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         return clp;
 203
 204 error:
 205         nfs_free_client(clp);
 206         return ERR_PTR(err);
 207 }
 208
 209 /*
 210  * Destroy the NFS4 callback service
 211  */
 212 static void nfs4_destroy_callback(struct nfs_client *clp)
 213 {
 214         if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
 215                 nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
 216 }
 217
 218 static void nfs4_shutdown_client(struct nfs_client *clp)
 219 {
 220         if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
 221                 nfs4_kill_renewd(clp);
 222         clp->cl_mvops->shutdown_client(clp);
 223         nfs4_destroy_callback(clp);
 224         if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
 225                 nfs_idmap_delete(clp);
 226
 227         rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
 228         kfree(clp->cl_serverowner);
 229         kfree(clp->cl_serverscope);
 230         kfree(clp->cl_implid);
 231         kfree(clp->cl_owner_id);
 232 }
 233
 234 void nfs4_free_client(struct nfs_client *clp)
 235 {
 236         nfs4_shutdown_client(clp);
 237         nfs_free_client(clp);
 238 }
 239
 240 /*
 241  * Initialize the NFS4 callback service
 242  */
 243 static int nfs4_init_callback(struct nfs_client *clp)
 244 {
 245         struct rpc_xprt *xprt;
 246         int error;
 247
 248         xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
 249
 250         if (nfs4_has_session(clp)) {
 251                 error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
 252                 if (error < 0)
 253                         return error;
 254         }
 255
 256         error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
 257         if (error < 0) {
 258                 dprintk("%s: failed to start callback. Error = %d\n",
 259                         __func__, error);
 260                 return error;
 261         }
 262         __set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
 263
 264         return 0;
 265 }
 266
 267 /**
 268  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
 269  * @clp - nfs_client to initialize
 270  *
 271  * Returns zero on success, or a negative errno if some error occurred.
 272  */
 273 int nfs40_init_client(struct nfs_client *clp)
 274 {
 275         struct nfs4_slot_table *tbl;
 276         int ret;
 277
 278         tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
 279         if (tbl == NULL)
 280                 return -ENOMEM;
 281
 282         ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
 283                                         "NFSv4.0 transport Slot table");
 284         if (ret) {
 285                 kfree(tbl);
 286                 return ret;
 287         }
 288
 289         clp->cl_slot_tbl = tbl;
 290         return 0;
 291 }
 292
 293 #if defined(CONFIG_NFS_V4_1)
 294
 295 /**
 296  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
 297  * @clp - nfs_client to initialize
 298  *
 299  * Returns zero on success, or a negative errno if some error occurred.
 300  */
 301 int nfs41_init_client(struct nfs_client *clp)
 302 {
 303         struct nfs4_session *session = NULL;
 304
 305         /*
 306          * Create the session and mark it expired.
 307          * When a SEQUENCE operation encounters the expired session
 308          * it will do session recovery to initialize it.
 309          */
 310         session = nfs4_alloc_session(clp);
 311         if (!session)
 312                 return -ENOMEM;
 313
 314         clp->cl_session = session;
 315
 316         /*
 317          * The create session reply races with the server back
 318          * channel probe. Mark the client NFS_CS_SESSION_INITING
 319          * so that the client back channel can find the
 320          * nfs_client struct
 321          */
 322         nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
 323         return 0;
 324 }
 325
 326 #endif  /* CONFIG_NFS_V4_1 */
 327
 328 /*
 329  * Initialize the minor version specific parts of an NFS4 client record
 330  */
 331 static int nfs4_init_client_minor_version(struct nfs_client *clp)
 332 {
 333         int ret;
 334
 335         ret = clp->cl_mvops->init_client(clp);
 336         if (ret)
 337                 return ret;
 338         return nfs4_init_callback(clp);
 339 }
 340
 341 /**
 342  * nfs4_init_client - Initialise an NFS4 client record
 343  *
 344  * @clp: nfs_client to initialise
 345  * @timeparms: timeout parameters for underlying RPC transport
 346  * @ip_addr: callback IP address in presentation format
 347  * @authflavor: authentication flavor for underlying RPC transport
 348  *
 349  * Returns pointer to an NFS client, or an ERR_PTR value.
