(struct rpc_task *task)
2268 {
2269         if (rpc_task_transmitted(task)) {
2270                 rpc_task_handle_transmitted(task);
2271                 return;
2272         }
2273
2274         task->tk_action = call_transmit_status;
2275         if (!xprt_prepare_transmit(task))
2276                 return;
2277         task->tk_status = 0;
2278         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2279                 if (!xprt_connected(task->tk_xprt)) {
2280                         task->tk_status = -ENOTCONN;
2281                         return;
2282                 }
2283                 xprt_transmit(task);
2284         }
2285         xprt_end_transmit(task);
2286 }
2287
2288 /*
2289  * 5a.  Handle cleanup after a transmission
2290  */
2291 static void
2292 call_transmit_status(struct rpc_task *task)
2293 {
2294         task->tk_action = call_status;
2295
2296         /*
2297          * Common case: success.  Force the compiler to put this
2298          * test first.
2299          */
2300         if (rpc_task_transmitted(task)) {
2301                 task->tk_status = 0;
2302                 xprt_request_wait_receive(task);
2303                 return;
2304         }
2305
2306         switch (task->tk_status) {
2307         default:
2308                 break;
2309         case -EBADMSG:
2310                 task->tk_status = 0;
2311                 task->tk_action = call_encode;
2312                 break;
2313                 /*
2314                  * Special cases: if we've been waiting on the
2315                  * socket's write_space() callback, or if the
2316                  * socket just returned a connection error,
2317                  * then hold onto the transport lock.
2318                  */
2319         case -ENOMEM:
2320         case -ENOBUFS:
2321                 rpc_delay(task, HZ>>2);
2322                 fallthrough;
2323         case -EBADSLT:
2324         case -EAGAIN:
2325                 task->tk_action = call_transmit;
2326                 task->tk_status = 0;
2327                 break;
2328         case -ECONNREFUSED:
2329         case -EHOSTDOWN:
2330         case -ENETDOWN:
2331         case -EHOSTUNREACH:
2332         case -ENETUNREACH:
2333         case -EPERM:
2334                 if (RPC_IS_SOFTCONN(task)) {
2335                         if (!task->tk_msg.rpc_proc->p_proc)
2336                                 trace_xprt_ping(task->tk_xprt,
2337                                                 task->tk_status);
2338                         rpc_call_rpcerror(task, task->tk_status);
2339                         return;
2340                 }
2341                 fallthrough;
2342         case -ECONNRESET:
2343         case -ECONNABORTED:
2344         case -EADDRINUSE:
2345         case -ENOTCONN:
2346         case -EPIPE:
2347                 task->tk_action = call_bind;
2348                 task->tk_status = 0;
2349                 break;
2350         }
2351         rpc_check_timeout(task);
2352 }
2353
2354 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2355 static void call_bc_transmit(struct rpc_task *task);
2356 static void call_bc_transmit_status(struct rpc_task *task);
2357
2358 static void
2359 call_bc_encode(struct rpc_task *task)
2360 {
2361         xprt_request_enqueue_transmit(task);
2362         task->tk_action = call_bc_transmit;
2363 }
2364
2365 /*
2366  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2367  * addition, disconnect on connectivity errors.
2368  */
2369 static void
2370 call_bc_transmit(struct rpc_task *task)
2371 {
2372         task->tk_action = call_bc_transmit_status;
2373         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2374                 if (!xprt_prepare_transmit(task))
2375                         return;
2376                 task->tk_status = 0;
2377                 xprt_transmit(task);
2378         }
2379         xprt_end_transmit(task);
2380 }
2381
2382 static void
2383 call_bc_transmit_status(struct rpc_task *task)
2384 {
2385         struct rpc_rqst *req = task->tk_rqstp;
2386
2387         if (rpc_task_transmitted(task))
2388                 task->tk_status = 0;
2389
2390         switch (task->tk_status) {
2391         case 0:
2392                 /* Success */
2393         case -ENETDOWN:
2394         case -EHOSTDOWN:
2395         case -EHOSTUNREACH:
2396         case -ENETUNREACH:
2397         case -ECONNRESET:
2398         case -ECONNREFUSED:
2399         case -EADDRINUSE:
2400         case -ENOTCONN:
2401         case -EPIPE:
2402                 break;
2403         case -ENOMEM:
2404         case -ENOBUFS:
2405                 rpc_delay(task, HZ>>2);
2406                 fallthrough;
2407         case -EBADSLT:
2408         case -EAGAIN:
2409                 task->tk_status = 0;
2410                 task->tk_action = call_bc_transmit;
2411                 return;
2412         case -ETIMEDOUT:
2413                 /*
2414                  * Problem reaching the server.  Disconnect and let the
2415                  * forechannel reestablish the connection.  The server will
2416                  * have to retransmit the backchannel request and we'll
2417                  * reprocess it.  Since these ops are idempotent, there's no
2418                  * need to cache our reply at this time.
