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9
10
11#define FSCACHE_DEBUG_LEVEL COOKIE
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/prefetch.h>
15#include "internal.h"
16
17static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *, int);
18static const struct fscache_state *fscache_kill_dependents(struct fscache_object *, int);
19static const struct fscache_state *fscache_drop_object(struct fscache_object *, int);
20static const struct fscache_state *fscache_initialise_object(struct fscache_object *, int);
21static const struct fscache_state *fscache_invalidate_object(struct fscache_object *, int);
22static const struct fscache_state *fscache_jumpstart_dependents(struct fscache_object *, int);
23static const struct fscache_state *fscache_kill_object(struct fscache_object *, int);
24static const struct fscache_state *fscache_lookup_failure(struct fscache_object *, int);
25static const struct fscache_state *fscache_look_up_object(struct fscache_object *, int);
26static const struct fscache_state *fscache_object_available(struct fscache_object *, int);
27static const struct fscache_state *fscache_parent_ready(struct fscache_object *, int);
28static const struct fscache_state *fscache_update_object(struct fscache_object *, int);
29static const struct fscache_state *fscache_object_dead(struct fscache_object *, int);
30
31#define __STATE_NAME(n) fscache_osm_##n
32#define STATE(n) (&__STATE_NAME(n))
33
34
35
36
37
38
39
40
41#define WORK_STATE(n, sn, f) \
42 const struct fscache_state __STATE_NAME(n) = { \
43 .name = #n, \
44 .short_name = sn, \
45 .work = f \
46 }
47
48
49
50
51#define transit_to(state) ({ prefetch(&STATE(state)->work); STATE(state); })
52
53#define NO_TRANSIT ((struct fscache_state *)NULL)
54
55
56
57
58
59
60
61
62#define WAIT_STATE(n, sn, ...) \
63 const struct fscache_state __STATE_NAME(n) = { \
64 .name = #n, \
65 .short_name = sn, \
66 .work = NULL, \
67 .transitions = { __VA_ARGS__, { 0, NULL } } \
68 }
69
70#define TRANSIT_TO(state, emask) \
71 { .events = (emask), .transit_to = STATE(state) }
72
73
74
75
76static WORK_STATE(INIT_OBJECT, "INIT", fscache_initialise_object);
77static WORK_STATE(PARENT_READY, "PRDY", fscache_parent_ready);
78static WORK_STATE(ABORT_INIT, "ABRT", fscache_abort_initialisation);
79static WORK_STATE(LOOK_UP_OBJECT, "LOOK", fscache_look_up_object);
80static WORK_STATE(OBJECT_AVAILABLE, "AVBL", fscache_object_available);
81static WORK_STATE(JUMPSTART_DEPS, "JUMP", fscache_jumpstart_dependents);
82
83static WORK_STATE(INVALIDATE_OBJECT, "INVL", fscache_invalidate_object);
84static WORK_STATE(UPDATE_OBJECT, "UPDT", fscache_update_object);
85
86static WORK_STATE(LOOKUP_FAILURE, "LCFL", fscache_lookup_failure);
87static WORK_STATE(KILL_OBJECT, "KILL", fscache_kill_object);
88static WORK_STATE(KILL_DEPENDENTS, "KDEP", fscache_kill_dependents);
89static WORK_STATE(DROP_OBJECT, "DROP", fscache_drop_object);
90static WORK_STATE(OBJECT_DEAD, "DEAD", fscache_object_dead);
91
92static WAIT_STATE(WAIT_FOR_INIT, "?INI",
93 TRANSIT_TO(INIT_OBJECT, 1 << FSCACHE_OBJECT_EV_NEW_CHILD));
94
95static WAIT_STATE(WAIT_FOR_PARENT, "?PRN",
96 TRANSIT_TO(PARENT_READY, 1 << FSCACHE_OBJECT_EV_PARENT_READY));
97
98static WAIT_STATE(WAIT_FOR_CMD, "?CMD",
99 TRANSIT_TO(INVALIDATE_OBJECT, 1 << FSCACHE_OBJECT_EV_INVALIDATE),
100 TRANSIT_TO(UPDATE_OBJECT, 1 << FSCACHE_OBJECT_EV_UPDATE),
101 TRANSIT_TO(JUMPSTART_DEPS, 1 << FSCACHE_OBJECT_EV_NEW_CHILD));
102
103static WAIT_STATE(WAIT_FOR_CLEARANCE, "?CLR",
