fs/nfs/nfs4client.c

   1 /*
   2  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
   3  * Written by David Howells (dhowells@redhat.com)
   4  */
   5 #include <linux/module.h>
   6 #include <linux/nfs_fs.h>
   7 #include <linux/nfs_mount.h>
   8 #include <linux/sunrpc/addr.h>
   9 #include <linux/sunrpc/auth.h>
  10 #include <linux/sunrpc/xprt.h>
  11 #include <linux/sunrpc/bc_xprt.h>
  12 #include <linux/sunrpc/rpc_pipe_fs.h>
  13 #include "internal.h"
  14 #include "callback.h"
  15 #include "delegation.h"
  16 #include "nfs4session.h"
  17 #include "nfs4idmap.h"
  18 #include "pnfs.h"
  19 #include "netns.h"
  20
  21 #define NFSDBG_FACILITY         NFSDBG_CLIENT
  22
  23 /*
  24  * Get a unique NFSv4.0 callback identifier which will be used
  25  * by the V4.0 callback service to lookup the nfs_client struct
  26  */
  27 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
  28 {
  29         int ret = 0;
  30         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
  31
  32         if (clp->rpc_ops->version != 4 || minorversion != 0)
  33                 return ret;
  34         idr_preload(GFP_KERNEL);
  35         spin_lock(&nn->nfs_client_lock);
  36         ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
  37         if (ret >= 0)
  38                 clp->cl_cb_ident = ret;
  39         spin_unlock(&nn->nfs_client_lock);
  40         idr_preload_end();
  41         return ret < 0 ? ret : 0;
  42 }
  43
  44 #ifdef CONFIG_NFS_V4_1
  45 /**
  46  * Per auth flavor data server rpc clients
  47  */
  48 struct nfs4_ds_server {
  49         struct list_head        list;   /* ds_clp->cl_ds_clients */
  50         struct rpc_clnt         *rpc_clnt;
  51 };
  52
  53 /**
  54  * Common lookup case for DS I/O
  55  */
  56 static struct nfs4_ds_server *
  57 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
  58 {
  59         struct nfs4_ds_server *dss;
  60
  61         rcu_read_lock();
  62         list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
  63                 if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
  64                         continue;
  65                 goto out;
  66         }
  67         dss = NULL;
  68 out:
  69         rcu_read_unlock();
  70         return dss;
  71 }
  72
  73 static struct nfs4_ds_server *
  74 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
  75                            struct nfs4_ds_server *new)
  76 {
  77         struct nfs4_ds_server *dss;
  78
  79         spin_lock(&ds_clp->cl_lock);
  80         list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
  81                 if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
  82                         continue;
  83                 goto out;
  84         }
  85         if (new)
  86                 list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
  87         dss = new;
  88 out:
  89         spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
  90         return dss;
  91 }
  92
  93 static struct nfs4_ds_server *
  94 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
  95 {
  96         struct nfs4_ds_server *dss;
  97
  98         dss = kmalloc(sizeof(*dss), GFP_NOFS);
  99         if (dss == NULL)
 100                 return ERR_PTR(-ENOMEM);
 101
 102         dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
 103         if (IS_ERR(dss->rpc_clnt)) {
 104                 int err = PTR_ERR(dss->rpc_clnt);
 105                 kfree (dss);
 106                 return ERR_PTR(err);
 107         }
 108         INIT_LIST_HEAD(&dss->list);
 109
 110         return dss;
 111 }
 112
 113 static void
 114 nfs4_free_ds_server(struct nfs4_ds_server *dss)
 115 {
 116         rpc_release_client(dss->rpc_clnt);
 117         kfree(dss);
 118 }
 119
 120 /**
 121 * Find or create a DS rpc client with th MDS server rpc client auth flavor
 122 * in the nfs_client cl_ds_clients list.
 123 */
 124 struct rpc_clnt *
 125 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
 126 {
 127         struct nfs4_ds_server *dss, *new;
 128         rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
 129
 130         dss = nfs4_find_ds_client(ds_clp, flavor);
 131         if (dss != NULL)
 132                 goto out;
 133         new = nfs4_alloc_ds_server(ds_clp, flavor);
 134         if (IS_ERR(new))
 135                 return ERR_CAST(new);
 136         dss = nfs4_add_ds_client(ds_clp, flavor, new);
 137         if (dss != new)
 138                 nfs4_free_ds_server(new);
 139 out:
 140         return dss->rpc_clnt;
 141 }
 142 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
 143
 144 static void
 145 nfs4_shutdown_ds_clients(struct nfs_client *clp)
 146 {
 147         struct nfs4_ds_server *dss;
 148         LIST_HEAD(shutdown_list);
 149
 150         while (!list_empty(&clp->cl_ds_clients)) {
 151                 dss = list_entry(clp->cl_ds_clients.next,
 152                                         struct nfs4_ds_server, list);
 153                 list_del(&dss->list);
 154                 rpc_shutdown_client(dss->rpc_clnt);
 155                 kfree (dss);
 156         }
 157 }
 158
 159 void nfs41_shutdown_client(struct nfs_client *clp)
 160 {
 161         if (nfs4_has_session(clp)) {
 162                 nfs4_shutdown_ds_clients(clp);
 163                 nfs4_destroy_session(clp->cl_session);
 164                 nfs4_destroy_clientid(clp);
 165         }
 166
 167 }
 168 #endif  /* CONFIG_NFS_V4_1 */
 169
 170 void nfs40_shutdown_client(struct nfs_client *clp)
 171 {
 172         if (clp->cl_slot_tbl) {
 173                 nfs4_shutdown_slot_table(clp->cl_slot_tbl);
 174                 kfree(clp->cl_slot_tbl);
 175         }
 176 }
 177
 178 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
