1 /* Internal definitions for FS-Cache
2 *
3 * Copyright (C) 2004-2007 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 /*
13 * Lock order, in the order in which multiple locks should be obtained:
14 * - fscache_addremove_sem
15 * - cookie->lock
16 * - cookie->parent->lock
17 * - cache->object_list_lock
18 * - object->lock
19 * - object->parent->lock
20 * - cookie->stores_lock
21 * - fscache_thread_lock
22 *
23 */
24
25 #ifdef pr_fmt
26 #undef pr_fmt
27 #endif
28
29 #define pr_fmt(fmt) "FS-Cache: " fmt
30
31 #include <linux/fscache-cache.h>
32 #include <trace/events/fscache.h>
33 #include <linux/sched.h>
34 #include <linux/seq_file.h>
35
36 #define FSCACHE_MIN_THREADS 4
37 #define FSCACHE_MAX_THREADS 32
38
39 /*
40 * cache.c
41 */
42 extern struct list_head fscache_cache_list;
43 extern struct rw_semaphore fscache_addremove_sem;
44
45 extern struct fscache_cache *fscache_select_cache_for_object(
46 struct fscache_cookie *);
47
48 /*
49 * cookie.c
50 */
51 extern struct kmem_cache *fscache_cookie_jar;
52
53 extern void fscache_free_cookie(struct fscache_cookie *);
54 extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
55 const struct fscache_cookie_def *,
56 const void *, size_t,
57 const void *, size_t,
58 void *, loff_t);
59 extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
60 extern void fscache_cookie_put(struct fscache_cookie *,
61 enum fscache_cookie_trace);
62
63 /*
64 * fsdef.c
65 */
66 extern struct fscache_cookie fscache_fsdef_index;
67 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
68
69 /*
70 * histogram.c
71 */
72 #ifdef CONFIG_FSCACHE_HISTOGRAM
73 extern atomic_t fscache_obj_instantiate_histogram[HZ];
74 extern atomic_t fscache_objs_histogram[HZ];
75 extern atomic_t fscache_ops_histogram[HZ];
76 extern atomic_t fscache_retrieval_delay_histogram[HZ];
77 extern atomic_t fscache_retrieval_histogram[HZ];
78
fscache_hist(atomic_t histogram[],unsigned long start_jif)79 static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
80 {
81 unsigned long jif = jiffies - start_jif;
82 if (jif >= HZ)
83 jif = HZ - 1;
84 atomic_inc(&histogram[jif]);
85 }
86
87 extern const struct seq_operations fscache_histogram_ops;
88
89 #else
90 #define fscache_hist(hist, start_jif) do {} while (0)
91 #endif
92
93 /*
94 * main.c
95 */
96 extern unsigned fscache_defer_lookup;
97 extern unsigned fscache_defer_create;
98 extern unsigned fscache_debug;
99 extern struct kobject *fscache_root;
100 extern struct workqueue_struct *fscache_object_wq;
101 extern struct workqueue_struct *fscache_op_wq;
102 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
103
fscache_object_congested(void)104 static inline bool fscache_object_congested(void)
105 {
106 return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
107 }
108
109 /*
110 * object.c
111 */
112 extern void fscache_enqueue_object(struct fscache_object *);
113
114 /*
115 * object-list.c
116 */
117 #ifdef CONFIG_FSCACHE_OBJECT_LIST
118 extern const struct file_operations fscache_objlist_fops;
119
120 extern void fscache_objlist_add(struct fscache_object *);
121 extern void fscache_objlist_remove(struct fscache_object *);
122 #else
123 #define fscache_objlist_add(object) do {} while(0)
124 #define fscache_objlist_remove(object) do {} while(0)
125 #endif
126
127 /*
128 * operation.c
129 */
130 extern int fscache_submit_exclusive_op(struct fscache_object *,
131 struct fscache_operation *);
132 extern int fscache_submit_op(struct fscache_object *,
133 struct fscache_operation *);
134 extern int fscache_cancel_op(struct fscache_operation *, bool);
135 extern void fscache_cancel_all_ops(struct fscache_object *);
136 extern void fscache_abort_object(struct fscache_object *);
137 extern void fscache_start_operations(struct fscache_object *);
138 extern void fscache_operation_gc(struct work_struct *);
139
140 /*
141 * page.c
142 */
