git.oblomov.eu Git - linux-2.6/blob - fs/afs/vlocation.c

   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 CONFIG_AFS_FSCACHE
 285         fscache_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 CONFIG_AFS_FSCACHE
 307         vl->cache = fscache_acquire_cookie(vl->cell->cache,
 308                                            &afs_vlocation_cache_index_def, vl);
 309 #endif
 310
 311         if (vl->valid) {
 312                 /* try to update a known volume in the cell VL databases by
 313                  * ID as the name may have changed */
 314                 _debug("found in cache");
 315                 ret = afs_vlocation_update_record(vl, key, &vldb);
 316         } else {
 317                 /* try to look up an unknown volume in the cell VL databases by
 318                  * name */
 319                 ret = afs_vlocation_access_vl_by_name(vl, key, &vldb);
 320                 if (ret < 0) {
 321                         printk("kAFS: failed to locate '%s' in cell '%s'\n",
 322                                vl->vldb.name, vl->cell->name);
 323                         return ret;
 324                 }
 325         }
 326
 327         afs_vlocation_apply_update(vl, &vldb);
 328         _leave(" = 0");
 329         return 0;
 330 }
 331
 332 /*
 333  * queue a vlocation record for updates
 334  */
 335 static void afs_vlocation_queue_for_updates(struct afs_vlocation *vl)
 336 {
 337         struct afs_vlocation *xvl;
 338
 339         /* wait at least 10 minutes before updating... */
 340         vl->update_at = get_seconds() + afs_vlocation_update_timeout;
 341
 342         spin_lock(&afs_vlocation_updates_lock);
 343
 344         if (!list_empty(&afs_vlocation_updates)) {
 345                 /* ... but wait at least 1 second more than the newest record
 346                  * already queued so that we don't spam the VL server suddenly
 347                  * with lots of requests
 348                  */
 349                 xvl = list_entry(afs_vlocation_updates.prev,
 350                                  struct afs_vlocation, update);
 351                 if (vl->update_at <= xvl->update_at)
 352                         vl->update_at = xvl->update_at + 1;
 353         } else {
 354                 queue_delayed_work(afs_vlocation_update_worker,
 355                                    &afs_vlocation_update,
 356                                    afs_vlocation_update_timeout * HZ);
 357         }
 358
 359         list_add_tail(&vl->update, &afs_vlocation_updates);
 360         spin_unlock(&afs_vlocation_updates_lock);
 361 }
 362
 363 /*
 364  * lookup volume location
 365  * - iterate through the VL servers in a cell until one of them admits knowing
 366  *   about the volume in question
 367  * - lookup in the local cache if not able to find on the VL server
 368  * - insert/update in the local cache if did get a VL response
 369  */
 370 struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *cell,
 371                                            struct key *key,
 372                                            const char *name,
 373                                            size_t namesz)
 374 {
 375         struct afs_vlocation *vl;
 376         int ret;
 377
 378         _enter("{%s},{%x},%*.*s,%zu",
 379                cell->name, key_serial(key),
 380                (int) namesz, (int) namesz, name, namesz);
 381
 382         if (namesz >= sizeof(vl->vldb.name)) {
 383                 _leave(" = -ENAMETOOLONG");
 384                 return ERR_PTR(-ENAMETOOLONG);
 385         }
 386
 387         /* see if we have an in-memory copy first */
 388         down_write(&cell->vl_sem);
 389         spin_lock(&cell->vl_lock);
 390         list_for_each_entry(vl, &cell->vl_list, link) {
 391                 if (vl->vldb.name[namesz] != '\0')
 392                         continue;
 393                 if (memcmp(vl->vldb.name, name, namesz) == 0)
 394                         goto found_in_memory;