 179 {
 180         int err;
 181         struct nfs_client *clp = nfs_alloc_client(cl_init);
 182         if (IS_ERR(clp))
 183                 return clp;
 184
 185         err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
 186         if (err)
 187                 goto error;
 188
 189         if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
 190                 err = -EINVAL;
 191                 goto error;
 192         }
 193
 194         spin_lock_init(&clp->cl_lock);
 195         INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
 196         INIT_LIST_HEAD(&clp->cl_ds_clients);
 197         rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
 198         clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
 199         clp->cl_minorversion = cl_init->minorversion;
 200         clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
 201         clp->cl_mig_gen = 1;
 202 #if IS_ENABLED(CONFIG_NFS_V4_1)
 203         init_waitqueue_head(&clp->cl_lock_waitq);
 204 #endif
 205         return clp;
 206
 207 error:
 208         nfs_free_client(clp);
 209         return ERR_PTR(err);
 210 }
 211
 212 /*
 213  * Destroy the NFS4 callback service
 214  */
 215 static void nfs4_destroy_callback(struct nfs_client *clp)
 216 {
 217         if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
 218                 nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
 219 }
 220
 221 static void nfs4_shutdown_client(struct nfs_client *clp)
 222 {
 223         if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
 224                 nfs4_kill_renewd(clp);
 225         clp->cl_mvops->shutdown_client(clp);
 226         nfs4_destroy_callback(clp);
 227         if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
 228                 nfs_idmap_delete(clp);
 229
 230         rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
 231         kfree(clp->cl_serverowner);
 232         kfree(clp->cl_serverscope);
 233         kfree(clp->cl_implid);
 234         kfree(clp->cl_owner_id);
 235 }
 236
 237 void nfs4_free_client(struct nfs_client *clp)
 238 {
 239         nfs4_shutdown_client(clp);
 240         nfs_free_client(clp);
 241 }
 242
 243 /*
 244  * Initialize the NFS4 callback service
 245  */
 246 static int nfs4_init_callback(struct nfs_client *clp)
 247 {
 248         struct rpc_xprt *xprt;
 249         int error;
 250
 251         xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
 252
 253         if (nfs4_has_session(clp)) {
 254                 error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
 255                 if (error < 0)
 256                         return error;
 257         }
 258
 259         error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
 260         if (error < 0) {
 261                 dprintk("%s: failed to start callback. Error = %d\n",
 262                         __func__, error);
 263                 return error;
 264         }
 265         __set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
 266
 267         return 0;
 268 }
 269
 270 /**
 271  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
 272  * @clp - nfs_client to initialize
 273  *
 274  * Returns zero on success, or a negative errno if some error occurred.
 275  */
 276 int nfs40_init_client(struct nfs_client *clp)
 277 {
 278         struct nfs4_slot_table *tbl;
 279         int ret;
 280
 281         tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
 282         if (tbl == NULL)
 283                 return -ENOMEM;
 284
 285         ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
 286                                         "NFSv4.0 transport Slot table");
 287         if (ret) {
 288                 kfree(tbl);
 289                 return ret;
 290         }
 291
 292         clp->cl_slot_tbl = tbl;
 293         return 0;
 294 }
 295
 296 #if defined(CONFIG_NFS_V4_1)
 297
 298 /**
 299  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
 300  * @clp - nfs_client to initialize
 301  *
 302  * Returns zero on success, or a negative errno if some error occurred.
 303  */
 304 int nfs41_init_client(struct nfs_client *clp)
 305 {
 306         struct nfs4_session *session = NULL;
 307
 308         /*
 309          * Create the session and mark it expired.
 310          * When a SEQUENCE operation encounters the expired session
 311          * it will do session recovery to initialize it.
 312          */
 313         session = nfs4_alloc_session(clp);
 314         if (!session)
 315                 return -ENOMEM;
 316
 317         clp->cl_session = session;
 318
 319         /*
 320          * The create session reply races with the server back
 321          * channel probe. Mark the client NFS_CS_SESSION_INITING
 322          * so that the client back channel can find the
 323          * nfs_client struct
 324          */
 325         nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
 326         return 0;
 327 }
 328
 329 #endif  /* CONFIG_NFS_V4_1 */
 330
 331 /*
 332  * Initialize the minor version specific parts of an NFS4 client record
 333  */
 334 static int nfs4_init_client_minor_version(struct nfs_client *clp)
 335 {
 336         int ret;
 337
 338         ret = clp->cl_mvops->init_client(clp);
 339         if (ret)
 340                 return ret;
 341         return nfs4_init_callback(clp);
 342 }
 343
 344 /**
 345  * nfs4_init_client - Initialise an NFS4 client record
 346  *
 347  * @clp: nfs_client to initialise
 348  * @timeparms: timeout parameters for underlying RPC transport
 349  * @ip_addr: callback IP address in presentation format
 350  * @authflavor: authentication flavor for underlying RPC transport
 351  *
 352  * Returns pointer to an NFS client, or an ERR_PTR value.
