invalidate_mapping_pages(): add cond_resched
[linux-2.6] / 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 unsigned afs_vlocation_timeout = 10;    /* volume location timeout in seconds */
19 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 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 }