 395         }
 396         spin_unlock(&cell->vl_lock);
 397
 398         /* not in the cell's in-memory lists - create a new record */
 399         vl = afs_vlocation_alloc(cell, name, namesz);
 400         if (!vl) {
 401                 up_write(&cell->vl_sem);
 402                 return ERR_PTR(-ENOMEM);
 403         }
 404
 405         afs_get_cell(cell);
 406
 407         list_add_tail(&vl->link, &cell->vl_list);
 408         vl->state = AFS_VL_CREATING;
 409         up_write(&cell->vl_sem);
 410
 411 fill_in_record:
 412         ret = afs_vlocation_fill_in_record(vl, key);
 413         if (ret < 0)
 414                 goto error_abandon;
 415         spin_lock(&vl->lock);
 416         vl->state = AFS_VL_VALID;
 417         spin_unlock(&vl->lock);
 418         wake_up(&vl->waitq);
 419
 420         /* update volume entry in local cache */
 421 #ifdef CONFIG_AFS_FSCACHE
 422         fscache_update_cookie(vl->cache);
 423 #endif
 424
 425         /* schedule for regular updates */
 426         afs_vlocation_queue_for_updates(vl);
 427         goto success;
 428
 429 found_in_memory:
 430         /* found in memory */
 431         _debug("found in memory");
 432         atomic_inc(&vl->usage);
 433         spin_unlock(&cell->vl_lock);
 434         if (!list_empty(&vl->grave)) {
 435                 spin_lock(&afs_vlocation_graveyard_lock);
 436                 list_del_init(&vl->grave);
 437                 spin_unlock(&afs_vlocation_graveyard_lock);
 438         }
 439         up_write(&cell->vl_sem);
 440
 441         /* see if it was an abandoned record that we might try filling in */
 442         spin_lock(&vl->lock);
 443         while (vl->state != AFS_VL_VALID) {
 444                 afs_vlocation_state_t state = vl->state;
 445
 446                 _debug("invalid [state %d]", state);
 447
 448                 if (state == AFS_VL_NEW || state == AFS_VL_NO_VOLUME) {
 449                         vl->state = AFS_VL_CREATING;
 450                         spin_unlock(&vl->lock);
 451                         goto fill_in_record;
 452                 }
 453
 454                 /* must now wait for creation or update by someone else to
 455                  * complete */
 456                 _debug("wait");
 457
 458                 spin_unlock(&vl->lock);
 459                 ret = wait_event_interruptible(vl->waitq,
 460                                                vl->state == AFS_VL_NEW ||
 461                                                vl->state == AFS_VL_VALID ||
 462                                                vl->state == AFS_VL_NO_VOLUME);
 463                 if (ret < 0)
 464                         goto error;
 465                 spin_lock(&vl->lock);
 466         }
 467         spin_unlock(&vl->lock);
 468
 469 success:
 470         _leave(" = %p", vl);
 471         return vl;
 472
 473 error_abandon:
 474         spin_lock(&vl->lock);
 475         vl->state = AFS_VL_NEW;
 476         spin_unlock(&vl->lock);
 477         wake_up(&vl->waitq);
 478 error:
 479         ASSERT(vl != NULL);
 480         afs_put_vlocation(vl);
 481         _leave(" = %d", ret);
 482         return ERR_PTR(ret);
 483 }
 484
 485 /*
 486  * finish using a volume location record
 487  */
 488 void afs_put_vlocation(struct afs_vlocation *vl)
 489 {
 490         if (!vl)
 491                 return;
 492
 493         _enter("%s", vl->vldb.name);
 494
 495         ASSERTCMP(atomic_read(&vl->usage), >, 0);
 496
 497         if (likely(!atomic_dec_and_test(&vl->usage))) {
 498                 _leave("");
 499                 return;
 500         }
 501
 502         spin_lock(&afs_vlocation_graveyard_lock);
 503         if (atomic_read(&vl->usage) == 0) {
 504                 _debug("buried");
 505                 list_move_tail(&vl->grave, &afs_vlocation_graveyard);
 506                 vl->time_of_death = get_seconds();
 507                 schedule_delayed_work(&afs_vlocation_reap,
 508                                       afs_vlocation_timeout * HZ);
