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