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36c95590 DH |
1 | /* FS-Cache object state machine handler |
2 | * | |
3 | * Copyright (C) 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 | * See Documentation/filesystems/caching/object.txt for a description of the | |
12 | * object state machine and the in-kernel representations. | |
13 | */ | |
14 | ||
15 | #define FSCACHE_DEBUG_LEVEL COOKIE | |
16 | #include <linux/module.h> | |
ef778e7a | 17 | #include <linux/slab.h> |
caaef690 | 18 | #include <linux/prefetch.h> |
36c95590 DH |
19 | #include "internal.h" |
20 | ||
caaef690 DH |
21 | static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *, int); |
22 | static const struct fscache_state *fscache_kill_dependents(struct fscache_object *, int); | |
23 | static const struct fscache_state *fscache_drop_object(struct fscache_object *, int); | |
24 | static const struct fscache_state *fscache_initialise_object(struct fscache_object *, int); | |
25 | static const struct fscache_state *fscache_invalidate_object(struct fscache_object *, int); | |
26 | static const struct fscache_state *fscache_jumpstart_dependents(struct fscache_object *, int); | |
27 | static const struct fscache_state *fscache_kill_object(struct fscache_object *, int); | |
28 | static const struct fscache_state *fscache_lookup_failure(struct fscache_object *, int); | |
29 | static const struct fscache_state *fscache_look_up_object(struct fscache_object *, int); | |
30 | static const struct fscache_state *fscache_object_available(struct fscache_object *, int); | |
31 | static const struct fscache_state *fscache_parent_ready(struct fscache_object *, int); | |
32 | static const struct fscache_state *fscache_update_object(struct fscache_object *, int); | |
e26bfebd | 33 | static const struct fscache_state *fscache_object_dead(struct fscache_object *, int); |
caaef690 DH |
34 | |
35 | #define __STATE_NAME(n) fscache_osm_##n | |
36 | #define STATE(n) (&__STATE_NAME(n)) | |
37 | ||
38 | /* | |
39 | * Define a work state. Work states are execution states. No event processing | |
40 | * is performed by them. The function attached to a work state returns a | |
41 | * pointer indicating the next state to which the state machine should | |
42 | * transition. Returning NO_TRANSIT repeats the current state, but goes back | |
43 | * to the scheduler first. | |
44 | */ | |
45 | #define WORK_STATE(n, sn, f) \ | |
46 | const struct fscache_state __STATE_NAME(n) = { \ | |
47 | .name = #n, \ | |
48 | .short_name = sn, \ | |
49 | .work = f \ | |
50 | } | |
51 | ||
52 | /* | |
53 | * Returns from work states. | |
54 | */ | |
55 | #define transit_to(state) ({ prefetch(&STATE(state)->work); STATE(state); }) | |
56 | ||
57 | #define NO_TRANSIT ((struct fscache_state *)NULL) | |
58 | ||
59 | /* | |
60 | * Define a wait state. Wait states are event processing states. No execution | |
61 | * is performed by them. Wait states are just tables of "if event X occurs, | |
62 | * clear it and transition to state Y". The dispatcher returns to the | |
63 | * scheduler if none of the events in which the wait state has an interest are | |
64 | * currently pending. | |
65 | */ | |
66 | #define WAIT_STATE(n, sn, ...) \ | |
67 | const struct fscache_state __STATE_NAME(n) = { \ | |
68 | .name = #n, \ | |
69 | .short_name = sn, \ | |
70 | .work = NULL, \ | |
71 | .transitions = { __VA_ARGS__, { 0, NULL } } \ | |
72 | } | |
73 | ||
74 | #define TRANSIT_TO(state, emask) \ | |
75 | { .events = (emask), .transit_to = STATE(state) } | |
76 | ||
77 | /* | |
78 | * The object state machine. | |
79 | */ | |
80 | static WORK_STATE(INIT_OBJECT, "INIT", fscache_initialise_object); | |
81 | static WORK_STATE(PARENT_READY, "PRDY", fscache_parent_ready); | |
82 | static WORK_STATE(ABORT_INIT, "ABRT", fscache_abort_initialisation); | |
83 | static WORK_STATE(LOOK_UP_OBJECT, "LOOK", fscache_look_up_object); | |
84 | static WORK_STATE(CREATE_OBJECT, "CRTO", fscache_look_up_object); | |
85 | static WORK_STATE(OBJECT_AVAILABLE, "AVBL", fscache_object_available); | |
86 | static WORK_STATE(JUMPSTART_DEPS, "JUMP", fscache_jumpstart_dependents); | |
87 | ||
88 | static WORK_STATE(INVALIDATE_OBJECT, "INVL", fscache_invalidate_object); | |
89 | static WORK_STATE(UPDATE_OBJECT, "UPDT", fscache_update_object); | |
90 | ||
91 | static WORK_STATE(LOOKUP_FAILURE, "LCFL", fscache_lookup_failure); | |
92 | static WORK_STATE(KILL_OBJECT, "KILL", fscache_kill_object); | |
93 | static WORK_STATE(KILL_DEPENDENTS, "KDEP", fscache_kill_dependents); | |
94 | static WORK_STATE(DROP_OBJECT, "DROP", fscache_drop_object); | |
e26bfebd | 95 | static WORK_STATE(OBJECT_DEAD, "DEAD", fscache_object_dead); |
caaef690 DH |
96 | |
97 | static WAIT_STATE(WAIT_FOR_INIT, "?INI", | |
98 | TRANSIT_TO(INIT_OBJECT, 1 << FSCACHE_OBJECT_EV_NEW_CHILD)); | |
99 | ||
100 | static WAIT_STATE(WAIT_FOR_PARENT, "?PRN", | |
101 | TRANSIT_TO(PARENT_READY, 1 << FSCACHE_OBJECT_EV_PARENT_READY)); | |
102 | ||
103 | static WAIT_STATE(WAIT_FOR_CMD, "?CMD", | |
104 | TRANSIT_TO(INVALIDATE_OBJECT, 1 << FSCACHE_OBJECT_EV_INVALIDATE), | |
105 | TRANSIT_TO(UPDATE_OBJECT, 1 << FSCACHE_OBJECT_EV_UPDATE), | |
106 | TRANSIT_TO(JUMPSTART_DEPS, 1 << FSCACHE_OBJECT_EV_NEW_CHILD)); | |
107 | ||
108 | static WAIT_STATE(WAIT_FOR_CLEARANCE, "?CLR", | |
109 | TRANSIT_TO(KILL_OBJECT, 1 << FSCACHE_OBJECT_EV_CLEARED)); | |
110 | ||
111 | /* | |
112 | * Out-of-band event transition tables. These are for handling unexpected | |
113 | * events, such as an I/O error. If an OOB event occurs, the state machine | |
