fs/nfs/nfs4state.c

   1 /*
   2  *  fs/nfs/nfs4state.c
   3  *
   4  *  Client-side XDR for NFSv4.
   5  *
   6  *  Copyright (c) 2002 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Kendrick Smith <kmsmith@umich.edu>
  10  *
  11  *  Redistribution and use in source and binary forms, with or without
  12  *  modification, are permitted provided that the following conditions
  13  *  are met:
  14  *
  15  *  1. Redistributions of source code must retain the above copyright
  16  *     notice, this list of conditions and the following disclaimer.
  17  *  2. Redistributions in binary form must reproduce the above copyright
  18  *     notice, this list of conditions and the following disclaimer in the
  19  *     documentation and/or other materials provided with the distribution.
  20  *  3. Neither the name of the University nor the names of its
  21  *     contributors may be used to endorse or promote products derived
  22  *     from this software without specific prior written permission.
  23  *
  24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  * Implementation of the NFSv4 state model.  For the time being,
  37  * this is minimal, but will be made much more complex in a
  38  * subsequent patch.
  39  */
  40
  41 #include <linux/kernel.h>
  42 #include <linux/slab.h>
  43 #include <linux/fs.h>
  44 #include <linux/nfs_fs.h>
  45 #include <linux/nfs_idmap.h>
  46 #include <linux/kthread.h>
  47 #include <linux/module.h>
  48 #include <linux/random.h>
  49 #include <linux/ratelimit.h>
  50 #include <linux/workqueue.h>
  51 #include <linux/bitops.h>
  52 #include <linux/jiffies.h>
  53
  54 #include <linux/sunrpc/clnt.h>
  55
  56 #include "nfs4_fs.h"
  57 #include "callback.h"
  58 #include "delegation.h"
  59 #include "internal.h"
  60 #include "nfs4session.h"
  61 #include "pnfs.h"
  62 #include "netns.h"
  63
  64 #define NFSDBG_FACILITY         NFSDBG_STATE
  65
  66 #define OPENOWNER_POOL_SIZE     8
  67
  68 const nfs4_stateid zero_stateid;
  69 static DEFINE_MUTEX(nfs_clid_init_mutex);
  70
  71 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
  72 {
  73         struct nfs4_setclientid_res clid = {
  74                 .clientid = clp->cl_clientid,
  75                 .confirm = clp->cl_confirm,
  76         };
  77         unsigned short port;
  78         int status;
  79         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
  80
  81         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
  82                 goto do_confirm;
  83         port = nn->nfs_callback_tcpport;
  84         if (clp->cl_addr.ss_family == AF_INET6)
  85                 port = nn->nfs_callback_tcpport6;
  86
  87         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
  88         if (status != 0)
  89                 goto out;
  90         clp->cl_clientid = clid.clientid;
  91         clp->cl_confirm = clid.confirm;
  92         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
  93 do_confirm:
  94         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
  95         if (status != 0)
  96                 goto out;
  97         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
  98         nfs4_schedule_state_renewal(clp);
  99 out:
 100         return status;
 101 }
 102
 103 /**
 104  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
 105  *
 106  * @clp: nfs_client under test
 107  * @result: OUT: found nfs_client, or clp
 108  * @cred: credential to use for trunking test
 109  *
 110  * Returns zero, a negative errno, or a negative NFS4ERR status.
 111  * If zero is returned, an nfs_client pointer is planted in
 112  * "result".
 113  *
 114  * Note: The returned client may not yet be marked ready.
 115  */
 116 int nfs40_discover_server_trunking(struct nfs_client *clp,
 117                                    struct nfs_client **result,
 118                                    struct rpc_cred *cred)
 119 {
 120         struct nfs4_setclientid_res clid = {
 121                 .clientid = clp->cl_clientid,
 122                 .confirm = clp->cl_confirm,
 123         };
 124         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 125         unsigned short port;
 126         int status;
 127
 128         port = nn->nfs_callback_tcpport;
 129         if (clp->cl_addr.ss_family == AF_INET6)
 130                 port = nn->nfs_callback_tcpport6;
 131
 132         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 133         if (status != 0)
 134                 goto out;
 135         clp->cl_clientid = clid.clientid;
 136         clp->cl_confirm = clid.confirm;
 137
 138         status = nfs40_walk_client_list(clp, result, cred);
 139         switch (status) {
 140         case -NFS4ERR_STALE_CLIENTID:
 141                 set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 142         case 0:
 143                 /* Sustain the lease, even if it's empty.  If the clientid4
 144                  * goes stale it's of no use for trunking discovery. */
 145                 nfs4_schedule_state_renewal(*result);
 146                 break;
 147         }
 148
 149 out:
 150         return status;
 151 }
 152
 153 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
 154 {
 155         struct rpc_cred *cred = NULL;
 156
 157         if (clp->cl_machine_cred != NULL)
 158                 cred = get_rpccred(clp->cl_machine_cred);
 159         return cred;
 160 }
 161
 162 static void nfs4_clear_machine_cred(struct nfs_client *clp)
 163 {
 164         struct rpc_cred *cred;
 165
 166         spin_lock(&clp->cl_lock);
 167         cred = clp->cl_machine_cred;
 168         clp->cl_machine_cred = NULL;
 169         spin_unlock(&clp->cl_lock);
 170         if (cred != NULL)
 171                 put_rpccred(cred);
 172 }
 173
 174 static struct rpc_cred *
 175 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
 176 {
 177         struct rpc_cred *cred = NULL;
 178         struct nfs4_state_owner *sp;
 179         struct rb_node *pos;
 180
 181         for (pos = rb_first(&server->state_owners);
 182              pos != NULL;
 183              pos = rb_next(pos)) {
 184                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 185                 if (list_empty(&sp->so_states))
 186                         continue;
 187                 cred = get_rpccred(sp->so_cred);
 188                 break;
 189         }
 190         return cred;
 191 }
 192
 193 /**
 194  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
 195  * @clp: client state handle
 196  *
 197  * Returns an rpc_cred with reference count bumped, or NULL.
 198  * Caller must hold clp->cl_lock.
 199  */
 200 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
 201 {
 202         struct rpc_cred *cred = NULL;
 203         struct nfs_server *server;
 204
 205         /* Use machine credentials if available */
 206         cred = nfs4_get_machine_cred_locked(clp);
 207         if (cred != NULL)
 208                 goto out;
 209
 210         rcu_read_lock();
 211         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 212                 cred = nfs4_get_renew_cred_server_locked(server);
 213                 if (cred != NULL)
 214                         break;
 215         }
 216         rcu_read_unlock();
 217
 218 out:
 219         return cred;
 220 }
 221
 222 #if defined(CONFIG_NFS_V4_1)
 223
 224 static int nfs41_setup_state_renewal(struct nfs_client *clp)
 225 {
 226         int status;
 227         struct nfs_fsinfo fsinfo;
 228
 229         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 230                 nfs4_schedule_state_renewal(clp);
 231                 return 0;
 232         }
 233
 234         status = nfs4_proc_get_lease_time(clp, &fsinfo);
 235         if (status == 0) {
 236                 /* Update lease time and schedule renewal */
 237                 spin_lock(&clp->cl_lock);
 238                 clp->cl_lease_time = fsinfo.lease_time * HZ;
 239                 clp->cl_last_renewal = jiffies;
 240                 spin_unlock(&clp->cl_lock);
 241
 242                 nfs4_schedule_state_renewal(clp);
 243         }
 244
 245         return status;
 246 }
 247
 248 /*
 249  * Back channel returns NFS4ERR_DELAY for new requests when
 250  * NFS4_SESSION_DRAINING is set so there is no work to be done when draining
 251  * is ended.
