linux/fs/afs/vlocation.c
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   1/* AFS volume location management
   2 *
   3 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/slab.h>
  15#include <linux/init.h>
  16#include <linux/sched.h>
  17#include "internal.h"
  18
  19static unsigned afs_vlocation_timeout = 10;     /* volume location timeout in seconds */
  20static unsigned afs_vlocation_update_timeout = 10 * 60;
  21
  22static void afs_vlocation_reaper(struct work_struct *);
  23static void afs_vlocation_updater(struct work_struct *);
  24
  25static LIST_HEAD(afs_vlocation_updates);
  26static LIST_HEAD(afs_vlocation_graveyard);
  27static DEFINE_SPINLOCK(afs_vlocation_updates_lock);
  28static DEFINE_SPINLOCK(afs_vlocation_graveyard_lock);
  29static DECLARE_DELAYED_WORK(afs_vlocation_reap, afs_vlocation_reaper);
  30static DECLARE_DELAYED_WORK(afs_vlocation_update, afs_vlocation_updater);
  31static struct workqueue_struct *afs_vlocation_update_worker;
  32
  33/*
  34 * iterate through the VL servers in a cell until one of them admits knowing
  35 * about the volume in question
  36 */
  37static int afs_vlocation_access_vl_by_name(struct afs_vlocation *vl,
  38                                           struct key *key,
  39                                           struct afs_cache_vlocation *vldb)
  40{
  41        struct afs_cell *cell = vl->cell;
  42        struct in_addr addr;
  43        int count, ret;
  44
  45        _enter("%s,%s", cell->name, vl->vldb.name);
  46
  47        down_write(&vl->cell->vl_sem);
  48        ret = -ENOMEDIUM;
  49        for (count = cell->vl_naddrs; count > 0; count--) {
  50                addr = cell->vl_addrs[cell->vl_curr_svix];
  51
  52                _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr);
  53
  54                /* attempt to access the VL server */
  55                ret = afs_vl_get_entry_by_name(&addr, key, vl->vldb.name, vldb,
  56                                               &afs_sync_call);
  57                switch (ret) {
  58                case 0:
  59                        goto out;
  60                case -ENOMEM:
  61                case -ENONET:
  62                case -ENETUNREACH:
  63                case -EHOSTUNREACH:
  64                case -ECONNREFUSED:
  65                        if (ret == -ENOMEM || ret == -ENONET)
  66                                goto out;
  67                        goto rotate;
  68                case -ENOMEDIUM:
  69                case -EKEYREJECTED:
  70                case -EKEYEXPIRED:
  71                        goto out;
  72                default:
  73                        ret = -EIO;
  74                        goto rotate;
  75                }
  76
  77                /* rotate the server records upon lookup failure */
  78        rotate:
  79                cell->vl_curr_svix++;
  80                cell->vl_curr_svix %= cell->vl_naddrs;
  81        }
  82
  83out:
  84        up_write(&vl->cell->vl_sem);
  85        _leave(" = %d", ret);
  86        return ret;
  87}
  88
  89/*
  90 * iterate through the VL servers in a cell until one of them admits knowing
  91 * about the volume in question
  92 */
  93static int afs_vlocation_access_vl_by_id(struct afs_vlocation *vl,
  94                                         struct key *key,
  95                                         afs_volid_t volid,
  96                                         afs_voltype_t voltype,
  97                                         struct afs_cache_vlocation *vldb)
  98{
  99        struct afs_cell *cell = vl->cell;
 100        struct in_addr addr;
 101        int count, ret;
 102
 103        _enter("%s,%x,%d,", cell->name, volid, voltype);
 104
 105        down_write(&vl->cell->vl_sem);
 106        ret = -ENOMEDIUM;
 107        for (count = cell->vl_naddrs; count > 0; count--) {
 108                addr = cell->vl_addrs[cell->vl_curr_svix];
 109
 110                _debug("CellServ[%hu]: %08x", cell->vl_curr_svix, addr.s_addr);
 111
 112                /* attempt to access the VL server */
 113                ret = afs_vl_get_entry_by_id(&addr, key, volid, voltype, vldb,
 114                                             &afs_sync_call);
 115                switch (ret) {
 116                case 0:
 117                        goto out;
 118                case -ENOMEM:
 119                case -ENONET:
 120                case -ENETUNREACH:
 121                case -EHOSTUNREACH:
 122                case -ECONNREFUSED:
 123                        if (ret == -ENOMEM || ret == -ENONET)
 124                                goto out;
 125                        goto rotate;
 126                case -EBUSY:
 127                        vl->upd_busy_cnt++;
 128                        if (vl->upd_busy_cnt <= 3) {
 129                                if (vl->upd_busy_cnt > 1) {
 130                                        /* second+ BUSY - sleep a little bit */
 131                                        set_current_state(TASK_UNINTERRUPTIBLE);
 132                                        schedule_timeout(1);
 133                                        __set_current_state(TASK_RUNNING);
 134                                }
 135                                continue;
 136                        }
 137                        break;
 138                case -ENOMEDIUM:
 139                        vl->upd_rej_cnt++;
 140                        goto rotate;
 141                default:
 142                        ret = -EIO;
 143                        goto rotate;
 144                }
 145
 146                /* rotate the server records upon lookup failure */
 147        rotate:
 148                cell->vl_curr_svix++;
 149                cell->vl_curr_svix %= cell->vl_naddrs;
 150                vl->upd_busy_cnt = 0;
 151        }
 152
 153out:
 154        if (ret < 0 && vl->upd_rej_cnt > 0) {
 155                printk(KERN_NOTICE "kAFS:"
 156                       " Active volume no longer valid '%s'\n",
 157                       vl->vldb.name);
 158                vl->valid = 0;
 159                ret = -ENOMEDIUM;
 160        }
 161
 162        up_write(&vl->cell->vl_sem);
 163        _leave(" = %d", ret);
 164        return ret;
 165}
 166
 167/*
 168 * allocate a volume location record
 169 */
 170static struct afs_vlocation *afs_vlocation_alloc(struct afs_cell *cell,
 171                                                 const char *name,
 172                                                 size_t namesz)
 173{
 174        struct afs_vlocation *vl;
 175
 176        vl = kzalloc(sizeof(struct afs_vlocation), GFP_KERNEL);
 177        if (vl) {
 178                vl->cell = cell;
 179                vl->state = AFS_VL_NEW;
 180                atomic_set(&vl->usage, 1);
 181                INIT_LIST_HEAD(&vl->link);
 182                INIT_LIST_HEAD(&vl->grave);
 183                INIT_LIST_HEAD(&vl->update);
 184                init_waitqueue_head(&vl->waitq);
 185                spin_lock_init(&vl->lock);
 186                memcpy(vl->vldb.name, name, namesz);
 187        }
 188
 189        _leave(" = %p", vl);
 190        return vl;
 191}
 192
 193/*
 194 * update record if we found it in the cache
 195 */
 196static int afs_vlocation_update_record(struct afs_vlocation *vl,
 197                                       struct key *key,
 198                                       struct afs_cache_vlocation *vldb)
 199{
 200        afs_voltype_t voltype;
 201        afs_volid_t vid;
 202        int ret;
 203
 204        /* try to look up a cached volume in the cell VL databases by ID */
 205        _debug("Locally Cached: %s %02x { %08x(%x) %08x(%x) %08x(%x) }",
 206               vl->vldb.name,
 207               vl->vldb.vidmask,
 208               ntohl(vl->vldb.servers[0].s_addr),
 209               vl->vldb.srvtmask[0],
 210               ntohl(vl->vldb.servers[1].s_addr),
 211               vl->vldb.srvtmask[1],
 212               ntohl(vl->vldb.servers[2].s_addr),
 213               vl->vldb.srvtmask[2]);
 214
 215        _debug("Vids: %08x %08x %08x",
 216               vl->vldb.vid[0],
 217               vl->vldb.vid[1],
 218               vl->vldb.vid[2]);
 219
 220        if (vl->vldb.vidmask & AFS_VOL_VTM_RW) {
 221                vid = vl->vldb.vid[0];
 222                voltype = AFSVL_RWVOL;
 223        } else if (vl->vldb.vidmask & AFS_VOL_VTM_RO) {
 224                vid = vl->vldb.vid[1];
 225                voltype = AFSVL_ROVOL;
 226        } else if (vl->vldb.vidmask & AFS_VOL_VTM_BAK) {
 227                vid = vl->vldb.vid[2];
 228                voltype = AFSVL_BACKVOL;
 229        } else {
 230                BUG();
 231                vid = 0;
 232                voltype = 0;
 233        }
 234
 235        /* contact the server to make sure the volume is still available
 236         * - TODO: need to handle disconnected operation here
 237         */
 238        ret = afs_vlocation_access_vl_by_id(vl, key, vid, voltype, vldb);