114 | * clears and disables the event and forces a transition to the nominated work | |
115 | * state (acurrently executing work states will complete first). | |
116 | * | |
117 | * In such a situation, object->state remembers the state the machine should | |
118 | * have been in/gone to and returning NO_TRANSIT returns to that. | |
119 | */ | |
120 | static const struct fscache_transition fscache_osm_init_oob[] = { | |
121 | TRANSIT_TO(ABORT_INIT, | |
122 | (1 << FSCACHE_OBJECT_EV_ERROR) | | |
123 | (1 << FSCACHE_OBJECT_EV_KILL)), | |
124 | { 0, NULL } | |
36c95590 | 125 | }; |
caaef690 DH |
126 | |
127 | static const struct fscache_transition fscache_osm_lookup_oob[] = { | |
128 | TRANSIT_TO(LOOKUP_FAILURE, | |
129 | (1 << FSCACHE_OBJECT_EV_ERROR) | | |
130 | (1 << FSCACHE_OBJECT_EV_KILL)), | |
131 | { 0, NULL } | |
132 | }; | |
133 | ||
134 | static const struct fscache_transition fscache_osm_run_oob[] = { | |
135 | TRANSIT_TO(KILL_OBJECT, | |
136 | (1 << FSCACHE_OBJECT_EV_ERROR) | | |
137 | (1 << FSCACHE_OBJECT_EV_KILL)), | |
138 | { 0, NULL } | |
440f0aff DH |
139 | }; |
140 | ||
8b8edefa TH |
141 | static int fscache_get_object(struct fscache_object *); |
142 | static void fscache_put_object(struct fscache_object *); | |
caaef690 | 143 | static bool fscache_enqueue_dependents(struct fscache_object *, int); |
36c95590 DH |
144 | static void fscache_dequeue_object(struct fscache_object *); |
145 | ||
36c95590 DH |
146 | /* |
147 | * we need to notify the parent when an op completes that we had outstanding | |
148 | * upon it | |
149 | */ | |
150 | static inline void fscache_done_parent_op(struct fscache_object *object) | |
151 | { | |
152 | struct fscache_object *parent = object->parent; | |
153 | ||
154 | _enter("OBJ%x {OBJ%x,%x}", | |
155 | object->debug_id, parent->debug_id, parent->n_ops); | |
156 | ||
157 | spin_lock_nested(&parent->lock, 1); | |
36c95590 | 158 | parent->n_obj_ops--; |
1362729b | 159 | parent->n_ops--; |
36c95590 DH |
160 | if (parent->n_ops == 0) |
161 | fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED); | |
162 | spin_unlock(&parent->lock); | |
163 | } | |
164 | ||
ef778e7a | 165 | /* |
caaef690 | 166 | * Object state machine dispatcher. |
ef778e7a | 167 | */ |
caaef690 | 168 | static void fscache_object_sm_dispatcher(struct fscache_object *object) |
ef778e7a | 169 | { |
caaef690 DH |
170 | const struct fscache_transition *t; |
171 | const struct fscache_state *state, *new_state; | |
172 | unsigned long events, event_mask; | |
173 | int event = -1; | |
36c95590 DH |
174 | |
175 | ASSERT(object != NULL); | |
176 | ||
177 | _enter("{OBJ%x,%s,%lx}", | |
caaef690 DH |
178 | object->debug_id, object->state->name, object->events); |
179 | ||
180 | event_mask = object->event_mask; | |
181 | restart: | |
182 | object->event_mask = 0; /* Mask normal event handling */ | |
183 | state = object->state; | |
184 | restart_masked: | |
185 | events = object->events; | |
186 | ||
187 | /* Handle any out-of-band events (typically an error) */ | |
188 | if (events & object->oob_event_mask) { | |
189 | _debug("{OBJ%x} oob %lx", | |
190 | object->debug_id, events & object->oob_event_mask); | |
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 | } | |
d461d26d | 200 | } |
caaef690 | 201 | } |
36c95590 | 202 | |
caaef690 DH |
203 | /* Wait states are just transition tables */ |
204 | if (!state->work) { | |
205 | if (events & event_mask) { | |
206 | for (t = state->transitions; t->events; t++) { | |
207 | if (events & t->events) { | |
208 | new_state = t->transit_to; | |
209 | event = fls(events & t->events) - 1; | |
210 | clear_bit(event, &object->events); | |
211 | _debug("{OBJ%x} ev %d: %s -> %s", | |
212 | object->debug_id, event, | |
213 | state->name, new_state->name); | |
214 | object->state = state = new_state; | |
215 | goto execute_work_state; | |
216 | } | |
217 | } | |
36c95590 | 218 | |
caaef690 DH |
219 | /* The event mask didn't include all the tabled bits */ |
220 | BUG(); | |
36c95590 | 221 | } |
caaef690 DH |
222 | /* Randomly woke up */ |
223 | goto unmask_events; | |
36c95590 DH |
224 | } |
225 | ||
caaef690 DH |
226 | execute_work_state: |
227 | _debug("{OBJ%x} exec %s", object->debug_id, state->name); | |
36c95590 | 228 | |
caaef690 DH |
229 | new_state = state->work(object, event); |
230 | event = -1; | |
231 | if (new_state == NO_TRANSIT) { | |
232 | _debug("{OBJ%x} %s notrans", object->debug_id, state->name); | |
e26bfebd DH |
233 | if (unlikely(state == STATE(OBJECT_DEAD))) { |
234 | _leave(" [dead]"); | |
235 | return; | |
236 | } | |
caaef690 DH |
237 | fscache_enqueue_object(object); |
238 | event_mask = object->oob_event_mask; | |
239 | goto unmask_events; | |
36c95590 DH |
240 | } |
241 | ||
caaef690 DH |
242 | _debug("{OBJ%x} %s -> %s", |
243 | object->debug_id, state->name, new_state->name); | |
244 | object->state = state = new_state; | |
36c95590 | 245 | |
caaef690 | 246 | if (state->work) { |
e26bfebd | 247 | if (unlikely(state == STATE(OBJECT_DEAD))) { |
caaef690 DH |
248 | _leave(" [dead]"); |
249 | return; | |
250 | } | |
251 | goto restart_masked; | |
252 | } | |
36c95590 | 253 | |
caaef690 DH |
254 | /* Transited to wait state */ |
255 | event_mask = object->oob_event_mask; | |
256 | for (t = state->transitions; t->events; t++) | |
257 | event_mask |= t->events; | |
258 | ||
259 | unmask_events: | |
260 | object->event_mask = event_mask; | |
261 | smp_mb(); | |
262 | events = object->events; | |
263 | if (events & event_mask) | |
264 | goto restart; | |
265 | _leave(" [msk %lx]", event_mask); | |
36c95590 DH |