2419                  */
2420                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2421                         "error: %d\n", task->tk_status);
2422                 xprt_conditional_disconnect(req->rq_xprt,
2423                         req->rq_connect_cookie);
2424                 break;
2425         default:
2426                 /*
2427                  * We were unable to reply and will have to drop the
2428                  * request.  The server should reconnect and retransmit.
2429                  */
2430                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2431                         "error: %d\n", task->tk_status);
2432                 break;
2433         }
2434         task->tk_action = rpc_exit_task;
2435 }
2436 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2437
2438 /*
2439  * 6.   Sort out the RPC call status
2440  */
2441 static void
2442 call_status(struct rpc_task *task)
2443 {
2444         struct rpc_clnt *clnt = task->tk_client;
2445         int             status;
2446
2447         if (!task->tk_msg.rpc_proc->p_proc)
2448                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2449
2450         status = task->tk_status;
2451         if (status >= 0) {
2452                 task->tk_action = call_decode;
2453                 return;
2454         }
2455
2456         trace_rpc_call_status(task);
2457         task->tk_status = 0;
2458         switch(status) {
2459         case -EHOSTDOWN:
2460         case -ENETDOWN:
2461         case -EHOSTUNREACH:
2462         case -ENETUNREACH:
2463         case -EPERM:
2464                 if (RPC_IS_SOFTCONN(task))
2465                         goto out_exit;
2466                 /*
2467                  * Delay any retries for 3 seconds, then handle as if it
2468                  * were a timeout.
2469                  */
2470                 rpc_delay(task, 3*HZ);
2471                 fallthrough;
2472         case -ETIMEDOUT:
2473                 break;
2474         case -ECONNREFUSED:
2475         case -ECONNRESET:
2476         case -ECONNABORTED:
2477         case -ENOTCONN:
2478                 rpc_force_rebind(clnt);
2479                 break;
2480         case -EADDRINUSE:
2481                 rpc_delay(task, 3*HZ);
2482                 fallthrough;
2483         case -EPIPE:
2484         case -EAGAIN:
2485                 break;
2486         case -ENFILE:
2487         case -ENOBUFS:
2488         case -ENOMEM:
2489                 rpc_delay(task, HZ>>2);
2490                 break;
2491         case -EIO:
2492                 /* shutdown or soft timeout */
2493                 goto out_exit;
2494         default:
2495                 if (clnt->cl_chatty)
2496                         printk("%s: RPC call returned error %d\n",
2497                                clnt->cl_program->name, -status);
2498                 goto out_exit;
2499         }
2500         task->tk_action = call_encode;
2501         rpc_check_timeout(task);
2502         return;
2503 out_exit:
2504         rpc_call_rpcerror(task, status);
2505 }
2506
2507 static bool
2508 rpc_check_connected(const struct rpc_rqst *req)
2509 {
2510         /* No allocated request or transport? return true */
2511         if (!req || !req->rq_xprt)
2512                 return true;
2513         return xprt_connected(req->rq_xprt);
2514 }
2515
2516 static void
2517 rpc_check_timeout(struct rpc_task *task)
2518 {
2519         struct rpc_clnt *clnt = task->tk_client;
2520
2521         if (RPC_SIGNALLED(task))
2522                 return;
2523
2524         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2525                 return;
2526
2527         trace_rpc_timeout_status(task);
2528         task->tk_timeouts++;
2529
2530         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2531                 rpc_call_rpcerror(task, -ETIMEDOUT);
2532                 return;
2533         }
2534
2535         if (RPC_IS_SOFT(task)) {
2536                 /*
2537                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2538                  * been sent, it should time out only if the transport
2539                  * connection gets terminally broken.
2540                  */
2541                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2542                     rpc_check_connected(task->tk_rqstp))
2543                         return;
2544
2545                 if (clnt->cl_chatty) {
2546                         pr_notice_ratelimited(
2547                                 "%s: server %s not responding, timed out\n",
2548                                 clnt->cl_program->name,
2549                                 task->tk_xprt->servername);
2550                 }
2551                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2552                         rpc_call_rpcerror(task, -ETIMEDOUT);
2553                 else
2554                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2555                 return;
2556         }
2557
2558         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2559                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2560                 if (clnt->cl_chatty) {
2561                         pr_notice_ratelimited(
2562                                 "%s: server %s not responding, still trying\n",
2563                                 clnt->cl_program->name,
2564                                 task->tk_xprt->servername);
2565                 }
2566         }
2567         rpc_force_rebind(clnt);
2568         /*
2569          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2570          * event? RFC2203 requires the server to drop all such requests.