 350  */
 351 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
 352                                     const struct nfs_client_initdata *cl_init)
 353 {
 354         char buf[INET6_ADDRSTRLEN + 1];
 355         const char *ip_addr = cl_init->ip_addr;
 356         struct nfs_client *old;
 357         int error;
 358
 359         if (clp->cl_cons_state == NFS_CS_READY) {
 360                 /* the client is initialised already */
 361                 dprintk("<-- nfs4_init_client() = 0 [already %p]\n", clp);
 362                 return clp;
 363         }
 364
 365         /* Check NFS protocol revision and initialize RPC op vector */
 366         clp->rpc_ops = &nfs_v4_clientops;
 367
 368         if (clp->cl_minorversion != 0)
 369                 __set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
 370         __set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
 371         __set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
 372
 373         error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
 374         if (error == -EINVAL)
 375                 error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
 376         if (error < 0)
 377                 goto error;
 378
 379         /* If no clientaddr= option was specified, find a usable cb address */
 380         if (ip_addr == NULL) {
 381                 struct sockaddr_storage cb_addr;
 382                 struct sockaddr *sap = (struct sockaddr *)&cb_addr;
 383
 384                 error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
 385                 if (error < 0)
 386                         goto error;
 387                 error = rpc_ntop(sap, buf, sizeof(buf));
 388                 if (error < 0)
 389                         goto error;
 390                 ip_addr = (const char *)buf;
 391         }
 392         strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
 393
 394         error = nfs_idmap_new(clp);
 395         if (error < 0) {
 396                 dprintk("%s: failed to create idmapper. Error = %d\n",
 397                         __func__, error);
 398                 goto error;
 399         }
 400         __set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
 401
 402         error = nfs4_init_client_minor_version(clp);
 403         if (error < 0)
 404                 goto error;
 405
 406         if (!nfs4_has_session(clp))
 407                 nfs_mark_client_ready(clp, NFS_CS_READY);
 408
 409         error = nfs4_discover_server_trunking(clp, &old);
 410         if (error < 0)
 411                 goto error;
 412
 413         if (clp != old)
 414                 clp->cl_preserve_clid = true;
 415         nfs_put_client(clp);
 416         return old;
 417
 418 error:
 419         nfs_mark_client_ready(clp, error);
 420         nfs_put_client(clp);
 421         dprintk("<-- nfs4_init_client() = xerror %d\n", error);
 422         return ERR_PTR(error);
 423 }
 424
 425 /*
 426  * SETCLIENTID just did a callback update with the callback ident in
 427  * "drop," but server trunking discovery claims "drop" and "keep" are
 428  * actually the same server.  Swap the callback IDs so that "keep"
 429  * will continue to use the callback ident the server now knows about,
 430  * and so that "keep"'s original callback ident is destroyed when
 431  * "drop" is freed.
 432  */
 433 static void nfs4_swap_callback_idents(struct nfs_client *keep,
 434                                       struct nfs_client *drop)
 435 {
 436         struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
 437         unsigned int save = keep->cl_cb_ident;
 438
 439         if (keep->cl_cb_ident == drop->cl_cb_ident)
 440                 return;
 441
 442         dprintk("%s: keeping callback ident %u and dropping ident %u\n",
 443                 __func__, keep->cl_cb_ident, drop->cl_cb_ident);
 444
 445         spin_lock(&nn->nfs_client_lock);
 446
 447         idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
 448         keep->cl_cb_ident = drop->cl_cb_ident;
 449
 450         idr_replace(&nn->cb_ident_idr, drop, save);
 451         drop->cl_cb_ident = save;
 452
 453         spin_unlock(&nn->nfs_client_lock);
 454 }
 455
 456 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
 457                 const struct nfs_client *clp2)
 458 {
 459         if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
 460                 return true;
 461         return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
 462 }
 463
 464 /**
 465  * nfs40_walk_client_list - Find server that recognizes a client ID
 466  *
 467  * @new: nfs_client with client ID to test
 468  * @result: OUT: found nfs_client, or new
 469  * @cred: credential to use for trunking test
 470  *
 471  * Returns zero, a negative errno, or a negative NFS4ERR status.
 472  * If zero is returned, an nfs_client pointer is planted in "result."
 473  *
 474  * NB: nfs40_walk_client_list() relies on the new nfs_client being
 475  *     the last nfs_client on the list.