266 | } |
267 | ||
268 | /* | |
269 | * execute an object | |
270 | */ | |
610be24e | 271 | static void fscache_object_work_func(struct work_struct *work) |
36c95590 DH |
272 | { |
273 | struct fscache_object *object = | |
274 | container_of(work, struct fscache_object, work); | |
275 | unsigned long start; | |
276 | ||
277 | _enter("{OBJ%x}", object->debug_id); | |
278 | ||
36c95590 | 279 | start = jiffies; |
caaef690 | 280 | fscache_object_sm_dispatcher(object); |
36c95590 | 281 | fscache_hist(fscache_objs_histogram, start); |
8b8edefa | 282 | fscache_put_object(object); |
36c95590 | 283 | } |
610be24e DH |
284 | |
285 | /** | |
286 | * fscache_object_init - Initialise a cache object description | |
287 | * @object: Object description | |
288 | * @cookie: Cookie object will be attached to | |
289 | * @cache: Cache in which backing object will be found | |
290 | * | |
291 | * Initialise a cache object description to its basic values. | |
292 | * | |
293 | * See Documentation/filesystems/caching/backend-api.txt for a complete | |
294 | * description. | |
295 | */ | |
296 | void fscache_object_init(struct fscache_object *object, | |
297 | struct fscache_cookie *cookie, | |
298 | struct fscache_cache *cache) | |
299 | { | |
caaef690 DH |
300 | const struct fscache_transition *t; |
301 | ||
610be24e DH |
302 | atomic_inc(&cache->object_count); |
303 | ||
caaef690 DH |
304 | object->state = STATE(WAIT_FOR_INIT); |
305 | object->oob_table = fscache_osm_init_oob; | |
306 | object->flags = 1 << FSCACHE_OBJECT_IS_LIVE; | |
610be24e DH |
307 | spin_lock_init(&object->lock); |
308 | INIT_LIST_HEAD(&object->cache_link); | |
309 | INIT_HLIST_NODE(&object->cookie_link); | |
310 | INIT_WORK(&object->work, fscache_object_work_func); | |
311 | INIT_LIST_HEAD(&object->dependents); | |
312 | INIT_LIST_HEAD(&object->dep_link); | |
313 | INIT_LIST_HEAD(&object->pending_ops); | |
314 | object->n_children = 0; | |
315 | object->n_ops = object->n_in_progress = object->n_exclusive = 0; | |
caaef690 | 316 | object->events = 0; |
610be24e DH |
317 | object->store_limit = 0; |
318 | object->store_limit_l = 0; | |
319 | object->cache = cache; | |
320 | object->cookie = cookie; | |
321 | object->parent = NULL; | |
7026f192 DH |
322 | #ifdef CONFIG_FSCACHE_OBJECT_LIST |
323 | RB_CLEAR_NODE(&object->objlist_link); | |
324 | #endif | |
caaef690 DH |
325 | |
326 | object->oob_event_mask = 0; | |
327 | for (t = object->oob_table; t->events; t++) | |
328 | object->oob_event_mask |= t->events; | |
329 | object->event_mask = object->oob_event_mask; | |
330 | for (t = object->state->transitions; t->events; t++) | |
331 | object->event_mask |= t->events; | |
610be24e DH |
332 | } |
333 | EXPORT_SYMBOL(fscache_object_init); | |
440f0aff | 334 | |
f09b443d DH |
335 | /* |
336 | * Mark the object as no longer being live, making sure that we synchronise | |
337 | * against op submission. | |
338 | */ | |
339 | static inline void fscache_mark_object_dead(struct fscache_object *object) | |
340 | { | |
341 | spin_lock(&object->lock); | |
342 | clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags); | |
343 | spin_unlock(&object->lock); | |
344 | } | |
345 | ||
caaef690 DH |
346 | /* |
347 | * Abort object initialisation before we start it. | |
348 | */ | |
349 | static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *object, | |
350 | int event) | |
351 | { | |
caaef690 DH |
352 | _enter("{OBJ%x},%d", object->debug_id, event); |
353 | ||
354 | object->oob_event_mask = 0; | |
caaef690 | 355 | fscache_dequeue_object(object); |
caaef690 DH |
356 | return transit_to(KILL_OBJECT); |
357 | } | |
358 | ||
36c95590 DH |
359 | /* |
360 | * initialise an object | |
361 | * - check the specified object's parent to see if we can make use of it | |
362 | * immediately to do a creation | |
363 | * - we may need to start the process of creating a parent and we need to wait | |
364 | * for the parent's lookup and creation to complete if it's not there yet | |
36c95590 | 365 | */ |
caaef690 DH |
366 | static const struct fscache_state *fscache_initialise_object(struct fscache_object *object, |
367 | int event) | |
36c95590 DH |
368 | { |
369 | struct fscache_object *parent; | |
caaef690 | 370 | bool success; |
36c95590 | 371 | |
caaef690 | 372 | _enter("{OBJ%x},%d", object->debug_id, event); |
36c95590 | 373 | |
caaef690 | 374 | ASSERT(list_empty(&object->dep_link)); |
36c95590 DH |
375 | |
376 | parent = object->parent; | |
377 | if (!parent) { | |
caaef690 | 378 | _leave(" [no parent]"); |
1362729b | 379 | return transit_to(DROP_OBJECT); |
caaef690 | 380 | } |
36c95590 | 381 | |
1362729b | 382 | _debug("parent: %s of:%lx", parent->state->name, parent->flags); |
caaef690 DH |
383 | |
384 | if (fscache_object_is_dying(parent)) { | |
385 | _leave(" [bad parent]"); | |
1362729b | 386 | return transit_to(DROP_OBJECT); |
caaef690 DH |
387 | } |
388 | ||
389 | if (fscache_object_is_available(parent)) { | |
390 | _leave(" [ready]"); | |
391 | return transit_to(PARENT_READY); | |
392 | } | |
393 | ||
394 | _debug("wait"); | |
395 | ||
396 | spin_lock(&parent->lock); | |
397 | fscache_stat(&fscache_n_cop_grab_object); | |
398 | success = false; | |
399 | if (fscache_object_is_live(parent) && | |
400 | object->cache->ops->grab_object(object)) { | |
401 | list_add(&object->dep_link, &parent->dependents); | |
402 | success = true; | |
403 | } | |
404 | fscache_stat_d(&fscache_n_cop_grab_object); | |
405 | spin_unlock(&parent->lock); | |
406 | if (!success) { | |
407 | _leave(" [grab failed]"); | |