 252  */
 253 static void nfs4_end_drain_session(struct nfs_client *clp)
 254 {
 255         struct nfs4_session *ses = clp->cl_session;
 256         struct nfs4_slot_table *tbl;
 257
 258         if (ses == NULL)
 259                 return;
 260         tbl = &ses->fc_slot_table;
 261         if (test_and_clear_bit(NFS4_SESSION_DRAINING, &ses->session_state)) {
 262                 spin_lock(&tbl->slot_tbl_lock);
 263                 nfs41_wake_slot_table(tbl);
 264                 spin_unlock(&tbl->slot_tbl_lock);
 265         }
 266 }
 267
 268 /*
 269  * Signal state manager thread if session fore channel is drained
 270  */
 271 void nfs4_session_drain_complete(struct nfs4_session *session,
 272                 struct nfs4_slot_table *tbl)
 273 {
 274         if (nfs4_session_draining(session))
 275                 complete(&tbl->complete);
 276 }
 277
 278 static int nfs4_wait_on_slot_tbl(struct nfs4_slot_table *tbl)
 279 {
 280         spin_lock(&tbl->slot_tbl_lock);
 281         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
 282                 INIT_COMPLETION(tbl->complete);
 283                 spin_unlock(&tbl->slot_tbl_lock);
 284                 return wait_for_completion_interruptible(&tbl->complete);
 285         }
 286         spin_unlock(&tbl->slot_tbl_lock);
 287         return 0;
 288 }
 289
 290 static int nfs4_begin_drain_session(struct nfs_client *clp)
 291 {
 292         struct nfs4_session *ses = clp->cl_session;
 293         int ret = 0;
 294
 295         set_bit(NFS4_SESSION_DRAINING, &ses->session_state);
 296         /* back channel */
 297         ret = nfs4_wait_on_slot_tbl(&ses->bc_slot_table);
 298         if (ret)
 299                 return ret;
 300         /* fore channel */
 301         return nfs4_wait_on_slot_tbl(&ses->fc_slot_table);
 302 }
 303
 304 static void nfs41_finish_session_reset(struct nfs_client *clp)
 305 {
 306         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 307         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
 308         /* create_session negotiated new slot table */
 309         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
 310         nfs41_setup_state_renewal(clp);
 311 }
 312
 313 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 314 {
 315         int status;
 316
 317         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 318                 goto do_confirm;
 319         nfs4_begin_drain_session(clp);
 320         status = nfs4_proc_exchange_id(clp, cred);
 321         if (status != 0)
 322                 goto out;
 323         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 324 do_confirm:
 325         status = nfs4_proc_create_session(clp, cred);
 326         if (status != 0)
 327                 goto out;
 328         nfs41_finish_session_reset(clp);
 329         nfs_mark_client_ready(clp, NFS_CS_READY);
 330 out:
 331         return status;
 332 }
 333
 334 /**
 335  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
 336  *
 337  * @clp: nfs_client under test
 338  * @result: OUT: found nfs_client, or clp
 339  * @cred: credential to use for trunking test
 340  *
 341  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
 342  * If NFS4_OK is returned, an nfs_client pointer is planted in
 343  * "result".
 344  *
 345  * Note: The returned client may not yet be marked ready.
 346  */
 347 int nfs41_discover_server_trunking(struct nfs_client *clp,
 348                                    struct nfs_client **result,
 349                                    struct rpc_cred *cred)
 350 {
 351         int status;
 352
 353         status = nfs4_proc_exchange_id(clp, cred);
 354         if (status != NFS4_OK)
 355                 return status;
 356         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 357
 358         return nfs41_walk_client_list(clp, result, cred);
 359 }
 360
 361 struct rpc_cred *nfs4_get_exchange_id_cred(struct nfs_client *clp)
 362 {
 363         struct rpc_cred *cred;
 364
 365         spin_lock(&clp->cl_lock);
 366         cred = nfs4_get_machine_cred_locked(clp);
 367         spin_unlock(&clp->cl_lock);
 368         return cred;
 369 }
 370
 371 #endif /* CONFIG_NFS_V4_1 */
 372
 373 static struct rpc_cred *
 374 nfs4_get_setclientid_cred_server(struct nfs_server *server)
 375 {
 376         struct nfs_client *clp = server->nfs_client;
 377         struct rpc_cred *cred = NULL;
 378         struct nfs4_state_owner *sp;
 379         struct rb_node *pos;
 380
 381         spin_lock(&clp->cl_lock);
 382         pos = rb_first(&server->state_owners);
 383         if (pos != NULL) {
 384                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
 385                 cred = get_rpccred(sp->so_cred);
 386         }
 387         spin_unlock(&clp->cl_lock);
 388         return cred;
 389 }
 390
 391 /**
 392  * nfs4_get_setclientid_cred - Acquire credential for a setclientid operation
 393  * @clp: client state handle
 394  *
 395  * Returns an rpc_cred with reference count bumped, or NULL.
 396  */
 397 struct rpc_cred *nfs4_get_setclientid_cred(struct nfs_client *clp)
 398 {
 399         struct nfs_server *server;
 400         struct rpc_cred *cred;
 401
 402         spin_lock(&clp->cl_lock);
 403         cred = nfs4_get_machine_cred_locked(clp);
 404         spin_unlock(&clp->cl_lock);
 405         if (cred != NULL)
 406                 goto out;
 407
 408         rcu_read_lock();
 409         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 410                 cred = nfs4_get_setclientid_cred_server(server);
 411                 if (cred != NULL)
 412                         break;
 413         }
 414         rcu_read_unlock();
 415
 416 out:
 417         return cred;
 418 }
 419
 420 static struct nfs4_state_owner *
 421 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
 422 {
 423         struct rb_node **p = &server->state_owners.rb_node,
 424                        *parent = NULL;
 425         struct nfs4_state_owner *sp;
 426
 427         while (*p != NULL) {
 428                 parent = *p;
 429                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 430
 431                 if (cred < sp->so_cred)
 432                         p = &parent->rb_left;
 433                 else if (cred > sp->so_cred)
 434                         p = &parent->rb_right;
 435                 else {
 436                         if (!list_empty(&sp->so_lru))
 437                                 list_del_init(&sp->so_lru);
 438                         atomic_inc(&sp->so_count);
 439                         return sp;
 440                 }
 441         }
 442         return NULL;
 443 }
 444
 445 static struct nfs4_state_owner *
 446 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
 447 {
 448         struct nfs_server *server = new->so_server;
 449         struct rb_node **p = &server->state_owners.rb_node,
 450                        *parent = NULL;
 451         struct nfs4_state_owner *sp;
 452         int err;
 453
 454         while (*p != NULL) {
 455                 parent = *p;
 456                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
 457
 458                 if (new->so_cred < sp->so_cred)
 459                         p = &parent->rb_left;
 460                 else if (new->so_cred > sp->so_cred)
 461                         p = &parent->rb_right;
 462                 else {
 463                         if (!list_empty(&sp->so_lru))
 464                                 list_del_init(&sp->so_lru);
 465                         atomic_inc(&sp->so_count);
 466                         return sp;
 467                 }
 468         }
 469         err = ida_get_new(&server->openowner_id, &new->so_seqid.owner_id);
 470         if (err)
 471                 return ERR_PTR(err);
 472         rb_link_node(&new->so_server_node, parent, p);
 473         rb_insert_color(&new->so_server_node, &server->state_owners);
 474         return new;
 475 }
 476
 477 static void
 478 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
 479 {
 480         struct nfs_server *server = sp->so_server;
 481
 482         if (!RB_EMPTY_NODE(&sp->so_server_node))
 483                 rb_erase(&sp->so_server_node, &server->state_owners);
 484         ida_remove(&server->openowner_id, sp->so_seqid.owner_id);
 485 }
 486
 487 static void
 488 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
 489 {
 490         sc->create_time = ktime_get();
 491         sc->flags = 0;
 492         sc->counter = 0;
 493         spin_lock_init(&sc->lock);
 494         INIT_LIST_HEAD(&sc->list);
 495         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
 496 }
 497
 498 static void
 499 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
 500 {
 501         rpc_destroy_wait_queue(&sc->wait);
 502 }
 503
 504 /*
 505  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
 506  * create a new state_owner.