 476  */
 477 int nfs40_walk_client_list(struct nfs_client *new,
 478                            struct nfs_client **result,
 479                            struct rpc_cred *cred)
 480 {
 481         struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
 482         struct nfs_client *pos, *prev = NULL;
 483         struct nfs4_setclientid_res clid = {
 484                 .clientid       = new->cl_clientid,
 485                 .confirm        = new->cl_confirm,
 486         };
 487         int status = -NFS4ERR_STALE_CLIENTID;
 488
 489         spin_lock(&nn->nfs_client_lock);
 490         list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
 491
 492                 if (pos->rpc_ops != new->rpc_ops)
 493                         continue;
 494
 495                 if (pos->cl_minorversion != new->cl_minorversion)
 496                         continue;
 497
 498                 /* If "pos" isn't marked ready, we can't trust the
 499                  * remaining fields in "pos" */
 500                 if (pos->cl_cons_state > NFS_CS_READY) {
 501                         atomic_inc(&pos->cl_count);
 502                         spin_unlock(&nn->nfs_client_lock);
 503
 504                         nfs_put_client(prev);
 505                         prev = pos;
 506
 507                         status = nfs_wait_client_init_complete(pos);
 508                         if (status < 0)
 509                                 goto out;
 510                         status = -NFS4ERR_STALE_CLIENTID;
 511                         spin_lock(&nn->nfs_client_lock);
 512                 }
 513                 if (pos->cl_cons_state != NFS_CS_READY)
 514                         continue;
 515
 516                 if (pos->cl_clientid != new->cl_clientid)
 517                         continue;
 518
 519                 if (!nfs4_match_client_owner_id(pos, new))
 520                         continue;
 521
 522                 atomic_inc(&pos->cl_count);
 523                 spin_unlock(&nn->nfs_client_lock);
 524
 525                 nfs_put_client(prev);
 526                 prev = pos;
 527
 528                 status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
 529                 switch (status) {
 530                 case -NFS4ERR_STALE_CLIENTID:
 531                         break;
 532                 case 0:
 533                         nfs4_swap_callback_idents(pos, new);
 534
 535                         prev = NULL;
 536                         *result = pos;
 537                         dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
 538                                 __func__, pos, atomic_read(&pos->cl_count));
 539                         goto out;
 540                 case -ERESTARTSYS:
 541                 case -ETIMEDOUT:
 542                         /* The callback path may have been inadvertently
 543                          * changed. Schedule recovery!
 544                          */
 545                         nfs4_schedule_path_down_recovery(pos);
 546                 default:
 547                         goto out;
 548                 }
 549
 550                 spin_lock(&nn->nfs_client_lock);
 551         }
 552         spin_unlock(&nn->nfs_client_lock);
 553
 554         /* No match found. The server lost our clientid */
 555 out:
 556         nfs_put_client(prev);
 557         dprintk("NFS: <-- %s status = %d\n", __func__, status);
 558         return status;
 559 }
 560
 561 #ifdef CONFIG_NFS_V4_1
 562 /*
 563  * Returns true if the client IDs match
 564  */
 565 static bool nfs4_match_clientids(struct nfs_client *a, struct nfs_client *b)
 566 {
 567         if (a->cl_clientid != b->cl_clientid) {
 568                 dprintk("NFS: --> %s client ID %llx does not match %llx\n",
 569                         __func__, a->cl_clientid, b->cl_clientid);
 570                 return false;
 571         }
 572         dprintk("NFS: --> %s client ID %llx matches %llx\n",
 573                 __func__, a->cl_clientid, b->cl_clientid);
 574         return true;
 575 }
 576
 577 /*
 578  * Returns true if the server major ids match
 579  */
 580 static bool
 581 nfs4_check_clientid_trunking(struct nfs_client *a, struct nfs_client *b)
 582 {
 583         struct nfs41_server_owner *o1 = a->cl_serverowner;
 584         struct nfs41_server_owner *o2 = b->cl_serverowner;
 585
 586         if (o1->major_id_sz != o2->major_id_sz)
 587                 goto out_major_mismatch;
 588         if (memcmp(o1->major_id, o2->major_id, o1->major_id_sz) != 0)
 589                 goto out_major_mismatch;
 590
 591         dprintk("NFS: --> %s server owners match\n", __func__);
 592         return true;
 593
 594 out_major_mismatch:
 595         dprintk("NFS: --> %s server owner major IDs do not match\n",
 596                 __func__);
 597         return false;
 598 }
 599
 600 /**
 601  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
 602  *
 603  * @new: nfs_client with client ID to test
 604  * @result: OUT: found nfs_client, or new
 605  * @cred: credential to use for trunking test
 606  *
 607  * Returns zero, a negative errno, or a negative NFS4ERR status.