1362729b | 408 | return transit_to(DROP_OBJECT); |
36c95590 DH |
409 | } |
410 | ||
caaef690 DH |
411 | /* fscache_acquire_non_index_cookie() uses this |
412 | * to wake the chain up */ | |
413 | fscache_raise_event(parent, FSCACHE_OBJECT_EV_NEW_CHILD); | |
414 | _leave(" [wait]"); | |
415 | return transit_to(WAIT_FOR_PARENT); | |
416 | } | |
417 | ||
418 | /* | |
419 | * Once the parent object is ready, we should kick off our lookup op. | |
420 | */ | |
421 | static const struct fscache_state *fscache_parent_ready(struct fscache_object *object, | |
422 | int event) | |
423 | { | |
424 | struct fscache_object *parent = object->parent; | |
425 | ||
426 | _enter("{OBJ%x},%d", object->debug_id, event); | |
427 | ||
428 | ASSERT(parent != NULL); | |
429 | ||
430 | spin_lock(&parent->lock); | |
431 | parent->n_ops++; | |
432 | parent->n_obj_ops++; | |
433 | object->lookup_jif = jiffies; | |
434 | spin_unlock(&parent->lock); | |
435 | ||
36c95590 | 436 | _leave(""); |
caaef690 | 437 | return transit_to(LOOK_UP_OBJECT); |
36c95590 DH |
438 | } |
439 | ||
440 | /* | |
441 | * look an object up in the cache from which it was allocated | |
442 | * - we hold an "access lock" on the parent object, so the parent object cannot | |
443 | * be withdrawn by either party till we've finished | |
36c95590 | 444 | */ |
caaef690 DH |
445 | static const struct fscache_state *fscache_look_up_object(struct fscache_object *object, |
446 | int event) | |
36c95590 DH |
447 | { |
448 | struct fscache_cookie *cookie = object->cookie; | |
caaef690 | 449 | struct fscache_object *parent = object->parent; |
fee096de | 450 | int ret; |
36c95590 | 451 | |
caaef690 DH |
452 | _enter("{OBJ%x},%d", object->debug_id, event); |
453 | ||
454 | object->oob_table = fscache_osm_lookup_oob; | |
36c95590 | 455 | |
36c95590 DH |
456 | ASSERT(parent != NULL); |
457 | ASSERTCMP(parent->n_ops, >, 0); | |
458 | ASSERTCMP(parent->n_obj_ops, >, 0); | |
459 | ||
460 | /* make sure the parent is still available */ | |
493f7bc1 | 461 | ASSERT(fscache_object_is_available(parent)); |
36c95590 | 462 | |
493f7bc1 | 463 | if (fscache_object_is_dying(parent) || |
1362729b DH |
464 | test_bit(FSCACHE_IOERROR, &object->cache->flags) || |
465 | !fscache_use_cookie(object)) { | |
caaef690 DH |
466 | _leave(" [unavailable]"); |
467 | return transit_to(LOOKUP_FAILURE); | |
36c95590 DH |
468 | } |
469 | ||
1362729b DH |
470 | _debug("LOOKUP \"%s\" in \"%s\"", |
471 | cookie->def->name, object->cache->tag->name); | |
36c95590 DH |
472 | |
473 | fscache_stat(&fscache_n_object_lookups); | |
52bd75fd | 474 | fscache_stat(&fscache_n_cop_lookup_object); |
fee096de | 475 | ret = object->cache->ops->lookup_object(object); |
52bd75fd | 476 | fscache_stat_d(&fscache_n_cop_lookup_object); |
36c95590 | 477 | |
1362729b | 478 | fscache_unuse_cookie(object); |
36c95590 | 479 | |
fee096de DH |
480 | if (ret == -ETIMEDOUT) { |
481 | /* probably stuck behind another object, so move this one to | |
482 | * the back of the queue */ | |
483 | fscache_stat(&fscache_n_object_lookups_timed_out); | |
caaef690 DH |
484 | _leave(" [timeout]"); |
485 | return NO_TRANSIT; | |
fee096de DH |
486 | } |
487 | ||
caaef690 DH |
488 | if (ret < 0) { |
489 | _leave(" [error]"); | |
490 | return transit_to(LOOKUP_FAILURE); | |
491 | } | |
492 | ||
493 | _leave(" [ok]"); | |
494 | return transit_to(OBJECT_AVAILABLE); | |
36c95590 DH |
495 | } |
496 | ||
497 | /** | |
498 | * fscache_object_lookup_negative - Note negative cookie lookup | |
499 | * @object: Object pointing to cookie to mark | |
500 | * | |
501 | * Note negative lookup, permitting those waiting to read data from an already | |
502 | * existing backing object to continue as there's no data for them to read. | |
503 | */ | |
504 | void fscache_object_lookup_negative(struct fscache_object *object) | |
505 | { | |
506 | struct fscache_cookie *cookie = object->cookie; | |
507 | ||
caaef690 | 508 | _enter("{OBJ%x,%s}", object->debug_id, object->state->name); |
36c95590 | 509 | |
caaef690 | 510 | if (!test_and_set_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) { |
36c95590 DH |
511 | fscache_stat(&fscache_n_object_lookups_negative); |
512 | ||
caaef690 DH |
513 | /* Allow write requests to begin stacking up and read requests to begin |
514 | * returning ENODATA. | |
515 | */ | |
36c95590 | 516 | set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); |
94d30ae9 | 517 | clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); |
36c95590 DH |
518 | |
519 | _debug("wake up lookup %p", &cookie->flags); | |
caaef690 | 520 | clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags); |
36c95590 | 521 | wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP); |
36c95590 | 522 | } |
36c95590 DH |
523 | _leave(""); |
524 | } | |
525 | EXPORT_SYMBOL(fscache_object_lookup_negative); | |
526 | ||
527 | /** | |
528 | * fscache_obtained_object - Note successful object lookup or creation | |
529 | * @object: Object pointing to cookie to mark | |
530 | * | |
531 | * Note successful lookup and/or creation, permitting those waiting to write | |
532 | * data to a backing object to continue. | |
533 | * | |
534 | * Note that after calling this, an object's cookie may be relinquished by the | |
535 | * netfs, and so must be accessed with object lock held. | |
536 | */ | |
537 | void fscache_obtained_object(struct fscache_object *object) | |
538 | { | |
539 | struct fscache_cookie *cookie = object->cookie; | |
540 | ||
caaef690 | 541 | _enter("{OBJ%x,%s}", object->debug_id, object->state->name); |
36c95590 DH |
542 | |