104 TRANSIT_TO(KILL_OBJECT, 1 << FSCACHE_OBJECT_EV_CLEARED));
105
106
107
108
109
110
111
112
113
114
115static const struct fscache_transition fscache_osm_init_oob[] = {
116 TRANSIT_TO(ABORT_INIT,
117 (1 << FSCACHE_OBJECT_EV_ERROR) |
118 (1 << FSCACHE_OBJECT_EV_KILL)),
119 { 0, NULL }
120};
121
122static const struct fscache_transition fscache_osm_lookup_oob[] = {
123 TRANSIT_TO(LOOKUP_FAILURE,
124 (1 << FSCACHE_OBJECT_EV_ERROR) |
125 (1 << FSCACHE_OBJECT_EV_KILL)),
126 { 0, NULL }
127};
128
129static const struct fscache_transition fscache_osm_run_oob[] = {
130 TRANSIT_TO(KILL_OBJECT,
131 (1 << FSCACHE_OBJECT_EV_ERROR) |
132 (1 << FSCACHE_OBJECT_EV_KILL)),
133 { 0, NULL }
134};
135
136static int fscache_get_object(struct fscache_object *,
137 enum fscache_obj_ref_trace);
138static void fscache_put_object(struct fscache_object *,
139 enum fscache_obj_ref_trace);
140static bool fscache_enqueue_dependents(struct fscache_object *, int);
141static void fscache_dequeue_object(struct fscache_object *);
142static void fscache_update_aux_data(struct fscache_object *);
143
144
145
146
147
148static inline void fscache_done_parent_op(struct fscache_object *object)
149{
150 struct fscache_object *parent = object->parent;
151
152 _enter("OBJ%x {OBJ%x,%x}",
153 object->debug_id, parent->debug_id, parent->n_ops);
154
155 spin_lock_nested(&parent->lock, 1);
156 parent->n_obj_ops--;
157 parent->n_ops--;
158 if (parent->n_ops == 0)
159 fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED);
160 spin_unlock(&parent->lock);
161}
162
163
164
165
166static void fscache_object_sm_dispatcher(struct fscache_object *object)
167{
168 const struct fscache_transition *t;
169 const struct fscache_state *state, *new_state;
170 unsigned long events, event_mask;
171 bool oob;
172 int event = -1;
173
174 ASSERT(object != NULL);
175
176 _enter("{OBJ%x,%s,%lx}",
177 object->debug_id, object->state->name, object->events);
178
179 event_mask = object->event_mask;
180restart:
181 object->event_mask = 0;
182 state = object->state;
183restart_masked:
184 events = object->events;
185
186
187 if (events & object->oob_event_mask) {
188 _debug("{OBJ%x} oob %lx",
189 object->debug_id, events & object->oob_event_mask);
190 oob = true;
191 for (t = object->oob_table; t->events; t++) {
192 if (events & t->events) {
193 state = t->transit_to;
194 ASSERT(state->work != NULL);
195 event = fls(events & t->events) - 1;
196 __clear_bit(event, &object->oob_event_mask);
197 clear_bit(event, &object->events);
198 goto execute_work_state;
199 }
200 }
201 }
202 oob = false;
203
204
205 if (!state->work) {
206 if (events & event_mask) {
207 for (t = state->transitions; t->events; t++) {
208 if (events & t->events) {
209 new_state = t->transit_to;
210 event = fls(events & t->events) - 1;
211 trace_fscache_osm(object, state,
212 true, false, event);
213 clear_bit(event, &object->events);
214 _debug("{OBJ%x} ev %d: %s -> %s",
215 object->debug_id, event,
216 state->name, new_state->name);
217 object->state = state = new_state;
218 goto execute_work_state;
219 }
220 }
221
222
223 BUG();
224 }
225
226 goto unmask_events;
227 }
228
229execute_work_state:
230 _debug("{OBJ%x} exec %s", object->debug_id, state->name);
231
232 trace_fscache_osm(object, state, false, oob, event);
233 new_state = state->work(object, event);
234 event = -1;
235 if (new_state == NO_TRANSIT) {
236 _debug("{OBJ%x} %s notrans", object->debug_id, state->name);
237 if (unlikely(state == STATE(OBJECT_DEAD))) {
238 _leave(" [dead]");
239 return;