 353  */
 354 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 355                                     const struct nfs_client_initdata *cl_init)
 356 {
 357         char buf[INET6_ADDRSTRLEN + 1];
 358         const char *ip_addr = cl_init->ip_addr;
 359         struct nfs_client *old;
 360         int error;
 361
 362         if (clp->cl_cons_state == NFS_CS_READY) {
 363                 /* the client is initialised already */
 364                 dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
 365                 return clp;
 366         }
 367
 368         /* Check NFS protocol revision and initialize RPC op vector */
 369         clp->rpc_ops = &nfs_v4_clientops;
 370
 371         if (clp->cl_minorversion != 0)
 372                 __set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
 373         __set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
 374         __set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
 375
 376         error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
 377         if (error == -EINVAL)
 378                 error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
 379         if (error < 0)
 380                 goto error;
 381
 382         /* If no clientaddr= option was specified, find a usable cb address */
 383         if (ip_addr == NULL) {
 384                 struct sockaddr_storage cb_addr;
 385                 struct sockaddr *sap = (struct sockaddr *)&cb_addr;
 386
 387                 error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
 388                 if (error < 0)
 389                         goto error;
 390                 error = rpc_ntop(sap, buf, sizeof(buf));
 391                 if (error < 0)
 392                         goto error;
 393                 ip_addr = (const char *)buf;
 394         }
 395         strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
 396
 397         error = nfs_idmap_new(clp);
 398         if (error < 0) {
 399                 dprintk("%s: failed to create idmapper. Error = %d\n",
 400                         __func__, error);
 401                 goto error;
 402         }
 403         __set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
 404
 405         error = nfs4_init_client_minor_version(clp);
 406         if (error < 0)
 407                 goto error;
 408
 409         if (!nfs4_has_session(clp))
 410                 nfs_mark_client_ready(clp, NFS_CS_READY);
 411
 412         error = nfs4_discover_server_trunking(clp, &old);
 413         if (error < 0)
 414                 goto error;
 415
 416         if (clp != old)
 417                 clp->cl_preserve_clid = true;
 418         nfs_put_client(clp);
 419         return old;
 420
 421 error:
 422         nfs_mark_client_ready(clp, error);
 423         nfs_put_client(clp);
 424         dprintk("<-- nfs4_init_client() = xerror %d\n", error);
 425         return ERR_PTR(error);
 426 }
 427
 428 /*
 429  * SETCLIENTID just did a callback update with the callback ident in
 430  * "drop," but server trunking discovery claims "drop" and "keep" are
 431  * actually the same server.  Swap the callback IDs so that "keep"
 432  * will continue to use the callback ident the server now knows about,
 433  * and so that "keep"'s original callback ident is destroyed when
 434  * "drop" is freed.
 435  */
 436 static void nfs4_swap_callback_idents(struct nfs_client *keep,
 437                                       struct nfs_client *drop)
 438 {
 439         struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
 440         unsigned int save = keep->cl_cb_ident;
 441
 442         if (keep->cl_cb_ident == drop->cl_cb_ident)
 443                 return;
 444
 445         dprintk("%s: keeping callback ident %u and dropping ident %u\n",
 446                 __func__, keep->cl_cb_ident, drop->cl_cb_ident);
 447
 448         spin_lock(&nn->nfs_client_lock);
 449
 450         idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
 451         keep->cl_cb_ident = drop->cl_cb_ident;
 452
 453         idr_replace(&nn->cb_ident_idr, drop, save);
 454         drop->cl_cb_ident = save;
 455
 456         spin_unlock(&nn->nfs_client_lock);
 457 }
 458
 459 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
 460                 const struct nfs_client *clp2)
 461 {
 462         if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
 463                 return true;
 464         return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
 465 }
 466
 467 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
 468 {
 469         return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
 470 }
 471
 472 /**
 473  * nfs40_walk_client_list - Find server that recognizes a client ID
 474  *
 475  * @new: nfs_client with client ID to test
 476  * @result: OUT: found nfs_client, or new
 477  * @cred: credential to use for trunking test
 478  *
 479  * Returns zero, a negative errno, or a negative NFS4ERR status.
 480  * If zero is returned, an nfs_client pointer is planted in "result."
 481  *
 482  * NB: nfs40_walk_client_list() relies on the new nfs_client being
 483  *     the last nfs_client on the list.
 484  */
 485 int nfs40_walk_client_list(struct nfs_client *new,
 486                            struct nfs_client **result,
 487                            struct rpc_cred *cred)
 488 {
 489         struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
 490         struct nfs_client *pos, *prev = NULL;
 491         struct nfs4_setclientid_res clid = {
 492                 .clientid       = new->cl_clientid,
 493                 .confirm        = new->cl_confirm,
 494         };
 495         int status = -NFS4ERR_STALE_CLIENTID;
 496
 497         spin_lock(&nn->nfs_client_lock);
 498         list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
 499
 500                 if (pos->rpc_ops != new->rpc_ops)
 501                         continue;
 502
 503                 if (pos->cl_minorversion != new->cl_minorversion)
 504                         continue;
 505
 506                 /* If "pos" isn't marked ready, we can't trust the
 507                  * remaining fields in "pos" */
 508                 if (pos->cl_cons_state > NFS_CS_READY) {
 509                         atomic_inc(&pos->cl_count);
 510                         spin_unlock(&nn->nfs_client_lock);
 511
 512                         nfs_put_client(prev);
 513                         prev = pos;
 514
 515                         status = nfs_wait_client_init_complete(pos);
 516                         if (status < 0)
 517                                 goto out;
 518                         status = -NFS4ERR_STALE_CLIENTID;
 519                         spin_lock(&nn->nfs_client_lock);
 520                 }
 521                 if (pos->cl_cons_state != NFS_CS_READY)
 522                         continue;
 523
 524                 if (pos->cl_clientid != new->cl_clientid)
 525                         continue;
 526
 527                 if (!nfs4_match_client_owner_id(pos, new))
 528                         continue;
 529                 /*
 530                  * We just sent a new SETCLIENTID, which should have
 531                  * caused the server to return a new cl_confirm.  So if
 532                  * cl_confirm is the same, then this is a different
 533                  * server that just returned the same cl_confirm by
 534                  * coincidence:
 535                  */
 536                 if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
 537                                                        &new->cl_confirm))
 538                         continue;
 539                 /*
 540                  * But if the cl_confirm's are different, then the only
 541                  * way that a SETCLIENTID_CONFIRM to pos can succeed is
 542                  * if new and pos point to the same server:
 543                  */
 544                 atomic_inc(&pos->cl_count);
 545                 spin_unlock(&nn->nfs_client_lock);
 546
 547                 nfs_put_client(prev);
 548                 prev = pos;
 549
 550                 status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
 551                 switch (status) {
 552                 case -NFS4ERR_STALE_CLIENTID:
 553                         break;
 554                 case 0:
 555                         nfs4_swap_callback_idents(pos, new);
 556                         pos->cl_confirm = new->cl_confirm;
 557
 558                         prev = NULL;
 559                         *result = pos;
 560                         dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
 561                                 __func__, pos, atomic_read(&pos->cl_count));
 562                         goto out;
 563                 case -ERESTARTSYS:
 564                 case -ETIMEDOUT:
 565                         /* The callback path may have been inadvertently
 566                          * changed. Schedule recovery!