 239        switch (ret) {
 240                /* net error */
 241        default:
 242                printk(KERN_WARNING "kAFS:"
 243                       " failed to update volume '%s' (%x) up in '%s': %d\n",
 244                       vl->vldb.name, vid, vl->cell->name, ret);
 245                _leave(" = %d", ret);
 246                return ret;
 247
 248                /* pulled from local cache into memory */
 249        case 0:
 250                _leave(" = 0");
 251                return 0;
 252
 253                /* uh oh... looks like the volume got deleted */
 254        case -ENOMEDIUM:
 255                printk(KERN_ERR "kAFS:"
 256                       " volume '%s' (%x) does not exist '%s'\n",
 257                       vl->vldb.name, vid, vl->cell->name);
 258
 259                /* TODO: make existing record unavailable */
 260                _leave(" = %d", ret);
 261                return ret;
 262        }
 263}
 264
 265/*
 266 * apply the update to a VL record
 267 */
 268static void afs_vlocation_apply_update(struct afs_vlocation *vl,
 269                                       struct afs_cache_vlocation *vldb)
 270{
 271        _debug("Done VL Lookup: %s %02x { %08x(%x) %08x(%x) %08x(%x) }",
 272               vldb->name, vldb->vidmask,
 273               ntohl(vldb->servers[0].s_addr), vldb->srvtmask[0],
 274               ntohl(vldb->servers[1].s_addr), vldb->srvtmask[1],
 275               ntohl(vldb->servers[2].s_addr), vldb->srvtmask[2]);
 276
 277        _debug("Vids: %08x %08x %08x",
 278               vldb->vid[0], vldb->vid[1], vldb->vid[2]);
 279
 280        if (strcmp(vldb->name, vl->vldb.name) != 0)
 281                printk(KERN_NOTICE "kAFS:"
 282                       " name of volume '%s' changed to '%s' on server\n",
 283                       vl->vldb.name, vldb->name);
 284
 285        vl->vldb = *vldb;
 286
 287#ifdef CONFIG_AFS_FSCACHE
 288        fscache_update_cookie(vl->cache);
 289#endif
 290}
 291
 292/*
 293 * fill in a volume location record, consulting the cache and the VL server
 294 * both
 295 */
 296static int afs_vlocation_fill_in_record(struct afs_vlocation *vl,
 297                                        struct key *key)
 298{
 299        struct afs_cache_vlocation vldb;
 300        int ret;
 301
 302        _enter("");
 303
 304        ASSERTCMP(vl->valid, ==, 0);
 305
 306        memset(&vldb, 0, sizeof(vldb));
 307
 308        /* see if we have an in-cache copy (will set vl->valid if there is) */
 309#ifdef CONFIG_AFS_FSCACHE
 310        vl->cache = fscache_acquire_cookie(vl->cell->cache,
 311                                           &afs_vlocation_cache_index_def, vl);
 312#endif
 313
 314        if (vl->valid) {
 315                /* try to update a known volume in the cell VL databases by
 316                 * ID as the name may have changed */
 317                _debug("found in cache");
 318                ret = afs_vlocation_update_record(vl, key, &vldb);
 319        } else {
 320                /* try to look up an unknown volume in the cell VL databases by
 321                 * name */
 322                ret = afs_vlocation_access_vl_by_name(vl, key, &vldb);
 323                if (ret < 0) {
 324                        printk("kAFS: failed to locate '%s' in cell '%s'\n",
 325                               vl->vldb.name, vl->cell->name);
 326                        return ret;
 327                }
 328        }
 329
 330        afs_vlocation_apply_update(vl, &vldb);
 331        _leave(" = 0");
 332        return 0;
 333}
 334
 335/*
 336 * queue a vlocation record for updates
 337 */
 338static void afs_vlocation_queue_for_updates(struct afs_vlocation *vl)
 339{
 340        struct afs_vlocation *xvl;
 341
 342        /* wait at least 10 minutes before updating... */
 343        vl->update_at = get_seconds() + afs_vlocation_update_timeout;
 344
 345        spin_lock(&afs_vlocation_updates_lock);
 346
 347        if (!list_empty(&afs_vlocation_updates)) {
 348                /* ... but wait at least 1 second more than the newest record
 349                 * already queued so that we don't spam the VL server suddenly
 350                 * with lots of requests
 351                 */
 352                xvl = list_entry(afs_vlocation_updates.prev,
 353                                 struct afs_vlocation, update);
 354                if (vl->update_at <= xvl->update_at)
 355                        vl->update_at = xvl->update_at + 1;