240 }
241 fscache_enqueue_object(object);
242 event_mask = object->oob_event_mask;
243 goto unmask_events;
244 }
245
246 _debug("{OBJ%x} %s -> %s",
247 object->debug_id, state->name, new_state->name);
248 object->state = state = new_state;
249
250 if (state->work) {
251 if (unlikely(state == STATE(OBJECT_DEAD))) {
252 _leave(" [dead]");
253 return;
254 }
255 goto restart_masked;
256 }
257
258
259 event_mask = object->oob_event_mask;
260 for (t = state->transitions; t->events; t++)
261 event_mask |= t->events;
262
263unmask_events:
264 object->event_mask = event_mask;
265 smp_mb();
266 events = object->events;
267 if (events & event_mask)
268 goto restart;
269 _leave(" [msk %lx]", event_mask);
270}
271
272
273
274
275static void fscache_object_work_func(struct work_struct *work)
276{
277 struct fscache_object *object =
278 container_of(work, struct fscache_object, work);
279
280 _enter("{OBJ%x}", object->debug_id);
281
282 fscache_object_sm_dispatcher(object);
283 fscache_put_object(object, fscache_obj_put_work);
284}
285
286
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288
289
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291
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293
294
295
296
297void fscache_object_init(struct fscache_object *object,
298 struct fscache_cookie *cookie,
299 struct fscache_cache *cache)
300{
301 const struct fscache_transition *t;
302
303 atomic_inc(&cache->object_count);
304
305 object->state = STATE(WAIT_FOR_INIT);
306 object->oob_table = fscache_osm_init_oob;
307 object->flags = 1 << FSCACHE_OBJECT_IS_LIVE;
308 spin_lock_init(&object->lock);
309 INIT_LIST_HEAD(&object->cache_link);
310 INIT_HLIST_NODE(&object->cookie_link);
311 INIT_WORK(&object->work, fscache_object_work_func);
312 INIT_LIST_HEAD(&object->dependents);
313 INIT_LIST_HEAD(&object->dep_link);
314 INIT_LIST_HEAD(&object->pending_ops);
315 object->n_children = 0;
316 object->n_ops = object->n_in_progress = object->n_exclusive = 0;
317 object->events = 0;
318 object->store_limit = 0;
319 object->store_limit_l = 0;
320 object->cache = cache;
321 object->cookie = cookie;
322 fscache_cookie_get(cookie, fscache_cookie_get_attach_object);
323 object->parent = NULL;
324#ifdef CONFIG_FSCACHE_OBJECT_LIST
325 RB_CLEAR_NODE(&object->objlist_link);
326#endif
327
328 object->oob_event_mask = 0;
329 for (t = object->oob_table; t->events; t++)
330 object->oob_event_mask |= t->events;
331 object->event_mask = object->oob_event_mask;
332 for (t = object->state->transitions; t->events; t++)
333 object->event_mask |= t->events;
334}
335EXPORT_SYMBOL(fscache_object_init);
336
337
338
339
340
341static inline void fscache_mark_object_dead(struct fscache_object *object)
342{
343 spin_lock(&object->lock);
344 clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
345 spin_unlock(&object->lock);
346}
347
348
349
350
351static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *object,
352 int event)
353{
354 _enter("{OBJ%x},%d", object->debug_id, event);
355
356 object->oob_event_mask = 0;
357 fscache_dequeue_object(object);
358 return transit_to(KILL_OBJECT);
359}
360
361
362
363
364
365
366
367
368static const struct fscache_state *fscache_initialise_object(struct fscache_object *object,
369 int event)
370{
371 struct fscache_object *parent;
372 bool success;
373
374 _enter("{OBJ%x},%d", object->debug_id, event);
375
376 ASSERT(list_empty(&object->dep_link));
377
378 parent = object->parent;
379 if (!parent) {
380 _leave(" [no parent]");