 567                          */
 568                         nfs4_schedule_path_down_recovery(pos);
 569                 default:
 570                         goto out;
 571                 }
 572
 573                 spin_lock(&nn->nfs_client_lock);
 574         }
 575         spin_unlock(&nn->nfs_client_lock);
 576
 577         /* No match found. The server lost our clientid */
 578 out:
 579         nfs_put_client(prev);
 580         dprintk("NFS: <-- %s status = %d\n", __func__, status);
 581         return status;
 582 }
 583
 584 #ifdef CONFIG_NFS_V4_1
 585 /*
 586  * Returns true if the client IDs match
 587  */
 588 static bool nfs4_match_clientids(u64 a, u64 b)
 589 {
 590         if (a != b) {
 591                 dprintk("NFS: --> %s client ID %llx does not match %llx\n",
 592                         __func__, a, b);
 593                 return false;
 594         }
 595         dprintk("NFS: --> %s client ID %llx matches %llx\n",
 596                 __func__, a, b);
 597         return true;
 598 }
 599
 600 /*
 601  * Returns true if the server major ids match
 602  */
 603 static bool
 604 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
 605                                 struct nfs41_server_owner *o2)
 606 {
 607         if (o1->major_id_sz != o2->major_id_sz)
 608                 goto out_major_mismatch;
 609         if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
 610                 goto out_major_mismatch;
 611
 612         dprintk("NFS: --> %s server owner major IDs match\n", __func__);
 613         return true;
 614
 615 out_major_mismatch:
 616         dprintk("NFS: --> %s server owner major IDs do not match\n",
 617                 __func__);
 618         return false;
 619 }
 620
 621 /*
 622  * Returns true if server minor ids match
 623  */
 624 static bool
 625 nfs4_check_serverowner_minor_id(struct nfs41_server_owner *o1,
 626                                 struct nfs41_server_owner *o2)
 627 {
 628         /* Check eir_server_owner so_minor_id */
 629         if (o1->minor_id != o2->minor_id)
 630                 goto out_minor_mismatch;
 631
 632         dprintk("NFS: --> %s server owner minor IDs match\n", __func__);
 633         return true;
 634
 635 out_minor_mismatch:
 636         dprintk("NFS: --> %s server owner minor IDs do not match\n", __func__);
 637         return false;
 638 }
 639
 640 /*
 641  * Returns true if the server scopes match
 642  */
 643 static bool
 644 nfs4_check_server_scope(struct nfs41_server_scope *s1,
 645                         struct nfs41_server_scope *s2)
 646 {
 647         if (s1->server_scope_sz != s2->server_scope_sz)
 648                 goto out_scope_mismatch;
 649         if (memcmp(s1->server_scope, s2->server_scope,
 650                    s1->server_scope_sz) != 0)
 651                 goto out_scope_mismatch;
 652
 653         dprintk("NFS: --> %s server scopes match\n", __func__);
 654         return true;
 655
 656 out_scope_mismatch:
 657         dprintk("NFS: --> %s server scopes do not match\n",
 658                 __func__);
 659         return false;
 660 }
 661
 662 /**
 663  * nfs4_detect_session_trunking - Checks for session trunking.
 664  *
 665  * Called after a successful EXCHANGE_ID on a multi-addr connection.
 666  * Upon success, add the transport.
 667  *
 668  * @clp:    original mount nfs_client
 669  * @res:    result structure from an exchange_id using the original mount
 670  *          nfs_client with a new multi_addr transport
 671  *
 672  * Returns zero on success, otherwise -EINVAL
 673  *
 674  * Note: since the exchange_id for the new multi_addr transport uses the
 675  * same nfs_client from the original mount, the cl_owner_id is reused,
 676  * so eir_clientowner is the same.