 608  * If zero is returned, an nfs_client pointer is planted in "result."
 609  *
 610  * NB: nfs41_walk_client_list() relies on the new nfs_client being
 611  *     the last nfs_client on the list.
 612  */
 613 int nfs41_walk_client_list(struct nfs_client *new,
 614                            struct nfs_client **result,
 615                            struct rpc_cred *cred)
 616 {
 617         struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
 618         struct nfs_client *pos, *prev = NULL;
 619         int status = -NFS4ERR_STALE_CLIENTID;
 620
 621         spin_lock(&nn->nfs_client_lock);
 622         list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
 623
 624                 if (pos == new)
 625                         goto found;
 626
 627                 if (pos->rpc_ops != new->rpc_ops)
 628                         continue;
 629
 630                 if (pos->cl_minorversion != new->cl_minorversion)
 631                         continue;
 632
 633                 /* If "pos" isn't marked ready, we can't trust the
 634                  * remaining fields in "pos", especially the client
 635                  * ID and serverowner fields.  Wait for CREATE_SESSION
 636                  * to finish. */
 637                 if (pos->cl_cons_state > NFS_CS_READY) {
 638                         atomic_inc(&pos->cl_count);
 639                         spin_unlock(&nn->nfs_client_lock);
 640
 641                         nfs_put_client(prev);
 642                         prev = pos;
 643
 644                         status = nfs_wait_client_init_complete(pos);
 645                         spin_lock(&nn->nfs_client_lock);
 646                         if (status < 0)
 647                                 break;
 648                         status = -NFS4ERR_STALE_CLIENTID;
 649                 }
 650                 if (pos->cl_cons_state != NFS_CS_READY)
 651                         continue;
 652
 653                 if (!nfs4_match_clientids(pos, new))
 654                         continue;
 655
 656                 /*
 657                  * Note that session trunking is just a special subcase of
 658                  * client id trunking. In either case, we want to fall back
 659                  * to using the existing nfs_client.
 660                  */
 661                 if (!nfs4_check_clientid_trunking(pos, new))
 662                         continue;
 663
 664                 /* Unlike NFSv4.0, we know that NFSv4.1 always uses the
 665                  * uniform string, however someone might switch the
 666                  * uniquifier string on us.
 667                  */
 668                 if (!nfs4_match_client_owner_id(pos, new))
 669                         continue;
 670 found:
 671                 atomic_inc(&pos->cl_count);
 672                 *result = pos;
 673                 status = 0;
 674                 dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
 675                         __func__, pos, atomic_read(&pos->cl_count));
 676                 break;
 677         }
 678
 679         spin_unlock(&nn->nfs_client_lock);
 680         dprintk("NFS: <-- %s status = %d\n", __func__, status);
 681         nfs_put_client(prev);
 682         return status;
 683 }
 684 #endif  /* CONFIG_NFS_V4_1 */
 685
 686 static void nfs4_destroy_server(struct nfs_server *server)
 687 {
 688         nfs_server_return_all_delegations(server);
 689         unset_pnfs_layoutdriver(server);
 690         nfs4_purge_state_owners(server);
 691 }
 692
 693 /*
 694  * NFSv4.0 callback thread helper
 695  *
 696  * Find a client by callback identifier
 697  */
 698 struct nfs_client *
 699 nfs4_find_client_ident(struct net *net, int cb_ident)
 700 {
 701         struct nfs_client *clp;
 702         struct nfs_net *nn = net_generic(net, nfs_net_id);
 703
 704         spin_lock(&nn->nfs_client_lock);
 705         clp = idr_find(&nn->cb_ident_idr, cb_ident);
 706         if (clp)
 707                 atomic_inc(&clp->cl_count);
 708         spin_unlock(&nn->nfs_client_lock);
 709         return clp;
 710 }
 711
 712 #if defined(CONFIG_NFS_V4_1)
 713 /* Common match routine for v4.0 and v4.1 callback services */
 714 static bool nfs4_cb_match_client(const struct sockaddr *addr,
 715                 struct nfs_client *clp, u32 minorversion)
 716 {
 717         struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
 718
 719         /* Don't match clients that failed to initialise */
 720         if (!(clp->cl_cons_state == NFS_CS_READY ||