381 return transit_to(DROP_OBJECT);
382 }
383
384 _debug("parent: %s of:%lx", parent->state->name, parent->flags);
385
386 if (fscache_object_is_dying(parent)) {
387 _leave(" [bad parent]");
388 return transit_to(DROP_OBJECT);
389 }
390
391 if (fscache_object_is_available(parent)) {
392 _leave(" [ready]");
393 return transit_to(PARENT_READY);
394 }
395
396 _debug("wait");
397
398 spin_lock(&parent->lock);
399 fscache_stat(&fscache_n_cop_grab_object);
400 success = false;
401 if (fscache_object_is_live(parent) &&
402 object->cache->ops->grab_object(object, fscache_obj_get_add_to_deps)) {
403 list_add(&object->dep_link, &parent->dependents);
404 success = true;
405 }
406 fscache_stat_d(&fscache_n_cop_grab_object);
407 spin_unlock(&parent->lock);
408 if (!success) {
409 _leave(" [grab failed]");
410 return transit_to(DROP_OBJECT);
411 }
412
413
414
415 fscache_raise_event(parent, FSCACHE_OBJECT_EV_NEW_CHILD);
416 _leave(" [wait]");
417 return transit_to(WAIT_FOR_PARENT);
418}
419
420
421
422
423static const struct fscache_state *fscache_parent_ready(struct fscache_object *object,
424 int event)
425{
426 struct fscache_object *parent = object->parent;
427
428 _enter("{OBJ%x},%d", object->debug_id, event);
429
430 ASSERT(parent != NULL);
431
432 spin_lock(&parent->lock);
433 parent->n_ops++;
434 parent->n_obj_ops++;
435 spin_unlock(&parent->lock);
436
437 _leave("");
438 return transit_to(LOOK_UP_OBJECT);
439}
440
441
442
443
444
445
446static const struct fscache_state *fscache_look_up_object(struct fscache_object *object,
447 int event)
448{
449 struct fscache_cookie *cookie = object->cookie;
450 struct fscache_object *parent = object->parent;
451 int ret;
452
453 _enter("{OBJ%x},%d", object->debug_id, event);
454
455 object->oob_table = fscache_osm_lookup_oob;
456
457 ASSERT(parent != NULL);
458 ASSERTCMP(parent->n_ops, >, 0);
459 ASSERTCMP(parent->n_obj_ops, >, 0);
460
461
462 ASSERT(fscache_object_is_available(parent));
463
464 if (fscache_object_is_dying(parent) ||
465 test_bit(FSCACHE_IOERROR, &object->cache->flags) ||
466 !fscache_use_cookie(object)) {
467 _leave(" [unavailable]");
468 return transit_to(LOOKUP_FAILURE);
469 }
470
471 _debug("LOOKUP \"%s\" in \"%s\"",
472 cookie->def->name, object->cache->tag->name);
473
474 fscache_stat(&fscache_n_object_lookups);
475 fscache_stat(&fscache_n_cop_lookup_object);
476 ret = object->cache->ops->lookup_object(object);
477 fscache_stat_d(&fscache_n_cop_lookup_object);
478
479 fscache_unuse_cookie(object);
480
481 if (ret == -ETIMEDOUT) {
482
483
484 fscache_stat(&fscache_n_object_lookups_timed_out);
485 _leave(" [timeout]");
486 return NO_TRANSIT;
487 }
488
489 if (ret < 0) {
490 _leave(" [error]");
491 return transit_to(LOOKUP_FAILURE);
492 }
493
494 _leave(" [ok]");
495 return transit_to(OBJECT_AVAILABLE);
496}
497
498
499
500
501
502
503
504
505void fscache_object_lookup_negative(struct fscache_object *object)
506{
507 struct fscache_cookie *cookie = object->cookie;
508
509 _enter("{OBJ%x,%s}", object->debug_id, object->state->name);
510
511 if (!test_and_set_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) {
512 fscache_stat(&fscache_n_object_lookups_negative);
513
514
515
516
517 set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
518 clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
519
520 clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags);
521 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
522 }
523 _leave("");
524}
525EXPORT_SYMBOL(fscache_object_lookup_negative);
526
527