 509
 510                 /* suspend updates on this record */
 511                 if (!list_empty(&vl->update)) {
 512                         spin_lock(&afs_vlocation_updates_lock);
 513                         list_del_init(&vl->update);
 514                         spin_unlock(&afs_vlocation_updates_lock);
 515                 }
 516         }
 517         spin_unlock(&afs_vlocation_graveyard_lock);
 518         _leave(" [killed?]");
 519 }
 520
 521 /*
 522  * destroy a dead volume location record
 523  */
 524 static void afs_vlocation_destroy(struct afs_vlocation *vl)
 525 {
 526         _enter("%p", vl);
 527
 528 #ifdef CONFIG_AFS_FSCACHE
 529         fscache_relinquish_cookie(vl->cache, 0);
 530 #endif
 531         afs_put_cell(vl->cell);
 532         kfree(vl);
 533 }
 534
 535 /*
 536  * reap dead volume location records
 537  */
 538 static void afs_vlocation_reaper(struct work_struct *work)
 539 {
 540         LIST_HEAD(corpses);
 541         struct afs_vlocation *vl;
 542         unsigned long delay, expiry;
 543         time_t now;
 544
 545         _enter("");
 546
 547         now = get_seconds();
 548         spin_lock(&afs_vlocation_graveyard_lock);
 549
 550         while (!list_empty(&afs_vlocation_graveyard)) {
 551                 vl = list_entry(afs_vlocation_graveyard.next,
 552                                 struct afs_vlocation, grave);
 553
 554                 _debug("check %p", vl);
 555
 556                 /* the queue is ordered most dead first */
 557                 expiry = vl->time_of_death + afs_vlocation_timeout;
 558                 if (expiry > now) {
 559                         delay = (expiry - now) * HZ;
 560                         _debug("delay %lu", delay);
 561                         if (!schedule_delayed_work(&afs_vlocation_reap,
 562                                                    delay)) {
 563                                 cancel_delayed_work(&afs_vlocation_reap);
 564                                 schedule_delayed_work(&afs_vlocation_reap,
 565                                                       delay);
 566                         }
 567                         break;
 568                 }
 569
 570                 spin_lock(&vl->cell->vl_lock);
 571                 if (atomic_read(&vl->usage) > 0) {
 572                         _debug("no reap");
 573                         list_del_init(&vl->grave);
 574                 } else {
 575                         _debug("reap");
 576                         list_move_tail(&vl->grave, &corpses);
 577                         list_del_init(&vl->link);
 578                 }
 579                 spin_unlock(&vl->cell->vl_lock);
 580         }
 581
 582         spin_unlock(&afs_vlocation_graveyard_lock);
 583
 584         /* now reap the corpses we've extracted */
 585         while (!list_empty(&corpses)) {
 586                 vl = list_entry(corpses.next, struct afs_vlocation, grave);
 587                 list_del(&vl->grave);
 588                 afs_vlocation_destroy(vl);
 589         }
 590
 591         _leave("");
 592 }
 593
 594 /*
 595  * initialise the VL update process
 596  */
 597 int __init afs_vlocation_update_init(void)
 598 {
 599         afs_vlocation_update_worker =
 600                 create_singlethread_workqueue("kafs_vlupdated");
 601         return afs_vlocation_update_worker ? 0 : -ENOMEM;
 602 }
 603
 604 /*
 605  * discard all the volume location records for rmmod
 606  */
 607 void afs_vlocation_purge(void)
 608 {
 609         afs_vlocation_timeout = 0;
 610
 611         spin_lock(&afs_vlocation_updates_lock);
 612         list_del_init(&afs_vlocation_updates);
 613         spin_unlock(&afs_vlocation_updates_lock);
 614         cancel_delayed_work(&afs_vlocation_update);
 615         queue_delayed_work(afs_vlocation_update_worker,
 616                            &afs_vlocation_update, 0);
 617         destroy_workqueue(afs_vlocation_update_worker);
 618