2571          */
2572         rpcauth_invalcred(task);
2573 }
2574
2575 /*
2576  * 7.   Decode the RPC reply
2577  */
2578 static void
2579 call_decode(struct rpc_task *task)
2580 {
2581         struct rpc_clnt *clnt = task->tk_client;
2582         struct rpc_rqst *req = task->tk_rqstp;
2583         struct xdr_stream xdr;
2584         int err;
2585
2586         if (!task->tk_msg.rpc_proc->p_decode) {
2587                 task->tk_action = rpc_exit_task;
2588                 return;
2589         }
2590
2591         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2592                 if (clnt->cl_chatty) {
2593                         pr_notice_ratelimited("%s: server %s OK\n",
2594                                 clnt->cl_program->name,
2595                                 task->tk_xprt->servername);
2596                 }
2597                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2598         }
2599
2600         /*
2601          * Did we ever call xprt_complete_rqst()? If not, we should assume
2602          * the message is incomplete.
2603          */
2604         err = -EAGAIN;
2605         if (!req->rq_reply_bytes_recvd)
2606                 goto out;
2607
2608         /* Ensure that we see all writes made by xprt_complete_rqst()
2609          * before it changed req->rq_reply_bytes_recvd.
2610          */
2611         smp_rmb();
2612
2613         req->rq_rcv_buf.len = req->rq_private_buf.len;
2614         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2615
2616         /* Check that the softirq receive buffer is valid */
2617         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2618                                 sizeof(req->rq_rcv_buf)) != 0);
2619
2620         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2621                         req->rq_rcv_buf.head[0].iov_base, req);
2622         err = rpc_decode_header(task, &xdr);
2623 out:
2624         switch (err) {
2625         case 0:
2626                 task->tk_action = rpc_exit_task;
2627                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2628                 xdr_finish_decode(&xdr);
2629                 return;
2630         case -EAGAIN:
2631                 task->tk_status = 0;
2632                 if (task->tk_client->cl_discrtry)
2633                         xprt_conditional_disconnect(req->rq_xprt,
2634                                                     req->rq_connect_cookie);
2635                 task->tk_action = call_encode;
2636                 rpc_check_timeout(task);
2637                 break;
2638         case -EKEYREJECTED:
2639                 task->tk_action = call_reserve;
2640                 rpc_check_timeout(task);
2641                 rpcauth_invalcred(task);
2642                 /* Ensure we obtain a new XID if we retry! */
2643                 xprt_release(task);
2644         }
2645 }
2646
2647 static int
2648 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2649 {
2650         struct rpc_clnt *clnt = task->tk_client;
2651         struct rpc_rqst *req = task->tk_rqstp;
2652         __be32 *p;
2653         int error;
2654
2655         error = -EMSGSIZE;
2656         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2657         if (!p)
2658                 goto out_fail;
2659         *p++ = req->rq_xid;
2660         *p++ = rpc_call;
2661         *p++ = cpu_to_be32(RPC_VERSION);
2662         *p++ = cpu_to_be32(clnt->cl_prog);
2663         *p++ = cpu_to_be32(clnt->cl_vers);
2664         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2665
2666         error = rpcauth_marshcred(task, xdr);
2667         if (error < 0)
2668                 goto out_fail;
2669         return 0;
2670 out_fail:
2671         trace_rpc_bad_callhdr(task);
2672         rpc_call_rpcerror(task, error);
2673         return error;
2674 }
2675
2676 static noinline int
2677 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2678 {
2679         struct rpc_clnt *clnt = task->tk_client;
2680         int error;
2681         __be32 *p;
2682
2683         /* RFC-1014 says that the representation of XDR data must be a
2684          * multiple of four bytes
2685          * - if it isn't pointer subtraction in the NFS client may give
2686          *   undefined results
2687          */
2688         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2689                 goto out_unparsable;
2690
2691         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2692         if (!p)
2693                 goto out_unparsable;
2694         p++;    /* skip XID */
2695         if (*p++ != rpc_reply)
2696                 goto out_unparsable;
2697         if (*p++ != rpc_msg_accepted)
2698                 goto out_msg_denied;
2699
2700         error = rpcauth_checkverf(task, xdr);
2701         if (error)
2702                 goto out_verifier;
2703
2704         p = xdr_inline_decode(xdr, sizeof(*p));
2705         if (!p)
2706                 goto out_unparsable;
2707         switch (*p) {
2708         case rpc_success:
2709                 return 0;
2710         case rpc_prog_unavail:
2711                 trace_rpc__prog_unavail(task);
2712                 error = -EPFNOSUPPORT;