528
529
530
531
532
533
534
535
536
537void fscache_obtained_object(struct fscache_object *object)
538{
539 struct fscache_cookie *cookie = object->cookie;
540
541 _enter("{OBJ%x,%s}", object->debug_id, object->state->name);
542
543
544
545 if (!test_and_set_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) {
546 fscache_stat(&fscache_n_object_lookups_positive);
547
548
549 clear_bit_unlock(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
550 clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
551
552
553
554
555 clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags);
556 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
557 } else {
558 fscache_stat(&fscache_n_object_created);
559 }
560
561 set_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
562 _leave("");
563}
564EXPORT_SYMBOL(fscache_obtained_object);
565
566
567
568
569static const struct fscache_state *fscache_object_available(struct fscache_object *object,
570 int event)
571{
572 _enter("{OBJ%x},%d", object->debug_id, event);
573
574 object->oob_table = fscache_osm_run_oob;
575
576 spin_lock(&object->lock);
577
578 fscache_done_parent_op(object);
579 if (object->n_in_progress == 0) {
580 if (object->n_ops > 0) {
581 ASSERTCMP(object->n_ops, >=, object->n_obj_ops);
582 fscache_start_operations(object);
583 } else {
584 ASSERT(list_empty(&object->pending_ops));
585 }
586 }
587 spin_unlock(&object->lock);
588
589 fscache_stat(&fscache_n_cop_lookup_complete);
590 object->cache->ops->lookup_complete(object);
591 fscache_stat_d(&fscache_n_cop_lookup_complete);
592
593 fscache_stat(&fscache_n_object_avail);
594
595 _leave("");
596 return transit_to(JUMPSTART_DEPS);
597}
598
599
600
601
602static const struct fscache_state *fscache_jumpstart_dependents(struct fscache_object *object,
603 int event)
604{
605 _enter("{OBJ%x},%d", object->debug_id, event);
606
607 if (!fscache_enqueue_dependents(object, FSCACHE_OBJECT_EV_PARENT_READY))
608 return NO_TRANSIT;
609 return transit_to(WAIT_FOR_CMD);
610}
611
612
613
614
615static const struct fscache_state *fscache_lookup_failure(struct fscache_object *object,
616 int event)
617{
618 struct fscache_cookie *cookie;
619
620 _enter("{OBJ%x},%d", object->debug_id, event);
621
622 object->oob_event_mask = 0;
623
624 fscache_stat(&fscache_n_cop_lookup_complete);
625 object->cache->ops->lookup_complete(object);
626 fscache_stat_d(&fscache_n_cop_lookup_complete);
627
628 set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags);
629
630 cookie = object->cookie;
631 set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
632 if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
633 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
634
635 fscache_done_parent_op(object);
636 return transit_to(KILL_OBJECT);
637}
638
639
640
641
642
643static const struct fscache_state *fscache_kill_object(struct fscache_object *object,
644 int event)
645{
646 _enter("{OBJ%x,%d,%d},%d",
647 object->debug_id, object->n_ops, object->n_children, event);
648
649 fscache_mark_object_dead(object);
650 object->oob_event_mask = 0;
651
652 if (test_bit(FSCACHE_OBJECT_RETIRED, &object->flags)) {
653
654 clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
655 fscache_cancel_all_ops(object);
656 }
657
658 if (list_empty(&object->dependents) &&
659 object->n_ops == 0 &&
660 object->n_children == 0)
661 return transit_to(DROP_OBJECT);
662
663 if (object->n_in_progress == 0) {
664 spin_lock(&object->lock);
665 if (object->n_ops > 0 && object->n_in_progress == 0)