 677  */
 678 int nfs4_detect_session_trunking(struct nfs_client *clp,
 679                                  struct nfs41_exchange_id_res *res,
 680                                  struct rpc_xprt *xprt)
 681 {
 682         /* Check eir_clientid */
 683         if (!nfs4_match_clientids(clp->cl_clientid, res->clientid))
 684                 goto out_err;
 685
 686         /* Check eir_server_owner so_major_id */
 687         if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
 688                                              res->server_owner))
 689                 goto out_err;
 690
 691         /* Check eir_server_owner so_minor_id */
 692         if (!nfs4_check_serverowner_minor_id(clp->cl_serverowner,
 693                                              res->server_owner))
 694                 goto out_err;
 695
 696         /* Check eir_server_scope */
 697         if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
 698                 goto out_err;
 699
 700         /* Session trunking passed, add the xprt */
 701         rpc_clnt_xprt_switch_add_xprt(clp->cl_rpcclient, xprt);
 702
 703         pr_info("NFS:  %s: Session trunking succeeded for %s\n",
 704                 clp->cl_hostname,
 705                 xprt->address_strings[RPC_DISPLAY_ADDR]);
 706
 707         return 0;
 708 out_err:
 709         pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
 710                 xprt->address_strings[RPC_DISPLAY_ADDR]);
 711
 712         return -EINVAL;
 713 }
 714
 715 /**
 716  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
 717  *
 718  * @new: nfs_client with client ID to test
 719  * @result: OUT: found nfs_client, or new
 720  * @cred: credential to use for trunking test
 721  *
 722  * Returns zero, a negative errno, or a negative NFS4ERR status.
 723  * If zero is returned, an nfs_client pointer is planted in "result."
 724  *
 725  * NB: nfs41_walk_client_list() relies on the new nfs_client being
 726  *     the last nfs_client on the list.
 727  */
 728 int nfs41_walk_client_list(struct nfs_client *new,
 729                            struct nfs_client **result,
 730                            struct rpc_cred *cred)
 731 {
 732         struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
 733         struct nfs_client *pos, *prev = NULL;
 734         int status = -NFS4ERR_STALE_CLIENTID;
 735
 736         spin_lock(&nn->nfs_client_lock);
 737         list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
 738
 739                 if (pos == new)
 740                         goto found;
 741
 742                 if (pos->rpc_ops != new->rpc_ops)
 743                         continue;
 744
 745                 if (pos->cl_minorversion != new->cl_minorversion)
 746                         continue;
 747
 748                 /* If "pos" isn't marked ready, we can't trust the
 749                  * remaining fields in "pos", especially the client
 750                  * ID and serverowner fields.  Wait for CREATE_SESSION
 751                  * to finish. */
 752                 if (pos->cl_cons_state > NFS_CS_READY) {
 753                         atomic_inc(&pos->cl_count);
 754                         spin_unlock(&nn->nfs_client_lock);
 755
 756                         nfs_put_client(prev);
 757                         prev = pos;
 758
 759                         status = nfs_wait_client_init_complete(pos);
 760                         spin_lock(&nn->nfs_client_lock);
 761                         if (status < 0)
 762                                 break;
 763                         status = -NFS4ERR_STALE_CLIENTID;
 764                 }
 765                 if (pos->cl_cons_state != NFS_CS_READY)
 766                         continue;
 767
 768                 if (!nfs4_match_clientids(pos->cl_clientid, new->cl_clientid))
 769                         continue;
 770
 771                 /*
 772                  * Note that session trunking is just a special subcase of
 773                  * client id trunking. In either case, we want to fall back
 774                  * to using the existing nfs_client.
 775                  */
 776                 if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
 777                                                      new->cl_serverowner))
 778                         continue;
 779
 780                 /* Unlike NFSv4.0, we know that NFSv4.1 always uses the
 781                  * uniform string, however someone might switch the
 782                  * uniquifier string on us.
 783                  */
 784                 if (!nfs4_match_client_owner_id(pos, new))
 785                         continue;
 786 found:
 787                 atomic_inc(&pos->cl_count);
 788                 *result = pos;
 789                 status = 0;
 790                 dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
 791                         __func__, pos, atomic_read(&pos->cl_count));
 792                 break;
 793         }
 794
 795         spin_unlock(&nn->nfs_client_lock);
 796         dprintk("NFS: <-- %s status = %d\n", __func__, status);
 797         nfs_put_client(prev);
 798         return status;
 799 }
 800 #endif  /* CONFIG_NFS_V4_1 */
 801
 802 static void nfs4_destroy_server(struct nfs_server *server)
 803 {
 804         nfs_server_return_all_delegations(server);
 805         unset_pnfs_layoutdriver(server);
 806         nfs4_purge_state_owners(server);
 807 }
 808
 809 /*
 810  * NFSv4.0 callback thread helper
 811  *
 812  * Find a client by callback identifier
 813  */
 814 struct nfs_client *
 815 nfs4_find_client_ident(struct net *net, int cb_ident)
 816 {
 817         struct nfs_client *clp;
 818         struct nfs_net *nn = net_generic(net, nfs_net_id);
 819
 820         spin_lock(&nn->nfs_client_lock);
 821         clp = idr_find(&nn->cb_ident_idr, cb_ident);
 822         if (clp)
 823                 atomic_inc(&clp->cl_count);
 824         spin_unlock(&nn->nfs_client_lock);
 825         return clp;
 826 }
 827
 828 #if defined(CONFIG_NFS_V4_1)
 829 /* Common match routine for v4.0 and v4.1 callback services */
 830 static bool nfs4_cb_match_client(const struct sockaddr *addr,
 831                 struct nfs_client *clp, u32 minorversion)
 832 {
 833         struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
 834
 835         /* Don't match clients that failed to initialise */
 836         if (!(clp->cl_cons_state == NFS_CS_READY ||
 837             clp->cl_cons_state == NFS_CS_SESSION_INITING))