2713                 goto out_err;
2714         case rpc_prog_mismatch:
2715                 trace_rpc__prog_mismatch(task);
2716                 error = -EPROTONOSUPPORT;
2717                 goto out_err;
2718         case rpc_proc_unavail:
2719                 trace_rpc__proc_unavail(task);
2720                 error = -EOPNOTSUPP;
2721                 goto out_err;
2722         case rpc_garbage_args:
2723         case rpc_system_err:
2724                 trace_rpc__garbage_args(task);
2725                 error = -EIO;
2726                 break;
2727         default:
2728                 goto out_unparsable;
2729         }
2730
2731 out_garbage:
2732         clnt->cl_stats->rpcgarbage++;
2733         if (task->tk_garb_retry) {
2734                 task->tk_garb_retry--;
2735                 task->tk_action = call_encode;
2736                 return -EAGAIN;
2737         }
2738 out_err:
2739         rpc_call_rpcerror(task, error);
2740         return error;
2741
2742 out_unparsable:
2743         trace_rpc__unparsable(task);
2744         error = -EIO;
2745         goto out_garbage;
2746
2747 out_verifier:
2748         trace_rpc_bad_verifier(task);
2749         switch (error) {
2750         case -EPROTONOSUPPORT:
2751                 goto out_err;
2752         case -EACCES:
2753                 /* Re-encode with a fresh cred */
2754                 fallthrough;
2755         default:
2756                 goto out_garbage;
2757         }
2758
2759 out_msg_denied:
2760         error = -EACCES;
2761         p = xdr_inline_decode(xdr, sizeof(*p));
2762         if (!p)
2763                 goto out_unparsable;
2764         switch (*p++) {
2765         case rpc_auth_error:
2766                 break;
2767         case rpc_mismatch:
2768                 trace_rpc__mismatch(task);
2769                 error = -EPROTONOSUPPORT;
2770                 goto out_err;
2771         default:
2772                 goto out_unparsable;
2773         }
2774
2775         p = xdr_inline_decode(xdr, sizeof(*p));
2776         if (!p)
2777                 goto out_unparsable;
2778         switch (*p++) {
2779         case rpc_autherr_rejectedcred:
2780         case rpc_autherr_rejectedverf:
2781         case rpcsec_gsserr_credproblem:
2782         case rpcsec_gsserr_ctxproblem:
2783                 rpcauth_invalcred(task);
2784                 if (!task->tk_cred_retry)
2785                         break;
2786                 task->tk_cred_retry--;
2787                 trace_rpc__stale_creds(task);
2788                 return -EKEYREJECTED;
2789         case rpc_autherr_badcred:
2790         case rpc_autherr_badverf:
2791                 /* possibly garbled cred/verf? */
2792                 if (!task->tk_garb_retry)
2793                         break;
2794                 task->tk_garb_retry--;
2795                 trace_rpc__bad_creds(task);
2796                 task->tk_action = call_encode;
2797                 return -EAGAIN;
2798         case rpc_autherr_tooweak:
2799                 trace_rpc__auth_tooweak(task);
2800                 pr_warn("RPC: server %s requires stronger authentication.\n",
2801                         task->tk_xprt->servername);
2802                 break;
2803         default:
2804                 goto out_unparsable;
2805         }
2806         goto out_err;
2807 }
2808
2809 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2810                 const void *obj)
2811 {
2812 }
2813
2814 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2815                 void *obj)
2816 {
2817         return 0;
2818 }
2819
2820 static const struct rpc_procinfo rpcproc_null = {
2821         .p_encode = rpcproc_encode_null,
2822         .p_decode = rpcproc_decode_null,
2823 };
2824
2825 static const struct rpc_procinfo rpcproc_null_noreply = {
2826         .p_encode = rpcproc_encode_null,
2827 };
2828
2829 static void
2830 rpc_null_call_prepare(struct rpc_task *task, void *data)
2831 {
2832         task->tk_flags &= ~RPC_TASK_NO_RETRANS_TIMEOUT;
2833         rpc_call_start(task);
2834 }
2835
2836 static const struct rpc_call_ops rpc_null_ops = {
2837         .rpc_call_prepare = rpc_null_call_prepare,
2838         .rpc_call_done = rpc_default_callback,
2839 };
2840
2841 static
2842 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2843                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2844                 const struct rpc_call_ops *ops, void *data)
2845 {
2846         struct rpc_message msg = {
2847                 .rpc_proc = &rpcproc_null,
2848         };
2849         struct rpc_task_setup task_setup_data = {
2850                 .rpc_client = clnt,
2851                 .rpc_xprt = xprt,
2852                 .rpc_message = &msg,
2853                 .rpc_op_cred = cred,
2854                 .callback_ops = ops ?: &rpc_null_ops,
2855                 .callback_data = data,
2856                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2857                          RPC_TASK_NULLCREDS,
2858         };
2859
2860         return rpc_run_task(&task_setup_data);
2861 }
2862
2863 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2864 {