666 fscache_start_operations(object);
667 spin_unlock(&object->lock);
668 }
669
670 if (!list_empty(&object->dependents))
671 return transit_to(KILL_DEPENDENTS);
672
673 return transit_to(WAIT_FOR_CLEARANCE);
674}
675
676
677
678
679static const struct fscache_state *fscache_kill_dependents(struct fscache_object *object,
680 int event)
681{
682 _enter("{OBJ%x},%d", object->debug_id, event);
683
684 if (!fscache_enqueue_dependents(object, FSCACHE_OBJECT_EV_KILL))
685 return NO_TRANSIT;
686 return transit_to(WAIT_FOR_CLEARANCE);
687}
688
689
690
691
692static const struct fscache_state *fscache_drop_object(struct fscache_object *object,
693 int event)
694{
695 struct fscache_object *parent = object->parent;
696 struct fscache_cookie *cookie = object->cookie;
697 struct fscache_cache *cache = object->cache;
698 bool awaken = false;
699
700 _enter("{OBJ%x,%d},%d", object->debug_id, object->n_children, event);
701
702 ASSERT(cookie != NULL);
703 ASSERT(!hlist_unhashed(&object->cookie_link));
704
705 if (test_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags)) {
706 _debug("final update");
707 fscache_update_aux_data(object);
708 }
709
710
711
712
713 spin_lock(&cookie->lock);
714 hlist_del_init(&object->cookie_link);
715 if (hlist_empty(&cookie->backing_objects) &&
716 test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags))
717 awaken = true;
718 spin_unlock(&cookie->lock);
719
720 if (awaken)
721 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
722 if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
723 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
724
725
726
727
728
729 spin_lock(&object->lock);
730 spin_unlock(&object->lock);
731
732
733 spin_lock(&cache->object_list_lock);
734 list_del_init(&object->cache_link);
735 spin_unlock(&cache->object_list_lock);
736
737 fscache_stat(&fscache_n_cop_drop_object);
738 cache->ops->drop_object(object);
739 fscache_stat_d(&fscache_n_cop_drop_object);
740
741
742 if (parent) {
743 _debug("release parent OBJ%x {%d}",
744 parent->debug_id, parent->n_children);
745
746 spin_lock(&parent->lock);
747 parent->n_children--;
748 if (parent->n_children == 0)
749 fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED);
750 spin_unlock(&parent->lock);
751 object->parent = NULL;
752 }
753
754
755 fscache_put_object(object, fscache_obj_put_drop_obj);
756 fscache_stat(&fscache_n_object_dead);
757
758 _leave("");
759 return transit_to(OBJECT_DEAD);
760}
761
762
763
764
765static int fscache_get_object(struct fscache_object *object,
766 enum fscache_obj_ref_trace why)
767{
768 int ret;
769
770 fscache_stat(&fscache_n_cop_grab_object);
771 ret = object->cache->ops->grab_object(object, why) ? 0 : -EAGAIN;
772 fscache_stat_d(&fscache_n_cop_grab_object);
773 return ret;
774}
775
776
777
778
779static void fscache_put_object(struct fscache_object *object,
780 enum fscache_obj_ref_trace why)
781{
782 fscache_stat(&fscache_n_cop_put_object);
783 object->cache->ops->put_object(object, why);
784 fscache_stat_d(&fscache_n_cop_put_object);
785}
786
787
788
789
790
791
792
793void fscache_object_destroy(struct fscache_object *object)
794{
795
796 fscache_cookie_put(object->cookie, fscache_cookie_put_object);
797 object->cookie = NULL;
798}
799EXPORT_SYMBOL(fscache_object_destroy);
800
801
802
803
804void fscache_enqueue_object(struct fscache_object *object)
805{
806 _enter("{OBJ%x}", object->debug_id);
807
808 if (fscache_get_object(object, fscache_obj_get_queue) >= 0) {
809 wait_queue_head_t *cong_wq =