 507  *
 508  */
 509 static struct nfs4_state_owner *
 510 nfs4_alloc_state_owner(struct nfs_server *server,
 511                 struct rpc_cred *cred,
 512                 gfp_t gfp_flags)
 513 {
 514         struct nfs4_state_owner *sp;
 515
 516         sp = kzalloc(sizeof(*sp), gfp_flags);
 517         if (!sp)
 518                 return NULL;
 519         sp->so_server = server;
 520         sp->so_cred = get_rpccred(cred);
 521         spin_lock_init(&sp->so_lock);
 522         INIT_LIST_HEAD(&sp->so_states);
 523         nfs4_init_seqid_counter(&sp->so_seqid);
 524         atomic_set(&sp->so_count, 1);
 525         INIT_LIST_HEAD(&sp->so_lru);
 526         return sp;
 527 }
 528
 529 static void
 530 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
 531 {
 532         struct rb_node *rb_node = &sp->so_server_node;
 533
 534         if (!RB_EMPTY_NODE(rb_node)) {
 535                 struct nfs_server *server = sp->so_server;
 536                 struct nfs_client *clp = server->nfs_client;
 537
 538                 spin_lock(&clp->cl_lock);
 539                 if (!RB_EMPTY_NODE(rb_node)) {
 540                         rb_erase(rb_node, &server->state_owners);
 541                         RB_CLEAR_NODE(rb_node);
 542                 }
 543                 spin_unlock(&clp->cl_lock);
 544         }
 545 }
 546
 547 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
 548 {
 549         nfs4_destroy_seqid_counter(&sp->so_seqid);
 550         put_rpccred(sp->so_cred);
 551         kfree(sp);
 552 }
 553
 554 static void nfs4_gc_state_owners(struct nfs_server *server)
 555 {
 556         struct nfs_client *clp = server->nfs_client;
 557         struct nfs4_state_owner *sp, *tmp;
 558         unsigned long time_min, time_max;
 559         LIST_HEAD(doomed);
 560
 561         spin_lock(&clp->cl_lock);
 562         time_max = jiffies;
 563         time_min = (long)time_max - (long)clp->cl_lease_time;
 564         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 565                 /* NB: LRU is sorted so that oldest is at the head */
 566                 if (time_in_range(sp->so_expires, time_min, time_max))
 567                         break;
 568                 list_move(&sp->so_lru, &doomed);
 569                 nfs4_remove_state_owner_locked(sp);
 570         }
 571         spin_unlock(&clp->cl_lock);
 572
 573         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 574                 list_del(&sp->so_lru);
 575                 nfs4_free_state_owner(sp);
 576         }
 577 }
 578
 579 /**
 580  * nfs4_get_state_owner - Look up a state owner given a credential
 581  * @server: nfs_server to search
 582  * @cred: RPC credential to match
 583  *
 584  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
 585  */
 586 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
 587                                               struct rpc_cred *cred,
 588                                               gfp_t gfp_flags)
 589 {
 590         struct nfs_client *clp = server->nfs_client;
 591         struct nfs4_state_owner *sp, *new;
 592
 593         spin_lock(&clp->cl_lock);
 594         sp = nfs4_find_state_owner_locked(server, cred);
 595         spin_unlock(&clp->cl_lock);
 596         if (sp != NULL)
 597                 goto out;
 598         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
 599         if (new == NULL)
 600                 goto out;
 601         do {
 602                 if (ida_pre_get(&server->openowner_id, gfp_flags) == 0)
 603                         break;
 604                 spin_lock(&clp->cl_lock);
 605                 sp = nfs4_insert_state_owner_locked(new);
 606                 spin_unlock(&clp->cl_lock);
 607         } while (sp == ERR_PTR(-EAGAIN));
 608         if (sp != new)
 609                 nfs4_free_state_owner(new);
 610 out:
 611         nfs4_gc_state_owners(server);
 612         return sp;
 613 }
 614
 615 /**
 616  * nfs4_put_state_owner - Release a nfs4_state_owner
 617  * @sp: state owner data to release
 618  *
 619  * Note that we keep released state owners on an LRU
 620  * list.
 621  * This caches valid state owners so that they can be
 622  * reused, to avoid the OPEN_CONFIRM on minor version 0.
 623  * It also pins the uniquifier of dropped state owners for
 624  * a while, to ensure that those state owner names are
 625  * never reused.
 626  */
 627 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
 628 {
 629         struct nfs_server *server = sp->so_server;
 630         struct nfs_client *clp = server->nfs_client;
 631
 632         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
 633                 return;
 634
 635         sp->so_expires = jiffies;
 636         list_add_tail(&sp->so_lru, &server->state_owners_lru);
 637         spin_unlock(&clp->cl_lock);
 638 }
 639
 640 /**
 641  * nfs4_purge_state_owners - Release all cached state owners
 642  * @server: nfs_server with cached state owners to release
 643  *
 644  * Called at umount time.  Remaining state owners will be on
 645  * the LRU with ref count of zero.
 646  */
 647 void nfs4_purge_state_owners(struct nfs_server *server)
 648 {
 649         struct nfs_client *clp = server->nfs_client;
 650         struct nfs4_state_owner *sp, *tmp;
 651         LIST_HEAD(doomed);
 652
 653         spin_lock(&clp->cl_lock);
 654         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
 655                 list_move(&sp->so_lru, &doomed);
 656                 nfs4_remove_state_owner_locked(sp);
 657         }
 658         spin_unlock(&clp->cl_lock);
 659
 660         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
 661                 list_del(&sp->so_lru);
 662                 nfs4_free_state_owner(sp);
 663         }
 664 }
 665
 666 static struct nfs4_state *
 667 nfs4_alloc_open_state(void)
 668 {
 669         struct nfs4_state *state;
 670
 671         state = kzalloc(sizeof(*state), GFP_NOFS);
 672         if (!state)
 673                 return NULL;
 674         atomic_set(&state->count, 1);
 675         INIT_LIST_HEAD(&state->lock_states);
 676         spin_lock_init(&state->state_lock);
 677         seqlock_init(&state->seqlock);
 678         return state;
 679 }
 680
 681 void
 682 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
 683 {
 684         if (state->state == fmode)
 685                 return;
 686         /* NB! List reordering - see the reclaim code for why.  */
 687         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
 688                 if (fmode & FMODE_WRITE)
 689                         list_move(&state->open_states, &state->owner->so_states);
 690                 else
 691                         list_move_tail(&state->open_states, &state->owner->so_states);
 692         }
 693         state->state = fmode;
 694 }
 695
 696 static struct nfs4_state *
 697 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
 698 {
 699         struct nfs_inode *nfsi = NFS_I(inode);
 700         struct nfs4_state *state;
 701
 702         list_for_each_entry(state, &nfsi->open_states, inode_states) {
 703                 if (state->owner != owner)
 704                         continue;
 705                 if (atomic_inc_not_zero(&state->count))
 706                         return state;
 707         }
 708         return NULL;
 709 }
 710
 711 static void
 712 nfs4_free_open_state(struct nfs4_state *state)
 713 {
 714         kfree(state);
 715 }
 716
 717 struct nfs4_state *
 718 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
 719 {
 720         struct nfs4_state *state, *new;
 721         struct nfs_inode *nfsi = NFS_I(inode);
 722
 723         spin_lock(&inode->i_lock);
 724         state = __nfs4_find_state_byowner(inode, owner);
 725         spin_unlock(&inode->i_lock);
 726         if (state)
 727                 goto out;
 728         new = nfs4_alloc_open_state();
 729         spin_lock(&owner->so_lock);
 730         spin_lock(&inode->i_lock);
 731         state = __nfs4_find_state_byowner(inode, owner);
 732         if (state == NULL && new != NULL) {
 733                 state = new;
 734                 state->owner = owner;
 735                 atomic_inc(&owner->so_count);
 736                 list_add(&state->inode_states, &nfsi->open_states);
 737                 ihold(inode);
 738                 state->inode = inode;
 739                 spin_unlock(&inode->i_lock);
 740                 /* Note: The reclaim code dictates that we add stateless
 741                  * and read-only stateids to the end of the list */
 742                 list_add_tail(&state->open_states, &owner->so_states);
 743                 spin_unlock(&owner->so_lock);
 744         } else {
 745                 spin_unlock(&inode->i_lock);
 746                 spin_unlock(&owner->so_lock);
 747                 if (new)
 748                         nfs4_free_open_state(new);
 749         }
 750 out:
 751         return state;
 752 }
 753
 754 void nfs4_put_open_state(struct nfs4_state *state)
 755 {
 756         struct inode *inode = state->inode;
 757         struct nfs4_state_owner *owner = state->owner;
 758
 759         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
 760                 return;
 761         spin_lock(&inode->i_lock);
 762         list_del(&state->inode_states);
 763         list_del(&state->open_states);
 764         spin_unlock(&inode->i_lock);
 765         spin_unlock(&owner->so_lock);
 766         iput(inode);
 767         nfs4_free_open_state(state);
 768         nfs4_put_state_owner(owner);
 769 }
 770
 771 /*
 772  * Close the current file.