 721             clp->cl_cons_state == NFS_CS_SESSION_INITING))
 722                 return false;
 723
 724         smp_rmb();
 725
 726         /* Match the version and minorversion */
 727         if (clp->rpc_ops->version != 4 ||
 728             clp->cl_minorversion != minorversion)
 729                 return false;
 730
 731         /* Match only the IP address, not the port number */
 732         return rpc_cmp_addr(addr, clap);
 733 }
 734
 735 /*
 736  * NFSv4.1 callback thread helper
 737  * For CB_COMPOUND calls, find a client by IP address, protocol version,
 738  * minorversion, and sessionID
 739  *
 740  * Returns NULL if no such client
 741  */
 742 struct nfs_client *
 743 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
 744                            struct nfs4_sessionid *sid, u32 minorversion)
 745 {
 746         struct nfs_client *clp;
 747         struct nfs_net *nn = net_generic(net, nfs_net_id);
 748
 749         spin_lock(&nn->nfs_client_lock);
 750         list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
 751                 if (nfs4_cb_match_client(addr, clp, minorversion) == false)
 752                         continue;
 753
 754                 if (!nfs4_has_session(clp))
 755                         continue;
 756
 757                 /* Match sessionid*/
 758                 if (memcmp(clp->cl_session->sess_id.data,
 759                     sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
 760                         continue;
 761
 762                 atomic_inc(&clp->cl_count);
 763                 spin_unlock(&nn->nfs_client_lock);
 764                 return clp;
 765         }
 766         spin_unlock(&nn->nfs_client_lock);
 767         return NULL;
 768 }
 769
 770 #else /* CONFIG_NFS_V4_1 */
 771
 772 struct nfs_client *
 773 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
 774                            struct nfs4_sessionid *sid, u32 minorversion)
 775 {
 776         return NULL;
 777 }
 778 #endif /* CONFIG_NFS_V4_1 */
 779
 780 /*
 781  * Set up an NFS4 client
 782  */
 783 static int nfs4_set_client(struct nfs_server *server,
 784                 const char *hostname,
 785                 const struct sockaddr *addr,
 786                 const size_t addrlen,
 787                 const char *ip_addr,
 788                 rpc_authflavor_t authflavour,
 789                 int proto, const struct rpc_timeout *timeparms,
 790                 u32 minorversion, struct net *net)
 791 {
 792         struct nfs_client_initdata cl_init = {
 793                 .hostname = hostname,
 794                 .addr = addr,
 795                 .addrlen = addrlen,
 796                 .ip_addr = ip_addr,
 797                 .nfs_mod = &nfs_v4,
 798                 .proto = proto,
 799                 .minorversion = minorversion,
 800                 .net = net,
 801                 .timeparms = timeparms,
 802         };
 803         struct nfs_client *clp;
 804         int error;
 805
 806         dprintk("--> nfs4_set_client()\n");
 807
 808         if (server->flags & NFS_MOUNT_NORESVPORT)
 809                 set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
 810         if (server->options & NFS_OPTION_MIGRATION)
 811                 set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
 812
 813         /* Allocate or find a client reference we can use */
 814         clp = nfs_get_client(&cl_init, authflavour);
 815         if (IS_ERR(clp)) {
 816                 error = PTR_ERR(clp);
 817                 goto error;
 818         }
 819
 820         /*
 821          * Query for the lease time on clientid setup or renewal
 822          *
 823          * Note that this will be set on nfs_clients that were created
 824          * only for the DS role and did not set this bit, but now will
 825          * serve a dual role.
 826          */
 827         set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
 828
 829         server->nfs_client = clp;
 830         dprintk("<-- nfs4_set_client() = 0 [new %p]\n", clp);
 831         return 0;
 832 error:
 833         dprintk("<-- nfs4_set_client() = xerror %d\n", error);
 834         return error;
 835 }
 836
 837 /*
 838  * Set up a pNFS Data Server client.
 839  *
 840  * Return any existing nfs_client that matches server address,port,version
 841  * and minorversion.
 842  *
 843  * For a new nfs_client, use a soft mount (default), a low retrans and a
 844  * low timeout interval so that if a connection is lost, we retry through
 845  * the MDS.