810 &get_cpu_var(fscache_object_cong_wait);
811
812 if (queue_work(fscache_object_wq, &object->work)) {
813 if (fscache_object_congested())
814 wake_up(cong_wq);
815 } else
816 fscache_put_object(object, fscache_obj_put_queue);
817
818 put_cpu_var(fscache_object_cong_wait);
819 }
820}
821
822
823
824
825
826
827
828
829
830
831
832
833
834bool fscache_object_sleep_till_congested(signed long *timeoutp)
835{
836 wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait);
837 DEFINE_WAIT(wait);
838
839 if (fscache_object_congested())
840 return true;
841
842 add_wait_queue_exclusive(cong_wq, &wait);
843 if (!fscache_object_congested())
844 *timeoutp = schedule_timeout(*timeoutp);
845 finish_wait(cong_wq, &wait);
846
847 return fscache_object_congested();
848}
849EXPORT_SYMBOL_GPL(fscache_object_sleep_till_congested);
850
851
852
853
854
855
856
857
858static bool fscache_enqueue_dependents(struct fscache_object *object, int event)
859{
860 struct fscache_object *dep;
861 bool ret = true;
862
863 _enter("{OBJ%x}", object->debug_id);
864
865 if (list_empty(&object->dependents))
866 return true;
867
868 spin_lock(&object->lock);
869
870 while (!list_empty(&object->dependents)) {
871 dep = list_entry(object->dependents.next,
872 struct fscache_object, dep_link);
873 list_del_init(&dep->dep_link);
874
875 fscache_raise_event(dep, event);
876 fscache_put_object(dep, fscache_obj_put_enq_dep);
877
878 if (!list_empty(&object->dependents) && need_resched()) {
879 ret = false;
880 break;
881 }
882 }
883
884 spin_unlock(&object->lock);
885 return ret;
886}
887
888
889
890
891static void fscache_dequeue_object(struct fscache_object *object)
892{
893 _enter("{OBJ%x}", object->debug_id);
894
895 if (!list_empty(&object->dep_link)) {
896 spin_lock(&object->parent->lock);
897 list_del_init(&object->dep_link);
898 spin_unlock(&object->parent->lock);
899 }
900
901 _leave("");
902}
903
904
905
906
907
908
909
910
911
912
913
914
915
916enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
917 const void *data, uint16_t datalen,
918 loff_t object_size)
919{
920 enum fscache_checkaux result;
921
922 if (!object->cookie->def->check_aux) {
923 fscache_stat(&fscache_n_checkaux_none);
924 return FSCACHE_CHECKAUX_OKAY;
925 }
926
927 result = object->cookie->def->check_aux(object->cookie->netfs_data,
928 data, datalen, object_size);
929 switch (result) {
930
931 case FSCACHE_CHECKAUX_OKAY:
932 fscache_stat(&fscache_n_checkaux_okay);
933 break;
934
935
936 case FSCACHE_CHECKAUX_NEEDS_UPDATE:
937 fscache_stat(&fscache_n_checkaux_update);
938 break;
939
940
941 case FSCACHE_CHECKAUX_OBSOLETE:
942 fscache_stat(&fscache_n_checkaux_obsolete);
943 break;
944
945 default:
946 BUG();
947 }
948
949 return result;
950}
951EXPORT_SYMBOL(fscache_check_aux);
952
953
954
955
956static const struct fscache_state *_fscache_invalidate_object(struct fscache_object *object,
957 int event)
958{
959 struct fscache_operation *op;
960 struct fscache_cookie *cookie = object->cookie;
961
962 _enter("{OBJ%x},%d", object->debug_id, event);
963
964
965
966
967 if (!fscache_use_cookie(object)) {
968 ASSERT(radix_tree_empty(&object->cookie->stores));
969 set_bit(FSCACHE_OBJECT_RETIRED, &object->flags);
970 _leave(" [no cookie]");
971 return transit_to(KILL_OBJECT);
972 }
973
974
975 fscache_invalidate_writes(cookie);
976 clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
977 fscache_cancel_all_ops(object);
978
979
980 op = kzalloc(sizeof(*op), GFP_KERNEL);
981 if (!op)
982 goto nomem;
983