 773  */
 774 static void __nfs4_close(struct nfs4_state *state,
 775                 fmode_t fmode, gfp_t gfp_mask, int wait)
 776 {
 777         struct nfs4_state_owner *owner = state->owner;
 778         int call_close = 0;
 779         fmode_t newstate;
 780
 781         atomic_inc(&owner->so_count);
 782         /* Protect against nfs4_find_state() */
 783         spin_lock(&owner->so_lock);
 784         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
 785                 case FMODE_READ:
 786                         state->n_rdonly--;
 787                         break;
 788                 case FMODE_WRITE:
 789                         state->n_wronly--;
 790                         break;
 791                 case FMODE_READ|FMODE_WRITE:
 792                         state->n_rdwr--;
 793         }
 794         newstate = FMODE_READ|FMODE_WRITE;
 795         if (state->n_rdwr == 0) {
 796                 if (state->n_rdonly == 0) {
 797                         newstate &= ~FMODE_READ;
 798                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
 799                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 800                 }
 801                 if (state->n_wronly == 0) {
 802                         newstate &= ~FMODE_WRITE;
 803                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
 804                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
 805                 }
 806                 if (newstate == 0)
 807                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
 808         }
 809         nfs4_state_set_mode_locked(state, newstate);
 810         spin_unlock(&owner->so_lock);
 811
 812         if (!call_close) {
 813                 nfs4_put_open_state(state);
 814                 nfs4_put_state_owner(owner);
 815         } else
 816                 nfs4_do_close(state, gfp_mask, wait);
 817 }
 818
 819 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
 820 {
 821         __nfs4_close(state, fmode, GFP_NOFS, 0);
 822 }
 823
 824 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
 825 {
 826         __nfs4_close(state, fmode, GFP_KERNEL, 1);
 827 }
 828
 829 /*
 830  * Search the state->lock_states for an existing lock_owner
 831  * that is compatible with current->files
 832  */
 833 static struct nfs4_lock_state *
 834 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
 835 {
 836         struct nfs4_lock_state *pos;
 837         list_for_each_entry(pos, &state->lock_states, ls_locks) {
 838                 if (type != NFS4_ANY_LOCK_TYPE && pos->ls_owner.lo_type != type)
 839                         continue;
 840                 switch (pos->ls_owner.lo_type) {
 841                 case NFS4_POSIX_LOCK_TYPE:
 842                         if (pos->ls_owner.lo_u.posix_owner != fl_owner)
 843                                 continue;
 844                         break;
 845                 case NFS4_FLOCK_LOCK_TYPE:
 846                         if (pos->ls_owner.lo_u.flock_owner != fl_pid)
 847                                 continue;
 848                 }
 849                 atomic_inc(&pos->ls_count);
 850                 return pos;
 851         }
 852         return NULL;
 853 }
 854
 855 /*
 856  * Return a compatible lock_state. If no initialized lock_state structure
 857  * exists, return an uninitialized one.
 858  *
 859  */
 860 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
 861 {
 862         struct nfs4_lock_state *lsp;
 863         struct nfs_server *server = state->owner->so_server;
 864
 865         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
 866         if (lsp == NULL)
 867                 return NULL;
 868         nfs4_init_seqid_counter(&lsp->ls_seqid);
 869         atomic_set(&lsp->ls_count, 1);
 870         lsp->ls_state = state;
 871         lsp->ls_owner.lo_type = type;
 872         switch (lsp->ls_owner.lo_type) {
 873         case NFS4_FLOCK_LOCK_TYPE:
 874                 lsp->ls_owner.lo_u.flock_owner = fl_pid;
 875                 break;
 876         case NFS4_POSIX_LOCK_TYPE:
 877                 lsp->ls_owner.lo_u.posix_owner = fl_owner;
 878                 break;
 879         default:
 880                 goto out_free;
 881         }
 882         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
 883         if (lsp->ls_seqid.owner_id < 0)
 884                 goto out_free;
 885         INIT_LIST_HEAD(&lsp->ls_locks);
 886         return lsp;
 887 out_free:
 888         kfree(lsp);
 889         return NULL;
 890 }
 891
 892 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
 893 {
 894         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
 895         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
 896         kfree(lsp);
 897 }
 898
 899 /*
 900  * Return a compatible lock_state. If no initialized lock_state structure
 901  * exists, return an uninitialized one.
 902  *
 903  */
 904 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner, pid_t pid, unsigned int type)
 905 {
 906         struct nfs4_lock_state *lsp, *new = NULL;
 907
 908         for(;;) {
 909                 spin_lock(&state->state_lock);
 910                 lsp = __nfs4_find_lock_state(state, owner, pid, type);
 911                 if (lsp != NULL)
 912                         break;
 913                 if (new != NULL) {
 914                         list_add(&new->ls_locks, &state->lock_states);
 915                         set_bit(LK_STATE_IN_USE, &state->flags);
 916                         lsp = new;
 917                         new = NULL;
 918                         break;
 919                 }
 920                 spin_unlock(&state->state_lock);
 921                 new = nfs4_alloc_lock_state(state, owner, pid, type);
 922                 if (new == NULL)
 923                         return NULL;
 924         }
 925         spin_unlock(&state->state_lock);
 926         if (new != NULL)
 927                 nfs4_free_lock_state(state->owner->so_server, new);
 928         return lsp;
 929 }
 930
 931 /*
 932  * Release reference to lock_state, and free it if we see that
 933  * it is no longer in use
 934  */
 935 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
 936 {
 937         struct nfs4_state *state;
 938
 939         if (lsp == NULL)
 940                 return;
 941         state = lsp->ls_state;
 942         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
 943                 return;
 944         list_del(&lsp->ls_locks);
 945         if (list_empty(&state->lock_states))
 946                 clear_bit(LK_STATE_IN_USE, &state->flags);
 947         spin_unlock(&state->state_lock);
 948         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
 949                 if (nfs4_release_lockowner(lsp) == 0)
 950                         return;
 951         }
 952         nfs4_free_lock_state(lsp->ls_state->owner->so_server, lsp);
 953 }
 954
 955 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
 956 {
 957         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
 958
 959         dst->fl_u.nfs4_fl.owner = lsp;
 960         atomic_inc(&lsp->ls_count);
 961 }
 962
 963 static void nfs4_fl_release_lock(struct file_lock *fl)
 964 {
 965         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
 966 }
 967
 968 static const struct file_lock_operations nfs4_fl_lock_ops = {
 969         .fl_copy_lock = nfs4_fl_copy_lock,
 970         .fl_release_private = nfs4_fl_release_lock,
 971 };
 972
 973 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
 974 {
 975         struct nfs4_lock_state *lsp;
 976
 977         if (fl->fl_ops != NULL)
 978                 return 0;
 979         if (fl->fl_flags & FL_POSIX)
 980                 lsp = nfs4_get_lock_state(state, fl->fl_owner, 0, NFS4_POSIX_LOCK_TYPE);
 981         else if (fl->fl_flags & FL_FLOCK)
 982                 lsp = nfs4_get_lock_state(state, NULL, fl->fl_pid,
 983                                 NFS4_FLOCK_LOCK_TYPE);
 984         else
 985                 return -EINVAL;
 986         if (lsp == NULL)
 987                 return -ENOMEM;
 988         fl->fl_u.nfs4_fl.owner = lsp;
 989         fl->fl_ops = &nfs4_fl_lock_ops;
 990         return 0;
 991 }
 992
 993 static bool nfs4_copy_lock_stateid(nfs4_stateid *dst, struct nfs4_state *state,
 994                 const struct nfs_lockowner *lockowner)
 995 {
 996         struct nfs4_lock_state *lsp;
 997         fl_owner_t fl_owner;
 998         pid_t fl_pid;
 999         bool ret = false;
1000
1001
1002         if (lockowner == NULL)
1003                 goto out;
1004
1005         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
1006                 goto out;
1007
1008         fl_owner = lockowner->l_owner;
1009         fl_pid = lockowner->l_pid;
1010         spin_lock(&state->state_lock);
1011         lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
1012         if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1013                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
1014                 ret = true;
1015         }
1016         spin_unlock(&state->state_lock);
1017         nfs4_put_lock_state(lsp);
1018 out:
1019         return ret;
1020 }
1021
1022 static void nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1023 {
1024         int seq;
1025
1026         do {
1027                 seq = read_seqbegin(&state->seqlock);
1028                 nfs4_stateid_copy(dst, &state->stateid);
1029         } while (read_seqretry(&state->seqlock, seq));
1030 }
1031
1032 /*
1033  * Byte-range lock aware utility to initialize the stateid of read/write
1034  * requests.