543 | /* if we were still looking up, then we must have a positive lookup | |
544 | * result, in which case there may be data available */ | |
caaef690 | 545 | if (!test_and_set_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) { |
36c95590 DH |
546 | fscache_stat(&fscache_n_object_lookups_positive); |
547 | ||
caaef690 DH |
548 | /* We do (presumably) have data */ |
549 | clear_bit_unlock(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); | |
94d30ae9 | 550 | clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); |
36c95590 | 551 | |
caaef690 DH |
552 | /* Allow write requests to begin stacking up and read requests |
553 | * to begin shovelling data. | |
554 | */ | |
555 | clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags); | |
36c95590 | 556 | wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP); |
36c95590 | 557 | } else { |
36c95590 | 558 | fscache_stat(&fscache_n_object_created); |
36c95590 DH |
559 | } |
560 | ||
caaef690 | 561 | set_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags); |
36c95590 DH |
562 | _leave(""); |
563 | } | |
564 | EXPORT_SYMBOL(fscache_obtained_object); | |
565 | ||
566 | /* | |
567 | * handle an object that has just become available | |
568 | */ | |
caaef690 DH |
569 | static const struct fscache_state *fscache_object_available(struct fscache_object *object, |
570 | int event) | |
36c95590 | 571 | { |
caaef690 DH |
572 | _enter("{OBJ%x},%d", object->debug_id, event); |
573 | ||
574 | object->oob_table = fscache_osm_run_oob; | |
36c95590 DH |
575 | |
576 | spin_lock(&object->lock); | |
577 | ||
36c95590 DH |
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); | |
36c95590 DH |
582 | fscache_start_operations(object); |
583 | } else { | |
584 | ASSERT(list_empty(&object->pending_ops)); | |
585 | } | |
586 | } | |
587 | spin_unlock(&object->lock); | |
588 | ||
52bd75fd | 589 | fscache_stat(&fscache_n_cop_lookup_complete); |
36c95590 | 590 | object->cache->ops->lookup_complete(object); |
52bd75fd | 591 | fscache_stat_d(&fscache_n_cop_lookup_complete); |
36c95590 DH |
592 | |
593 | fscache_hist(fscache_obj_instantiate_histogram, object->lookup_jif); | |
594 | fscache_stat(&fscache_n_object_avail); | |
595 | ||
596 | _leave(""); | |
caaef690 | 597 | return transit_to(JUMPSTART_DEPS); |
36c95590 DH |
598 | } |
599 | ||
600 | /* | |
caaef690 | 601 | * Wake up this object's dependent objects now that we've become available. |
36c95590 | 602 | */ |
caaef690 DH |
603 | static const struct fscache_state *fscache_jumpstart_dependents(struct fscache_object *object, |
604 | int event) | |
36c95590 | 605 | { |
caaef690 | 606 | _enter("{OBJ%x},%d", object->debug_id, event); |
36c95590 | 607 | |
caaef690 DH |
608 | if (!fscache_enqueue_dependents(object, FSCACHE_OBJECT_EV_PARENT_READY)) |
609 | return NO_TRANSIT; /* Not finished; requeue */ | |
610 | return transit_to(WAIT_FOR_CMD); | |
611 | } | |
36c95590 | 612 | |
caaef690 DH |
613 | /* |
614 | * Handle lookup or creation failute. | |
615 | */ | |
616 | static const struct fscache_state *fscache_lookup_failure(struct fscache_object *object, | |
617 | int event) | |
618 | { | |
619 | struct fscache_cookie *cookie; | |
6897e3df | 620 | |
caaef690 | 621 | _enter("{OBJ%x},%d", object->debug_id, event); |
36c95590 | 622 | |
caaef690 | 623 | object->oob_event_mask = 0; |
36c95590 | 624 | |
caaef690 DH |
625 | fscache_stat(&fscache_n_cop_lookup_complete); |
626 | object->cache->ops->lookup_complete(object); | |
627 | fscache_stat_d(&fscache_n_cop_lookup_complete); | |
36c95590 | 628 | |
6515d1db DH |
629 | set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags); |
630 | ||
caaef690 DH |
631 | cookie = object->cookie; |
632 | set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags); | |
1362729b | 633 | if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) |
caaef690 | 634 | wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP); |
36c95590 | 635 | |
caaef690 DH |
636 | fscache_done_parent_op(object); |
637 | return transit_to(KILL_OBJECT); | |
638 | } | |
639 | ||
640 | /* | |
641 | * Wait for completion of all active operations on this object and the death of | |
642 | * all child objects of this object. | |
643 | */ | |
644 | static const struct fscache_state *fscache_kill_object(struct fscache_object *object, | |
645 | int event) | |
646 | { | |
647 | _enter("{OBJ%x,%d,%d},%d", | |
648 | object->debug_id, object->n_ops, object->n_children, event); | |
649 | ||
f09b443d | 650 | fscache_mark_object_dead(object); |
1362729b | 651 | object->oob_event_mask = 0; |
caaef690 | 652 | |
6bdded59 DH |
653 | if (test_bit(FSCACHE_OBJECT_RETIRED, &object->flags)) { |
654 | /* Reject any new read/write ops and abort any that are pending. */ | |
655 | clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); | |
656 | fscache_cancel_all_ops(object); | |
657 | } | |
658 | ||
caaef690 DH |
659 | if (list_empty(&object->dependents) && |
660 | object->n_ops == 0 && | |
661 | object->n_children == 0) | |
1362729b | 662 | return transit_to(DROP_OBJECT); |
caaef690 | 663 | |
1362729b DH |
664 | if (object->n_in_progress == 0) { |
665 | spin_lock(&object->lock); | |
666 | if (object->n_ops > 0 && object->n_in_progress == 0) | |
667 | fscache_start_operations(object); | |
668 | spin_unlock(&object->lock); | |
669 | } | |
caaef690 DH |
670 | |
671 | if (!list_empty(&object->dependents)) | |
672 | return transit_to(KILL_DEPENDENTS); | |
673 | ||
674 | return transit_to(WAIT_FOR_CLEARANCE); | |
36c95590 DH |
675 | } |
676 | ||
677 | /* | |
caaef690 | 678 | * Kill dependent objects. |
36c95590 | 679 | */ |