984 fscache_operation_init(cookie, op, object->cache->ops->invalidate_object,
985 NULL, NULL);
986 op->flags = FSCACHE_OP_ASYNC |
987 (1 << FSCACHE_OP_EXCLUSIVE) |
988 (1 << FSCACHE_OP_UNUSE_COOKIE);
989 trace_fscache_page_op(cookie, NULL, op, fscache_page_op_invalidate);
990
991 spin_lock(&cookie->lock);
992 if (fscache_submit_exclusive_op(object, op) < 0)
993 goto submit_op_failed;
994 spin_unlock(&cookie->lock);
995 fscache_put_operation(op);
996
997
998
999
1000
1001 set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
1002
1003
1004
1005
1006 if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags))
1007 wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
1008 _leave(" [ok]");
1009 return transit_to(UPDATE_OBJECT);
1010
1011nomem:
1012 fscache_mark_object_dead(object);
1013 fscache_unuse_cookie(object);
1014 _leave(" [ENOMEM]");
1015 return transit_to(KILL_OBJECT);
1016
1017submit_op_failed:
1018 fscache_mark_object_dead(object);
1019 spin_unlock(&cookie->lock);
1020 fscache_unuse_cookie(object);
1021 kfree(op);
1022 _leave(" [EIO]");
1023 return transit_to(KILL_OBJECT);
1024}
1025
1026static const struct fscache_state *fscache_invalidate_object(struct fscache_object *object,
1027 int event)
1028{
1029 const struct fscache_state *s;
1030
1031 fscache_stat(&fscache_n_invalidates_run);
1032 fscache_stat(&fscache_n_cop_invalidate_object);
1033 s = _fscache_invalidate_object(object, event);
1034 fscache_stat_d(&fscache_n_cop_invalidate_object);
1035 return s;
1036}
1037
1038
1039
1040
1041static void fscache_update_aux_data(struct fscache_object *object)
1042{
1043 fscache_stat(&fscache_n_updates_run);
1044 fscache_stat(&fscache_n_cop_update_object);
1045 object->cache->ops->update_object(object);
1046 fscache_stat_d(&fscache_n_cop_update_object);
1047}
1048
1049
1050
1051
1052static const struct fscache_state *fscache_update_object(struct fscache_object *object,
1053 int event)
1054{
1055 _enter("{OBJ%x},%d", object->debug_id, event);
1056
1057 fscache_update_aux_data(object);
1058
1059 _leave("");
1060 return transit_to(WAIT_FOR_CMD);
1061}
1062
1063
1064
1065
1066
1067
1068
1069
1070void fscache_object_retrying_stale(struct fscache_object *object)
1071{
1072 fscache_stat(&fscache_n_cache_no_space_reject);
1073}
1074EXPORT_SYMBOL(fscache_object_retrying_stale);
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084void fscache_object_mark_killed(struct fscache_object *object,
1085 enum fscache_why_object_killed why)
1086{
1087 if (test_and_set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags)) {
1088 pr_err("Error: Object already killed by cache [%s]\n",
1089 object->cache->identifier);
1090 return;
1091 }
1092
1093 switch (why) {
1094 case FSCACHE_OBJECT_NO_SPACE:
1095 fscache_stat(&fscache_n_cache_no_space_reject);
1096 break;
1097 case FSCACHE_OBJECT_IS_STALE:
1098 fscache_stat(&fscache_n_cache_stale_objects);
1099 break;
1100 case FSCACHE_OBJECT_WAS_RETIRED:
1101 fscache_stat(&fscache_n_cache_retired_objects);
1102 break;
1103 case FSCACHE_OBJECT_WAS_CULLED:
1104 fscache_stat(&fscache_n_cache_culled_objects);
1105 break;
1106 }
1107}
1108EXPORT_SYMBOL(fscache_object_mark_killed);
1109
1110
1111
1112
1113
1114
1115
1116static const struct fscache_state *fscache_object_dead(struct fscache_object *object,
1117 int event)
1118{
1119 if (!test_and_set_bit(FSCACHE_OBJECT_RUN_AFTER_DEAD,
1120 &object->flags))
1121 return NO_TRANSIT;
1122
1123 WARN(true, "FS-Cache object redispatched after death");
1124 return NO_TRANSIT;
1125}
1126