2865         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2866 }
2867 EXPORT_SYMBOL_GPL(rpc_call_null);
2868
2869 static int rpc_ping(struct rpc_clnt *clnt)
2870 {
2871         struct rpc_task *task;
2872         int status;
2873
2874         if (clnt->cl_auth->au_ops->ping)
2875                 return clnt->cl_auth->au_ops->ping(clnt);
2876
2877         task = rpc_call_null_helper(clnt, NULL, NULL, 0, NULL, NULL);
2878         if (IS_ERR(task))
2879                 return PTR_ERR(task);
2880         status = task->tk_status;
2881         rpc_put_task(task);
2882         return status;
2883 }
2884
2885 static int rpc_ping_noreply(struct rpc_clnt *clnt)
2886 {
2887         struct rpc_message msg = {
2888                 .rpc_proc = &rpcproc_null_noreply,
2889         };
2890         struct rpc_task_setup task_setup_data = {
2891                 .rpc_client = clnt,
2892                 .rpc_message = &msg,
2893                 .callback_ops = &rpc_null_ops,
2894                 .flags = RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2895         };
2896         struct rpc_task *task;
2897         int status;
2898
2899         task = rpc_run_task(&task_setup_data);
2900         if (IS_ERR(task))
2901                 return PTR_ERR(task);
2902         status = task->tk_status;
2903         rpc_put_task(task);
2904         return status;
2905 }
2906
2907 struct rpc_cb_add_xprt_calldata {
2908         struct rpc_xprt_switch *xps;
2909         struct rpc_xprt *xprt;
2910 };
2911
2912 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2913 {
2914         struct rpc_cb_add_xprt_calldata *data = calldata;
2915
2916         if (task->tk_status == 0)
2917                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2918 }
2919
2920 static void rpc_cb_add_xprt_release(void *calldata)
2921 {
2922         struct rpc_cb_add_xprt_calldata *data = calldata;
2923
2924         xprt_put(data->xprt);
2925         xprt_switch_put(data->xps);
2926         kfree(data);
2927 }
2928
2929 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2930         .rpc_call_prepare = rpc_null_call_prepare,
2931         .rpc_call_done = rpc_cb_add_xprt_done,
2932         .rpc_release = rpc_cb_add_xprt_release,
2933 };
2934
2935 /**
2936  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2937  * @clnt: pointer to struct rpc_clnt
2938  * @xps: pointer to struct rpc_xprt_switch,
2939  * @xprt: pointer struct rpc_xprt
2940  * @in_max_connect: pointer to the max_connect value for the passed in xprt transport
2941  */
2942 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2943                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2944                 void *in_max_connect)
2945 {
2946         struct rpc_cb_add_xprt_calldata *data;
2947         struct rpc_task *task;
2948         int max_connect = clnt->cl_max_connect;
2949
2950         if (in_max_connect)
2951                 max_connect = *(int *)in_max_connect;
2952         if (xps->xps_nunique_destaddr_xprts + 1 > max_connect) {
2953                 rcu_read_lock();
2954                 pr_warn("SUNRPC: reached max allowed number (%d) did not add "
2955                         "transport to server: %s\n", max_connect,
2956                         rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR));
2957                 rcu_read_unlock();
2958                 return -EINVAL;
2959         }
2960
2961         data = kmalloc(sizeof(*data), GFP_KERNEL);
2962         if (!data)
2963                 return -ENOMEM;
2964         data->xps = xprt_switch_get(xps);
2965         data->xprt = xprt_get(xprt);
2966         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2967                 rpc_cb_add_xprt_release(data);
2968                 goto success;
2969         }
2970
2971         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2972                         &rpc_cb_add_xprt_call_ops, data);
2973         if (IS_ERR(task))
2974                 return PTR_ERR(task);
2975
2976         data->xps->xps_nunique_destaddr_xprts++;
2977         rpc_put_task(task);
2978 success:
2979         return 1;
2980 }
2981 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2982
2983 static int rpc_clnt_add_xprt_helper(struct rpc_clnt *clnt,
2984                                     struct rpc_xprt *xprt,
2985                                     struct rpc_add_xprt_test *data)
2986 {
2987         struct rpc_task *task;
2988         int status = -EADDRINUSE;
2989
2990         /* Test the connection */
2991         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2992         if (IS_ERR(task))
2993                 return PTR_ERR(task);
2994
2995         status = task->tk_status;
2996         rpc_put_task(task);
2997
2998         if (status < 0)
2999                 return status;
3000
3001         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
3002         data->add_xprt_test(clnt, xprt, data->data);
3003
3004         return 0;
3005 }
3006
3007 /**
3008  * rpc_clnt_setup_test_and_add_xprt()
3009  *
3010  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
3011  *   1) caller of the test function must dereference the rpc_xprt_switch
3012  *   and the rpc_xprt.
