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