 356        } else {
 357                queue_delayed_work(afs_vlocation_update_worker,
 358                                   &afs_vlocation_update,
 359                                   afs_vlocation_update_timeout * HZ);
 360        }
 361
 362        list_add_tail(&vl->update, &afs_vlocation_updates);
 363        spin_unlock(&afs_vlocation_updates_lock);
 364}
 365
 366/*
 367 * lookup volume location
 368 * - iterate through the VL servers in a cell until one of them admits knowing
 369 *   about the volume in question
 370 * - lookup in the local cache if not able to find on the VL server
 371 * - insert/update in the local cache if did get a VL response
 372 */
 373struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *cell,
 374                                           struct key *key,
 375                                           const char *name,
 376                                           size_t namesz)
 377{
 378        struct afs_vlocation *vl;
 379        int ret;
 380
 381        _enter("{%s},{%x},%*.*s,%zu",
 382               cell->name, key_serial(key),
 383               (int) namesz, (int) namesz, name, namesz);
 384
 385        if (namesz >= sizeof(vl->vldb.name)) {
 386                _leave(" = -ENAMETOOLONG");
 387                return ERR_PTR(-ENAMETOOLONG);
 388        }
 389
 390        /* see if we have an in-memory copy first */
 391        down_write(&cell->vl_sem);
 392        spin_lock(&cell->vl_lock);
 393        list_for_each_entry(vl, &cell->vl_list, link) {
 394                if (vl->vldb.name[namesz] != '\0')
 395                        continue;
 396                if (memcmp(vl->vldb.name, name, namesz) == 0)
 397                        goto found_in_memory;
 398        }
 399        spin_unlock(&cell->vl_lock);
 400
 401        /* not in the cell's in-memory lists - create a new record */
 402        vl = afs_vlocation_alloc(cell, name, namesz);
 403        if (!vl) {
 404                up_write(&cell->vl_sem);
 405                return ERR_PTR(-ENOMEM);
 406        }
 407
 408        afs_get_cell(cell);
 409
 410        list_add_tail(&vl->link, &cell->vl_list);
 411        vl->state = AFS_VL_CREATING;
 412        up_write(&cell->vl_sem);
 413
 414fill_in_record:
 415        ret = afs_vlocation_fill_in_record(vl, key);
 416        if (ret < 0)
 417                goto error_abandon;
 418        spin_lock(&vl->lock);
 419        vl->state = AFS_VL_VALID;
 420        spin_unlock(&vl->lock);
 421        wake_up(&vl->waitq);
 422
 423        /* update volume entry in local cache */
 424#ifdef CONFIG_AFS_FSCACHE
 425        fscache_update_cookie(vl->cache);
 426#endif
 427
 428        /* schedule for regular updates */
 429        afs_vlocation_queue_for_updates(vl);
 430        goto success;
 431
 432found_in_memory:
 433        /* found in memory */
 434        _debug("found in memory");
 435        atomic_inc(&vl->usage);
 436        spin_unlock(&cell->vl_lock);
 437        if (!list_empty(&vl->grave)) {
 438                spin_lock(&afs_vlocation_graveyard_lock);
 439                list_del_init(&vl->grave);
 440                spin_unlock(&afs_vlocation_graveyard_lock);
 441        }
 442        up_write(&cell->vl_sem);
 443
 444        /* see if it was an abandoned record that we might try filling in */
 445        spin_lock(&vl->lock);
 446        while (vl->state != AFS_VL_VALID) {
 447                afs_vlocation_state_t state = vl->state;
 448
 449                _debug("invalid [state %d]", state);
 450
 451                if (state == AFS_VL_NEW || state == AFS_VL_NO_VOLUME) {
 452                        vl->state = AFS_VL_CREATING;
 453                        spin_unlock(&vl->lock);
 454                        goto fill_in_record;
 455                }
 456
 457                /* must now wait for creation or update by someone else to
 458                 * complete */
 459                _debug("wait");
 460
 461                spin_unlock(&vl->lock);
 462                ret = wait_event_interruptible(vl->waitq,
 463                                               vl->state == AFS_VL_NEW ||
 464                                               vl->state == AFS_VL_VALID ||
 465                                               vl->state == AFS_VL_NO_VOLUME);
 466                if (ret < 0)
 467                        goto error;
 468                spin_lock(&vl->lock);
 469        }
 470        spin_unlock(&vl->lock);
 471
 472success:
 473        _leave(" = %p", vl);