 846  */
 847 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
 848                 const struct sockaddr *ds_addr, int ds_addrlen,
 849                 int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
 850                 u32 minor_version, rpc_authflavor_t au_flavor)
 851 {
 852         struct rpc_timeout ds_timeout;
 853         struct nfs_client *mds_clp = mds_srv->nfs_client;
 854         struct nfs_client_initdata cl_init = {
 855                 .addr = ds_addr,
 856                 .addrlen = ds_addrlen,
 857                 .nodename = mds_clp->cl_rpcclient->cl_nodename,
 858                 .ip_addr = mds_clp->cl_ipaddr,
 859                 .nfs_mod = &nfs_v4,
 860                 .proto = ds_proto,
 861                 .minorversion = minor_version,
 862                 .net = mds_clp->cl_net,
 863                 .timeparms = &ds_timeout,
 864         };
 865         struct nfs_client *clp;
 866         char buf[INET6_ADDRSTRLEN + 1];
 867
 868         if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
 869                 return ERR_PTR(-EINVAL);
 870         cl_init.hostname = buf;
 871
 872         if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
 873                 __set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
 874
 875         /*
 876          * Set an authflavor equual to the MDS value. Use the MDS nfs_client
 877          * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
 878          * (section 13.1 RFC 5661).
 879          */
 880         nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
 881         clp = nfs_get_client(&cl_init, au_flavor);
 882
 883         dprintk("<-- %s %p\n", __func__, clp);
 884         return clp;
 885 }
 886 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
 887
 888 /*
 889  * Session has been established, and the client marked ready.
 890  * Set the mount rsize and wsize with negotiated fore channel
 891  * attributes which will be bound checked in nfs_server_set_fsinfo.
 892  */
 893 static void nfs4_session_set_rwsize(struct nfs_server *server)
 894 {
 895 #ifdef CONFIG_NFS_V4_1
 896         struct nfs4_session *sess;
 897         u32 server_resp_sz;
 898         u32 server_rqst_sz;
 899
 900         if (!nfs4_has_session(server->nfs_client))
 901                 return;
 902         sess = server->nfs_client->cl_session;
 903         server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
 904         server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
 905
 906         if (server->rsize > server_resp_sz)
 907                 server->rsize = server_resp_sz;
 908         if (server->wsize > server_rqst_sz)
 909                 server->wsize = server_rqst_sz;
 910 #endif /* CONFIG_NFS_V4_1 */
 911 }
 912
 913 static int nfs4_server_common_setup(struct nfs_server *server,
 914                 struct nfs_fh *mntfh, bool auth_probe)
 915 {
 916         struct nfs_fattr *fattr;
 917         int error;
 918
 919         /* data servers support only a subset of NFSv4.1 */
 920         if (is_ds_only_client(server->nfs_client))
 921                 return -EPROTONOSUPPORT;
 922
 923         fattr = nfs_alloc_fattr();
 924         if (fattr == NULL)
 925                 return -ENOMEM;
 926
 927         /* We must ensure the session is initialised first */
 928         error = nfs4_init_session(server->nfs_client);
 929         if (error < 0)
 930                 goto out;
 931
 932         /* Set the basic capabilities */
 933         server->caps |= server->nfs_client->cl_mvops->init_caps;
 934         if (server->flags & NFS_MOUNT_NORDIRPLUS)
 935                         server->caps &= ~NFS_CAP_READDIRPLUS;
 936         /*
 937          * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
 938          * authentication.