 838                 return false;
 839
 840         smp_rmb();
 841
 842         /* Match the version and minorversion */
 843         if (clp->rpc_ops->version != 4 ||
 844             clp->cl_minorversion != minorversion)
 845                 return false;
 846
 847         /* Match only the IP address, not the port number */
 848         return rpc_cmp_addr(addr, clap);
 849 }
 850
 851 /*
 852  * NFSv4.1 callback thread helper
 853  * For CB_COMPOUND calls, find a client by IP address, protocol version,
 854  * minorversion, and sessionID
 855  *
 856  * Returns NULL if no such client
 857  */
 858 struct nfs_client *
 859 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
 860                            struct nfs4_sessionid *sid, u32 minorversion)
 861 {
 862         struct nfs_client *clp;
 863         struct nfs_net *nn = net_generic(net, nfs_net_id);
 864
 865         spin_lock(&nn->nfs_client_lock);
 866         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 867                 if (nfs4_cb_match_client(addr, clp, minorversion) == false)
 868                         continue;
 869
 870                 if (!nfs4_has_session(clp))
 871                         continue;
 872
 873                 /* Match sessionid*/
 874                 if (memcmp(clp->cl_session->sess_id.data,
 875                     sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
 876                         continue;
 877
 878                 atomic_inc(&clp->cl_count);
 879                 spin_unlock(&nn->nfs_client_lock);
 880                 return clp;
 881         }
 882         spin_unlock(&nn->nfs_client_lock);
 883         return NULL;
 884 }
 885
 886 #else /* CONFIG_NFS_V4_1 */
 887
 888 struct nfs_client *
 889 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
 890                            struct nfs4_sessionid *sid, u32 minorversion)
 891 {
 892         return NULL;
 893 }
 894 #endif /* CONFIG_NFS_V4_1 */
 895
 896 /*
 897  * Set up an NFS4 client
 898  */
 899 static int nfs4_set_client(struct nfs_server *server,
 900                 const char *hostname,
 901                 const struct sockaddr *addr,
 902                 const size_t addrlen,
 903                 const char *ip_addr,
 904                 int proto, const struct rpc_timeout *timeparms,
 905                 u32 minorversion, struct net *net)
 906 {
 907         struct nfs_client_initdata cl_init = {
 908                 .hostname = hostname,
 909                 .addr = addr,
 910                 .addrlen = addrlen,
 911                 .ip_addr = ip_addr,
 912                 .nfs_mod = &nfs_v4,
 913                 .proto = proto,
 914                 .minorversion = minorversion,
 915                 .net = net,
 916                 .timeparms = timeparms,
 917         };
 918         struct nfs_client *clp;
 919         int error;
 920
 921         dprintk("--> nfs4_set_client()\n");
 922
 923         if (server->flags & NFS_MOUNT_NORESVPORT)
 924                 set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
 925         if (server->options & NFS_OPTION_MIGRATION)
 926                 set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
 927
 928         /* Allocate or find a client reference we can use */
 929         clp = nfs_get_client(&cl_init);
 930         if (IS_ERR(clp)) {
 931                 error = PTR_ERR(clp);
 932                 goto error;
 933         }
 934
 935         if (server->nfs_client == clp) {
 936                 error = -ELOOP;
 937                 goto error;
 938         }
 939
 940         /*
 941          * Query for the lease time on clientid setup or renewal
 942          *
 943          * Note that this will be set on nfs_clients that were created
 944          * only for the DS role and did not set this bit, but now will
 945          * serve a dual role.
 946          */
 947         set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
 948
 949         server->nfs_client = clp;
 950         dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
 951         return 0;
 952 error:
 953         dprintk("<-- nfs4_set_client() = xerror %d\n", error);
 954         return error;
 955 }
 956
 957 /*
 958  * Set up a pNFS Data Server client.
 959  *
 960  * Return any existing nfs_client that matches server address,port,version
 961  * and minorversion.
 962  *
 963  * For a new nfs_client, use a soft mount (default), a low retrans and a
 964  * low timeout interval so that if a connection is lost, we retry through
 965  * the MDS.
 966  */
 967 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
 968                 const struct sockaddr *ds_addr, int ds_addrlen,
 969                 int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
 970                 u32 minor_version)
 971 {
 972         struct rpc_timeout ds_timeout;
 973         struct nfs_client *mds_clp = mds_srv->nfs_client;
 974         struct nfs_client_initdata cl_init = {
 975                 .addr = ds_addr,
 976                 .addrlen = ds_addrlen,
 977                 .nodename = mds_clp->cl_rpcclient->cl_nodename,
 978                 .ip_addr = mds_clp->cl_ipaddr,
 979                 .nfs_mod = &nfs_v4,
 980                 .proto = ds_proto,
 981                 .minorversion = minor_version,
 982                 .net = mds_clp->cl_net,
 983                 .timeparms = &ds_timeout,
 984         };
 985         struct nfs_client *clp;
 986         char buf[INET6_ADDRSTRLEN + 1];
 987
 988         if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
 989                 return ERR_PTR(-EINVAL);
 990         cl_init.hostname = buf;
 991
 992         if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
 993                 __set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
 994
 995         /*
 996          * Set an authflavor equual to the MDS value. Use the MDS nfs_client
 997          * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
 998          * (section 13.1 RFC 5661).
 999          */
1000         nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
1001         clp = nfs_get_client(&cl_init);
1002
1003         dprintk("<-- %s %p\n", __func__, clp);
1004         return clp;
1005 }
1006 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
1007
1008 /*
1009  * Session has been established, and the client marked ready.
1010  * Set the mount rsize and wsize with negotiated fore channel
1011  * attributes which will be bound checked in nfs_server_set_fsinfo.