143 extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
144 extern int fscache_wait_for_operation_activation(struct fscache_object *,
145 struct fscache_operation *,
146 atomic_t *,
147 atomic_t *);
148 extern void fscache_invalidate_writes(struct fscache_cookie *);
149
150 /*
151 * proc.c
152 */
153 #ifdef CONFIG_PROC_FS
154 extern int __init fscache_proc_init(void);
155 extern void fscache_proc_cleanup(void);
156 #else
157 #define fscache_proc_init() (0)
158 #define fscache_proc_cleanup() do {} while (0)
159 #endif
160
161 /*
162 * stats.c
163 */
164 #ifdef CONFIG_FSCACHE_STATS
165 extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
166 extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
167
168 extern atomic_t fscache_n_op_pend;
169 extern atomic_t fscache_n_op_run;
170 extern atomic_t fscache_n_op_enqueue;
171 extern atomic_t fscache_n_op_deferred_release;
172 extern atomic_t fscache_n_op_initialised;
173 extern atomic_t fscache_n_op_release;
174 extern atomic_t fscache_n_op_gc;
175 extern atomic_t fscache_n_op_cancelled;
176 extern atomic_t fscache_n_op_rejected;
177
178 extern atomic_t fscache_n_attr_changed;
179 extern atomic_t fscache_n_attr_changed_ok;
180 extern atomic_t fscache_n_attr_changed_nobufs;
181 extern atomic_t fscache_n_attr_changed_nomem;
182 extern atomic_t fscache_n_attr_changed_calls;
183
184 extern atomic_t fscache_n_allocs;
185 extern atomic_t fscache_n_allocs_ok;
186 extern atomic_t fscache_n_allocs_wait;
187 extern atomic_t fscache_n_allocs_nobufs;
188 extern atomic_t fscache_n_allocs_intr;
189 extern atomic_t fscache_n_allocs_object_dead;
190 extern atomic_t fscache_n_alloc_ops;
191 extern atomic_t fscache_n_alloc_op_waits;
192
193 extern atomic_t fscache_n_retrievals;
194 extern atomic_t fscache_n_retrievals_ok;
195 extern atomic_t fscache_n_retrievals_wait;
196 extern atomic_t fscache_n_retrievals_nodata;
197 extern atomic_t fscache_n_retrievals_nobufs;
198 extern atomic_t fscache_n_retrievals_intr;
199 extern atomic_t fscache_n_retrievals_nomem;
200 extern atomic_t fscache_n_retrievals_object_dead;
201 extern atomic_t fscache_n_retrieval_ops;
202 extern atomic_t fscache_n_retrieval_op_waits;
203
204 extern atomic_t fscache_n_stores;
205 extern atomic_t fscache_n_stores_ok;
206 extern atomic_t fscache_n_stores_again;
207 extern atomic_t fscache_n_stores_nobufs;
208 extern atomic_t fscache_n_stores_oom;
209 extern atomic_t fscache_n_store_ops;
210 extern atomic_t fscache_n_store_calls;
211 extern atomic_t fscache_n_store_pages;
212 extern atomic_t fscache_n_store_radix_deletes;
213 extern atomic_t fscache_n_store_pages_over_limit;
214
215 extern atomic_t fscache_n_store_vmscan_not_storing;
216 extern atomic_t fscache_n_store_vmscan_gone;
217 extern atomic_t fscache_n_store_vmscan_busy;
218 extern atomic_t fscache_n_store_vmscan_cancelled;
219 extern atomic_t fscache_n_store_vmscan_wait;
220
221 extern atomic_t fscache_n_marks;
222 extern atomic_t fscache_n_uncaches;
223
224 extern atomic_t fscache_n_acquires;
225 extern atomic_t fscache_n_acquires_null;
226 extern atomic_t fscache_n_acquires_no_cache;
227 extern atomic_t fscache_n_acquires_ok;
228 extern atomic_t fscache_n_acquires_nobufs;
229 extern atomic_t fscache_n_acquires_oom;
230
231 extern atomic_t fscache_n_invalidates;
232 extern atomic_t fscache_n_invalidates_run;
233
234 extern atomic_t fscache_n_updates;
235 extern atomic_t fscache_n_updates_null;
236 extern atomic_t fscache_n_updates_run;
237
238 extern atomic_t fscache_n_relinquishes;
239 extern atomic_t fscache_n_relinquishes_null;
240 extern atomic_t fscache_n_relinquishes_waitcrt;
241 extern atomic_t fscache_n_relinquishes_retire;
242
243 extern atomic_t fscache_n_cookie_index;
244 extern atomic_t fscache_n_cookie_data;
245 extern atomic_t fscache_n_cookie_special;
246
247 extern atomic_t fscache_n_object_alloc;