caaef690 DH |
680 | static const struct fscache_state *fscache_kill_dependents(struct fscache_object *object, |
681 | int event) | |
36c95590 | 682 | { |
caaef690 | 683 | _enter("{OBJ%x},%d", object->debug_id, event); |
36c95590 | 684 | |
caaef690 DH |
685 | if (!fscache_enqueue_dependents(object, FSCACHE_OBJECT_EV_KILL)) |
686 | return NO_TRANSIT; /* Not finished */ | |
687 | return transit_to(WAIT_FOR_CLEARANCE); | |
36c95590 DH |
688 | } |
689 | ||
36c95590 | 690 | /* |
caaef690 DH |
691 | * Drop an object's attachments |
692 | */ | |
693 | static const struct fscache_state *fscache_drop_object(struct fscache_object *object, | |
694 | int event) | |
36c95590 | 695 | { |
caaef690 | 696 | struct fscache_object *parent = object->parent; |
1362729b | 697 | struct fscache_cookie *cookie = object->cookie; |
caaef690 | 698 | struct fscache_cache *cache = object->cache; |
1362729b | 699 | bool awaken = false; |
36c95590 | 700 | |
caaef690 | 701 | _enter("{OBJ%x,%d},%d", object->debug_id, object->n_children, event); |
36c95590 | 702 | |
1362729b DH |
703 | ASSERT(cookie != NULL); |
704 | ASSERT(!hlist_unhashed(&object->cookie_link)); | |
705 | ||
706 | /* Make sure the cookie no longer points here and that the netfs isn't | |
707 | * waiting for us. | |
708 | */ | |
709 | spin_lock(&cookie->lock); | |
710 | hlist_del_init(&object->cookie_link); | |
94d30ae9 DH |
711 | if (hlist_empty(&cookie->backing_objects) && |
712 | test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) | |
1362729b DH |
713 | awaken = true; |
714 | spin_unlock(&cookie->lock); | |
715 | ||
716 | if (awaken) | |
717 | wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING); | |
caaef690 DH |
718 | |
719 | /* Prevent a race with our last child, which has to signal EV_CLEARED | |
720 | * before dropping our spinlock. | |
721 | */ | |
36c95590 | 722 | spin_lock(&object->lock); |
36c95590 DH |
723 | spin_unlock(&object->lock); |
724 | ||
caaef690 DH |
725 | /* Discard from the cache's collection of objects */ |
726 | spin_lock(&cache->object_list_lock); | |
727 | list_del_init(&object->cache_link); | |
728 | spin_unlock(&cache->object_list_lock); | |
729 | ||
730 | fscache_stat(&fscache_n_cop_drop_object); | |
731 | cache->ops->drop_object(object); | |
732 | fscache_stat_d(&fscache_n_cop_drop_object); | |
733 | ||
734 | /* The parent object wants to know when all it dependents have gone */ | |
735 | if (parent) { | |
736 | _debug("release parent OBJ%x {%d}", | |
737 | parent->debug_id, parent->n_children); | |
738 | ||
739 | spin_lock(&parent->lock); | |
740 | parent->n_children--; | |
741 | if (parent->n_children == 0) | |
742 | fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED); | |
743 | spin_unlock(&parent->lock); | |
744 | object->parent = NULL; | |
745 | } | |
746 | ||
747 | /* this just shifts the object release to the work processor */ | |
748 | fscache_put_object(object); | |
749 | fscache_stat(&fscache_n_object_dead); | |
36c95590 DH |
750 | |
751 | _leave(""); | |
caaef690 | 752 | return transit_to(OBJECT_DEAD); |
36c95590 DH |
753 | } |
754 | ||
755 | /* | |
8b8edefa | 756 | * get a ref on an object |
36c95590 | 757 | */ |
8b8edefa | 758 | static int fscache_get_object(struct fscache_object *object) |
36c95590 | 759 | { |
52bd75fd | 760 | int ret; |
36c95590 | 761 | |
52bd75fd DH |
762 | fscache_stat(&fscache_n_cop_grab_object); |
763 | ret = object->cache->ops->grab_object(object) ? 0 : -EAGAIN; | |
764 | fscache_stat_d(&fscache_n_cop_grab_object); | |
765 | return ret; | |
36c95590 DH |
766 | } |
767 | ||
768 | /* | |
caaef690 | 769 | * Discard a ref on an object |
36c95590 | 770 | */ |
8b8edefa | 771 | static void fscache_put_object(struct fscache_object *object) |
36c95590 | 772 | { |
52bd75fd DH |
773 | fscache_stat(&fscache_n_cop_put_object); |
774 | object->cache->ops->put_object(object); | |
775 | fscache_stat_d(&fscache_n_cop_put_object); | |
36c95590 DH |
776 | } |
777 | ||
1362729b DH |
778 | /** |
779 | * fscache_object_destroy - Note that a cache object is about to be destroyed | |
780 | * @object: The object to be destroyed | |
781 | * | |
782 | * Note the imminent destruction and deallocation of a cache object record. | |
783 | */ | |
784 | void fscache_object_destroy(struct fscache_object *object) | |
785 | { | |
786 | fscache_objlist_remove(object); | |
787 | ||
788 | /* We can get rid of the cookie now */ | |
789 | fscache_cookie_put(object->cookie); | |
790 | object->cookie = NULL; | |
791 | } | |
792 | EXPORT_SYMBOL(fscache_object_destroy); | |
793 | ||
36c95590 DH |
794 | /* |
795 | * enqueue an object for metadata-type processing | |
796 | */ | |
797 | void fscache_enqueue_object(struct fscache_object *object) | |
798 | { | |
799 | _enter("{OBJ%x}", object->debug_id); | |
800 | ||
8b8edefa TH |
801 | if (fscache_get_object(object) >= 0) { |
802 | wait_queue_head_t *cong_wq = | |
803 | &get_cpu_var(fscache_object_cong_wait); | |
804 | ||
805 | if (queue_work(fscache_object_wq, &object->work)) { | |
806 | if (fscache_object_congested()) | |
807 | wake_up(cong_wq); | |
808 | } else | |
809 | fscache_put_object(object); | |
810 | ||
811 | put_cpu_var(fscache_object_cong_wait); | |
812 | } | |
813 | } | |
814 | ||
815 | /** | |
816 | * fscache_object_sleep_till_congested - Sleep until object wq is congested | |
caaef690 | 817 | * @timeoutp: Scheduler sleep timeout |
8b8edefa TH |
818 | * |
819 | * Allow an object handler to sleep until the object workqueue is congested. | |
820 | * | |
821 | * The caller must set up a wake up event before calling this and must have set | |