 619         cancel_delayed_work(&afs_vlocation_reap);
 620         schedule_delayed_work(&afs_vlocation_reap, 0);
 621 }
 622
 623 /*
 624  * update a volume location
 625  */
 626 static void afs_vlocation_updater(struct work_struct *work)
 627 {
 628         struct afs_cache_vlocation vldb;
 629         struct afs_vlocation *vl, *xvl;
 630         time_t now;
 631         long timeout;
 632         int ret;
 633
 634         _enter("");
 635
 636         now = get_seconds();
 637
 638         /* find a record to update */
 639         spin_lock(&afs_vlocation_updates_lock);
 640         for (;;) {
 641                 if (list_empty(&afs_vlocation_updates)) {
 642                         spin_unlock(&afs_vlocation_updates_lock);
 643                         _leave(" [nothing]");
 644                         return;
 645                 }
 646
 647                 vl = list_entry(afs_vlocation_updates.next,
 648                                 struct afs_vlocation, update);
 649                 if (atomic_read(&vl->usage) > 0)
 650                         break;
 651                 list_del_init(&vl->update);
 652         }
 653
 654         timeout = vl->update_at - now;
 655         if (timeout > 0) {
 656                 queue_delayed_work(afs_vlocation_update_worker,
 657                                    &afs_vlocation_update, timeout * HZ);
 658                 spin_unlock(&afs_vlocation_updates_lock);
 659                 _leave(" [nothing]");
 660                 return;
 661         }
 662
 663         list_del_init(&vl->update);
 664         atomic_inc(&vl->usage);
 665         spin_unlock(&afs_vlocation_updates_lock);
 666
 667         /* we can now perform the update */
 668         _debug("update %s", vl->vldb.name);
 669         vl->state = AFS_VL_UPDATING;
 670         vl->upd_rej_cnt = 0;
 671         vl->upd_busy_cnt = 0;
 672
 673         ret = afs_vlocation_update_record(vl, NULL, &vldb);
 674         spin_lock(&vl->lock);
 675         switch (ret) {
 676         case 0:
 677                 afs_vlocation_apply_update(vl, &vldb);
 678                 vl->state = AFS_VL_VALID;
 679                 break;
 680         case -ENOMEDIUM:
 681                 vl->state = AFS_VL_VOLUME_DELETED;
 682                 break;
 683         default:
 684                 vl->state = AFS_VL_UNCERTAIN;
 685                 break;
 686         }
 687         spin_unlock(&vl->lock);
 688         wake_up(&vl->waitq);
 689
 690         /* and then reschedule */
 691         _debug("reschedule");
 692         vl->update_at = get_seconds() + afs_vlocation_update_timeout;
 693
 694         spin_lock(&afs_vlocation_updates_lock);
 695
 696         if (!list_empty(&afs_vlocation_updates)) {
 697                 /* next update in 10 minutes, but wait at least 1 second more
 698                  * than the newest record already queued so that we don't spam
 699                  * the VL server suddenly with lots of requests
 700                  */
 701                 xvl = list_entry(afs_vlocation_updates.prev,
 702                                  struct afs_vlocation, update);
 703                 if (vl->update_at <= xvl->update_at)
 704                         vl->update_at = xvl->update_at + 1;
 705                 xvl = list_entry(afs_vlocation_updates.next,
 706                                  struct afs_vlocation, update);
 707                 timeout = xvl->update_at - now;
 708                 if (timeout < 0)
 709                         timeout = 0;
 710         } else {
 711                 timeout = afs_vlocation_update_timeout;
 712         }
 713
 714         ASSERT(list_empty(&vl->update));
 715
 716         list_add_tail(&vl->update, &afs_vlocation_updates);
 717
 718         _debug("timeout %ld", timeout);
 719         queue_delayed_work(afs_vlocation_update_worker,
 720                            &afs_vlocation_update, timeout * HZ);
 721         spin_unlock(&afs_vlocation_updates_lock);
 722         afs_put_vlocation(vl);
 723 }