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