1012  */
1013 static void nfs4_session_set_rwsize(struct nfs_server *server)
1014 {
1015 #ifdef CONFIG_NFS_V4_1
1016         struct nfs4_session *sess;
1017         u32 server_resp_sz;
1018         u32 server_rqst_sz;
1019
1020         if (!nfs4_has_session(server->nfs_client))
1021                 return;
1022         sess = server->nfs_client->cl_session;
1023         server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
1024         server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
1025
1026         if (server->rsize > server_resp_sz)
1027                 server->rsize = server_resp_sz;
1028         if (server->wsize > server_rqst_sz)
1029                 server->wsize = server_rqst_sz;
1030 #endif /* CONFIG_NFS_V4_1 */
1031 }
1032
1033 static int nfs4_server_common_setup(struct nfs_server *server,
1034                 struct nfs_fh *mntfh, bool auth_probe)
1035 {
1036         struct nfs_fattr *fattr;
1037         int error;
1038
1039         /* data servers support only a subset of NFSv4.1 */
1040         if (is_ds_only_client(server->nfs_client))
1041                 return -EPROTONOSUPPORT;
1042
1043         fattr = nfs_alloc_fattr();
1044         if (fattr == NULL)
1045                 return -ENOMEM;
1046
1047         /* We must ensure the session is initialised first */
1048         error = nfs4_init_session(server->nfs_client);
1049         if (error < 0)
1050                 goto out;
1051
1052         /* Set the basic capabilities */
1053         server->caps |= server->nfs_client->cl_mvops->init_caps;
1054         if (server->flags & NFS_MOUNT_NORDIRPLUS)
1055                         server->caps &= ~NFS_CAP_READDIRPLUS;
1056         /*
1057          * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1058          * authentication.
1059          */
1060         if (nfs4_disable_idmapping &&
1061                         server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1062                 server->caps |= NFS_CAP_UIDGID_NOMAP;
1063
1064
1065         /* Probe the root fh to retrieve its FSID and filehandle */
1066         error = nfs4_get_rootfh(server, mntfh, auth_probe);
1067         if (error < 0)
1068                 goto out;
1069
1070         dprintk("Server FSID: %llx:%llx\n",
1071                         (unsigned long long) server->fsid.major,
1072                         (unsigned long long) server->fsid.minor);
1073         nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1074
1075         nfs4_session_set_rwsize(server);
1076
1077         error = nfs_probe_fsinfo(server, mntfh, fattr);
1078         if (error < 0)
1079                 goto out;
1080
1081         if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1082                 server->namelen = NFS4_MAXNAMLEN;
1083
1084         nfs_server_insert_lists(server);
1085         server->mount_time = jiffies;
1086         server->destroy = nfs4_destroy_server;
1087 out:
1088         nfs_free_fattr(fattr);
1089         return error;
1090 }
1091
1092 /*
1093  * Create a version 4 volume record
1094  */
1095 static int nfs4_init_server(struct nfs_server *server,
1096                 struct nfs_parsed_mount_data *data)
1097 {
1098         struct rpc_timeout timeparms;
1099         int error;
1100
1101         dprintk("--> nfs4_init_server()\n");
1102
1103         nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1104                         data->timeo, data->retrans);
1105
1106         /* Initialise the client representation from the mount data */
1107         server->flags = data->flags;
1108         server->options = data->options;
1109         server->auth_info = data->auth_info;
1110
1111         /* Use the first specified auth flavor. If this flavor isn't
1112          * allowed by the server, use the SECINFO path to try the
1113          * other specified flavors */
1114         if (data->auth_info.flavor_len >= 1)
1115                 data->selected_flavor = data->auth_info.flavors[0];
1116         else
1117                 data->selected_flavor = RPC_AUTH_UNIX;
1118
1119         /* Get a client record */
1120         error = nfs4_set_client(server,
1121                         data->nfs_server.hostname,
1122                         (const struct sockaddr *)&data->nfs_server.address,
1123                         data->nfs_server.addrlen,
1124                         data->client_address,
1125                         data->nfs_server.protocol,
1126                         &timeparms,
1127                         data->minorversion,
1128                         data->net);
1129         if (error < 0)
1130                 goto error;
1131
1132         if (data->rsize)
1133                 server->rsize = nfs_block_size(data->rsize, NULL);
1134         if (data->wsize)
1135                 server->wsize = nfs_block_size(data->wsize, NULL);
1136
1137         server->acregmin = data->acregmin * HZ;
1138         server->acregmax = data->acregmax * HZ;
1139         server->acdirmin = data->acdirmin * HZ;
1140         server->acdirmax = data->acdirmax * HZ;
1141
1142         server->port = data->nfs_server.port;
1143
1144         error = nfs_init_server_rpcclient(server, &timeparms,
1145                                           data->selected_flavor);
1146
1147 error:
1148         /* Done */
1149         dprintk("<-- nfs4_init_server() = %d\n", error);
1150         return error;
1151 }
1152
1153 /*
1154  * Create a version 4 volume record
1155  * - keyed on server and FSID
1156  */
1157 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1158                                       struct nfs_fh *mntfh)*/
1159 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1160                                       struct nfs_subversion *nfs_mod)
1161 {
1162         struct nfs_server *server;
1163         bool auth_probe;
1164         int error;
1165
1166         dprintk("--> nfs4_create_server()\n");
1167
1168         server = nfs_alloc_server();
1169         if (!server)
1170                 return ERR_PTR(-ENOMEM);
1171
1172         auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1173
1174         /* set up the general RPC client */
1175         error = nfs4_init_server(server, mount_info->parsed);
1176         if (error < 0)
1177                 goto error;
1178
1179         error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1180         if (error < 0)
1181                 goto error;
1182
1183         dprintk("<-- nfs4_create_server() = %p\n", server);
1184         return server;
1185
1186 error:
1187         nfs_free_server(server);
1188         dprintk("<-- nfs4_create_server() = error %d\n", error);
1189         return ERR_PTR(error);
1190 }
1191
1192 /*
1193  * Create an NFS4 referral server record
1194  */
1195 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1196                                                struct nfs_fh *mntfh)
1197 {
1198         struct nfs_client *parent_client;
1199         struct nfs_server *server, *parent_server;
1200         bool auth_probe;
1201         int error;
1202
1203         dprintk("--> nfs4_create_referral_server()\n");
1204
1205         server = nfs_alloc_server();
1206         if (!server)
1207                 return ERR_PTR(-ENOMEM);
1208
1209         parent_server = NFS_SB(data->sb);
1210         parent_client = parent_server->nfs_client;
1211
1212         /* Initialise the client representation from the parent server */
1213         nfs_server_copy_userdata(server, parent_server);
1214
1215         /* Get a client representation.