822 | * the appropriate sleep mode (such as TASK_UNINTERRUPTIBLE) and tested its own | |
823 | * condition before calling this function as no test is made here. | |
824 | * | |
825 | * %true is returned if the object wq is congested, %false otherwise. | |
826 | */ | |
827 | bool fscache_object_sleep_till_congested(signed long *timeoutp) | |
828 | { | |
170d800a | 829 | wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait); |
8b8edefa TH |
830 | DEFINE_WAIT(wait); |
831 | ||
832 | if (fscache_object_congested()) | |
833 | return true; | |
834 | ||
835 | add_wait_queue_exclusive(cong_wq, &wait); | |
836 | if (!fscache_object_congested()) | |
837 | *timeoutp = schedule_timeout(*timeoutp); | |
838 | finish_wait(cong_wq, &wait); | |
839 | ||
840 | return fscache_object_congested(); | |
36c95590 | 841 | } |
8b8edefa | 842 | EXPORT_SYMBOL_GPL(fscache_object_sleep_till_congested); |
36c95590 DH |
843 | |
844 | /* | |
caaef690 DH |
845 | * Enqueue the dependents of an object for metadata-type processing. |
846 | * | |
847 | * If we don't manage to finish the list before the scheduler wants to run | |
848 | * again then return false immediately. We return true if the list was | |
849 | * cleared. | |
36c95590 | 850 | */ |
caaef690 | 851 | static bool fscache_enqueue_dependents(struct fscache_object *object, int event) |
36c95590 DH |
852 | { |
853 | struct fscache_object *dep; | |
caaef690 | 854 | bool ret = true; |
36c95590 DH |
855 | |
856 | _enter("{OBJ%x}", object->debug_id); | |
857 | ||
858 | if (list_empty(&object->dependents)) | |
caaef690 | 859 | return true; |
36c95590 DH |
860 | |
861 | spin_lock(&object->lock); | |
862 | ||
863 | while (!list_empty(&object->dependents)) { | |
864 | dep = list_entry(object->dependents.next, | |
865 | struct fscache_object, dep_link); | |
866 | list_del_init(&dep->dep_link); | |
867 | ||
caaef690 | 868 | fscache_raise_event(dep, event); |
8b8edefa | 869 | fscache_put_object(dep); |
36c95590 | 870 | |
caaef690 DH |
871 | if (!list_empty(&object->dependents) && need_resched()) { |
872 | ret = false; | |
873 | break; | |
874 | } | |
36c95590 DH |
875 | } |
876 | ||
877 | spin_unlock(&object->lock); | |
caaef690 | 878 | return ret; |
36c95590 DH |
879 | } |
880 | ||
881 | /* | |
882 | * remove an object from whatever queue it's waiting on | |
36c95590 | 883 | */ |
caaef690 | 884 | static void fscache_dequeue_object(struct fscache_object *object) |
36c95590 DH |
885 | { |
886 | _enter("{OBJ%x}", object->debug_id); | |
887 | ||
888 | if (!list_empty(&object->dep_link)) { | |
889 | spin_lock(&object->parent->lock); | |
890 | list_del_init(&object->dep_link); | |
891 | spin_unlock(&object->parent->lock); | |
892 | } | |
893 | ||
894 | _leave(""); | |
895 | } | |
896 | ||
897 | /** | |
898 | * fscache_check_aux - Ask the netfs whether an object on disk is still valid | |
899 | * @object: The object to ask about | |
900 | * @data: The auxiliary data for the object | |
901 | * @datalen: The size of the auxiliary data | |
902 | * | |
1362729b DH |
903 | * This function consults the netfs about the coherency state of an object. |
904 | * The caller must be holding a ref on cookie->n_active (held by | |
905 | * fscache_look_up_object() on behalf of the cache backend during object lookup | |
906 | * and creation). | |
36c95590 DH |
907 | */ |
908 | enum fscache_checkaux fscache_check_aux(struct fscache_object *object, | |
909 | const void *data, uint16_t datalen) | |
910 | { | |
911 | enum fscache_checkaux result; | |
912 | ||
913 | if (!object->cookie->def->check_aux) { | |
914 | fscache_stat(&fscache_n_checkaux_none); | |
915 | return FSCACHE_CHECKAUX_OKAY; | |
916 | } | |
917 | ||
918 | result = object->cookie->def->check_aux(object->cookie->netfs_data, | |
919 | data, datalen); | |
920 | switch (result) { | |
921 | /* entry okay as is */ | |
922 | case FSCACHE_CHECKAUX_OKAY: | |
923 | fscache_stat(&fscache_n_checkaux_okay); | |
924 | break; | |
925 | ||
926 | /* entry requires update */ | |
927 | case FSCACHE_CHECKAUX_NEEDS_UPDATE: | |
928 | fscache_stat(&fscache_n_checkaux_update); | |
929 | break; | |
930 | ||
931 | /* entry requires deletion */ | |
932 | case FSCACHE_CHECKAUX_OBSOLETE: | |
933 | fscache_stat(&fscache_n_checkaux_obsolete); | |
934 | break; | |
935 | ||
936 | default: | |
937 | BUG(); | |
938 | } | |
939 | ||
940 | return result; | |
941 | } | |
942 | EXPORT_SYMBOL(fscache_check_aux); | |
ef778e7a DH |
943 | |
944 | /* | |
945 | * Asynchronously invalidate an object. | |
946 | */ | |
caaef690 DH |
947 | static const struct fscache_state *_fscache_invalidate_object(struct fscache_object *object, |
948 | int event) | |
ef778e7a DH |
949 | { |
950 | struct fscache_operation *op; | |
951 | struct fscache_cookie *cookie = object->cookie; | |
952 | ||
caaef690 DH |
953 | _enter("{OBJ%x},%d", object->debug_id, event); |
954 | ||
1362729b DH |
955 | /* We're going to need the cookie. If the cookie is not available then |
956 | * retire the object instead. | |
957 | */ | |
958 | if (!fscache_use_cookie(object)) { | |
959 | ASSERT(object->cookie->stores.rnode == NULL); | |
94d30ae9 | 960 | set_bit(FSCACHE_OBJECT_RETIRED, &object->flags); |
1362729b DH |
961 | _leave(" [no cookie]"); |
962 | return transit_to(KILL_OBJECT); | |
963 | } | |
ef778e7a DH |
964 | |
965 | /* Reject any new read/write ops and abort any that are pending. */ | |
966 | fscache_invalidate_writes(cookie); | |
967 | clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags); | |
968 | fscache_cancel_all_ops(object); | |
969 | ||