 939          */
 940         if (nfs4_disable_idmapping &&
 941                         server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
 942                 server->caps |= NFS_CAP_UIDGID_NOMAP;
 943
 944
 945         /* Probe the root fh to retrieve its FSID and filehandle */
 946         error = nfs4_get_rootfh(server, mntfh, auth_probe);
 947         if (error < 0)
 948                 goto out;
 949
 950         dprintk("Server FSID: %llx:%llx\n",
 951                         (unsigned long long) server->fsid.major,
 952                         (unsigned long long) server->fsid.minor);
 953         nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
 954
 955         nfs4_session_set_rwsize(server);
 956
 957         error = nfs_probe_fsinfo(server, mntfh, fattr);
 958         if (error < 0)
 959                 goto out;
 960
 961         if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
 962                 server->namelen = NFS4_MAXNAMLEN;
 963
 964         nfs_server_insert_lists(server);
 965         server->mount_time = jiffies;
 966         server->destroy = nfs4_destroy_server;
 967 out:
 968         nfs_free_fattr(fattr);
 969         return error;
 970 }
 971
 972 /*
 973  * Create a version 4 volume record
 974  */
 975 static int nfs4_init_server(struct nfs_server *server,
 976                 struct nfs_parsed_mount_data *data)
 977 {
 978         struct rpc_timeout timeparms;
 979         int error;
 980
 981         dprintk("--> nfs4_init_server()\n");
 982
 983         nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
 984                         data->timeo, data->retrans);
 985
 986         /* Initialise the client representation from the mount data */
 987         server->flags = data->flags;
 988         server->options = data->options;
 989         server->auth_info = data->auth_info;
 990
 991         /* Use the first specified auth flavor. If this flavor isn't
 992          * allowed by the server, use the SECINFO path to try the
 993          * other specified flavors */
 994         if (data->auth_info.flavor_len >= 1)
 995                 data->selected_flavor = data->auth_info.flavors[0];
 996         else
 997                 data->selected_flavor = RPC_AUTH_UNIX;
 998
 999         /* Get a client record */
1000         error = nfs4_set_client(server,
1001                         data->nfs_server.hostname,
1002                         (const struct sockaddr *)&data->nfs_server.address,
1003                         data->nfs_server.addrlen,
1004                         data->client_address,
1005                         data->selected_flavor,
1006                         data->nfs_server.protocol,
1007                         &timeparms,
1008                         data->minorversion,
1009                         data->net);
1010         if (error < 0)
1011                 goto error;
1012
1013         if (data->rsize)
1014                 server->rsize = nfs_block_size(data->rsize, NULL);
1015         if (data->wsize)
1016                 server->wsize = nfs_block_size(data->wsize, NULL);
1017
1018         server->acregmin = data->acregmin * HZ;
1019         server->acregmax = data->acregmax * HZ;
1020         server->acdirmin = data->acdirmin * HZ;
1021         server->acdirmax = data->acdirmax * HZ;
1022
1023         server->port = data->nfs_server.port;
1024
1025         error = nfs_init_server_rpcclient(server, &timeparms,
1026                                           data->selected_flavor);
1027
1028 error:
1029         /* Done */
1030         dprintk("<-- nfs4_init_server() = %d\n", error);
1031         return error;
1032 }
1033
1034 /*
1035  * Create a version 4 volume record
1036  * - keyed on server and FSID
1037  */
1038 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1039                                       struct nfs_fh *mntfh)*/
1040 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1041                                       struct nfs_subversion *nfs_mod)
1042 {
1043         struct nfs_server *server;
1044         bool auth_probe;
1045         int error;
1046
1047         dprintk("--> nfs4_create_server()\n");
1048
1049         server = nfs_alloc_server();
1050         if (!server)
1051                 return ERR_PTR(-ENOMEM);
1052
1053         auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1054
1055         /* set up the general RPC client */
1056         error = nfs4_init_server(server, mount_info->parsed);
1057         if (error < 0)
1058                 goto error;
1059
1060         error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1061         if (error < 0)
1062                 goto error;
1063
1064         dprintk("<-- nfs4_create_server() = %p\n", server);
1065         return server;
1066
1067 error:
1068         nfs_free_server(server);
1069         dprintk("<-- nfs4_create_server() = error %d\n", error);
1070         return ERR_PTR(error);
1071 }
1072
1073 /*
1074  * Create an NFS4 referral server record
1075  */
1076 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1077                                                struct nfs_fh *mntfh)
1078 {
1079         struct nfs_client *parent_client;
1080         struct nfs_server *server, *parent_server;
1081         bool auth_probe;
1082         int error;
1083
1084         dprintk("--> nfs4_create_referral_server()\n");
1085
1086         server = nfs_alloc_server();
1087         if (!server)
1088                 return ERR_PTR(-ENOMEM);
1089
1090         parent_server = NFS_SB(data->sb);
1091         parent_client = parent_server->nfs_client;
1092
1093         /* Initialise the client representation from the parent server */
1094         nfs_server_copy_userdata(server, parent_server);
1095
1096         /* Get a client representation.