 474        return vl;
 475
 476error_abandon:
 477        spin_lock(&vl->lock);
 478        vl->state = AFS_VL_NEW;
 479        spin_unlock(&vl->lock);
 480        wake_up(&vl->waitq);
 481error:
 482        ASSERT(vl != NULL);
 483        afs_put_vlocation(vl);
 484        _leave(" = %d", ret);
 485        return ERR_PTR(ret);
 486}
 487
 488/*
 489 * finish using a volume location record
 490 */
 491void afs_put_vlocation(struct afs_vlocation *vl)
 492{
 493        if (!vl)
 494                return;
 495
 496        _enter("%s", vl->vldb.name);
 497
 498        ASSERTCMP(atomic_read(&vl->usage), >, 0);
 499
 500        if (likely(!atomic_dec_and_test(&vl->usage))) {
 501                _leave("");
 502                return;
 503        }
 504
 505        spin_lock(&afs_vlocation_graveyard_lock);
 506        if (atomic_read(&vl->usage) == 0) {
 507                _debug("buried");
 508                list_move_tail(&vl->grave, &afs_vlocation_graveyard);
 509                vl->time_of_death = get_seconds();
 510                queue_delayed_work(afs_wq, &afs_vlocation_reap,
 511                                   afs_vlocation_timeout * HZ);
 512
 513                /* suspend updates on this record */
 514                if (!list_empty(&vl->update)) {
 515                        spin_lock(&afs_vlocation_updates_lock);
 516                        list_del_init(&vl->update);
 517                        spin_unlock(&afs_vlocation_updates_lock);
 518                }
 519        }
 520        spin_unlock(&afs_vlocation_graveyard_lock);
 521        _leave(" [killed?]");
 522}
 523
 524/*
 525 * destroy a dead volume location record
 526 */
 527static void afs_vlocation_destroy(struct afs_vlocation *vl)
 528{
 529        _enter("%p", vl);
 530
 531#ifdef CONFIG_AFS_FSCACHE
 532        fscache_relinquish_cookie(vl->cache, 0);
 533#endif
 534        afs_put_cell(vl->cell);
 535        kfree(vl);
 536}
 537
 538/*
 539 * reap dead volume location records
 540 */
 541static void afs_vlocation_reaper(struct work_struct *work)
 542{
 543        LIST_HEAD(corpses);
 544        struct afs_vlocation *vl;
 545        unsigned long delay, expiry;
 546        time_t now;
 547
 548        _enter("");
 549
 550        now = get_seconds();
 551        spin_lock(&afs_vlocation_graveyard_lock);
 552
 553        while (!list_empty(&afs_vlocation_graveyard)) {
 554                vl = list_entry(afs_vlocation_graveyard.next,
 555                                struct afs_vlocation, grave);
 556
 557                _debug("check %p", vl);
 558
 559                /* the queue is ordered most dead first */
 560                expiry = vl->time_of_death + afs_vlocation_timeout;
 561                if (expiry > now) {
 562                        delay = (expiry - now) * HZ;
 563                        _debug("delay %lu", delay);
 564                        if (!queue_delayed_work(afs_wq, &afs_vlocation_reap,
 565                                                delay)) {
 566                                cancel_delayed_work(&afs_vlocation_reap);
 567                                queue_delayed_work(afs_wq, &afs_vlocation_reap,
 568                                                   delay);
 569                        }
 570                        break;
 571                }
 572
 573                spin_lock(&vl->cell->vl_lock);
 574                if (atomic_read(&vl->usage) > 0) {
 575                        _debug("no reap");
 576                        list_del_init(&vl->grave);
 577                } else {
 578                        _debug("reap");
 579                        list_move_tail(&vl->grave, &corpses);
 580                        list_del_init(&vl->link);
 581                }
 582                spin_unlock(&vl->cell->vl_lock);
 583        }
 584
 585        spin_unlock(&afs_vlocation_graveyard_lock);
 586
 587        /* now reap the corpses we've extracted */
 588        while (!list_empty(&corpses)) {
 589                vl = list_entry(corpses.next, struct afs_vlocation, grave);
 590                list_del(&vl->grave);
 591                afs_vlocation_destroy(vl);
 592        }
 593
 594        _leave("");
 595}
 596
 597/*
 598 * initialise the VL update process
 599 */
 600int __init afs_vlocation_update_init(void)
 601{
 602        afs_vlocation_update_worker =
 603                create_singlethread_workqueue("kafs_vlupdated");
 604        return afs_vlocation_update_worker ? 0 : -ENOMEM;
 605}
 606
 607/*