1035  */
1036 void nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
1037                 fmode_t fmode, const struct nfs_lockowner *lockowner)
1038 {
1039         if (nfs4_copy_delegation_stateid(dst, state->inode, fmode))
1040                 return;
1041         if (nfs4_copy_lock_stateid(dst, state, lockowner))
1042                 return;
1043         nfs4_copy_open_stateid(dst, state);
1044 }
1045
1046 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1047 {
1048         struct nfs_seqid *new;
1049
1050         new = kmalloc(sizeof(*new), gfp_mask);
1051         if (new != NULL) {
1052                 new->sequence = counter;
1053                 INIT_LIST_HEAD(&new->list);
1054                 new->task = NULL;
1055         }
1056         return new;
1057 }
1058
1059 void nfs_release_seqid(struct nfs_seqid *seqid)
1060 {
1061         struct nfs_seqid_counter *sequence;
1062
1063         if (list_empty(&seqid->list))
1064                 return;
1065         sequence = seqid->sequence;
1066         spin_lock(&sequence->lock);
1067         list_del_init(&seqid->list);
1068         if (!list_empty(&sequence->list)) {
1069                 struct nfs_seqid *next;
1070
1071                 next = list_first_entry(&sequence->list,
1072                                 struct nfs_seqid, list);
1073                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1074         }
1075         spin_unlock(&sequence->lock);
1076 }
1077
1078 void nfs_free_seqid(struct nfs_seqid *seqid)
1079 {
1080         nfs_release_seqid(seqid);
1081         kfree(seqid);
1082 }
1083
1084 /*
1085  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1086  * failed with a seqid incrementing error -
1087  * see comments nfs_fs.h:seqid_mutating_error()
1088  */
1089 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1090 {
1091         switch (status) {
1092                 case 0:
1093                         break;
1094                 case -NFS4ERR_BAD_SEQID:
1095                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1096                                 return;
1097                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1098                                         " sequence-id error on an"
1099                                         " unconfirmed sequence %p!\n",
1100                                         seqid->sequence);
1101                 case -NFS4ERR_STALE_CLIENTID:
1102                 case -NFS4ERR_STALE_STATEID:
1103                 case -NFS4ERR_BAD_STATEID:
1104                 case -NFS4ERR_BADXDR:
1105                 case -NFS4ERR_RESOURCE:
1106                 case -NFS4ERR_NOFILEHANDLE:
1107                         /* Non-seqid mutating errors */
1108                         return;
1109         };
1110         /*
1111          * Note: no locking needed as we are guaranteed to be first
1112          * on the sequence list
1113          */
1114         seqid->sequence->counter++;
1115 }
1116
1117 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1118 {
1119         struct nfs4_state_owner *sp = container_of(seqid->sequence,
1120                                         struct nfs4_state_owner, so_seqid);
1121         struct nfs_server *server = sp->so_server;
1122
1123         if (status == -NFS4ERR_BAD_SEQID)
1124                 nfs4_drop_state_owner(sp);
1125         if (!nfs4_has_session(server->nfs_client))
1126                 nfs_increment_seqid(status, seqid);
1127 }
1128
1129 /*
1130  * Increment the seqid if the LOCK/LOCKU succeeded, or
1131  * failed with a seqid incrementing error -
1132  * see comments nfs_fs.h:seqid_mutating_error()
1133  */
1134 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1135 {
1136         nfs_increment_seqid(status, seqid);
1137 }
1138
1139 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1140 {
1141         struct nfs_seqid_counter *sequence = seqid->sequence;
1142         int status = 0;
1143
1144         spin_lock(&sequence->lock);
1145         seqid->task = task;
1146         if (list_empty(&seqid->list))
1147                 list_add_tail(&seqid->list, &sequence->list);
1148         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1149                 goto unlock;
1150         rpc_sleep_on(&sequence->wait, task, NULL);
1151         status = -EAGAIN;
1152 unlock:
1153         spin_unlock(&sequence->lock);
1154         return status;
1155 }
1156
1157 static int nfs4_run_state_manager(void *);
1158
1159 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1160 {
1161         smp_mb__before_clear_bit();
1162         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1163         smp_mb__after_clear_bit();
1164         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1165         rpc_wake_up(&clp->cl_rpcwaitq);
1166 }
1167
1168 /*
1169  * Schedule the nfs_client asynchronous state management routine
1170  */
1171 void nfs4_schedule_state_manager(struct nfs_client *clp)
1172 {
1173         struct task_struct *task;
1174         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1175
1176         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1177                 return;
1178         __module_get(THIS_MODULE);
1179         atomic_inc(&clp->cl_count);
1180
1181         /* The rcu_read_lock() is not strictly necessary, as the state
1182          * manager is the only thread that ever changes the rpc_xprt
1183          * after it's initialized.  At this point, we're single threaded. */
1184         rcu_read_lock();
1185         snprintf(buf, sizeof(buf), "%s-manager",
1186                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1187         rcu_read_unlock();
1188         task = kthread_run(nfs4_run_state_manager, clp, buf);
1189         if (IS_ERR(task)) {
1190                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1191                         __func__, PTR_ERR(task));
1192                 nfs4_clear_state_manager_bit(clp);
1193                 nfs_put_client(clp);
1194                 module_put(THIS_MODULE);
1195         }
1196 }
1197
1198 /*
1199  * Schedule a lease recovery attempt
1200  */
1201 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1202 {
1203         if (!clp)
1204                 return;
1205         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1206                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1207         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1208                         clp->cl_hostname);
1209         nfs4_schedule_state_manager(clp);
1210 }
1211 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1212
1213 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1214 {
1215         int res;
1216
1217         might_sleep();
1218
1219         res = wait_on_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1220                         nfs_wait_bit_killable, TASK_KILLABLE);
1221         if (res)
1222                 return res;
1223
1224         if (clp->cl_cons_state < 0)
1225                 return clp->cl_cons_state;
1226         return 0;
1227 }
1228
1229 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1230 {
1231         unsigned int loop;
1232         int ret;
1233
1234         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1235                 ret = nfs4_wait_clnt_recover(clp);
1236                 if (ret != 0)
1237                         break;
1238                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1239                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1240                         break;
1241                 nfs4_schedule_state_manager(clp);
1242                 ret = -EIO;
1243         }
1244         return ret;
1245 }
1246
1247 /*
1248  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1249  * @clp: client to process
1250  *
1251  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1252  * resend of the SETCLIENTID and hence re-establish the
1253  * callback channel. Then return all existing delegations.
1254  */
1255 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1256 {
1257         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1258         nfs_expire_all_delegations(clp);
1259         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1260                         clp->cl_hostname);
1261 }
1262
1263 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1264 {
1265         nfs40_handle_cb_pathdown(clp);
1266         nfs4_schedule_state_manager(clp);
1267 }
1268
1269 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1270 {
1271
1272         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1273         /* Don't recover state that expired before the reboot */
1274         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1275                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1276                 return 0;
1277         }
1278         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1279         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1280         return 1;
1281 }
1282
1283 static int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1284 {
1285         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1286         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1287         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1288         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1289         return 1;
1290 }
1291
1292 void nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1293 {
1294         struct nfs_client *clp = server->nfs_client;
1295
1296         nfs4_state_mark_reclaim_nograce(clp, state);
1297         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1298                         clp->cl_hostname);
1299         nfs4_schedule_state_manager(clp);
1300 }
1301 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1302
1303 void nfs_inode_find_state_and_recover(struct inode *inode,
1304                 const nfs4_stateid *stateid)
1305 {
1306         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1307         struct nfs_inode *nfsi = NFS_I(inode);
1308         struct nfs_open_context *ctx;
1309         struct nfs4_state *state;
1310         bool found = false;
1311
1312         spin_lock(&inode->i_lock);
1313         list_for_each_entry(ctx, &nfsi->open_files, list) {
1314                 state = ctx->state;
1315                 if (state == NULL)
1316                         continue;
1317                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
1318                         continue;
1319                 if (!nfs4_stateid_match(&state->stateid, stateid))
1320                         continue;
1321                 nfs4_state_mark_reclaim_nograce(clp, state);
1322                 found = true;
1323         }
1324         spin_unlock(&inode->i_lock);
1325         if (found)
1326                 nfs4_schedule_state_manager(clp);
1327 }
1328
1329
1330 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1331 {
1332         struct inode *inode = state->inode;
1333         struct nfs_inode *nfsi = NFS_I(inode);
1334         struct file_lock *fl;
1335         int status = 0;
1336
1337         if (inode->i_flock == NULL)
1338                 return 0;
1339
1340         /* Guard against delegation returns and new lock/unlock calls */
1341         down_write(&nfsi->rwsem);
1342         /* Protect inode->i_flock using the BKL */
1343         lock_flocks();
1344         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
1345                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
1346                         continue;
1347                 if (nfs_file_open_context(fl->fl_file)->state != state)
1348                         continue;
1349                 unlock_flocks();
1350                 status = ops->recover_lock(state, fl);
1351                 switch (status) {
1352                         case 0:
1353                                 break;
1354                         case -ESTALE:
1355                         case -NFS4ERR_ADMIN_REVOKED:
1356                         case -NFS4ERR_STALE_STATEID:
1357                         case -NFS4ERR_BAD_STATEID:
1358                         case -NFS4ERR_EXPIRED:
1359                         case -NFS4ERR_NO_GRACE:
1360                         case -NFS4ERR_STALE_CLIENTID:
1361                         case -NFS4ERR_BADSESSION:
1362                         case -NFS4ERR_BADSLOT:
1363                         case -NFS4ERR_BAD_HIGH_SLOT:
1364                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1365                                 goto out;
1366                         default:
1367                                 printk(KERN_ERR "NFS: %s: unhandled error %d. "
1368                                         "Zeroing state\n", __func__, status);
1369                         case -ENOMEM:
1370                         case -NFS4ERR_DENIED:
1371                         case -NFS4ERR_RECLAIM_BAD:
1372                         case -NFS4ERR_RECLAIM_CONFLICT:
1373                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
1374                                 status = 0;
1375                 }
1376                 lock_flocks();
1377         }
1378         unlock_flocks();
1379 out:
1380         up_write(&nfsi->rwsem);
1381         return status;
1382 }
1383
1384 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1385 {
1386         struct nfs4_state *state;
1387         struct nfs4_lock_state *lock;
1388         int status = 0;
1389
1390         /* Note: we rely on the sp->so_states list being ordered
1391          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1392          * states first.