248 extern atomic_t fscache_n_object_no_alloc;
249 extern atomic_t fscache_n_object_lookups;
250 extern atomic_t fscache_n_object_lookups_negative;
251 extern atomic_t fscache_n_object_lookups_positive;
252 extern atomic_t fscache_n_object_lookups_timed_out;
253 extern atomic_t fscache_n_object_created;
254 extern atomic_t fscache_n_object_avail;
255 extern atomic_t fscache_n_object_dead;
256
257 extern atomic_t fscache_n_checkaux_none;
258 extern atomic_t fscache_n_checkaux_okay;
259 extern atomic_t fscache_n_checkaux_update;
260 extern atomic_t fscache_n_checkaux_obsolete;
261
262 extern atomic_t fscache_n_cop_alloc_object;
263 extern atomic_t fscache_n_cop_lookup_object;
264 extern atomic_t fscache_n_cop_lookup_complete;
265 extern atomic_t fscache_n_cop_grab_object;
266 extern atomic_t fscache_n_cop_invalidate_object;
267 extern atomic_t fscache_n_cop_update_object;
268 extern atomic_t fscache_n_cop_drop_object;
269 extern atomic_t fscache_n_cop_put_object;
270 extern atomic_t fscache_n_cop_sync_cache;
271 extern atomic_t fscache_n_cop_attr_changed;
272 extern atomic_t fscache_n_cop_read_or_alloc_page;
273 extern atomic_t fscache_n_cop_read_or_alloc_pages;
274 extern atomic_t fscache_n_cop_allocate_page;
275 extern atomic_t fscache_n_cop_allocate_pages;
276 extern atomic_t fscache_n_cop_write_page;
277 extern atomic_t fscache_n_cop_uncache_page;
278 extern atomic_t fscache_n_cop_dissociate_pages;
279
280 extern atomic_t fscache_n_cache_no_space_reject;
281 extern atomic_t fscache_n_cache_stale_objects;
282 extern atomic_t fscache_n_cache_retired_objects;
283 extern atomic_t fscache_n_cache_culled_objects;
284
fscache_stat(atomic_t * stat)285 static inline void fscache_stat(atomic_t *stat)
286 {
287 atomic_inc(stat);
288 }
289
fscache_stat_d(atomic_t * stat)290 static inline void fscache_stat_d(atomic_t *stat)
291 {
292 atomic_dec(stat);
293 }
294
295 #define __fscache_stat(stat) (stat)
296
297 int fscache_stats_show(struct seq_file *m, void *v);
298 #else
299
300 #define __fscache_stat(stat) (NULL)
301 #define fscache_stat(stat) do {} while (0)
302 #define fscache_stat_d(stat) do {} while (0)
303 #endif
304
305 /*
306 * raise an event on an object
307 * - if the event is not masked for that object, then the object is
308 * queued for attention by the thread pool.
309 */
fscache_raise_event(struct fscache_object * object,unsigned event)310 static inline void fscache_raise_event(struct fscache_object *object,
311 unsigned event)
312 {
313 BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
314 #if 0
315 printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
316 object->debug_id, object->event_mask, (1 << event));
317 #endif
318 if (!test_and_set_bit(event, &object->events) &&
319 test_bit(event, &object->event_mask))
320 fscache_enqueue_object(object);
321 }
322
fscache_cookie_get(struct fscache_cookie * cookie,enum fscache_cookie_trace where)323 static inline void fscache_cookie_get(struct fscache_cookie *cookie,
324 enum fscache_cookie_trace where)
325 {
326 int usage = atomic_inc_return(&cookie->usage);
327
328 trace_fscache_cookie(cookie, where, usage);
329 }
330
331 /*
332 * get an extra reference to a netfs retrieval context
333 */
334 static inline
fscache_get_context(struct fscache_cookie * cookie,void * context)335 void *fscache_get_context(struct fscache_cookie *cookie, void *context)
336 {
337 if (cookie->def->get_context)
338 cookie->def->get_context(cookie->netfs_data, context);
339 return context;
340 }
341
342 /*
343 * release a reference to a netfs retrieval context
344 */
345 static inline
fscache_put_context(struct fscache_cookie * cookie,void * context)346 void fscache_put_context(struct fscache_cookie *cookie, void *context)
347 {
348 if (cookie->def->put_context)
349 cookie->def->put_context(cookie->netfs_data, context);
350 }
351
352 /*
353 * Update the auxiliary data on a cookie.