 608 * discard all the volume location records for rmmod
 609 */
 610void afs_vlocation_purge(void)
 611{
 612        afs_vlocation_timeout = 0;
 613
 614        spin_lock(&afs_vlocation_updates_lock);
 615        list_del_init(&afs_vlocation_updates);
 616        spin_unlock(&afs_vlocation_updates_lock);
 617        cancel_delayed_work(&afs_vlocation_update);
 618        queue_delayed_work(afs_vlocation_update_worker,
 619                           &afs_vlocation_update, 0);
 620        destroy_workqueue(afs_vlocation_update_worker);
 621
 622        cancel_delayed_work(&afs_vlocation_reap);
 623        queue_delayed_work(afs_wq, &afs_vlocation_reap, 0);
 624}
 625
 626/*
 627 * update a volume location
 628 */
 629static void afs_vlocation_updater(struct work_struct *work)
 630{
 631        struct afs_cache_vlocation vldb;
 632        struct afs_vlocation *vl, *xvl;
 633        time_t now;
 634        long timeout;
 635        int ret;
 636
 637        _enter("");
 638
 639        now = get_seconds();
 640
 641        /* find a record to update */
 642        spin_lock(&afs_vlocation_updates_lock);
 643        for (;;) {
 644                if (list_empty(&afs_vlocation_updates)) {
 645                        spin_unlock(&afs_vlocation_updates_lock);
 646                        _leave(" [nothing]");
 647                        return;
 648                }
 649
 650                vl = list_entry(afs_vlocation_updates.next,
 651                                struct afs_vlocation, update);
 652                if (atomic_read(&vl->usage) > 0)
 653                        break;
 654                list_del_init(&vl->update);
 655        }
 656
 657        timeout = vl->update_at - now;
 658        if (timeout > 0) {
 659                queue_delayed_work(afs_vlocation_update_worker,
 660                                   &afs_vlocation_update, timeout * HZ);
 661                spin_unlock(&afs_vlocation_updates_lock);
 662                _leave(" [nothing]");
 663                return;
 664        }
 665
 666        list_del_init(&vl->update);
 667        atomic_inc(&vl->usage);
 668        spin_unlock(&afs_vlocation_updates_lock);
 669
 670        /* we can now perform the update */
 671        _debug("update %s", vl->vldb.name);
 672        vl->state = AFS_VL_UPDATING;
 673        vl->upd_rej_cnt = 0;
 674        vl->upd_busy_cnt = 0;
 675
 676        ret = afs_vlocation_update_record(vl, NULL, &vldb);
 677        spin_lock(&vl->lock);
 678        switch (ret) {
 679        case 0:
 680                afs_vlocation_apply_update(vl, &vldb);
 681                vl->state = AFS_VL_VALID;
 682                break;
 683        case -ENOMEDIUM:
 684                vl->state = AFS_VL_VOLUME_DELETED;
 685                break;
 686        default:
 687                vl->state = AFS_VL_UNCERTAIN;
 688                break;
 689        }
 690        spin_unlock(&vl->lock);
 691        wake_up(&vl->waitq);
 692
 693        /* and then reschedule */
 694        _debug("reschedule");
 695        vl->update_at = get_seconds() + afs_vlocation_update_timeout;
 696
 697        spin_lock(&afs_vlocation_updates_lock);
 698
 699        if (!list_empty(&afs_vlocation_updates)) {
 700                /* next update in 10 minutes, but wait at least 1 second more
 701                 * than the newest record already queued so that we don't spam
 702                 * the VL server suddenly with lots of requests
 703                 */
 704                xvl = list_entry(afs_vlocation_updates.prev,
 705                                 struct afs_vlocation, update);
 706                if (vl->update_at <= xvl->update_at)
 707                        vl->update_at = xvl->update_at + 1;
 708                xvl = list_entry(afs_vlocation_updates.next,
 709                                 struct afs_vlocation, update);
 710                timeout = xvl->update_at - now;
 711                if (timeout < 0)
 712                        timeout = 0;
 713        } else {
 714                timeout = afs_vlocation_update_timeout;
 715        }
 716
 717        ASSERT(list_empty(&vl->update));
 718
 719        list_add_tail(&vl->update, &afs_vlocation_updates);
 720
 721        _debug("timeout %ld", timeout);
 722        queue_delayed_work(afs_vlocation_update_worker,
 723                           &afs_vlocation_update, timeout * HZ);
 724        spin_unlock(&afs_vlocation_updates_lock);
 725        afs_put_vlocation(vl);
 726}
 727
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