3013  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
3014  *   the rpc_call_done routine.
3015  *
3016  * Upon success (return of 1), the test function adds the new
3017  * transport to the rpc_clnt xprt switch
3018  *
3019  * @clnt: struct rpc_clnt to get the new transport
3020  * @xps:  the rpc_xprt_switch to hold the new transport
3021  * @xprt: the rpc_xprt to test
3022  * @data: a struct rpc_add_xprt_test pointer that holds the test function
3023  *        and test function call data
3024  */
3025 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
3026                                      struct rpc_xprt_switch *xps,
3027                                      struct rpc_xprt *xprt,
3028                                      void *data)
3029 {
3030         int status = -EADDRINUSE;
3031
3032         xprt = xprt_get(xprt);
3033         xprt_switch_get(xps);
3034
3035         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
3036                 goto out_err;
3037
3038         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3039         if (status < 0)
3040                 goto out_err;
3041
3042         status = 1;
3043 out_err:
3044         xprt_put(xprt);
3045         xprt_switch_put(xps);
3046         if (status < 0)
3047                 pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not "
3048                         "added\n", status,
3049                         xprt->address_strings[RPC_DISPLAY_ADDR]);
3050         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
3051         return status;
3052 }
3053 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
3054
3055 /**
3056  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
3057  * @clnt: pointer to struct rpc_clnt
3058  * @xprtargs: pointer to struct xprt_create
3059  * @setup: callback to test and/or set up the connection
3060  * @data: pointer to setup function data
3061  *
3062  * Creates a new transport using the parameters set in args and
3063  * adds it to clnt.
3064  * If ping is set, then test that connectivity succeeds before
3065  * adding the new transport.
3066  *
3067  */
3068 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
3069                 struct xprt_create *xprtargs,
3070                 int (*setup)(struct rpc_clnt *,
3071                         struct rpc_xprt_switch *,
3072                         struct rpc_xprt *,
3073                         void *),
3074                 void *data)
3075 {
3076         struct rpc_xprt_switch *xps;
3077         struct rpc_xprt *xprt;
3078         unsigned long connect_timeout;
3079         unsigned long reconnect_timeout;
3080         unsigned char resvport, reuseport;
3081         int ret = 0, ident;
3082
3083         rcu_read_lock();
3084         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3085         xprt = xprt_iter_xprt(&clnt->cl_xpi);
3086         if (xps == NULL || xprt == NULL) {
3087                 rcu_read_unlock();
3088                 xprt_switch_put(xps);
3089                 return -EAGAIN;
3090         }
3091         resvport = xprt->resvport;
3092         reuseport = xprt->reuseport;
3093         connect_timeout = xprt->connect_timeout;
3094         reconnect_timeout = xprt->max_reconnect_timeout;
3095         ident = xprt->xprt_class->ident;
3096         rcu_read_unlock();
3097
3098         if (!xprtargs->ident)
3099                 xprtargs->ident = ident;
3100         xprtargs->xprtsec = clnt->cl_xprtsec;
3101         xprt = xprt_create_transport(xprtargs);
3102         if (IS_ERR(xprt)) {
3103                 ret = PTR_ERR(xprt);
3104                 goto out_put_switch;
3105         }
3106         xprt->resvport = resvport;
3107         xprt->reuseport = reuseport;
3108
3109         if (xprtargs->connect_timeout)
3110                 connect_timeout = xprtargs->connect_timeout;
3111         if (xprtargs->reconnect_timeout)
3112                 reconnect_timeout = xprtargs->reconnect_timeout;
3113         if (xprt->ops->set_connect_timeout != NULL)
3114                 xprt->ops->set_connect_timeout(xprt,