1393          * This is needed to ensure that the server won't give us any
1394          * read delegations that we have to return if, say, we are
1395          * recovering after a network partition or a reboot from a
1396          * server that doesn't support a grace period.
1397          */
1398 restart:
1399         spin_lock(&sp->so_lock);
1400         list_for_each_entry(state, &sp->so_states, open_states) {
1401                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1402                         continue;
1403                 if (state->state == 0)
1404                         continue;
1405                 atomic_inc(&state->count);
1406                 spin_unlock(&sp->so_lock);
1407                 status = ops->recover_open(sp, state);
1408                 if (status >= 0) {
1409                         status = nfs4_reclaim_locks(state, ops);
1410                         if (status >= 0) {
1411                                 spin_lock(&state->state_lock);
1412                                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1413                                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1414                                                 pr_warn_ratelimited("NFS: "
1415                                                         "%s: Lock reclaim "
1416                                                         "failed!\n", __func__);
1417                                 }
1418                                 spin_unlock(&state->state_lock);
1419                                 nfs4_put_open_state(state);
1420                                 goto restart;
1421                         }
1422                 }
1423                 switch (status) {
1424                         default:
1425                                 printk(KERN_ERR "NFS: %s: unhandled error %d. "
1426                                         "Zeroing state\n", __func__, status);
1427                         case -ENOENT:
1428                         case -ENOMEM:
1429                         case -ESTALE:
1430                                 /*
1431                                  * Open state on this file cannot be recovered
1432                                  * All we can do is revert to using the zero stateid.
1433                                  */
1434                                 memset(&state->stateid, 0,
1435                                         sizeof(state->stateid));
1436                                 /* Mark the file as being 'closed' */
1437                                 state->state = 0;
1438                                 break;
1439                         case -NFS4ERR_ADMIN_REVOKED:
1440                         case -NFS4ERR_STALE_STATEID:
1441                         case -NFS4ERR_BAD_STATEID:
1442                         case -NFS4ERR_RECLAIM_BAD:
1443                         case -NFS4ERR_RECLAIM_CONFLICT:
1444                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1445                                 break;
1446                         case -NFS4ERR_EXPIRED:
1447                         case -NFS4ERR_NO_GRACE:
1448                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1449                         case -NFS4ERR_STALE_CLIENTID:
1450                         case -NFS4ERR_BADSESSION:
1451                         case -NFS4ERR_BADSLOT:
1452                         case -NFS4ERR_BAD_HIGH_SLOT:
1453                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1454                                 goto out_err;
1455                 }
1456                 nfs4_put_open_state(state);
1457                 goto restart;
1458         }
1459         spin_unlock(&sp->so_lock);
1460         return 0;
1461 out_err:
1462         nfs4_put_open_state(state);
1463         return status;
1464 }
1465
1466 static void nfs4_clear_open_state(struct nfs4_state *state)
1467 {
1468         struct nfs4_lock_state *lock;
1469
1470         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1471         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1472         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1473         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1474         spin_lock(&state->state_lock);
1475         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1476                 lock->ls_seqid.flags = 0;
1477                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1478         }
1479         spin_unlock(&state->state_lock);
1480 }
1481
1482 static void nfs4_reset_seqids(struct nfs_server *server,
1483         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1484 {
1485         struct nfs_client *clp = server->nfs_client;
1486         struct nfs4_state_owner *sp;
1487         struct rb_node *pos;
1488         struct nfs4_state *state;
1489
1490         spin_lock(&clp->cl_lock);
1491         for (pos = rb_first(&server->state_owners);
1492              pos != NULL;
1493              pos = rb_next(pos)) {
1494                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1495                 sp->so_seqid.flags = 0;
1496                 spin_lock(&sp->so_lock);
1497                 list_for_each_entry(state, &sp->so_states, open_states) {
1498                         if (mark_reclaim(clp, state))
1499                                 nfs4_clear_open_state(state);
1500                 }
1501                 spin_unlock(&sp->so_lock);
1502         }
1503         spin_unlock(&clp->cl_lock);
1504 }
1505
1506 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1507         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1508 {
1509         struct nfs_server *server;
1510
1511         rcu_read_lock();
1512         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1513                 nfs4_reset_seqids(server, mark_reclaim);
1514         rcu_read_unlock();
1515 }
1516
1517 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1518 {
1519         /* Mark all delegations for reclaim */
1520         nfs_delegation_mark_reclaim(clp);
1521         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1522 }
1523
1524 static void nfs4_reclaim_complete(struct nfs_client *clp,
1525                                  const struct nfs4_state_recovery_ops *ops)
1526 {
1527         /* Notify the server we're done reclaiming our state */
1528         if (ops->reclaim_complete)
1529                 (void)ops->reclaim_complete(clp);
1530 }
1531
1532 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1533 {
1534         struct nfs_client *clp = server->nfs_client;
1535         struct nfs4_state_owner *sp;
1536         struct rb_node *pos;
1537         struct nfs4_state *state;
1538
1539         spin_lock(&clp->cl_lock);
1540         for (pos = rb_first(&server->state_owners);
1541              pos != NULL;
1542              pos = rb_next(pos)) {
1543                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1544                 spin_lock(&sp->so_lock);
1545                 list_for_each_entry(state, &sp->so_states, open_states) {
1546                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1547                                                 &state->flags))
1548                                 continue;
1549                         nfs4_state_mark_reclaim_nograce(clp, state);
1550                 }
1551                 spin_unlock(&sp->so_lock);
1552         }
1553         spin_unlock(&clp->cl_lock);
1554 }
1555
1556 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1557 {
1558         struct nfs_server *server;
1559
1560         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1561                 return 0;
1562
1563         rcu_read_lock();
1564         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1565                 nfs4_clear_reclaim_server(server);
1566         rcu_read_unlock();
1567
1568         nfs_delegation_reap_unclaimed(clp);
1569         return 1;
1570 }
1571
1572 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1573 {
1574         if (!nfs4_state_clear_reclaim_reboot(clp))
1575                 return;
1576         nfs4_reclaim_complete(clp, clp->cl_mvops->reboot_recovery_ops);
1577 }
1578
1579 static void nfs_delegation_clear_all(struct nfs_client *clp)
1580 {
1581         nfs_delegation_mark_reclaim(clp);
1582         nfs_delegation_reap_unclaimed(clp);
1583 }
1584
1585 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1586 {
1587         nfs_delegation_clear_all(clp);
1588         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1589 }
1590
1591 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1592 {
1593         switch (error) {
1594                 case 0:
1595                         break;
1596                 case -NFS4ERR_CB_PATH_DOWN:
1597                         nfs40_handle_cb_pathdown(clp);
1598                         break;
1599                 case -NFS4ERR_NO_GRACE:
1600                         nfs4_state_end_reclaim_reboot(clp);
1601                         break;
1602                 case -NFS4ERR_STALE_CLIENTID:
1603                 case -NFS4ERR_LEASE_MOVED:
1604                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1605                         nfs4_state_clear_reclaim_reboot(clp);
1606                         nfs4_state_start_reclaim_reboot(clp);
1607                         break;
1608                 case -NFS4ERR_EXPIRED:
1609                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1610                         nfs4_state_start_reclaim_nograce(clp);
1611                         break;
1612                 case -NFS4ERR_BADSESSION:
1613                 case -NFS4ERR_BADSLOT:
1614                 case -NFS4ERR_BAD_HIGH_SLOT:
1615                 case -NFS4ERR_DEADSESSION:
1616                 case -NFS4ERR_SEQ_FALSE_RETRY:
1617                 case -NFS4ERR_SEQ_MISORDERED:
1618                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1619                         /* Zero session reset errors */
1620                         break;
1621                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1622                         set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1623                         break;
1624                 default:
1625                         dprintk("%s: failed to handle error %d for server %s\n",
1626                                         __func__, error, clp->cl_hostname);
1627                         return error;
1628         }
1629         dprintk("%s: handled error %d for server %s\n", __func__, error,
1630                         clp->cl_hostname);
1631         return 0;
1632 }
1633
1634 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1635 {
1636         struct nfs4_state_owner *sp;
1637         struct nfs_server *server;
1638         struct rb_node *pos;
1639         int status = 0;
1640
1641 restart:
1642         rcu_read_lock();
1643         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1644                 nfs4_purge_state_owners(server);
1645                 spin_lock(&clp->cl_lock);
1646                 for (pos = rb_first(&server->state_owners);
1647                      pos != NULL;
1648                      pos = rb_next(pos)) {