1097          * Note: NFSv4 always uses TCP, */
1098         error = nfs4_set_client(server, data->hostname,
1099                                 data->addr,
1100                                 data->addrlen,
1101                                 parent_client->cl_ipaddr,
1102                                 data->authflavor,
1103                                 rpc_protocol(parent_server->client),
1104                                 parent_server->client->cl_timeout,
1105                                 parent_client->cl_mvops->minor_version,
1106                                 parent_client->cl_net);
1107         if (error < 0)
1108                 goto error;
1109
1110         error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1111         if (error < 0)
1112                 goto error;
1113
1114         auth_probe = parent_server->auth_info.flavor_len < 1;
1115
1116         error = nfs4_server_common_setup(server, mntfh, auth_probe);
1117         if (error < 0)
1118                 goto error;
1119
1120         dprintk("<-- nfs_create_referral_server() = %p\n", server);
1121         return server;
1122
1123 error:
1124         nfs_free_server(server);
1125         dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
1126         return ERR_PTR(error);
1127 }
1128
1129 /*
1130  * Grab the destination's particulars, including lease expiry time.
1131  *
1132  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1133  * we have cached.
1134  */
1135 static int nfs_probe_destination(struct nfs_server *server)
1136 {
1137         struct inode *inode = d_inode(server->super->s_root);
1138         struct nfs_fattr *fattr;
1139         int error;
1140
1141         fattr = nfs_alloc_fattr();
1142         if (fattr == NULL)
1143                 return -ENOMEM;
1144
1145         /* Sanity: the probe won't work if the destination server
1146          * does not recognize the migrated FH. */
1147         error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1148
1149         nfs_free_fattr(fattr);
1150         return error;
1151 }
1152
1153 /**
1154  * nfs4_update_server - Move an nfs_server to a different nfs_client
1155  *
1156  * @server: represents FSID to be moved
1157  * @hostname: new end-point's hostname
1158  * @sap: new end-point's socket address
1159  * @salen: size of "sap"
1160  * @net: net namespace
1161  *
1162  * The nfs_server must be quiescent before this function is invoked.
1163  * Either its session is drained (NFSv4.1+), or its transport is
1164  * plugged and drained (NFSv4.0).
1165  *
1166  * Returns zero on success, or a negative errno value.
1167  */
1168 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1169                        struct sockaddr *sap, size_t salen, struct net *net)
1170 {
1171         struct nfs_client *clp = server->nfs_client;
1172         struct rpc_clnt *clnt = server->client;
1173         struct xprt_create xargs = {
1174                 .ident          = clp->cl_proto,
1175                 .net            = net,
1176                 .dstaddr        = sap,
1177                 .addrlen        = salen,
1178                 .servername     = hostname,
1179         };
1180         char buf[INET6_ADDRSTRLEN + 1];
1181         struct sockaddr_storage address;
1182         struct sockaddr *localaddr = (struct sockaddr *)&address;
1183         int error;
1184
1185         dprintk("--> %s: move FSID %llx:%llx to \"%s\")\n", __func__,
1186                         (unsigned long long)server->fsid.major,
1187                         (unsigned long long)server->fsid.minor,
1188                         hostname);
1189
1190         error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1191         if (error != 0) {
1192                 dprintk("<-- %s(): rpc_switch_client_transport returned %d\n",
1193                         __func__, error);
1194                 goto out;
1195         }
1196
1197         error = rpc_localaddr(clnt, localaddr, sizeof(address));
1198         if (error != 0) {
1199                 dprintk("<-- %s(): rpc_localaddr returned %d\n",
1200                         __func__, error);
1201                 goto out;
1202         }
1203
1204         error = -EAFNOSUPPORT;
1205         if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0) {
1206                 dprintk("<-- %s(): rpc_ntop returned %d\n",
1207                         __func__, error);
1208                 goto out;
1209         }
1210
1211         nfs_server_remove_lists(server);
1212         error = nfs4_set_client(server, hostname, sap, salen, buf,
1213                                 clp->cl_rpcclient->cl_auth->au_flavor,
1214                                 clp->cl_proto, clnt->cl_timeout,
1215                                 clp->cl_minorversion, net);
1216         nfs_put_client(clp);
1217         if (error != 0) {
1218                 nfs_server_insert_lists(server);
1219                 dprintk("<-- %s(): nfs4_set_client returned %d\n",
1220                         __func__, error);
1221                 goto out;
1222         }
1223
1224         if (server->nfs_client->cl_hostname == NULL)
1225                 server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1226         nfs_server_insert_lists(server);
1227
1228         error = nfs_probe_destination(server);
1229         if (error < 0)
1230                 goto out;
1231
1232         dprintk("<-- %s() succeeded\n", __func__);
1233
1234 out:
1235         return error;
1236 }