3115                                 connect_timeout,
3116                                 reconnect_timeout);
3117
3118         rpc_xprt_switch_set_roundrobin(xps);
3119         if (setup) {
3120                 ret = setup(clnt, xps, xprt, data);
3121                 if (ret != 0)
3122                         goto out_put_xprt;
3123         }
3124         rpc_xprt_switch_add_xprt(xps, xprt);
3125 out_put_xprt:
3126         xprt_put(xprt);
3127 out_put_switch:
3128         xprt_switch_put(xps);
3129         return ret;
3130 }
3131 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
3132
3133 static int rpc_xprt_probe_trunked(struct rpc_clnt *clnt,
3134                                   struct rpc_xprt *xprt,
3135                                   struct rpc_add_xprt_test *data)
3136 {
3137         struct rpc_xprt *main_xprt;
3138         int status = 0;
3139
3140         xprt_get(xprt);
3141
3142         rcu_read_lock();
3143         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3144         status = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3145                                    (struct sockaddr *)&main_xprt->addr);
3146         rcu_read_unlock();
3147         xprt_put(main_xprt);
3148         if (status || !test_bit(XPRT_OFFLINE, &xprt->state))
3149                 goto out;
3150
3151         status = rpc_clnt_add_xprt_helper(clnt, xprt, data);
3152 out:
3153         xprt_put(xprt);
3154         return status;
3155 }
3156
3157 /* rpc_clnt_probe_trunked_xprt -- probe offlined transport for session trunking
3158  * @clnt rpc_clnt structure
3159  *
3160  * For each offlined transport found in the rpc_clnt structure call
3161  * the function rpc_xprt_probe_trunked() which will determine if this
3162  * transport still belongs to the trunking group.
3163  */
3164 void rpc_clnt_probe_trunked_xprts(struct rpc_clnt *clnt,
3165                                   struct rpc_add_xprt_test *data)
3166 {
3167         struct rpc_xprt_iter xpi;
3168         int ret;
3169
3170         ret = rpc_clnt_xprt_iter_offline_init(clnt, &xpi);
3171         if (ret)
3172                 return;
3173         for (;;) {
3174                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
3175
3176                 if (!xprt)
3177                         break;
3178                 ret = rpc_xprt_probe_trunked(clnt, xprt, data);
3179                 xprt_put(xprt);
3180                 if (ret < 0)
3181                         break;
3182                 xprt_iter_rewind(&xpi);
3183         }
3184         xprt_iter_destroy(&xpi);
3185 }
3186 EXPORT_SYMBOL_GPL(rpc_clnt_probe_trunked_xprts);
3187
3188 static int rpc_xprt_offline(struct rpc_clnt *clnt,
3189                             struct rpc_xprt *xprt,
3190                             void *data)
3191 {
3192         struct rpc_xprt *main_xprt;
3193         struct rpc_xprt_switch *xps;
3194         int err = 0;
3195
3196         xprt_get(xprt);
3197
3198         rcu_read_lock();
3199         main_xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
3200         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
3201         err = rpc_cmp_addr_port((struct sockaddr *)&xprt->addr,
3202                                 (struct sockaddr *)&main_xprt->addr);
3203         rcu_read_unlock();
3204         xprt_put(main_xprt);
3205         if (err)
3206                 goto out;
3207
3208         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {
3209                 err = -EINTR;
3210                 goto out;
3211         }
3212         xprt_set_offline_locked(xprt, xps);
3213
3214         xprt_release_write(xprt, NULL);
3215 out:
3216         xprt_put(xprt);
3217         xprt_switch_put(xps);
3218         return err;
3219 }
3220
3221 /* rpc_clnt_manage_trunked_xprts -- offline trunked transports
3222  * @clnt rpc_clnt structure
3223  *
3224  * For each active transport found in the rpc_clnt structure call
3225  * the function rpc_xprt_offline() which will identify trunked transports
3226  * and will mark them offline.