1649                         sp = rb_entry(pos,
1650                                 struct nfs4_state_owner, so_server_node);
1651                         if (!test_and_clear_bit(ops->owner_flag_bit,
1652                                                         &sp->so_flags))
1653                                 continue;
1654                         atomic_inc(&sp->so_count);
1655                         spin_unlock(&clp->cl_lock);
1656                         rcu_read_unlock();
1657
1658                         status = nfs4_reclaim_open_state(sp, ops);
1659                         if (status < 0) {
1660                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1661                                 nfs4_put_state_owner(sp);
1662                                 return nfs4_recovery_handle_error(clp, status);
1663                         }
1664
1665                         nfs4_put_state_owner(sp);
1666                         goto restart;
1667                 }
1668                 spin_unlock(&clp->cl_lock);
1669         }
1670         rcu_read_unlock();
1671         return status;
1672 }
1673
1674 static int nfs4_check_lease(struct nfs_client *clp)
1675 {
1676         struct rpc_cred *cred;
1677         const struct nfs4_state_maintenance_ops *ops =
1678                 clp->cl_mvops->state_renewal_ops;
1679         int status;
1680
1681         /* Is the client already known to have an expired lease? */
1682         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1683                 return 0;
1684         spin_lock(&clp->cl_lock);
1685         cred = ops->get_state_renewal_cred_locked(clp);
1686         spin_unlock(&clp->cl_lock);
1687         if (cred == NULL) {
1688                 cred = nfs4_get_setclientid_cred(clp);
1689                 status = -ENOKEY;
1690                 if (cred == NULL)
1691                         goto out;
1692         }
1693         status = ops->renew_lease(clp, cred);
1694         put_rpccred(cred);
1695 out:
1696         return nfs4_recovery_handle_error(clp, status);
1697 }
1698
1699 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1700  * and for recoverable errors on EXCHANGE_ID for v4.1
1701  */
1702 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1703 {
1704         switch (status) {
1705         case -NFS4ERR_SEQ_MISORDERED:
1706                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1707                         return -ESERVERFAULT;
1708                 /* Lease confirmation error: retry after purging the lease */
1709                 ssleep(1);
1710                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1711                 break;
1712         case -NFS4ERR_STALE_CLIENTID:
1713                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1714                 nfs4_state_clear_reclaim_reboot(clp);
1715                 nfs4_state_start_reclaim_reboot(clp);
1716                 break;
1717         case -NFS4ERR_CLID_INUSE:
1718                 pr_err("NFS: Server %s reports our clientid is in use\n",
1719                         clp->cl_hostname);
1720                 nfs_mark_client_ready(clp, -EPERM);
1721                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1722                 return -EPERM;
1723         case -EACCES:
1724                 if (clp->cl_machine_cred == NULL)
1725                         return -EACCES;
1726                 /* Handle case where the user hasn't set up machine creds */
1727                 nfs4_clear_machine_cred(clp);
1728         case -NFS4ERR_DELAY:
1729         case -ETIMEDOUT:
1730         case -EAGAIN:
1731                 ssleep(1);
1732                 break;
1733
1734         case -NFS4ERR_MINOR_VERS_MISMATCH:
1735                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1736                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1737                 dprintk("%s: exit with error %d for server %s\n",
1738                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1739                 return -EPROTONOSUPPORT;
1740         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1741                                  * in nfs4_exchange_id */
1742         default:
1743                 dprintk("%s: exit with error %d for server %s\n", __func__,
1744                                 status, clp->cl_hostname);
1745                 return status;
1746         }
1747         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1748         dprintk("%s: handled error %d for server %s\n", __func__, status,
1749                         clp->cl_hostname);
1750         return 0;
1751 }
1752
1753 static int nfs4_establish_lease(struct nfs_client *clp)
1754 {
1755         struct rpc_cred *cred;
1756         const struct nfs4_state_recovery_ops *ops =
1757                 clp->cl_mvops->reboot_recovery_ops;
1758         int status;
1759
1760         cred = ops->get_clid_cred(clp);
1761         if (cred == NULL)
1762                 return -ENOENT;
1763         status = ops->establish_clid(clp, cred);
1764         put_rpccred(cred);
1765         if (status != 0)
1766                 return status;
1767         pnfs_destroy_all_layouts(clp);
1768         return 0;
1769 }
1770
1771 /*
1772  * Returns zero or a negative errno.  NFS4ERR values are converted
1773  * to local errno values.
1774  */
1775 static int nfs4_reclaim_lease(struct nfs_client *clp)
1776 {
1777         int status;
1778
1779         status = nfs4_establish_lease(clp);
1780         if (status < 0)
1781                 return nfs4_handle_reclaim_lease_error(clp, status);
1782         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1783                 nfs4_state_start_reclaim_nograce(clp);
1784         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1785                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1786         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1787         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1788         return 0;
1789 }
1790
1791 static int nfs4_purge_lease(struct nfs_client *clp)
1792 {
1793         int status;
1794
1795         status = nfs4_establish_lease(clp);
1796         if (status < 0)
1797                 return nfs4_handle_reclaim_lease_error(clp, status);
1798         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1799         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1800         nfs4_state_start_reclaim_nograce(clp);
1801         return 0;
1802 }
1803
1804 /**
1805  * nfs4_discover_server_trunking - Detect server IP address trunking
1806  *
1807  * @clp: nfs_client under test
1808  * @result: OUT: found nfs_client, or clp
1809  *
1810  * Returns zero or a negative errno.  If zero is returned,
1811  * an nfs_client pointer is planted in "result".
1812  *
1813  * Note: since we are invoked in process context, and
1814  * not from inside the state manager, we cannot use
1815  * nfs4_handle_reclaim_lease_error().
1816  */
1817 int nfs4_discover_server_trunking(struct nfs_client *clp,
1818                                   struct nfs_client **result)
1819 {
1820         const struct nfs4_state_recovery_ops *ops =
1821                                 clp->cl_mvops->reboot_recovery_ops;
1822         rpc_authflavor_t *flavors, flav, save;
1823         struct rpc_clnt *clnt;
1824         struct rpc_cred *cred;
1825         int i, len, status;
1826
1827         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
1828
1829         len = NFS_MAX_SECFLAVORS;
1830         flavors = kcalloc(len, sizeof(*flavors), GFP_KERNEL);
1831         if (flavors == NULL) {
1832                 status = -ENOMEM;
1833                 goto out;
1834         }
1835         len = rpcauth_list_flavors(flavors, len);
1836         if (len < 0) {
1837                 status = len;
1838                 goto out_free;
1839         }
1840         clnt = clp->cl_rpcclient;
1841         save = clnt->cl_auth->au_flavor;
1842         i = 0;
1843
1844         mutex_lock(&nfs_clid_init_mutex);
1845         status  = -ENOENT;
1846 again:
1847         cred = ops->get_clid_cred(clp);
1848         if (cred == NULL)
1849                 goto out_unlock;
1850
1851         status = ops->detect_trunking(clp, result, cred);
1852         put_rpccred(cred);
1853         switch (status) {
1854         case 0:
1855                 break;
1856
1857         case -EACCES:
1858                 if (clp->cl_machine_cred == NULL)
1859                         break;
1860                 /* Handle case where the user hasn't set up machine creds */
1861                 nfs4_clear_machine_cred(clp);
1862         case -NFS4ERR_DELAY:
1863         case -ETIMEDOUT:
1864         case -EAGAIN:
1865                 ssleep(1);
1866                 dprintk("NFS: %s after status %d, retrying\n",
1867                         __func__, status);
1868                 goto again;
1869
1870         case -NFS4ERR_CLID_INUSE:
1871         case -NFS4ERR_WRONGSEC:
1872                 status = -EPERM;
1873                 if (i >= len)
1874                         break;
1875
1876                 flav = flavors[i++];
1877                 if (flav == save)
1878                         flav = flavors[i++];
1879                 clnt = rpc_clone_client_set_auth(clnt, flav);
1880                 if (IS_ERR(clnt)) {
1881                         status = PTR_ERR(clnt);
1882                         break;
1883                 }
1884                 clp->cl_rpcclient = clnt;
1885                 goto again;
1886
1887         case -NFS4ERR_MINOR_VERS_MISMATCH:
1888                 status = -EPROTONOSUPPORT;
1889                 break;
1890
1891         case -EKEYEXPIRED:
1892         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1893                                  * in nfs4_exchange_id */
1894                 status = -EKEYEXPIRED;
1895         }
1896
1897 out_unlock:
1898         mutex_unlock(&nfs_clid_init_mutex);
1899 out_free:
1900         kfree(flavors);
1901 out:
1902         dprintk("NFS: %s: status = %d\n", __func__, status);
1903         return status;
1904 }
1905
1906 #ifdef CONFIG_NFS_V4_1
1907 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
1908 {
1909         struct nfs_client *clp = session->clp;
1910
1911         switch (err) {
1912         default:
1913                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1914                 break;
1915         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1916                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1917         }
1918         nfs4_schedule_lease_recovery(clp);
1919 }
1920 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
1921
1922 static void nfs41_ping_server(struct nfs_client *clp)
1923 {
1924         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
1925         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1926         nfs4_schedule_state_manager(clp);
1927 }
1928
1929 void nfs41_server_notify_target_slotid_update(struct nfs_client *clp)
1930 {
1931         nfs41_ping_server(clp);
1932 }
1933
1934 void nfs41_server_notify_highest_slotid_update(struct nfs_client *clp)
1935 {
1936         nfs41_ping_server(clp);
1937 }
1938
1939 static void nfs4_reset_all_state(struct nfs_client *clp)