354 */
355 static inline
fscache_update_aux(struct fscache_cookie * cookie,const void * aux_data)356 void fscache_update_aux(struct fscache_cookie *cookie, const void *aux_data)
357 {
358 void *p;
359
360 if (!aux_data)
361 return;
362 if (cookie->aux_len <= sizeof(cookie->inline_aux))
363 p = cookie->inline_aux;
364 else
365 p = cookie->aux;
366
367 if (memcmp(p, aux_data, cookie->aux_len) != 0) {
368 memcpy(p, aux_data, cookie->aux_len);
369 set_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags);
370 }
371 }
372
373 /*****************************************************************************/
374 /*
375 * debug tracing
376 */
377 #define dbgprintk(FMT, ...) \
378 printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
379
380 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
381 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
382 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
383
384 #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
385
386 #ifdef __KDEBUG
387 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
388 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
389 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
390
391 #elif defined(CONFIG_FSCACHE_DEBUG)
392 #define _enter(FMT, ...) \
393 do { \
394 if (__do_kdebug(ENTER)) \
395 kenter(FMT, ##__VA_ARGS__); \
396 } while (0)
397
398 #define _leave(FMT, ...) \
399 do { \
400 if (__do_kdebug(LEAVE)) \
401 kleave(FMT, ##__VA_ARGS__); \
402 } while (0)
403
404 #define _debug(FMT, ...) \
405 do { \
406 if (__do_kdebug(DEBUG)) \
407 kdebug(FMT, ##__VA_ARGS__); \
408 } while (0)
409
410 #else
411 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
412 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
413 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
414 #endif
415
416 /*
417 * determine whether a particular optional debugging point should be logged
418 * - we need to go through three steps to persuade cpp to correctly join the
419 * shorthand in FSCACHE_DEBUG_LEVEL with its prefix
420 */
421 #define ____do_kdebug(LEVEL, POINT) \
422 unlikely((fscache_debug & \
423 (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
424 #define ___do_kdebug(LEVEL, POINT) \
425 ____do_kdebug(LEVEL, POINT)
426 #define __do_kdebug(POINT) \
427 ___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
428
429 #define FSCACHE_DEBUG_CACHE 0
430 #define FSCACHE_DEBUG_COOKIE 1
431 #define FSCACHE_DEBUG_PAGE 2
432 #define FSCACHE_DEBUG_OPERATION 3
433
434 #define FSCACHE_POINT_ENTER 1
435 #define FSCACHE_POINT_LEAVE 2
436 #define FSCACHE_POINT_DEBUG 4
437
438 #ifndef FSCACHE_DEBUG_LEVEL
439 #define FSCACHE_DEBUG_LEVEL CACHE
440 #endif
441
442 /*
443 * assertions
444 */
445 #if 1 /* defined(__KDEBUGALL) */
446
447 #define ASSERT(X) \
448 do { \
449 if (unlikely(!(X))) { \
450 pr_err("\n"); \
451 pr_err("Assertion failed\n"); \
452 BUG(); \
453 } \
454 } while (0)
455
456 #define ASSERTCMP(X, OP, Y) \
457 do { \
458 if (unlikely(!((X) OP (Y)))) { \
459 pr_err("\n"); \
460 pr_err("Assertion failed\n"); \
461 pr_err("%lx " #OP " %lx is false\n", \
462 (unsigned long)(X), (unsigned long)(Y)); \
463 BUG(); \
464 } \
465 } while (0)
466
467 #define ASSERTIF(C, X) \
468 do { \
469 if (unlikely((C) && !(X))) { \
470 pr_err("\n"); \
471 pr_err("Assertion failed\n"); \
472 BUG(); \
473 } \
474 } while (0)
475
476 #define ASSERTIFCMP(C, X, OP, Y) \
477 do { \
478 if (unlikely((C) && !((X) OP (Y)))) { \
479 pr_err("\n"); \
480 pr_err("Assertion failed\n"); \
481 pr_err("%lx " #OP " %lx is false\n", \
482 (unsigned long)(X), (unsigned long)(Y)); \
483 BUG(); \
484 } \
485 } while (0)
486
487 #else
488
489 #define ASSERT(X) do {} while (0)
490 #define ASSERTCMP(X, OP, Y) do {} while (0)
491 #define ASSERTIF(C, X) do {} while (0)
492 #define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
493
494 #endif /* assert or not */
495