3227  */
3228 void rpc_clnt_manage_trunked_xprts(struct rpc_clnt *clnt)
3229 {
3230         rpc_clnt_iterate_for_each_xprt(clnt, rpc_xprt_offline, NULL);
3231 }
3232 EXPORT_SYMBOL_GPL(rpc_clnt_manage_trunked_xprts);
3233
3234 struct connect_timeout_data {
3235         unsigned long connect_timeout;
3236         unsigned long reconnect_timeout;
3237 };
3238
3239 static int
3240 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
3241                 struct rpc_xprt *xprt,
3242                 void *data)
3243 {
3244         struct connect_timeout_data *timeo = data;
3245
3246         if (xprt->ops->set_connect_timeout)
3247                 xprt->ops->set_connect_timeout(xprt,
3248                                 timeo->connect_timeout,
3249                                 timeo->reconnect_timeout);
3250         return 0;
3251 }
3252
3253 void
3254 rpc_set_connect_timeout(struct rpc_clnt *clnt,
3255                 unsigned long connect_timeout,
3256                 unsigned long reconnect_timeout)
3257 {
3258         struct connect_timeout_data timeout = {
3259                 .connect_timeout = connect_timeout,
3260                 .reconnect_timeout = reconnect_timeout,
3261         };
3262         rpc_clnt_iterate_for_each_xprt(clnt,
3263                         rpc_xprt_set_connect_timeout,
3264                         &timeout);
3265 }
3266 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
3267
3268 void rpc_clnt_xprt_set_online(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3269 {
3270         struct rpc_xprt_switch *xps;
3271
3272         xps = rpc_clnt_xprt_switch_get(clnt);
3273         xprt_set_online_locked(xprt, xps);
3274         xprt_switch_put(xps);
3275 }
3276
3277 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3278 {
3279         struct rpc_xprt_switch *xps;
3280
3281         if (rpc_clnt_xprt_switch_has_addr(clnt,
3282                 (const struct sockaddr *)&xprt->addr)) {
3283                 return rpc_clnt_xprt_set_online(clnt, xprt);
3284         }
3285
3286         xps = rpc_clnt_xprt_switch_get(clnt);
3287         rpc_xprt_switch_add_xprt(xps, xprt);
3288         xprt_switch_put(xps);
3289 }
3290 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
3291
3292 void rpc_clnt_xprt_switch_remove_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
3293 {
3294         struct rpc_xprt_switch *xps;
3295
3296         rcu_read_lock();
3297         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3298         rpc_xprt_switch_remove_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
3299                                     xprt, 0);
3300         xps->xps_nunique_destaddr_xprts--;
3301         rcu_read_unlock();
3302 }
3303 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_remove_xprt);
3304
3305 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
3306                                    const struct sockaddr *sap)
3307 {
3308         struct rpc_xprt_switch *xps;
3309         bool ret;
3310
3311         rcu_read_lock();
3312         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
3313         ret = rpc_xprt_switch_has_addr(xps, sap);
3314         rcu_read_unlock();
3315         return ret;
3316 }
3317 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
3318
3319 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3320 static void rpc_show_header(void)
3321 {
3322         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
3323                 "-timeout ---ops--\n");
3324 }
3325
3326 static void rpc_show_task(const struct rpc_clnt *clnt,
3327                           const struct rpc_task *task)
3328 {
3329         const char *rpc_waitq = "none";
3330
3331         if (RPC_IS_QUEUED(task))
3332                 rpc_waitq = rpc_qname(task->tk_waitqueue);
3333
3334         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
3335                 task->tk_pid, task->tk_flags, task->tk_status,
3336                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
3337                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
3338                 task->tk_action, rpc_waitq);
3339 }
3340
3341 void rpc_show_tasks(struct net *net)
3342 {
3343         struct rpc_clnt *clnt;
3344         struct rpc_task *task;
3345         int header = 0;
3346         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
3347
3348         spin_lock(&sn->rpc_client_lock);
3349         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3350                 spin_lock(&clnt->cl_lock);
3351                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3352                         if (!header) {
3353                                 rpc_show_header();
3354                                 header++;
3355                         }
3356                         rpc_show_task(clnt, task);
3357                 }
3358                 spin_unlock(&clnt->cl_lock);
3359         }
3360         spin_unlock(&sn->rpc_client_lock);
3361 }
3362 #endif
3363
3364 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3365 static int
3366 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3367                 struct rpc_xprt *xprt,
3368                 void *dummy)
3369 {
3370         return xprt_enable_swap(xprt);
3371 }
3372
3373 int
3374 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3375 {
3376         while (clnt != clnt->cl_parent)
3377                 clnt = clnt->cl_parent;
3378         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3379                 return rpc_clnt_iterate_for_each_xprt(clnt,
3380                                 rpc_clnt_swap_activate_callback, NULL);
3381         return 0;
3382 }
3383 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3384
3385 static int
3386 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3387                 struct rpc_xprt *xprt,
3388                 void *dummy)
3389 {
3390         xprt_disable_swap(xprt);
3391         return 0;
3392 }
3393
3394 void
3395 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3396 {
3397         while (clnt != clnt->cl_parent)
3398                 clnt = clnt->cl_parent;
3399         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3400                 rpc_clnt_iterate_for_each_xprt(clnt,
3401                                 rpc_clnt_swap_deactivate_callback, NULL);
3402 }
3403 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3404 #endif /* CONFIG_SUNRPC_SWAP */