1216          * Note: NFSv4 always uses TCP, */
1217         error = nfs4_set_client(server, data->hostname,
1218                                 data->addr,
1219                                 data->addrlen,
1220                                 parent_client->cl_ipaddr,
1221                                 rpc_protocol(parent_server->client),
1222                                 parent_server->client->cl_timeout,
1223                                 parent_client->cl_mvops->minor_version,
1224                                 parent_client->cl_net);
1225         if (error < 0)
1226                 goto error;
1227
1228         error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1229         if (error < 0)
1230                 goto error;
1231
1232         auth_probe = parent_server->auth_info.flavor_len < 1;
1233
1234         error = nfs4_server_common_setup(server, mntfh, auth_probe);
1235         if (error < 0)
1236                 goto error;
1237
1238         dprintk("<-- nfs_create_referral_server() = %p\n", server);
1239         return server;
1240
1241 error:
1242         nfs_free_server(server);
1243         dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1244         return ERR_PTR(error);
1245 }
1246
1247 /*
1248  * Grab the destination's particulars, including lease expiry time.
1249  *
1250  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1251  * we have cached.
1252  */
1253 static int nfs_probe_destination(struct nfs_server *server)
1254 {
1255         struct inode *inode = d_inode(server->super->s_root);
1256         struct nfs_fattr *fattr;
1257         int error;
1258
1259         fattr = nfs_alloc_fattr();
1260         if (fattr == NULL)
1261                 return -ENOMEM;
1262
1263         /* Sanity: the probe won't work if the destination server
1264          * does not recognize the migrated FH. */
1265         error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1266
1267         nfs_free_fattr(fattr);
1268         return error;
1269 }
1270
1271 /**
1272  * nfs4_update_server - Move an nfs_server to a different nfs_client
1273  *
1274  * @server: represents FSID to be moved
1275  * @hostname: new end-point's hostname
1276  * @sap: new end-point's socket address
1277  * @salen: size of "sap"
1278  * @net: net namespace
1279  *
1280  * The nfs_server must be quiescent before this function is invoked.
1281  * Either its session is drained (NFSv4.1+), or its transport is
1282  * plugged and drained (NFSv4.0).
1283  *
1284  * Returns zero on success, or a negative errno value.
1285  */
1286 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1287                        struct sockaddr *sap, size_t salen, struct net *net)
1288 {
1289         struct nfs_client *clp = server->nfs_client;
1290         struct rpc_clnt *clnt = server->client;
1291         struct xprt_create xargs = {
1292                 .ident          = clp->cl_proto,
1293                 .net            = net,
1294                 .dstaddr        = sap,
1295                 .addrlen        = salen,
1296                 .servername     = hostname,
1297         };
1298         char buf[INET6_ADDRSTRLEN + 1];
1299         struct sockaddr_storage address;
1300         struct sockaddr *localaddr = (struct sockaddr *)&address;
1301         int error;
1302
1303         dprintk("--> %s: move FSID %llx:%llx to \"%s\")\n", __func__,
1304                         (unsigned long long)server->fsid.major,
1305                         (unsigned long long)server->fsid.minor,
1306                         hostname);
1307
1308         error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1309         if (error != 0) {
1310                 dprintk("<-- %s(): rpc_switch_client_transport returned %d\n",
1311                         __func__, error);
1312                 goto out;
1313         }
1314
1315         error = rpc_localaddr(clnt, localaddr, sizeof(address));
1316         if (error != 0) {
1317                 dprintk("<-- %s(): rpc_localaddr returned %d\n",
1318                         __func__, error);
1319                 goto out;
1320         }
1321
1322         error = -EAFNOSUPPORT;
1323         if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0) {
1324                 dprintk("<-- %s(): rpc_ntop returned %d\n",
1325                         __func__, error);
1326                 goto out;
1327         }
1328
1329         nfs_server_remove_lists(server);
1330         error = nfs4_set_client(server, hostname, sap, salen, buf,
1331                                 clp->cl_proto, clnt->cl_timeout,
1332                                 clp->cl_minorversion, net);
1333         nfs_put_client(clp);
1334         if (error != 0) {
1335                 nfs_server_insert_lists(server);
1336                 dprintk("<-- %s(): nfs4_set_client returned %d\n",
1337                         __func__, error);
1338                 goto out;
1339         }
1340
1341         if (server->nfs_client->cl_hostname == NULL)
1342                 server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1343         nfs_server_insert_lists(server);
1344
1345         error = nfs_probe_destination(server);
1346         if (error < 0)
1347                 goto out;
1348
1349         dprintk("<-- %s() succeeded\n", __func__);
1350
1351 out:
1352         return error;
1353 }