1940 {
1941         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
1942                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1943                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1944                 nfs4_state_start_reclaim_nograce(clp);
1945                 dprintk("%s: scheduling reset of all state for server %s!\n",
1946                                 __func__, clp->cl_hostname);
1947                 nfs4_schedule_state_manager(clp);
1948         }
1949 }
1950
1951 static void nfs41_handle_server_reboot(struct nfs_client *clp)
1952 {
1953         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
1954                 nfs4_state_start_reclaim_reboot(clp);
1955                 dprintk("%s: server %s rebooted!\n", __func__,
1956                                 clp->cl_hostname);
1957                 nfs4_schedule_state_manager(clp);
1958         }
1959 }
1960
1961 static void nfs41_handle_state_revoked(struct nfs_client *clp)
1962 {
1963         nfs4_reset_all_state(clp);
1964         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
1965 }
1966
1967 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
1968 {
1969         /* This will need to handle layouts too */
1970         nfs_expire_all_delegations(clp);
1971         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
1972                         clp->cl_hostname);
1973 }
1974
1975 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
1976 {
1977         nfs_expire_all_delegations(clp);
1978         if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
1979                 nfs4_schedule_state_manager(clp);
1980         dprintk("%s: server %s declared a backchannel fault\n", __func__,
1981                         clp->cl_hostname);
1982 }
1983
1984 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
1985 {
1986         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
1987                 &clp->cl_state) == 0)
1988                 nfs4_schedule_state_manager(clp);
1989 }
1990
1991 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
1992 {
1993         if (!flags)
1994                 return;
1995
1996         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
1997                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
1998
1999         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2000                 nfs41_handle_server_reboot(clp);
2001         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
2002                             SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2003                             SEQ4_STATUS_ADMIN_STATE_REVOKED |
2004                             SEQ4_STATUS_LEASE_MOVED))
2005                 nfs41_handle_state_revoked(clp);
2006         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2007                 nfs41_handle_recallable_state_revoked(clp);
2008         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2009                 nfs41_handle_backchannel_fault(clp);
2010         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2011                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2012                 nfs41_handle_cb_path_down(clp);
2013 }
2014
2015 static int nfs4_reset_session(struct nfs_client *clp)
2016 {
2017         struct rpc_cred *cred;
2018         int status;
2019
2020         if (!nfs4_has_session(clp))
2021                 return 0;
2022         nfs4_begin_drain_session(clp);
2023         cred = nfs4_get_exchange_id_cred(clp);
2024         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2025         if (status && status != -NFS4ERR_BADSESSION &&
2026             status != -NFS4ERR_DEADSESSION) {
2027                 status = nfs4_recovery_handle_error(clp, status);
2028                 goto out;
2029         }
2030
2031         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2032         status = nfs4_proc_create_session(clp, cred);
2033         if (status) {
2034                 dprintk("%s: session reset failed with status %d for server %s!\n",
2035                         __func__, status, clp->cl_hostname);
2036                 status = nfs4_handle_reclaim_lease_error(clp, status);
2037                 goto out;
2038         }
2039         nfs41_finish_session_reset(clp);
2040         dprintk("%s: session reset was successful for server %s!\n",
2041                         __func__, clp->cl_hostname);
2042 out:
2043         if (cred)
2044                 put_rpccred(cred);
2045         return status;
2046 }
2047
2048 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2049 {
2050         struct rpc_cred *cred;
2051         int ret;
2052
2053         if (!nfs4_has_session(clp))
2054                 return 0;
2055         nfs4_begin_drain_session(clp);
2056         cred = nfs4_get_exchange_id_cred(clp);
2057         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2058         if (cred)
2059                 put_rpccred(cred);
2060         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2061         switch (ret) {
2062         case 0:
2063                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2064                         __func__, clp->cl_hostname);
2065                 break;
2066         case -NFS4ERR_DELAY:
2067                 ssleep(1);
2068                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2069                 break;
2070         default:
2071                 return nfs4_recovery_handle_error(clp, ret);
2072         }
2073         return 0;
2074 }
2075 #else /* CONFIG_NFS_V4_1 */
2076 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2077 static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
2078
2079 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2080 {
2081         return 0;
2082 }
2083 #endif /* CONFIG_NFS_V4_1 */
2084
2085 static void nfs4_state_manager(struct nfs_client *clp)
2086 {
2087         int status = 0;
2088         const char *section = "", *section_sep = "";
2089
2090         /* Ensure exclusive access to NFSv4 state */
2091         do {
2092                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2093                         section = "purge state";
2094                         status = nfs4_purge_lease(clp);
2095                         if (status < 0)
2096                                 goto out_error;
2097                         continue;
2098                 }
2099
2100                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2101                         section = "lease expired";
2102                         /* We're going to have to re-establish a clientid */
2103                         status = nfs4_reclaim_lease(clp);
2104                         if (status < 0)
2105                                 goto out_error;
2106                         continue;
2107                 }
2108
2109                 /* Initialize or reset the session */
2110                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2111                         section = "reset session";
2112                         status = nfs4_reset_session(clp);
2113                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2114                                 continue;
2115                         if (status < 0)
2116                                 goto out_error;
2117                 }
2118
2119                 /* Send BIND_CONN_TO_SESSION */
2120                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2121                                 &clp->cl_state)) {
2122                         section = "bind conn to session";
2123                         status = nfs4_bind_conn_to_session(clp);
2124                         if (status < 0)
2125                                 goto out_error;
2126                         continue;
2127                 }
2128
2129                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2130                         section = "check lease";
2131                         status = nfs4_check_lease(clp);
2132                         if (status < 0)
2133                                 goto out_error;
2134                         continue;
2135                 }
2136
2137                 /* First recover reboot state... */
2138                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2139                         section = "reclaim reboot";
2140                         status = nfs4_do_reclaim(clp,
2141                                 clp->cl_mvops->reboot_recovery_ops);
2142                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
2143                             test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
2144                                 continue;
2145                         nfs4_state_end_reclaim_reboot(clp);
2146                         if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2147                                 continue;
2148                         if (status < 0)
2149                                 goto out_error;
2150                 }
2151
2152                 /* Now recover expired state... */
2153                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2154                         section = "reclaim nograce";
2155                         status = nfs4_do_reclaim(clp,
2156                                 clp->cl_mvops->nograce_recovery_ops);
2157                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) ||
2158                             test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) ||
2159                             test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
2160                                 continue;
2161                         if (status < 0)
2162                                 goto out_error;
2163                 }
2164
2165                 nfs4_end_drain_session(clp);
2166                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2167                         nfs_client_return_marked_delegations(clp);
2168                         continue;
2169                 }
2170
2171                 nfs4_clear_state_manager_bit(clp);
2172                 /* Did we race with an attempt to give us more work? */
2173                 if (clp->cl_state == 0)
2174                         break;
2175                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2176                         break;
2177         } while (atomic_read(&clp->cl_count) > 1);
2178         return;
2179 out_error:
2180         if (strlen(section))
2181                 section_sep = ": ";
2182         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2183                         " with error %d\n", section_sep, section,
2184                         clp->cl_hostname, -status);
2185         ssleep(1);
2186         nfs4_end_drain_session(clp);
2187         nfs4_clear_state_manager_bit(clp);
2188 }
2189
2190 static int nfs4_run_state_manager(void *ptr)
2191 {
2192         struct nfs_client *clp = ptr;
2193
2194         allow_signal(SIGKILL);
2195         nfs4_state_manager(clp);
2196         nfs_put_client(clp);
2197         module_put_and_exit(0);
2198         return 0;
2199 }
2200
2201 /*
2202  * Local variables:
2203  *  c-basic-offset: 8
2204  * End:
2205  */