970 | /* Now we have to wait for in-progress reads and writes */ | |
971 | op = kzalloc(sizeof(*op), GFP_KERNEL); | |
1362729b DH |
972 | if (!op) |
973 | goto nomem; | |
ef778e7a | 974 | |
d3b97ca4 DH |
975 | fscache_operation_init(op, object->cache->ops->invalidate_object, |
976 | NULL, NULL); | |
1362729b DH |
977 | op->flags = FSCACHE_OP_ASYNC | |
978 | (1 << FSCACHE_OP_EXCLUSIVE) | | |
979 | (1 << FSCACHE_OP_UNUSE_COOKIE); | |
ef778e7a DH |
980 | |
981 | spin_lock(&cookie->lock); | |
982 | if (fscache_submit_exclusive_op(object, op) < 0) | |
8d76349d | 983 | goto submit_op_failed; |
ef778e7a DH |
984 | spin_unlock(&cookie->lock); |
985 | fscache_put_operation(op); | |
986 | ||
987 | /* Once we've completed the invalidation, we know there will be no data | |
988 | * stored in the cache and thus we can reinstate the data-check-skip | |
989 | * optimisation. | |
990 | */ | |
991 | set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags); | |
992 | ||
993 | /* We can allow read and write requests to come in once again. They'll | |
994 | * queue up behind our exclusive invalidation operation. | |
995 | */ | |
caaef690 DH |
996 | if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) |
997 | wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING); | |
998 | _leave(" [ok]"); | |
999 | return transit_to(UPDATE_OBJECT); | |
8d76349d | 1000 | |
1362729b | 1001 | nomem: |
f09b443d | 1002 | fscache_mark_object_dead(object); |
1362729b DH |
1003 | fscache_unuse_cookie(object); |
1004 | _leave(" [ENOMEM]"); | |
1005 | return transit_to(KILL_OBJECT); | |
1006 | ||
8d76349d | 1007 | submit_op_failed: |
f09b443d | 1008 | fscache_mark_object_dead(object); |
8d76349d | 1009 | spin_unlock(&cookie->lock); |
920bce20 | 1010 | fscache_unuse_cookie(object); |
8d76349d | 1011 | kfree(op); |
8d76349d | 1012 | _leave(" [EIO]"); |
caaef690 DH |
1013 | return transit_to(KILL_OBJECT); |
1014 | } | |
1015 | ||
1016 | static const struct fscache_state *fscache_invalidate_object(struct fscache_object *object, | |
1017 | int event) | |
1018 | { | |
1019 | const struct fscache_state *s; | |
1020 | ||
1021 | fscache_stat(&fscache_n_invalidates_run); | |
1022 | fscache_stat(&fscache_n_cop_invalidate_object); | |
1023 | s = _fscache_invalidate_object(object, event); | |
1024 | fscache_stat_d(&fscache_n_cop_invalidate_object); | |
1025 | return s; | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * Asynchronously update an object. | |
1030 | */ | |
1031 | static const struct fscache_state *fscache_update_object(struct fscache_object *object, | |
1032 | int event) | |
1033 | { | |
1034 | _enter("{OBJ%x},%d", object->debug_id, event); | |
1035 | ||
1036 | fscache_stat(&fscache_n_updates_run); | |
1037 | fscache_stat(&fscache_n_cop_update_object); | |
1038 | object->cache->ops->update_object(object); | |
1039 | fscache_stat_d(&fscache_n_cop_update_object); | |
1040 | ||
1041 | _leave(""); | |
1042 | return transit_to(WAIT_FOR_CMD); | |
ef778e7a | 1043 | } |
182d919b DH |
1044 | |
1045 | /** | |
1046 | * fscache_object_retrying_stale - Note retrying stale object | |
1047 | * @object: The object that will be retried | |
1048 | * | |
1049 | * Note that an object lookup found an on-disk object that was adjudged to be | |
1050 | * stale and has been deleted. The lookup will be retried. | |
1051 | */ | |
1052 | void fscache_object_retrying_stale(struct fscache_object *object) | |
1053 | { | |
1054 | fscache_stat(&fscache_n_cache_no_space_reject); | |
1055 | } | |
1056 | EXPORT_SYMBOL(fscache_object_retrying_stale); | |
1057 | ||
1058 | /** | |
1059 | * fscache_object_mark_killed - Note that an object was killed | |
1060 | * @object: The object that was culled | |
1061 | * @why: The reason the object was killed. | |
1062 | * | |
1063 | * Note that an object was killed. Returns true if the object was | |
1064 | * already marked killed, false if it wasn't. | |
1065 | */ | |
1066 | void fscache_object_mark_killed(struct fscache_object *object, | |
1067 | enum fscache_why_object_killed why) | |
1068 | { | |
1069 | if (test_and_set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags)) { | |
1070 | pr_err("Error: Object already killed by cache [%s]\n", | |
1071 | object->cache->identifier); | |
1072 | return; | |
1073 | } | |
1074 | ||
1075 | switch (why) { | |
1076 | case FSCACHE_OBJECT_NO_SPACE: | |
1077 | fscache_stat(&fscache_n_cache_no_space_reject); | |
1078 | break; | |
1079 | case FSCACHE_OBJECT_IS_STALE: | |
1080 | fscache_stat(&fscache_n_cache_stale_objects); | |
1081 | break; | |
1082 | case FSCACHE_OBJECT_WAS_RETIRED: | |
1083 | fscache_stat(&fscache_n_cache_retired_objects); | |
1084 | break; | |
1085 | case FSCACHE_OBJECT_WAS_CULLED: | |
1086 | fscache_stat(&fscache_n_cache_culled_objects); | |
1087 | break; | |
1088 | } | |
1089 | } | |
1090 | EXPORT_SYMBOL(fscache_object_mark_killed); | |
e26bfebd DH |
1091 | |
1092 | /* | |
1093 | * The object is dead. We can get here if an object gets queued by an event | |
1094 | * that would lead to its death (such as EV_KILL) when the dispatcher is | |
1095 | * already running (and so can be requeued) but hasn't yet cleared the event | |
1096 | * mask. | |
1097 | */ | |
1098 | static const struct fscache_state *fscache_object_dead(struct fscache_object *object, | |
1099 | int event) | |
1100 | { | |
1101 | if (!test_and_set_bit(FSCACHE_OBJECT_RUN_AFTER_DEAD, | |
1102 | &object->flags)) | |
1103 | return NO_TRANSIT; | |
1104 | ||
1105 | WARN(true, "FS-Cache object redispatched after death"); | |
1106 | return NO_TRANSIT; | |
1107 | } |